24-30 July 2016
Highfield Campus, University of Southampton
Europe/London timezone

Axion Phenomenology from Unquenched Lattice QCD

29 Jul 2016, 14:00
20m
Building 32 Room 1015 (Highfield Campus, University of Southampton)

Building 32 Room 1015

Highfield Campus, University of Southampton

Talk Nonzero Temperature and Density Nonzero Temperature and Density

Speaker

Prof. Guido Martinelli (Universita' di Roma "La Sapienza" and Cern)

Description

We investigate the topological properties of $N_f = 2 + 1$ QCD with physical quark masses, both at zero and finite temperature. At zero temperature both finite size and finite cut-off effects have been studied by comparing the continuum extrapolated results for the topological susceptibility $\chi$ with the predictions from chiral perturbation theory. At finite temperature, we explore a region going from $T_c$ up to around $4T_c$, where continuum extrapolated results for the topological susceptibility and for the fourth moment of the topological charge distribution are obtained. While the fourth moment converges to the dilute instanton gas prediction the topological susceptibility differs strongly both in the size and in the temperature dependence. This results in a shift of the axion dark matter window of almost one order of magnitude with respect to the instanton computation.

Primary author

Prof. Guido Martinelli (Universita' di Roma "La Sapienza" and Cern)

Co-authors

Dr Claudio Bonati (Università di Pisa) Mr Francesco Sanfilippo (University of Southampton) Prof. Giovanni Villadoro (ICTP) Massimo D'Elia (University of Pisa and INFN) Mr Michele Mesiti (University of Pisa and INFN - Sezione di Pisa)

Presentation Materials