Fri·Mar 4, 2022Friday·March 4, 2022

1. 01*

   Good things to do with extra Higgs doublets

   Hooman Davoudiasl🇺🇸 · Ian M. Lewis🇺🇸 · Matthew Sullivan🇺🇸

   In this contribution to the Snowmass 2021 process, we outline models with two or three Higgs doublets that address open questions of particle physics and cosmology. In particular, we show that with two additional Higgs doublets one can provide a mechanism for the generation of lepton asymmetry and hence baryon asymmetry, through CP violating Higgs decays, near weak scale temperatures. In another model with only one extra Higgs doublet, we illustrate that Yukawa couplings to quarks and neutrinos can lead to a viable mechanism for the generation of Dirac neutrino masses, sourced by the QCD chiral condensate of strange quarks. We adapt Spontaneous Flavor Violation -- a framework for coupling light fermions to new Higgs doublets while avoiding tree level flavor-changing neutral currents -- in constructing these models. In both cases, flavor data provide interesting constraints on the parameter space. Either scenario includes $\mathcal{O}(1)$ couplings of light quarks to the Higgs doublets which allow a future 100 TeV $pp$ collider to have reach for the new scalars up to $\mathcal{O}(10\mathrm{TeV})$ masses, through resonant single production. In the neutrino mass model, collider data can shed light on the mass hierarchy of neutrinos. This article is based on work presented in Refs. [1,2].

   hep-phhep-ex4 citations
2. 02*

   Doubly-polarized WZ hadronic cross sections at NLO QCD+EW accuracy

   Duc Ninh Le🇻🇳 · Julien Baglio🇨🇭

   We present new results for next-to-leading order (NLO) electroweak (EW) corrections to double polarization signals in the $WZ$ production channel at the LHC using the $e^{+}{\nu }_e{\mu }^{+}{\mu }^{-}$ final state. It is found that the EW corrections are most sizable in the transverse momentum distributions of the doubly longitudinal polarization, being around -10% compared to the NLO QCD prediction at $p_{T,e}\approx 200$ GeV, which is in the accessible energy range of the current LHC data.

   hep-phhep-exEPJC(2022)·45 citations
3. 03*

   Probing the dark photon via polarized DIS scattering at the HERA and EIC

   Bin Yan🇺🇸

   The dark photon is widely predicted in many new physics beyond the Standard Model. In this work, we propose to utilize the polarized lepton cross section in neutral current DIS process at the HERA and upcoming Electron-Ion Collider (EIC) to probe the properties of the dark photon. It shows that we can constrain the mixing parameter $ϵ<0.02$ when the dark photon mass $m_{A_D}<10\mathrm{GeV}$ at the HERA with polarized lepton beam and this bound is comparable to the limit from the unpolarized HERA data. With the help of high integrated luminosity and high electron beam polarization of the EIC, the upper limit of the $ϵ$ could be further improved. Depending on the assumption of the systematic error of the cross section measurements, we obtain $ϵ<0.01\sim 0.02$ for the mass region $m_{A_D}<10\mathrm{GeV}$ under the integrated luminosity of $300{\mathrm{fb}}^{-1}$. We also discuss the complementary roles between the cross section and the single-spin asymmetry measurements in probing the dark photon.

   hep-phhep-exnucl-exPLB(2022)·40 citations
4. 04*

   Observing Axion Emission from Supernova with Collider Detectors

   Shoji Asai🇯🇵 · Yoshiki Kanazawa🇯🇵 · Takeo Moroi🇯🇵 · Thanaporn Sichanugrist🇯🇵

   We consider a possibility to observe the axion emission from a nearby supernova (SN) in the future, which can be known in advance by the pre-SN alert system, by collider detectors like the LHC detectors (i.e., the ATLAS and the CMS) and the ILC detectors (i.e., the ILD and SiD). The axion from the SN can be converted to the photon by the strong magnetic field in the detector and the photon can be detected by electromagnetic calorimeter. We estimate the numbers of signal and background events due to a nearby SN and show that the number of signal may be sizable. The axion emission from a nearby SN may be observed if, at the time of the SN, the beam is stopped and the detector operation is switched to the one for the SN axion search.

