Wed·May 29, 2024Wednesday·May 29, 2024

1. 01*

   Gravitationally produced Dark Matter and primordial black holes

   Enrico Bertuzzo🇮🇹 · Yuber F. Perez-Gonzalez🇬🇧 · Gabriel M. Salla🇧🇷 · Renata Zukanovich Funchal🇧🇷

   We examine how the existence of a population of primordial black holes (PBHs) influences cosmological gravitational particle production (CGPP) for spin-0 and spin-1 particles. In addition to the known effects of particle production and entropy dilution resulting from PBH evaporation, we find that the generation of dark matter (DM) through CGPP is profoundly influenced by a possible era of PBH matter domination. This early matter dominated era results in an enhancement of the particle spectrum from CGPP. Specifically, it amplifies the peak comoving momentum $k_{\star }$ for spin-1 DM, while enhancing the plateau of the spectrum for minimally coupled spin-0 particles for low comoving momenta. At the same time, the large entropy dilution may partially or completely compensate for the increase of the spectrum and strongly mitigates the DM abundance produced by CGPP. Our results show that, in the computation of the final abundance, CGPP and PBH evaporation cannot be disentangled, but the parameters of both sectors must be considered together to obtain the final result. Furthermore, we explore the potential formation of PBHs from density fluctuations arising from CGPP and the associated challenges in such a scenario.

   hep-phastro-ph.HEJCAP(2024)·13 citations
2. 02*

   Diphoton Signals of Muon-philic Scalars at DarkQuest

   Nikita Blinov🇨🇦 · Stefania Gori🇺🇸 · Nick Hamer🇺🇸

   We analyze the unique capability of the DarkQuest proton beam-dump experiment at Fermilab to discover new light resonances decaying into photons. As an example model, we focus on muon-philic scalar particles that decay to photons. This is one of the few minimal models that can address the $(g-2{)}_{\mu }$ anomaly at low mass. These scalars can be copiously produced by meson decays and muon bremsstrahlung. We point out that thanks to DarkQuest's compact geometry, muons can propagate through the dump and efficiently produce dark scalars near the end of the dump. This mechanism enables DarkQuest to be sensitive to both long-lived and prompt scalars. At the same time, di-photon signatures are generically not background free, and we discuss in detail the different sources of background and strategies to mitigate them. We find that the backgrounds can be sufficiently reduced for DarkQuest to test currently-viable $(g-2{)}_{\mu }$ parameter space.

   hep-phhep-exPRD(2024)·12 citations
3. 03*

   $J/\psi$ photoproduction: threshold to very high energy

   Lin Tang🇨🇳 · Yi-Xuan Yang🇨🇳 · Zhu-Fang Cui🇨🇳 · Craig D. Roberts🇨🇳

   A reaction model for $\gamma +p\to J/\psi +p$ photoproduction, which exposes the $c\bar{c}$ content of the photon in making the transition $\gamma \to c\bar{c}+\mathbb{P}\to J/\psi$ and couples the intermediate $c\bar{c}$ system to the proton's valence quarks via Pomeron ($\mathbb{P}$) exchange, is used to deliver a description of available data, viz. both differential and total cross sections from near threshold, where data has newly been acquired, to invariant mass $W\approx 300$GeV. The study suggests that it is premature to link existing $\gamma +p\to J/\psi +p$ data with, for instance, in-proton gluon distributions, the quantum chromodynamics trace anomaly, or pentaquark production. Further developments in reaction theory and higher precision data are necessary before the validity of any such connections can be assessed.

   hep-phhep-exhep-latnucl-ex+1PLB(2024)·15 citations
4. 04*

   Implications of neutrino species number and summed mass measurements in cosmological observations

   N. Sasao (Okayama U)🇯🇵 · M. Yoshimura (Okayama U)🇯🇵 · M. Tanaka (Osaka U)🇯🇵

   We confront measurable neutrino degrees of freedom $N_{\mathrm{eff}}$ and summed neutrino mass in the early universe to particle physics at the energy scale beyond the standard model (BSM), in particular including the issue of neutrino mass type distinction. The Majorana-type of massive neutrino is perfectly acceptable by Planck observations, while the Dirac-type neutrino may survive in a restricted class of models that suppresses extra right-handed contribution to $\Delta N_{\mathrm{eff}}=N_{\mathrm{eff}}-3$ at a nearly indistinguishable level from the Majorana case. There is a chance that supersymmetry energy scale may be identified in supersymmetric extension of left-right symmetric model if improved $N_{\mathrm{eff}}$ measurements discover a finite value. Combined analysis of this quantity with the summed neutrino mass helps to determine the neutrino mass ordering pattern, if measurement accuracy of order, $60\sim 80$meV, is achieved, as in CMB-S4.

