Wed·Sep 27, 2023Wednesday·September 27, 2023

1. 01*

   QCD Running in Lepton Number Violating Meson and Tau Decays

   Marcela González🇨🇱 · Nicolás A. Neill🇨🇱

   Below the electroweak scale, new physics that violates lepton number in two units ($\Delta L=2$) and is mediated by heavy particle exchange can be parameterized by a dimension-9 low-energy effective Lagrangian. Operators in this Lagrangian involving first-generation quarks and leptons contribute to the short-range mechanism of neutrinoless double beta decay ($0\nu \beta \beta$) and therefore they are strongly constrained. On the other hand, operators with other quark and lepton families are bounded by the non-observation of different lepton number violating (LNV) meson and tau decays, such as $M_1^{-}\to M_2^{+}{\ell }_1^{-}{\ell }_2^{-}$ and ${\tau }^{-}\to {\ell }^{+}{M}_1^{-}{M}_2^{-}$. In this work, we calculate RGE-improved bounds on the Wilson coefficients involved in these decays. We calculate QCD corrections to the dimension-9 operator basis and find RG evolution matrices that describe the evolution of the Wilson coefficients across different energy scales. Unlike the running of operators involved in $0\nu \beta \beta$-decay, the general flavor structure leads to the mixing of not only different Lorentz structures but also of different quark-flavor configurations. Additionally, operators that vanish for the identical lepton case need to be added to the operator basis. We find new constraints on previously unbounded operators and the enhancement of bounds for specific Wilson coefficients. We also find new bounds coming from the mixing between operators with different quark-flavor configurations.

   hep-phPRD(2025)·1 citation
2. 02*

   New narrow resonance in the $e^{+}{e}^{-}\to \varphi \eta$ data by Belle collaboration

   Peter Lichard🇨🇿

   Fitting the recent $e^{+}{e}^{-}\text{ra}\varphi \eta$ data by the Belle collaboration with a theoretical formula reveals, besides the dominant $\varphi (1680)$ resonance, two narrow resonances: expected $\varphi (2170)$ resonance and an unexpected resonance with the mass of about 1851 MeV. Close proximity to the $X(1835)$ resonance suggests that the new resonance may be interpreted as the $p\bar{p}$ baryonium in an excited state. Follow-up analysis found the same resonance also in $e^{+}{e}^{-}\text{ra}\omega \eta$ data by CMD-3 experiment.

   hep-phhep-exPRD(2023)·2 citations
3. 03*

   Near-threshold hadron scattering with effective field theory

   Katsuyoshi Sone🇯🇵 · Tetsuo Hyodo🇯🇵

   When an exotic hadron locates near the threshold with the channel couplings, the internal structure of the exotic hadron is related to the scattering length. To incorporate the threshold effect, the Flatté amplitude has been often used to determine the scattering length. It is however known that an additional constraint is imposed on the Flatte amplitude near the threshold. We discuss this problem by using the effective field theory for the coupled-channel scattering.

   hep-phnucl-thEPJ Web Conf.(2024)·1 citation
4. 04*

   Finite volume effects of the Nambu-Jona-Lasinio model with the running coupling constant

   Shou-Zheng Su🇨🇳 · Ye-Yin Zhao🇨🇳 · Xin-Jian Wen🇨🇳

   With the Schwinger's proper-time formalism of the Nambu-Jona-Lasinio model, we investigate the finite volume effects in the presence of magnetic fields. Since the coupling constant $G$ can be influenced by strong magnetic fields, the model is solved with a running coupling constant $G(B)$ which is fitted by the lattice average $({\Sigma }_u+{\Sigma }_d)/2$ and difference ${\Sigma }_u-{\Sigma }_d$. The investigation mainly focuses on the constituent quark mass and the thermal susceptibility depending on the magnetic fields, the temperatures and the finite sizes. For the model in finite or infinite volume, the magnetic fields can increase the constituent quark mass while the temperatures can decrease it inversely. There is a narrow range of the box length that makes the effects of finite volume perform prominently. The model will behave close to infinite volume limit for larger box length. It is shown that the influence of finite volume can be changed by magnetic fields and temperatures. Finally, we discuss the thermal susceptibility depending on the temperature in finite volume in the presence of magnetic fields.

   hep-phhep-latJ.Phys.G(2025)·0 citations
5. 05*

   Threshold-cusp explanation for $X$ and $Z_{cs}$ in $B^{+}\to J/\psi \varphi K^{+}$

   S.X. Nakamura (Shandong Univ.)🇨🇳 · X. Luo (Anhui Univ.)🇨🇳

   Several $X$ and $Z_{cs}$ exotic hadrons were claimed in the LHCb's amplitude analysis on $B^{+}\to J/\psi \varphi K^{+}$. The data shows that all the peaks and also dips in the spectra are located at thresholds of seemingly relevant meson-meson channels. While the LHCb analysis fitted the peaks with Breit-Wigner resonances, threshold kinematical cusps might be the cause of such structures. We thus analyze the LHCb data considering the threshold cusps. Our model is simultaneously fitted to $J/\psi \varphi$, $J/\psi K^{+}$, and $K^{+}\varphi$ invariant mass distributions. The threshold cusps fit well all the $X$, $Z_{cs}$, and dip structures. Our analysis indicates that spin-parity of the $X(4274)$ and $X(4500)$ structures are $0^{-}$ and $1^{-}$, respectively. This is different from the LHCb's spin-parity assignments ($1^{+}$ and $0^{+}$). The number of fitting parameters can be significantly reduced by considering the relevant threshold cusps. Our analysis shows that $D_s^{(\ast )}{\bar{D}}^{\ast }$ scattering lengths are consistent with zero. This disfavors an explanation of $Z_{cs}(4000)$ and $Z_{cs}(4220)$ as $D_s^{(\ast )}{\bar{D}}^{\ast }$ molecules, which is consistent with lattice QCD via the SU(3) relation.

