Tue·Jan 14, 2025Tuesday·January 14, 2025

1. 01*

   $\mu$-Hybrid Inflation and Metastable Cosmic Strings in $\mathbf{SU}(3{)}_{\mathbf{c}}\times \mathbf{SU}(2{)}_{\mathbf{L}}\times \mathbf{SU}(2{)}_{\mathbf{R}}\times \mathbf{U}(1{)}_{\mathbf{B}-\mathbf{L}}$

   Muhammad Nadeem Ahmad🇵🇰 · Maria Mehmood🇵🇰 · Mansoor Ur Rehman🇵🇰 · Qaisar Shafi🇺🇸

   We develop a scenario based on $\mu$-hybrid inflation within the framework of a left-right symmetric model defined by the gauge symmetry group $G_{3221}=SU(3{)}_c\times SU(2{)}_L\times SU(2{)}_R\times U(1{)}_{B-L}$. This model features a two-stage symmetry breaking to the Standard Model, with inflation occurring between the two stages, resulting in the dilution of primordial monopoles produced during the symmetry breaking of $SU(2{)}_R$ to $U(1{)}_R$. The second symmetry breaking gives rise to a network of metastable cosmic strings, which produces gravitational waves that can be observed by current and future experiments. A crucial aspect of this model is the inclusion of $R$-symmetry breaking terms in the superpotential, which helps explain the origin of the first symmetry breaking scale and ensures experimentally viable inflation with a minimal (canonical) Kähler potential. We show that the model successfully implements consistent inflation, leptogenesis, metastable cosmic strings, and gravitino dark matter, all in agreement with the observational data and constraints on reheating temperature from leptogenesis and gravitino overproduction bounds. We explore the potential embedding of $G_{3221}$ within the gauge symmetry $G_{422}=SU(4{)}_c\times SU(2{)}_L\times SU(2{)}_R$, and provide a brief discussion on the proton decay predictions, which can be tested by the upcoming experiments.

   hep-phPRD(2025)·13 citations
2. 02*

   Coherent dynamics of flavor mode entangled neutrinos

   Ashutosh Kumar Alok🇮🇳 · Massimo Blasone🇮🇹 · Trambak Jyoti Chall🇮🇳 · Neetu Raj Singh Chundawat🇮🇳 · Gaetano Lambiase🇮🇹

   As the lynchpin of all quantum correlations, quantum coherence is fundamental for distinguishing quantum systems from classical ones and is essential for realizing quantum advantages in areas such as computation, communication, and metrology. In this study, we investigate the relationship between quantum coherence and neutrino oscillations within the two and three flavor-mode qubit frameworks. Our analysis extends beyond the commonly used $l_1$-norm and relative entropy of coherence to include all relevant measures of coherence such as robustness of coherence, coherence concurrence, trace-norm distance measure of coherence, coherence of formation, Schatten-$p$-norm-based functionals, geometric coherence and logarithmic coherence rank, each offering unique insights into the quantum correlations in these systems. Notably, while the $l_1$-norm and relative entropy-based measures apply to general quantum states, the other measures are particularly relevant for entangled systems, highlighting the critical role of entanglement in neutrino oscillations. We present a detailed methodology for calculating coherence measures in both two-flavor and three-flavor mixing scenarios, contributing to a deeper understanding of how quantum coherence manifests and evolves in mode-entangled neutrino systems. Our findings emphasize the potential of these systems as robust candidates for quantum information tasks, facilitated by the weak interaction nature of neutrinos.

   hep-phquant-phNPB(2026)·8 citations
3. 03*

   The Instantaneous Breit Equation with an Application to Charmonium

   Walter S. Jaronski🇺🇸

   The solution of the Breit equation with an instantaneous potential for the case of two spin-1/2 particles in a pseudoscalar bound state is considered. This is then applied to charmonium using a potential of the Cornell type. The masses of the two JP = 0^- states below charm threshold are calculated in this model. We allow different mixtures of the Lorentz nature (vector or scalar) of the linear confining term and investigate the effect of these on the bound-state energies. Some general comments are made on the issue of how the bound nature of these states depends on the vector-scalar mix.

   hep-phquant-ph0 citations
4. 04*

   Quark flavor equilibration of the quark-gluon plasma

   Andrew Gordeev🇺🇸 · Steffen A. Bass🇺🇸 · Berndt Mueller🇺🇸 · Jean-Francois Paquet🇺🇸

   The early stage of a heavy-ion collision is marked by rapid entropy production and the transition from a gluon saturated initial condition to a plasma of quarks and gluons that evolves hydrodynamically. However, during the early times of the hydrodynamic evolution, the chemical composition of the QCD medium is still largely unknown. We present a study of quark chemical equilibration in the (Q)GP using a novel model of viscous hydrodynamic evolution in partial chemical equilibrium. Motivated by the success of gluon saturated initial condition models, we initialize the QCD medium as a completely gluon dominated state. Local quark production during the hydrodynamic phase is then simulated through the evolution of time-dependent fugacities for each independent quark flavor, with the timescales set as free parameters to compare different rates of equilibration. We present the results of complete heavy-ion collision simulations using this partial chemical equilibrium model, and show the effects on hadronic and electromagnetic observables. In particular, we show that the development of flow is sensitive to the equilibration timescale, providing an empirical way to probe the chemical equilibration of the QCD medium.

   hep-phnucl-thPRC(2026)·2 citations
5. 05*

   Line Operators in the Left-Right Symmetric Model

   Jiaming Guo🇨🇳 · Rui Yang🇨🇳 · Xun Xue🇨🇳

   In this paper, we studied line operators in the Left-Right Symmetric Model. The gauge group of Left-Right Symmetric Electroweak Model is $G=SU(3)\times SU(2{)}_L\times SU(2{)}_R\times U(1{)}_{B-L}$. We derived the spectrum of line operators in all possible scenarios within left-right symmetric models. We then studied the $\theta$ angles in left-right symmetric model. We also discuss the effect of symmetry breaking on the spectrum of line operators and $\theta$ angles.

