scholarly journals On Nonleptonic Decays of Supermultiplets

2000 ◽  
Vol 53 (6) ◽  
pp. 737 ◽  
Author(s):  
R. Delbourgo ◽  
Dongsheng Liu
Keyword(s):  
Heavy Quark ◽  
Pseudoscalar Meson ◽  
Constituent Quark ◽  
Weak Interactions ◽  
Weak Decay ◽  
Soft Gluon ◽  
Strong Interactions ◽  
Heavy Particles ◽  
Quark Masses ◽  
Quark Theory

By describing strong interactions between hadrons via a relativistic supermultiplet scheme and regarding weak interactions as a perturbation thereof, we derive expressions for nonleptonic weak decay amplitudes in terms of constituent quark masses and CKM angles, with no other parameters. Application of this method leads to ΔI = dominance in some pseudoscalar meson decays if one scales down the couplings of heavy particles by M mass factors, in keeping with heavy quark theory expectations. However, certain B and D decay processes to kaons are badly predicted and point to substantial soft gluon renormalisation effects inW-quark interactions.

SYMMETRIES FOR STRONGLY INTERACTING HEAVY PARTICLES

2002 ◽  
Vol 17 (09) ◽  
pp. 1199-1206
Author(s):  
MARK B. WISE
Keyword(s):  
Heavy Quark ◽  
Strong Interactions ◽  
Isospin Symmetry ◽  
Heavy Particles ◽  
Charm Quarks ◽  
Heavy Quark Symmetry ◽  
Strongly Interacting

Strongly interacting theories with heavy particles can exhibit symmetries that are not manifest in the Lagrangian. Two examples are discussed. The first is Wigner spin–isospin symmetry for the strong interactions of nuclei. The second is heavy quark symmetry for the strong interactions of bottom and charm quarks.

Parity conservation in strong interactions

1958 ◽  
Vol 246 (1247) ◽  
pp. 481-482
Keyword(s):  
Cross Section ◽  
Selection Rule ◽  
Radiative Capture ◽  
Weak Interactions ◽  
Relative Strength ◽  
Strong Interactions ◽  
Longitudinal Polarization ◽  
Heavy Particles ◽  
Parity Conservation ◽  
Γ Rays

The recent discovery that parity is not conserved in certain weak interactions has opened the question of the degree to which it is conserved in the strong interactions (internucleonic and electromagnetic). Parity non-conservation in such interactions may be detected by: (i) The violation of a selection rule which is absolute if parity is conserved. (ii) The presence of circular polarization of γ-rays or longitudinal polarization of heavy particles in reactions involving unpolarized initial systems and where the apparatus itself defines no screw sense. (iii) The presence of odd powers of cos θ in the angular distribution of radiations coming from well-defined nuclear states. Two experiments have been performed in class (i). The radiative capture 4 He(d, γ) 6 Li through the 0 + state at 3·57 MeV has been sought and its absence corresponds to F 2 < 1 X 10 -7 ( F is the relative strength of the parity non-conserving interaction). The reaction 7 Be( n , α)α with thermal neutrons has been sought and the limit on the cross-section corresponds to F 2 < 1 X 10 -7 .

scholarly journals EXCLUSIVE PRODUCTION OF HEAVY MESON PAIRS IN e+e− ANNIHILATION

1995 ◽  
Vol 10 (04) ◽  
pp. 465-476 ◽  
Author(s):  
V. V. KISELEV
Keyword(s):  
Pair Production ◽  
Heavy Quark ◽  
Quark Model ◽  
Constituent Quark ◽  
Constituent Quark Model ◽  
Heavy Meson ◽  
Leading Order ◽  
Exclusive Production ◽  
Quark Theory

A constituent quark model is used to calculate the exclusive pair production of [Formula: see text] and [Formula: see text] mesons in e+e− annihilation. It allows one to illuminate the meaning of the 1/mb,c corrections to the leading order of the effective heavy quark theory.

