Tue·Oct 24, 2023Tuesday·October 24, 2023

1. 01*

   Prospects for detecting long-lived particles at the Large Hadron Collider

   Rafał Masełek🇵🇱

   This thesis summarises four years of research aiming at revealing the prospects for detection of long-lived particles at the LHC. It contains results of four projects, which have been published as independent articles. Each of the projects investigated prospects for the detection of long-lived particles predicted by one of the many BSM models, e.g. supersymmetry, seesaw, radiative neutrino mass generation models, and simplified models. The sensitivity to New Physics of ATLAS, CMS and (for the first time) MoEDAL experiments was estimated.

   hep-phhep-ex1 citation
2. 02*

   Gauge Boson Mass Dependence and Chiral Anomalies in Generalized Massless Schwinger models

   Howard Georgi🇺🇸

   I bosonize the position-space correlators of flavor-diagonal scalar fermion bilinears in arbitrary generalizations of the Schwinger model with $n_F$ massless fermions coupled to $n_A$ gauge bosons for $n_F\ge n_A$. For $n_A=n_F$, the fermion bilinears can be bosonized in terms of $n_F$ scalars with masses proportional to the gauge couplings. As in the Schwinger model, bosonization can be used to find all correlators, including those that are forbidden in perturbation theory by anomalous chiral symmetries, but there are subtleties when there is more than one gauge boson. The new result here is the general treatment of the dependence on gauge boson masses in models with more than one gauge symmetry. For $n_A<n_F$, there are fermion bilinears with nontrivial anomalous dimensions and there are unbroken chiral symmetries so some correlators vanish while others are non-zero due to chiral anomlies. Taking careful account of the dependence on the masses, I show how the $n_A<n_F$ models emerge from $n_A=n_F$ as gauge couplings (and thus gauge boson masses) go to zero. When this is done properly, the limit of zero gauge coupling is smooth. Our consistent treatment of gauge boson masses guarantees that anomalous symmetries are broken while unbroken chiral symmetries are preserved because correlators that break the non-anomalous symmetries go to zero in the limit of zero gauge coupling.

   hep-phhep-thJHEP(2024)·0 citations
3. 03*

   NLO corrections to the deeply virtual meson production revisited: impact on the extraction of generalized parton distributions

   Marija Čuić🇭🇷 · Goran Duplančić🇭🇷 · Krešimir Kumerički🇭🇷 · Kornelija Passek-K.🇭🇷

   We revisit the next-to-leading order (NLO) perturbative QCD corrections for the deeply virtual meson production (DVMP) process, exploring its phenomenology both in isolation and in a multichannel fit combined with deeply virtual Compton scattering (DVCS). Our approach involves the conformal partial wave (CPaW) formalism, which allows for the straightforward inclusion of higher-order contributions and evolutionary effects. Our findings indicate that a description of the longitudinal component of the vector meson DVMP cross-section at high energies is achievable only at NLO within the standard collinear approach. Furthermore, we demonstrate a simultaneous description of DIS, DVCS, and DVMP processes, providing insights into the proton structure described at NLO by unique universal generalized parton distribution (GPD) functions.

   hep-phJHEP(2023)·27 citations
4. 04*

   Holographic Schwinger effect in spinning black hole backgrounds

   Yi-ze Cai🇨🇳 · Zi-qiang Zhang🇨🇳

   We perform the potential analysis for the holographic Schwinger effect in spinning Myers-Perry black holes. We compute the potential between the produced pair by evaluating the classical action of a string attaching on a probe D3-brane sitting at an intermediate position in the AdS bulk. It turns out that increasing the angular momentum reduces the potential barrier thus enhancing the Schwinger effect, consistent with previous findings obtained from the local Lorentz transformation. In particular, these effects are more visible for the particle pair lying in the transversal plane compared with that along the longitudinal orientation. In addition, we discuss how the Schwinger effect changes with the shear viscosity to entropy density ratio at strong coupling under the influence of angular momentum.

   hep-phCPC(2024)·8 citations
5. 05*

   Reduction of Couplings in the Type-II 2HDM

   M. A. May Pech🇲🇽 · M. Mondragón🇲🇽 · G. Patellis🇵🇹 · G.Zoupanos🇬🇷

   The idea of reduction of couplings consists in the search for relations between seemingly independent couplings of a renormalizable theory that are renormalization group invariant. In this article, we demonstrate the existence of such 1-loop relations among the top Yukawa, the Higgs quartic and the gauge colour couplings of the Type-II Two Higgs Doublet Model at a high-energy boundary. The phenomenological viability of the reduced theory suggests the value of $\tan \beta$ and the scale in which new physics may appear.

   hep-phhep-thEPJC(2023)·5 citations
6. 06*

   A note on the tensor and vector exchange contributions to $K\bar{K}\to K\bar{K},D\bar{D}\to D\bar{D}$ and ${\pi }^{+}{\pi }^{-}\to {\pi }^{+}{\pi }^{-}$ reactions

