Mon·Mar 11, 2019Monday·March 11, 2019

1. 01*

   Exact solution for the non-equilibrium attractor in number-conserving relaxation time approximation

   Michael Strickland🇺🇸 · Ubaid Tantary🇺🇸

   We extend previous studies of the conformal 0+1d kinetic non-equilibrium attractor in relaxation time approximation by enforcing number conservation through the introduction of a dynamical fugacity (chemical potential). We derive two coupled integral equations for the effective temperature and fugacity which are then solved numerically to obtain the exact solution. The resulting solutions exhibit convergence to a unique non-equilibrium attractor when the scaled moments of the distribution function are plotted as a function of the rescaled time w = tau/tau_eq. This occurs even though the system is out of chemical equilibrium at late times. In addition, compared to the case where number conservation was not imposed, we find that the moments converge to their respective attractors more quickly, particularly for moments with m=0. Finally, we compare the resulting attractor moments with predictions from different hydrodynamic frameworks.

   hep-phnucl-thJHEP(2019)·44 citations
2. 02*

   Double SU(4) model

   Jose A.R. Cembranos🇪🇸 · Pablo Diez-Valle🇪🇸

   In this manuscript we study the Double SU(4) model as a grand unified theory based on the gauge group $SU(4)\times SU(4)\left(\times {\mathcal{Z}}_2\right)$. A complete set of generators is constructed according to a pattern of symmetry breaking via a Pati-Salam stage. Furthermore, the gauge boson matrices are derived and the extended Gell-Mann Okubo relation is calculated. All known elementary particles and antiparticles, besides exotic degrees of freedom, are unified in multiplets which are transformed as $(4,4)$ and $(\bar{4},\bar{4})$ under the proposed gauge group.

   hep-ph5 citations
3. 03*

   Master Majorana neutrino mass parametrization

   Isabel Cordero-Carrión🇪🇸 · Martin Hirsch🇪🇸 · Avelino Vicente🇪🇸

   After showing that the neutrino mass matrix in all Majorana models can be described by a general master formula, we will present a master parametrization for the Yukawa matrices, also valid for all Majorana models, that automatically ensures agreement with neutrino oscillation data. The application of the master parametrization will be illustrated in an example model.

   hep-phJ.Phys.Conf.Ser.(2020)·0 citations
4. 04*

   A New Left-Right Symmetry Model

   Apriadi Salim Adam (Hiroshima University)🇯🇵 · Akmal Ferdiyan (Universitas Jenderal Soedirman)🇮🇩 · Mirza Satriawan (Universitas Gadjah Mada)🇮🇩

   We propose a new L-R symmetry model where the L-R symmetry transformation reverses both the L-R chirality and the local quantum number. We add to the model a global quantum number $F$ whose value is one for fermions (minus one for anti fermion) and vanishes for bosons. For each standard model (SM) particle, we have the corresponding L-R dual particle whose mass is very large and which should have decayed at the current low energy level. Due to the global quantum number $F$, there is no Majorana neutrino in the model but a Dirac seesaw mechanism can still occur and the usual three active neutrinos oscillation can still be realized. We add two leptoquarks and their L-R duals, for generating the baryon number asymmetry and for facilitating the decay of the L-R dual particles. The decay of the L-R dual particles will produce a large entropy to the SM sector and gives a mechanism for avoiding the big bang nucleosynthesis constraint.

   hep-phAdv.High Energy Phys.(2020)·3 citations
5. 05*

   Spin Physics with a fixed-target experiment at the LHC

   M.G. Echevarria · S.J. Brodsky · G. Cavoto · C. Da Silva · F. Donato · E.G. Ferreiro · C. Hadjidakis · I. Hřivnáčová · D. Kikola · A. Klein · A. Kurepin · A. Kusina and 21 other authors

   The multi-TeV proton and ion beams of the LHC would allow for the most energetic fixed-target experiment ever. In particular, $pp$, $p$d and $p$A collisions could be performed at $\sqrt{s_{NN}}$ = 115~GeV, as well as Pb$p$ and PbA collisions at $\sqrt{s_{NN}}$ = 72~GeV, in a parasitic way by making use of the already existing LHCb and ALICE detectors in fixed-target mode. This would offer the possibility to carry out a ground-breaking physics program, to study the nucleon and nuclear structure at high $x$, the spin content of the nucleon and the phases of the nuclear matter from a new rapidity viewpoint. In this talk I focus on the spin physics axis of the full program developed so far by the AFTER@LHC study group.

