Measurement of the Branching Fraction and anti-Lambda Polarization in B0 ---> anti-Lambda p pi-

We present a measurement of the B0 --> Lambda-bar p pi- branching fraction performed using the BaBar detector at the PEP-II asymmetric e+e- collider. Based on a sample of 467 million BB-bar pairs we measure B(B0 --> Lambda-bar p pi-) = [3.07 pm 0.31 (stat.) pm 0.23 (syst.)] x 10^{-6}. The measured differential spectrum as a function of the di-baryon invariant mass m(Lambda p) shows a near-threshold enhancement similar to that observed in other baryonic B decays. We study the Lambda-bar polarization as a function of Lambda-bar energy in the B0 rest frame (E*_Lambda) and compare it with theoretical expectations of fully longitudinally right-polarized Lambda-bar at large E*_Lambda.

Note:

12 pages, 6 figures, submitted to PRD

13.60.Rj
13.25.Hw
electron positron: annihilation
B: pair production
B0: hadronic decay
B0: branching ratio
Antilambda: polarization
energy dependence
BaBar
SLAC PEP Stor

References(16)

Figures(6)

Observation of B0 ---> p anti-Lambda pi-

Belle

Collaboration

•

M.Z. Wang
(
- Taiwan, Natl. Taiwan U.
)

et al.

- Phys.Rev.Lett. 90 (2003) 201802
•
e-Print:
- hep-ex/0302024
•
DOI:
- 10.1103/PhysRevLett.90.201802

Measurement of the $B^+ \to p \bar{p} K^+$ branching fraction and study of the decay dynamics

BaBar

Collaboration

•

Bernard Aubert
(
- Annecy, LAPP
)

et al.

- Phys.Rev.D 72 (2005) 051101
•
e-Print:
- hep-ex/0507012
•
DOI:
- 10.1103/PhysRevD.72.051101

Study of B+ ---> p anti-Lambda gamma, p anti-Lambda pi0 and B0 ---> p anti-Lambda pi-

Belle

Collaboration

•

M.-Z. Wang
(
- Taiwan, Natl. Taiwan U.
)

et al.

- Phys.Rev.D 76 (2007) 052004
•
e-Print:
- 0704.2672
•
DOI:
- 10.1103/PhysRevD.76.052004

Pathways to rare baryonic B decays

Wei-Shu Hou
(
- Taiwan, Natl. Taiwan U.
)
,
A. Soni
(
- Brookhaven
)

- Phys.Rev.Lett. 86 (2001) 4247-4250
•
e-Print:
- hep-ph/0008079
•
DOI:
- 10.1103/PhysRevLett.86.4247

Three body baryonic anti-B ---> Lambda anti-p pi decays and such

- Eur.Phys.J.C 29 (2003) 27-35
•
e-Print:
- hep-ph/0211240
•
DOI:
- 10.1140/epjc/s2003-01203-8

- Comments Nucl.Part.Phys. 29 15

The BaBar detector

BaBar

Collaboration

•

Bernard Aubert
(
- Annecy, LAPP
)

et al.

- Nucl.Instrum.Meth.A 479 (2002) 1-116
•
e-Print:
- hep-ex/0105044
•
DOI:
- 10.1016/S0168-9002(01)02012-5

GEANT4 - A Simulation Toolkit

GEANT4

Collaboration

•

S. Agostinelli
(
- Genoa U.
)

et al.

- Nucl.Instrum.Meth.A 506 (2003) 250-303
•
DOI:
- 10.1016/S0168-9002(03)01368-8

T violation in baryonic B decays

- Int.J.Mod.Phys.A 21 (2006) 897-900
•
e-Print:
- hep-ph/0509235
•
DOI:
- 10.1142/S0217751X06032265

Review of Particle Physics

et al.

- Phys.Lett.B 667 (2008) 1-1340
•
DOI:
- 10.1016/j.physletb.2008.07.018

Bagging Predictors

Leo Breiman
(
- UC, Berkeley
)

- Machine Learning 24 (1996) 123-140
•
DOI:
- 10.1007/BF00058655

Decay chain fitting with a Kalman filter

Wouter D. Hulsbergen
(
- Maryland U.
)

- Nucl.Instrum.Meth.A 552 (2005) 566-575
•
e-Print:
- physics/0503191
•
DOI:
- 10.1016/j.nima.2005.06.078

Evidence for Jet Structure in Hadron Production by e+ e- Annihilation

G. Hanson
(
- LBL, Berkeley and
- SLAC
)
,
G.S. Abrams
(
- LBL, Berkeley and
- SLAC
)
,
A. Boyarski
(
- LBL, Berkeley and
- SLAC
)
,
Martin Breidenbach
(
- LBL, Berkeley and
- SLAC
)
,
F. Bulos
(
- LBL, Berkeley and
- SLAC
)

et al.

- Phys.Rev.Lett. 35 (1975) 1609-1612,
- In *Cahn, R.N., Goldhaber, G.: The experimental foundations of particle physics* 318-321,
- In *Stanford 1975, Proceedings, Summer Institute on Particle Physics*, Stanford 1975, 237-246
•
DOI:
- 10.1103/PhysRevLett.35.1609

The use of multiple measurements in taxonomic problems

Ronald Aylmer Fisher

- Annals Eugen. 7 (1936) 179-188
•
DOI:
- 10.1111/j.1469-1809.1936.tb02137.x

SPlot: A Statistical tool to unfold data distributions

Muriel Pivk
(
- CERN
)
,
Francois R. Le Diberder
(
- Orsay, LAL
)

- Nucl.Instrum.Meth.A 555 (2005) 356-369
•
e-Print:
- physics/0402083
•
DOI:
- 10.1016/j.nima.2005.08.106

Exclusive Hadronic Decays of $B$ Mesons

ARGUS

Collaboration

•

H. Albrecht
(
- DESY
)

et al.

- Z.Phys.C 48 (1990) 543-552
•
DOI:
- 10.1007/BF01614687