   Luciano M. Abreu🇧🇷 · Jing Song🇨🇳 · Pedro C. S. Brandão🇧🇷 · Eulogio Oset🇪🇸

   In this note we study the tensor and vector exchange contributions to the elastic reactions involving the pseudoscalars mesons ${\pi }^{+}{\pi }^{-}$, $K^{+}{K}^{-}$ and $D^{+}{D}^{-}$. In the case of the tensor-exchange contributions we assume that an intermediate tensor $f_2(1270)$ is dynamically generated from the interaction of two virtual $\rho$ mesons, with the use of a pole approximation. The calculation of the two-loop amplitude is facilitated since the triangle loops can be factorized and computed separately. The results show very small contributions coming from the tensor-exchange mechanisms when compared with those from the vector-exchange processes. We compare our results for $\pi \pi$ and $K\bar{K}$ scattering with those obtained in other works where the $f_2(1270)$ is considered as an ordinary $q\bar{q}$ meson. Our picture provides a smaller contribution but of similar order of magnitude for pion scattering and stabilizes the results in the case of $K\bar{K}$, allowing us to make estimates for $D\bar{D}$ scattering.

   hep-phEPJA(2024)·1 citation
7. 07*

   Linking solar bosonic dark matter halos and active neutrinos

   Ilídio Lopes🇵🇹

   Our study investigates the complex interaction between active neutrinos and the ultralight bosonic dark matter halo surrounding the Sun. This halo extends over several solar radii due to the Sun's gravitational field, and we represent it as a coherent oscillating classical field configuration of bosonic dark matter particles that vary in time. Our investigation has revealed that, based on the available solar neutrino flux data, these novel models do not surpass the performance of the conventional neutrino flavour oscillation model. Furthermore, we discuss how next-generation solar neutrino detectors have the potential to provide evidence for the existence or absence of the ultralight dark matter halo.

   hep-phastro-ph.COastro-ph.SRhep-ex+1PRD(2023)·5 citations
8. 08*

   Tau data-driven evaluation of the Hadronic Vacuum Polarization

   Pere Masjuan🇪🇸 · Alejandro Miranda🇪🇸 · Pablo Roig🇲🇽

   Windows in Euclidean time have become a standard tool for comparing lattice QCD and data-driven computations of the hadronic vacuum polarization (HVP) contribution to the muon $g-2$. Here we review our results, obtained using isospin-rotated ${\tau }^{-}\to {\pi }^{-}{\pi }^0{\nu }_{\tau }$ data instead of $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ measurements, and compare them to other approaches. Consistency of the tau-based and lattice results hints to underestimated uncertainties in the $e^{+}{e}^{-}$ data. If that is the case, the theory prediction of the muon $g-2$ would only lie at $\sim 2\sigma$ from its measured value.

   hep-phhep-latNucl.Part.Phys.Proc.(2024)·4 citations
9. 09*

   Spin asymmetry and dipole moments in $\tau$-pair production with ultraperipheral heavy ion collisions

   Ding Yu Shao🇨🇳 · Bin Yan🇨🇳 · Shu-Run Yuan🇨🇳 · Cheng Zhang🇨🇳

   The anomalous magnetic (MDM) and electric (EDM) dipole moments of the $\tau$ lepton serve as crucial indicators of new physics beyond the Standard Model. Leveraging azimuthal angular asymmetry as a novel tool in ultraperipheral collisions (UPCs), we attain unparalleled precision in the study of these key properties. Driven by the highly linear polarization of coherent photons, this method uniquely enables both the MDM and EDM to contribute to the $\cos 2\varphi$ angular distribution in similar magnitudes. Importantly, our approach substantially narrows the parameter space, excluding more than half of it compared to expected UPC-based measurements reliant solely on the total cross-section. This method not only provides improved constraints but also minimizes the need for additional theoretical assumptions.

   hep-phhep-exnucl-exnucl-thSCPMA(2024)·45 citations
10. 10*

    High-$x$ quark density and their impact on $Z^{\prime }$-boson dilepton searches

    Francesco Giuli🇨🇭

    In this proceeding, we study the influence of theoretical systematic uncertainties due to the quark density on LHC experimental searches for $Z^{\prime }$-bosons. Using an approach originally proposed in the context of the ABMP16 PDF set for the high-$x$ behaviour of the quark density, we presents results on differential cross section and Forward-Backward asymmetry observables commonly used to study $Z^{\prime }$ signals in dilepton channels.

    hep-phPoS(2024)·0 citations
11. 11*

    Pion gravitational form factors at large momentum transfer in the instant-form relativistic impulse approximation approach

    A.F. Krutov🇷🇺 · V.E. Troitsky🇷🇺

    We extend our relativistic theory of gravitational structure of composite hadrons to obtain the pion gravitational form factors at large momentum transfers. The approach was used in the case of intermediate region of the variable in our preceding works arXiv:2010.11640 and arXiv:2201.04991. The calculation is carried out in the framework of a relativistic composite-particle model complemented by the special relativistic form of impulse approximation. It is found that in the limit of massless and pointlike quarks, the obtained asymptotic expansion coincides with the predictions of perturbative QCD for gravitational pion form factors. The principal contribution to the asymptotics, coinciding with the predictions of QCD, is given by the relativistic effect of spin rotation. In particular, the asymptotics of the D form factor is completely determined by this kinematic effect. Several constraints on the allowed form of gravitational form factors of quarks are derived.