   hep-phhep-exPoS(2019)·1 citation
6. 06*

   Influence of an inert charged Higgs boson on the muon $g-2$ and radiative neutrino masses in a scotogenic model

   Chuan-Hung Chen🇹🇼 · Takaaki Nomura🇰🇷

   A simple extension of Ma's approach in a scotogenic model is studied for the purpose of simultaneously interpreting the neutrino data and the excess of muon anomalous magnetic moment (muon $g-2$). The feasible minimal extension is to add an $Z_2$-odd vector-like lepton doublet to the Ma's model. It is found that in addition to the neutrino data, the strict constraints on the relevant parameters are from the electroweak oblique parameters and the induced lepton-flavor violation processes, such as ${\ell }_i\to {\ell }_j\gamma$ and ${\ell }_i\to {\ell }_j^{-}{\ell }_j^{-}{\ell }_j^{+}$. Performing parameter scan, we numerically demonstrate that when the constraint conditions are satisfied, the muon $g-2$ of $O(10^{-9})$ can be achieved, where it can be expected that with a $5\sigma$ observation, the Muon $g-2$ experiment at Fermilab can observe $a_{\mu }\approx 13.31\times 10^{-10}$ when the current experiment and the SM errors are reduced by a factor of 4 and 2, respectively. Moreover, the branching ratio of the $\tau \to \mu \gamma$ decay can match the Belle II sensitivity of $O(10^{-9})$ with an integrated luminosity of 50 ab${}^{-1}$.

   hep-phhep-exPRD(2019)·17 citations
7. 07*

   Mass Correction to Chiral Kinetic Equations

   Ziyue Wang🇨🇳 · Xingyu Guo🇨🇳 · Shuzhe Shi🇨🇦 · Pengfei Zhuang🇨🇳

   We study fermion mass correction to chiral kinetic equations in electromagnetic fields. Different from the chiral limit where fermion number density is the only independent distribution, the number and spin densities are coupled to each other for massive fermion systems. To the first order in $\hslash$, we derived the quantum correction to the classical on-shell condition and the Boltzmann-type transport equations. To the linear order in the fermion mass, the mass correction does not change the structure of the chiral kinetic equations and behaves like additional collision terms. While the mass correction exists already at classical level in general electromagnetic fields, it is only a first order quantum correction in the study of chiral magnetic effect.

   hep-phhep-thPRD(2019)·106 citations
8. 08*

   Inferring the covariant $\Theta$-exact noncommutative coupling in the top quark pair production at linear colliders

   Selvaganapathy J.🇮🇳 · Partha Konar🇮🇳 · Prasanta Kumar Das🇮🇳

   A novel non-minimal interaction of neutral right-handed fermion and abelian gauge field in the covariant $\Theta$-exact noncommutative standard model (NCSM) which is invariant under Very Special Relativity (VSR) Lorentz subgroup, opens an avenue to study the top quark pair production at linear colliders. Here the coupling denoted as $\kappa$ and the noncommutative (NC) scale $\Lambda$. In this work, we consider two types of analysis, one is without considering helicity basis and another, considering helicity states of the polarized and unpolarized initial and final particles. In the first case, when $\kappa$ is positive and for certain values of $\Lambda$, we arrived a specific threshold value of machine energy (units of GeV) $\sqrt{s_0}$ ($\simeq 2.52\Lambda +39$ ) may be quite useful to probe NCSM with the unpolarized beam. The statistical ${\chi }^2$ analysis of the azimuthal anisotropy is quite possible when $\kappa$ takes negative value $0>\kappa >-0.596$ which persuade a lower limit on NC scale $\Lambda$ ($1.0\text{to}2.4\text{TeV}$) at ${\kappa }_{max}=-0.296(95\%$ C.L) according to luminosity ranging from $100f{b}^{-1}\text{to}1000f{b}^{-1}$ at machine energy $\sqrt{s}=1.4\text{TeV}\text{and}3.0\text{TeV}$. In another case, we performed polarized beam analysis to probe NCSM in the light of following observables azimuthal anisotropy, helicity correlation, and top quark helicity left-right asymmetry. The polarization of the initial beam $\{P_{e^{-}},P_{e^{+}}\}=\{-0.8,0.3\}(\{-0.8,0.6\})$ enhances the ranges of lower limit on $\Lambda$, $i.e.1.13\text{to}2.80\text{TeV}$ at ${\kappa }_{max}$ alongside the ${\kappa }_{max}$ enhanced into $-0.5445(-0.607)$ $95\%$C.L accord with luminosity and $\sqrt{s}$. Finally, we studied the intriguing mixing of the UV and the IR by invoking $T(2)$ VSR Lorentz subgroup symmetry on NC tensor ${\Theta }_{\mu \nu }$.

