Tracker Operation and Performance at the Magnet Test and Cosmic Challenge

During summer 2006 a fraction of the CMS silicon strip tracker was operated in a comprehensive slice test called the Magnet Test and Cosmic Challenge (MTCC). At the MTCC, cosmic rays detected in the muon chambers were used to trigger the readout of all CMS sub-detectors in the general data acquisition system and in the presence of the 4 T magnetic field produced by the CMS superconducting solenoid. This document describes the operation of the Tracker hardware and software prior, during and after data taking. The performance of the detector as resulting from the MTCC data analysis is also presented

Nietzsches gelijk: Waarom wijsheid achteraf onbillijk is

A search is performed for a massive new vector-like quark T, with charge 2/3, that is pair produced together with its antiparticle in proton-proton collisions. The data were collected by the CMS experiment at the Large Hadron Collider in 2012 at sqrt(s) = 8 TeV and correspond to an integrated luminosity of 19.5 inverse femtobarns. The T quark is assumed to decay into three different final states, bW, tZ, and tH. The search is carried out using events with at least one isolated lepton. No deviations from standard model expectations are observed, and lower limits are set on the T quark mass at 95% confidence level. The lower limit lies between 687 and 782 GeV for all possible values of the branching fractions into the three different final states assuming strong production. These limits are the most stringent constraints to date on the existence of such a quark

Mechanical stability of the CMS strip tracker measured with a laser alignment system

Peer reviewe

Observation of the diphoton decay of the Higgs boson and measurement of its properties

Peer reviewe

Measurement of the jet mass in highly boosted t(t)over-bar events from pp collisions at root s=8TeV

Peer reviewe

Measurement of the Zγ production cross section in pp collisions at 8 TeV and search for anomalous triple gauge boson couplings

Open Access, Copyright CERN, for the benefit of the CMS Collaboration. Article funded by SCOAP3.Abstract: The cross section for the production of Zγ in proton-proton collisions at 8 TeV is measured based on data collected by the CMS experiment at the LHC corresponding to an integrated luminosity of 19.5 fb−1. Events with an oppositely-charged pair of muons or electrons together with an isolated photon are selected. The differential cross section as a function of the photon transverse momentum is measured inclusively and exclusively, where the exclusive selection applies a veto on central jets. The observed cross sections are compatible with the expectations of next-to-next-to-leading-order quantum chromodynamics. Limits on anomalous triple gauge couplings of ZZγ and Zγγ are set that improve on previous experimental results obtained with the charged lepton decay modes of the Z boson

Search for lepton-flavour-violating decays of the Higgs boson

Peer reviewe

Search for neutral resonances decaying into a Z boson and a pair of b jets or tau leptons

Peer reviewe

Fatal long distance roaming of a male bear highlights survival threats to dispersing bears in the Apennines, central Italy

From September 2006 through May 2010, we repeatedly detected an adult male bear (G70) through non-invasive sampling in the Sibillini National Park (SNP; central Apennines, Italy), at the northernmost periphery of the reported Apennine bear range. Notwithstanding sustained sampling effort, we failed to detect bear G70 in SNP after May 2010, but in autumn 2010 it was twice detected, through non-invasive sampling, in the Duchessa Nature Reserve (76 km south of the SNP), revealing its southward travel across the central Apennines. More than one year later (16 January 2012), a male bear was live-captured in the Sirente-Velino Regional Park showing clinical symptoms of Aujeszld's disease. The bear died overnight, and genotyping revealed it to be bear G70. Although the causes of death were not clearly determined, poisoning, shooting and vehicle accident were ruled out, suggesting more subtle mortality factors (e.g., diseases) were responsible. The long distance movements and the fate of this adult male bear indicate that, even though protected and suitable areas are connected across the Apennines to some degree, the expected expansion of the Apennine bear range from the core distribution might be suffering from undisclosed anthropogenic risks of mortality in the peripheral portions of the range