Thu·Dec 24, 2020Thursday·December 24, 2020

1. 01*

   Boosted Top Quarks in the Peak Region with N${}^3$LL Resummation

   Brad Bachu🇺🇸 · André H. Hoang🇦🇹 · Vicent Mateu🇪🇸 · Aditya Pathak🇬🇧 · Iain W. Stewart🇺🇸

   We present results for the 2-jettiness differential distribution for boosted top quark pairs produced in $e^{+}{e}^{-}$ collisions in the peak region accounting for QCD large-logarithm resummation at next-to-next-to-next-to-leading logarithmic (N${}^3$LL) order and fixed-order corrections to matrix elements at next-to-next-to-leading order (NNLO) calculated in the framework of soft-collinear effective theory and boosted heavy quark effective theory. Electroweak and finite-width effects are included at leading order. We study the perturbative convergence of the cross section in the pole and MSR mass schemes, with and without soft gap subtractions. We find that there is a partial cancellation between the pole mass and soft function renormalons. When renormalon subtractions concerning the top mass and the soft function are implemented, the perturbative uncertainties are, however, systematically smaller and an improvement in the stability of the peak position is observed. We find that the top MSR mass may be determined with perturbative uncertainties well below $100$\,MeV from the peak position of the 2-jettiness distribution. This result has important applications for Monte Carlo top quark mass calibrations.

   hep-phPRD(2021)·49 citations
2. 02*

   Evolution of Primordial Neutrino Helicities in Astrophysical Magnetic Fields and Implications for their Detection

   Gordon Baym🇺🇸 · Jen-Chieh Peng🇺🇸

   Since decoupling in the early universe in helicity states, primordial neutrinos propagating in astrophysical magnetic fields precess and undergo helicity changes. In view of the XENON1T experiment possibly finding a large magnetic moment of solar neutrinos, we estimate the helicity flipping for relic neutrinos in both cosmic and galactic magnetic fields. The flipping probability is sensitive both to the neutrino magnetic moment and the structure of the magnetic fields, thus potentially a probe of the fields. As we find, even a magnetic moment well below that suggested by XENON1T could significantly affect relic neutrino helicities and their detection rate via inverse tritium beta decay.

   hep-phastro-ph.COhep-exnucl-thPRL(2021)·15 citations
3. 03*

   Fully heavy pentaquarks

   Hong-Tao An🇨🇳 · Kan Chen🇨🇳 · Zhan-Wei Liu🇨🇳 · Xiang Liu🇨🇳

   Very recently, the LHCb Collaboration reported a fully charmed tetraquark state $X(6900)$ in the invariant mass spectrum of $J/\psi$ pairs. If one $J/\psi$ meson is replaced with a fully charmed baryon, we obtain a fully charmed pentaquark candidate. In this work, we perform a systematic study on the mass spectra of the S-wave fully heavy pentaquark $QQQQ\bar{Q}$ in the framework of the chromomagnetic interaction model. Based on our results in two different schemes, we further investigate the decay behaviors for them. We hope that our study will be helpful in searching for such types of exotic pentaquark states in experiments in the future.

   hep-phhep-exPRD(2021)·45 citations
4. 04*

   Categorization of two-loop Feynman diagrams in the $\mathcal{O}({\alpha }^2)$ correction to $e^{+}{e}^{-}\to ZH$

   Zhao Li🇨🇳 · Yefan Wang🇨🇳 · Quan-feng Wu🇨🇳

   The $e^{+}{e}^{-}\to ZH$ process is the dominant process for the Higgs boson production at the future Higgs factory. In order to match the analysis on the Higgs properties with the highly precise experiment data, it will be crucial to include the theoretical prediction to the full next-to-next-to-leading order electroweak effect in the production rate $\sigma (e^{+}{e}^{-}\to ZH)$. In this inspiring work, we categorize the two-loop Feynman diagrams of the $\mathcal{O}({\alpha }^2)$ correction to $e^{+}{e}^{-}\to ZH$ into 6 categories according to the relevant topological structures. Although 25377 diagrams contribute to the $\mathcal{O}({\alpha }^2)$ correction in total, the number of the most challenging diagrams with seven denominators is 2250, which contain only 312 non-planar diagrams with 155 independent types. This categorization could be a valuable reference for the complete calculation in the future.