   hep-phhep-th1 citation
6. 06*

   Transition balance in QCD nucleation

   Tianzhe Zhou🇨🇳 · Qiuze Sun🇨🇳 · Jin Hu🇨🇳 · Carsten Greiner🇩🇪 · Zhe Xu🇨🇳

   As an extended and more complete version of the primary QCD nucleation model presented in Ref. [1], the new model introduces explicitly the transition balance and formulates it in both macroscopic and microscopic descriptions. The microscopic description of the transition balance in QCD nucleation is implemented in a kinetic parton cascade model and tested for a first-order phase transition from gluons to pions in a one-dimensional expansion with Bjorken boost invariance.

   hep-phnucl-thPRC(2026)·0 citations
7. 07*

   Very Special Relativity in Accelerated Frames: Non-relativistic Effects in Gravitational Spectroscopy of Ultracold Neutrons

   Alessandro Santoni🇦🇹 · Enrique Muñoz🇨🇱 · Hartmut Abele🇦🇹 · Benjamin Koch🇦🇹

   In this paper, we investigate the phenomenology of fermionic systems in uniform gravitational fields within the framework of Very Special Relativity (VSR). We focus on the case of gravitational spectroscopy with ultracold neutrons, explored in experiments like \emph{q}\textsc{Bounce}. Calculating the leading ($c^0$) and next-to-leading ($c^{-1}$) order corrections to the non-relativistic Hamiltonian in an accelerated frame, we obtain the perturbed fermionic energy spectrum. At leading order, we do not find any modifications except for a trivial mass shift, thus preserving the equivalence between inertial and gravitational mass and particle-antiparticle sectors. The next-to-leading order corrections, instead, introduce time-dependent anisotropic contributions depending on the preferred spatial direction in VSR, and can then be used to probe novel Lorentz-violating signatures. Taking \emph{q}\textsc{Bounce} sensitivity as a benchmark, we derive a first rough constraint for the neutron VSR parameter. Finally, we suggest alternative spin-flipping setups to better probe VSR effects and foresee potential future research directions.

   hep-phgr-qcPRD(2025)·1 citation
8. 08*

   The strength of the interaction between quarks and gluons

   Mattia Dalla Brida🇮🇹 · Roman Höllwieser🇩🇪 · Francesco Knechtli🇩🇪 · Tomasz Korzec🇩🇪 · Alberto Ramos🇪🇸 · Stefan Sint🇮🇪 · Rainer Sommer🇩🇪

   Modern particle physics experiments, e.g. at the Large Hadron Collider (LHC) at CERN, crucially depend on the precise description of the scattering processes in terms of the known fundamental forces. This is limited by our current understanding of the strong nuclear force, as quantified by the strong coupling, ${\alpha }_s$, between quarks and gluons. Relating ${\alpha }_s$ to experiments poses a major challenge as the strong interactions lead to the confinement of quarks and gluons inside hadronic bound states. At high energies, however, the strong interactions become weaker ("asymptotic freedom") and thus amenable to an expansion in powers of the coupling. Attempts to relate both regimes usually rely on modeling of the bound state problem in one way or another. Using large scale numerical simulations of a first principles formulation of Quantum Chromodynamics on a space-time lattice, we have carried out a model-independent determination of ${\alpha }_s$ with unprecedented precision. The uncertainty, about half that of all other results combined, originates predominantly from the statistical Monte Carlo evaluation and has a clear probabilistic interpretation. The result for ${\alpha }_s$ describes a variety of physical phenomena over a wide range of energy scales. If used as input information, it will enable significantly improved analyses of many high energy experiments, by removing an important source of theoretical uncertainty. This will increase the likelihood to uncover small effects of yet unknown physics, and enable stringent precision tests of the Standard Model. In summary, this result boosts the discovery potential of the LHC and future colliders, and the methods developed in this work pave the way for even higher precision in the future.

   hep-phhep-latNature(2026)·24 citations
9. 09*

   Precise measurement of CP violating $\tau$ EDM through $e^{+}{e}^{-}\to {\gamma }^{\ast },\psi (2s)\to {\tau }^{+}{\tau }^{-}$

   Xiao-Gang He🇨🇳 · Chia-Wei Liu🇨🇳 · Jian-Ping Ma🇨🇳 · Chang Yang🇨🇳 · Zi-Yue Zou🇨🇳

   A nonzero electric dipole moment of a tauon, $d_{\tau }$, signals CP violation and provides an important probe for new physics. We study methods to measure $d_{\tau }$ at low energy $e^{+}{e}^{-}$ colliders through the processes $e^{+}{e}^{-}\to {\gamma }^{\ast },\psi (2S)\to {\tau }^{+}{\tau }^{-}$ with ${\tau }^{\pm }$ decays into a charged hadron and a tau neutrino. We point out that, with measuring energies of the charged hadron, Im$(d_{\tau })$ can be measured. On the other hand, selecting events of $\tau$ decays after traveling more than the detector resolution distance, Re$(d_{\tau })$ can also be determined. We find that the precision at Super Tau-Charm Facility (STCF) running at the center energy of $m_{\psi (2S)}$ for 10 year data accumulation, the precision of Im$(d_{\tau })$ and Re$(d_{\tau })$ are found to be 1.8 and 11 in unit of $10^{-18}e\text{cm}$, respectively. The sensitivity for $d_{\tau }$ measurement precision at the STCF can be reached its optimum at a central energy of $6.3\text{GeV}$, achieving a precision of $0.7$ for Im$(d_{\tau })$ and $2.8$ for Re$(d_{\tau })$ in unit of $10^{-18}e\text{cm}$.

   hep-phhep-exJHEP(2025)·8 citations
10. 10*

    Tagging ultra-boosted jets at FCC-hh using machine learning techniques

    Sanchari Bhattacharyya🇮🇳 · Biplob Bhattacherjee🇮🇳 · Camellia Bose🇮🇳 · Debtosh Chowdhury🇮🇳 · Swagata Mukherjee🇮🇳

