Wed·Oct 21, 2020Wednesday·October 21, 2020

1. 01*

   Unitarity limits on thermal dark matter in (non-)standard cosmologies

   Disha Bhatia🇮🇳 · Satyanarayan Mukhopadhyay🇮🇳

   Using the upper bound on the inelastic reaction cross-section implied by S-matrix unitarity, we derive the thermally averaged maximum dark matter (DM) annihilation rate for general $k\to 2$ number-changing reactions, with $k\ge 2$, taking place either entirely within the dark sector, or involving standard model fields. This translates to a maximum mass of the particle saturating the observed DM abundance, which, for dominantly $s$-wave annihilations, is obtained to be around $130$ TeV, $1$ GeV, $7$ MeV and $110$ keV, for $k=2,3,4$ and $5$, respectively, in a radiation dominated Universe, for a real or complex scalar DM stabilized by a minimal symmetry. For modified thermal histories in the pre-big bang nucleosynthesis era, with an intermediate period of matter domination, values of reheating temperature higher than $\mathcal{O}(200)$ GeV for $k\ge 4$, $\mathcal{O}(1)$ TeV for $k=3$ and $\mathcal{O}(50)$ TeV for $k=2$ are strongly disfavoured by the combined requirements of unitarity and DM relic abundance, for DM freeze-out before reheating.

   hep-phastro-ph.COJHEP(2021)·34 citations
2. 02*

   MSSM at future Higgs factories

   Honglei Li🇨🇳 · Huayang Song🇺🇸 · Shufang Su🇺🇸 · Wei Su🇦🇺 · Jin Min Yang🇨🇳

   In this work, we study the implication of Higgs precision measurements at future Higgs factories on the MSSM parameter space, focusing on the dominant stop sector contributions. We perform a multi-variable fit to both the signal strength for various Higgs decay channels at Higgs factories and the Higgs mass. The chi-square fit results show sensitivity to mA, tan beta, stop mass parameter mSUSY as well as the stop left-right mixing parameter Xt. We also study the impact of the Higgs mass prediction on the MSSM and compare the sensitivities of different Higgs factories.

   hep-phCPC(2021)·8 citations
3. 03*

   Domain Wall Constraints on Two Higgs Doublet Models with $Z_2$ Symmetry

   Richard A. Battye🇬🇧 · Apostolos Pilaftsis🇬🇧 · Dominic G. Viatic🇬🇧

   The Two Higgs Doublet Model (2HDM) with spontaneously broken $Z_2$ symmetry predicts a production of domain walls at the electroweak scale. We derive cosmological constraints on model parameters for both Type-I and Type-II 2HDMs from the requirement that domain walls do not dominate the Universe by the present day. For Type-I 2HDMs, we deduce the lower bound on the key parameter $\tan \beta >10^5$ for a wide range of Higgs-boson masses $\sim$ 100 GeV or greater close to the Standard Model alignment limit. In addition, we perform numerical simulations of the 2HDM with an approximate as well as an exact $Z_2$ symmetry but biased initial conditions. In both cases, we find that domain wall networks are unstable and, hence, do not survive at late times. The domain walls experience an exponential suppression of scaling in these models which can help ameliorate the stringent constraints found in the case of an exact discrete symmetry. For a 2HDM with softly-broken $Z_2$ symmetry, we relate the size of this exponential suppression to the soft-breaking bilinear parameter $m_{12}$ allowing limits to be placed on this parameter of order $\mu$eV, such that domain wall domination can be avoided. In particular, for Type-II 2HDMs, we obtain a corresponding lower limit on the CP-odd phase $\theta$ generated by QCD instantons, $\theta \stackrel{>}{{}_{\sim }}10^{-11}/(\sin \beta \cos \beta )$, which is in some tension with the upper limit of $\theta \stackrel{<}{{}_{\sim }}10^{-11}$--$10^{-10}$, as derived from the non-observation of a non-zero neutron electric dipole moment. For a $Z_2$-symmetric 2HDM with biased initial conditions, we are able to relate the size of the exponential suppression to a biasing parameter $\epsilon$ so as to avoid domain wall domination.

