arXiv subjects

T. F. Feng

Publications and source records attributed to T. F. Feng.

6 recordsLinked to original sources

arXiv2026

Effects of nucleon-nucleon short-range correlation and symmetry energy on the evolution of newly born magnetars

Millisecond magnetars are widely suggested as the central engines powering hydrogen-poor superluminous supernovae (SLSNe). These magnetars primarily lose huge rotational energy through gravitational wave radiation (GWR) and magnetic dipole radiation (MDR), with MDR serving as an energy source for SLSNe. We study the evolution of the magnetar spin, magnetic inclination angle, and the resulting thermal radiative luminosity of the SLSNe, where the impacts of the nucleon-nucleon short-range correlation, the mass and initial spin of the magnetar, and the density-dependent symmetry energy of the dense nuclear matter on the evolution are discussed. The relativistic mean-field theory is employed to calculate the nuclear matter properties, and we particularly concentrate on the time- and space-dependent bulk viscosity which is crucial for the magnetic inclination angle evolution. It is found that the nucleon-nucleon short-range correlation weakens the damping of bulk viscosity of dense matter and therefore inhibits the growth of magnetic inclination angle, and it reduces the MDR (GWR) peak luminosity of a canonical magnetar by several times while it raises the peak thermal radiation luminosity of SLSNe by several times. For magnetars with nonrotating mass obviously lower than the $ 1.4 M_\odot$ with slow initial rotation, the magnetic inclination angle is more likely to evolve towards 0 degrees quickly, and these magnetars are not suitable as the central engine for SLSNe. Within the "family" of FSUGarnet interaction, a stiffer symmetry energy gives a lower threshold of direct Urca process and hence gives a much larger bulk viscosity coefficient, and thus it promotes the growth of the magnetic inclination angle and the GWR for canonical stars but reduces the peak brightness of SLSNe significantly.

astro-ph.HE↗

arXiv2003

The anomalous lepton magnetic moment, LFV decays and the fourth generation

We investigate the lepton flavor violation (LFV) decays, $τ\to lγ$ ($l=μ, e$) and $μ\to eγ$, and the newly observed muon $g-2$ anomaly in the framwork of a squential fourth generation model with a heavy fourth neutrino, $ν'$. By using the recent experimental bounds, we take the constraints of the $4\times 4$ leptonic mixing matrix element factors, $|V_{1ν'} V_{2ν'}|^2$, $|V_{1ν'} V_{3ν'}|^2 $ and $|V_{3ν'} V_{2ν'}|^2$. We find that LFV decays and $g_μ-2$ can exclude most of the parameter space of the 4th generation neutrino mass $m_{ν'}$ and give stringent constraints on the existence of the fourth generation.

hep-ph↗

arXiv2002

Lepton flavor violation two-body decays of quarkoniums

In this paper we firstly study various model-independent bounds on lepton flavor violation (LFV) in processes of $J/Ψ$, $Ψ'$ and $Υ$ two-body decays, then calculate their branch ratios % By using the constraints from other ways, we obtain %the indirect bounds of ${\rm Br} (J/Ψ,Ψ',Υ\to ll')$ in models of the leptoquark, $R$ violating MSSM and topcolor assisted technicolor(TC2) models.

hep-ph↗

arXiv2002

Anomalous magnetic and electric moments of $τ$ and lepton flavor mixing matrix in effective lagrangian approach

In an effective lagrangian approach [EM97] to new physics, the authors in ref. [HL99] pushed tau anomalous magnetic and electric dipole moments (AMDM and EDM) down to $10^{-11}$ and $10^{-25} e cm$ by using a Fritzsch-Xing lepton mass matrix ansatz. In this note, we find that, in this approach, there exists the connection between $τ$ AMDM and EDM and the lepton flavor mixing matrix. By using the current neutrino oscillation experimental results, we investigate the parameter space of lepton mixing angles to $τ$ AMDM and EDM. We can obtain the same or smaller bounds of $δa_τ$ and $d_τ$ acquired in ref. [HL99] and constrain $θ_l$ (the mixing angle obtained by long-baseline neutrino oscillation experiments) from $τ$ AMDM and EDM.

hep-ph↗

arXiv2002

Constraints of the fourth generation from $g_μ-2$

We investigate the newly observed muon $g_μ-2$ anomaly in the framework of a sequential fourth generation model with a heavy fourth neutrino, $ν'$. We find that $g_μ-2$ can exclude most values of $m_{ν'}$ and put a very stringent constraint on the existence of the fourth generation. We also obtain bounds of a $4\times 4$ leptonic mixing matrix elements, $V_{2ν'}$ if it really exists.

hep-ph↗

arXiv1998

Bilinear R-parity Violation and $τ^{\mp} \tildeκ^{\pm}$ mixing production in e^+ e^- colliders

A R-parity breaking SUSY model characterized by an effective bilinear violation with only $τ$-lepton number breaking in the superpotential is outlined. The CP-odd Higgs boson masses and those of charged Higgs bosons are discussed. In the model, several interesting mass mixings else such as the mixing between $τ$ lepton and charginos etc in the model are discussed too. Being one of example, we have computed the mixing production $e^{+} e^{-} \to τ^{\mp} \tildeκ^{\pm}_{i} (i=1,2)$ in e^+ e^- colliders, where $τ^{\mp}, \tildeκ^{\pm}_{i}(i=1,2)$ denote the physical $τ$ lepton and charginos.

hep-ph↗