   hep-phhep-exnucl-thNuovo Cim.C(2024)·2 citations
6. 06*

   One-loop Matching of the Type-III Seesaw Model onto the Standard Model Effective Field Theory

   Xu Li🇨🇳 · Shun Zhou🇨🇳

   In previous works arXiv:2107.12133 and arXiv:2201.05082, we have performed the one-loop matching of both type-I and type-II seesaw models for neutrino masses onto the Standard Model Effective Field Theories (SMEFT). In the present paper, by matching the type-III seesaw model onto the SMEFT at the one-loop level, we complete this series of studies on the construction of low-energy effective field theories (EFTs) for the canonical seesaw models. After integrating out the heavy fermionic triplets in the type-III seesaw model via both functional and diagrammatic approaches, we find 33 dimension-six (dim-6) operators in the Warsaw basis and their Wilson coefficients, while the number of dim-6 operators is 31 (or 41) for the EFT of type-I (or type-II) seesaw model. Furthermore, we calculate the branching ratios of radiative decays of charged leptons in the EFT. Then, the relationship between the beta function of the quartic Higgs coupling $\lambda$ in the full theory and that of ${\lambda }_{\mathrm{EFT}}^{}$ in the EFT is clarified. Finally, we briefly discuss the phenomenological implications of three types of seesaw EFTs and propose working observables that are sensitive to the four-fermion operators, which could be used to distinguish among different seesaw models in collider experiments.

   hep-phhep-exJHEP(2024)·7 citations
7. 07*

   Three-loop $b\to s\gamma$ vertex with current-current operators

   Matteo Fael🇨🇭 · Fabian Lange🇩🇪 · Kay Schoenwald🇨🇭 · Matthias Steinhauser🇩🇪

   We compute three-loop vertex corrections to $b\to s\gamma$ induced by current-current operators. The results are presented as expansions in $m_c/m_b$ with numerical coefficients which allow to cover all relevant values for the heavy quark masses in different renormalization schemes. Moreover we provide for the first time analytic results for the next-to-leading order contribution. Our results present an important building block to the next-to-next-to-leading order interference contributions of the current-current operators $Q_1$ and $Q_2$ with the electric dipole operator $Q_7$.

   hep-phJHEP(2023)·12 citations
8. 08*

   The Q_{1,2}-Q_7 interference contributions to b -> s gamma at O(alpha_s^2) for the physical value of m_c

   M. Czaja🇵🇱 · M. Czakon🇩🇪 · T. Huber🇩🇪 · M. Misiak🇵🇱 · M. Niggetiedt🇩🇪 · A. Rehman🇨🇦 · K. Schönwald🇨🇭 · M. Steinhauser🇩🇪

   The B -> X_s gamma branching ratio is currently measured with around 5% accuracy. Further improvement is expected from Belle II. To match such a precision on the theoretical side, evaluation of O(alpha_s^2) corrections to the partonic decay b -> X_s^part gamma are necessary, which includes the b -> s gamma, b -> s g gamma, b -> s g g gamma, b -> s qbar q gamma decay channels. Here, we evaluate the unrenormalized contribution to b -> s gamma that stems from the interference of the photonic dipole operator Q_7 and the current-current operators Q_1 and Q_2. Our results, obtained in the cut propagator approach at the 4-loop level, agree with those found in parallel by Fael et al. who have applied the amplitude approach at the 3-loop level. Partial results for the same quantities recently determined by Greub et al. agree with our findings, too.

   hep-phEPJC(2023)·13 citations
9. 09*

   Unveiling Neutrino Mysteries with $\Delta (27)$ Symmetry

   Manash Dey🇮🇳 · Subhankar Roy🇮🇳

   An elegant model is proposed by extending the Standard Model using the $\Delta (27)\times Z_3\times Z_{10}$ symmetry within the framework of the Type-I + Type-II seesaw mechanism. This model is particularly noteworthy for its ability to restrict the atmospheric mixing angle, ${\theta }_{23}$, to specific values, and provides an explanation for the observed hierarchy of charged lepton masses. The neutrino mass matrix texture defined by three real parameters, predicts the three neutrino mass eigenvalues and the two Majorana phases. Furthermore, the model is tested against the experimental results of neutrino-less double beta ($0\nu \beta \beta$) decay and charged lepton flavour violation (cLFV) experiments.

   hep-phPLB(2025)·7 citations
10. 10*

    Axion emission from supernovae: a cheatsheet

    Pierluca Carenza🇸🇪

    Supernovae provide fascinating opportunities to study various particles and their interactions. Among these there are neutrinos, axions, and other light weakly interacting particles, which play a significant role in our understanding of fundamental physics. In this study, the focus lies on the recent advancements made in characterizing axion emission from nuclear matter within the context of supernovae. The main production mechanisms for axions coupled with nucleons, bremsstrahlung and pion-axion conversion, are extensively discussed. These findings shed light on the behavior of axions in dense and hot nuclear matter, encountered in these extreme astrophysical environments.

