High Energy Physics (Phenomenology)
Gauge-invariant Higgs mechanism via gradient-flow regularization
Gunnar S. Bali
We provide a manifestly gauge-invariant description of the
Higgs mechanism in the Standard Model, casting it not as the breaking of a local
symmetry, but as a smooth, analytic crossover from a high-temperature symmetric phase to a low-temperature
Higgs phase. Taking the
vacuum expectation value of a gauge-invariant local scalar operator and constructing composite quasi-particle states from the original fields of the Lagrangian usually introduces contact-term divergences. Previous attempts to circumvent this issue via bilocal operators remain unsatisfactory. Here we demonstrate that the gradient flow at a flow time $t$ provides a clean, structurally sound, and Lorentz-covariant regularization that permits a consistent, renormalon-free matching onto the standard $\overline{\text{MS}}$ scheme at a scale $\mu \sim 1/\sqrt{2t}\gg m_t$. Beyond its theoretical appeal, this construction clarifies a number of conceptional and practical questions. We demonstrate the utility of this framework at the one-loop level, thereby establishing the foundation for future electroweak precision physics in this approach.
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High Energy Physics (Phenomenology) · Cross-listed from astro-ph.CO
Probing Inflationary Origins of Primordial Black Holes with LIGO–Virgo–KAGRA O1–O4a data
Haipeng An, Huai-Ke Guo, Mai Qiao et al. (+3 more)
Large primordial
curvature perturbations not only produce primordial black holes (PBHs) but also inevitably source a scalar-induced
stochastic gravitational-wave background upon horizon reentry. We analyze the combined LIGO–Virgo–KAGRA O1–O4a data to constrain two representative inflationary mechanisms for generating such perturbations: ultra-slow-roll inflation and an inflationary phase transition. Detecting no evidence for either scenario, we place 95% credible upper limits on the
curvature-spectrum amplitude across the frequency range accessible to ground-based interferometers. Translated into the PBH context, these limits already exceed conventional constraints, probing abundance fractions far below unity. Our results remain robust even when the PBHs themselves are too rare to be directly detected or have evaporated. This work demonstrates that
stochastic gravitational-wave observations offer a powerful and complementary probe of small-scale inflationary physics and PBH formation, with upcoming interferometers promising to extend sensitivity to a wider range of inflationary epochs and PBH masses.
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All authors Haipeng An, Huai-Ke Guo, Mai Qiao, Lian-Tao Wang, Chen Yang, Yue Zhao
High Energy Physics (Phenomenology)
Supernova cooling from neutrinophilic dark matter
Yugen Lin
Core-collapse
supernova serve as a powerful laboratory for testing physics beyond the Standard Model (BSM), particularly regarding new, light states interacting feebly with SM particles. In this work, we investigate for the first time the production of dark matter (DM) via the
neutrino-
neutrino scattering processes inside a core-collapse
supernova, which contributes to the excessive cooling. By incorporating state-of-the-art
supernova simulation data , we derive stringent and robust limits on sub-GeV dark matter with effective couplings to
neutrinos. We find that the existing and projected constraints from indirect detection are quite weak. Our
supernova cooling bounds on DM-
neutrino reference cross section can improve indirect detection limits more than ten orders of magnitude for DM masses below $\mathcal{O}(100)$ MeV, and it can also provide strong complementarity with other cosmological constraints. Our results highlight the exceptional sensitivity of core-collapse
supernova to feebly interacting particles and motivate future
supernova neutrino observations as a powerful probe of light dark sectors.
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High Energy Physics (Phenomenology)
Reconstructing the Dark Matter Equation of State with Compact Object Inspirals
Boris Betancourt Kamenetskaia, Qianhang Ding and Hui-Yu Zhu
We investigate the gravitational wave (GW) signatures of compact binaries embedded in extended dark matter (DM) configurations in hydrostatic
equilibrium. If a
neutron star is surrounded by a sufficiently massive and extended envelope, an inspiraling companion experiences dynamical friction (DF) in addition to the standard GW energy loss. We show that this environmental effect can be isolated through a GW observable, the $D$-function, which directly characterizes the additional dissipative power induced by the surrounding medium. Since the density of the envelope is directly determined by the DM equation of state together with the stellar boundary conditions, the frequency dependence of the $D$-function provides direct information about the macroscopic properties of the dark sector. We develop a regression-based framework to reconstruct both the density profile and the DM equation of state over the density range probed by observations of the GW inspiral. Using representative DM models as
benchmarks, we demonstrate that the method accurately recovers the input equation of state while remaining largely independent of the microscopic realization of DM. Our results show that future GW observations of compact binaries can provide a probe of the equation of state of DM.
