The central feature of the CMS Link alignment system is a network of Amorphous Silicon Position Detectors distributed throughout the muon spectrometer that are connected by multiple laser lines. The ...data collected during the years from 2008 to 2015 is presented confirming an outstanding performance of the photo sensors during more than seven years of operation. Details of the photo sensor readout of the laser signals are presented. The mechanical motions of the CMS detector are monitored using these photosensors and good agreement with distance sensors is obtained.
Magnet Cycles and Stability Periods of the CMS Experiment are studied with the Alignment Link System data recorded along the 2008–2013 years of operation. The motions of the mechanical structures due ...to the magnetic field forces are studied and the mechanical stability of the detector during the physics data taking periods is verified.
A study of the photo-response behaviour of carbon-doped hydrogenated amorphous silicon photo-detectors over 2800h of continuous illumination with white light is presented. Both direct and inverse ...Staebler–Wronski effects are observed in the data.
Silica nanoparticles with different sizes (from 14 to 60 nm) and different surface modifications (hydrophobic treatment, core–shell structures) are synthesized as colloids and introduced at different ...concentrations in polysiloxane type coatings in order to perform indentation and scratch experiments. The adding of fillers increases the Young's modulus of the coatings but decreases the 200-μm scratch resistance. The weakness of matrix–filler interactions has no significant effect on the Young's Modulus, but also alter the 200-μm scratch resistance. Core–shell fillers, i.e. silica particles coated with a low modulus polymeric shell, can be equivalent to non modified silica particles as far as the 200-μm scratch test is concerned, but they weakly improve the Young's modulus of the Glymo films, suggesting a poor resistance of filled coatings to small scratches.
This document presents an overview of the induced photocurrents in the Amorphous Silicon Position Detectors used in the network of diode lasers and photo sensors of the CMS Link alignment system ...recorded during its eleven years of operation. After a description of the sensors characteristics, the layout of the sensors network is discussed. The sensors are distributed throughout the muon spectrometer and connected by laser lines. The data used correspond to readout information obtained during some of the physics runs from 2008 to 2018.
We present the first measurement of polarization and CP-violating asymmetries in a B{sub s}{sup 0} decay into two light vector mesons, B{sub s}{sup 0}{yields}{phi}{phi}, and an improved determination ...of its branching ratio using 295 decays reconstructed in a data sample corresponding to 2.9 fb{sup -1} of integrated luminosity collected by the CDF experiment at the Fermilab Tevatron collider. The fraction of longitudinal polarization is determined to be f{sub L}=0.348{+-}0.041(stat){+-}0.021(syst), and the branching ratio B(B{sub s}{sup 0}{yields}{phi}{phi})=2.32{+-}0.18(stat){+-}0.82(syst)x10{sup -5}. Asymmetries of decay angle distributions sensitive to CP violation are measured to be A{sub u}=-0.007{+-}0.064(stat){+-}0.018(syst) and A{sub v}=-0.120{+-}0.064(stat){+-}0.016(syst).
We present the results of a search for pair production of a heavy toplike (t') quark decaying to Wq final states using data corresponding to an integrated luminosity of 5.6 fb{sup -1} collected by ...the CDF II detector in pp collisions at {radical}(s)=1.96 TeV. We perform parallel searches for t'{yields}Wb and t'{yields}Wq (where q is a generic down-type quark) in events containing a lepton and four or more jets. By performing a fit to the two-dimensional distribution of total transverse energy versus reconstructed t{sup '} quark mass, we set upper limits on the t't' production cross section and exclude a standard model fourth-generation t' quark decaying to Wb (Wq) with mass below 358 (340) GeV/c{sup 2} at 95% C.L.
We present a measurement of the top-quark mass using a sample of tt events in 5.7 fb{sup -1} of integrated luminosity from pp collisions at the Fermilab Tevatron with {radical}(s)=1.96 TeV and ...collected by the CDF II Detector. We select events having large missing transverse energy, and four, five, or six jets with at least one jet tagged as coming from a b quark, and reject events with identified charged leptons. This analysis considers events from the semileptonic tt decay channel, including events that contain tau leptons. The measurement is based on a multidimensional template method. We fit the data to signal templates of varying top-quark masses and background templates, and measure a top-quark mass of M{sub top}=172.32{+-}2.4(stat){+-}1.0(syst) GeV/c{sup 2}.
The observation of the bottom, strange baryon {Xi}{sub b}{sup 0} through the decay chain {Xi}{sub b}{sup 0}{yields}{Xi}{sub c}{sup +}{pi}{sup -}, where {Xi}{sub c}{sup +}{yields}{Xi}{sup -}{pi}{sup ...+}{pi}{sup +}, {Xi}{sup -}{yields}{Lambda}{pi}{sup -}, and {Lambda}{yields}p{pi}{sup -}, is reported by using data corresponding to an integrated luminosity of 4.2 fb{sup -1} from pp collisions at {radical}(s)=1.96 TeV recorded with the Collider Detector at Fermilab. A signal of 25.3{sub -5.4}{sup +5.6} candidates is observed whose probability of arising from a background fluctuation is 3.6x10{sup -12}, corresponding to 6.8 Gaussian standard deviations. The {Xi}{sub b}{sup 0} mass is measured to be 5787.8{+-}5.0(stat){+-}1.3(syst) MeV/c{sup 2}. In addition, the {Xi}{sub b}{sup -} baryon is observed through the process {Xi}{sub b}{sup -}{yields}{Xi}{sub c}{sup 0}{pi}{sup -}, where {Xi}{sub c}{sup 0}{yields}{Xi}{sup -}{pi}{sup +}, {Xi}{sup -}{yields}{Lambda}{pi}{sup -}, and {Lambda}{yields}p{pi}{sup -}.
We report on the first measurement of the angular distributions of final state electrons in pp{yields}{gamma}{sup *}/Z{yields}e{sup +}e{sup -}+X events produced in the Z boson mass region at ...{radical}(s)=1.96 TeV. The data sample collected by the CDF II detector for this result corresponds to 2.1 fb{sup -1} of integrated luminosity. The angular distributions are studied as a function of the transverse momentum of the electron-positron pair and show good agreement with the Lam-Tung relation, consistent with a spin-1 description of the gluon, and demonstrate that, at high values of the transverse momentum, Z bosons are produced via quark-antiquark annihilation and quark-gluon Compton processes.
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