PJC: Giovanna Paola Perdonà "Topological gauge dynamics of Standard Model $\theta$ vacua"

Thursday 30 Apr 2026, 13:00 → 14:30 Europe/Rome

Sala Direzione INFN

It is well known that the topological angle of the electroweak sector of the Standard Model (SM) is unphysical, as it can be removed by an anomalous B+L chiral rotation. Recent claims ( https://arxiv.org/abs/2408.07535 ) suggest that a parametrically light pseudo-scalar degree of freedom -- dubbed the $\eta'_{W}$ -- exists in the spectrum, associated with the anomalous breaking of B+L symmetry. To determine whether such a light degree of freedom exists within the SM, we perform explicit calculations of the topological susceptibility and of the B+L breaking "condensate", along with a detailed analysis and comparison with the Schwinger model and QCD in the large-$N_c$ limit.