Семинар «Теория квантового поля»

Дата и время: четверг, 26 мая 2022 г., в 11:30

Место: аудитория им. Д. И. Блохинцева (4-й этаж), Лаборатория теоретической физики им. Н.Н. Боголюбова; онлайн-конференция в Zoom

Тема семинара: «The effective potential of gluodynamics in the background of Polyakov loop and colormagnetic field»

Докладчик: Михаэль Бордаг (Лейпцигский университет, Германия)

Аннотация:

In SU(N) gluodynamics, the effective potential has minima at non-zero A0-background fields (Polyakov loop) in the two-loop approximation. Also, it has a minimum at non-zero chromomagnetic background field, known as ‘Savvidy’-vacuum.
We investigate the effective potential when both background fields, A0 and B, are present. The aim is to find a common minimum, in the (A0-B)-plane. In literature, there are statements that the imaginary part, present in the ‘Savvidy’-vacuum, is in fact absent when accounting for higher loops like ring diagrams. We find in the (A0-B) plane an unphysical behavior of the effective potential and conclude that a more thorough treatment of the higher loops is necessary.
The talk is based on EPJC 81:998 (2021) and EPJC 82:390 (2022).