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Related papers: RG/Pade Estimate of the Three-Loop Contribution to…

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We present the three-loop calculations of the nonrelativistic QCD (NRQCD) current renormalization constants and corresponding anomalous dimensions, and the matching coefficients for the spatial-temporal tensor and spatial-spatial…

High Energy Physics - Phenomenology · Physics 2023-10-19 Wei Tao , Zhen-Jun Xiao

We derive a general formula for the RG improved effective (Coleman-Weinberg) potential for classically conformal models, applying it to several examples of physical interest, and in particular a model of QCD coupled via quarks to a…

High Energy Physics - Theory · Physics 2010-01-15 Krzysztof A. Meissner , Hermann Nicolai

We compute the matching coefficient between the quantum chromodynamics (QCD) and the non-relativistic QCD ( NRQCD) for the flavor-changing scalar current involving the heavy charm and bottom quark, up to the three-loop order within the…

High Energy Physics - Phenomenology · Physics 2023-05-03 Wei Tao , Ruilin Zhu , Zhen-Jun Xiao

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

In the framework of analytic approach to QCD, which has been recently intensively developed, the dependence of nonperturbative contributions in a running coupling of strong interaction on initial perturbative approximation to 3-loop order…

High Energy Physics - Phenomenology · Physics 2007-05-23 Aleksey I. Alekseev

We calculate numerically the renormalization group (RG) flow of lattice QCD in two-coupling space, $(\beta_{1\times 1},\beta_{1\times 2})$. This is the first explicit calculation of the RG flow of SU(3) gauge theory. From the RG flow,a…

High Energy Physics - Lattice · Physics 2007-05-23 TARO Collaboration , Ph. de Forcrand et al

We calculate the third coefficient of the lattice beta function in QCD with Wilson fermions, extending the pure gauge results of Luescher and Weisz; we show how this coefficient modifies the scaling function on the lattice. We also…

High Energy Physics - Lattice · Physics 2009-10-30 B. Alles , C. Christou , A. Feo , H. Panagopoulos , E. Vicari

We studied the correlated quasi-one-dimensional systems by one-loop renormalization group techniques in weak coupling. In contrast to conventional g-ology approach, we formulate the theory in terms of bilinear currents and obtain all…

Strongly Correlated Electrons · Physics 2009-11-11 Ming-Shyang Chang , Wei Chen , Hsiu-Hau Lin

We present a functional renormalization group (fRG) study of the two dimensional Hubbard model, performed with an algorithmic implementation which lifts some of the common approximations made in fRG calculations. In particular, in our fRG…

Strongly Correlated Electrons · Physics 2019-10-23 Agnese Tagliavini , Cornelia Hille , Fabian B. Kugler , Sabine Andergassen , Alessandro Toschi , Carsten Honerkamp

We present the first analytic results of N$^3$LO QCD corrections to the top-quark decay width. We focus on the dominant leading color contribution, which includes light-quark loops. At NNLO, this dominant contribution accounts for 95% of…

High Energy Physics - Phenomenology · Physics 2024-04-26 Long-Bin Chen , Hai Tao Li , Zhao Li , Jian Wang , Yefan Wang , Quan-feng Wu

The paper is devoted to application of recently devised ghost-free Analytic Perturbation Theory (APT) for analysis of some QCD observables. We start with the discussion of the main problem of the perturbative QCD -- ghost singularities and…

High Energy Physics - Phenomenology · Physics 2011-09-13 D. V. Shirkov

We investigate the RG-time integration of the effective potential in the functional renormalization group in the presence of spontaneous symmetry breaking and its subsequent convexity restoration on the example of a scalar theory in $d=3$.…

High Energy Physics - Theory · Physics 2023-06-21 Friederike Ihssen , Franz R. Sattler , Nicolas Wink

I compute the two-loop effective potential in the Landau gauge for a general renormalizable field theory in four dimensions. Results are presented for the \bar{MS} renormalization scheme based on dimensional regularization, and for the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Stephen P. Martin

As a step towards deriving universal amplitude ratios of the superconductive phase transition we calculate the vacuum energy density in the symmetric phase of O(N)-symmetric scalar QED in D=4-epsilon dimensions in an epsilon-expansion using…

Statistical Mechanics · Physics 2007-05-23 Boris Kastening , Hagen Kleinert , Bruno Van den Bossche

We include the full second-order corrections to the static QCD potential in the analysis of the ttbar threshold cross section. There is an unexpectedly large difference between the QCD potential improved by the renormalization-group…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Jezabek , J. H. Kuhn , M. Peter , Y. Sumino , T. Teubner

We compute the suppression of bottomonium in the quark-gluon plasma using the three-loop QCD static potential. The potential describes the spin-averaged bottomonium spectrum below threshold with a less than 1% error. Within potential…

High Energy Physics - Phenomenology · Physics 2024-03-26 Nora Brambilla , Tom Magorsch , Michael Strickland , Antonio Vairo , Peter Vander Griend

A field-theoretic description of the critical behaviour of systems with quenched defects obeying a power law correlations $\sim |{\bf x}|^{-a}$ for large separations ${\bf x}$ is given. Directly for three-dimensional systems and different…

Disordered Systems and Neural Networks · Physics 2009-10-31 V. V. Prudnikov , A. A. Fedorenko

We compute the running QCD coupling on the lattice by evaluating two-point and three-point off-shell gluon Green's functions in a fixed gauge and imposing non-perturbative renormalisation conditions on them. Our exploratory study is…

High Energy Physics - Lattice · Physics 2009-03-09 B. Alles , D. S. Henty , H. Panagopoulos , C. Parrinello , C. Pittori , D. G. Richards

The QCD free energy can be studied by dimensional reduction to a three-dimensional (3d) effective theory, whereby non-perturbative lattice simulations become less demanding. To connect to the original QCD a perturbative matching computation…

High Energy Physics - Lattice · Physics 2007-05-23 C. Torrero , F. Di Renzo , V. Miccio , M. Laine , Y. Schroder

In this Letter we consider renormalization of a class of scalar operators with fixed hypercharge $Q$ within the Standard Model. We carry out explicit computation of the corresponding anomalous dimensions up to the three-loop order. In spite…

High Energy Physics - Phenomenology · Physics 2024-04-04 A. V. Bednyakov