scholarly journals OPE and quark-hadron duality for two-point functions of tetraquark currents in the 1/Nc expansion

2021 ◽  
Vol 103 (1) ◽  
Author(s):  
Wolfgang Lucha ◽  
Dmitri Melikhov ◽  
Hagop Sazdjian
Keyword(s):  
Hadron Duality

scholarly journals Quark-hadron duality for heavy meson mixings in the ’t Hooft model

2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Hiroyuki Umeeda
Keyword(s):  
Heavy Meson ◽  
Four Dimensions ◽  
Width Difference ◽  
Dimensional Spacetime ◽  
Gim Mechanism ◽  
Order Of Magnitude ◽  
Space Function ◽  
Inclusive Analysis ◽  
Phase Space Function ◽  
Hadron Duality

Abstract We study local quark-hadron duality and its violation for the $$ {D}^0-{\overline{D}}^0 $$ D 0 − D ¯ 0 , $$ {B}_d^0-{\overline{B}}_d^0 $$ B d 0 − B ¯ d 0 and $$ {B}_s^0-{\overline{B}}_s^0 $$ B s 0 − B ¯ s 0 mixings in the ’t Hooft model, offering a laboratory to test QCD in two-dimensional spacetime together with the large-Nc limit. With the ’t Hooft equation being numerically solved, the width difference is calculated as an exclusive sum over two-body decays. The obtained rate is compared to inclusive one that arises from four-quark operators to check the validity of the heavy quark expansion (HQE). In view of the observation in four-dimensions that the HQE prediction for the width difference in the $$ {D}^0-{\overline{D}}^0 $$ D 0 − D ¯ 0 mixing is four orders of magnitude smaller than the experimental data, in this work we investigate duality violation in the presence of the GIM mechanism. We show that the order of magnitude of the observable in the $$ {D}^0-{\overline{D}}^0 $$ D 0 − D ¯ 0 mixing is enhanced in the exclusive analysis relative to the inclusive counterpart, when the 4D-like phase space function is used for the inclusive analysis. By contrast, it is shown that for the $$ {B}_d^0-{\overline{B}}_d^0 $$ B d 0 − B ¯ d 0 and $$ {B}_s^0-{\overline{B}}_s^0 $$ B s 0 − B ¯ s 0 mixings, small yet non-negligible corrections to the inclusive result emerge, which are still consistent with what is currently indicated in four-dimensions.

On local parton-hadron duality

1989 ◽  
Vol 44 (3) ◽  
pp. 455-460 ◽  
Author(s):  
B. Andersson ◽  
P. Dahlqvist ◽  
G. Gustafson
Keyword(s):  
Hadron Duality

scholarly journals RESTRICTED LOCALITY OF QUARK-HADRON DUALITY IN EXCLUSIVE MESON PHOTOPRODUCTION REACTIONS ABOVE THE RESONANCE REGION

2005 ◽  
Vol 20 (08n09) ◽  
pp. 1910-1913 ◽  
Author(s):  
QIANG ZHAO ◽  
FRANK E. CLOSE
Keyword(s):  
Cross Sections ◽  
Differential Cross ◽  
Scaling Laws ◽  
Resonance Region ◽  
Meson Photoproduction ◽  
Counting Rule ◽  
Dimensional Scaling ◽  
Exclusive Processes ◽  
Photoproduction Reactions ◽  
Hadron Duality

We show how deviations from the dimensional scaling laws for exclusive processes may be related to a breakdown in the locality of quark-hadron duality, i.e. the "restricted locality". For exclusive reactions like meson photo- and electroproduction above the resonance region, we explore the effects arising from such a local duality breaking and propose that it can be a possible source for oscillations about the smooth quark counting rule predicted by pQCD in the 90-degree differential cross sections.

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