Fri·Sep 5, 2025Friday·September 5, 2025

1. 01*

   Strong CP Violation and large-$N_c$ spin-flavor symmetry

   Thomas R. Richardson🇺🇸

   We revisit the contribution of the QCD $\bar{\theta }$ term to the CP violating pion-nucleon couplings and the nucleon electric dipole moment in a combined large-$N_c$ and chiral perturbation theory framework. In particular, we approach this issue through the emergent spin-flavor symmetry of the baryon sector at large but finite $N_c$. We obtain good agreement with previous analyses for the pion-nucleon couplings and show that the large-$N_c$ framework indicates that tree-level contributions to the electric dipole moment possibly play a dominant role. The spin-flavor symmetry also enables us to provide novel constraints on CP violating pion-$\Delta$ couplings as well as the $\Delta$ electric dipole moment and $\Delta N$ transition moment.

   hep-phhep-latnucl-thPRD(2025)·3 citations
2. 02*

   Jet broadening and radiation in the early anisotropic plasma in heavy-ion collisions

   Alois Altenburger🇦🇹 · Kirill Boguslavski🇦🇹 · Florian Lindenbauer🇦🇹

   Measuring the energy loss of energetic jet partons may provide experimental opportunities to constrain the initial nonequilibrium stages in heavy-ion collisions, which requires theoretical predictions for the jet-medium potential. In this letter, we go beyond the usual harmonic approximation, extract this potential for the first time using QCD kinetic theory simulations, and provide a simple cutoff-independent small-distance form. We find significant differences to thermal media at early times in momentum and position space, as well as substantial angular dependence. Applying our results to the gluon splitting rates using a novel computational method reveals tensions in the current kinetic theory implementations for early times.

   hep-phnucl-th14 citations
3. 03*

   Signatures from Non-classical Features of Axion Dark Matter in Cavity Haloscopes

   Erik W. Lentz🇺🇸

   I present in this article how non-classical features in the local axion dark matter state may imprint on cavity haloscopes. Example signatures from squeezed and pair-entangled DM states are presented and their potential for sensitivity enhancements of experimental searches attuned to these signatures compared to traditional classical field signatures are discussed.

   hep-phhep-exquant-ph2 citations
4. 04*

   The mass-coupling effect in leptogenesis

   Shinya Kanemura🇯🇵 · Shao-Ping Li🇯🇵

   Particle decay in leptogenesis provides a simple avenue to explain the baryon asymmetric universe, where the decaying particle can provide the out-of-equilibrium condition to create a net lepton asymmetry. It is widely anticipated that the lepton asymmetry would be changed significantly by varying couplings and the decaying particle mass, especially in the weak washout regime. Contrary to this naive expectation, we demonstrate a general phenomenon in a class of leptogenesis scenarios from heavy particle decay, where varying the mass and couplings would not modify the lepton asymmetry in a noticeable way, as these mass and coupling effects are largely canceled out from the evolution of the decaying particle. It points out that a much broader parameter space in the mass and couplings will open automatically once leptogenesis is realized in a benchmark point; however, tuning the mass and couplings to boost leptogenesis will be challenging.

   hep-ph2 citations
5. 05*

   Probing the Chern-Simons Portal at the HL-LHC through Displaced Vertices from W Boson Associated Production

   Mohammad Nourbakhsh🇮🇷 · Mojtaba Mohammadi Najafabadi🇮🇷

   This study explores the Chern-Simons portal model, an extension of the Standard Model that introduces a massive neutral vector boson $X$ associated with a $U_X(1)$ gauge symmetry. Motivated by gauge anomaly cancellation, the model incorporates heavy chiral fermions that induce observable effects through topological Chern-Simons interactions, despite being inaccessible at Large Hadron Collider energies. We investigate the associated production of the $X$ boson with a $W$ boson and jets at the High-Luminosity LHC with a center-of-mass energy of 14 TeV, considering different $X$ masses benchmarks. A multivariate analysis using Boosted Decision Trees is employed to separate signal from background processes. Detector effects are modeled using a fast simulation tuned to the HL-LHC environment, including realistic pile-up conditions with an average of 200 interactions per bunch crossing. We derive expected $95\%$ confidence level exclusion limits in two-dimensional parameter spaces involving the $X$ boson couplings. Our results demonstrate that the HL-LHC can achieve high sensitivity to gauge-anomaly-induced interactions, setting robust constraints on the $X$ boson coupling to the $W$ boson down to $\mathcal{O}(10^{-4})$, depending on $m_X$.