    The Future Circular Hadron Collider (FCC-hh) will probe unprecedented energy regimes, enabling direct searches for new elementary particles at a scale of tens of TeV. FCC-hh is currently in the planning stage, and one of its primary physics goals is to search for physics beyond the Standard Model by exploring a previously inaccessible kinematic domain. While venturing into uncharted high-energy territories promises excitement, reconstructing objects with enormous transverse momenta will require overcoming major experimental challenges. This work investigates the identification of boosted $W$ bosons and boosted top quarks in the context of three beyond the Standard Model scenarios: heavy vector-like quark ($B^{\prime }$), heavy neutral gauge boson ($Z^{\prime }$), and heavy neutral Higgs boson ($H$). We employ machine learning techniques, including eXtreme Gradient Boosting (XGBoost) and convolutional neural networks (CNN), to identify these ultra-boosted objects in the collider from their SM background counterpart. We evaluate the performance of these techniques in distinguishing $W$ jets and top jets from QCD jets at extremely high transverse momenta ($p_T$) values, demonstrating their potential for future FCC-hh analyses.

    hep-phhep-exPRD(2025)·1 citation
11. 11*

    Longitudinal leading-twist distribution amplitude of the ${}^1{P}_1$-state $b_1(1235)$ meson and its implications on $B\to b_1(1235){\ell }^{+}{\nu }_{\ell }$ decays

    Long Zeng🇨🇳 · Xing-Gang Wu🇨🇳 · Dan-Dan Hu🇨🇳 · Hai-Bing Fu🇨🇳 · Tao Zhong🇨🇳

    In the paper, we derive the $\xi$-moments $⟨{\xi }_{2;b_1}^{n;\Vert }⟩$ of the longitudinal leading-twist distribution amplitude ${\varphi }_{2;b_1}^{\Vert }$ for ${}^1{P}_1$-state $b_1(1235)$-meson by using the QCD sum rules under the background field theory. Considering the contributions from the vacuum condensates up to dimension-six, its first two non-zero $\xi$-moments at the scale 1 GeV are $⟨{\xi }_{2;b_1}^{1;\Vert }⟩=-0.647_{-0.113}^{+0.118}$ and $⟨{\xi }_{2;b_1}^{3;\Vert }⟩=-0.328_{-0.052}^{+0.055}$, respectively. Using those moments, we then fix the Gegenbauer expansion series of ${\varphi }_{2;b_1}^{\Vert }$ and apply it to calculate $B\to b_1(1235)$ transition form factors (TFFs) that are derived by using the QCD light-cone sum rules. Those TFFs are then extrapolated to the physically allowable $q^2$-range via the simplified series expansion. As for the branching fractions, we obtain $\mathcal{B}({\bar{B}}^0\to b_1^{+}(1235)e^{-}{\bar{\nu }}_e)=2.179_{-0.422}^{+0.553}\times 10^{-4}$, $\mathcal{B}(B^0\to b_1^{-}(1235){\mu }^{+}{\nu }_{\mu })=2.166_{-0.415}^{+0.544}\times 10^{-4}$, $\mathcal{B}(B^{+}\to b_1^0(1235)e^{+}{\nu }_e)=2.353_{-0.456}^{+0.597}\times 10^{-4}$, and $\mathcal{B}(B^{+}\to b_1^0(1235){\mu }^{+}{\nu }_{\mu })=2.339_{-0.448}^{+0.587}\times 10^{-4}$, respectively.

    hep-phPRD(2025)·3 citations
12. 12*

    Direct CP violation in ${\bar{B}}_s\to K^{+}{K}^{-}{K}^{+}{K}^{-}$ decay process induced by interferences of the intermediate vector particles

    Chang-Chang Zhang🇨🇳 · Gang Lü🇨🇳

    We investigate CP violation in the decay process ${\bar{B}}_s\to VV\to K^{+}{K}^{-}{K}^{+}{K}^{-}$ within the framework of perturbative QCD, where V represents vector mesons $\varphi$, $\rho$, and $\omega$. We analyze the mixing mechanism among $\varphi -{\rho }^0-\omega$ and provide amplitudes for these decay processes. Moreover, we explore CP violation in the four-body decay process of ${\bar{B}}_s^0\to K^{+}{K}^{-}{K}^{+}{K}^{-}$ involving intermediate vector mesons and their mixing. Notably, significant CP violation is observed for specific two-vector meson intermediate states. Additionally, a substantial amount of CP violation arises from vector mixing when the invariant mass of $K^{+}{K}^{-}$ falls within a certain range. This study holds potential implications for future detection by the LHC experiment.

    hep-phPRD(2025)·2 citations
13. 13*

    Signals for a 2HDM with $Z^{\prime }$ at the LHC

    Anjan Kumar Barik🇮🇳 · Santosh Kumar Rai🇮🇳 · Agnivo Sarkar🇮🇳

    We consider a neutrinophilic $U(1)$ extension of the Standard Model (SM) under which only a second Higgs doublet and SM singlet scalars and fermions are charged. The new gauge boson $Z^{\prime }$ couples to SM minimally, generated by $Z-Z^{\prime }$ mixing. As the $Z^{\prime }$ is very weakly coupled, it can mostly be produced through the decay of the scalars from the second Higgs doublet at the Large Hadron Collider (LHC). We discuss the scalar sector of the model in detail and consider decay modes such as $(H^{\pm }\to W^{\pm }{Z}^{\prime },h_2\to VV,(V=W^{\pm },Z,Z^{\prime }),A_2\to h_1{Z}^{\prime }(Z))$ that lead to multilepton signals at the LHC from the pair production of the scalars. We analyze the signal with a representative value of the $Z^{\prime }$ mass to show the discovery potential of the 2HDM scalars at the LHC.

