  The effects of high-temperature, dense systems, and strong magnetic fields on
Quantum Chromodynamics related phenomena are studied in different perspectives:
in the high-temperature and densities, the QCD-phase diagram from the Linear
Sigma Model point of view is computed. In particular, the CEP location and
transition lines for chiral restoration were found. In the intense magnetic
fields and high-gluon density, the gluon fusion and gluon splitting channels
are proposed as new photon production sources to better explain the
experimental data in the so-called "photon puzzle". Finally, the thermal and
magnetic screening properties for gluons encoded into the polarization tensor
were addressed in terms of the Debye mass.