    hep-phEur.Phys.J.Plus(2023)·31 citations
11. 11*

    Rapidity distribution of pseudo-scalar Higgs boson to ${\text{NNLO}}_{\mathrm{A}}+\overline{\text{NNLL}}$

    V. Ravindran🇮🇳 · Aparna Sankar🇮🇳 · Surabhi Tiwari🇮🇳

    We present the differential predictions for the rapidity distribution of pseudo-scalar Higgs boson through gluon fusion at the LHC. These results are obtained taking into account the soft-virtual (SV) as well as the next-to-soft virtual (NSV) resummation effects to next-to-next-to-leading-logarithmic ($\overline{\mathrm{NNLL}}$) accuracy and matching them to the approximate fixed order next-to-next-to-leading-order ($\mathrm{NNL}{\mathrm{O}}_{\mathrm{A}}$) computation. We perform the resummation in two dimensional Mellin space using our recent formalism \cite{Ajjath:2020lwb} by limiting ourselves to the contributions only from gluon-gluon ($gg$) initiated channels. The $\mathrm{NNL}{\mathrm{O}}_{\mathrm{A}}$ rapidity distribution of pseudo-scalar Higgs is obtained by applying a ratio method on the NNLO rapidity distribution of the scalar Higgs boson. We also present the first analytical results of ${\mathrm{N}}^3\mathrm{LO}$ rapidity distribution of pseudo-scalar Higgs at SV+NSV accuracy. The phenomenological impacts of ${\mathrm{NNLO}}_{\mathrm{A}}+\overline{\mathrm{NNLL}}$ predictions for 13 TeV LHC are studied. We observe that, for $m_A$ =125(700) GeV, the SV+NSV resummation at $\overline{\mathrm{NNLL}}$ level brings about 14.76\% (11.48\%) corrections to the ${\mathrm{NNLO}}_{\mathrm{A}}$ results at the central scale value of ${\mu }_R={\mu }_F=m_A$. Further, we find that the sensitivity to the renormalisation scale gets improved substantially by the inclusion of NSV resummed predictions at $\overline{\mathrm{NNLL}}$ accuracy.

    hep-phPRD(2024)·5 citations
12. 12*

    $t\bar{t}jj$ -- NLO QCD corrections to top quark pair production and decays at the LHC

    Daniel Stremmer🇩🇪

    In these proceedings we present the calculation of NLO QCD corrections to $pp\to t\bar{t}jj$ in the dilepton decay channel. The narrow width approximation is used to model the decays of the top quark pair preserving spin correlations. Jet radiation and QCD corrections are consistently included in the production and decay of the top quarks. We discuss the size of NLO QCD corrections and the main theoretical uncertainties of fiducial cross sections at the integrated and differential level. In addition, we examine the contributions of jet radiation in the production and decay of the top-quark pair, as well as of a mixed configuration where jet radiation is present simultaneously in the production and decay stages.

    hep-phhep-exPoS(2023)·0 citations
13. 13*

    Two-Loop Amplitude Reduction with HELAC

    Giuseppe Bevilacqua🇬🇷 · Dhimiter Canko🇬🇷 · Costas Papadopoulos🇬🇷

    We discuss recent progress towards extending the Helac framework to the calculation of two-loop amplitudes. A general algorithm for the automated computation of two-loop integrands is described. The algorithm covers all the steps of the computation, from the generation of loop topologies up to the construction of recursion relations for two loop integrands. Finally, first steps towards the formulation of a new approach for reducing two-loop amplitudes to a basis of master integrals are discussed.

    hep-phPoS(2024)·6 citations
14. 14*

    Baryonium Dark Matter: Events with Circle Configurations in the Atmosphere and on the Surface of Earth

    O.I. Piskounova🇷🇺

    This research supposes the parallel study of the manifestations of Baryonium Dark Matter (BDM) in astroparticle collisions in the atmosphere and among the footprints of the massive extraterrestrial objects that fall on the surface of Earth. These objects differ from stone asteroids and are seen as lightning bolides that are burning with a blue flame. Since BDM is a QCD state, the characteristics of BDM disintegration events can be analyzed with the same Quark-Gluon Strings Model (QGSM) as hadroproproduction data on colliders. It was concluded that the HE event, which was detected in the stratosphere in 1975, differs from the collision of the nucleus. The signatures of such events are 1) the circle distribution of heavy secondary hadrons with almost nothing inside the ring and 2) the presence of heavy secondary particles with a mass out of range of known hadrons. The circle will also be the signature of heavy BDM conglomerate that disintegrate in the atmosphere (or in space) for a few similar lower-mass BDMs. These signatures should be observed in super-heavy BDM collapses on the Earth. The traces of such events are seen as circles of pits or shafts in the ground rocks. There are at least two pieces of evidence of such holes: cenotes on the Yucatan peninsula (Mexico) and pits in Durrington Walls (England). The vertical pits, or wells (because sometimes they are filled with water) have a depth of 5 - 50 meters. These super-heavy BDM collapses differ from the meteorite crash, because they do not form the craters. The existence of these places around the globe indicates the rare likelihood of meeting the super-massive BDM in proximity to Earth. The Tunguska meteorite could also be a BDM collapse. Finally, some suggestions are made about the emission of Baryonium Dark Matter toroidal conglomerates with the jets from giant active Supermassive Black Holes (SMBH).

