Papers

We study two-Higgs-doublet models, extensions of the Standard Model (SM) containing two Higgs doublets rather than one. Tree-level Higgs-mediated interactions that change quark or lepton flavor are conventionally suppressed by a discrete $\mathbb{Z}_2$ symmetry. Motivated by string compactifications, we instead impose a non-invertible Fibonacci selection rule at a matching scale $\Lambda$ for that purpose. This rule also forbids the independent mass parameter that normally allows the additional Higgs particles to become arbitrarily heavy, while renormalization-group evolution regenerates it below $\Lambda$. An allowed $\mathbb{Z}_2$-breaking quartic interaction simultaneously avoids stable cosmological domain walls. In the exact alignment limit, requiring perturbative unitarity and boundedness from below up to the matching scale bounds the masses of the three non-SM Higgs states; for $\Lambda=10^{19}\,\mathrm{GeV}$, they lie below about $150\,\mathrm{GeV}$. The scanned parameter space predicts a suppressed Higgs diphoton signal strength within the projected reach of the HL-LHC. This illustrates how a stringy non-invertible selection rule can leave testable signatures in Higgs physics.

Hidden-heavy pentaquarks can be identified as bound states in diabatic Born-Oppenheimer potentials that are repulsive color-Coulomb potentials at short distance, cross below a heavy-hadron-pair threshold, and then approach that threshold at long distance. We identify the pentaquarks $P_{c\bar{c}}(4312)^+$, $P_{c\bar{c}}(4337)^+$, $P_{c\bar{c}}(4440)^+$, and $P_{c\bar{c}}(4457)^+$ as the ground-state quartet for $c \bar c$ in the two coupled potentials associated with a spin-$3/2$ adjoint baryon. We predict that their $J^P$ quantum numbers are $\frac{1}{2}^-$, $\frac{3}{2}^-$, $\frac{3}{2}^-$, and $\frac{5}{2}^-$, respectively. Our prediction for $P_{c\bar{c}}(4457)^+$ differs from almost all previous predictions. Our prediction that there are only four hidden-charm pentaquarks differs qualitatively from that of simple molecular models that there should be seven. We identify the strange hidden-charm pentaquarks $P_{c\bar{c}s}(4338)^0$ and $P_{c\bar{c}s}(4459)^0$ as two members of the ground-state triplet for $c \bar c$ in the potential associated with a spin-$1/2$ strange adjoint baryon. We also present model-independent predictions for pentaquark decays into charmonium plus a light baryon and into a charm baryon and a charm meson.

Motivated by the deviations between experimental data and SM predictions for the branching fractions of $\bar{B}_{(s)}^{0} \to D_{(s)}^{(*)+}L^-$ decays with $L=\pi,K^{(*)},\rho$, we investigate whether the type-IV scalar diquark can offer a plausible explanation for them. By matching the renormalized amplitudes in the full theory onto those in the low-energy effective theory formulated in the diquark operator basis, we extract the corresponding Wilson coefficients up to NLO in $\alpha_s$ at the NP scale $\mu_\phi=M_{\phi}$. We then rewrite the obtained operators in the SM basis and apply the renormalization-group running to evolve the Wilson coefficients down to the hadronic scale $\mu_b=m_b$. For the hadronic matrix elements of the relevant NP operators, we employ the QCD factorization approach to evaluate the non-factorizable one-loop vertex corrections, and confront our theoretical predictions to the latest data to constrain the diquark parameter space. In the single-coupling case, we find that the purely left-handed coupling $\Delta_{d(s)}^{LL}$ can reconcile the discrepancies at $1\sigma$, while the mixed right-left coupling $\Delta_{d(s)}^{RL}$ remains compatible with data only at about $2\sigma$. Extending to the two-coupling case, we find viable parameter regions as long as $\Delta_{d(s)}^{LL}\neq 0$. Incorporating the LHCb measurement of the ratio $R_{\pi/\mu\nu_{\mu}}$ further reduces the allowed range of $\Delta_{d}^{LL}$, but does not yield meaningful extra restriction on $\Delta_{d}^{RL}$. Hence, while either $\Delta_{d(s)}^{LL}$ or $\Delta_{d(s)}^{RL}$ can separately provide an acceptable NP interpretation, our phenomenological results favor a scenario dominated by purely left-handed diquark-quark couplings. Finally, we present updated predictions for the branching fractions and the ratios $R_{(s)L}^{(*)}$, which can be probed by forthcoming LHCb and Belle II measurements.

