Tue·Jul 6, 2021Tuesday·July 6, 2021

1. 01*

   In-medium screening effects for the Galactic halo and solar-reflected dark matter detection in semiconductor targets

   Zheng-Liang Liang🇨🇳 · Chongjie Mo🇨🇳 · Ping Zhang🇨🇳

   Recently, the importance of the electronic many-body effect in the dark matter (DM) detection has been recognized and a coherent formulation of the DM-electron scattering in terms of the dielectric response of the target material has been well established in literatures. In this paper, we put relevant formulas into practical density functional theory (DFT) estimation of the excitation event rates for the diamond and silicon semiconductor targets. Moreover, we compare the event rates calculated from the energy loss functions with and without the local field effects. For a consistency check of this numerical method, we also compare the differential spectrum and detection reach of the silicon with those computed with the $\mathtt{GPAW}$ code. It turns out that this DFT approach is quite consistent and robust. As an interesting extension, we also investigate the in-medium effect on the detection of the solar-reflected DM flux in silicon-based detectors, where the screening effect is found to be also remarkable in the optically thick regime, and to turn insignificant in the optically thin regime, depending on the energies of the reflected DM particles.

   hep-phPRD(2021)·14 citations
2. 02*

   TMD Evolution and Multi-Jet Merging

   A. Bermudez Martinez🇩🇪 · F. Hautmann🇬🇧 · M.L. Mangano🇨🇭

   The theoretical description of the physics of multi-jets in hadronic collisions at high energies is based on "merging" methods, which combine short-timescale production of jets with long-timescale evolution of partonic showers. We point out potential implications of the evolution of transverse momentum dependent (TMD) distributions on the structure of multi-jet states at high energies, and in particular on the theoretical systematics associated with multi-jet merging. To analyze this, we propose a new merging methodology, and illustrate its impact by comparing our theoretical results with experimental measurements for Z-boson + jets production at the Large Hadron Collider (LHC).

   hep-phPLB(2021)·55 citations
3. 03*

   A massive variable flavour number scheme for the Drell-Yan process

   R. Gauld🇳🇱

   The prediction of differential cross-sections in hadron-hadron scattering processes is typically performed in a scheme where the heavy-flavour quarks ($c,b,t$) are treated either as massless or massive partons. In this work, a method to describe the production of colour-singlet processes which combines these two approaches is presented. The core idea is that the contribution from power corrections involving the heavy-quark mass can be numerically isolated from the rest of the massive computation. These power corrections can then be combined with a massless computation (where they are absent), enabling the construction of differential cross-section predictions in a massive variable flavour number scheme. As an example, the procedure is applied to the low-mass Drell-Yan process within the LHCb fiducial region, where predictions for the rapidity and transverse-momentum distributions of the lepton pair are provided. To validate the procedure, it is shown how the $n_f$-dependent coefficient of a massless computation can be recovered from the massless limit of the massive one. This feature is also used to differentially extract the massless ${\text{N}}^3\text{LO}$ coefficient of the Drell-Yan process in the gluon-fusion channel.

   hep-phhep-exSciPost Phys.(2022)·16 citations
4. 04*

   Gluon matter distribution in the proton and pion from extended holographic light-front QCD

   Guy F. de Téramond🇨🇷 · H. G. Dosch🇩🇪 · Tianbo Liu🇨🇳 · Raza Sabbir Sufian🇺🇸 · Stanley J. Brodsky🇺🇸 · Alexandre Deur🇺🇸

   The holographic light-front QCD framework provides a unified nonperturbative description of the hadron mass spectrum, form factors and quark distributions. In this article we extend holographic QCD in order to describe the gluonic distribution in both the proton and pion from the coupling of the metric fluctuations induced by the spin-two Pomeron with the energy momentum tensor in anti--de Sitter space, together with constraints imposed by the Veneziano model{\color{blue},} without additional free parameters. The gluonic and quark distributions are shown to have significantly different effective QCD scales.

   hep-phhep-latnucl-exnucl-thPRD(2021)·42 citations
5. 05*

   Higgs portal vector dark matter interpretation: review of Effective Field Theory approach and ultraviolet complete models

   Mohamed Zaazoua🇲🇦 · Loan Truong🇿🇦 · Kétévi A. Assamagan🇺🇸 · Farida Fassi🇲🇦

   A review of the Higgs portal-vector dark matter interpretation of the spin-independent dark-matter nucleon elastic scattering cross section is presented, where the invisible Higgs decay width measured at the LHC is used. Effective Field Theory and ultraviolet complete models are discussed. LHC interpretations show only the scalar and Majorana dark-matter scenarios; we propose to include interpretation for vector dark matter in the EFT and UV completions theoretical framework. In addition, our studies suggest an extension of the LHC dark matter interpretations to the sub-GeV regime.

   hep-phLHEP(2022)·23 citations
6. 06*

   Inflation and type III seesaw mechanism in $\nu$-gauge mediated supersymmetry breaking

   Shinsuke Kawai🇰🇷 · Nobuchika Okada🇺🇸

   We discuss realization of cosmic inflation in the $\nu$-gauge mediated supersymmetry breaking scenario, in which a set of 24-dimensional chiral superfields responsible for the type III seesaw mechanism play the role of the messenger fields in gauge mediation. Using the data from neutrino oscillations, we show that the model satisfies constraints from the lepton flavor violation, perturbativity of the unified gauge couplings, the observed abundance of dark matter as well as the Higgs mass of 125.1 GeV. The predicted spectrum of the cosmic microwave background radiation fits well with the observation. We also comment on the falsifiability of this scenario by future experiments.

   hep-phastro-ph.COPRD(2021)·3 citations
7. 07*

   The N${}^3$LO Scheme-invariant QCD Evolution of the Non-singlet Structure Functions \boldmath $F_2^{\mathrm{NS}}(x,Q^2)$ and $g_1^{\mathrm{NS}}(x,Q^2)$

   J. Blümlein🇩🇪 · M. Saragnese🇩🇪

   We present the scheme-invariant unpolarized and polarized flavor non-singlet evolution equation to N${}^3$LO for the structure functions $F_2(x,Q^2)$ and $g_1(x,Q^2)$ including the charm- and bottom quark effects in the asymptotic representation. The corresponding evolution is based on the experimental measurement of the non-singlet structure functions at a starting scale $Q_0^2$. In this way the evolution does only depend on the strong coupling constant ${\alpha }_s(M_Z)$ or the QCD scale ${\Lambda }_{\mathrm{QCD}}$ and the charm and bottom quark masses $m_c$ and $m_b$ and provides one of the cleanest ways to measure the strong coupling constant in future high luminosity deep-inelastic scattering experiments. The yet unknown parts of the 4-loop anomalous dimensions introduce only a marginal error in this analysis.

