Magnetic field instability in a neutron star driven by the electroweak electron-nucleon interaction versus the chiral magnetic effect
| Autor: | Maxim Dvornikov, Victor B. Semikoz |
|---|---|
| Přispěvatelé: | Томский государственный университет Физический факультет Научные подразделения ФФ |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics Nuclear and High Energy Physics нейтронные звезды нуклоны Electroweak interaction FOS: Physical sciences Electron Magnetic field High Energy Physics - Phenomenology symbols.namesake Neutron star High Energy Physics - Phenomenology (hep-ph) Magnetic helicity Dirac equation Quantum electrodynamics магнитные поля symbols Neutron Astrophysics - High Energy Astrophysical Phenomena Nucleon электроны |
| Zdroj: | Physical Review D. 2015. Vol. 91, № 6. P. 061301-1-061301-6 |
| Popis: | We show that the Standard Model electroweak interaction of ultrarelativistic electrons with nucleons ($eN$ interaction) in a neutron star (NS) permeated by a seed large-scale helical magnetic field provides its growth up to $\gtrsim 10^{15}\thinspace\text{G}$ during a time comparable with the ages of young magnetars $\sim 10^4\thinspace\text{yr}$. The magnetic field instability originates from the parity violation in the $eN$ interaction entering the generalized Dirac equation for right and left massless electrons in an external uniform magnetic field. We calculate the averaged electric current given by the solution of the modified Dirac equation containing an extra current for right and left electrons (positrons), which turns out to be directed along the magnetic field. Such current includes both a changing chiral imbalance of electrons and the $eN$ potential given by a constant neutron density in NS. Then we derive the system of the kinetic equations for the chiral imbalance and the magnetic helicity which accounts for the $eN$ interaction. By solving this system, we show that a sizable chiral imbalance arising in a neutron protostar due to the Urca-process $e^-_\mathrm{L} + p\to N + \nu_\mathrm{eL}$ diminishes very rapidly because of a huge chirality flip rate. Thus the $eN$ term prevails the chiral effect providing a huge growth of the magnetic helicity and the helical magnetic field. Comment: 6 pages in Revtex4.1, two columns, 2 eps figures; text was slightly extended, multiple misprints were corrected, some references were added; version published in Phys.Rev.D as a Rapid Communication |
| Databáze: | OpenAIRE |
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