Electromagnetic quarkonium decays at order v
نویسندگان
چکیده
We compute S-wave and P-wave electromagnetic quarkonium decays at order v7 in the heavy-quark velocity expansion. In the S-wave case, our calculation confirms and completes previous findings. In the P-wave case, our results are in disagreement with previous ones; in particular, we find that two matrix elements less are needed. The cancellation of infrared singularities in the matching procedure is discussed.
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