   hep-phCPC(2021)·4 citations
5. 05*

   Universality in High Energy Collisions of small and large systems

   P.Castorina🇮🇹 · A.Iorio🇨🇿 · D.Lanteri🇮🇹 · H.Satz🇩🇪 · M.Spousta🇨🇿

   Strangeness enhancement and collective flow are considered signatures of the quark gluon plasma formation. These phenomena have been detected not only in relativistic heavy ion collisions but also in high energy, high multiplicity events of proton-proton and proton-nucleus (small systems) scatterings. A universal behavior emerges by considering the parton density in the transverse plane as the dynamical quantity to specify the initial condition of the collisions, which in electron-positron annihilation at the available energies is too low to expect collective effects.

   hep-phPoS(2021)·2 citations
6. 06*

   Hiding neutrinoless double beta decay in the minimal seesaw mechanism

   Takehiko Asaka🇯🇵 · Hiroyuki Ishida🇯🇵 · Kazuki Tanaka🇯🇵

   We present a possibility that the neutrinoless double beta decay can be hidden in the minimal seesaw mechanism where the standard model is extended by two right-handed neutrinos which have a hierarchical mass structure. In this framework, the lepton number is violated due to the massive Majorana neutrinos. Especially, we investigate the case that the heavier right-handed neutrino is sufficiently heavy to decouple from the decay while the lighter one is lighter enough than the typical Fermi-momentum scale of nuclei and gives a sizable contribution to the decay. Under the specific condition on mixing elements, the lighter right-handed neutrino can give a significant destructive contribution which suppresses or even hides to the effective mass of the neutrinoless double beta decay. In this case, the flavor structure of the mixing element of the lighter right-handed neutrino with ordinary neutrinos is predicted depending on the Majorana CP violating phase of active neutrinos.

   hep-phhep-exPRD(2021)·18 citations
7. 07*

   The Chiral Phase Transitions of Helical Matter

   Shen-Song Wan🇨🇳 · Marco Ruggieri🇨🇳

   We study the thermodynamics of helical matter, namely quark matter in which a net helicity, $n_H$, is in equilibrium. Interactions are modeled by the renormalized quark-meson model with two flavors of quarks. Helical density is described within the grand-canonical ensemble formalism via a chemical potential, ${\mu }_H$. We study the transitions from the normal quark matter and hadron gas to the helical matter, drawing the phase diagram at zero temperature. We study the restoration of chiral symmetry at finite temperature and show that the net helical density softens the transition, moving the critical endpoint to lower temperature and higher baryon chemical potential. Finally, we discuss briefly the effect of a rigid rotation on the helical matter, in particular on the fluctuations of $n_H$, and show that these are enhanced by the rotation.

   hep-phhep-lathep-thnucl-thPRD(2021)·3 citations
8. 08*

   Supernova neutrino fluxes in HALO-1kT, Super-Kamiokande, and JUNO

   A. Gallo Rosso🇨🇦

   When the next galactic core-collapse supernova occurs, we must be ready to obtain as much information as possible. Although many present and future detectors are well equipped to detect ${\overline{\nu }}_{\mathrm{e}}$ and ${\nu }_x$ neutrinos, the detection of the ${\nu }_{\mathrm{e}}$ species presents the biggest challenges. We assess the impact that a 1 ktonne lead-based detector, such as HALO-1kT, can have in constraining electron neutrino time-integrated fluxes. The study involves the detector taken alone as well as when combined with massive ${\overline{\nu }}_{\mathrm{e}}$-sensitive detectors such as Super-Kamiokande and JUNO. We find that HALO-1kT alone is not able to strongly constrain the emission parameters. When combined with other detectors, however, the orthogonal information might be helpful in improving the ${\nu }_{\mathrm{e}}$ total emitted energy and mean energy accuracy, up to about $50\%$, if no other ${\nu }_{\mathrm{e}}$-sensitive channel is implemented. A discussion on the reconstruction of ${\overline{\nu }}_{\mathrm{e}}$ and ${\nu }_x$ species, as well as the total emitted energy, is also presented.

