Fri·Dec 1, 2023Friday·December 1, 2023

1. 01*

   Anomalies in Hadronic $B$ Decays

   Raphaël Berthiaume🇨🇦 · Bhubanjyoti Bhattacharya🇺🇸 · Rida Boumris🇨🇦 · Alexandre Jean🇨🇦 · Suman Kumbhakar🇨🇦 · David London🇨🇦

   In this paper, we perform fits to $B\to PP$ decays, where $B=\{B^0,B^{+},B_s^0\}$ and the pseudoscalar $P=\{\pi ,K\}$, under the assumption of flavor SU(3) symmetry [SU(3)${}_F$]. Although the fits to $\Delta S=0$ or $\Delta S=1$ decays individually are good, the combined fit is very poor: there is a $3.6\sigma$ disagreement with the SU(3)${}_F$ limit of the standard model (SM${}_{{\mathrm{SU}(3)}_{\mathrm{F}}}$). One can remove this discrepancy by adding SU(3)${}_F$-breaking effects, but 1000% SU(3)${}_F$ breaking is required. The above results are rigorous, group-theoretically - no dynamical assumptions have been made. When one adds an assumption motivated by QCD factorization, the discrepancy with the SM${}_{{\mathrm{SU}(3)}_{\mathrm{F}}}$ grows to $4.4\sigma$.

   hep-phhep-exPRL(2024)·31 citations
2. 02*

   Discovering Heavy Neutral Leptons with the Higgs Boson

   Nicolás Bernal🇦🇪 · Kuldeep Deka🇦🇪 · Marta Losada🇦🇪

   We study the dominant signatures that arise in Higgs physics at colliders when extending the Standard Model (SM) with a Yukawa interaction to heavy neutral leptons (HNL), while suppressing their mixing to active neutrinos. We focus on the production of HNLs from Higgs bosons that subsequently decay via the Higgs to SM fermions to determine the experimental reach at the LHC detectors and far detectors such as FASER and MATHUSLA. We also determine the impact of precision Higgs constraints on beyond-SM parameters in this scenario.

   hep-phPRD(2024)·6 citations
3. 03*

   Exploring light nuclei production at RHIC and LHC energies with A Multi-Phase Transport model and a coalescence afterburner

   Yoshini Bailung🇮🇳 · Neha Shah🇮🇳 · Ankhi Roy🇮🇳

   In heavy-ion collisions, understanding how light nuclei species are produced can provide insight into the nature of hadronic interactions in extreme conditions. It can also shed light on understanding the matter-antimatter asymmetry and dark matter searches in astrophysical processes. To investigate the production mechanism of light nuclei such as deuteron, triton, and helium-3, we use a naive coalescence afterburner coupled to the well-known $‘‘$A Multi-Phase Transport model" (AMPT). We focus on studying the production of light nuclei in central Au+Au collisions at different center of mass energies ($\sqrt{s_{{}_{\mathrm{NN}}}}$ = 19.6, 39, and 200 GeV) and in Pb+Pb collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}$ = 2.76 TeV, at mid-rapidity. We generate events with the string melting version of AMPT, and feed the information of the nucleons with spatial and momentum conditions into the coalescence afterburner. Our study reports differential and integrated yields in transverse momentum ($p_{\mathrm{T}}$) of the light nuclei in different center of mass energies. We also estimate the coalescence parameters ($B_A$) as a function of $p_{\mathrm{T}}$ and collision energy for (anti-)deuterons, tritons and helium-3s for Au+Au and Pb+Pb collisions, which are compared to other light nuclei production studies. All results are compared with measurements from the STAR and ALICE experiments.

   hep-phNPA(2023)·5 citations
4. 04*

   Natural anomaly-mediation from the landscape with implications for LHC SUSY searches

   Howard Baer🇺🇸 · Vernon Barger🇺🇸 · Jessica Bolich🇺🇸 · Juhi Dutta🇺🇸 · Dibyashree Sengupta🇮🇹

   Supersymmetric models with the anomaly-mediated SUSY breaking (AMSB) arose in two different settings: 1. extra-dimensional models where SUSY breaking occurred in a sequestered sector and 2. 4-d models with dynamical SUSY breaking in a hidden sector where scalars gain masses of order the gravitino mass m_{3/2} but with gauginos and trilinear soft terms of the AMSB form. Both have run into serious conflicts with 1. LHC sparticle and Higgs mass constraints, 2. constraints from wino-like WIMP dark matter searches and 3. bounds from naturalness. These conflicts may be avoided by introducing minor changes to the underlying phenomenological models consisting of non-universal bulk scalar Higgs masses and A-terms, providing a setting for {\it natural anomaly-mediation} (nAMSB). In nAMSB, the wino is still expected to be the lightest of the gauginos, but the higgsinos are expected to be the lightest electroweakinos (EWinos) in accord with naturalness. We examine what sort of spectra are expected to emerge when nAMSB arises from a string landscape setting. We explore the LHC phenomenology of nAMSB models via higgsino pair production and wino pair production. We characterize the dominant LHC signatures arising from the remaining patch of parameter space which should be fully testable at high-luminosity LHC via EWino pair production searches.

