Measurements of BR (b ---> tau- anti-nu(tau) X) and BR (b ---> tau- anti-nu(tau) D*+- X) and upper limits on BR (B- ---> tau- anti-nu(tau)) and BR (b---> s nu anti-nu)

Inclusive branching ratios involving b to tau transitions are measured in approximately four million hadronic Z decays collected by the ALEPH detector at LEP. The fully-inclusive branching ratio b -> tau nu X and the semi-inclusive branching ratio b -> tau nu D*+/- X are measured to be (2.43 +/- 0.20 +/- 0.25)% and (0.88 +/- 0.31 +/- 0.28)%, in agreement with the standard model predictions. Upper limits on the branching fractions b -> tau nu and b -> s nu nubar are set to 8.3 10**-4 and 6.4 10**-4 at the 90% C.L. These results allow a 90% C.L. lower limit of 0.40 (GeV/c**2)**-1 to be set on the tan(beta)/mH+/- ratio, in the framework of type-II two-Higgs-doublet mode

Note:

25 pages, 8 figures Report-no: CERN-EP/2000-126

electron positron: colliding beams
electron positron: annihilation
Z0: electroproduction
Z0: hadronic decay
bottom
quark: pair production
quark: semileptonic decay
quark: branching ratio
B-: leptonic decay
B-: branching ratio

References(33)

Figures(9)

Heavy quark expansion for the inclusive decay anti-B ---> tau anti-neutrino X

Adam F. Falk
(
- UC, San Diego and
- Johns Hopkins U.
)
,
Zoltan Ligeti
(
- Weizmann Inst.
)
,
Matthias Neubert
(
- CERN
)
,
Yosef Nir
(
- Weizmann Inst.
)

- Phys.Lett.B 326 (1994) 145-153
•
e-Print:
- hep-ph/9401226
•
DOI:
- 10.1016/0370-2693(94)91206-8

Semileptonic Decays of $B$ Mesons into $\tau \nu_\tau$ in a Two Higgs Doublet Model

Jan Kalinowski
(
- Munich, Tech. U.
)

- Phys.Lett.B 245 (1990) 201-206
•
DOI:
- 10.1016/0370-2693(90)90134-R

The Inclusive anti-B ---> tau anti-neutrino X decay in two Higgs doublet models

Yuval Grossman
(
- Weizmann Inst.
)
,
Zoltan Ligeti
(
- Weizmann Inst.
)

- Phys.Lett.B 332 (1994) 373-380
•
e-Print:
- hep-ph/9403376
•
DOI:
- 10.1016/0370-2693(94)91267-X

QCD corrections to charged Higgs mediated b ---> c tau-neutrino decay

- Phys.Lett.B 357 (1995) 630-636
•
e-Print:
- hep-ph/9507213
•
DOI:
- 10.1016/0370-2693(95)00946-I

Searching for $B \to D \tau \bar{\tau}$ - neutrino at the 10-percent level

Bohdan Grzadkowski
(
- UC, Davis
)
,
Wei-Shu Hou
(
- PSI, Villigen
)

- Phys.Lett.B 283 (1992) 427-433
•
DOI:
- 10.1016/0370-2693(92)90043-4

Enhanced charged Higgs boson effects in B- ---> tau anti-neutrino, mu anti-neutrino and b ---> tau anti-neutrino + X

Wei-Shu Hou
(
- Taiwan, Natl. Taiwan U.
)

- Phys.Rev.D 48 (1993) 2342-2344
•
DOI:
- 10.1103/PhysRevD.48.2342

New limit on inclusive $B \to X_{s}$ anti-neutrino neutrino decay and constraints on new physics

- Nucl.Phys.B 465 (1996) 369-398,
- Nucl.Phys.B 480 (1996) 753-754 (erratum)
•
e-Print:
- hep-ph/9510378
•
DOI:
- 10.1016/0550-3213(96)00051-X

New limit on inclusive $B \to X_{s}$ anti-neutrino neutrino decay and constraints on new physics

- Nucl.Phys.B 465 (1996) 369-398,
- Nucl.Phys.B 480 (1996) 753-754 (erratum)
•
e-Print:
- hep-ph/9510378
•
DOI:
- 10.1016/0550-3213(96)00051-X

Measurement of the b ---> tau- anti-tau-neutrino X branching ratio

ALEPH

Collaboration

•

D. Buskulic
(
- Annecy, LAPP
)

et al.

