Fri·Jul 25, 2025Friday·July 25, 2025

1. 01*

   On the addition of an $SU(2)$ quadruplet of scalars to the Standard Model

   Darius Jurčiukonis🇱🇹 · Luís Lavoura🇵🇹

   We consider the extension of the Standard electroweak Model through an $SU(2)$ quadruplet of scalars with hypercharge either $3/2$ or $1/2$ (with an additional reflection symmetry in the latter case). We establish, through $\text{exact analytical equations}$, the boundaries of the phase spaces of the gauge-invariant terms that appear in the (renormalizable) scalar potentials. We devise procedures for the determination of necessary and sufficient bounded-from-below conditions on those potentials; we emphasize that one mostly needs to scan the scalar potential over a few $\text{lines}$, instead of $\text{surfaces}$, in order to establish the boundedness-from-below; this fact allows one $\text{to reduce by three orders of magnitude the computational time}$ devoted to that establishment.

   hep-phSciPost Phys.Core(2026)·2 citations
2. 02*

   Endpoint Factorization for Semileptonic Decays of Boosted and Resonant Off-Shell Top Quarks with a Large-Radius Bottom Jet

   Andre H. Hoang🇦🇹 · Christoph Regner🇦🇹

   We derive a factorization formula for boosted double resonant top-antitop pair production in $e^{+}{e}^{-}$ annihilation with a semileptonic top quark decay in the phase space region where the $b$-jet invariant mass is small. The decaying top quark state is defined through invariant mass measurements on the final states in the top and antitop hemispheres, and the $b$-jet is defined from clustering all hadrons in the top hemisphere. The factorization does not rely on the narrow width limit and accounts for the QCD off-shell and interference effects. The approach employs Soft-Collinear-Effective Theory and boosted Heavy-Quark-Effective-Theory and relies on a combination of factorization theorems known from $e^{+}{e}^{-}$ dijet production and inclusive semileptonic heavy meson endpoint decays. The result provides a first principles treatment of the dominant hadronization effects, which can be determined from $e^{+}{e}^{-}$ event shapes. In the factorization a new distribution function arises, called the ultra-collinear-soft (ucs) function, which encodes the Fermi motion of the decaying top quark within the state defined from the invariant mass measurement. The ucs function is a differential generalization of the inclusive bHQET jet function and shares properties of the shape function in semileptonic heavy meson decays. In frames where the top quark is very slow, it describes the coherent soft radiation arising from top production, propagation and decay, and encodes all effects that are non-factorizable from the perspective of the NW limit. Its form and renormalization depend on two light-cone momenta related to the top-jet and $b$-jet directions and their relative angle. Due to the large top quark width, the ucs function can be computed perturbatively, and we determine the QCD corrections at $\mathcal{O}({\alpha }_s)$. The anomalous dimension is known to three loops.

   hep-phJHEP(2026)·2 citations
3. 03*

   Constraints on millicharged particles from nuclear gamma-decays

   Ting Gao🇺🇸 · Maxim Pospelov🇺🇸

   We consider nuclear gamma decays and $\gamma$-emitting reactions that can be an efficient source of hypothetical millicharged particles ($\chi$). In particular, we revisit the production of millicharged particles in nuclear reactor environment, pointing out that $\gamma$ cascades from ${}^{239}$U is an overlooked yet a powerful source of $\chi \bar{\chi }$ pairs. This leads to an increased flux compared to previous studies. We then apply new estimates of the flux to derive novel limits on the value of millicharge, $\epsilon =Q_{\chi }/e$, from the electron recoil searched for in a variety of experiments placed in proximity to the reactor cores. The derived limits on $\epsilon$ are the strongest in the interval of masses $\sim 0.7-2$ MeV. We also derive the MCP flux from the Sun and point out potential sensitivity of the low-threshold dark matter search experiments.

   hep-phhep-exnucl-thPRD(2026)·7 citations
4. 04*

   Axionlike particle-assisted supercooling chiral phase transition in QCD: Identifying Coleman-Weinberg type-chiral phase transition in QCD-like scenarios

   Zheng-liang Jiang🇨🇳 · Yuepeng Guan🇨🇳 · Mamiya Kawaguchi🇨🇳 · Shinya Matsuzaki🇨🇳 · Akio Tomiya🇯🇵 · He-Xu Zhang🇨🇳

   We propose a new scenario to realize the Coleman-Weinberg (CW) type chiral phase transition in the QCD thermal history. This scenario predicts a heavy axionlike particle (ALP) with mass $\sim$ 5 MeV, consistently with the current experimental and cosmological bounds. The chiral phase transition is evaluated by monitoring ordinary QCD setup in a view of a two-flavor Nambu-Jona-Lasinio model including a simplified meson fluctuation contribution. The present work thus can open a new window to search for the ALP associated with the QCD phase transition epoch of the thermal history. The new QCD cosmological scenario potentially predicts rich epochs around the QCD scale: a mini-inflation; a nonperturbative preheating and/or reheating, which can provide characteristic gravitational wave and primordial black hole productions. This proposal is based on a generic classification of the order of the chiral phase transition at the level of the mean field approximation in view of the scale violation classes: the soft-scale breaking term and the CW-type scale anomaly term, in or off the medium with or without chemical potentials. On this theoretical ground, we also revisit existing scenarios which undergo the supercooling chiral phase transition, such as nearly scale-invariant QCD and QCD with a large baryon chemical potential.