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High Energy Physics (Phenomenology)
Associated $W$ + charm production: indications for PDF analysis
Ville Alanko, Ilkka Helenius and Hannu Paukkunen
The strange
quark and antiquark contents of the
proton remain weakly constrained compared to the other light
quarks, particularly the asymmetry between the two. Production of a $W^\mp$
boson in association with a charmed
meson $D^{(*)\pm}$ could provide additional constraints in future fits of parton distribution functions. We calculate this process in general-mass variable-flavor-number scheme at next-to-leading order in perturbative
Quantum Chromodynamics. We investigate the production ratio between events with oppositely charged $W$
bosons, in which various theoretical uncertainties largely cancel while sensitivity to PDFs remains. We compare our predictions for this quantity with the recent ATLAS data at $\sqrt{s} = 13$ TeV and find that CT18ANLO, which sets the strangeness asymmetry to zero, yields good agreement with the data while MSHT20NLO and NNPDF4.0NLO, which have positive strangeness asymmetry in the relevant range of momentum fraction $x$, show more tension with the data. An approximate PDF-level analysis of the production ratio indicates that this tension could be attributed to a too large strangeness asymmetry.
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High Energy Physics (Phenomenology) · Cross-listed from hep-ex
The DALI Haloscope: A Magnetized Phased Array Coupled to a Semi-Open Fabry–Pérot Resonator
Javier De Miguel, Antonios Gardikiotis, Eduardo David González-Carretero et al. (+10 more)
DALI is an
axion haloscope consisting of a magnetized phased array backed by a conducting mirror and coupled in the near field to a semi-open Fabry–Pérot resonator. The applied static
magnetic field makes both the dielectric interfaces and the conducting mirror sensitive to
axion-induced electromagnetic conversion. Each interface acts as a radiating surface, and the resulting fields are projected onto the mode collected by the resonator and delivered to the receiver. We derive the detected power in terms of the power available from the magnetized mirror, the coherent contribution of the dielectric interfaces, the transverse mode overlap, the loaded quality factor, and the receiver-coupling coefficient. This formulation separates two distinct enhancement mechanisms. The dielectric-interface emissions may add coherently, producing a dielectric boost, while the semi-open Fabry–Pérot resonator provides enhancement through resonant storage of the coupled electromagnetic field. These contributions depend differently on the dielectric thicknesses, spacings, and resonant mode, and should therefore be evaluated independently. The same assembly can operate between the limits of a coherently boosted dielectric haloscope and a mirror-sourced, resonantly enhanced Fabry–Pérot haloscope. This combined architecture offers a flexible approach to resonant
axion searches at frequencies for which conventional closed microwave cavities become increasingly limited in conversion volume.
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All authors Javier De Miguel, Antonios Gardikiotis, Eduardo David González-Carretero, Elvio Hernández-Suárez, Roger J. Hoyland, Enrique Joven, Abaz Kryemadhi, Marios Maroudas, Chiko Otani, J. Alberto Rubiño-Martín, Yannis K. Semertzidis, Michael E. Tobar, Konstantin Zioutas
High Energy Physics (Phenomenology) · Cross-listed from hep-ex
Constraints on Galactic Dark Photons from a DALI Prototype
Javier De Miguel, Antonios Gardikiotis, Elvio Hernández-Suárez et al. (+10 more)
An analysis of 36 hours of data from a DALI haloscope reveals no statistically significant excess attributable to dark-
photon dark matter. We therefore set new constraints in the 6.88691–6.91792 GHz band, reaching a dark-
photon-to-
photon kinetic mixing strength of $\chi\lesssim 6.8\times10^{-14}$ at $28.54 \, \mu\mathrm{eV}$. To our knowledge, this result established the strongest laboratory-based exclusion limit in this frequency range.
