2,991 research outputs found

    Status of CDF Silicon Tracking

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    A snapshot of the status of the CDF Run II Silicon Detector dated July 2002 is presented, with a summary of commissioning issues since the start of Run II, current performance of the detector, and the use of the data in both the trigger and offline reconstruction

    Status of the CDF Run II Silicon Detector

    No full text
    A snapshot of the status of the CDF Run II Silicon Detector is presented, with a summary of commissioning issues since the start of Run II, current performance of the detector, and the use of the data in both the trigger and offline reconstruction

    Probing color coherence effects in pp collisions at √s = 7 TeV

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    Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. Funded by SCOAP3 / License Version CC BY 4.0.A study of color coherence effects in pp collisions at a center-of-mass energy of 7TeV is presented. The data used in the analysis were collected in 2010 with the CMS detector at the LHC and correspond to an integrated luminosity of 36 pb-1. Events are selected that contain at least three jets and where the two jets with the largest transverse momentum exhibit a back-to-back topology. The measured angular correlation between the second- and third-leading jet is shown to be sensitive to color coherence effects, and is compared to the predictions of Monte Carlo models with various implementations of color coherence. None of the models describe the data satisfactorily.BMWF and FWF (Austria); FNRS and FWO(Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil);MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF(Cyprus); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NIH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Republic of Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, andUASLPFAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS and RFBR(Russia);MESTD (Serbia); SEIDI and CPAN(Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); ThEPCenter, IPST, STAR and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA)

    W boson pair production at L3

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    Measurement of WZ and ZZ production in pp collisions at √s = 8 TeV in final states with b-tagged jets

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    Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. Funded by SCOAP3 / License Version CC BY 4.0.Measurements are reported of the WZ and ZZ production cross sections in proton-proton collisions at s √ =8 TeV in final states where one Z boson decays to b-tagged jets. The other gauge boson, either W or Z, is detected through its leptonic decay (either W→eν , μν or Z→e + e − , μ + μ − , or νν ¯ ). The results are based on data corresponding to an integrated luminosity of 18.9 fb −1 collected with the CMS detector at the Large Hadron Collider. The measured cross sections, σ(pp→WZ)=30.7±9.3(stat.)±7.1(syst.)±4.1(th.)±1.0(lum.)pb and σ(pp→ZZ)=6.5±1.7(stat.)±1.0(syst.)±0.9(th.)±0.2(lum.)pb , are consistent with next-to-leading order quantum chromodynamics calculationsBMWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES and CS (Croatia); RPF (Cyprus); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF(Germany);GSRT(Greece);OTKAand NIH(Hungary);DAEand DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Republic of Korea); LAS (Lithuania);MOE and UM(Malaysia); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS and RFBR (Russia); MESTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); ThEPCenter, IPST, STAR and NSTDA(Thailand); TUBITAK and TAEK (Turkey); NASU and SFFR (Ukraine); STFC (United Kingdom); DOE and NSF (USA)

    Inclusive Electroweak measurements in the muon channel with pp collisions at [the square root of] s=7 TeV

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2011.In title on title-page, "[the square root of]" appears as the mathematical symbol. Cataloged from PDF version of thesis.Includes bibliographical references (p. 237-243).In this thesis, we perform the measurement of the production of W and Z bosons in proton-proton collisions at [the square root of]s = 7 TeV with the Large Hadron Collider (LHC). In the LHC, W and Z bosons are produced at a high rate, providing for large yields, which along with the clean signature of W boson decay into a muon and neutrino and the Z boson decay into two muons, allow for precision measurement of their production within the first year of operation. Deviation of these values from standard model predictions gives a clear indication of new physics interactions occurring at the LHC. We present the measurement of the inclusive W--> [mu] [epsilon] and Z --> [mu]+ [mu]- cross sections along with the W boson charge ratio (W+/W-) and the W/Z production ratio in the muon channel using the first data corresponding to 35.9 pb-1 of proton proton collisions at [the square root of]s = 7 TeV. Measured values of ... are in agreement with the most advanced NNLO predictions. These are currently the most precise Electroweak measurements at the LHC.by Philip Coleman Harris.Ph.D

    Dijet Azimuthal Decorrelations in pp Collisions at √s=7  [square root of s=7] TeV

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    Measurements of dijet azimuthal decorrelations in pp collisions at √s=7  [square root of s=7] TeV using the CMS detector at the CERN LHC are presented. The analysis is based on an inclusive dijet event sample corresponding to an integrated luminosity of 2.9  pb-1 [pb superscript -1]. The results are compared to predictions from perturbative QCD calculations and various Monte Carlo event generators. The dijet azimuthal distributions are found to be sensitive to initial-state gluon radiation.United States. Dept. of EnergyNational Science Foundation (U.S.

    Measurement of the B-s(0)-(B)over-bar(s)(0) oscillation frequency

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    We present the first precise measurement of the B-s(0)-(B) over bar (0)(s) oscillation frequency Delta m(s). We use 1 fb(-1) of data from p (p) over bar collisions at root s=1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. The sample contains signals of 3600 fully reconstructed hadronic B-s decays and 37 000 partially reconstructed semileptonic B-s decays. We measure the probability as a function of proper decay time that the B-s decays with the same, or opposite, flavor as the flavor at production, and we find a signal consistent with B-s(0)-(B) over bar (0)(s) oscillations. The probability that random fluctuations could produce a comparable signal is 0.2%. Under the hypothesis that the signal is due to B-s(0)-(B) over bar (0)(s) oscillations, we measure Delta m(s)=17.31(-0.18)(+0.33)(stat)+/- 0.07(syst) ps(-1) and determine vertical bar V-td/V-ts vertical bar=0.208(-0.002)(+0.001)(expt)(-0.006)(+0.008)(theor)

    Measurement of b hadron lifetimes in pp collisions at root s = 8TeV (vol 78, 2018)

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    We have corrected Eqs. (17)–(20) from Section 8 of the original paper. The published versions of Eqs. (17) and (18) were mistakenly the same and Eqs. (19) and (20) were reversed. Below are the corrected equations: (Formula presented.) Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecomm ons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.0info:eu-repo/semantics/publishe

    Measurement of the B s 0 → J / ψK S 0 effective lifetime from proton-proton collisions at s = 13 TeV

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    Abstract The effective lifetime of the B s 0 meson in the decay B s 0 → J / ψK S 0 is measured using data collected during 2016–2018 with the CMS detector in s = 13 TeV proton-proton collisions at the LHC, corresponding to an integrated luminosity of 140 fb−1. The effective lifetime is determined by performing a two-dimensional unbinned maximum likelihood fit to the B s 0 meson invariant mass and proper decay time distributions. The resulting value of 1.59 ± 0.07(stat) ± 0.03(syst) ps is the most precise measurement to date and is in good agreement with the expected value
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