scholarly journals Higgs production cross-section in a Standard Model with four generations at the LHC

2011 ◽  
Vol 702 (4) ◽  
pp. 224-227 ◽  
Author(s):  
Charalampos Anastasiou ◽  
Stephan Buehler ◽  
Elisabetta Furlan ◽  
Franz Herzog ◽  
Achilleas Lazopoulos
2005 ◽  
Vol 20 (15) ◽  
pp. 3302-3304
Author(s):  
LORENZO FELIGIONI

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.


2007 ◽  
Vol 22 (38) ◽  
pp. 2873-2884
Author(s):  
DANIEL WHITESON

The dilepton decays of the top quark are a powerful laboratory for probing the Standard Model and searching for hints of a more fundamental theory. We present a detailed analysis of the production cross section and the kinematic qualities of top quark pair candidate events in [Formula: see text] collisions at [Formula: see text] = 1.96 TeV collected by the CDF detector which include two leptons in the final state, suggesting the decay [Formula: see text]. We describe the selection of candidate events to suppress major backgrounds and present the number of observed events over background. As a test of the top quark hypothesis, the kinematics of the events are analyzed via a measurement of M top with unprecedented precision.


2001 ◽  
Vol 16 (supp01a) ◽  
pp. 348-350
Author(s):  
FABIO COSSUTTI

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.


2005 ◽  
Vol 20 (15) ◽  
pp. 3314-3316
Author(s):  
◽  
DONGWOOK JANG

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.


2001 ◽  
Vol 16 (supp01a) ◽  
pp. 342-344
Author(s):  
GIUSEPPE DELLA RICCA

Data collected with the DELPHI detector at [Formula: see text] up to LEP2 highest energies (i.e. exceeding 205 GeV) have been used to extract preliminary values of the cross-sections for quark-antiquark pair-production in e + e - annihilations. The values found were used to test the Standard Model predictions and to seek for physics beyond it.


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