   hep-phhep-exJHEP(2019)·7 citations
9. 09*

   Hard dilepton production from a weakly magnetized hot QCD medium

   Aritra Das🇮🇳 · Najmul Haque🇮🇳 · Munshi G. Mustafa🇮🇳 · Pradip K. Roy🇮🇳

   We have computed the hard dilepton production rate from a weakly magnetized deconfined QCD medium within one-loop photon self-energy by considering one hard and one thermomagnetic resummed quark propagator in the loop. In the presence of the magnetic field, the resummed propagator leads to four quasiparticle modes. The production of hard dileptons consists of rates when all four quasiquarks originating from the poles of the propagator individually annihilate with a hard quark coming from a bare propagator in the loop. Besides these, there are also contributions from a mixture of pole and Landau cut part. In weak field approximation, the magnetic field appears as a perturbative correction to the thermal contribution. Since the calculation is very involved, for a first effort as well as for simplicity, we obtained the rate up to first order in the magnetic field, i.e., $\mathcal{O}[(eB)]$, which causes a marginal improvement over that in the absence of magnetic field.

   hep-phnucl-thPRD(2019)·24 citations
10. 10*

    Photoproduction of axion-like particles

    Daniel Aloni🇮🇱 · Cristiano Fanelli🇺🇸 · Yotam Soreq🇨🇭 · Mike Williams🇺🇸

    We explore the sensitivity of photon-beam experiments to axion-like particles (ALPs) with QCD-scale masses whose dominant coupling to the Standard Model is either to photons or gluons. We introduce a novel data-driven method that eliminates the need for knowledge of nuclear form factors or the photon-beam flux when considering coherent Primakoff production off a nuclear target, and show that data collected by the PrimEx experiment could substantially improve the sensitivity to ALPs with $0.03\lesssim m_a\lesssim 0.3$ GeV. Furthermore, we explore the potential sensitivity of running the GlueX experiment with a nuclear target and its planned PrimEx-like calorimeter. For the case where the dominant coupling is to gluons, we study photoproduction for the first time, and predict the future sensitivity of the GlueX experiment using its nominal proton target. Finally, we set world-leading limits for both the ALP-gluon coupling and the ALP-photon coupling based on public mass plots.

    hep-phhep-exnucl-exPRL(2019)·160 citations
11. 11*

    Dark Matter through the Higgs portal

    Giorgio Arcadi🇩🇪 · Abdelhak Djouadi🇫🇷 · Martti Raidal🇪🇪

    We review scenarios in which the particles that account for the Dark Matter (DM) in the Universe interact only through their couplings with the Higgs sector of the theory, the so-called Higgs-portal models. In a first step, we use a general and model-independent approach in which the DM particles are singlets with spin $0,\frac{1}{2}$ or $1$, and assume a minimal Higgs sector with the presence of only the Standard Model (SM) Higgs particle observed at the LHC. In a second step, we discuss non-minimal scenarios in which the spin-$\frac{1}{2}$ DM particle is accompanied by additional lepton partners and consider several possibilities like sequential, singlet-doublet and vector-like leptons. In a third step, we examine the case in which it is the Higgs sector of the theory which is enlarged either by a singlet scalar or pseudoscalar field, an additional two Higgs doublet field or by both; in this case, the matter content is also extended in several ways. Finally, we investigate the case of supersymmetric extensions of the SM with neutralino DM, focusing on the possibility that the latter couples mainly to the neutral Higgs particles of the model which then serve as the main portals for DM phenomenology. In all these scenarios, we summarize and update the present constraints and future prospects from the collider physics perspective, namely from the determination of the SM Higgs properties at the LHC and the search for its invisible decays into DM, and the search for heavier Higgs bosons and the DM companion particles at high-energy colliders. We then compare these results with the constraints and prospects obtained from the cosmological relic abundance as well as from direct and indirect DM searches in astroparticle physics experiments. The complementarity of collider and astroparticle DM searches is investigated in all the considered models.