   hep-phJCAP(2024)·2 citations
5. 05*

   Manifestation of antiquark nuggets in collisions with the Earth

   V. V. Flambaum🇦🇺 · I. B. Samsonov🇦🇺 · G. K. Vong🇦🇺

   Antiquark nuggets are hypothetical compact composite objects conjectured to account for a significant fraction of dark matter in the Universe. In contrast to quark nuggets, these objects consist of antimatter. They may remain undetected if they possess a sufficiently small cross section relative to their mass. In this paper, we investigate the allowed region in the parameter space of this model that is consistent with the observed neutrino flux from the Sun and the Earth, and the non-observation of seismic events with specific signatures of dark matter particles. We found the allowed values of the antibaryon charge number in this model to be in the interval $2\times 10^{24}<A<8\times 10^{25}$, while the probability of nucleon annihilation upon collisions with the antiquark core is constrained by $0.1\lesssim \kappa <0.25$. Although very large values of the antibaryon charge, $A>10^{33}$, are not fully excluded by the present study, we show that they conflict with the non-observation of rare catastrophic explosion-like events on the Earth.

   hep-phastro-ph.COPRD(2025)·5 citations
6. 06*

   The flavor-dependent $U(1{)}_F$ model

   Jin-Lei Yang🇨🇳 · Hai-Bin Zhang🇨🇳 · Tai-Fu Feng🇨🇳

   A flavor-dependent model (FDM) is proposed in this work. The model extends the Standard Model by an extra $U(1{)}_F$ local gauge group, two scalar doublets, one scalar singlet and two right-handed neutrinos, where the additional $U(1{)}_F$ charges are related to the particles' flavor. The new fermion sector in the FDM can explain the flavor mixings puzzle and the mass hierarchy puzzle simultaneously, and the nonzero Majorana neutrino masses can be obtained naturally by the Type I see-saw mechanism. In addition, the $B$ meson rare decay processes $\bar{B}\to X_s\gamma$, $B_s^0\to {\mu }^{+}{\mu }^{-}$, the top quark rare decay processes $t\to ch$, $t\to uh$ and the $\tau$ lepton flavor violation processes $\tau \to 3e$, $\tau \to 3\mu$, $\mu \to 3e$ predicted in the FDM are analyzed.

   hep-phEPJC(2024)·7 citations
7. 07*

   Shedding Light on Dark Sectors with Gravitational Waves

   Nelleke Bunji🇺🇸 · Bartosz Fornal🇺🇸 · Kassandra Garcia🇺🇸

   The nature of dark matter remains one of the greatest unsolved mysteries in elementary particle physics. It might well be that the dark matter particle belongs to a dark sector completely secluded or extremely weakly coupled to the visible sector. We demonstrate that gravitational waves arising from first order phase transitions in the early Universe can be used to look for signatures of such dark sector models connected to neutron physics. This introduces a new connection between gravitational wave physics and nuclear physics experiments. Focusing on two particular extensions of the Standard Model with dark U(1) and SU(2) gauge groups constructed to address the neutron lifetime puzzle, we show how those signatures can be searched for in future gravitational wave and astrometry experiments.

   hep-phgr-qcPRD(2024)·3 citations
8. 08*

   Strong limits on keV-scale galactic sterile neutrino dark matter with stray light from NuSTAR after 11 years of operation

   R.A. Krivonos🇷🇺 · V.V. Barinov🇷🇺 · A.A. Mukhin🇷🇺 · D.S. Gorbunov🇷🇺

   Using tremendous photon statistics gained with the stray light aperture of the NuSTAR telescope over 11 years of operation, we set strong limits on the emission of close to monochromatic photons from the radiative decays of putative dark matter sterile neutrinos in the Milky Way. In the energy range of 3-20 keV covered by the NuSTAR, the obtained limits reach the bottom edge of theoretical predictions of realistic models where sterile neutrinos are produced in the early Universe. Only a small region is left to explore, if the sterile neutrinos form the entire dark matter component.

   hep-phastro-ph.HEPRL(2024)·27 citations
9. 09*

   Constraining vector dark matter and dark photon with degenerate mass in a hidden local SU(2) model

   Takaaki Nomura🇨🇳 · Xinran Xu🇨🇳

   We discuss degenerate vector dark matter and dark photon that are induced from hidden $SU(2{)}_H$ gauge sector where it is spontaneously broken by vacuum expectation value of $SU(2{)}_H$ doublet. Kinetic mixing between $SU(2{)}_H$ and $U(1{)}_Y$ gauge fields can be generated by introducing dimension six operator realizing dark photon interactions. In estimating relic density we focus on the process in which dark matter annihilates into dark photons, and search for the region of dark matter mass and gauge coupling realizing observed relic density. We then discuss constraints from dark photon physics, thermalization of dark sector and direct detection of dark matter. It is then found that constraints from direct detection experiments give us the strongest upper limits on the dark photon interactions.

   hep-phhep-exCPC(2025)·2 citations
10. 10*

    Threshold Effects on the Massless Neutrino in the Canonical Seesaw Mechanism

    Di Zhang🇩🇪

    In this work, we revisit the one-loop renormalization group equations (RGEs) among non-degenerate seesaw scales, i.e., threshold effects in the canonical seesaw mechanism, which have been obtained for more than two decades. Different from the previous work only focusing on the Weinberg operator, we derive the complete one-loop RGEs of all three dimension-five operators in the Standard Model effective field theory with right-handed neutrinos ($\nu$SMEFT) and apply them to threshold effects in the canonical seesaw mechanism. We find some contributions from the Weinberg operator to its Wilson coefficient, the neutrino Yukawa coupling matrix, and the Higgs quartic coupling absent in the previous calculations. Based on the updated one-loop RGEs, we derive the RGE of the effective neutrino mass matrix's determinant without any approximation. Then, for the first time, we provide a strict proof that the one-loop RG running effects among non-degenerate seesaw scales can not generate a non-zero mass for the initial massless neutrino in the minimal type-I seesaw mechanism or in the canonical one with a rank-degenerate neutrino Yukawa coupling matrix. One has to include two- or higher-loop corrections to achieve a non-zero mass for the massless neutrino.