    hep-phPRD(2025)·1 citation
14. 14*

    Systematic uncertainties from higher-twist corrections in DIS at large x

    Matteo Cerutti🇺🇸 · Alberto Accardi🇺🇸 · Ishara P. Fernando🇺🇸 · Shujie Li🇺🇸 · Joseph F. Owens🇺🇸 · Sanghwa Park🇺🇸

    We investigate the systematic uncertainties and potential biases arising from the inclusion of large-$x$ corrections to proton and deuteron deep inelastic scattering (DIS) data in global quantum chromodynamics (QCD) analyses. Using the CTEQ-JLab framework, we examine various approaches to implementing higher-twist corrections in nucleon structure functions and off-shell PDF modifications in deuteron targets. We analyze how these components interact and influence the determination of the $d$-quark PDF and the neutron structure function at large $x$. We find that it is very important to consider isospin-dependent higher-twist corrections in order to minimize implementation biases in the extracted quantities.

    hep-phhep-exnucl-thPRD(2025)·19 citations
15. 15*

    Family Matters

    Ferruccio Feruglio🇮🇹

    Quarks and leptons, the fundamental building blocks of the subatomic world, manifest in three families - replicas with identical quantum numbers that differ only in their masses. After revisiting the key milestones that led to the discovery of this peculiar structure, a non-technical overview is presented of the main attempts to explain its origin and trace it back to an as-yet-unknown fundamental principle.

    hep-ph0 citations
16. 16*

    Constraint on the magnetic field for the stable strange quark matter

    Xin-Jian Wen🇨🇳 · Xiao-Wen Jiang🇨🇳

    The quasiparticle model is employed to investigate the quark matter at finite chemical potential. The effective bag constant is derived to be dependent on both the chemical potential and the magnetic field. The self-consistent thermodynamics is fulfilled that the free energy minimum corresponds to the zero pressure. It is shown that the strong magnetic field is helpful for the stabilization of the strange quark matter. However, the increase in the coupling constant and the vacuum bag constant could reduce the stability. For the absolutely stable strange quark matter, there is a lower limit of the allowed magnetic field, which rises with the increase in the coupling constant and the vacuum bag constant.

    hep-phnucl-thMod.Phys.Lett.A(2025)·0 citations
17. 17*

    Test for universality of short-range correlations in pion-induced Drell-Yan Process

    Fei Huang🇨🇳 · Shu-Man Hu🇨🇳 · De-Min Li🇨🇳 · Ji Xu🇨🇳

    We investigate nuclear modification and the universality of short-range correlation (SRC) in pion-induced Drell-Yan process. Employing nuclear parton distribution functions (nPDFs) and pion PDFs, the ratio of differential cross sections of different nuclei relative to the free nucleon is presented. A kind of universal modification function was proposed which would provide nontrivial tests of SRC universality on the platform of pion-induced Drell-Yan. This work improves our understanding of nuclear structure and strong interactions.

    hep-phnucl-thEPJC(2025)·3 citations
18. 18*

    Inferring Interpretable Models of Fragmentation Functions using Symbolic Regression

    Nour Makke🇶🇦 · Sanjay Chawla🇶🇦

    Machine learning is rapidly making its path into natural sciences, including high-energy physics. We present the first study that infers, directly from experimental data, a functional form of fragmentation functions. The latter represent a key ingredient to describe physical observables measured in high-energy physics processes that involve hadron production, and predict their values at different energy. Fragmentation functions can not be calculated in theory and have to be determined instead from data. Traditional approaches rely on global fits of experimental data using a pre-assumed functional form inspired from phenomenological models to learn its parameters. This novel approach uses a ML technique, namely symbolic regression, to learn an analytical model from measured charged hadron multiplicities. The function learned by symbolic regression resembles the Lund string function and describes the data well, thus representing a potential candidate for use in global FFs fits. This study represents an approach to follow in such QCD-related phenomenology studies and more generally in sciences.

    hep-phcs.LGcs.SChep-thMach.Learn.Sci.Tech.(2025)·6 citations
19. 19*

    Two-loop gradient-flow renormalization of scalar QCD

    J. Borgulat🇩🇪 · N. Felten🇩🇪 · R.V. Harlander🇩🇪 · J.T. Kohnen🇩🇪

    The gradient-flow formalism is applied to a non-Abelian gauge theory with scalar and fermionic particles, dubbed "scalar QCD". It is shown that the flowed scalar quark requires a field renormalization, albeit only beyond the one-loop level. A pseudo-physical, t-dependent renormalization scheme is defined, and the corresponding renormalization constant is evaluated at the two-loop level. We also calculate the gluon action density as well as the condensate of the scalar and the fermionic quark at three-loop level in this theory. The results validate the consistency of the gradient-flow formalism in this theory and provide a further step towards applying the gradient-flow formalism to the full Standard Model.

    hep-phhep-latSciPost Phys.Core(2025)·3 citations
20. 20*

    Neutrino Physics at the LHC: Status and Prospects

    Felix Kling🇩🇪

    The LHC is not only the most powerful collider built to date but also the source of an intense beam of the most energetic neutrinos ever produced by humankind. After nearly 15 years of LHC operation, these neutrinos have been observed for the first time by the FASER and SND@LHC experiments. This breakthrough marks the dawn of a new field: collider neutrino physics. Further neutrino measurements at the LHC will offer novel opportunities to advance neutrino physics, constrain the strong interaction in uncharted kinematic regimes, provide critical input for addressing outstanding questions in astroparticle physics, and search for phenomena predicted by scenarios of physics beyond the Standard Model. This proceeding reviews the existing and proposed neutrino detectors, presents their first results, and summarizes their physics potential.

