SEARCH FOR CHARGINOS AND NEUTRALINOS WITH THE DELPHI DETECTOR AT LEP

2001 ◽  
Vol 16 (supp01b) ◽  
pp. 775-777
Author(s):  
◽  
THOMAS ALDERWEIRELD
Keyword(s):  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Branching Fraction ◽  
Centre Of Mass ◽  
Mass Energy ◽  
Delphi Detector ◽  
Upper Limit

Search for charginos and neutralinos are presented, based on the data samples recorded in 1999 and 2000 by the DELPHI detector at centre-of-mass energies from 192 to 209 GeV. No evidence for a signal was found. The lower chargino mass limits are 5-6 GeV /c2 higher than those obtained at a centre-of-mass energy of 189 GeV. The (μ, M 2) MSSM domain excluded by combining the chargino searches with neutralino searches at the Z resonance implies a limit on the mass of the lightest neutralino which, for a heavy sneutrino, is constrained to be above 37.6 GeV /c2 for tan β≥1. Upper limit at 95% CL on the neutralino production cross-section times branching fraction are derived.

MEASUREMENT OF THE W PAIR PRODUCTION CROSS SECTION AND W BRANCHING RATIOS WITH THE DELPHI DETECTOR

2001 ◽  
Vol 16 (supp01a) ◽  
pp. 348-350
Author(s):  
FABIO COSSUTTI
Keyword(s):  
Standard Model ◽  
Pair Production ◽  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Branching Ratios ◽  
Centre Of Mass ◽  
Delphi Detector ◽  
The Standard Model ◽  
Pair Production Cross Section

Data collected with the DELPHI detector at centre-of-mass energies up to the highest values explored by the LEP collider of about 206 GeV have been used to extract preliminary values of the cross-section for the process e+e- → W+W-. The branching ratios of the W decay were also measured; from them the value of |Vcs| was extracted. The results are compared with the most recent calculations in the framework of the Standard Model.

scholarly journals Search for long-lived particles decaying to $$e ^\pm $$ $$\mu ^\mp $$ $$\nu $$

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
R. Aaij ◽  
◽  
C. Abellán Beteta ◽  
T. Ackernley ◽  
B. Adeva ◽  
...  
Keyword(s):  
Pair Production ◽  
Cross Section ◽  
Production Cross ◽  
Branching Fraction ◽  
Charged Current ◽  
Centre Of Mass ◽  
Mass Energy ◽  
Upper Limits ◽  
Lhcb Detector ◽  
Current Production

AbstractLong-lived particles decaying to $${e ^\pm } {\mu ^\mp } {\nu } $$ e ± μ ∓ ν , with masses between 7 and $$50 \,\text {GeV/}c^2 $$ 50 GeV/ c 2 and lifetimes between 2 and $$50 \,\text {ps} $$ 50 ps , are searched for by looking at displaced vertices containing electrons and muons of opposite charges. The search is performed using $$5.4 \,\text {fb} ^{-1} $$ 5.4 fb - 1 of $$p $$ p $$p $$ p collisions collected with the LHCb detector at a centre-of-mass energy of $$\sqrt{s} = 13 \,\text {TeV} $$ s = 13 TeV . Three mechanisms of production of long-lived particles are considered: the direct pair production from quark interactions, the pair production from the decay of a Standard-Model-like Higgs boson with a mass of $$125 \,\text {GeV/}c^2 $$ 125 GeV/ c 2 , and the charged current production from an on-shell $$W $$ W boson with an additional lepton. No evidence of these long-lived states is obtained and upper limits on the production cross-section times branching fraction are set on the different production modes.

Searches for Technicolor Particles at DØ

2005 ◽  
Vol 20 (15) ◽  
pp. 3302-3304
Author(s):  
LORENZO FELIGIONI
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Model Parameters ◽  
Decay Channels ◽  
Upper Limit ◽  
200 Gev ◽  
Quark Jets ◽  
B Quark

We present preliminary results of searches for technirho (ρT) and techniomega (ωT) particles, using the decay channels (ρT), ωT → e+e- and [Formula: see text], where [Formula: see text], [Formula: see text]. These searches are based respectively on 200 pb-1 and 238 pb-1 of data collected in Run II of the Fermilab Tevatron. We select events with b–quark jets by identifying secondary vertices in the jets. We interpret our findings in terms of limits on the production of particles predicted by extended technicolor models. For the WπT analysis, in the absence of an excess over standard model background, we compute a 95% C.L. upper limit on the techniparticle production cross section for the mass combination m(ρT) = 200 GeV and m(πT) = 105 GeV of 6.4 pb. In the e+e- channel, for certain model parameters, we exclude the existence of degenerate ρT and ωT states with masses below 367 GeV; the most restrictive constraints on dilepton technicolor decays to date.

Search for MSSM Higgs Decaying to Tau Pairs

2005 ◽  
Vol 20 (15) ◽  
pp. 3314-3316
Author(s):  
◽  
DONGWOOK JANG
Keyword(s):  
Higgs Boson ◽  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Branching Fraction ◽  
Higgs Production ◽  
The Other ◽  
Tau Leptons ◽  
Higgs Boson Decaying ◽  
Tau Pairs

We present the results of a search for a neutral MSSM Higgs boson decaying to a pair of tau leptons. The analyzed data sample corresponds to integrated luminosity of approximately 200 pb-1 of [Formula: see text] collisions at [Formula: see text]. It was collected by the CDF detector during Run 2 of the Fermilab Tevatron. We select tau pairs in which one of the taus decays hadronically and the other to e or μ and neutrinos. We see no evidence of signal and perform a fit to the (partially) reconstructed di-tau mass to set limits on the product of Higgs production cross-section and its branching fraction to taus.

scholarly journals Measurements of the production cross section and forward–backward asymmetry at centre-of-mass energies above the Z pole at LEP

2000 ◽  
Vol 485 (1-3) ◽  
pp. 71-84 ◽  
Author(s):  
M. Acciarri ◽  
P. Achard ◽  
O. Adriani ◽  
M. Aguilar-Benitez ◽  
J. Alcaraz ◽  
...  
Keyword(s):  
Cross Section ◽  
Production Cross Section ◽  
Production Cross ◽  
Centre Of Mass
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