Wednesday weekly meeting

Wednesday 8 Jan 2025, 11:00 → 12:00 Asia/Tehran

Gholamhossein Haghighat (IPM)

General weekly meeting of the school of particles and accelerators (hybrid format)

• Meeting Place: Seminar Room, School of Particles and Accelerators, IPM
• Link to join virtually: https://www.skyroom.online/ch/ipm-particles/weekly-seminar

1 A novel global charge conservation in the symmetric phase of the early universe

In the Standard Model at high temperatures, anomalous effects contribute to the violation of baryon number ($B$) and lepton number ($L$), separately, while $B-L$ remains conserved. There are also corresponding changes in the helicity of the hypermagnetic field ($h$) and the Chern-Simons numbers of the non-Abelian gauge fields ($N_{\rm CS,W}$ and $N_{\rm CS,S}$). In this study, we investigate a baryogenesis process in the symmetric phase of the early Universe by taking into account the Abelian and non-Abelian anomalous effects as well as the perturbative chirality-flip processes of all fermions. We calculate explicitly the time evolution of all relevant physical quantities, including those of $h$ and $N_{\rm CS,W}$, and show that there is another conserved global charge involving total matter-antimatter asymmetry $B+L$, hypermagnetic helicity $h_B$ and $N_{\rm CS,W}$.

Speaker: Dr Saeed Abbaslu (School of Physics, Institute for Research in Fundamental Sciences (IPM))