Lattice QCD Input to Axion Cosmology

by Dr Evan Berkowitz (Lawrence Livermore National Laboratory)

Monday 27 Jul 2015, 12:00 → 13:00 Asia/Tokyo

Room 433 in Main Research Building (RIKEN Wako)

Date: Jul 27 (Mon) Time: 12:00 - Place: Main Research bldg. 433 Speaker: Evan Berkowitz (Lawrence Livermore National Laboratory) Title: Lattice QCD Input to Axion Cosmology Abstract: The Strong CP Problem can be resolved by introducing an additional global symmetry known as Peccei-Quinn symmetry.  Once PQ symmetry is broken the pNGB, the axion, is a plausible dark matter candidate.  Calculating the cosmological energy density of the axion requires knowledge of the high-temperature topological susceptibility of QCD.  I will discuss a pure Yang--Mills calculation of this quantity and use it as input to the cosmological equations of motion to derive a lower bound on the axion mass. This work is based on http://arxiv.org/abs/1505.07455 which will soon appear in PRD. See more QHP seminars