    hep-phhep-exJHEP(2024)·11 citations
11. 11*

    Forward $J/\psi +J/\psi$ and $J/\psi +{\psi }^{\prime }$ production with High Energy Factorization

    S.P. Baranov🇷🇺 · A.V. Lipatov🇷🇺 · M.A. Malyshev🇷🇺 · A.A. Prokhorov🇷🇺 · P.M. Zhang🇨🇳

    We calculate the cross sections of associated $J/\psi +{\psi }^{\prime }$ and $J/\psi +J/\psi$ production in $pp$ collisions at $\sqrt{s}=13$ TeV in the forward kinematic region. The High Energy Factorization ($k_T$-factorization) framework supplemented with the Catani-Ciafaloni-Fiorani-Marchesini evolution of gluon densities in a proton is applied. We demonstrate that latest data on $J/\psi +J/\psi$ production and first experimental data on $J/\psi +{\psi }^{\prime }$ events taken very recently by the LHCb Collaboration can be described well by the color singlet terms and contributions from the double parton scattering (DPS) with the standard choice for ${\sigma }_{\mathrm{eff}}$ parameter. The relative production rate $\sigma (J/\psi +{\psi }^{\prime })/\sigma (J/\psi +J/\psi )$ is found to be sensitive to the DPS terms as well as to feeddown contributions.

    hep-phPRD(2024)·2 citations
12. 12*

    Anomalous dimensions for hard exclusive processes

    S. Van Thurenhout🇭🇺

    We give an overview of recent developments in the computation of the anomalous dimension matrix of composite operators in non-forward kinematics. The elements of this matrix determine the scale dependence of non-perturbative parton distributions, such as GPDs, and hence constitute important input for phenomenological studies of exclusive processes like deeply-virtual Compton scattering. Particular emphasis will be put on a recently developed method that exploits consistency relations for the anomalous dimension matrix which follow from the renormalization structure of the operators.

    hep-phhep-thPoS(2025)·0 citations
13. 13*

    Dalitz-plot analysis of B+- --> K+-K+K- decays

    L. Lesniak🇵🇱 · P. Zenczykowski🇵🇱

    We study B+- -- > K+-K+K- decays using the QCD factorization model with final state interactions between K+ and K- mesons taken into account. The parameters of the model are fitted to the data of the BABAR and LHCb collaborations. We describe the K Kbar effective mass distributions and examine the CP-violating asymmetry effects in the full range of the Dalitz plot.

    hep-phPRD(2024)·2 citations
14. 14*

    Constraining axion-gluon coupling in monohadron processes

    Shou-shan Bao🇨🇳 · Wenhai Gao🇨🇳 · Hong Zhang🇨🇳 · Jian Zhou🇨🇳

    The axion-gluon coupling can be constrained directly through hard exclusive processes at the LHC. Specifically, we study the associated production of a long-lived axion with a ${\rho }^0$ meson in ultra-peripheral $AA$ collisions and in $pp$ collisions. With the axion escaped from the detector, the final state is characterized by a mono-hadron signature. The main background in our analysis originates from the ${\rho }^0+{\pi }^0$ process, where the photons from the ${\pi }^0$ decay are undetected due to limited detector performance. Our analysis yields an exclusion limit of the axion-gluon coupling that is comparable to the limit obtained from the mono-jet process at the LHC.

    hep-phPRD(2024)·2 citations
15. 15*

    Theoretical bounds on dark Higgs mass in a self-interacting dark matter model with $U(1{)}^{\prime }$

    Song Li🇨🇳 · Jin Min Yang🇨🇳 · Mengchao Zhang🇨🇳 · Rui Zhu🇨🇳

    Motivated by the null results of current dark matter searches and the small-scale problems, we study a dark sector charged by a spontaneous broken gauge $U(1{)}^{\prime }$. To explore the parameter space of this model, in addition to the consideration of the small-scale data, we also consider the theoretical bounds on the dark Higgs mass, with the upper bound coming from the tree-level perturbative unitarity and the lower bound from the one-loop Linde-Weinberg bound. We deeply examine the dependence of the Linde-Weinberg bound on gauge choice and energy scale, and present a Linde-Weinberg bound that is gauge and scale independent. Combining the theoretical and observational constraints, we obtain the following ranges for the parameter space: the dark matter mass is 10-500 GeV, the mediator (dark photon) mass is 0.5-5 MeV, the dark Higgs mass is 0.05-50 MeV, and the dark fine-structure constant is 0.001-0.4. We conclude that the dark Higgs in this model cannot be ignored in the phenomenological study of the dark sector.

