Speaker
Dr
Andrew Lytle
(University of Glasgow)
Description
We use both non-relativistic QCD (NRQCD) and fully relativistic formalisms to calculate
semileptonic form factors for the decays B_c -> eta_c lv and B_c -> J/psi lv over the entire q^2 range. To achieve this we employ a highly improved lattice quark action at several lattice spacings down to a=.044 fm, which allows a fully relativistic treatment of charm and simulation of the full q^2 range with controlled continuum extrapolation. We have two ways of treating the b quark: either with an O(alpha_s) improved NRQCD formalism or by extrapolating a heavy mass m_h to m_b in the relativistic formalism. Comparison of the two approaches provides an important cross-check of methodologies in lattice QCD. Nonperturbative renormalisation of the currents in the relativistic theory also allows us then to fix NRQCD-charm normalisation for b to c decays such as B -> D and B -> D^*.
Primary author
Dr
Andrew Lytle
(University of Glasgow)
Co-authors
Dr
Brian Colquhoun
(University of Glasgow)
Prof.
Christine Davies
(University of Glasgow)
Dr
Craig McNeile
(Plymouth University)
Dr
Jonna Koponen
(University of Glasgow)