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All authors Javier De Miguel, Antonios Gardikiotis, Elvio Hernández-Suárez, Roger J. Hoyland, Enrique Joven, Abaz Kryemadhi, Haroldo Lorenzo-Hernández, Marios Maroudas, Chiko Otani, J. Alberto Rubiño-Martín, Yannis K. Semertzidis, Michael E. Tobar, Konstantin Zioutas
High Energy Physics (Phenomenology) · Cross-listed from gr-qc
Intrinsic pressure anisotropy in spherical Proca stars
Ilídio Lopes
Pressure anisotropy in relativistic
stars is commonly prescribed through a phenomenological closure, obscuring its microscopic origin and relation to stress-energy conservation. Here it is derived directly from the minimally coupled Einstein-complex-Proca theory. For spherical Proca
stars, the principal-pressure difference admits an exact on-shell form whose sign is controlled solely by the local mass-shell threshold. The stress is radially dominated in the core, reverses on a surface of fixed gravitational
redshift, and becomes tangentially dominated in the envelope. At the first mass maximum, the fractional anisotropy reaches about 21% near the density maximum, whilst the region beyond the reversal contains about 9% of the mass. Its exact atmospheric limit is approximately 24%, equal in magnitude and opposite in sign to the scalar-
boson-
star limit. Because the usual local fluid variables remain non-zero at the crossing, no sign-definite closure constructed from them can reproduce the profile. These results identify an intrinsically vectorial stress reversal, generated without additional interactions, and provide a first-principles
benchmark for anisotropic bosonic compact objects.
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High Energy Physics (Phenomenology)
Comparision of modeling of prompt photon production in proton-proton collisions at energies NICA $\sqrt{s}$ =10 GeV in PYTHIA and calculations using FeynCalc
Mohsun R.Alizada, Azar I.Akhmedov, Sarhaddin K.Abdullayev et al. (+2 more)
The process of
prompt photon production in
proton-
proton collisions at energies of $\sqrt{s}$=10 GeV at the NICA accelerator complex, modulated using PYTHIA 8.316 and calculated in FeynCalc. The main focus is on three main subprocesses: Compton scattering of a
quark-gluon $qg \rightarrow q\gamma$, annihilation of a
quark-antiquark pair $q\bar{q} \rightarrow g\gamma$ and bremsstrahlung of
quarks $qq \rightarrow qq\gamma$. Main statistical parameters: number of produced
prompt photon on
photon energy, rapidity and invariant mass
photon pairs are determined. The distribution of the number of produced
photons by energy$ E_{\gamma } $ and rapidity
photons can be mathematically described by the logarithmic-normal and normal law, correspondingly. The analysis shows that Compton scattering of a
quark-gluon $qg \rightarrow q\gamma$ makes a dominant contribution to the total cross section of the process, accounting for 51.27%, while the contributions of annihilation of
quark-antiquark pair $q\bar{q} \rightarrow g\gamma$ and bremsstrahlung of
quarks $qq \rightarrow qq\gamma$, correspondingly are is 47.22% and 0.003%. The difference between the results obtained from the PYTHIA modeling and those calculated by FeynCalc is explained. The use of modern modeling tools such as PYTHIA not only improves the accuracy of experimental predictions, but also plays a key role in the development of new technologies for particle detection and data analysis.