   hep-phhep-exPLB(2021)·48 citations
8. 08*

   Confronting the inverse seesaw mechanism with the recent muon g-2 result

   João Paulo Pinheiro (Universitat de Barcelona)🇧🇷 · C. A. de S. Pires (Paraiba U.)🇧🇷 · Farinaldo S. Queiroz (IIP, Brazil and Rio Grande do Norte U.)🇧🇷 · Yoxara S. Villamizar (IIP, Brazil and Rio Grande do Norte U.)🇧🇷

   Since the heavy neutrinos of the inverse seesaw mechanism mix largely with the standard ones, the charged currents formed with them and the muons have the potential of generating robust and positive contribution to the anomalous magnetic moment of the muon. Ho\-we\-ver, bounds from the non-unitary in the leptonic mixing matrix may restrict so severely the parameters of the mechanism that, depending on the framework under which the mechanism is implemented, may render it unable to explain the recent muon g-2 result. In this paper we show that this happens when we implement the mechanism into the standard model and into two versions of the 3-3-1 models.

   hep-phPLB(2021)·14 citations
9. 09*

   Nuclear $0\nu 2\beta$ decays in $B-L$ symmetric SUSY model and in TeV scale left-right symmetric model

   Jin Lei Yang🇨🇳 · Chao-Hsi Chang🇨🇳 · Tai-Fu Feng🇨🇳

   In this paper we take B-L supersymmetric standard model (B-LSSM) and TeV scale left-right symmetric model (LRSM) as two representations of the two kinds of new physics models to study the nuclear neutrinoless double beta decays ($0\nu 2\beta$) so as to see the senses onto these two kinds of models when the decays are taken into account additionally. Within the parameter spaces allowed by all the exist experimental data, the decay half-life of the nucleus ${}^{76}$Ge and ${}^{136}$Xe, $T_{1/2}^{0\nu }$(${}^{76}$Ge, ${}^{136}$Xe), is precisely calculated and the results are presented properly. Based on the numerical results, we conclude that the room of LRSM type models for the foreseeable future experimental observations on the decays is greater than that of B-LSSM type models.

   hep-phCommun.Theor.Phys.(2022)·6 citations
10. 10*

    Analysis of $W^{\pm }+4\gamma$ in the 2HDM Type-I at the LHC

    Yan Wang🇨🇳 · A. Arhrib🇲🇦 · R. Benbrik🇲🇦 · M. Krab🇲🇦 · B. Manaut🇲🇦 · S. Moretti🇬🇧 · Qi-Shu Yan🇨🇳

    We analyse a light charged Higgs boson in the 2-Higgs Doublet Model (2HDM) Type-I, when its mass satisfies the condition $M_{H^{\pm }}<M_t+M_b$ and the parameter space is consistent with theoretical requirements of self-consistency as well as the latest experimental constraints from Large Hadron Collider (LHC) and other data. Over such a parameter space, wherein the Standard Model (SM)-like state discovered at the LHC in 2012 is the heaviest CP-even state of the 2HDM, it is found that the decay modes of the charged Higgs boson are dominated by $H^{\pm }\to W^{\pm \ast }h$. Furthermore, the light neutral Higgs boson $h$ dominantly decays into two photons. Under these conditions, we find that the production and decay process $pp\to H^{\pm }h\to {W^{\pm }}^{(\ast )}hh\to l{\nu }_l+4\gamma$ ($l=e,\mu$) is essentially background free. However, since the $W^{\pm (\ast )}$ could be largely off-shell and the $h$ state is very light, so that both the lepton coming from the former and the photons coming from the latter could be rather soft, we perform here a full Monte Carlo (MC) analysis at the detector level demonstrating that such a $W^{\pm }+4\gamma$ signal is very promising, as it would be yielding significant excesses at the LHC with an integrated luminosity of $L=$ 300 $f{b}^{-1}$ at both $\sqrt{s}=13$ and $14\text{TeV}$.

    hep-phJHEP(2021)·26 citations
11. 11*

    Leptogenesis in Type Ib seesaw models

    Bowen Fu🇬🇧 · Stephen F. King🇬🇧

    We study leptogenesis in three different realisations of the type Ib seesaw mechanism, where the effective masses of the neutrinos are obtained by the spontaneous symmetry breaking of two different Higgs doublets. In the minimal type Ib seesaw model, where two right-handed neutrinos form a Dirac mass, we show that it is impossible to produce the correct baryon asymmetry, even including a pseudo-Dirac mass splitting. In an extended type Ib seesaw model, with a third very heavy Majorana right-handed neutrino, together with the low scale Dirac pair of right-handed (RH) neutrinos and an extra singlet Higgs boson, we find that the imbalance of matter and antimatter can be explained by resonant leptogenesis. In the resulting low scale effective type Ib seesaw mechanism, we derive the allowed range of the seesaw couplings consistent with resonant leptogenesis. Dark matter may also be included via the right-handed neutrino portal. The Dirac RH neutrino masses may lie in the 1-100 GeV mass range, accessible to the future experiments SHiP and FCC-$ee$, allowing the type Ib seesaw mechanism with leptogenesis and dark matter to be tested.

    hep-phPRD(2022)·9 citations
12. 12*

    Affleck-Dine Baryogenesis with Observable Neutron-Anti-Neutron Oscillation

    Rabindra N. Mohapatra🇺🇸 · Nobuchika Okada🇺🇸

    We discuss the implications of Affleck-Dine (AD) baryogenesis for different classes of baryon and lepton number violating processes: specially focussing on implications for neutron-anti-neutron ($n-\bar{n}$) oscillation. The class of AD baryogenesis scenarios we work with uses the AD field also as the inflaton which is nonminimally coupled to gravity. We find that adequate baryogenesis and no washout by the baryon number ($B$) or the lepton number ($L$) violating operators implies constraints on the observability of the process or in the case of neutrino mass with compatibility with neutrino oscillation observations. In particular, for $n-\bar{n}$ oscillation, we study some of the familiar operators that connect the AD field to $n-\bar{n}$ oscillation and find that a split scalar spectrum model turns out to be most advantageous for obtaining an observable $n-\bar{n}$ while remaining consistent with AD baryogenesis. It is interesting that this spectrum is similar to a non-supersymmetyric SO(10) model for observable $n-\bar{n}$ oscillation discussed before, suggesting that this AD scenario can be embedded into a grand unified SO(10) model. We also find that for a low scale (all scales in the 100 TeV range), there is a narrow range of parameters where the observable $n-\bar{n}$ oscillation is compatible with viable AD baryogenesis. A feature of this baryogenesis scenario for $n-\bar{n}$ oscillation is that it necessarily predicts processes with $\Delta B=4$ or higher, all be it with highly suppressed amplitudes.