   hep-phastro-ph.COhep-thPRD(2020)·29 citations
4. 04*

   Signatures of $\alpha$ clustering in ${}^{16}$O by using a multiphase transport model

   Yi-An Li🇨🇳 · Song Zhang🇨🇳 · Yu-Gang Ma🇨🇳

   $\alpha$-clustered structures in light nuclei could be studied through "snapshots" taken by relativistic heavy-ion collisions. A multiphase transport (AMPT) model is employed to simulate the initial structure of collision nuclei and the proceeding collisions at center of mass energy $\sqrt{s_{NN}}$ = 6.37 TeV. This initial structure can finally be reflected in the subsequent observations, such as elliptic flow ($v_2$), triangular flow ($v_3$) and quadrangular flow ($v_4$). Three sets of the collision systems are chosen to illustrate system scan is a good way to identify the exotic $\alpha$-clustered nuclear structure, case I: ${}^{16}\mathrm{O}$ nucleus (with or without $\alpha$-cluster) + ordinary nuclei (always in Woods-Saxon distribution) in most central collisions, case II: ${}^{16}\mathrm{O}$ nucleus (with or without $\alpha$-cluster) + ${}^{197}\mathrm{Au}$ nucleus collisions for centrality dependence, and case III: symmetric collision systems (namely, ${}^{10}$B + ${}^{10}$B, ${}^{12}$C + ${}^{12}$C, ${}^{16}$O + ${}^{16}$O (with or without $\alpha$-cluster), ${}^{20}$Ne + ${}^{20}$Ne, and ${}^{40}$Ca + ${}^{40}$Ca) in most central collisions. Our calculations propose that relativistic heavy-ion collision experiments at $\sqrt{s_{NN}}$ = 6.37 TeV are promised to distinguish the tetrahedron structure of ${}^{16}\mathrm{O}$ from the Woods-Saxon one and shed lights on the system scan projects in experiments.

   hep-phnucl-exnucl-thPRC(2020)·62 citations
5. 05*

   PAAI in the sky : towards a particulate mechanism for Dark Energy and concordant Dark Matter

   R. B. MacKenzie🇨🇦 · M. B. Paranjape🇨🇦 · U. A. Yajnik🇮🇳

   We propose the origins of Dark Energy in a hidden sector with a pair of very light fermions, oppositely charged under an abelian gauge force $U(1{)}_X$ but of unequal mass. The system is dubbed PAAI, plasma which is abelian, asymmetric and idealised. For a range of the hidden fine structure constant values and the value of mass of the lightest fermion the PAAI is argued to simulate Dark Energy. Additional fermions from the same sector are shown to account for Dark Matter. Further, residual $X$-magnetic fields can mix with Maxwell electromagnetism to provides the seed for cosmic-scale magnetic fields. Thus the scenario can explain several cosmological puzzles from within the same hidden sector.

   hep-phSpringer Proc.Phys.(2020)·1 citation
6. 06*

   The study of exotic state $Z_c^{\pm }(3900)$ decaying to $J/\psi {\pi }^{\pm }$ in the $pp$ collisions at $\sqrt{s}$ = 1.96, 7, and 13 TeV

   Zhen Zhang🇨🇳 · Liang Zheng🇨🇳 · Gang Chen🇨🇳 · Hong-Ge Xu🇨🇳 · Dai-Mei Zhou🇨🇳 · Yu-Liang Yan🇨🇳 · Ben-Hao Sa🇨🇳

   A dynamically constrained phase-space coalescence model plus PACIAE model was used to predict the exotic resonant state $Z_c^{\pm }(3900)$ yield, transverse momentum distribution, and the rapidity distribution with $|y|<6$ and $p_T<10$ GeV/c in $pp$ collisions at $\sqrt{s}=1.96,7$ and 13 TeV, respectively. The yield of the $Z_c^{\pm }(3900)$ is estimated to be around $10^{-6}$ to $10^{-5}$. We also present the energy dependence of the transverse momentum distributions and rapidity distributions for $Z_c^{+}(3900)$ and $Z_c^{-}(3900)$. The production of $Z_c^{+}(3900)$ and its anti-particle $Z_c^{-}(3900)$ is found to be quite similar to each other.