    hep-phPRD(2023)·6 citations
12. 12*

    Progress in two-loop electroweak corrections to gg -> HH and gg -> gH

    Hantian Zhang🇩🇪

    In these proceedings, we summarise our recent calculations of next-to-leading order electroweak corrections to Higgs boson pair and Higgs boson plus jet production. The calculations are divided into different regions. In the high-energy region, we analytically calculate the Higgs boson contribution to the leading two-loop Yukawa corrections for $gg\to HH$. These corrections are generated by a single virtual Higgs boson exchange within the top quark loop. Our high-energy expansion yields precise predictions for the region where the Higgs boson transverse momenta $p_T>120$ GeV. In the low-energy region, we compute the complete two-loop electroweak corrections to $gg\to HH$ and $gg\to gH$. We obtain analytic results through the large top quark mass expansion, covering all sectors of the Standard Model.

    hep-phPoS(2024)·1 citation
13. 13*

    Photoproduction of doubly heavy baryons at future $e^{+}{e}^{-}$ colliders

    Xi-Jie Zhan🇨🇳 · Xing-Gang Wu🇨🇳 · Xu-Chang Zheng🇨🇳

    The photoprodution of doubly heavy baryon (${\Xi }_{cc},{\Xi }_{bb},{\Xi }_{bc}$) is investigated in the context of future high-energy and high-luminosity $e^{+}{e}^{-}$ colliders. The study incorporates two sources of initial photons, namely the LBS photon and the WWA photon. Alongside the direct photoproduction via the sub-process $\gamma +\gamma \to {\Xi }_{Q{Q}^{{}^{\prime }}}+\bar{Q}+\overline{Q^{{}^{\prime }}}$ ($Q^{{(}^{\prime })}=c,b$), the resolved photoproduction channels are specifically considered, encompassing the sub-processes $\gamma +g\to {\Xi }_{Q{Q}^{{}^{\prime }}}+\bar{Q}+\overline{Q^{{}^{\prime }}}$, $g+g\to {\Xi }_{Q{Q}^{{}^{\prime }}}+\bar{Q}+\overline{Q^{{}^{\prime }}}$, and $q+\bar{q}\to {\Xi }_{Q{Q}^{{}^{\prime }}}+\bar{Q}+\overline{Q^{{}^{\prime }}}$ with $q=u,d,s$. Within the framework of non-relativistic QCD, two $(cc(bb))$-diquark configurations, ${}_{\bar{\text{3}}}[{}^3{S}_1]$ and ${}_{\text{6}}[{}^1{S}_0]$, and four $(bc)$-diquark configurations, $(bc{)}_{\bar{\text{3}}}[{}^3{S}_1]$, $(bc{)}_{\text{6}}[{}^1{S}_0]$, $(bc{)}_{\text{6}}[{}^3{S}_1]$ and $(bc{)}_{\bar{\text{3}}}[{}^1{S}_0]$, are considered in the calculations. Numerical results show that the single resolved photoproduction processes provide dominant contributions under certain collision configuration. At the future $e^{+}{e}^{-}$ colliders, the doubly heavy baryon generated via the photoproduction mechanism is promisingly observable and can be well studied.

    hep-phPRD(2023)·8 citations
14. 14*

    Strangelets at finite temperature: nucleon emission rates, interface and shell effects

    Hao-Song You🇨🇳 · Huai-Min Chen🇨🇳 · Jian-Feng Xu · Cheng-Jun Xia🇨🇳 · Guang-Xiong Peng🇨🇳 · Ren-Xin Xu

    We investigate the properties of strangelets at finite temperature $T$, where an equivparticle model is adopted with both the linear confinement and leading-order perturbative interactions accounted for using density-dependent quark masses. The shell effects are examined by solving the Dirac equations for quarks in the mean-field approximation, which diminish with temperature as the occupation probability of each single-particle levels fixed by the Fermi-Dirac statistics, i.e., shell dampening. Consequently, instead of decreasing with temperature, the surface tension extracted from a liquid-drop formula increases with $T$ until reaching its peak at $T\approx 20$-40 MeV with vanishing shell corrections, where the formula roughly reproduces the free energy per baryon of all strangelets. The curvature term, nevertheless, decreases with $T$ despite the presence of shell effects. The neutron and proton emission rates are fixed microscopically according to the external nucleon gas densities that are in equilibrium with strangelets, which generally increase with $T$ ($\lesssim 50$ MeV) for stable strangelets but decrease for those that are unstable against nucleon emission at $T=0$. The energy, free energy, entropy, charge-to-mass ratio, strangeness per baryon, and root-mean-square radius of $\beta$-stable strangelets obtained with various parameter sets are presented as well. The results indicated in this work are useful for understanding the products of binary compact star mergers and heavy-ion collisions.

    hep-phnucl-thPRD(2024)·5 citations
15. 15*

    Rational terms of UV origin to all loop orders

    Claude Duhr🇩🇪 · Paarth Thakkar🇩🇪

    Numerical approaches to computations typically reconstruct the numerators of Feynman diagrams in four dimensions. In doing so, certain rational terms arising from the (D-4)-dimensional part of the numerator multiplying ultraviolet (UV) poles in dimensional regularisation are not captured and need to be obtained by other means. At one-loop these rational terms of UV origin can be computed from a set of process-independent Feynman rules. Recently, it was shown that this approach can be extended to two loops. In this paper, we show that to all loop orders it is possible to compute rational terms of UV origin through process-independent vertices that are polynomial in masses and momenta.

    hep-phJHEP(2024)·1 citation
16. 16*

    Unified description of the $Qs\bar{q}\bar{q}$ molecular bound states, molecular resonances and compact tetraquark states in the quark potential model

