Wed·Jan 28, 2026Wednesday·January 28, 2026

1. 01*

   Constraining axial non-standard interactions of neutrinos with long baseline experiments

   Yasaman Farzan🇮🇷 · Saeed Abbaslu🇮🇷

   Thanks to a number of neutrino oscillation and Coherent Elastic neutrino Nucleus Scattering (CE$\nu$NS) experiments, the vector Non-Standard Interactions (NSI) of neutrinos have been well studied and constrained. We show that the long-sought-after new physics may hide in the ``axial" non-standard interactions rather than in the vector NSI. We then show how by studying neutral current scattering events in the detectors of long baseline experiments, MINOS, MINOS$+$ and DUNE, the impact of the axial NSI can be discovered.

   hep-ph1 citation
2. 02*

   Probing Lepton Flavor Violation at the ILC and CLIC

   Pankaj Munbodh🇺🇸

   Lepton flavor violation in the $\tau \mu$ sector would be a clear sign of Beyond Standard Model physics. We employ the SMEFT framework to study the process $e^{+}{e}^{-}\to \tau \mu$ at the ILC and CLIC. We find that the $e^{+}{e}^{-}$ beam polarizations achievable at these machines allow us to probe the chirality structure of the SMEFT operators. In addition, the high center of mass energy leads to a substantial increase in sensitivity to the four-fermion operators that rivals, and in some cases, surpasses tau decay projections from Belle-II.

   hep-ph0 citations
3. 03*

   Low Energy Neutrinos in Milky Way and Cloud-9

   Eduardo Flores🇺🇸 · Elise Cantu🇺🇸 · Ian Marano🇺🇸 · Osvan Vivar-Garcia🇺🇸 · Shabhaz Khalandar🇺🇸 · Patrick Walker🇺🇸

   We study low-energy galactic neutrinos in the Milky Way under two descriptions of gravity and show that they can prove gravity underlying nature. If gravity is quantum, its long-range interaction produces an atom-like bound neutrino structure. However, we find that withing 292 kpc, this structure contributes only 10 to the -29 of the galaxy dark matter, ruling it out as a deark-matter candidate. Its detection would nevertheless provide direct evidence for quantum gravity mediated by gravitons. If gravity instead arises from spacetime curvature, neutrinos interact only through the short-range weak force and behave as free, collisionless classical particles orbiting the galaxy. In this regime, they do not experience Fermi pressure and can form a sufficiently compact population to reproduce the Milky Way rotation curve. We further model Cloud-9 dark-matter compoent as free, collisionless neutrinos. Because neutrino-antinetrino annihilation cross section is extremely small, neutrinos and antineutrinos may remai near equilibrium over cosmological timescales, potentially relating this framework to the observed matter-antimatter assymmetry.

   hep-phastro-ph.GA0 citations
4. 04*

   Origin of the nucleon gravitational form factor $B_N(t)$: Exposition in light-front holographic QCD

   Xianghui Cao🇨🇳 · Bheemsehan Gurjar🇮🇳 · Chandan Mondal🇨🇳 · Chen Chen🇨🇳 · Yang Li🇨🇳

   Recent lattice QCD simulations and phenomenological models indicate that the nucleon's gravitational form factor $B_N(t)$ remains remarkably small at finite momentum transfer $t$. While $B_N(0)=0$ is a known consequence of the equivalence principle, the physical origin of its suppression at finite $t$ has not been fully elucidated. In this work, we demonstrate that the smallness of $B_N(t)$ arises from a fundamental cancellation within the nucleon's wave functions. Using light-front holographic QCD, we show that $B_N(t)$ is governed by an antisymmetric factor in the longitudinal dynamics that leads to the exact vanishing of the form factor in the symmetric limit and significant suppression for realistic nucleon structures. Our results suggest that the smallness of $B_N(t)$ is a signature of the nucleon's dominant S-wave character, providing a formal justification for its frequent omission in practical applications like near-threshold $J/\psi$ production.

   hep-phhep-thnucl-thPRD(2026)·2 citations
5. 05*

   Analysing Toponium at the LHC using Recursive Jigsaw Reconstruction

   Aman Desai🇦🇺 · Amelia Lovison🇦🇺 · Paul Jackson🇦🇺

   Recent results from the \ATLAS ~and the \CMS ~experiments at the Large Hadron Collider indicate the presence of a top-quark pair bound state near the threshold region. We present a way to reconstruct a toponium state at the $t\bar{t}$ threshold region formed at the Large Hadron Collider using the Recursive Jigsaw Reconstruction. We have considered the Non-Relativistic QCD based toponium model implemented in MadGraph5\_aMC@NLO. The final states considered consist of two b-jets, two oppositely charged leptons, and missing energy that arises from two neutrinos. The goal of the Recursive Jigsaw Reconstruction is to make use of rules that can help resolve combinatorics ambiguity in preparing the decay tree for a given physics event. Additionally, missing energy coming from two neutrinos needs to be resolved in order to reconstruct the event. We apply four different methods within the \RF~package and compare the reconstruction resulting from each of the methods. Due to this method, one can also access kinematic variables in the rest frames belonging to intermediate particle states, providing additional means to discriminate the SM $\text{ttbar}$ background from the toponium signal. We propose using two angular variables to enhance sensitivity to the toponium signal. Our preliminary results indicate that the improvement in sensitivity can be as much as 12\% over the current strategy in the LHC's Run 3 configuration. This method may be useful for gaining additional insight into the physics phenomenology in the $\text{ttbar}$ threshold region.

   hep-phEPJC(2026)·1 citation
6. 06*

   Confinement and Chiral Phase Transitions: The Role of Polyakov Loop Kinetics Terms