   hep-phEPJC(2021)·10 citations
7. 07*

   Matter and dark matter asymmetry from a composite Higgs model

   M. Ahmadvand🇮🇷

   We propose a low scale leptogenesis scenario in the framework of composite Higgs models supplemented with singlet heavy neutrinos. One of the neutrinos can also be considered as a dark matter candidate whose stability is guaranteed by a discrete ${\mathbb{Z}}_2$ symmetry of the model. In the spectrum of the strongly coupled system, bound states heavier than the pseudo Nambu-Goldstone Higgs boson can exist. Due to the decay of these states to heavy right-handed neutrinos, an asymmetry in the visible and dark sector is simultaneously generated. The resulting asymmetry is transferred to the standard model leptons which interact with visible right-handed neutrinos. We show that the sphaleron-induced baryon asymmetry can be provided at the TeV scale for resonant bound states. Depending on the coupling strength of dark neutrino interaction, a viable range of the dark matter mass is allowed in the model. Furthermore, taking into account the effective interactions of dark matter, we discuss low-energy processes and experiments.

   hep-phastro-ph.COEPJC(2021)·4 citations
8. 08*

   Double Covering of the Modular $A_5^{}$ Group and Lepton Flavor Mixing in the Minimal Seesaw Model

   Xin Wang🇨🇳 · Bingrong Yu🇨🇳 · Shun Zhou🇨🇳

   In this paper, we investigate the double covering of modular ${\Gamma }_5^{}\simeq A_5^{}$ group and derive all the modular forms of weight one for the first time. The modular forms of higher weights are also explicitly given by decomposing the direct products of weight-one forms. For the double covering group ${\Gamma }_5^{\prime }\simeq A_5^{\prime }$, there exist two inequivalent two-dimensional irreducible representations, into which we can assign two right-handed neutrino singlets in the minimal seesaw model. Two concrete models with such a salient feature have been constructed to successfully explain lepton mass spectra and flavor mixing pattern. The allowed parameter space for these two minimal scenarios has been numerically explored, and analytically studied with some reasonable assumptions.

   hep-phPRD(2021)·98 citations
9. 09*

   Sterile neutrino searches at tagged kaon beams

   Luis Delgadillo🇺🇸 · Patrick Huber🇺🇸

   Tagged kaon beams are attractive neutrino sources, which would provide flavor pure ${\nu }_e$-beams with exactly measured normalization. We point out that this also leads to an anti-tagged flavor pure ${\nu }_{\mu }$-beam, with equally well known normalization. Exposing a 1 kt liquid argon detector at a baseline of 1 km to this combination of unique beams allows to decisively test recent indications by IceCube and Neutrino-4 of sterile neutrino oscillations in the multi-eV range.

   hep-phhep-exnucl-exPRD(2021)·3 citations
10. 10*

    Gauge/gravity dual dynamics for the strongly coupled sector of composite Higgs models

    Johanna Erdmenger🇩🇪 · Nick Evans🇬🇧 · Werner Porod🇩🇪 · Konstantinos S. Rigatos🇬🇧

    A holographic model of chiral symmetry breaking is used to study the dynamics plus the meson and baryon spectrum of the underlying strong dynamics in composite Higgs models. The model is inspired by top-down D-brane constructions. We introduce this model by applying it to $N_f=2$ QCD. We compute meson masses, decay constants and the nucleon mass. The spectrum is improved by including higher dimensional operators to reflect the UV physics of QCD. Moving to composite Higgs models, we impose perturbative running for the anomalous dimension of the quark condensate in a variety of theories with varying number of colors and flavours. We compare our results in detail to lattice simulations for the following theories: $SU(2)$ gauge theory with two Dirac fundamentals; $Sp(4)$ gauge theory with fundamental and sextet matter; and $SU(4)$ gauge theory with fundamental and sextet quarks. In each case, the holographic results are encouraging since they are close to lattice results for masses and decay constants. Moreover, our models allow us to compute additional observables not yet computed on the lattice, to relax the quenched approximation and move to the precise fermion content of more realistic composite Higgs models not possible on the lattice. We also provide a new holographic description of the top partners including their masses and structure functions. With the addition of higher dimension operators, we show the top Yukawa coupling can be made of order one, to generate the observed top mass. Finally, we predict the spectrum for the full set of models with top partners proposed by Ferretti and Karateev.