   hep-phPRD(2024)·13 citations
5. 05*

   Recent Developments of Small-$x$ Evolution for Quark and Gluon Helicity

   Yossathorn Tawabutr🇫🇮

   Helicity of quarks and gluons inside the proton at small Bjorken $x$ is one of the missing pieces of the proton spin puzzle, with limited experimental results due to various challenges. To address the problem, we derive under the framework of color glass condensate (CGC) effective theory a renormalization group equation in rapidity for the parton helicity distributions, which resums double-logarithmic factor, ${\alpha }_s{\ln }^2(1/x)$, with ${\alpha }_s$ being the strong coupling constant. With running coupling, the equation produces results at Bjorken $x\le 0.1$ that are consistent with the world polarized scattering data. There is an evidence for a significant parton helicity contribution from the small-$x$ region. However, the helicity estimate still contains a large uncertainty that will dramatically reduce with the upcoming measurements from the Electron-Ion Collider (EIC). Ongoing attempts to reduce the uncertainty of our helicity prediction in the medium term will also be discussed.

   hep-phnucl-th4 citations
6. 06*

   Quantum Simulations for Strong-Field QED

   Luis Hidalgo🇺🇸 · Patrick Draper🇺🇸

   Quantum field theory in the presence of strong background fields contains interesting problems where quantum computers may someday provide a valuable computational resource. In the NISQ era it is useful to consider simpler benchmark problems in order to develop feasible approaches, identify critical limitations of current hardware, and build new simulation tools. Here we perform quantum simulations of strong-field QED (SFQED) in $3+1$ dimensions, using real-time nonlinear Breit-Wheeler pair-production as a prototypical process. The strong-field QED Hamiltonian is derived and truncated in the Furry-Volkov mode expansion, and the interactions relevant for Breit-Wheeler are transformed into a quantum circuit. Quantum simulations of a "null double slit" experiment are found to agree well with classical simulations following the application of various error mitigation strategies, including an asymmetric depolarization algorithm which we develop and adapt to the case of Trotterization with a time-dependent Hamiltonian. We also discuss longer-term goals for the quantum simulation of SFQED.

   hep-phquant-phPRD(2024)·15 citations
7. 07*

   Decays of radially excited vector mesons ${\rho }^{\prime }$ and ${\omega }^{\prime }$ in the extended NJL model

   M.K. Volkov🇷🇺 · A.B. Arbuzov🇷🇺 · A.A. Pivovarov🇷🇺 · K. Nurlan🇷🇺

   The decay widths of ${\rho }^{\prime }\to \pi \pi ,\omega \pi ,\rho \eta$, ${\omega }^{\prime }\to \rho \pi ,\omega \eta$ and ${\pi }^{\prime }\to \rho \pi$ are recalculated within the extended NJL quark model. It is shown that the mass of ${\rho }^{\prime }(1450)$ meson in the derived in the NJL model agrees with the one given in Particle Data Group tables but significantly deviates from the recent result of CMD-3 collaboration. Comparisons with earlier theoretical results are presented.

   hep-phInt.J.Mod.Phys.A(2024)·2 citations
8. 08*

   Predicted ${\Xi }_b(6087{)}^0$ and further predictions

   Wei-Han Tan🇨🇳 · Hui-Min Yang🇨🇳 · Hua-Xing Chen🇨🇳

   The methods of QCD sum rules and light-cone sum rules within the framework of heavy quark effective theory have been widely applied to study the singly heavy baryons, and especially, we have applied these methods to predict not only the mass and width of the ${\Xi }_b(6087{)}^0$ recently discovered by LHCb, but also its observation channel and its mass difference from the ${\Xi }_b(6100{)}^{-}$. We apply the same approach to perform a complete study on the $P$-wave bottom baryons of the $SU(3)$ flavor ${\bar{3}}_F$ and investigate their fine structure. Besides the ${\Lambda }_b(5912{)}^0$, ${\Lambda }_b(5920{)}^0$, ${\Xi }_b(6087{)}^0$, and ${\Xi }_b(6100{)}^{-}$, our results suggest the existence of the other two ${\Lambda }_b$ and two ${\Xi }_b$ baryons, whose widths are limited. They are the ${\Lambda }_b(J^P=3/2^{-})$ with the mass and width about $(5.93_{-0.13}^{+0.13}\mathrm{GeV},0.0_{-0.0}^{+12.0}\mathrm{MeV})$, the ${\Lambda }_b(5/2^{-})$ with $(5.94_{-0.13}^{+0.13}\mathrm{GeV},\approx 0\mathrm{MeV})$, the ${\Xi }_b(3/2^{-})$ with $(6.10_{-0.10}^{+0.15}\mathrm{GeV},1.4{}_{-1.4}^{+11.6}\mathrm{MeV})$, and the ${\Xi }_b(5/2^{-})$ with $(6.11_{-0.10}^{+0.15}\mathrm{GeV},1.0{}_{-1.0}^{+7.4}\mathrm{MeV})$. Their mass splittings are calculated to be $M_{{\Lambda }_b(5/2^{-})}-M_{{\Lambda }_b(3/2^{-})}=17\pm 7\mathrm{MeV}$ and $M_{{\Xi }_b(5/2^{-})}-M_{{\Xi }_b(3/2^{-})}=14\pm 7\mathrm{MeV}$. All these baryons are explained as the $P$-wave bottom baryons of the $\rho$-mode, where the orbital excitation is between the two light quarks. However, the existence of this mode is still controversial, so their experimental searches can verify both our approach and the existence of the $\rho$-mode, which can significantly improve our understanding on the internal structure of hadrons.

