Tue·Jul 8, 2025Tuesday·July 8, 2025

1. 01*

   Neutrino mass generation via the inverse seesaw mechanism in a $U(1{)}_{B-L}$ gauge extension

   Higo Barros Nogueira🇧🇷 · Job Saraiva Furtado Neto🇧🇷 · Raimundo Nogueira da Costa Filho🇧🇷 · Júlio Rafael da Silva Leite🇪🇸

   We present anomaly-free solutions suitable for an inverse seesaw realization within a $U(1{)}_{B-L}$ extension. Implementing such a mechanism, in a phenomenologically viable way, requires the inclusion of at least four exotic fermions, assumed to be Standard Model singlets. In order to build anomaly-free models, the $B-L$ charges of these exotic fermions must satisfy two constraint equations, known as the anomaly equations. Here, we focus on solutions involving four to eight new right-handed fermions, favoring cases where all the $B-L$ charges of these fermions are rational numbers. We showed that, when considering only the right-handed fermions necessary to realize the mechanism, the solutions must have irrational charge values. By adding one more exotic singlet fermion, which does not directly enter the mechanism mass matrix, it becomes possible to find solutions with rational charges, while the addition of a second one enables a reduction of the scalar sector. On top of the two anomaly equations, a set of inequalities and additional constraint equations were added to correctly account for neutrino masses and to minimize the scalar content. So here we present sets of charges that obey the anomaly equations as well as these additional constraints. Finally, we explore the phenomenological implications of such solutions by analyzing their capacity to provide a framework for dark matter candidates, choosing one particular solution as an example.

   hep-ph1 citation
2. 02*

   The Milky Way is a Laboratory for New Ultra-long-baseline Neutrino Physics

   Miller MacDonald🇺🇸 · Kiara Carloni🇺🇸 · Carlos A. Argüelles🇺🇸 · Rafael Alves Batista🇫🇷 · Ivan Martínez-Soler🇬🇧

   The IceCube Neutrino Observatory recently published evidence for diffuse neutrino emission from the Galactic Plane at $4.5\sigma$ significance. This new source of astrophysical neutrinos provides an exciting laboratory for probing the nature of neutrino masses. In particular, extremely small mass splittings, such as those predicted by quasi-Dirac neutrino mass models, and finite neutrino lifetimes from neutrino decays, would induce effects on the spectra and flavor ratios of neutrinos with TeV-scale energies traversing kiloparsec-scale baselines. Using $\mathtt{TANDEM}$, an upcoming three dimensional galactic neutrino emission model, we explore the sensitivity of IceCube and KM3NeT/ARCA to these ultra-long-baseline phenomena. We find that a combined analysis would be sensitive to quasi-Dirac mass splittings $10^{-14.0}\mathrm{e}{\mathrm{V}}^2\lesssim \delta m^2\lesssim 10^{11.6}\mathrm{e}{\mathrm{V}}^2$ and neutrino lifetimes $m/\tau \gtrsim 10^{-14.1}\mathrm{e}{\mathrm{V}}^2$ at $>1\sigma$, both regions constituting as-yet unexplored parameter space. Our results demonstrate the potential that astrophysical neutrino sources and global neutrino telescope networks have in probing new regions of exotic neutrino mass models.

   hep-phastro-ph.HEPoS(2025)·1 citation
3. 03*

   tZ FCNC Case study: LLM Application in signal/Background discrimination analyses in Particle Physics

   A. Saqlain🇹🇷 · Z. E. Çabukoğlu · J. Smiesko🇨🇭 · S. Kartal🇹🇷

   We present a case study exploring the potential of OpenAI's o3 model as a process-agnostic tool (within fixed topology) for predicting optimized selection cuts in high-energy physics analyses. Specifically, we investigate the effectiveness of the model in separating signal from relevant Standard Model backgrounds in the context of Flavour-Changing Neutral Current (FCNC) top-quark couplings, focusing on the rare decay process t \rightarrow uZ. The study is performed at the Future Circular Collider in hadron-hadron mode (FCC-hh) setup. We prompt the o3 model on detector level data for signal and background processes to predict selection cuts that enhance Signal-to-Background (S/B) discrimination. A comparative analysis is then carried out between the efficiencies resulting from o3-predicted cuts, TMVA BDT separation and those derived from traditional manually designed strategies used by a control group; all utilizing the same parameters for the sake of the integrity of the study. Our results demonstrate that the o3 model performs a degree better than the control group, suggesting its promise as a fast and generalizable tool for new physics searches. Meanwhile, BDT results were considerably higher than both the o3 and the traditional cut-based methods. Furthermore, in order to test its limitations, o3 cuts were applied to data generated via the approved High-Luminosity Large Hadron Collider (HL-LHC) and the proposed High-Energy LHC (HE-LHC) setup in order to examine its effectiveness at different energy scales when provided with data at FCC energies.

   hep-ph3 citations
4. 04*

   The nano-hertz and milli-hertz stochastic gravitational waves in the minimal clockwork axion model