    hep-phhep-lathep-thJHEP(2021)·81 citations
11. 11*

    Quasielastic production of polarized $\tau$ leptons in ${\nu }_{\tau }$ and ${\bar{\nu }}_{\tau }$ scattering from nucleons

    A. Fatima🇮🇳 · M. Sajjad Athar🇮🇳 · S. K. Singh🇮🇳

    The cross sections and polarization components of the $\tau$ leptons produced in the charged current induced quasielastic ${\nu }_{\tau }({\bar{\nu }}_{\tau })-N$ scattering have been studied. The theoretical uncertainties arising due to the use of different vector form factors and the axial dipole mass in the axial vector form factor have been investigated. Due to the high mass of $\tau$ lepton, the contributions from the term containing pseudoscalar and second class current form factors are non-negligible and contribute to the uncertainty in the cross section and polarization observables as these form factors are not well known. In view of the currently proposed experiments by DUNE, SHiP and DsTau collaborations to study the production of $\tau$ lepton, an updated calculation of the cross sections and polarizations of tau leptons in the case of quasielastic production have been done and the numerical results have been presented along with a discussion of the theoretical uncertainties.

    hep-phhep-exPRD(2020)·21 citations
12. 12*

    Medium evolution of a static quark-antiquark pair in the large $N_c$ limit

    Miguel Ángel Escobedo🇪🇸

    We study the transitions between the different color states of a static quark-antiquark pair, singlet and octet, in a thermal medium. This is done non-perturbatively exploiting the infinite mass limit of QCD. This study is interesting because it can be used for future developments within the framework of Effective Field Theories (EFTs) and because it can be combined with other techniques, like lattice QCD or AdS/CFT, to gain non-perturbative information about the evolution of quarkonium in a medium. We also study the obtained expressions in the large $N_c$ limit. This allows us to learn lessons that are useful to simplify phenomenological models of quarkonium in a plasma.

    hep-phnucl-thPRD(2021)·13 citations
13. 13*

    Magnetic field inside of a nucleon and the quark-Zeeman effect

    Marek Matas🇨🇿

    Zeeman effect has been an invaluable tool for the detection and measurement of the effects of a magnetic field on the internal behavior of atoms and nuclei. Along with Mössbauer effect, it has been used to determine the magnitude of the magnetic field present in nuclei of atoms but has not been detected inside nucleons so far. In this work, we present a possible signature of the Zeeman-like effect in nucleons that one can extract from the parton distributions with the use of statistical models and Fermi-Dirac distribution. These effects in turn---if electromagnetically dominated---predict the presence of magnetic fields of an unprecedented magnitude inside protons.

    hep-ph0 citations
14. 14*

    Advancing MiNNLO${}_{\mathrm{PS}}$ to diboson processes: $Z\gamma$ production at NNLO+PS

    Daniele Lombardi🇩🇪 · Marius Wiesemann🇩🇪 · Giulia Zanderighi🇩🇪

    We consider $Z\gamma$ production in hadronic collisions and present the first computation of next-to-next-to-leading order accurate predictions consistently matched to parton showers (NNLO+PS). Spin correlations, interferences and off-shell effects are included by calculating the full process $pp\to {\ell }^{+}{\ell }^{-}\gamma$. We extend the recently developed MiNNLO${}_{\mathrm{PS}}$ method to genuine $2\to 2$ hard scattering processes at the LHC, which paves the way for NNLO+PS simulations of all diboson processes. This is the first $2\to 2$ NNLO+PS calculation that does not require an a-posteriori multi-differential reweighting. We find that both NNLO corrections and matching to parton showers are crucial for an accurate simulation of the $Z\gamma$ process. Our predictions are in very good agreement with recent ATLAS data.

