8998 1806.09632 10.1007/JHEP09(2018)070 70 70 Universal magnetoresponse in QCD and N=4 $$ \mathcal{N}=4 $$ SYM Regular Article - Theoretical Physics 1 19 2018 9 13 2018 7 22 2018 8 22 2018 9 13 The Author(s) 2018 Gergely Endrődi endrodi@th.physik.uni-frankfurt.de Matthias Kaminski mski@ua.edu Andreas Schäfer andreas.schaefer@physik.uni-regensburg.de Jackson Wu jmwu@ua.edu Laurence Yaffe yaffe@phys.washington.edu 0000 0004 1936 9721 grid.7839.5 Institute for Theoretical Physics Goethe Universität Frankfurt D-60438 Frankfurt am Main Germany 0000 0001 0727 7545 grid.411015.0 Department of Physics and Astronomy University of Alabama Tuscaloosa AL 35487 U.S.A. 0000 0001 2190 5763 grid.7727.5 Institut für Theoretische Physik Universität Regensburg 93040 Regensburg Germany 0000000122986657 grid.34477.33 Department of Physics University of Washington Seattle WA 98195-1560 U.S.A. Abstract Using recent lattice data on the thermodynamics of QCD in the presence of a background magnetic field, we show that the ratio of transverse to longitudinal pressure exhibits, to good accuracy, a simple scaling behavior over a wide range of temperature and magnetic field, essentially depending only on the ratio T/B $$ T/\sqrt{B} $$. We compare this QCD response to the corresponding magnetoresponse in maximally supersymmetric Yang Mills theory. Given suitable calibrations defining the comparison, we find excellent agreement. This may be viewed as a further test of the applicability of holographic models for hot QCD. Keywords Conformal Field Theory Gauge-gravity correspondence Lattice QCD Quark-Gluon Plasma ArXiv ePrint: 1806.09632