Exclusive Processes in Quantum Chromodynamics and the Light-Cone Fock Representation

2000 ◽  
Author(s):  
Stanley J Brodsky
Keyword(s):  
Quantum Chromodynamics ◽  
Light Cone ◽  
Fock Representation ◽  
Exclusive Processes

Charmonia production in W → (cc̄)Ds(∗) decays

2021 ◽  
Vol 36 (09) ◽  
pp. 2150058
Author(s):  
A. V. Luchinsky ◽  
A. K. Likhoded
Keyword(s):  
Quantum Chromodynamics ◽  
Light Cone ◽  
Relativistic Quantum ◽  
Branching Fractions ◽  
Color Singlet ◽  
Leading Order ◽  
Paper Production ◽  
Quantum Numbers ◽  
Numerical Predictions ◽  
State Formula

In this paper, production of charmonium state [Formula: see text] in exclusive [Formula: see text] decays is analyzed in the framework of both leading order Non-relativistic Quantum Chromodynamics (NRQCD) and light-cone (LC) expansion models. Analytical and numerical predictions for the branching fractions of these decays in both the approaches are given. The typical value of the branching fractions is [Formula: see text][Formula: see text][Formula: see text] and it turns out that the LC results are significantly larger than NRQCD ones (approximately two or four times increase depending on the quantum numbers of the final particles), so the effect of internal quark motion should be taken into account. Some rough estimates of color-octet contributions are presented and it is shown that these contributions could be comparable with color-singlet results.

scholarly journals Light-cone distribution amplitudes of light mesons with QED effects

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Martin Beneke ◽  
Philipp Böer ◽  
Jan-Niklas Toelstede ◽  
K. Keri Vos
Keyword(s):  
Light Cone ◽  
Electromagnetic Coupling ◽  
First Order ◽  
Order Expansion ◽  
Group Evolution ◽  
Fixed Order ◽  
Light Mesons ◽  
Charged Mesons ◽  
Qed Effects ◽  
Exclusive Processes

Abstract We discuss the generalization of the leading-twist light-cone distribution amplitude for light mesons including QED effects. This generalization was introduced to describe virtual collinear photon exchanges at the strong-interaction scale ΛQCD in the factorization of QED effects in non-leptonic B-meson decays. In this paper we study the renormalization group evolution of this non-perturbative function. For charged mesons, in particular, this exhibits qualitative differences with respect to the well-known scale evolution in QCD only, especially regarding the endpoint-behaviour. We analytically solve the evolution equation to first order in the electromagnetic coupling αem, which resums large logarithms in QCD on top of a fixed-order expansion in αem. We further provide numerical estimates for QED corrections to Gegenbauer coefficients as well as inverse moments relevant to (QED-generalized) factorization theorems for hard exclusive processes.

scholarly journals Double charmonia production in exclusive Z-boson decays

2018 ◽  
Vol 33 (14) ◽  
pp. 1850078 ◽  
Author(s):  
A. K. Likhoded ◽  
A. V. Luchinsky
Keyword(s):  
Quantum Chromodynamics ◽  
Z Boson ◽  
Light Cone ◽  
Relativistic Quantum ◽  
Branching Fractions ◽  
Systematic Analysis ◽  
Charmonium Production ◽  
Theoretical Predictions ◽  
Z Boson Decays

This paper is devoted to systematic analysis of double charmonium production in exclusive Z-boson decays in the framework of non-relativistic quantum chromodynamics (NRQCD) and leading twist light-cone (LC) models. Theoretical predictions for branching fractions of all considered decays are presented. According to the obtained results in the case of the allowed helicity suppression rule processes, the effect of internal quark motion increases the branching fractions by a factor 1.5, while for forbidden reactions the LC predictions are strictly zero, while NRQCD ones are significantly smaller than for allowed.

The light-cone gauge

1986 ◽  
Vol 64 (5) ◽  
pp. 624-632 ◽  
Author(s):  
H. C. Lee
Keyword(s):  
Quantum Chromodynamics ◽  
Quantum Electrodynamics ◽  
Light Cone ◽  
Field Theories ◽  
Special Role ◽  
Quantum Field Theories ◽  
Quantum Field ◽  
Light Cone Gauge ◽  
Yang Mills ◽  
Kaluza Klein

Some aspects of recent development in the light-cone gauge and its special role in quantum-field theories are reviewed. Topics discussed include the two- and four-component formulations of the light-cone gauge, Slavnov–Taylor and Becchi– Rouet–Stora identities, quantum electrodynamics, quantum chromodynamics, renormalization of Yang–Mills theory and supersymmetric theory, gravity, and the quantum-induced compactification of Kaluza–Klein theories in the light-cone gauge.

Re-examined radiative decayB*q Bq  in light-cone quantum chromodynamics

2002 ◽  
Vol 28 (10) ◽  
pp. 2583-2595 ◽  
Author(s):  
Zuo-Hong Li ◽  
Xiang-Yao Wu ◽  
Tao Huang
Keyword(s):  
Quantum Chromodynamics ◽  
Light Cone
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