Mon·Aug 18, 2025Monday·August 18, 2025

1. 01*

   Cooling of quark stars from perturbative QCD

   Úrsula Fonseca🇧🇷 · Eduardo S. Fraga🇧🇷

   We investigate the thermal evolution of quark stars with and without a hadronic crust using an equation of state derived from perturbative QCD that incorporates the running of the strong coupling and the strange quark mass. Our analysis reveals that bare quark stars cool too rapidly to match the luminosity data, including those of the coldest observed isolated neutron stars, even when the uncertainty from the renormalization scale is taken into account. In contrast, configurations featuring a hadronic crust exhibit slower cooling and improved agreement with observational data. We also observe that the cooling band for bare quark stars narrows significantly after $t\sim 1$ year, whereas the configurations with a crust exhibit a larger uncertainty throughout their time evolution.

   hep-phastro-ph.HEPRD(2026)·1 citation
2. 02*

   On CP-violation and quark masses: reducing the number of free parameters

   A. Kleppe🇳🇴

   A physically viable ansatz for quark mass matrices must satisfy certain constraints, like the constraint imposed by CP-violation. In this article we study a concrete example, by looking at some generic matrices with a nearly democratic texture, and the implications of the constraints imposed by CP-violation, specifically the Jarlskog invariant. This constraint reduces the number of parameters from six to five, implying that the six mass eigenvalues of the up-quarks and the down-quarks are interdependent, which in our approach is explicitly demonstrated.

   hep-ph0 citations
3. 03*

   $D$-wave dimeson resonance interpretation to the $Z_c/Z_{cs}/Z_b$ states

   Kan Chen🇨🇳 · Jun-Zhang Wang🇨🇳

   In this work, we construct the $S$-wave, $P$-wave, and $D$-wave $D^{(\ast )}{\bar{D}}_{(s)}^{\ast }$/$B^{(\ast )}{\bar{B}}_{(s)}^{\ast }$ interactions by considering the lowest order contributions from the leading order (LO), next-to-leading order (NLO), and next-to-next-to-next-to-leading order (N${}^3$LO) contact terms, respectively. After solving the corresponding Lippmann-Schwinger equation (LSE), we obtain the typical pole trajectory for the $S$-wave/$P$-wave/$D$-wave state. We adjust the $P$-wave low energy constant (LEC) and {accordingly obtain a $P$-wave $D{\bar{D}}^{\ast }/D^{\ast }\bar{D}$} resonance state that may correspond to the observed $G(3900)$, { and its $P$-wave $D^{\ast }{\bar{D}}^{\ast }$ and $B^{(\ast )}{\bar{B}}^{\ast }$ partners are also predicted}. Then we proceed to adjust the $D$-wave LECs to looking for the $D$-wave $D^{(\ast )}{\bar{D}}_{(s)}^{(\ast )}$/$B^{(\ast )}{\bar{B}}_{(s)}^{(\ast )}$ resonances. The satisfactory consistencies between our results { and the experimental resonance parameters} of $Z_c(3900)$/$Z_c(4020)$, $Z_b(10610)$/$Z_b(10650)$, and $Z_{cs}(4000)$/$Z_{cs}(4220)$ indicate that the $D$-wave resonance interpretation may provide a unified picture to understand these { isovector charmoniumlike states. Especially, the broad width features of $Z_{cs}(4000)$ and $Z_{cs}(4220)$ can be naturally reproduced by interpreting them as $D$-wave $D{\bar{D}}_s^{\ast }$ and $D^{\ast }{\bar{D}}_s^{\ast }$ resonances, respectively.

   hep-phhep-ex2 citations
4. 04*

   Nonmaximal symmetry breaking patterns in the supersymmetric $\widehat{\mathfrak{su}}(8{)}_{k_U=1}$ theory

   Ning Chen🇨🇳 · Jianan Tian🇨🇳 · Bin Wang🇨🇳

   We study the nonmaximal symmetry breaking patterns of $\mathfrak{su}(8)\to {\mathfrak{g}}_{531}/{\mathfrak{g}}_{351}$ allowed in a supersymmetric theory with the affine Lie algebra of $\widehat{\mathfrak{su}}(8{)}_{k_U=1}$, which was recently proposed to explain the three-generational standard model quark/lepton mass hierarchies as well as the Cabbibo-Kobayashi-Maskawa mixing pattern. Three gauge couplings are found to achieve the unification below the Planck scales, according to the unification relations determined by the affine Lie algebra at level of $1$. We also prove that a separate nonmaximal symmetry breaking pattern of $\mathfrak{su}(8)\to {\mathfrak{g}}_{621}$ is unrealistic due to the additional massless vectorlike quarks in the spectrum.