   hep-phEPJC(2025)·0 citations
6. 06*

   Single spin asymmetry $A_{UL}^{\sin (3{\varphi }_h-{\varphi }_R)}$ in dihadron production in SIDIS

   Lei Tan🇨🇳 · Gang Li🇨🇳 · Mao Song🇨🇳 · Xuan Luo🇨🇳

   In the field of particle physics, the phenomenon of dihadron production in semi-inclusive deep inelastic scattering (SIDIS) process has always been a significant focus. This paper focuses on the single longitudinal spin asymmetry $A_{UL}^{\sin (3{\varphi }_h-{\varphi }_R)}$ in the dihadron production during this process and combines the transverse-momentum-dependent dihadron fragmentation function (DiFF) $H_1^{\perp }$ to deeply analyze its underlying mechanism. Here, the involved DiFF $H_1^{\perp }$ is the analogue of the Collins function for single-hadron production and it describes the fragmentation of a transversely polarized quark at leading twist. Recent studies have shown that the azimuthal asymmetry signal observed by the COMPASS collaboration in the dihadron SIDIS is weak. To reveal the reason for this small signal and to study the asymmetry, we calculate the unknown T-odd DiFF $H_1^{\perp }$ using the spectator model. The spectator model, widely used in SIDIS, describes the internal structure of hadrons and the hadronization mechanism. This model has successfully explained dihadron production in unpolarized and single-polarized processes. During the research process, while maintaining the transverse momentum dependence of the hadron pair, we employ the transverse momentum dependent(TMD) factorization framework, using this method and the model, we first simulate the asymmetry in the COMPASS energy region and compare it with experimental data. Furthermore, we predict the same asymmetry at the HERMES, expecting to provide valuable theoretical references for relevant experimental studies.

   hep-phEPJC(2025)·0 citations
7. 07*

   Beyond the Starobinsky model after ACT

   Min Gi Park🇰🇷 · Dhong Yeon Cheong🇰🇷 · Seong Chan Park🇰🇷

   We revisit higher order corrections to the Starobinsky inflationary model using the most recent P-ACT-LB-BK18 data, which exhibits a mild but definite tension with the predictions of the original model. Our results demonstrate how even small {higher order} deformations of the Ricci scalar (e.g. $R^3,R^4,\cdots$) can bring the model into better agreement with current data and impose nontrivial constraints on the post-inflationary dynamics.

   hep-phgr-qcPLB(2026)·9 citations
8. 08*

   UV origins of CP-violating leptonic Yukawa couplings

   Nejc Košnik🇸🇮 · Ajdin Palavrić🇨🇭 · Aleks Smolkovič🇸🇮

   Probing the CP nature of the Higgs Yukawa couplings is a promising avenue for unraveling new physics effects. In this work, we investigate the possible single- and two-field UV origins of CP-violating leptonic Yukawa couplings, using the Standard Model Effective Field Theory as a stepping stone. We demonstrate a rich set of constraints on the UV model parameters, including direct Higgs measurements, electric and magnetic dipole moments of leptons, charged lepton flavor violating observables, and electroweak precision tests. Studying representative flavor assumptions we find that the precision constraints are often, but not always, more constraining than the dedicated LHC analyses of modified leptonic Yukawa couplings.