   hep-phPLB(2022)·5 citations
5. 05*

   Electroweak Phase Transition and Gravitational Waves in the Type-II Seesaw Model

   Ruiyu Zhou🇨🇳 · Ligong Bian🇨🇳 · Yong Du🇨🇳

   The type-II seesaw model is a possible candidate for simultaneously explaining non-vanishing neutrino masses and the observed baryon asymmetry of the Universe. In this work, we study in detail the pattern of phase transition and the gravitational wave production of this model. We find a strong first-order electroweak phase transition generically prefers positive Higgs portal couplings and a light triplet below $\sim 550$ GeV. In addition, we find the gravitational wave yield generated during the phase transition would be at the edge of BBO sensitivity and could be further examined by Ultimate-DECIGO.

   hep-phastro-ph.COJHEP(2022)·42 citations
6. 06*

   Third order fiducial predictions for Drell-Yan at the LHC

   X. Chen🇩🇪 · T. Gehrmann🇨🇭 · E.W.N. Glover🇬🇧 · A. Huss🇨🇭 · P. Monni🇨🇭 · E. Re🇫🇷 · L. Rottoli🇨🇭 · P. Torrielli🇮🇹

   The Drell-Yan process at hadron colliders is a fundamental benchmark for the study of strong interactions and the extraction of electro-weak parameters. The outstanding precision of the LHC demands very accurate theoretical predictions with a full account of fiducial experimental cuts. In this letter we present a state-of-the-art calculation of the fiducial cross section and of differential distributions for this process at third order in the strict fixed-order expansion in the strong coupling, as well as including the all-order resummation of logarithmic corrections. Together with these results, we present a detailed study of the subtraction technique used to carry out the calculation for different sets of experimental cuts, as well as of the sensitivity of the fiducial cross section to infrared physics. We find that residual theory uncertainties are reduced to the percent level and that the robustness of the predictions can be improved by a suitable adjustment of fiducial cuts.

   hep-phhep-exPRL(2022)·117 citations
7. 07*

   Single ${\pi }^0$ production in $\mu e$ scattering at MUonE

   E. Budassi🇮🇹 · C. M. Carloni Calame🇮🇹 · C. L. Del Pio🇮🇹 · F. Piccinini🇮🇹

   The recently proposed MUonE experiment at CERN aims at providing a novel determination of the leading order hadronic contribution to the muon anomalous magnetic moment through the study of elastic muon-electron scattering at relatively small momentum transfer. The anticipated accuracy of the order of 10ppm demands for high-precision prediction in radiative corrections to the $\mu e$ scattering as well as for robust quantitative estimates of all possible background processes. In this letter, the contribution due to the emission of a neutral pion through the process $\mu e\to \mu e{\pi }^0$ is studied and its numerical impact is discussed in different phase space configurations by means of the upgraded Monte Carlo event generator MESMER. In fact, single ${\pi }^0$ production could be a source of reducible background for the measurement of the QED running coupling constant at MUonE and it could be also an important background for possible New Physics searches at MUonE involving $2\to 3$ processes, in phase space regions complementary to the ones characteristic of the elastic $\mu e$ scattering.

   hep-phhep-exPLB(2022)·21 citations
8. 08*

   Isolated photon-hadron production in high energy $pp$ and $pA$ collisions at RHIC and LHC

