### Abstract

We investigate the B and D mesons in the relativistic quark model by applying the variational method with the Gaussian wave function. We calculate the Fermi momentum parameter pF, and obtain pF=0.50-0.54 GeV, which is almost independent of the input parameters α_{s}, m_{b}, m_{c}, and m_{sp}. We then calculate the ratio fB/fD, and obtain a result which is larger, by a factor of about 1.3, than √M^{D}/m^{B} given by the naive nonrelativistic analogy. This result is in a good agreement with the recent lattice calculations. We also calculate the ratio (M_{B}*-M_{B})/(M_{D}*-M_{D}). In these calculations the wave function at the origin ψ(0) is essential. We also determine pF by comparing the theoretical prediction of the ACCMM model with the lepton energy spectrum of B→eνX from the recent ARGUS analysis, and find that (formula presented) GeV, when we use (formula presented)=1.5 GeV. However, this experimentally determined value of pF is strongly dependent on the value of the input parameter m_{c}.

Original language | English |
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Pages (from-to) | 4951-4956 |

Number of pages | 6 |

Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |

Volume | 53 |

Issue number | 9 |

DOIs | |

Publication status | Published - 1996 |

### All Science Journal Classification (ASJC) codes

- Nuclear and High Energy Physics
- Physics and Astronomy (miscellaneous)

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## Cite this

*Physical Review D - Particles, Fields, Gravitation and Cosmology*,

*53*(9), 4951-4956. https://doi.org/10.1103/PhysRevD.53.4951