Fri·Feb 23, 2024Friday·February 23, 2024

1. 01*

   Introductory visual lecture on QCD at large-$N_c$: bound states, chiral models, and phase diagram

   Francesco Giacosa🇵🇱

   In these lectures, we present the behavior of conventional $\bar{q}q$ mesons, glueballs, and hybrids in the large-$N_c$ limit of QCD. To this end, we use an approach based on rather simple NJL-like bound-state equations. The obtained large-$N_c$ scaling laws are general and coincide with the known results. A series of consequences, such as the narrowness of certain mesons and the smallness of some interaction types, the behavior of chiral and dilaton models at large-$N_c,$ and the relation to the compositeness condition and the standard derivation of large-$N_c$ results, are explained. The bound-state formalism shows also that mesonic molecular and dynamically generated states do not form in the large-$N_c$ limit. The same fate seems to apply also for tetraquark states, but here further studies are needed. Next, following the same approach, baryons are studied as bound states of a generalized diquark ($N_c-1$ antisymmetric object) and a quark. Similarities and differences with regular mesons are discussed. All the standard scaling laws for baryons and their interaction with mesons are correctly reproduced. The behavior of chiral models involving baryons and describing chirally invariant mass generation is investigated. Finally, properties of QCD in the medium at large-$N_c$ are studied: the deconfinement phase transition is investigated along the temperature and the chemical potential directions, respectively. Within the QCD phase diagrams, the features of different models at large-$N_c$ are reviewed and the location of the critical endpoint is discussed. In the end, the very existence of nuclei and the implications of large-$N_c$ arguments for neutron stars are outlined.

   hep-phhep-thnucl-thActa Phys.Polon.B(2024)·4 citations
2. 02*

   Constraints on new physics with (anti)neutrino-nucleon scattering data

   Oleksandr Tomalak🇺🇸 · Minerba Betancourt🇺🇸 · Kaushik Borah🇺🇸 · Richard J. Hill🇺🇸 · Thomas Junk🇺🇸

   New physics contributions to the (anti)neutrino-nucleon elastic scattering process can be constrained by precision measurements, with controlled Standard Model uncertainties. In a large class of new physics models, interactions involving charged leptons of different flavor can be related, and the large muon flavor component of accelerator neutrino beams can mitigate the lepton mass suppression that occurs in other low-energy measurements. We employ the recent high-statistics measurement of the cross section for ${\bar{\nu }}_{\mu }p\to {\mu }^{+}n$ scattering on the hydrogen atom by MINERvA to place new confidence intervals on tensor and scalar neutrino-nucleon interactions: $\mathfrak{Re}{C}_T=-1_{-13}^{+14}\times 10^{-4}$, $|\mathfrak{Im}{C}_T|\le 1.3\times 10^{-3}$, and $|\mathfrak{Im}{C}_S|=45_{-19}^{+13}\times 10^{-3}$. These results represent a reduction in uncertainty by a factor of $2.1$, $3.1$, and $1.2$, respectively, compared to existing constraints from precision beta decay.

   hep-phhep-exnucl-exnucl-thPLB(2024)·7 citations
3. 03*

   Finite-energy sum rules at finite chemical potential and zero temperature

   Alfredo Raya🇲🇽 · Cristian Villavicencio🇨🇱

   In this article we explore the effect of chemical potential at zero temperature in the implementation of in-medium effects in the perturbative sector in finite energy sum rules. For this purpose, we explore the axial, axial-pseudoscalar and pseudoscalar current correlators involving charged pions. The inclusion of non-normal ordered condensates with chemical potential effects in the operator mixing is considered. As a result, the contribution of the operator mixing with chemical potential dependence cancels all the explicit chemical potential contribution of the perturbative sector, aligned with the so-called "silver blaze problem". We find an abrupt transition when $\mu =\sqrt{s_0}/2$, with $s_0$ representing the hadronic continuum threshold. Exploring beyond this critical chemical potential we found similarities with low-energy effective meson models at high chemical potential.

   hep-phnucl-thEPJC(2025)·0 citations
4. 04*

   Center-of-mass recoil effects on the annihilation and formation of dark matter bound pairs

   Simone Biondini🇨🇭 · Nora Brambilla🇩🇪 · Gramos Qerimi🇩🇪 · Antonio Vairo🇩🇪

   For a quantitative investigation on the time evolution of heavy thermal dark matter at and after thermal freeze-out, near-threshold processes need to be taken into account which have a large impact on the observed dark matter relic abundance. In this conference paper, we study the recoil effect of heavy dark matter pairs in a thermal bath and compute the annihilation cross section and the decay width as well as the bound-state formation cross section of dark matter fermion-antifermion pairs in the laboratory frame within the framework of potential non-relativistic effective field theories at finite temperature. For the considered hierarchy of energy scales, we highlight the effect of the recoil corrections to the thermal rates.