   Banghui Hua🇨🇳 · Jiang Zhu🇨🇳

   We studied a crucial but often oversimplified ingredient in predicting gravitational-wave signals from QCD-type phase transitions: the kinetic term of the Polyakov loop. For the first time, we derive this term from first principles in finite-temperature pure SU(3) Yang-Mills theory, incorporating a field-dependent renormalization factor--a calculation we also extend to theories with more colors. Employing this derived kinetic term alongside three commonly-used effective potentials (the Haar-measure, polynomial, and quasi-particle models), we demonstrate that it substantially modifies the predicted GW energy spectrum from confinement transitions by 1-2 orders of magnitude. Based on this, we provide the first complete analysis of the chiral transition within the Polyakov-Nambu-Jona-Lasinio (PNJL) framework, described by the quark condensate. Our results reveal a clear dichotomy: while the Polyakov-loop kinetic term critically shapes GWs from confinement transitions, it has a negligible impact on the dynamics of the chiral transition, which is dominated by fermion condensation effects.

   hep-phhep-th2 citations
7. 07*

   Constraints on Primordial Black Holes from Galactic Diffuse Synchrotron Emissions

   Chen-Wei Du🇨🇳 · Yu-Feng Zhou🇨🇳

   We investigate the possibility of constraining primordial black holes (PBHs) with masses $M_{\mathrm{PBH}}\gtrsim 10^{15}\mathrm{g}$ through Galactic diffuse synchrotron emissions. Due to Hawking radiation, these types of PBHs are expected to be stable sources of cosmic-ray (CR) electrons and positrons with energies below $\mathcal{O}(10\mathrm{MeV})$. In many CR propagation models with diffusive re-acceleration characterized by a significant Alfvén velocity $V_a\sim \mathcal{O}(10)km/s$, the energies of the evaporated electrons/positrons can be further enhanced to $\mathcal{O}(100)\mathrm{MeV}$ through their scattering with the Galactic random magnetic fields. Consequently, the observation of Galactic synchrotron emissions at frequencies above $\sim 20\mathrm{MHz}$ can provide useful constraints on the abundance of PBHs. Using the AMS-02 and Voyager-1 data on the boron-to-carbon nuclei flux ratio, we confirm that a significant Alfvén velocity $V_a\sim 20km/s$ is favored in several benchmark diffusive re-acceleration models. We show that, in this scenario, the observed low-frequency synchrotron emissions (from 22 MHz to 1.4 GHz) can provide stringent constraints on PBH abundance. The obtained conservative constraints are stronger than those derived from the Voyager-1 all-electron (electron plus positron) data by more than one order of magnitude for $M_{\mathrm{PBH}}\gtrsim 1\times 10^{16}\mathrm{g}$, and also stronger than our previous constraints derived from the AMS-02 positron data for $M_{\mathrm{PBH}}\gtrsim 2\times 10^{16}\mathrm{g}$.

   hep-phastro-ph.HECommun.Theor.Phys.(2026)·0 citations
8. 08*

   Probing New Physics and CP Violation in ${\nu }_{\tau }n\to {\Lambda }_c{\tau }^{-}({\pi }^{-}{\nu }_{\tau })$ and ${\bar{\nu }}_{\tau }p\to \Lambda {\tau }^{+}({\pi }^{+}{\bar{\nu }}_{\tau })$

   E. Hernández🇪🇸 · J. Nieves🇪🇸 · J. E. Sobczyk🇸🇪

   We study the processes ${\nu }_{\tau }n\to {\Lambda }_c{\tau }^{-}({\pi }^{-}{\nu }_{\tau })$ and ${\bar{\nu }}_{\tau }p\to \Lambda {\tau }^{+}({\pi }^{+}{\bar{\nu }}_{\tau })$, with particular emphasis on the pion energy and angular distributions, as a possible signal for lepton flavor universality violation, and in general of physics beyond the Standard Model (SM), as well as a sensitive probe of the $\tau$ polarization vector. We work within an effective low-energy extension of the SM with all dimension-six four-fermion operators. In this framework, complex Wilson coefficients which encode new physics can generate CP-violating contributions. We propose an observable that provides a genuine CP-odd signal due to its sensitivity to particular transverse components of the $\tau$ polarization vector. Namely, we show that the asymmetry in the azimuthal-angle distribution of the pion in the decay ${\tau }^{\pm }\to {\pi }^{\pm }{\nu }_{\tau }$ constitutes a smoking-gun prediction of such a beyond the SM scenario. We estimate the strength of this effect extrapolating nucleon-hyperon form factors recently obtained from lattice QCD calculations.

   hep-phnucl-thPRD(2026)·0 citations
9. 09*

   Lepton flavor violating signals driven by CP symmetry of order 4

   Bei Liu🇨🇳 · Igor P. Ivanov🇨🇳

   CP4 3HDM is a curious version of the three-Higgs-doublet model built upon a CP symmetry of order 4 (dubbed CP4). When extended to fermions, CP4 leads to unusually tight correlations between the scalar and Yukawa sectors and induces tree-level flavor changing neutral couplings. Still, viable scenarios exist, in which quark flavor changing signals remain within experimental limits. In this work, we extend CP4 to the lepton sector and investigate whether the lepton-Higgs couplings and lepton flavor violating (LFV) signals can also be kept under control. We consider two classes of LFV processes: tree-level lepton decays of the 125 GeV Higgs boson and one-loop radiative decay $\mu \to e\gamma$. For each CP4-invariant lepton Yukawa scenario, we perform a focused Yukawa sector scan that uses physical lepton properties as input and suppresses LFV effects. We identify a promising CP4 3HDM scenario compatible with the present-day experimental constraints, show that it can accommodate the recent CMS hint of a 146 GeV scalar decaying to $e\mu$, and argue that this interpretation can be tested at future colliders.