    hep-phhep-exJ.Phys.Conf.Ser.(2025)·2 citations
15. 15*

    Factorization of covariant Feynman graphs for the effective action

    Gero von Gersdorff🇧🇷

    We prove a neat factorization property of Feynman graphs in covariant perturbation theory. The contribution of the graph to the effective action is written as a product of a massless scalar momentum integral that only depends on the basic graph topology, and a background-field dependent piece that contains all the information of spin, gauge representations, masses etc. We give a closed expression for the momentum integral in terms of four graph polynomials whose properties we derive in some detail. Our results can also be useful for standard (non-covariant) perturbation theory.

    hep-phhep-thJHEP(2023)·5 citations
16. 16*

    The $\eta /{\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}\gamma$ Decays within BHLS${}_2$ and the Muon HVP

    Maurice Benayoun🇫🇷 · Luigi DelBuono🇫🇷 · Fred Jegerlehner🇩🇪

    The departure of the latest FNAL experimental average for the muon anomalous magnetic moment $a_{\mu }=(g_{\mu }-2)/2$ measurements having increased from $4.2\sigma$ to $5.0\sigma$, with respect to the White Paper consensus, it may indicate a hint for new physics. As the most delicate piece of $a_{\mu }$ is its leading order HVP part $a_{\mu }^{HVP-LO}$, methods to ascertain its theoretical value are crucial to interpret this discrepancy. We propose to examine the dipion spectra from the $\eta /{\eta }^{\prime }\to {\pi }^{+}{\pi }^{-}\gamma$ decays in the Hidden Local Symmetry (HLS) context using its BHLS${}_2$ broken variant. We thus have at our disposal a framework where the close relationship of the dipion spectra from the $\eta /{\eta }^{\prime }$ and $\tau$ decays and of the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ annihilation can be simultaneously considered. A special focus is put to the high statistic dipion spectra from the $\eta$ decay collected by the KLOE/KLOE2 Collaboration and ${\eta }^{\prime }$ decay collected by the BESIII Collaboration, and it is shown that the BHLS${}_2$ framework provides a fair account of their dipion spectra. More precisely, it is first proven that a single Omnès representation real polynomial is requested, common to both the $\eta$ and ${\eta }^{\prime }$ dipion spectra. Moreover, it is shown that fits involving the $\eta /{\eta }^{\prime }/\tau$ dipion spectra, and excluding the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ annihilation data, allow for a prediction of the pion vector form factor data $F_{\pi }(s)$ which fairly agree with the usual dipion spectra collected in the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ annihilation channel. Even if more precise $\eta /{\eta }^{\prime }/\tau$ dipion spectra would help to be fully conclusive, this confirms the Dispersive Approach results for $a_{\mu }^{HVP-LO}$ and points towards a common non experiment-dependent origin to this tension with the now well accepted LQCD result.

    hep-phEPJC(2024)·4 citations
17. 17*

    Singlet-doublet Dirac fermion dark matter from Peccei-Quinn symmetry

    Robinson Longas🇨🇴 · Andres Rivera🇨🇴 · Cristian Ruiz🇨🇴 · David Suarez🇨🇴

    Weakly Interacting Massive Particles (WIMPs) and axions are arguably the most compelling dark matter (DM) candidates in the literature. Here, we consider a model where the PQ symmetry solves the strong CP problem, generates radiatively Dirac neutrino masses, and gives origin to multicomponent dark sector. Specifically, scotogenic Dirac neutrino masses arise at one-loop level. The lightest fermionic mediator acts as the second DM candidate due to a residual $Z_2$ symmetry resulting from the PQ symmetry breaking. The WIMP DM component resembles the well-known singlet-doublet fermion DM. While the lower WIMP dark mass region is usually excluded, our model reopens that portion of the parameter space (for DM masses below $\lesssim 100$ GeV). Therefore, we perform a phenomenological analysis that addresses the constraints from direct searches of DM, neutrino oscillation data, and charged lepton flavor violating (LFV) processes. The model can be tested in future facilities where DM annihilation into SM particles is searched for by neutrino telescopes.

    hep-phInt.J.Mod.Phys.A(2024)·3 citations
18. 18*

    Gluon-gluon fusion contribution to the productions of three gauge bosons at the LHC

    Jianpeng Dai🇨🇳 · Zhenghong Hu🇨🇳 · Tao Liu🇨🇳 · Jin Min Yang🇨🇳

    Productions of multiple gauge bosons at the LHC are sensitive to triple or quartic gauge couplings and thus provide a sensitive test for the electroweak sector of the Standard Model and allow for a probe of new physics. In this work we calculate the gluon-gluon initiate state contribution to the productions of three gauge bosons ($Z\gamma \gamma$, $ZZ\gamma$ and $W^{+}{W}^{-}\gamma$) at the LHC, which is formally part of NNLO effects compared to the LO quark-antiquark channels corrections. For each process we present the ratio between the gluon-gluon channels contribution and the quark-antiquark channels contribution. We found that such a ratio for $Z\gamma \gamma$ ($ZZ\gamma$) is of the order of $10^{-3}$ ($10^{-4}$), much smaller than the corresponding ratio for the diboson production due to the decrease of gluon PDF when more particles appear in the final states. These small ratios imply that gluon-gluon fusion contribution is phenomenological negligible for the productions of $Z\gamma \gamma$ and $ZZ\gamma$. However, for $W^{+}{W}^{-}\gamma$ production, the ratio is about 5\%, which is of the same order of magnitude as the ratio for $W^{+}{W}^{-}$ production due to the big cancellation between the amplitudes of quark-antiquark channels. While such an effect can be neglected currently at the LHC, it may be accessible at the HL-LHC.