We study environment-dependent annihilation of quasi-Dirac Higgsino dark matter coupled to an axion-like particle with a mass slightly below the Higgsino-pair threshold. Axion-mediated annihilation becomes more important relative to electroweak annihilation in the Sun and Galactic halo than during cosmological reannihilation following late nonthermal production. This separation arises from both the low-velocity enhancement of the subthreshold propagator and the change from a coannihilating Higgsino multiplet to the lightest neutral state. In solar capture-annihilation equilibrium, a dominant annihilation channel into massless dark photons suppresses the high-energy neutrino signal while leaving capture efficient. Higgsinos can consequently account for a few percent of the total dark matter abundance while satisfying solar-neutrino constraints and retaining an appreciable terrestrial inelastic-scattering rate, with implications for the LZ high-recoil candidate. In the Galactic halo, the enhanced cross section instead produces correlated continuum and line gamma-ray signals, with the lines potentially close to the present sensitivity for a cuspy Galactic dark-matter profile. We discuss supersymmetric realizations based on generalized mirage mediation and hidden strong dynamics, as well as an extended Higgs-sector alternative. The dark photons also contribute to dark radiation, providing a complementary cosmological probe.

Evidence for excesses observed at LHC tend to cluster mostly around 95 GeV and 650 GeV. We claim that a consequent interpretation of the 650 GeV and some additional indications calls for a Randall Sundrum sequence of Kaluza Klein graviton resonances. A common prejudice claims that such resonances should be very heavy, out of reach for LHC. We argue that this is no so. Although present LHC searches seem to exclude these particles below 2 TeV, we explain why this 650 GeV resonance could be one of them. We also explain why ongoing analyses ignore this scenario and apply selections which are only valid for scalar resonances. This could also apply to ongoing searches for Higgs pairs where the search for resonances decaying into SM Higgs pairs ignores the KK graviton scenario. We expect that with a correct treatment, one could very significantly increase the detection efficiency for ZZ and hh channels and achieve, with present data, a convincing proof of our expectations. Channels like h(95)h(125) and h(95)h(95) should be added to present selections. Such improvements should allow to reach a discovery. For the ZZ and WW channels, one can use semi-leptonic and purely hadronic final states, to confirm the tower of KK resonances indicated up to 3 TeV.

In this work, we propose a new natural dark matter candidate: Kaluza-Klein towers of vectors from $d\geq 2$ extra-dimensional models. Their naturalness follows from two key features: (i) they arise unavoidably from the Kaluza-Klein decomposition of the higher-dimensional metric, and (ii) if the Standard Model is localised on a brane, they do not couple directly to it and interact only gravitationally through the other components of the higher-dimensional metric. Remarkably, the rich particle content comes with as few as a single extra parameter. We first explain the general idea for $d\geq 2$, then focus on the $d=2$ case as our benchmark scenario. We derive the field content and interactions among the model particle content, and show how the geometry of the extra dimension unitarises the relevant processes for cosmology. We then compute the multi-component relic abundances of the vectors from freeze-in and discuss the available parameter space.

We examine the role of the Bakamjian–Thomas (BT) construction in achieving current-component independence for pseudoscalar-to-pseudoscalar semileptonic form factors in light-front (LF) dynamics. An exactly solvable covariant Bethe–Salpeter (BS) model provides an off-shell benchmark. Its transverse-current zero-mode contribution is calculated directly from the shrinking nonvalence region and reproduced by an effective operator in the valence convolution. In the BT-based LF quark model, the one-body current kernel is constructed from on-shell constituent spinors, while interactions are encoded in the mass operator and wave functions. In this realization, the $(+,\perp)$ current-component extraction is zero-mode free and is saturated by the on-shell overlap. Using the free constituent invariant masses consistently in the internal projections yields the same $f_-(q^2)$ from the $(+,\perp)$ and $(+,-)$ current-component extractions after integration. We establish this equality analytically for rotationally invariant radial wave functions with the LF Jacobian and the adopted pseudoscalar spin coupling, provided the reduced overlaps converge. The difference from the minus-current projection using physical meson masses defines an interaction-dependent BT completion, distinct from the BS endpoint contribution. A mass-weighted complex transverse contour permits direct evaluation of the Gaussian $D\to K$ overlaps throughout the physical timelike interval, including zero recoil, without a form-factor parametrization or extrapolation. These results establish current-component independence within the specified BT realization and clarify the dynamical dependence of zero-mode assignments.