    hep-phhep-exJHEP(2021)·58 citations
15. 15*

    Precise predictions for photon pair production matched to parton showers in GENEVA

    Simone Alioli🇮🇹 · Alessandro Broggio🇮🇹 · Alessandro Gavardi🇮🇹 · Stefan Kallweit🇮🇹 · Matthew A. Lim🇮🇹 · Riccardo Nagar🇮🇹 · Davide Napoletano🇮🇹 · Luca Rottoli🇨🇭

    We present a new calculation for the production of isolated photon pairs at the LHC with NNLL${}_{{\mathcal{T}}_0}^{\prime }$+NNLO accuracy. This is the first implementation within the GENEVA Monte Carlo framework of a process with a nontrivial Born-level definition which suffers from QED singularities. Throughout the computation we use a smooth-cone isolation algorithm to remove such divergences. The higher-order resummation of the 0-jettiness resolution variable ${\mathcal{T}}_0$ is based on a factorisation formula derived within Soft-Collinear Effective Theory which predicts all of the singular, virtual and real NNLO corrections. Starting from this precise parton-level prediction and by employing the GENEVA method, we provide fully showered and hadronised events using PYTHIA8, while retaining the NNLO QCD accuracy for observables which are inclusive over the additional radiation. We compare our final predictions to LHC data at 7 TeV and find good agreement.

    hep-phhep-exJHEP(2021)·56 citations
16. 16*

    Single-top final states as a probe of top-flavoured dark matter models at the LHC

    Monika Blanke🇩🇪 · Priscilla Pani🇩🇪 · Giacomo Polesello🇮🇹 · Giulia Rovelli🇮🇹

    Models incorporating flavoured dark matter provide an elegant solution to the dark matter problem, evading the tight LHC and direct direction constraints on simple WIMP models. In Dark Minimal Flavour Violation, a simple framework of flavoured dark matter with new sources of flavour violation, the constraints from thermal freeze-out, direct detection experiments, and flavour physics create well-defined benchmark scenarios for these models. We study the LHC phenomenology of four such scenarios, focusing on final states where a single top quark is produced accompanied by no jets, one jet from the fragmentation of light quarks or a $b$-tagged jet. For each of these signatures we develop a realistic LHC analysis, and we show that the proposed analyses would increase the parameter space coverage for the four benchmarks, compared to existing flavour-conserving LHC analyses. Finally we show the projected discovery potential of the considered signatures for the full LHC statistics at 14 TeV, and for the High Luminosity LHC.

    hep-phhep-exJHEP(2021)·14 citations
17. 17*

    de Sitter Complementarity, TCC, and the Swampland

    Alek Bedroya🇺🇸

    Motivated by the coincidence of scrambling time in de Sitter and maximum lifetime given by the $\text{Trans-Planckian Censorship Conjecture}$ (TCC), we study the relation between the de Sitter complementarity and the Swampland conditions. We study thermalization in de Sitter space from different perspectives and show that TCC implies de Sitter space cannot live long enough to be considered a thermal background. We also revisit $\alpha$-vacua in light of this work and show that TCC imposes multiple initial condition/fine-tuning problems on any conventional inflationary scenario.

    ↳ hep-thastro-ph.COgr-qchep-phLHEP(2021)·42 citations
18. 18*

    From high $p_{\perp }$ theory and data to inferring anisotropy of Quark-Gluon Plasma

    Magdalena Djordjevic🇷🇸 · Stefan Stojku🇷🇸 · Dusan Zigic🇷🇸 · Bojana Ilic🇷🇸 · Jussi Auvinen🇷🇸 · Igor Salom🇷🇸 · Marko Djordjevic🇷🇸 · Pasi Huovinen🇷🇸