   hep-phPoS(2024)·2 citations
5. 05*

   The quark flavor-violating ALPs in light of B mesons and hadron colliders

   Tong Li🇨🇳 · Zhuoni Qian🇨🇳 · Michael A. Schmidt🇦🇺 · Man Yuan🇨🇳

   The axion-like particle (ALP) may induce flavor-changing neutral currents (FCNCs) when their Peccei-Quinn charges are not generation universal. The search for flavor-violating ALP couplings with a bottom quark so far focused on FCNC processes of $B$ mesons at low energies. The recent measurements of $B\to K+X$ rare decays place stringent bounds on the quark flavor violations of a light ALP in different decay modes. In this work we propose a novel direct search for bottom flavor-violating interaction of a heavy ALP at the LHC and its upgrades, namely QCD production of an ALP associated with one $b$ jet and one light jet $pp\to bja$. We consider the decay of the ALP to photons, muons and invisible ALP decays. The Boosted Decision Tree (BDT) algorithm is used to analyze the events and we train the BDT classifier by feeding in the kinematic observables of signal and backgrounds. Finally, we show the complementarity between the search prospects of hadron colliders and the low-energy $B$ meson constraints from $B$ meson mixing and $B$ meson decays to a light ALP.

   hep-phhep-exJHEP(2024)·20 citations
6. 06*

   Phenomenology of vector-meson electroproduction on spinless targets

   S.I. Manaenkov🇷🇺

   Advantages of the amplitude method for the vector-meson-production description in respect of the spin-density-matrix-element (SDME) method are discussed. It is shown that for any nonzero amplitudes the angular distribution of final particles is non-negative. The exact formula for $R=\frac{d{\sigma }_L}{dt}/\frac{d{\sigma }_T}{dt}$ in terms of the SDMEs for spinless targets and the new approximate formula for nucleons are presented.

   hep-phPhys.Atom.Nucl.(2024)·0 citations
7. 07*

   Properties of the ground and excited states of triply heavy spin-1/2 baryons

   Z. Rajabi Najjar🇮🇷 · K. Azizi🇮🇷 · H. R. Moshfegh🇮🇷

   We study the triply heavy spin-1/2 baryons with quark contents $ccb$ and $bbc$, and calculate their mass and residue using QCD sum rules. In the calculations, we consider the ground (1S), first orbitally excited (1P) and first radially excited (2S) states. Aiming to achieve higher accuracies in the results, we perform the computations by taking into account the non-perturbative operators up to eight mass dimensions. We compare our results with the predictions of other theoretical studies existing in the literature. The obtained results may help experimental groups in their search for these yet unseen, but previously predicted by the quark model, interesting particles.

   hep-phhep-exhep-latEPJC(2024)·14 citations
8. 08*

   Leptogenesis consequences of trimaximal mixing and $\mu$-$\tau$ reflection symmetry in the most minimal seesaw model

   Zhen-hua Zhao🇨🇳 · Hong-Yu Shi🇨🇳 · Yan Shao🇨🇳

   In this paper we have studied the realizations of the popular TM1 neutrino mixing and neutrino $\mu$-$\tau$ reflection symmetry (which are well motivated from the neutrino oscillation data and lead to interesting phenomenological consequences) in the most minimal seesaw model with a pseudo-Dirac pair of right-handed neutrinos, and their consequences for leptogenesis. In order to realize the low-scale resonant leptogenesis scenario, we have considered two possible ways of generating the tiny mass splitting between the two right-handed neutrinos: one way is to modify their Majorana mass matrix to a form as shown in Eq. (25); the other way is to consider the renormalization-group corrections for their masses. For the $\mu$-$\tau$ reflection symmetry, in order for leptogenesis to work, we have further considered the flavor-dependent conversion efficiencies from the lepton asymmetry to the baryon asymmetry during the sphaleron processes, and its breaking via the renormalization-group corrections.

