The eta(c)gamma gamma* transition form factor in the decay eta(c)->gamma l(+)l(-) and in the crossed channels gamma e(-)->eta(c)e(-) and e(+)e(-)->eta(c)gamma

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2000-08-01

Author

Di Salvo, E
Rekalo, MP
Tomasi-Gustafsson, E

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The Dalitz distribution and the effective mass spectrum of the lepton pair produced in the decay eta(c) --> gamma l(+)l(-), as well as the differential cross sections for the crossed channels gamma e(-) --> eta(c)e(-) and e(+)e(-) --> eta(c)gamma, are calculated in terms of the sole electromagnetic transition form factor for the vertex eta(c) --> gamma gamma*, where gamma* is a virtual photon with a space-like (for gamma e(-) --> eta(c)e(-)) or a time-like (for e(+)e(-) --> eta(c)gamma and eta(c) --> gamma l(+)l(-)) four-momentum. Explicit parameterizations of the transition form factor are found in two different approaches, namely in the vector dominance model and in a QCD-inspired consideration on the basis of the process c (c) over bar --> gamma l(+)l(-), with zero relative three-momentum of the annihilating quarks.

Subject Keywords

Physics and Astronomy (miscellaneous), Engineering (miscellaneous)

URI

https://hdl.handle.net/11511/67081

Journal

EUROPEAN PHYSICAL JOURNAL C

DOI

https://doi.org/10.1007/s100520050022

Collections

Department of Physics, Article

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Citation Formats

E. Di Salvo, M. Rekalo, and E. Tomasi-Gustafsson, “The eta(c)gamma gamma* transition form factor in the decay eta(c)->gamma l(+)l(-) and in the crossed channels gamma e(-)->eta(c)e(-) and e(+)e(-)->eta(c)gamma,” EUROPEAN PHYSICAL JOURNAL C, pp. 295–302, 2000, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/67081.