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All authors Mohsun R.Alizada, Azar I.Akhmedov, Sarhaddin K.Abdullayev, Mejid Sh.Gojayev, Mammed R.Rajabov
High Energy Physics (Phenomenology)
Phase Structure and Gravitational-Wave Phenomenology of a Thermal First-Order Phase Transition
Gayatri Ghosh
We investigate the phase structure and gravitational-wave (GW) phenomenology of a cosmological first-order phase transition described by the finite-temperature effective potential $V(\phi,T)=D(T^2-T_0^2)\phi^2-ET\phi^3+\lambda\phi^4/4$. We derive the critical temperature and the broken-phase order parameter and identify the dimensionless combination $E^2/(D\lambda)$ that controls the critical-temperature shift. We then construct a dense numerical atlas containing $30\,000$ parameter points and map the resulting transition parameters onto the characteristic GW frequency and peak amplitude. The scan resolves the multidimensional correlations among $T_*$, $\alpha$, $\beta/H_*$, $v_w$, $f_{\rm peak}$ and $\Omega_{\rm GW}^{\rm peak}h^2$. The present analysis is phenomenological: $T_*$ is defined by the prescription $T_*=0.95T_c$, while $\beta/H_*$ and $v_w$ are treated as scan inputs. Consequently, the resulting GW signals are not interpreted as first-principles predictions. We identify the additional ingredients required for a predictive calculation, including the thermal bounce action, nucleation and percolation temperatures, the transition duration and a microscopic treatment of bubble-wall friction. The resulting framework provides a systematic numerical characterization of the connection between the phase structure of the finite-temperature potential and the corresponding phenomenological GW parameter space.
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High Energy Physics (Phenomenology)
Observables in exclusive heavy quarkonium electroproduction at NLO and prospects for the EIC
Chris A. Flett
We perform various phenomenological studies of exclusive heavy-quarkonium electroproduction in $ep$ collisions that are relevant for both the existing measurements from HERA and the forthcoming Electron-Ion
Collider (EIC). We provide quantitative predictions at next-to-leading order (NLO) in perturbative QCD (pQCD) for various observables accessible at HERA for $J/\psi$ electroproduction that serve as valuable
benchmarks across a broad range of
photon virtualities $Q^2$ and $\gamma^* p$ centre-of-mass energies. We then discuss how the forthcoming EIC will complement existing measurements and end by advocating the need for a dedicated and systematic resummation framework for $J/\psi$ electroproduction at large $Q^2$.
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High Energy Physics (Phenomenology)
Minimal Flavoured DFSZ Axion Models: Predictive Yukawa Textures and Flavour Constraints
Peter Cox, Maaz Hayat and Raymond R. Volkas
We study a predictive class of flavoured DFSZ
axion models in which the Peccei–Quinn
symmetry is fully horizontal and the domain wall number is unity. These Minimal F-DFSZ models simultaneously resolve the strong CP problem and avoid the post-inflationary domain wall problem, while enforcing a predictive set of texture-zero
quark mass
matrices. Remarkably, the entire
quark Yukawa sector can be reconstructed in terms of the measured
quark masses and Cabibbo–Kobayashi–Maskawa parameters. We derive analytic expressions for the resulting flavour-violating
Higgs and
axion couplings, thereby making explicit how the new-physics effects are determined by Standard Model observables. We then analyse the full flavour phenomenology of the framework and obtain bounds on the scale of new physics from precision flavour observables.
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High Energy Physics (Phenomenology)
Comprehensive study of spectroscopic properties of $D_{(s)}$ mesons
Janki. J. Patel, Dhaval Achary, Dhruvesh Maiya et al. (+3 more)
We decode the excited open charm
mesons $D$ ($c\bar{q}$, $q=u,d$) and charm strange $D_s$ ($c\bar{s}$) families within a nonrelativistic
quark-antiquark potential model based on the Cornell (Coulomb plus linear) potential supplemented by a Gaussian smeared
spin-
spin interaction. With only seven parameters determined by fitting the ground state masses, the numerically solved Schrödinger equation reproduces the masses of essentially every confirmed $D$ and $D_s$ state to better than $1\%$. The same wave functions are then employed to get a complete decay analysis including pseudoscalar and vector decay constants ($f_D = 231.8$~MeV, $f_{D_s} = 252.2$~MeV, the latter within $0.4\%$ of the world average), leptonic branching fractions reproducing the measured $\mu\nu$ and $\tau\nu$ modes, electromagnetic $E1$/$M1$ widths, and all kinematically open strong channels in heavy
quark effective theory (HQET). Going beyond width ratios, we extract the full set of HQET couplings $g_H$, $g_S$, $g_T$, $g_X$, $g_Y$, $g_Z$, and $g_R$ directly from the measured total widths and convert our predictions into absolute widths. The $D$ and $D_s$ sector extractions of each coupling agree ($g_T = 0.42$ vs. $0.39$, $g_X = 0.22$ vs. $0.21$, $g_Y = 0.39$ vs. $0.40$), a nontrivial test of heavy
quark flavor
symmetry, while the pure $c\bar{s}$ picture demands a $1^3P_0$ width nearly two orders of magnitude above the observed $D_{s0}^*(2317)$ bound demanding it to be of exotic nature. Linear and parallel Regge trajectories in the $(J,M^2)$ and $(n_r,M^2)$ planes, with slopes $\alpha \simeq 0.55-0.65$~GeV$^{-2}$ and $\beta \simeq 0.36 - 0.39$~GeV$^{-2}$, identify the assignments of $D_J(3000)^0$, $D_J^*(3000)^0$, and $D_2^*(3000)^0$ as the $3^1S_0$, $3^3S_1$, and $3^3P_2$ states. Our predictions provide concrete, testable targets for LHCb, BESIII, and Belle~II.