    Yan-Ke Chen🇨🇳 · Wei-Lin Wu🇨🇳 · Lu Meng🇩🇪 · Shi-Lin Zhu🇨🇳

    We calculate the mass spectrum of the $Qs\bar{q}\bar{q}$ $(Q=c,b)$ tetraquark states with $J^P=(0,1,2{)}^{+}$ using the AL1 quark potential model, which successfully describes the conventional hadron spectrum. We employ the Gaussian expansion method to solve the four-body Schrödinger equation, and use the complex scaling method to identify the resonances. With the notation $T_{Qs,I(J)}^{\text{Theo. }}(M)$, we find several near-threshold bound states and resonances, including $T_{cs,0(0)}^{Theo.}(2350)$, $T_{cs,0(0)}^{Theo.}(2906)$, $T_{bs,0(0)}^{Theo.}(5781)$, $T_{bs,0(1)}^{Theo.}(5840)$, and $T_{bs,0(0)}^{Theo.}(6240)$ which are close to the $D\bar{K}$, $D^{\ast }{\bar{K}}^{\ast }$, $\bar{B}\bar{K}$, ${\bar{B}}^{\ast }\bar{K}$ and ${\bar{B}}^{\ast }{\bar{K}}^{\ast }$ thresholds, respectively. Furthermore, their spatial structures clearly support their molecular natures. The resonance $T_{cs,0(0)}^{Theo.}(2906)$ has a mass of $2906$ MeV, a width of $20$ MeV, and quantum numbers $I(J^P)=0(0^{+})$, which may serve as a good candidate for the experimental $T_{cs0}(2900)$ state. We strongly urge the experimental search of the predicted states.

    hep-phhep-exhep-latnucl-thPRD(2024)·24 citations
17. 17*

    Revisiting Yukawa's Bilocal Field Theory for Composite Scalar Bosons

    Christopher T. Hill🇺🇸

    Yukawa's old bilocal field theory, with modernization in the treatment of "relative time," can describe a relativistic bound state of chiral fermions. This connects to bosonized effective chiral Lagrangians and the Nambu-Jona-Lasinio (NJL) model, providing a description of the internal dynamics of the bound states. It features a static internal wave-function, $\varphi (\vec{r})$, in the center-of-mass frame that satisfies a Schrödinger-Klein-Gordon equation with eigenvalues $m^2$. We analyze the "coloron" model (single perturbative massive gluon exchange) which yields a UV completion of the NJL model. This has a BCS-like enhancement of its interaction, $\propto N_c$, the number of colors. It is classically critical, with $g_{critical}$ remarkably close to the NJL quantum critical coupling. Negative eigenvalues for $m^2$ lead to spontaneous symmetry breaking, and the Yukawa coupling of the bound state to constituent fermions is emergent.

    hep-phhep-thEntropy(2024)·5 citations
18. 18*

    Polarised cross sections for vector boson production with SHERPA

    Mareen Hoppe🇩🇪 · Marek Schönherr🇬🇧 · Frank Siegert🇩🇪

    Measurements of vector boson polarisation in vector boson production processes offer a powerful probe of the electroweak symmetry breaking mechanism, scrutinising the Standard Model and new physics scenarios alike. Since massive vector bosons can only be observed as intermediate particles, polarised cross section templates from simulation are necessary to extract their polarisation from measurable unpolarised distributions. In this work we present an extension of the SHERPA Monte-Carlo event generator allowing the simulation of polarised cross sections for vector boson production processes. Based on the narrow-width approximation, polarised cross sections of all possible polarisation combinations for an arbitrary number of intermediate vector bosons can be simulated in a single simulation run. In addition, it is possible to directly predict the interference between different intermediate polarisation states, and various differing polarisation definitions can be studied simultaneously. Besides the simulation of polarised cross sections at fixed LO and LO+PS accuracy as well as in multijet merged calculations, we also present parton-shower-matched polarised cross sections with approximate NLO QCD corrections in the vector boson production processes. We demonstrate that the differences of this approximation to full NLO QCD predictions are small and it thus opens up the possibility for fully-simulated calculations at the hadron level including polarisation information and higher-order QCD effects for the first time.

    hep-phhep-exJHEP(2024)·43 citations
19. 19*

    On the generalized Friedrichs-Lee model with multiple discrete and continuous states

    Zhiguang Xiao🇨🇳 · Zhi-Yong Zhou🇨🇳

    In this study, we present several improvements of the non-relativistic Friedrichs-Lee model with multiple discrete and continuous states and still retain its solvability. Our findings establish a solid theoretical basis for the exploration of resonance phenomena in scenarios involving multiple interfering states across various channels. The scattering amplitudes associated with the continuum states naturally adhere to coupled-channel unitarity, rendering this framework particularly valuable for investigating hadronic resonant states appearing in multiple coupled channels. Moreover, this generalized framework exhibits a wide-range applicability, enabling investigations into resonance phenomena across diverse physical domains, including hadron physics, nuclear physics, optics, and cold atom physics, among others.

    hep-phmath-phmath.MPnucl-th+1CPC(2025)·7 citations
20. 20*

    $B\to K\nu \bar{\nu }$, MiniBooNE and muon $g-2$ anomalies from a dark sector

    Alakabha Datta🇺🇸 · Danny Marfatia🇺🇸 · Lopamudra Mukherjee🇨🇳

    Belle II has reported the first evidence for $B^{+}\to K^{+}\nu \bar{\nu }$ with a branching ratio $2.7\sigma$ higher than the standard model expectation. We explain this, and the MiniBooNE and muon anomalous magnetic moment anomalies in a model with a dark scalar that couples to a slightly heavier sterile Dirac neutrino and that communicates with the visible sector via a Higgs portal. We make predictions for rare kaon and other $B$ meson decays.

