Magnetic susceptibility of QCD at zero and at finite temperature from the lattice
Date
2012Author
Bali, G. S.Bruckmann, F.
Constantinou, Martha
Costa, Marios Gil
Endrödi, Gergely
Katz, Sándor D.
Panagopoulos, Haralambos G.
Schäfer, A.
ISSN
1550-7998Source
Physical Review D - Particles, Fields, Gravitation and CosmologyVolume
86Issue
9Google Scholar check
Metadata
Show full item recordAbstract
The response of the QCD vacuum to a constant external (electro)magnetic field is studied through the tensor polarization of the chiral condensate and the magnetic susceptibility at zero and at finite temperature. We determine these quantities using lattice configurations generated with the tree-level Symanzik improved gauge action and N f=1+1+1 flavors of stout smeared staggered quarks with physical masses. We carry out the renormalization of the observables under study and perform the continuum limit both at T>0 and at T=0, using different lattice spacings. Finite size effects are studied by using various spatial lattice volumes. The magnetic susceptibilities χ f reveal a spin-diamagnetic behavior we obtain at zero temperature χ u=-(2.08±0.08)GeV -2, χ d=-(2. 02±0.09)GeV -2 and χ s=-(3.4±1.4)GeV -2 for the up, down and strange quarks, respectively, in the MS̄ scheme at a renormalization scale of 2GeV. We also find the polarization to change smoothly with the temperature in the confinement phase and then to drastically reduce around the transition region. © 2012 American Physical Society.