   hep-phPRD(2026)·1 citation
10. 10*

    Predictions of effective Majorana neutrino mass under radiative corrections to $\mu -\tau$ reflection symmetry

    Prokash Pegu🇮🇳 · Chandan Duarah🇮🇳

    The search for neutrinoless double beta decay ($0\nu \beta \beta$) is currently one of the key objectives in neutrino physics research. The decay rate of $0\nu \beta \beta$ decay depends on the effective Majorana neutrino mass $|⟨m{⟩}_{ee}|$. In this work we study the numerical prediction of $|⟨m{⟩}_{ee}|$ in the scenario of deviation from the $\mu$-$\tau$ reflection symmetry due to radiative corrections, as an extension of our earlier work \cite{pegu}. In \cite{pegu}, we consider an exact $\mu$-$\tau$ reflection symmetry in the light effective Majorana neutrino mass matrix and in the corresponding lepton mixing matrix as well at the seesaw scale. We choose numerical values of all the mixing parameters and neutrino mass eigenvalues at the seesaw scale as inputs and estimate the values of mass eigenvalues and mixing parameters at the electroweak scale due to radiative corrections. We find these low energy predictions consistent with global $3\sigma$ oscillation data. In the present work, we compute the effective Majorana neutrino mass $|⟨m{⟩}_{ee}|$ using these low energy values at the electroweak scale. We find that the low energy predictions of $|⟨m{⟩}_{ee}|$ are consistent with the latest upper bound $|⟨m{⟩}_{ee}|<(0.028-0.122)eV$ provided by KamLAND-Zen Collaboration.

    hep-phJ.Subatomic Part.Cosmol.(2026)·1 citation
11. 11*

    Radiative Dirac neutrino masses and dark matter in a $U(1{)}_{B-L}$ extended model

    Chayan Majumdar🇨🇳 · Utkarsh Patel🇮🇳 · Supriya Senapati🇨🇳 · Sudhanwa Patra🇮🇳

    We study a $U(1{)}_{B-L}$ extension of the Standard Model (SM) in which Dirac neutrino masses are generated radiatively at the one-loop level through the exchange of new beyond the SM fields. This framework establishes a direct connection between neutrino mass generation and the dark sector, with the stability of the dark matter ensured by a residual discrete $Z_6$ symmetry arising from the spontaneous breaking of $U(1{)}_{B-L}$. We investigate the resulting charged lepton flavor violating processes and dark matter phenomenology, saturating relic observations and direct-detection constraints, and analyze the collider signatures of the dark sector at the Large Hadron Collider, its proposed high luminosity extension and at a future muon collider. We have identified excellent prospects for observing the considered dark matter candidates in these colliders, even with lower integrated luminosities than the proposed one.

    hep-phJHEP(2026)·0 citations
12. 12*

    Spectrum of radiation from global strings and the relic axion density

    Richard A. Battye🇬🇧 · Lukasz P. Bunio🇬🇧 · Steven J. Cotterill🇬🇧 · Pranav B. Gangrekalve Manoj🇬🇧

    We discuss key aspects of the nature of radiation from global strings and its impact on the relic axion density. Using a simple model we demonstrate the dependence on the spectrum of radiation emitted by strings. We then study the radiation emitted by perturbed straight strings paying particular attention to the difference between the overall phase of the field and the small perturbations about the string solution which are the axions. We find that a significant correction is required to be sure that one is analyzing the axions and not the self-field of the string. Typically this requires one to excise a sizeable region around the string - something which is not usually done in the case of numerical field theory simulations of string networks. We have measured the spectrum of radiation from these strings and find that it is compatible with an exponential, as predicted by the Nambu-like Kalb-Ramond action, and in particular is not a ``hard'' spectrum often found in string network simulations. We conclude by attempting to assess the uncertainties on relic density and find that this leads to a range of possible axion masses when compared to the measured density from the Cosmic Microwave Background, albeit that they are typically higher than what is predicted by the Initial Misalignment Mechanism. If the decay is via a ``soft spectrum'' from loops produced close to the backreaction scale we find that $m_{\mathrm{a}}\approx 160\mu \mathrm{eV}$ and a detection frequency $f\approx 38\mathrm{GHz}$. If axions are emitted directly by the string network, and we use emission spectra reported in field theory simulations, then $m_{\mathrm{a}}\approx 4\mu \mathrm{eV}$ and $f\approx 1\mathrm{GHz}$, however this increases to $m_a\approx 125\mu \mathrm{eV}$ and $f\approx 30\mathrm{GHz}$ using our spectra for the case of an oscillating string. In all scenarios there are significant remaining uncertainties that we delineate.

    hep-phastro-ph.COhep-thPRD(2026)·2 citations
13. 13*

    Event generation with exponential scaling in multiplicity using AmpliCol

    Rikkert Frederix🇸🇪 · Timea Vitos🇸🇪

    Efficient generation of LHC events is hindered by the rapidly rising cost of evaluating QCD matrix elements with increasing multiplicity. We build on a recently proposed two-step strategy in which unweighted events are first generated using the leading-colour (LC) approximation and then reweighted to full-colour (FC) accuracy, utilising the LC integration efficiency while recovering the exact FC prediction. In this work we extend the method to general Standard Model processes and present AmpliCol, a standalone implementation designed for LHC collisions. We benchmark multi-jet, $t\bar{t}$+jets, $ZZ$+jets, and Drell-Yan+jets production, measuring the time required to obtain a fixed number of unweighted events at FC accuracy. Across all processes, the runtime exhibits a stable exponential scaling with multiplicity, far milder than the factorial growth of conventional matrix-element generators. This demonstrates that the AmpliCol code enables efficient event generation at multiplicities that are otherwise computationally prohibitive.

