Wed·Mar 13, 2019Wednesday·March 13, 2019

1. 01*

   CPT Violation in ${\mathbf{B}}_{\mathbf{s}}^0$--${\bar{\mathbf{B}}}_{\mathbf{s}}^0$ mixing and the measurement of CP Violation in ${\mathbf{B}}_{\mathbf{s}}\to {\mathbf{K}}^{+}{\mathbf{K}}^{-}$

   Francisco J. Botella (Valencia U. and IFIC)🇪🇸 · Miguel Nebot (Lisbon IST and CFTP)🇵🇹

   A simple analysis of time-dependent $B_s\to K^{+}{K}^{-}$ transitions, based on recent results from the LHCb experiment, is presented. The benefits of adopting a fully consistent theoretical description of the $B_s^0$--${\bar{B}}_s^0$ mixing are stressed. It is shown that bounds on CPT violation in the $B_s^0$--${\bar{B}}_s^0$ system can be consistently obtained and that direct CP violation in $B_s\to K^{+}{K}^{-}$ can be robustly established, even in the presence of CPT violation in the mixing.

   hep-phhep-ex2 citations
2. 02*

   The Dynamical Diquark Model: First Numerical Results

   Jesse F. Giron🇺🇸 · Richard F. Lebed🇺🇸 · Curtis T. Peterson🇺🇸

   We produce the first numerical predictions of the dynamical diquark model of multiquark exotic hadrons. Using Born-Oppenheimer potentials calculated numerically on the lattice, we solve coupled and uncoupled systems of Schroedinger equations to obtain mass eigenvalues for multiplets of states that are, at this stage, degenerate in spin and isospin. Assuming reasonable values for these fine-structure splittings, we obtain a series of bands of exotic states with a common parity eigenvalue that agree well with the experimentally observed charmoniumlike states, and we predict a number of other unobserved states. In particular, the most suitable fit to known pentaquark states predicts states below the charmonium-plus-nucleon threshold. Finally, we examine the strictest form of Born-Oppenheimer decay selection rules for exotics and, finding them to fail badly, we propose a resolution by relaxing the constraint that exotics must occur as heavy-quark spin-symmetry eigenstates.

   hep-phnucl-thJHEP(2019)·67 citations
3. 03*

   CMB circular and B-mode polarization from new interactions

   Nicola Bartolo🇮🇹 · Ahmad Hoseinpour🇮🇷 · Sabino Matarrese🇮🇹 · Giorgio Orlando🇮🇹 · Moslem Zarei🇮🇷

   Standard models describing the radiation transfer of the cosmic microwave background (CMB) through Compton scattering predict that cosmological scalar perturbations at linear order are not able to source V and B polarization modes. In this work, we investigate the possibility that such CMB polarization modes are generated even in the presence of linear scalar perturbations only. We provide a general parametrization of the photon-fermion forward-scattering amplitude and compute mixing terms between different CMB polarization modes. We discuss different general extensions of Standard Model interactions which violate discrete symmetries, while preserving the combination of charge conjugation, parity and time reversal. We show that it is possible to source CMB circular polarization by violating parity and charge conjugation symmetries. Instead, B-mode generation is associated to the violation of symmetry for time-reversal. Our results provide a useful tool to constrain new physics using CMB data.

   hep-phastro-ph.COPRD(2019)·33 citations
4. 04*

   Strongly interacting dark matter and the DAMA signal

   Maxim Laletin🇧🇪 · Jean-René Cudell🇧🇪

   We show that models of strongly interacting (SIMP) dark matter built to reproduce the DAMA signal actually cannot account for its time dependence. We discuss the constraints on this type of models coming from direct detection experiments and study the propagation of thermalised dark matter particles in the ground for the allowed values of the parameters. We consider a simple 1D diffusion and a more detailed 3D diffusion. In both cases the predicted signal has either the wrong phase of the annual modulation or a much larger amplitude of the diurnal modulation.

