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Physics High Energy Physics (Experiment)

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Wednesday 14 October · still arriving

High Energy Physics (Experiment)

Measurement of electromagnetic transition form factors in two-photon collisions at BESIII

Max Lellmann

The muon anomalous magnetic moment, $a_\mu = (g-2)_\mu/2$, shows a sizeable discrepancy between Standard Model (SM) predictions and direct measurements, hinting at either New Physics or limitations in modeling low-energy strong interactions. As the uncertainty in the SM predictions currently exceeds the experimental uncertainty by a substantial margin, further improvements in theoretical precision are essential to clarify the origin of this discrepancy. The SM theoretical uncertainty is dominated by hadronic processes. The hadronic light-by-light (HLbL) scattering contribution relies on highly accurate data for hadron production via two-photon fusion. Operating at $\sqrt{s}=3.773\,\text{GeV}$ with over $20\,\text{fb}^{-1}$ of integrated luminosity, the BESIII experiment is ideally suited to probe these processes at small momentum transfers. By precisely measuring channels like $e^+e^-\to e^+ e^-\pi^0$ and $e^+e^-\to e^+ e^-\pi^0\pi^0$, BESIII provides the critical experimental input necessary to sharpen the SM prediction and clarify the true nature of the $a_\mu$ anomaly.
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High Energy Physics (Experiment)

Measurement of Born cross sections of $e^+e^-\to pK^{-}\bar\Sigma^{0}$ + c.c. at $\sqrt{s}$ = 3.5-4.9 GeV and partial wave analysis at $\sqrt{s}$ = 3.773 GeV

BESIII Collaboration: M. Ablikim, M. N. Achasov, P. Adlarson et al. (+770 more)