    hep-phJHEP(2026)·4 citations
14. 14*

    Probing EFT breakdown in the tails of $W^{+}{W}^{-}$ observables

    Daniel Gillies🇬🇧 · Andrea Banfi🇬🇧 · Adam Martin🇺🇸

    In this letter, we test clipping effective field theory (EFT) simulations as a method of ensuring EFT validity. The procedure imposes that, at the level of the simulation, the invariant mass of a $W^{+}{W}^{-}$ pair $M_{WW}$ is less than the new physics scale $\Lambda$. We compare this to two other methods, comparison bin by bin of dimension-6 and dimension-8 squared contributions and implementing a cut on data. We find that setting $M_{WW}<\Lambda$ is not strict enough to ensure that the hierarchy of EFT operators is respected for dimension-6 and dimension-8 contributions. We also show that, even when using a stricter cut on $M_{WW}$, due to different correlations between $M_{WW}$ and $M_{e\mu }$ at different EFT orders, the bins in $M_{e\mu }$ (the invariant mass of the leptons originating from $W$ decays) used in an EFT fit may not truly be in the regime of EFT validity when performing a dimension-6 fit with $M_{WW}<\Lambda$. We also explore the correlations of three transverse mass observables: $M_{T1},M_{T2}$ and $M_{T3}$, finding that $M_{T1}$ and $M_{T3}$ follow the $M_{WW}$ distribution more closely than $M_{e\mu }$. We present sensitivity studies using both the $M_{T3}$ distribution and $M_{e\mu }$ distribution. We test implementing an experimental cut on $M_{T3}$ in place of clipping the EFT simulation at $M_{WW}<\Lambda$. We finally comment that adding $M_{WW}<\Lambda$ cuts only to the EFT simulation could be interpreted as modifying the SMEFT expansion by a form factor and could therefore impact the model independence of EFT fits under this procedure.

    hep-phhep-ex2 citations
15. 15*

    Radiative return at NLOPS accuracy

    Ettore Budassi🇮🇹 · Carlo M. Carloni Calame🇮🇹 · Marco Ghilardi🇮🇹 · Andrea Gurgone🇮🇹 · Guido Montagna🇮🇹 · Mauro Moretti🇮🇹 · Oreste Nicrosini🇮🇹 · Fulvio Piccinini🇮🇹 · Francesco P. Ucci🇮🇹

    The radiative return, together with the energy scan, is the method used at flavour factories to measure the pion form factor, which is a crucial input for the data-driven dispersive computation of the leading-order hadronic contribution to the muon anomalous magnetic moment. We consider the radiative hadronic and leptonic channels of main experimental interest, namely the processes $e^{+}{e}^{-}\to X^{+}{X}^{-}\gamma$, with $X=\{\pi ,\mu \}$. For such processes, we compute the exact next-to-leading order (NLO) corrections matched to a Parton Shower (PS) to describe exclusive multiple photon emission. All sources of radiative corrections from initial-state and final-state radiation, as well as their interference, are considered according to QED for $e^{+}{e}^{-}\to {\mu }^{+}{\mu }^{-}\gamma$ and QED$\oplus$F$\times$sQED (Factorised scalar QED) for $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}\gamma$. We describe in detail the novel features of our PS approach to compute the fixed-order corrections in association with higher-order contributions to $2\to 3$ processes, with a hard photon in the final state. We present validation tests and comparisons with NLO predictions available in the literature to cross-check various ingredients of our formulation. We also show numerical results at NLOPS accuracy according to realistic event selection criteria for precision measurements at flavour factories. Our calculation is implemented in an updated version of the Monte Carlo event generator BabaYaga@NLO, which can be used for fully exclusive simulations and data analysis in radiative return experiments.

    hep-phhep-exJHEP(2026)·14 citations
16. 16*

    Testing Modified Teleparallel Gravity by Neutrino Oscillations

    H. Yazdani Ahmadabadi🇮🇷 · H. Mohseni Sadjadi🇮🇷

    In the framework of modified teleparallel gravity, we study neutrino flavor conversion. We show how the presence of spacetime torsion modifies both neutrino flavor oscillation and the matter-enhanced Mikheyev-Smirnov-Wolfenstein (MSW) resonance. Using data from solar neutrino experiments, we perform an analysis to place new bounds on the modified teleparallel model parameters and neutrino-torsion coupling. Our numerical results indicate that the resulting modifications to the neutrino survival probability may explain potential observational discrepancies in current and future observatories without invoking new physics or non-standard interactions.

    hep-phgr-qchep-thPLB(2026)·1 citation
17. 17*

    How well does NRQCD describe quarkonium production?

    Mathias Butenschoen🇩🇪

    The question how well nonrelativistic QCD (NRQCD) factorization can describe quarkonium production has been subject to debate since its invention. We review our recent reanalysis of a classic next-to-leading order color octet (CO) long distance matrix element (LDME) fit to large transverse momentum $p_T$ $J/\psi$ and ${\eta }_c$ LHC production data. Our analysis differs from previous analyses of this kind not only by implementing for the first time a systematic treatment of scale uncertainties, but also by scrutinizing a much broader range of observables. Surprisingly, $J/\psi$ hadroproduction is well described up to the highest measured values of $p_T$. Potential NRQCD based relations nontrivially lead to a perfect description of ${\rm Y}(nS)$ production data. Furthermore, $J/\psi$ production in $\gamma p$ and $\gamma \gamma$ collisions is, contrary to prevailing conceptions, reproduced down to $p_T=1$ GeV, as long as the region of large inelasticity $z$ is excluded. The overall picture is much rosier than usually perceived, the more so as the remaining discrepancies appear in phase space regions where solutions via varying kinds of resummations have been proposed.

    hep-phPoS(2026)·0 citations
18. 18*

    Discriminating QCD Compton and Quark-Antiquark Annihilation Processes in $\gamma$ + Jets Using Interpretable Machine Learning

