Search for lepton flavor violation in e+ e- collisions at s**(1/2) = 189-GeV - 209-GeV

We search for lepton flavour violating events (e μ , e τ and μτ ) that could be directly produced in e + e − annihilations, using the full available data sample collected with the OPAL detector at centre-of-mass energies between 189 GeV and 209 GeV. In general, the Standard Model expectations describe the data well for all the channels and at each s . A single e μ event is observed where according to our Monte Carlo simulations only 0.019 events are expected from Standard Model processes. We obtain the first limits on the cross-sections σ (e + e − →e μ , e τ and μτ ) as a function of s at LEP2 energies.

Note:

15 pages, 4 figures, Accepted by Physics Letters B Report-no: CERN-EP-2001-061

electron positron: colliding beams
electron positron: annihilation
lepton: pair production
flavor: violation
channel cross section: energy dependence
upper limit
OPAL
experimental results
CERN LEP Stor
electron positron --> muon electron

References(35)

Figures(0)

Measurement of a small atmospheric muon-neutrino / electron-neutrino ratio

Super-Kamiokande

Collaboration

•

Y. Fukuda
(
- Tokyo U., ICRR
)

et al.

- Phys.Lett.B 433 (1998) 9-18
•
e-Print:
- hep-ex/9803006
•
DOI:
- 10.1016/S0370-2693(98)00476-6

Study of the atmospheric neutrino flux in the multi-GeV energy range

Super-Kamiokande

Collaboration

•

Y. Fukuda
(
- Tokyo U., ICRR
)

et al.

- Phys.Lett.B 436 (1998) 33-41
•
e-Print:
- hep-ex/9805006
•
DOI:
- 10.1016/S0370-2693(98)00876-4

Evidence for oscillation of atmospheric neutrinos

Super-Kamiokande

Collaboration

•

Y. Fukuda
(
- Tokyo U., ICRR
)

et al.

- Phys.Rev.Lett. 81 (1998) 1562-1567
•
e-Print:
- hep-ex/9807003
•
DOI:
- 10.1103/PhysRevLett.81.1562

Latest results from K2K

K2K

Collaboration

•

Takanobu Ishii
(
- KEK, Tsukuba
)

for the collaboration.

e-Print:
- hep-ex/0106008

Measurement of the rate of $\nu_e+d \to p+p+e^-$ interactions produced by $^8$ B solar neutrinos at the Sudbury Neutrino Observatory

SNO

Collaboration

•

Q.R. Ahmad
(
- CENPA, Seattle
)

et al.

- Phys.Rev.Lett. 87 (2001) 071301
•
e-Print:
- nucl-ex/0106015
•
DOI:
- 10.1103/PhysRevLett.87.071301

Violations of lepton flavor and CP in supersymmetric unified theories

Riccardo Barbieri
(
- Pisa U. and
- INFN, Pisa
)
,
Lawrence J. Hall
(
- UC, Berkeley
)
,
Alessandro Strumia
(
- Pisa U. and
- INFN, Pisa
)

- Nucl.Phys.B 445 (1995) 219-251
•
e-Print:
- hep-ph/9501334
•
DOI:
- 10.1016/0550-3213(95)00208-A

SUSY phenomenology

Yasuhiro Okada
(
- KEK, Tsukuba
)

•
e-Print:
- hep-ph/9811502

Search for neutrinoless tau decays

ARGUS

Collaboration

•

H. Albrecht
(
- DESY
)

et al.

- Z.Phys.C 55 (1992) 179-190

Search for Neutrinoless Decays of the $\tau$ Lepton

CLEO

Collaboration

•

T.J.V. Bowcock
(
- Harvard U.
)

et al.

- Phys.Rev.D 41 (1990) 805
•
DOI:
- 10.1103/PhysRevD.41.805

A Search for lepton flavor violation in Z0 decays

OPAL

Collaboration

•

M.Z. Akrawy
(
- Queen Mary, U. of London
)

et al.