    hep-phastro-ph.COhep-thPRD(2025)·10 citations
16. 16*

    Model Dependent Analysis of D_((s))^+ arrows {\eta}^((')) l^+ {\nu}_l Decays in Beyond Standard Model

    S. Mahata🇮🇳 · M. Mandal🇮🇳 · H. Mahapatra🇮🇳 · S. Biswas🇮🇳 · S. Sahoo🇮🇳

    Motivated by the recent experimental results of branching fractions for D_((s))^+ arrows {\eta}^((')) l^+ {\nu}_l decays, which deviate from their SM predictions, we have investigated these decays in W' model and scalar leptoquark model to find possible signatures of new physics (NP) in semileptonic charm decays induced by c arrow(s,d)l {nu}_l transitions. Using recent experimental results of branching fractions for semileptonic D meson decays, new coupling parameters are predicted for the above NP models. Branching fraction, forward-backward asymmetry and lepton polarization asymmetry are studied taking the predicted NP coupling parameters. Results of branching fractions in scalar leptoquark model are found very close to the experimental results and exist around the range 1{sigma} deviation. We have presented a comparative study of the NP models to check their sensitivity on these decays. We anticipate that further research on these decays will significantly support our findings.

    hep-phCPC(2024)·3 citations
17. 17*

    Full and approximated NLO predictions for like-sign W-boson scattering at the LHC

    Stefan Dittmaier🇩🇪 · Christopher Schwan🇩🇪 · Ramon Winterhalder🇧🇪

    We report on a recent calculation of next-to-leading-order (NLO) QCD and electroweak corrections to like-sign W-boson scattering at the Large Hadron Collider, including all partonic channels and W-boson decays in the process $pp\to e^{+}{\nu }_e{\mu }^{+}{\nu }_{\mu }jj+X$. The calculation is implemented in the Monte Carlo integrator Bonsay and comprises the full tower of NLO contributions of the orders ${\alpha }_s^3{\alpha }^4$, ${\alpha }_s^2{\alpha }^5$, ${\alpha }_s{\alpha }^6$, and ${\alpha }^7$. Our numerical results confirm and extend previous results, in particular the occurrence of large purely electroweak corrections of the order of $\sim -12\%$ for integrated cross sections, which get even larger in distributions. We construct a "VBS approximation" for the NLO prediction based on partonic channels and gauge-invariant (sub)matrix elements potentially containing the vector-boson scattering (VBS) subprocess and on resonance expansions of the Wdecays. The VBS approximation reproduces the full NLO predictions within $\sim 1.5\%$ in the most important regions of phase space. Moreover, we discuss results from different versions of "effective vector-boson approximations" at leading order, based on the collinear emission of W bosons of incoming (anti)quarks. However, owing to the only mild collinear enhancement and the design of VBS analysis cuts, the quality of this approximation turns out to be only qualitative at the LHC.

    hep-phPoS(2024)·0 citations
18. 18*

    Revisiting the decoupling limit of the Georgi-Machacek model with a scalar singlet

    Geneviève Bélanger🇫🇷 · Juhi Dutta🇺🇸 · Rohini M. Godbole🇮🇳 · Sabine Kraml🇫🇷 · Manimala Mitra🇮🇳 · Rojalin Padhan🇰🇷 · Abhishek Roy🇮🇳

    We study the connection between collider and dark matter phenomenology in the singlet extension of the Georgi-Machacek model. In this framework, the singlet scalar serves as a suitable thermal dark matter (DM) candidate. Our focus lies on the region $v_{\chi }<1$ GeV, where $v_{\chi }$ is the common vacuum expectation value of the neutral components of the scalar triplets of the model. Setting bounds on the model parameters from theoretical, electroweak precision and LHC experimental constraints, we find that the BSM Higgs sector is highly constrained. Allowed values for the masses of the custodial fiveplets, triplets and singlet are restricted to the range $140\mathrm{GeV}<M_{H_5}<350\mathrm{GeV}$, $150\mathrm{GeV}<M_{H_3}<270\mathrm{GeV}$ and $145\mathrm{GeV}<M_H<300\mathrm{GeV}$. The extended scalar sector provides new channels for DM annihilation into BSM scalars that allow to satisfy the observed relic density constraint while being consistent with direct DM detection limits. The allowed region of the parameter space of the model can be explored in the upcoming DM detection experiments, both direct and indirect. In particular, the possible high values of BR$(H_5^0\to \gamma \gamma )$ can lead to an indirect DM signal within the reach of CTA. The same feature also provides the possibility of exploring the model at the High-Luminosity run of the LHC. In a simple cut-based analysis, we find that a signal of about $4\sigma$ significance can be achieved in final states with at least two photons for one of our benchmark points.

    hep-phJHEP(2024)·7 citations
19. 19*

    Cosmological phase transitions at three loops: the final verdict on perturbation theory

