TY - JOUR
T1 - Factorization in B→Kπ + - Decays
AU - Grinstein, Benjamín
AU - Pirjol, Dan
PY - 2006
Y1 - 2006
N2 - We derive factorization relations for the transverse helicity amplitudes in B→Kπ + - at leading order in Λ/mb, in the kinematical region with an energetic kaon and a soft pion. We identify and compute a new contribution of leading order in Λ/mb to the B→Kπ + - amplitude which is not present in the one-body decay B→K* + -. As an application we study the forward-backward asymmetry (FBA) of the lepton momentum angular distribution in B→Kπ + - decays on and off the K* resonance. The FBA in these decays has a zero at q02=q02(MKπ), which can be used, in principle, for determining the Wilson coefficients C7,9 and testing the standard model. We point out that the slope of the q02(MKπ2) curve contains the same information about the Wilson coefficients as the location of the zero, but is less sensitive to unknown nonperturbative dynamics. We estimate the location of the zero at leading order in factorization, and using a resonant model for the B→Kπ + - nonfactorizable amplitude.
AB - We derive factorization relations for the transverse helicity amplitudes in B→Kπ + - at leading order in Λ/mb, in the kinematical region with an energetic kaon and a soft pion. We identify and compute a new contribution of leading order in Λ/mb to the B→Kπ + - amplitude which is not present in the one-body decay B→K* + -. As an application we study the forward-backward asymmetry (FBA) of the lepton momentum angular distribution in B→Kπ + - decays on and off the K* resonance. The FBA in these decays has a zero at q02=q02(MKπ), which can be used, in principle, for determining the Wilson coefficients C7,9 and testing the standard model. We point out that the slope of the q02(MKπ2) curve contains the same information about the Wilson coefficients as the location of the zero, but is less sensitive to unknown nonperturbative dynamics. We estimate the location of the zero at leading order in factorization, and using a resonant model for the B→Kπ + - nonfactorizable amplitude.
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U2 - 10.1103/PhysRevD.73.094027
DO - 10.1103/PhysRevD.73.094027
M3 - Article
AN - SCOPUS:33744548128
SN - 1550-7998
VL - 73
JO - Physical Review D - Particles, Fields, Gravitation and Cosmology
JF - Physical Review D - Particles, Fields, Gravitation and Cosmology
IS - 9
M1 - 094027
ER -