The gluon content of the $η$ and $η^{\prime}$ mesons
Abstract
Description
We analyze power-suppressed contributions to singlet pseudoscalar $η$ and $η^{\prime}$ meson transition form factors. These corrections stem from endpoint singularities and help improve the agreement between QCD theory and the experimental data, in particular, at low-momentum transfers. Using the CLEO data, we extract information on the profile of the $η_1$ and $η_8$ distribution amplitudes in the $SU(3)_{F}$ octet-singlet basis employing both the one-angle and the two-angle mixing schemes. In the former scheme, we find good agreement with the CLEO data, while in the second case, our approach requires non-asymptotic profiles for these mesons.
19 pages, 6 figures consisting of 9 eps files. Needs here.sty. Typo in $beta_1$ corrected. Invited plenary talk presented by the first author at Second Symposium on Threshold Meson Production in pp and pd Interactions. Extended COSY-11 collaboration meeting. Collegium Maius, Cracow, Poland, May 31-June 3, 2004
19 pages, 6 figures consisting of 9 eps files. Needs here.sty. Typo in $beta_1$ corrected. Invited plenary talk presented by the first author at Second Symposium on Threshold Meson Production in pp and pd Interactions. Extended COSY-11 collaboration meeting. Collegium Maius, Cracow, Poland, May 31-June 3, 2004