   hep-phPRD(2024)·2 citations
9. 09*

   Production of $P_{\psi s}^{\Lambda }(4338)$ from ${\Xi }_b$ decay

   Qi Wu🇨🇳 · Dian-Yong Chen🇨🇳

   In the present work, we investigate the production of the newly observed $P_{\psi s}^{\Lambda }(4338)$ state in ${\Xi }_b^{-}$ decay, where the $P_{\psi s}^{\Lambda }(4338)$ is assigned as a ${\Xi }_c\bar{D}$ molecular state. By using an effective Lagrangian approach, we evaluate the branching fractions of ${\Xi }_b^{-}\to P_{\psi s}^{\Lambda }(4338)K^{-}$ via the triangle loop mechanism. The branching fractions of ${\Xi }_b^{-}\to P_{\psi s}^{\Lambda }(4338)K^{-}$ are in the order of $10^{-4}$; the result is compared with our previous work of ${\Xi }_b^{-}\to P_{\psi s}^{\Lambda }(4459)K^{-}$. We also predict the ratio of $P_{\psi s}^{\Lambda }(4459)$ and $P_{\psi s}^{\Lambda }(4338)$ productions in the decay ${\Xi }_b^{-}\to P_{\psi s}^{\Lambda }{K}^{-}\to J/\psi \Lambda K^{-}$. The predicted branching fractions and their ratios could be tested experimentally, which may be helpful for understanding the molecular picture of $P_{\psi s}^{\Lambda }(4338)$ as well as other hidden-charm pentaquark states with strangeness. Moreover, the experimental potential of observing $P_{\psi s}^{\Lambda }(4338)$ in the ${\Xi }_b^{-}\to K^{-}J/\psi \Lambda$ is discussed.

   hep-phPRD(2024)·14 citations
10. 10*

    Baryogenesis and leptogenesis with relativistic bubble walls

    Miguel Vanvlasselaer🇧🇪

    In this talk, we study the impact of first order phase transitions with fast bubble walls on mechanisms of leptogenesis and baryogenesis. We begin our exploration with the usual leptogenesis where the breaking of $B-L$ occurs via a PT with fast walls. Then we move to a more exotic case where the $B-L$ breaking phase transition creates heavy particles in the plasma and catalizes the leptogenesis. Finally, we apply the same production mechanism to the EWPT at low energy and build a new model of EWBG. Those models are all original and contain crucial new phenomenological aspects like the emission of large amount of Gravitational waves.

    hep-phastro-ph.COPoS(2024)·1 citation
11. 11*

    Detecting a Fifth-Force Gauge Boson via Superconducting Josephson Junctions

    Yu Cheng🇨🇳 · Jie Sheng🇨🇳 · Tsutomu T. Yanagida🇯🇵

    A new fifth force between particles carrying $B-L$ charges is well-motivated by the intriguing $U(1{)}_{B-L}$ extension of the standard model. The gauge boson mediator, Féeton, also serves as a dark matter candidate. In this letter, we propose a novel experimental design to detect the quantum phase difference caused by this fifth force using a superconducting Josephson junction. We find that the experiment has the best sensitivity to the gauge coupling when the gauge boson is within the mass range of $0.01$eV to $10$eV, which is an interesting mass region for the Féeton dark matter. This opens up a new avenue for the measurement of new physics at small scale below millimeter.

    hep-phquant-phPLB(2025)·9 citations
12. 12*

    Radiative Corrections in Super Rosenbluth Experiments

    Quinn Stefan🇺🇸 · Axel Schmidt🇺🇸

    Super Rosenbluth experiments, elastic electron-proton scattering experiments that eschew traditional electron detection and opt instead for the detection of the recoiling proton, have several experimental advantages. One claimed advantage is that radiative corrections are more favorable, i.e., smaller and with less kinematic dependence. In this paper, we explore this claim by conducting Monte Carlo simulations of both Super Rosenbluth and traditional Rosenbluth experiments with different models of radiative effects. When using a model that employs the peaking approximation, we indeed confirm the reduced kinematic dependence of the radiative corrections. However, we find that more sophisticated models that avoid the peaking approximation are unable to produce numerically stable results, due to a large enhancement to the cross section for bremsstrahlung radiation from the proton when the momentum transfer, $Q^2$, approaches zero. Since this enhancement is not modelled in the peaking approximation, a more robust approach to radiative corrections in Super Rosenbluth experiments is needed.

    hep-phnucl-exnucl-thEPJA(2024)·2 citations
13. 13*

    FlexibleSUSY extended to automatically compute physical quantities in any Beyond the Standard Model theory: Charged Lepton Flavor Violation processes, Higgs decays, and user-defined observables

    Uladzimir Khasianevich🇩🇪 · Wojciech Kotlarski🇵🇱 · Dominik Stöckinger🇩🇪 · Alexander Voigt🇩🇪

    FlexibleSUSY is a framework for the automated computation of physical quantities (observables) in models beyond the Standard Model (BSM). This paper describes an extension of FlexibleSUSY which allows to define and add new observables that can be enabled and computed in applicable user-defined BSM models. The extension has already been used to include Charged Lepton Flavor Violation (CLFV) observables, but further observables can now be added straightforwardly. The paper is split into two parts. The first part is non-technical and describes from the user's perspective how to enable the calculation of predefined observables, in particular CLFV observables. The second part of the paper explains how to define new observables such that their automatic computation in any applicable BSM model becomes possible. A key ingredient is the new NPointFunctions extension which allows to use tree-level and loop calculations in the model-independent setup of observables. Three examples of increasing complexity are fully worked out. This illustrates the features and provides code snippets that may be used as a starting point for implementation of further observables.