   hep-phJCAP(2021)·10 citations
9. 09*

   SU(3) analysis of fully-light tetraquarks in heavy meson weak decays

   Yu-Ji Shi🇩🇪 · Ye Xing🇨🇳 · Zhen-Xing Zhao🇨🇳

   We perform a SU(3) analysis for both semi-leptonic and non-leptonic heavy meson weak decays into a pseudoscalar meson and a fully-light tetraquark in 10 or 27 representation. A reduction of the SU(3) representation tensor for the fully-light tetraquarks is produced and all the flavor components for each representation tensor are listed. The decay channels we analysis include $B/D\to U/TPl\nu$, $B/D\to U/TP$ and $B_c\to U/TP/D$, with $U/T$ represents a fully-light tetraquark in 10 or 27 representation and $P$ is a pseudoscalar meson. Finally, among these results we list all the golden decay channels which are expected to have more possibilities to be observed in experiments.

   hep-phhep-exEPJC(2021)·9 citations
10. 10*

    Electroweak effective theory and beyond Standard Model resonances

    Juan Jose Sanz-Cillero🇪🇸 · Antonio Pich🇪🇸 · Ignasi Rosell🇪🇸

    We consider a non-linear realization of the electroweak symmetry-breaking pattern $SU(2{)}_L\times SU(2{)}_R/SU(2{)}_{L+R}$ to construct a low-energy effective theory, later extended by the inclusion of heavy new-physics resonances. After assuming appropriate high-energy constraints given by Weinberg sum-rules and the asymptotic behaviour of form-factors, we obtain relations between resonance masses and some low-energy effective couplings. These predictions are compared with current experimental data and some resonance mass bounds are inferred.

    hep-phNucl.Part.Phys.Proc.(2021)·3 citations
11. 11*

    Inclusive and exclusive neutrino-nucleus cross sections and the reconstruction of the interaction kinematics

    Bruno Bourguille🇪🇸 · Juan Nieves🇪🇸 · Federico Sanchez🇨🇭

    We present a full kinematic analysis of neutrino-nucleus charged current quasielastic interactions based on the Local Fermi Gas model and the Random PhaseApproximation. The model was implemented in the NEUT Monte Carlo framework, which allows us to investigate potentially measurable observables, including hadron distributions. We compare the predictions simultaneously to the most recent T2K and MINERvA charged current (CC) inclusive, CC0$\pi$ and transverse kinematic-imbalance variable results. We pursuit a microscopic interpretation of the relevant reaction mechanisms, with the aim of achieving in neutrino oscillation experiments a correct reconstruction of the incoming neutrino kinematics, free of conceptual biasses. Such study is of the utmost importance for the ambitious experimental program which is underway to precisely determine neutrino properties, test the three-generation paradigm, establish the order of mass eigenstates and investigate leptonic CP violation.

    hep-phnucl-thJHEP(2021)·28 citations
12. 12*

    Loops and polarization in strong-field QED

    Greger Torgrimsson🇩🇪

    In a previous paper we showed how higher-order strong-field-QED processes in long laser pulses can be approximated by multiplying sequences of "strong-field Mueller matrices". We obtained expressions that are valid for arbitrary field shape and polarization. In this paper we derive practical approximations of these Mueller matrices in the locally-constant- and the locally-monochromatic-field regimes. We allow for arbitrary laser polarization as well as arbitrarily polarized initial and final particles. The spin and polarization can also change due to loop contributions (the mass operator for electrons and the polarization operator for photons). We derive Mueller matrices for these as well.