   hep-phPRD(2025)·9 citations
9. 09*

   Nonrelativistic meson masses from the Curci-Ferrari model

   Anaclara Alvez🇫🇷 · Nahuel Barrios🇺🇾 · Florencia Benítez🇺🇾 · Marcela Peláez🇺🇾

   We study the mass spectrum of nonrelativistic mesons composed of charm and bottom quarks within the framework of the Curci-Ferrari model in the Landau gauge, focusing on the influence of the gluon mass on our results. We derive the Hamiltonian from the scattering amplitude of a single massive gluon exchange. By incorporating a confining Cornell potential we solve the Schrödinger equation for the dominant terms of the Hamiltonian, which include the kinetic energy and a Yukawa-type potential. Corrections to the energy are then introduced perturbatively. By studying the parameter space of the model we fit the experimental mass spectrum of charmonium, bottomonium and charm-bottom mesons. From the five parameters of our approach, we allow the gluon mass and the gauge coupling to run with the energy scale according to the ultraviolet one-loop renormalization flows, computed in [1]. Our results show very good agreement with the data, suggesting that a nonvanishing gluon mass provides a better description of the spectrum of heavy mesons than the massless case.

   hep-phhep-lathep-th2 citations
10. 10*

    3HDM with softly broken $\Delta (54)$ and $\Sigma (36)$

    Gonçalo Barreto🇵🇹 · Ivo de Medeiros Varzielas🇵🇹

    We perform an analysis of the scalar sector of 3-Higgs doublet models with softly broken $\Delta (54)$ and $\Sigma (36)$ symmetries. We consider the various vacuum expectation value alignments and consider, for each, softly broken terms that deviate the alignment. We check the evolution of the minima, present analytical and numerical results for the lifting of degeneracies of the physical eigenstates, and describe the decays of the states considering any residual symmetries.

    hep-phEPJC(2025)·2 citations
11. 11*

    Prominence: A discriminator of gravitational wave signals

    João Gonçalves🇵🇹 · Danny Marfatia🇺🇸 · António P. Morais🇵🇹

    The concept of prominence is familiar to signal engineers, topographers and mountaineers. We introduce Prominence $\mathcal{P}$ as a discriminator of gravitational wave (GW) signals. We treat black hole and neutron star binaries as astrophysical background sources, and show how $\mathcal{P}$ can be used to distinguish between GW spectra produced by first-order phase transitions, domain walls and cosmic strings, and combinations thereof. Prominence can also be used to discriminate between these and off-piste sources of GWs. The uncertainty in the measured energy density in GWs at Pulsar Timing Arrays needs to be at the sub-percent to percent level for $\mathcal{P}$ to achieve discrimination at 3$\sigma$. LISA and ET data are expected to have sufficiently small uncertainties that Prominence can play a central role in their analysis. We define and apply a ${\chi }^2$ statistic based on an inner product in signal space to show that sources indistinguishable at $2\sigma$ using the signal-to-noise ratio can be distinguished using $\mathcal{P}$ with significances above and in some cases far above $3\sigma$.

    hep-phastro-ph.COgr-qchep-ex0 citations
12. 12*

    On $\tau$ Spin Use with KKMCee

    J. M. John🇵🇱 · Ananya Tapadar🇵🇱 · Zbigniew Was🇵🇱

    Spin of $\tau$ represents an interesting phenomenology data point in both its production from $e^{+}{e}^{-}$ collision and its subsequent decay. In precision applications such as Belle-II or FCC, where precision tagging is comparable or better than $0.1\%$ Monte Carlo applications are usually necessary. \texttt{KKMCee}, the precision Monte Carlo program, is assuring such high precision in a broad energy range. But so far, spin effects were not easy to grasp. We introduce into \texttt{KKMCee}, \texttt{HepMC3} format output, new entries, $\tau$ helicity-like information (with weights to evaluate approximation), and $\tau$ polarimetric vectors to enable weight calculations to introduce hard interaction additional couplings. The physics details of the introduced implementations are presented, as well as examples of applications and ambiguities evaluation. The most recent updates and the useful codes of our work is provided at \href{https://th.ifj.edu.pl/kkmc-demos/}{https://th.ifj.edu.pl/kkmc-demos/index.html}.