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

   Unveiling Skewness Dependence of Quark Wigner Distributions

   Sujit Jana🇮🇳 · Vikash Kumar Ojha🇮🇳

   We present a detailed investigation of the skewness dependence of quark Wigner distributions within the light-front dressed quark model. While previous studies have largely focused on the forward limit, we explore the impact of nonzero longitudinal momentum transfer (\(\xi \neq 0\)) on the full set of leading-twist quark Wigner distributions across various polarization configurations. We observe characteristic distortions in the spatial and momentum correlations with increasing skewness, including the emergence of dipole and quadrupole patterns, asymmetries, and localization effects. These features reflect spin-orbit correlations and quantum interference between light-front wave function components with differing orbital angular momentum.

   hep-ph0 citations
6. 06*

   Light hybrid baryons in QCD sum rules

   Wei Chen · Qi-Nan Wang🇨🇳 · Ding-Kun Lian🇨🇳 · Hui-Min Yang🇨🇳 · Hua-Xing Chen · J. H · T. G. Steele🇨🇦

   We have calculated the mass spectra of nucleon and delta hybrid baryons with both positive-parity and negative-parity by using the method of QCD sum rules. We predicte that the lowest-lying hybrid baryons are the negative-parity $N_{1/2^{-}}$ and ${\Delta }_{1/2^{-}}$ states, while the positive-parity ones are much heavier. We suggest to search for these light hybrid baryons via the ${\chi }_{cJ}/{\rm Y}$ decay processes in the future.

   hep-phPoS(2026)·0 citations
7. 07*

   Renormalon effect of quasi-PDF in gradient flow formalism

   Jia-lu Zhang🇨🇳

   We investigate the behavior of renormalon ambiguities in the context of quasi-parton distribution functions (quasi-PDFs) defined using gradient-flowed fields. We examine how this impacts the UV and IR renomalons. Using the large ${\beta }_0$ approximation, we find that UV renormalons for zero external momentum quasi-PDF are eliminated by the flow, while IR renormalons persist but are modified at finite flow time. Moreover, we observe that large numerical coefficients associated with flowed operators can enhance power-suppressed contributions, making higher-dimensional operators non-negligible even at small flow times.

   hep-phPRD(2025)·5 citations
8. 08*

   New superconvergence relations for spin and tensor structure functions of $\gamma \gamma$ fusion

   Vladimir Pascalutsa (JGU Mainz)🇩🇪

   The Burkhardt--Cottingham sum rule is an exact superconvergence relation for a spin-structure function, derived from general principles of light absorption and scattering, and valid at any momentum transfer $Q^2$. I illustrate how a class of such relations emerges from the Siegert point, an unphysical kinematical point where both the probe and the target are at rest. From light-by-light scattering, new sum rules for ${\gamma }^{\ast }{\gamma }^{\ast }$ fusion are emerging, valid for arbitrary photon virtualities. Regarding the convergence of these relations, there is a simple argument for the suppression of longitudinal photon polarizations at high energy. Among its consequences is the prediction of ${\sigma }_L/{\sigma }_T\to 0$ at high energy, for the ratio of unpolarized nucleon photoabsorption cross sections.

   hep-phhep-thnucl-thPLB(2025)·0 citations
9. 09*

   Revisiting the Muon Anomaly from $e^{+}{e}^{-}\to$ Hadrons

   Stephan Narison (LUPM and iHEPMAD)🇫🇷

   In this talk, I revisit and present a more comprehensive estimate of the lowest order Hadronic Vacuum Polarization (HVP) contribution $a_{\mu }{|}_{hvp}^{lo}$ to the muon anomalous magnetic moment (muon anomaly) from $e^{+}{e}^{-}\to$ Hadrons obtained recently in Ref.[1]. New CMD-3 data on $e^{+}{e}^{-}\to 2\pi$ [2] and precise BABAR [3] and recent BELLE2 [4] $e^{+}{e}^{-}\to 3\pi$ data are usedto update the estimate of the $I=0$ isoscalar channel below the $\varphi$-meson mass. Adding the data compiled by PDG22 [5] above 1 GeV and the QCD improved continuum used in Ref. [1], one deduces: $a_{\mu }{|}_{lo}^{hvp}=(7043\pm 37)\times 10^{-11}$.A comparison with previous data driven ($e^{+}{e}^{-}$ and $\tau$-decays) estimates is done.Including the Higher Order $a_{\mu }{|}_{hvp}^{ho}$ corrections, the phenomenological estimate of the Hadronic Light by Light scattering up to NLO and the QED and Electroweak (EW) contributions, one obtains: $\Delta a_{\mu }^{pheno}\equiv a_{\mu }^{exp}-a_{\mu }^{pheno}=(81\pm 41)\times 10^{-11}$ where the recent experimental value $a_{\mu }^{exp}$ [6] has been used. This result consolidates the previous one in Ref.[1], after adding the ${\pi }^0\gamma ,\eta \gamma$ contributions, and can be compared with the one from the most precise Lattice result $\Delta a_{\mu }^{lattice}=(90\pm 56)\times 10^{-11}$. Then, we deduce the (tentative) SM prediction average : $\Delta a_{\mu }^{SM}=(87\pm 33)\times 10^{-11}$. We complete the paper by revising our predictions on the LO HVP contributions in adding the ${\pi }^0\gamma ,\eta \gamma$ contributions to the ones in Ref.[1]. Then, we obtain: $a_{\tau }{|}_{lo}^{hvp}=(3516\pm 25)\times 10^{-11}$ and $\Delta {\alpha }_{had}^{(5)}(M_Z^2)=(2770.7\pm 4.5)\times 10^{-5}$ for 5 flavours.