   hep-phhep-exEPJC(2024)·15 citations
9. 09*

   Linear response theory for spin alignment of vector mesons in thermal media

   Wen-Bo Dong🇨🇳 · Yi-Liang Yin🇨🇳 · Xin-Li Sheng🇮🇹 · Shi-Zheng Yang🇨🇳 · Qun Wang🇨🇳

   We present a calculation of the spin alignment for unflavored vector mesons in thermalized quark-gluon plasma based on the Kubo formula in linear response theory. This is achieved by expanding the system to the first order of the coupling constant and the spatial gradient. The effect strongly relies on the vector meson's spectral functions which are determined by the interaction and medium properties. The spectral functions are calculated for the one-quark-loop self-energy with meson-quark interaction. The numerical results show that the correction to the spin alignment from the thermal shear tensor is of the order $10^{-4}\sim 10^{-5}$ for the chosen values of quark-meson coupling constant, if the magnitude of thermal shear tensor is $10^{-2}$.

   hep-phhep-thnucl-thPRD(2024)·31 citations
10. 10*

    Searching for exclusive leptoquarks with the Nambu-Jona-Lasinio composite model at the LHC and HL-LHC

    Sehar Ajmal🇮🇹 · Jethro Gaglione🇺🇸 · Alfredo Gurrola🇺🇸 · Orlando Panella🇮🇹 · Matteo Presilla🇩🇪 · Francesco Romeo🇺🇸 · Hao Sun🇨🇳 · She-Sheng Xue🇮🇹

    We present a detailed study concerning a new physics scenario involving four fermion operators of the Nambu-Jona-Lasinio type characterized by a strong-coupling ultraviolet fixed point where composite particles are formed as bound states of elementary fermions at the scale $\Lambda =\mathcal{O}(\text{TeV})$. After implementing the model in the Universal FeynRules Output format, we focus on the phenomenology of the scalar leptoquarks at the LHC and the High-Luminosity option. Leptoquark particles have undergone extensive scrutiny in the literature and experimental searches, primarily relying on pair production and, more recently, incorporating single, t-channel, and lepton-induced processes. This study marks, for the first time, the examination of these production modes at varying jet multiplicities. Novel mechanisms emerge, enhancing the total production cross-section, especially for leptoquarks couplings to higher fermion generations. A global strategy is devised to capture all final state particles produced in association with leptoquarks or originating from their decay, which we termed ``exclusive'', in an analogy to the nomenclature used in nuclear reactions. The assessment of the significance in current and future LHC runs, focusing on the case of leptoquark coupling to a muon - $\text{c}$ quark pair, reveals superior sensitivity compared to ongoing searches. Given this heightened discovery potential, we advocate the incorporation of exclusive leptoquark searches in future investigations at the LHC.

    hep-phJHEP(2024)·4 citations
11. 11*

    Heavy quark dynamics via Gribov-Zwanziger approach

    Sumit🇮🇳 · Arghya Mukherjee🇮🇳 · Najmul Haque🇮🇳 · Binoy Krishna Patra🇮🇳

    In this work, we investigate the momentum-dependent drag and diffusion coefficient of heavy quarks (HQs) moving in the quark-gluon plasma (QGP) background. The leading order scattering amplitudes required for this purpose have been obtained using the Gribov-Zwanziger propagator for the mediator gluons to incorporate the non-perturbative effects relevant to the phenomenologically accessible temperature regime. The drag and diffusion coefficients so obtained have been implemented to estimate the temperature and momentum dependence of the energy loss of the HQ as well as the temperature dependence of the specific shear viscosity ($\eta /s$) of the background medium. Our results suggest a higher energy loss of the propagating HQ compared to the perturbative estimates, whereas the $\eta /s$ is observed to comply with the AdS/CFT estimation over a significantly wider temperature range compared to the perturbative expectation.

    hep-phPRD(2024)·8 citations
12. 12*

    Effect of color randomization on $p_T$ broadening of fast partons in turbulent quark-gluon plasma

    B.G. Zakharov🇷🇺

    We analyze the effect of the parton color randomization on $p_T$ broadening in the quark-gluon plasma with turbulent color fields. We calculate the transport coefficient for a simplified model of fluctuating color fields in the form of alternating sequential transverse layers with homogenous transverse chromomagnetic fields with random orientation in the SU(3) group and gaussian distribution in the magnitude. Our numerical results show that the color randomization can lead to a sizable reduction of the turbulent contribution to $\hat{q}$. The magnitude of the effect grows with increasing ratio of the electric and magnetic screening masses.

