Measurement of lepton momentum moments in the decay anti-B ---> X l anti-nu and determination of heavy quark expansion parameters and |V(cb)|
Collaboration
21 pages
Published in:
- Phys.Rev.D 67 (2003) 072001
e-Print:
- hep-ex/0212051 [hep-ex]
PDG: -QUARK MASS
Report number:
- CLNS-02-1810,
- CLEO-02-16
Experiments:
View in:
Citations per year
Abstract:
We measure the primary lepton momentum spectrum in B-bar to X l nu decays, for p_l > 1.5 GeV/c in the B rest frame. From this, we calculate various moments of the spectrum. In particular, we find R_0 = [int(E_l>1.7) (dGam/dE_sl)*dE_l] / [int(E_l>1.5) (dGam/dE_sl)*dE_l] = 0.6187 +/- 0.0014_stat +/- 0.0016_sys and R_1 = [int(E_l>1.5) E_l(dGam/dE_sl)*dE_l] / [int(E_l>1.5) (dGam/dE_sl)*dE_l] = (1.7810 +/- 0.0007_stat +/- 0.0009_sys) GeV. We use these moments to determine non-perturbative parameters governing the semileptonic width. In particular, we extract the Heavy Quark Expansion parameters Lambda-bar = (0.39 +/- 0.03_stat +/- 0.06_sys +/- 0.12_th) GeV and lambda_1 = (-0.25 +/- 0.02_stat +/- 0.05_sys +/- 0.14_th) GeV^2. The theoretical constraints used are evaluated through order 1/M_B^3 in the non-perturbative expansion and beta_0*alpha__s^2 in the perturbative expansion. We use these parameters to extract |V_cb| from the world average of the semileptonic width and find |V_cb| = (40.8 +/- 0.5_Gam-sl +/- 0.4_(lambda_1,Lambda-bar)-exp +/- 0.9_th) x 10^-3. In addition, we extract the short range b-quark mass m_b^1S = (4.82 +/- 0.07_exp +/- 0.11_th) GeV/c^2. Finally, we discuss the implications of our measurements for the theoretical understanding of inclusive semileptonic processes.- 14.60.Cd
- 14.60.Ef
- 14.65.Fy
- 12.39.Hg
- electron positron: colliding beams
- electron positron: annihilation
- Upsilon(10570): electroproduction
- B: pair production
- anti-B: semileptonic decay
- lepton: momentum spectrum
References(30)
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