Global Fit in the Kinetic Scheme to the Moments in B -> Xclnu and B -> Xsgamma

The fit uses all public moment measurements of the hadronic mass and lepton energy distributions in B -> Xclnu and photon energy distribution in B -> Xsgamma decays where correlation matrices are available. It follows closely the approach of Phys.Rev. D78 (2008) 032016.

It is based on calculations in Eur.Phys.J. C34 (2004) 181-189 and Nucl.Phys. B710 (2005) 371-401. Theoretical errors concerning the accuracy in the expression for a given moment have been assigned following the recipes given by the authors of the above publications.


Fit Results in the Kinetic Scheme

Input |Vcb| (10-3) mbkin (GeV) mu2pi (GeV2) chi2/ndf.
all moments (Xclnu and Xsgamma) 41.67 +/- 0.43(fit) +/- 0.08(tauB) +/- 0.58(th) 4.601 +/- 0.034 0.440 +/- 0.040 details 29.7 / (64-7)
Xclnu only 41.48 +/- 0.47(fit) +/- 0.08(tauB) +/- 0.58(th) 4.659 +/- 0.049 0.428 +/- 0.044 details 24.1 / (53-7)

Figures of the Delta chi2=1 ellipses can be found here:


Fit input

We consider two data samples for the fit (Table 1), using:

  1. the full set of input data currently available
  2. only the semileptonic moments, i.e., hadron and lepton moments only
Table 1. The list of the moment measurements that form the basis for the combined fit. The symbol 'n' indicates the order of the moment while 'c' indicates the value of the minimum lepton or photon energy (in GeV) with which the moments are measured.
Experiment Hadron moments Lepton moments Photon moments References
BaBar n=2 c=0.9,1.1,1.3,1.5
n=4 c=0.8,1.0,1.2,1.4 [1]
n=0 c=0.6,1.2,1.5
n=1 c=0.6,0.8,1.0,1.2,1.5
n=2 c=0.6,1.0,1.5
n=3 c=0.8,1.2 [2]
n=1 c=1.9,2.0
n=2 c=1.9 [3,4]
[1] arXiv:0707.2670
[2] Phys.Rev. D69 (2004) 111104
[3] Phys.Rev. D72 (2005) 052004
[4] Phys. Rev. Lett. 97, 171803 (2006)
Belle n=2 c=0.7,1.1,1.3,1.5
n=4 c=0.7,0.9,1.3 [5]
n=0 c=0.6,1.0,1.4
n=1 c=0.6,0.8,1.0,1.2,1.4
n=2 c=0.6,1.0,1.4
n=3 c=0.8,1.0, 1.2 [6]
n=1 c=1.8,1.9
n=2 c=1.8,2.0 [7]
[5] Phys.Rev. D75 (2007) 032005
[6] Phys.Rev. D75 (2007) 032001
[7] arXiv:0804.1580
CDF n=2 c=0.7
n=4 c=0.7 [8]
. . [8] Phys.Rev. D71 (2005) 051103
CLEO n=2 c=1.0,1.5
n=4 c=1.0,1.5 [9]
. n=1 c=2.0 [10] [9] Phys.Rev. D70 (2004) 032002
[10] Phys.Rev.Lett. 87 (2001) 251807
DELPHI n=2 c=0.0
n=4 c=0.0 [11]
n=1 c=0.0
n=2 c=0.0
n=3 c=0.0 [11]
. [11] Eur.Phys.J. C45 (2006) 35-59

last update: Aug 12, 2008 by C.Schwanda