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V. Braguta

Publications and source records attributed to V. Braguta.

4 recordsLinked to original sources

On the angular momentum and free energy of rotating gluon plasma

We study the free energy and the angular momentum of rotating hot gluon matter using first-principle numerical simulations of the $\textrm{SU}(3)$ lattice Yang-Mills theory. We calculate the specific moment of inertia and the specific deformation of the gluon matter as, respectively, the leading and next-to-leading terms in a series in angular velocity over a broad range of temperatures and various spatial boundary conditions. We show that the specific deformation, similarly to the moment of inertia, takes negative values in a phenomenologically interesting region of temperatures above the phase transition and turns positive at higher temperatures.

hep-lat

Temperature dependence of the axial magnetic effect in two-color quenched QCD

The Axial Magnetic Effect is the generation of an equilibrium dissipationless energy flow of chiral fermions in the direction of the axial (chiral) magnetic field. At finite temperature the dissipationless energy transfer may be realized in the absence of any chemical potentials. We numerically study the temperature behavior of the Axial Magnetic Effect in quenched SU(2) lattice gauge theory. We show that in the confinement (hadron) phase the effect is absent. In the deconfinement transition region the conductivity quickly increases, reaching the asymptotic $T^2$ behavior in a deep deconfinement (plasma) phase. Apart from an overall proportionality factor, our results qualitatively agree with theoretical predictions for the behavior of the energy flow as a function of temperature and strength of the axial magnetic field.

hep-lat

Numerical evidence of the axial magnetic effect

The axial magnetic field, which couples to left- and right-handed fermions with opposite signs, may generate an equilibrium dissipationless energy flow of fermions in the direction of the field even in the presence of interactions. We report on numerical observation of this Axial Magnetic Effect in quenched SU(2) lattice gauge theory. We find that in the deconfinement (plasma) phase the energy flow grows linearly with the increase of the strength of the axial magnetic field. In the confinement (hadron) phase the Axial Magnetic Effect is absent. Our study indirectly confirms the existence of the Chiral Vortical Effect since both these effects have the same physical origin related to the presence of the gravitational anomaly.

hep-lat

Future e^+ e^- Colliders Sensitivity to H b b-bar Coupling and CP Violation

We perform a complete simulation of the process e^+ e^- --> b b-bar nu nu-bar, where nu can be an electron, muon or tau neutrino, in the context of a general Higgs coupling to b quarks. We parametrize the H b b-bar coupling as m_b/v (a + i gamma_5 b). Taking into account interference effects between pure Higgs and Standard Model contributions, we find that sensitivities of the order of 2% and 20% can be obtained at a future e^+ e^- collider for deviations of the $a$ and $b$ parameters respectively from their Standard Model values. Combining our analysis with an independent measurement of Gamma_{H --> b b-bar} can provide evidence about the CP nature of the Higgs sector.

hep-ph