TTP08-07 Modelling light-cone distribution amplitudes from non-relativistic bound states

TTP08-07 Modelling light-cone distribution amplitudes from non-relativistic bound states

TTP08-07 Modelling light-cone distribution amplitudes from non-relativistic bound states

We calculate light-cone distribution amplitudes for non-relativistic bound states, including radiative corrections from relativistic gluon exchange to first order in the strong coupling constant. We distinguish between bound states of quarks with equal (or similar) mass, m_1 ~ m_2, and between bound states where the quark masses are hierarchical, m_1 » m_2. For both cases we calculate the distribution amplitudes at the non-relativistic scale and discuss the renormalization-group evolution for the leading-twist and 2-particle distributions. Our results apply to hard exclusive reactions with non-relativistic bound states in the QCD factorization approach like, for instance, (B_c → eta_c l nu) or (e^+ e^- → J/psi eta_c). They also serve as a toy model for light-cone distribution amplitudes of light mesons or heavy B and D mesons, for which certain model-independent properties can be derived. In particular, we calculate the anomalous dimension for the B meson distribution amplitude phi_B^-(w) in the Wandzura-Wilczek approximation and derive the according solution of the evolution equation at leading logarithmic accuracy.

Guido Bell and Thorsten Feldmann
JHEP 0804 061 2008
PDF PostScript arXiv
This website uses cookies for visitor traffic analysis. By using the website, you agree with storing the cookies on your computer.More information