    hep-ph0 citations
13. 13*

    Time, quantum entanglement, and particle decay

    J. A. Aguilar-Saavedra🇪🇸

    We investigate the role of time ordering in entanglement experiments involving unstable particles, focusing on ${\mu }^{+}{\mu }^{-}$ pairs produced in a maximally-entangled spin state. We analyse the correlations between measurements performed by two experimenters, Alice (who measures ${\mu }^{-}$ spin) and Bob (who measures ${\mu }^{+}$ decay products). Remarkably, the observed correlations persist irrespective of whether Bob's muon decays before or after Alice's spin measurement. We further discuss different interpretations of the same empirical results depending on the observer's reference frame. The findings reinforce the viewpoint that the Copenhagen interpretation of measurement is a mathematical tool rather than a literal account of physical reality.

    hep-phhep-exquant-phPoS(2026)·2 citations
14. 14*

    Light nuclei under magnetic field and the lithium problem

    Nodoka Yamanaka🇯🇵

    We analyze the effect of the magnetic field on the proton and neutron density distributions of the nuclei 2H, 3H, 3He, which are calculated ab initio, and the 6Li nucleus in the alpha-cluster model. It is found that the asymptotic exponential damp of the probability density at long distance is modified, and that the linear component of the exponent with respect to the magnetic field yields the leading contribution, while those of the second derivative and the confining magnetic force are subleading. Due to the linear dependence of the exponent, fluctuating magnetic fields always enhance the tunneling rate, i.e. the cross section of low energy nuclear reactions which occur at large separation across the Coulomb barrier. While this mechanism cannot suppress the production of 7Be in the early Universe, it has the potential to resolve the lithium problem either by increasing the reaction rate of 7Be + p -> 8B at the bigbang nucleosynthesis era if the magnetic field at this time was sufficiently strong, or by correcting the systematically enlarged 4He + 3He -> 7Be cross section by the unwanted magnetic field generated in the nuclear experimental setup, which was so far used as the input of the simulation of bigbang nucleosynthesis.

    ↳ nucl-thastro-ph.COhep-phnucl-ex2 citations
15. 15*

    Electric flux tube solutions in SU(3) gauge theory

    Jude Pereira🇺🇸 · Tanmay Vachaspati🇺🇸

    We consider electric flux tube solutions in SU(3) gauge theory with scalar fields in the fundamental representation. Such solutions can possibly be constructed in two classes, corresponding to the two maximally commuting generators ${\lambda }_3$ and ${\lambda }_8$ of SU(3). We successfully construct the 3-type solution with two scalar fields and show that it is immune to decay through Schwinger pair production of gauge bosons but we have not been able to construct an 8-type solution.

    ↳ hep-thhep-phPRD(2026)·0 citations
16. 16*

    Exploring the fluid behavior in p+p collisions at $\sqrt{s}=13\mathrm{TeV}$ with viscous anisotropic hydrodynamics

    Shujun Zhao🇨🇳 · Yiyang Peng🇨🇳 · Ulrich W. Heinz🇺🇸 · Huichao Song🇨🇳

    The applicability of hydrodynamics in small collision systems remains controversial due to the small size and short lifetime of the system. In this letter, we employ viscous anisotropic hydrodynamics (VAH), which incorporates large pressure anisotropies, to study the collectivity in p+p collisions at $\sqrt{s}=13\mathrm{TeV}$.VAH provides a good description for $v_2\{2\}$ and $v_3\{2\}$ over a wide range of multiplicities and correctly reproduces the experimentally observed negative $c_2\{4\}$. Traditional second-order viscous hydrodynamics (VH), on the other hand, can describe the measurements, in particular the negative $c_2\{4\}$, only with model parameters for which the bulk of the evolution is characterized by large values of the shear Knudsen number. It also can not capture the large longitudinal/transverse pressure anisotropy during the early evolution. These demonstrate the failure of traditional viscous hydrodynamics in small collision systems and establish viscous anisotropic hydrodynamics as a more reliable framework to describe the bulk evolution and the observed anisotropic flow in p-p collisions at the LHC.