   Xiangwei Yin🇨🇳 · Cheng-Wei Chiang🇹🇼 · Bo-Qiang Lu🇨🇳 · Tianjun Li🇨🇳

   The clockwork framework can realize TeV-scale $U(1{)}_{PQ}$ symmetry breaking while generating a large axion decay constant \(f_a\). We propose a minimal clockwork axion model with three scalar fields, in which two domain walls (DWs) have non-zero tension. The DW associated with one of the fields is formed following the Peccei-Quinn (PQ) symmetry breaking and subsequently collapses due to the potential bias induced by the QCD instanton. The nano-hertz stochastic gravitational waves (GWs) generated from this DW annihilation can be probed by Pulsar Timing Arrays experiments. In addition, the DW related to the other field is annihilated by a bias potential originating from higher-dimensional operators, producing a significant GW signal with a peak frequency around \(9.41\times10^{-5}\) Hz, which can be detected by the LISA, Taiji, and TianQin experiments. Constraints on the model from SN1987, dark matter overproduction, Big Bang Nucleosynthesis, cosmic microwave background, and primordial black holes have been considered. The relic density of QCD axion dark matter can be explained through the misalignment mechanism.

   hep-ph0 citations
5. 05*

   From $U(1)\times U(1)$ Symmetry Breaking to Majoron Cosmology: Insights from NANOGrav 15-year Data

   Tathagata Ghosh🇮🇳 · Kousik Loho🇮🇳 · Sudip Manna🇮🇳

   We study the cosmology of a modified majoron model motivated by the need to protect a global $U(1)$ symmetry from gravity-induced hard explicit breaking (by $d\le 4$ operators) at the Planck scale. The model extends the Standard Model by introducing a gauged $U(1{)}_{B-L}$ and an approximate global $U(1)$ symmetry, each spontaneously broken by a corresponding complex scalar singlet. This setup gives rise to a network of effectively global and local cosmic strings, whose stochastic gravitational wave signals can jointly account for the spectrum observed by the NANOGrav collaboration, particularly for majoron masses $m_{\chi }<10^{-23}$ eV. Although the fit is not as strong as that from supermassive black hole mergers, the model still provides an alternative explanation rooted in high-energy physics. The model also generates light neutrino masses via the seesaw mechanism and avoids cosmological constraints from $\Delta N_{\text{eff}}$, CMB anisotropies, and isocurvature fluctuations. Although the majoron can contribute to dark matter through thermal, coherent oscillation, and string-induced production mechanisms, its relic abundance remains subdominant in the NANOGrav-compatible region. In contrast, the measured dark matter relic density is achievable at higher $m_{\chi }$, though at the cost of tension with cosmological bounds. If the NANOGrav fits are viewed as constraints, given their comparatively lower Bayes factors, they yield bounds that are significantly stronger than those imposed by the CMB and other cosmological data.

   hep-phastro-ph.COastro-ph.HEPRD(2026)·5 citations
6. 06*

   Revisit the diquark of ${\Lambda }_c$ in the ${\Lambda }_c\to \Lambda K^{+}$ and ${\Lambda }_c\to {\Sigma }^0{K}^{+}$ processes

   Peng-Yu Niu🇨🇳 · Qian Wang🇨🇳 · Qiang Zhao🇨🇳

   The spatial distributions of $[ud]$ diquark and heavy-light diquark of the SU(3)-flavor antitriplet charmed baryons are investigated by the two singly Cabibbo-suppressed hadronic weak decays, ${\Lambda }_c\to \Lambda K^{+}$ and ${\Lambda }_c\to {\Sigma }^0{K}^{+}$ within the nonrelativistic constituent quark model. The above two spatial distributions are reflected by the two parameters ${\alpha }_{\rho }$ and ${\alpha }_{\lambda }$, which are the harmonic oscillator strength parameters of the charmed baryons. These two parameters obtain strong constraints from the decay widths of ${\Lambda }_c\to \Lambda K^{+}$ and ${\Lambda }_c\to {\Sigma }^0{K}^{+}$. The larger the harmonic oscillator parameter is, the more compact the spatial distribution will become. The current ${\alpha }_{\rho }$ and ${\alpha }_{\lambda }$ indicate that neither the light diquark nor the heavy-light diquark turns out to favor a compact structure. In addition, some selection rules, including the ``$\Lambda$ selection rule'', can be useful for the search of excited baryons in the heavy-flavor baryon hadronic weak decays.

   hep-ph1 citation
7. 07*

   MonoHiggsology

   Ernest Ma (UC Riverside)🇺🇸

   Flavor symmetry and other ideas beyond the standard model (SM) may be achieved in a renormalizable theory using the dark sector, while keeping only the one SM Higgs doublet.

   hep-phMod.Phys.Lett.A(2025)·2 citations
8. 08*

   Comparison of chiral limit studies in curvature mass versus on-shell renormalized quark-meson model using ChPT

   Vivek Kumar Tiwari🇮🇳

   Consistent chiral limit has been investigated in the curvature mass parametrized quark-meson (QM) model with the quark one-loop vacuum term (QMVT) employing the infrared regularized Chiral perturbation theory (ChPT) predicted scaling of the pion,~kaon decay constants $f_{\pi },f_K$ and $M_{\eta }^2=m_{\eta }^2+m_{{\eta }^{\prime }}^2$ when the $\pi \text{and}K$ meson masses are reduced as one moves away from the physical point in the Columbia plot.~Comparing the QMVT model Columbia plots with the corresponding Columbia plots computed,~in the very recent work of Ref.~\cite{vkt25} using the on-shell renormalized QM (RQM) model and the earlier work of Ref.~\cite{Resch} using functional renormalization group techniques in the extended mean field approximation of QM (e-MFA:QM-FRG) model,~it has been estimated how the first, second and crossover chiral transition regions in the $m_{\pi }-m_K$($m_{ud}-m_s$) and the $\mu -m_K$($\mu -m_s$) planes,~get modified by different methods of implementing the quark one-loop vacuum fluctuations in the QM model.~Since both the e-MFA:QM-FRG and the QMVT model,~use curvature meson masses to fix the parameters and the dimensional regularization of vacuum divergences are incorporated equivalently,~the differences in their results can be attributed to different methods of approaching the chiral limit.