   hep-phastro-ph.COJCAP(2019)·8 citations
5. 05*

   Comments on the dispersion relation method to vector-vector interaction

   R. Molina🇧🇷 · L. S. Geng🇨🇳 · E. Oset🇪🇸

   We study in detail the method proposed recently to study the vector-vector interaction using the $N/D$ method and dispersion relations, which concludes that, while for $J=0$, one finds bound states, in the case of $J=2$, where the interaction is also attractive and much stronger, no bound state is found. In that work, approximations are done for $N$ and $D$ and a subtracted dispersion relation for $D$ is used, with subtractions made up to a polynomial of second degree in $s-s_{\mathrm{th}}$, matching the expression to $1-VG$ at threshold. We study this in detail for the $\rho -\rho$ interaction and to see the convergence of the method we make an extra subtraction matching $1-VG$ at threshold up to $(s-s_{\mathrm{th}}{)}^3$. We show that the method cannot be used to extrapolate the results down to 1270 MeV where the $f_2(1270)$ resonance appears, due to the artificial singularity stemming from the "on shell" factorization of the $\rho$ exchange potential. In addition, we explore the same method but folding this interaction with the mass distribution of the $\rho$, and we show that the singularity disappears and the method allows one to extrapolate to low energies, where both the $(s-s_{\mathrm{th}}{)}^2$ and $(s-s_{\mathrm{th}}{)}^3$ expansions lead to a zero of $\mathrm{Re}D(s)$, at about the same energy where a realistic approach produces a bound state. Even then, the method generates a large $\mathrm{Im}D(s)$ that we discuss is unphysical.

   hep-phPTEP(2019)·11 citations
6. 06*

   A model-independent approach to the reconstruction of multi-flavor supernova neutrino energy spectra

   Hui-Ling Li🇨🇳 · Xin Huang🇨🇳 · Yu-Feng Li🇨🇳 · Liang-Jian Wen🇨🇳 · Shun Zhou🇨🇳

   The model-independent reconstruction of the energy spectra of ${\overline{\nu }}_e^{}$, ${\nu }_e^{}$ and ${\nu }_x^{}$ (i.e., ${\nu }_{\mu }^{}$, ${\nu }_{\tau }^{}$ and their antiparticles) from the future observation of a galactic core-collapse supernova (SN) is of crucial importance to understand the microscopic physics of SN explosions. To this end, we propose a practically useful method to combine the multi-channel detection of SN neutrinos in a large liquid-scintillator detector (e.g., JUNO), namely, the inverse beta decay ${\overline{\nu }}_e^{}+p\to e^{+}+n$, the elastic neutrino-proton scattering $\nu +p\to \nu +p$ and the elastic neutrino-electron scattering $\nu +e^{-}\to \nu +e^{-}$, and reconstruct the energy spectra of ${\overline{\nu }}_e^{}$, ${\nu }_e^{}$ and ${\nu }_x^{}$ by making the best use of the observational data in those three channels. In addition, the neutrino energy spectra from the numerical simulations of the delayed neutrino-driven SN explosions are implemented to demonstrate the robustness of our method. Taking the ordinary matter effects into account, we also show how to extract the initial neutrino energy spectra in the presence of neutrino flavor conversions.

   hep-phastro-ph.HEPRD(2019)·26 citations
7. 07*

   Masses and decays of the bottom-charm hybrid meson $c\bar{b}g$

   Tomokazu Miyamoto🇯🇵 · Shigehiro Yasui🇯🇵

   We study gluonic excitations inside a $B_c$ meson in the constituent gluon model, treating a bottom-charm hybrid meson $c\bar{b}g$ as a three-body system. We obtain the mass spectra for the hybrid mesons with magnetic gluon and electric gluon and see that their lowest states appear above the $DB$ threshold. Also, we consider the decays of the low-lying states of the hybrid meson into $DB,D^{\ast }B,D{B}^{\ast }$, $D^{\ast }{B}^{\ast }$, $D_s{B}_s$, and $D_s{B}_s^{\ast }$ mesons, developing an existing model for the strong decays. We estimate their partial decay widths and find that the widths have a heavy dependence on the final meson states. We argue that the accuracy of our model will be tested experimentally when the branching ratios of the decays are measured. Our results suggest that there could be a prospect that the hybrid meson will be discovered as its first excited state rather than its lowest state.