    Andreas Ekstedt🇸🇪 · Philipp Schicho🇩🇪 · Tuomas V. I. Tenkanen🇫🇮

    We complete the perturbative program for equilibrium thermodynamics of cosmological first-order phase transitions by determining the finite-temperature effective potential of gauge-Higgs theories at next-to-next-to-next-to-next-to-leading order (N${}^4$LO). The computation of the three-loop effective potential required to reach this order is extended to generic models in dimensionally reduced effective theories in a companion article. Our N${}^4$LO result is the last perturbative order before confinement renders electroweak gauge-Higgs theories non-perturbative at four loops. By contrasting our analysis with non-perturbative lattice results, we find a remarkable agreement. As a direct application for predictions of gravitational waves produced by a first-order transition, our computation provides the final fully perturbative results for the phase transition strength and speed of sound.

    hep-phastro-ph.COhep-thPRD(2024)·53 citations
20. 20*

    Photon self-energy at all temperatures and densities in all of phase space

    Hugo Schérer🇨🇦 · Katelin Schutz🇨🇦

    In an isotropic background comprised of free charges, the transverse and longitudinal modes of the photon acquire large corrections to their dispersion relations, described by the in-medium photon self-energy. Previous work has developed simple approximations that describe the propagation of on-shell photons in plasmas of varying temperatures and densities. However, off-shell excitations can also receive large medium-induced corrections, and the on-shell approximations have often been used in an effort to capture these effects. In this work we show that the off-shell self-energy can be qualitatively very different than the on-shell case. We develop analytic approximations that are accurate everywhere in phase space, especially in classical and degenerate plasmas. From these, we recover the on-shell expressions in the appropriate limit. Our expressions also reproduce the well-known Lindhard response function from solid-state physics for the longitudinal mode.

    hep-phJHEP(2024)·9 citations
21. 21*

    Radiative corrections to superallowed $\beta$ decays in effective field theory

    Vincenzo Cirigliano🇺🇸 · Wouter Dekens🇺🇸 · Jordy de Vries🇳🇱 · Stefano Gandolfi🇺🇸 · Martin Hoferichter🇨🇭 · Emanuele Mereghetti🇺🇸

    The accuracy of $V_{ud}$ determinations from superallowed $\beta$ decays critically hinges on control over radiative corrections. Recently, substantial progress has been made on the single-nucleon, universal corrections, while nucleus-dependent effects, typically parameterized by a quantity ${\delta }_{\text{NS}}$, are much less well constrained. Here, we lay out a program to evaluate this correction from effective field theory (EFT), highlighting the dominant terms as predicted by the EFT power counting. Moreover, we compare the results to a dispersive representation of ${\delta }_{\text{NS}}$ and show that the expected momentum scaling applies even in the case of low-lying intermediate states. Our EFT framework paves the way towards ab-initio calculations of ${\delta }_{\text{NS}}$ and thereby addresses the dominant uncertainty in $V_{ud}$.

    hep-phhep-exhep-latnucl-ex+1PRL(2024)·42 citations
22. 22*

    Symbolic Regression for Beyond the Standard Model Physics

    Shehu AbdusSalam🇮🇷 · Steve Abel🇬🇧 · Miguel Crispim Romao🇬🇧

    We propose symbolic regression as a powerful tool for studying Beyond the Standard Model physics. As a benchmark model, we consider the so-called Constrained Minimal Supersymmetric Standard Model, which has a four-dimensional parameter space defined at the GUT scale. We provide a set of analytical expressions that reproduce three low-energy observables of interest in terms of the parameters of the theory: the Higgs mass, the contribution to the anomalous magnetic moment of the muon, and the cold dark matter relic density. To demonstrate the power of the approach, we employ the symbolic expressions in a global fits analysis to derive the posterior probability densities of the parameters, which are obtained extremely rapidly in comparison with conventional methods.

    hep-phcs.AIcs.LGhep-th+1PRD(2025)·24 citations
23. 23*

    Dark Matter Catalyzed Baryon Destruction

    Yohei Ema🇺🇸 · Robert McGehee🇺🇸 · Maxim Pospelov🇺🇸 · Anupam Ray🇺🇸

    WIMP-type dark matter may have additional interactions that break baryon number, leading to induced nucleon decays which are subject to direct experimental constraints from proton decay experiments. In this work, we analyze the possibility of continuous baryon destruction, deriving strong limits from the dark matter accumulating inside old neutron stars, as such a process leads to excess heat generation. We construct the simplest particle dark matter model that breaks baryon and lepton numbers separately but conserves $B-L$. Virtual exchange by DM particles in this model results in di-nucleon decay via $nn\to n\bar{\nu }$ and $np\to n{e}^{+}$ processes.

    hep-phastro-ph.COastro-ph.HEPRD(2025)·26 citations
24. 24*

    Baryon number violation involving tau leptons

    Julian Heeck🇺🇸 · Dima Watkins🇺🇸

    Baryon number violation is our most sensitive probe of physics beyond the Standard Model, especially through the study of nucleon decays. Angular momentum conservation requires a lepton in the final state of such decays, kinematically restricted to electrons, muons, or neutrinos. We show that operators involving taus, which are at first sight too heavy to play a role in nucleon decays, still lead to clean nucleon decay channels with tau neutrinos. While many of them are already constrained from existing two-body searches such as $p\to {\pi }^{+}\nu$, other operators induce many-body decays such as $p\to \eta {\pi }^{+}{\bar{\nu }}_{\tau }$ and $n\to K^{+}{\pi }^{-}{\nu }_{\tau }$ that have never been searched for.

