1111.1151 (Feng-Kun Guo et al.)

Examining coupled-channel effects in radiative charmonium transitions    [PDF]

Feng-Kun Guo, Ulf-G. Meißner

Coupled-channel effects due to coupling of charmonia to the charmed and
anticharmed mesons are of current interest in heavy quarkonium physics.
However, the effects have not been unambiguously established. In this paper, a
clean method is proposed in order to examine the coupled-channel effects in
charmonium transitions. We show that the hindered M1 radiative transitions from
the 2P to 1P charmonia are suitable for this purpose. We suggest to measure one
or more of the ratios Gamma(h_c'-->chi_{cJ} gamma)/Gamma(chi_{cJ}'-->chi_{cJ}
pi^0) and Gamma(chi_{cJ}'-->h_c gamma)/Gamma(chi_{cJ}'-->chi_{cJ} pi^0), for
which highly nontrivial and parameter-free predictions are given. The picture
can also be tested using both unquenched and quenched lattice calculations.

View original: http://arxiv.org/abs/1111.1151