   hep-phPRD(2019)·6 citations
8. 08*

   Gauge ambiguity of the quark spectrum in the Color Glass Condensate

   Francois Gelis🇫🇷 · Naoto Tanji🇮🇹

   In the Color Glass Condensate, the inclusive spectrum of produced quarks in a heavy ion collision is obtained as the Fourier transform of a $2$-fermion correlation function. Due to its non-locality, the two points of this function must be linked by a Wilson line in order to have a gauge invariant result, but when the quark spectrum is evaluated in a background that has a non-zero chromo-magnetic field, this procedure suffers from an ambiguity related to the choice of the contour defining the Wilson line. In this paper, we use an analytically tractable toy model of the background field in order to study this contour dependence. We show that for a straight contour, unphysical contributions to the spectrum in $p_{\perp }^{-2}$ and $p_{\perp }^{-3}$ cancel, leading to a spectrum with a tail in $p_{\perp }^{-4}$. If the contour defining the Wilson line deviates from a straight line, the path dependence is at most of order $p_{\perp }^{-5}$ if its curvature is bounded, and of order $p_{\perp }^{-4}$ otherwise. When the contour is forced to go through a fixed point, the path dependence is even larger, of order $p_{\perp }^{-2}$.

   hep-phnucl-thNPA(2019)·2 citations
9. 09*

   Proton radius reconstruction from simulated electron-proton elastic scattering cross sections at low transfer momenta

   S.Belostotski🇷🇺 · N.Sagidova🇷🇺 · A.Vorobyev🇷🇺

   This note is motivated by preparations of a new $ep$ elastic scattering experiment in the low transfer momentum region to be carried out in the 720 MeV electron beam of the Mainz Microtron MAMI. This experiment will use an innovative method allowing for detection of recoil protons in coincidence with the scattered electrons. The goal is to measure the $ep$ differential cross sections in the $Q^2$ range from 0.001 GeV${}^2$ to 0.04 GeV${}^2$ and to determine the proton charge radius with sub-percent precision.

   hep-phhep-ex3 citations
10. 10*

    New feature in the differential cross sections at $13$ TeV be measured at the LHC

    O.V. Selyugin🇷🇺

    Analysis of $d\sigma /dt$ of the TOTEM Collaboration data, carried out without model assumptions, showed the existence of a new effect in the behavior of the hadron scattering amplitude at a small momentum transfer at a high confidence level. The quantitatively description of the data in the framework of the HEGS model support such phenomenon which can be connect with quark potentials at large distances.

    hep-phhep-exPLB(2019)·20 citations
11. 11*

    GUT Physics in the era of the LHC

    Djuna Croon🇨🇦 · Tomás E. Gonzalo🇳🇴 · Lukas Graf🇩🇪 · Nejc Košnik🇸🇮 · Graham White🇨🇦

    Grand Unified Theories (GUTs) are one of the most interesting high-energy completions of the Standard Model, because they provide a rich, powerful and elegant group-theoretical framework able to resolve a variety of problems remaining in our current understanding of particle physics. They usually act as motivators for many low energy BSM theories, such as left-right symmetric or supersymmetric models, and they serve to fill the gap between the experimentally reachable low energies and the physics in the ultraviolet. In recent years, however, they have fallen slightly from the spotlight, in favour of `simplified' models with more specific phenomenological predictions. The aim of this review is to summarize the state of the art on GUTs and argue for their importance in modern physics. Recent advances in experiments permit to test the predictions of GUTs at different energy scales. First, as GUTs can play a role in the inflationary dynamics of the early Universe, their imprints could be found in the CMB observations by the Planck satellite. Remarkably enough, GUTs could manifest themselves also in terrestrial tests; several planned experiments aim to probe the proton stability and to establish order of magnitude higher bounds on its lifetime. Moreover, the predictions of specific GUT models could be tested even at the LHC thanks to its high energy reach, via searches for exotic states or additional contributions to flavour anomalies.

    hep-phhep-thFront.in Phys.(2019)·77 citations
12. 12*

    The $ss\bar{s}\bar{s}$ tetraquark states and the newly observed structure $X(2239)$ by BESIII Collaboration

    Qi-Fang Lü🇨🇳 · Kai-Lei Wang🇨🇳 · Yu-Bing Dong🇨🇳

    We investigate the mass spectrum of the $ss\bar{s}\bar{s}$ tetraquark states within the relativized quark model. By solving the Schrödinger-like equation with the relativized potential, the masses of the $S-$ and $P-$wave $ss\bar{s}\bar{s}$ tetraquarks are obtained. The screening effects are also taken into account. It is found that the observed resonant structure $X(2239)$ in the $e^{+}{e}^{-}\to K^{+}{K}^{-}$ process by BESIII Collaboration can be assigned as a $P-$wave $1^{--}$ $ss\bar{s}\bar{s}$ tetraquark state. Furthermore, the radiative transition and strong decay behaviors of this structure are also estimated, which can provide helpful information for future experimental searches.

