arXiv subjects

She-Sheng Xue

Publications and source records attributed to She-Sheng Xue.

At least 37 records · Page 2Linked to original sources

arXiv2022

Relativistic Effects and GRB Polarization in Power-Law Evolution

Despite decades of polarization observations and high-significance polarized $γ$-ray, X-ray, optical, and radio emissions in gamma-ray bursts (GRBs) have been accumulating in dozens of cases, people have yet to find a consistent scenario for understanding the globally observed timing properties of GRB polarization to date. Here, we report that the observed properties of GRB polarization exhibit a four-segment timing evolution at the cosmological distance: (I) an initial hump early on (within the first few seconds); (II) a later on power-law decay (from $\sim$10$^{1}$ to $\sim$10$^{4}$ s), which takes the form of $π_{\rm obs} \propto t^{-0.50 \pm 0.02}$; (III) afterwards a late-time rebrightening hump (from $\sim$10$^{4}$ to $\sim$10$^{5}$ s); and (IV) finally a flatting power-law decay (from $\sim$ 10$^{5}$ to $\sim$ 10$^{7}$ s), with the the form of $π_{\rm obs} \propto t^{-0.21 \pm 0.08}$. These findings may present a challenge to the mainstream of polarization models that assume the polarization time evolution change in different emission regions. We show that these results can be explained by relativistic and geometric effects of a highly relativistic and magnetized jet generated by the central engine, and "magnetic patches" distributed as a globally random but locally coherent form. Our analysis suggests that there is a single dominant mechanism that might account for the global observational properties of GRB polarization, and other emission mechanisms and effects might play a role in spatially local and temporally short effects on GRB polarization.

astro-ph.HE↗

arXiv2022

Spontaneous Peccei-Quinn symmetry breaking renders sterile neutrino, axion and $χ$boson to be candidates for dark matter particles

We study the Peccei-Quinn (PQ) symmetry of the sterile right-handed neutrino sector and the gauge symmetries of the Standard Model. Due to four-fermion interactions, spontaneous breaking of these symmetries at the electroweak scale generates top-quark Dirac mass and sterile-neutrino Majorana mass. The top quark channel yields massive Higgs, $W^\pm$ and $Z^0$ bosons. The sterile neutrino channel yields the heaviest sterile neutrino Majorana mass, sterile Nambu-Goldstone axion (or majoron) and massive scalar $χ$boson. Four-fermion operators effectively induce their tiny couplings to SM particles. We show that a sterile QCD axion is the PQ solution to the strong CP problem. The lightest and heaviest sterile neutrinos ($m_N^e\sim 10^2$ keV and $m_N^τ\sim 10^2$ GeV), a sterile QCD axion ($m_a< 10^{-8}$ eV, $g_{aγ}< 10^{-13} {\rm GeV}^{-1}$) and a Higgs-like $χ$boson ($m_χ\sim 10^2$ GeV) can be dark matter particle candidates, for the constraints of their tiny couplings and long lifetimes inferred from the $W$-boson decay width, Xenon1T and precision fine-structure-constant experiments. The axion and $χ$boson couplings to SM particles are below the values reached by current laboratory experiments and astrophysical observations for directly or indirectly detecting dark matter particles.

hep-ph↗

arXiv2022

Massive particle pair production and oscillation in Friedman Universe: dark energy and matter interaction

The classical Friedman equations of time-varying Hubble function $H$, dark-energy and matter densities couple to quantised field equations for massive modes $M\gg H$. Numerically solving these equations, we show the particle-antiparticle pairs production and oscillation in microscopic time scale ${\mathcal O}(M^{-1})$. A massive pair plasma state is formed in macroscopic time scale ${\mathcal O}(H^{-1})$. Its density and pressure introduce the interaction of matter and dark energy densities in the Friedman equations. Focusing on epochs after reheating, we show that the negative dark energy tracks down the radiation energy in the radiation epoch. Such tracking dynamics ends, and dark energy becomes positive in the matter epoch. The matter converts to dark energy, and their present values are comparable, explaining the cosmic coincidence. As a result, a class of effective interacting dark energy models is advocated to confront cosmological observations.