   hep-phhep-exhep-latJ.Subatomic Part.Cosmol.(2025)·0 citations
10. 10*

    ${\Lambda }_c(2910)$ and ${\Lambda }_c(2940)$ productions in association with $D_{s0}^{\ast }(2317{)}^{-}$ and $D_{s1}(2460{)}^{-}$ via $K^{-}p$ scattering

    Quan-Yun Guo · Zi-Li Yue · Dian-Yong Chen

    In the present work, we investigate the productions of ${\Lambda }_c(2910)$ and ${\Lambda }_c(2940)$ in association with $D_{s0}^{\ast }(2317{)}^{-}$ and $D_{s1}(2460{)}^{-}$ via $K^{-}p$ scattering, where we assign ${\Lambda }_c(2910)$ and ${\Lambda }_c(2940)$ as $D^{\ast }N$ molecular states with $J^P$ quantum numbers to be $1/2^{-}$ and $3/2^{-}$, respectively, while treating $D_{s0}^{\ast }(2317)$ and $D_{s1}(2460)$ as $S-$wave $DK$ and $D^{\ast }K$ molecular states, respectively. Utilizing an effective Lagrangian approach, we evaluated the cross sections for $K^{-}p\to D_{s0}^{\ast }(2317{)}^{-}{\Lambda }_c(2910)/{\Lambda }_c(2940)$ and $K^{-}p\to D_{s1}(2460{)}^{-}{\Lambda }_c(2910)/{\Lambda }_c(2940)$. Our estimations at $p_K=20$ GeV yield the following cross sections: \begin{eqnarray} \sigma(K^-p \to D^{\ast}_{s0}(2317)^- \Lambda_{c}(2910)) &=&\left(1.681^{+4.643}_{-1.296}\right)\ \mathrm{nb}, \nonumber \sigma(K^-p \to D^{\ast}_{s0}(2317)^- \Lambda_{c}(2940)) &=& \left(49.07^{+136.30}_{-37.86}\right)\ \mathrm{nb}, \nonumber \sigma(K^-p \to D_{s1}(2460)^{-} \Lambda_{c}(2910)) &=&\left(84.46^{+238.6}_{-65.35}\right)\ \mathrm{nb}, \nonumber \sigma(K^-p \to D_{s1}(2460)^{-} \Lambda_{c}(2940)) &=&\left(13.71^{+38.85}_{-10.61}\right)\ \mathrm{nb}, \nonumber \end{eqnarray} where the central values are estimated with ${\Lambda }_r=1.1$ GeV, while the uncertainties come from the variation of ${\Lambda }_r$ from 1.0 to 1.2 GeV. However, the ratios of the cross sections for the considered processes are evaluate to be very weakly dependent on the model parameters. In addition, the differential cross sections for the relevant processes are evaluated, and our estimations indicate that these differential cross sections reach the maximum at the forward angle limit.

    hep-phEPJC(2025)·0 citations
11. 11*

    Fresh look at the LHC limits on vector leptoquarks

    Arijit Das🇮🇳 · Tanumoy Mandal🇮🇳 · Subhadip Mitra🇮🇳 · Rachit Sharma🇮🇳

    Vector leptoquarks (vLQs) are popular candidates for searching for physics beyond the Standard Model. In this paper, we present updated exclusion limits on various vLQ species, accounting for all the relevant production mechanisms at the LHC. In particular, we highlight the critical role of indirect production and its interference with the Standard Model Drell-Yan process. This interference can be constructive or destructive, depending on the specific quantum numbers of the vLQ, and significantly impacts the sensitivity of current searches. Furthermore, we demonstrate that including QCD-QED mixed pair production channels leads to a noticeable shift in model-independent mass limits. Additionally, we examine the validity of the full theory with vLQs and corresponding effective operators in the high mass regime. Overall, our analysis yields a substantial improvement in the exclusion limits on vLQs compared to the existing results in the literature.