    hep-phhep-exnucl-thCPC(2020)·33 citations
13. 13*

    Introduction to flavour physics

    Jure Zupan🇺🇸

    We give a brief introduction to flavour physics. The first part covers the flavour structure of the Standard Model, how the Kobayashi-Maskawa mechanism is tested and provides examples of searches for new physics using flavour observables, such as meson mixing and rare decays. In the second part we give a brief overview of the recent flavour anomalies and how the Higgs can act as a new flavour probe.

    hep-phhep-exCERN Yellow Rep.School Proc.(2019)·41 citations
14. 14*

    Searching for Boosted Dark Matter via Dark-Strahlung

    Doojin Kim🇺🇸 · Jong-Chul Park🇰🇷 · Seodong Shin🇰🇷

    We propose a new search channel for boosted dark matter (BDM) signals coming from the present universe, which are distinct from simple neutrino signals including those coming from the decay or pair-annihilation of dark matter. The signal process is initiated by the scattering of high-energetic BDM off either an electron or a nucleon. If the dark matter is dark-sector U(1)-charged, the scattered BDM may radiate a dark gauge boson (called "dark-strahlung") which subsequently decays to a Standard Model fermion pair. We point out that the existence of this channel may allow for the interpretation that the associated signal stems from BDM, not from the dark-matter-origin neutrinos. Although the dark-strahlung process is generally subleading compared to the lowest-order simple elastic scattering of BDM, we find that the BDM with a significant boost factor may induce an O(10-20%) event rate in the parameter regions unreachable by typical beam-produced dark-matter. We further find that the dark-strahlung channel may even outperform the leading-order channel in the search for BDM, especially when the latter is plagued by substantial background contamination. We argue that cosmogenic BDM searches readily fall in such a case, hence taking full advantage of dark-strahlung. As a practical application, experimental sensitivities expected in the leading-order and dark-strahlung channels are contrasted in dark gauge boson parameter space, under the environment of DUNE far-detectors, revealing usefulness of dark-strahlung.

    hep-phhep-exPRD(2019)·24 citations
15. 15*

    X-ray Signatures of Axion Conversion in Magnetic White Dwarf Stars

    Christopher Dessert🇺🇸 · Andrew J. Long🇺🇸 · Benjamin R. Safdi🇺🇸

    White dwarf (WD) stars may radiate keV-energy axions produced in their stellar cores. This has been extensively studied as an extra channel by which WDs may cool, with some analyses even suggesting that axions can help explain the observed WD luminosity function. We show that the radiated axions may convert into X-rays in the strong magnetic fields surrounding the WDs, leading to observable X-ray signatures. We use Suzaku observations of the WD RE J0317-853 to set the strongest constraints to date on the combination of the axion-electron ($g_{aee}$) times axion-photon ($g_{a\gamma \gamma }$) couplings, and we show that dedicated observations of magnetic WDs by telescopes such as Chandra, XMM-Newton, and NuSTAR could increase the sensitivity to $|g_{aee}{g}_{a\gamma \gamma }|$ by over an order of magnitude, allowing for a definitive test of the axion-like-particle explanation of the stellar cooling anomalies.

    hep-phastro-ph.HEastro-ph.SRPRL(2019)·75 citations
16. 16*

    The Axion Quark Nugget Dark Matter Model: Size Distribution and Survival Pattern

    Shuailiang Ge🇨🇦 · Kyle Lawson🇨🇦 · Ariel Zhitnitsky🇨🇦

    We consider the formation and evolution of Axion Quark Nugget dark matter particles in the early universe. The goal of this work is to estimate the mass distribution of these objects and assess their ability to form and survive to the present day. We argue that this model allows a broad range of parameter space in which the AQN may account for the observed dark matter mass density, naturally explains a similarity between the "dark" and "visible" components, i.e. ${\Omega }_{\mathrm{dark}}\sim {\Omega }_{\mathrm{visible}}$, and also offer an explanation for a number of other long standing puzzles such as "Primordial Lithium Puzzle" and "the Solar Corona Mystery" among many other cosmological puzzles.