Using $e^+e^-$ collision data collected by the BESIII detector at BEPCII corresponding to a total integrated luminosity of 44.6 $\rm fb^{-1}$, we present the first measurement of the Born cross sections for the process $e^+e^-\to pK^{-}\bar{\Sigma}^{0}$ + c.c. at fifty-six center-of-mass energies between 3.51 and 4.95~GeV. By fitting the dressed cross sections of $e^+e^-\to pK^{-}\bar{\Sigma}^{0}$ + c.c. with the assumption of a power-law function plus a charmonium(-like) resonance, i.e., $\psi(3770)$, $\psi(4040)$, $\psi(4160)$, $Y(4230)$, $Y(4360)$, $\psi(4415)$, $\psi(4500)$, $Y(4660)$ or $\psi(4710)$, no significant charmonium(-like) state decaying into $pK^{-}\bar{\Sigma}^{0}$ + c.c. is observed. The product of branching fractions and electronic partial widths including their upper limits at the 90% confidence level are provided for each decay. In addition, a partial wave analysis of the process $e^+e^-\to pK^{-}\bar{\Sigma}^{0}$ + c.c. at $\sqrt{s}$ = 3.773 GeV is performed to investigate $N^{*}$, $\Lambda^{*}$ and $\Sigma^{*}$ resonances in the $K^{-}\bar{\Sigma}^{0}$ and $pK^{-}$ invariant mass spectra. Significant contributions are found from the $\Lambda(1520)$, $\Sigma(1670)$, $\Sigma(1915)$, $N(1900)$, $N(2300)$ and $N(2570)$. The masses, widths and production fractions for each component are determined.
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All authors BESIII Collaboration: M. Ablikim, M. N. Achasov, P. Adlarson, X. C. Ai, C. S. Akondi, R. Aliberti, A. Amoroso, Q. An, Y. H. An, M. S. Anderson, Y. Bai, O. Bakina, H. R. Bao, X. L. Bao, M. Barbagiovanni, V. Batozskaya, K. Begzsuren, N. Berger, M. Berlowski, M. B. Bertani, D. Bettoni, F. Bianchi, E. Bianco, A. Bortone, I. Boyko, R. A. Briere, A. Brueggemann, D. Cabiati, H. Cai, M. H. Cai, X. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Cetin, X. Y. Chai, J. F. Chang, T. T. Chang, G. R. Che, Y. Z. Che, C. H. Chen, Chao Chen, G. Chen, H. S. Chen, H. Y. Chen, M. L. Chen, S. J. Chen, S. M. Chen, T. Chen, W. Chen, X. R. Chen, X. T. Chen, X. Y. Chen, Y. B. Chen, Y. Q. Chen, Z. K. Chen, J. Cheng, L. N. Cheng, S. K. Choi, X. Chu, G. Cibinetto, F. Cossio, J. Cottee-Meldrum, H. L. Dai, J. P. Dai, X. C. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, C. Q. Deng, Z. Y. Deng, A. Denig, I. Denisenko, M. Destefanis, F. De Mori, E. Di Fiore, X. X. Ding, Y. Ding, Y. X. Ding, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, Z. J. Dong, M. C. Du, S. X. Du, Shaoxu Du, X. L. Du, Y. Q. Du, Y. Y. Duan, Z. H. Duan, P. Egorov, G. F. Fan, J. J. Fan, K. X. Fan, Y. H. Fan, J. Fang, Jin Fang, S. S. Fang, W. X. Fang, Y. Q. Fang, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, J. H. Feng, Q. X. Feng, Y. T. Feng, M. Fritsch, C. D. Fu, J. L. Fu, Y. W. Fu, H. Gao, Xu Gao, Y. Gao, Y. N. Gao, Y. Y. Gao, Yunong Gao, Z. Gao, S. Garbolino, I. Garzia, L. Ge, P. T. Ge, Z. W. Ge, C. Geng, A. Gilman, K. Goetzen, J. Gollub, J. B. Gong, J. D. Gong, L. Gong, W. X. Gong, W. Gradl, M. Greco, M. D. Gu, M. H. Gu, C. Y. Guan, A. Q. Guo, H. Guo, J. N. Guo, L. B. Guo, M. J. Guo, R. P. Guo, X. Guo, Y. P. Guo, Z. Guo, A. Guskov, J. Gutierrez, J. Y. Han, T. T. Han, X. Han, F. Hanisch, K. D. Hao, X. Q. Hao, F. A. Harris, C. Z. He, K. K. He, K. L. He, F. H. Heinsius, C. H. Heinz, Y. K. Heng, C. Herold, P. C. Hong, G. Y. Hou, X. T. Hou, Y. R. Hou, Z. L. Hou, H. M. Hu, J. F. Hu, Q. P. Hu, S. L. Hu, T. Hu, Y. Hu, Y. X. Hu, Z. M. Hu, G. S. Huang, K. X. Huang, L. Q. Huang, P. Huang, X. T. Huang, Y. P. Huang, Y. S. Huang, T. Hussain, N. Hüsken, N. in der Wiesche, J. Jackson, Q. Ji, Q. P. Ji, W. Ji, X. B. Ji, X. L. Ji, Y. Y. Ji, L. K. Jia, X. Q. Jia, D. Jiang, S. J. Jiang, X. S. Jiang, Y. Jiang, J. B. Jiao, J. K. Jiao, Z. Jiao, L. C. L. Jin, S. Jin, Y. Jin, M. Q. Jing, X. M. Jing, T. Johansson, S. Kabana, X. L. Kang, X. S. Kang, B. C. Ke, V. Khachatryan, A. Khoukaz, O. B. Kolcu, B. Kopf, L. Kröger, L. Krümmel, Y. Y. Kuang, X. Kui, N. Kumar, A. Kupsc, W. Kühn, Q. Lan, W. N. Lan, T. T. Lei, M. Lellmann, T. Lenz, C. Li, C. H. Li, C. K. Li, Chunkai Li, Cong Li, D. M. Li, F. Li, G. Li, H. B. Li, H. J. Li, H. L. Li, H. N. Li, H. P. Li, Hui Li, J. N. Li, J. S. Li, J. W. Li, K. Li, K. L. Li, L. J. Li, L. K. Li, Lei Li, M. H. Li, M. R. Li, M. T. Li, P. L. Li, P. R. Li, Q. M. Li, Q. X. Li, R. Li, S. Li, S. X. Li, S. Y. Li, Shanshan Li, T. Li, T. Y. Li, W. D. Li, W. G. Li, X. Li, X. H. Li, X. K. Li, X. L. Li, X. Y. Li, X. Z. Li, Y. Li, Y. H. Li, Y. B. Li, Y. C. Li, Y. G. Li, Y. P. Li, Z. H. Li, Z. J. Li, Z. L. Li, Z. X. Li, Z. Y. Li, C. Liang, H. Liang, Y. F. Liang, Y. T. Liang, Z. Z. Liang, G. R. Liao, L. B. Liao, M. H. Liao, Y. P. Liao, J. Libby, A. Limphirat, C. C. Lin, C. X. Lin, D. X. Lin, T. Lin, B. J. Liu, B. X. Liu, C. Liu, C. X. Liu, F. Liu, F. H. Liu, Feng Liu, G. M. Liu, H. Liu, H. B. Liu, H. M. Liu, Huihui Liu, J. B. Liu, J. J. Liu, K. Liu, K. Y. Liu, Ke Liu, Kun Liu, L. Liu, L. C. Liu, Lu Liu, M. H. Liu, P. L. Liu, Q. Liu, S. B. Liu, T. Liu, W. M. Liu, W. T. Liu, X. Liu, X. K. Liu, X. L. Liu, X. P. Liu, X. T. Liu, X. Y. Liu, Y. Liu, Y. B. Liu, Yi Liu, Z. A. Liu, Z. D. Liu, Z. L. Liu, Z. Q. Liu, Z. X. Liu, Z. Y. Liu, X. C. Lou, H. J. Lu, J. G. Lu, X. L. Lu, Y. Lu, Y. H. Lu, Y. P. Lu, Z. H. Lu, C. L. Luo, J. R. Luo, J. S. Luo, M. X. Luo, T. Luo, X. L. Luo, Z. Y. Lv, X. R. Lyu, Y. F. Lyu, Y. H. Lyu, F. C. Ma, H. L. Ma, Heng Ma, J. L. Ma, L. L. Ma, L. R. Ma, Q. M. Ma, R. Q. Ma, R. Y. Ma, T. Ma, X. T. Ma, X. Y. Ma, F. E. Maas, I. MacKay, M. Maggiora, S. Maity, S. Malde, L. M. Mansur, Y. J. Mao, Z. P. Mao, S. Marcello, A. Marshall, F. M. Melendi, Y. H. Meng, Z. X. Meng, G. Mezzadri, H. Miao, T. J. Min, R. E. Mitchell, X. H. Mo, B. Moses, N. Yu. Muchnoi, J. Muskalla, Y. Nefedov, F. Nerling, H. Neuwirth, Z. Ning, S. Nisar, Q. L. Niu, W. D. Niu, Y. Niu, C. Normand, S. L. Olsen, Q. Ouyang, I. V. Ovtin, S. Pacetti, Y. Pan, C. Y. Pang, A. Pathak, Y. P. Pei, M. Pelizaeus, G. L. Peng, H. P. Peng, X. J. Peng, Y. Y. Peng, K. Peters, K. Petridis, J. L. Ping, R. G. Ping, S. Plura, V. Prasad, L. Pöpping, F. Z. Qi, H. R. Qi, S. Qian, W. B. Qian, C. F. Qiao, J. H. Qiao, J. J. Qin, J. L. Qin, L. Q. Qin, L. Y. Qin, P. B. Qin, X. P. Qin, X. S. Qin, Z. H. Qin, J. F. Qiu, Z. H. Qu, J. Rademacker, K. Ravindran, C. F. Redmer, A. Rivetti, M. Rolo, G. Rong, S. S. Rong, F. Rosini, Ch. Rosner, M. Q. Ruan, W. R. Ruangyoo, N. Salone, A. Sarantsev, Y. Schelhaas, M. Schernau, K. Schoenning, M. Scodeggio, W. Shan, X. Y. Shan, Z. J. Shang, J. F. Shangguan, L. G. Shao, M. Shao, C. P. Shen, H. F. Shen, W. H. Shen, X. Y. Shen, B. A. Shi, Ch. Y. Shi, H. Shi, J. L. Shi, J. Y. Shi, M. H. Shi, S. S. Shi, S. Y. Shi, X. Shi, H. L. Song, J. J. Song, M. H. Song, T. Z. Song, W. M. Song, Y. X. Song, Zirong Song, S. Sosio, S. Spataro, S. Stansilaus, F. Stieler, M. Stolte, S. S Su, G. B. Sun, G. X. Sun, H. Sun, H. K. Sun, J. F. Sun, K. Sun, L. Sun, R. Sun, S. S. Sun, T. Sun, W. Y. Sun, Y. C. Sun, Y. H. Sun, Y. J. Sun, Y. Z. Sun, Z. Q. Sun, Z. T. Sun, H. Tabaharizato, N. T. Tagsinsit, C. J. Tang, G. Y. Tang, J. Tang, J. J. Tang, L. F. Tang, Y. A. Tang, Z. H. Tang, L. Y. Tao, M. Tat, J. X. Teng, J. Y. Tian, W. H. Tian, Y. Tian, Z. F. Tian, K. Yu. Todyshev, I. Uman, E. van der Smagt, B. Wang, Bin Wang, Bo Wang, C. Wang, Chao Wang, Cong Wang, D. Y. Wang, F. K. Wang, H. J. Wang, H. R. Wang, J. Wang, J. J. Wang, J. P. Wang, K. Wang, L. L. Wang, L. W. Wang, M. Wang, Mi Wang, N. Y. Wang, P. Wang, S. Wang, Shun Wang, T. Wang, W. Wang, W. P. Wang, X. F. Wang, X. L. Wang, X. N. Wang, Xin Wang, Y. Wang, Y. D. Wang, Y. F. Wang, Y. H. Wang, Y. J. Wang, Y. L. Wang, Y. N. Wang, Yanning Wang, Yaqian Wang, Yi Wang, Yuan Wang, Z. Wang, Z. L. Wang, Z. Q. Wang, Z. Y. Wang, Zhi Wang, Ziyi Wang, D. Wei, D. H. Wei, D. J. Wei, H. R. Wei, F. Weidner, H. R. Wen, S. P. Wen, U. Wiedner, G. Wilkinson, J. F. Wu, L. H. Wu, L. J. Wu, Lianjie Wu, S. G. Wu, S. M. Wu, X. W. Wu, Z. Wu, H. L. Xia, L. Xia, B. H. Xiang, D. Xiao, G. Y. Xiao, H. Xiao, Y. L. Xiao, Z. J. Xiao, C. Xie, K. J. Xie, Y. Xie, Y. G. Xie, Y. H. Xie, Z. P. Xie, T. Y. Xing, D. B. Xiong, G. F. Xu, H. Y. Xu, Q. J. Xu, Q. N. Xu, T. D. Xu, X. P. Xu, Y. Xu, Y. C. Xu, Z. S. Xu, F. Yan, L. Yan, W. B. Yan, W. C. Yan, W. H. Yan, W. P. Yan, X. Q. Yan, Y. Y. Yan, H. J. Yang, H. L. Yang, H. X. Yang, J. H. Yang, R. J. Yang, X. Y. Yang, Y. Yang, Y. G. Yang, Y. H. Yang, Y. M. Yang, Y. Q. Yang, Y. Z. Yang, Youhua Yang, Z. Y. Yang, W. J. Yao, Z. P. Yao, M. Ye, M. H. Ye, Z. J. Ye, K. Yi, Junhao Yin, Qiqin Yin, Z. Y. You, B. X. Yu, C. X. Yu, G. Yu, J. S. Yu, L. W. Yu, T. Yu, X. D. Yu, Y. C. Yu, Yongchao Yu, C. Z. Yuan, H. Yuan, J. Yuan, Jie Yuan, L. Yuan, M. K. Yuan, S. H. Yuan, Y. Yuan, C. X. Yue, Ying Yue, A. A. Zafar, F. R. Zeng, S. H. Zeng, X. Zeng, Y. J. Zeng, Yujie Zeng, Y. C. Zhai, Y. H. Zhan, B. L. Zhang, B. X. Zhang, D. H. Zhang, G. Y. Zhang, Gengyuan Zhang, H. Zhang, H. C. Zhang, H. H. Zhang, H. L. Zhang, H. Q. Zhang, H. R. Zhang, H. Y. Zhang, Han Zhang, J. Zhang, J. J. Zhang, J. L. Zhang, J. Q. Zhang, J. S. Zhang, J. W. Zhang, J. X. Zhang, J. Y. Zhang, J. Z. Zhang, Jianyu Zhang, Jin Zhang, Jiyuan Zhang, L. M. Zhang, Lei Zhang, N. Zhang, P. Zhang, Q. Zhang, Q. Y. Zhang, Q. Z. Zhang, R. Y. Zhang, S. H. Zhang, S. N. Zhang, Shulei Zhang, X. M. Zhang, X. Y. Zhang, Y. T. Zhang, Y. H. Zhang, Y. P. Zhang, Yao Zhang, Yu Zhang, Yu Zhang, Z. Zhang, Z. D. Zhang, Z. H. Zhang, Z. L. Zhang, Z. X. Zhang, Z. Y. Zhang, Zh. Zh. Zhang, Zhilong Zhang, Ziyang Zhang, Ziyu Zhang, G. Zhao, J.-P. Zhao, J. Y. Zhao, J. Z. Zhao, L. Zhao, Lei Zhao, M. G. Zhao, R. P. Zhao, S. J. Zhao, Y. B. Zhao, Y. L. Zhao, Y. P. Zhao, Y. X. Zhao, Z. G. Zhao, A. Zhemchugov, B. Zheng, B. M. Zheng, J. P. Zheng, W. J. Zheng, W. Q. Zheng, X. R. Zheng, Y. H. Zheng, B. Zhong, C. Zhong, X. Zhong, H. Zhou, J. Q. Zhou, S. Zhou, X. Zhou, X. K. Zhou, X. R. Zhou, X. Y. Zhou, Y. X. Zhou, Y. Z. Zhou, A. N. Zhu, J. Zhu, K. Zhu, K. J. Zhu, K. S. Zhu, L. X. Zhu, Lin Zhu, S. H. Zhu, T. J. Zhu, W. D. Zhu, W. J. Zhu, W. Z. Zhu, Y. C. Zhu, Z. A. Zhu, X. Y. Zhuang, M. Zhuge, J. H. Zou, J. Zu

High Energy Physics (Experiment) · Cross-listed from hep-ph

The dead-cone effect in charm, bottom and top quark jets in angular and momentum space

Redamy Perez-Ramos, Stefan Kluth and Wolfgang Ochs

The dead-cone effect reflects the mass dependence of QCD radiation from heavy quarks. We investigate this phenomenon from charm and bottom to top quarks using two-dimensional angular distributions and single-particle inclusive momentum spectra. The angular distributions illustrate the depletion of radiation around the heavy-quark direction, while the momentum spectra provide a quantitative observable of the effect. For charm and bottom jets, fragmentation functions reconstructed from LEP data at the $Z$ pole exhibit a strong suppression of high-momentum particles, quantitatively described within the Modified Leading Logarithmic Approximation of perturbative QCD. The analysis is extended to $\sqrt{s}=1$ TeV using Monte Carlo simulations. A hypothetical stable-top sample isolates the primary top-quark radiation pattern, whereas the physical decay $t\to bW$ introduces coherent radiation from the $tb$ colour dipole, obscuring the primary dead cone. By exploiting the dependence on the $b$-quark emission angle $\Theta_b$, we reconstruct the primary top-quark parton momentum spectrum through extrapolation to $\Theta_b\to0$. In contrast, the small-angle gluon and parton distributions do not converge to the stable-top dead-cone pattern because of radiation from the decay $b$ quark. These findings establish the inclusive momentum spectrum as a robust quantitative observable of the top-quark dead-cone effect and provide a unified description of mass-dependent QCD radiation from charm to top.
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High Energy Physics (Experiment) · Cross-listed from physics.ins-det