   hep-phPRD(2026)·1 citation
5. 05*

   Tetraquark states in the quark model

   Wei-Lin Wu🇨🇳 · Yan-Ke Chen🇨🇳 · Yao Ma🇨🇳 · Lu Meng🇨🇳 · Shi-Lin Zhu🇨🇳

   We perform systematical investigations of heavy flavor tetraquark systems, including fully heavy $QQ\bar{Q}\bar{Q}$ ($Q=b,c$), doubly heavy $Q{Q}^{(\prime )}\bar{q}\bar{q}$ ($q=u,d$), and singly heavy $Qs\bar{q}\bar{q}$ tetraquark systems, within the framework of quark potential model. We employ the Gaussian expansion method and complex scaling method to solve the four-body Hamiltonian and identify bound and resonant states. We further calculate the root mean square radii to study the spatial configurations of tetraquarks. Our calculations reveal a rich spectrum of tetraquark states exhibiting diverse spatial configurations. In particular, we find good candidates for experimental states $X(6900)$, $X(7200)$, $T_{cc}(3875{)}^{+}$, and $T_{\bar{c}\bar{s}0}^{\ast }(2870)$. The fully charmed tetraquark resonances $X(6900)$ and $X(7200)$ are compact teraquark states, while doubly charmed tetraquark bound state $T_{cc}(3875{)}^{+}$ and charm-strange tetraquark resonance $T_{\bar{c}\bar{s}0}^{\ast }(2870)$ are meson molecules. Additionally, more tetraquark bound and resonant states are predicted and may be searched for in future experiments.

   hep-phhep-exJ.Subatomic Part.Cosmol.(2025)·4 citations
6. 06*

   Probes for String-Inspired Foam, Lorentz, and CPT Violations in Astrophysics

   Chengyi Li🇨🇳 · Bo-Qiang Ma🇨🇳

   Lorentz invariance is such a basic principle in fundamental physics that it must be constantly tested and that any proposal of its violation and breakdown of CPT symmetry, that might characterize some approaches to quantum gravity, should be treated with care. In this review we examine, among other scenarios, such instances in supercritical~(Liouville) string theory, particularly in some brane models for ``quantum foam''. Using the phenomenological formalism introduced here, we analyze the observational hints of Lorentz violation in time-of-flight lags of cosmic photons and neutrinos which fit excellently stringy space-time foam scenarios. We further demonstrate how stringent constraints from other astrophysical data, including the recent first detections of multi-TeV events in $\gamma$-ray burst 221009A and PeV cosmic photons by the Large High Altitude Air Shower Observatory~(LHAASO), are satisfied in this context. Such models thus provide a unified framework for all currently observed phenomenologies of space-time symmetry breaking at Planckian scales.

   hep-phastro-ph.HEgr-qcSymmetry(2025)·7 citations
7. 07*

   Search for doubly charged scalars in type-II seesaw mechanism through photon fusion at the LHC

   Hang Zhou🇨🇳 · Ning Liu🇨🇳

   Small neutrino masses can be generated through the well-known seesaw mechanisms, among which the type-II scenario predicts a triplet scalar with doubly charged components. Except for the Drell-Yan production at the Large Hadron Collider (LHC), the doubly charged scalars ${\Delta }^{\pm \pm }$ can also be produced through photon fusion along with ultraperipheral collision of protons, the outgoing protons from which can be detected by forward detectors at the LHC, providing a promising way to explore related new physics. We study the pair production through such processes at the 14 TeV LHC, focusing on the final states of ${\mu }^{+}{\mu }^{+}{\mu }^{-}{\mu }^{-}$ and $e^{+}{e}^{+}{e}^{-}{e}^{-}$ under normal (NH) and inverted hierarchy (IH) of the neutrino mass spectra, respectively. Promising sensitivity can be reached via our proposed search strategy. With luminosity of 36.1 fb${}^{-1}$(100 fb${}^{-1}$), $m_{\Delta }\sim 430(520)$ GeV can be excluded at 95% C.L. under the NH via ${\mu }^{+}{\mu }^{+}{\mu }^{-}{\mu }^{-}$ states searching, while the mass bound can be extended to 730(880) GeV under the IH via $e^{+}{e}^{+}{e}^{-}{e}^{-}$ states. The exclusion limits on $m_{\Delta }$ can be improved up to 1 TeV and even higher with integrated luminosity accumulated to 3 ab${}^{-1}$.