gr-qc↗

arXiv2021

Gravo-thermal catastrophe in gravitational collapse and energy progenitor of Gamma-Ray Bursts

We study the homologous collapse of stellar nuclear core, the virial theorem for hadron collisional relaxations, and photon productions from hadron collisions. We thus show the gravo-thermal dynamical process that transforms gravitational energy to photon energy. The process is energetically and entropically favourable. The total baryon number conservation, Euler equation for energy-momentum conservation and Poisson's equation for gravitational potential are adopted to describe homologous core collapses. The virial theorem determines the hadron collision energy gain from gravitational potential. The hadronic photon production rate determines the photon energy density. The time scales of macroscopic and microscopic processes are studied to verify approximations. As a result, we show the formation of opaque photon-pair spheres, whose total energy, size, temperature and number density, accounting for the main energetic features of Gamma-Ray Burst progenitors. We obtain the intrinsic correlations of these quantities. They depend only on the averaged thermal index of the stellar core. We discuss the possibility to confront them with observational data.

astro-ph.HE↗

arXiv2021

Relieving the $H_0$ tension with a new interacting dark energy model

We investigate an extended cosmological model motivated by the asymptotic safety of gravitational field theory, in which the matter and radiation densities and the cosmological constant receive a correction parametrized by the parameters $δ_G$ and $δ_Λ$, leading to that both the evolutions of the matter and radiation densities and the cosmological constant slightly deviate from the standard forms. Here we explain this model as a scenario of vacuum energy interacting with matter and radiation. We consider two cases of the model: {(i) ${\tildeΛ}$CDM with one additional free parameter $δ_G$, with $δ_{\rm G}$ and $δ_Λ$ related by a low-redshift limit relation and (ii) e${\tildeΛ}$CDM with two additional free parameters $δ_G$ and $δ_Λ$ that are independent of each other.} We use two data combinations, CMB+BAO+SN (CBS) and CMB+BAO+SN+$H_0$ (CBSH), to constrain the models. We find that, in the case of using the CBS data, neither ${\tildeΛ}$CDM nor e${\tildeΛ}$CDM can effectively alleviate the $H_0$ tension. However, it is found that using the CBSH data the $H_0$ tension can be greatly relieved by the models. In particular, in the case of e${\tildeΛ}$CDM, the $H_0$ tension can be resolved to 0.71$σ$. We conclude that as an interacting dark energy model, ${\tildeΛ}$CDM is much better than $Λ(t)$CDM in the sense of both relieving the $H_0$ tension and fitting to the current observational data.

astro-ph.CO↗

arXiv2021

Cosmological $Λ$ driven inflation and produced massive particles

Suppose that the early Universe starts with a quantum spacetime originated cosmological $Λ$-term at the Planck scale $M_{\rm pl}$. The cosmological energy density $ρ_{_{_Λ}}$ drives inflation and simultaneously reduces its value to create the matter-energy density $ρ_{_{_M}}$ via the continuous pair productions of massive fermions and antifermions. The decreasing $ρ_{_{_Λ}}$ and increasing $ρ_{_{_M}}$, in turn, slows down the inflation to its end when the pair production rate $Γ_M$ is larger than the Hubble rate $H$. The density $ρ_{_{_Λ}}$ and Hubble rate $H$ are uniquely determined by two independent equations from the Einstein equation and energy conservation law, besides the $ρ_{_{_M}}$ is determined by pair productions. As a result, inflation naturally appears and theoretical results agree with Planck 2018 observations. Suppose that the reheating efficiently converts $ρ_{_{_Λ}}$ to $ρ_{_{_M}}\gg ρ_{_{_Λ}}$ accounting for the most relevant Universe mass, and some massive pairs decay to relativistic particles of energy density $ρ_{_{_R}}$ starting the hot Big Bang. The back reaction $ρ_{_{_M}}\leftrightarrow H\leftrightarrow ρ_{_{_Λ}}$ is weak but continues. As a consequence, $ρ_{_Λ}$ closely tracks down $ρ_{_R}$ from the reheating end up to the radiation-matter equilibrium, then it varies very slowly, $ρ_{_Λ}\propto$ constant, due to the transition from radiation dominant epoch to matter dominant epoch. Therefore the cosmic coincidence problem can be possibly avoided.