A low-cost compact muon detector for millikelvin operation

Tengiz Ibrayev, Danish Khan, Alex Herscovics et al. (+5 more)

Ionizing radiation produces correlated errors in superconducting qubits, posing some challenges to quantum error correction. In addition, it causes background events in other superconducting cryogenic devices, such as kinetic inductance detectors and superconducting nanowire single-photon detectors. Cosmic muons are a component of this background that can only be partly shielded against at ground level, but can be tagged by an independent detector inside the cryostat, so that the affected data can be vetoed, or the muon tags incorporated into error correction. We present a low-cost, compact muon detector consisting of two plastic scintillator modules, each read out by a silicon photomultiplier (SiPM), operated in coincidence. We characterize the SiPMs from room temperature down to 10 mK, including the breakdown and upper-limit voltages that define the operating bias range. Operated as a muon counter, the detector measures a coincidence rate that, as expected, is independent of temperature within uncertainties and agrees with analytical and Monte Carlo predictions. Below approximately 8 K, each muon event produces two pulses, one narrow and one broad, an effect that, to our knowledge, has not been reported before. Coincidences with an independent muon detector outside the cryostat confirm that muons are still counted reliably in this regime. By studying the appearance of double pulses as a function of temperature and magnetic field up to 4.5 T, we find a behavior consistent with the phase diagram of a type-II superconductor. This links the double pulses to a superconducting material in the SiPM, likely an adhesion layer or diffusion barrier introduced during manufacturing. The mechanism by which the superconducting state produces the second pulse is not yet understood.
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All authors Tengiz Ibrayev, Danish Khan, Alex Herscovics, Komal Kataruka, Matilda Lawton, Sandhya Sharma, Steven Waddy, Laura Manenti

High Energy Physics (Experiment)

MoEDAL-MAPP: the first dedicated search experiment at the LHC

John R. Ellis, Nick E. Mavromatos, Vasiliki A. Mitsou et al. (+1 more)

This special issue brings together a collection of original research articles and review papers addressing topics directly related to the MoEDAL-MAPP experiment at the Large Hadron Collider (LHC). The experiment is designed to search for (meta-)stable, anomalously ionising particles predicted by theoretical extensions of the Standard Model. Several contributions explore the theoretical and phenomenological aspects of models of particular relevance to the experiment, including scenarios involving magnetic monopoles, highly electrically charged particles, and millicharged particles. Other contributions focus on experimental developments, highlighting novel detection techniques and technological advances aimed at identifying these unconventional signatures and probing new phenomena beyond the Standard Model.
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All authors John R. Ellis, Nick E. Mavromatos, Vasiliki A. Mitsou, James L. Pinfold

High Energy Physics (Experiment) · Cross-listed from hep-ph

Quantum-enhanced Search for Galactic Dark Photons Using Cat-State Cavities

Aoying Wang, Yanjie Zeng, Yanyan Cai et al. (+4 more)

We present a quantum-enhanced search for the Galactic dark-photon background (GDPB), a relativistic and anisotropic vector field that can be produced by dark-matter decay or annihilation in the Milky Way halo. We reinterpret an existing quantum-enhanced dark-photon dataset obtained with a superconducting circuit QED platform originally developed for wave-like dark-photon dark-matter searches, consisting of a high-$Q$ niobium cavity in the $\mathrm{TM}_{010}$ mode dispersively coupled to a transmon qubit. By preparing four-component cat states and performing repeated quantum non-demolition parity measurements, analyzed with a hidden Markov model, we extract photon-transition probabilities for multiple cat amplitudes and integration times. The coupling to the GDPB is governed by a polarization- and angle-dependent cavity overlap function, which predicts a distinctive diurnal modulation of the excitation rate for both longitudinal and transverse polarizations. From the absence of such modulation, we set 90% confidence-level bounds on the kinetic-mixing parameter $\epsilon$ for two benchmark production mechanisms (parametric and cascade decay) over the relativistic mass range $m_X \ll \omega_c$.
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All authors Aoying Wang, Yanjie Zeng, Yanyan Cai, Jing Shu, Bin Xu, Yuan Xu, Pan Zheng

High Energy Physics (Experiment)

Achieving a 0.49 keV threshold in the COSINE-100 dark matter experiment

J. Kim, N. Carlin, D. F. F. S. Cavalcante et al. (+58 more)

The COSINE-100 experiment searched for weakly interacting massive particles (WIMPs) with NaI(Tl) crystals at the Yangyang Underground Laboratory. Using its full 6-year dataset, we lower the analysis threshold to 0.49 keV. A multi-layer perceptron classifier separates scintillation events from photomultiplier tube noise. It is trained with approximately $3\times10^{6}$ simulated scintillation waveforms per crystal, separately for groups of events with similar numbers of photoelectron clusters. The selection keeps more than 10% of scintillation events at 0.49 keV while limiting noise contamination to below 1%. The selection efficiency is validated with $^{22}$Na-calibration data and internal $^{22}$Na events, and the selection performance is stable over the six years of data taking. With this threshold, the median expected upper limit on the spin-dependent WIMP-proton cross section reaches $1.1\times10^{-36}$ cm$^2$ at a WIMP mass of 2.5 GeV/$c^2$, probing previously unexplored parameter space in the 2.0-2.8 GeV/$c^2$ mass range.
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All authors J. Kim, N. Carlin, D. F. F. S. Cavalcante, J. Y. Cho, S. J. Cho, S. Choi, A. C. Ezeribe, L. E. França, O. Gileva, C. Ha, I. S. Hahn, E. J. Jeon, H. W. Joo, W. G. Kang, M. Kauer, B. H. Kim, D. Y. Kim, H. J. Kim, K. W. Kim, S. H. Kim, S. K. Kim, W. K. Kim, Y. D. Kim, Y. H. Kim, B. R. Ko, Y. J. Ko, B. C. Koh, D. H. Lee, E. K. Lee, H. Lee, H. S. Lee, H. Y. Lee, I. S. Lee, J. Lee, J. Y. Lee, M. H. Lee, S. H. Lee, S. H. Lee, Y. J. Lee, D. S. Leonard, N. T. Luan, V. H. A. Machado, B. B. Manzato, R. H. Maruyama, R. F. Muhdi, S. L. Olsen, H. K. Park, H. S. Park, J. C. Park, J. S. Park, K. S. Park, K. Park, S. D. Park, R. L. C. Pitta, H. Prihtiadi, C. Rott, K. A. Shin, M. K. Son, L. T. Truc, L. Yang, G. H. Yu

High Energy Physics (Experiment) · Cross-listed from hep-ph

Constraints on pion parton distributions at small $x$ from leading-neutron electroproduction data

C. Yang, P. C. Barry, W. Melnitchouk et al. (+1 more)

We revisit the extraction of parton distribution functions (PDFs) in the pion in a global QCD analysis of pion–nucleus Drell–Yan and leading-neutron (LN) electroproduction data, in view of recent suggestions that uncertainties on the pion PDFs at small parton momentum fraction $x$ are dramatically underestimated. We perform a set of controlled fits that vary the LN data coverage, PDF parametrization, and positivity constraints, determining both the PDFs and pion-nucleon splitting functions simultaneously. While the use of a restricted H1 LN data sample used by the Fantômas group is found to enlarge the PDF uncertainties and admit solutions with vanishing gluon PDFs, our global analysis provides a good description of an extended H1 and ZEUS LN database, significantly reducing the parametrization dependence and strongly disfavoring a zero gluon distribution.
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All authors C. Yang, P. C. Barry, W. Melnitchouk, N. Sato

Tuesday 13 October · still arriving

High Energy Physics (Experiment) · Cross-listed from hep-ph

Pythia-Contrib: a modular contribution framework for the Pythia 8 event generator

Benoit Assi, Christian Bierlich, Rikab Gambhir et al. (+6 more)

Pythia is a general-purpose Monte Carlo event generator used in particle, astroparticle, and nuclear physics, by theorists and experimentalists, to simulate particle collisions. Because of the size and diversity of the user community, it is challenging to address all of the needs for new and varied physics models. This paper describes the Pythia-Contrib system, which allows for third-party developers to contribute code to Pythia without introducing external software dependencies to the Pythia code base.
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All authors Benoit Assi, Christian Bierlich, Rikab Gambhir, Philip Ilten, Tony Menzo, Stephen Mrenna, Manuel Szewc, Michael K. Wilkinson, Jure Zupan

High Energy Physics (Experiment) · Cross-listed from hep-ph

Born-Oppenheimer chiral effective field theory and its application to $X_b$

Yu Zhang, Feng-Kun Guo, Christoph Hanhart et al. (+2 more)

Following the discovery of the exotic state $X(3872)$ in the charmonium spectrum, the possible existence of an analogous state, $X_b$, in the bottomonium sector has attracted considerable attention of the hadronic physics community. In this work, we lay the ground for the development of Born-Oppenheimer chiral effective field theory (BO$\chi$EFT), that allows us to include both quark and hadron degrees of freedom as well as the full complexity of the meson-exchange potential in a systematic way. For illustration, the formalism to leading order (LO) is applied to the system of $\chi_{b1}$ states and in particular the $X_b$. The two parameters that are present at this order are constrained using experimental information on the bottomonium spectrum together with lattice input on static quark-antiquark potentials, including string breaking effects. The framework identifies the observed $1^{++}$ state at 10.513 GeV with a predominantly molecular $X_b$, the bottom counterpart of the $X(3872)$, and predicts an additional predominantly compact bottomonium state at 10.544 GeV, about 60 MeV below the $B\bar{B}^*$ threshold.
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All authors Yu Zhang, Feng-Kun Guo, Christoph Hanhart, Alexey Nefediev, Paul Pütz