    hep-phEPJC(2024)·0 citations
19. 19*

    Improved constraints for axion-like particles from 3-photon events at $e^{+}{e}^{-}$ colliders

    Aleksandr Pustyntsev🇩🇪 · Marc Vanderhaeghen🇩🇪

    Axions and axion-like particles (ALPs) are one of the most widely discussed extensions of the Standard Model when it comes to the strong CP problem and dark matter candidates. Current experiments are focused on the indirect searches of invisible pseudoscalars in a wide parameter range. In this paper we investigate limits on ALP mass, and its couplings to photons and leptons from 3-photon annihilation at $e^{+}{e}^{-}$ colliders. We provide detailed calculations and apply them to the particular kinematics of the Belle II experiment, covering the ALP mass range from few hundred MeV to around 10 GeV. Our results, which improve upon previous analyses by also including the ALP coupling to electrons, show that such future analyses will allow to significantly extend the ALP search range and impose much more stringent restrictions on their couplings.

    hep-phEPJC(2024)·6 citations
20. 20*

    Gravitational Production of Spin-3/2 Particles During Reheating

    Kunio Kaneta🇯🇵 · Wenqi Ke🇫🇷 · Yann Mambrini🇫🇷 · Keith A. Olive🇺🇸 · Sarunas Verner🇺🇸

    We compute the density of a spin-$\frac{3}{2}$ particle, the raritron, produced at the end of inflation due to gravitational interactions. We consider a background inflaton condensate as the source of this production, mediated by the exchange of a graviton. This production greatly exceeds the gravitational production from the emergent thermal bath during reheating. The relic abundance limit sets an absolute minimum mass for a stable raritron, though there are also model dependent constraints imposed by unitarity. We also examine the case of gravitational production of a gravitino, taking into account the goldstino evolution during reheating. We compare these results with conventional gravitino production mechanisms.

    hep-phastro-ph.COhep-thPRD(2023)·33 citations
21. 21*

    Software Citation in HEP: Current State and Recommendations for the Future

    Matthew Feickert🇺🇸 · Daniel S. Katz🇺🇸 · Mark S. Neubauer🇺🇸 · Elizabeth Sexton-Kennedy🇺🇸 · Graeme A. Stewart🇨🇭

    In November 2022, the HEP Software Foundation and the Institute for Research and Innovation for Software in High-Energy Physics organized a workshop on the topic of Software Citation and Recognition in HEP. The goal of the workshop was to bring together different types of stakeholders whose roles relate to software citation, and the associated credit it provides, in order to engage the community in a discussion on: the ways HEP experiments handle citation of software, recognition for software efforts that enable physics results disseminated to the public, and how the scholarly publishing ecosystem supports these activities. Reports were given from the publication board leadership of the ATLAS, CMS, and LHCb experiments and HEP open source software community organizations (ROOT, Scikit-HEP, MCnet), and perspectives were given from publishers (Elsevier, JOSS) and related tool providers (INSPIRE, Zenodo). This paper summarizes key findings and recommendations from the workshop as presented at the 26th International Conference on Computing in High Energy and Nuclear Physics (CHEP 2023).

    ↳ hep-exhep-phEPJ Web Conf.(2024)·2 citations
22. 22*

    Gauge-Invariant Scalar-Induced Gravitational Waves from Physical Observables

    Vincent Comeau🇨🇦

    This paper discusses the gauge issue touching the gravitational waves induced at the second order by the scalar modes of cosmological perturbations. These waves are known to depend on the gauge used for their calculation. In this paper, we propose a simple method of obtaining physically meaningful expressions for such scalar-induced gravitational waves at the leading order. The method is centred on well-defined observables, such as the magnetic part of the Weyl tensor, or the Cotton tensor of a slicing of spacetime, which vanish in the background and do not depend linearly on the scalar perturbations. Generalizing the Stewart-Walker lemma, it is shown that the gravitational waves contributing to such observables at the second order are automatically gauge-invariant, even when the observable itself does not vanish at the first order. In each case, the scalar-induced gravitational waves are related to the ones computed in the Newtonian gauge, first for a general background, and then for the particular case of a spacetime dominated by either radiation or cold matter.

    ↳ gr-qchep-phhep-th4 citations
23. 23*

    Symmetric teleparallel cosmology with boundary corrections

    Andronikos Paliathanasis🇿🇦

    We investigate the geometrodynamical effects of introducing the boundary term in symmetric teleparallel gravity. Specifically, we consider a homogeneous and isotropic universe in $f\left(Q,B\right)$, where $Q$ is the non-metricity scalar, and $B$ is the boundary term that relates the non-metricity and Ricci scalars. For the connection in the coincidence gauge, we find that the field equations are of fourth-order, and the fluid components introduced by the boundary are attributed to a scalar field. In the coincidence gauge, the cosmological field equations are equivalent to those of teleparallelism with a boundary term. Nevertheless, for the connection defined in the non-coincidence gauge, the geometrodynamical fluid consists of three scalar fields. We focus on the special case of $f\left(Q,B\right)=Q+F\left(B\right)$ theory, and we determine a new analytic cosmological solution that can explain the late-time acceleration of the universe and provide a geometric mechanism for the unification of dark energy with dark matter.