    hep-phhep-thNew J.Phys.(2021)·51 citations
13. 13*

    Properties of Ultralight Bosons from Spins of Heavy Quasars via Superradiance

    Caner Unal🇨🇿 · Fabio Pacucci🇺🇸 · Abraham Loeb🇺🇸

    The mass and the spin of accreting and jetted black holes, at the center of Active Galactic Nuclei (AGNs), can be probed by analyzing their electromagnetic spectra. For this purpose, we use the Spin-Modified Fundamental Plane of black hole activity, which non-linearly connects the following four variables (in the source frame): radio luminosity, X-ray or optical luminosity (via the [OIII] emission line), black hole mass and spin. Taking into account the uncertainties in luminosity measurements, conversion factors, relativistic beaming and physical properties of the AGN system, we derive lower bounds on the spins of a group of heavy, jetted AGNs. Using these results, we study the direct implications on the mass spectrum of the ultra-light particles of scalar (axion-like), vector (dark photon) and tensor types (additional spin-2 particles). We close unexplored gap in the parameter space $10^{-20}-10^{-19}$eV. We obtain upper bounds on the axion decay constant (equivalently lower bounds on the self-interaction strength) considering self-interactions could prevent the axion particles entering the instability, and be the reason for non-observation of superradiance. Assuming axion/scalar is described by mass and decay constant, we obtain upper limits on what fraction of dark matter can be formed by ultra-light particles and find that single spieces axion-like light particle can constitute at most $10\%$ of the dark matter in the mass range: $10^{-21}<\mu (\mathrm{eV})<10^{-17}$. Moreover, we derive similar bounds for vector and spin-2 particles and find that light vector fields can constitute at most $10^{-6}$ of the dark matter in $10^{-21}\mathrm{eV}<\mu <10^{-17}\mathrm{eV}$ range, and light spin-2 fields can constitute at most $10^{-9}$ of the dark matter in $10^{-23}\mathrm{eV}<\mu <10^{-17}\mathrm{eV}$ range.

    hep-phastro-ph.COastro-ph.HEgr-qc+1JCAP(2021)·96 citations
14. 14*

    Dark Matter and Nature of Electroweak Phase Transition with an Inert Doublet

    Sven Fabian🇩🇪 · Florian Goertz🇩🇪 · Yun Jiang🇨🇳

    We provide a comprehensive and up-to-date analysis of the prospects to realize Dark Matter (DM) in the Inert Doublet Model, while simultaneously enhancing the Electroweak Phase Transition (EWPhT) such as to allow for electroweak baryogenesis. Instead of focusing on certain aspects or mass hierarchies, we perform extensive, yet fine-grained, parameter space scans, where we analyze the nature of the EWPhT in both the light and the heavy DM regions, confronting it with the amount of DM potentially residing in the lightest inert-doublet state. Thereby, we point out a viable region where a non-trivial two-step EWPhT can appear, without being in conflict with direct-detection bounds, which could leave interesting imprints in gravitational wave signatures. We propose new benchmarks with this feature as well as update benchmarks with a strong first-order transition in the light of new XENON1T limits. Moreover, taking into account these latest bounds as well as relevant collider constraints, we envisage a new region for light DM with a small mass splitting, lifting the usual assumption of exact degeneracy of the new non-DM scalars, such as to avoid collider bounds while providing a fair DM abundance over a rather large DM mass range. This follows from a detailed survey of the impact of co-annihilations on the abundance, dissecting the various channels.

    hep-phhep-exJCAP(2021)·36 citations
15. 15*

    Lunar neutrinos

    S. Demidov🇷🇺 · D. Gorbunov🇷🇺

    Cosmic rays bombard the lunar surface producing mesons, which attenuate inside the regolith. They get slower and decay weakly into mostly sub-GeV neutrinos leaving the surface. Thus the Moon shines in neutrinos. Here we calculate spectra of low energy neutrinos, which exhibit bright features potentially recognisable above isotropic neutrino background in the direction towards the Moon. Their observation, though a very challenging task for future neutrino large volume experiments, would make the Moon the nearest astrophysical source for which the concept of multimessenger astronomy works truly. Remarkably, some features of the lunar neutrino flux are sensitive to the surface mass density of the Moon.

