The β-term for D * → D γ within a heavy-light chiral quark model
Department of Physics, University of Oslo, P.O. Box 1048 Blindern, N-0316 Oslo, Norway
Accepted: 25 March 2003
Published online: 16 March 2004
We present a calculation of the β-term for D * → D γ within a quark model which exhibits both chiral symmetry and heavy quark symmetry. Soft gluon effects in terms of a model dependent gluon condensate are included. Also, calculations of 1/m c corrections are performed. We find that the value of β is rather sensitive to the constituent quark mass compared to other quantities calculated within the same model. Also, to obtain a value close to the experimental value, one has to choose a constituent light quark mass larger than for other quantities studied in previous papers. For a light quark mass in the range 250 to 300 MeV and a quark condensate in the range -(250 - 270 MeV)3 we find the value (2.5 ± 0.6) GeV–1. This value is in agreement with the value of β extracted from experiment (2.7 ± 0.2) GeV–1.
© Società Italiana di Fisica, Springer-Verlag, 2005