gr-qc↗

arXiv2020

Shedding New Light on Sterile Neutrinos from XENON1T Experiment

The XENON1T collaboration recently reported the excess of events from recoil electrons, possibly giving an insight into new area beyond the Standard Model (SM) of particle physics. We try to explain this excess by considering effective interactions between the sterile neutrinos and the SM particles. In this paper, we present an effective model based on one-particle-irreducible interaction vertices at low energies that are induced from the SM gauge symmetric four-fermion operators at high energies. The effective interaction strength is constrained by the SM precision measurements, astrophysical and cosmological observations. We introduce a novel effective electromagnetic interaction between sterile neutrinos and SM neutrinos, which can successfully explain the XENON1T event rate through inelastic scattering of the sterile neutrino dark matter from Xenon electrons. We find that sterile neutrinos with masses around $90$ keV and specific effective coupling can fit well with the XENON1T data where the best fit points preserving DM constraints and possibly describe the anomalies in other experiments.

hep-ph↗

arXiv2020

Supercritically charged objects and electron-positron pair creation

We investigate the stability and $e^+e^-$ pair creation of supercritically charged superheavy nuclei, $ud$QM nuggets, strangelets, and strangeon nuggets based on Thomas-Fermi approximation. The model parameters are fixed by reproducing their masses and charge properties reported in earlier publications. It is found that $ud$QM nuggets, strangelets, and strangeon nuggets may be more stable than ${}^{56}$Fe at $A\gtrsim 315$, $5\times10^4$, and $1.2\times10^8$, respectively. For those stable against neutron emission, the most massive superheavy element has a baryon number $\sim$965, while $ud$QM nuggets, strangelets, and strangeon nuggets need to have baryon numbers larger than $39$, 433, and $2.7\times10^5$. The $e^+e^-$ pair creation will inevitably start for superheavy nuclei with charge numbers $Z\geq177$, $ud$QM nuggets with $Z\geq163$, strangelets with $Z\geq 192$, and strangeon nuggets with $Z\geq 212$. A universal relation $Q/R_e = \left(m_e - \barμ_e\right)/α$ is obtained at a given electron chemical potential $\barμ_e$, where $Q$ is the total charge and $R_e$ the radius of electron cloud. This predicts the maximum charge number by taking $\barμ_e=-m_e$. For supercritically charged objects with $\barμ_e<-m_e$, the decay rate for $e^+e^-$ pair production is estimated based on the JWKB approximation. It is found that most positrons are emitted at $t\lesssim 10^{-15}$ s, while a long lasting positron emission is observed for large objects with $R\gtrsim 1000$ fm. The emission and annihilation of positrons from supercritically charged objects may be partially responsible for the short $γ$-ray burst during the merger of binary compact stars, the 511 keV continuum emission, as well as the narrow faint emission lines in X-ray spectra from galaxies and galaxy clusters.

nucl-th↗

arXiv2020

Cosmological constant, matter, cosmic inflation and coincidence

We present a possible understanding to the issues of cosmological constant, inflation, matter and coincidence problems based only on the Einstein equation and Hawking particle production. The inflation appears and results agree to observations. The CMB large-scale anomaly can be explained and the dark-matter acoustic wave is speculated. The entropy and reheating are discussed. The cosmological term $Ω_{_Λ}$ tracks down the matter $Ω_{_M}$ until the radiation-matter equilibrium, then slowly varies, thus the cosmic coincidence problem can be avoided. The relation between $Ω_{_Λ}$ and $Ω_{_M}$ is shown and can be examined at large redshifts.

physics.gen-ph↗

arXiv2020

Phenomenology at the LHC of composite particles from strongly interacting Standard Model fermions via four-fermion operators of NJL type

