11368920
Inclusive measurement of the photon energy spectrum in b --> sgamma decays.
We report a fully inclusive measurement of the flavor changing neutral current decay b --> sgamma in the energy range 1.8 GeV < or = E*gamma < or = 2.8 GeV, covering 95% of the total spectrum. Using 140 fb(-1), we obtain B(b --> sgamma) = (3.55+/-0.32(+0.30+0.11)(-0.31-0.07)) x 10(-4), where the errors are statistical, systematic, and from theory corrections. We also measure the first and second moments of the photon energy spectrum above 1.8 GeV and obtain (Egamma) = 2.292+/-0.026+/-0.034 GeV and (E2gamma) - (Egamma)2 = 0.0305+/-0.0074+/-0.0063 GeV2, where the errors are statistical and systematic.
122757815
Performance Study of the CMS Barrel Resistive Plate Chambers with Cosmic Rays
In October and November 2008, the CMS collaboration conducted a programme of cosmic ray data taking, which has recorded about 270 million events. The Resistive Plate Chamber system, which is part of the CMS muon detection system, was successfully operated in the full barrel. More than 98% of the channels were operational during the exercise with typical detection efficiency of 90%. In this paper, the performance of the detector during these dedicated runs is reported.
62211675
PAT: The CMS Physics Analysis Toolkit
The CMS Physics Analysis Toolkit (PAT) is presented. The PAT is a high-level analysis layer enabling the development of common analysis efforts across and within Physics Analysis Groups. It aims at fulfilling the needs of most CMS analyses, providing both ease-of-use for the beginner and flexibility for the advanced user. The main PAT concepts are described in detail and some examples from physics analyses are given.
199676084
Measurement of the differential q**2 spectrum and forward-backward asymmetry for B ---> K* l+ l-
209834639
Search for supersymmetry in events with b-quark jets and missing transverse energy in pp collisions at 7 TeV
Results are presented from a search for physics beyond the standard model based on events with large missing transverse energy, at least three jets, and at least one, two, or three b-quark jets. The study is performed using a sample of proton-proton collision data collected at sqrt(s)=7 TeV with the CMS detector at the LHC in 2011, with the missing transverse energy distribution as the principal search variable. The integrated luminosity of the sample is 4.98 inverse femtobarns. The observed number of events is found to be consistent with the standard model expectation, which is evaluated using control samples in the data. The results are used to constrain cross sections for the production of supersymmetric particles decaying to b-quark-enriched final states in the context of simplified model spectra.
118843154
Performance and operation of the CMS electromagnetic calorimeter
The operation and general performance of the CMS electromagnetic calorimeter using cosmic-ray muons are described. These muons were recorded after the closure of the CMS detector in late 2008. The calorimeter is made of lead tungstate crystals and the overall status of the 75 848 channels corresponding to the barrel and endcap detectors is reported. The stability of crucial operational parameters, such as high voltage, temperature and electronic noise, is summarised and the performance of the light monitoring system is presented.
121929249
Momentum analysis of kaon and pion pairs produced from time-like photons at 1.6 GeV energy
We present results for the total cross section of e+e− annihilation into two hadrons at 1.6 GeV: σππ = σKK = (1.8 ± 1.1) × 10-33 cm2.From these values we obtain the time-like electromagnetic form factors these mesons: |Fπ|2 = 0.24 ± 0.14 and |FK|2 = 0.46 ± 0.26.
73677709
Vibrational excitation induced by electron beam and cosmic rays in superconductive aluminum bars
We report new measurements of the acoustic excitation of an Al5056 superconductive bar when hit by an electron beam, in a previously unexplored temperature range, down to 0.35 K. These data, analyzed together with previous results obtained for T > 0.54 K, show a vibrational response enhanced by a factor ~ 4.9 with respect to that measured in the normal state. This enhancement explains the anomalous large signals due to cosmic rays previously detected in the NAUTILUS gravitational wave detector.
125308314
STUDY OF (PI+ PI- PI+ PI-) AND (PI+ PI- PI0) CHANNEL IN E+ E- ANNIHILATION AT 1.450-GEV - 1.875-GEV center-of-mass ENERGY
18453536
Atmospheric neutrino induced muons in the MACRO detector
A measurement of the flux of neutrino-induced muons using the MACRO detector is presented. Different event topologies, corresponding to different neutrino parent energies can be detected. The upward throughgoing muon sample is larger event sample. For this sample, produced by neutrinos having an average energy around 100 GeV, the ratio of the number of observed to expected events integrated over all zenith angles is 0.74 ± 0.036stat ± 0.046syst ± 0.13theor. We have investigated whether the observed number of events and the shape of the zenith distribution can be explained by an hypothesis of νμ → ντ oscillation. The best probability (17%) is obtained for sin2 2θ ≅ 1.0 and Δm2 of a few times 10−3 eV2, while the probability for the no oscillation hypothesis is 0.1%. The other samples are due to the internally produced events and to upward-going stopping muons; the average parent neutrino energy is of the order of 4 GeV. The low energy data sets show a deficit of observed events similar to the one predicted by the oscillation model with maximum mixing suggested from the upward throughgoing muon sample.
197440585
Overview of the MACRO Detector at the Gran Sasso Laboratory