arXiv subjects

B. S. Xie

Publications and source records attributed to B. S. Xie.

22 records · Page 2Linked to original sources

arXiv2016

Pair production in strong SU(2) background fields

The fermion particle pair production in strong SU(2) gauged chromoelectric fields is studied by using Boltzmann-Vlasov equation in a classical way. The existence of pre-production process in a classical description is shown with the distribution evolution of non-Abelian particle production. It is interesting to find that the distribution center of particle number density is on two islands and has a split on color charge sphere as it evolutes and reaches a steady state at last, which is related to the amplitude and the varying of the field.

hep-ph↗

arXiv2015

Effects of electric field polarizations on pair production

The effects of electric field polarizations on pair production from a vacuum are investigated numerically by employing the real-time Dirac-Heisenberg-Wigner formalism. For few-cycle fields, it is found that the interference pattern in momentum spectra is absent and the circular distortion of momentum distribution becomes more apparent with the increase of polarization. For multi-cycle fields, it is found that the interference effects in momentum spectra are obvious. And as the polarization increases, the momentum distribution is split into two parts in the momentum $q_y$ direction first and then two separated parts are connected into a ring. The effects of polarizations on the number density of created particles exhibits two different characteristics. For a small laser frequency, the particle number density deceases with the polarization, while for a large laser frequency, the relation between them is sensitive to the field frequency nonlinearly. Some interpretations for the obtained results in this study, which is expected to be valuable to deepen the understanding of pair production in complex fields and also helpful for the study associated to strong-field ionization.

quant-ph↗

arXiv2015

Nonperturbative signatures in pair production for general elliptic polarization fields

The momentum signatures in nonperturbative multiphoton pair production for general elliptic polarization electric fields are investigated by employing the real-time Dirac-Heisenberg-Wigner formalism. For a linearly polarized electric field we find that the positions of the nodes in momenta spectra of created pairs depend only on the electric field frequency. The polarization of external fields could not only change the node structures or even make the nodes disappear but also change the thresholds of pair production. The momentum signatures associated to the node positions in which the even-number-photon pair creation process is forbid could be used to distinguish the orbital angular momentum of created pairs on the momenta spectra. These distinguishable momentum signatures could be relevant for providing the output information of created particles and also the input information of ultrashort laser pulses.

quant-ph↗

arXiv2014

Mass shift effects in nonperturbative multiphoton pair production for arbitrary polarized electric fields

The mass shift effects in multiphoton pair production of a nonperturbative nature for arbitrary polarized electric fields are investigated numerically by employing the real-time Dirac-Heisenberg-Wigner formalism, and theoretically by proposing an effective energy concept. It is found that the theoretical results are agreement with the numerical ones very well. It is the first time to consider the roles of the momenta of created particles and the polarizations of external fields played in the mass shift effects. These results can deepen the understanding of pair production in the nonperturbative threshold regime. Moreover, the distinct mass shift effects are observable in the forthcoming experiments and can be used as a probe to distinguish the electron-positron pair production from other background events.

hep-ph↗