    ↳ gr-qchep-phmath-phmath.MPPhys.Dark Univ.(2024)·30 citations
24. 24*

    Probing the existence of \eta^3He mesic nucleus with a few-body approach

    Qian Wu🇨🇳 · Gang Xie🇨🇳 · Xurong Chen🇨🇳

    Motivated by the two recent observations in the WASA-at-COSY detector, we investigate the ${\eta }^3$He nucleus with the $\eta NNN$ few body method. We construct the effective $s$-wave energy dependent $\eta N$ potential which reproduce the $\eta N$ subthreshold scattering amplitude in the 2005 Green-Wycech model. It gives the $\eta$ separation energy and decay width of 0.19 MeV and 1.71 MeV, respectively. We also construct various sets of effective $s$-wave energy independent $\eta N$ potentials where the corresponding complex scattering lengths (a) are within the range given in most theoretical models. We obtain the bound ${\eta }^3$He nucleus with decay width of about 5 MeV when a is (1.0 fm, 0.3 fm), and of about 10 MeV when a is (1.0 fm, 0.5 fm).

    ↳ nucl-thhep-phPLB(2024)·1 citation
25. 25*

    Gravitational wave search through electromagnetic telescopes

    Asuka Ito🇯🇵 · Kazunori Kohri🇯🇵 · Kazunori Nakayama🇯🇵

    We study the graviton-photon conversion in the magnetic fields of the Earth, the Milky Way Galaxy, and intergalactic regions. Requiring that the photon flux converted from gravitons does not exceed the observed photon flux with telescopes, we derive upper limits on the stochastic gravitational waves in frequency ranges from $10^7$Hz to $10^{35}$Hz. Remarkably, the upper limits on $h^2{\Omega }_{\mathrm{GW}}$ could be less than unity in the frequency range of $10^{18}$-$10^{23}$ Hz in a specific case. The detection of gravitational waves using telescopes would open up a new avenue for high frequency gravitational wave observations.

    ↳ gr-qcastro-ph.COhep-phPTEP·32 citations
26. 26*

    Relativistic hydrodynamics with phase transition

    F. Taghinavaz🇮🇷

    Assessing the applicability of hydrodynamic expansions close to phase transition points is crucial from either theoretical or phenomenological points of view. We explore this within the gauge/gravity duality, using the Einstein-Klein-Gordon model, a bottom-up string theory construction. This model incorporates a parameter, $B_4$, that simulates different types of phase transitions in the strongly coupled field theory existing at the boundary. We thoroughly examine the thermodynamics and dynamics of time-dependent, linearized perturbations in the spin-2, spin-1, and spin-0 sectors. Our findings suggest that "hydrodynamic series breakdown near transition points" is valid exclusively for second-order phase transitions, not for crossovers or first-order phase transitions. Additionally, we observe that the high-temperature and low-temperature limits of the radius of convergence for the hydrodynamic series ($q_c^2$) are equal. We also discover that the relationship $(\text{Max}|q_c^2|{)}_{\text{spin-2}}<(\text{Max}|q_c^2|{)}_{\text{spin-0}}<(\text{Max}|q_c^2|{)}_{\text{spin-1}}$ is consistent for different spin sectors, regardless of the phase transition type. At the chaos point, we observe the emergence of pole-skipping behavior for both gravity and scalar perturbations at ${\omega }_n=-2\pi Tni$. Lastly, comparing the chaos momentum with $q_c^2$, we find that $q_{ps}^2<q_c^2$, except for extremely high temperatures.

    ↳ hep-thhep-phnucl-thEPJC(2024)·3 citations
27. 27*

    Comparison of $\bar{N}N$ optical models

    Jaume Carbonell🇫🇷 · Guillaume Hupin🇫🇷 · Sławomir Wycech🇵🇱

    We compare the strong part of the $\bar{N}N$ interaction obtained by the Nijmegen partial wave analysis and the results of some of the most popular $\bar{N}N$ optical potentials in configuration space. We have found severe discrepancies in most of the partial waves, especially above $p_{Lab}$=400 MeV/c where the partial wave analysis displays a resonant-like structure in the ${}^{31}$S${}_0$ and ${}^{33}$P${}_0$ waves. Some theoretical difficulties to interpret this behaviour in terms of dynamical resonances are pointed pout and an alternative explanation is suggested. A much better stability is observed in the low energy parameters, apart from some discrepancies due to the presence of near-threshold quasi-bound states in particular waves. Large deviations have also been found between the corresponding potentials, at short and medium-range ($r\gtrsim 1$ fm) distances.