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All authors Janki. J. Patel, Dhaval Achary, Dhruvesh Maiya, Keval Gandhi, Nakul R. Soni, Jignesh N. Pandya
High Energy Physics (Phenomenology)
Leptogenesis Determined By Low Energy Parameters
Xiao-Gang He, Zhong-Lv Huang, Raymond R. Volkas et al. (+1 more)
We study thermal leptogenesis in three predictive type-I seesaw models in which the
neutrino Dirac mass
matrix is equal to the mass
matrix of up-type
quarks, or down-type
quarks, or charged leptons. In this framework, the seesaw relation permits a full reconstruction of the heavy right-handed
neutrino mass
matrix from low-energy
neutrino parameters, which greatly reduces the parameter freedom. A systematic numerical scan based on density
matrix Boltzmann equations is performed to examine whether the observed baryon asymmetry of the Universe can be obtained. Successful leptogenesis occurs for normal ordering of light
neutrino masses with nonzero Majorana phases. In this case, viable solutions are found in model B, associated with down-type
quarks, and model C, associated with charged leptons. Both point to a close-mass pair of heavy
neutrinos satisfying $|M_i-M_j|/M_i<10^{-3}$, while remaining outside the conventional quasi-degenerate resonant regime. Four representative
benchmark points are selected to show the
evolution of the asymmetry and the impact of different treatments of spectator effects. Neutrinoless double beta decay is further studied for all parameter points that can generate an acceptable baryon asymmetry $\eta_B = (6.12 \pm 0.20)\times 10^{-10}$. The predicted effective Majorana mass for certain cases can be probed by next generation experiments with sub-10 meV sensitivity, such as LEGEND-1000, nEXO, JUNO 50 tons, and CUPID-1T. This framework therefore provides clear targets for future searches.
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All authors Xiao-Gang He, Zhong-Lv Huang, Raymond R. Volkas, Yu-Qi Xiao
High Energy Physics (Phenomenology)
DIS Dijet Production: An operator basis bridging eikonal and TMD regimes
Tiyasa Kar, Swagato Mukherjee, Vladimir Skokov et al. (+2 more)
We propose an operator basis for the unpolarized deep-inelastic scattering (DIS)
quark-antiquark dijet production process smoothly connecting the all-twist eikonal regime to the back-to-back leading-twist TMD regime at arbitrary Bjorken x. Starting from the background-field
quark propagator we construct an operator basis that organizes the eikonal and twist expansions within a unified formulation. Utilizing this operator basis we derive the dijet production amplitudes retaining all contributions required by either the leading-eikonal or the leading-twist description. In the eikonal limit the resulting amplitudes reproduce the all-twist Color Glass Condensate result, while in the back-to-back limit they reduce to the leading-twist gluon TMD-based result at arbitrary x. The operator basis can be systematically extended to include sub-eikonal and higher-twist corrections. Further, by examining the relationship of this operator basis to the improved TMD (iTMD) factorization we recover the iTMD structure in the eikonal limit. However, we find at non-zero x the transverse resummation generates longitudinal phases that prevent factorization in terms of a conventional TMD operator.
