Speaker
            Mr
    Evgeny Kozyrev
        
            (Budker Institute of Nuclear Physics)
        
    Description
We study the process $e^+e^-\to e^+e^- \eta'$ in the double-tag mode and measure for the first time the $\gamma^{\star}\gamma^{\star} \to \eta'$ transition form factor $F_{\eta'}(Q_1^2, Q_2^2)$ in the momentum-transfer
range $2 < Q_1^2, Q_2^2 < 60$ GeV$^2$. The analysis is based on data with an integrated luminosity 469 fb$^{-1}$ collected at the PEP-II $e^+e^-$ collider with the BABAR detector at center-of-mass energies near 10.6 GeV. The results for the form factor are compared with the predictions based on pQCD and VMD.
Authors
        
            
                
                
                    
                        Fabio Anulli
                    
                
                
                        (Sapienza Universita e INFN, Roma I (IT))
                    
            
        
            
                
                        Mr
                    
                
                    
                        Evgeny Kozyrev
                    
                
                
                        (Budker Institute of Nuclear Physics)