    ↳ nucl-thhep-phnucl-exPRL(2026)·2 citations
17. 17*

    Primordial black holes versus their impersonators at gravitational wave observatories

    Andrea Begnoni🇮🇹 · Stefano Profumo🇺🇸

    The detection of primordial black holes (PBHs) would mark a major breakthrough, with far-reaching implications for early universe cosmology, fundamental physics, and the nature of dark matter. Gravitational wave observations have recently emerged as a powerful tool to test the existence and properties of PBHs, as these objects leave distinctive imprints on the gravitational waveform. Notably, there are no known astrophysical processes that can form sub-solar mass black holes, making their discovery a compelling signal of new physics. In addition to PBHs, we consider other exotic compact object (ECO) candidates-such as strange quark stars and boson stars-which can produce similar gravitational signatures and potentially mimic PBHs. In this work, we employ the Fisher matrix formalism to explore a broad parameter space, including binary masses, spins, and a variety of nuclear and quark matter equations of state. Our goal is to assess the ability of next-generation gravitational wave detectors-specifically Cosmic Explorer and the Einstein Telescope-to distinguish PBHs from ECOs, stellar BHs and neutron stars. We compute the maximum luminosity distances at which confident ($\ge 3\sigma$) detections of sub-solar masses or tidal effects are possible, providing quantitative benchmarks for PBH identification or exclusion under various observational scenarios. Our results indicate that next-generation detectors will be capable of probing sub-solar mass PBHs out to cosmological distances of $z\sim 3$. For heavier objects with masses up to $M\lesssim 2M_{\odot }$, we show that PBHs can be distinguished from neutron stars via their lack of tidal effects up to redshifts of $z\sim 0.2$.

    ↳ astro-ph.COgr-qchep-phJCAP(2026)·2 citations
18. 18*

    Toward precision physics tests with future COHERENT detectors

    M. Atzori Corona🇮🇹 · M. Cadeddu🇮🇹 · N. Cargioli🇮🇹 · F. Dordei🇮🇹 · C. Giunti🇮🇹 · R. Pavarani🇮🇹

    We present a comprehensive sensitivity study of future CE$\nu$NS detectors, focusing on a cryogenic cesium iodide detector and a tonne-scale liquid argon one, currently being developed by the COHERENT Collaboration. These setups will enable precision measurements of the weak mixing angle at low energies and allow accurate extraction of the neutron nuclear distribution radius. We also demonstrate that next-generation detectors will place constraints on the neutrino charge radius comparable to or better than current global fits. In addition, we explore the sensitivity to non standard neutrino electromagnetic properties, such as magnetic moments and millicharges, as well as new mediators. These findings reinforce the role of CE$\nu$NS experiments in the upcoming precision era, with future detectors playing a key role in advancing our understanding of neutrino interactions and electroweak physics at low energies.

    ↳ physics.ins-dethep-exhep-phUniverse(2025)·7 citations
19. 19*

    Cosmic-Ray Boosted Diffuse Supernova Neutrinos

    Alexander Sandrock🇩🇪

    The subject of boosted fluxes of dark matter or cosmic relic neutrinos via scattering on cosmic rays has received considerable attention recently. This article investigates the boosted neutrino flux from scattering of cosmic rays and the so-far undetected diffuse supernova neutrino background, taking into account both galactic and extragalactic cosmic rays. The calculated flux is many orders of magnitude smaller than either the galactic diffuse neutrino emission, the extragalactic astrophysical flux measured by IceCube, or the cosmogenic neutrino flux expected at the highest energies.

    ↳ astro-ph.HEhep-phAstronomy(2025)·3 citations
20. 20*

    Neutrino absorption in two-flavor color-superconducting quark matter

    Mark G. Alford🇺🇸 · Liam Brodie🇺🇸 · Michael Buballa🇩🇪 · Hosein Gholami🇩🇪 · Alexander Haber🇺🇸 · Marco Hofmann🇩🇪

    We calculate the absorption mean free paths of electron and muon neutrinos in two-flavor color-superconducting (2SC) quark matter in the density and temperature range that is relevant to binary neutron star mergers. We model the strong interaction between quarks using a Nambu--Jona-Lasinio model, performing calculations self-consistently in the mean-field approximation. Since the 2SC gap is large we restrict our analysis to the contribution of unpaired quarks. We find that at low temperatures absorption by a down quark $\nu +d\to u+e^{-}/{\mu }^{-}$ is kinematically not allowed, so absorption by a strange quark $\nu +s\to u+e^{-}/{\mu }^{-}$ dominates the mean free path. As temperature or neutrino energy rises, the $d$ quark absorption channel becomes active, and the mean free path shrinks. We find that in equilibrated 2SC matter with an electron lepton fraction $Y_{L_e}=0.1$, the neutrinos form a degenerate gas with a mean free path of meters or less, independent of the temperature.

