HEP Phenomenology·hep-ph

Wed·Sep 23, 2026Wednesday·September 23, 2026

12 papers—6 primary·6 cross-listed

01
Elastic toroidal vector dark matter through a dark photon in the LUX-ZEPLIN high recoil window
Imtiaz Khan · Salvatore Capozziello · G. Mustafa · Farkhod Botirov · Ahmadjon Abdujabbarov · Farruh Atamurotov · Phongpichit Channuie
The 2026 LUX-ZEPLIN search reports one nuclear recoil candidate at $248 \pm 2 3_{stat} \pm 2 3_{sys} keV$ in an extended window reaching about $270 keV$ . We consider elastic scattering of neutral complex vector dark matter through its dimension-six toroidal electromagnetic moment and find appreciable spectral weight in this recoil region. The nonrelativistic reduction correlates $O_{17}$ and $O_{20}$ , relating a coherent charge branch to a transverse spin tensor branch. For $m_{X} = 1 TeV$ , natural xenon exhibits a broad high recoil maximum at $204.8$ to $206.6 keV$ and retains $80.4$ to $85.4%$ of this maximum at $248 keV$ . Resolving the interaction through a dark photon relates the high-to-low recoil ratio to the mediator mass. A renormalizable $S U (2)_{X} \times U (1)_{D}$ realization stabilizes the complex vector by a residual $Z_{3}$ gauge symmetry and generates the toroidal current through vectorlike messengers carrying a physical CP phase. For a benchmark with $m_{X} = 0.998 TeV$ and $m_{A^{'}} = 0.450 GeV$ , $R (248) / R (50) = 1.43$ for GCN and $1.21$ for JJ55, while the odd $A$ xenon fraction remains above $99.9%$ . The response level ratio between the $350$ to $590 keV$ and $100$ to $270 keV$ intervals is about $0.46$ at this benchmark. The tensor branch is absent for spin zero argon, whereas annual modulation remains at the few percent level. The resulting spectral, isotope, target, timing, mediator, and high energy dependences give correlated tests of an elastic tensor interpretation of the LZ recoil.
hep-ph
02
System-size dependence of bottomonium suppression from Pb-Pb to light-ion collisions
Nora Brambilla · Tom Magorsch · Antonio Vairo
We test the system-size dependence of bottomonium suppression using the same open-quantum-system transport framework for Pb-Pb, O-O, and Ne-Ne collisions. The microscopic transport coefficients are retained from previous Pb-Pb analyses. Using QTraj, we solve the next-to-leading-order pNRQCD Lindblad equation in anisotropic hydrodynamic backgrounds and calculate integrated $Υ$ double ratios. The QGP-induced evolution reproduces the observed sequential hierarchy and overall magnitude of the O-O suppression measured by CMS and LHCb. We quantify the sensitivity to both transport coefficients and to the termination temperature of the in-medium evolution. The Ne-Ne measurement favors somewhat stronger suppression than predicted, although the present experimental uncertainty is large. The extension from Pb-Pb to light ions supports, at least for observables less sensitive to cold nuclear matter effects, a common microscopic origin of bottomonium suppression in deconfined matter, characterized by the same temperature-dependent transport coefficients despite the large change in collision-system size.
hep-phhep-exhep-latnucl-ex+1
03
Cosmic Birefringence and Axiogenesis
Raymond T. Co · Lawrence J. Hall · Keisuke Harigaya · Taegyu Lee
Recent analyses of Planck and ACT CMB data report a $2 - 4 σ$ hint of isotropic cosmic birefringence ( $β \approx 0. 3^{\circ}$ ), corresponding to a parity-violating rotation of polarization planes that points to potential new physics. We show that both the hint of cosmic birefringence and the observed baryon asymmetry can be simultaneously explained by the rotation of an axion-like field. The minimal setup predicts a positive birefringence angle, consistent with the CMB hint, and matter and kination domination ending around a temperature of $O (3 - 50)$ MeV, making the model falsifiable by astrophysical probes and potentially giving rise to characteristic gravitational-wave signals. We also introduce a mechanism that can exponentially enhance the angular momentum of the rotation generated by the Affleck-Dine mechanism.
hep-phastro-ph.CO
04
Bin-to-bin correlations in the extraction of proton's transverse structure
Laurent Favart · Francesco Hautmann · Aleksandra Lelek · Louis Moureaux
We investigate the determination of non-perturbative QCD contributions, associated with proton's transverse structure, from high-precision experimental data for electroweak boson production at the LHC. We demonstrate that these determinations are strongly affected by correlated uncertainties across transverse-momentum bins in the region of low boson's transverse momenta. We illustrate our results through a detailed analysis of LHCb measurements of $Z$ -boson spectra at forward rapidities, and a comparison with CMS measurements at central rapidities. We further examine the influence on the extraction of the non-perturbative parameters from final-state electromagnetic radiation, photon-induced background, large- $x$ contributions to parton distributions in the forward region, matching to perturbative next-to-leading order. We comment on the comparison of our results with those from the underlying-event tuning of parton-shower Monte Carlo event generators.