    hep-ph4 citations
21. 21*

    Constraints on extended axion structures from the lensing of fast radio bursts

    Jan Tristram Acuña🇹🇼 · Kuan-Yen Chou🇹🇼 · Po-Yan Tseng🇹🇼

    Axions are hypothetical pseudoscalar particles that have been regarded as promising dark matter (DM) candidates. On the other hand, extended compact objects such as axion stars, which are supported by gravity and axion self interactions, may have also been formed in the early Universe and comprise part of DM. In this work, we consider the lensing of electromagnetic signals from distant sources by axion stars, as a way to constrain the properties of axion stars and fundamental axion parameters. Accounting for the effect of the finite size of the axion star, we study the lensing effect induced by gravity, and by axion-photon interactions. The latter effect is frequency dependent, and is relevant in the low frequency band, which motivates the use of fast radio burst (FRB) signals as a probe. We calculate the predicted number of lensed FRB events by specifying the fundamental axion parameters, axion star radial profile, fraction of DM residing in axion stars, and imposing lensing criteria based on the flux ratio and time delay between the brightest images from lensing. Assuming an optimistic case of $10^4$ observed FRB events, and a timing resolution of $1\mu \mathrm{s}$, the lack of observed FRB lensing events in CHIME allows us to probe axion stars with mass $\gtrsim 10^{-2}{M}_{\odot }$, corresponding to axion masses $\lesssim 10^{-10}\mathrm{eV}$ and for negligible axion-photon couplings. Even lighter axion stars up to $\sim 10^{-3}{M}_{\odot }$ can be probed, assuming axion-photon couplings of at least $10^{-6}{\mathrm{GeV}}^{-1}$. Our results indicate that while FRB lensing by axion stars lead to sensitivities that are competitive with conventional microlensing searches operating in the optical band, it remains a challenge to probe axion-photon induced lensing effects.

    hep-phastro-ph.COastro-ph.HEJCAP(2025)·0 citations
22. 22*

    Dominance of Electric Fields in the Charge Splitting of Elliptic Flow

    Ankit Kumar Panda🇮🇳

    In this study, we investigate the impact of electromagnetic fields, highlighting the dominant effect of electric fields on the splitting of elliptic flow, \( \Delta v_2 \) with transverse momentum ($p_T$). The velocity and temperature profiles of quark-gluon plasma (QGP) is described through thermal model calculations. The electromagnetic field evolution is however determined from the solutions of Maxwell's equations, assuming constant electric and chiral conductivities. We find that the slower decay of the electric fields compared to the magnetic fields makes its impact on the splitting of the elliptic flow more dominant. We further estimated that the maximum value of \( |\langle eF \rangle| \), evaluated by averaging the field values over all spatial points on the hypersurface and across all field components, is approximately \( (0.010003 \pm 0.000195) \, m_{\pi}^2 \) for \( \sqrt{s_{\text{NN}}} = 7.7 \, \text{GeV} \), which could describe the splitting of elliptic flow data within the current experimental uncertainty reasonably well.

    hep-phhep-thnucl-thJ.Phys.G(2025)·5 citations
23. 23*

    Phenomenological anatomy of top-quark FCNCs induced by a light scalar singlet

    Biao-Feng Hou🇨🇳 · Xin-Qiang Li🇨🇳 · Ya-Dong Yang🇨🇳 · Xing-Bo Yuan🇨🇳 · Ming-Wang Zhang🇨🇳

    Scalar singlets under the Standard Model gauge group appear naturally in many well-motivated New Physics scenarios, such as the composite Higgs models. Unlike the Higgs boson in the Standard Model, they can induce large flavour-changing neutral currents (FCNCs) in the top sector. We investigate systematically the effects of a light scalar singlet $S$ with top-quark FCNC couplings, by including the low-energy constraints from the $B_s\to {\mu }^{+}{\mu }^{-}$ decay, the muon anomalous magnetic moment $(g-2{)}_{\mu }$ and the neutron Electric Dipole Moment (EDM). We also perform a detailed Monte-Carlo simulation of the channel $pp\to tS+j$ with $S\to {\mu }^{+}{\mu }^{-}$ and $S\to b\bar{b}$, and investigate the LHC sensitivity to the $tcS$ couplings. It is found that the scalar singlet $S$ can induce scalar-type contributions to the $B_s\to {\mu }^{+}{\mu }^{-}$ decay, which do not suffer from the helicity suppression and contain a large CKM factor $V_{cs}^{\ast }{V}_{tb}$. As a result, constraints on the $tcS$ couplings from the measured branching ratio $\mathcal{B}(B_s\to {\mu }^{+}{\mu }^{-})$ are quite stringent, being even stronger than the expected LHC sensitivity in some parameter spaces. Besides the CP-conserving $tcS$ couplings, we have also considered the case of CP-violating $tcS$ couplings, with $y_{R,L}^{ct}=|y_{R,L}^{ct}|e^{i{\theta }_{R,L}}$. It is found that the CP observables ${\mathcal{A}}_{\Delta {\Gamma }_s}^{\mu \mu }$ and ${\mathcal{S}}_{\mu \mu }$ of the $B_s\to {\mu }^{+}{\mu }^{-}$ decay are sensitive to the phase ${\theta }_R$, while the neutron EDM can provide bounds on the phase difference ${\theta }_L-{\theta }_R$. Therefore, they are complementary to each other in probing the CP phases of the $tcS$ couplings.

    hep-phJHEP(2025)·2 citations
24. 24*

    Rationalisation of multiple square roots in Feynman integrals

    Georgios Papathanasiou🇬🇧 · Stefan Weinzierl🇩🇪 · Konglong Wu🇨🇳 · Yang Zhang🇨🇳

    Feynman integrals are very often computed from their differential equations. It is not uncommon that the $\epsilon$-factorised differential equation contains only dlog-forms with algebraic arguments, where the algebraic part is given by (multiple) square roots. It is well-known that if all square roots are simultaneously rationalisable, the Feynman integrals can be expressed in terms of multiple polylogarithms. This is a sufficient, but not a necessary criterium. In this paper we investigate weaker requirements. We discuss under which conditions we may use different rationalisations in different parts of the calculation. In particular we show that we may use different rationalisations if they correspond to different parameterisations of the same integration path. We present a non-trivial example -- the one-loop pentagon function with three adjacent massive external legs involving seven square roots -- where this technique can be used to express the result in terms of multiple polylogarithms.

