1205.3026 (Zhi-Wei Huang et al.)

Analytic calculation of doubly heavy hadron spectral density in
coordinate space    [PDF]

Zhi-Wei Huang, Jueping Liu

A systematic and easy-to-use method is developed to directly calculate the doubly heavy hadron spectral density in the coordinate space. The correlation function is expressed in terms of hypergeometric functions, and the spectral density is obtained through two independent approaches: the simple integral representation method and the $\epsilon$-expansion method, respectively. It is found that the spectral density of doubly heavy hadrons can be analytically expressed through commonly known simple functions. This method can drastically simplify and improve the QCD spectral sum rule calculation of the doubly heavy hadrons.

View original: http://arxiv.org/abs/1205.3026