    hep-phastro-ph.COPRD(2019)·73 citations
17. 17*

    Neutrino -- Dark Matter Scattering and Coincident Detections of UHE Neutrinos with EM Sources

    Seth Koren🇺🇸

    The scattering of neutrinos off dark matter can induce time delays in their propagation compared to that of photons, which would wash out correlations between ultra-high-energy neutrinos and electromagnetic observations of their sources - while preserving the observed diffuse neutrino flux. This may explain the significant discrepancy between predictions of neutrino fluxes from gamma ray bursts and the lack of neutrinos correlated with EM observations of GRBs. Conversely, the detection of an UHE neutrino in association with a source provides a strong constraint on such interactions. We consider an effective model of dark photon dark matter interacting with neutrinos which exhibits this effect.

    hep-phastro-ph.COastro-ph.HEJCAP(2019)·22 citations
18. 18*

    Detecting Dark Matter with Superconducting Nanowires

    Yonit Hochberg🇮🇱 · Ilya Charaev🇺🇸 · Sae-Woo Nam🇺🇸 · Varun Verma🇺🇸 · Marco Colangelo🇺🇸 · Karl K. Berggren🇺🇸

    We propose the use of superconducting nanowires as both target and sensor for direct detection of sub-GeV dark matter. With excellent sensitivity to small energy deposits on electrons, and demonstrated low dark counts, such devices could be used to probe electron recoils from dark matter scattering and absorption processes. We demonstrate the feasibility of this idea using measurements of an existing fabricated tungsten-silicide nanowire prototype with 0.8 eV energy threshold and 4.3 nanograms with 10 thousand seconds of exposure, which showed no dark counts. The results from this device already place meaningful bounds on dark matter-electron interactions, including the strongest terrestrial bounds on sub-eV dark photon absorption to date. Future expected fabrication on larger scales and with lower thresholds should enable probing new territory in the direct detection landscape, establishing the complementarity of this approach to other existing proposals.

    hep-phcond-mat.supr-conhep-exquant-phPRL(2019)·180 citations
19. 19*

    Decay of Cosmic String Loops Due to Particle Radiation

    Daiju Matsunami🇨🇦 · Levon Pogosian🇨🇦 · Ayush Saurabh🇺🇸 · Tanmay Vachaspati🇺🇸

    Constraints on the tension and the abundance of cosmic strings depend crucially on the rate at which they decay into particles and gravitational radiation. We study the decay of cosmic string loops in the Abelian-Higgs model by performing field theory simulations of loop formation and evolution. We find that our set of string loops emit particle radiation primarily due to kink collisions, and that their decay time due to these losses is proportional to $L^p$ with $p\approx 2$ where $L$ is the loop length. In contrast, the decay time to gravitational radiation scales in proportion to $L$, and we conclude that particle emission is the primary energy loss mechanism for loops smaller than a critical length scale, while gravitational losses dominate for larger loops.

    hep-phastro-ph.COastro-ph.HEhep-thPRL(2019)·108 citations
20. 20*

    The Short-Baseline Neutrino Program at Fermilab

    Pedro A. N. Machado🇺🇸 · Ornella Palamara🇺🇸 · David W. Schmitz🇺🇸

    The Short-Baseline Neutrino, or SBN, program consists of three liquid argon time projection chamber detectors located along the Booster Neutrino Beam at the Fermi National Accelerator Laboratory. Its main goals include searches for new physics - particularly eV-scale sterile neutrinos, detailed studies of neutrino-nucleus interactions at the GeV energy scale, and the advancement of the liquid argon detector technology that will also be used in the DUNE/LBNF long-baseline neutrino experiment in the next decade. Here we review these science goals and the current experimental status of SBN.

    ↳ hep-exhep-phAnn.Rev.Nucl.Part.Sci.(2019)·303 citations
21. 21*

    Messengers from the Early Universe: Cosmic Neutrinos and Other Light Relics

    Daniel Green🇺🇸 · Mustafa A. Amin🇺🇸 · Joel Meyers🇺🇸 · Benjamin Wallisch🇺🇸 · Kevork N. Abazajian🇺🇸 · Muntazir Abidi🇬🇧 · Peter Adshead🇺🇸 · Zeeshan Ahmed🇺🇸 · Behzad Ansarinejad🇬🇧 · Robert Armstrong🇺🇸 · Carlo Baccigalupi🇮🇹 · Kevin Bandura🇺🇸 and 127 other authors