High Energy Physics (Experiment) · Cross-listed from hep-ph

Measuring $V_{cb}$ at electron-proton colliders

David Marzocca

We study the prospects for an independent determination of $V_{cb}$ from bottom-tagged charged-current deep-inelastic scattering at future electron-proton colliders: the EIC, LHeC, and FCC-eh. The transition $e^- c \to \nu_e b$ probes $|V_{cb}|^2$ through a process with different theoretical and experimental uncertainties from semileptonic $B$ decays. We fit ratios of $b$-tagged charged-current event counts over flavour-inclusive ones in kinematic bins, including correlated parton-distribution and flavour-tag calibration uncertainties, and floating the other CKM parameters. With projected parton distributions and tagging performance motivated by existing studies, we find a potential relative sensitivity in $|V_{cb}|$ of about $0.8\%$ at the LHeC with $1\,\rm{ab}^{-1}$ of integrated luminosity and $0.7\%$ at FCC-eh with $2\,\rm{ab}^{-1}$. The corresponding EIC sensitivity is instead at the level of $20 - 30 \%$, depending on the configuration. The LHeC could thus provide a high-energy determination competitive with low-energy ones, but with substantially different dominant systematic uncertainties, on the timescale of its proposed operation between the HL-LHC and FCC-ee. We identify precise flavour-tag calibration and control of the kinematic response as the main requirements for realising this potential sensitivity.
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High Energy Physics (Experiment)

Probing the proton structure with minimum bias and low-pt dimuon events at hadron colliders

Kyle Cormier

This paper presents two methods for probing the proton structure and the number of partonic interactions in proton-proton collisions using dimuon production and minimum bias events. At the LHC these targeted measurements can provide information on the average number of partonic scatters in different event classes, their dependence on the partonic momentum fraction, x, and potentially partonic flavour. Within a simple mostly geometric model of multiparton interactions as quasi-independent scatters, the measurements can be used to make inference about the proton-proton overlap dependence on impact parameter and its partonic-x dependence.
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High Energy Physics (Experiment) · Cross-listed from hep-ph

HEPTABench: A framework for portable and controlled agentic evaluations in high energy physics

Tony Menzo, Alexander Roman, George T. Fleming et al. (+3 more)

Quantifying the capability and reliability of agentic systems in high-energy physics (HEP) requires repeated evaluations under controlled configurations. Establishing whether changes to models, tools, or harnesses improve performance also requires these components to be varied independently. We present the High Energy Physics Tool-and-Agent Benchmarking (HEPTABench) framework for portable and controlled evaluations of agentic systems, with separately configurable tasks, scaffolding, models, providers, harnesses, and domain capabilities. The framework combines HEP benchmark tasks and scientific rubrics with experiment execution and versioned tool interfaces. To support inspection, reproducibility, and post-hoc grading, the framework prioritizes recording and reporting complete experiment specifications, agent trajectories, and experiment artifacts. We demonstrate the framework in two benchmark campaigns. The first campaign evaluates a forward long-lived-particle reach calculation across four frontier coding-agent systems, comparing their built-in coding tools with the same tools supplemented by HEP domain tools. We show that including these HEP domain tools improves numerical accuracy and reduces trial-to-trial dispersion for every tested system. In a complementary campaign covering eight symbolic two-body decay tasks, we show that adding symbolic domain tools increases the fraction of successful trials for Claude Haiku 4.5 from $8\%$ to $79\%$, while GPT-5.5 succeeds in every trial with built-in tools alone. Through systematic evaluation of agentic systems, HEPTABench enables the identification of factors that improve the accuracy and reliability of their scientific work.
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All authors Tony Menzo, Alexander Roman, George T. Fleming, Sergei Gleyzer, Konstantin Matchev, Stephen Mrenna

High Energy Physics (Experiment) · Cross-listed from nucl-th

Femtoscopic parameters of pion emission sources in EPOS4 Au+Au collisions from 7.7 to 200 GeV

Yan Huang and Máté Csanád

Three-dimensional femtoscopy probes the space-time structure of particle-emitting sources in relativistic heavy-ion collisions. The collision-energy dependence of Lévy source parameters may reveal the evolution of strongly interacting matter and possible signatures of the QCD phase diagram. We previously studied the excitation function of three-dimensional Lévy source parameters for pion pairs in Au+Au collisions with EPOS4, analyzing the pair-distance distribution \(D(\rho)\) through one-dimensional projections. Here, we analyze the full three-dimensional source distribution and correlation function directly. We construct \(D(\rho_{\rm out},\rho_{\rm side},\rho_{\rm long})\) as a 3D histogram, transform it into \(C(q_{\rm out},q_{\rm side},q_{\rm long})\) using a Fast Fourier Transform, and fit the correlation function with the analytic Lévy formula. This approach can reduce biases arising when one-dimensional projections are used to describe a non-elliptical source. We apply the method across the RHIC Beam Energy Scan range and compare the extracted energy dependence with results from the projection-based method and recent UrQMD calculations. We focus on the out-side observables \(R_{\rm diff}^{2}=R_{\rm out}^{2}-R_{\rm side}^{2}\) and \(R_{\rm out}/R_{\rm side}\), whose different energy dependences in EPOS4 and UrQMD may illuminate the roles of emission duration and source dynamics. This work establishes a direct three-dimensional framework for comparison with future femtoscopic measurements and for exploring possible non-monotonic structures associated with the QCD phase diagram.
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High Energy Physics (Experiment) · Cross-listed from hep-ph

Signature of GW from the Hidden Sector in light of the Recent LZ Event

Sujit Kumar Sahoo, Narendra Sahu and Vicky Singh Thounaojam

The LZ collaboration has recently reported a single nuclear-recoil event at $E_R=248\pm23_\text{stat}\pm23_\text{sys}$ keV, observed in a 2.84 tonne-year exposure with a local significance of $3.4\sigma$, pointing towards an inelastic dark matter (DM) interpretation. We explain this event within a gauged $U(1)_X$ hidden-sector model, spontaneously broken by a singlet scalar whose vacuum expectation value (VEV) gives rise to: (i) gauge boson mass, (ii) a small Majorana mass for the vector-like singlet fermion, the DM candidate, charged under the new symmetry, which splits the fermion into two pseudo-Dirac states (mass splitting proportional to the scalar VEV) thus resulting in a purely off-diagonal vector current, (iii) the frequency and the amplitude of the GW signal arising from the hidden sector symmetry breaking via first-order phase transition (FOPT). The symmetry-breaking scale thus provides a multi-messenger probe connecting terrestrial direct-detection kinematics at the LZ and early-universe FOPT thermodynamics while obtaining thermal DM relic abundance. We delineate the viable parameter space compatible with the LZ event, correct relic density, and detectable GW signals in the low frequency regimes at future interferometers like $\mu {\rm ARES}$ and THEIA while satisfying existing cosmological, astrophysical, and terrestrial bounds.
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High Energy Physics (Experiment) · Cross-listed from physics.ins-det

Cryogenic characterisation of the FBK NUV-HD-cryo Silicon Photomultipliers for the DarkSide-20k dark matter experiment

