Using the CLEO II detector at CESR, we measure the η′ energy spectra in Y(1S) decays that we compare with models of the η′ g*g form factor. This form factor, especially at large η′ energies, may provide an explanation of the large rate for B→Xs η′. Our data do not support a large anomalous coupling at higher q2 and thus the large η′ rate remains a mystery, possibly requiring a non-standard-model explanation.
ASJC Scopus subject areas
- Nuclear and High Energy Physics