    hep-phhep-exPRD(2026)·2 citations
12. 12*

    Quark and lepton mixing in the asymptotically safe Standard Model

    Astrid Eichhorn🇩🇪 · Zois Gyftopoulos🇩🇪 · Aaron Held🇫🇷

    The quark mixing (CKM) matrix is near-diagonal, whereas the lepton mixing (PMNS) matrix is not. We learn that both observations can generically be explained within an ultraviolet completion of the Standard Model with gravity. We find that certain relations between CKM matrix elements should hold approximately because of asymptotically safe regimes, including $|V_{ud}{|}^2+|V_{us}{|}^2\approx 1$ and $|V_{cd}{|}^2+|V_{cs}{|}^2\approx 1$. Theoretically, the accuracies of these relations determine the length of the asymptotically safe regimes. Experimental data confirms these relations with an accuracy of $10^{-5}$ and $10^{-3}$, respectively. This difference in accuracies is also expected, because the ultraviolet completion consists in a fixed-point cascade during which one relation is established already much deeper in the ultraviolet. This results in $|V_{ub}{|}^2<|V_{cb}{|}^2$ and translates into measurable properties of $B$-mesons. Similar results would hold for the PMNS matrix, if neutrino Yukawa couplings were large. The ultraviolet complete theory therefore must -- and in fact can -- avoid such an outcome. It contains a mechanism that dynamically limits the size of neutrino Yukawa couplings. Below an upper bound on the sum of Dirac neutrino masses, this allows the PMNS matrix to avoid a near-diagonal structure like the CKM matrix. Thus, large neutrino mixing is intimately tied to small Dirac neutrino masses, $\sum m_{\nu }\lesssim \mathcal{O}(1)\mathrm{eV}$ and a mass gap in the Standard Model fermion masses.

    hep-phgr-qchep-th12 citations
13. 13*

    Tensor-polarized parton density in the $N\to \Delta$ transition

    June-Young Kim🇺🇸 · Christian Weiss🇺🇸

    The generalized parton distributions for transitions between baryon states with different masses have a forward limit in which they behave as parton densities (light-front momentum transfer ${\Delta }^{+},{\Delta }_T=0$, energy transfer ${\Delta }^{-}\ne 0$). These "transition parton densities'' can realize spin/isospin quantum numbers not accessible in the ground-state nucleon. The $N\to \Delta$ transition gives rise to a new parton density proportional to the $1/2\to 3/2$ spin transition tensor. Its properties are derived, and its magnitude is estimated in the chiral quark-soliton model based on the large-$N_c$ limit of QCD.

    hep-phPLB(2025)·5 citations
14. 14*

    Study of $\Lambda p$ and $\bar{\Lambda }p$ scatterings via quasipotential Bethe-Salpeter equation

    Yaning Chen🇨🇳 · Jun He🇨🇳

    Motivated by recent BESIII measurements of the $\Lambda p\to \Lambda p$ and $\bar{\Lambda }p\to \bar{\Lambda }p$ scattering processes, we investigate these reactions within the framework of the quasipotential Bethe-Salpeter equation using an effective Lagrangian approach. The interaction potentials are constructed via a one-boson-exchange model incorporating pseudoscalar, scalar, and vector meson exchanges, along with coupled-channel effects from the $\Sigma N$ and $\bar{\Sigma }N$ channels. For the $\Lambda p\to \Lambda p$ reaction, the total cross sections from threshold up to $\sqrt{s}=2.5\text{GeV}$ are well reproduced. A mild enhancement near the $\Sigma N$ threshold is attributed to coupled-channel dynamics. Using parameters constrained by the total cross section data, our model also predicts differential cross sections at $\sqrt{s}=2.24\text{GeV}$, which exhibit weak angular dependence, consistent with experimental observations. Partial-wave analysis indicates that the $1^{+}$ partial wave dominates over the entire energy range, while the $0^{+}$ wave plays a significant role near threshold. For the $\bar{\Lambda }p\to \bar{\Lambda }p$ reaction, our predicted total cross sections show good agreement with the BESIII data. The $1^{-}$ partial wave is found to dominate in most of the energy region. Notably, the calculated differential cross sections exhibit a strong forward peaking behavior, consistent with experimental findings and understood as resulting from constructive interference among various partial waves. This forward-peaked angular distribution persists across a range of energies, highlighting the distinct dynamics of the $\bar{\Lambda }p$ interaction.

    hep-phnucl-thPLB(2025)·3 citations
15. 15*

    New contribution to the anomalous ${\pi }^0\to \gamma \gamma$ decay in SU(2) chiral perturbation theory

    Zhen-Yan Lu🇨🇳 · Shu-Peng Wang🇨🇳 · Qi Lu🇨🇳

    The introduction of axions gives rise to additional one-loop diagrams for the two-photon decays of neutral pions via axion-pion mixing. We compute this correction that has been overlooked in existing calculations, within the framework of SU(2) chiral perturbation theory. Our analysis shows that the correction is proportional to the axion-photon coupling and the square of the axion mass. In the classical axion parameter space, this correction is strongly suppressed by the axion decay constant. However, for QCD axions in the MeV or higher mass range, the correction may become significant. Furthermore, when combined with experimental measurements of the decay width of the ${\pi }^0\to \gamma \gamma$ process, our results rule out the standard QCD axion as a viable explanation for the observed discrepancy between chiral perturbation theory predictions and experimental data.

    hep-phhep-exMDPI Proc.(2025)·0 citations
16. 16*

    Three-flavor neutrino oscillations using the Phase Space Approach

    Mariane Mangin-Brinet🇫🇷 · Angel Bauge🇫🇷 · Denis Lacroix🇫🇷

    The Phase-Space Approximation (PSA) approach, originally applied in [Phys. Rev. D 106, 123006 (2022)] to describe neutrino oscillations from a stellar object in the two-flavor limit, is extended here to describe the more realistic case where neutrinos can oscillate between three different flavors. The approach is successfully validated against the exact solutions up to eight neutrinos. In all cases where the exact solution is feasible, the PSA provides excellent reproduction of the neutrino oscillation dynamics. By replacing the full problem with a set of simple mean-field equations, the PSA offers a versatile, predictive, and easily parallelizable approach for tackling three-flavor problems. This enables the simulation of large-scale neutrino oscillations, as illustrated here with simulations involving up to 300 neutrinos. Additionally, the method provides insight into the system's equilibration properties.

