Measurement of the production cross section for Z gamma -> nu(nu)over-bar gamma in pp collisions at √s=7 TeV and limits on ZZ gamma and Z gamma gamma triple gauge boson couplings

This article is the pre-print version of the final published paper that is available from the link below.A measurement of the Z → vvγ cross section in pp collisions at root s = 7TeV is presented, using data corresponding to an integrated luminosity of 5.0 fb-1 collected with the CMS detector. This measurement is based on the observation of events with an imbalance of transverse energy in excess of 130 GeV and a single photon in the absolute pseudorapidity range |n| < 1:4 with transverse energy above 145 GeV. The Z →vvγ production cross section is measured to be 21.1±4.2 (stat:)±4.3 (syst:)±0.5 (lum:) fb, which agrees with the standard model prediction of 21.9±1.1 fb. The results are combined with the CMS measurement of Z production in the l+l- γ final state (where l is an electron or a muon) to yield the most stringent limits to date on triple gauge boson couplings: |hZ3|< 2.7 x 10-3, |hZ4| < 1,3 x 10-5 for ZZγ and |hγ3| < 2.9 x10-3, |hγ4| < 1.5 x 10-5 for Zγγ couplings

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Concert ProgramJazz Innovations Series Part 1 May 20, 201

Searches for long-lived charged particles in pp collisions at root s=7 and 8 TeV

Results of searches for heavy stable charged particles produced in pp collisions at {Mathematical expression} = 7 and 8 TeV are presented corresponding to an integrated luminosity of 5.0 fb and 18.8 fb, respectively. Data collected with the CMS detector are used to study the momentum, energy deposition, and time-of-flight of signal candidates. Leptons with an electric charge between e/3 and 8 e, as well as bound states that can undergo charge exchange with the detector material, are studied. Analysis results are presented for various combinations of signatures in the inner tracker only, inner tracker and muon detector, and muon detector only. Detector signatures utilized are long time-of-flight to the outer muon system and anomalously high (or low) energy deposition in the inner tracker. The data are consistent with the expected background, and upper limits are set on the production cross section of long-lived gluinos, scalar top quarks, and scalar τ leptons, as well as pair produced long-lived leptons. Corresponding lower mass limits, ranging up to 1322 GeV/c for gluinos, are the most stringent to date. [Figure not available: see fulltext.] © 2013 Cern for the benefit of the CMS collaboration

Study of the underlying event at forward rapidity in pp collisions at root s=0.9, 2.76, and 7 TeV

The underlying event activity in proton-proton collisions at forward pseudorapidity (-6.6 < eta < -5.2) is studied with the CMS detector at the LHC, using a novel observable: the ratio of the forward energy density, dE/d(eta), for events with a charged-particle jet produced at central pseudorapidity (vertical bar eta(jet)vertical bar < 2) to the forward energy density for inclusive events. This forward energy density ratio is measured as a function of the central jet transverse momentum, p(T), at three different pp centre-of-mass energies (root s = 0.9, 2.76, and 7 TeV). In addition, the root s evolution of the forward energy density is studied in inclusive events and in events with a central jet. The results are compared to those of Monte Carlo event generators for pp collisions and are discussed in terms of the underlying event. Whereas the dependence of the forward energy density ratio on jet p(T), at each root s separately can be well reproduced by some models, all models fail to simultaneously describe the increase of the forward energy density with root s in both inclusive events and in events with a central jet

Measurement of the production cross section for Z gamma -> nu(nu)over-bar gamma in pp collisions at root s=7 TeV and limits on ZZ gamma and Z gamma gamma triple gauge boson couplings

A measurement of the Z gamma -> nu(nu) over bar gamma cross section in pp collisions at root s = 7 TeV is presented, using data corresponding to an integrated luminosity of 5.0 fb(-1) collected with the CMS detector. This measurement is based on the observation of events with an imbalance of transverse energy in excess of 130 GeV and a single photon in the absolute pseudorapidity range vertical bar eta vertical bar nugamma production cross section is measured to be 21.1 +/- 4.2(stat.)+/- 4.3(syst.)+/- 0.5(lum.)fb, which agrees with the standard model prediction of 21.9 +/- 1.1 fb. The results are combined with the CMS measurement of Z gamma production in the l(+)l(-)gamma final state (where l is an electron or a muon) to yield the most stringent limits to date on triple gauge boson couplings. vertical bar h(3)(Z)vertical bar < 2.7 x 10(-3), vertical bar h(4)(Z)vertical bar < 1.3 x 10(-5) for ZZ gamma and vertical bar h(3)(gamma)vertical bar < 2.9 x 10(-3), vertical bar h(4)(gamma)vertical bar < 1.5 x 10(-5) for Z gamma gamma couplings

Searches for long-lived charged particles in pp collisions at root s=7 and 8 TeV

Results of searches for heavy stable charged particles produced in pp collisions at root s = 7 and 8 TeV are presented corresponding to an integrated luminosity of 5.0 fb(-1) and 18.8 fb(-1), respectively. Data collected with the CMS detector are used to study the momentum, energy deposition, and time-of-flight of signal candidates. Leptons with an electric charge between e/3 and 8e, as well as bound states that can undergo charge exchange with the detector material, are studied. Analysis results are presented for various combinations of signatures in the inner tracker only, inner tracker and muon detector, and muon detector only. Detector signatures utilized are long time-of-flight to the outer muon system and anomalously high (or low) energy deposition in the inner tracker. The data are consistent with the expected background, and upper limits are set on the production cross section of long-lived gluinos, scalar top quarks, and scalar tau leptons, as well as pair produced long-lived leptons. Corresponding lower mass limits, ranging up to 1322 GeV/c(2) for gluinos, are the most stringent to date