The LHCb physics programme

A brief overview of the LHCb experiment is given, with an emphasis on the features important for heavy-flavour physics distinguishing it from the larger LHC experiments, ATLAS and CMS. The observables constraining the important unitarity triangles are discussed, and the expected LHCb performance for each of them is presented. Where appropriate this performance is compared with the expected performance of other experiments

Event Generators for Bhabha Scattering

The results obtained by the "Event Generators for Bhabha Scattering" working group during the CERN Workshop "Physics at LEP2" (1994/1995) are presented.Comment: 70 pages, PostScript file. To appear in the Report of the Workshop on Physics at LEP2, G. Altarelli T. Sjostrand and F. Zwirner ed

Beam Spot Position Measurement at the LEP Collider

A precise knowledge of the beam spot position is required for many physics topics at LEP2. The movement of the beam spot is studied at LEP1 using beam orbit monitors close to the interaction points and compared with measurements from tracks produced in e+e- collisions. The beam orbit monitors are found to follow the beam spot position well, particularly when corrected for movements of nearby quadrupole magnets. Data from the LEP high energy run of November 1995 are also analysed, and projections made for the prospects at LEP2

MICE: the Muon Ionization Cooling Experiment. Step I: First Measurement of Emittance with Particle Physics Detectors

The Muon Ionization Cooling Experiment (MICE) is a strategic R&D project intended to demonstrate the only practical solution to providing high brilliance beams necessary for a neutrino factory or muon collider. MICE is under development at the Rutherford Appleton Laboratory (RAL) in the United Kingdom. It comprises a dedicated beamline to generate a range of input muon emittances and momenta, with time-of-flight and Cherenkov detectors to ensure a pure muon beam. The emittance of the incoming beam will be measured in the upstream magnetic spectrometer with a scintillating fiber tracker. A cooling cell will then follow, alternating energy loss in Liquid Hydrogen (LH2) absorbers to RF cavity acceleration. A second spectrometer, identical to the first, and a second muon identification system will measure the outgoing emittance. In the 2010 run at RAL the muon beamline and most detectors were fully commissioned and a first measurement of the emittance of the muon beam with particle physics (time-of-flight) detectors was performed. The analysis of these data was recently completed and is discussed in this paper. Future steps for MICE, where beam emittance and emittance reduction (cooling) are to be measured with greater accuracy, are also presented

The present theoretical error on the Bhabha scattering cross section in the luminometry region at LEP

The results concerning the theoretical evaluation of the small-angle Bhabha Scattering cross section obtained during the Workshop on Physics at LEP2 (CERN, Geneva, Switzerland, 1995) by the Working Group ``Event Generators for Bhabha Scattering'' are summarized. The estimate of the theoretical error on the cross section in the luminometry region is updated

Measurement of Exclusive rho^0 rho^0 Production in Two-Photon Collisions at High Q^2 at LEP

Exclusive rho rho production in two-photon collisions involving a single highly virtual photon is studied with data collected at LEP at centre-of-mass energies 89GeV < \sqrt{s} < 209GeV with a total integrated luminosity of 854.7pb^-1 The cross section of the process gamma gamma^* -> rho rho is determined as a function of the photon virtuality, Q^2 and the two-photon centre-of-mass energy, Wgg, in the kinematic region: 1.2GeV^2 < Q^2 < 30GeV^2 and 1.1GeV < Wgg < 3GeV

Measurement of the Lifetime of the Tau Lepton

The tau lepton lifetime is measured with the L3 detector at LEP using the complete data taken at centre-of-mass energies around the Z pole resulting in tau_tau = 293.2 +/- 2.0 (stat) +/- 1.5 (syst) fs. The comparison of this result with the muon lifetime supports lepton universality of the weak charged current at the level of six per mille. Assuming lepton universality, the value of the strong coupling constant, alpha_s is found to be alpha_s(m_tau^2) = 0.319 +/- 0.015(exp.) +/- 0.014 (theory)