Muon pair and tau pair production in two photon collisions at LEP

The QED processes e^+ e^- -> e^+ e^- \mu^+ \mu^- and e^+ e^- -> e^+ e^- \tau^+ \tau^- are studied with the L3 detector at LEP using an untagged data sample collected at centre-of-mass energies 161 GeV < sqrt{s} < 209 GeV. The tau-pairs are observed through the associated decay of one tau into e\nu\nu and the other into \pi\pi\nu . The cross sections are measured as a function of sqrt{s}. For muon pairs, the cross section of the \gamma\gamma -> \mu^+\mu^- process is also measured as a function of the two-photon centre-of-mass energy for 3 GeV < W_{\gamma\gamma} < 40 GeV. Good agreement is found between these measurements and the O(\alpha^4) QED expectations. In addition, limits on the anomalous magnetic and electric dipole moments of the tau lepton are extracted.

electron positron: colliding beams
exchange: two-photon
photon photon: interaction
muon: pair production
tau: pair production
tau: semileptonic decay
tau: leptonic decay
channel cross section: energy dependence
tau: magnetic moment
tau: electric moment

References(28)

Figures(10)

The Construction of the L3 Experiment

L3

Collaboration

•

B. Adeva
(
- CERN
)

et al.

- Nucl.Instrum.Meth.A 289 (1990) 35-102
•
DOI:
- 10.1016/0168-9002(90)90250-A

Results from the L3 experiment at LEP

L3

Collaboration

•

O. Adriani

et al.

- Phys.Rept. 236 (1993) 1-146
•
DOI:
- 10.1016/0370-1573(93)90027-B

High-energy Cosmic Muons and the Calibration of the L3 Electromagnetic Calorimeter

J.A. Bakken
(
- Princeton U.
)
,
L. Barone
(
- Rome U. and
- INFN, Rome
)
,
J.J. Blaising
(
- Annecy, LAPP
)
,
T. Boehringer
(
- Lausanne U.
)
,
B. Borgia
(
- Rome U. and
- INFN, Rome
)

et al.

- Nucl.Instrum.Meth.A 275 (1989) 81-88,
- NUCL. INSTRUM. METHODS A275 (1989) 81-88 AND CERN GENEVA - CERN-EP 88-079 (88,REC.JUL.) 25p
•
DOI:
- 10.1016/0168-9002(89)90338-0

Hadron calorimetry in the L3 detector

L3

Collaboration

•

O. Adriani
(
- Florence U. and
- INFN, Florence
)

et al.

- Nucl.Instrum.Meth.A 302 (1991) 53-62
•
DOI:
- 10.1016/0168-9002(91)90491-8

A High resolution muon detector

B. Adeva
(
- CERN
)
,
M. Aguilar-Benitez
(
- Madrid, CIEMAT
)
,
J. Alcaraz
(
- Madrid, CIEMAT
)
,
A. Aloisio
(
- INFN, Naples and
- Naples U.
)
,
M.G. Alviggi
(
- INFN, Naples and
- Naples U.
)

et al.

- Nucl.Instrum.Meth.A 323 (1992) 109-124,
- Nucl. Instrum. Methods A323 (1992) 109-124. (see HIGH ENERGY PHYSICS INDEX 31 (1993) No. 3072)
•
DOI:
- 10.1016/0168-9002(92)90277-B

The Construction and performance of a large cylindrical wire chamber with cathode readout

et al.

- Nucl.Instrum.Meth.A 323 (1992) 162-168,
- Nucl. Instrum. Methods A323 (1992) 162-168 and Zeuthen DESY-IfH - PHE 91-015 (91/12,rec.Mar.92) 18 p. (203808) (see HIGH ENERGY PHYSICS INDEX 31 (1993) No. 3072)
•
DOI:
- 10.1016/0168-9002(92)90283-A

Test beam results for an upgraded forward tagger of the L3 Experiment at LEP-2

et al.

- Nucl.Instrum.Meth.A 349 (1994) 345-355
•
DOI:
- 10.1016/0168-9002(94)91198-3

The L3 silicon microvertex detector

L3 SMD

Collaboration

•

M. Acciarri
(
- Aachen, Tech. Hochsch.
)

et al.