    hep-phComput.Phys.Commun.(2024)·2 citations
14. 14*

    Production of singly charm pentaquark from meson-baryon interaction in B decay

    Na Li🇨🇳 · Ye Xing🇨🇳 · Ke-Fan Jiang🇨🇳

    In the paper, we discuss the possible interpretation of the $J^P=1/2^{-}$ singly charm pentaquark as hadronic molecules. With the effective Lagrangian method, we further analyze the production properties of singly charm pentaquark from decays of $B$ meson, including strong coupling constants and production branching ratios of the charm pentaquark. Our numerical results show that the branching ratio of production of pentaquark from B meson can reach to order of $10^{-6}$.

    hep-phPRD(2024)·3 citations
15. 15*

    On electroweak corrections to neutral current Drell-Yan with the POWHEG BOX

    Mauro Chiesa🇮🇹 · Clara Lavinia Del Pio🇮🇹 · Fulvio Piccinini🇮🇹

    Motivated by the requirement of a refined and flexible treatment of electroweak corrections to the neutral current Drell-Yan process, we report on recent developments on various input parameter/renormalization schemes for the calculation of fully differential cross sections, including both on-shell and MSbar schemes. The latter are particularly interesting for direct determinations of running couplings at the highest LHC energies. The calculations feature next-to-leading order precision with additional higher order contributions from universal corrections such as $\Delta \alpha$ and $\Delta \rho$. All the discussed input parameter/renormalization scheme options are implemented in the package of POWHEG-BOX-V2 dedicated to the neutral current Drell-Yan simulation, i.e. Z_ew-BMNNPV, which is used to obtain the presented numerical results. In particular, a comprehensive analysis on physical observables calculated with different input parameter/renormalization schemes is presented, addressing the Z peak invariant mass region as well as the high energy window. We take the opportunity of reporting also on additional improvements and options introduced in the package Z_ew-BMNNPV after svn revision 3376, such as different options for the treatment of the hadronic contribution to the running of the electromagnetic coupling and for the handling of the unstable Z resonance.

    hep-phEPJC(2024)·26 citations
16. 16*

    The cosmological constant and scale hierarchies with emergent gauge symmetries

    Steven D. Bass🇵🇱

    Motivated by the stability of the electroweak Higgs vacuum we consider the possibility that the Standard Model might work up to large scales between about $10^{10}$ GeV and close to the Planck scale. A plausible scenario is an emergent Standard Model with gauge symmetries originating in some topological like phase transition deep in the ultraviolet. In this case the cosmological constant scale and neutrino masses should be of similar size, suppressed by factor of the large scale of emergence. The key physics involves a subtle interplay of Poincaré invariance, mass generation and renormalisation group invariance. The Higgs mass would be environmentally selected in connection with vacuum stability. Consequences for dark matter scenarios are discussed.

    hep-phastro-ph.COgr-qcPhil.Trans.Roy.Soc.Lond.A(2023)·10 citations
17. 17*

    Full quantum tomography of top quark decays

    J. A. Aguilar-Saavedra🇪🇸

    Quantum tomography in high-energy physics processes has usually been restricted to the spin degrees of freedom. We address the case of top quark decays $t\to Wb$, in which the orbital angular momentum ($L$) and the spins of $W$ and $b$ are intertwined into a 54-dimensional $LWb$ density operator. The entanglement between $L$ and the $W$ or $b$ spin is large and could be determined for decays of single top quarks produced at the Large Hadron Collider with Run 2 data. With the foreseen statistical and systematic uncertainties, the significance is well above $5\sigma$ from the separability hypothesis for $L$-$W$ entanglement, and $3.2\sigma$ for $L$-$b$. These would be the first entanglement measurements between orbital and spin angular momenta in high-energy physics. Likewise, the genuine tripartite entanglement between $L$ and the two spins could be established with more than $5\sigma$. The method presented paves the way for similar measurements in other processes.