    hep-phnucl-th2 citations
13. 13*

    UV-complete Gauged Anomaly-free U(1) Froggatt-Nielsen Model

    Johan Rathsman🇸🇪 · Felix Tellander🇩🇪

    We investigate the possibility of understanding all fermion masses and mixings within a gauged Froggatt-Nielsen framework. Continuing the work from [J. Rathsman and F. Tellander, Phys. Rev. D \textbf{100}, 055032 (2019)] we especially focus on a UV completion of this type of models. Independent of the UV completion, we construct an anomaly-free two Higgs doublet model with a gauged $U(1{)}_F$ flavor symmetry and three right-handed neutrinos explaining all observed masses and mixings in the fermion sector. We then investigate two different UV completions: one through fermions and one through scalars. The fermion completion has low lying Landau poles in the gague couplings while the scalar completion is viable up to the gravity scale.

    hep-ph3 citations
14. 14*

    Double-Virtual NNLO QCD Corrections for Five-Parton Scattering: The Quark Channels

    Giuseppe De Laurentis🇬🇧 · Harald Ita🇨🇭 · Vasily Sotnikov🇨🇭

    We complete the computation of two-loop helicity amplitudes required to obtain next-to-next-to-leading order QCD corrections for three-jet production at hadron colliders, including all contributions beyond the leading-color approximation. The analytic expressions are reconstructed from finite-field samples obtained with the numerical unitarity method. We find that the reconstruction is significantly facilitated by exploiting the overlaps between rational coefficient functions of quark and gluon processes, and we display their compact generating sets in the appendix of the paper. We implement our results in a public code, and demonstrate its suitability for phenomenological applications.

    hep-phhep-thPRD(2024)·55 citations
15. 15*

    Electrobaryonic axion: hair of neutron stars

    Yang Bai🇺🇸 · Carlos Henrique de Lima🇨🇦

    Axion-like particles are predicted in many physics scenarios beyond the Standard Model (SM). Their interactions with SM particles may arise from the triangle anomaly of the associated global symmetry, along with other SM global and gauge symmetries, including anomalies with the global baryon number and electromagnetic gauge symmetries. We initiate the phenomenological study of the corresponding ``electrobaryonic axion", a particle that couples with both the baryon chemical potential and the electromagnetic field. Neutron stars, particularly magnetars, possessing high baryon density and strong magnetic fields, can naturally develop a thin axion hair around their surface. In this study, we calculate this phenomenon, considering the effects of neutron star rotation and general relativity. For axion particles lighter than the neutron star rotation frequency, the anomalous interaction can also induce the emission of axion particles from the neutron star. This emission, in the light axion regime, can have a significant contribution to the neutron star cooling rate.

    hep-phastro-ph.HEhep-thJHEP(2024)·9 citations
16. 16*

    Glauber Phases in Non-Global LHC Observables: Resummation for Gluon-Initiated Processes

    Philipp Böer🇩🇪 · Patrick Hager🇩🇪 · Matthias Neubert🇩🇪 · Michel Stillger🇩🇪 · Xiaofeng Xu (JGU Mainz)🇩🇪

    The resummation of the ''Glauber series'' in non-global LHC observables is extended to processes with gluons in the initial state. This series simultaneously incorporates large double-logarithmic corrections, the so-called ''super-leading logarithms'', together with higher-order exchanges of pairs of Glauber gluons associated with the large numerical factor $(i\pi {)}^2$. On a technical level, the main part of this work is devoted to the systematic reduction of the appearing color traces and construction of basis structures, which consist of thirteen elements for $gg$ and eleven elements for $qg$ scattering. Numerical estimates for wide-angle gap-between-jet cross sections at the parton level show that, in particular for $gg$ scattering at relatively small vetoes $Q_0$, the contribution involving four Glauber exchanges gives a sizeable correction and should not be neglected.

    hep-phhep-thJHEP(2024)·10 citations
17. 17*

    Schwinger-Dyson equation on the complex plane -- A four-fermion interaction model at finite temperature --

    Hidekazu Tanaka🇯🇵 · Shuji Sasagawa🇯🇵

    We extend the Schwinger-Dyson equation (SDE) on the complex plane, which was treated in our previous research, to finite temperature. As a simple example, we solve the SDE for a model with four-fermion interactions in the (1+1) space-time dimensions at strong coupling region. We investigate the properties of the effective mass and energy for the fermions, especially near the phase transition temperature.

    hep-phhep-thnucl-thPTEP(2024)·0 citations
18. 18*

    Anomaly Detection in Collider Physics via Factorized Observables

    Eric M. Metodiev🇺🇸 · Jesse Thaler🇺🇸 · Raymond Wynne🇺🇸

    To maximize the discovery potential of high-energy colliders, experimental searches should be sensitive to unforeseen new physics scenarios. This goal has motivated the use of machine learning for unsupervised anomaly detection. In this paper, we introduce a new anomaly detection strategy called FORCE: factorized observables for regressing conditional expectations. Our approach is based on the inductive bias of factorization, which is the idea that the physics governing different energy scales can be treated as approximately independent. Assuming factorization holds separately for signal and background processes, the appearance of non-trivial correlations between low- and high-energy observables is a robust indicator of new physics. Under the most restrictive form of factorization, a machine-learned model trained to identify such correlations will in fact converge to the optimal new physics classifier. We test FORCE on a benchmark anomaly detection task for the Large Hadron Collider involving collimated sprays of particles called jets. By teasing out correlations between the kinematics and substructure of jets, our method can reliably extract percent-level signal fractions. This strategy for uncovering new physics adds to the growing toolbox of anomaly detection methods for collider physics with a complementary set of assumptions.