    hep-phastro-ph.HEnucl-thquant-phPRD(2026)·7 citations
17. 17*

    Resonant enhancement of axion dark matter decay

    Yu-Ang Liu🇨🇳 · Bilal Ahmad🇨🇳 · Nick Houston🇨🇳

    The axion is particularly well motivated candidate for the dark matter comprising most of the mass of our visible Universe, leading to worldwide experimental and observational efforts towards its discovery. As is well known, resonant cavities are a primary tool in this search, where they are used to enhance the conversion rate of axions into photons in a background electromagnetic field. What is perhaps less well appreciated is that resonant cavities can also enhance the rate at which axions decay to two photons, a manifestation of the Purcell effect. We examine this possibility and show that it offers a previously unexplored method to search the axion parameter space in a way that is competitive and complementary to other approaches, with the capability to probe a well-motivated region for QCD axion dark matter. Furthermore, we establish that this method can be implemented via pre-existing axion heterodyne detection schemes, enabling such experiments to perform these searches with minimal modification.

    hep-phhep-exPRResearch(2026)·2 citations
18. 18*

    Radiative corrections to the $\mathrm{S},\mathrm{T},\mathrm{U}$ parameters and their impact on the $W$ boson mass in the 331 model

    Muhammad Rehman🇵🇰 · Muhammad Adeel Iqbal🇵🇰 · Mario E. Gomez🇪🇸 · Orlando Panella🇮🇹

    We investigate radiative corrections to electroweak precision observables, specifically the Peskin--Takeuchi parameters $\mathrm{S}$, $\mathrm{T}$, and $\mathrm{U}$, in the $SU(3{)}_C\times SU(3{)}_L\times U(1{)}_X$ (331) model with $\beta =-\sqrt{3}$. Using the SARAH and SPheno packages, we compute the mass spectrum and low-energy observables. We show that these parameters place strong constraints on the model, requiring most of the scalar masses to lie in the TeV range or below, and imposing indirect bounds on the newly predicted gauge bosons. Furthermore, we demonstrate that the model can accommodate the $W$ boson mass anomaly reported by the CDF collaboration, should future measurements confirm its persistence.

    hep-phPRD(2025)·4 citations
19. 19*

    Is the $3S$-$2D$ mixing strong for the charmonia $\psi (4040)$ and $\psi (4160)$?

    Zi-Long Man🇨🇳 · Si-Qiang Luo🇨🇳 · Xiang Liu🇨🇳

    In this work, we revisit the $3S$-$2D$ mixing scheme for the charmonia $\psi (4040)$ and $\psi (4160)$. We introduce a coupled-channel mechanism-distinct from the tensor-force contribution in potential models, which alone is insufficient to induce significant mixing-to describe the mixing between these states. Our analysis yields mixing angles of ${\theta }_1=7^{\circ }$ and ${\theta }_2=10^{\circ }$, inconsistent with the larger angle inferred from experimental data, such as the dilectronic widths of the $\psi (4040)$ and $\psi (4160)$. We discuss possible origins of this discrepancy and emphasize the need for future experiments to resolve it. Precise measurements of the resonance parameters and dilectronic decay widths, via both inclusive and exclusive processes, will be crucial in clarifying this issue.

    hep-phhep-exPRD(2025)·7 citations
20. 20*

    Rapidity-Dependent Spin Decomposition of the Nucleon

    Florian Hechenberger🇺🇸 · Kiminad A. Mamo🇺🇸 · Ismail Zahed🇺🇸

    We show that the two-dimensional Fourier transform of the generalized parton distributions (GPDs) has two distinct interpretations: at zero skewness ($\eta =0$) it yields the familiar impact-parameter density, while at finite skewness ($\eta \ne 0$) it encodes a genuine parton-nucleon correlation whose norm decreases predictably with the rapidity gap $\Delta y=2\mathrm{artanh}\eta$. This rapidity dependence produces universal rapidity-modified Ji identities linking helicity, orbital, and total angular momenta analytically. Using linear open- and closed string Regge trajectories constrained by empirical PDFs, spectroscopy and form factor data, we obtain the leading twist GPDs $H,E,\tilde{H}$ across the full $(x,\eta ,t)$ range. Numerical Mellin Barnes inversion agrees with existing lattice data and yields rapidity resolved predictions for Jefferson Lab 12 GeV, the Electron Ion Collider, and forthcoming lattice studies.