    hep-phhep-exquant-phPLB(2024)·31 citations
18. 18*

    TMD factorisation for diffractive jets in photon-nucleus interactions

    S. Hauksson🇫🇷 · E. Iancu🇫🇷 · A.H. Mueller🇺🇸 · D.N. Triantafyllopoulos🇮🇹 · S.Y. Wei🇨🇳

    Using the colour dipole picture and the colour glass condensate effective theory, we study the diffractive production of two or three jets via coherent photon-nucleus interactions at high energy. We consider the hard regime where the photon virtuality and/or the transverse momenta of the produced jets are much larger than the saturation momentum $Q_s$ of the nuclear target. We show that, despite this hardness, the leading-twist contributions are controlled by relatively large parton configurations, with transverse sizes $R\sim 1/Q_s$, which undergo strong scattering and probe gluon saturation. For exclusive dijets, this implies that both final jets have semi-hard transverse momenta ($P_{\perp }\sim Q_s$) and that one of them is aligned with the photon. The dominant contributions to the diffractive production of hard dijets ($P_{\perp }\gg Q_s$) rather come from three-jet final states, which are very asymmetric and will be referred to as 2+1 jets: two of the jets are hard, while the third one is semi-hard. We demonstrate that the leading-twist contributions to both exclusive dijets and the diffractive production of 2+1 jets admit transverse-momentum dependent (TMD) factorisation, in terms of quark and gluon diffractive TMD distribution functions, for which we obtain explicit expressions from first principles. We show that the contribution of 2+1 jets to diffractive SIDIS (semi-inclusive deep inelastic scattering) takes the form of one step in the DGLAP evolution of the quark diffractive PDF.

    hep-phnucl-thJHEP(2024)·27 citations
19. 19*

    Catani's generalization of collinear factorization breaking

    Leandro Cieri🇪🇸 · Prasanna K. Dhani🇪🇸 · Germán Rodrigo🇪🇸

    We consider the most general form of soft and collinear factorization for hard-scattering amplitudes to all orders in perturbative Quantum Chromodynamics. Specifically, we present the generalization of collinear factorization to configurations with several collinear directions, where the most singular behaviour is encoded by generalized collinear splitting amplitudes that manifestly embed the breaking of strict collinear factorization in space-like collinear configurations. We also extend the analysis to the simultaneous soft-collinear factorization with multiple collinear directions where na\"ıve multiplicative factorization does not hold. As an illustrative example of factorization breaking, we present explicit results at the one-loop level in the soft-collinear limit.

    hep-phhep-exhep-thPRD(2026)·24 citations
20. 20*

    Generalized eikonal identities for charged currents

    Ryan Plestid🇺🇸

    We discuss QED radiative corrections to contact operators coupling two heavy fields and one light field. New eikonal identities are derived in the static limit that demonstrate the equivalence of a class of ladder graphs to an equivalent theory with a single heavy-light vertex and a background Coulomb field which communicates exclusively with the light field. We apply these new identities to nuclear beta decays and demonstrates that the "independent particle model" used by Jaus, Rasche, Sirlin \& Zucchini is closely related, though not identical, to a model independent EFT calculation.

    hep-phhep-thnucl-thJHEP(2024)·10 citations
21. 21*

    Exclusion bounds for neutral gauge bosons

    Zoltán Péli🇭🇺 · Zoltán Trócsányi🇭🇺

    We study how the recent experimental results constrain the gauge sectors of U(1) extensions of the standard model using a novel representation of the parameter space. We determine the bounds on the mixing angle between the massive gauge bosons, or equivalently, the new gauge coupling as a function of the mass $M_{Z^{\prime }}$ of the new neutral gauge boson $Z^{\prime }$ in the approximate range $(10^{-2},10^4)$GeV/$c^2$. We consider the most stringent bounds obtained from direct searches for the $Z^{\prime }$. We also exhibit the allowed parameter space by comparing the predicted and measured values of the $\rho$ parameter and those of the mass of the $W$ boson. Finally, we discuss the prospects of $Z^{\prime }$ searches at future colliders.

    hep-phPRD(2024)·4 citations
22. 22*

    Hidden-Bottom Pentaquarks: Mass Spectrum, Magnetic Moments and Partial Widths

    Ankush Sharma🇮🇳 · Alka Upadhyay🇮🇳

    By taking into light the discovery of pentaquark structures like $P_{\psi s}^{\Lambda }(4338{)}^0$, $P_c(4380)$ and $P_c(4450)$, we performed the spectroscopy of hidden-bottom pentaquarks. By utilizing special unitary representations, we systematically classified the hidden bottom pentaquarks into two distinct configurations within the SU(3) flavor representation: the octet and decuplet. In this study, we employed an extended version of the GR mass formula along with the effective mass scheme to provide estimations of the masses associated with hidden-bottom pentaquarks. Furthermore, we extend our analysis to estimate the magnetic moments using the effective mass scheme and screened charge scheme. Moreover, by employing the effective Lagrangian, we computed the partial widths for the octet configuration. This comprehensive analysis offers crucial insights into the decay mechanisms and lifetimes of these exotic particles, enhancing our understanding of their fundamental properties. Our findings, which include calculations of masses and magnetic moments, demonstrate reasonable agreement with existing theoretical predictions.

