0000000000224130

AUTHOR

R. Denis

showing 3 related works from this author

Search for contact interactions in the reactionse + e −→l + l − ande + e −→γγ

1993

Contact interactions are searched for using the differential cross sections for the reactions e + e -→ e + e -, e + e -→ µ + µ -, e + e -→ τ + τ - and e + e -→γγ measured at 12 energies around the Z peak and corresponding to about 20 pb-1 of cumulated luminosity. Four-fermion contact term models assuming various chiralities of lepton currents are fitted to the lepton data and lower limits on the energy scale Λ of such terms are set at 95% c.l. The limits vary in the range 0.9 4.7 TeV, depending on the model and on the lepton flavour. The eeγγ contact terms are searched for assuming various chiralities. Limits on the energy scale Λ between 79 and 130 GeV are extracted from the data. The resu…

PhysicsRange (particle radiation)Particle physicsPhysics and Astronomy (miscellaneous)PhysicsElectron–positron annihilationHigh Energy Physics::PhenomenologyElementary particleLuminosityNuclear physicsALEPH ExperimentHigh Energy Physics::ExperimentField theory (psychology)Quantum field theoryEngineering (miscellaneous)ALEPH experimentLepton
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Four-fermion production in $e^+e^-$ collisions at centre-of-mass energies of 130 and 136 GeV

1996

Four-fermion events have been selected in a data sample of 5.8 pb(-1) collected with the ALEPH detector at centre-of-mass energies of 130 and 136 GeV. The final states l(+)l(-), l(+)l(-)l(+)l(-), , and <l(+)l(-) have been examined Five events are observed in the data, in agreement with the Standard Model predictions of 6.67 +/- 0.38 events from four-fermion processes and 0.14(-0.05)(+0.19) from background processes. RI ANTONELLI, ANTONELLA/C-6238-2011; Passalacqua, Luca/F-5127-2011; Murtas, Fabrizio/B-5729-2012; Sanchez, Federico/F-5809-2012; Ferrante, Isidoro/F-1017-2012

PhysicsNuclear and High Energy PhysicsAleph[PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex]010308 nuclear & particles physicsPhysicsFermion01 natural sciencesStandard ModelNuclear physicsALEPH Experiment0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Production (computer science)010306 general physicsParticle Physics - Experiment
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A measurement of the QCD colour factors and a limit on the light gluino

1997

Using data collected from 1992 to 1995 with the ALEPH detector at LEP, a measurement of the colour factor ratios C-A/C-F and T-F/C-F and the strong coupling constant = C-F alpha(s), (M-Z)/(2 pi) has been performed by fitting theoretical predictions simultaneously to the measured differential two-jet rate and angular distributions in four-jet events. The result is found to be in excellent agreement with QCD. C-A/C-F = 2.20 +/- 0.09 (stat) +/- 0.13 (syst), T-F/C-F = 0.29 +/- 0.05 (stat) +/- 0.06 (syst). Fixing C-A/C-F and T-F/C-F to the QCD values permits a determination of alpha(s) (M-Z) and n(f), the number of active flavours. With this measurement the existence of a gluino with mass below …

Quantum chromodynamicsPhysicsGluinoParticle physicsPhysics and Astronomy (miscellaneous)PhysicsElectron–positron annihilationHigh Energy Physics::PhenomenologyLower limitNuclear physicsStrong couplingHigh Energy Physics::ExperimentLimit (mathematics)Particle Physics - ExperimentParticle Physics - Phenomenology
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