    hep-phnucl-thPRD(2026)·7 citations
21. 21*

    Strong CP Phase and Parity in the Hamiltonian Formalism

    Ravi Kuchimanchi🇺🇸

    We show using the Hamiltonian formalism that if parity is a good symmetry of QCD, then the strong CP phase $\bar{\theta }$ must be $0$ or $\pi$. We find that for $P$ to be a physical symmetry, it must leave the Hilbert space ${\mathcal{H}}_{\theta }$ associated with the $\theta$-vacuum invariant ($P:{\mathcal{H}}_{\theta }\to {\mathcal{H}}_{\theta }$), which is possible only for $\theta =0$ or $\pi$. We also show that forming linear combinations of states from different $\theta$-sectors produces only classical statistical mixtures, consistent with superselection rules, confirming that ${\mathcal{H}}_{\theta }$ is the most general Hilbert space for the quantum theory. Furthermore, we demonstrate that requiring $[P,\Omega ]=0$, where $\Omega$ is the generator of large gauge transformations, independently enforces $\bar{\theta }=0$ (mod $\pi$), and that for complex quark mass matrix $M$, if a generalized parity operator $\mathcal{P}$ is a symmetry, then the value of $\theta$ gets determined so that it exactly cancels $ArgDetM$, again giving $\bar{\theta }=0$ (mod $\pi$). These results establish the equivalence of the Hamiltonian and Lagrangian approaches to the strong CP problem.

    hep-phhep-exhep-thPRD(2025)·0 citations
22. 22*

    Diagonalising the LEFT

    Sophie Renner🇬🇧 · Benjamin Smith🇬🇧 · Dave Sutherland🇬🇧

    We organise the four-fermion vector current interactions below the weak scale -- i.e., in the low energy effective field theory (LEFT) -- into irreps of definite parity and $SU(N)$ flavour symmetry. Their coefficients are thus arranged into small subsets with distinct phenomenology, which are significantly smaller than traditional groupings of operators by individual fermion number. As these small subsets only mix among themselves, we show that the renormalisation group evolution is soluble semi-analytically, and examine the resulting eigenvalues and eigenvectors of the one- and two-loop running. This offers phenomenological insights, for example into the radiative stability of lepton flavour non-universality. We use these to study model-independent implications for $b\to s\tau \tau$ decays, as well as setting indirect bounds on flavour changing four-quark interactions.

    hep-phJHEP(2025)·3 citations
23. 23*

    Scalar-glueball-mediated scale-anomaly dominance of the confining pressure of the pion in holographic QCD

    Daisuke Fujii🇯🇵 · Akihiro Iwanaka🇯🇵 · Mitsuru Tanaka🇯🇵

    In this work, we analyze the energy density and the stress distribution inside the pion derived from gravitational form factors in top-down holographic QCD. In particular, we show that the dominance of the scale anomaly in the confining pressure, previously observed in the instant form for the nucleon, also holds for the pion in the light-front form. Furthermore, we find that in large-$N_c$ QCD described by this approach, the scalar glueball plays a mediating role in transmitting the confining pressure. These findings support the universal role of the scale anomaly in the stability of hadrons.

    hep-phhep-exhep-thnucl-thPRD(2025)·10 citations
24. 24*

    Can WIMPs Survive the Legacy of a Magnetised Early Universe?

    María Olalla Olea-Romacho🇬🇧 · Malcolm Fairbairn🇬🇧 · Pranjal Ralegankar🇮🇹

    Primordial magnetic fields (PMFs) can seed additional small-scale matter fluctuations, leading to the formation of dense, early-collapsing dark matter structures known as minihalos. These minihalos may dramatically amplify the dark matter annihilation signal if dark matter is composed of self-annihilating thermal relic particles such as WIMPs. In this work, we analyse the annihilation signal from minihalos with prompt central cusps, $\rho \propto r^{-3/2}$, formed due to the enhanced power spectrum induced by PMFs, using gamma-ray observations of the Virgo cluster. We consider benchmarks motivated by cosmological phase transitions, focusing in particular on the electroweak and QCD transitions, where we assume maximal magnetic energy density and horizon-sized coherence length at generation (upper-limit scenarios). In addition, we include a data-driven case corresponding to the best-fit present-day PMF amplitude inferred from DESI BAO and Planck CMB measurements. Under these assumptions, we find that PMFs can place stringent bounds on WIMP annihilation. Magnetic fields with amplitudes matching the DESI-Planck best-fit values are in strong tension with self-annihilating WIMPs across a wide mass range extending beyond the TeV scale, while the electroweak- and QCD-phase-transition toy-model benchmarks would exclude thermal relics with masses below $300\mathrm{GeV}$ and $3\mathrm{TeV}$, respectively. Although weaker PMFs would yield weaker annihilation signals, our results demonstrate that whenever PMFs enhance small-scale structure, indirect-detection limits on dark matter must be revisited.

    hep-phSciPost Phys.(2026)·8 citations
25. 25*

    Anomalous scaling of linear power corrections

    Casey Farren-Colloty🇬🇧 · Jack Helliwell🇦🇺 · Rtvik Patel🇬🇧 · Gavin P. Salam🇬🇧 · Silvia Zanoli🇬🇧

    Non-perturbative corrections to hadronic observables represent a critical obstacle to increasing accuracy at colliders. Long taken to scale simply as $1/Q$, where $Q$ is the centre-of-mass scattering energy, recent work has opened the path towards calculating the anomalous dimension that modifies that scaling. A priori, the problem is complex, requiring a resummation involving arbitrary numbers of large-angle and low-energy gluons. Within a specific framework for kinematic recoil, we show that it reduces to a simple exponential for key observables like the thrust, $C$-parameter and energy correlators. This simplicity holds for a specific hadron mass scheme, and also even beyond the two-jet limit.