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All authors Tiyasa Kar, Swagato Mukherjee, Vladimir Skokov, Shaswat Tiwari, Fei Yao
High Energy Physics (Phenomenology)
Spin-independent scattering of pseudoscalar-mediated dark matter
Nicole F. Bell, Giorgio Busoni, Peter Cox et al. (+6 more)
Dark matter with pseudoscalar couplings provides a well-motivated scenario in which direct-detection signals are suppressed at tree level, since the scattering off
nuclei is both
spin-dependent and momentum suppressed. While
spin-independent scattering is absent at tree level, it arises at one loop and can provide the leading direct-detection signal. We revisit this scenario in a general sub-electroweak effective field theory with a light pseudoscalar mediator, including interactions through to mass-dimension-six. We compute the matching onto the
quark and gluon operators relevant for direct detection to determine whether this scenario could be detectable at future experiments, while also requiring consistency with the observed dark matter relic-abundance and indirect-detection limits. We find that while models with a pseudoscalar mediator can generate
spin-independent cross sections above the
neutrino floor, this generally requires additional new physics below the TeV scale.
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All authors Nicole F. Bell, Giorgio Busoni, Peter Cox, Laura W. Fang, John Gargalionis, Jayden L. Newstead, Ewan N. V. Wallace, Martin J. White, Anthony G. Williams
High Energy Physics (Phenomenology)
Tensor-polarized twist-3 distribution function $f_{LT}$ of spin-1 deuteron
S. Kumano and Kenshi Kuroki
We investigate the twist-2 and twist-3 tensor-polarized partonic structures of the
spin-1 deuteron. Using the operator product expansion with local operators, we derive a Wandzura-Wilczek (WW)-like twist-2 relation between the tensor-polarized twist-2
quark distribution $f_{1LL}$ and the twist-3 distribution $f_{LT}$, together with a Burkhardt-Cottingham (BC)-like sum rule. The local-operator formalism makes the Lorentz structure and rotational invariance manifest and provides useful constraints on the twist-3 sector. We then use a phenomenological parametrization of the twist-2 distribution $f_{1LL}(x)$, constrained by HERMES data on the deuteron structure function $b_1$ at $Q^2=2.5~\text{GeV}^2$, to quantitatively estimate the twist-3 distribution $f_{LT}(x)$ within the WW approximation. The resulting $f_{LT}(x)$ has a shape and magnitude comparable to those of $f_{1LL}(x)$, indicating that subleading-twist effects may be relevant for future experiments at relatively low $Q^2$. In this contribution, we summarize the theoretical derivation of the WW-like relation and BC-like sum rule and present a phenomenological estimate of the tensor-polarized twist-3
quark distribution $f_{LT}$ in the deuteron.
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High Energy Physics (Phenomenology)
Simple Modular $S_3$ Models for Lepton Masses and Mixing
V. V. Vien and Mayengbam Kishan Singh
We perform a systematic study of an economical class of modular $S_3$ lepton-flavor models without enlarging the continuous gauge
symmetry or introducing right-handed
neutrinos or additional flavon fields. We provide a complete classification of all inequivalent realizations allowed by the $S_3$ singlet–doublet representation structure and the admissible modular-weight assignments. Their phenomenological viability is investigated for both normal ordering (NO) and inverted ordering (IO) using
Bayesian model comparison and parameter-correlation analysis based on current
neutrino-oscillation data. We identify 18 viable models for NO and 19 for IO, with 14 satisfying the experimental constraints in both orderings. The viable models successfully accommodate current
neutrino-oscillation data while yielding nontrivial predictions for leptonic CP violation, Majorana phases, and observables probing the absolute
neutrino-mass scale. Among these predictions, the absolute-mass observables provide the clearest separation between the two orderings. At the best-fit points, the predicted ranges of the effective electron-
neutrino mass ($m_\beta$) are completely disjoint between NO and IO, whereas those of the sum of
neutrino masses ($\sum_i m_i$) and the effective Majorana mass ($m_{\beta\beta}$) show only partial separation. The IO models generally predict a higher absolute
neutrino-mass scale and are consequently more strongly constrained by cosmological observations and more accessible to neutrinoless double-beta-decay searches. Our results show that, despite its economical field content, the modular $S_3$ framework accommodates a diverse set of phenomenologically viable lepton-flavor realizations with experimentally testable predictions.
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