Inverse magnetic catalysis and regularization in the quark-meson model

Understand

Motivated by recent work on inverse magnetic catalysis at finite temperature, we study the quark-meson model using both dimensional regularization and a sharp cutoff.

• We calculate the critical temperature for the chiral transition as a function of the Yukawa coupling in the mean-field approximation varying the renormalization scale and the value of the ultraviolet cutoff.
• We show that the results depend sensitively on how one treats the fermionic vacuum fluctuations in the model and in particular on the regulator used.
• Finally, we explore a $B$-dependent transition temperature for the Polyakov loop potential $T_0(B)$ using the functional renormalization group.