    hep-phEur.Phys.J.Plus(2024)·11 citations
23. 23*

    Universal predictions of Siegel modular invariant theories near the fixed points

    Gui-Jun Ding🇨🇳 · Ferruccio Feruglio🇮🇹 · Xiang-Gan Liu🇺🇸

    We analyze a general class of locally supersymmetric, CP and modular invariant models of lepton masses depending on two complex moduli taking values in the vicinity of a fixed point, where the theory enjoys a residual symmetry under a finite group. Like in models that depend on a single modulus, we find that all physical quantities exhibit a universal scaling with the distance from the fixed point. There is no dependence on the level of the construction, the weights of matter multiplets and their representations, with the only restriction that electroweak lepton doublets transform as irreducible triplets of the finite modular group. Also the form of the kinetic terms, which here are assumed to be neither minimal nor flavor blind, is irrelevant to the outcome. The result is remarkably simple and the whole class of examined theories gives rise to five independent patterns of neutrino mass matrices. Only in one of them, the predicted scaling agrees with the observed neutrino mass ratios and lepton mixing angles, exactly as in single modulus theories living close to $\tau =i$.

    hep-phJHEP(2024)·19 citations
24. 24*

    Upper Bound on the Speed of Sound in Nuclear Matter from Transport

    Mauricio Hippert🇺🇸 · Jorge Noronha🇺🇸 · Paul Romatschke🇺🇸

    We point out that there is an upper bound on the speed of sound squared given by $c_s^2\le 0.781$ valid for all known systems described by relativistic transient hydrodynamics where calculations of certain ratios of hydrodynamic transport coefficients can be performed from first principles. Assuming this bound is valid for ultradense matter implies that the maximum mass of isolated (non-rotating) neutron stars cannot be larger than 2.7 solar masses.

    ↳ nucl-thastro-ph.HEhep-phPLB(2025)·27 citations
25. 25*

    High Frequency Gravitational Wave Bounds from Galactic Neutron Stars

    Virgile Dandoy🇩🇪 · Toni Bertólez-Martínez🇪🇸 · Francesco Costa🇩🇪

    High-Frequency Gravitational Waves (HFGWs) constitute a unique window on the early Universe as well as exotic astrophysical objects. If the current gravitational wave experiments are more dedicated to the low frequency regime, the graviton conversion into photons in a strong magnetic field constitutes a powerful tool to probe HFGWs. In this paper, we show that neutron stars, due to their extreme magnetic field, are a perfect laboratory to study the conversion of HFGWs into photons. Using realistic models for the galactic neutron star population, we calculate for the first time the expected photon flux induced by the conversion of an isotropic stochastic gravitational wave background in the magnetosphere of the ensemble of neutron stars present in the Milky Way. We compare this photon flux to the observed one from several telescopes and derive upper limits on the stochastic gravitational wave background in the frequency range $10^8\mathrm{Hz}$ - $10^{25}\mathrm{Hz}$. We find our limits to be competitive in the frequency range $10^8\mathrm{Hz}$ - $10^{15}\mathrm{Hz}$.

    ↳ gr-qcastro-ph.HEhep-phJCAP(2024)·23 citations
26. 26*

    Broadband noise and quasi-periodic oscillation characteristics of the X-ray pulsar RX J0440.9+4431

    P. P. Li🇺🇸 · L. Tao🇨🇳 · R. C. Ma · M. Y. Ge · Q. C. Zhao🇨🇳 · S. J. Zhao🇨🇳 · L. Zhang🇨🇳 · Q. C. Bu · L. D. Kong · Y. L. Tuo · L. Ji · S. Zhang🇨🇳 and 6 other authors

    We present a comprehensive timing analysis on the Be/X-ray binary pulsar RX J0440.9+4431 using observations from \textit{NICER} and \textit{Insight}-HXMT during the 2022--2023 outburst. The power density spectrum (PDS) of RX J0440.9+4431 exhibits typical aperiodic variability in X-ray flux across a wide frequency range. During a super-critical accretion state, we detect quasi-periodic oscillations (QPOs) at 0.2--0.5\,Hz in the light curves of five pulses for RX J0440.9+4431. The observed QPOs manifest during flares, while the flares appear at the peaks of the pulse profiles on a timescale of seconds and are primarily caused by an increase in hard photons. These flares can be explained by increased material ingestion in the accretion column at a fixed phase, primarily generating hard photons. Alternatively, an increase in accretion rate, independent of phase, may result in highly beamed hard photons within the accretion column, causing the flares. We argue the origin of QPOs to instabilities within the accretion flow. Additionally, we find that the break frequencies in the noise power spectra align well with $\propto L_{\mathrm{x}}^{3/7}$ across three orders of magnitude in the luminosity, which points to a relatively strong magnetic field in RX J0440.9+4431, estimated to be \textasciitilde$10^{13}$\,G.