    ↳ nucl-thhep-exhep-phnucl-ex+1EPJA(2023)·12 citations
28. 28*

    Timing properties of the X-ray accreting pulsar RX J0440.9+4431 studied with Insight-HXMT and NICER

    P. P. Li🇺🇸 · L. Tao🇨🇳 · Y. L. Tuo · M. Y. Ge · L. D. Kong · L. Zhang🇨🇳 · Q. C. Bu · L. Ji🇨🇳 · J. L. Qu · S. Zhang🇨🇳 · S. N. Zhang🇨🇳 · Y. Huang🇨🇳 and 11 other authors

    RX J0440.9+4431, a Be/X-ray binary, had its brightest outburst in 2022 since its discovery, with a peak X-ray flux of 2.25 Crab (as recorded by Swift/BAT, 15-50 keV). We analyze the timing properties of this giant outburst using data from Insight-HXMT and NICER, focusing on the evolution of the pulse profile and pulse fraction. We observe that when the luminosity reached around ~ 3*10^{37} er s^{-1}, a transition from double-peaked to single-peaked pulse profiles occurred across the energy range, with the peak of the low-energy profile aligning gradually with the peak of the high-energy profile. This change indicates a transition from subcritical to supercritical accretion. Additionally, we found a concave in the pulse fraction as a function of energy around 20-30 keV throughout the entire outburst period. Compared to the low luminosity, the concave becomes weaker in high luminosities, and overall, the pulse fraction is higher. We propose that this concave could be caused by the scattering of high-energy photons by the atmosphere of a neutron star, leading to a dilution of the pulse fraction. As the accretion reaches the supercritical state, the accretion column height increases, resulting in a larger direct component of strongly beamed X-ray flux, and an elevated pulse fraction.

    ↳ astro-ph.HEhep-phMNRAS(2023)·8 citations
29. 29*

    The electric charge of black holes within galaxies

    Nelson D. Padilla🇦🇷 · Ignacio J. Araya🇨🇱 · Federico Stasyszyn🇦🇷

    We present improved estimates of the electric charge that black holes could hold when these are embedded in the ionised plasma within galaxies. We have implemented the spontaneous emission of charges of opposite sign to that of the black hole via athermal Hawking evaporation, including its dependence on black hole spin, and we have estimated the equilibrium charge that arises as this charge loss is balanced by the continuous accretion of charges from the surrounding plasma. The resulting charge can be several orders of magnitude lower than previously estimated upper limits, but it can surpass the pair production limit noted by Gibbons (1974) by a margin that increases with the amplitude of the black hole spin and the density of the plasma. We also implement a calculation for the net charge of galaxies due to their stellar black holes and to primordial black holes in the case these make up a fraction of the dark matter. We find that these charges lie within the range that would produce adequate magnetic field seeds at the onset of galaxy formation.

    ↳ astro-ph.COhep-phJCAP(2024)·4 citations
30. 30*

    Gravitational to Coulomb force ratio and the origin of the Cosmic magnetic field

    Nelson D. Padilla🇦🇷 · Juan Racker🇦🇷 · Ignacio J. Araya🇨🇱 · Federico Stasyszyn🇦🇷

    The origin of the seeds of galactic magnetic fields is a subject that remains under debate. Here we will explore a simple source based on tiny charge asymmetries in slowly rotating protogalaxies. We use current knowledge of galaxy formation and evolution to estimate that a charge imbalance of $1$ every $\sim 10^{38\pm 5}$ charge carriers in slowly rotating protogalaxies can provide adequate seeds for the galactic dynamos. Interestingly, this is of the same order than the ratio of gravitational to Coulomb forces between the elementary plasma constituents. Motivated by this fact, we study different mechanisms for generating such charge imbalances from a direct interplay of gravitational and Coulomb forces, namely the possibility that these are of primordial origin, that stellar or primordial black holes redistribute charge in protogalaxies, or that the imbalance is sourced by gravity as the galaxy forms in quasi-hydrostatic equilibrium. Our results show that primordial asymmetries drop to small values by the onset of galaxy formation, with an amplitude that is similar to the possible charge asymmetries that could be produced by black holes. Although these charge asymmetries can have values within the range of interest, they are much smaller than the gravitationally induced one in hydrostatic equilibrium conditions. The latter lies in the upper range of the required charge imbalance.

    ↳ astro-ph.COhep-ph2 citations
31. 31*

    A comprehensive forecast for cosmological parameter estimation using joint observations of gravitational waves and short $\gamma$-ray bursts

    Tao Han🇺🇸 · Shang-Jie Jin🇺🇸 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    In the third-generation (3G) gravitational-wave (GW) detector era, the multi-messenger GW observation for binary neutron star (BNS) merger events can exert great impacts on exploring the cosmic expansion history. In this work, we comprehensively explore the potential of 3G GW standard siren observations in cosmological parameter estimations by considering the 3G GW detectors and the future short $\gamma$-ray burst (GRB) detector THESEUS-like telescope joint observations. Based on the 10-year observation of different detection strategies, we predict that the numbers of detectable GW-GRB events are 334--674 with the redshifts $z<3.5$ and the inclination angles $\iota <15^{\circ }$. For the cosmological analysis, we consider the $\Lambda$CDM, $w$CDM, $w_0{w}_a$CDM models, and interacting dark energy (IDE) models. We find that GW can tightly constrain the Hubble constant with precisions of $0.345\%-0.065\%$, but perform not well in constraining other cosmological parameters. Fortunately, GW could effectively break the cosmological parameter degeneracies generated by the mainstream EM observations, CMB+BAO+SN (CBS). When combining the mock GW data with the CBS data, CBS+GW can tightly constrain the equation of state of dark energy $w$ with a precision of 1.26\%, close to the standard of precision cosmology. Meanwhile, the addition of GW to CBS could improve constraints on cosmological parameters by $34.2\%-94.9\%$. In conclusion, GW standard siren observations from 3G GW detectors could play a crucial role in helping solve the Hubble tension and probe the fundamental nature of dark energy.