hep-ph
05
Limitations of quantum tomography in Higgs-boson decays to four leptons
Morgan Del Gratta · Fabio Maltoni · Davide Pagani · Giovanni Pelliccioli
We investigate the limitations of the two-qutrit quantum tomography in Higgs-boson decays to four charged leptons. At next-to-leading order, the standard reconstruction can yield an operator that is not positive semidefinite, even when radiatively improved spin-analysing powers are used. We trace this failure to the coherent combination of photon- and Z-mediated contributions to the off-shell dilepton system, whose distinct production and decay structures invalidate the assumed universal decay analysers. Nevertheless, the rank-two angular sector remains accessible and perturbatively stable, enabling a robust lower bound on the squared concurrence, and hence a reliable assessment of entanglement beyond leading order.
hep-phhep-ex
06
A Unitary Fixed Point Away from Threshold: Momentum-Surface EFT for Strong Mixing
Lorenzo De Ros · Javier Reig Navarro
Radiative capture in a non-relativistic system can become non-perturbative even when the underlying transition interaction is weak. We demonstrate this mechanism in a simple quantum-mechanical two-channel model with a systematic power counting, where strong mixing between scattering and bound states develops in a narrow region around a finite momentum $k_{0}$ , leading to a perturbative violation of unitarity. In this regime, the enhanced contributions factorize, reducing the dynamics to a free scattering state interacting through a strong local coupling. Under RG evolution in the factorization scale, this local interaction approaches a unitary fixed point, analogous to that of systems with an anomalously large scattering length. This motivates an EFT organized around the finite-momentum surface $∣ k ∣ = k_{0}$ , describing fermions at unitarity with a linear dispersion relation. The resummation resulting from the EFT restores unitarity and provides a systematic expansion for both elastic scattering and radiative capture.
hep-phcond-mat.otherhep-thnucl-th
07
Cross-Detector Transfer Learning with Parnassus: From ALEPH to SLD
Ya-Feng Lo · Chi Lung Cheng · Benjamin Nachman
Parnassus is a fast detector-simulation and reconstruction framework that maps truth-level particles directly to reconstructed particles. In this work, we investigate cross-detector transfer learning by adapting a Parnassus model for the ALEPH detector to the SLD detector. ALEPH and SLD have similar detector responses, as they were both targeting hadronic $Z$ -pole $e^{+} e^{-}$ events, while differing substantially in the underlying detector technology, reconstruction, and archived data representation. We initialize the SLD particle model with weights learned on ALEPH, fine-tune it on SLD, and compare it with the same architecture trained directly on SLD. The ALEPH-initialized model gives substantially improved particle- and jet-level agreement with the SLD reference, including a factor of 5.2 improvement in the charged-particle angular response and an improvement in the jet angular resolution from $1.73$ to $1.15$ times the SLD reference. The results show that detector-response information learned on ALEPH can be reused when modeling SLD and motivate reusable pretrained Parnassus models for legacy $e^{+} e^{-}$ detectors, which is especially critical for experiments without access to the original software pipeline. With this paper, we also release an AI-ready version of simulated SLD $e^{+} e^{-}$ events.
↳ physics.ins-dethep-exhep-ph
08
Mass-Scaling of Quantum Tunnelling in Hydrogen Bonds: Analytical Model and Comparison with Multidimensional Potentials
Krishna Kingkar Pathak
Quantum tunnelling plays a central role in the structure and spectroscopy of hydrogen-bonded systems, and its sensitivity to isotopic substitution provides a stringent probe of the underlying potential-energy landscape. Despite extensive numerical studies, many high-level approaches tend to obscure the simple physical relationships linking effective mass, barrier geometry, and tunnelling amplitudes. Here, we develop a Cornell-type analytical--numerical framework to describe proton and deuteron tunnelling, combining a semi-analytical localized wavefunction ansatz with numerical solutions of the one-dimensional Schrödinger equation. The resulting tunnelling splittings exhibit an exponential dependence on the square root of the effective isotope mass, $ln (Δ E) \propto - μ_{eff}$ , in agreement with semiclassical Wentzel--Kramers--Brillouin (WKB) theory. Comparison with multidimensional reaction-space calculations for the formic acid dimer shows that this scaling persists in fully coupled 3D and 5D quantum models, yielding an empirical relation $ln (Δ E) = - 1.75 μ_{eff} + 2.60$ . The present framework provides a transparent and computationally efficient approach for quantifying mass-scaling and tunnelling dynamics in hydrogen-bonded and other double-well systems.
