A measurement is presented of the t t-bar cross section (sigma[ttbar]) in proton-proton collisions at a centre-of-mass energy of 7 TeV, in the all-jet final state that contains at least six jets, two of which are tagged as originating from b quarks. The data correspond to an integrated luminosity of 3.54 inverse femtobarns, collected with the CMS detector at the LHC. The cross section is determined through an unbinned maximum likelihood fit of background and t t-bar signal to the reconstructed mass spectrum of t t-bar candidates in the data, in which events are subjected to a kinematic fit assuming a t t-bar to W+ b W- b-bar to 6 jets hypothesis. The measurement yields sigma[ttbar] = 139 +/- 10 (stat.) +/- 26 (syst.) +/- 3 (lum.) pb, a result consistent with those obtained in other t t-bar decay channels, as well as with predictions of the standard model.
Measurement of the tbart production cross section in the all-jet final state in pp collisions at sqrts = 7 TeV
CAVALLO, Nicola;FABOZZI, FRANCESCO;
2013-01-01
Abstract
A measurement is presented of the t t-bar cross section (sigma[ttbar]) in proton-proton collisions at a centre-of-mass energy of 7 TeV, in the all-jet final state that contains at least six jets, two of which are tagged as originating from b quarks. The data correspond to an integrated luminosity of 3.54 inverse femtobarns, collected with the CMS detector at the LHC. The cross section is determined through an unbinned maximum likelihood fit of background and t t-bar signal to the reconstructed mass spectrum of t t-bar candidates in the data, in which events are subjected to a kinematic fit assuming a t t-bar to W+ b W- b-bar to 6 jets hypothesis. The measurement yields sigma[ttbar] = 139 +/- 10 (stat.) +/- 26 (syst.) +/- 3 (lum.) pb, a result consistent with those obtained in other t t-bar decay channels, as well as with predictions of the standard model.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