    hep-phastro-ph.COhep-exPRD(2021)·30 citations
13. 13*

    Heavy and light flavor jet quenching in different collision systems at the LHC energies

    Yu-Fei Liu🇨🇳 · Wen-Jing Xing🇨🇳 · Xiang-Yu Wu🇨🇳 · Guang-You Qin🇨🇳 · Shanshan Cao🇨🇳 · Hongxi Xing

    Recent experiments have observed large anisotropic collective flows in high multiplicity proton-lead collisions at the Large Hadron Collider (LHC), which indicates the possible formation of mini quark-gluon plasma (QGP) in small collision systems. However, no jet quenching has been confirmed in such small systems so far. To understand this intriguing result, the system size scan experiments have been proposed to bridge the gap between large and small systems. In this work, we perform a systematic study on both heavy and light flavor jet quenching in different collision systems at the LHC energies. Using our state-of-the-art jet quenching model, which combines the next-to-leading-order perturbative QCD framework, a linear Boltzmann transport model and the (3+1)-dimensional viscous hydrodynamics simulation, we provide a good description of nuclear modification factor $R_{\mathrm{AA}}$ for charged hadrons and $D$ mesons in central and mid-central Pb+Pb and Xe+Xe collisions measured by CMS collaboration. We further predict the transverse momentum and centrality dependences of $R_{AA}$ for charged hadrons, $D$ and $B$ mesons in Pb+Pb, Xe+Xe, Ar+Ar and O+O collisions at the LHC energies. Our numerical results show a clear system size dependence for both light and heavy flavor hadron $R_{AA}$ across different collision systems. Sizable jet quenching effect is obtained for both heavy and light flavor hadrons in central O+O collisions at the LHC energies. Our study provides a significant bridge for jet quenching from large to small systems, and should be helpful for finding the smallest QGP droplet and the disappearance of QGP in relativistic nuclear collisions.

    hep-phnucl-exnucl-thPRC(2022)·18 citations
14. 14*

    A new texture of neutrino mass matrix with three constraints

    Radha Raman Gautam🇮🇳 · Sanjeev Kumar🇮🇳

    We present a new texture of neutrino mass matrix having three complex relations among its elements and study in detail the phenomenological implications. A characteristic feature of the resulting neutrino mass matrix is that the atmospheric neutrino mixing angle is predicted to lie in a very narrow region near $45^{\circ }$. We illustrate how such a form of the neutrino mass matrix can be realized using the non-Abelian flavor symmetry $A_4$ in the framework of type-I+II seesaw mechanism.

    hep-phPLB(2021)·3 citations
15. 15*

    Electro-magnetic field fluctuation and its correlation with the participant plane in Au+Au and isobaric collisions at $\sqrt{s_{NN}}=200$ GeV

    Sk Noor Alam🇮🇳 · Victor Roy🇮🇳 · Shakeel Ahmad🇮🇳 · Subhasis Chattopadhyay🇮🇳

    Intense transient electric ({\bf E}) and magnetic ({\bf B}) fields are produced in the high energy heavy-ion collisions. The electromagnetic fields produced in such high-energy heavy-ion collisions are proposed to give rise to a multitude of exciting phenomenon including the Chiral Magnetic Effect. We use a Monte Carlo (MC) Glauber model to calculate the electric and magnetic fields, more specifically their scalar product $\mathbf{E}\cdot \mathbf{B}$, as a function of space-time on an event-by-event basis for the Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV for different centrality classes. We also calculate the same for the isobars Ruthenium and Zirconium at $\sqrt{s_{NN}}=200$ GeV. In the QED sector $\mathbf{E}\cdot \mathbf{B}$ acts as a source of Chiral Separation Effect, Chiral Magnetic Wave, etc., which are associated phenomena to the Chiral Magnetic Effect. We also study the relationships between the electromagnetic symmetry plane angle defined by $\mathbf{E}\cdot \mathbf{B}$ (${\psi }_{E.B}$) and the participant plane angle ${\psi }_P$ defined from the participating nucleons for the second-fifth order harmonics.

    hep-phnucl-thPRD(2021)·12 citations
16. 16*

    FIMP DM in the Extended Hyperchargeless Higgs Triplet Model

    Pritam Das🇮🇳 · Mrinal Kumar Das🇮🇳 · Najimuddin Khan🇮🇳

    We perform an exclusive study on the Feebly Interacting Massive Particle (FIMP) dark matter candidate in an extended hyperchargeless ($Y=0$) Higgs triplet model. The additional $Z_2$ odd neutral fermion singlet plays the role of dark matter with support from two other vector-like fermion doublets. The mixing between the neutral component of a doublet and singlet fermions controls the current relic density through the Freeze-in mechanism, whereas the additional doublet fermion helps to get the neutrino mass and mixing angles. We obtain a broad region of the parameter spaces satisfying the current relic density and neutrino mass and mixing angles.

    hep-phPRD(2021)·3 citations
17. 17*

    Constraint on the Higgs-Dilaton potential via Warm inflation in Two-Time Physics

    Vo Quoc Phong🇻🇳 · Ngo Phuc Duc Loc🇻🇳

    Within the $SP(2,R)$ symmetry, the Two-time model (2T model) has six dimensions with two dimensions of time and the dilaton field that can be identified as inflaton in a warm inflation scenario with potential of the form $\sim {\varphi }^4$. From that consideration, we derive the range of parameters for the Higgs-Dilaton potential, the coupling constant between Higgs and Dialton ($\alpha$) is larger than $0.0053$ and the mass of Dilaton is smaller than $10^{-7}$ GeV. Therefore, the 2T-model indirectly suggests that extra-dimension can also be a source of inflation.