   hep-phCPC(2026)·2 citations
8. 08*

   Studying the in-medium $\varphi$ meson spectrum through kaons in proton-nucleus reactions

   Gabor Balassa🇰🇷 · Kazuya Aoki🇯🇵 · Philipp Gubler🇯🇵 · Su Houng Lee🇰🇷 · Hiroyuki Sako🇯🇵 · Gyorgy Wolf🇭🇺

   Exploring the mass modifications of $\varphi$ mesons in nuclei provides insights into the nature of strongly interacting matter. Specifically, $\varphi$ meson mass shifts can be related to the in-medium modification of the strange quark condensate. Therefore, the partial restoration of chiral symmetry can be studied by observing the mass shifts through the decay channels $\varphi \to e^{+}{e}^{-}$, and $\varphi \to K^{+}{K}^{-}$. In this paper, we examine the possibility of observing the $\varphi$ meson mass modifications of the $\varphi$ mesons in 30 GeV proton-nucleus (C, Cu, Pb) collisions, to be studied at the J-PARC E88 experiment, through the kaonic decay channel, with the off-shell Budapest Boltzmann-Uehling-Uhlenbeck (BuBUU) transport model. By applying different mean fields to the kaons, we examine their effects on the invariant mass spectra. Our simulations suggest that, although different mean fields for the kaons do affect the spectrum, there is a common observable effect primarily driven by the $\varphi$ mass shift. However, due to the threshold associated with the two kaons, the signal we observe is quite different from the one expected in dilepton spectra. Therefore, to meaningfully constrain the mass shift, it will be useful to include both kaon and dilepton channels in the analysis of the experimental data.

   hep-phnucl-thPTEP(2025)·3 citations
9. 09*

   Nambu-Goldstone boson phenomenology in Domain-Wall Standard Model

   Puja Das🇺🇸 · Nobuchika Okada🇺🇸 · Digesh Raut🇺🇸 · Desmond Villalba🇺🇸

   We investigate the Domain-Wall Standard Model (DWSM), a five-dimensional framework in which all Standard Model (SM) particles are localized on a domain wall embedded in a non-compact extra spatial dimension. A distinctive feature of this setup is the emergence of a Nambu-Goldstone (NG) boson, arising from the spontaneous breaking of translational invariance in the extra dimension due to the localization of SM chiral fermions. This NG boson couples via Yukawa interactions to SM fermions and their Kaluza-Klein (KK) excitations. We study the phenomenology of this NG boson and derive constraints from astrophysical processes (supernova cooling), Big Bang Nucleosynthesis (BBN), and collider searches for KK-mode fermions at the Large Hadron Collider (LHC). The strongest limits arise from LHC data: we reinterpret existing mass bounds on squarks and sleptons in simplified supersymmetric models (assuming a massless lightest neutralino), as well as limits on exotic hadrons containing long-lived squarks or long-lived charged sleptons in the regime of extremely small Yukawa couplings. From this analysis, we obtain a conservative lower bound of 1 TeV on the masses of KK-mode quarks and charged leptons. Finally, we discuss the prospects for producing KK-mode fermions at future high-energy lepton colliders and outline strategies to distinguish their signatures from those of sfermions.

   hep-phastro-ph.COhep-exhep-thEPJC(2025)·1 citation
10. 10*

    Two-Loop Extraction of the Pion-Nucleon Sigma Term

    Ze-Rui Liang🇨🇳 · Han-Xue Chen🇨🇳 · Feng-Kun Guo🇨🇳 · Zhi-Hui Guo🇨🇳 · De-Liang Yao🇨🇳