    hep-phhep-exphysics.data-anPRD(2024)·16 citations
19. 19*

    Flow Matching Beyond Kinematics: Generating Jets with Particle-ID and Trajectory Displacement Information

    Joschka Birk🇩🇪 · Erik Buhmann🇩🇪 · Cedric Ewen🇩🇪 · Gregor Kasieczka🇩🇪 · David Shih🇺🇸

    We introduce the first generative model trained on the JetClass dataset. Our model generates jets at the constituent level, and it is a permutation-equivariant continuous normalizing flow (CNF) trained with the flow matching technique. It is conditioned on the jet type, so that a single model can be used to generate the ten different jet types of JetClass. For the first time, we also introduce a generative model that goes beyond the kinematic features of jet constituents. The JetClass dataset includes more features, such as particle-ID and track impact parameter, and we demonstrate that our CNF can accurately model all of these additional features as well. Our generative model for JetClass expands on the versatility of existing jet generation techniques, enhancing their potential utility in high-energy physics research, and offering a more comprehensive understanding of the generated jets.

    hep-phcs.LGhep-exphysics.data-anPRD(2025)·20 citations
20. 20*

    Anatomy of Diluted Dark Matter in the Minimal Left-Right Symmetric Model

    Miha Nemevšek🇸🇮 · Yue Zhang🇨🇦

    Temporary matter domination and late entropy dilution, injected by a "long-lived" particle in the early universe, serves as a standard mechanism for yielding the correct dark matter relic density. We recently pointed out the cosmological significance of diluting particle's partial decay into dark matter. When repopulated in such a way, dark matter carries higher momentum than its thermal counterpart, resulting in a suppression of the linear matter power spectrum that is constrained by the large scale structure observations. In this work, we study the impact of such constraints on the minimal left-right symmetric model that accounts for the origin of neutrino mass. We map out a systematic anatomy of possible dilution scenarios with viable parameter spaces, allowed by cosmology and various astrophysical and terrestrial constraints. We show that to accommodate the observed dark matter relic abundance the spontaneous left-right symmetry breaking scale must be above PeV and cosmology will continue to provide the most sensitive probes of it. In case the dilutor is one of the heavier right-handed neutrinos, it can be much lighter and lie near the electroweak scale.

    hep-phastro-ph.COPRD(2024)·21 citations
21. 21*

    Phenomenology of superheavy decaying dark matter from string theory

    Rouzbeh Allahverdi🇺🇸 · Chiara Arina🇧🇪 · Marco Chianese🇮🇹 · Michele Cicoli🇮🇹 · Fabio Maltoni🇧🇪 · Daniele Massaro🇮🇹 · Jacek K. Osiński🇵🇱

    We study the phenomenology of superheavy decaying dark matter with mass around $10^{10}$ GeV which can arise in the low-energy limit of string compactifications. Generic features of string theory setups (such as high scale supersymmetry breaking and epochs of early matter domination driven by string moduli) can accommodate superheavy dark matter with the correct relic abundance. In addition, stringy instantons induce tiny $R$-parity violating couplings which make dark matter unstable with a lifetime well above the age of the Universe. Adopting a model-independent approach, we compute the flux and spectrum of high-energy gamma rays and neutrinos from three-body decays of superheavy dark matter and constrain its mass-lifetime plane with current observations and future experiments. We show that these bounds have only a mild dependence on the exact nature of neutralino dark matter and its decay channels. Applying these constraints to an explicit string model sets an upper bound of $\mathcal{O}(0.1)$ on the string coupling, ensuring that the effective field theory is in the perturbative regime.

    hep-phhep-thJHEP(2024)·16 citations
22. 22*

    $M_{W_R}$ dependence of leptogenesis in Minimal Left-Right Symmetric Model with different strengths of Type-II seesaw mass

    Ankita Kakoti🇮🇳 · Mrinal Kumar Das🇮🇳

    Left Right Symmetric Model (LRSM) being an extension of the Standard model of particle physics incorporates within itself Type-I and Type-II seesaw mass terms naturally. Both the mass terms can have significant amount of contribution to the resulting light neutrino mass within the model and hence on the different phenomenology associated within. In this paper, we have thoroughly analyzed and discussed the implications of specifying different weightages to the type-I and type-II mass terms and also the study has been carried out for different values of $M_{W_R}$ which is mass of the right-handed gauge boson. This paper also gives a deeper insight into the new physics contributions of Neutrinoless Double Beta Decay $(0\nu \beta \beta )$ and their variations with the net baryon asymmetry arising out of the model. Therefore, the main objective of the present paper rests on investigating the implications of imposing different weightage to the type-I and type-II seesaw terms and different values of $M_{W_R}$ on the new physics contributions of $0\nu \beta \beta$ and net baryon asymmetry arising out as a result of resonant leptogenesis. LRSM in this work has been realized using modular group of level 3, $\Gamma (3)$ which is isomorphic to non-abelian discrete symmetry group $A_4$, the advantage being the non-requirement of flavons within the model and hence maintaining the minimality of the model.

