122010968
LUMINOSITY MONITORING AT LHCb
121605096
Performance of an irradiated LHCb prototype p-on-n silicon microstrip detector
Abstract A prototype silicon detector for the LHCb experiment has been irradiated non-uniformly with fluences of up to 10 15 p / cm 2 of 24 GeV protons and tested with LHC speed electronics in a test beam. After doses equivalent to one year of operation at the LHC, the detector was operational, and deteriorated after higher doses. The performance of this detector identifies particular risks associated with a p-on-n fine pitch design with a double metal layer.
208345688
VELO Geometry Optimisation
New possible layouts of the LHCb Vertex Locator (VELO) have been compared with the existing baseline design outlined in the Technical Proposal. Based on a comparison of essential figures of merit, namely vertex resolutions, event selection efficiencies, trigger performance, and technical constraints an updated baseline design is proposed. The new design retains the same number of electronic channels as that in the Technical Proposal, but has an increased number of measuring stations (25 rather than 17) with a reduced inner radius (8mm rather than 10mm).
109046686
Beam incidents - High particle rate tests of an LHCb/Velo silicon strip module
L. Eklund ∗a, K. Akiba b, O. Behrendt c, M. van Beuzekom b, J. Buytaert c, P. Collins c, M. Ferro-Luzzi c, K. Hennessy d, J. Imong e aUniversity of Glasgow, Glasgow, UK. bNikhef, National Institute for Subatomic Physics, Amsterdam, Netherlands. cEuropean Organisation for Nuclear Research (CERN), Geneva, Switzerland. dUniversity of Liverpool, Liverpool, UK eH.H. Wills Physics Laboratory, University of Bristol, Bristol, United Kingdom. E-mail: Lars.Eklund@cern.ch
15273175
The LHCb trigger strategy and performance
Precise measurements of CP-violating asymmetries, oscillation parameters and branching ratios on numerous B-decay channels will allow an overdetermination of CKM parameters, with possible inconsistencies pointing to physics beyond the Standard Model. In order to achieve this, an experiment capable of triggering on the various decay modes of B-mesons (in particular hadronic modes) is desirable. LHCb [ 1] is an experiment dedicated to such precision studies at the large hadron collider (LHC). It is designed as a forward spectrometer, because BB pairs are expected to be predominantly produced at small polar angles. An overview of the LHCb detector and trigger scheme is shown in Figure 1.
1648236
The LHCb VELO: status and upgrade developments
The VErtex LOcator (VELO) is the silicon microstrip vertexing and triggering sub-detector of the LHCb experiment. It consists of a series of forward disks with the active region extending to just 8 mm from the LHC beams. The current status of the VELO is presented. Due to the high radiation environment, the VELO may have to be replaced after some years, possibly with new materials. A candidate material is Czochralski silicon. We present here promising new results on the first test beam of a large, high resistivity Czochralski microstrip silicon detector read out with LHC speed electronics. The performance was studied before and after irradiation with high energy protons. A signal to noise of over 20:1 was obtained from the detector and significant charge collection efficiencies were measured at relatively modest voltages after a fluence of 4.3/spl times/10/sup 14/ 1 MeV neutron equivalents (n/sub eq/) per cm/sup 2/. Studies using the Transient Current Technique probed the electric field within MCz test detectors and proved that MCz silicon does not type invert up until a radiation level of at least 5/spl times/10/sup 14/ 24GeV/c p/cm/sup 2/. This would mean the VELO could possibly replace, in a potential upgrade, n/sup +/-on-n DOFZ sensors and the complicated processing involved, for standard p/sup +/-on-n processing with MCz.
123022326
A fit of baryon decay rates within SU(3)
Abstract A test of the consistency between observed resonant amplitudes or decay rates for baryon resonances with SU(3) predictions has been made. Coupling constants describing the decays are determined and predictions are given for decays into stable baryons and mesons.
107426806
LHC bunch filling schemes for commissioning and initial luminosity optimization
125673698
Determination of the Luminosity at the LHC Experiments
122279335
The real part of the forward scattering amplitude in π±p elastic scattering below 2 GeV/c
Abstract The differential cross section for π ± p elastic scattering below 2 GeV/ c has been measured at small forward pion angles by an electronics experiment. The interference effects observed between the Coulomb and the nuclear interaction have been used to determine the magnitude and sign of the real parts of the π ± p forward scattering amplitude. The latter are compared to the values predicted by the dispersion relations.
126241664
Impact of Vertex Detectors on Luminosity Calibration Measurements at the LHC