English
Related papers

Related papers: Two-loop evolution equations for light-ray operato…

200 papers

In this paper we consider the matching coefficients up to two loops between Quantum Chromodynamics (QCD) and Non-Relativistic QCD (NRQCD) for the vector, axial-vector, scalar and pseudo-scalar currents. The structure of the effective theory…

High Energy Physics - Phenomenology · Physics 2009-11-11 B. A. Kniehl , A. Onishchenko , J. H. Piclum , M. Steinhauser

We present a determination of a new class of Feynman diagrams relevant for second-order QCD corrections to the top quark decay t -> b W. Modern computing techniques allow us to perform a reduction of the original loop integrals to master…

High Energy Physics - Phenomenology · Physics 2017-08-23 Maciej Slusarczyk

The infrared exponentiation properties of dimensionally-regularized multi-loop scattering amplitudes are typically hidden at the level of the integrand, materializing only after integral evaluation. We address this long-standing problem by…

High Energy Physics - Theory · Physics 2019-07-22 Robert M. Schabinger

We provide a complete set of supersymmetric constraints for the anomalous dimensions of the conformal twist-two operators to all orders of perturbation theory. Employing them we derive new relations between the exclusive evolution kernels…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. V. Belitsky , D. Müller

Parton evolution equations in QCD are controlled by the anomalous dimensions of gauge-invariant twist-two spin-$N$ quark and gluon operators. Under renormalization, these mix with gauge-variant operators of the same quantum numbers,…

High Energy Physics - Phenomenology · Physics 2024-12-11 G. Falcioni , F. Herzog , S. Moch , S. Van Thurenhout

Perturbative corrections beyond leading-log accuracy to BFKL and BK equations, describing the rapidity evolution of QCD scattering amplitudes at high energy, exhibit strong convergence problems due to radiative corrections enhanced by large…

High Energy Physics - Phenomenology · Physics 2015-07-21 E. Iancu , J. D. Madrigal , A. H. Mueller , G. Soyez , D. N. Triantafyllopoulos

Two-loop QCD correction to massive spin-2 Graviton decaying to $q ~ + ~ \bar{q}~ + ~g$ is presented considering a generic universal spin-2 coupling to the SM through the conserved energy-momentum tensor. Such a massive spin-2 particle can…

High Energy Physics - Phenomenology · Physics 2016-12-21 Taushif Ahmed , Goutam Das , Prakash Mathews , Narayan Rana , V. Ravindran

Evanescent operators are a special class of operators that vanish in four-dimensional spacetime but are non-zero in $d=4-2\epsilon$ dimensions. In this paper, we continue our systematic study of the evanescent operators in the pure…

High Energy Physics - Theory · Physics 2023-02-14 Qingjun Jin , Ke Ren , Gang Yang , Rui Yu

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 present the two-loop virtual amplitudes for heavy-quark pair production in light quark-antiquark annihilation and gluon fusion channels, including full spin and color dependence. We use expansions around kinematical limits and numerical…

High Energy Physics - Phenomenology · Physics 2018-04-18 L. Chen , M. Czakon , R. Poncelet

We calculate the unpolarized and polarized two--loop massless off--shell operator matrix elements in QCD to $O(\varepsilon)$ in the dimensional parameter in an automated way. Here we use the method of arbitrary high Mellin moments and…

High Energy Physics - Phenomenology · Physics 2022-05-04 J. Blümlein , P. Marquard , C. Schneider , K. Schönwald

We discuss the structure of the non-anticommutative N=2 non-linear sigma-model in two dimensions, constructing differential operators which implement the deformed supersymmetry generators and using them to reproduce the classical action. We…

High Energy Physics - Theory · Physics 2009-07-22 I. Jack , R. Purdy

Conformal symmetry of QCD is restored at the Wilson-Fisher critical point in noninteger $4-2\epsilon$ space-time dimensions. Correlation functions of multiplicatively renormalizable operators with different anomalous dimensions at the…

High Energy Physics - Phenomenology · Physics 2022-09-07 V. M. Braun , K. G. Chetyrkin , A. N. Manashov

One of the distinctive feature of the QCD phase diagram is the possible emergence of a critical endpoint. The critical region around the critical point and the path dependency of the critical exponents is investigated within effective…

High Energy Physics - Phenomenology · Physics 2012-02-16 Bernd-Jochen Schaefer , Mathias Wagner

The Lange-Neubert evolution equation describes the scale dependence of the wave function of a meson built of an infinitely heavy quark and light antiquark at light-like separations, which is the hydrogen atom problem of QCD. It has numerous…

High Energy Physics - Phenomenology · Physics 2015-06-18 V. M. Braun , A. N. Manashov

Two-loop anomalous dimensions and one-loop renormalization scheme matching factors are calculated for six-quark operators responsible for neutron-antineutron transitions. When combined with lattice QCD determinations of the matrix elements…

High Energy Physics - Phenomenology · Physics 2018-10-03 Michael I. Buchoff , Michael Wagman

In the framework of nonlocal light-cone expansion of two current operators we construct bilocal as well as trilocal QCD light-cone operators with definite geometric twist. We are able to decompose uniquely the appearing QCD light-cone…

High Energy Physics - Phenomenology · Physics 2007-05-23 Markus Lazar

In a previous publication, we have constructed a set of non-linear evolution equations for dipole scattering amplitudes in QCD at high energy, which extends the Balitsky-JIMWLK hierarchy by including the effects of fluctuations in the gluon…

High Energy Physics - Phenomenology · Physics 2011-01-25 E. Iancu , D. N. Triantafyllopoulos

The improved light-cone distribution amplitudes (LCDAs) of the $\Lambda$ baryon are examined on the basis of the QCD conformal partial wave expansion approach. The calculations are carried out to the next-to-leading order of conformal spin…

High Energy Physics - Phenomenology · Physics 2014-09-16 Yong-Lu Liu , Chun-Yu Cui , Ming-Qiu Huang

We evaluate the one-loop soft current for the emission of two soft gluons or a soft quark-anti-quark pair in massless Quantum Chromodynamics. The results are exact in dimensional regularisation up to a single Feynman integral. Two terms of…

High Energy Physics - Phenomenology · Physics 2023-04-20 Michał Czakon , Felix Eschment , Tom Schellenberger