   hep-phPRD(2025)·3 citations
9. 09*

   Probing maximal flavor changing $Z^{\prime }$ in $U(1{)}_{L_{\mu }-L_{\tau }}$ at $\mu$TRISTAN

   Fei Huang🇨🇳 · Jin Sun🇰🇷

   We explore the potential to detect the $U(1{)}_{L_{\mu }-L_{\tau }}$ model featuring triplet scalars $\Delta$ at the $\mu$TRISTAN collider. The new gauge boson $Z^{\prime }$, arising from the spontaneous breaking of $U(1{)}_{L_{\mu }-L_{\tau }}$, can exhibit maximal flavor changing interactions under the exchange symmetry, while $\Delta$ mediates the flavor conserving interactions. The absence of muon $(g-2{)}_{\mu }$ can be explained by interference effects arising from opposite contributions of $Z^{\prime }$ and $\Delta$, with similar interference patterns also manifesting in the tau decay process $\tau \to \mu \nu \bar{\nu }$. These counteracting effects render the model phenomenologically interesting and warrant further investigation. For the mass $m_{Z^{\prime }}$ in the range of hundreds of GeV, we find that ${\mu }^{+}{\mu }^{+}$ and ${\mu }^{+}{e}^{-}$ collider at the $\mu$TRISTAN can probe many regions inaccessible to current experiments and offer greater projected sensitivity than opposite-sign muon colliders. This suggests that $\mu$TRISTAN can serve as complementary exploration to the $U(1{)}_{L_{\mu }-L_{\tau }}$ model, providing compelling motivation for the next generation of high-energy lepton colliders.

   hep-phPLB(2026)·2 citations
10. 10*

    A Rephasing Invariant Formula for the Dirac CP Phase and General Perturbative Expansion: Prospects for DUNE and T2HK

    Masaki J. S. Yang🇯🇵

    We present a formula for the Dirac CP phase $\delta =\arg (U_{e1}{U}_{e2}{U}_{\mu 3}{U}_{\tau 3}/U_{e3}\det U_{\mathrm{MNS}})$, directly derived from the lepton mixing matrix in an arbitrary basis of phases. In contrast to the numerically suppressed Jarlskog invariant, this expression is computationally simple and less sensitive to approximations. We apply the formula to derive general perturbative corrections from charged-lepton mixing $s_{ij}^e$ to the underlying CP phase of neutrinos ${\delta }_{\nu }$. A compact analytic expressions $\delta ={\delta }_{\nu }+s_{12}^e{D}_{12}+s_{13}^e{D}_{13}+s_{23}^e{D}_{23}$ shows that these corrections can substantially exceed $O(10^{\circ })$, potentially within the reach of future long-baseline experiments such as DUNE and T2HK.

    hep-phPLB(2025)·14 citations
11. 11*

    Entropy from decoherence: a case study using glasma-based occupation numbers

    Gabriele Coci🇮🇹 · Gabriele Parisi🇮🇹 · Salvatore Plumari🇮🇹 · Marco Ruggieri🇮🇹

    We compute the entropy-per-particle, $S/N$, produced by the decoherence of a coherent state interacting with an environment, using an analytical open quantum system approach. The coherent state considered is characterized by occupation numbers borrowed from the glasma fields produced in the early stages of high-energy nuclear collisions. The environment is modeled as the vacuum, and decoherence arises from the interaction of the state with vacuum fluctuations. We describe the system-environment interaction via a phase-damping model, which represents continuous measurements on the system without altering its energy or particle number. Starting from the occupation numbers typical of the Glasma in high-energy proton-nucleus and nucleus-nucleus collisions, we find that the final $S/N$ after decoherence is lower than that of a two-dimensional thermal bath of ultrarelativistic gluons, except for proton-nucleus collisions at small values of $g\mu$. Our results indicate that quantum decoherence alone does not generate sufficient entropy to transform the initial coherent state into a thermalized gluon bath.

    hep-phquant-phEur.Phys.J.Plus(2026)·2 citations
12. 12*

    Cross section of the process $e^{+}+e^{-}\to {\Xi }^0+{\bar{\Xi }}^0$ in the vicinity of charmonium $\psi (3770)$ and in the charmonium (-like) state including the $D$-meson loop and three-gluon contributions