    hep-phPRD(2026)·9 citations
26. 26*

    Not-quite-primordial black holes seeded by cosmic string loops

    Bryce Cyr🇺🇸

    Cosmic strings appear in many well-motivated extensions to the standard model of particle physics. If they exist, an abundant population of compact objects known as cosmic string loops permeate the Universe at all times, providing a secondary source of density perturbations that are large amplitude and non-gaussian in nature. In general, these loops are not stationary in the rest frame of the dark matter, thus their relative velocities will typically seed both spherical and filamentary overdensities in the matter era. Building upon previous work, we provide an improved framework to compute the complete halo mass function for these string seeded overdensities, valid for any loop velocity distribution. Using this mass function, we also compute the subset of halos capable of undergoing a direct collapse, forming a population of black holes with initial mass $10^{4-5}{M}_{\odot }$ at high redshifts. Interestingly, for reasonable values of the string parameters, one can reproduce the abundance of ``Little Red Dots" as inferred by JWST.

    ↳ astro-ph.COgr-qchep-ph5 citations
27. 27*

    Collapsar Disk Outflows III: Detectable Neutrino and Gravitational Wave Signatures

    Rodrigo Fernández🇨🇦 · Silas Janke🇨🇦 · Coleman Dean🇨🇦 · Irene Tamborra🇩🇰

    We investigate the neutrino and gravitational wave (GW) signals from accretion disks formed during the failed collapse of a rotating massive star (a collapsar). Following black hole formation, a neutrino-cooled, shocked accretion disk forms, which displays non-spherical oscillations for a period of seconds before becoming advective and exploding the star. We compute the neutrino and GW signals (matter quadrupole, frequencies $\lesssim 100$ Hz) from collapsar disks using global axisymmetric, viscous hydrodynamic simulations. The neutrino signal with typical energies of O$(10)$ MeV is maximal during the neutrino-cooled (NDAF) phase that follows shock formation. This phase lasts for a few seconds and is easily detectable within O$(10-100)$ kpc by the IceCube Neutrino Telescope. Additional neutrino signatures from a precursor equatorial shock and by stochastic accretion plumes during the advective phase are detectable within the galaxy. The GW signal during the NDAF phase is detectable in the galaxy by current and next-generation ground-based observatories. The explosion (memory) GW signal is similar to that of standard core-collapse supernovae and can be probed with a deci-Hertz space-based detector. Shock oscillations during the NDAF phase impart time variations with frequency O$(10-100)$ Hz to the neutrino and GW signals, encoding information about the shock dynamics and inner disk. These time variations can be detectable in neutrinos by IceCube within O$(1-10)$ kpc depending on progenitor model, flavor transformation scenario, and detailed properties of the angular momentum transport mechanism.

    ↳ astro-ph.HEastro-ph.SRgr-qchep-ph+1PRD(2025)·1 citation
28. 28*

    Matter Spectral Functions from Quantum Gravity

    Varun Kher🇬🇧 · Brandon King🇬🇧 · Daniel F. Litim🇬🇧 · Manuel Reichert🇬🇧

    We investigate Lorentzian quantum gravity coupled to a template matter sector with gauge fields, scalars and fermions. In the absence of quantised gravity, the matter sector by itself is renormalisable, but UV-incomplete. Provided quantum gravity offers an asymptotically safe UV-completion, we determine the photon and scalar two-point functions in the presence of gravitational fluctuations, and show that both possess a Källén-Lehmann spectral representation. Our results are achieved using functional renormalisation adapted for theories in Lorentzian signature. We explain why and how interactions with gravity modify both the infrared as well as the ultraviolet behaviour of matter spectral functions. We further determine the corresponding form factors on the level of the quantum effective action. Limitations and extensions of our study are discussed alongside implications for particle physics and unitarity of quantum gravity with matter.

    ↳ hep-thgr-qchep-ph11 citations
29. 29*

    Updated constraints on modified gravity from binary pulsars

    S. Bussieres🇪🇸 · M. Caldarola🇪🇸 · S. Nesseris🇪🇸

    Binary pulsars offer a unique natural laboratory to test General Relativity (GR) and probe for deviations from its paradigm, as predicted by alternative theories of gravity. In this paper, we study two such possible deviations: a time variation of Newton's constant $G$ and the emission of dipolar gravitational radiation. We use updated data for some well-known pulsars, namely PSR J1738+0333, PSR J1012+5307, and PSR J1713+0747, to extract the Keplerian and post-Keplerian parameters that characterize their orbital dynamics, using recent high-precision pulsar timing data and a Bayesian parameter estimation with Markov chain Monte Carlo (MCMC) techniques. We do this via the TEMPO2 software, the MCMC4Tempo2 plugin, and a unified python pipeline to analyze the data. We then perform a combined analysis of different binary systems to constrain both the time evolution of Newton's constant and the dipolar emission parameter ${\kappa }_D$. For the best of our three pulsars (PSR J1713+0747), we obtain $\dot{G}/G=(0.32\pm 0.31)\times 10^{-12}{\text{yr}}^{-1}$ at 95\% confidence, along with a stringent constraint on the dipolar emission parameter, ${\kappa }_D=(-0.04\pm 0.14)\times 10^{-4}$. Thanks to the recent high-precision timing data sets, we provide updated bounds on key parameters relevant to modified gravity theories, and we find that our results are consistent with GR.

