0000000000135715
AUTHOR
M. Haguenauer
Monte Carlo study of forward pi(0) production spectra to be measured by the LHCf experiment for the purpose of benchmarking hadron interaction models at 10(17) eV
Abstract The LHCf experiment aims to improve knowledge of forward neutral particle production spectra at the LHC energy which is relevant for the interpretation of air shower development of high energy cosmic rays. Two detectors, each composed of a pair of sampling and imaging calorimeters, have been installed at the forward region of IP1 to measure π0 energy spectra above 600 GeV. In this paper, we present a Monte Carlo study of the π0 measurements to be performed with one of the LHCf detectors for proton–proton collisions at s = 14 TeV. In approximately 40 min of operation at luminosity 0.8 × 10 29 cm - 2 s - 1 during the beam commissioning phase of LHC, about 1.5 × 104 π0 events are exp…
The real part of the elastic-scattering amplitude at the $$S\bar ppS$$ and predictions at LHC and SSCand predictions at LHC and SSC
A precise measurement of\(\bar pp\) elastic scattering in the Coulomb strong-interaction interference region was performed at the CERN\(S\bar ppS\) Collider at a centre-of-mass energy of 541 GeV. The ratio of the real-to-imaginary part of the forward elastic-scattering amplitude was found to be ρ=0.135±0.015. The slope of the exponential fall-off of the strong-interaction part was also measured to beb=15.5±0.1 GeV−2. Using this new result, an overall fit to the data on the total cross-section and on the real part for\(\bar pp\) and pp was performed using dispersion relations. Numerical predictions are presented for total cross-sections at LHC and SSC energies.
Measurement of the proton-antiproton total cross section at the SppS collider by a luminosity dependent method
Abstract The proton-antiproton total cross section was measured at the center-of-mass energy of s = 541 GeV at the S p pS at CERN using a luminosity dependent method. The result σtot=63.0±2.1 mb is in agreement with the luminosity independent measurement performed earlier by the UA4 Collaboration.
The UA4/2 experiment at the CERN SpS collider
Abstract The UA4/2 experiment performed at CERN to measure the ratio of the real to the imaginary part of the forward elastic scattering amplitude is described. The accent is placed on the improvements with respect to the previous UA4 experiment, especially on the much improved design of the high-β insertion and a high-resolution, highly multiplexed scintillating fiber tracking detector.
Early results of the LHCf experiment and their contribution to ultra-high-energy cosmic ray physics
LHCf is an experiment dedicated to the measurement of neutral particles emitted in the very forward region of LHC collisions. The physics goal is to provide data for calibrating hadron interaction models that are used in the study of Extremely High-Energy Cosmic-Rays. The LHCf experiment acquired data from April to July 2010 during commissioning time of LHC operations at low luminosity. Production spectra of photons and neutrons emitted in the very forward region ($��>$ 8.4) have been obtained. In this paper preliminary results of the photon spectra taken at $\sqrt{s}$ = 7TeV are reported.
A precise measurement of the real part of the elastic scattering amplitude at the Sp̄pS
Abstract A precise measurement of pp elastic scattering in the Coulomb-strong interaction interference region was performed at the CERN SppS Collider at a centre-of-mass energy of 541 GeV. The ratio of the real to the imaginary part of the forward elastic scattering amplitude was found to be ρ = 0.135 ± 0.015. The slope of the exponential fall off of the strong interaction part was also measured to be b = 15.5 ± 0.1 GeV −2 .
Evaluation of a commercial APD array (Avalanche PhotoDiode) for a readout detector in a hadrontherapy beam characterization application
The aim of the present work is the characterization of the S8898–128–02 Avalanche PhotoDiode array (APDs) from Hamamatsu Photonics. This work includes the implementation of a readout system as well as electronic noise estimation in APDs under several conditions varying integration times and clock frequencies.
Search forBs0→μ+μ−andB0→μ+μ−Decays with CDF II
A search has been performed for B{sub s}{sup 0} {yields} {mu}{sup +}{mu}{sup -} and B{sup 0} {yields} {mu}{sup +}{mu}{sup -} decays using 7 fb{sup -1} of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron collider. The observed number of B{sup 0} candidates is consistent with background-only expectations and yields an upper limit on the branching fraction of {Beta}(B{sup 0} {yields} {mu}{sup +}{mu}{sup -}) < 6.0 x 10{sup -9} at 95% confidence level. We observe an excess of B{sub s}{sup 0} candidates. The probability that the background processes alone could produce such an excess or larger is 0.27%. The probability that the combination of background and the expe…
Measurement of thett¯production cross section inpp¯collisions ats=1.96 TeVusing soft electronb-tagging
The authors present a measurement of the t{bar t} production cross section using events with one charged lepton and jets from p{bar p} collisions at a center-of-mass energy of 1.96 TeV. A b-tagging algorithm based on the probability of displaced tracks coming from the event interaction vertex is applied to identify b quarks from top decay. Using 318 pb{sup -1} of data collected with the CDF II detector, they measure the t{bar t} production cross section in events with at least one restrictive (tight) b-tagged jet and obtain 8.9{sub -1.0}{sup +1.0}(stat.){sub -1.0}{sup +1.1}(syst.) pb. The cross section value assumes a top quark mass of m{sub t} is presented in the paper. This result is cons…