    Azad I. Ahmadov🇦🇿

    In this paper, we investigate the production of a ${\Xi }^0{\bar{\Xi }}^0$ using $e^{+}{e}^{-}$ collision data at ten center-of-mass energies between 3.51 and 4.95 GeV collected with the BESIII detector at the BEPCII collider and corresponding to an integrated luminosity of 30 ${\mathrm{fb}}^{-1}$ to study the structure of baryons. The data collected by the BESIII detector are useful for the study of XYZ states, and this collaboration continues the exploration of these exotic charmonium-like states. We explore a hyperon pair produced in the electron-positron annihilation reactions. In the present paper we present the phenomenological results of our studies on the production of ${\Xi }^0{\bar{\Xi }}^0$ in $e^{+}{e}^{-}$ annihilation at the BESIII detector at the BEPCII Collider. In the reaction $e^{+}{e}^{-}\to {\Xi }^0{\bar{\Xi }}^0$, we consider two different contributions: one from the $D$ meson loop and the ofther from the three-gluon charmonium annihilation. We compute the total cross section of the process $e^{+}{e}^{-}\to {\Xi }^0{\bar{\Xi }}^0$ including the contributions of the $D$-meson loop and three-gluon loops as well as the interference of all diagrams. As for the purely electromagnetic mechanism, large relative phases are generated for these contributions. For a large momentum transferred region we get as a byproduct a fit of the electromagnetic form factor of the ${\Xi }^0$ - hyperon. In this paper, in addition to the $\psi (3770)$ charmonium, we also take into account the contributions of other charmonium (-like) states, such as $\psi (4040)$, $\psi (4160)$, $Y(4230)$, $Y(4360)$, $\psi (4415)$, and $Y(4660)$. On the whole our results are in good agreement with the available experimental data.

    hep-phPRC(2026)·0 citations
13. 13*

    Modelling top-quark decays in $t\bar{t}t\bar{t}$ production at the LHC

    Manal Alsairafi🇩🇪 · Nikolaos Dimitrakopoulos🇩🇪 · Malgorzata Worek🇩🇪

    We compare the fixed-order NLO QCD predictions for the $pp\to t\bar{t}t\bar{t}+X$ process in the $4\ell$ decay channel with the parton-shower based results obtained with the POWHEG and MC@NLO matching methods. In the first case, NLO QCD corrections are consistently included in both the $t\bar{t}t\bar{t}$ production step and the decays of the four top quarks, preserving all spin correlations. In the second approach, higher-order effects in top-quark decays with approximate spin correlations are simulated in the PYTHIA parton-shower framework. Additionally, we analyse the impact of including the so-called matrix element corrections in top-quark decays in both parton-shower matched predictions. The comparison is performed at the integrated and differential fiducial cross-section level for the LHC centre-of-mass energy of $\sqrt{s}=13.6$ TeV.

    hep-phhep-exPRD(2025)·2 citations
14. 14*

    More visualisation of decay-time-dependent asymmetries in multibody B-meson decays

    Tim Gershon🇬🇧 · Thomas Latham🇬🇧 · Peilian Li🇨🇭 · Andy Morris🇫🇷 · Wenbin Qian🇨🇳 · Mark Whitehead🇬🇧 · Ao Xu🇮🇹

    Methods have been proposed recently to weight data in order to allow visualisation of CP-violation effects in transitions of neutral B mesons to multibody final states that are not CP-eigenstates. These are useful since integration of the unweighted data over the phase space would otherwise wash out the effects of interest. A similar method, elaborated upon here, with a different weighting function can also be used to visualise CP-conserving $B_{(s)}^0$--$\overline{B}{}_{(s)}^0$ oscillations, rather than the CP-violating asymmetries. Together with the other weighting functions, this new method could be useful, for example, to demonstrate the accuracy of the calibration of the flavour tagging algorithms that are crucial for analyses such as the measurement of the CP-violating phase in $B_s^0\to J/\psi \varphi$ decays. Their application to the formalism in common use for such decays is explicitly demonstrated.

    hep-phhep-exEPJC(2025)·0 citations
15. 15*

    Effect of Off-diagonal NSI Parameters on Entanglement Measurements in Neutrino Oscillations

    Lekhashri Konwar🇮🇳 · Papia Panda🇮🇳 · Rukmani Mohanta🇮🇳

    In this work, we explore the influence of off-diagonal non-standard interaction (NSI) parameters on quantum entanglement within the three-flavor neutrino oscillation framework. By expressing three key entanglement measures: Entanglement of Formation (EOF), Concurrence, and Negativity in terms of oscillation probabilities, we analyze how these quantum correlations are affected by the NSI parameters ${ϵ}_{e\mu }$, ${ϵ}_{e\tau }$, and ${ϵ}_{\mu \tau }$, including their complex phases. The quantum correlation measures considered in this work cannot be extracted directly from event rates, but solely in terms of oscillation probabilities. Using the DUNE experiment as a reference point, our analysis shows that NSI effects are most pronounced at lower energies, while Negativity continuing to dominate even at higher energies. It is observed that ${ϵ}_{e\mu }$ and ${ϵ}_{e\tau }$ affect entanglement measures mainly through the appearance channel, while the impact of ${ϵ}_{\mu \tau }$ on EOF, Concurrence, and Negativity is predominantly linked to the disappearance channel. Further, our results show that Negativity is more sensitive than EOF and Concurrence in the [Energy ($E$) - ${\delta }_{CP}$] plane under the influence of off-diagonal NSI scenarios, displaying a clear dependence of the CP-violating phase, ${\delta }_{CP}$ on specific energy ranges, particularly in the lower energy regime.

    hep-phJ.Phys.G(2026)·4 citations
16. 16*

    Eta Fragmentation Functions Revisited

    Christine A. Aidala🇺🇸 · Devon A. Loomis🇺🇸 · Ramiro Tomas Martinez🇦🇷 · Rodolfo Sassot🇦🇷 · Marco Stratmann🇩🇪