   Sanjin Benić🇭🇷 · Oscar Garcia-Montero🇩🇪 · Anton Perkov🇭🇷

   We compute the isolated photon production in association with a charged hadron at mid rapidity in $pp$ and $pA$ based on the Color Glass Condensate (CGC) framework of high energy QCD where, for the first time, we incorporate the Sudakov effect of soft gluon emissions. Our results are based on the leading order $qg\to q\gamma$ channel in the CGC framework and confronted with the recent data from RHIC and LHC concerning the angular distributions and out-of-plane transverse momentum distributions. We find that, while the CGC computation alone results in too narrow distributions, with the help of the Sudakov effect, we can get a satisfactory description of the data. With this as a benchmark, we provide predictions for the magnitude of the nuclear effect brought by the phenomena of gluon saturation in the CGC.

   hep-phPRD(2022)·34 citations
9. 09*

   Matching resummed endpoint and continuum $\gamma$-ray spectra from dark-matter annihilation

   Martin Beneke🇩🇪 · Kai Urban🇩🇪 · Martin Vollmann🇩🇪

   For the minimal wino and Higgsino benchmark models we provide accurate energy spectra of high-energy photons from TeV scale dark-matter annihilation $\chi \chi \to \gamma +X$ by merging electroweak Sudakov resummation near maximal energy with the electroweak parton-shower PPPC4DM, and accounting for the Sommerfeld effect. Electroweak resummation significantly changes the shape of the photon-energy spectrum in the wide range $E_{\gamma }\sim (0.6\dots 1)m_{\chi }$ and hence the form of the so-called "line-signal".

   hep-phastro-ph.HEPLB(2022)·21 citations
10. 10*

    Plutonium-241 as a possible isotope for neutrino mass measurement and capture

    Nicolo de Groot🇳🇱

    Tritium has been the isotope of choice for measurements of the neutrino mass and planned detection of the relic neutrino background. The low mass of ${}^3$H leads to large recoil energy of the nucleus. This has emerged as a limiting factor for both measurements. We investigate ${}^{241}$Pu as an alternative. The recoil is 80x smaller and it has similar decay energy and lifetime as ${}^3$H. We evaluate for the first time its soft-neutrino capture cross-section and find $(\sigma v{)}_{\nu }=1.52\times 10^{-45}$. This is 40% of the capture cross-section for tritium and makes ${}^{241}$Pu an interesting alternative for ${}^3$H.

    hep-phnucl-thJ.Phys.G(2023)·10 citations
11. 11*

    Probing axion-like particles coupling to gluons at the LHC

    Filmon Andom Ghebretinsaea🇨🇳 · Zeren Simon Wang🇹🇼 · Kechen Wang🇨🇳

    Assuming ALPs couple to gluons only, they can be produced via the $pp\to aj$ process and decay into two jets at the LHC. When the coupling parameter, $C_{\tilde{G}}/f_a$, is small, the lifetime of ALPs can be long enough leading to displaced final state jets. In this paper, we consider the signal including both the prompt and long-lived cases of ALPs by employing a specialized Delphes module to handle displaced jets. Relevant background processes are generated and simulated at the detector level, and multivariate analyses based on machine-learning are performed to discriminate signal and background events and achieve the best sensitivities. Based on the data accumulated for this study, we forecast the expected upper limits on $C_{\tilde{G}}/f_a$ for ALP mass $m_a$ in the range 5$-$2300 GeV at 2-, 3- and 5-$\sigma$ significances at the High Luminosity-LHC with 14 TeV center-of-mass energy and 3 ab${}^{-1}$ integrated luminosity. Vast previously unprobed regions in the parameter space spanned by $C_{\tilde{G}}/f_a$ and $m_a$ are probed and the best upper limits on $C_{\tilde{G}}/f_a$ at 2-$\sigma$ significance is found to be around $1.0\times 10^{-2}\mathrm{Te}{\mathrm{V}}^{-1}$ for $m_a\sim 500$ GeV. The ALP mass is reconstructed from the kinematics of final state jets and we find that it is measurable in this method when $m_a$ is below about 1 TeV at the HL-LHC. The effects of systematic uncertainties and validation of the EFT framework are also checked and discussed.