    hep-phhep-exJHEP(2024)·13 citations
25. 25*

    Sensitivity to Kaon Decays to ALPs at Fixed Target Experiments

    Joshua Berger🇺🇸 · Gray Putnam🇺🇸

    We study the sensitivity of fixed target experiments to hadronically-coupled axion like particles (ALPs) produced in kaon decays, with a particular emphasis on current and upcoming short-baseline neutrino experiments. We demonstrate that below the kaon decay mass threshold ($m_a<m_K-m_{\pi }$) kaon decay is the dominant production mechanism for ALPs at neutrino experiments, larger by many orders of magnitude than production in psuedo-scalar mixing. Such axions can be probed principally by the di-photon and di-muon final states. In the latter case, even if the axion does not couple to muons at tree level, such a coupling is induced by the renormalization group flow from the UV scale. We reinterpret prior results by CHARM and MicroBooNE through these channels and show that they constrain new areas of heavy axion parameter space. We also show projections of the sensitivity of the SBN and DUNE experiments to axions through these channels, which reach up to multiple decades higher in the axion decay constant beyond existing constraints. DUNE projects to have a sensitivity competitive with other world-leading upcoming experiments.

    hep-phhep-exPRD(2024)·16 citations
26. 26*

    Genuine lepton-flavor-universality-violating observables in the $\tau -\mu$ sector of $B\to (K,K^{\ast })\ell \ell$ decays

    Ashutosh Kumar Alok🇮🇳 · Neetu Raj Singh Chundawat🇮🇳 · Jitendra Kumar🇮🇳 · Arindam Mandal🇮🇳 · Umberto Tamponi🇮🇹

    It was previously shown that unlike the ratios $R_K^{\mu e}\equiv R_K\equiv \Gamma (B\to K{\mu }^{+}{\mu }^{-})/\Gamma (B\to K{e}^{+}{e}^{-})$ and $R_{K^{\ast }}^{\mu e}\equiv R_{K^{\ast }}\equiv \Gamma (B\to K^{\ast }{\mu }^{+}{\mu }^{-})/\Gamma (B\to K^{\ast }{e}^{+}{e}^{-})$, the ratios $R_K^{\tau \mu }$ and $R_{K^{\ast }}^{\tau \mu }$ can deviate from their Standard Model (SM) predictions even with universal new physics couplings. This observation highlights the critical need to identify and establish genuine lepton flavor universality violating (LFUV) observables in the $\tau -\mu$ sector. This work embarks on establishing genuine LFUV ratio observables in $B\to K\ell \ell$ and $B\to K^{\ast }\ell \ell$ decays through comprehensive analysis of their angular distributions. We find that like $R_{K^{\ast }}^{\tau \mu }$, the ratios $R_{A_{FB}}^{\tau \mu }$ and $R_{f_L}^{\tau \mu }$ do not qualify as genuine LFUV observables, whereas the ratios of all optimized observables in $B\to K^{\ast }\ell \ell$ decays within the $\tau -\mu$ sector definitively do. In the case of $B\to K\ell \ell$ decays, similar to $R_K^{\tau \mu }$, the ratio $R_{F_H}$ is influenced by mass effects and therefore cannot be considered a genuine LFUV observable in the $\tau -\mu$ sector. However, the ratio ${\Gamma }_{\tau }(1-F_H^{\tau })/{\Gamma }_{\mu }(1-F_H^{\mu })$ stands as the sole genuine LFUV observable in $B\to K\ell \ell$ decays. Furthermore, by making use of new physics Lorentz structures which provide a better fit to the current $b\to s\ell \ell$ data as compared to the SM, we demonstrate how the non-genuine LFUV ratios $R_{A_{FB}}^{\tau \mu }$ and $R_{f_L}^{\tau \mu }$ can be employed to distinguish between framework with solely universal lepton couplings and those with both universal and non-universal couplings.

    hep-phhep-exPRD(2024)·6 citations
27. 27*

    From the Dawn of Neutrino Astronomy to A New View of the Extreme Universe

    C. A. Argüelles🇺🇸 · F. Halzen🇺🇸 · N. Kurahashi🇺🇸

    Over the past decade, neutrino astronomy has emerged as a new window into the extreme and hidden universe. Current-generation experiments have detected high-energy neutrinos of astrophysical origin and identified the first sources, opening the field to discovery. Looking ahead, the authors of this Perspective identify seven major open questions in neutrino astrophysics and particle physics that could lead to transformative discoveries over the next 20 years. These multidisciplinary questions range from understanding the vicinity of a black hole to unveiling the nature of neutrino mass, among other topics. Additionally, we critically review the current experimental capabilities and their limitations and, from there, discuss the interplay between different proposed neutrino telescope technologies and analysis techniques. The authors firmly believe that achieving the immense discovery potential over the next two decades demands a model of global partnership and specialized, complementary detectors. This collaborative neutrino telescope network will pave the way for a thriving multimessenger era, transforming our understanding of neutrino physics, astrophysics, and the extreme universe.