    hep-phhep-exPhys.Rept.(2020)·387 citations
12. 12*

    As Scales Become Separated: Lectures on Effective Field Theory

    Timothy Cohen🇺🇸

    These lectures aim to provide a pedagogical introduction to the philosophical underpinnings and technical features of Effective Field Theory (EFT). Improving control of $S$-matrix elements in the presence of a large hierarchy of physical scales $m\ll M$ is emphasized. Utilizing $\lambda \sim m/M$ as a power counting expansion parameter, we show how matching an ultraviolet (UV) model onto an EFT makes manifest the notion of separating scales. Renormalization Group (RG) techniques are used to run the EFT couplings from the UV to the infrared (IR), thereby summing large logarithms that would otherwise reduce the efficacy of perturbation theory. A variety of scalar field theory based toy examples are worked out in detail. An approach to consistently evolving a coupling across a heavy particle mass threshold is demonstrated. Applying the same method to the scalar mass term forces us to confront the hierarchy problem. The summation of a logarithm that lacks explicit dependence on an RG scale is performed. After reviewing the physics of IR divergences, we build a scalar toy version of Soft Collinear Effective Theory (SCET), highlighting many subtle aspects of these constructions. We show how SCET can be used to sum the soft and collinear IR Sudakov double logarithms that often appear for processes involving external interacting light-like particles. We conclude with the generalization of SCET to theories of gauge bosons coupled to charged fermions. These lectures were presented at TASI 2018.

    hep-phPoS(2019)·96 citations
13. 13*

    $\mathbf{C}\mathbf{P}$ violation in Higgs-gauge interactions: from tabletop experiments to the LHC

    Vincenzo Cirigliano🇺🇸 · Andreas Crivellin🇨🇭 · Wouter Dekens🇺🇸 · Jordy de Vries🇺🇸 · Martin Hoferichter🇺🇸 · Emanuele Mereghetti🇺🇸

    We investigate the interplay between the high- and low-energy phenomenology of $CP$-violating interactions of the Higgs boson with gauge bosons. For this purpose we use an effective field theory approach and consider all dimension-6 operators arising in so-called universal theories. We compute their loop-induced contributions to electric dipole moments and the $CP$ asymmetry in $B\to X_s\gamma$, and compare the resulting current and prospective constraints to the projected sensitivity of the LHC. Low-energy measurements are shown to generally have a far stronger constraining power, which results in highly correlated allowed regions in coupling space, a distinctive pattern that could be probed at the high-luminosity LHC.

    hep-phPRL(2019)·74 citations
14. 14*

    Production of $X(3872)$ Accompanied by a Soft Pion at Hadron Colliders

    Eric Braaten🇺🇸 · Li-Ping He🇺🇸 · Kevin Ingles🇺🇸

    If the $X(3872)$ is a weakly bound charm-meson molecule, it can be produced by the creation of $D^{\ast 0}{\bar{D}}^0$ or $D^0{\bar{D}}^{\ast 0}$ at short distances followed by the formation of the bound state from the charm-meson pair. The $X$ can also be produced by the creation of $D^{\ast }{\bar{D}}^{\ast }$ at short distances followed by the rescattering of the charm-meson pair into $X\pi$. At a high-energy hadron collider, the prompt cross section from this mechanism has a narrow peak in the $X\pi$ invariant mass distribution near the $D^{\ast }{\bar{D}}^{\ast }$ threshold from a charm-meson triangle singularity. An order-of-magnitude estimate of the ratio of the cross section for producing the peak in the $X{\pi }^{\pm }$ distribution to the cross section for producing $X$ without an accompanying pion suggests that the peak may be observable at the LHC.

    hep-phPRD(2019)·22 citations
15. 15*

    Observable Predictions for Massive-Neutrino Cosmologies with Model-Independent Dark Energy

