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

Abstract

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 sℓ = Γ(D + s → φℓ + ν ℓ )/Γ(D + s → φπ + ) provided that the phenomenological parameter a 1 is 1.23. Such a comparison presents a genuine test of factorization. We calculate the longitudinal polarization fraction,, in the three scenarios for the q 2dependence 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.

Nonleptonic two-body charmed meson decays in an effective model for their semileptonic decays

“…The nonleptonic D meson decays are challenging to understand theoretically [1,2,3,4,5,6,7,8,9,10,11,12,13,14]. The short distance effects are now well understood [15,16], but the nonperturbative techniques required for the evaluation of certain matrix elements are based on the approximate models.…”

Extraction ofa1anda2fromB→ψK(Cheng1, Tseng2 1995Phys. Rev. D351350View full textAdd to dashboardCite

“…[1]). However, it was pointed out recently that there are two experimental data for B → ψK ( * ) which cannot be accounted for simultaneously by all commonly used models [7,8]. That is, all the known models in the literature fail to reproduce the data of either the production ratio R = Γ(B → ψK * )/Γ(B → ψK) or the fraction of longitudinal polarization Γ L /Γ in B → ψK * or both.…”

“…Based on factorization, it was shown recently that currently used B → K ( * ) form factors fail to explain the data of R and Γ L /Γ simultaneously [7,8]. This might be attributed either to a failure of the factorization method (see e.g.…”

Nonfactorization and the decaysD s +→φπ +,φρ + andφl + ν l

“…Scenario 5: A 1 (q 2 ) and A 2 (q 2 ) flat and V (q 2 ) extrapolates in q 2 as monopole with pole mass 2.11 GeV [13]. We get…”

“…Though the problem has been discussed in [13], we revisit it with the purpose of investigating the role of nonfactorized contribution in a formalism that uses the N c = 3 values of a 1 (m c ) and a 2 (m c ). The reason for choosing the Cabibbo-favored decays of D + s is that the hadronic final states involve only a single isospin and, consequently, one does not have to worry about the interference effects due to final state interactions.…”