F. Acerbi, P. Adhikari, P. Agnes et al. (+299 more)

Liquid Argon Time Projection Chambers (TPCs) are highly promising detectors for dark matter searches due to their uniform response, scalability to large target masses, and compatibility with ultra-low background conditions. The DarkSide-20k (DS-20k) experiment, currently under construction at Istituto Nazionale di Fisica Nucleare (INFN) Laboratori Nazionali del Gran Sasso (LNGS), aims to achieve unprecedented sensitivity to Weakly Interacting Massive Particles (WIMPs), approaching the neutrino fog. At the heart of the detector is a dual-phase TPC filled and surrounded by low-radioactivity argon from underground sources (i.e. Underground Argon (UAr)), functioning both as the WIMP target and detection medium. The experiment employs Fondazione Bruno Kessler (FBK) NUV-HD-cryo Silicon Photomultipliers (SiPMs) as the chosen photon sensors for its optical planes. Key SiPM properties such as dark noise rate, gain and direct crosstalk were measured using specialized test setups at 77 K. The photon detection efficiency (PDE) was measured under vacuum at 77 K over the wavelength range 350-820 nm. Secondary photon emission, which can give rise to external optical crosstalk, was measured under vacuum at 86 K over the wavelength range 550-1020 nm.
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All authors F. Acerbi, P. Adhikari, P. Agnes, I. Ahmad, S. Albergo, I. F. Albuquerque, T. Alexander, A. K. Alton, P. Amaudruz, G. A. Anastasi, M. Angiolilli, E. Aprile, D. J. Auty, M. Ave Pernas, O. Azzolini, H. O. Back, Z. Balmforth, A. Barrado Olmedo, P. Barrillon, G. Batignani, S. Bharat, P. Bhowmick, S. Blua, V. Bocci, W. Bonivento, B. Bottino, M. G. Boulay, T. Braun, A. Buchowicz, J. Busto, M. Cadeddu, M. Cadoni, R. Calabrese, V. I. Calì, A. Caminata, N. Canci, M. Caravati, M. Cardenas-Montes, N. Cargioli, M. Carlini, L. Castellani, P. Castello, D. F. F. S. Cavalcante, P. Cavalcante, S. Cebrian, A. Chepurnov, L. Cifarelli, Y. Coadou, I. Coarasa, V. Cocco, E. Conde Vilda, L. Consiglio, H. Coombes, A. F. V. Cortez, B. S. Costa, P. A. Costa e Silva, M. Czubak, S. D'Auria, M. D. Da Rocha Rolo, A. Dainty, G. Darbo, S. Davini, R. de Asmundis, S. De Cecco, M. De Napoli, G. Dellacasa, A. Derbin, L. Di Noto, P. Di Stefano, D. Díaz Mairena, C. Dionisi, G. Dolganov, F. Dordei, A. Elersich, E. Ellingwood, T. Erjavec, N. Fearon, M. Fernandez Diaz, L. Ferro, A. Ficorella, G. Fiorillo, D. Fleming, L. Flores, P. Franchini, D. Franco, H. Frandini Gatti, F. Gabriele, D. Gahan, C. Galbiati, G. Galiński, G. Gallina, M. Garbini, P. Garcia Abia, A. Gawdzik, G. K. Giovanetti, A. Gola, L. Grandi, G. Grauso, G. Grilli di Cortona, A. Grobov, M. Gromov, J. Guerrero Cánovas, M. Gulino, S. B. Habtemariam, B. R. Hackett, A. Hallin, M. Haranczyk, T. Hessel, C. Hidalgo, J. Hollingham, S. Horikawa, J. Hu, F. Hubaut, D. Huff, T. Hugues, A. Ianni, A. Ianni, V. Ippolito, A. Jamil, C. Jillings, P. Kachru, R. Keloth, N. Kemmerich, A. Kemp, K. Kondo, G. Korga, L. Kotsiopoulou, S. Koulosousas, P. Kunze, M. Kuss, M. Kuźniak, M. Kuzwa, M. I. Kwon, M. La Commara, M. Lai, E. Le Guirriec, E. Leason, A. Leoni, L. Lidey, J. D. Lipp, L. Lippolis, M. Lissia, L. Luzzi, O. Lychagina, O. Macfadyen, J. Machts, I. Machulin, S. Mameli, S. Manecki, I. Manthos, A. Marasciulli, S. M. Mari, C. Mariani, J. Maricic, M. Martinez, G. Matteucci, K. Mavrokoridis, A. Mazzi, A. B. McDonald, L. Meng, A. Messina, R. Milincic, G. Miller, S. Minutoli, A. Mitra, J. Monroe, M. Morrocchi, A. Morsy, V. Muratova, M. Murra, C. Muscas, P. Musico, R. Nania, M. Nessi, G. Nieradka, K. Nikolopoulos, E. Nikoloudaki, J. Nowak, K. Olchanski, A. Oleinik, P. Organtini, A. Ortiz de Solórzano, A. Padmanabhan, M. Pallavicini, L. Pandola, E. Pantic, E. Paoloni, D. Papi, L. Parellada Monreal, B. Park, G. Pastuszak, G. Paternoster, R. Pavarani, A. Peck, P. A. Pegoraro, K. Pelczar, R. Perez, V. Pesudo, S. Piacentini, N. Pino, G. Plante, A. Pocar, S. Pordes, P. Pralavorio, E. Preosti, D. Price, G. Prior, M. Pronesti, S. Puglia, M. Queiroga Bazetto, F. Raffaelli, F. Ragusa, Y. Ramachers, A. Ramirez, S. Ravinthiran, K. Raymond, M. Razeti, A. L. Renshaw, A. Repond, M. Rescigno, S. Resconi, F. Retiere, A. Ritchie-Yates, A. Rivetti, A. Roberts, C. Roberts, D. Rodríguez Rodas, G. Rogers, L. Romero, M. Rossi, D. Rudik, J. Runge, M. Sabia, C. Salerno, P. Salomone, O. Samoylov, S. Sanfilippo, D. Santone, R. Santorelli, E. M. Santos, I. Sargeant, M. L. Sarsa, C. Savarese, E. Scapparone, D. Semenov, C. Seoane, A. Serrecchia, M. Sestu, V. Shalamova, S. Sharma Poudel, A. Sheshukov, M. Simeone, D. Sitzia, P. Skensved, M. Skorokhvatov, O. Smirnov, T. Smirnova, B. Smith, F. Spadoni, M. Spangenberg, A. Steri, M. R. Stock, V. Stornelli, S. Stracka, A. Sung, C. Sunny, Y. Suvorov, A. M. Szelc, O. Taborda, B. Tam, R. Tartaglia, A. Taylor, J. Taylor, G. Testera, A. Thompson, S. Torres-Lara, A. Tricomi, S. Tullio, E. Unzhakov, M. Van Uffelen, P. Ventura, G. Vera Díaz, S. Viel, A. Vishneva, R. B. Vogelaar, J. Vossebeld, B. Vyas, M. Wada, M. Walczak, Y. Wang, S. Westerdale, L. Williams, M. M. Wojcik, M. Wojcik, Z. Xu, J. Yin, A. Zabihi, P. Zakhary, A. Zani, H. Zhan, Y. Zhang, G. Zuzel

High Energy Physics (Experiment)

Amplitude analysis of $\psi(3686)$ radiative decays into $\pi^{0} \pi^{0}$ system

BESIII Collaboration: M. Ablikim, M. N. Achasov, P. Adlarson et al. (+767 more)