    Ana Diaz Rivero🇺🇸 · V. Miranda🇺🇸 · Cora Dvorkin🇺🇸

    We investigate the bounds on the sum of neutrino masses in a cosmic-acceleration scenario where the equation of state $w(z)$ of dark energy (DE) is constructed in a model-independent way, using a basis of principal components (PCs) that are allowed to cross the phantom barrier $w(z)=-1$. We find that the additional freedom provided to $w(z)$ means the DE can undo changes in the background expansion induced by massive neutrinos at low redshifts. This has two significant consequences: (1) it leads to a substantial increase in the upper bound for the sum of the neutrino masses ($M_{\nu }<0.33-0.55$ eV at the 95\% C.L. depending on the data sets and number of PCs included) compared to studies that choose a specific parametrization for $w(z)$; and (2) it causes $\sim 1\sigma$ deviations from $\Lambda$CDM in the luminosity distance and the Hubble expansion rate at higher redshifts ($z\gtrsim 2$), where the contribution of DE is subdominant and there is little constraining data. The second point consequently means that there are also observable deviations in the shear power spectrum and in the matter power spectrum at low redshift, since the clustering of matter throughout cosmic time depends on the expansion rate. This provides a compelling case to pursue high-$z$ BAO and SN measurements as a way of disentangling the effects of neutrinos and dark energy. Finally, we find that the additional freedom given to the dark energy component has the effect of lowering $S_8$ with respect to $\Lambda$CDM.

    ↳ astro-ph.COhep-phPRD(2019)·26 citations
16. 16*

    Astrophysical Tests of Dark Matter with Maunakea Spectroscopic Explorer

    Ting S. Li · Manoj Kaplinghat · Keith Bechtol · Adam S. Bolton · Jo Bovy · Timothy Carleton · Chihway Chang · Alex Drlica-Wagner · Denis Erkal · Marla Geha · Johnny P. Greco · Carl J. Grillmair and 18 other authors

    We discuss how astrophysical observations with the Maunakea Spectroscopic Explorer (MSE), a high-multiplexity (about 4300 fibers), wide field-of-view (1.5 square degree), large telescope aperture (11.25 m) facility, can probe the particle nature of dark matter. MSE will conduct a suite of surveys that will provide critical input for determinations of the mass function, phase-space distribution, and internal density profiles of dark matter halos across all mass scales. N-body and hydrodynamical simulations of cold, warm, fuzzy and self-interacting dark matter suggest that non-trivial dynamics in the dark sector could have left an imprint on structure formation. Analysed within these frameworks, the extensive and unprecedented datasets produced by MSE will be used to search for deviations away from cold and collisionless dark matter model. MSE will provide an improved estimate of the local density of dark matter, critical for direct detection experiments, and will improve estimates of the J-factor for indirect searches through self-annihilation or decay into Standard Model particles. MSE will determine the impact of low mass substructures on the dynamics of Milky Way stellar streams in velocity space, and will allow for estimates of the density profiles of the dark matter halos of Milky Way dwarf galaxies using more than an order of magnitude more tracers. In the low redshift Universe, MSE will provide critical redshifts to pin down the luminosity functions of vast numbers of satellite systems, and MSE will be an essential component of future strong lensing measurements to constrain the halo mass function. Across nearly all mass scales, the improvements offered by MSE, in comparison to other facilities, are such that the relevant analyses are limited by systematics rather than statistics.

    ↳ astro-ph.COastro-ph.GAastro-ph.IMhep-ph10 citations
17. 17*

    On the parametrization of the distributions of depth of shower maximum of ultra-high energy extensive air showers

    Luan Arbeletche🇧🇷 · Vitor de Souza🇧🇷

    The distribution of depth in which a cosmic ray air shower reaches its maximum number of particles ($X_{max}$) is studied and parametrized. Three functions are studied for proton, carbon, silicon, and iron primary particles with energies ranging from $10^{17}$ eV to $10^{20}$ eV for three hadronic interaction models: EPOS-LHC, QGSJetII.04, and Sibyll2.3c. The function which best describes the $X_{max}$ distribution of a mixed composition is also studied. A very large number of simulated showers and a detailed analysis procedure were used to guarantee negligible effects of undersampling and of fitting in the final results. For the first time, a comparison of several functions is presented under the same assumption with the intention of selecting the best functional form to describe the $X_{max}$ distribution. The Generalized Gumbel distribution is shown to be the best option for a general description of all cases. The Log-normal distribution is also a good choice for some cases while the Exponentially Modified Gaussian distribution has shown to be the worst choice in almost all cases studied. All three functions are parametrized as a function of energy and primary mass.