    hep-phhep-thJHEP(2025)·5 citations
25. 25*

    Advancing Higgsino Searches by Integrating ML for Boosted Object Tagging and Event Selection

    Rameswar Sahu🇮🇳 · Debabrata Sahoo🇮🇳 · Kirtiman Ghosh🇮🇳

    Higgsinos near the TeV mass range are highly motivated as they offer an elegant solution to the naturalness problem in the Standard Model. Extensive searches for such higgsinos within the framework of General Gauge Mediation (GGM) have been conducted by both the ATLAS and CMS collaborations. However, the sensitivity of these searches in the hadronic channel remains limited, primarily due to the reliance on traditional substructure-based techniques for fat jet identification. In this work, we present a novel search strategy that leverages graph neural networks (GNNs) to improve the characterization of fat jets originating from W/Z/h bosons, top quarks, and QCD-initiated light quarks and gluons. The GNN scores, combined with a boosted decision tree (BDT) classifier, enhance signal-background discrimination, offering a significant improvement in sensitivity for higgsino searches at the LHC.

    hep-phNPB(2026)·1 citation
26. 26*

    A Comprehensive Search for Leptoquarks Decaying into Top-$\tau$ Final States at the Future LHC

    Debabrata Sahoo🇮🇳 · Rameswar Sahu🇮🇳 · Kirtiman Ghosh🇮🇳

    We studied the collider phenomenology of third-generation scalar leptoquarks at the Large Hadron Collider (LHC) with a 14 TeV center-of-mass energy. The analysis focuses on leptoquarks decaying exclusively into top quarks and tau leptons, employing machine learning-based tagging techniques for identifying hadronically decaying boosted top quarks, W/Z, and Higgs bosons, as well as a multivariate classifier to distinguish signal events from Standard Model (SM) backgrounds. The expected 95% confidence level (CL) upper limits on the leptoquark production cross-section are computed assuming integrated luminosities of 200 and 500 inverse femtobarns at the 14 TeV LHC. The results demonstrate significant sensitivity improvements for detecting leptoquarks at masses beyond the current experimental limits.

    hep-phPLB(2026)·3 citations
27. 27*

    Relativistic Correction to the Magnetic Moment of the Charged Lepton

    Abdelhamid Albaid🇸🇦

    We derive a general relativistic Hamiltonian valid for both bound and scattering systems by reducing the four-component Dirac equation to a two-component Dirac-Pauli form. Unlike conventional approaches, our formulation includes first-order relativistic corrections in a compact, gauge-consistent expression applicable to arbitrary electromagnetic fields - including non-uniform and time-dependent configurations. As an application, we compute the O(alpha^2) relativistic correction to the Lande g-factor in hydrogen-like atoms, revealing a novel mj^2-dependent term that generalizes the Breit result. This correction is experimentally testable in Penning trap spectroscopy. We further show that relativistic effects become comparable to QFT corrections in highly charged ions where Z ~ 1/sqrt(alpha)

    hep-phhep-thPhys.Scripta(2025)·1 citation
28. 28*

    Future collider sensitivities to $\nu$SMEFT interactions

    Lucía Duarte🇺🇾 · Daniel Chalençon Maisian🇪🇸 · Tomás Urruzola🇺🇾

    The discovery of neutrino oscillations and masses provides strong motivation to extend the Standard Model by including right-handed neutrinos, which lead to heavy neutrino states that could exist at the electroweak scale. These states may also be influenced by new high-scale, weakly interacting physics. Incorporating right-handed neutrinos into an effective field theory framework -- the $\nu$SMEFT -- offers a systematic approach to study the phenomenology of heavy neutrinos in current and upcoming experiments. In this work, we present the first prospective 95\% exclusion plots achievable at a future lepton collider operating at a center-of-mass energy of $\sqrt{s}=0.5\mathrm{TeV}$ for what we term the agnostic $\nu$SMEFT scenario. This study focuses on the high-mass regime where the heavy neutrino $N$ decays promptly into leptons and jets. Specifically, we analyze the processes $e^{+}{e}^{-}\to \nu N\to \nu {\mu }^{-}{\mu }^{+}\nu$ and $e^{+}{e}^{-}\to \nu N\to \nu {\mu }^{-}\mathrm{jj}$, deriving the exclusion regions in the $\frac{\alpha }{{\Lambda }^2}$ vs. $m_N$ parameter space. When compared to prospective limits for the LHeC, we find that the semi-leptonic process with final jets in a lepton collider offers the greatest sensitivity, even with a straightforward cut-based analysis. The expected bounds are as stringent as those considered in recent studies for the low-mass regime where the $N$ may be long-lived and detectable via displaced decay searches, both at the LHC and future colliders.

    hep-phJ.Phys.G(2025)·10 citations
29. 29*

    Exploring constraints on the core radius and density jumps inside Earth using atmospheric neutrino oscillations

    Anuj Kumar Upadhyay🇮🇳 · Anil Kumar🇮🇳 · Sanjib Kumar Agarwalla🇮🇳 · Amol Dighe🇮🇳

    Atmospheric neutrinos, through their weak interactions, can serve as an independent tool for exploring the internal structure of Earth. The information obtained would be complementary to that provided by seismic and gravitational measurements. The Earth matter effects in neutrino oscillations depend upon the energy of neutrinos and the electron density distribution that they encounter during their journey through Earth, and hence, can be used to probe the inner structure of Earth. In this contribution, we demonstrate how well an atmospheric neutrino experiment, such as an iron calorimeter detector (ICAL), would simultaneously constrain the density jumps inside Earth and determine the location of the core-mantle boundary. In this work, we employ a five-layered density model of Earth, where the layer densities and core radius are modified to explore the parameter space, ensuring that the mass and moment of inertia of Earth remain constant while satisfying the hydrostatic equilibrium condition. We further demonstrate that the charge identification capability of an ICAL-like detector would play a crucial role in obtaining these correlated constraints.