    We revisit the extraction of parton-to-eta meson fragmentation functions at next-to-leading order accuracy in QCD in the light of the recent hadroproduction measurements in proton-proton collisions obtained by the PHENIX, LHCb, and ALICE collaborations. In addition to an increased precision, the data explore complementary rapidity ranges and center-of-mass system energies. The analysis exploits the theoretical scale dependence to ease tensions among the data sets at different energies that are potentially caused by QCD corrections beyond the next-to-leading order. The resulting set of fragmentation functions yields a consistent description of all available data. Estimates of uncertainties are obtained with the Monte Carlo replica method.

    hep-phPRD(2026)·4 citations
17. 17*

    Spin alignment of vector mesons in heavy-ion collision

    Xin-Li Sheng🇮🇹 · Qun Wang🇨🇳

    We give a brief review on the spin alignment induced by the strong field and the shear-stress tensor. In experiments, a significant positive deviation from 1/3 is observed for the $\varphi$ meson, which can be explained by the anisotropy of the strong field fluctuation in the meson's rest frame, while the anisotropy is mainly a consequence of the motion of meson relative to the quark-gluon plasma. On the other hand, the shear-induced spin alignment is of the order $10^{-4}\sim 10^{-5}$ if the magnitude of thermal shear tensor is $10^{-2}$.

    hep-phnucl-thJ.Subatomic Part.Cosmol.(2025)·0 citations
18. 18*

    Weak decays of $B_s$ meson in self-consistent covariant light-front approach

    Thejus Mary S.🇮🇳 · Rohit Dhir🇮🇳

    We present a comprehensive study of weak transition form factors and decay observables of the $B_s$ meson in transitions to pseudoscalar ($P$) and vector ($V$) mesons. The $B_s\to P(V)$ form factors are calculated using the self-consistent covariant light-front quark model, with a model-independent $z$-series expansion calibrated to lattice QCD and phenomenological inputs for quark masses and $\beta$ parameters. This enables reliable $q^2$-resolved predictions across the full kinematic range. Based on these form factors, we predict branching ratios and angular observables, including forward-backward asymmetries, polarization fractions, and leptonic convexity parameters for semileptonic decays. Nonleptonic two-body decay rates for $B_s\to PP$ and $B_s\to PV$ modes are also computed within the standard factorization framework using the same dynamical input. Comparisons with results from lattice QCD, light-cone sum rules, and other approaches are presented, highlighting both theoretical consistency and persistent tensions with experiment.

    hep-phhep-exEPJC(2025)·1 citation
19. 19*

    Recasting Experimental Constraints on Relativistic Magnetic Monopoles

    Daniele Perri🇵🇱 · Michele Doro🇮🇹 · Takeshi Kobayashi🇮🇹

    Magnetic monopoles with masses up to $10^{14}$ GeV can be accelerated to relativistic velocities in Galactic and intergalactic magnetic fields. The cosmic flux of relativistic monopoles is constrained by various experiments, with the limits given as functions of the monopole velocity (Lorentz factor) at the detectors. The velocity, however, is usually treated as a free parameter due to the ambiguity in the computation of the acceleration before the monopoles arrive at Earth. We explicitly evaluate the velocity by exploiting recent studies on cosmic magnetic fields and the monopole acceleration therein, to recast experimental limits in terms of the mass of monopoles. By applying our method to various terrestrial experiments, including the Pierre Auger Observatory, IceCube, MACRO, and the upcoming Cherenkov Telescope Array Observatory, as well as to astrophysical constraints, we report limits on the flux of monopoles for a wide range of monopole masses. We also highlight the role of monopoles as messengers of cosmic magnetic fields, and discuss the possibility of using monopole experiments to probe intergalactic magnetic fields.

    hep-phastro-ph.COastro-ph.HEhep-exPhys.Dark Univ.(2025)·7 citations
20. 20*

    A subthreshold pole in electron-positron annihilation into the $D_s^{+}{D}_s^{-}$ final state

    Peter Lichard🇨🇿 · Josef Juráň🇨🇿

    Using precise data from the BESIII collaboration, we obtained compelling evidence of a subthreshold pole in the $e^{+}{e}^{-}\to D_s^{+}{D}_s^{-}$ process with mass of (3896${}_{-22}^{+13}$)~MeV. The latter suggests the identification of this subthreshold pole with the $G$(3900) state, which behaves as a resonance in the $e^{+}{e}^{-}\to D\bar{D}$ processes.

    hep-phhep-ex1 citation
21. 21*

    Partial Compositeness: from Anarchy to Symmetry

    Kaustubh Agashe🇺🇸 · Lorenzo Ricci🇺🇸 · Raman Sundrum🇺🇸

    Within the Composite Higgs paradigm, Partial Compositeness has emerged as an elegant mechanism for generating large flavor hierarchies such as are observed in the quark and lepton masses and mixings. This mechanism exploits the strong renormalization group effects of the compositeness dynamics when these are {\it not} flavor-symmetric. Despite its remarkable properties, at this point it is stringently constrained by the body of flavor- and CP-violation tests, so that the compositeness scale must be at least $O(100)$ TeV, beyond the direct reach of proposed colliders. On the other hand, Composite Higgs theories with flavor-symmetric strong dynamics, but with realistic flavor-violating hierarchies introduced in an ad hoc manner, can extend the GIM mechanism of the standard model and thereby be far less constrained, at the edge of LHC reach and well within reach of future colliders. We show how the best features of both these types of dynamics can be combined if flavor-symmetries of the strong composite dynamics are emergent in the IR near the compositeness scale but absent in the far UV. In this case, flavor hierarchies can be generated by the renormalization group flow in the UV, followed by an IR stage in which the dynamics flows towards accidental flavor and CP symmetries. We point out how the collider and low-energy phenomenology is significantly impacted by the IR stage. Our analysis includes a discussion of the distinctive features of the small neutrino masses and their large mixings.