    ↳ nucl-thastro-ph.HEhep-ph12 citations
21. 21*

    Three models for charged hadron nuclear modification from light to heavy ions

    Wilke van der Schee🇨🇭 · Isobel Kolbé🇿🇦 · Govert Nijs🇨🇭 · Kumail Ruhani🇵🇰 · Ishtiaq Ahmed🇵🇰 · Shahin Iqbal🇵🇰

    In July 2025 the Large Hadron Collider (LHC) collided ${}^{16}$O${}^{16}$O and ${}^{20}$Ne${}^{20}$Ne isotopes in a quest to understand the physics of ultrarelativistic light ion collisions. One of the key motivations for this run is to discover partonic energy loss in systems with a small quark-gluon plasma (QGP). In this letter we combine a BDMPS-Z based model, a path-length based energy loss prescription, and JEWEL together with two realistic geometries of the ${}^{16}$O and ${}^{20}$Ne isotopes. The different sizes of the ions affect the energy loss in characteristically different ways depending on the model.

    ↳ nucl-thhep-phnucl-ex15 citations
22. 22*

    A Generalized Nonlinear Extension of Quantum Mechanics

    Alan Chodos🇺🇸 · Fred Cooper

    We construct the most general form of our previously proposed nonlinear extension of quantum mechanics that possesses three basic properties. Unlike the simpler model, the new version is not completely integrable, but it has an underlying Hamiltonian structure. We analyze a particular solution in detail, and we use a natural extension of the Born rule to compute particle trajectories. We find that closed particle orbits are possible.

    ↳ quant-phhep-phhep-thSymmetry(2025)·2 citations
23. 23*

    Elliptical Wilson loops in $\mathcal{N}=4$ Super Yang-Mills

    Thales Azevedo🇧🇷 · Alfonso Ballon-Bayona🇧🇷 · Leonardo Pazito🇧🇷

    We investigate elliptical Wilson loops in $\mathcal{N}=4$ Super Yang--Mills theory at weak and strong coupling for small values of the eccentricity. We obtain analytical results for the vacuum expectation value of the Wilson loop in the form of a series in the eccentricity parameter. At weak coupling, we use perturbation theory in $\mathcal{N}=4$ Super Yang--Mills. At strong coupling, we use the AdS/CFT correspondence, which maps the Wilson loop to the minimal-area worldsheet of an open string in AdS space. We present a novel perturbative method to solve the Nambu--Goto equations allowing us to describe the minimal surface in terms of a coordinate parameterization in Euclidean AdS${}_3$. Our results for the regularized area agree with those obtained by Dekel in [1] based on the Polyakov action.

    ↳ hep-thhep-phPRD(2025)·0 citations
24. 24*

    Wave Packet Sizes in Quantum Mechanical Scatterings: New Perspective

    Kenzo Ishikawa🇯🇵 · Osamu Jinnouchi🇯🇵

    Particles exist with a probability of 1 and are represented by wave packets in quantum mechanics. These wave packets satisfy the Schrödinger equation and are classified as either bound states or continuum states with finite coherence lengths. They undergo transitions according to unambiguous absolute probabilities, the magnitudes of which depend on the sizes of the wave packets. Because these sizes are not universal constants but depend on the environment and experimental conditions, their accurate estimation is essential. The sizes of propagating wave packets are determined by their environmental coherence lengths, whereas those of bound states are determined by their wave functions. Here, we present a systematic analysis of wave-packet sizes.

    ↳ quant-phhep-ph2 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.