Naslov
The leading-twist two gluon distribution amplitude in exclusive processes involving eta and eta' mesons

Autori
Passek-Kumerički, Kornelija

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Mini-proceedings of the Workshop on Spontaneously Broken Chiral Symmetry and Hard QCD-Phenomena / Frankfurt, L. ; Goeke, K. ; Pobylitsa, P. V. ; Polyakov, M. V. ; Strikman, M. ; Weise, W. - , 2002, 27-27

Skup
Workshop on Spontaneously Broken Chiral Symmetry and Hard QCD-Phenomena

Mjesto i datum
Bad Honnef, Njemačka, 15.07.2002. - 19.07.2002

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
eta; eta'; gluon distribution amplitude; quark distribution amplitude; transition form factor

Sažetak
The brief review of work in progress has been presented. The formalism for treating the leading- twist two-gluon Fock components appearing in hard processes that involve eta and eta' mesons has been reexamined permitting a critical appraisal of the relevant literature. A consistent set of conventions for the definition of the gluon distribution amplitude, the anomalous dimensions as well as the projector of a two-gluon state onto an eta or eta' state has been established. The eta, eta'-photon transition form factor has been calculated to order alpha_s and as a crucial test of the consistency of this set of conventions the cancellation of the collinear and UV singularities has been explicitly shown. An estimate of the lowest Gegenbauer coefficients of the gluon and quark distribution amplitudes has been obtained from a fit to the eta, eta'-photon transition form factor data. The results were applied to chi ->eta eta (eta' eta') decays, deeply virtual electroproduction of eta and \eta' mesons (DVEM) and g^* g^* eta' vertex. While for DVEM the two- gluon contributions are suppressed for small momentum transfer t, for the g^* g^* eta' vertex a significant dependence on gg contributions has been observed.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

Napomena
[arXiv:hep-ph/0211291]

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