    hep-phAdv.High Energy Phys.(2022)·2 citations
18. 18*

    The newly observed state $D_{s0}(2590{)}^{+}$

    Guo-Li Wang🇨🇳 · Wei Li🇨🇳 · Tai-Fu Feng🇨🇳 · Ying-Long Wang🇨🇳 · Yu-Bin Liu🇨🇳

    We choose the Reduction Formula, PCAC and Low Energy Theory to reduce the $S$ matrix of a OZI allowed two-body strong decay involving a light pseudoscalar, the covariant transition amplitude formula with relativistic wave functions as input is derived. After confirm this method by the decay $D^{\ast }(2010)\to D\pi$, we study the newly observed $D_{s0}(2590{)}^{+}$ with supposing it to be the state $D_s(2^1{S}_0{)}^{+}$, we find its decay width $\Gamma$ is highly sensitive to the $D_{s0}(2590{)}^{+}$ mass, which result in the meaningless comparison of widths by different models with various input masses. Instead of width, we studied the overlap integral over the wave functions of initial and final states, here we parameterized it as $X$ which is model-independent, and the ratio $\Gamma /|{\vec{P}}_f{|}^3$, both are almost mass independent, to give us useful information. The results show that, all the existing theoretical predictions $X_{D_s(2S)\to D^{\ast }K}=0.25\sim 0.41$ and $\Gamma /|{\vec{P}}_f{|}^3=0.81\sim 1.77$ MeV${}^{-2}$ are smaller than experimental data $0.585_{-0.035}^{+0.015}$ and $4.54_{-0.52}^{+0.25}$ MeV${}^{-2}$. Further compared with $X_{D^{\ast }(2010)\to D\pi }^{ex}=0.540\pm 0.009$, the current data $X_{D_s(2S)\to D^{\ast }K}^{ex}=0.585_{-0.035}^{+0.015}$ is too big to be an reasonable value, so it is early to say $D_{s0}(2590{)}^{+}$ is the conventional $D_s(2^1{S}_0{)}^{+}$ meson.

    hep-phhep-exEPJC(2022)·8 citations
19. 19*

    $cos(2{\varphi }_h)$ asymmetry in $J/\psi$ production in unpolarized $ep$ collision in NRQCD

    Raj Kishore🇮🇳 · Asmita Mukherjee🇮🇳 · Mariyah Siddiqah🇮🇳

    We present a recent calculation of the transverse momentum dependent gluon distributions inside unpolarised protons and show how the ratio of the linearly polarized and the unpolarized gluon distribution in the proton can be probed by looking at $Cos(2{\varphi }_h)$ asymmetry in $J/\psi$ production in unpolarized $ep$ collision. We use NRQCD for estimating $J/\psi$ production and include contributions both from color singlet and color octet states.

    hep-ph0 citations
20. 20*

    Analysis of flux-integrated semi-exclusive cross sections for charged current quasi-elastic neutrino scattering off 40Ar at energies available at the MicroBooNE experiment

    A.V. Butkevich🇷🇺

    Flux-integrated semi-exclusive differential and integral cross sections for quasi-elastic neutrino charged-current scattering on argon are analyzed. We calculate these cross sections using the relativistic distorted-wave impulse approximation and compare with recent MicroBooNE data. We found that the measured cross sections can be described well within the experimental uncertainties with value of the nucleon axial mass $1<M_A<1.2$ GeV. The contribution of the exclusive channel $\text{boldmath}({\nu }_{\mu },\mu p)$ to the flux-integrated inclusive cross sections is about 50\%.

    hep-phnucl-thPRC(2022)·14 citations
21. 21*

    Multiloop corrections for collider processes using auxiliary mass flow

    Xiao Liu🇨🇳 · Yan-Qing Ma🇨🇳

    With a key improvement, the auxiliary mass flow method is now able to compute Feynman integrals encountered in cutting-edge collider processes. We have successfully applied it to compute some integrals involved in two-loop electroweak corrections to $e^{+}{e}^{-}\to HZ$, two-loop QCD corrections to $3j$, $W/Z/H+2j$, $t\bar{t}H$ and $4j$ production at hadron colliders, and three-loop QCD corrections to $t\bar{t}$ production at hadron colliders, all of which are crucial for precision frontier in collider physics in the following decade. Our results are important building blocks and benchmarks for future studies of these processes.

    hep-phPRD(2022)·130 citations
22. 22*

    Anisotropic flow and correlations between azimuthal anisotropy Fourier harmonics in Xe-Xe collisions at $\sqrt{s_{NN}}$ = 5.44 TeV under HYDJET++ framework

    Saraswati Pandey🇮🇳 · B. K. Singh🇮🇳

    The study of anisotropic harmonic flow coefficients $v_n$(n=2,3,4) is performed in Xe-Xe collisions at $\sqrt{s_{NN}}$ = 5.44 TeV under Monte Carlo HYDJET++ model (HYDrodynamics plus JETs) framework. Anisotropic flow of identified particles and correlation between the azimuthal harmonic flow amplitudes is presented. Here, we have considered body-body and tip-tip type of geometrical configurations for Xe-Xe collision systems. The kinematic ranges $|\eta |<0.8$, $0<p_T<5.0$ GeV/c, and $|\delta /\eta |>2$ are considered. The results have been shown for seven classes of centrality and compared with the ALICE experimental data. The anisotropic flow of identified charged particles show a strong centrality dependence. Mass ordering is observed for $v_2,v_3$ and $v_4$. Mass ordering is different for different ranges of transverse momentum $p_T$. Strong correlation is observed between $v_3-v_2$, $v_4-v_2$, and $v_4-v_3$. Such correlation is centrality dependent and is different in different centrality windows. The anisotropic flow coefficients show a clear dependence on the total charged particle multiplicity. HYDJET++ model justifies experimental data well enough.

    hep-phJ.Phys.G(2022)·11 citations
23. 23*

    Hadron wave functions in high-energy scattering, form factors and strong decays: the effects of the Lorentz contracted form

    Yu. A. Simonov🇷🇺

    We study the class of processes where the dynamics depends essentially on the properties of the hadron wave functions involved in the reactions. In this case the momentum dependence of the form of wave functions imposed by Lorentz invariance and in particular by the Lorentz contraction can be tested in the experiment and may strongly influence the resulting cross sections. One example of such observables is given by the hadron form factors, where it was shown that the large Q behavior is mostly frozen, when the Lorentz contraction of the hadron wave functions is taken into account. Another example considered previously is the strong hadron decay with high energy emission. In this paper we study the role of the Lorentz contraction in the high-energy hadron-hadron scattering process at large momentum transfer. For the $pp$ and $p\bar{p}$ scattering at large $s$ it is shown that at small $-t<<s$ the picture of two exponential slopes in the differential cross section explained previously by the author is stable while the backward scattering cross section is strongly increased by the Lorentz contraction.