    hep-phJHEP(2022)·35 citations
12. 12*

    Sleptonic SUSY: From UV Framework to IR Phenomenology

    Kaustubh Agashe🇺🇸 · Majid Ekhterachian🇨🇭 · Zhen Liu🇺🇸 · Raman Sundrum🇺🇸

    We study an attractive scenario, "Sleptonic SUSY", which reconciles the $125$ GeV Higgs scalar and the non-observation of superpartners thus far with potentially pivotal roles for slepton phenomenology: providing viable ongoing targets for LHC discovery, incorporating a co-annihilation partner for detectable thermal relic dark matter, and capable of mediating the potential muon $g-2$ anomaly. This is accomplished by a modestly hierarchical spectrum, with sub-TeV sleptons and electroweakinos and with multi-TeV masses for the other new states. We study new elements in the UV MSSM realization of Sleptonic SUSY based on higher-dimensional sequestering and the synergy between the resulting gaugino-mediation, hypercharge $D$-term mediation and Higgs-mediation of SUSY-breaking, so as to more fully capture the range of possibilities. This framework stands out by harmoniously solving the flavor, CP and $\mu -B\mu$ problems of the supersymmetric paradigm. We discuss its extension to orbifold GUTs, including gauge-coupling and $b$-tau unification. We also develop a non-minimal model with extra Higgs fields, in which the electroweak vacuum is more readily cosmologically stable against decay to a charge-breaking vacuum, allowing a broader range of sleptonic spectra than in the MSSM alone. We survey the rich set of signals possible at the LHC and future colliders, covering both $R$-parity conservation and violation, as well as for dark matter detection. While the multi-TeV squarks imply a Little Hierarchy Problem, intriguingly, small changes in parameter space to improve naturalness result in dramatic phase transitions to either electroweak-preservation or charge-breaking. In a Multiverse setting, the modest unnaturalness may then be explained by the "principle of living dangerously".

    hep-phhep-exJHEP(2022)·16 citations
13. 13*

    Axial and Vector Structure Functions for Lepton-Nucleon Scattering, NuFact 2021 Update

    Arie Bodek🇺🇸 · Un-ki Yang.🇰🇷 · Yang Xu🇰🇷

    We report on an update (2021) of a phenomenological model for inelastic neutrino- and electron-nucleon scattering cross sections using effective leading order parton distribution functions with a new scaling variable ${\xi }_w$. Non-perturbative effects are well described using the ${\xi }_w$ scaling variable in combination with multiplicative $K$ factors at low $Q^2$. The model describes all inelastic charged-lepton-nucleon scattering data (HERA/NMC/BCDMS/SLAC/JLab) ranging from very high $Q^2$ to very low $Q^2$ and down to the $Q^2=0$ photo-production region. The model has been developed to be used in analyses of neutrino oscillation experiments in the few GeV region. The 2021 update accounts for the difference between axial and vector structure functions which brings it into much better agreement with neutrino-nucleon total cross section measurements. The model has been developed primarily for hadronic final state masses $W$ above 1.8 GeV. However with additional parameters the model also describes the $average$ neutrino cross sections in the resonance region down to $W$=1.4 GeV.

