Kohichi Seo | Searcharxiv

arXiv2010

Mixing angle between $^3P_1$ and $^1P_1$ in HQET

Some claim that there are two independent mixing angles ($θ= 35.3^\circ$, $-54.7^\circ$) between $^3P_1$ and $^1P_1$ states of heavy-light mesons in heavy quark symmetric limit, and others claim there is only one ($θ= 35.3^\circ$). We clarify the difference between these two and suggest which should be adopted. General arguments on the mixing angle between $^3L_L$ and $^1L_L$ of heavy-light mesons are given in HQET and a general relation is derived in heavy quark mass limit as well as that including the first order correction in $1/m_Q$.

hep-ph↗

arXiv2007

Construction of Lorentz Invariant Amplitudes from Rest Frame Wave Functions in HQET

Succeeding in predicting 0^+ and 1^+ states of D and D_s heavy mesons by our semi-relativistic quark potential model, we examine a method how to construct Lorentz-invariant scattering amplitudes and/or decay widths and develop a formulation to calculate Lorentz-boosted ones given the rest frame wave functions in our model. To show how effective this is, we apply the formulation to calculate the semileptonic weak form factors out of the rest frame wave functions of heavy mesons and numerically calculate the dynamical 1/m_Q corrections to those for the process B-bar -> D^{(*)}\ellνbased on our model for heavy mesons. It is shown that nonvanishing expressions for ρ_1(ω)=ρ_2(ω) and ρ_3(ω)=ρ_4(ω)=0 are obtained in a special Lorentz frame, where ρ_i(ω) are the parameters used in the Neubert-Rieckert decomposition of form factors. Various values of form factors are estimated, which are compatible with recent experimental data as well as other theoretical calculations.

hep-ph↗