    hep-phastro-ph.HEPRD(2021)·5 citations
16. 16*

    The Future of High-Energy Astrophysical Neutrino Flavor Measurements

    Ningqiang Song🇨🇦 · Shirley Weishi Li🇺🇸 · Carlos A. Argüelles🇺🇸 · Mauricio Bustamante🇩🇰 · Aaron C. Vincent🇨🇦

    We critically examine the ability of future neutrino telescopes, including Baikal-GVD, KM3NeT, P-ONE, TAMBO, and IceCube-Gen2, to determine the flavor composition of high-energy astrophysical neutrinos, ie, the relative number of ${\nu }_e$, ${\nu }_{\mu }$, and ${\nu }_{\tau }$, in light of improving measurements of the neutrino mixing parameters. Starting in 2020, we show how measurements by JUNO, DUNE, and Hyper-Kamiokande will affect our ability to determine the regions of flavor composition at Earth that are allowed by neutrino oscillations under different assumptions of the flavor composition that is emitted by the astrophysical sources. From 2020 to 2040, the error on inferring the flavor composition at the source will improve from $>40\%$ to less than $6\%$. By 2040, under the assumption that pion decay is the principal production mechanism of high-energy astrophysical neutrinos, a sub-dominant mechanism could be constrained to contribute less than 20\% of the flux at 99.7\% credibility. These conclusions are robust in the nonstandard scenario where neutrino mixing is non-unitary, a scenario that is the target of next-generation experiments, in particular the IceCube-Upgrade. Finally, to illustrate the improvement in using flavor composition to test beyond-the-Standard-Model physics, we examine the possibility of neutrino decay and find that, by 2040, combined neutrino telescope measurements will be able to limit the decay rate of the heavier neutrinos to below $1.8\times 10^{-5}(m/\mathrm{eV})$~s${}^{-1}$, at 95\% credibility.

    hep-phastro-ph.HEJCAP(2021)·116 citations
17. 17*

    Quark cluster expansion model for interpreting finite-T lattice QCD thermodynamics

    D. Blaschke🇵🇱 · Kirill A. Devyatyarov🇷🇺 · Olaf Kaczmarek🇩🇪

    We present a unified approach to the thermodynamics of hadron-quark-gluon matter at finite temperatures on the basis of a quark cluster expansion in the form of a generalized Beth-Uhlenbeck approach with a generic ansatz for the hadronic phase shifts that fulfills the Levinson theorem. The change in the composition of the system from a hadron resonance gas to a quark-gluon plasma takes place in the narrow temperature interval of $150-185$ MeV where the Mott dissociation of hadrons is triggered by the dropping quark mass as a result of the restoration of chiral symmetry. The deconfinement of quark and gluon degrees of freedom is regulated by the Polyakov loop variable that signals the breaking of the $Z(3)$ center symmetry of the color $SU(3)$ group of QCD. We suggest a Polyakov-loop quark-gluon plasma model with $\mathcal{O}({\alpha }_s)$ virial correction and solve the stationarity condition of the thermodynamic potential (gap equation) for the Polyakov loop. The resulting pressure is in excellent agreement with lattice QCD simulations up to high temperatures.

    hep-phnucl-thSymmetry(2021)·2 citations
18. 18*

    Second order chiral kinetic theory under gravity and antiparallel charge-energy flow