    hep-phhep-exMod.Phys.Lett.A(2021)·2 citations
24. 24*

    CP violation and determination of the $bs$ "flat" unitarity triangle at FCCee

    Roy Aleksan🇫🇷 · L. Oliver🇫🇷 · Emmanuel Perez🇨🇭

    We investigate the sensitivity with which two angles of the "flat" unitarity triangle, defined by $V_{ub}^{\ast }{V}_{us}+V_{cb}^{\ast }{V}_{cs}+V_{tb}^{\ast }{V}_{ts}=0$, can possibly be measured directly at FCCee. We show that the measured errors on the angle ${\alpha }_s=\arg (-V_{ub}^{\ast }{V}_{us}/V_{tb}^{\ast }{V}_{ts})$ and ${\beta }_s=\arg (-V_{tb}^{\ast }{V}_{ts}/V_{cb}^{\ast }{V}_{cs})$ should be better than $0.4^{\circ }$ and $0.035^{\circ }$, respectively. These measurements, combined with the measurement of the 3rd angle ${\gamma }_s=\arg (-V_{cb}^{\ast }{V}_{cs}/V_{ub}^{\ast }{V}_{us})$, discussed in a different paper, will contribute to probe further the consistency of the CP sector of the Standard Model with unprecedented level of accuracy.

    hep-phPRD(2022)·19 citations
25. 25*

    Isospin asymmetric matter in a nonlocal chiral quark model

    J.P. Carlomagno🇦🇷 · D. Gomez Dumm🇦🇷 · N.N. Scoccola🇦🇷

    We analyze the features of strongly interacting matter in the presence of nonzero isospin chemical potential ${\mu }_I$, within a nonlocal two-flavor Polyakov-Nambu-Jona-Lasinio (PNJL) model. For a system at finite temperature $T$, we describe the behavior of various thermodynamic quantities and study the phase diagram in the ${\mu }_I-T$ plane. In particular, it is found that for values of ${\mu }_I$ larger than the pion mass and temperatures lower than a critical value of about 170 MeV the system lies in an isospin symmetry broken phase signaled by the presence of a nonzero pion condensate. Our results for the phase diagram are found to be in better agreement with those arising from lattice QCD calculations, as compared to the predictions from other theoretical approaches like the local PNJL model.

    hep-phPRD(2021)·7 citations
26. 26*

    Next-to-leading-order study of $J/\psi$ angular distributions in $e^{+}{e}^{-}\to J/\psi +{\eta }_c,{\chi }_{cJ}$ at $\sqrt{s}\approx 10.6$ GeV

    Zhan Sun🇨🇳

    In this paper, we present a detailed next-to-leading-order (NLO) study of $J/\psi$ angular distributions in $e^{+}{e}^{-}\to J/\psi +{\eta }_c,{\chi }_{cJ}$ ($J=0,1,2$) within the nonrelativistic QCD factorization (NRQCD). The numerical NLO expressions for total and differential cross sections, i.e., $\frac{d\sigma }{d\cos \theta }=A+B{\cos }^2\theta$, are both derived. With the inclusion of the newly-calculated QCD corrections to $A$ and $B$, the ${\alpha }_{\theta }(=B/A)$ parameters in $J/\psi +{\chi }_{c0}$ and $J/\psi +{\chi }_{c1}$ are moderately enhanced, while the magnitude of ${{\alpha }_{\theta }}_{J/\psi +{\chi }_{c2}}$ is significantly reduced; regarding the production of $J/\psi +{\eta }_c$, the ${\alpha }_{\theta }$ value remains unchanged. By comparing with experiment, we find the predicted ${{\alpha }_{\theta }}_{J/\psi +{\eta }_c}$ is in good agreement with the $\text{B}\text{ELLE}$ measurement; however, ${{\alpha }_{\theta }}_{J/\psi +{\chi }_{c0}}$ is still totally incompatible with the experimental result, and this discrepancy seems to hardly be cured by proper choices of the charm-quark mass, the renormalization scale, and the NRQCD matrix elements.

    hep-phJHEP(2021)·13 citations
27. 27*

    Resonant leptogenesis and TM${}_1$ mixing in minimal Type-I seesaw model with S${}_4$ symmetry

    Bikash Thapa🇮🇳 · Ng. K. Francis🇮🇳

    We present an S${}_4$ flavour symmetric model within a minimal seesaw framework resulting in mass matrices that leads to TM${}_1$ mixing. Minimal seesaw is realized by adding two right-handed neutrinos to the Standard Model. The model predicts Normal Hierarchy (NH) for neutrino masses. Using the constrained six-dimensional parameter space, we have evaluated the effective Majorana neutrino mass, which is the parameter of interest in neutrinoless double beta decay experiments. The possibility of explaining baryogenesis via resonant leptogenesis is also examined within the model. A non-zero, resonantly enhanced CP asymmetry generated from the decay of right-handed neutrinos at the TeV scale is studied, considering flavour effects. The evolution of lepton asymmetry is discussed by solving the set of Boltzmann equations numerically and obtain the value of baryon asymmetry to be $|{\eta }_B|=6.3\times 10^{-10}$.

    hep-phEPJC(2021)·9 citations
28. 28*

    Aspects of High Scale Leptogenesis with Low-Energy Leptonic CP Violation

    A. Granelli🇮🇹 · K. Moffat🇬🇧 · S. T. Petcov🇮🇹

    Using the density matrix equations (DME) for high scale leptogenesis based on the type I seesaw mechanism, in which the CP violation (CPV) is provided by the low-energy Dirac or/and Majorana phases of the neutrino mixing (PMNS) matrix, we investigate the 1-to-2 and the 2-to-3 flavour regime transitions, where the 1, 2 and 3 leptogenesis flavour regimes in the generation of the baryon asymmetry of the Universe ${\eta }_B$ are described by the Boltzmann equations. Concentrating on the 1-to-2 flavour transition we determine the general conditions under which ${\eta }_B$ goes through zero and changes sign in the transition. Analysing in detail the behaviour of ${\eta }_B$ in the transition in the case of two heavy Majorana neutrinos $N_{1,2}$ with hierarchical masses, $M_1\ll M_2$, we find, in particular, that i) the Boltzmann equations in many cases fail to describe correctly the generation of ${\eta }_B$ in the 1, 2 and 3 flavour regimes, ii) the 2-flavour regime can persist above (below) $\sim 10^{12}$ GeV ($\sim 10^9$ GeV), iii) the flavour effects in leptogenesis persist beyond the typically considered maximal for these effects leptogenesis scale of $10^{12}$ GeV. We further determine the minimal scale $M_{1\text{min}}$ at which we can have successful leptogenesis when the CPV is provided only by the Dirac or Majorana phases of the PMNS matrix as well as the ranges of scales and values of the phases for having successful leptogenesis. We show, in particular, that when the CPV is due to the Dirac phase $\delta$, there is a direct relation between the sign of $\sin \delta$ and the sign of ${\eta }_B$ in the regions of viable leptogenesis in the case of normal hierarchical light neutrino mass spectrum; for the inverted hierarchical spectrum the same result holds for $M_1\lesssim 10^{13}$ GeV. The considered scenarios of leptogenesis are testable and falsifiable in low-energy neutrino experiments.

