Heavy Meson Spectroscopy and Prediction of Bottom Mesons

Abstract

The approximate symmetries of Quantum Chromo Dynamics in the infinite heavy quark (Q  c,b) mass limit ( 0) Q m  and in the chiral limit for the light quarks ( 0, , , ) q m  q  u d s can be used together to build up an effective chiral Lagrangian for heavy and light mesons describing strong interactions among effective meson fields. We studied the heavy mesons masses, where by the symmetries of heavy and light quarks are exploited to formulate a theory that describes the low energy interaction among heavy mesons. Within the framework of heavy quark effective theory and chiral perturbation theory, masses of even and odd parity heavy mesons are studied. Mass formulae are developed for ground state 0 p J   and 1 and first excited state, 0 p J   and 1 for the heavy meson up to 1/  Q O m corrections. We begin by constructing an effective Lagrangian which includes all possible terms that transform correctly under the symmetries, and is typically non-renormalizable with an infinite number of terms. These terms are organized in importance by power counting in a small parameter. Identifying a small expansion parameter usually depends on having scales which are widely separated. Further the hadronic mass terms are developed from the Lagrangian in terms of , 1  and 2  , where 1  and 2  are non-peturbative parameters of QCD. Effective field theory approach has been used where different scales in the problem are separated, so as to concentrate on the interesting physics at a our 1GeV scale. Furthermore, the power counting gives us a way to estimate the uncertainty in working at this given order. Also we have calculated the bottom meson masses, by using the data of charm meson masses and their hyperfine splitting.