    ↳ gr-qcastro-ph.COhep-ph2 citations
30. 30*

    New models of nonsingular black hole dark matter from limiting curvature

    Selin Aşmanoğlu🇺🇸 · Jens Boos🇩🇪 · Christopher D. Carone🇺🇸

    We consider phenomenological models for nonsingular black holes that satisfy the limiting curvature condition (i.e., that have curvatures that are always sub-Planckian in size) while having a more general dependence on the black hole mass than the most studied examples. These models allow black holes to exist while having regulators that are larger than the horizon scale; it has been shown previously that this can lead to observable consequences in an astrophysical setting, for allowed choices for the regulator scale. Noting that substantial horizon-scale modifications of the metric will affect black hole thermodynamics and Hawking radiation, we study these metrics in the context of primordial black hole dark matter. Considering examples with de\,Sitter and Minkowski cores, respectively, we study the effect of the regulator in these metrics on the allowed black hole mass ranges (or ``bands"), the black hole temperature, specific heat and lifetime, and the bounds on the primordial black hole fraction of the total dark matter density from the observed extragalactic gamma ray background.

    ↳ gr-qcastro-ph.HEhep-phPRD(2025)·10 citations
31. 31*

    Monte Carlo studies of the emergent spacetime in the polarized IKKT model

    Chien-Yu Chou🇯🇵 · Jun Nishimura🇯🇵 · Cheng-Tsung Wang🇯🇵

    The IKKT matrix model has been investigated as a promising nonperturbative formulation of superstring theory. One of the recent developments concerning this model is the discovery of the dual supergravity solution corresponding to the model obtained after supersymmetry-preserving mass deformation, which is dubbed the polarized IKKT model. Here we perform Monte Carlo simulations of this model in the case of matrix size N = 2 for a wide range of the deformation parameter Omega. While we reproduce precisely the known result for the partition function obtained by the localization method developed for supersymmetric theories, we also calculate the observables, which were not accessible by previous work, in order to probe the spacetime structure emergent from the dominant matrix configurations. In particular, we find that the saddle point corresponding to the original IKKT model is smoothly connected to the saddle represented by the fuzzy sphere dominant at large Omega, whereas the dominant configurations become diverging commuting matrices at small Omega.

    ↳ hep-thgr-qchep-lathep-phPRL(2025)·13 citations
32. 32*

    Probing Spin and Lifetime Correlations in Entangled Hyperon-AntiHyperon Pairs

    Aihong Tang🇺🇸

    Quantum entanglement has now been demonstrated in several hadronic systems, revealing that non-classical spin correlations survive even through the strong-interaction hadronization process. To date, however, all studies have focused exclusively on angular observables, leaving the possibility untouched that quantum coherence might also influence the decay times of entangled partners. In this work we propose data-driven tests of spin-lifetime and lifetime-lifetime correlations for Lambda-antiLambda pairs produced in high-energy collisions. By examining the opening-angle distribution in slices of Delta t, constructing a pair-wise spin-lifetime correlator, and testing a simple lifetime-lifetime covariance, we search for deviations from independent exponential decay that align with known spin correlations. Observation of nonzero lifetime correlations would compel a reassessment of how entanglement manifests in decaying systems, revealing hitherto unexplored temporal coherence.

    ↳ nucl-exhep-exhep-phnucl-thPLB(2025)·6 citations
33. 33*

    Insight-HXMT Spectral and Timing Studies of a Giant Outburst in RX J0440.9+4431

    Prahlad R. Epili · Wei Wang🇨🇳

    The Be/X-ray binary pulsar RX J0440.9+4431 underwent a giant outburst in late 2022 and lasted three months. The Insight-HXMT has observed this source at several instances of the entire outburst in 2022-2023. We used these bright outburst observations of the pulsar to study its X-ray spectral and timing variability. The pulse profiles obtained at similar luminosity during the progress and declining phases of the outburst show a similar shape behavior.With the increase in source luminosity, the complex pulse profile with multiple peaks at low luminosity becomes a single peaked pulse profile at the high luminosity at the outburst peak. The phase-averaged spectra of the pulsar in 1-120 keV are explained with an absorbed cutoff power-law continuum model. During the outburst phases, we have found the evidence of a cyclotron resonance scattering feature in the spectra varying in energies ($\sim$ 33.6- 41.6 keV) having broad linewidth > 5 keV . In declining phases of the outburst, we have also found the hints of first cyclotron harmonic varying in 65-75 keV . The application of thermal and bulk Comptonization model to the phase-averaged and phase-resolved spectra reveals a high surface magnetic field ($B\sim 10^{13}$ G) for the pulsar.

    ↳ astro-ph.HEastro-ph.SRhep-phAstron.Astrophys.(2025)·2 citations
34. 34*

    Four Loop Renormalisation Group Equations in general Gross-Neveu-Yukawa Theories

    Tom Steudtner🇩🇪

    We compute template formulae of all four-loop $\beta$-functions and anomalous dimensions of arbitrary renormalisable quantum field theories with fermions and scalar fields in the $\overline{\text{MS}}$ scheme. Using these results, novel contributions to the $\beta$-functions of the Higgs and top coupling are extracted. We discuss how four loops present a challenge to dimensional continuation from four to three dimensions and propose a solution.

    ↳ hep-thhep-phJHEP(2025)·7 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.