    The hot dense environment of the early universe is known to have produced large numbers of baryons, photons, and neutrinos. These extreme conditions may have also produced other long-lived species, including new light particles (such as axions or sterile neutrinos) or gravitational waves. The gravitational effects of any such light relics can be observed through their unique imprint in the cosmic microwave background (CMB), the large-scale structure, and the primordial light element abundances, and are important in determining the initial conditions of the universe. We argue that future cosmological observations, in particular improved maps of the CMB on small angular scales, can be orders of magnitude more sensitive for probing the thermal history of the early universe than current experiments. These observations offer a unique and broad discovery space for new physics in the dark sector and beyond, even when its effects would not be visible in terrestrial experiments or in astrophysical environments. A detection of an excess light relic abundance would be a clear indication of new physics and would provide the first direct information about the universe between the times of reheating and neutrino decoupling one second later.

    ↳ astro-ph.COhep-phBull.Am.Astron.Soc.(2019)·89 citations
22. 22*

    Chiral phase transition temperature in (2+1)-Flavor QCD

    H.-T. Ding🇨🇳 · P. Hegde🇮🇳 · O. Kaczmarek🇩🇪 · F. Karsch🇩🇪 · Anirban Lahiri🇩🇪 · S.-T. Li🇨🇳 · Swagato Mukherjee🇺🇸 · H. Ohno🇯🇵 · P. Petreczky🇺🇸 · C. Schmidt🇩🇪 · P. Steinbrecher🇺🇸

    We present a lattice QCD based determination of the chiral phase transition temperature in QCD with two degenerate, massless quarks and a physical strange quark mass. We propose and calculate two novel estimators for the chiral transition temperature for several values of the light quark masses, corresponding to Goldstone pion masses in the range of $58\mathrm{MeV}\lesssim m_{\pi }\lesssim 163\mathrm{MeV}$. The chiral phase transition temperature is determined by extrapolating to vanishing pion mass using universal scaling analysis. Finite volume effects are controlled by extrapolating to the thermodynamic limit using spatial lattice extents in the range of $2.8$-$4.5$ times the inverse of the pion mass. Continuum extrapolations are carried out by using three different values of the lattice cut-off, corresponding to lattices with temporal extent $N_{\tau }=6,8$ and $12$. After thermodynamic, continuum and chiral extrapolations we find the chiral phase transition temperature $T_c^0=132_{-6}^{+3}$ MeV.

    ↳ hep-lathep-phhep-thnucl-thPRL(2019)·306 citations
23. 23*

    Intra-day variability of three Seyfert Galaxies measured with XMM-Newton

    Ashutosh Tripathi🇨🇳 · Paul J. Wiita🇺🇸 · Alok C. Gupta🇮🇳 · Minfeng Gu🇨🇳 · M. Liao🇨🇳

    We present and analyze the variability of three Seyfert galaxies on intra-day timescales. We have analyzed in a uniform manner the 38 longest ( $>30$ ks) observations made for NGC 4051, MCG$-06-30-15$ and NGC 4151 by XMM-Newton between 2000 and 2015. The nuclei were quite active during essentially all of these observations and the overall X-ray fluxes (0.3-10 keV) varied by an order of magnitude. Most of the observations do appear to show characteristic timescales, estimated through their auto-correlation functions, ranging between $\sim 2.9$ ks and $\sim 45.3$ ks. The hard (2-10 keV) and soft (0.3-02 keV) bands are very well correlated but consideration of their hardness ratios show that the sources typically soften during flares. We also provide new estimates of the central black hole masses for these three AGN that support the hypothesis that Narrow Line Seyfert 1 galaxies have relatively small central black holes.

    ↳ astro-ph.HEhep-phRes.Astron.Astrophys.(2019)·0 citations
24. 24*

    Probing GHz Gravitational Waves with Graviton-magnon Resonance

    Asuka Ito🇯🇵 · Tomonori Ikeda🇯🇵 · Kentaro Miuchi🇯🇵 · Jiro Soda🇯🇵

    A novel method for extending frequency frontier in gravitational wave observations is proposed. It is shown that gravitational waves can excite a magnon. Thus, gravitational waves can be probed by a graviton-magnon detector which measures resonance fluorescence of magnons. Searching for gravitational waves with a wave length $\lambda$ by using a ferromagnetic sample with a dimension $l$, the sensitivity of the graviton-magnon detector reaches spectral densities, around $5.4\times 10^{-22}\times (\frac{l}{\lambda /2\pi }{)}^{-2}[{\mathrm{Hz}}^{-1/2}]$ at 14 GHz and $8.6\times 10^{-21}\times (\frac{l}{\lambda /2\pi }{)}^{-2}[{\mathrm{Hz}}^{-1/2}]$ at 8.2 GHz, respectively.

