Tag: News
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DAQ
The first integrated data-taking and analysis in a High Energy Physics experiment. The procedure of data-taking and analysis at hadron colliders is performed in two steps. In the first one, called by physicists “online”, the data are recorded by the detector, read-out by fast electronics and computers, and finally a selected fraction of events is
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sin2the
[ sin2θWeff = 0.23142±0.00073(stat)±0.00052(sys)±0.00056(theory) ] The LHCb collaboration has submitted a paper based on run 1 data which reports the measurement of a fundamental parameter of the Standard Model (SM), the electroweak mixing angle, θW. This parameter quantifies the relative strengths of electromagnetism and the weak force. It is, therefore, an important experimental challenge to
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Vub
The LHCb collaboration published today in Nature Physics a paper based on run 1 data which reports the determination of the parameter
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FirstRun2
Measurement of J/ψ production cross-sections in pp collisions at 13 TeV. [ σ(prompt Jψ) = 15.35±0.03±0.85 μb; σ(Jψ-from-b-hadron) = 2.36±0.01±0.13 μb; σ( bb) = 518±2±53 μb ] At the EPS-HEP 2015 conference in Vienna the LHCb collaboration has presented today the first measurement of the probability to produce a J/ψ meson in proton-proton collisions at
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Penta
pentaquark-charmonium states, seen in Λb0 → J/ψpK– decays. [ m(Pc+(4450)) = 4449.8±1.7±2.5 MeV, Γ = 39±5±19 MeV ] [ m(Pc+(4380)) = 4380±8±29 MeV, Γ = 205±18±86 MeV ] The LHCb collaboration submitted today a paper based on run 1 data which reports the observation of pentaquark-charmonium states decaying into a J/ψ meson and a proton
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FiPh13TeV
LHC Run 2 started today. LHCb physicists have been eagerly awaiting this moment since 14 February 2013 when the last Run 1 collisions took place. The LHC has reached the “Stable Beams” state for the first time for two years. In these conditions the experiments could switch on safely their sensitive sub-detectors. This allowed LHCb
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RDst
Measurement of the decay B0 → D*+τ– ντ [ Branching fraction ratio B0 → D*+τ– ντ/ B0 → D*+μ– νμ = 0.336±0.027±0.030 ] Today, at the 13th Flavor Physics and CP violation conference in Nagoya (Japan), the LHCb collaboration presented the preliminary result from a measurement of the branching fraction ratio R(D*): B0 → D*+τ–
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Collim
Today, proton beams collided at 13 TeV for the first time inside the LHCb detector. The collisions were part of the ongoing accelerator tests, and are not useful for physics studies. The collected data are, however, useful for refining the synchronization of the readout time of different parts of the calorimeters and muon detectors. The
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LHCbCMS
Observation of the rare Bs0→μμ decay from the combined analysis of CMS and LHCb data [ Branching fraction Bs0→μμ = (2.8+0.7-0.6)x10-9 ; B0→μμ = (3.9+1.6-1.4)x10-10 ] The CMS and LHCb Collaborations have published today in Nature the first observation of the decay Bs0→μμ, with a statistical significance exceeding six standard deviations, and the best measurement
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450col
Today, for the first time in over two years, protons have collided inside the LHCb detector. Each proton beam had an energy of 450 GeV, which is the value they have when injected from the SPS to the LHC. At this injection energy the proton beams are large and therefore the big blocks of metal