### Abstract

We study the nuclear (or A) dependence of the coherent η photoproduction reaction in a relativistic impulse approximation approach. We use a standard relativistic parametrization of the elementary amplitude, based on a set of four Lorentz-and gauge-invariant amplitudes, to calculate the coherent production cross section from ^{4}He, ^{12}C, and ^{40}Ca. In contrast to nonrelativistic treatments, our approach maintains the full relativistic structure of the process. The nuclear structure affects the process through the ground-state tensor density. This density is sensitive to relativistic effects and depends on A in a different manner than the vector density used in nonrelativistic approaches. This peculiar dependence results in ^{4}He having a cross section significantly smaller than that of ^{12}C - in contrast to existent nonrelativistic calculations. Distortion effects are incorporated through an η-nucleus optical potential that is computed in a simple "tp" approximation.

Original language | English |
---|---|

Pages (from-to) | 2053-2056 |

Number of pages | 4 |

Journal | Physical Review C - Nuclear Physics |

Volume | 57 |

Issue number | 4 |

Publication status | Published - Apr 1998 |

Externally published | Yes |

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### ASJC Scopus subject areas

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

### Cite this

*Physical Review C - Nuclear Physics*,

*57*(4), 2053-2056.

**Nuclear dependence of the coherent η photoproduction reaction in a relativistic approach.** / Aburaddad, Laith; Piekarewicz, J.; Sarty, A. J.; Benmerrouche, M.

Research output: Contribution to journal › Article

*Physical Review C - Nuclear Physics*, vol. 57, no. 4, pp. 2053-2056.

}

TY - JOUR

T1 - Nuclear dependence of the coherent η photoproduction reaction in a relativistic approach

AU - Aburaddad, Laith

AU - Piekarewicz, J.

AU - Sarty, A. J.

AU - Benmerrouche, M.

PY - 1998/4

Y1 - 1998/4

N2 - We study the nuclear (or A) dependence of the coherent η photoproduction reaction in a relativistic impulse approximation approach. We use a standard relativistic parametrization of the elementary amplitude, based on a set of four Lorentz-and gauge-invariant amplitudes, to calculate the coherent production cross section from 4He, 12C, and 40Ca. In contrast to nonrelativistic treatments, our approach maintains the full relativistic structure of the process. The nuclear structure affects the process through the ground-state tensor density. This density is sensitive to relativistic effects and depends on A in a different manner than the vector density used in nonrelativistic approaches. This peculiar dependence results in 4He having a cross section significantly smaller than that of 12C - in contrast to existent nonrelativistic calculations. Distortion effects are incorporated through an η-nucleus optical potential that is computed in a simple "tp" approximation.

AB - We study the nuclear (or A) dependence of the coherent η photoproduction reaction in a relativistic impulse approximation approach. We use a standard relativistic parametrization of the elementary amplitude, based on a set of four Lorentz-and gauge-invariant amplitudes, to calculate the coherent production cross section from 4He, 12C, and 40Ca. In contrast to nonrelativistic treatments, our approach maintains the full relativistic structure of the process. The nuclear structure affects the process through the ground-state tensor density. This density is sensitive to relativistic effects and depends on A in a different manner than the vector density used in nonrelativistic approaches. This peculiar dependence results in 4He having a cross section significantly smaller than that of 12C - in contrast to existent nonrelativistic calculations. Distortion effects are incorporated through an η-nucleus optical potential that is computed in a simple "tp" approximation.

UR - http://www.scopus.com/inward/record.url?scp=0032374949&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0032374949&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0032374949

VL - 57

SP - 2053

EP - 2056

JO - Physical Review C - Nuclear Physics

JF - Physical Review C - Nuclear Physics

SN - 0556-2813

IS - 4

ER -