We investigate the mass spectra and two-body nonleptonic weak decays of ground-state doubly and triply heavy baryons in a nonrelativistic quark-diquark model. To account for the finite size of the diquark, we generalize the convoluted quark-diquark interaction to unequal-mass diquarks using mass-weighted constituent coordinates and distinct pairwise spin-spin couplings. The resulting Schrödinger equations provide the baryon masses and wave functions used consistently in the decay calculation. The predicted masses differ from existing lattice QCD results by less than $1.5\%$, and our calculated mass of $\Omega_{cc}^{+}$ is consistent with recent LHCb observations. The calculated hyperfine splittings are systematically slightly smaller than the lattice values, indicating a residual uncertainty in the spin-dependent interaction. Within the factorization approximation, we evaluate the $c\to s$ and $b\to c$ transitions with pion or kaon emission. At leading nonrelativistic order, the vector contribution vanishes for the $3/2^+\to1/2^+$ transitions, while both vector and axial contributions enter the $3/2^+\to3/2^+$ channels. The $b\to c$ spatial overlaps are substantially smaller than their $c\to s$ counterparts. Together with the Cabibbo-Kobayashi-Maskawa hierarchy, this reduces the corresponding $b \to c$ width by approximately two orders of magnitude. In the $3/2^+\to1/2^+$ charm transitions, the leading $|\bm{k}|^3$ dependence enhances the suppression of kaon emission. In bottom transitions with a larger energy release, the smaller relative phase-space difference brings the ratios close to the scaling determined by the Cabibbo-Kobayashi-Maskawa elements and meson decay constants. These results provide benchmark estimates for future studies of multiply heavy baryons and quantify the role of recoil dynamics within the finite-size quark-diquark framework.

We investigate the relative $P$-wave excitations of the $D^{(*)}\bar D^{(*)}$ systems using the QCD sum rule method. By introducing a covariant derivative between two ground-state charmed meson fields, we construct color-singlet interpolating currents to describe the relative orbital excitation between the two meson clusters. The $P$-wave $D\bar D$, $D\bar D^*/D^*\bar D$, and $D^*\bar D^*$ configurations with $J^{P}=1^{-}$ are systematically studied. Their masses are predicted to be around $3.8$, $3.9$, and $4.0$-$4.1$GeV, respectively. These values are close to the corresponding thresholds and are compatible with the structures around $X(3790)$ and $G(3900)$, supporting their possible interpretations as $P$-wave $D\bar D$ and $D\bar D^*/D^*\bar D$ configurations, respectively. In addition, we find that the $J^{PC}=1^{-+}$ and $1^{--}$ combinations in the $D\bar D^*/D^*\bar D$ sector possess identical correlation functions in the present QCD sum rule framework, leading to degenerate mass predictions for these two channels. These results indicate that relative $P$-wave excitations of heavy meson pairs may constitute another interesting class of near-threshold hadronic configurations worthy of further experimental investigation.

We present a likelihood analysis of observables in deeply virtual exclusive $\pi^o$ electro-production off the proton. We use experimental data for the cross section as well as the beam and target spin asymmetries measured in various longitudinal polarization configurations at Jefferson Lab Hall A and Hall B. Performing a local extraction, for each kinematic bin, we derive a joint likelihood for the various helicity amplitudes defining the different polarization configurations. We subsequently extract the Compton form factors that parameterize the underlying QCD scattering amplitudes in the chiral-odd sector. Markov chain Monte Carlo (MCMC) methods are employed to explore the full parameter space, extracting the parameter uncertainties, correlations and credible intervals. The joint likelihood analysis of the cross-section and asymmetry data constrains the parameter space indicating that a larger kinematic coverage and additional polarization configurations, e.g. in the transverse sector, will improve the precision of the parameters. We also report a determination of the proton tensor charge and tensor anomalous magnetic moment extracted in a Bayesian statistical framework using deeply virtual exclusive scattering data.

We study the phenomenological implications of anomaly-free dark photon models using low-energy solar neutrino-electron elastic scattering data from the ton-scale PandaX-4T and XENONnT experiments. Focusing on $U(1)_X$ gauge extensions that incorporate both kinetic and mass mixing, we derive novel exclusion limits across the parameter spaces of six benchmark models. Our analysis demonstrates that the stringency of these limits is directly correlated with the theoretical leptonic charge assignments of the respective models. Additionally, we provide model-independent limits by isolating the pure kinetic and pure mass mixing scenarios. In the sub-MeV mediator mass regime, our results meaningfully improve upon existing limits from previous neutrino-electron scattering experiments, such as CHARM-II, TEXONO, and GEMMA. Ultimately, these findings yield improved limits on low-mass dark photon models, demonstrating their complementarity with other ventures in the global search for dark portals.