    hep-phPoS(2022)·2 citations
14. 14*

    Phenomenological Aspects of Axion-Like Particles in Cosmology and Astrophysics

    Ahmed Ayad🇿🇦

    Cosmology and particle physics are closer today than ever before, with several searches underway at the interface between cosmology, particle physics, and field theory. The mystery of dark matter (DM) is one of the greatest common unsolved problems between these fields. It is established now based on many astrophysical and cosmological observations that only a small fraction of the total matter content of the universe is made of baryonic matter, while the vast majority is constituted by dark matter. However, the nature of such a component is still unknown. One theoretically well-motivated approach to understanding the nature of dark matter would be through looking for light pseudo-scalar candidates for dark matter such as axions and axion-like particles (ALPs). Axions are hypothetical elementary particles resulting from the Peccei-Quinn (PQ) solution to the strong CP (charge-parity) problem in quantum chromodynamics (QCD). Furthermore, many theoretically well-motivated extensions to the standard model of particle physics (SMPP) predicted the existence of more pseudo-scalar particles similar to the QCD axion and called ALPs. Axions and ALPs are characterized by their coupling with two photons. While the coupling parameter for axions is related to the axion mass, there is no direct relation between the coupling parameter and the mass of ALPs. Nevertheless, it is expected that ALPs share the same phenomenology of axions. In the past years, axions and ALPs regained popularity and slowly became one of the most appealing candidates that possibly contribute to the dark matter density of the universe. In this thesis, we focus on studying the phenomenology of axions and ALPs interactions with photons to constrain some of their properties.

    hep-phastro-ph.HE1 citation
15. 15*

    Sterile neutrino portals to Majorana dark matter: effective operators and UV completions

    Leonardo Coito🇪🇸 · Carlos Faubel🇪🇸 · Juan Herrero-García🇪🇸 · Arcadi Santamaria🇪🇸 · Arsenii Titov🇪🇸

    Stringent constraints on the interactions of dark matter with the Standard Model suggest that dark matter does not take part in gauge interactions. In this regard, the possibility of communicating between the visible and dark sectors via gauge singlets seems rather natural. We consider a framework where the dark matter talks to the Standard Model through its coupling to sterile neutrinos, which generate active neutrino masses. We focus on the case of Majorana dark matter, with its relic abundance set by thermal freeze-out through annihilations into sterile neutrinos. We use an effective field theory approach to study the possible sterile neutrino portals to dark matter. We find that both lepton-number-conserving and lepton-number-violating operators are possible, yielding an interesting connection with the Dirac/Majorana character of active neutrinos. In a second step, we open the different operators and outline the possible renormalisable models. We analyse the phenomenology of the most promising ones, including a particular case in which the Majorana mass of the sterile neutrinos is generated radiatively.

    hep-phJHEP(2022)·31 citations
16. 16*

    Exploiting a future galactic supernova to probe neutrino magnetic moments

    Sudip Jana🇩🇪 · Yago P Porto-Silva🇧🇷 · Manibrata Sen🇩🇪

    A core-collapse supernova (SN) offers an excellent astrophysical laboratory to test non-zero neutrino magnetic moments. In particular, the neutronization burst phase, which lasts for few tens of milliseconds post-bounce, is dominated by electron neutrinos and can offer exceptional discovery potential for transition magnetic moments. We simulate the neutrino spectra from the burst phase in forthcoming neutrino experiments like the Deep Underground Neutrino Experiment (DUNE), and the Hyper-Kamiokande (HK), by taking into account spin-flavour conversions of SN neutrinos, caused by interactions with ambient magnetic fields. We find that the neutrino transition magnetic moments which can be explored by these experiments for a galactic SN are an order to several orders of magnitude better than the current terrestrial and astrophysical limits. Additionally, we also discuss how this realization might shed light on three important neutrino properties: (a) the Dirac/Majorana nature, (b) the neutrino mass ordering, and (c) the neutrino mass-generation mechanism.

    hep-phastro-ph.HEastro-ph.SRhep-exJCAP(2022)·39 citations
17. 17*

    Flavor hierarchies, flavor anomalies, and Higgs mass from a warped extra dimension

    Javier Fuentes-Martin🇪🇸 · Gino Isidori🇨🇭 · Javier M. Lizana🇨🇭 · Nudzeim Selimovic🇨🇭 · Ben A. Stefanek🇨🇭

