Formula omitted]-Pair synchrotron emission in neutron-star matter based on a relativistic quantum approach

Tomoyuki Maruyama,A Baha Balantekin,Myung-Ki Cheoun,Toshitaka Kajino,Grant J Mathews

doi:10.1016/j.physletb.2020.135413

Abstract

We study the νν¯-pair synchrotron emission from electrons and protons in a relativistic quantum approach. This process occurs only in the presence of a strong magnetic field, and it is considered to be one of effective processes for neutron star cooling. In this work we calculate the luminosity of the νν¯-pairs emitted from neutron-star-matter with a magnetic field of about 1015 G. We find that the energy loss is much larger than that of the modified Urca process. The νν¯-pair emission processes in strong magnetic fields is expected to contribute significantly to the cooling of the magnetars.

Highlights

We study the νν-pair synchrotron emission from electrons and protons in a relativistic quantum approach
Neutron stars are cooled by neutrino emission, and a magnetic field is expected to affect the emission mechanism largely because a strong magnetic field can supply energy and momentum into the process
Pairs can be emitted by synchrotron radiation in a strong magnetic field [6, 7, 8, 9] and by bremsstrahlung through two particle collisions [10, 11]

Summary

Preprint submitted to Elsevier

Neutrino antineutrino (νν)-pair emission is an important cooling processes in the surface region of NSs. It was concluded that this process is insignificant van Dalen et al [9] calculated the νν-pair emission in a strong magnetic field of B ≥ 1016 G In such strong magnetic fields and low temperatures, T ≤ 1 MeV, energy intervals between two states with different Landau numbers are much larger than the temperature. [14] we calculated the axion production in the same way, and found that the transition between two states with different Landau numbers gives significant contributions even if the temperature is low, T ≤ 1 keV, when the strength of the magnetic field is large, B = 1015 G In this case the energy interval between the two states is much larger than the temperature. We apply our quantum theoretical approach to νν-pair synchrotron production in strong magnetic fields and calculate this through the transition between different Landau levels for electrons and protons. When T ≪ E∗F, the strength is concentrated in the narrow energy region between

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