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Your search keyword '"Maleknejad, Azadeh"' showing total 2 results
Start Over Author "Maleknejad, Azadeh" Topic nonabelian groups
2 results on '"Maleknejad, Azadeh"'

1. Chiral gravity waves and leptogenesis in inflationary models with non-Abelian gauge fields.

Author

Maleknejad, Azadeh

Subjects
*GRAVITY waves, *NONABELIAN groups, *PARTICLE physics, *BARYONS, *ELECTRONS, *COSMIC background radiation
Abstract

We present a leptogenesis scenario associated with inflationary models involving non-Abelian gauge fields within the standard model (SM) of particle physics. We show that this class of inflationary models generates intrinsic birefringent gravitational waves that following Alexander, Peskin, and Sheikh-Jabbari [Phys. Rev. Lett. 96, 081301 (2006)], through the gravitational chiral anomaly in the SM, can naturally create a net lepton number density. The CP-violating interaction is produced by tensor fluctuations of the gauge field, while the efficiency of this process is determined by the effective background value of the gauge field. We demonstrate that this mechanism can create the observed value of baryon to photon number density in a natural range of parameters of these models. [ABSTRACT FROM AUTHOR]

Published
2014
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2. Leptogenesis in inflationary models with non-Abelian gauge fields.

Author

Maleknejad, Azadeh, Noorbala, Mahdiyar, and Sheikh-Jabbari, M. M.

Subjects
*PHYSICAL cosmology, *LEPTONS (Nuclear physics), *NONABELIAN groups, *GAUGE field theory, *GRAVITATION
Abstract

A scenario of leptogenesis was introduced in Alexander et al. (Phys Rev Lett 96:081301, 2006) which works during inflationary period within standard model of particle physics setup. In this scenario lepton number is created by the gravitational chiral anomaly which has a non-zero expectation value for models of inflation driven by pseudoscalar field(s). Here, we observe that models of inflation involving non-Abelian gauge fields, e.g. the chromo-natural inflation (Adshead and Wyman in Phys Rev Lett 108:261302, 2012) or the gauge-flation (Maleknejad and Sheikh-Jabbari in Phys Lett B 723:224, 2013. arXiv:1102.1513 [hep-ph]), have a parity-violating tensor mode (graviton) spectrum and naturally lead to a non-vanishing expectation value for the gravitational chiral anomaly. Therefore, one has a natural leptogenesis scenario associated with these inflationary setups, inflato-natural leptogenesis. We argue that the observed value of baryon-to-photon number density can be explained in a natural range of parameters in these models. [ABSTRACT FROM AUTHOR]

Published
2018
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