↳ physics.chem-phhep-phChemical Physics 607 (2026) 113203
09
Gradient Flow for the Jet Transport Coefficient: A Quenched Lattice Benchmark
Hai-Tao Shu · Cheng Zhang
We apply the gradient-flow framework to determine the nonperturbative medium contribution to the jet transport coefficient $q^$ using quenched lattice QCD in the temperature range $0.76 T_{c} \leq T \leq 2.25 T_{c}$ . The calculation focuses on the leading-twist contribution at leading order for an asymptotically energetic quark propagating through a thermal pure-gluon plasma. In the infinite-energy limit, the operator-product expansion expresses $q^/ T^{3}$ in pure gauge theory as the product of a perturbative short-distance coefficient and the entropy density $s / T^{3}$ . The latter is determined from the gradient-flow energy-momentum tensor at three lattice spacings for each temperature and the former is estimated perturbatively at one-loop order. We find that $q^/ T^{3}$ is strongly suppressed below $T_{c}$ , rises rapidly across the deconfinement transition, and remains approximately constant at $q^/ T^{3} ≃ 1.1$ throughout the deconfined temperature range studied. This is statistically consistent with the previous quenched lattice determination based on a different renormalization procedure, providing a nontrivial validation of the gradient-flow framework for the jet transport coefficient. The systematic treatment of operator renormalization and matching provided by gradient flow becomes particularly important in full QCD, because the need to renormalize quark operators and account for their mixing with the gluonic sector can likewise be addressed within the same framework.
↳ hep-lathep-phnucl-exnucl-th
10
Experiment $\leftrightarrow$ lattice QCD: understanding high-temperature QCD matter
Bedangadas Mohanty
Relativistic heavy-ion collisions provide a unique experimental opportunity to study strongly interacting matter at extreme temperature and density, while lattice quantum chromodynamics (QCD) offers a first-principles approach to the equilibrium properties of such matter in the non-perturbative regime. The interplay between experiment and lattice QCD has therefore become central to establishing the properties and phase structure of QCD matter. Selected areas where this connection is particularly informative are discussed, including the QCD equation of state and its role in hydrodynamic descriptions of heavy-ion collisions, transport properties of the quark-gluon plasma, conserved-charge fluctuations and their relation to experimental cumulants, and the ongoing search for a critical point in the QCD phase diagram. Particular attention is given to the limitations involved in confronting equilibrium lattice calculations with the finite, dynamical and experimentally constrained systems produced in heavy-ion collisions. Recent developments increasingly allow quantitative tests of QCD thermodynamics over an extended range of temperature and baryon chemical potential. The continuing experimental programmes at RHIC and the LHC, together with future measurements at FAIR, NICA and the Electron-Ion Collider, provide important opportunities for an increasingly close interplay between lattice QCD, phenomenology and experiment.
↳ hep-lathep-exhep-phhep-th
11
Quantum Clausius relation beyond de Sitter equilibrium
Jinn-Ouk Gong · TaeHun Kim · Junghwan Lee · Chang Sub Shin
We establish a direct quantum Clausius relation for conformal fields inside the apparent horizon of a quasi-de Sitter spacetime. We compute the net heat flow across the horizon from the renormalized stress-energy tensor, and independently determine the time evolution of the renormalized von Neumann entropy using the replica method. At leading order in the Hubble-flow expansion, the two calculations agree exactly, without using the gravitational equations of motion. Beyond leading order, we find a scheme-independent entropy balance that includes the corresponding Wald entropy. Our results provide a quantum field theoretic realization of dynamical horizon thermodynamics beyond exact de Sitter equilibrium.
↳ hep-thastro-ph.COgr-qchep-ph
12
Nonlocal advantage of quantum coherence in tau-lepton pairs from electron--positron collisions
Yoav Afik · Juan Ramón Muñoz de Nova · Sarthak Sharma · Surya Sundar Raman
Quantum correlations have recently attracted significant attention in collider physics, with Nonlocal Advantage of Quantum Coherence (NAQC) representing the strongest form of quantum correlation studied so far. Owing to its strength, NAQC is considerably more challenging to observe than Bell nonlocality since it is only present in narrower regions of phase space. Unlike other systems, tau-lepton pair ( $τ^{+} τ^{-}$ ) production in electron--positron ( $e^{+} e^{-}$ ) collisions provides an ideal testing ground, as it exhibits strong quantum correlations and, in particular, NAQC over a large region of phase space. In this paper, we investigate NAQC in $e^{+} e^{-} \to τ^{+} τ^{-}$ production at center-of-mass energies of 10.58 and 91.19~GeV, corresponding to the ongoing Belle~II and future FCC- $ee$ experiments, respectively. Remarkably, for our experimental proposal, we develop a dedicated NAQC witness, which allows to certify NAQC presence by measuring one single magnitude. We estimate the experimental sensitivities needed to establish the presence of NAQC, finding that a large fraction of the number of events (specifically, 0.18 for Belle~II and 0.31 for FCC- $ee$ ) contribute to the NAQC signal. A 5 $σ$ observation of NAQC requires a precision of approximately 1\% at Belle~II, while a precision of a few percent is sufficient at FCC- $ee$ . The resulting observation would constitute the strongest form of quantum correlation measured in a collider to date. In addition, we design an experimental scheme to implement the steering game leading to the NAQC definition, representing the first implementation of a steering game in a high-energy collider. Our results are easily extendable to other electron--positron colliders with different center-of-mass energies.
↳ quant-phhep-exhep-phhep-th