    Monalini Samal🇮🇳 · Nihar Ranjan Sahoo🇮🇳

    We investigate how effectively final-state jet substructure can discriminate between QCD Compton and quark-antiquark annihilation processes from photon-jet production in $pp$ collisions at $\sqrt{s}=13$ TeV. Using infrared- and collinear-safe jet observables, multivariate classifiers -- boosted decision trees and multilayer perceptrons -- are trained on labeled quark- and gluon-initiated jets from dijet events and applied to photon-jet samples. Observables probing soft and wide-angle radiation, in particular jet multiplicity and jet girth, dominate the discrimination. The jet mass provides a complementary but weaker contribution, while the jet charge exhibits negligible discriminating power. A comparison of the two classifiers demonstrates that the achievable separation is limited primarily by QCD radiation effects rather than by classifier complexity. These findings quantify the extent to which information about the underlying hard process survives hadronization and realistic jet reconstruction, providing a physics-driven baseline for precision jet measurements in $pp$, $ep/$A, and heavy-ion collisions.

    hep-phhep-exnucl-ex0 citations
19. 19*

    From $B_c$ mesons to the baryon asymmetry: a unified $B$ Mesogenesis Framework

    M. Burgos Marcos🇳🇱 · A. Verheyden🇳🇱 · K. K. Vos🇳🇱

    $B$ mesogenesis offers an interesting mechanism to generate the baryon asymmetry of the universe by converting the CP violation of the Standard Model into a net baryon number asymmetry. In this work we refine and extend the $B$ mesogenesis framework by incorporating all relevant $B$ meson channels active after low-temperature reheating. We first update the known neutral-meson contribution using time-integrated decay rates. While the $B_s^0$ contribution remains essentially unchanged, we find a suppression of the $B_d^0$ term by a factor $\sim 0.4$ with respect to previous analyses, alleviating the tension associated with its expected negative sign. We then perform a systematic study of $B_c^{+}$ decays, which are basically unexplored. We provide branching-ratio predictions using both leading-order factorization and a data-driven approach inspired by $D\to M_1{M}_2$ decays. These estimates allow us to quantify two $B_c^{+}$ sources of mesogenesis: the previously discussed $B_c^{+}\to B^{+}{M}^0$ channel and a new mechanism introduced in this work, $B_c^{+}\to B_q^{0}M$, in which the asymmetry is generated by combining direct CP violation with neutral-meson oscillations. Interestingly, in these channels the charm quark decays. Therefore, these decays give access to {\it charm CP violation} in modes with percent level branching ratios. With moderate assumptions, we find that $B_c^{+}$ mesogenesis can match or exceed the neutral contribution. Finally, we combine all three mechanisms and explore their viability in terms of the direct CP asymmetry, neutral-meson mixing parameters and early-universe fragmentation fractions. We find that successful baryogenesis can be achieved in a broad parameter space, showing the viability of $B$ mesogenesis. Future measurements of $B_c^{+}$ modes are thus highly anticipated to further probe the viability of unified $B$ mesogenesis.

    hep-ph1 citation
20. 20*

    The leading Lyapunov exponent in the glasma

    Pooja🇫🇮 · Dana Avramescu🇫🇮 · Tuomas Lappi🇫🇮

    We show that small perturbations in the boost-invariant color fields of the glasma exhibit an exponential growth with the square root of time. We interpret this growth rate as a Lyapunov exponent, related to entropy production and the thermalization timescale in the earliest stage of heavy-ion collisions. Working in a regime that is linear in this perturbation, we extract the time dependence of this mode as $\sim \exp (0.4\sqrt{g^2\mu \tau })$ for SU($2$), where $g^2\mu$ is proportional to the saturation scale and the square-root dependence is caused by the boost-invariant expansion of the system. We show that the growth rate of this mode is, unlike its amplitude, remarkably insensitive to the details of how the perturbations are initialized. In particular, we show that the unstable mode couples to all momentum scales present in the initial perturbation.

    hep-phhep-latnucl-thPRD(2026)·1 citation
21. 21*

    Glueball mass from RGZ-inspired infrared gluodynamics: a Euclidean Bethe-Salpeter approach

    Rodrigo Carmo Terin🇪🇸

    We formulate and solve a Euclidean Bethe-Salpeter equation for the lightest scalar glueball (0++) in pure Yang-Mills theory, using the refined Gribov-Zwanziger gluon tree-level propagator as an infrared-complete input. In a minimal ladder truncation with an effective constant kernel strength g_C^2 and the dominant s-wave component, we extract scalar glueball masses in the range 1.7-2.3 GeV for representative values of g_C^2, with a preferred value around 1.9 GeV near g_C^2 = 0.54. The result is consistent with RGZ correlator-based infrared moment analyses and with lattice expectations, providing a cross-check of RGZ-inspired infrared gluodynamics from a bound-state viewpoint.

    hep-phhep-lathep-th0 citations
22. 22*

    Strong CP and the QCD Axion: Lecture Notes via Effective Field Theory

    Francesco Sannino🇩🇰

    These lecture notes provide a self-contained, graduate-level introduction to the strong $CP$ problem and QCD axion physics from an effective field theory (EFT) viewpoint. We review the construction of the chiral EFT of QCD yielding a $\theta$-dependent potential, from which vacuum alignment, $\theta$ periodicity and branch structure follow. We further show how the framework leads to the Witten-Veneziano relation highlighting the role of the pure-glue topological susceptibility in organizing $\theta$-dependent hadronic observables. Using these tools, we show how to extract representative $CP$-odd mesonic and baryonic amplitudes, including the chiral estimate underlying the neutron EDM bound, and how to generalize the effective framework to confining SU(N) theories with fermions in arbitrary representations. We further show how to employ the Veneziano-Yankielowicz effective Lagrangian for N=1 supersymmetric Yang-Mills theory to extract salient information on the $\theta$-dependent physics of one-flavour QCD via orientifold planar equivalence. We also revisit a recent no strong $CP$ claim based on an ordering of limits in the sum over topological sectors and show, in the EFT language, that it amounts to introducing an extra non-propagating axion-like degree of freedom not required by QCD. We then present the standard dynamical resolution to the strong $CP$ problem, i.e. the Peccei-Quinn mechanism, the resulting axion potential and mass from chiral EFT and briefly review associated time-honored UV completions, and the axion quality problem from gravitational corrections.