    ↳ astro-ph.HEhep-phMNRAS(2024)·12 citations
27. 27*

    Color-flavor locked strange stars admixed with mirror dark matter and the observations of compact stars

    S.-H. Yang🇨🇳 · C.-M. Pi🇨🇳

    We investigate the structure and the tidal deformability of the color-flavor locked strange stars admixed with mirror dark matter. Assuming the stars in the GW170817 event have a mirror-dark-matter core or a mirror-dark-matter halo, the observations of the central compact object within the supernova remnant HESS J1731-347 and the compact objects in the GW190814 and GW170817 events could be explained simultaneously with a pairing gap much smaller than 200 MeV. In contrast, a pairing gap larger than about 200 MeV must be employed without the consideration of a mirror-dark-matter core (halo). More importantly, we find that for the case of the quartic coefficient $a_4<0.589$, if the mass fraction of the mirror mdark matter ($f_D$) of the compact stars in GW170817 is in a certain range (eg., $22.8\%<f_D<77.2\%$ for $a_4=0.55$), the minimum allowed value of the pairing gap could be less than 46.5 MeV (i.e., one half of the value of the strange quark mass which is taken as 93 MeV in this paper), which leads to the result that all astrophysical observations mentioned above could be satisfied without violating the conformal bound or the recently proposed positive trace anomally bound.

    ↳ astro-ph.HEhep-phJCAP(2024)·12 citations
28. 28*

    Two-dimensional models of core-collapse supernova explosions assisted by heavy sterile neutrinos

    Kanji Mori🇯🇵 · Tomoya Takiwaki🇯🇵 · Kei Kotake🇯🇵 · Shunsaku Horiuchi🇺🇸

    Core-collapse supernovae can be a copious source of sterile neutrinos, hypothetical particles that mix with active neutrinos. We develop two-dimensional stellar core-collapse models that incorporate the mixing between tau neutrinos and heavy sterile neutrinos -- those with the mass of 150--200 MeV -- to investigate signatures of sterile neutrinos in supernova observables. We find that the decay channel of a sterile neutrino into a pion and a tau neutrino can enhance the explosion energy and the synthesized nickel mass. Although the inclusion of sterile neutrinos considered in this study slightly reduce the neutrino and gravitational-wave signals, we find that they are still detectable for a Galactic event. Furthermore, we point out that if sterile neutrinos are as massive as ~200 MeV, they produce high-energy tau antineutrinos with energies of ~80 MeV, the detection of which can be a smoking signature of the sterile neutrinos and where Hyper-Kamiokande should play a pivotal role.

    ↳ astro-ph.HEhep-phPRD(2024)·9 citations
29. 29*

    Chern-Simons gravity and PT Symmetry

    Nick E. Mavromatos🇬🇷 · Sarben Sarkar🇬🇧

    This paper considers the possibility that, starting from a relativistic Hermitian quantum field theory in the ultraviolet (UV) regime, and applying a non-perturbative renormalization-group (RG) flow, we arrive at a situation where there are infrared (IR) singularities in the RG flow of couplings. The latter can be resolved by assuming that the theory can have a phase described by a related non-Hermitian PT-symmetric modification in the IR. The UV-to-IR (Hermitian-to-PT-symmetric) transition can occur in a single renormalization-group flow of the pertinent couplings, as demonstrated in concrete examples. When embedded in a gravitational setting such a transition can lead to a repulsive gravity phase. If there is a RG flow to a repulsive PT -symmetric gravity, then this would be an alternative to dark energy. The discussion here is presented in the context of a string-inspired Chern-Simons gravitational effective action, which involves a pseudoscalar (axion-like) field coupled to Abelian gauge fields and gravity; it may also hold more generally in gravity with torsion. The validity of such a scenario in realistic theories might alleviate the need for de Sitter phases in the current epoch of cosmological evolution, thus avoiding their associated conceptual and technical complications.

    ↳ hep-thgr-qchep-phPRD(2024)·11 citations
30. 30*

    $X(3872)$ Relevant $D{\bar{D}}^{\ast }$ Scattering in $N_f=2$ Lattice QCD

    Haozheng Li🇨🇳 · Chunjiang Shi🇨🇳 · Ying Chen🇨🇳 · Ming Gong🇨🇳 · Juzheng Liang🇨🇳 · Zhaofeng Liu🇨🇳 · Wei Sun🇨🇳

    We study the $S$-wave $D{\bar{D}}^{\ast }(I=0)$ scattering at four different pion masses $m_{\pi }$ ranging from 250 MeV to 417 MeV from $N_f=2$ lattice QCD. Three energy levels $E_{2,3,4}$ are extracted at each $m_{\pi }$. The analysis of $E_{2,3}$ using the effective range expansion (ERE) comes out with a shallow bound state below the $D{\bar{D}}^{\ast }$ threshold, and the phase shifts at $E_{3,4}$ indicate the possible existence of a resonance near 4.0 GeV. We also perform a joint analysis to $E_{2,3,4}$ through the $K$-matrix parameterization of the scattering amplitude. In this way, we observe a $D{\bar{D}}^{\ast }$ bound state whose properties are almost the same as that from the ERE analysis. At each $m_{\pi }$, this joint analysis also results in a resonance pole with a mass slightly above 4.0 GeV and a width around 40-60 MeV, which are compatible with the properties of the newly observed ${\chi }_{c1}(4010)$ by LHCb. More scrutinized lattice QCD calculations are desired to check the existence of this resonance.