We study the decay \(\eta_c\to p\bar{p}\eta\) by combining the SU(3) flavor structure of the primary production with final-state interactions in the \(p\eta\) and \(\bar{p}\eta\) subsystems, using the chiral unitary approach. The low-energy \(S_{11}\) dynamics, including the dynamically generated \(N^*(1535)\), is incorporated into the complete coupled-channel amplitude, and a phenomenological \(N^*(1895)\) contribution is included coherently. The \(p\eta\) and \(\bar{p}\eta\) invariant-mass distributions are well described, and the \(p\bar{p}\) distribution is predicted as a kinematic reflection of the \(\eta N\) dynamics. The results support the dynamical interpretation of the \(N^*(1535)\) and suggest possible additional \(S_{11}\) strength near \(1.9\)~GeV.

In this paper, we present a machine-learning-based framework for identifying leptonically decaying, highly boosted top quarks, $t\to b\ell\nu$, at the Future Circular Collider: hadron-hadron mode (FCC-hh) operating at a center-of-mass energy of $\sqrt{s}=100$~TeV. At these energies, the large Lorentz boost causes the top-quark decay products to become highly collimated, with the lepton embedded within the resulting top-quark jet. In this regime, it is not a priori clear whether constituent-based jet taggers, which rely on information from individual jet constituents, retain the high discrimination power achieved at LHC energies. To answer this question, we employ two complementary approaches: a variable-based tagger trained with a deep neural network (DNN) using physics-motivated observables and a constituent-based Particle Transformer (ParT) acting on the jet constituents. Both approaches are optimised for the characteristic non-isolated lepton signature of boosted leptonic top decays and achieve comparable performance in discriminating leptonic top jets from hadronic top jets and heavy-flavor $b$- and $c$-jet backgrounds. We then incorporate the tagging framework into an event-level search for single production of a vector-like $B^\prime$ quark decaying through $B^\prime\to tW$, and use it to evaluate sensitivity to $B^\prime$ in the range of $3$ to $10$~TeV. For the reference $B^\prime$ benchmark, the proposed search strategy achieves a $5\sigma$ discovery reach of approximately $7$~TeV under the width requirement $\Gamma_{B^\prime}/m_{B^\prime}<25\%$, in both the statistics-only and $10\%$ background systematic uncertainty scenarios. Relaxing the width requirement to $\Gamma_{B^\prime}/m_{B^\prime}\lesssim 50\%$ extends the discovery reach to approximately $10$~TeV.

We develop a new model that provides a unified description of the equilibration and subsequent transport of conserved charges, including baryon number, electric charge, and strangeness, as well as the dynamical formation and evolution of the quark-gluon plasma medium in high-energy nuclear collisions. This is achieved by extending the state-of-the-art model of dynamical core-corona initialization to incorporate phenomenological source terms for conserved charges within a full (3+1)-dimensional hydrodynamic framework; the updated model is referred to as DCCI3. Consequently, the model simultaneously describes the core (equilibrium) and corona (nonequilibrium), including their mutual interactions. We present a detailed construction of the DCCI3 model and employ it in numerical simulations of Pb+Pb collisions at $\sqrt{s_{NN}}=2.76~\mathrm{TeV}$ to investigate the resulting dynamics of matter and conserved charges, with particular emphasis on the longitudinal structure. We find that each of the chemical potentials exhibits sizable fluctuations around midrapidity, which challenges the conventional assumption of vanishing values as an oversimplification. Moreover, the baryon chemical potential increases sharply with rapidity and becomes comparable to the temperature at forward rapidities. This suggests that the Rapidity Scan (RS) approach in high-energy nuclear collisions can serve as a complementary probe to the Beam Energy Scan (BES) in exploring the QCD phase diagram.

We propose a spin-density-matrix framework for probing anomalous $Wtb$ interactions in top-quark pair production by exploiting the polarizations of the $b$ quark and the $W$ boson and their spin correlations. The $b$-quark spin is analyzed through angular distributions in semileptonic $\Lambda_b$ decay following fragmentation, while the leptonic $W$ decay serves as a $W$-polarization analyzer. We derive the $bW$ spin density matrix in the presence of anomalous $Wtb$ couplings and show that its polarization and spin-correlation parameters provide linear sensitivity to these couplings. We construct experimentally accessible angular observables associated with these parameters and evaluate their statistical sensitivities. For the HL-LHC at $\sqrt{s}=14~ \mathrm{TeV}$ with an integrated luminosity of $3000~ \mathrm{fb}^{-1}$, the proposed method yields improved constraints on most anomalous $W t b$ couplings, with the sensitivity to $V_R$ enhanced by a factor of 8 and that to $g_L$ by a factor of about 6.