    hep-phJHEP(2024)·4 citations
23. 23*

    Supermassive Black Hole Binaries in Ultralight Dark Matter

    Benjamin C. Bromley🇺🇸 · Pearl Sandick🇺🇸 · Barmak Shams Es Haghi🇺🇸

    We investigate the evolution of supermassive black hole (SMBH) binaries and the possibility that their merger is facilitated by ultralight dark matter (ULDM). When ULDM is the main dark matter (DM) constituent of a galaxy, its wave nature enables the formation of massive quasiparticles throughout the galactic halo. Here we show that individual encounters between quasiparticles and a SMBH binary can lead to the efficient extraction of energy and angular momentum from the binary. The relatively short coherence time of ULDM provides a steady-state population of massive quasiparticles, and consequently a potential solution to the final parsec problem. Furthermore, we demonstrate that, in the presence of stars, ULDM quasiparticles can also act as massive perturbers to enhance the stellar relaxation rate locally, replenish the stellar loss cone efficiently, and consequently resolve the final parsec problem.

    ↳ astro-ph.GAastro-ph.COgr-qchep-phPRD(2024)·36 citations
24. 24*

    A Non-Perturbative Mixed Anomaly and Fractional Hydrodynamic Transport

    Joe Davighi🇨🇭 · Nakarin Lohitsiri🇬🇧 · Napat Poovuttikul🇹🇭

    We present a new non-perturbative 't Hooft anomaly afflicting a quantum field theory with symmetry group $G=U(1)\times {\mathbb{Z}}_2$ in four dimensions. We use the Adams spectral sequence to compute that the bordism group ${\Omega }_5^{\text{Spin}}(BG)$, which classifies anomalies that remain when perturbative anomalies cancel, is ${\mathbb{Z}}_4$. By constructing a mapping torus and evaluating the Atiyah-Patodi-Singer $\eta$-invariant, we show that the mod 4 anomaly is generated by a pair of Weyl fermions that are vector-like under $U(1)$, but with only one component charged under ${\mathbb{Z}}_2$. We construct a simple microscopic field theory that realises the anomaly, before investigating its impact in the hydrodynamic limit. We find that the anomaly dictates transport phenomena in the $U(1)$ current and energy-momentum tensor akin to the chiral vortical and magnetic effects (even though the perturbative anomalies here vanish), but with the conductivities being fractionally quantised in units of a quarter, reflecting the mod 4 nature of the bordism group.Along the way, we compute the (relevant) bordism groups ${\Omega }_d^{\text{Spin}}(B{\mathbb{Z}}_2\times BU(1))$ and ${\Omega }_d^{{\text{Pin}}^{-}}(BU(1))$ in all degrees $d=0$ through 5.

    ↳ hep-thcond-mat.mes-hallhep-phJHEP(2024)·4 citations
25. 25*

    Electromagnetic Signatures of Mirror Stars

    Isabella Armstrong🇨🇦 · Berkin Gurbuz🇨🇦 · David Curtin🇨🇦 · Christopher Matzner🇨🇦

    Mirror Stars are a generic prediction of dissipative dark matter models, including minimal atomic dark matter and twin baryons in the Mirror Twin Higgs. Mirror Stars can capture regular matter from the interstellar medium through extremely suppressed kinetic mixing interactions between the regular and the dark photon. This accumulated "nugget" will draw heat from the mirror star core and emit highly characteristic X-ray and optical signals. In this work, we devise a general parameterization of mirror star nugget properties that is independent of the unknown details of mirror star stellar physics, and use the Cloudy spectral synthesis code to obtain realistic and comprehensive predictions for the thermal emissions from optically thin mirror star nuggets. We find that mirror star nuggets populate an extremely well-defined and narrow region of the HR diagram that only partially overlaps with the white dwarf population. Our detailed spectral predictions, which we make publicly available, allow us to demonstrate that optically thin nuggets can be clearly distinguished from white dwarf stars by their continuum spectrum shape, and from planetary nebulae and other optically thin standard sources by their highly exotic emission line ratios. Our work will enable realistic mirror star telescope searches, which may reveal the detailed nature of dark matter.

    ↳ astro-ph.HEastro-ph.COastro-ph.GAastro-ph.SR+1ApJ(2024)·16 citations
26. 26*

    A New Stability Equation for the Abelian Higgs-Kibble Model with a Dim.6 Derivative Operator

    Andrea Quadri (INFN, Milan)🇮🇹

    We show that the dynamics of the scalar Higgs field in the Abelian Higgs-Kibble model, supplemented with a dimension 6 derivative operator, can be constrained at the quantum level by a certain stability equation. The latter holds true in the Landau gauge and is derived within the recently proposed extended field formalism where the physical scalar is described by a gauge-invariant field variable. Physical implications of the stability equation are discussed.

