### Abstract

We compute in order αs the nonrelativistic QCD (NRQCD) short-distance coefficients that match quark-antiquark operators of all orders in the heavy-quark velocity v to the electromagnetic current. We employ a new method to compute the one-loop NRQCD contribution to the matching condition. The new method uses full-QCD expressions as a starting point to obtain the NRQCD contribution, thus greatly streamlining the calculation. Our results show that, under a mild constraint on the NRQCD operator matrix elements, the NRQCD velocity expansion for the quark-antiquark-operator contributions to the electromagnetic current converges. The velocity expansion converges rapidly for approximate J/ψ operator matrix elements.

Original language | English |
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Article number | 014007 |

Journal | Physical Review D - Particles, Fields, Gravitation and Cosmology |

Volume | 79 |

Issue number | 1 |

DOIs | |

Publication status | Published - 2009 Jan 5 |

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### ASJC Scopus subject areas

- Nuclear and High Energy Physics

### Cite this

*Physical Review D - Particles, Fields, Gravitation and Cosmology*,

*79*(1), [014007]. https://doi.org/10.1103/PhysRevD.79.014007