scholarly journals Heavy quark masses from sum rules in four-loop approximation

2007 ◽  
Vol 778 (1-2) ◽  
pp. 192-215 ◽  
Author(s):  
Johann H. Kühn ◽  
Matthias Steinhauser ◽  
Christian Sturm
Keyword(s):  
Heavy Quark ◽  
Sum Rules ◽  
Quark Masses ◽  
Loop Approximation

scholarly journals A Survey of Heavy Quark Theory for PDF Analyses

2012 ◽  
Vol 222-224 ◽  
pp. 52-60 ◽  
Author(s):  
K. Kovařík ◽  
T. Stavreva ◽  
A. Kusina ◽  
T. Jezo ◽  
F.I. Olness ◽  
...  
Keyword(s):  
Heavy Quark ◽  
Quark Theory

scholarly journals The Charm and Beauty of Strong Interactions

2018 ◽  
Vol 172 ◽  
pp. 02005 ◽  
Author(s):  
Bruno El-Bennich
Keyword(s):  
Mass Spectrum ◽  
Strong Interaction ◽  
Bound States ◽  
Flavor Physics ◽  
Weak Decay ◽  
Strong Interactions ◽  
Interaction Models ◽  
Common Features ◽  
Decay Constants

We briefly review common features and overlapping issues in hadron and flavor physics focussing on continuum QCD approaches to heavy bound states, their mass spectrum and weak decay constants in different strong interaction models.

CHIRAL QCD GENERATES CONSTITUENT QUARK MASSES

1988 ◽  
Vol 03 (16) ◽  
pp. 1595-1602 ◽  
Author(s):  
J. PRASCHIFKA ◽  
R.T. CAHILL ◽  
C.D. ROBERTS
Keyword(s):  
Form Factor ◽  
Quark Mass ◽  
Constituent Quark ◽  
Bound State ◽  
Variational Technique ◽  
Quark Masses ◽  
Constituent Quark Mass ◽  
Insight Into

Constituent quark masses are shown to arise naturally in an approximation to chiral QCD. The colour [Formula: see text] diquark component of the nucleon is studied using a new variational technique to solve a Bethe-Salpeter equation for this qq bound state in massless QCD. The resultant diquark form factor Γ(q) exhibits a dramatic peaking for (Euclidean) momentum q2≈(0.2 GeV )2 which, we show, signals the generation of a constituent quark mass of ≈270 MeV , and which provides a significant insight into deep inelastic leptonnucleon scattering results.

scholarly journals On the relation between pole and running heavy quark masses beyond the four-loop approximation

2018 ◽  
Vol 191 ◽  
pp. 04005 ◽  
Author(s):  
A. L. Kataev ◽  
V. S. Molokoedov
Keyword(s):  
Heavy Quark ◽  
Perturbative Qcd ◽  
Mass Relation ◽  
Coupling Constant ◽  
Quark Masses ◽  
Asymptotic Nature ◽  
Asymptotic Expressions ◽  
Loop Approximation ◽  
Euclidean Region ◽  
Direct Calculations

The effective charges motivated method is applied to the relation between pole and M̅S̅-scheme heavy quark masses to study high order perturbative QCD corrections in the observable quantities proportional to the running quark masses. The non-calculated five- and six-loop perturbative QCD coefficients are estimated. This approach predicts for these terms the sign-alternating expansion in powers of number of lighter flavors nl, while the analyzed recently infrared renormalon asymptotic expressions do not reproduce the same behavior. We emphasize that coefficients of the quark mass relation contain proportional to π2 effects, which result from analytical continuation from the Euclidean region, where the scales of the running masses and QCD coupling constant are initially fixed, to the Minkowskian region, where the pole masses and the running QCD parameters are determined. For the t-quark the asymptotic nature of the non-resummed PT mass relation does not manifest itself at six-loops, while for the b-quark the minimal PT term appears at the probed by direct calculations four-loop level. The recent infrared renormalon based studies support these conclusions.

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