Search for new physics with jets and missing transverse momentum in pp collisions at √s = 7 TeV

A search for new physics is presented based on an event signature of at least three jets accompanied by large missing transverse momentum, using a data sample corresponding to an integrated luminosity of 36 pb-1 collected in proton-proton collisions at √s = 7TeV with the CMS detector at the LHC. No excess of events is observed above the expected standard model backgrounds, which are all estimated from the data. Exclusion limits are presented for the constrained minimal supersymmetric extension of the standard model. Cross section limits are also presented using simplified models with new particles decaying to an undetected particle and one or two jets

Determination of the top-quark pole mass and strong coupling constant from the t(t)over-bar production cross section in pp collisions at root s=7 TeV

The inclusive cross section for top-quark pair production measured by the CMS experiment in proton-proton collisions at a center-of-mass energy of 7 TeV is compared to the QCD prediction at next-to-next-to-leading order with various parton distribution functions to determine the top-quark pole mass, mtpole, or the strong coupling constant, αS. With the parton distribution function set NNPDF2.3, a pole mass of 176. 7+3.8-3.4 GeV is obtained when constraining αS at the scale of the Z boson mass, mZ, to the current world average. Alternatively, by constraining mtpole to the latest average from direct mass measurements, a value of αS(mZ) = 0. 1151+0.0033-0.0032 is extracted. This is the first determination of αS using events from top-quark production. © 2013 The Authors. Published by Elsevier B.V