Nonperturbative m[subscript X] cut effects in -->X[subscript s]l[superscript +]l[superscript -] observables

• Main Authors: Lee, Keith S. M. (Contributor), Tackmann, Frank (Contributor)
• Other Authors: Massachusetts Institute of Technology. Center for Theoretical Physics (Contributor), Massachusetts Institute of Technology. Laboratory for Nuclear Science (Contributor)
• Format: Article
• Language: English
• Published: American Physical Society, 2010-03-18T18:59:36Z.
• Subjects: Article
• Online Access: Get fulltext

 Recently, it was shown that in inclusive B→X[subscript s]ℓ[superscript +]ℓ[superscript -] decay, an angular decomposition provides three independent (q2 dependent) observables. A strategy was formulated to extract all measurable Wilson coefficients in B→X[subscript s]ℓ[superscript +]ℓ[superscript -] from a few simple integrals of these observables in the low q[superscript 2] region. The experimental measurements in the low q[superscript 2] region require a cut on the hadronic invariant mass, which introduces a dependence on nonperturbative b quark distribution functions. The associated hadronic uncertainties could potentially limit the sensitivity of these decays to new physics. We compute the nonperturbative corrections to all three observables at leading and subleading order in the power expansion in Λ[subscript QCD]/m[subscript b]. We find that the subleading power corrections give sizeable corrections, of order -5% to -10% depending on the observable and the precise value of the hadronic mass cut. They cause a shift of order -0.05  GeV[superscript 2] to -0.1   GeV[superscript 2] in the zero of the forward-backward asymmetry.