    hep-phhep-exphysics.geo-ph0 citations
30. 30*

    Widen the Resonance: Probing a New Regime of Neutrino Self-Interactions with Astrophysical Neutrinos

    Isaac R. Wang🇺🇸 · Xun-Jie Xu🇨🇳 · Bei Zhou🇺🇸

    Neutrino self-interactions beyond the standard model have profound implications in astrophysics and cosmology. In this Letter, we study an uncharted scenario in which one of the three neutrino species has a mass smaller than the temperature of the cosmic neutrino background. This results in a relativistic component that significantly broadens the absorption feature on the astrophysical neutrino spectra, in contrast to the sharply peaked absorption expected in the extensively studied scenarios assuming a fully nonrelativistic cosmic neutrino background. By solving the Boltzmann equations for neutrino absorption and regeneration, we demonstrate that this mechanism provides novel sensitivity to sub-keV mediator masses, well below the traditional $\sim 1$--100 MeV range. Future observations of the diffuse supernova neutrino background with Hyper-Kamiokande could probe coupling strengths down to $g\sim 10^{-8}$, surpassing existing constraints by orders of magnitude. These findings open new directions for discoveries and offer crucial insights into the interplay between neutrinos and the dark sector.

    hep-phastro-ph.COastro-ph.HEhep-exPRL(2025)·18 citations
31. 31*

    Probing New Physics with the Electron Yukawa coupling

    Barbara Anna Erdelyi🇮🇹 · Ramona Gröber🇮🇹 · Nudzeim Selimovic🇮🇹

    A dedicated run of a future electron-positron collider (FCC-ee) at a center-of-mass energy equal to the Higgs boson mass would enable a direct measurement of the electron Yukawa coupling. However, it poses substantial experimental difficulties due to large backgrounds, the requirement for monochromatised $e^{+}{e}^{-}$ beams, and the potential extension of the FCC-ee timeline. Given this, we explore the extent to which the electron Yukawa coupling can be enhanced in simplified UV models and examine whether such scenarios can be constrained by other FCC-ee runs or upcoming experiments at the intensity frontier. Our results indicate that in certain classes of models, the $(g-2{)}_e$ provides a probe of the electron Yukawa coupling that is as effective or better than the FCC-ee. Nevertheless, there exist models that can lead to sizeable deviations in the electron Yukawa coupling which can only be probed in a dedicated run at the Higgs pole mass.

    hep-phhep-exJHEP(2025)·20 citations
32. 32*

    A lower bound on the right-handed neutrino mass from wash-in leptogenesis

    Martin A. Mojahed🇩🇪 · Kai Schmitz🇩🇪 · Dominik Wilken🇩🇪

    Leptogenesis is an attractive scenario for the generation of the baryon asymmetry of the Universe that relies on the dynamics of right-handed neutrinos (RHNs) in the seesaw extension of the Standard Model. In standard thermal leptogenesis, the RHN mass scale $M_N$ is subject to the Davidson--Ibarra bound, $M_N\gtrsim 10^9\text{GeV}$, which builds on the assumption that RHN decays are responsible for the violation of both charge-parity invariance ($CP$) and baryon-minus-lepton number ($B-L$). In this paper, we relax this assumption in the context of the more flexible framework of wash-in leptogenesis, in which $CP$ violation is encoded in the initial conditions and the only remaining task of the RHN decays is to violate $B-L$. Solving the relevant set of Boltzmann equations for vanishing initial baryon and lepton numbers (i.e., $B=L_e=L_{\mu }=L_{\tau }=0$ initially), we find that, in wash-in leptogenesis, the RHN mass scale can be as low as 7~TeV. Wash-in leptogenesis at such low RHN masses requires the presence of a primordial charge asymmetry between right-handed electrons and left-handed positrons. We discuss several possibilities for the origin of such an asymmetry and comment on its implications for the chiral instability of the Standard Model plasma.

    hep-phgr-qcPLB(2025)·5 citations
33. 33*

    Macroscopic properties of the XTE J1814-338 as a dark matter admixed strange star

    Luiz L. Lopes🇧🇷

    In this letter, I discuss the macroscopic properties of the ultracompact object XTE J1814-338, whose inferred mass and radius read $M$ = 1.21 $\pm$ 0.05 $M_{\odot }$ and R = 7.0 $\pm$ 0.4 km. By using the neutralino as WIMP dark matter with a fixed Fermi momentum, I calculated the maximum possible mass of this object, the moment of inertia, the gravitational redshift, the dimensionless tidal parameter, and the total amount of dark matter for a 1.2$M_{\odot }$ star.

    ↳ astro-ph.HEhep-phAstrophys.Space Sci.(2025)·8 citations
34. 34*

    Probing Signals of Self-Interacting Dark Matter Core Collapse in HI-Rich Galaxies

    Demao Kong🇺🇸 · Hai-Bo Yu🇺🇸

    We analyze rotation curves of five HI-rich galaxies recently discovered with MeerKAT. These galaxies exhibit sharply rising rotation curves, while their baryonic components are not dynamically dominant, suggesting that their dark matter halos have high inner densities. When fitting the standard Navarro-Frenk-White (NFW) halo model, four galaxies require extremely high halo concentrations, exceeding the cosmological median by $5\sigma$. In contrast, self-interacting dark matter (SIDM) halos in the core-collapse phase naturally account for the high densities in these galaxies. For halos with masses around $10^{11}{\mathrm{M}}_{\odot }$, those in cosmic filaments exhibit concentrations consistent with the cosmological average, while halos in cosmic nodes show relatively higher concentrations that align with the SIDM fits but remain insufficient for the NFW fits. Our analysis indicates that these HI-rich galaxies may have formed in cosmic nodes of dark matter with significant self-interactions.