    ↳ hep-lathep-exhep-ph21 citations
31. 31*

    Engineering and Revealing Dirac Strings in Spinor Condensates

    Gui-Sheng Xu · Mudit Jain🇺🇸 · Xiang-Fa Zhou · Guang-Can Guo🇨🇳 · Mustafa A. Amin🇺🇸 · Han Pu🇺🇸 · Zheng-Wei Zhou

    Artificial monopoles have been engineered in various systems, yet there has been no systematic study of the singular vector potentials associated with the monopole field. We show that the Dirac string, the line singularity of the vector potential, can be engineered, manipulated, and made manifest in a spinor atomic condensate. We elucidate the connection among spin, orbital degrees of freedom, and the artificial gauge, and show that there exists a mapping between the vortex filament and the Dirac string. We also devise a proposal where preparing initial spin states with relevant symmetries can result in different vortex patterns, revealing an underlying correspondence between the internal spin states and the spherical vortex structures. Such a mapping also leads to a new way of constructing spherical Landau levels, and monopole harmonics. Our observation provides insights into the behavior of quantum matter possessing internal symmetries in curved spaces.

    ↳ cond-mat.quant-gashep-phhep-thPRResearch(2024)·4 citations
32. 32*

    Towards the quark mass dependence of $T_{cc}^{+}$ from lattice QCD

    Sara Collins🇩🇪 · Alexey Nefediev🇸🇮 · M. Padmanath🇮🇳 · Sasa Prelovsek🇸🇮

    The $D{D}^{\ast }$ scattering phase shifts in the $T_{cc}^{+}=cc\bar{u}\bar{d}$ channel are extracted from lattice QCD for five different charm quark masses and a fixed light-quark mass corresponding to $m_{\pi }\simeq 280$~MeV. The phase shifts are analysed employing two approaches: effective range expansion and Lippmann--Schwinger equation derived in the effective field theory. In the latter case, the results imply an attraction at short range parametrised by contact terms and a slight repulsion at long range mediated by one-pion exchange with $m_{\pi }>m_{D^{\ast }}-m_D$. The poles in the amplitude across the complex energy plane are extracted and their trajectories are discussed as the charm quark mass is varied. Two complex conjugate poles corresponding to a resonance below threshold are found for $m_c$ close to the physical value. They turn into a pair of virtual states at the largest $m_c$ studied. With further increasing $m_c$, one virtual pole representing $T_{cc}^{+}$ is expected to move towards the two-body threshold and turn into a bound state. The light-quark mass dependence of the $T_{cc}^{+}$ pole is briefly discussed using the data on $D{D}^{\ast }$ scattering from other lattice collaborations.

    ↳ hep-lathep-phnucl-thPRD(2024)·69 citations
33. 33*

    Renormalization of the primordial inflationary power spectra

    Silvia Pla🇬🇧 · Ben A. Stefanek🇬🇧

    It has been suggested that the effects of renormalization significantly reduce the amplitude of the inflationary spectra at scales measurable in the cosmic microwave background. Via a gauge-invariant analysis, we compute the renormalized scalar and tensor power spectra and follow their evolution in an inflating universe that undergoes a transition to an FRW phase with a growing horizon. For perturbations originating from Minkowski vacuum fluctuations, we show that the standard prediction for the spectra on superhorizon scales is a late-time attractor, while they are UV finite at all times. Our result is independent of the equation of state after inflation, showing that the standard prediction is fully robust.

    ↳ gr-qchep-phhep-thPLB(2024)·10 citations
34. 34*

    Consistent particle physics in metric-affine gravity from extended projective symmetry

    Will Barker🇬🇧 · Sebastian Zell🇧🇪

    It is well-known that the Einstein-Hilbert action exhibits a projective invariance in metric-affine gravity, generated by a single vector (just like diffeomorphisms). However, this symmetry offers no protection against formulating inconsistent models, e.g., with ghost and strong coupling problems. In this letter, we observe that non-minimal kinetic terms of Dirac spinors point to a new extended projective (EP) symmetry generated by a pair of vectors. We prove that the most general EP-invariant theory (at most quadratic in field strengths) is naturally free from all pathologies. Its spectrum only features the massless graviton and a single additional scalar field arising from the square of the Holst curvature. The scalar potential is suitable for inflation and our model moreover contains effective 4-Fermi interactions capable of producing fermionic dark matter. Finally, we point out an alternative double-vector symmetry that similarly leads to a healthy theory with a propagating vector field.

    ↳ hep-thastro-ph.COgr-qchep-ph31 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.