A model-independent amplitude analysis of the $\pi^{0} \pi^{0}$ system produced in radiative $\psi(3686)$ decays is presented. The analysis is based on the unique dataset of $(2712.4\pm14.3)\times10^6$ $\psi(3686)$ decays collected by the BESIII detector. Scalar and tensor partial-wave contributions are obtained as piecewise functions of $M_{\text{inv}}(\pi^{0} \pi^{0})$ with minimal model assumptions. The observed contribution of the scalar partial wave exhibits similar behavior to the one reported in the study of radiative $J/\psi$ decays, while the tensor contributions provide no evidence for resonance-like structures except for the clearly visible $f_2(1270)$. The results are presented in the form of log-likelihood scans in $M_{\text{inv}}(\pi^{0} \pi^{0})$ bins, which preserve all the statistical information and account for relevant systematic uncertainties. The model-independent description provided in this paper allows to combine the presented results with other related data in the development of phenomenological models.
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All authors BESIII Collaboration: M. Ablikim, M. N. Achasov, P. Adlarson, X. C. Ai, C. S. Akondi, R. Aliberti, A. Amoroso, Q. An, Y. H. An, M. S. Anderson, Y. Bai, O. Bakina, H. R. Bao, X. L. Bao, M. Barbagiovanni, V. Batozskaya, K. Begzsuren, N. Berger, M. Berlowski, M. B. Bertani, D. Bettoni, F. Bianchi, E. Bianco, A. Bortone, I. Boyko, R. A. Briere, A. Brueggemann, D. Cabiati, H. Cai, M. H. Cai, X. Cai, A. Calcaterra, G. F. Cao, N. Cao, S. A. Cetin, X. Y. Chai, J. F. Chang, T. T. Chang, G. R. Che, Y. Z. Che, C. H. Chen, Chao Chen, G. Chen, H. S. Chen, H. Y. Chen, M. L. Chen, S. J. Chen, S. M. Chen, T. Chen, W. Chen, X. R. Chen, X. T. Chen, X. Y. Chen, Y. B. Chen, Y. Q. Chen, Z. K. Chen, J. Cheng, L. N. Cheng, S. K. Choi, X. Chu, G. Cibinetto, F. Cossio, J. Cottee-Meldrum, H. L. Dai, J. P. Dai, X. C. Dai, A. Dbeyssi, R. E. de Boer, D. Dedovich, C. Q. Deng, Z. Y. Deng, A. Denig, I. Denisenko, M. Destefanis, F. De Mori, E. Di Fiore, X. X. Ding, Y. Ding, Y. X. Ding, J. Dong, L. Y. Dong, M. Y. Dong, X. Dong, Z. J. Dong, M. C. Du, S. X. Du, Shaoxu Du, X. L. Du, Y. Q. Du, Y. Y. Duan, Z. H. Duan, P. Egorov, G. F. Fan, J. J. Fan, Y. H. Fan, J. Fang, Jin Fang, S. S. Fang, W. X. Fang, Y. Q. Fang, L. Fava, F. Feldbauer, G. Felici, C. Q. Feng, J. H. Feng, Q. X. Feng, Y. T. Feng, M. Fritsch, C. D. Fu, J. L. Fu, Y. W. Fu, H. Gao, Xu Gao, Y. Gao, Y. N. Gao, Y. Y. Gao, Yunong Gao, Z. Gao, S. Garbolino, I. Garzia, L. Ge, P. T. Ge, Z. W. Ge, C. Geng, A. Gilman, K. Goetzen, J. Gollub, J. B. Gong, J. D. Gong, L. Gong, W. X. Gong, W. Gradl, M. Greco, M. D. Gu, M. H. Gu, C. Y. Guan, A. Q. Guo, H. Guo, J. N. Guo, L. B. Guo, M. J. Guo, R. P. Guo, X. Guo, Y. P. Guo, Z. Guo, A. Guskov, J. Gutierrez, J. Y. Han, T. T. Han, X. Han, F. Hanisch, K. D. Hao, X. Q. Hao, F. A. Harris, C. Z. He, K. K. He, K. L. He, F. H. Heinsius, C. H. Heinz, Y. K. Heng, C. Herold, P. C. Hong, G. Y. Hou, X. T. Hou, Y. R. Hou, Z. L. Hou, H. M. Hu, J. F. Hu, Q. P. Hu, S. L. Hu, T. Hu, Y. Hu, Y. X. Hu, Z. M. Hu, G. S. Huang, K. X. Huang, L. Q. Huang, P. Huang, X. T. Huang, Y. P. Huang, Y. S. Huang, T. Hussain, N. Hüsken, N. in der Wiesche, J. Jackson, Q. Ji, Q. P. Ji, W. Ji, X. B. Ji, X. L. Ji, Y. Y. Ji, L. K. Jia, X. Q. Jia, D. Jiang, S. J. Jiang, X. S. Jiang, Y. Jiang, J. B. Jiao, J. K. Jiao, Z. Jiao, L. C. L. Jin, S. Jin, Y. Jin, M. Q. Jing, X. M. Jing, T. Johansson, S. Kabana, X. L. Kang, X. S. Kang, B. C. Ke, V. Khachatryan, A. Khoukaz, O. B. Kolcu, B. Kopf, L. Kröger, L. Krümmel, Y. Y. Kuang, X. Kui, N. Kumar, A. Kupsc, W. Kühn, Q. Lan, W. N. Lan, T. T. Lei, M. Lellmann, T. Lenz, C. Li, C. H. Li, C. K. Li, Chunkai Li, Cong Li, D. M. Li, F. Li, G. Li, H. B. Li, H. J. Li, H. L. Li, H. N. Li, H. P. Li, Hui Li, J. N. Li, J. S. Li, J. W. Li, K. Li, K. L. Li, L. J. Li, L. K. Li, Lei Li, M. H. Li, M. R. Li, M. T. Li, P. L. Li, P. R. Li, Q. M. Li, Q. X. Li, R. Li, S. Li, S. X. Li, S. Y. Li, Shanshan Li, T. Li, T. Y. Li, W. D. Li, W. G. Li, X. Li, X. H. Li, X. K. Li, X. L. Li, X. Y. Li, X. Z. Li, Y. Li, Y. H. Li, Y. B. Li, Y. C. Li, Y. G. Li, Y. P. Li, Z. H. Li, Z. J. Li, Z. L. Li, Z. X. Li, Z. Y. Li, C. Liang, H. Liang, Y. F. Liang, Y. T. Liang, Z. Z. Liang, G. R. Liao, L. B. Liao, M. H. Liao, Y. P. Liao, J. Libby, A. Limphirat, C. C. Lin, C. X. Lin, D. X. Lin, T. Lin, B. J. Liu, B. X. Liu, C. Liu, C. X. Liu, F. Liu, F. H. Liu, Feng Liu, G. M. Liu, H. Liu, H. B. Liu, H. M. Liu, Huihui Liu, J. B. Liu, J. J. Liu, K. Liu, K. Y. Liu, Ke Liu, Kun Liu, L. Liu, L. C. Liu, Lu Liu, M. H. Liu, P. L. Liu, Q. Liu, S. B. Liu, T. Liu, W. M. Liu, W. T. Liu, X. Liu, X. K. Liu, X. L. Liu, X. P. Liu, X. T. Liu, X. Y. Liu, Y. Liu, Y. B. Liu, Yi Liu, Z. A. Liu, Z. D. Liu, Z. L. Liu, Z. Q. Liu, Z. X. Liu, Z. Y. Liu, X. C. Lou, H. J. Lu, J. G. Lu, X. L. Lu, Y. Lu, Y. H. Lu, Y. P. Lu, Z. H. Lu, C. L. Luo, J. R. Luo, J. S. Luo, M. X. Luo, T. Luo, X. L. Luo, Z. Y. Lv, X. R. Lyu, Y. F. Lyu, Y. H. Lyu, F. C. Ma, H. L. Ma, Heng Ma, J. L. Ma, L. L. Ma, L. R. Ma, Q. M. Ma, R. Q. Ma, R. Y. Ma, T. Ma, X. T. Ma, X. Y. Ma, F. E. Maas, I. MacKay, M. Maggiora, S. Maity, S. Malde, L. M. Mansur, Y. J. Mao, Z. P. Mao, S. Marcello, A. Marshall, F. M. Melendi, Y. H. Meng, Z. X. Meng, G. Mezzadri, H. Miao, T. J. Min, R. E. Mitchell, X. H. Mo, B. Moses, N. Yu. Muchnoi, J. Muskalla, Y. Nefedov, F. Nerling, H. Neuwirth, Z. Ning, S. Nisar, Q. L. Niu, W. D. Niu, Y. Niu, C. Normand, S. L. Olsen, Q. Ouyang, I. V. Ovtin, S. Pacetti, Y. Pan, C. Y. Pang, A. Pathak, Y. P. Pei, M. Pelizaeus, G. L. Peng, H. P. Peng, X. J. Peng, Y. Y. Peng, K. Peters, K. Petridis, J. L. Ping, R. G. Ping, S. Plura, V. Prasad, L. Pöpping, F. Z. Qi, H. R. Qi, S. Qian, W. B. Qian, C. F. Qiao, J. H. Qiao, J. J. Qin, J. L. Qin, L. Q. Qin, L. Y. Qin, P. B. Qin, X. P. Qin, X. S. Qin, Z. H. Qin, J. F. Qiu, Z. H. Qu, J. Rademacker, K. Ravindran, C. F. Redmer, A. Rivetti, M. Rolo, G. Rong, S. S. Rong, F. Rosini, Ch. Rosner, M. Q. Ruan, W. R. Ruangyoo, N. Salone, A. Sarantsev, Y. Schelhaas, M. Schernau, K. Schoenning, M. Scodeggio, W. Shan, X. Y. Shan, Z. J. Shang, J. F. Shangguan, L. G. Shao, M. Shao, C. P. Shen, H. F. Shen, W. H. Shen, X. Y. Shen, B. A. Shi, Ch. Y. Shi, H. Shi, J. L. Shi, J. Y. Shi, M. H. Shi, S. Y. Shi, X. Shi, H. L. Song, J. J. Song, M. H. Song, T. Z. Song, W. M. Song, Y. X. Song, Zirong Song, S. Sosio, S. Spataro, S. Stansilaus, F. Stieler, M. Stolte, S. S Su, G. B. Sun, G. X. Sun, H. Sun, H. K. Sun, J. F. Sun, K. Sun, L. Sun, R. Sun, S. S. Sun, T. Sun, W. Y. Sun, Y. C. Sun, Y. H. Sun, Y. J. Sun, Y. Z. Sun, Z. Q. Sun, Z. T. Sun, H. Tabaharizato, N. T. Tagsinsit, C. J. Tang, G. Y. Tang, J. Tang, J. J. Tang, L. F. Tang, Y. A. Tang, Z. H. Tang, L. Y. Tao, M. Tat, J. X. Teng, J. Y. Tian, W. H. Tian, Y. Tian, Z. F. Tian, K. Yu. Todyshev, I. Uman, E. van der Smagt, B. Wang, Bin Wang, Bo Wang, C. Wang, Chao Wang, Cong Wang, D. Y. Wang, F. K. Wang, H. J. Wang, H. R. Wang, J. Wang, J. J. Wang, J. P. Wang, K. Wang, L. L. Wang, L. W. Wang, M. Wang, Mi Wang, N. Y. Wang, P. Wang, S. Wang, Shun Wang, T. Wang, W. Wang, W. P. Wang, X. F. Wang, X. L. Wang, X. N. Wang, Xin Wang, Y. Wang, Y. D. Wang, Y. F. Wang, Y. H. Wang, Y. J. Wang, Y. L. Wang, Y. N. Wang, Yanning Wang, Yaqian Wang, Yi Wang, Yuan Wang, Z. Wang, Z. L. Wang, Z. Q. Wang, Z. Y. Wang, Zhi Wang, Ziyi Wang, D. Wei, D. H. Wei, D. J. Wei, H. R. Wei, F. Weidner, H. R. Wen, S. P. Wen, U. Wiedner, G. Wilkinson, J. F. Wu, L. H. Wu, L. J. Wu, Lianjie Wu, S. G. Wu, S. M. Wu, X. W. Wu, Z. Wu, H. L. Xia, L. Xia, B. H. Xiang, D. Xiao, G. Y. Xiao, H. Xiao, Y. L. Xiao, Z. J. Xiao, C. Xie, K. J. Xie, Y. Xie, Y. G. Xie, Y. H. Xie, Z. P. Xie, T. Y. Xing, D. B. Xiong, G. F. Xu, H. Y. Xu, Q. J. Xu, Q. N. Xu, T. D. Xu, X. P. Xu, Y. Xu, Y. C. Xu, Z. S. Xu, F. Yan, L. Yan, W. B. Yan, W. C. Yan, W. H. Yan, W. P. Yan, X. Q. Yan, Y. Y. Yan, H. J. Yang, H. L. Yang, H. X. Yang, J. H. Yang, R. J. Yang, X. Y. Yang, Y. Yang, Y. G. Yang, Y. H. Yang, Y. M. Yang, Y. Q. Yang, Y. Z. Yang, Youhua Yang, Z. Y. Yang, W. J. Yao, Z. P. Yao, M. Ye, M. H. Ye, Z. J. Ye, K. Yi, Junhao Yin, Z. Y. You, B. X. Yu, C. X. Yu, G. Yu, J. S. Yu, L. W. Yu, T. Yu, X. D. Yu, Y. C. Yu, Yongchao Yu, C. Z. Yuan, H. Yuan, J. Yuan, Jie Yuan, L. Yuan, M. K. Yuan, S. H. Yuan, Y. Yuan, C. X. Yue, Ying Yue, A. A. Zafar, F. R. Zeng, S. H. Zeng, X. Zeng, Y. J. Zeng, Yujie Zeng, Y. C. Zhai, Y. H. Zhan, B. L. Zhang, B. X. Zhang, D. H. Zhang, G. Y. Zhang, Gengyuan Zhang, H. Zhang, H. C. Zhang, H. H. Zhang, H. L. Zhang, H. Q. Zhang, H. R. Zhang, H. Y. Zhang, Han Zhang, J. Zhang, J. J. Zhang, J. L. Zhang, J. Q. Zhang, J. S. Zhang, J. W. Zhang, J. X. Zhang, J. Y. Zhang, J. Z. Zhang, Jianyu Zhang, Jin Zhang, Jiyuan Zhang, L. M. Zhang, Lei Zhang, N. Zhang, P. Zhang, Q. Zhang, Q. Y. Zhang, Q. Z. Zhang, R. Y. Zhang, S. H. Zhang, S. N. Zhang, Shulei Zhang, X. M. Zhang, X. Y. Zhang, Y. T. Zhang, Y. H. Zhang, Y. P. Zhang, Yao Zhang, Yu Zhang, Yu Zhang, Z. Zhang, Z. D. Zhang, Z. H. Zhang, Z. L. Zhang, Z. X. Zhang, Z. Y. Zhang, Zh. Zh. Zhang, Zhilong Zhang, Ziyang Zhang, Ziyu Zhang, G. Zhao, J.-P. Zhao, J. Y. Zhao, J. Z. Zhao, L. Zhao, Lei Zhao, M. G. Zhao, R. P. Zhao, S. J. Zhao, Y. B. Zhao, Y. L. Zhao, Y. P. Zhao, Y. X. Zhao, Z. G. Zhao, A. Zhemchugov, B. Zheng, B. M. Zheng, J. P. Zheng, W. J. Zheng, W. Q. Zheng, X. R. Zheng, Y. H. Zheng, B. Zhong, C. Zhong, X. Zhong, H. Zhou, J. Q. Zhou, S. Zhou, X. Zhou, X. K. Zhou, X. R. Zhou, X. Y. Zhou, Y. X. Zhou, Y. Z. Zhou, A. N. Zhu, J. Zhu, K. Zhu, K. J. Zhu, K. S. Zhu, L. X. Zhu, Lin Zhu, S. H. Zhu, T. J. Zhu, W. D. Zhu, W. J. Zhu, W. Z. Zhu, Y. C. Zhu, Z. A. Zhu, X. Y. Zhuang, M. Zhuge, J. H. Zou, J. Zu