    The pion-nucleon sigma term, characterizing the mass component of Higgs origin related to $u$ and $d$ quarks inside the nucleon, is investigated within relativistic baryon chiral perturbation theory at leading two-loop order using the extended-on-mass-shell renormalization scheme. The two-loop representation of the sigma term is derived from the nucleon mass via the Feynman-Hellmann theorem and verified through a direct calculation of the forward isoscalar-scalar nucleon matrix element. We apply the derived chiral expression to extract the physical pion-nucleon sigma term by extrapolating $N_f=2+1$ lattice quantum chromodynamics (QCD) data at unphysical quark masses. We find that, at the two-loop level, the long-standing tension between lattice QCD and dispersive determinations can be naturally resolved, owing to the incorporation of intermediate $\pi \pi$ rescattering effects that begin to contribute at two-loop order. Our final result for the nucleon sigma term based on recent lattice QCD calculations is ${\sigma }_{\pi N}=55.9(2.5)$ MeV. It is compatible with the result of the Roy-Steiner equation analysis and thus provides a satisfactory resolution to the previous debate between lattice QCD and phenomenological determinations.

    hep-phhep-lat4 citations
11. 11*

    The Masses of Fermions in the context of the Supersymmetric $SU(3{)}_C\times SU(3{)}_L\times U(1{)}_N$ Model

    M. C. Rodriguez🇧🇷

    We will study in details the masses spectrum of fermions of the Minimal Supersymmetric $SU(3{)}_C\times SU(3{)}_L\times U(1{)}_N$ Model. We will consider the case in which all the usual neutral scalars fields of this model obtain vacuum expectation values, in both case when we have $R$-parity conservation, respect the invariance of the quantum number, $\mathcal{F}\equiv B+L$, where $B$ is the baryon number while $L$ is the total lepton number, and the oppposite ones, it means $R$-parity violation. We will present numerical predictions for all the fermions of this model, we will show that all masses and mixing angles are in agreement with current experimental data.

    hep-ph0 citations
12. 12*

    Exotic Heavy Hadrons

    H- Garcilazo🇲🇽 · A. Valcarce🇪🇸

    We review our recent findings on the structure and properties of exotic heavy hadrons, focusing on two main topics. First, we examine the role of correlations driven by the short-range Coulomb-like color interaction in hidden heavy-flavor pentaquarks. We show how this framework consistently accounts for the observed pattern of $P_c$ and $P_{cs}$ states in the hidden-charm sector and enables predictions for the hidden-bottom sector, where experimental data are still lacking. The second topic explores the possibility of forming stable multihadron molecules from deeply bound two-hadron exotic states. In this context, a bound state of three $B$ mesons, denoted as $T_{bbb}$, with quantum numbers $(I)J^P=(1/2)2^{-}$, is presented. We find that the binding energy generally decreases as the number of hadrons increases, primarily due to effects of the Pauli principle and the appearance of new decay thresholds. Nonetheless, resonances may still arise in specific cases, depending on the internal thresholds of the system. Finally, we discuss how the decay width of an exotic multihadron resonance can offer valuable insights into its internal structure and underlying~dynamics.

    hep-phnucl-thSymmetry(2025)·4 citations
13. 13*

    Tensor-polarized parton density in the $N\to \Delta$ transition from the large-$N_c$ light-cone wave function

    June-Young Kim🇺🇸

    The tensor-polarized parton density is defined by the forward matrix element of a partonic operator in the $N\to \Delta$ transition. In this work, we investigate it by employing the large-$N_c$ light-cone wave function derived from the mean-field approach. The mean-field picture is based on low-energy effective dynamics in the large-$N_c$ limit, where the baryon wave function is formulated in the rest frame. By exploiting the covariance of the mean-field solution, we derive the corresponding large-$N_c$ light-cone wave function$–$decomposed unambiguously into $3Q$, $5Q$, $7Q$, and higher Fock components$–$in the infinite momentum frame. Evaluating the overlap of these wave functions, we derive an overlap representation of the tensor-polarized parton density in the $N\to \Delta$ transition and find that the leading contribution arises from the $5Q$ Fock sector. This indicates that the tensor-polarized parton density directly probes the genuine $5Q$ component and is governed by chiral dynamics. Our numerical analysis shows that the $N\to \Delta$ tensor-polarized parton density is suppressed, consistent with standard large-$N_c$ expectations. Finally, we establish connections among the tensor-polarized parton density, the generalized parton distribution $H_X$, and the energy-momentum tensor form factor $F_4$.