    ↳ astro-ph.COgr-qchep-phEPJC(2024)·38 citations
32. 32*

    Experimental Limits on Solar Reflected Dark Matter with a New Approach on Accelerated-Dark-Matter-Electron Analysis in Semiconductors

    Z. Y. Zhang🇨🇳 · L. T. Yang🇨🇳 · Q. Yue🇨🇳 · K. J. Kang🇨🇳 · Y. J. Li🇨🇳 · H. P. An🇨🇳 · Greeshma C.🇹🇼 · J. P. Chang🇨🇳 · Y. H. Chen🇨🇳 · J. P. Cheng🇨🇳 · W. H. Dai🇨🇳 · Z. Deng🇨🇳 and 72 other authors

    Recently a dark matter-electron (DM-electron) paradigm has drawn much attention. Models beyond the standard halo model describing DM accelerated by high energy celestial bodies are under intense examination as well. In this Letter, a velocity components analysis (VCA) method dedicated to swift analysis of accelerated DM-electron interactions via semiconductor detectors is proposed and the first HPGe detector-based accelerated DM-electron analysis is realized. Utilizing the method, the first germanium based constraint on sub-GeV solar reflected DM-electron interaction is presented with the 205.4 kg$\cdot$day dataset from the CDEX-10 experiment. In the heavy mediator scenario, our result excels in the mass range of 5$-$15 keV/$c^2$, achieving a 3 orders of magnitude improvement comparing with previous semiconductor experiments. In the light mediator scenario, the strongest laboratory constraint for DM lighter than 0.1 MeV/$c^2$ is presented. The result proves the feasibility and demonstrates the vast potential of the VCA technique in future accelerated DM-electron analyses with semiconductor detectors.

    ↳ hep-exhep-phphysics.ins-detPRL(2024)·26 citations
33. 33*

    Induced gravitational waves and baryon asymmetry fluctuations from primordial black hole formation

    Chiara Altavista🇮🇹 · Julián Rey🇩🇪

    We consider black hole formation due to the gravitational collapse produced by large density fluctuations during an epoch of reheating with a stiff equation of state and calculate the induced gravitational wave spectrum. By considering the existing bounds on the total energy density of gravitational waves today, we find constraints on the parameter space of this scenario. We also calculate the lepton asymmetry generated by metric perturbations via the chiral gravitational anomaly present in the Standard Model and find that, once the electroweak sphaleron processes have taken place, the large spectrum of scalar perturbations responsible for black hole formation induces a peak in the baryon asymmetry fluctuations on small scales.

    ↳ astro-ph.COhep-phJCAP(2024)·11 citations
34. 34*

    Implications of Pulsar Timing Array Results for High Frequency Gravitational Waves

    Junsong Cang🇨🇳 · Yu Gao🇨🇳 · Yiming Liu🇨🇳 · Sichun Sun🇨🇳

    Several pulsar timing array (PTA) experiments such as NANOGrav and PPTA recently reported evidence of a gravitational wave (GW) background at nano-Hz frequency band. This signal can originate from scalar-induced gravitational waves (SIGW) generated by the enhanced curvature perturbation. Production of SIGW is expected to be accompanied by formation of primordial black holes (PBH), which can emit GW through binary mergers. Here we perform a joint likelihood inference on PTA datasets in combination with existing limits on PBH abundance and GW density, we derive full Bayesian posteriors for PBH distribution and relevant PBH merger signal. Our results show that analysis using PTA data alone implies significant overproduction of PBHs, and accounting for current PBH limits causes visible shifts in SIGW posterior. If PTA signals are indeed of SIGW origin, the required curvature perturbation amplitude produces PBHs in a narrow mass window of $[6\times 10^{-2},2\times 10^{-1}]m_{\odot }$. Mergers of these PBHs can leave a strong GW signature in $[10^{-3},10^5]$ Hz frequency range, to be detectable at upcoming interferometers such as LISA, aLIGO, Einstein Telescope, DECIGO and BBO, etc. This offers a multi-frequency opportunity to further scrutinize the source of the observed PTA signal and can potentially improve current PBH constraints by up to 5 orders of magnitudes.

    ↳ astro-ph.COgr-qchep-phPLB(2025)·20 citations
35. 35*

    Probing light relics through cosmic dawn

    Nanoom Lee🇺🇸 · Selim C. Hotinli🇺🇸

    We explore the prospects of upcoming 21-cm surveys of cosmic dawn ($12\lesssim z\lesssim 30$) to provide cosmological information on top of upcoming cosmic microwave background (CMB) and large-scale structure surveys, such as CMB-S4, Simons Observatory (SO) and DESI. We focus on the effective number of relativistic species $N_{\mathrm{eff}}$ which is a promising observable for probing beyond the Standard Model theories. We show including upcoming 21-cm surveys such as the Square Kilometre Array (SKA) can allow probing a wide range of models for light particles at $2\sigma$ level achieving $2\sigma (N_{\mathrm{eff}})=0.034$ with CMB-S4, for example. Taking into account the degeneracy between $N_{\mathrm{eff}}$ and primordial helium fraction $Y_p$, one can achieve improvements in sensitivities to cosmological parameters, in particular, by more than a factor of 2 for $N_{\mathrm{eff}}$ and dark matter fractional energy density ${\omega }_c$.

    ↳ astro-ph.COhep-phPRD(2024)·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.