TY - JOUR
T1 - Fermion production during and after axion inflation
AU - Adshead, Peter
AU - Sfakianakis, Evangelos I.
PY - 2015/11/11
Y1 - 2015/11/11
N2 - We study derivatively coupled fermions in axion-driven inflation, specifically mφ2φ2 and monodromy inflation, and calculate particle production during the inflationary epoch and the post-inflationary axion oscillations. During inflation, the rolling axion acts as an effective chemical potential for helicity which biases the gravitational production of one fermion helicity over the other. This mechanism allows for efficient gravitational production of heavy fermion states that would otherwise be highly suppressed. Following inflation, the axion oscillates and fermions with both helicities are produced as the effective frequency of the fermion field changes non-adiabatically. For certain values of the fermion mass and axion-fermion coupling strength, the two helicity states are produced asymmetrically, resulting in unequal number-densities of left- and right-helicity fermions.
AB - We study derivatively coupled fermions in axion-driven inflation, specifically mφ2φ2 and monodromy inflation, and calculate particle production during the inflationary epoch and the post-inflationary axion oscillations. During inflation, the rolling axion acts as an effective chemical potential for helicity which biases the gravitational production of one fermion helicity over the other. This mechanism allows for efficient gravitational production of heavy fermion states that would otherwise be highly suppressed. Following inflation, the axion oscillates and fermions with both helicities are produced as the effective frequency of the fermion field changes non-adiabatically. For certain values of the fermion mass and axion-fermion coupling strength, the two helicity states are produced asymmetrically, resulting in unequal number-densities of left- and right-helicity fermions.
KW - axions
KW - ination
KW - leptogenesis
UR - http://www.scopus.com/inward/record.url?scp=84948756137&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84948756137&partnerID=8YFLogxK
U2 - 10.1088/1475-7516/2015/11/021
DO - 10.1088/1475-7516/2015/11/021
M3 - Article
AN - SCOPUS:84948756137
SN - 1475-7516
VL - 2015
JO - Journal of Cosmology and Astroparticle Physics
JF - Journal of Cosmology and Astroparticle Physics
IS - 11
M1 - 021
ER -