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Related papers: Two-loop QED with External Magnetic Field

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We calculate the leading mass-suppressed two-loop contribution, proportional to alpha_s^3/(m_q r^2), to the potential of a heavy quark-antiquark system. This contribution originates in the nonabelian nature of quantum chromodynamics (QCD)…

High Energy Physics - Phenomenology · Physics 2011-07-19 Bernd A. Kniehl , Alexander A. Penin , Vladimir A. Smirnov , Matthias Steinhauser

We have gone through a detailed calculation of the two-point correlation function of vector currents at finite density and magnetic field by employing the real time formalism of finite temperature field theory and Schwinger's proper time…

High Energy Physics - Phenomenology · Physics 2022-08-10 Sarthak Satapathy , Snigdha Ghosh , Sabyasachi Ghosh

The heat kernel expansion for field theory at finite temperature is constructed. It is based on the imaginary time formalism and applies to generic Klein-Gordon operators in flat space-time. Full gauge invariance is manifest at each order…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. Megias , E. Ruiz Arriola , L. L. Salcedo

We compute the pressure of a finite density quark-gluon plasma at zero temperature to leading order in hard-thermal-loop perturbation theory, which includes the fermionic excitations and Landau damping. The result is compared with the…

High Energy Physics - Phenomenology · Physics 2009-10-31 R. Baier , K. Redlich

We give a recurrence relation for two-loop integrals encountered in the effective field theory of an infinitely heavy quark, Q, interacting with gluons and Nl massless quarks, q, from which we obtain exact two-loop results, in any dimension…

High Energy Physics - Phenomenology · Physics 2010-11-01 D. J. Broadhurst , A. G. Grozin

We revisit the calculation of the fermion self-energy in QED in the presence of a magnetic field. We show that, after carrying out the renormalization procedure and identifying the most general perturbative tensor structure for the modified…

High Energy Physics - Phenomenology · Physics 2021-07-14 Alejandro Ayala , Jorge David Castaño-Yepes , M. Loewe , Enrique Muñoz

The parity and time-reversal invariant effective lagrangian for a heavy fermion interacting with an abelian gauge field, i.e., NRQED, is constructed through order $1/M^4$. The implementation of Lorentz invariance in the effective theory…

High Energy Physics - Phenomenology · Physics 2013-04-03 Richard J. Hill , Gabriel Lee , Gil Paz , Mikhail P. Solon

We extend a previous investigation of the QCD phase diagram with heavy quarks in the context of background field methods by including the two-loop corrections to the background field effective potential. The nonperturbative dynamics in the…

High Energy Physics - Phenomenology · Physics 2018-05-02 J. Maelger , U. Reinosa , J. Serreau

We compute the effective action of QED at one loop order for an electric field which points in the $\hat{z}$ direction and depends arbitrarily upon the light cone time coordinate, $x^+ = (x^0 + x^3)/\sqrt{2}$. This calculation generalizes…

High Energy Physics - Theory · Physics 2009-11-07 H. M. Fried , R. P. Woodard

This paper investigates the density expansion of the thermodynamic properties of a two component plasma under the influence of a weak constant uniform magnetic field. We start with the fugacity expansion for the Helmholtz free energy. The…

Plasma Physics · Physics 2009-10-31 M. Steinberg , W. Ebeling , J. Ortner

We explore the low-energy regime of quantum chromodynamics subjected to an external magnetic field by deriving the two-loop representations for the entropy density and the magnetization within chiral perturbation theory (CHPT). At fixed…

High Energy Physics - Phenomenology · Physics 2021-08-04 Christoph P. Hofmann

The off-shell two-loop correction to the massive quark propagator in an arbitrary covariant gauge is calculated and results for the bare and renormalized propagator are presented. The calculations were performed by means of a set of new…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. Fleischer , F. Jegerlehner , O. V. Tarasov , O. L. Veretin

We compute the electrical conductivity of the strongly interacting medium in the presence of strong magnetic background fields, $eB=4,9~GeV^2$, and for different values of the temperature, both in the confined and in the deconfined…

We obtain explicit expressions for thermodynamic quantities of a relativistic degenerate free electron gas in a magnetic field in terms of Hurwitz Zeta functions. The formulation allows for systematic expansion in all regimes. Three energy…

Mathematical Physics · Physics 2009-10-31 Claudio O. Dib , Olivier R. Espinosa

The effect of an external magnetic field in QCD phase diagram, namely, in the the location of the critical end point (CEP) is investigated. Using the 2+1 flavor Nambu--Jona-Lasinio model with Polyakov loop, it is shown that when an external…

High Energy Physics - Phenomenology · Physics 2015-09-04 Márcio Ferreira , Pedro Costa , Constança Providência

A critical set of two-loop QED corrections to the $g$ factor of hydrogenlike ions is calculated without expansion in the nuclear binding field. These corrections are due to the polarization of the external magnetic field by the quantum…

Atomic Physics · Physics 2021-03-17 V. Debierre , B. Sikora , H. Cakir , N. S. Oreshkina , V. A. Yerokhin , C. H. Keitel , Z. Harman

On the basis of a new approach proposed in our previous work we develope a formalism for calculating of the effective action for some models containing fermion fields. This method allows us to calculate the fermionic part of the effective…

High Energy Physics - Theory · Physics 2015-06-26 B. A. Faizullaev , M. M. Musakhanov

We discuss the phase structure and the equation of state for QCD at non-zero temperature and density. Derivatives of $\ln Z$ with respect to quark chemical potential $\mu_q$ up to fourth order are calculated for 2-flavor QCD, enabling…

High Energy Physics - Lattice · Physics 2008-11-26 Shinji Ejiri , Chris R. Allton , Simon J. Hands , Olaf Kaczmarek , Frithjof Karsch , Edwin Laermann , Christian Schmidt

We derive the two-loop QCD helicity amplitudes for the processes $l q \to l qg$ ($l \bar q \to l \bar q g$) and $l g \to l q\bar q$, which are the partonic reactions yielding $(2+1)$-jet final states in deep inelastic lepton nucleon…

High Energy Physics - Phenomenology · Physics 2009-06-25 T. Gehrmann , E. W. N. Glover

The two-flavor quark-meson model is used as a low-energy effective model for QCD to study inhomogeneous chiral condensates at finite quark chemical potential $\mu$ in a constant magnetic background $B$. We determine the parameters of the…

High Energy Physics - Phenomenology · Physics 2017-10-24 Jens O. Andersen , Patrick Kneschke
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