- Phys.Lett.B 298 (1993) 479-491
•
DOI:
- 10.1016/0370-2693(93)91853-F

Measurement of the b ---> tau- anti-tau-neutrino X branching ratio and an upper limit on B- ---> tau- anti-tau-neutrino

ALEPH

Collaboration

•

D. Buskulic
(
- Annecy, LAPP
)

et al.

- Phys.Lett.B 343 (1995) 444-452
•
DOI:
- 10.1016/0370-2693(94)01584-Y

ALEPH: A detector for electron-positron annnihilations at LEP

ALEPH

Collaboration

•

D. Decamp
(
- Annecy, LAPP
)

et al.

- Nucl.Instrum.Meth.A 294 (1990) 121-178,
- Nucl.Instrum.Meth.A 303 (1991) 393 (erratum)
•
DOI:
- 10.1016/0168-9002(90)91831-U

Performance of the ALEPH detector at LEP

ALEPH

Collaboration

•

D. Buskulic
(
- Annecy, LAPP
)

et al.

- Nucl.Instrum.Meth.A 360 (1995) 481-506
•
DOI:
- 10.1016/0168-9002(95)00138-7

A Precise measurement of Gamma ( $Z \to b \bar{b}$ ) / Gamma ( $Z \to$ hadrons)

ALEPH

Collaboration

•

D. Buskulic
(
- Annecy, LAPP
)

et al.

- Phys.Lett.B 313 (1993) 535-548,
- Phys. Lett. B313 (1993) 535-548 and CERN Geneva - CERN-PPE-93-108 (93/06,rec.Sep.) 16 p
•
DOI:
- 10.1016/0370-2693(93)90028-G

Determination of the Number of Light Neutrino Species

ALEPH

Collaboration

•

D. Decamp
(
- Annecy, LAPP
)

et al.

- Phys.Lett.B 231 (1989) 519-529
•
DOI:
- 10.1016/0370-2693(89)90704-1

Measurement of the $B_s^0$ lifetime

ALEPH

Collaboration

•

D. Buskulic
(
- Annecy, LAPP
)

et al.

- Phys.Lett.B 322 (1994) 275-286
•
DOI:
- 10.1016/0370-2693(94)91120-7

Heavy quark tagging with leptons in the ALEPH detector

ALEPH

Collaboration

•

D. Buskulic
(
- Annecy, LAPP
)

et al.

- Nucl.Instrum.Meth.A 346 (1994) 461-475
•
DOI:
- 10.1016/0168-9002(94)90582-7

Production of charmed mesons in Z decays

ALEPH

Collaboration

•

D. Buskulic
(
- Annecy, LAPP
)

et al.

- Z.Phys.C 62 (1994) 1-14
•
DOI:
- 10.1007/BF01559519

The Lund Monte Carlo for Jet Fragmentation and e+ e- Physics. Jetset Version 6.3: An Update

- Comput.Phys.Commun. 43 (1987) 367
•
DOI:
- 10.1016/0010-4655(87)90054-3

High-energy physics event generation with PYTHIA 5.7 and JETSET 7.4

Torbjorn Sjostrand
(
- CERN
)

- Comput.Phys.Commun. 82 (1994) 74-90,
- CERN Geneva - TH. 7111 (93/12,rec.Jan.94) 17 p. and e: CERN th-7111-93
•
DOI:
- 10.1016/0010-4655(94)90132-5

Exclusive rare B decays in the heavy quark limit

Ahmed Ali
(
- DESY
)
,
T. Mannel
(
- DESY
)

- Phys.Lett.B 264 (1991) 447-454,
- Phys.Lett.B 274 (1992) 526 (erratum)
•
DOI:
- 10.1016/0370-2693(91)90376-2

TAUOLA: A Library of Monte Carlo programs to simulate decays of polarized tau leptons

- Comput.Phys.Commun. 64 (1990) 275-299,
- Comput. Phys. Commun. 64 (1990) 275-299 and CERN Geneva - TH. 5856 (90,rec.Oct.) 37 p
•
DOI:
- 10.1016/0010-4655(91)90038-M

The Monte Carlo program KORALZ, version 3.8, for the lepton or quark pair production at LEP / SLC energies

Stanislaw Jadach
(
- CERN
)
,
B.F.L. Ward
(
- Tennessee U. and
- SLAC
)
,
Zbigniew Was
(
- Cracow, INP
)

- Comput.Phys.Commun. 66 (1991) 276-292,
- Comput. Phys. Commun. 66 (1991) 276-292 and CERN Geneva - TH. 5994 (91/02,rec.May) 24 p
•
DOI:
- 10.1016/0010-4655(91)90077-X