- Phys.Lett.B 254 (1991) 293-302
•
DOI:
- 10.1016/0370-2693(91)90437-U

Searches for new particles in $Z$ decays using the ALEPH detector

ALEPH

Collaboration

•

D. Decamp
(
- Annecy, LAPP
)

et al.

- Phys.Rept. 216 (1992) 253-340
•
DOI:
- 10.1016/0370-1573(92)90177-2

A Search for lepton flavor violation in Z0 decays

DELPHI

Collaboration

•

P. Abreu

et al.

- Phys.Lett.B 298 (1993) 247-256
•
DOI:
- 10.1016/0370-2693(93)91737-8

Search for lepton flavor violation in Z decays

L3

Collaboration

•

O. Adriani

et al.

- Phys.Lett.B 316 (1993) 427-434,
- Phys. Lett. B316 (1993) 427-434. and CERN Geneva - CERN-PPE-93-151 (93/08,rec.Oct.) 16 p. C
•
DOI:
- 10.1016/0370-2693(93)90348-L

The OPAL detector at LEP

OPAL

Collaboration

•

K. Ahmet

et al.

- Nucl.Instrum.Meth.A 305 (1991) 275-319
•
DOI:
- 10.1016/0168-9002(91)90547-4

The extended OPAL silicon strip microvertex detector

OPAL

Collaboration

•

S. Anderson
(
- Indiana U.
)

et al.

- Nucl.Instrum.Meth.A 403 (1998) 326-350
•
DOI:
- 10.1016/S0168-9002(97)01093-0

The OPAL silicon - tungsten calorimeter front end electronics

OPAL

Collaboration

•

B.E. Anderson

et al.

- IEEE Trans.Nucl.Sci. 41 (1994) 845-852
•
DOI:
- 10.1109/23.322818

- Nucl.Instrum.Meth.A 416 266

New fermions at e+ e- colliders. 1. Production and decay

A. Djouadi
(
- Montreal U.
)

- Z.Phys.C 63 (1994) 317-326
•
e-Print:
- hep-ph/9308339
•
DOI:
- 10.1007/BF01411024

Excited fermions at e+ e- and e P colliders

- Z.Phys.C 57 (1993) 425-450,
- Z. Phys. C57 (1993) 425-449 and Hamburg DESY - DESY 92-116 (92/08,rec.Aug.) 58 p
•
DOI:
- 10.1007/BF01474339

The Detector simulation program for the OPAL experiment at LEP

OPAL

Collaboration

•

J. Allison
(
- Manchester U.
)

et al.

- Nucl.Instrum.Meth.A 317 (1992) 47-74
•
DOI:
- 10.1016/0168-9002(92)90593-S

Coherent exclusive exponentiation CEEX: The Case of the resonant e+ e- collision

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

- Phys.Lett.B 449 (1999) 97-108
•
e-Print:
- hep-ph/9905453
•
DOI:
- 10.1016/S0370-2693(99)00038-6

The Monte Carlo program KORALZ, version 4.0, for the lepton or quark pair production at LEP / SLC energies

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

- Comput.Phys.Commun. 79 (1994) 503-522
•
DOI:
- 10.1016/0010-4655(94)90190-2

BHWIDE 1.00: O(alpha) YFS exponentiated Monte Carlo for Bhabha scattering at wide angles for LEP-1 / SLC and LEP-2

S. Jadach
(
- Cracow, INP and
- CERN
)
,
W. Placzek
(
- Tennessee U.
)
,
B.F.L. Ward
(
- Tennessee U. and
- SLAC and
- CERN
)

- Phys.Lett.B 390 (1997) 298-308
•
e-Print:
- hep-ph/9608412
•
DOI:
- 10.1016/S0370-2693(96)01382-2

Radiative Bhabha Scattering for Singly Tagged and Untagged Configurations

D. Karlen
(
- SLAC
)

- Nucl.Phys.B 289 (1987) 23-35
•
DOI:
- 10.1016/0550-3213(87)90369-5

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

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