    hep-phhep-exPRD(2024)·54 citations
21. 21*

    Factorial growth at low orders in perturbative QCD: Control over truncation uncertainties

    Andreas S. Kronfeld🇺🇸

    A method, known as ``minimal renormalon subtraction'' [Phys. Rev. D 97 (2018) 034503, JHEP 2017 (2017) 62], relates the factorial growth of a perturbative series (in QCD) to the power~$p$ of a power correction ${\Lambda }^p/Q^p$. ($\Lambda$ is the QCD scale, $Q$ some hard scale.) Here, the derivation is simplified and generalized to any~$p$, more than one such correction, and cases with anomalous dimensions. Strikingly, the well-known factorial growth is seen to emerge already at low or medium orders, as a consequence of constraints on the $Q$ dependence from the renormalization group. The effectiveness of the method is studied with the gluonic energy between a static quark and static antiquark (the ``static energy''). Truncation uncertainties are found to be under control after next-to-leading order, despite the small exponent of the power correction ($p=1$) and associated rapid growth seen in the first four coefficients of the perturbative series.

    hep-phhep-thJHEP(2023)·6 citations
22. 22*

    Probing Transverse Momentum Dependent Structures with Azimuthal Dependence of Energy Correlators

    Zhong-Bo Kang🇺🇸 · Kyle Lee🇺🇸 · Ding Yu Shao🇨🇳 · Fanyi Zhao🇺🇸

    We study the azimuthal angle dependence of the energy-energy correlators $⟨\mathcal{E}({\hat{n}}_1)\mathcal{E}({\hat{n}}_2)⟩$ in the back-to-back region for $e^{+}{e}^{-}$ annihilation and deep inelastic scattering (DIS) processes with general polarization of the proton beam. We demonstrate that the polarization information of the beam and the underlying partons from the hard scattering is propagated into the azimuthal angle dependence of the energy-energy correlators. In the process, we define the Collins-type EEC jet functions and introduce a new EEC observable using the lab-frame angles in the DIS process. Furthermore, we extend our formalism to explore the two-point energy correlation between hadrons with different quantum numbers ${\mathbb{S}}_i$ in the back-to-back limit $⟨{\mathcal{E}}_{{\mathbb{S}}_1}({\hat{n}}_1){\mathcal{E}}_{{\mathbb{S}}_2}({\hat{n}}_2)⟩$. We find that in the Operator Product Expansion (OPE) region the nonperturbative information is entirely encapsulated by a single number. Using our formalism, we present several phenomenological studies that showcase how energy correlators can be used to probe transverse momentum dependent structures.

    hep-phhep-exnucl-exnucl-thJHEP(2024)·51 citations
23. 23*

    Machine Learning Classification of Sphalerons and Black Holes at the LHC

    Aurora Singstad Grefsrud🇳🇴 · Trygve Buanes🇳🇴 · Fotis Koutroulis🇵🇱 · Anna Lipniacka🇳🇴 · Rafał Masełek🇵🇱 · Andreas Papaefstathiou🇺🇸 · Kazuki Sakurai🇵🇱 · Therese B. Sjursen🇳🇴 · Igor Slazyk🇳🇴

    In models with large extra dimensions, "miniature" black holes (BHs) might be produced in high-energy proton-proton collisions at the Large Hadron Collider (LHC). In the semi-classical regime, those BHs thermally decay, giving rise to large-multiplicity final states with jets and leptons. On the other hand, similar final states are also expected in the production of electroweak sphaleron/instanton-induced processes. We investigate whether one can discriminate these scenarios when BH or sphaleron-like events are observed in the LHC using machine learning (ML) methods. Classification among several BH scenarios with different numbers of extra dimensions and the minimal BH masses is also examined. In this study we consider three ML models: XGBoost algorithms with (1) high- and (2) low-level inputs, and (3) a Residual Convolutional Neural Network. In the latter case, the low-level detector information is converted into an input format of three-layer binned event images, where the value of each bin corresponds to the energy deposited in various detector subsystems. We demonstrate that only a small number of detected events are sufficient to effectively discriminate between the sphaleron and BH processes. Separation between BH scenarios with different minimal masses is possible with an order of 10 events passing the preselection. A sufficient number of events could be observed in combined Run-2 and -3 data, if the production cross section is not much smaller than the present limit ~ 0.1 fb. We find, however, that a large number of events is needed to discriminate between BH hypotheses with the same minimal BH mass, but different numbers of extra dimensions.

    hep-phhep-exEPJC(2024)·6 citations
24. 24*

    First Results from a Broadband Search for Dark Photon Dark Matter in the $44$ to $52\mu$eV range with a coaxial dish antenna

    Stefan Knirck🇺🇸 · Gabe Hoshino🇺🇸 · Mohamed H. Awida🇺🇸 · Gustavo I. Cancelo🇺🇸 · Martin Di Federico🇺🇸 · Benjamin Knepper🇺🇸 · Alex Lapuente🇺🇸 · Mira Littmann🇺🇸 · David W. Miller🇺🇸 · Donald V. Mitchell🇺🇸 · Derrick Rodriguez🇺🇸 · Mark K. Ruschman🇺🇸 and 16 other authors

