### Abstract

We calculate, within the NRQCD factorization formalism, the leading color-octet contributions to ψ production in photon-nucleon and electron-nucleon collisions. The expressions we obtaine depend on the NRQCD matrix elements 〈O _{8} ^{ψ}( ^{1}S _{0})〉 and (O _{8} ^{ψ}( ^{3}P _{0})〉. These matrix elements can be determined by fitting to experimental data. The color-octet contribution to ψ photoproduction is in the forward region of phase space, where there may be large corrections to the NRQCD result from higher twist terms. As to ψ leptoproduction we point out that the theoretical uncertainties plaguing the photoproduction calculation vanish in the large momentum transfer limit. In this region of phase space the NRQCD formalism should be valid, making ψ leptoproduction an ideal laboratory for testing the theory.

Original language | English (US) |
---|---|

Pages (from-to) | 3995-4004 |

Number of pages | 10 |

Journal | International Journal of Modern Physics A |

Volume | 12 |

Issue number | 22 |

State | Published - Sep 10 1997 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Physics and Astronomy(all)
- Mathematical Physics
- Nuclear and High Energy Physics

### Cite this

**Determining color-octet ψ-production matrix elements from γp and ep processes.** / Fleming, Sean P.

Research output: Contribution to journal › Article

*International Journal of Modern Physics A*, vol. 12, no. 22, pp. 3995-4004.

}

TY - JOUR

T1 - Determining color-octet ψ-production matrix elements from γp and ep processes

AU - Fleming, Sean P

PY - 1997/9/10

Y1 - 1997/9/10

N2 - We calculate, within the NRQCD factorization formalism, the leading color-octet contributions to ψ production in photon-nucleon and electron-nucleon collisions. The expressions we obtaine depend on the NRQCD matrix elements 〈O 8 ψ( 1S 0)〉 and (O 8 ψ( 3P 0)〉. These matrix elements can be determined by fitting to experimental data. The color-octet contribution to ψ photoproduction is in the forward region of phase space, where there may be large corrections to the NRQCD result from higher twist terms. As to ψ leptoproduction we point out that the theoretical uncertainties plaguing the photoproduction calculation vanish in the large momentum transfer limit. In this region of phase space the NRQCD formalism should be valid, making ψ leptoproduction an ideal laboratory for testing the theory.

AB - We calculate, within the NRQCD factorization formalism, the leading color-octet contributions to ψ production in photon-nucleon and electron-nucleon collisions. The expressions we obtaine depend on the NRQCD matrix elements 〈O 8 ψ( 1S 0)〉 and (O 8 ψ( 3P 0)〉. These matrix elements can be determined by fitting to experimental data. The color-octet contribution to ψ photoproduction is in the forward region of phase space, where there may be large corrections to the NRQCD result from higher twist terms. As to ψ leptoproduction we point out that the theoretical uncertainties plaguing the photoproduction calculation vanish in the large momentum transfer limit. In this region of phase space the NRQCD formalism should be valid, making ψ leptoproduction an ideal laboratory for testing the theory.

UR - http://www.scopus.com/inward/record.url?scp=0242656507&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0242656507&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0242656507

VL - 12

SP - 3995

EP - 4004

JO - International Journal of Modern Physics A

JF - International Journal of Modern Physics A

SN - 0217-751X

IS - 22

ER -