- Nucl.Instrum.Meth.A 351 (1994) 300-312
•
DOI:
- 10.1016/0168-9002(94)91357-9

The L3 lead scintillating fiber calorimeter

G. Basti
(
- Rome U. and
- INFN, Rome
)
,
Mario Campanelli
(
- Rome U. and
- INFN, Rome
)
,
F. Cavallari
(
- Rome U. and
- INFN, Rome
)
,
F. de Notaristefani
(
- Rome U. and
- INFN, Rome
)
,
M. Diemoz
(
- Rome U. and
- INFN, Rome
)

et al.

- Nucl.Instrum.Meth.A 374 (1996) 293-298
•
DOI:
- 10.1016/0168-9002(96)00206-9

The Forward muon detector of L3

et al.

- Nucl.Instrum.Meth.A 383 (1996) 342-366
•
DOI:
- 10.1016/S0168-9002(96)00777-2

Production of e, mu and tau pairs in untagged two photon collisions at LEP

L3

Collaboration

•

M. Acciarri

et al.

- Phys.Lett.B 407 (1997) 341-350
•
DOI:
- 10.1016/S0370-2693(97)00731-4

A Study of muon pair production and evidence for tau pair production in photon-photon collisions at LEP

OPAL

Collaboration

•

R. Akers

et al.

- Z.Phys.C 60 (1993) 593-600
•
DOI:
- 10.1007/BF01558388

Review of particle physics. Particle Data Group

et al.

- Phys.Rev.D 66 (2002) 010001
•
DOI:
- 10.1103/PhysRevD.66.010001

Tau pair production via photon-photon collisions at LEP

- Phys.Rev.D 53 (1996) 1181-1184
•
e-Print:
- hep-ph/9503466
•
DOI:
- 10.1103/PhysRevD.53.1181

The new inner-TEC trigger of the L3 experiment using a hardwired neural network processor

- Nucl.Instrum.Meth.A 420 (1999) 101-116
•
DOI:
- 10.1016/S0168-9002(98)01134-6

First level charged particle trigger for the L3 detector

et al.

- Nucl.Instrum.Meth.A 306 (1991) 150-158
•
DOI:
- 10.1016/0168-9002(91)90313-F

The L3 Energy Trigger

R. Bizzarri
(
- Rome U. and
- Calabria U.
)
,
F. Cesaroni
(
- Rome U. and
- Calabria U.
)
,
S. Gentile
(
- Rome U. and
- Calabria U.
)
,
G. Lunadei
(
- Rome U. and
- Calabria U.
)
,
M. Fukushima
(
- MIT, LNS
)

et al.

- Nucl.Instrum.Meth.A 283 (1989) 799-802
•
DOI:
- 10.1016/0168-9002(89)91461-7

Complete Lowest Order Calculations for Four Lepton Final States in electron-Positron Collisions

- Nucl.Phys.B 253 (1985) 441-463
•
DOI:
- 10.1016/0550-3213(85)90541-3

Two Photon Processes at Very High-Energies

J.A.M. Vermaseren
(
- NIKHEF, Amsterdam
)

- Nucl.Phys.B 229 (1983) 347-371
•
DOI:
- 10.1016/0550-3213(83)90336-X

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

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

Photoproduction within the two component dual parton model. 1. Amplitudes and cross-sections

R. Engel
(
- Leipzig U. and
- Siegen U.
)

- Z.Phys.C 66 (1995) 203-214
•
DOI:
- 10.1007/BF01496594

Hadronic photon-photon interactions at high-energies

R. Engel
(
- Leipzig U. and
- Siegen U.
)
,
J. Ranft
(
- Annecy, LAPP
)

- Phys.Rev.D 54 (1996) 4244-4262
•
e-Print:
- hep-ph/9509373
•
DOI:
- 10.1103/PhysRevD.54.4244

Improving the equivalent photon approximation in electron - positron collisions

Gerhard A. Schuler
(
- CERN
)

e-Print:
- hep-ph/9610406

Improved bounds on the electromagnetic dipole moments of the $\tau$ lepton

R. Escribano
(
- Barcelona, Autonoma U.
)
,
E. Masso
(
- Barcelona, Autonoma U. and
- Orsay, LPT
)

- Phys.Lett.B 395 (1997) 369-372
•
e-Print:
- hep-ph/9609423
•
DOI:
- 10.1016/S0370-2693(97)00059-2

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