Subleading shape functions in B ---> X(u) lepton anti-nu and the determination of |V(ub)|

May, 2002
6 pages
Published in:
  • Phys.Lett.B 543 (2002) 261-268
e-Print:
Report number:
  • UCSD-PTH-02-12

Citations per year

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Abstract:
We calculate the subleading twist contributions to the endpoint of the inclusive lepton energy spectrum in B -> X_u l \nu. We show that the same two subleading twist functions that appear in the decay B -> X_s \gamma govern the subleading effects in this decay. Using these results we find large O(Lambda/mB) corrections to the determination of |Vub| from the endpoint of the charged lepton spectrum. Using a simple model for the relevant subleading shape functions, we estimate the uncertainty in |Vub| from Lambda/mb corrections to be at the ~ 15% level for a lower lepton energy cut of 2.2 GeV.
Note:
  • 6 pages, 2 figures Report-no: UCSD/PTH 02-12
  • B: semileptonic decay
  • decay: inclusive reaction
  • up
  • lepton: energy spectrum
  • effect: higher-twist
  • B: radiative decay
  • quantum chromodynamics: Lambda parameter
  • B: mass
  • CKM matrix matrix
  • B: structure function