    We present first results from a dark photon dark matter search in the mass range from 44 to 52 $\mu \mathrm{eV}$ ($10.7-12.5\mathrm{GHz}$) using a room-temperature dish antenna setup called GigaBREAD. Dark photon dark matter converts to ordinary photons on a cylindrical metallic emission surface with area $0.5{\mathrm{m}}^2$ and is focused by a novel parabolic reflector onto a horn antenna. Signals are read out with a low-noise receiver system. A first data taking run with 24 days of data does not show evidence for dark photon dark matter in this mass range, excluding dark photon - photon mixing parameters $\chi \gtrsim 10^{-12}$ in this range at 90% confidence level. This surpasses existing constraints by about two orders of magnitude and is the most stringent bound on dark photons in this range below 49 $\mu$eV.

    ↳ hep-exastro-ph.IMhep-phphysics.ins-detPRL(2024)·39 citations
25. 25*

    High-energy Neutrinos from Merging Stellar-mass Black Holes in Active Galactic Nuclei Accretion Disk

    Jin-Ping Zhu🇦🇺

    A population of binary stellar-mass black hole (BBH) mergers are believed to occur embedded in the accretion disk of active galactic nuclei (AGNs). In this {\em Letter}, we demonstrate that the jets from these BBH mergers can propagate collimatedly within the disk atmosphere along with a forward shock and a reverse shock forming at the jet head. Efficient proton acceleration by these shocks is usually expected before the breakout, leading to the production of TeV$-$PeV neutrinos through interactions between these protons and electron-radiating photons via photon-meson production. AGN BBH mergers occurring in the outer regions of the disk are more likely to produce more powerful neutrino bursts. Taking the host AGN properties of the potential GW190521 electromagnetic (EM) counterpart as an example, one expects $\gtrsim 1$ neutrino events detectable by IceCube if the jet is on-axis and the radial location of the merger is $R\gtrsim 10^5{R}_{\mathrm{g}}$, where $R_{\mathrm{g}}$ is the gravitational radius of the supermassive BH. Neutrino bursts from AGN BBH mergers could be detected by IceCube following the observation of gravitational waves (GWs), serving as precursor signals before the detection of EM breakout signals. AGN BBH mergers are potential target sources for future joint GW, neutrino, and EM multi-messenger observations.

    ↳ astro-ph.HEhep-phMNRAS(2023)·11 citations
26. 26*

    MOND as manifestation of modified inertia

    Mordehai Milgrom🇮🇱

    Practically all the full-fledged MOND theories propounded to date are of the modified-gravity (MG) type: they modify only the Newtonian, Poisson action of the gravitational potential, or the general-relativistic Einstein-Hilbert action, leaving other terms (inertia) intact. Here, I discuss the interpretation of MOND as modified inertia (MI). My main aim is threefold: (a) to advocate exploring MOND theories beyond MG, and appreciating their idiosyncrasies, (b) to highlight the fact that secondary predictions of such theories can differ materially from those of MG theories, (c) to demonstrate some of this with specific MI models. I discuss some definitions and generalities concerning MI. I then present instances of MI in physics, and the lessons we can learn from them for MOND. I then concentrate on a specific class of nonrelativistic, MOND, MI models, and contrast their predictions with those of the two workhorse, MG theories -- AQUAL and QUMOND. The MI models predict possibly a stronger external-field effect -- e.g. on low acceleration systems in the solar neighborhood -- such as very wide binary stars -- and on vertical motions in disc galaxies. More generally, the workings of the effect are rather different, and depend in different ways on dimensionless characteristics of the system, such as frequency ratios of the external and internal fields, eccentricity of trajectories, etc. These models predict a {\it much} weaker effect of the Galactic field in the inner Solar System than is predicted by AQUAL/QUMOND. I also show how noncircular motions -- such as those perpendicular to the disc -- modify the standard, algebraic mass-discrepancy-acceleration relation (aka RAR) that is predicted by MI for exactly circular orbits. These differences, and more that are discussed, can potentially offer ways to distinguish between theories.

    ↳ astro-ph.GAastro-ph.COgr-qchep-ph13 citations
27. 27*

    Anisotropies in Scalar-Induced Gravitational-Wave Background from Inflaton-Curvaton Mixed Scenario with Sound Speed Resonance

    Yan-Heng Yu🇨🇳 · Sai Wang🇨🇳

    We propose a new model to generate large anisotropies in the scalar-induced gravitational wave (SIGW) background via sound speed resonance in the inflaton-curvaton mixed scenario. Cosmological curvature perturbations are not only exponentially amplified at a resonant frequency, but also preserve significant non-Gaussianity of local type described by $f_{\mathrm{nl}}$. Besides a significant enhancement of energy-density fraction spectrum, large anisotropies in SIGWs can be generated, because of super-horizon modulations of the energy density due to existence of primordial non-Gaussianity. A reduced angular power spectrum ${\tilde{C}}_{\ell }$ could reach an amplitude of $[\ell (\ell +1){\tilde{C}}_{\ell }{]}^{1/2}\sim 10^{-2}$, leading to potential measurements via planned gravitational-wave detectors such as DECIGO. The large anisotropies in SIGWs would serve as a powerful probe of the early universe, shedding new light on the inflationary dynamics, primordial non-Gaussianity, and primordial black hole dark matter.

