Use and misuse of QCD sum rules in heavy-to-light transitions: The decay B{r_arrow}{rho}e{nu} reexamined

Journal Article · Thu May 01 04:00:00 EDT 1997 · Physical Review, D

DOI:https://doi.org/10.1103/PhysRevD.55.5561· OSTI ID:562449

Ball, P ^[1]; Braun, V M ^[2]

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1. Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, Illinois 60510 (United States)
2. NORDITA, Blegdamsvej 17, DK-2100 Copenhagen (Denmark)

The existing calculations of the form factors describing the decay B{r_arrow}{rho}e{nu} from QCD sum rules have yielded conflicting results at small values of the invariant mass squared of the lepton pair. We demonstrate that the disagreement originates from the failure of the short-distance expansion to describe the {rho} meson distribution amplitude in the region where almost the whole momentum is carried by one of the constituents. This limits the applicability of QCD sum rules based on the short-distance expansion of a three-point correlation function to heavy-to-light transitions and calls for an expansion around the light cone, as realized in the light-cone sum rule approach. We derive and update light-cone sum rules for all the semileptonic form factors, using recent results on the {rho} meson distribution amplitudes. The results are presented in detail together with a careful analysis of the uncertainties, including estimates of higher-twist effects, and compared to lattice calculations and recent CLEO measurements. We also derive a set of {open_quotes}improved{close_quotes} three-point sum rules, in which some of the problems of the short-distance expansion are avoided and whose results agree to good accuracy with those from light-cone sum rules. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 562449
• Journal Information: Physical Review, D, Journal Name: Physical Review, D Journal Issue: 9 Vol. 55; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
B MESONS
CORRELATION FUNCTIONS
FORM FACTORS
LIGHT CONE
MASS
QUANTUM CHROMODYNAMICS
RHO-770 MESONS
SEMILEPTONIC DECAY
SUM RULES