    Tomoya Hayata🇯🇵 · Yoshimasa Hidaka🇯🇵 · Kazuya Mameda🇯🇵

    We derive the chiral kinetic theory under the presence of a gravitational Riemann curvature. It is well-known that in the chiral kinetic theory there inevitably appears a redundant ambiguous vector corresponding to the choice of the Lorentz frame. We reveal that on top of this conventional frame choosing vector, higher-order quantum correction to the chiral kinetic theory brings an additional degrees of freedom to specify the distribution function. Based on this framework, we derive new types of fermionic transport, that is, the charge current and energy-momentum tensor induced by the gravitational Riemann curvature. Such novel phenomena arise not only under genuine gravity but also in a (pseudo-)relativistic fluid, for which inhomogeneous vorticity or temperature are effectively represented by spacetime metric tensor. It is especially found that the charge and energy currents are antiparallelly induced by an inhomogeneous fluid vorticity (more generally, by the Ricci tensor ${R_0}^i$), as a consequence of the spin-curvature coupling. We also briefly discuss possible applications to Weyl/Dirac semimetals and heavy-ion collision experiments.

    ↳ hep-thcond-mat.mes-hallgr-qchep-phJHEP(2021)·25 citations
19. 19*

    The fate of nonlinear perturbations near the QCD critical point

    Golam Sarwar🇮🇳 · Md Hasanujjaman🇮🇳 · Mahfuzur Rahaman🇮🇳 · Abhijit Bhattacharyya🇮🇳 · Jan-e Alam🇮🇳

    The impact of the QCD critical point on the propagation of nonlinear waves has been studied. The effects have been investigated within the scope of second-order causal dissipative hydrodynamics by incorporating the critical point into the equation of state, and the scaling behaviour of transport coefficients and of thermodynamic response functions. Near the critical point, the nonlinear waves are found to be significantly damped which may result in the disappearance of the Mach cone effects of the away side jet. Such damping may lead to enhancement in the fluctuations of elliptic and higher flow coefficients. Therefore, the disappearance of Mach cone effects and the enhancement of fluctuations in flow harmonics in the event-by-event analysis may be considered as signals of the critical endpoint.

    ↳ nucl-thhep-phnucl-exPLB(2021)·6 citations
20. 20*

    Exact Solutions to Non-Linear Symmetron Theory II: One and Two Mirror Systems

    Mario Pitschmann🇦🇹

    We derive the exact analytical solutions to the symmetron field theory equations in the presence of a one or two mirror system in the case of a spontaneously broken phase in vacuum as well as in matter. This complements a similar analysis performed in a previous article [1], in which the symmetron is in the spontaneously broken phase in vacuum but in the symmetric phase in matter. Here again, the one dimensional equations of motion are integrated exactly for both systems and their solutions are expressed in terms of Jacobi elliptic functions. In the case of two parallel mirrors the equations of motion provide also in this case a discrete set of solutions with increasing number of nodes and energies. The solutions obtained herein can be applied to qBOUNCE experiments, neutron interferometry and to the calculation of the symmetron field induced "Casimir force" in the Cannex experiment and allow to extend the investigation to hitherto unavailable regions in symmetron parameter space.

    ↳ gr-qchep-phPRD(2021)·23 citations
21. 21*

    Lattice gauge equivariant convolutional neural networks

    Matteo Favoni🇦🇹 · Andreas Ipp🇦🇹 · David I. Müller🇦🇹 · Daniel Schuh🇦🇹

    We propose Lattice gauge equivariant Convolutional Neural Networks (L-CNNs) for generic machine learning applications on lattice gauge theoretical problems. At the heart of this network structure is a novel convolutional layer that preserves gauge equivariance while forming arbitrarily shaped Wilson loops in successive bilinear layers. Together with topological information, for example from Polyakov loops, such a network can in principle approximate any gauge covariant function on the lattice. We demonstrate that L-CNNs can learn and generalize gauge invariant quantities that traditional convolutional neural networks are incapable of finding.