A new physics scenario shows that four-fermion operators of Nambu-Jona-Lasinio (NJL) type have a strong-coupling UV fixed point, where composite fermions $F$ (bosons $Π$) form as bound states of three (two) SM elementary fermions and they couple to their constituents via effective contact interactions at the composite scale $Λ\approx {\cal O} $(TeV). We present a phenomenological study to investigate such composite particles at the LHC by computing the production cross sections and decay widths of composite fermions in the context of the relevant experiments at the LHC with $pp$ collisions at $\sqrt{s}={\rm 13}$ TeV and $\sqrt{s}={\rm 14}$ TeV. Systematically examining all the different composite particles $F$ and the signatures with which they can manifest, we found a vast spectrum of composite particles $F$ that has not yet been explored at the LHC. Recasting the recent CMS results of the resonant channel $pp\rightarrow e^+F \rightarrow e^+e^- q\bar{q}'$, we find that the composite fermion mass $m_F$ below 4.25 TeV is excluded for $Λ$/$m_F$ = 1. We further highlight the region of parameter space where this specific composite particle $F$ can appear using 3 ab$^{-1}$, expected by the High-Luminosity LHC, computing 3 and 5 $σ$ contour plots of its statistical significance.

hep-ph↗

arXiv2020

Light by Light Scattering as a New Probe for Axions

We study the impact of virtual axions on the polarization of photons inside a cavity during the interaction of high-power laser pulses. A novel detection scheme for measuring the axion-induced ellipticity signal during the Light-by-Light (LBL) scattering process is investigated. We show that a momentum exchange between photons in a probe laser beam and a high-intensity target beam may lead to a resonance at the physical mass of the axion. Consequently, the resonant enhancement of vacuum birefringence gives rise to a large ellipticity signal. This signal enhancement can be applied in order to discriminate between the axion contribution to LBL scattering and the standard model contribution due to electron-positron pairs. The sensitivity of the scheme is studied for experimentally feasible probe light sources and ultrahigh intensity laser backgrounds. It is shown that this technique has the potential to probe the QCD axion in the mass range $10^{-2} \textrm{eV} \lesssim m_{a} \lesssim 1 \textrm{eV}$. In this region the axion induced signal surpasses the standard model background.

hep-ph↗

arXiv2019

Effect of Schwinger pair production on the evolution of the Hubble constant in de~Sitter spacetime

In this proceeding we consider a massive charged scalar field in a uniform electric field background in a de~Sitter spacetime (dS). We compute the in-vacuum expectation value of the trace of the energy-momentum tensor for the created Schwinger pairs, and using adiabatic subtraction scheme the trace is regularized. The effect of the Schwinger pair creation on the evolution of the Hubble constant is investigated. We find that the production of the semiclassical pairs leads to a decay of the Hubble constant. Whereas, the production of a light scalar field in the weak electric field regime leads to a superacceleration phenomenon.

hep-th↗

arXiv2019

Distinguishing Dirac from Majorana neutrinos in a microwave cavity

We propose a novel scheme for distinguishing between the Dirac and Majorana nature of neutrinos via interaction of a neutrino beam with microwave photons inside a cavity. We study the effective photon-photon polarization exchange induced by the photon-neutrino scattering. The quantum field theoretical studies of such effective picture are presented for both Dirac and Majorana neutrinos. Our phenomenological analyses show that the difference between Dirac and Majorana neutrinos can manifest itself in scattering rate of the photons. To enhance the effect a cavity scheme is employed. An experimental setup based on microwave cavities is then designed and simulated by finite element method to measure the scattering rate. Our results suggest that an experiment based on the current state-of-the-art technology will be able to probe the difference in about one year. However, it can be done in a few days by enhancing the neutrino beam flux or implementing with the near future equipments. Therefore, our work provides the possibility %puts the grounds for solving the long lasting puzzle of Dirac or Majorana nature of neutrinos.

hep-ph↗

arXiv2019

Probing Lorentz violation effects via a laser beam interacting with a high-energy charged lepton beam