    hep-phPRD(2026)·2 citations
14. 14*

    Two-loop BSM contributions to Higgs pair production in the aligned THDM

    Giuseppe Degrassi🇮🇹 · Ramona Gröber🇮🇹 · Pietro Slavich🇫🇷

    We study the impact of the two-loop corrections controlled by the BSM Higgs couplings on the cross section for the production of a pair of SM-like Higgs bosons via gluon fusion in the aligned THDM. To this aim, we reassess the two-loop calculation of ${\lambda }_{hhh}$, we compute for the first time the two-loop corrections to ${\lambda }_{hhH}$, and we include the relevant corrections to the Higgs-gluon couplings and to the s-channel propagators entering the $gg\to hh$ amplitude. We discuss the numerical impact of the two-loop BSM contributions, first on the individual couplings and then on the prediction for the pair-production cross section, in two benchmark scenarios for the aligned THDM.

    hep-phJHEP(2026)·8 citations
15. 15*

    The energy dependence of exclusive heavy vector meson photoproduction cross-sections and NLO BFKL evolution

    Martin Hentschinski🇲🇽 · Ricardo Rangel Ramírez🇲🇽

    We study the energy dependence of the cross-section for exclusive photoproduction of vector mesons $J/\psi$ and ${\rm Y}$, using a solution to the next-to-leading order (NLO) Balitsky-Fadin-Kuraev-Lipatov (BFKL) equation. Our goal is to use BFKL evolution as a benchmark to provide evidence for the presence of non-linear QCD dynamics and signs for the onset of gluon saturation at highest center of mass energies. Our approach determines initial conditions for the proton from the Bartels-Golec Biernat-Kowalski (BGK) dipole model, and evolves the resulting unintegrated gluon distribution using NLO BFKL evolution. For the nucleus, initial conditions are generated through both the impact parameter dependent saturation model (IP-Sat), using a Wood-Saxon distribution, and a $A^{1/3}$ scaling of the saturation scale of the original BGK model. We find that NLO BFKL evolution provides a very good description of the nuclear modification factor for $J/\psi$ production, if initial conditions are generated through a $A^{1/3}$ scaled BGK model, while the description fails, if initial conditions are created using the IP-Sat model.

    hep-phPRD(2026)·9 citations
16. 16*

    String-based model with Hagedorn temperature of $T_H\sim 300$MeV describes the spectrum of mesons and glueballs

    Michał Marczenko🇵🇱 · Győző Kovács🇵🇱 · Larry McLerran🇺🇸 · Krzysztof Redlich🇵🇱

    We consider the thermodynamics of a color-confined phase of quantum chromodynamics (QCD) and pure gauge theory within a string-inspired model, corresponding to a physical spatial dimension, d = 3. We show that the physical mass spectrum of massive mesons--in both the strange and non-strange sectors separately--is reasonably well described and extended by the exponential mass spectrum of open strings, $\rho (m)$, characterized by a unique Hagedorn temperature, $T_H=\sqrt{3\sigma /2\pi }$, expressed by the string tension, $\sigma$. This $T_H$ is the value appropriate for d = 3 spatial dimensions, and is of order $T_H\sim 300\mathrm{MeV}$ for typical values of the string tension. It is much larger than the values of $T_H$, which have been phenomenologically extracted so far to describe the meson spectrum. Glueball states in pure gauge theory, modeled by closed strings, exhibit a similarly large Hagedorn temperature, highlighting a universal feature of the exponential spectrum. We further analyze the thermodynamic properties of the equation of state at finite temperature and demonstrate that, in the confined phase, the string models agree with lattice QCD results. This lends further support to the recent interpretation of the QCD phase diagram that incorporates strings as relevant degrees of freedom.

    hep-phPRD(2025)·8 citations
17. 17*

    Thermalization of Bottomonium in the Quark-Gluon Plasma

    Nora Brambilla🇩🇪 · Tom Magorsch🇩🇪 · Antonio Vairo🇩🇪

    We study the approach to equilibrium of bottomonium in the quark-gluon plasma within the open quantum system framework. We perform large-scale simulations of the long-time behavior in three dimensions using the quantum trajectory method to observe the emergence of steady states and determine the timescale of thermalization in position-, angular-momentum-, and color-space. We find that the thermalization timescale increases with decreasing temperature and decreasing coupling to the medium, which is given by transport coefficients of the medium. Additionally, we observe that the steady states exhibit small corrections to the Gibbs state due to medium interactions and show that these corrections diminish for weaker medium coupling and higher temperature. At a temperature of $450$MeV, quarkonium relaxes to a state that is approximately thermal, with the most significant correction being a smaller overlap of the $1S$ state with respect to the Gibbs state. We compare these findings with the master equation obtained at leading order in the expansion of the binding energy over the temperature, which we find to have a trivial steady state.