    The recent B-meson anomalies are coherently explained at the TeV scale by 4321 gauge models with hierarchical couplings reminiscent of the Standard Model Yukawas. We show that such models arise as the low-energy limit of a complete theory of flavor, based on a warped fifth dimension where each Standard Model family is quasi-localized in a different brane. The Higgs is identified as a pseudo-Nambu-Goldstone boson emerging from the same dynamics responsible for 4321 symmetry breaking. This novel construction unifies quarks and leptons in a flavor non-universal manner, provides a natural description of flavor hierarchies, and addresses the electroweak hierarchy problem.

    hep-phPLB(2022)·97 citations
18. 18*

    Neutrino Self-Interactions: A White Paper

    Jeffrey M. Berryman🇺🇸 · Nikita Blinov🇨🇦 · Vedran Brdar🇺🇸 · Thejs Brinckmann🇮🇹 · Mauricio Bustamante🇩🇰 · Francis-Yan Cyr-Racine🇺🇸 · Anirban Das🇺🇸 · André de Gouvêa🇺🇸 · Peter B. Denton🇺🇸 · P.S. Bhupal Dev🇺🇸 · Bhaskar Dutta🇺🇸 · Ivan Esteban🇺🇸 and 22 other authors

    Neutrinos are the Standard Model (SM) particles which we understand the least, often due to how weakly they interact with the other SM particles. Beyond this, very little is known about interactions among the neutrinos, i.e., their self-interactions. The SM predicts neutrino self-interactions at a level beyond any current experimental capabilities, leaving open the possibility for beyond-the-SM interactions across many energy scales. In this white paper, we review the current knowledge of neutrino self-interactions from a vast array of probes, from cosmology, to astrophysics, to the laboratory. We also discuss theoretical motivations for such self-interactions, including neutrino masses and possible connections to dark matter. Looking forward, we discuss the capabilities of searches in the next generation and beyond, highlighting the possibility of future discovery of this beyond-the-SM physics.

    hep-phastro-ph.HEhep-exhep-thPhys.Dark Univ.(2023)·146 citations
19. 19*

    The $Higgs\to b\bar{b},c\bar{c},gg$ measurement at CEPC

    Yongfeng Zhu🇨🇳 · Hanhua Cui🇨🇳 · Manqi Ruan🇨🇳

    Accurately measuring the properties of the Higgs boson is one of the core physics objectives of the Circular Electron Positron Collider (CEPC). As a Higgs factory, the CEPC is expected to operate at a centre-of-mass energy of $240GeV$, deliver an integrated luminosity of $5.6a{b}^{-1}$, and produce one million Higgs bosons according to the CEPC Conceptual Design Report (CDR). Combining measurements of the ${\ell }^{+}{\ell }^{-}H$, $\nu \bar{\nu }H$, and $q\bar{q}H$ channels, we conclude that the signal strength of $H\to b\bar{b}/c\bar{c}/gg$ can be measured with a relative accuracy (statistic uncertainty only) of 0.27\%/4.03\%/1.56\%. Extrapolating to the recently released TDR operating parameters corresponding to the integrated luminosity of $20a{b}^{-1}$, the relative accuracy of $H\to b\bar{b}/c\bar{c}/gg$ signal strength is 0.14\%/2.13\%/0.82\%. We analyze the dependence of the expected accuracies on the critical detector performances: Color Singlet Identification (CSI) for the $q\bar{q}H$ channel and flavor tagging for both $\nu \bar{\nu }H$ and $q\bar{q}H$ channels. We observe that compared to the baseline CEPC detector performance, ideal flavor tagging increases the $H\to b\bar{b}/c\bar{c}/gg$ signal strength accuracy by 2\%/63\%/13\% in the $\nu \bar{\nu }H$ channel and 35\%/122\%/181\% in the $q\bar{q}H$ channel. In addition, better performance of CSI can significantly improve the anticipated accuracy of signal strength. The relevant systematics are also discussed in this paper.