    ↳ hep-thhep-phTheor.Math.Phys.(2023)·1 citation
27. 27*

    Probing the Dark Matter Capture Rate in a Local Population of Brown Dwarfs with IceCube Gen 2

    Pooja Bhattacharjee🇫🇷 · Francesca Calore🇫🇷

    This study explores the potential for dark matter annihilation within brown dwarfs, investigating an unconventional mechanism for neutrino production. Motivated by the efficient accumulation of dark matter particles in brown dwarfs through scattering interactions, we focus on a mass range above 10 GeV, considering dark matter annihilation channels $\chi \chi \to \nu \bar{\nu }\nu \bar{\nu }$ through long-lived mediators. Using the projected sensitivity of IceCube Generation 2, we assess the detection capability of the local population of brown dwarfs within 20 pc and exclude dark matter-nucleon scattering with cross-sections as low as a few multiples of $10^{-36}\mathrm{c}{\mathrm{m}}^2$.

    ↳ astro-ph.HEastro-ph.EPastro-ph.SRhep-phParticles(2024)·10 citations
28. 28*

    Search for Hidden Neutrinos at the European Spallation Source: the SHiNESS experiment

    Stefano Roberto Soleti🇪🇸 · Pilar Coloma🇪🇸 · Juan Jose Gómez Cadenas🇪🇸 · Anatael Cabrera🇫🇷

    The upcoming European Spallation Source (ESS) will soon provide the most intense neutrino source in the world. We propose the Search for Hidden Neutrinos at the ESS (SHiNESS) experiment, highlighting its unique opportunities to search for the existence of sterile neutrinos across a wide range of scales: anomalous oscillations at short baselines; non-unitarity mixing in the active neutrino sector; or an excess of events with multiple leptons in the final state, produced in the decay of heavy neutrinos. The baseline design of the detector comprises an active volume filled with 42 ton of liquid scintillator, located 25 m far from the ESS beam target. We show that SHiNESS will be able to considerably improve current global limits for the three cases outlined above. Although in this work we focus on new physics in the neutrino sector, the proposed setup may also be used to search for signals from weakly interacting particles in a broader context.

    ↳ hep-exhep-phJHEP(2024)·11 citations
29. 29*

    A Comparison Between Invariant and Equivariant Classical and Quantum Graph Neural Networks

    Roy T. Forestano🇺🇸 · Marçal Comajoan Cara🇪🇸 · Gopal Ramesh Dahale🇮🇳 · Zhongtian Dong🇺🇸 · Sergei Gleyzer🇺🇸 · Daniel Justice🇺🇸 · Kyoungchul Kong🇺🇸 · Tom Magorsch🇩🇪 · Konstantin T. Matchev🇺🇸 · Katia Matcheva🇺🇸 · Eyup B. Unlu🇺🇸

    Machine learning algorithms are heavily relied on to understand the vast amounts of data from high-energy particle collisions at the CERN Large Hadron Collider (LHC). The data from such collision events can naturally be represented with graph structures. Therefore, deep geometric methods, such as graph neural networks (GNNs), have been leveraged for various data analysis tasks in high-energy physics. One typical task is jet tagging, where jets are viewed as point clouds with distinct features and edge connections between their constituent particles. The increasing size and complexity of the LHC particle datasets, as well as the computational models used for their analysis, greatly motivate the development of alternative fast and efficient computational paradigms such as quantum computation. In addition, to enhance the validity and robustness of deep networks, one can leverage the fundamental symmetries present in the data through the use of invariant inputs and equivariant layers. In this paper, we perform a fair and comprehensive comparison between classical graph neural networks (GNNs) and equivariant graph neural networks (EGNNs) and their quantum counterparts: quantum graph neural networks (QGNNs) and equivariant quantum graph neural networks (EQGNN). The four architectures were benchmarked on a binary classification task to classify the parton-level particle initiating the jet. Based on their AUC scores, the quantum networks were shown to outperform the classical networks. However, seeing the computational advantage of the quantum networks in practice may have to wait for the further development of quantum technology and its associated APIs.

    ↳ quant-phcs.LGhep-phstat.MLAxioms(2024)·16 citations
30. 30*

    Scaling behaviour of $dN/dy$ in high-energy collisions

    Gábor Kasza🇭🇺 · Tamás Csörgő🇭🇺

    From a recently found family of analytic, finite and accelerating 1+1-dimensional solutions to perfect fluid relativistic hydrodynamics, we derive simple and powerful formulae to describe the rapidity and pseudorapidity density distributions. By introducing a new scaling function, we notice that the rapidity distribution data of the different experiments all collapse into a single curve. This data-collapsing (or scaling) behaviour in the rapidity distributions suggests that high-energy $p+p$ collisions may be described as collective systems.