In this work, the conversion of linear polarization of a laser beam to circular one through its forward scattering by a TeV order charged lepton beam in the presence of Lorentz violation correction is explored. We calculate the ratio of circular polarization to linear one (Faraday Conversion phase $Δϕ_{\rm{FC}}$) of the laser beam interacting with either electron or the muon beam in the framework of the quantum Boltzmann equation. Regarding the experimentally available sensitivity to the Faraday conversion $Δϕ_{\rm{FC}}\simeq 10^{-3}-10^{-2}$, we show that the scattering of a linearly polarized laser beam with energy $k_0\sim 0.1$ eV and an electron/muon beam with flux $\barε_{e,μ}\sim 10^{10}/10^{12}$ TeV cm$^{-2}$ s$^{-1}$ places an upper bound on the combination of lepton sector Lorentz violation coefficients $c_{μν}$ components $(c_{TT}+1.4~c_{(TZ)}+0.25(c_{XX}+c_{YY}+2~c_{ZZ}))$. The obtained bound on the combination for the electron beam is at the $4.35\times 10^{-15}$ level and for the muon beam at the $3.9\times 10^{-13}$ level. It should be mentioned that the laser and charged lepton beams considered here to reach the experimentally measurable $Δϕ_{\rm{FC}}$ are currently available or will be accessible in the near future. This study provides a valuable supplementary to other theoretical and experimental frameworks for measuring and constraining Lorentz violation coefficients.

hep-ph↗

arXiv2019

A model of interacting dark fluids tested with supernovae and Baryon Acoustic Oscillations data

We compare supernovae and Baryon Acoustic Oscillations data to the predictions of a cosmological model of interacting dark matter and dark energy. This theoretical model can be derived from the effective field theory of Einstein-Cartan gravity with two scaling exponents $δ_G$ and $δ_Λ$, related to the interaction between dark matter and dark energy. We perform a $χ^2$ fit to the data to compare and contrast it with the standard $Λ$CDM model. We then explore the range of parameter of the model which gives a better $χ^2$ than the standard cosmological model. All those results lead to tight constraints on the scaling exponents of the model. Our conclusion is that this class of models, provides a decent alternative to the $Λ$CDM model.

astro-ph.CO↗

arXiv2018

Composite Fermions and their Pair States in a Strongly-Coupled Fermi Liquid

Our goal is to understand the phenomena arising in optical lattice fermions at low temperature in an external magnetic field. Varying the field, the attraction between any two fermions can be made arbitrarily strong, where composite bosons form via so-called Feshbach resonances. By setting up strong-coupling equations for fermions, we find that in spatial dimension $d>2$ they couple to bosons which dress up fermions and lead to new massive composite fermions. At low enough temperature, we obtain the critical temperature at which composite bosons undergo the Bose-Einstein condensate (BEC), leading to BEC-dressing massive fermions. These form tightly bound pair states which are new bosonic quasi-particles producing a BEC-type condensate. A quantum critical point is found and the formation of condensates of complex quasi-particles is speculated over.

cond-mat.quant-gas↗

arXiv2018

Physical renormalization condition for de Sitter QED

We considered a new renormalization condition for the vacuum expectation values of the scalar and spinor currents induced by a homogeneous and constant electric field background in de Sitter spacetime. Following a semiclassical argument, the condition named maximal subtraction imposes the exponential suppression on the massive charged particle limit of the renormalized currents. The maximal subtraction changes the behaviors of the induced currents previously obtained by the conventional minimal subtraction scheme. The maximal subtraction is favored for a couple of physically decent predictions including the identical asymptotic behavior of the scalar and spinor currents, the removal of the infrared (IR) hyperconductivity from the scalar current, and the finite current for the massless fermion.

gr-qc↗

arXiv2017

Charged cosmological black hole

The cosmological black holes are black holes living not in an asymptotically flat universe but in an expanding spacetime. They have a rich dynamics in particular for their mass and horizon. In this article we perform a natural step in investigating this new type of black hole: we consider the possibility of a \textit{charged} cosmological black hole. We derive the general equations of motion governing its dynamics and report a new analytic solution for the special case of the charged Lemaître-Tolman-Bondi equations of motion that describe a charged cosmological black hole. We then study various relevant quantities for the characterization of the black hole such as the C-function, the effect of the charge on the black hole flux and the nature of the singularity. We also perform numerical investigations to strengthen our results. Finally we challenge a model of gamma ray burst within our framework.

gr-qc↗