    ↳ astro-ph.HEhep-phAstropart.Phys.(2020)·15 citations
18. 18*

    Science from an Ultra-Deep, High-Resolution Millimeter-Wave Survey

    Neelima Sehgal · Ho Nam Nguyen · Joel Meyers · Moritz Munchmeyer · Tony Mroczkowski · Luca Di Mascolo · Eric Baxter · Francis-Yan Cyr-Racine · Mathew Madhavacheril · Benjamin Beringue · Gil Holder · Daisuke Nagai and 57 other authors

    Opening up a new window of millimeter-wave observations that span frequency bands in the range of 30 to 500 GHz, survey half the sky, and are both an order of magnitude deeper (about 0.5 uK-arcmin) and of higher-resolution (about 10 arcseconds) than currently funded surveys would yield an enormous gain in understanding of both fundamental physics and astrophysics. In particular, such a survey would allow for major advances in measuring the distribution of dark matter and gas on small-scales, and yield needed insight on 1.) dark matter particle properties, 2.) the evolution of gas and galaxies, 3.) new light particle species, 4.) the epoch of inflation, and 5.) the census of bodies orbiting in the outer Solar System.

    ↳ astro-ph.COastro-ph.GAhep-phBull.Am.Astron.Soc.(2019)·29 citations
19. 19*

    Update of a Multi-Phase Transport Model with Modern Parton Distribution Functions and Nuclear Shadowing

    Chao Zhang🇨🇳 · Liang Zheng🇨🇳 · Feng Liu🇨🇳 · Shusu Shi🇨🇳 · Zi-Wei Lin🇺🇸

    A multi-phase transport (AMPT) model has been successful in explaining a wide range of observables in relativistic heavy ion collisions. In this work, we implement a modern set of free proton parton distribution functions and an impact parameter-dependent nuclear shadowing in the AMPT model. After refitting the parameters of the two-component initial condition model to the experimental data on $pp$ and $p\bar{p}$ total and inelastic cross sections from $\sqrt{s}\sim$ 4 GeV to 13 TeV, we study particle productions in $pp$ and $AA$ collisions. We show that the updated AMPT model with string melting can reasonably describe the overall particle yields and transverse momentum spectra for both $pp$ and $AA$ collisions at RHIC and LHC energies after we introduce a nuclear scaling of the minijet transverse momentum cutoff for $AA$ collisions at LHC energies that is motivated by the color glass condensate. Since heavy flavor and high-$p_{\mathrm{T}}$ particles are produced by perturbative-QCD processes and thus directly depend on parton distribution functions of nuclei, the updated AMPT model is expected to provide a more reliable description of these observables.

    ↳ nucl-thhep-phnucl-exPRC(2019)·31 citations
20. 20*

    Constraining dark matter-neutrino interactions with IceCube-170922A

    Ki-Young Choi🇰🇷 · Jongkuk Kim🇰🇷 · Carsten Rott🇰🇷

    Astrophysical neutrinos travel long distances from their sources to the Earth traversing dark matter halos of clusters of galaxies and that of our own Milky Way. The interaction of neutrinos with dark matter may affect the flux of neutrinos. The recent multi-messenger observation of a high energy neutrino, IceCube-170922A, can give a robust upper bound $\sigma /M_{dm}\lesssim 5.1\times 10^{-23}{\mathrm{cm}}^2/$GeV on the interaction between neutrino and dark matter at a neutrino energy of 290 TeV allowing 90\% suppression. Combining the constraints from CMB and LSS at different neutrino energies, we can constrain models of dark matter-neutrino interactions.

    ↳ astro-ph.COhep-phPRD(2019)·70 citations
21. 21*

    Mapping neutron star data to the equation of state using the deep neural network

    Yuki Fujimoto🇯🇵 · Kenji Fukushima🇯🇵 · Koichi Murase🇯🇵

    The densest state of matter in the universe is uniquely realized inside central cores of the neutron star. While first-principles evaluation of the equation of state of such matter remains as one of the longstanding problems in nuclear theory, evaluation in light of neutron star phenomenology is feasible. Here we show results from a novel theoretical technique to utilize deep neural network with supervised learning. We input up-to-date observational data from neutron star X-ray radiations into the trained neural network and estimate a relation between the pressure and the mass density. Our results are consistent with extrapolation from the conventional nuclear models and the experimental bound on the tidal deformability inferred from gravitational wave observation.