    ↳ astro-ph.COgr-qchep-phPRD(2024)·33 citations
28. 28*

    Axionic Wormholes with $R^2$ Correction in Metric and Palatini Formulations

    Yoshiki Kanazawa🇯🇵

    QCD axion models have been proposed as a solution to the strong CP problem. QCD instanton effects explicitly violate the global U(1) Peccei-Quinn (PQ) symmetry, and the axion potential is minimized at the CP conserving points. However, it is expected that the global U(1) PQ symmetry is explicitly violated by quantum gravity. This gravitational violation may potentially undermine the PQ solution to the strong CP problem, which is referred to as the axion quality problem. One source of explicit PQ violation is axionic wormholes, such as the Giddings-Strominger model. Generally speaking, the extent to which the U(1) PQ symmetry is violated depends on models. One straightforward extension of the Einstein gravity involves quadratic scalar curvature, which is motivated in cosmological contexts, such as inflation. The aim of this work is to investigate the effects of $R^2$ corrections on axionic wormholes. In this paper, we compute wormhole solutions and evaluate the size of explicit PQ violation in the models with the $R^2$ term. Furthermore, We illustrate the differences between the metric and Palatini formulations.

    ↳ hep-thhep-phPRD(2024)·3 citations
29. 29*

    On energy and particle production in cosmology: the particular case of the gravitino

    Gabriele Casagrande🇫🇷 · Emilian Dudas🇫🇷 · Marco Peloso🇮🇹

    It is well-known that the number of particles produced in cosmology, commonly defined in the literature from the Fock space of the instantaneous hamiltonian of the canonically normalized fields, is ambiguous. On the other hand, the energy computed from the energy-momentum tensor should be physical. We compare the corresponding Fock spaces and relate them through a Bogolyubov transformation. We find that for particles of spin $0$, $1$ and $3/2$ the two Fock spaces are different, whereas they are the same for spin $1/2$ fermions. For spin $0$ and $1$, for particles of high momenta the two Fock spaces align, as intuitively expected. For the spin $3/2$, one finds two puzzles. The first one is that the two corresponding Fock spaces do not match even in the limit of high momenta. The second is that whereas we provide evidence for the equivalence theorem between longitudinal gravitinos and the goldstino in terms of an exact matching between the lagrangians and the instantaneous hamiltonians for the canonically normalized fields, the energy operator computed from the Rarita--Schwinger action does not seem to be captured in a simple way by the goldstino action. Our results suggest a re-analysis of non-thermal gravitino production in cosmology.

    ↳ hep-thastro-ph.COhep-phJHEP(2024)·12 citations
30. 30*

    Analytic asymptotics of the integrable XXX critical spin chains in the small external-field limit from TBA

    Yizhuang Liu🇵🇱

    In this note, inspired partly by the works on the analytic trans-series of free-energies in 2D integrable QFTs in the UV limit, we study the corresponding asymptotic expansions in the IR limit of the integrable XXX spin chains, at the anti-ferromagnetic critical point. Starting from the linear TBA integral equation, we generate the perturbative series in the minimal-scheme coupling constants, up to the first order where the ${\zeta }_3$ appears. To all perturbative orders, at spin one-half, the perturbative series relates to that of the ${\beta }^2=8{\pi }^{-}$ massive sine-Gordon by a sign flip of the coupling constant, and this relation generalizes for an arbitrary spin, to certain massive deformation of $su(2{)}_k$ WZW. This relation partially supports the conjectured field-theoretical interpretations of such critical points, at the leading-power $\&\&$ all-logarithmic accuracy. We also compute the perturbative coefficients attached to the first exponentially-small corrections up to the order where ${\zeta }_3$ appears, in case $s>1$. An interesting feature is that the largest exponentially-small corrections at the locations $h^{2+\frac{2k}{s}}$ are non-vanishing, but the corresponding Borel singularities in the perturbative series are canceled for generic $s>1$, not necessarily integers or half-integers. This becomes most dramatic in the a 't Hooft type large $s$ limit, in which the perturbative series has a finite convergence radius, while these exponentially small corrections still survive.

    ↳ hep-thcond-mat.stat-mechhep-phmath-ph+12 citations
31. 31*

    Can prompt cusps of WIMP dark matter be detected as individual gamma-ray sources?

    M. Sten Delos🇺🇸

    Prompt $\rho \propto r^{-1.5}$ density cusps are the densest and most abundant dark matter systems. If the dark matter is a weakly interacting massive particle (WIMP), recent studies have shown that prompt cusps dominate the aggregate dark matter annihilation rate. This article explores whether individual prompt cusps could be detected as gamma-ray sources. At the Fermi telescope's point-source sensitivity, WIMPs with the canonical annihilation cross section could form detectable prompt cusps if the particle mass is of order 10 GeV. These objects could be 10-100 pc away and weigh under a solar mass; they would subtend around 0.1 degrees on the sky. For GeV-scale dark matter particles with below-canonical cross sections, searches for individual prompt cusps can be more sensitive than searches for the annihilation signals from galactic dark matter halos.