    ↳ hep-exhep-phJHEP(2022)·15 citations
20. 20*

    Overview of intermittency analysis in heavy-ion collisions

    Zhiming Li🇨🇳

    In this paper, a search for power-law fluctuations with fractality and intermittency analysis to explore the QCD phase diagram and the critical point is summarized. Experimental data on self-similar correlations and fluctuations with respect to the size of phase space volume in various high energy heavy-ion collisions are presented, with special emphasis on background subtraction and efficiency correction of the measurement. Phenomenological modelling and theoretical work on the subject are discussed. Finally, we highlight possible directions for future research.

    ↳ nucl-thhep-phnucl-exMod.Phys.Lett.A(2022)·13 citations
21. 21*

    Assessment of Dark Matter Models Using Dark Matter Correlations across Dwarf Spheroidal Galaxies

    Ahmad Borzou🇺🇸

    The predicted size of dark matter substructures in kilo-parsec scales is model-dependent. Therefore, if the correlations between dark matter mass densities as a function of the distances between them are measured via observations, we can scrutinize dark matter scenarios. In this paper, we present an assessment procedure of dark matter scenarios. First, we use Gaia's data to infer the single-body phase-space density of the stars in the Fornax dwarf spheroidal galaxy. The latter, together with the Jeans equation, after eliminating the gravitational potential using the Poisson equation, reveals the mass density of dark matter as a function of its position in the galaxy. We derive the correlations between dark matter mass densities as a function of distances between them. No statistically significant correlation is observed. Second, for the sake of comparison with the standard cold dark matter, we also compute the correlations between dark matter mass densities in a small halo of the Eagle hydrodynamics simulation. We show that the correlations from the simulation and from Gaia are in agreement. Third, we show that Gaia observations can be used to limit the parameter space of the Ginzburg--Landau statistical field theory of dark matter mass densities and subsequently shrink the parameter space of any dark matter model. As two examples, we show how to leave limitations on (i) a classic gas dark matter and (ii) a superfluid dark matter.

    ↳ astro-ph.GAastro-ph.COcond-mat.otherhep-phUniverse(2022)·1 citation
22. 22*

    Interpretation of the puzzling gamma-ray spectrum of the Geminga halo

    Kun Fang🇨🇳 · Xiao-Jun Bi🇨🇳

    The gamma-ray halo around Geminga is formed owing to the slow diffusion of the electrons released by the Geminga PWN. The latest HAWC and HESS observations exhibit complex features in the TeV gamma-ray spectrum of the Geminga halo. We first show that the new results cannot be interpreted by the commonly used simple model, where a single power-law injection spectrum and an energy index of $\delta =1/3$ for the diffusion coefficient are assumed. We then propose a two-population electron injection model based on the x-ray observations of the Geminga PWN, which consists of a population of freshly accelerated electrons escaping from the PWN through rapid outflows and a population trapped longer inside the PWN before escaping. The two-population model interprets the HAWC and HESS data well, and the goodness of fit improves significantly compared with the single power-law injection model. It also predicts a different energy dependency of the gamma-ray profile from the single power-law model, which could be tested by LHAASO in the coming future. We note that a $\delta$ slightly larger than 1 is needed to fit the HAWC and HESS data consistently. We also discuss the possible improvements by adopting the two-zone diffusion model.

    ↳ astro-ph.HEhep-phPRD(2022)·11 citations
23. 23*

    Hyperbolic inflationary model with nonzero curvature

    Andronikos Paliathanasis (DUT, Durban and Chile Austral U., Valdivia)🇿🇦 · Genly Leon (Catolica del Norte U. and DUT, Durban)🇨🇱

    We consider a cosmological model consisting of two scalar fields defined in the hyperbolic plane known as hyperbolic inflation. For the background space, we consider a homogeneous and isotropic spacetime with nonzero curvature. We study the asymptotic behaviour of solutions and we search for attractors in the expanding regime. We prove that two hyperbolic inflationary stages are stable solutions that can solve the flatness problem and describe acceleration for both open and closed models, and additionally we obtain a Milne-like attractor solution for the open model. We also investigate the contracting branch obtaining mirror solutions with the opposite dynamical behaviours.