    hep-phhep-thPRD(2025)·3 citations
22. 22*

    Searching for top-philic heavy resonances in boosted four-top final states

    Luc Darmé🇫🇷 · Benjamin Fuks🇫🇷 · Hao-Lin Li🇨🇳 · Matteo Maltoni🇧🇪 · Julien Touchèque🇧🇪

    New heavy resonances with sizeable couplings to top quarks can be probed through searches for beyond-the-Standard-Model effects in four-top production at the LHC. In this work, we present the first next-to-leading-order QCD predictions for the full on-shell and off-shell production of four-top events via new electroweak singlet states, along with dedicated analysis strategies based on the reconstruction and tagging of all final-state top quarks. We develop a detector-level simulation incorporating recent advances in top-tagging and boosted object reconstruction. Moreover, we demonstrate that searches at LHC Run 3 and high-luminosity phase in the zero-lepton, one-lepton and same-sign di-lepton channels can improve the sensitivity to the new physics cross sections by up to two orders of magnitude. In particular, colour-octet resonances with masses up to 2-2.5 TeV and colour-singlet states with masses up to 1-1.5 TeV are within reach for coupling values in the 0.1-1 range.

    hep-phhep-exJHEP(2025)·5 citations
23. 23*

    Gravitational Photon Polarization Twist to Probe the Early Universe and the Galactic Center

    Rodolfo Capdevilla🇺🇸

    It is known that gravitational wave backgrounds (GWBs) change the polarization state of photons. This letter explores the possibility of using this effect to detect GWBs. The proposed experiment features a vertically polarized laser pulse traveling through a GWB before reaching a birefringent material which separates photons by polarization. Photons that emerge the birefringent material horizontally polarized are counted as signal photons. A space-based setup of a million km (comparable to the LISA mission) with a millisecond laser pulse is capable to detect the hypothetical pulsars responsible for the excess of gamma rays from the galactic center. Varying the duration of the pulse can reveal a variety of GWBs from the early Universe as well.

    hep-ph4 citations
24. 24*

    Impact of First-order Electroweak Phase Transition on QCD Axion

    Dipendu Bhandari🇮🇳 · Soumen Kumar Manna🇮🇳 · Arunansu Sil🇮🇳

    The QCD axion addresses the strong CP problem and dark matter via the misalignment mechanism, typically requiring a decay constant $f_a\sim \mathcal{O}(10^{12}$ GeV), unless the initial misalignment angle (${\theta }_i$) is fine-tuned. This work presents a novel approach where the possibility that the QCD axion satisfying the correct relic is extended over a broad range for $f_a\in [10^8,10^{14}$] GeV without fine-tuning the ${\theta }_i$, by introducing a new phase of axion oscillation dynamics across the electroweak phase transition (EWPT). This mechanism, we call it {\it{recurrent ~misalignment}}, is a result of a non-renormalizable Peccei-Quinn symmetry breaking interaction involving the axion and the sector responsible for making the EWPT of first order. The scenario not only enhances the QCD axion parameter space in terms of its detection possibility, but also provides a unique probe by detectable gravitational waves.

    hep-ph1 citation
25. 25*

    Spin Dependence of Meson Thresholds in the Diabatic Dynamical Diquark Model

    Richard F. Lebed🇺🇸

    The diabatic dynamical diquark model is designed to unify diquark and molecular approaches for exotic hadrons, by including the effects of di-meson thresholds on fundamental diquark-antidiquark states in order to form physical tetraquarks. We generalize this model by implementing the consequences of heavy-quark spin symmetry for each di-meson pair. We include the specific spin factors and mass differences associated with mesons related by this symmetry (such as $D,D^{\ast }$), both features being necessary for the systematic incorporation of effects beyond the static, heavy-source limit inherent to the (adiabatic) Born-Oppenheimer treatment. We obtain explicit interaction potentials for all $J=0,1,2$ states, along the way deriving unusual variants of Fierz reordering identities, and discuss the application of the potentials to specific physical states such as ${\chi }_{c1}(3872)$ and $T_{c\bar{c}1}(3900)$.

    hep-phPRD(2025)·1 citation
26. 26*

    Primordial black hole ringdown: The irreducible stochastic gravitational wave background

    Valerio De Luca🇺🇸 · Antonio J. Iovino🇦🇪 · Antonio Riotto🇨🇭

    Independently from the formation mechanism of primordial black holes in the early Universe, their generation is accompanied by a ringdown phase during which they relax to a stationary configuration and gravitational waves under the form of quasinormal modes are emitted. Such gravitational waves generate an irreducible and unavoidable stochastic background which is testable by current and future experiments. In particular, for primordial black holes with masses exceeding $10^{14}{M}_{\odot }$, the associated stochastic background lies within the frequency range accessible to current and upcoming cosmic microwave background experiments, thereby providing a direct observational way to probe the existence of such extremely massive objects.