    ↳ nucl-thhep-phUniverse(2024)·2 citations
31. 31*

    Moments of parton distribution functions of any order from lattice QCD

    Andrea Shindler🇩🇪

    We describe a procedure to determine moments of parton distribution functions of any order in lattice quantum chromodynamics (QCD). The procedure is based on the gradient flow for fermion and gauge fields. The flowed matrix elements of twist-2 operators renormalize multiplicatively, and the matching with the physical matrix elements can be obtained using continuum symmetries and the irreducible representations of Euclidean 4-dimensional rotations. We calculate the matching coefficients at one-loop in perturbation theory for moments of any order in the flavor nonsinglet case. We also give specific examples of operators that could be used in lattice QCD computations. It turns out that it is possible to choose operators with identical Lorentz indices and still have a multiplicative matching. One can thus use twist-2 operators exclusively with temporal indices, thus substantially improving the signal-to-noise ratio in the computation of the hadronic matrix elements.

    ↳ hep-lathep-phnucl-thPRD(2024)·44 citations
32. 32*

    ${\mathbb{Z}}_2\times {\mathbb{Z}}_2$ Equivariant Quantum Neural Networks: Benchmarking against Classical Neural Networks

    Zhongtian Dong🇺🇸 · Marçal Comajoan Cara🇪🇸 · Gopal Ramesh Dahale🇮🇳 · Roy T. Forestano🇺🇸 · Sergei Gleyzer🇺🇸 · Daniel Justice🇺🇸 · Kyoungchul Kong🇺🇸 · Tom Magorsch🇩🇪 · Konstantin T. Matchev🇺🇸 · Katia Matcheva🇺🇸 · Eyup B. Unlu🇺🇸

    This paper presents a comprehensive comparative analysis of the performance of Equivariant Quantum Neural Networks (EQNN) and Quantum Neural Networks (QNN), juxtaposed against their classical counterparts: Equivariant Neural Networks (ENN) and Deep Neural Networks (DNN). We evaluate the performance of each network with two toy examples for a binary classification task, focusing on model complexity (measured by the number of parameters) and the size of the training data set. Our results show that the ${\mathbb{Z}}_2\times {\mathbb{Z}}_2$ EQNN and the QNN provide superior performance for smaller parameter sets and modest training data samples.

    ↳ quant-phcs.LGhep-phstat.MLAxioms(2024)·9 citations
33. 33*

    Tunneling Potentials to Nothing

    J.J. Blanco-Pillado🇪🇸 · J.R. Espinosa🇪🇸 · J. Huertas🇪🇸 · K. Sousa🇪🇸

    The catastrophic decay of a spacetime with compact dimensions, via bubbles of nothing (BoNs), is probably a generic phenomenon. BoNs admit a 4-dimensional description as singular Coleman-de Luccia bounces of the size modulus field, stabilized by some potential $V(\varphi )$. We apply the tunneling potential approach to this 4d description to provide a very simple picture of BoNs. Using it we identify four different types of BoN, corresponding to different classes of higher dimensional theories. We study the quenching of BoN decays and their interplay with standard vacuum decays.

    ↳ hep-thgr-qchep-phPRD(2024)·10 citations
34. 34*

    Constraining Glueball Couplings

    Andrea L. Guerrieri🇮🇹 · Aditya Hebbar🇫🇷 · Balt C. van Rees🇫🇷

    We set up a numerical S-matrix bootstrap problem to rigorously constrain bound state couplings given by the residues of poles in elastic amplitudes. We extract upper bounds on these couplings that follow purely from unitarity, crossing symmetry, and the Roy equations within their proven domain of validity. First we consider amplitudes with a single spin 0 or spin 2 bound state, both with or without a self-coupling. Subsequently we investigate amplitudes with the spectrum of bound states corresponding to the estimated glueball masses of pure SU(3) Yang-Mills. In the latter case the 'glue-hedron', the space of allowed couplings, provides a first-principles constraint for future lattice estimates.

    ↳ hep-thhep-lathep-phPRD(2025)·21 citations
35. 35*

    Bubbles of Nothing: The Tunneling Potential Approach

    J.J. Blanco-Pillado🇪🇸 · J.R. Espinosa🇪🇸 · J. Huertas🇪🇸 · K. Sousa🇪🇸

    Bubbles of nothing (BoNs) describe the decay of spacetimes with compact dimensions and are thus of fundamental importance for many higher dimensional theories proposed beyond the Standard Model. BoNs admit a 4-dimensional description in terms of a singular Coleman-de Luccia (CdL) instanton involving the size modulus field, stabilized by some potential $V(\varphi )$. Using the so-called tunneling potential ($V_t$) approach, we study which types of BoNs are possible and for which potentials $V(\varphi )$ can they be present. We identify four different types of BoN, characterized by different asymptotic behaviours at the BoN core and corresponding to different classes of higher dimensional theories, which we also classify. Combining numerous analytical and numerical examples, we study the interplay of BoN decays with other standard decay channels, identify the possible types of quenching of BoN decays and show how BoNs for flux compactifications can also be described in 4 dimensions by a multifield $V_t$. The use of the $V_t$ approach greatly aids our analyses and offers a very simple picture of BoNs which are treated in the same language as any other standard vacuum decays.

    ↳ hep-thgr-qchep-phJCAP(2024)·17 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.