    ↳ gr-qcastro-ph.COhep-phEPJC(2020)·105 citations
25. 25*

    Spectrum of anomalous dimensions in hypercubic theories

    Oleg Antipin🇭🇷 · Jahmall Bersini🇭🇷

    We compute the spectrum of anomalous dimensions of non-derivative composite operators with an arbitrary number of fields $n$ in the $O(N)$ vector model with cubic anisotropy at the one-loop order in the $ϵ$-expansion. The complete closed-form expression for the anomalous dimensions of the operators which do not undergo mixing effects is derived and the structure of the general solution to the mixing problem is outlined. As examples, the full explicit solution for operators with up to $n=6$ fields is presented and a sample of the OPE coefficients is calculated. The main features of the spectrum are described, including an interesting pattern pointing to the deeper structure.

    ↳ hep-thcond-mat.stat-mechhep-phPRD(2019)·21 citations
26. 26*

    Multimessenger TeV Dark Matter: a mini review

    Viviana Gammaldi🇪🇸

    We briefly review the general insight into the indirect searches of dark matter. We discuss the primary equation in a three-level multimessenger approach (gamma rays, neutrinos and antiprotons), and we introduce the reader to the main topics and related uncertainties (e.g. dark matter density distribution, cosmic rays, particle physics). As an application of the general concept, we focus on the multi-TeV dark matter candidate among other weak interactive massive particles. We present the state-of-the-art on this sub-field, and we discuss open questions and experimental limitations.

    ↳ astro-ph.HEastro-ph.COhep-phFront.Astron.Space Sci.(2019)·11 citations
27. 27*

    On Some Hypergeometric Solutions of the Conformal Ward Identities of Scalar 4-point Functions in Momentum Space

    Claudio Corianò🇮🇹 · Matteo Maria Maglio🇮🇹

    We discuss specific hypergeometric solutions of the conformal Ward identities (CWI's) of scalar 4-point functions of primary fields in momentum space, in $d$ spacetime dimensions. We determine such solutions using various dual conformal ansätze (DCA's). We start from a generic dual conformal correlator, and require it to be conformally covariant in coordinate space. The two requirements constrain such solutions to take a unique hypergeometric form. They describe correlators which are at the same time conformal and dual conformal in any dimension. These specific ansätze also show the existence of a link between 3- and 4-point functions of a CFT for such class of exact solutions, similarly to what found for planar ladder diagrams. We show that in $d=4$ only the box diagram and its melonic variants, in free field theory, satisfies such conditions, the remaining solutions being nonperturbative. We then turn to the analysis of some approximate high energy fixed angle solutions of the CWI's which also in this case take the form of generalized hypergeometric functions. We show that they describe the behaviour of the 4-point functions at large energy and momentum transfers, with a fixed $-t/s$. The equations, in this case, are solved by linear combinations of Lauricella functions of 3 variables and can be rewritten as generalized 4K integrals. In both cases the CWI's alone are sufficient to identify such solutions and their special connection with generalized hypergeometric systems of equations.

    ↳ hep-thhep-phJHEP(2019)·52 citations
28. 28*

    Classical Lagrangians for the nonminimal Standard-Model Extension at higher orders in Lorentz violation

    M. Schreck🇧🇷

    The current paper is dedicated to determining perturbative expansions for Lagrangians describing classical, relativistic, pointlike particles subject to Lorentz violation parameterized by the nonminimal Standard-Model Extension (SME). An iterative technique recently developed and applied to a Lorentz-violating scalar field theory is now adopted to treat the spin-degenerate SME fermion sector. Lagrangians are obtained at third order in Lorentz violation for the operators ${\hat{a}}_{\mu }$, ${\hat{c}}_{\mu }$, $\hat{e}$, $\hat{f}$, and $\hat{m}$ for arbitrary mass dimension. The results demonstrate the impact of nonzero spin on classical particle propagation. They will be useful for phenomenological studies of modified gravity and could provide useful insights into explicit Lorentz violation in curved spacetimes.