    ↳ gr-qcastro-ph.COhep-phPLB(2022)·7 citations
24. 24*

    Classifications of magnetized $T^4$ and $T^4/Z_2$ orbifold models

    Shota Kikuchi🇯🇵 · Tatsuo Kobayashi🇯🇵 · Kaito Nasu🇯🇵 · Hikaru Uchida🇯🇵

    We study constructions and classifications of three-generation models based on magnetized $T^4$ and $T^4/Z_2$ orbifold as candidates of the compact space. We focus on chiral fermion zero-mode wave functions in the extra dimensions. Freedoms of constant gauge fields, called Scherk-Schwarz phases are taken into account. Infinite number of three-generation models are yielded, corresponding to the ways in which the magnetic flux can be turned on. We classify them in a systematic manner, clarifying the relationship between different models. The Higgs sector is also studied by analyzing possible assignments of the magnetic flux and Scherk-Schwarz phases, etc. to left- and right-handed fermions.

    ↳ hep-thhep-phJHEP(2022)·17 citations
25. 25*

    Inspiralling compact objects with generic deformations

    Nicholas Loutrel🇮🇹 · Richard Brito🇵🇹 · Andrea Maselli🇮🇹 · Paolo Pani🇮🇹

    Self-gravitating bodies can have an arbitrarily complex shape, which implies a much richer multipolar structure than that of a black hole in General Relativity. With this motivation, we study the corrections to the dynamics of a binary system due to generic, nonaxisymmetric mass quadrupole moments to leading post-Newtonian (PN) order. Utilizing the method of osculating orbits and a multiple scale analysis, we find analytic solutions to the precession and orbital dynamics of a (generically eccentric) binary in terms of the dimensionless modulus parameters ${ϵ}_m$, corresponding to axial $m=1$ and polar $m=2$ corrections from oblateness/prolateness. The solutions to the precession dynamics are exact for $0\le {ϵ}_2<1$, and perturbative in ${ϵ}_1\ll 1$. We further compute the leading order corrections to the gravitational wave amplitude and phase for a quasi-circular binary due to mass quadrupole effects. Making use of the stationary phase approximation and shifted uniform asymptotics (SUA), the corrections to the phase enter at relative 2PN order, while the amplitude modulations enter at -0.5PN order with a SUA amplitude correction at 3.25PN order, relative 2PN order to the leading order SUA correction. By investigating the dephasing due to generic quadrupole moments, we find that a phase difference $\gtrsim 0.1$~radians is achievable for ${ϵ}_m\gtrsim 10^{-3}$, which suggests that constraints with current and future ground-based gravitational wave detectors are possible. Our results can be implemented in parameter estimation studies to constrain generic multipolar deformations of the Kerr geometry and of neutron stars.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2022)·26 citations
26. 26*

    Gaussian processes and effective field theory of $f(T)$ gravity under the $H_0$ tension

    Xin Ren🇨🇳 · Sheng-Feng Yan🇨🇳 · Yaqi Zhao🇨🇳 · Yi-Fu Cai🇨🇳 · Emmanuel N. Saridakis🇬🇷

    We consider the effective field theory formulation of torsional gravity in a cosmological framework to alter the background evolution. Then we use the latest $H_0$ measurement from the SH0ES Team as well as observational Hubble data from cosmic chronometer (CC) and radial baryon acoustic oscillations (BAO) and we reconstruct the $f(T)$ form in a model-independent way by applying Gaussian processes. Since the special square-root term does not affect the evolution at the background level, we finally summarize a family of functions that can produce the background evolution required by the data. Lastly, performing a fitting using polynomial functions, and implementing the Bayesian Information Criterion (BIC), we find an analytic expression that may describe the cosmological evolution in great agreement with observations.

    ↳ astro-ph.COgr-qchep-phhep-thApJ(2022)·83 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.