    hep-phJHEP(2021)·28 citations
29. 29*

    One-loop Feynman integrals for $2\to 3$ scattering involving many scales including internal masses

    Nikolaos Syrrakos🇬🇷

    We study several multiscale one-loop five-point families of Feynman integrals. More specifically, we employ the Simplified Differential Equations approach to obtain results in terms of Goncharov polylogarithms of up to transcendental weight four for families with two and three massive external legs and massless propagators, as well as with one massive internal line and up to two massive external legs. This is the first time this computational approach is applied to cases involving internal masses.

    hep-phhep-thJHEP(2021)·7 citations
30. 30*

    The anomalous $Zb\bar{b}$ couplings at the HERA and EIC

    Bin Yan🇺🇸 · Zhite Yu🇺🇸 · C.-P. Yuan🇺🇸

    To resolve the long-standing discrepancy between the precision measurement of bottom quark forward-backward asymmetry at LEP/SLC and the Standard Model prediction, we propose a novel method to probe the $Zb\bar{b}$ coupling by measuring the single-spin asymmetry $A_e^b$ of the polarized lepton cross section in neutral current DIS processes with a $b$-tagged jet at HERA and EIC. Depending on the tagging efficiency of the final state $b$-jet, the measurement of $A_e^b$ at HERA can already partially break the degeneracy found in the anomalous $Zb\bar{b}$ coupling, as implied by the LEP and SLC precision electroweak data. In the first year run of the EIC, the measurement of $A_e^b$ can already break the degeneracy, due to its much larger luminosity and higher electron beam polarization. With enough integrated luminosity collected at the EIC, it is possible to either verify or exclude the LEP data and resolve the $A_{\mathrm{FB}}^b$ puzzle. We also discuss the complementary roles between the proposed $A_e^b$ measurement at EIC and the measurement of $gg\to Zh$ cross section at the HL-LHC in constraining the anomalous $Zb\bar{b}$ coupling.

    hep-phhep-exnucl-exnucl-thPLB(2021)·33 citations
31. 31*

    $E1$ and M1 radiative transitions involving heavy-light axial, pseudoscalar and vector quarkonia in the framework of Bethe-Salpeter equation

    Vaishali Guleria🇮🇳 · Eshete Gebrehana🇪🇹 · Shashank Bhatnagar🇮🇳

    This work is an extension of our previous work in \cite{bhatnagar20} to calculate M1 transitions, $0^{-+}\to 1^{--}\gamma$, and E1 transitions involving axial vector mesons such as, $1^{+-}\to 0^{-+}\gamma$, and $0^{-+}\to 1^{+-}\gamma$ for which very little data is available as of now. We make use of the general structure of the transition amplitude, $M_{fi}$ derived in our previous work \cite{bhatnagar20} as a linear superposition of terms involving all possible combinations of $++$, and $--$ components of Salpeter wave functions of final and initial hadrons. In the present work, we make use of leading Dirac structures in the hadronic Bethe-Salpeter wave functions of the involved hadrons, which makes the formulation more rigorous. We evaluate the decay widths for both the above mentioned $M1$ and $E1$ transitions. We have used algebraic forms of Salpeter wave functions obtained through analytic solutions of mass spectral equations for ground and excited states of $1^{--}$,$0^{-+}$ and $1^{+-}$ heavy-light quarkonia in approximate harmonic oscillator basis to do analytic calculations of their decay widths. We have compared our results with experimental data, where ever available, and other models.

    hep-phPRD(2021)·17 citations
32. 32*

    Supernova bounds on axion-like particles coupled with nucleons and electrons

    Francesca Calore🇫🇷 · Pierluca Carenza🇮🇹 · Maurizio Giannotti🇺🇸 · Joerg Jaeckel🇩🇪 · Giuseppe Lucente🇮🇹 · Alessandro Mirizzi🇮🇹

    We investigate the potential of type II supernovae (SNe) to constrain axion-like particles (ALPs) coupled simultaneously to nucleons and electrons. ALPs coupled to nucleons can be efficiently produced in the SN core via nucleon-nucleon bremsstrahlung and, for a wide range of parameters, leave the SN unhindered, producing a large ALP flux. For masses exceeding 1 MeV, these ALPs would decay into electron-positron pairs, generating a positron flux. In the case of Galactic SNe, the annihilation of the created positrons with the electrons present in the Galaxy would contribute to the 511 keV annihilation line. Using the SPI (SPectrometer on INTEGRAL) observation of this line, allows us to exclude a wide range of the axion-electron coupling, $10^{-19}\lesssim g_{ae}\lesssim 10^{-11}$, for $g_{ap}\sim 10^{-9}$. Additionally, ALPs from extra-galactic SNe decaying into electron-positron pairs would yield a contribution to the cosmic X-ray background. In this case, we constrain the ALP-electron coupling down to $g_{ae}\sim 10^{-20}$.

    hep-phastro-ph.HEPRD(2021)·50 citations
33. 33*

    Particle Convolution for High Energy Physics

    Chase Shimmin🇺🇸

    We introduce the Particle Convolution Network (PCN), a new type of equivariant neural network layer suitable for many tasks in jet physics. The particle convolution layer can be viewed as an extension of Deep Sets and Energy Flow network architectures, in which the permutation-invariant operator is promoted to a group convolution. While the PCN can be implemented for various kinds of symmetries, we consider the specific case of rotation about the jet axis the $\eta -\varphi$ plane. In two standard benchmark tasks, q/g tagging and top tagging, we show that the rotational PCN (rPCN) achieves performance comparable to graph networks such as ParticleNet. Moreover, we show that it is possible to implement an IRC-safe rPCN, which significantly outperforms existing IRC-safe tagging methods on both tasks. We speculate that by generalizing the PCN to include additional convolutional symmetries relevant to jet physics, it may outperform the current state-of-the-art set by graph networks, while offering a new degree of control over physically-motivated inductive biases.

    hep-phcs.LGhep-ex38 citations
34. 34*

    Studying of final states in p-Au and p-Pb collisions

    Tetiana Obikhod🇺🇦 · Ievgenii Petrenko🇺🇦

    In the framework of PYTHIA8.2 program we considered p-Pb and p-Au heavy ion collisions at the energy of 5.02 TeV and 8 TeV. The advantage of this program is in the combining of several nucleon-nucleon collisions into one heavy ion collision, based on phenomenological treatment of a hadron as a vortex line in a color superconducting medium, the consistent treatment of the central rapidity region with improvements of Glauber-like model where diffractive excitation processes are taken into account. We have considered the influence of impact parameter correlations on the production cross sections of p-Pb and p-Au processes to estimate the influence of hard and soft subprocesses on basic hadronic final-state properties in proton-ion collisions. Using these characteristics based on semi-hard multiparton interaction model we received the transverse momentum and rapidity distributions of K-meson and Lambda baryon at the energy of 5.02 TeV and 8.14 TeV.