    High $p_{\perp }$ theory and data are commonly used to study high $p_{\perp }$ parton interactions with QGP, while low $p_{\perp }$ data and corresponding models are employed to infer QGP bulk properties. On the other hand, with a proper description of high $p_{\perp }$ parton-medium interactions, high $p_{\perp }$ probes become also powerful tomography tools, since they are sensitive to global QGP features, such as different temperature profiles or initial conditions. This tomographic role of high $p_{\perp }$ probes can be utilized to assess the spatial anisotropy of the QCD matter. With our dynamical energy loss formalism, we show that a (modified) ratio of $R_{AA}$ and $v_2$ presents a reliable and robust observable for straightforward extraction of initial state anisotropy. We analytically estimated the proportionality between the $v_2/(1-R_{AA})$ and anisotropy coefficient ${ϵ}_{2L}$, and found surprisingly good agreement with full-fledged numerical calculations. Within the current error bars, the extraction of the anisotropy from the existing data using this approach is still inaccessible. However, with the expected accuracy improvement in the upcoming LHC runs, the anisotropy of the QGP formed in heavy ion collisions can be straightforwardly derived from the data. Such a data-based anisotropy parameter would present an important test to models describing the initial stages of heavy-ion collision and formation of QGP, and demonstrate the usefulness of high $p_{\perp }$ theory and data in obtaining QGP properties.

    ↳ nucl-thhep-phNPA(2021)·0 citations
19. 19*

    Solving relativistic three-body integral equations in the presence of bound states

    Andrew W. Jackura🇺🇸 · Raúl A. Briceño🇺🇸 · Sebastian M. Dawid🇺🇸 · Md Habib E Islam🇺🇸 · Connor McCarty🇺🇸

    We present a systematically improvable method for numerically solving relativistic three-body integral equations for the partial-wave projected amplitudes. The method consists of a discretization procedure in momentum space, which approximates the continuum problem with a matrix equation. It is solved for different matrix sizes, and in the end, an extrapolation is employed to restore the continuum limit. Our technique is tested by solving a three-body problem of scalar particles with an $S$ wave two-body bound state. We discuss two methods of incorporating the pole contribution in the integral equations, both of them leading to agreement with previous results obtained using finite-volume spectra of the same theory. We provide an analytic and numerical estimate of the systematic errors. Although we focus on kinematics below the three-particle threshold, we provide numerical evidence that the methods presented allow for determination of amplitude above this threshold as well.

    ↳ hep-lathep-phnucl-thPRD(2021)·61 citations
20. 20*

    New Solutions for Rotating Boson Stars

    Felix Kling🇺🇸 · Arvind Rajaraman🇺🇸 · Freida Liz Rivera🇺🇸

    It has been shown that scalar fields can form gravitationally bound compact objects called boson stars. In this study, we analyze boson star configurations where the scalar fields contain a small amount of angular momentum and find two new classes of solutions. In the first case all particles are in the same slowly rotating state and in the second case the majority of particles are in the non-rotating ground state and a small number of particles are in an excited rotating state. In both cases, we solve the underlying Gross-Pitaevskii-Poisson equations that describe the profile of these compact objects both numerically as well as analytically through series expansions.

    ↳ hep-thgr-qchep-phPRD(2021)·13 citations
21. 21*

    Standard Model from A Supergravity Model with a Naturally Small Cosmological Constant

    Shing Yan Li🇺🇸 · Yu-Cheng Qiu🇨🇳 · S.-H. Henry Tye🇨🇳

    Guided by the naturalness criterion for an exponentially small cosmological constant, we present a string theory motivated 4-dimensional $\mathcal{N}=1$ non-linear supergravity model (or its linear version with a nilpotent superfield) with spontaneous supersymmetry breaking. The model encompasses the minimal supersymmetric standard model, the racetrack Kähler uplift, and the KKLT anti-$D3$-branes, and use the nilpotent superfield to project out the undesirable interaction terms as well as the unwanted degrees of freedom to end up with the standard model (not the supersymmetric version) of strong and electroweak interactions.

    ↳ hep-thhep-phJHEP(2021)·8 citations
22. 22*

    Graviton loop contribution to Higgs potential in gauge-Higgs unification

    Yasunari Nishikawa🇯🇵

    We study a two-loop finiteness of an effective potential for a Higgs boson that is the fifth component of a gauge field in an $U(1)$ gauge theory coupled to quantum gravity on the five-dimensional space-time $M^4\times S^1$. There are two types of diagrams including quantum gravitational corrections. We find that only one type of diagram contributes to the effective potential for the Higgs boson in fact and its magnitude is finite.