    hep-phnucl-exnucl-thJHEP(2026)·6 citations
18. 18*

    TeV-scale scalar leptoquarks motivated by B anomalies improve Yukawa unification in SO(10) GUT

    Xiyuan Gao🇩🇪 · Ulrich Nierste🇩🇪

    It is common practice to explain deviations between data and Standard-Model (SM) predictions by postulating new particles at the TeV scale ad-hoc. This approach becomes much more convincing, if one successfully embeds the postulated particles into a UV completion which addresses other conceptual or phenomenological shortcomings of the SM. We present a study of an SO(10) grand unified theory which contains scalar leptoquark fields employed to explain the ``flavour anomalies'' in $b\to s$ and $b\to c$ decays. We find that the additional degrees of freedom improve the renormalization-group (RG) evolution of the SM parameters. In particular, the light leptoquarks modify the RG evolution of the Yukawa couplings such that successful bottom-tau unification becomes possible in a minimal SO(10) GUT with only a $126$-plet coupling to fermions. If we amend the Yukawa interaction of the minimal one-generation model with a second fermion multiplet and small flavor-violating terms, we find the flavour violation in the leptoquark couplings growing with the RG evolution while it stays small in the Yukawa interaction of the SM Higgs boson. By employing mass splittings among the members of the $126$-plet one can increase the effect and obtain large flavor violation in leptoquark couplings from tiny perturbations at the GUT scale, because the flavour-conserving limit is an unstable initial condition for the RG equations.

    hep-phJHEP(2026)·2 citations
19. 19*

    Extra-natural production of superheavy Kaluza-Klein particles

    Yusuke Yamada🇯🇵

    Gauge fields in extra compact dimensions can drive inflation in the four-dimensional (4D) non-compact spacetime, a scenario known as extra-natural inflation. A time-dependent gauge field configuration generates the electric field along the compact dimension, enabling the production of Kaluza-Klein (KK) particles charged under the field via the Schwinger effect. We construct the extra-natural inflation model within a five-dimensional (5D) quantum electrodynamics (QED) framework coupled to gravity including matter fields that generate the inflationary one-loop effective potential. In general, multiple charged fields can exist, and we show that KK particle production occurs under these conditions. Since KK momentum is conserved, the produced KK particles may become superheavy dark matter or dominate the universe, depending on the model parameters. Furthermore, we show that even when the gauge field acts not as the inflaton but as a spectator field, its post-inflationary oscillations, initiated when the Hubble friction becomes negligible, can also generate superheavy KK modes. This suggests that KK particle production is a generic outcome when gauge potentials along compact dimensions are light.

    ↳ hep-thastro-ph.COgr-qchep-phJHEP(2025)·2 citations
20. 20*

    Cut-off scale of quantum gravity as a sign to unify interactions

    Asya Aynbund🇷🇺 · V.V. Kiselev🇷🇺

    Dynamics of gravity interaction with matter at one-loop level of effective quantum field theory naturally sets the cut-off scale ${\Lambda }_E$ in a sub-Planckian region through incorporating the gauge coupling constant $\alpha ({\Lambda }_E)$ and the reduced Planckian mass ${\tilde{m}}_{\text{pl}}$ into relation ${\Lambda }_E\sim {\tilde{m}}_{\text{pl}}\alpha ({\Lambda }_E)/(4\pi )$ numerically yielding ${\Lambda }_E\sim 10^{16}$ GeV. Such two scales are empirically inherent for an inflationary cosmology.

    ↳ hep-thgr-qchep-ph0 citations
21. 21*

    Anomaly cancellation for a $U(1)$ factor

    Ben Gripaios🇬🇧 · Khoi Le Nguyen Nguyen🇬🇧

    We use methods of arithmetic geometry to find solutions to the abelian local anomaly cancellation equations for a four-dimensional gauge theory whose Lie algebra has a single ${\mathfrak{u}}_1$ summand, assuming that a non-trivial solution exists. The resulting polynomial equations in the integer ${\mathfrak{u}}_1$ charges define a projective cubic hypersurface over the field of rational numbers. Generically, such a hypersurface is (by a theorem of Kollár) unirational, making it possible to find a finitely-many-to-one parameterization of infinitely many solutions using secant and tangent constructions. As an example, for the Standard Model Lie algebra with its three generations of quarks and leptons (or even with just a single generation and two ${\mathfrak{su}}_3\oplus {\mathfrak{su}}_2$ singlet right-handed neutrinos), it follows that there are infinitely many anomaly-free possibilities for the ${\mathfrak{u}}_1$ hypercharges. We also discuss whether it is possible to find all solutions in this way.