    hep-phnucl-thPoS(2022)·1 citation
35. 35*

    Towards Robust Constraints on Axion Dark Matter using PSR J1745-2900

    R. A. Battye🇬🇧 · J. Darling🇺🇸 · J. McDonald🇧🇪 · S. Srinivasan🇬🇧

    We apply novel, recently developed plasma ray-tracing techniques to model the propagation of radio photons produced by axion dark matter in neutron star magnetospheres and combine this with both archival and new data for the galactic centre magnetar PSR J1745-2900. The emission direction to the observer and the magnetic orientation are not constrained for this object leading to parametric uncertainty. Our analysis reveals that ray-tracing greatly reduces the signal sensitivity to this uncertainty, contrary to previous calculations where there was no emission at all in some directions. Based on a Goldreich-Julian model for the magnetosphere and a Navarro-Frank-White model for axion density in the galactic centre, we obtain the most robust limits on the axion-photon coupling, to date. These are comparable to those from the CAST solar axion experiment in the mass range $\sim 4.2-60\mu \mathrm{eV}$. If the dark matter density is larger, as might predicted by a "spike" model, the limits could be much stronger. The dark matter density in the region of the galactic centre is now the biggest uncertainty in these calculations.

    ↳ astro-ph.COhep-phPRD(2022)·64 citations
36. 36*

    Novel Neutron Star Structures with Nucleon Mass Radius

    Wei Kou🇨🇳 · Xiaopeng Wang🇨🇳 · Xurong Chen🇨🇳

    In order to reveal the difference between the latest neutron star observation experiment GW170817 and the existing theory, we mainly consider the effect of the nucleon radius on the neutron star from the existing theory. We believe that the effect of nucleon radius in neutron star is not negligible, and the mass radius of nucleon should be used instead of the charge radius. The nucleon mass radius is set as $r_m=0.55\pm 0.09$ fm from the new measurements. It is considered as an input to the "Excluded Volume Effects" model in the equation of state of nuclear matter. We propose a novel neutron star mass-radius relation by using proton mass radius is consistent with the observation GW170817.

    ↳ nucl-thhep-ph0 citations
37. 37*

    Gravitational waves from bubble collisions in FLRW spacetime

    Haowen Zhong🇨🇳 · Biping Gong🇨🇳 · Taotao Qiu🇨🇳

    Stochastic gravitational wave background (SGWB) is a promising tool to probe the very early universe where the standard model of particle physics and cosmology are connected closely. As a possible component of SGWB, gravitational waves (GW) from bubble collisions during the first order cosmological phase transitions deserve comprehensive analyses. In 2017, Ryusuke Jinno and Masahiro Takimoto proposed an elegant analysis approach to derive the analytical expressions of energy spectra of GW from bubble collisions in Minkowski spacetime avoiding large-scale numerical simulations for the first time[26]. However, they neglect the expansion of the universe and regard the duration of phase transitions as infinity in their derivation which could deviate their estimations from true values. For these two reasons, we give a new expression of GW spectra by adopting their method, switching spacetime background to FLRW spacetime, and considering a finite duration of phase transitions. By denoting $\sigma$ as the fraction of the speed of phase transitions to the expansion speed of the universe, we find when $\sigma$ is around $\mathcal{O}(10)$, the maxima of estimated GW energy spectra drop by around 1 order of magnitude than the results given by their previous work. Even when $\sigma =100$, the maximum of GW energy spectrum is only $65\%$ of their previous estimation. Such a significant decrease may bring about new challenges for the detectability of GW from bubble collisions. Luckily, by comparing new spectra with PLI (\textit{power-law integrated}) sensitivity curves of GW detectors, we find that the detection prospect for GW from bubble collisions is still promising for DECIGO, BBO, LISA, and TianQin in the foreseeable future.

    ↳ gr-qcastro-ph.COhep-phhep-thJHEP(2022)·23 citations
38. 38*

    Cusp in the Symmetry Energy, Speed of Sound in Neutron Stars and Emergent Pseudo-Conformal Symmetry

    Hyun Kyu Lee🇰🇷 · Yong-Liang Ma🇨🇳 · Won-Gi Paeng🇰🇵 · Mannque Rho🇫🇷

    We review how the "cusp" predicted in the nuclear symmetry energy generated by a topology change at density $n_{1/2}\text{gsim}2n_0$ can have a surprising consequence, so far unrecognized in nuclear physics and astrophysics communities, on the structure of dense compact-star matter. The topology change, when translated into nuclear EFT with "effective" QCD degrees of freedom in terms of hidden local and scale symmetries duly taken into account, predicts an EoS that is soft below and stiff above $n\text{gsim}{n}_{1/2}$, involving no low-order phase transitions, and yields the macrophysical properties of neutron stars consistent -- so far with no tension -- with the astrophysical observations, including the maximum mass $2.0\text{lsim}M/M_{\odot }\text{lsim}2.2$ as well as the GW data. Furthermore it describes the interior core of the massive stars populated by baryon-charge-fractionalized quasi-fermions that are neither baryonic nor quarkonic. It is argued that the cusp "buried" in the symmetry energy resulting from strong correlations with hidden heavy degrees of freedom leads, at $n\text{gsim}{n}_{1/2}$, to what we dubbed "pseudo-conformal" sound speed, $v_{pcs}^2/c^2\approx 1/3$, precociously converged from below at $n_{1/2}$. It is not strictly conformal since the trace of energy-momentum tensor is not zero even in the chiral limit. This observation with the topology change identified with the putative hadron-quark continuity, taking place at at density $\text{gsim}2n_0$, implies that the quantities accurately measured at $\sim n_0$ cannot give a stringent constraint for what takes place at the core density of compact stars $\sim (3-7)n_0$. This is because the change of degrees of freedom in effective field theory is involved. We discuss the implication of this on the recent PREX-II "dilemma" in the measured skin thickness of ${}^{208}$Pb.