    ↳ astro-ph.COastro-ph.HEhep-phPRD(2024)·6 citations
32. 32*

    Emergent particles of de Sitter: thermal interpretation of the stochastic formalism and beyond

    TaeHun Kim🇰🇷

    A thermal interpretation of the stochastic formalism of a slow-rolling scalar field in de Sitter (dS) is given. We construct a correspondence between Hubble patches of dS and particles living in another space called an abstract space. By assuming a dual description of scalar fields and classical mechanics in the abstract space, we show that the stochastic evolution of the infrared part of the field is equivalent to the Brownian motion in the abstract space filled with a heat bath of massless particles. The 1st slow-roll condition and the Hubble expansion are also reinterpreted in the abstract space as the speed of light and a transfer of conserved energy, respectively. Inspired by this, we sketch quantum emergent particles, which may realize the Hubble expansion by an exponential particle production. This gives another meaning of dS entropy as entropy per Hubble volume.

    ↳ gr-qcastro-ph.COhep-phJCAP(2024)·0 citations
33. 33*

    Null energy constraints on two-dimensional RG flows

    Thomas Hartman🇺🇸 · Grégoire Mathys🇺🇸

    We study applications of spectral positivity and the averaged null energy condition (ANEC) to renormalization group (RG) flows in two-dimensional quantum field theory. We find a succinct new proof of the Zamolodchikov $c$-theorem, and derive further independent constraints along the flow. In particular, we identify a natural $C$-function that is a completely monotonic function of scale, meaning its derivatives satisfy the alternating inequalities $(-1{)}^n{C}^{(n)}({\mu }^2)\ge 0$. The completely monotonic $C$-function is identical to the Zamolodchikov $C$-function at the endpoints, but differs along the RG flow. In addition, we apply Lorentzian techniques that we developed recently to study anomalies and RG flows in four dimensions, and show that the Zamolodchikov $c$-theorem can be restated as a Lorentzian sum rule relating the change in the central charge to the average null energy. This establishes that the ANEC implies the $c$-theorem in two dimensions, and provides a second, simpler example of the Lorentzian sum rule.

    ↳ hep-thhep-phJHEP(2024)·33 citations
34. 34*

    Flavor Anisotropy in the High-Energy Astrophysical Neutrino Sky

    Bernanda Telalovic🇩🇰 · Mauricio Bustamante🇩🇰

    High-energy astrophysical neutrinos, with TeV--PeV energies, offer unique insight into astrophysics and particle physics. Their incoming directions and flavor composition -- i.e., the proportion of electron, muon, and tau neutrinos in their flux -- are, individually, rewarding observables. Combined, they offer new opportunities, hitherto unexplored, that we expose for the first time. Anisotropy in the arrival directions of electron, muon, and tau neutrinos may reveal multiple populations of neutrino sources, differently distributed in the sky, and test whether neutrinos of different flavor propagate preferentially along certain directions, such as expected from breaking Lorentz invariance. Using 7.5 years of public IceCube High-Energy Starting Events, we make the first measurement of the directional flavor composition of high-energy astrophysical neutrinos, constrain the presence of flavor dipoles and quadrupoles, and improve constraints on "compass asymmetries" introduced by Lorentz invariance violation. In the near future, upcoming neutrino telescopes will improve these measurements across the board.

    ↳ astro-ph.HEhep-exhep-phhep-thJCAP(2025)·17 citations
35. 35*

    A Fermi-LAT Study of Globular Cluster Dynamical Evolution in the Milky Way: Millisecond Pulsars as the Probe

    Li Feng🇹🇼 · Zhongqun Cheng🇨🇳 · Wei Wang🇨🇳 · Zhiyuan Li · Yang Chen🇺🇸

    Using archival {\it Fermi}-LAT data with a time span of $\sim 12$ years, we study the population of Millisecond Pulsars (MSPs) in Globular Clusters (GlCs) and investigate their dependence on cluster dynamical evolution in the Milky Way Galaxy. We show that the $\gamma$-ray luminosity ($L_{\gamma }$) and emissivity (${ϵ}_{\gamma }=L_{\gamma }/M$) are good indicators of the population and abundance of MSPs in GlCs, and they are highly dependent on the dynamical evolution history of the host clusters. Specifically speaking, the dynamically older GlCs with more compact structures are more likely to have larger $L_{\gamma }$ and ${ϵ}_{\gamma }$, and these trends can be summarized as strong correlations with cluster stellar encounter rate $\Gamma$ and the specific encounter rate ($\Lambda =\Gamma /M$), with $L_{\gamma }\propto {\Gamma }^{0.70\pm 0.11}$ and ${ϵ}_{\gamma }\propto {\Lambda }^{0.73\pm 0.13}$ for dynamically normal GlCs. However, as GlCs evolve into deep core collapse, these trends are found to be reversed, implying that strong encounters may have lead to the ejection of MSPs from core-collapsed Systems. Besides, the GlCs are found to exhibit larger ${ϵ}_{\gamma }$ with increasing stellar mass function slope, decreasing tidal radius and distances from the Galactic Center (GC). These correlations indicate that, as GlCs losing kinetic energy and spiral in towards GC, tidal stripping and mass segregation have a preference in leading to the loss of normal stars from GlCs, while MSPs are more likely to concentrate to cluster center and be deposited into the GC. Moreover, we gauge ${ϵ}_{\gamma }$ of GlCs is $\sim 10-1000$ times larger than the Galactic bulge, the latter is thought to reside thousands of unresolved MSPs and may responsible for the GC $\gamma$-ray excess, which support that GlCs are generous contributors to the population of MSPs in the GC.

    ↳ astro-ph.GAhep-phRes.Astron.Astrophys.(2024)·5 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.