    ↳ hep-thhep-phmath.AGJHEP(2026)·1 citation
22. 22*

    Quantum Simulation of Collective Neutrino Oscillations in Dense Neutrino Environment

    Shvetaank Tripathi🇮🇳 · Sandeep Joshi🇮🇳 · Garima Rajpoot🇮🇳 · Prashant Shukla🇮🇳

    Inside dense neutrino gases, such as neutron star mergers or core-collapse supernovae, collective neutrino effects cause the transformation of one neutrino flavour into another. Due to strong neutrino self-interactions in these environments, there is prevalence of flavour swapping. Considering these environments to be isotropic and homogeneous, we present a study of collective neutrino oscillations by simulating such a system on a noisy quantum simulator (Qiskit AerSimulator) and a quantum processor (ibm\_brisbane). We model the effective Hamiltonian governing neutrino interactions and by applying the Trotter-Suzuki approximation, decompose it into a tractable form suitable for quantum circuit implementation of the time-evolution propagator. Encoding the neutrino state for a system of two- and three-neutrinos onto qubits, we compute the time evolution of the inversion probability relative to the initial product state. Furthermore, we present quantum circuits to evaluate the concurrence as a measure of entanglement between the neutrinos.

    ↳ quant-phhep-phnucl-thQuant.Inf.Proc.(2026)·5 citations
23. 23*

    Implementing the finite-volume three-pion scattering formalism across all non-maximal isospins

    Athari Alotaibi🇬🇧 · Maxwell T. Hansen🇬🇧 · Raúl A. Briceño🇺🇸

    We present a numerical exploration of the relativistic-field-theory (RFT) formalism for three pions with all possible values of non-maximal isospin, $I_{\pi \pi \pi }=2$, $1$ and $0$. Using the generic-isospin extension of the RFT formalism and applying our open-source Python library to implement the framework, we predict a range of three-pion energies for illustrative values of the two-to-two scattering amplitudes for various finite-volume irreps also with non-zero total momentum $\mathbf{P}$ in the finite-volume frame. The results restrict attention to the case of a vanishing intrinsic three-body interaction so that the spectra can be understood as a baseline. In future lattice QCD calculations, deviations from these values will be translated into evidence for intrinsic three-body effects in the various scattering channels.

    ↳ hep-lathep-phJHEP(2026)·6 citations
24. 24*

    About possibility to observe spin dichroism effect (the effect of tensor polarization acquiring) for the effect of tensor polarization acquiring by a nonpolarized deuteron beam passing through the nonpolarized internal target of Nuclotron

    S.V. Anischenko · V.G. Baryshevsky🇧🇾 · A.A. Gurinovich · V.P. Ladygin

    Deuteron passage through a nonpolarized target is accompanied by birefringence effect which reveals as diverse phenomena, namely: rotation of spin and tensor polarization about the momentum direction, spin oscillations, vector polarization conversion to tensor that and vice versa, spin dichroism. Possibility to study deuteron spin dichroism effect i.e. the effect of tensor polarization acquiring by a nonpolarized deuteron beam moving in NuclotronM and passing through its internal target is discussed.

    ↳ nucl-thhep-phnucl-ex1 citation
25. 25*

    Log Gaussian Cox Process Background Modeling in High Energy Physics

    Yuval Frid🇮🇱 · Liron Barak🇮🇱 · Pavani Jairam🇺🇸 · Michael Kagan🇺🇸 · Rachel Jordan Hyneman🇺🇸

    Background modeling is one of the most critical components in high energy physics data analyses, and for smooth backgrounds it is often performed by fitting using an analytic functional form. In this paper a novel method based on Log Gaussian Cox Processes (LGCP) is introduced to model smooth backgrounds while making minimal assumptions on the underlying shape. In LGCP, samples are assumed to be drawn from a non-homogeneous Poisson process, with an intensity function drawn from a Gaussian process. Markov Chain Monte Carlo is used for optimizing the hyper parameters and drawing the final fit for the background estimate from the posterior. Synthetic experiments comparing background modeling from functional forms and the LGCP are used to compare the different methods.

    ↳ physics.data-anhep-exhep-phMach.Learn.Sci.Tech.(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.