Hadronic B decays involving even-parity charmed mesons -: art. no. 094005

Hadronic B decays containing an even-parity charmed meson in the final state are studied. Specifically we focus on the Cabibbo-allowed decays (B) over bar -->D**pi(rho), D**(D) over bar (()(s)*()), (D) over bar (s)**D-(*()) and (B) over bar (s)-->D-s**pi(rho), where D** denotes generically a p-wave charmed meson. The B-->D** transition form factors are studied in the improved version of the Isgur-Scora-Grinstein-Wise quark model. We apply heavy quark effective theory and chiral symmetry to study the strong decays of p-wave charmed mesons and determine the magnitude of the D-1(1/2)-D-1(3/2) mixing angle (the superscript standing for the total angular momentum of the light quark). Except for the decay to D-1(2427)(0)pi(-) the predictions of B(B--->D**(0)pi(-)) agree with experiment. The sign of the D-1(1/2)-D-1(3/2) mixing angle is found to be positive in order to avoid a severe suppression of the production of D-1(2427)(0)pi(-). The interference between color-allowed and color-suppressed tree amplitudes is expected to be destructive in the decay B--->D-1(2427)(0)pi(-). Hence, an observation of the ratio D-1(2427)(0)pi(-)/D-1(2427)(+)pi(-) can be used to test the relative signs of various form factors as implied by heavy quark symmetry. Although the predicted B--->D-1(2420)(0)rho(-) at the level of 3x10(-3) exceeds the present upper limit, it leads to the ratio D-1(2420)rho(-)/D-1(2420)pi(-)approximate to2.6, as expected from the factorization approach and from the ratio f(rho)/f(pi)approximate to1.6. Therefore, it is crucial to have a measurement of this mode to test the factorization hypothesis. For (B) over bar -->(D) over bar (s)**D decays, it is expected that (D) over bar (s0)*Dgreater than or similar to(D) over bar D-s1 as the decay constants of the multiplet (D-s0*,D-s1) become the same in the heavy quark limit. The preliminary Belle observation of fairly less abundant production of (D) over bar (s0)*D than (D) over bar D-s1 is thus a surprise. What is the cause for the discrepancy between theory and experiment remains unclear. Meanwhile, it is also important to measure the B decay into (D) over bar (s1)(2536)D-(*()) to see if it is suppressed relative to (D) over bar (s1)(2463)D-(*()) to test the heavy quark symmetry relation f(Ds1)(2536)(D) over bar (s2)*D-(*()) could imply the importance of final-state rescattering effects.