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 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.

Study of Υ(nS) → Bcρ and BcK∗ decays within the QCD factorization

2016 ◽  
Vol 31 (38) ◽  
pp. 1650209
Author(s):  
Qin Chang ◽  
Yunyun Zhang ◽  
Lin Han
Keyword(s):  
Large Hadron Collider ◽  
Quantum Chromodynamics ◽  
Branching Fractions ◽  
Hadron Collider ◽  
Heavy Flavor ◽  
Leading Order ◽  
Text Data ◽  
Weak Decays ◽  
Qcd Factorization ◽  
Belle Ii

Motivated by the heavy-flavor experiments at running Large Hadron Collider (LHC) and upgrading SuperKEKB, which provide abundant [Formula: see text] data samples, the tree-dominated [Formula: see text] and [Formula: see text] (n =1, 2, 3) weak decays are studied within the framework of quantum chromodynamics (QCD) factorization. The QCD corrections to the longitudinal and transverse amplitudes are evaluated at next-to-leading order, and the branching fractions and polarization fractions are predicted. Numerically, the [Formula: see text] decays have relatively large branching fractions at the order of [Formula: see text] and are in the scope of the LHC and SuperKEKB/Belle-II experiments.

scholarly journals CHARMONIUM PRODUCTION AT HERA

2007 ◽  
Vol 22 (02n03) ◽  
pp. 455-463
Author(s):  
ANDREAS B. MEYER
Keyword(s):  
Quantum Chromodynamics ◽  
Cross Sections ◽  
Relativistic Quantum ◽  
Gluon Fusion ◽  
Color Singlet ◽  
Charmonium Production ◽  
Color Octet ◽  
The Cross

Measurements of Charmonium production at the electron proton collider HERA are presented. In inelastic production the charmonium is formed from [Formula: see text] pairs that are produced in photon gluon fusion. The measurements of the cross sections and helicity distributions are compared to calculations performed in the framework of non-relativistic quantum chromodynamics (NRQCD), which includes both color-singlet and color-octet contributions.

scholarly journals Analysis of the buildup of spatiotemporal correlations and their bounds outside of the light cone

2018 ◽  
Vol 5 (5) ◽  
Author(s):  
Nils O. Abeling ◽  
Lorenzo Cevolani ◽  
Stefan Kehrein
Keyword(s):  
Correlation Function ◽  
Power Law ◽  
Light Cone ◽  
Relativistic Quantum ◽  
Initial State ◽  
Quantum Theories ◽  
Luttinger Model ◽  
Power Law Decay ◽  
Exactly Solvable ◽  
Exponentially Small

In non-relativistic quantum theories the Lieb-Robinson bound defines an effective light cone with exponentially small tails outside of it. In this work we use it to derive a bound for the correlation function of two local disjoint observables at different times if the initial state has a power-law decay. We show that the exponent of the power-law of the bound is identical to the initial (equilibrium) decay. We explicitly verify this result by studying the full dynamics of the susceptibilities and correlations in the exactly solvable Luttinger model after a sudden quench from the non-interacting to the interacting model.

scholarly journals PATH INTEGRATION IN RELATIVISTIC QUANTUM MECHANICS

1993 ◽  
Vol 08 (09) ◽  
pp. 1629-1635 ◽  
Author(s):  
IAN H. REDMOUNT ◽  
WAI-MO SUEN
Keyword(s):  
Path Integral ◽  
Light Cone ◽  
Proper Time ◽  
Relativistic Quantum ◽  
Free Particle ◽  
Wkb Approximation ◽  
Relativistic Quantum Mechanics ◽  
Path Integral Formulation ◽  
Quantum Theories ◽  
Short Time

The simple physics of a free particle reveals important features of the path-integral formulation of relativistic quantum theories. The exact quantum-mechanical propagator is calculated here for a particle described by the simple relativistic action proportional to its proper time. This propagator is nonvanishing outside the light cone, implying that spacelike trajectories must be included in the path integral. The propagator matches the WKB approximation to the corresponding configuration-space path integral far from the light cone; outside the light cone that approximation consists of the contribution from a single spacelike geodesic. This propagator also has the unusual property that its short-time limit does not coincide with the WKB approximation, making the construction of a concrete skeletonized version of the path integral more complicated than in nonrelativistic theory.

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.

scholarly journals Hadronization and confinement in quantum chromodynamics

1991 ◽  
Vol 69 (6) ◽  
pp. 684-691 ◽  
Author(s):  
V. N. Pervushin ◽  
Nguyen Suan Han
Keyword(s):  
Quantum Chromodynamics ◽  
Gauge Fields ◽  
Destructive Interference ◽  
Quantum Numbers ◽  
Covariant Description

We discuss the consistency of the standard ideas of confinement with the recent phenomenological procedure of measurement of colour quantum numbers. We show that the scheme of quantization of gauge fields, most adequate for the covariant description of hadrons, also contains a confinement mechanism as a destructive interference of phase factors of topological degeneration.

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