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Status of the LHCb Experiment,高原宁清华大学高能物理研究中心,Introduction & physics motivationsStatus of the detector constructionTopics on physics potentialsConclusions,高能物理学会第七界学术年会 2006年10月29日 桂林,LHCb is a dedicated B physics experiment at the LHC,Forward spectrometer (running in pp collider mode),Great potential for B physics!,Physics motivations,The Standard model CP violation is described by the single complex phase in the CKM matrix, two unitarity triangles relevant to B physics at LHCb stat.,Current SM fit of the Unitarity Triangles (including CDF result on Dms),a = 94.6 4.6b = 23.9 1.0 = 61.3 4.5fs= 2.1 0.2, high statistics Bd and Bs samples are essential robust and efficient trigger, even for non-leptonic decays good decay vertex resolution; good tracking; good particle identification,Many final states need to be reconstructed ,HIGH STATISTICS,News from the experiment,r- and measuring sensors rather than x,y fast and easy impact parameters for use in the trigger,VErtex LOcator “VELO”,-sensor:radial strips (inner and outer)2048 stripsstereo angle(-20, +10)3798 m pitchr-sensor:concentric strips2048 strips4 sectors (45)40-103 mm pitch,harsh radiation environment: n-n sensors: keep good resolution if undepleted sensor cooling to -5C with CO2 cooling system,good impact parameters detectors as close as 8mm to LHC beam sensors placed in secondary vacuum (10-9 mbar) separated from beam-vacuum just by an 300mm Al “RF-foil”move sensors out during filling (3cm) re-positioning accuracy: 1520 V 98% 200 m,Outer Tracker Installation,Support bridge, installed,with modules,1/4 of the stations are already equipped with modulesnow: testing, cabling, survey,selection of specific B-decay channels for CP measurements without particle ID, the bkg-dilutes/overwhelms the signal,RICH Particle ID,Bs Ds,Bs Ds K,2 RICH Detectors with 3 Cherenkov Radiators,RICH1: 5cm silica aerogel (2-10GeV/c) 85cm C4F10 gas (50GeV/c) spherical (CF) and planar (glass) mirrors,RICH2: 170cm CF4 gas ( LHCb note,Bc mass & lifetime,Refinements due to Trigger change LHCb note soon,Selected topics on physics potentialOutlook,A possible scenario after the LHCb measurement of g: new physics?,Many other interesting topics not covered by this talk TDR, LHCb notes, ,Conclusions,LHCb is dedicated to the study of B physics, with a devoted trigger,excellent vertex and momentum resolution, and particle identificationConstruction of the experiment is progressing wellIt will be ready for first LHC collisions in 2007 (TELL1s from Tsinghua group are delivered to the experiment) LHCb will give unprecedented statistics for B decays, including access to the Bs