As a continuation of our previous work, with the grand desert hypothesis, we prove that we can probe the Supersymmetric Grand Unified Theories (GUTs) with gauge meidation at the future proton-proton collider and Hyper-Kamiokande experiment. For the GUT scale $M_{\rm GUT}$ less than or equal to $0.84\times10^{16}$~GeV, the proton lifetime for dimension-six proton decay via heavy gauge boson exchange is less than or around $5\times10^{34}$ years, and thus we can probe it at the Hyper-Kamiokande experiment. For $ M_{\rm GUT} \ge 0.84 \times 10^{16}$ GeV, the lightest neutralino is the Next to the Lightest Supersymmetric Particle (NLSP), as well as the upper mass bounds on the gluino and first two generation squarks are 8.64 TeV and 11.82 TeV, respectively. Therefore, the gluino and first two generation squarks can be probed at the future 100 TeV proton-proton collider such as ${\rm FCC}_{\rm hh}$ and SppC. Moreover, we discuss the mass spectra for the colored sparticles, sleptons, pseudo-scalar Higgs and electroweakinos. If the sparticles were discovered, it might give us hint on the messenger scale, the effective supersymmetry breaking scale, and the renormalization group evolution of the supersymmetry breaking soft terms.

Swampland principles, combined with the smallness of dark energy $\Lambda$, lead to the dark dimension scenario, with one extra dimension of micron size. We review this scenario and its predictions: KK graviton dark matter (or the KK tower of the quintessence field into which the gravitons convert), neutrino masses tied to $\Lambda^{1/4}$ via a bulk $B-L$ gauge symmetry, QCD axion decay constant $f_a\sim \Lambda^{1/12}\sim 10^9-10^{10}$ GeV at the 5d Planck scale $M_5$, connecting electroweak hierarchy to $\Lambda^{1/6}$, and a relation between the GUT and weak scales with $M_5$ as the geometric mean. The dark dimension also provides a concrete realization of an evolving dark sector: the evolution of its diameter correlates the variation of dark energy with that of the dark matter mass, fitting the recent DESI DR2 (+CMB+supernovae) data while avoiding the phantom crossing that the $w_0w_a$CDM parametrization would suggest—the apparent phantom behavior instead arises from the evolving dark matter mass. The fits suggest that the dark energy field sits in the interior of moduli space, near an unstable critical point. Motivated by this, we review recent progress on non-supersymmetric string vacua: isolated critical points protected by duality symmetries, in non-geometric flux compactifications and in Scherk–Schwarz compactifications of M-theory, and an emerging duality web for non-supersymmetric strings. This note is based on two talks given by the author at String Phenomenology 2026 (Paris) and Strings 2026 (Shanghai).

We study the refined de Sitter conjecture (RdSC), the Trans-Planckian Censorship Conjecture (TCC) and the species scale $\Lambda_s$ in the multifield flux potential of type IIB string theory compactified on one-parameter Calabi–Yau threefolds. The scalar potential depends on the axio-dilaton and on the single complex-structure modulus, and is no-scale along the Kähler directions. Restricting to $h^{2,1}=1$ allows us to work with the exact periods obtained from the Picard–Fuchs equations rather than with their large-complex-structure expansion, and therefore to probe the conifold region. For the mirror quintic, $(h^{2,1},h^{1,1})=(1,101)$, we scan 200 flux configurations and find unstable extrema in $96\%$ of the cases, with $c'=0.18$. Once the Kähler runaway is taken into account, the no-scale structure fixes the logarithmic slope of the potential at every critical point to the universal value $\sqrt6$, so that the first RdSC condition is satisfied throughout. Statistically, the complex structure is the heavier sector and the axio-dilaton dominates the unstable directions. For the TCC we obtain analytic results valid for the whole class of one-parameter models: the slope approaches the universal value $2$ at large complex structure, diverges at the conifold, and equals exactly $\sqrt2$ in the axio-dilaton directions, where the leading potential takes a single $SL(2)$-covariant form, as the multifield evolutions confirm numerically. The TCC further translates into a lower bound on the compactification volume, $v>v_0\sim e^{N}$, controlled by the number of e-folds. Finally, the field displacements along our trajectories are compatible with the species-scale field-range bound, and restoring the volume dependence of $\Lambda_s$ shows that $V\lesssim3\Lambda_s^2$ is implied by the TCC volume bound, which is thus the genuine constraint on these models.