High Energy Physics (Experiment)

Real-time monitoring of LHCb beam spot properties based on FPGA hit reconstruction

Giulio Cordova, Elena Graverini, Daniele Passaro et al. (+3 more)

We present a real-time trackless method to monitor the centre of the LHCb luminous region and the relative alignment of the two halves of the LHCb Vertex Locator, using cluster counts accumulated in selected regions of the detector and processed in firmware. A Principal Component Analysis performed on simulated data yields a set of weight vectors that reduce the position estimators to scalar products of the counter rates, executable with negligible computational overhead. With pp collision data from 2024, the transverse position of the luminous region is reconstructed with a statistical precision of approximately 4 micrometre per coordinate in a 90 millisecond accumulation window. A measurement of the longitudinal centre is demonstrated with a statistical precision of a few millimetres in simulated studies. The introduction of run-time configurable firmware counters has been studied in simulation to improve the transverse and longitudinal resolutions by a factor of three with respect to the fixed-geometry baseline.
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All authors Giulio Cordova, Elena Graverini, Daniele Passaro, Federico Lazzari, Michael J. Morello, Giovanni Punzi

High Energy Physics (Experiment)

New results from electron-positron heavy-flavor factories

Xiaodong Shi

The electron-positron heavy-flavor factories — BaBar, Belle, Belle~II, and BESIII — continue to deliver a broad and sensitive physics program. I report selected highlights presented at ICHEP 2026, covering neutral- and charged-current $B$ processes, tests of lepton-flavor universality in $b\to c\ell\nu$ transitions, precision measurement of Cabibbo–Kobayashi–Maskawa matrix elements, and hadron spectroscopy.
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Monday 12 October

High Energy Physics (Experiment) · Cross-listed from hep-ph

Parton and nuclear dynamics at large $x$: the CJ26 global QCD analysis

Alberto Accardi, Matteo Cerutti, Cynthia E. Keppel et al. (+4 more)

We present the new CTEQ-JLab global QCD analysis, called CJ26, that simultaneously fits parton distribution functions of the proton and nuclear effects in deuteron targets. This work includes, for the first time in a global fit, the full set of JLab 6 GeV inclusive DIS measurements and the first published JLab 12 GeV data. The analysis focuses on the large-$x$ region, and carefully treats the interplay between higher-twist effects and off-shell corrections in low-energy proton and deuteron target data. We discuss their effect on quark and gluon distributions, and highlight the importance of quantifying the experimental correlated systematic uncertainty to achieve fits of the highest accuracy. We also outline how upcoming data may help unravel the nuclear and partonic dynamics in light nuclei. The extracted next-to-leading order parton distributions are available on the CJ web pages in LHAPDF format for general use, accompanied by leading- and higher-twist structure functions calculated with the simultaneously fitted PDFs, higher-twist corrections, and off-shell corrections. This write up clarifies several points that became clearer while finalizing the CJ26 paper and can be read as a companion to the latter.
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All authors Alberto Accardi, Matteo Cerutti, Cynthia E. Keppel, Shujie Li, J. F. Owens, Sanghwa Park, Peter Risse

High Energy Physics (Experiment) · Cross-listed from physics.ins-det

FINESSE: A Versatile Beamline for Fundamental Interactions with Neutrons at the European Spallation SourcE

J. Amaral, J. Barrow, M. Bartis et al. (+71 more)

FINESSE (A Versatile Beamline for Fundamental Interactions with Neutrons at the European Spallation SourcE) is a proposed versatile beamline for fundamental interactions with neutrons at the European Spallation Source. Building on the HIBEAM design studies, FINESSE extends the original concept into a dual-guide beamline capable of operating either in a high-flux configuration or in a low-background configuration within a single ESS beam port. The high-flux branch is optimized for rare-process searches, including neutron–antineutron oscillations, neutron–sterile-neutron transitions, axion-like-particle searches, neutron charge measurements, and rare neutron decays. The low-background branch is designed for precision measurements requiring strong suppression of prompt and line-of-sight backgrounds, with a cryogenic neutron electric-dipole-moment experiment used as a benchmark case. A baseline exchangeable-guide concept has been developed in which only short guide sections inside the ESS bunker are exchanged, while the upstream extraction system and chopper positions remain fixed. A staged implementation, Short FINESSE, would use the upstream section of the high-flux beamline together with a compact magnetically controlled experimental region, enabling an early physics and R&D programme before completion of the full facility. This paper summarizes the scientific case, beamline concept, guide simulations, chopper and timing system, magnetic-field control, detector developments, and staged implementation strategy. FINESSE would establish a long-term particle-physics infrastructure at ESS, providing a beamline for both discovery-driven searches and precision neutron measurements throughout the lifetime of the facility.
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All authors J. Amaral, J. Barrow, M. Bartis, D. H. Beck, P. M. Bentley, J. Bijnens, G. Brooijmans, L. J. Broussard, A. Burgman, G. Cibinetto, G. Croci, D. D. Di Julio, P. Fierlinger, B. W. Filippone, C. Gatto, H. Gisbert, H. Gogoi, G. Gorini, A. Gutierrez-Rodriguez, A. Koberinski, M. Kaczmarek, M. Silarski, M. O'Riordan, A. Heinz, J. Henderson, M. Holl, H. T. Johansson, B. Jonsson, H. Henriksson, L. Jonsson, Y. Kamyshkov, M. P. Kuhl, P. Kinhult, R. Kolevatov, A. Kozela, W. T. Lee, K. K. H. Leung, T.-J. Liang, G. Luzin, B. Meirose, D. Milstead, R. Mohapatra, G. Muhrer, A. Muraro, A. Nepomuceno, N. Okada, A. Oskarsson, T. Palasz, R. Pasechnik, V. Larsson, L. B. Persson, O. Putignano, J. Ramsey, C. Snow, L. Werselius, B. Rataj, A. Rodriguez-Sanchez, A. Saunders, V. Santoro, F. Scioscioli, R. Shrock, D. Silvermyr, H. Sina, W. M. Snow, Y. V. Stadnik, L. Tchelidze, N. Tsapatsaris, A. Tureanu, A. Vilela Pereira, M. Wolke, J. Womersley, S. Xu, A. R. Young, K. Osterberg

High Energy Physics (Experiment) · Cross-listed from hep-ph

Lepton Flavour Universality in Semileptonic $\bar B_{(s)} \to D_{(s)}^{(\ast)}$ Transitions

Yu-Chen Hu, Cong-Cong Ye, Craig D. Roberts et al. (+1 more)

Using continuum Schwinger function methods, we deliver parameter-free pointwise predictions for the complete set of twelve Standard Model (SM) $\bar B_{(s)} \to D_{(s)}^{(\ast)}$, i.e., $b\to c$, semileptonic transition form factors on the entire kinematically accessible domain. Therewith, we calculate SM theory values for the decay-rate ratios of $\tau$ and $\mu$ final states: $\{ R(D) \, , \, R(D)^\ast \} = \{ 0.290(11) \, , \, 0.267(5) \}$, $\{ R(D_{s}) \, , \, R(D_{s}^{\ast}) \} = \{ 0.283(11) \, , \, 0.251(5) \}$. The former is consistent with an existing average of SM estimates, but disagrees with the experimental average by $2.8\sigma$. Comparing transitions with light quark and strange quark spectators, we find a $2.3\sigma$ signal for violation of SU$(3)$ flavour symmetry, expressed at the 5% level in $D_{(s)}^\ast$ final states. It is induced by Higgs boson couplings into the strong interaction and modulated by phenomena deriving from emergent features of the strong interaction.
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All authors Yu-Chen Hu, Cong-Cong Ye, Craig D. Roberts, Zhao-Qian Yao

High Energy Physics (Experiment) · Cross-listed from hep-ph

Neutrino Tridents and $W$-boson production at the Muon Collider

Felix Kling, Toni Mäkelä, Sebastian Trojanowski et al. (+1 more)