    ↳ hep-thhep-phPTEP(2021)·1 citation
23. 23*

    Radiation problems accompanying carrier production by an electric field in the graphene

    Sergey Gavrilov🇷🇺 · Dmitry Gitman🇷🇺 · Vadim Dmitriev🇷🇺 · Anatolii Panferov🇷🇺 · Stanislav Smolyansky🇷🇺

    A number of physical processes occurring in a flat one-dimensional graphene structure under the action of strong time-dependent electric fields are considered. It is assumed that the Dirac model can be applied to the graphene as a subsystem of the general system under consideration, which includes an interaction with quantized electromagnetic field. The Dirac model itself in the external electromagnetic field (in particular, the behavior of charged carriers) is treated nonperturbatively with respect to this field within the framework of strong-field QED with unstable vacuum. This treatment is combined with a kinetic description of the radiation of photons from the electron-hole plasma created from the vacuum under the action of the electric field. An interaction with quantized electromagnetic field is described perturbatively. A significant development of the kinetic equation formalism is presented. A number of specific results are derived in course of analytical and numerical study of the equations. We believe that some of predicted effects and properties of considered processes may be verified experimentally. Among these effects, it should be noted a characteristic spectral composition anisotropy of the quantum radiation and a possible presence of even harmonics of the external field in the latter radiation.

    ↳ hep-thcond-mat.mes-hallhep-phUniverse(2020)·7 citations
24. 24*

    Semi-parametric $\gamma$-ray modeling with Gaussian processes and variational inference

    Siddharth Mishra-Sharma🇺🇸 · Kyle Cranmer🇺🇸

    Mismodeling the uncertain, diffuse emission of Galactic origin can seriously bias the characterization of astrophysical gamma-ray data, particularly in the region of the Inner Milky Way where such emission can make up over 80% of the photon counts observed at ~GeV energies. We introduce a novel class of methods that use Gaussian processes and variational inference to build flexible background and signal models for gamma-ray analyses with the goal of enabling a more robust interpretation of the make-up of the gamma-ray sky, particularly focusing on characterizing potential signals of dark matter in the Galactic Center with data from the Fermi telescope.

    ↳ astro-ph.HEastro-ph.COastro-ph.IMhep-ph+114 citations
25. 25*

    Self-consistent 3D Supernova Models From -7 Minutes to +7 Seconds: a 1-bethe Explosion of a ~19 Solar-mass Progenitor

    R. Bollig (1)🇩🇪 · N. Yadav (1,2)🇩🇪 · D. Kresse (1,3)🇩🇪 · H.-Th. Janka (1)🇩🇪 · B. Mueller (4,5,6)🇦🇺 · A. Heger (4,5,7,8) ((1) MPI Astrophysics, Garching, (2) Excellence Cluster ORIGINS, (3) TU Muenchen, (4) Monash University, (5) ARCCEGWD, Clayton, (6) Queen's University Belfast, (7) ASTRO-3D, Australia, (8) JINA, Michigan State Univ.)🇦🇺

    To date, modern three-dimensional (3D) supernova (SN) simulations have not demonstrated that explosion energies of 10^{51} erg (=1 bethe = 1B) or more are possible for neutrino-driven SNe of non/slow-rotating M < 20 solar-mass progenitors. We present the first such model, considering a non-rotating, solar-metallicity 18.88 solar-mass progenitor, whose final 7 minutes of convective oxygen-shell burning were simulated in 3D and showed a violent oxygen-neon shell merger prior to collapse. A large set of 3D SN-models was computed with the Prometheus-Vertex code, whose improved convergence of the two-moment equations with Boltzmann closure allows now to fully exploit the implicit neutrino-transport treatment. Nuclear burning is treated with a 23-species network. We vary the angular grid resolution and consider different nuclear equations of state and muon formation in the proto-neutron star (PNS), which requires six-species transport with coupling of all neutrino flavors across all energy-momentum groups. Elaborate neutrino transport was applied until ~2 seconds after bounce. In one case the simulation was continued to >7 seconds with an approximate treatment of neutrino effects that allows for seamless continuation without transients. A spherically symmetric neutrino-driven wind does not develop. Instead, accretion downflows to the PNS and outflows of neutrino-heated matter establish a monotonic rise of the explosion energy until ~7 seconds post bounce, when the outgoing shock reaches about 50,000 km and enters the He-layer. The converged value of the explosion energy at infinity (with overburden subtracted) is roughly 1B and the ejected 56Ni mass up to 0.087 solar masses, both within a few 10 percent of the SN 1987A values. The final NS mass and kick are about 1.65 solar masses and over 450 km/s, respectively.