We investigate an information-geometric approach to dense two-color QCD using thermal states defined as normalized Gibbs states in the two-flavor Nambu–Jona-Lasinio model at the mean-field level. The Bures metric and quantum Fisher information are constructed from thermal states associated with effective Bogoliubov–de Gennes Hamiltonians reproducing the mean-field quasiparticle spectrum. On the thermodynamic parameter manifold $(T,\mu)$, where $T$ is temperature and $\mu$ is quark chemical potential, we analyze information-geometric quantities including the trace of the QFI matrix and the metric-volume density. The numerical results show pronounced enhancements of both quantities near the color-superconducting phase boundary, whereas only weaker signatures are observed across the chiral crossover. By contrast, neither observable exhibits a distinct feature associated with the BEC–BCS crossover.

Ultraperipheral collisions of heavy ions, dominated by the electromagnetic interaction, allow to investigate the photoproduction of baryons and mesons from the excited nuclei. At LHCb, thanks to the SMOG2 system, these studies can also be conducted in fixed-target collisions, exploiting a variety of target gases ranging from $^{4}$He to Xe. In the present work, we adapted our photonuclear model and the Giesen-Boltzmann-Uehling-Uhlenbeck (GiBUU) generator to study photoproduction of protons, neutrons as well as pions and kaons from excited $^{40}$Ar nuclei in fixed-target ultraperipheral collisions with the LHC $^{208}$Pb beam. We present predictions for the total and differential photoproduction cross sections in $p$ and $p_T$, both in the full phase-space and within the geometrical acceptance of the LHCb detector.

In quantum mechanics the modulus square of the wave function is the probability of an event — positivity is self-evident. Quantum field theory corresponds to quantum mechanics one-to-one: the wave function corresponds to the matrix element, so the probability of a process should be the modulus square of the matrix element, positive by construction. In the founding era of perturbative quantum field theory, however, Feynman, Schwinger and Tomonaga treated inclusive processes in quantum electrodynamics, where the truncation of the squared amplitude was forced by infrared cancellations and rendered harmless by the small coupling $\alpha\simeq1/137$. Carried over to exclusive processes in quantum chromodynamics, where the coupling is large, this practice produced negative decay and production rates already at NLO, persisting at NNLO. We point out that for exclusive processes, whose initial and final states are colorless for QCD and electrically neutral for QED, the infrared divergences cancel amplitude by amplitude and the KLN constraint is absent, so the complete modulus square of the truncated amplitude is the proper, manifestly positive definition of the probability. We formulate amplitude-level NRQCD factorization as the systematic prescription that restores positivity, show that every amplitude-level truncated observable admits the effective representation $\Gamma^{\mathrm{amp}}=\Gamma_{\mathrm{LO}}\bigl|1+\frac{\alpha_s}{\pi}(c_1+ic_2)+\frac{\alpha_s^2}{\pi^2}(c_3+ic_4)\bigr|^2$, and demonstrate, with the complete NNLO QCD corrections to $J/\psi\to3\gamma$, $\Upsilon\to3\gamma$, $e^+e^-\to J/\psi+J/\psi$ and the eight exclusive charmonium production channels at $B$ factories, that the prescription yields positive and better-converging predictions.

We report on the status and prospects of precision weak neutral current interaction measurements in fixed target scattering, atomic parity violation, as well as future collider measurements at momentum transfer $\sqrt{Q^2} \ll M_Z$, including the experiments in parity-violating electron scattering under construction at Jefferson Laboratory and at Mainz that are expected to commence data collection in the very near future.

Within rainbow-ladder truncation, we identify three contributions to the pion's gravitational form factors—graviton coupling to the quark, to the gluon dressing the quark, and to the gluon binding the pion—and separate them into quark and gluon parts. Using an algebraic quark model with a dynamical basis, we obtain $A(0)=1$, $D(0)=-1$ in the chiral limit, and momentum fractions $\langle x\rangle_q=0.896$, $\langle x\rangle_g=0.104$. The D-term obeys the same partition at the model scale.