Muon colliders are exceptionally intense sources of multi-TeV neutrinos, allowing even relatively small detectors to record large rates of neutrino interactions. In addition to serving as neutrino-ion collider for precision measurements of neutrino deep inelastic scattering, this setup allow to study even rare neutrino processes with at high statistics. In this study, we investigate the feasibility of measuring neutrino trident and on-shell W-boson production, predicting over one million trident events and one hundred thousand W-boson events in a 100 kg silicon-based active target over ten years and allowing to detect these processes for the first time. We further show that these measurements could constrain new vector and axial-vector interactions beyond projected DUNE sensitivities and provide unprecedented constraints on the high-x photon distribution through W-boson production near threshold. We also discuss strategies for signal-background discrimination and the resulting detector requirements.
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All authors Felix Kling, Toni Mäkelä, Sebastian Trojanowski, Bei Zhou

High Energy Physics (Experiment) · Cross-listed from physics.acc-ph

Anomaly Detection in Bunch Oscillations for Early Warning of Sudden Beam Loss at SuperKEKB

H. Haigh, P. Horak, G. Inguglia et al. (+5 more)

Sudden beam loss (SBL) events at the SuperKEKB collider result in the loss of a large fraction of the stored beam within just a few revolutions, on a timescale comparable to or shorter than the 20-30 {\mu}s latency of the existing abort system. Such events have damaged collimators and threaten Belle II subdetectors. Bunch Oscillation Recorders (BORs) capture transverse bunch positions at each revolution, which often show sizable oscillations that precede significant beam current loss. We test whether these precursors can be detected earlier than a charge-based reference that mimics the existing abort sensors. We apply several oscillation-based anomaly detection algorithms to 208 SBL events recorded in the low-energy ring during the 2024 run period, ranging from simple rolling statistics to machine learning models trained to forecast bunch oscillation. On 173 events not used for training or calibration, the best-balanced model (DeepLSTM) triggers before the charge-based reference in 86-90% of events across five training seeds, with a mean lead time of 25-30 {\mu}s. The only trigger classified as a false alarm fires on an oscillation that begins about 60 turns before the abort and persists until the beam is lost, making it more likely an early precursor than a spurious trigger. These results establish bunch oscillations as a viable early abort trigger and motivate a shadow-mode deployment to measure the false-alarm rate in continuous operation.
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All authors H. Haigh, P. Horak, G. Inguglia, C. Krause, G. Mitsuka, H. Nakayama, R. Nomaru, M. Tobiyama

High Energy Physics (Experiment) · Cross-listed from hep-ph

Implications for new physics solutions to the LSND and MiniBooNE anomalies after MicroBooNE results

Waleed Abdallah, Raj Gandhi and Samiran Roy

Over the past couple of decades, the Liquid Scintillator Neutrino Detector (LSND) and MiniBooNE (MB) neutrino experiments have provided statistically significant evidence of persistent and as yet unexplained electron-like event excesses. The MicroBooNE experiment, with sensitive particle identification capabilities designed to shed light on these anomalous results, has conducted a number of analyses to test whether the excess is due to photons, electrons or $e^+e^-$ pair productions, all of which give almost identical signals in LSND and MB. Recent MicroBooNE searches, in addition to checking Standard Model (SM) processes, have focused on proposed new physics scenarios involving new mediators and dark portals beyond the SM. We study the consequences and effects of these analyses for the many theoretical proposals put forth to generate the three types of signals above in order to understand the observed excesses. We discuss which classes of solutions are allowed, disallowed or require further scrutiny involving theoretical and experimental efforts. We give an example of a new solution that survives the restrictions imposed by MicroBooNE results and other existing bounds. We point out that a light ($m\leq 30$ MeV) dark neutral spin zero mediator with dominantly pseudoscalar couplings, decaying to an $e^+e^-$ pair, can account for the observations. We indicate that if such a model is realised, it may point to the possibility that neutrinos are Dirac particles, and that there are dark Heavy Neutral Leptons (HNLs) of mass ${\cal O}(100)$ MeV. We discuss issues related to CP violation and ultra-violet completion of these models. Finally we stress that a search for the excess in incoherent scattering channels in MicroBooNE and SBND could help clarify the physics behind these persistent anomalies.
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High Energy Physics (Experiment) · Cross-listed from hep-ph

Charged Lepton Flavor Violation: A Theory Overview

P. S. Bhupal Dev

We present a theory-oriented overview of the significance of charged-lepton flavor violation – one of the cleanest windows onto physics beyond the Standard Model. We also summarize the current experimental landscape and illustrate how different measurements can diagnose the underlying new physics.
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High Energy Physics (Experiment) · Cross-listed from astro-ph.HE

An end-to-end experimental pipeline for automated track identification for paleo-detectors

Claudio Galelli, Alessandro Testi and Lorenzo Caccianiga

Paleo-detectors aim to exploit the damage tracks left in natural minerals by cosmic messengers over geological times to reconstruct past fluxes of energetic particles. For cosmic rays, the expected signal is abundant, and the tracks are micron-scale, so they can be revealed by etching and read out with conventional optical microscopy; what remains challenging is turning a bulk sample into a calibrated track-length spectrum that can be quantitatively confronted with theoretical predictions. In this work we present the experimental pipeline we developed for this purpose within the INFN PRImuS experiment, from sample preparation and automated multi-focus microscopy to track recognition with OptimusPrimus, a two-stage machine-learning algorithm, and to a forward-folding model that propagates geometric sectioning, etching and the measured detection response into simulated spectra. The pipeline was built and validated on chemically etched obsidian where the recovered track-length distribution is statistically compatible with expert annotation. In parallel, we developed and characterized a dry argon-plasma etching protocol for halite, an evaporite mineral of particular interest as a low-background cosmic-ray paleo-detector. Since every stage of the pipeline is mineral-agnostic, with only the trained networks and the detection response to be re-derived from annotated data, we are now applying it to plasma-etched halite with the aim of identifying cosmic-ray-induced tracks.
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High Energy Physics (Experiment) · Cross-listed from hep-ph

Event Generation for Neutrino and Muon DIS at the LHC

Paulina Hernandez-Sainz, Felix Kling, Jelle Koorn et al. (+1 more)

Neutrinos and muons produced in the forward direction of LHC collisions and detected by the FASER and SND@LHC experiments enable a comprehensive deep-inelastic scattering (DIS) programme, covering both neutral and charged currents, at TeV energies. This programme aims to provide stringent constraints on proton and nuclear structure as well as on hadron fragmentation, and to offer novel insight into neutrino interactions at the highest energies achieved in a laboratory. Realising this potential requires accurate and precise simulations of neutral- and charged-current DIS. We systematically compare the predictions of NLO general-purpose Monte Carlo (MC) event generators for neutrino- and muon-initiated DIS at the LHC (Sherpa, Herwig7, and POWHEG) against analytical structure-function calculations (YADISM) and dedicated neutrino simulation packages (GENIE, NuWro, GiBUU). Within this framework, we quantify the role of higher-order QCD corrections, (nuclear) parton distribution functions (PDFs), parton shower and hadronisation modelling, and QED radiation both for inclusive observables and for the FASER fiducial selections. We also present representative applications to the FASER neutrino programme: comparisons with its most recent data from the emulsion and electronic sub-detectors, a study of strange PDF sensitivity in the dimuon final state, and predictions for charged-hadron production in semi-inclusive DIS. Our analysis highlights the agreement of modern event generators for inclusive and differential DIS observables once common settings are adopted, while differences remain for observables sensitive to the hadronic final state.
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All authors Paulina Hernandez-Sainz, Felix Kling, Jelle Koorn, Juan Rojo

High Energy Physics (Experiment) · Cross-listed from hep-ph

Conserved-charge diffusion in hot and dense QCD matter

Dushmanta Sahu, Kangkan Goswami and Raghunath Sahoo

We study the coupled diffusion of baryon number, electric charge, and strangeness in hot and dense quark matter using a three-flavor Nambu-Jona-Lasinio model with self-consistently generated constituent quark masses. The complete diffusion matrix is evaluated within a relaxation-time kinetic approach, including its diagonal and off-diagonal components. We find that the off-diagonal transport coefficients exhibit distinct temperature and baryon-chemical-potential dependence associated with the flavor-dependent composition of the charge carriers. We further investigate generalized charge diffusivities and mobilities obtained from the corresponding susceptibilities. At finite baryon chemical potential, the baryon and strangeness mobility scales cross, reflecting the different density dependence of their transport coefficients and susceptibilities. The results provide model benchmarks for coupled conserved-charge transport in baryon-rich QCD matter.
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High Energy Physics (Experiment)

Experimental Demonstration of Soft-Tissue Muon Scattering Tomography

Dipanwita Banerjee, Benjamin Banto Oberhauser, Paolo Crivelli et al. (+1 more)

Muons have fascinated physicists since their discovery in cosmic rays almost a century ago. Their large mass and relatively long lifetime allow relativistic muons to traverse large amounts of matter, a property that has been exploited to probe otherwise inaccessible structures, from volcanoes and archaeological monuments to shielded nuclear materials. Here, we experimentally demonstrate for the first time that muon scattering tomography can be extended to biological soft tissue. We image an anthropomorphic thorax phantom using a 2 GeV/c muon beam at the CERN Proton Synchrotron and reconstruct its three-dimensional scattering density from the measured deflections of individual muons. Despite the weak scattering produced by tissue-equivalent materials, the reconstructed density agrees with the expectation from simulation at the percent level. Our results extend muon imaging into a previously unexplored regime and open the possibility of using muons as a complementary probe for medical imaging.
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All authors Dipanwita Banerjee, Benjamin Banto Oberhauser, Paolo Crivelli, Laura Molina Bueno