    hep-phhep-exhep-lathep-thEPJC(2026)·11 citations
23. 23*

    Oscillating Resonances: Imprints of ultralight dark matter at colliders

    Martin Bauer🇬🇧 · Sreemanti Chakraborti🇬🇧

    In models where ultralight fields constitute dark matter, the misalignment mechanism leads to coherent, low-amplitude oscillations in fundamental constants. This effect arises from effective operators that couple dark matter to Standard Model fields. We present different models that can induce these effective operators by integrating out a mediator field. For mediator masses within the reach of collider searches, an alternative way to discover ultralight dark matter is to search for a resonance. Due to being a mediator to dark matter, the mass of the mediator oscillates. The resonance therefore, should not appear as a single isolated peak, but is smeared out once data is averaged over an oscillation cycle or more. Remarkably, the oscillation period and amplitude are in the range of current and future collider searches, even though constraints from atomic clocks probing variations of the fine-structure constant and the electron mass are very strong. We recast existing searches and projections from Belle II, LHCb and SHiP for an `oscillating resonance', and discuss how the periodicity of the signal can be used to reconstruct the peak from mass-binned data. We further show that time-stamped data would allow to unfold the signal via a fast Fourier transform and determine the significance of the signal for different background levels. The discovery of an oscillating resonance at a collider, with characteristics as predicted in ultralight dark matter scenarios, would constitute a powerful probe of dark matter's underlying nature.

    hep-phhep-ex2 citations
24. 24*

    A Comprehensive Effective Field Theory Framework for Coherent Elastic Neutrino-Nucleus Scattering

    Gang Li🇨🇳 · Chuan-Qiang Song🇨🇳 · Feng-Jie Tang🇨🇳 · Jiang-Hao Yu🇨🇳

    Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) stands out as a pivotal process for precision tests of the Standard Model electroweak sector, investigations of neutrino properties, and searches for new physics (NP). Recent experimental measurements by COHERENT, CONUS+, and ton-scale xenon detectors--including PandaX-4T and XENONnT--underscore the need for a systematic theoretical framework to bridge high-energy physics scenarios with low-energy observational data. In this work, we develop a comprehensive end-to-end effective field theory (EFT) framework for CE$\nu$NS, encompassing the complete energy scale hierarchy spanning the ultraviolet (UV) regime down to the nuclear sector. We consider the low-energy EFT (LEFT) operators up to dimension 8, incorporating their QCD renormalization group running effects, and employ the systematic spurion method to achieve the matching between these operators and the chiral Lagrangian. A full power counting analysis is performed, extending to nuclear response functions, which evaluates contributions from LEFT operators up to dimension 8 while accounting for the nucleon number enhancement effect intrinsic to CE$\nu$NS. Moreover, we match the relevant LEFT operators for CE$\nu$NS onto operators up to dimension 8 within the Standard Model EFT. By also providing their complete tree-level ultraviolet completions, this procedure establishes a consistent top-down theoretical workflow. Leveraging a broad suite of CE$\nu$NS experimental data, this framework enables a combined analysis to extract constraints on the scales of EFT operators and neutrino non-standard interaction parameters.

    hep-ph3 citations
25. 25*

    Next-to-Leading Order Running in the SMEFT

    Lukas Born🇨🇭 · Javier Fuentes-Martín🇪🇸 · Anders Eller Thomsen🇨🇭

    The next-to-leading order (NLO) Standard Model Effective Field Theory (SMEFT) renormalization group equations are needed to account for phenomenologically relevant operator mixing and ensure renormalization scale independence in NLO calculations of observables. For the first time, we present the renormalization group equations of the baryon-number-conserving sector of the dimension-six SMEFT up to two-loop order. Our calculations have been performed using functional methods with an anticommuting ${\gamma }_5$-scheme. A variety of strategies are employed to mitigate the reading-point ambiguities inherent to this scheme choice. We also describe how a local version of the ${\mathbf{R}}^{\ast }$-method is adapted to handle the evanescent operators arising in dimensional regularization. The results are provided in various supplementary files to make them accessible for both human inspection and numerical implementation.

    hep-ph17 citations
26. 26*

    FORM Version 5.0

    J. Davies🇬🇧 · T. Kaneko🇯🇵 · C. Marinissen🇳🇱 · T. Ueda🇯🇵 · J.A.M. Vermaseren🇳🇱

    We present FORM 5, a major release of the symbolic-manipulation system FORM. Version 5 introduces an integrated diagram generator, based on the GRACE graph-generator, to produce Feynman diagrams directly from FORM scripts. This release also adds support for arbitrary precision floating point coefficients, together with statements for the numerical evaluation of common mathematical functions as well as multiple zeta values and Euler sums. In addition, FORM 5 provides an interface to the FLINT library, offering substantially faster polynomial arithmetic. Various further functions and commands have been added alongside these major features, as well as performance improvements for TFORM and improved compression of FORM's temporary files. Compatibility with the previous release, FORM 4.3.1, is retained except where prior behaviour contradicted the manual or was experimental.

    hep-phcs.SChep-th27 citations
27. 27*

    Fully differential Higgs boson pair production at N${}^3$LO with top quark mass effects