    ↳ hep-exastro-ph.HEhep-phPRX(2025)·18 citations
28. 28*

    JUNO Sensitivity to Invisible Decay Modes of Neutrons

    JUNO Collaboration: Angel Abusleme🇨🇱 · Thomas Adam🇫🇷 · Kai Adamowicz🇩🇪 · Shakeel Ahmad🇵🇰 · Rizwan Ahmed🇵🇰 · Sebastiano Aiello🇮🇹 · Fengpeng An🇨🇳 · Qi An🇨🇳 · Giuseppe Andronico🇮🇹 · Nikolay Anfimov🇷🇺 · Vito Antonelli🇮🇹 · Tatiana Antoshkina🇷🇺 and 647 other authors

    We explore the decay of bound neutrons into invisible particles (e.g., $n\to 3\nu$ or $nn\to 2\nu$) in the JUNO liquid scintillator detector, which do not produce an observable signal. The invisible decay includes two decay modes: $n\to inv$ and $nn\to inv$. The invisible decays of $s$-shell neutrons in ${}^{12}\mathrm{C}$ will leave a highly excited residual nucleus. Subsequently, some de-excitation modes of the excited residual nuclei can produce a time- and space-correlated triple coincidence signal in the JUNO detector. Based on a full Monte Carlo simulation informed with the latest available data, we estimate all backgrounds, including inverse beta decay events of the reactor antineutrino ${\bar{\nu }}_e$, natural radioactivity, cosmogenic isotopes and neutral current interactions of atmospheric neutrinos. Pulse shape discrimination and multivariate analysis techniques are employed to further suppress backgrounds. With two years of exposure, JUNO is expected to give an order of magnitude improvement compared to the current best limits. After 10 years of data taking, the JUNO expected sensitivities at a 90% confidence level are $\tau /B(n\to inv)>5.0\times 10^{31}\mathrm{yr}$ and $\tau /B(nn\to inv)>1.4\times 10^{32}\mathrm{yr}$.

    ↳ hep-exhep-phEPJC(2025)·29 citations
29. 29*

    Deep learning inference of the neutron star equation of state

    Giulia Ventagli🇨🇿 · Ippocratis D. Saltas🇨🇿

    We present a pipeline to infer the equation of state of neutron stars from observations based on deep neural networks. In particular, using the standard (deterministic), as well as Bayesian (probabilistic) deep networks, we explore how one can infer the interior speed of sound of the star given a set of mock observations of total stellar mass, stellar radius and tidal deformability. We discuss in detail the construction of our simulated dataset of stellar observables starting from the solution of the gravitational equations, as well as the relevant architectures for the deep networks, along with their performance and accuracy. We further explain how our pipeline is capable to detect a possible QCD phase transition in the stellar core. Our results show that deep networks offer a promising tool towards solving the inverse problem of neutron stars, and the accurate inference of their interior from future stellar observations.

    ↳ astro-ph.HEastro-ph.IMgr-qchep-ph+1JCAP(2025)·16 citations
30. 30*

    Letter of Intent: Towards a Vacuum Birefringence Experiment at the Helmholtz International Beamline for Extreme Fields

    N. Ahmadiniaz🇩🇪 · C. Bähtz🇩🇪 · A. Benediktovitch🇩🇪 · C. Bömer🇩🇪 · L. Bocklage🇩🇪 · T. E. Cowan🇩🇪 · J. Edwards🇬🇧 · S. Evans🇺🇸 · S. Franchino Viñas🇩🇪 · H. Gies🇩🇪 · S. Göde🇩🇪 · J. Görs🇩🇪 and 40 other authors

    Quantum field theory predicts a nonlinear response of the vacuum to strong electromagnetic fields of macroscopic extent. This fundamental tenet has remained experimentally challenging and is yet to be tested in the laboratory. A particularly distinct signature of the resulting optical activity of the quantum vacuum is vacuum birefringence. This offers an excellent opportunity for a precision test of nonlinear quantum electrodynamics in an uncharted parameter regime. Recently, the operation of the high-intensity laser ReLaX provided by the Helmholtz International Beamline for Extreme Fields (HIBEF) has been inaugurated at the High Energy Density (HED) scientific instrument of the European XFEL. We make the case that this worldwide unique combination of an x-ray free-electron laser and an ultra-intense near-infrared laser together with recent advances in high-precision x-ray polarimetry, refinements of prospective discovery scenarios, and progress in their accurate theoretical modelling have set the stage for performing an actual discovery experiment of quantum vacuum nonlinearity.

    ↳ physics.ins-dethep-exhep-phphysics.opticsHigh Power Laser Sci.Eng.(2025)·44 citations
31. 31*

    Treatment of QED corrections in jet production in deep inelastic scattering at ZEUS

    Florian Lorkowski (for the ZEUS Collaboration)🇨🇭

    A new measurement of inclusive jet production in deep inelastic scattering was recently published by the ZEUS Collaboration. This contribution presents a detailed discussion of the treatment of higher-order QED effects in this measurement. A comprehensive treatment of these effects is crucial for a more direct comparison between ever more precise measurements and theoretical calculations. The present analysis is the only measurement of jet production in deep inelastic scattering that can be compared to full NNLO QCD + NLO electroweak predictions.