We present a minimal, predictive scenario for asymmetric fermionic dark matter (DM) generated through freeze-in. The standard model (SM) is extended by a Dirac fermion $\psi$ that serves as the DM candidate, an auxiliary Dirac fermion $\chi$, a real scalar mediator $\phi$, and a heavier real scalar $S$, all stabilized by a $Z_2 \times Z_2'$ discrete symmetry. The DM asymmetry is generated through the CP-violating out-of-equilibrium decays of the mediator $\phi$, while the heavier scalar $S$ plays a dual role: it generates the physical CP-violating phase required for the asymmetry through its interference with $\phi$, and it mediates the annihilation of the symmetric component of the DM population. We solve the coupled Boltzmann equations for the asymmetric yield $Y_-$ and the total yield $Y_\Sigma$, and identify the scaling relations $Y_-^\infty \propto \mu^2 \varepsilon / m_\phi$ and $\Omega_{\rm DM} h^2 \propto m_\psi \, \mu^2 \varepsilon / m_\phi$, which we verify numerically. The observed relic abundance $\Omega_{\rm DM} h^2 \simeq 0.12$ is naturally reproduced for a wide range of parameters; in particular, for $\varepsilon = 10^{-6}$ and $m_\phi = 200$~GeV, the correct relic density is obtained for $\mu \approx 2.7 \times 10^{-9}$~GeV and $m_\psi \approx 40$~GeV. We further confront the model with current experimental constraints, including direct detection, indirect detection, collider searches, and DM self-interactions, and show that the predicted signals lie far below the sensitivity of current experiments. This scenario provides a self-consistent and testable realization of asymmetric fermionic DM within the freeze-in framework.

We study how a minimal length can affect the chiral vortical effect, in which rotation produces a current in matter made of chiral fermions. We focus on an isotropic modification of the momentum-space density-of-state (DoS) and determine the vortical conductivity from the static, long-wavelength correlation between the current and momentum density. The analysis is carried out first for a single right-handed Weyl fermion and is then extended to general massless chiral fermion systems with mutually commuting conserved charges. We find that, for a broad class of analytic isotropic DoS modifications, the familiar leading contributions from chemical potential and temperature remain unchanged at first order within the DoS sector. Minimal-length effects instead appear through higher-order thermal and chemical-potential contributions. Some of these corrections contain the same chiral charge combinations that appear in gauge and mixed gauge-gravitational anomalies, while another contains an independent higher-order charge combination. Their coefficients depend on the form of the DoS modification and are therefore not fixed by the usual four-dimensional anomaly structure. For the Kempf-Mangano-Mann deformation, the exact result shows that a positive minimal-length parameter always reduces the DoS contribution to the vortical conductivity. We also find that a Planck-suppressed correction is extremely small under standard heavy-ion chemical freeze-out conditions. These results show that isotropic minimal-length modifications can change higher-order contributions to chiral vortical transport while leaving the familiar leading anomaly-related response unchanged within the DoS sector considered here.

We study the rare decay $\Lambda_b \rightarrow \Lambda(\rightarrow p\pi^-)\nu\bar{\nu}$ of polarized $\Lambda_b$ baryons produced at the $Z$ pole. We find that the differential decay distribution is characterized by five independent angular observables, four of which require initial $\Lambda_b$ polarization. While standard observables in mesonic $b \rightarrow s \nu \bar\nu$ decays ($B \rightarrow K^{(*)} \nu \bar{\nu}$, $B_s \rightarrow \phi \nu \bar{\nu}$) probe only two combinations of short-distance Wilson coefficients, $|C_L + C_R|$ and $|C_L - C_R|$, the angular observables in $\Lambda_b \rightarrow \Lambda(\rightarrow p\pi^-)\nu\bar{\nu}$ provide access to the orthogonal combinations $|C_R|^2 - |C_L|^2$ and $\text{Im}(C_L C_R^*)$. In particular, we identify a $T$-odd CP asymmetry, $A_5$, that directly probes CP-violating phases in the short-distance effective Hamiltonian. We present Standard Model predictions for the branching ratio and all angular observables using lattice QCD form factors, and evaluate the projected new physics sensitivity at the FCC-ee. Our results demonstrate that baryonic angular observables are essential for resolving parameter degeneracies and for completely characterizing the chiral and CP structure of possible new physics in $b \rightarrow s \nu \bar{\nu}$ transitions.

Exclusive $\gamma\gamma\to J/\psi+\gamma$ production is studied in the color-singlet channel at leading order in the heavy-quark velocity. The conventional next-to-leading-order (NLO) result $B+V$, comprising Born production and its interference with the renormalized one-loop amplitude, is compared with $B+V+Q$, where $Q$ retains the complete one-loop square. At photon-photon energies $W=80~\mathrm{GeV}$ and $160~\mathrm{GeV}$, the conventional spectrum becomes negative over finite high-$p_T$ intervals already at renormalization scale $\mu_R=W$, whereas the complete square remains non-negative. In contrast, the total partonic cross section exceeds Born at the larger energies in the energy scan, owing to positive virtual contributions from other scattering directions. For $p$-$p$ collisions at $14~\mathrm{TeV}$ and $Pb$-$Pb$ collisions at $\sqrt{s_{NN}}=5.52~\mathrm{TeV}$, $Q$ raises the central integrated ultraperipheral rates by $11.6\%$–$18.4\%$. Their absolute scale widths over $\mu_R=\{W/2,W,2W\}$ decrease by $36\%$–$67\%$. Retaining the complete one-loop square changes both the predicted integrated rates and the shapes of the differential distributions.

