物理所參與國際合作研究成果,發表於Physical Review Letters

物理所林及仁助理教授與美國College of William and Mary (William Detmold 助理教授,
Stefan Meinel 博士後研究員) 合作,有關 heavy hadron axial couplings 的成果,
於2012年4月27 日發表於 Physical Review Letters.。

Axial Couplings and Strong Decay Widths of Heavy Hadrons

Phys. Rev. Lett. 108, 172003 (2012)
DOI: 10.1103/PhysRevLett.108.172003
Published 27 April 2012

We calculate the axial couplings of mesons and baryons containing a heavy quark in the static limit using lattice QCD. These couplings
determine the leading interactions in heavy hadron chiral perturbation theory and are central quantities in heavy quark physics, as they
control strong decay widths and the light-quark mass dependence of heavy hadron observables. Our analysis makes use of lattice data at
six different pion masses, 227 MeV < m_\pi < 352 MeV, two lattice spacings, a=0.085, 0.112 fm, and a volume of (2.7 fm)^3. Our results
for the axial couplings are g_1=0.449(51), g_2=0.84(20), and g_3=0.71(13), where g_1 governs the interaction between heavy-light
mesons and pions and g_{2,3} are similar couplings between heavy-light baryons and pions. Using our lattice result for g_3, and constraining
1/m_Q corrections in the strong decay widths with experimental data for \Sigma_c^{(*)} decays, we obtain \Gamma[\Sigma_b^{(*)} \to
\Lambda_b \pi^\pm] = 4.2(1.0), 4.8(1.1), 7.3(1.6), 7.8(1.8) MeV for the \Sigma_b^+, \Sigma_b^-, \Sigma_b^{*+}, \Sigma_b^{*-} initial
states, respectively. We also derive upper bounds on the widths of the \Xi_b^{\prime(*)} baryons.