    ↳ astro-ph.HEhep-phApJ(2021)·216 citations
26. 26*

    The eigenvalue of the confined potential

    Cheng-Qun Pang🇨🇳 · Lei Huang🇨🇳 · Duo-jie Jia🇨🇳 · Tian-Jie Zhang🇨🇳

    Analytic solutions for the energy eigenvalues are obtained from a confined potentials of the form $br$ in 3 dimensions. The confinement is effected by linear term which is a very important part in Cornell potential. The analytic eigenvalues and numerical solutions are exactly matched.

    ↳ quant-phhep-phmath-phmath.MP0 citations
27. 27*

    Progress on Cosmological Magnetic Fields

    Tanmay Vachaspati🇺🇸

    A variety of observations impose upper limits at the nano Gauss level on magnetic fields that are coherent on inter-galactic scales while blazar observations indicate a lower bound $\sim 10^{-16}$ Gauss. Such magnetic fields can play an important astrophysical role, for example at cosmic recombination and during structure formation, and also provide crucial information for particle physics in the early universe. Magnetic fields with significant energy density could have been produced at the electroweak phase transition. The evolution and survival of magnetic fields produced on sub-horizon scales in the early universe, however, depends on the magnetic helicity which is related to violation of symmetries in fundamental particle interactions. The generation of magnetic helicity requires new CP violating interactions that can be tested by accelerator experiments via decay channels of the Higgs particle.

    ↳ astro-ph.COhep-phhep-thRept.Prog.Phys.(2021)·188 citations
28. 28*

    Global symmetry, Euclidean gravity, and the black hole information problem

    Daniel Harlow🇺🇸 · Edgar Shaghoulian🇺🇸

    In this paper we argue for a close connection between the non-existence of global symmetries in quantum gravity and a unitary resolution of the black hole information problem. In particular we show how the essential ingredients of recent calculations of the Page curve of an evaporating black hole can be used to generalize a recent argument against global symmetries beyond the AdS/CFT correspondence to more realistic theories of quantum gravity. We also give several low-dimensional examples of quantum gravity theories which do not have a unitary resolution of the black hole information problem in the usual sense, and which therefore can and do have global symmetries. Motivated by this discussion, we conjecture that in a certain sense Euclidean quantum gravity is equivalent to holography.

    ↳ hep-thgr-qchep-phquant-phJHEP(2021)·108 citations
29. 29*

    Vector dominance, one flavored baryons, and QCD domain walls from the "hidden" Wess-Zumino term

    Avner Karasik🇬🇧

    We further explore a recent proposal that the vector mesons in QCD have a special role as Chern-Simons fields on various QCD objects such as domain walls and the one flavored baryons. We compute contributions to domain wall theories and to the baryon current coming from a generalized Wess-Zumino term including vector mesons. The conditions that lead to the expected Chern-Simons terms and the correct spectrum of baryons, coincide with the conditions for vector meson dominance. This observation provides a theoretical explanation to the phenomenological principle of vector dominance, as well as an experimental evidence for the identification of vector mesons as the Chern-Simons fields. By deriving the Chern-Simons theories directly from an action, we obtain new results about QCD domain walls. One conclusion is the existence of a first order phase transition between domain walls as a function of the quarks' masses. We also discuss applications of our results to Seiberg duality between gluons and vector mesons and provide new evidence supporting the duality.

    ↳ hep-thhep-phnucl-thSciPost Phys.(2021)·28 citations

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