Determination of alpha(s) using jet rates at LEP with the OPAL detector

Hadronic events produced in e+e- collisions by the LEP collider and recorded by the OPAL detector were used to form distributions based on the number of reconstructed jets. The data were collected between 1995 and 2000 and correspond to energies of 91 GeV, 130-136 GeV and 161-209 GeV. The jet rates were determined using four different jet-finding algorithms (Cone, JADE, Durham and Cambridge). The differential two-jet rate and the average jet rate with the Durham and Cambridge algorithms were used to measure alpha(s) in the LEP energy range by fitting an expression in which order alpah_2s calculations were matched to a NLLA prediction and fitted to the data. Combining the measurements at different centre-of-mass energies, the value of alpha_s (Mz) was determined to be alpha(s)(Mz)=0.1177+-0.0006(stat.)+-0.0012$(expt.)+-0.0010(had.)+-0.0032(theo.) \.

Note:

40 pages, 17 figures, Submitted to Euro. Phys. J. C Report-no: CERN-PH-EP/2005-024

electron positron: colliding beams
electron positron: annihilation
jet: electroproduction
hadron: multiple production
jet: multiplicity
jet: particle identification
strong interaction: coupling constant
energy dependence
quantum chromodynamics: perturbation theory
ALEPH

References(38)

Figures(0)

$\alpha_s$ 2002

Siegfried Bethke
(
- Munich, Max Planck Inst.
)

- Nucl.Phys.B Proc.Suppl. 121 (2003) 74-81,
•
e-Print:
- hep-ex/0211012
•
DOI:
- 10.1016/S0920-5632(03)01817-6

A Determination of alpha-s (M (Z0)) at LEP using resummed QCD calculations

OPAL

Collaboration

•

P.D. Acton

et al.

- Z.Phys.C 59 (1993) 1-20
•
DOI:
- 10.1007/BF01555834

QCD studies with e+ e- annihilation data at 130-GeV and 136-GeV

OPAL

Collaboration

•

G. Alexander

et al.

- Z.Phys.C 72 (1996) 191-206
•
DOI:
- 10.1007/s002880050237

QCD studies with e+ e- annihilation data at 161-GeV

OPAL

Collaboration

•

K. Ackerstaff

et al.

- Z.Phys.C 75 (1997) 193-207
•
DOI:
- 10.1007/s002880050462

QCD studies with e+ e- annihilation data at 172-GeV - 189-GeV

OPAL

Collaboration

•

G. Abbiendi

et al.

- Eur.Phys.J.C 16 (2000) 185-210
•
e-Print:
- hep-ex/0002012
•
DOI:
- 10.1007/s100520050015

QCD analyses and determinations of alpha(s) in e+ e- annihilation at energies between 35-GeV and 189-GeV

JADE and
OPAL

Collaborations

•

P. Pfeifenschneider
(
- Aachen, Tech. Hochsch.
)

et al.

- Eur.Phys.J.C 17 (2000) 19-51
•
e-Print:
- hep-ex/0001055
•
DOI:
- 10.1007/s100520000432

Measurement of event shape distributions and moments in e+ e- ---> hadrons at 91-GeV - 209-GeV and a determination of alpha(s)

OPAL

Collaboration

•

G. Abbiendi

et al.

- Eur.Phys.J.C 40 (2005) 287-316
•
e-Print:
- hep-ex/0503051
•
DOI:
- 10.1140/epjc/s2005-02120-6

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

Precision luminosity for Z0 line shape measurements with a silicon tungsten calorimeter

OPAL

Collaboration

•

G. Abbiendi

et al.

- Eur.Phys.J.C 14 (2000) 373-425
•
e-Print:
- hep-ex/9910066
•
DOI:
- 10.1007/s100520000353

The Trigger system of the OPAL experiment at LEP

OPAL

Collaboration

•

M. Arignon
(
- Saclay
)

et al.

- Nucl.Instrum.Meth.A 313 (1992) 103-125
•
DOI:
- 10.1016/0168-9002(92)90087-K

The Data acquisition system of the OPAL detector at LEP

OPAL

Collaboration

•

J.T.M. Baines
(
- Manchester U.
)

et al.

- Nucl.Instrum.Meth.A 325 (1993) 271-293
•
DOI:
- 10.1016/0168-9002(93)91029-M

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

High-energy physics event generation with PYTHIA 6.1

et al.

- Comput.Phys.Commun. 135 (2001) 238-259
•
e-Print:
- hep-ph/0010017
•
DOI:
- 10.1016/S0010-4655(00)00236-8

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

HERWIG 6: An Event generator for hadron emission reactions with interfering gluons (including supersymmetric processes)

G. Corcella
(
- Rochester U.
)
,
I.G. Knowles
(
- Edinburgh U.
)
,
G. Marchesini
(
- Milan Bicocca U. and
- INFN, Milan
)
,
S. Moretti
(
- CERN
)
,
K. Odagiri
(
- KEK, Tsukuba
)

et al.

- JHEP 01 (2001) 010
•
e-Print:
- hep-ph/0011363
•
DOI:
- 10.1088/1126-6708/2001/01/010

- Z.Phys.C 69 534

Tests of models of color reconnection and a search for glueballs using gluon jets with a rapidity gap

OPAL

Collaboration

•

G. Abbiendi

et al.

- Eur.Phys.J.C 35 (2004) 293-312
•
e-Print:
- hep-ex/0306021
•
DOI:
- 10.1140/epjc/s2004-01809-2

The Precision Monte Carlo event generator K K for two fermion final states in e+ e- collisions

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

- Comput.Phys.Commun. 130 (2000) 260-325
•
e-Print:
- hep-ph/9912214
•
DOI:
- 10.1016/S0010-4655(00)00048-5

Monte Carlo program KORALW-1.02 for W pair production at LEP-2 / NLC energies with Yennie-Frautschi-Suura exponentiation

M. Skrzypek
(
- Cracow, INP
)
,
S. Jadach
(
- Cracow, INP and
- CERN
)
,
W. Placzek
(
- Tennessee U.
)
,
Z. Was
(
- CERN and
- Cracow, INP
)

- Comput.Phys.Commun. 94 (1996) 216-248,
- Comput. Phys. Commun. 94 (1996) 216-248, and CERN Geneva - CERN-TH-95-205 (95/07,rec.Oct.) 42 p
•
DOI:
- 10.1016/0010-4655(95)00133-6