    ↳ hep-thhep-phPLB(2019)·21 citations
29. 29*

    Exploring the influence of bulk viscosity of QCD on dilepton tomography

    Gojko Vujanovic🇺🇸 · Jean-François Paquet🇺🇸 · Chun Shen🇺🇸 · Gabriel S. Denicol🇧🇷 · Sangyong Jeon🇨🇦 · Charles Gale🇨🇦 · Ulrich Heinz🇺🇸

    The collective behavior of hadrons and of electromagnetic radiation in heavy-ion collisions has been widely used to study the properties of the the Quark-Gluon Plasma (QGP). Indeed this collectivity, as measured by anisotropic flow coefficients, can be used to constrain the transport properties of QGP. The goal of this contribution is to investigate the influence of the specific bulk viscosity ($\zeta /s$) on dilepton production, both at Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC) energies. We explore the sensitivity of dileptons to dynamical features that bulk viscosity induces on the evolution of a strongly-interacting medium, and highlight what makes them a valuable probe in the pursuit to also constrain $\zeta /s$.

    ↳ nucl-thhep-phnucl-exPRC(2020)·40 citations
30. 30*

    Machine Learning Solutions for High Energy Physics: Applications to Electromagnetic Shower Generation, Flavor Tagging, and the Search for di-Higgs Production

    Michela Paganini🇺🇸

    This thesis demonstrate the efficacy of designing and developing machine learning (ML) algorithms to selected use cases that encompass many of the outstanding challenges in the field of experimental high energy physics. Although simple implementations of neural networks and boosted decision trees have been used in high energy physics for a long time, the field of ML has quickly evolved by devising more complex, fast and stable implementations of learning algorithms. The complexity and power of state-of-the-art deep learning far exceeds those of the learning algorithms implemented in the CERN-developed \texttt{ROOT} library. All aspects of experimental high energy physics have been and will continue being revolutionized by the software- and hardware-based technological advances spearheaded by both academic and industrial research in other technical disciplines, and the emergent trend of increased interdisciplinarity will soon reframe many scientific domains. This thesis exemplifies this spirit of versatility and multidisciplinarity by bridging the gap between ML and particle physics, and exploring original lines of work to modernize the reconstruction, particle identification, simulation, and analysis workflows. This contribution documents a collection of novel approaches to augment traditional domain-specific methods with modern, automated techniques based on industry-standard, open-source libraries. Specifically, it contributes to setting the state-of-the-art for impact parameter-based flavor tagging and di-Higgs searches in the $\gamma \gamma b\bar{b}$ channel with the ATLAS detector at the LHC, it introduces and lays the foundations for the use of generative adversarial networks for the simulation of particle showers in calorimeters. These results substantiate the notion of ML powering particle physics in the upcoming years and establish baselines for future applications.

    ↳ hep-excs.LGhep-ph3 citations
31. 31*

    The analytic structure of the BFKL equation and reflection identities of harmonic sums at weight five

    Mohammad Joubat🇮🇱 · Alexander Prygarin🇮🇱

    We analyze the structure of the eigenvalue of the color-singlet Balitsky-Fadin-Kuraev-Lipatov~(BFKL) equation in N=4 SYM in terms of the meromorphic functions obtained by the analytic continuation of harmonic sums from positive even integer values of the argument to the complex plane. The meromorphic functions we discuss have pole singularities at negative integers and take finite values at all other points. We derive the reflection identities for harmonic sums at weight five decomposing a product of two harmonic sums with mixed pole structure into a linear combination of terms each having a pole at either negative or non-negative values of the argument. The pole decomposition demonstrates how the product of two simpler harmonic sums can build more complicated harmonic sums at higher weight. We list a minimal irreducible set of bilinear reflection identities at weight five which presents the main result of the paper. We show how the reflection identities can be used to restore the functional form of the next-to-leading eigenvalue of the color-singlet BFKL equation in N=4 SYM , i.e. we argue that it is possible to restore the full functional form on the entire complex plane provided one has information how the function looks like on just two lines on the complex plane. Finally we discuss how non-linear reflection identities can be constructed from our result with the use of well known quasi-shuffle relations for harmonic sums.

    ↳ hep-thhep-phInt.J.Mod.Phys.A(2019)·8 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.