    ↳ hep-latcs.LGhep-phhep-th+1PRL(2022)·112 citations
22. 22*

    Decoherence from General Relativity

    Itamar J. Allali🇺🇸 · Mark P. Hertzberg🇺🇸

    It is of great interest to explore matter in nontrivial quantum arrangements, including Schrodinger cat-like states. Such states are sensitive to decoherence from their environment. Recently, in Ref. [1] we computed the rate of decoherence of a piece of superposed matter that primarily only interacts gravitationally, a dark-matter-Schrodinger-cat-state (DMSCS), within the nonrelativistic approximation. In this work we improve this to a general relativistic analysis. We firstly derive a single particle relativistic Schrodinger equation for a probe particle that passes through the DMSCS; the interaction is provided by the weak field metric of general relativity from the source. For a static DMSCS we find a neat generalization of our previous results. We then turn to the interesting new case of a time dependent DMSCS, which can be provided by a coherently oscillating axion field leading to superposed time dependent oscillations in the metric; a truly quantum-general relativistic phenomenon. We use scattering theory to derive the decoherence rate in all these cases. When the DMSCS is in a superposition of distinct density profiles, we find that the decoherence rate can be appreciable. We then consider the novel special case in which the density is not in a superposition, but the phase of its field oscillation is; this is a property that cannot be decohered within the nonrelativistic framework. We find that if the probe particle and/or the DMSCS's velocity dispersion is slow, then the rate of decoherence of the phase is exponentially suppressed. However, if both the probe and the DMSCS's velocity dispersion are relativistic, then the phase can decohere more rapidly. As applications, we find that diffuse galactic axions with superposed phases are robust against decoherence, while dense boson stars and regions near black hole horizons are not, and we discuss implications for experiment.

    ↳ gr-qcastro-ph.COhep-phhep-th+1PRD(2021)·20 citations
23. 23*

    The Theory of Resummed Quantum Gravity: Phenomenological Implications

    B.F.L. Ward (1) ((1) Baylor University, Waco, TX, USA)🇺🇸

    We present an overview of the phenomenological implications of the theory of resummed quantum gravity. We discuss its prediction for the cosmological constant in the context of the Planck scale cosmology of Bonanno and Reuter, its relationship to Weinberg's asymptotic safety idea, and its relationship to Weinberg's soft graviton resummation theorem. We also discuss constraints and consistency checks of the theory.

    ↳ hep-thgr-qchep-phPoS(2021)·0 citations
24. 24*

    Dispersion of Light Traveling through the Interstellar Space, Induced and Intrinsic Lorentz Invariance Violation

    Iver Brevik🇳🇴 · Masud Chaichian🇫🇮 · Markku Oksanen🇫🇮

    Theoretical models and experimental observations suggest that gamma-ray bursts (GRB) and high-energy neutrino bursts travelling through the interstellar space may reach the Earth at different speeds. We propose and study in details the mechanism i), which always exists, where GRB are slowed down due to the dispersion of light in the interstellar medium. In addition to the standard media such as electrons and photons as CMB, we consider the medium with invisible axions. The amount of GRB delays in different media are calculated in details utilizing a novel technique in QFT by using the hitherto known or estimated densities of particles in the space without introducing any arbitrary parameter. Previously, the GRB delays have been interpreted as a sign of Lorentz invariance violation by modifying the dispersion relation of Special Relativity, which relates the energy, the momentum and the mass of a particle, based on different mechanisms ii), such as a stringy spacetime foam, coming from a quantum gravity effect and using an adjustable parameter. Obviously, all the above-mentioned mechanisms i) and ii) are induced (seeming) Lorentz invariance violations but not an intrinsic (genuine) one. The amount of GRB delay due to the two aforementioned interpretations can be distinguished by observing the time of arrival of light with different frequencies. Namely, dispersion of light i) predicts that the higher energy GRB arrive the Earth earlier, while in the other interpretations ii), they arrive later. We notice that the needed amount for delay due to the dispersion of light shall have the potential power to shed additional light on the microstructure of interstellar media with respect to the densities of constituent particles and the origins of their sources. Finally, we indicate the ways to detect the intrinsic Lorentz invariance violation and to interpret them theoretically.

    ↳ astro-ph.HEhep-phhep-thEPJC(2021)·17 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.