5–9 Dec 2016
Nordita, Stockholm
Europe/Stockholm timezone

Effective Lagrangian for pseudo-scalar mesons and axion

6 Dec 2016, 12:30
30m
FB53 (AlbaNova)

FB53

AlbaNova

Speaker

Paolo Di Vecchia (Nordita)

Description

We extend the effective Lagrangian for pseudo-scalar mesons that includes the effect of the axial anomaly, gives a satisfactory spectrum of pseudo-scalar mesons and allows one to compute the $\theta$ dependence of hadronic processes, to include the axion. We use it to show that the $\theta$ dependence disappears and we compute various properties of the axion. In particular, we show that the mass of the axion is given, in the chiral limit, by the Weinberg-Wilczek formula in terms of the quark masses with the addition of a term containing the topological susceptibility of Yang-Mills theory. This additional factor is irrelevant at zero temperature but could become important at finite temperature.

Primary author

Paolo Di Vecchia (Nordita)

Presentation materials