    ↳ nucl-thastro-ph.HEhep-phPRD(2020)·143 citations
22. 22*

    Ultra-light dark matter in disk galaxies

    Nitsan Bar🇮🇱 · Kfir Blum🇮🇱 · Joshua Eby🇮🇱 · Ryosuke Sato🇩🇪

    Analytic arguments and numerical simulations show that bosonic ultra-light dark matter (ULDM) would form cored density distributions (`solitons') at the center of galaxies. ULDM solitons offer a promising way to exclude or detect ULDM by looking for a distinctive feature in the central region of galactic rotation curves. Baryonic contributions to the gravitational potential pose an obstacle to such analyses, being (i) dynamically important in the inner galaxy and (ii) highly non-spherical in rotation-supported galaxies, resulting in non-spherical solitons. We present an algorithm for finding the ground state soliton solution in the presence of stationary non-spherical background baryonic mass distribution. We quantify the impact of baryons on the predicted ULDM soliton in the Milky Way and in low surface-brightness galaxies from the SPARC database.

    ↳ astro-ph.COastro-ph.GAhep-phPRD(2019)·99 citations
23. 23*

    Neutrino pion-production on a nucleon

    Fred Myhrer🇺🇸

    Heavy baryon chiral perturbation theory ($\chi$PT), where the $\Delta$ resonance is included, is used in order to examine the axial charged-current component of the weak interaction process at low neutrino energies. At leading chiral order the Adler theorems, derived using PCAC, are satisfied. At next-to-leading chiral order this effective field theory goes beyond these theorems. I will show that $\chi$PT generates deviation from the PCAC predictions, which means that some neutrino-nucleon models that are used in evaluating neutrino nucleus scattering amplitudes, might need modifications.

    ↳ nucl-thhep-phPoS(2019)·3 citations
24. 24*

    A Large Mass Hierarchy from a Small Non-minimal Coupling

    Christophe Ringeval🇧🇪 · Teruaki Suyama🇯🇵 · Masahide Yamaguchi🇯🇵

    We propose a simple but novel cosmological scenario where both the Planck mass and the dark energy scale emerge from the same super-Hubble quantum fluctuations of a non-minimally coupled ultra-light scalar field during primordial inflation. The current cosmic and solar-system observations constrain the non-minimal coupling to be small.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2019)·7 citations
25. 25*

    Frame-dependence of inflationary observables in scalar-tensor gravity

    Alexandros Karam🇪🇪 · Thomas Pappas🇬🇷 · Kyriakos Tamvakis🇬🇷

    By means of the Green's function method, we computed the spectral indices up to third order in the slow-roll approximation for a general scalar-tensor theory in both the Einstein and Jordan frames. Using quantities which are invariant under the conformal rescaling of the metric and transform as scalar functions under the reparametrization of the scalar field, we showed that the frames are equivalent up to this order due to the underlying assumptions. Nevertheless, care must be taken when defining the number of $e$-folds.

    ↳ gr-qcastro-ph.COhep-phPoS(2019)·7 citations
26. 26*

    Asymptotic Symmetries in $(d+2)$-Dimensional Gauge Theories

    Temple He🇺🇸 · Prahar Mitra🇺🇸

    We show that the subleading soft photon theorem in a $(d+2)$-dimensional massless abelian gauge theory gives rise to a Ward identity corresponding to divergent large gauge transformations acting on the celestial sphere at null infinity. We further generalize our analysis to $(d+2)$-dimensional non-abelian gauge theories and show that the leading and subleading soft gluon theorem give rise to Ward identities corresponding to asymptotic symmetries of the theory.

    ↳ hep-thhep-phJHEP(2019)·45 citations
27. 27*

    Fine-structure constant constraints on late-time dark energy transitions

    C. J. A. P. Martins🇵🇹 · M. Prat Colomer🇪🇸

    We use recent astrophysical and local tests of the stability of the fine-structure constant, $\alpha$, to constrain a particular phenomenological but physically motivated class of models in which the dark energy equation of state can undergo a rapid transition at low redshifts, perhaps associated with the onset of the acceleration phase. We set constraints on the phenomenological parameters describing such possible transitions, in particular improving previous constraints (which used only cosmological data) on the present-day value of the dark energy equation of state in these models. We specifically quantify how these constraints are improved by the addition of the $\alpha$ measurements. We find no evidence for a transition associated with the onset of acceleration. In this model the $\alpha$ measurements lead to a bound on Weak Equivalence Principle violations of $\eta <4\times 10^{-15}$ (at $68.3\%$ confidence level), improving on the recent MICROSCOPE bound by about a factor of three.

    ↳ astro-ph.COgr-qchep-phPLB(2019)·6 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.