Measurement of thepp¯→tt¯production cross section and the top quark mass ats=1.96

Abstract

We report the measurements of the t t production cross section and of the top quark mass using 1:02 fb ÿ1 of p p data collected with the CDF II detector at the Fermilab Tevatron. We select events with six or more jets on which a number of kinematical requirements are imposed by means of a neural network algorithm. At least one of these jets must be identified as initiated by a b-quark candidate by the reconstruction of a secondary vertex. The cross section is measured to be t t 8:3 1:0stat 2:0 ÿ1:5 syst 0:5lumi pb, which is consistent with the standard model prediction. The top quark mass of 174:0 2:2stat 4:8syst GeV=c 2 is derived from a likelihood fit incorporating reconstructed mass distributions representative of signal and background.

Searching for heavy charged Higgs boson with jet substructure at the LHC

“…Both of the neural network discriminant analysis and the boosted decision tree discriminant analysis are considered. TMVA methods have been broadly used in the top quark precision measurements by experimental collaborations [57,58,59] and W-jet substructure analysis [60], as well as new physics search studies, like Higgs boson search [61] and heavy quarks search [62,63,64]. The boost decision tree method has been adopted in the light charged Higgs boson search [65].…”

Updated predictions for the total production cross sections of top and of heavier quark pairs at the Tevatron and at the LHC

“…Different choices of A give rise to different resummed cross sections, all consistent with each other at the NLL level and NNLL level. 5 They therefore parametrize the possible exponentiation of finite, non-logarithmic terms appearing at orders higher than NLO. It was noticed already in [13] that the choice A = 0 was leading to a scale dependence typically a factor of two smaller than was obtained with A = 2.…”

Standard model backgrounds to supersymmetry searches

“…The theoretical prediction for inclusive tt production have already been well tested at the Tevatron [80][81][82] . For example, NLO calculations [37,38], enhanced by the resummation of leading [83] and subleading Sudakov logarithms [84][85][86] or by the inclusion of classes of NNLO terms [87][88][89] predict the total cross section with an accuracy consistent with the experimental uncertainty [90][91][92][93][94][95][96][97][98], as shown by fig. 16.…”