Screening mass of gluons in presence of external Abelian chromomagnetic field
Seminars
Seminar on Theory of hadronic matter under extreme conditions
Date and Time: Wednesday, 5 December 2018, at 4:00 PM
Venue: Blokhintsev Hall (4th floor), Bogoliubov Laboratory of Theoretical Physics
Seminar topic: “Screening mass of gluons in presence of external Abelian chromomagnetic field”
Speaker: Natalia Kolomoyets (Dnepropetrovsk National University, Ukraine)
Abstract:
Screening mass is the main macroscopic characteristic of a gauge field at finite temperature. It shows how fast the gauge field decreases in space. There are electric and magnetic screening masses. It is known that in SU(N) gauge theory the former one is proportional to gT, while the second one is proportional to g^2T. So, at high temperature, the magnetic mass is much less than electric one, and is harder to investigate. In the current research the contribution of various colour components of the chromomagnetic field into the magnetic mass is investigated by methods of lattice gluodynamics at finite temperature. The interaction between a monopole-antimonopole string and external neutral Abelian chromomagnetic field is considered. The string is introduced in the standard way described by Srednicki and Susskind. The neutral Abelian field is introduced in the form of a flux through the twisted boundary conditions. Monte Carlo simulations are performed on 4D lattices. The derivative of the free energy with respect to the inverse coupling is the measured quantity. In SU(2) case in the absence of the external Abelian flux, the result by DeGrand and Toussaint is reproduced. We have obtained that the flux addition weakens the screening of the string field. The contribution of the neutral Abelian flux to the measured quantity has the enhancing factor form. This behaviour independently confirms the long-range nature of the neutral Abelian field reported in the literature. In SU(3) case even without the additional Abelian flux the absence of screening of the monopole-antimonopole string has been obtained. This result is unexpected and is discussed within the context of the results of other investigations.