scholarly journals Ratios ofB andD meson decay constants with heavy quark symmetry

Pramana ◽  
1996 ◽  
Vol 47 (3) ◽  
pp. 261-261
Author(s):  
A K Giri ◽  
L Maharana ◽  
R Mohanta
Pramana ◽  
1996 ◽  
Vol 46 (6) ◽  
pp. 411-416
Author(s):  
A K Giri ◽  
L Maharana ◽  
R Mohanta

2001 ◽  
Vol 520 (1-2) ◽  
pp. 59-62 ◽  
Author(s):  
A Le Yaouanc ◽  
L Oliver ◽  
O Pène ◽  
J.-C Raynal ◽  
V Morénas

2012 ◽  
Vol 27 (27) ◽  
pp. 1250153 ◽  
Author(s):  
SEUNG-IL NAM

We study the weak-decay constants for the heavy pseudoscalar mesons, D, Ds, B and Bs. For this purpose, we employ the extended nonlocal chiral-quark model (ExNLChQM), motivated by the heavy-quark effective field theory as well as the instanton-vacuum configuration. In addition to the heavy-quark symmetry and the nonlocal interactions between quarks and pseudoscalar mesons in ExNLChQM, a correction for the strange-quark content inside Ds and Bs is also taken into account and found to be crucial to reproduce the empirical values. From those numerical results, we obtain fD, Ds, B, Bs = (207.53, 262.56, 208.13, 262.39) MeV , which are in good agreement with experimental data and other theoretical estimations. Using those numerical results, we estimate the CKM matrix elements and the Cabibbo angle with the various mesonic and leptonic heavy-meson decay channels, resulting in (|Vcd|, |Vcs|, |Vub|, |Vtd|/|Vts|) = (0.224, 0.968, <5.395×10-3, 0.215) and θC = 12.36° which are well compatible with available data.


2001 ◽  
Vol 16 (03) ◽  
pp. 377-408 ◽  
Author(s):  
W. Y. WANG ◽  
Y. L. WU

Within the complete heavy quark effective field theory (HQEFT), the QCD sum rule approach is used to evaluate the decay constants including 1/mQcorrections and the Isgur–Wise function and other additional important wave functions concerned at 1/mQfor the heavy–light mesons. The number of unknown wave functions or form factors in HQEFT is shown to be much less than the one in the usual heavy quark effective theory (HQET). The values of wave functions at zero recoil are found to be consistent with the ones extracted from the interesting relations (which are resulted from the HQEFT) between the hadron masses and wave functions at zero recoil. The results for the decay constants are consistent with the ones from full QCD sum rule and Lattice calculations. The 1/mQcorrections to the scaling law [Formula: see text] are found to be small in HQEFT, which demonstrates again the validity of 1/mQexpansion in HQEFT. It is also shown that the residual momentum v·k of heavy quark within heavy–light hadrons is indeed around the binding energy [Formula: see text] of the heavy hadrons, which turns out to be in agreement with the expected one in the HQEFT. Therefore such a calculation provides a consistent check on the HQEFT and shows that the HQEFT is more reliable than the usual HQET for describing a slightly off-mass shell heavy quark within hadron as the usual HQET seems to lead to large 1/mQcorrections in evaluating the meson decay constants. It is emphasized that the introduction of the "dressed heavy quark" mass is useful for the heavy–light mesons (Qq) with [Formula: see text], while for heavy–heavy bound states (ψ1ψ2) with masses m1, [Formula: see text], like bottom-charm hadrons or similarly for muonium in QED, one needs to treat both particles as heavy effective particles via 1/m1and 1/m2expansions and redefine the effective bound states and modified "dressed heavy quark" masses within the HQEFT.


1995 ◽  
Vol 48 (1) ◽  
pp. 55
Author(s):  
NR Jones ◽  
R Delbourgo

We use a covariant supermultiplet theory to determine the primary coupling constant associated with several types of two-body meson decay. Despite the diverse range of decays considered, the primary coupling constant is surprisingly uniform. We envisage the extension of the techniques to heavy quark cases, including as preliminary examples the calculation of the D*+ and D*o total decay widths with results 57 �7�1�5 keY and 42�5�2�6 keY respectively, as well as some predictions about D� and B* radiative decays.


2011 ◽  
Author(s):  
Wolfgang Lucha ◽  
Dmitri Melikhov ◽  
Silvano Simula

1997 ◽  
Vol 12 (03) ◽  
pp. 195-204 ◽  
Author(s):  
Debrupa Chakraverty ◽  
Triptesh De ◽  
Binayak Dutta-Roy ◽  
K. S. Gupta

We calculate the decay width for [Formula: see text] in the framework of a non-relativistic quark (NRQ) model of heavy baryons where the light quarks play the role of spectators. Our calculation does not make an explicit use of the heavy quark symmetry. The branching ratio for the above process as calculated here agrees reasonably well with the experimental value.


2010 ◽  
Author(s):  
Wolfgang Lucha ◽  
Dmitri Melikhov ◽  
Silvano Simula ◽  
Leonardo Angelini ◽  
Pietro Colangelo ◽  
...  

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