# **Nuclear Physics Colloquium **

Location: FIAS,
Ruth-Moufang-Straße 1, Lecture Hall 100, Time:
Thursday, May 16,
2013, 11:15am-12:15pm (plus
10min for discussion)

Contact: hees@fias.uni-frankfurt.de

# Chiral Transition and Deconfinement in Magnetic QCD

## Eduardo Fraga (Universidade Federal do Rio de Janeiro)

We review the influence of a magnetic background on the phase
diagram of strong interactions and how the chiral and deconfining
transitions can be affected. After some motivation, we summarize
results for both transitions obtained in the framework of the linear
sigma model coupled to quarks and to the Polyakov loop, and how they
compare to other effective model approaches and to lattice QCD. Then
we discuss the outcome of the magnetic MIT bag model that yields a
behavior for the critical deconfining temperature which is
compatible with recent lattice results and magnetic catalysis. The
qualitative success of the magnetic MIT bag model hints to $T_{c}$
being a confinement-driven quantity, and leads us to the discussion
of its behavior as predicted within the 't Hooft limit of QCD, which
is also in line with the most recent lattice QCD results provided
that quarks behave paramagnetically. Finally, we present the first
results of a perturbative calculation of the pressure in the limit
of very high magnetic fields with a surprising behavior in the
chiral limit.

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