Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10724045 | Physics Letters B | 2011 | 4 Pages |
Abstract
We determine the leading-order nonrelativistic quantum chromodynamics (NRQCD) matrix element ãO1ãÏ and the ratio ãq2ãÏ, for Ï=Ï(nS) with n=1, 2, and 3 by comparing the measured values for Î[Ïâe+eâ] with the NRQCD factorization formula in which relativistic corrections are resummed to all orders in the heavy-quark velocity v. The values for ãq2ãÏ, which is the ratio of order-v2 matrix element to ãO1ãÏ, are new. They can be used for NRQCD predictions involving Ï(nS) and ηb(nS) with relativistic corrections. As an application, we predict the two-photon decay rates for the spin-singlet states: Î[ηb(1S)âγγ]=0.512â0.094+0.096 keV, Î[ηb(2S)âγγ]=0.235â0.043+0.043 keV, and Î[ηb(3S)âγγ]=0.170â0.031+0.031 keV.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Nuclear and High Energy Physics
Authors
Hee Sok Chung, Jungil Lee, Chaehyun Yu,