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Title: Decay constants and radiative decays of heavy mesons in light-front quark model

Abstract

We investigate the magnetic dipole decays V{yields}P{gamma} of various heavy-flavored mesons such as (D,D*,D{sub s},D{sub s}*,{eta}{sub c},J/{psi}) and (B,B*,B{sub s},B{sub s}*,{eta}{sub b},{upsilon}) using the light-front quark model constrained by the variational principle for the QCD-motivated effective Hamiltonian. The momentum dependent form factors F{sub VP}(q{sup 2}) for V{yields}P{gamma}* decays are obtained in the q{sup +}=0 frame and then analytically continued to the timelike region by changing q{sub perpendicular} to iq{sub perpendicular} in the form factors. The coupling constant g{sub VP{gamma}} for real photon case is then obtained in the limit as q{sup 2}{yields}0, i.e. g{sub VP{gamma}}=F{sub VP}(q{sup 2}=0). The weak decay constants of heavy pseudoscalar and vector mesons are also calculated. Our numerical results for the decay constants and radiative decay widths for the heavy-flavored mesons are overall in good agreement with the available experimental data as well as other theoretical model calculations.

Authors:
 [1]
  1. Department of Physics, Teachers College, Kyungpook National University, Daegu, 702-701 (Korea, Republic of)
Publication Date:
OSTI Identifier:
21020253
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. D, Particles Fields; Journal Volume: 75; Journal Issue: 7; Other Information: DOI: 10.1103/PhysRevD.75.073016; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; B MESONS; COUPLING CONSTANTS; D MESONS; D S MESONS; D*-2010 MESONS; ELECTROMAGNETIC FORM FACTORS; ETA MESONS; FLAVOR MODEL; HADRONIC PARTICLE DECAY; HAMILTONIANS; J PSI-3097 MESONS; MAGNETIC DIPOLES; PARTICLE WIDTHS; PHOTONS; QUANTUM CHROMODYNAMICS; QUARK MODEL; RADIATIVE DECAY; RESONANCE PARTICLES; VARIATIONAL METHODS

