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Related papers: The four-loop beta-function in Quantum Chromodynam…

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We present an analytic computation of the two-loop QCD corrections to $u\bar{d}\to W^+b\bar{b}$ for an on-shell $W$-boson using the leading colour and massless bottom quark approximations. We perform an integration-by-parts reduction of the…

High Energy Physics - Phenomenology · Physics 2021-10-14 Simon Badger , Heribertus Bayu Hartanto , Simone Zoia

Conventionally, one calculates a zero in a beta function by computing this function to a given loop order and solving for the zero. Here we discuss a different method which is applicable in theories where one can perform a partial…

High Energy Physics - Theory · Physics 2015-07-02 Robert Shrock

In this contribution we consider the recent computation of the gauge coupling $\beta$-function at four loops and the Yukawa matrix $\beta$-function at three loops in the most general, renormalizable and four-dimensional quantum field…

High Energy Physics - Phenomenology · Physics 2021-10-15 Florian Herren

In this work, we present a compact analytical approximation for the quantum partition function of systems composed of quantum oscillators. The proposed formula is general and applicable to an arbitrary number of oscillators described by a…

Statistical Mechanics · Physics 2025-07-08 Michel Caffarel

We compute the one-loop QCD amplitudes for the decay of an off-shell vector boson with vector couplings into a quark-antiquark pair accompanied by two gluons keeping, for the first time, all orders in the number of colours. Together with…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. M. Campbell , E. W. N. Glover , D. J. Miller

We construct and study a previously defined quantum holographic effective action whose critical equation implies the holographic loop equation of large-N QCD_4 for planar self-avoiding loops in a certain regularization scheme. We extract…

High Energy Physics - Theory · Physics 2009-04-22 Marco Bochicchio

Calculations of observables in Quantum Chromodynamics are typically performed using a method that combines numerical integrations over the momenta of final state particles with analytical integrations over the momenta of virtual particles.…

High Energy Physics - Phenomenology · Physics 2009-10-31 Davison E. Soper

We present a brief introduction to QCD, the QCD phase diagram, and non-equilibrium phenomena in QCD. We emphasize aspects of the theory that can be addressed using computational methods, in particular euclidean path integral Monte Carlo,…

Nuclear Theory · Physics 2016-12-14 Thomas Schaefer

We study the beta functions for the dimensionless couplings in quadratic curvature gravity, and find that there is a simple argument to restrict the possible form of the beta functions as derived from the counterterms at an arbitrary loop.…

High Energy Physics - Theory · Physics 2024-07-12 Hikaru Kawai , Nobuyoshi Ohta

We show in a diagrammatic and regularization independent analysis that the quadratic contribu- tion to the beta function which has been conjectured to render quantum electrodynamics asymp- totically free near the Planck scale has its origin…

High Energy Physics - Theory · Physics 2011-05-18 J. C. C. Felipe , L. C. T. Brito , Marcos Sampaio , M. C. Nemes

We present the even-N moments N =< 20 of the fourth-order (N^3LO) contribution P_{gq}^(3)(x) to the quark-to-gluon splitting function in perturbative QCD. These moments, obtained by analytically computing off-shell operator matrix elements…

High Energy Physics - Phenomenology · Physics 2024-04-16 G. Falcioni , F. Herzog , S. Moch , A. Pelloni , A. Vogt

We study the dependence of beta-function on running coupling constant in holographic models supported by Einstein-dilaton-Maxwell action for light and heavy quarks. Although, in the previous paper [arXiv:2402.14512], we considered different…

High Energy Physics - Theory · Physics 2024-07-22 Irina Ya. Aref'eva , Ali Hajilou , Pavel Slepov , Marina Usova

We explicitly compute the complete three-loop (O(g^4)) contribution to the four-point function of chiral primary current-like operators <(q)^2 q^2 (q)^2 q^2> in any finite N=2 SYM theory. The computation uses N=2 harmonic supergraphs in…

High Energy Physics - Theory · Physics 2009-10-31 B. Eden , C. Schubert , E. Sokatchev

In this thesis, the infrared structure of squared matrix elements in quantum chromodynamics (QCD) is scrutinised. Specifically, the triple-collinear splitting functions are decomposed and improvements to antenna subtraction are sought…

High Energy Physics - Phenomenology · Physics 2024-02-14 Oscar Braun-White

For arbitrary scalar QFTs in four dimensions, renormalisation group equations of quartic and cubic interactions, mass terms, as well as field anomalous dimensions are computed at three-loop order in the $\overline{\text{MS}}$ scheme.…

High Energy Physics - Theory · Physics 2021-02-19 Tom Steudtner

In this paper we discuss techniques, which lead to a significant improvement of the efficiency of the Monte Carlo integration, when one-loop QCD amplitudes are calculated numerically with the help of the subtraction method and contour…

High Energy Physics - Phenomenology · Physics 2015-06-05 Sebastian Becker , Christian Reuschle , Stefan Weinzierl

Current status of the NNLO QCD corrections to B -> X_s gamma is reviewed. The calculations include three-loop matching conditions, four-loop anomalous dimensions as well as two- and three-loop on-shell amplitudes. Certain parts of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. Misiak

In this paper we compute the relation between heavy quark masses defined in the modified minimal subtraction and on-shell scheme. Detailed results are presented for all coefficients of the SU$(N_c)$ colour factors. The reduction of the…

High Energy Physics - Phenomenology · Physics 2016-11-23 Peter Marquard , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser , David Wellmann

We compute the purely gluonic contribution to the static QCD potential at three--loop order. This completes the computation of the static potential at this order.

High Energy Physics - Phenomenology · Physics 2010-04-06 C. Anzai , Y. Kiyo , Y. Sumino

We present a calculation of all matching coefficients for $N$-jettiness beam functions at next-to-next-to-next-to-leading order (N$^3$LO) in perturbative quantum chromodynamics (QCD). Our computation is performed starting from the…

High Energy Physics - Phenomenology · Physics 2023-03-01 Daniel Baranowski , Arnd Behring , Kirill Melnikov , Lorenzo Tancredi , Christopher Wever