    ↳ gr-qcastro-ph.COhep-phPRD(2026)·8 citations
27. 27*

    The Hybrid Elevated Radio Observatory for Neutrinos (HERON) Project

    Kumiko Kotera🇫🇷 · Ingo Allekotte🇦🇷 · Jaime Alvarez-Muñiz🇪🇸 · Sergio Cabana-Freire🇪🇸 · Valentin Decoene🇫🇷 · Luciano Ferreyro · Arsène Ferrière🇫🇷 · Matias Hampel🇦🇷 · Olivier Martineau-Huynh🇫🇷 · Valentin Niess🇫🇷 · Federico Sanchez🇦🇷 · Stephanie Wissel🇺🇸 · Andrew Zeolla (for the BEACON and GRAND Collaborations)

    Measuring ultra-high energy neutrinos, with energies above $10^{16}$ eV, is the next frontier of the emerging multi-messenger era. Their detection requires building a large-scale detector with 10 times the instantaneous sensitivity of current instruments, sub-degree angular resolution, and wide daily field of view. The Hybrid Elevated Radio Observatory for Neutrinos (HERON) is designed to be that discovery instrument. HERON combines the complementary features of two radio techniques being demonstrated by the BEACON and GRAND prototypes. Its preliminary design consists of 24 compact, elevated phased stations with 24 antennas each, embedded in a sparse array of 360 standalone antennas. This setup tunes the energy threshold to below 100 PeV, where the neutrino flux should be high. The sensitivity of the phased stations combines with the powerful reconstruction capacities of the standalone antennas to produce an optimal detector. HERON is planned to be installed at an elevation of 1,000 m across a 72 km-long mountain range overlooking a valley in Argentina's San Juan province. It would be connected to the worldwide network of multimessenger observatories and search for neutrino bursts from candidate sources of cosmic rays, like gamma-ray bursts and other powerful transients. With HERON's deep sensitivity, this strategy targets discoveries that cast new light into the inner workings of the most violent astrophysical sources at uncharted energies. We present the preliminary design, performances, and observation strategy of HERON.

    ↳ astro-ph.IMastro-ph.HEhep-phPoS(2025)·12 citations
28. 28*

    Spinning black holes in astrophysical environments

    Pedro G. S. Fernandes🇩🇪 · Vitor Cardoso🇩🇰

    We present stationary and axially-symmetric black hole solutions to the Einstein field equations sourced by an anisotropic fluid, describing rotating black holes embedded in astrophysical environments. We compute their physical properties, including quantities associated with the circular geodesics of massless and massive particles, analyze their shadows and image features, and energy conditions. Overall, we find that deviations from the Kerr metric grow with spin.

    ↳ gr-qcastro-ph.GAastro-ph.HEhep-phPRL(2025)·40 citations
29. 29*

    From Nuclear Matter with Quenched $g_A$ to Compact-Star Matter with a Signal for Emergent Hidden Scale Symmetry

    Mannque Rho🇫🇷

    An ``unorthodox" idea is developed that the long-standing mystery in nuclear physics of the effective axial-current coupling constant in nuclei, $g_A^{\mathrm{eff}}\approx 1$, could be interpreted in terms of an emerging hidden scale symmetry in dense compact-star matter. Arguments are presented using an effective field theory anchored on a renormalization-group approach to interacting baryons on the Fermi surface coupled with hidden symmetric heavy mesonic degrees of freedom that enables one to go beyond Weinberg's nuclear effective field theory involving nucleon and pion fields only, referred hereon to as $\chi$EFT${}_{\pi }$. Both hidden local and scale symmetries, the former involving the vector mesons $\rho$ and $\omega$ and the latter the hidden scalar meson, a dilaton $\hat{\sigma }$ (i.e., $f_0(500)$), play the crucial role. Going beyond the density regime applicable to normal nuclear matter $n_0$, the notion of ``hadron-quark continuity HQC)" is brought in via the skyrmion structure of the nucleon argued to be valid in QCD at large $N_c$ limit and the large $N^{\prime }$ limit of the Grassmannian model $G/H=[O(N^{\prime })/O(N^{\prime }-p)\times O(p)]$ where $N^{\prime }=4$ and $p=2$ for hidden local symmetry and the IR fixed point in QCD for $N_f\le 3$ involving ``genuine/QCD-conformal dilaton" for hidden scale symmetry. The connection between the quenched $g_A$ and the sound speed $v_s^2/c^2\approx 1/3$ inside dense compact stars could be interpreted as a signal for emergent ``pseudo-conformal" symmetry.

    ↳ nucl-thastro-ph.SRhep-phJ.Subatomic Part.Cosmol.(2025)·2 citations
30. 30*

    Science of the LISA mission: A Summary for the European Strategy for Particle Physics

    Chiara Caprini🇨🇭 · Anna Heffernan🇪🇸 · Richard Brito🇵🇹 · Gabriele Franciolini🇨🇭 · Germano Nardini🇳🇴 · Nicola Tamanini🇫🇷 · Danièle Steer🇫🇷

    The LISA mission is an international collaboration between ESA, its member states, and NASA, for the detection of gravitational waves from space. It was adopted in January 2024 and is scheduled for launch in the mid-2030's. It will be a constellation of three identical spacecraft forming a near-equilateral triangle in an heliocentric orbit, transferring laser beams over $2.5\cdot 10^6$ km long arms. Laser interferometry is used to track separations between test masses, thus measuring spacetime strain variations as a function of time. LISA Science Objectives tackle many open questions in astrophysics, fundamental physics and cosmology, including ESA's Cosmic Vision questions "What are the fundamental laws of the universe?" and "How did the universe originate and of what is it made?". In this contribution, based on the LISA Red Book, we present a summary of the LISA Science Objectives relevant for the European Strategy for Particle Physics.

