Thursday, February 9, 2012

1110.6402 (S. Noguera et al.)

The eta-photon transition form factor    [PDF]

S. Noguera, S. Scopetta
The eta-photon transition form factor is evaluated in a formalism based on a
phenomenological description at low values of the photon virtuality, and a
QCD-based description at high photon virtualities, matching at a scale
$Q_{0}^{2}$. The high photon virtuality description makes use of a Distribution
Amplitude calculated in the Nambu-Jona-Lasinio model with Pauli-Villars
regularization at the matching scale $Q_{0}^{2}$, and QCD evolution from
$Q_{0}^{2}$ to higher values of $Q^{2}$. A good description of the available
data is obtained. The analysis indicates that the recent data from the BaBar
collaboration on pion and eta transition form factor can be well reproduced, if
a small contribution of twist three at the matching scale $Q_{0}^{2}$ is
included.
View original: http://arxiv.org/abs/1110.6402

No comments:

Post a Comment