    ↳ hep-exhep-ph0 citations
32. 32*

    Feynman Integral Reductions by Intersection Theory with Orthogonal Bases and Closed Formulae

    Giulio Crisanti🇮🇹 · Sid Smith🇬🇧

    We present a prescription for choosing orthogonal bases of differential $n$-forms belonging to quadratic twisted period integrals, with respect to the intersection number inner product. To evaluate these inner products, we additionally propose a new closed formula for intersection numbers beyond $\mathrm{d}\log$ forms. These findings allow us to systematically construct orthonormal bases between twisted period integrals of this type. In the context of Feynman integrals, this represents all diagrams at one-loop.

    ↳ hep-thhep-phJHEP(2024)·20 citations
33. 33*

    Strange quark stars: the role of excluded volume effects

    G. Lugones🇧🇷 · A.G. Grunfeld🇦🇷

    We study cold strange quark stars employing an enhanced version of the quark-mass density-dependent model which incorporates excluded volume effects to address non-perturbative QCD repulsive interactions. We provide a comparative analysis of our mass formula parametrization with previous models from the literature. We identify the regions within the parameter space where three-flavor quark matter is more stable than the most tightly bound atomic nucleus (stability window). Specifically, we show that excluded volume effects do not change the Gibbs free energy per baryon at zero pressure, rendering the stability window unaffected. The curves of pressure versus energy density exhibit various shapes -- convex upward, concave downward, or nearly linear -- depending on the mass parametrization. This behavior results in different patterns of increase, decrease, or constancy in the speed of sound as a function of baryon number density. We analyze the mass-radius relationship of strange quark stars, revealing a significant increase in maximum gravitational mass and a shift in the curves towards larger radii as the excluded volume effect intensifies. Excluded volume effects render our models compatible with all modern astrophysical constraints, including the properties of the recently observed low-mass compact object HESSJ1731.

    ↳ nucl-thastro-ph.HEastro-ph.SRhep-phUniverse(2024)·8 citations
34. 34*

    Impact of the radial profile of atomic nuclei on observables in high-energy collisions

    Zhengxi Yan🇺🇸 · Jun Xu🇨🇳 · Jiangyong Jia🇺🇸

    In heavy-ion phenomenology, the nucleon density distribution in colliding nuclei is commonly described by a two-parameter Woods-Saxon (WS) distribution. However, this approach overlooks the detailed radial structure in the density distribution that arises from the quantal filling patterns of neutrons and protons. These fine structures, as estimated by the Skyrme-Hartree-Fock density functional, cause slight deviations in heavy-ion observables from the WS baseline, which cannot be captured by simply readjusting the WS parameters. These deviations depend on centrality and observable but often exhibit similar shapes for different nuclei. To fully exploit the exceptional sensitivity of isobar collisions to nuclear structure, such fine structures should be considered.

    ↳ nucl-thhep-phnucl-exPRC(2024)·1 citation
35. 35*

    Ab-initio electroweak corrections to superallowed $\beta$ decays and their impact on $V_{ud}$

    Vincenzo Cirigliano🇺🇸 · Wouter Dekens🇺🇸 · Jordy de Vries🇳🇱 · Stefano Gandolfi🇺🇸 · Martin Hoferichter🇨🇭 · Emanuele Mereghetti🇺🇸

    Radiative corrections are essential for an accurate determination of $V_{ud}$ from superallowed $\beta$ decays. In view of recent progress in the single-nucleon sector, the uncertainty is dominated by the theoretical description of nucleus-dependent effects, limiting the precision that can currently be achieved for $V_{ud}$. In this work, we provide a detailed account of the electroweak corrections to superallowed $\beta$ decays in effective field theory (EFT), including the power counting, potential and ultrasoft contributions, and factorization in the decay rate. We present a first numerical evaluation of the dominant corrections in light nuclei based on Quantum Monte Carlo methods, confirming the expectations from the EFT power counting. Finally, we discuss strategies how to extract from data the low-energy constants that parameterize short-distance contributions and whose values are not predicted by the EFT. Combined with advances in ab-initio nuclear-structure calculations, this EFT framework allows one to systematically address the dominant uncertainty in $V_{ud}$, as illustrated in detail for the ${}^{14}$O $\to$ ${}^{14}$N transition.

    ↳ nucl-thhep-exhep-lathep-ph+1PRC(2024)·42 citations
36. 36*

    On the deep superstring spectrum

    Thomas Basile🇧🇪 · Chrysoula Markou🇧🇪

    We propose a covariant method of constructing entire trajectories of physical states in superstring theory in the critical dimension. It is inspired by a recently developed covariant technology of excavating bosonic string trajectories, that is facilitated by the observation that the Virasoro constraints can be written as linear combinations of lowering operators of a bigger algebra, namely a symplectic algebra, which is Howe dual to the spacetime Lorentz algebra. For superstrings, it is the orthosymplectic algebra that appears instead, with its lowest weight states forming the simplest class of physical trajectories in the NS sector. To construct the simplest class in the R sector, the lowest weight states need to be supplemented with other states, which we determine. Deeper trajectories are then constructed by acting with suitable combinations of the raising operators of the orthosymplectic algebra, which we illustrate with several examples.

    ↳ hep-thhep-phJHEP(2024)·20 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.