Citation Formats

Choi, Ho-Meoyng. Decay constants and radiative decays of heavy mesons in light-front quark model. United States: N. p., 2007. Web. doi:10.1103/PHYSREVD.75.073016.
Choi, Ho-Meoyng. Decay constants and radiative decays of heavy mesons in light-front quark model. United States. doi:10.1103/PHYSREVD.75.073016.
Choi, Ho-Meoyng. Sun . "Decay constants and radiative decays of heavy mesons in light-front quark model". United States. doi:10.1103/PHYSREVD.75.073016.
@article{osti_21020253,
title = {Decay constants and radiative decays of heavy mesons in light-front quark model},
author = {Choi, Ho-Meoyng},
abstractNote = {We investigate the magnetic dipole decays V{yields}P{gamma} of various heavy-flavored mesons such as (D,D*,D{sub s},D{sub s}*,{eta}{sub c},J/{psi}) and (B,B*,B{sub s},B{sub s}*,{eta}{sub b},{upsilon}) using the light-front quark model constrained by the variational principle for the QCD-motivated effective Hamiltonian. The momentum dependent form factors F{sub VP}(q{sup 2}) for V{yields}P{gamma}* decays are obtained in the q{sup +}=0 frame and then analytically continued to the timelike region by changing q{sub perpendicular} to iq{sub perpendicular} in the form factors. The coupling constant g{sub VP{gamma}} for real photon case is then obtained in the limit as q{sup 2}{yields}0, i.e. g{sub VP{gamma}}=F{sub VP}(q{sup 2}=0). The weak decay constants of heavy pseudoscalar and vector mesons are also calculated. Our numerical results for the decay constants and radiative decay widths for the heavy-flavored mesons are overall in good agreement with the available experimental data as well as other theoretical model calculations.},
doi = {10.1103/PHYSREVD.75.073016},
journal = {Physical Review. D, Particles Fields},
number = 7,
volume = 75,
place = {United States},
year = {Sun Apr 01 00:00:00 EDT 2007},
month = {Sun Apr 01 00:00:00 EDT 2007}
}
  • We present a calculation of the quark distribution amplitudes (DAs), the Gegenbauer moments, and decay constants for {pi}, {rho}, K, and K* mesons using the light-front quark model. While the quark DA for {pi} is somewhat broader than the asymptotic one, that for {rho} meson is very close to the asymptotic one. The quark DAs for K and K* show asymmetric form due to the flavor SU(3)-symmetry breaking effect. The decay constants for the transversely polarized {rho} and K* mesons (f{sub {rho}}{sup T} and f{sub K*}{sup T}) as well as the longitudinally polarized ones (f{sub {rho}} and f{sub K*}) aremore » also obtained. Our averaged values for f{sub V}{sup T}/f{sub V}, i.e. (f{sub {rho}}{sup T}/f{sub {rho}}){sub av}=0.78 and (f{sub K*}{sup T}/f{sub K*}){sub av}=0.84, are found to be consistent with other model predictions. Especially, our results for the decay constants are in good agreement with the SU(6) symmetry relation, f{sub {rho}}{sub (K*)}{sup T}=(f{sub {pi}}{sub (K)}+f{sub {rho}}{sub (K*)})/2.« less
  • We investigate the {ital B} and {ital D} mesons in the relativistic quark model by applying the variational method with the Gaussian wave function. We calculate the Fermi momentum parameter {ital p}{sub {ital F}}, and obtain {ital p}{sub {ital F}}=0.50{minus}0.54 GeV, which is almost independent of the input parameters {alpha}{sub {ital s}}, {ital m}{sub {ital b}}, {ital m}{sub {ital c}}, and {ital m}{sub {ital sp}}. We then calculate the ratio {ital f}{sub {ital B}}/{ital f}{sub {ital D}}, and obtain a result which is larger, by a factor of about 1.3, than {radical}{ital M}{sub {ital D}}/{ital M}{sub {ital B}} given bymore » the naive nonrelativistic analogy. This result is in a good agreement with the recent lattice calculations. We also calculate the ratio ({ital M}{sub {ital B}{sup {asterisk}}}{minus}{ital M}{sub {ital B}})/({ital M}{sub {ital D}{sup {asterisk}}}{minus}{ital M}{sub {ital D}}). In these calculations the wave function at the origin {psi}(0) is essential. We also determine {ital p}{sub {ital F}} by comparing the theoretical prediction of the ACCMM model with the lepton energy spectrum of {ital B}{r_arrow}{ital e}{nu}{ital X} from the recent ARGUS analysis, and find that {ital p}{sub {ital F}}=0.27{plus_minus}{sub 0.27}{sup 0.22} GeV, when we use {ital m}{sub {ital c}}=1.5 GeV. However, this experimentally determined value of {ital p}{sub {ital F}} is strongly dependent on the value of the input parameter {ital m}{sub {ital c}}. {copyright} {ital 1996 The American Physical Society.}« less
  • The SU(3)-breaking effects in the leading and subleading parameters appearing in the heavy quark expansion of decay constants of the heavy-light mesons are systematically analyzed to two loop accuracy using QCD sum rules. We find that the SU(3)-breaking effects in the decay constant of the pseudoscalar are, respectively, about 20{percent} for the {ital b}-flavored meson, 17{percent} for the charmed meson, i.e., {ital f}{sub {ital B}{sub {ital s}}}/{ital f}{sub {ital B}}=1.20{plus_minus}0.04{plus_minus}0.03,{ital f}{sub {ital D}{sub {ital s}}}/{ital f}{sub {ital D}}=1.17{plus_minus}0 .03{plus_minus}0.03 (the first error comes from the sum rule uncertainty, the second one from the uncertainty in the strange quark mass) and,more » in the expansion of {ital f}{sub {ital P}{sub {ital s}}}{radical}{ital m}{sub {ital P}{sub {ital s}}}/{ital f}{sub {ital P}}{radical}{ital m}{sub {ital P}}, the subleading order is about {minus}3{percent} of the corresponding leading one for the {ital b}-flavored meson, about {minus}5.5{percent} for the charmed meson, and depends on the strange quark mass very weakly. In addition, the ratios of the vector to pseudoscalar meson decay constants are found to be {ital f}{sub {ital B}{sub {ital s}}{sup {asterisk}}}/{ital f}{sub {ital B}{sub {ital s}}}={ital f}{sub {ital B}{sup {asterisk}}}/{ital f}{sub {ital B}}=1.05{plus_minus}0.02 {asterisk}0.00, and the SU(3)-breaking effect in the mass is about 102{plus_minus}16{plus_minus}20 MeV. {copyright} {ital 1996 The American Physical Society.}« less
  • The radiative decays of the ground {ital S}-wave and the first excited {ital P}-wave mesons in light-quark {ital q{bar q}} systems are investigated in the covariant oscillator quark model. An important feature of this scheme is that the effective electromagnetic currents for respective processes, which are manifestly covariant and conserved, are given in a unified and systematic way. The results for the {ital S}-wave mesons seem to be in good agreement with experiment, and the results for the {ital P}-wave mesons are satisfactory, as far as the present poor experiments are concerned, except for the process {ital b}{sub 1}{sup +}{rmore » arrow}{pi}{sup +}{gamma}.« less