    ↳ gr-qcastro-ph.COhep-ph8 citations
31. 31*

    Interacting Scalar Fields as Dark Energy and Dark Matter in Einstein scalar Gauss Bonnet Gravity

    Saddam Hussain🇨🇳 · Simran Arora🇯🇵 · Yamuna Rana🇺🇸 · Benjamin Rose🇺🇸 · Anzhong Wang🇺🇸

    A Gauss-Bonnet (GB) coupled scalar field $\varphi$, responsible for the late-time cosmic acceleration and interacting with a coherent scalar field $\psi$ through an interaction potential $W(\varphi ,\psi )$, is considered from the point of view of particle physics for two different models. The non-minimal coupling between the GB curvature term and the field $\varphi$ leads to a time-dependent speed of gravitational waves (GWs), which is fixed to unity in order to be consistent with current GW observations, rendering the GB coupling function model-independent. We investigate the dynamical stability of the system by formulating it as an autonomous system, and provide a detailed discussion on the choice of initial conditions required to obtain stable background evolution of the models. We constrain the model parameters using various sets of observational data, including both early- and late-time probes. We incorporate the improved Dark Energy Survey (DES) 5-year Type Ia supernova sample (DES-SN5YR), referred to as DES-Dovekie, which exhibits substantially lower tension with the Pantheon+ supernova sample. We find that both models are physically viable and closely follow the $\Lambda$CDM trend for the Pantheon+ and DES samples. However, upon including the Roman mock data, a significant departure is observed at higher redshifts, yielding statistically strong preference over the flat $\Lambda$CDM model.

    ↳ gr-qchep-phJCAP(2026)·10 citations
32. 32*

    Extraction of ground-state nuclear deformations from ultra-relativistic heavy-ion collisions: Nuclear structure physics context

    J. Dobaczewski🇬🇧 · A. Gade🇺🇸 · K. Godbey🇺🇸 · R.V.F. Janssens🇺🇸 · W. Nazarewicz🇺🇸

    The collective-flow-assisted nuclear shape-imaging method in ultra-relativistic heavy-ion collisions has recently been used to characterize nuclear collective states. In this paper, we assess the foundations of the shape-imaging technique employed in these studies. We argue that some current UHIC nuclear imaging techniques neglect fundamental aspects of spontaneous symmetry-breaking and symmetry-restoration in colliding ions and incorrectly infer one-body multipole moments from studies of nucleonic correlations. Therefore, the impact of this approach on nuclear structure research has been overstated. Conversely, efforts to incorporate existing knowledge on nuclear shapes into analysis pipelines can be beneficial for benchmarking tools and calibrating models used to extract information from ultra-relativistic heavy-ion experiments.

    ↳ nucl-thhep-exhep-phnucl-exPRResearch(2025)·20 citations
33. 33*

    The neural networks with tensor weights and emergent fermionic Wick rules in the large-width limit

    Guojun Huang🇨🇳 · Kai Zhou🇨🇳

    In this paper, we study complex-valued neural network (CVNNs) with tensor-valued hidden-to-output weights within the framework of neural-network quantum field theory (NN-QFT). For standard CVNNs with scalar weights, we derive the generating functional and identify the exact Gaussian process that arises in the infinite-width limit, together with its associated effective quantum state. When the last-layer weights are promoted to Clifford-algebra-valued tensors, the network output becomes complex matrix-valued, and a fermion-like sign structure in the large-width correlation functions of the network output is induced. We show that, in the infinite-width limit, correlators with equal numbers of $f^{†}$ and $f$ obey fermionic Wick rules and can be written as determinants built from a scalar Euclidean kernel $S(x,y)=⟨f^{†}(x)f(y)⟩$. This provides a sign-structured extension of NN-QFT at the level of Euclidean correlators and Feynman rules, even though a microscopic Grassmann path integral representation for the network parameters has not yet been constructed. Our analysis thus pushes the NN-QFT correspondence beyond purely bosonic Gaussian fields and suggests a possible route to encoding fermion-like symmetries in neural architectures for QFT correspondence.

    ↳ hep-thcond-mat.dis-nncs.LGhep-phPLB(2026)·6 citations
34. 34*

    Infrared foundations for quantum geometry II: Catalogue of all torsion-like theories including new ghost-tachyon-free cases

    Will Barker🇨🇿 · Carlo Marzo🇪🇪 · Alessandro Santoni🇦🇹

    The construction of consistent effective field theories in the infrared demands that models be defined by their underlying gauge symmetries, rather than by an arbitrary tuning of couplings or a cherry-picking of operators which may not be stable against radiative corrections. Adhering to this principle, we systematically derive all linear, parity-conserving models that propagate a pair-antisymmetric rank-three field on a Minkowski background. Such models are relevant not only to torsion, but to many areas in high-energy physics ranging from dual graviton formulations to string theory and higher-spin theories. Following this exhaustive classification, we extract several unitary models. In the context of torsion, the results are remarkable. None of the models we obtain propagate scalar or pseudoscalar torsion, in stark contrast to the literature focus. Instead, all models propagate one or more vector torsion modes.

    ↳ hep-thgr-qchep-ph10 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.