    Xuan Chen🇨🇳 · Yuesheng Dai🇨🇳 · Hai Tao Li🇨🇳 · Shi-Yuan Li🇨🇳 · Hua-Sheng Shao🇫🇷 · Jian Wang🇨🇳

    Higgs-boson pair production is of fundamental importance for probing the Higgs potential. At hadron colliders, the dominant production channel proceeds via gluon-gluon fusion (ggF) mediated by a top-quark loop. We report the first fully differential predictions for Higgs-boson pair production through ggF at next-to-next-to-next-to-leading order (N${}^3$LO) in the strong coupling ${\alpha }_s$ in the heavy-top-quark limit (HTL). Fiducial cross section and selected differential distributions are presented at a center-of-mass energy of $\sqrt{s}$ = 14 TeV, under realistic experimental selection cuts. The N${}^3$LO QCD corrections reduce the scale uncertainties of the next-to-next-to-leading order fiducial and differential predictions by approximately a factor of three, bringing the theoretical uncertainty to the percent level in the HTL. After incorporating top-quark-mass effects at next-to-leading order in ${\alpha }_s$, we provide one of the most precise parton-level differential predictions to date for ongoing experimental searches for Higgs-boson pair production at the LHC.

    hep-phhep-exJHEP(2026)·5 citations
28. 28*

    Non-Abelian and Type-A Conformal Anomalies from Euler Descent

    Gleb Aminov🇮🇱 · Csaba Csáki🇺🇸 · Ofri Telem🇮🇱 · Shimon Yankielowicz🇮🇱

    We classify the non-Abelian anomaly of the Euclidean conformal group $SO(2n+1,1)$ in $2n$ dimensions via Stora-Zumino descent from its Euler invariant polynomial in $2n+2$ dimensions. In this way, we place the conformal anomaly on the same footing as ordinary perturbative 't Hooft anomalies. We also explore the relation of the non-Abelian anomaly to the known \textit{type-A Weyl anomaly}, which involves projecting into a Weyl cocycle. We discuss implications for anomaly inflow, and 't Hooft anomaly matching for the full conformal group with a Wess-Zumino-Witten term. In 4d, this enables the construction of a dilaton effective action matching the full non-Abelian $SO(5,1)$ conformal anomaly.

    ↳ hep-thhep-phJHEP(2026)·2 citations
29. 29*

    Q-balls from thermal balls during a first-order phase transition: a numerical study

    Yuan-Jie Li🇨🇳 · Jing Liu🇺🇸 · Zong-Kuan Guo🇨🇳

    We numerically study the Q-ball formation triggered by a cosmological first-order phase transition within the Friedberg-Lee-Sirlin model. By performing lattice simulations, we track the nonequilibrium dynamics throughout the transition, providing a precise description of the Q-ball formation mechanism and the resulting mass spectrum. Collapsing false-vacuum regions first form thermal balls, which subsequently cool via dissipative interactions and stabilize into long-lived Q-balls with nonzero spin. We observe a large population of low-mass Q-balls, as well as rare, massive Q-balls that are several times larger than the analytical prediction. The final Q-ball population exhibits a broad mass spectrum spanning over two orders of magnitude, characterized by an exponential tail of number density at large masses. The simulations suggest that the Q-ball abundance is approximately $50\%$ higher than predicted by analytical estimates, adjusting the result in the context of Q-balls as dark matter candidates.

    ↳ astro-ph.COhep-ph2 citations
30. 30*

    Interpolating conformal algebra in $(1+1)$ dimensions between the instant form and the light-front form of relativistic dynamics

    Chueng-Ryong Ji🇺🇸 · Hariprashad Ravikumar🇺🇸

    We present the interpolating conformal algebra between the instant form dynamics (IFD) and the light-front dynamics (LFD) in $(1+1)$ dimensions, along with a $4\times 4$ interpolating projective spacetime matrix representation. While there are six generators in the $(1+1)$ dimensional conformal algebra, the number of kinematic and dynamic generators dramatically changes in LFD, maximizing (minimizing) the number of kinematic (dynamic) generators to four (two) with respect to two (four) kinematic (dynamic) generators in IFD, as well as in any other forms of dynamics between IFD and LFD. It confirms and signifies the utility of LFD, saving substantial dynamical efforts in solving the $(1+1)$ dimensional quantum field theories. We also present $2\times 2$ Pauli matrix representation of $(1+0)$ and $(0+1)$ conformal groups, and creation/annihilation operators of quantum simple harmonic oscillator representations of $(1+0)$ dimensional conformal groups.

    ↳ hep-thhep-phmath-phmath.MPPRD(2026)·0 citations
31. 31*

    Extracting Nucleon Resonance Transition GPDs from $e^{-}N\to e^{-}\gamma N\pi$ Deeply Virtual Compton Scattering

    Matthew Rumley🇦🇺 · Anthony W. Thomas🇦🇺

    We investigate the process in which Deeply Virtual Compton Scattering (DVCS) excites a baryon resonance. In particular, we assess, in DVCS leading to the Roper resonance, the relative importance of a "background'' process in which a pion is first emitted by the nucleon, which then undergoes a DVCS event. Our numerical results, using realistic DVCS kinematics, indicate that there can be measurable interference effects. They suggest that this process could substantially modify the experimentally observed cross sections at CLAS12-like kinematics, motivating their inclusion in precision analyses of DVCS experiments. We further find that in spite of this background, the transition to a Roper-like state through DVCS does contribute significantly to the $e^{-}N\to e^{-}\gamma N\pi$ cross section in some kinematic regions. This suggests that the creation of nucleon resonances via DVCS is a useful method for extracting information about the nucleon transition GPDs and the internal structure of the excited states.

