Implications of factorization for the determination of hadronic form factors in Ds+→ φ transition

• Published in: Physics letters. B 1994-11, Vol.339 (1), p.173-180
• Main Authors: Gourdin, M., Kamal, A.N., Keum, Y.Y., Pham, X.Y.
• Format: Article
• Language: English
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/0370-2693(94)91151-7

Using factorization we determine the allowed domains of the ratios of form factors, x= A 2(0) A 1(0) and y= V(0) A 1(0) , from the experimentally measured ratio R h Γ(D s +→φϱ +) Γ(D s +→φπ +) assuming three different scenarios for the q 2-dependence of the form factors. We find that the allowed domains overlap with those obtained by using the experimentally measured ratio R s l = Γ(D s +→φ l +ν l Γ(D s +→φπ +) provided that the phenomenological paramet er a 1 is 1.23. Such a comparison presents a genuine test of factorization. We calculate the longitudinal polarization fraction, Γ L Γ  Γ(D s +→φ Lϱ L +) Γ(D s +→φϱ +) , in the three scenarios for the q 2-dependence of the form factors and emphasize the importance of measuring Γ L Γ . Finally we discuss the q 2-distribution of the semileptonic decay and find that it is rather insensitive to the scenarios for the q 2-dependence of the form factors, and unless very accurate data can be obtained it is unlikely to discriminate between the different scenarios. Useful information on the value of x might be obtained by the magnitude of the q 2-distribution near q 2 = 0. However the most precise information on x and y would come from the knowledge of the longitudinal and left-right transverse polarizations of the final vector mesons in hadronic and/or semileptonic decays.