A dark-matter core and a soft nuclear equation of state can produce similar mass–radius signatures, motivating a complementary probe through the $f$-mode spectrum. We compute quadrupolar $f$-mode frequencies and gravitational-wave damping times in full general relativity for cold, nonrotating neutron stars admixed with self-interacting bosonic dark matter (DM). Our two-fluid survey spans 21 nuclear equations of state covering nucleonic, hyperonic, $\Delta$-admixed, and combined hyperon–$\Delta$ compositions at $F_{\rm DM}=1$–$20\%$. The main sequences use $\lambda=\pi$ and boson masses of $500$ and $100\,\mathrm{MeV}$ for the core and halo studies, respectively. Independent normal-matter (NM) and DM displacements couple through the metric, yielding NM-led and DM-led $f$-mode branches whose radiative damping is determined by outgoing-wave boundary conditions. At $1.4\,M_\odot$, the core DM-led damping time decreases from order $10^3\,\mathrm{s}$ at $F_{\rm DM}=1\%$ to order $1\,\mathrm{s}$ at $20\%$, approximately following an empirical $F_{\rm DM}^{-2}$ dependence, while NM-led damping times remain within $0.12$–$0.33\,\mathrm{s}$. Halo DM-led damping instead increases with dark fraction: at the same stellar mass and $F_{\rm DM}=20\%$, dark radii approach $88\,\mathrm{km}$, frequencies fall to $0.14\,\mathrm{kHz}$, and damping times reach approximately $450\,\mathrm{s}$. Selected high-mass core sequences exhibit strong DM-led damping-time upturns not reproduced by the leading mass-quadrupole diagnostic. Representative core calculations show greater DM-led sensitivity to the bosonic self-coupling and retain both branches at $\ell=3$. Under the adopted nonrotating, circular-binary prescriptions, no evaluated configuration satisfies all geometric and perturbative conditions for a controlled linear tidal resonance.

Coherent motion of light scalar fields in the early Universe is typically attributed to an initial displacement, a primordial velocity, or a prescribed temperature-dependent potential. We identify a distinct microscopic mechanism in which differential thermal evolution of multiple non-aligned symmetry-breaking sources rotates the effective vacuum direction of a pseudo-Nambu–Goldstone boson (pNGB), driving motion from an initially stationary minimum. The mechanism is realized in the Majoron sector of a Type-I seesaw mechanism, where heavy neutrinos with separated thermal thresholds supply the required differential thermal evolution. For a representative benchmark, the thermal source direction rotates by $|\Delta\theta_T|\simeq0.76$~rad and drives the Majoron to a peak velocity $|\dot\theta|/H\simeq0.62$, while the field tracks the moving minimum to sub-milliradian accuracy. This establishes a microscopic finite-temperature origin for pNGB motion, with implications for spontaneous leptogenesis and, more generally, for any system with multiple non-aligned symmetry-breaking sources that evolve differently with temperature.

We propose a phenomenological toy framework promoted to a minimal three-state internal sector in $(3+1)$ dimensions and realized by composite strong dynamics. It is in a genuine three-body holonomy which originates in a relativistic $(1+1)$-dimensional Dirac system. The hypothesis is that the number three is not imposed first as a gauge symmetry, but is inherited from the primitive closed cyclic structure of the three-body holonomy. This threefold structure subsequently reappears as a three-state internal space, the three-site loop, a three-flavor hidden sector, and a cubic determinant interaction. We introduce an asymptotically free hidden $SU(3)_H$ gauge theory with three Standard-Model-singlet Dirac flavors. Strong hidden dynamics generates a composite condensate, while the inherited holonomy selects its cyclic internal orientation. The anomalous cubic determinant interaction produces a holonomy-dependent potential, and dimensional transmutation generates the characteristic composite scale. The radial composite excitation along the cyclic direction, denoted by $S_3$, couples to the Standard-Model Higgs doublet through a holonomy-dependent CP-even portal. The resulting condensate shifts the Higgs quadratic term and can trigger electroweak symmetry breaking. In the classically scale-invariant reference limit, the electroweak scale is induced from the dynamically generated hidden-sector scale through dimensionless portal couplings.