    ↳ nucl-thhep-phPRD(2026)·1 citation
32. 32*

    How transverse momentum conservation breaks azimuthal correlation factorization

    Jia-Lin Pei🇨🇳 · Guo-Liang Ma🇨🇳 · Adam Bzdak🇵🇱

    The breakdown of azimuthal two-particle correlation factorization, quantified by the ratios $r_2$ and $r_3$, serves as a sensitive probe of transverse-momentum-dependent flow fluctuations. While hydrodynamic models predict $r_3\le 1$, experimental data from CMS in p-Pb collisions exhibit $r_3>1$, presenting a clear puzzle. We show that transverse momentum conservation (TMC) is the key mechanism dictating this factorization breakdown in small systems. We systematically calculate the effect of TMC as a function of the momentum difference between particles across various multiplicity and momentum ranges. Our results are in quantitative agreement with CMS p-Pb data for both $r_2$ and $r_3$. A central finding is a sign rule: under TMC, the deviation $r_n-1$ follows ${\left(-1\right)}^{n+1}$, being negative for even and positive for odd harmonic orders $n$. This work establishes an analytical framework to quantify transverse-momentum-dependent flow fluctuations and provides new insights into the origin of collectivity in small colliding systems.

    ↳ nucl-thhep-phnucl-ex0 citations
33. 33*

    Octet baryon electroweak form factors in dense nuclear matter

    G. Ramalho🇰🇷 · K. Tsushima🇧🇷 · Myung-Ki Cheoun🇰🇷

    Motivated by the necessity of developing theoretical models for studying the electroweak structure of baryons in a nuclear medium, we apply a covariant quark model to study interactions of baryons with nuclear matter. The electromagnetic and axial form factors of the octet baryons are determined by combining a covariant quark model that takes into account the meson cloud dressing of the baryon cores, developed for free space, with the quark-meson coupling model in the extension to the nuclear medium. We discuss the medium modifications on the electroweak form factors of octet baryons for the range of densities from $\rho =0$ up to $\rho =2{\rho }_0$, where ${\rho }_0=0.15$ fm${}^{-3}$ is the normal nuclear matter density. We also study how the shape of the form factors is modified in finite nuclei due to the profile of the nuclear density distributions compared with calculations using the average density of the nucleus

    ↳ nucl-thhep-exhep-lathep-ph+1J.Subatomic Part.Cosmol.(2026)·0 citations
34. 34*

    A self-consistent calculation of non-spherical Bose-Einstein correlation functions with Coulomb final-state interaction

    Márton I. Nagy🇭🇺 · Máté Csanád🇭🇺 · Dániel Kincses🇭🇺

    Particle correlations and femtoscopy are a rich subfield of high-energy physics. As the experimental data become more precise, there is an increasing need for the theoretical calculations to provide better and more general descriptions of the measurements. One of the important new directions is the investigation of the precise shape of the Bose-Einstein correlation functions utilizing Lévy-stable distributions. This work is a direct follow-up to our previous study, in which we developed a novel method for calculating Bose-Einstein correlation functions including the Coulomb final-state interaction. In this paper, we present a self-consistent generalization of the previous approach to non-spherical source functions and investigate the validity of the previously applied approximations assuming spherical symmetry. We present a software package that includes the calculation of a fully three-dimensional correlation function including the Coulomb interaction.

    ↳ nucl-thhep-phhep-thEPJC(2026)·1 citation
35. 35*

    A study of dark matter-dark energy interaction under the DESI DR2 data constraint

    Amin Aboubrahim🇺🇸 · Pran Nath🇺🇸

    While $\Lambda$CDM provides a good fit to cosmological data, it fails to address many of the outstanding questions in contemporary cosmology. Chief among these are the Hubble tension and the apparent dynamical nature of dark energy as inferred from the recent DESI DR2 analysis. In this work, we analyze a field-theoretic description of cosmology where both dark energy and dark matter are interacting spin zero fields. We give a thorough study of a wide range of the interaction strength and demonstrate the effect on the dark energy equation of state and the Hubble tension. Using the recent cosmological data, we extract constraints on cosmological parameters including the free parameters of the model.

    ↳ astro-ph.COhep-ph2 citations
36. 36*

    Prompt cusps in hierarchical dark matter halos: Implications for annihilation boost

    Shin'ichiro Ando🇳🇱 · Martín Moró González🇳🇱 · Youyou Li🇳🇱

    Recent simulations have identified long-lived ``prompt cusps'' -- compact remnants of early density peaks with inner profiles $\rho \propto r^{-3/2}$. They can survive hierarchical assembly and potentially enhance signals of dark matter annihilation. In this work, we incorporate prompt cusps into the semi-analytic substructure framework SASHIMI, enabling a fully hierarchical, environment-dependent calculation of the annihilation luminosity that consistently tracks subhalos, sub-subhalos, and tidal stripping. We assign prompt cusps to first-generation microhalos and propagate their survival through the merger history, including an explicit treatment of cusps associated with stripped substructure. We find that the substructure hierarchy converges rapidly once a few levels are included, and that prompt cusps can raise the total annihilation boost of Milky-Way--size hosts at $z=0$ to $B\sim 50$ for fiducial cusp-occupation assumptions, compared to a subhalo-only baseline of $B_{\mathrm{sh}}\sim \mathrm{few}$. Across a wide range of host masses and redshifts, prompt cusps increase the normalization of $B(M_{\mathrm{host}},z)$ while largely preserving its mass and redshift trends. Compared to universal-average, peak-based estimates, our fiducial boosts are lower by about a factor of a few, primarily reflecting a correspondingly smaller inferred cusp abundance in host halos, highlighting the importance of unifying peak-based cusp formation with merger-tree evolution and environmental dependence.

    ↳ astro-ph.GAastro-ph.COastro-ph.HEhep-phJCAP(2026)·1 citation

* 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.