    ↳ nucl-thastro-ph.HEhep-phMod.Phys.Lett.A(2022)·36 citations
39. 39*

    Probing the explanation of the muon (g-2) anomaly and thermal light dark matter with the semi-visible dark photon channel

    C. Cazzaniga🇨🇭 · P. Odagiu🇨🇭 · E. Depero🇨🇭 · L. Molina Bueno🇨🇭 · Yu. M. Andreev🇷🇺 · D. Banerjee🇨🇭 · J. Bernhard🇨🇭 · V. E. Burtsev🇷🇺 · N. Charitonidis🇨🇭 · A. G. Chumakov🇷🇺 · D. Cooke🇬🇧 · P. Crivelli🇨🇭 and 46 other authors

    We report the results of a search for a new vector boson ($A^{\prime }$) decaying into two dark matter particles ${\chi }_1{\chi }_2$ of different mass. The heavier ${\chi }_2$ particle subsequently decays to ${\chi }_1$ and $A^{\prime }\to e^{-}{e}^{+}$. For a sufficiently large mass splitting, this model can explain in terms of new physics the recently confirmed discrepancy observed in the muon anomalous magnetic moment at Fermilab. Remarkably, it also predicts the observed yield of thermal dark matter relic abundance. A detailed Monte-Carlo simulation was used to determine the signal yield and detection efficiency for this channel in the NA64 setup. The results were obtained re-analyzing the previous NA64 searches for an invisible decay $A^{\prime }\to \chi \overline{\chi }$ and axion-like or pseudo-scalar particles $a\to \gamma \gamma$. With this method, we exclude a significant portion of the parameter space justifying the muon g-2 anomaly and being compatible with the observed dark matter relic density for $A^{\prime }$ masses from 2$m_e$ up to 390 MeV and mixing parameter $ϵ$ between $3\times 10^{-5}$ and $2\times 10^{-2}$.

    ↳ hep-exhep-phEPJC(2021)·42 citations
40. 40*

    A Muon-Ion Collider at BNL: the future QCD frontier and path to a new energy frontier of ${\mu }^{+}{\mu }^{-}$ colliders

    Darin Acosta🇺🇸 · Wei Li🇺🇸

    We propose the development and construction of a novel muon-ion collider (MuIC) at Brookhaven National Laboratory (BNL) in the USA as an upgrade to succeed the electron-ion collider (EIC) that is scheduled to commence in the early 2030s, by a joint effort of the nuclear and particle physics communities. The BNL facility could accommodate a muon storage beam with an energy up to about 1~TeV with existing magnet technology. When collided with a 275~GeV hadron beam, the MuIC center-of-mass energy of about 1~TeV will extend the kinematic coverage of deep inelastic scattering physics at the EIC (with polarized beams) by more than an order of magnitude in $Q^2$ and $x$, opening a new QCD frontier to address many fundamental scientific questions in nuclear and particle physics. This coverage is comparable to that of the proposed Large Hadron-Electron Collider (LHeC) at CERN, but with complementary lepton and hadron kinematics and beam polarization. Additionally, the developmentof a MuIC at BNL will focus the worldwide R\&D efforts on muon collider technology and serve as a demonstrator toward a future muon-antimuon collider at {$\mathcal{O}$}(10)~TeV energies, which is an attractive option to reach the next high energy frontier in particle physics at an affordable cost and a smaller footprint than a future circular hadron collider. We discuss here the possible design parameters of the MuIC, kinematic coverage, science cases, and detector design considerations including estimates of resolutions on DIS kinematic variables. A possible road map toward the future MuIC and muon-antimuon colliders is also presented.

    ↳ physics.acc-phhep-exhep-phnucl-ex+1Nucl.Instrum.Meth.A(2022)·34 citations
41. 41*

    Self-consistent interpretations of the multi-wavelength gamma-ray spectrum of LHAASO J0621$+$3755

    Kun Fang🇨🇳 · Shao-Qiang Xi🇨🇳 · Xiao-Jun Bi🇨🇳

    LHAASO J0621$+$3755 is a TeV gamma-ray halo newly identified by LHAASO-KM2A. It is likely to be generated by electrons trapped in a slow-diffusion zone around PSR J0622$+$3749 through inverse Compton scattering. When the gamma-ray spectrum of LHAASO-KM2A is fitted, the GeV fluxes derived by the commonly used one-zone normal diffusion model for electron propagation are significantly higher than the upper limits (ULs) of Fermi-LAT. In this work, we respectively adopt the one-zone superdiffusion and two-zone normal diffusion models to solve this conflict. For the superdiffusion scenario, we find that a model with superdiffusion index $\alpha \lesssim 1.2$ can meet the constraints of Fermi-LAT observation. For the two-zone diffusion scenario, the size of the slow-diffusion zone is required to be smaller than $\sim 50$ pc, which is consistent with theoretical expectations. Future precise measurements of the Geminga halo may further distinguish between these two scenarios for the electron propagation in pulsar halos.

    ↳ astro-ph.HEhep-phPRD(2021)·18 citations
42. 42*

    Constraining primordial black holes as dark matter using the global 21-cm signal with X-ray heating and excess radio background

    Shikhar Mittal (TIFR)🇮🇳 · Anupam Ray (TIFR)🇮🇳 · Girish Kulkarni (TIFR)🇮🇳 · Basudeb Dasgupta (TIFR)🇮🇳

    Using the global 21-cm signal measurement by the EDGES collaboration, we derive constraints on the fraction of the dark matter that is in the form of primordial black holes (PBHs) with masses in the range $10^{15}$-$10^{17}$g. Improving upon previous analyses, we consider the effect of the X-ray heating of the intergalactic medium on these constraints, and also use the full shape of the 21-cm absorption feature in our inference. In order to account for the anomalously deep absorption amplitude, we also consider an excess radio background motivated by LWA1 and ARCADE2 observations. Because the heating rate induced by PBH evaporation evolves slowly, the data favour a scenario in which PBH-induced heating is accompanied by X-ray heating. Also, for the same reason, using the full measurement across the EDGES observation band yields much stronger constraints on PBHs than just the redshift of absorption. We find that 21-cm observations exclude $f_{\mathrm{PBH}}\gtrsim 10^{-9.7}$ at 95% CL for $M_{\mathrm{PBH}}=10^{15}$g. This limit weakens approximately as $M_{\mathrm{PBH}}^4$ towards higher masses, thus providing the strongest constraints on ultralight evaporating PBHs as dark matter over the entire mass range $10^{15}$-$10^{17}$g. Under the assumption of a simple spherical gravitational collapse based on the Press-Schechter formalism, we also derive bounds on the curvature power spectrum at extremely small scales ($k\sim 10^{15}$Mpc${}^{-1}$). This highlights the usefulness of global 21-cm measurements, including non-detections, across wide frequency bands for probing exotic physical processes.

    ↳ astro-ph.COastro-ph.HEhep-phJCAP(2022)·131 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.