    ↳ astro-ph.GAhep-phPhys.Dark Univ.(2025)·14 citations
35. 35*

    Three-loop verification of the equations relating running of the gauge couplings in $\mathcal{N}=1$ SQCD+SQED

    Olesya Haneychuk🇷🇺 · Konstantin Stepanyantz🇷🇺

    We verify a recently derived equations relating the renormalization group running of two gauge couplings in $\mathcal{N}=1$ SQCD+SQED by the explicit three-loop calculation. It is demonstrated that these equations are really valid in the HD+MSL scheme. In other words, if a theory is regularized by higher covariant derivatives and the renormalization is made by minimal subtractions of logarithms, the analogs of the strong and electromagnetic gauge couplings do not run independently. However, in the $\overline{\text{mbox}DR}$ scheme the considered equations do not hold starting from the three-loop order, where the scheme dependence becomes essential. Therefore, they are valid only for a certain set of the renormalization prescriptions. We prove that all of them can be obtained from the HD+MSL scheme by finite renormalizations which satisfy a special constraint and illustrate how this works in the three-loop approximation.

    ↳ hep-thhep-phEPJC(2025)·5 citations
36. 36*

    Probing the sign-changeable interaction between dark energy and dark matter with DESI baryon acoustic oscillations and DES supernovae data

    Tian-Nuo Li🇺🇸 · Guo-Hong Du🇺🇸 · Yun-He Li🇺🇸 · Peng-Ju Wu🇨🇳 · Shang-Jie Jin🇺🇸 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    There is a possibility of interaction between dark energy and dark matter, and this interaction may also undergo a sign change during the evolution of the universe. In this paper, we utilize the latest observational data to constrain models of a sign-changeable interaction. The data we employ, in addition to the cosmic microwave background data, also encompass the first-year baryon acoustic oscillation data from DESI and the type Ia supernova data of the full 5-year observation from DES. To achieve high generality, we investigate four interacting dark energy (IDE) models with different forms of the interaction term $Q$: (i) IDE1 with $Q=\beta (a)H{\rho }_{\mathrm{de}}$; (ii) IDE2 with $Q=\beta (a)H{\rho }_{\mathrm{c}}$; (iii) IDE3 with $Q=\beta (a)H_0{\rho }_{\mathrm{de}}$; (iv) IDE4 with $Q=\beta (a)H_0{\rho }_{\mathrm{c}}$. From the analysis, we observe that $\beta (z)>0$ at early times and $\beta (z)<0$ at late times, with the coupling $\beta (z)$ crossing the non-interacting line $\beta (z)=0$ during cosmic evolution at the 2$\sigma$ confidence level for the IDE1, IDE3, and IDE4 models. However, for the IDE2 model, $\beta (z)$ remains consistently negative and does not cross $\beta (z)=0$ at the 2$\sigma$ confidence level. Our findings indicate that the energy transfer is from dark matter to dark energy when dark matter dominates the universe, and from dark energy to dark matter when dark energy dominates, for the IDE1 and IDE3 models. Furthermore, Bayesian evidence suggests that the IDE1 and IDE3 models are moderately preferred over the $\Lambda$CDM model. The overall outcomes of this study clearly indicate that, based on current observational data, the sign-changeable IDE models are quite compelling and merit further attention.

    ↳ astro-ph.COgr-qchep-phSCPMA(2026)·118 citations
37. 37*

    Advection Algorithms for Quantum Neutrino Moment Transport

    Evan Grohs🇺🇸 · Sherwood Richers🇺🇸 · Julien Froustey🇺🇸 · Francois Foucart🇺🇸 · James P. Kneller🇺🇸 · Gail C. McLaughlin🇺🇸

    Neutrino transport in compact objects is an inherently challenging multi-dimensional problem. This difficulty is compounded if one includes flavor transformation -- an intrinsically quantum phenomenon requiring one to follow the coherence between flavors and thus necessitating the introduction of complex numbers. To reduce the computational burden, simulations of compact objects that include neutrino transport often make use of momentum-angle-integrated moments (the lowest order ones being commonly referred to as the energy density and flux) and these quantities can be generalized to include neutrino flavor, i.e., they become quantum moments. Numerous finite-volume approaches to solving the moment evolution equations for classical neutrino transport have been developed based on solving a Riemann problem at cell interfaces. In this paper we describe our generalization of a Riemann solver for quantum moments, specifically decomposing complex numbers in terms of a (signed) magnitude and phase instead of real and imaginary parts. We then test our new algorithm in numerous cases showing a neutrino fast flavor instability, varying from toy models with analytic solutions to snapshots from neutron star merger simulations. Compared to previous algorithms for neutrino transport with flavor mixing, we find uniformly smaller growth rates of the flavor transformation along with concomitantly larger length-scales, and that the results are a better match with the growth rates seen from multi-angle codes.

    ↳ astro-ph.HEhep-phPRD(2025)·7 citations
38. 38*

    Ultra-Light Dark Matter Simulations and Stellar Dynamics: Tension in Dwarf Galaxies for $m<5\times 10^{-21}$ eV

    Luca Teodori🇮🇱 · Andrea Caputo🇨🇭 · Kfir Blum🇮🇱

    We present numerical simulations of dark matter and stellar dynamics in ultra light dark matter halos tailored to mimic dwarf galaxies. An important effect we observe is the dynamical evolution of the stellar half-light radius and velocity dispersion, which makes previous equilibrium models significantly incomplete. Based on half-light radius dynamical evolution, as well as velocity peaks due to soliton core condensation, we show that data from the Fornax, Carina, and Leo II dwarf galaxies disfavores particle masses in the range $5\times 10^{-22}\text{ eV}\lesssim m\lesssim 5\times 10^{-21}$ eV. Smaller boson masses, around $m\approx 1\times 10^{-22}$ eV, could cause strong dynamical heating, but we caution that tidal stripping by the Milky Way could moderate the effect. A caveat in our analysis is the omission of stellar self-gravity, which could affect extrapolation back in time if the stellar body was much more compact in the past.

    ↳ astro-ph.GAhep-phPRD(2026)·29 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.