Measurement of the differential cross section and of the tensor and vector analyzing powers for the fragmentation of 4.5-GeV/c deuterons on beryllium in the reaction involving proton emission at an angle of 80 mrad

The invariant differential cross section, the tensor analyzing power A _yy , and the vector analyzing power A _y for the reaction ⁹Be(d, p)X are measured at an initial deuteron momentum of 4.5 GeV/c and a proton detection angle of about 80 mrad. The data obtained for the differential cross section are consistent with the results of measurements at 3.5 and 5.78 GeV/c and a proton emission angle of 2.5°. The values found for the tensor analyzing power A _yy are compared with similar data obtained previously for the deuteron-fragmentation process occurring on a carbon target at various values of the initial deuteron momentum and leading to proton emission at zero angle. The data on the differential cross section for the reaction ⁹Be(d, p)X can be satisfactorily described within the relativistic impulse approximation by using standard deuteron wave functions; however, the approach based on this conceptual framework proves to be inadequate in dealing with data on the tensor analyzing power. These results indicate that it is necessary either to change the method for describing the relativistic deuteron or to take into account additional mechanisms.     

Tensor analyzing power T 20 of the dd → 3Hen and dd → 3Hp reactions at zero angle for energies 140, 200, and 270 MeV

RIKEN Accelerator Research Facility data on the tensor analyzing power T ₂₀ of the dd → ³Hen and dd → ³Hp reactions at zero angle for deuteron kinetic energies of 140, 200, and 270 MeV are reported. The observed positive sign of T ₂₀ clearly demonstrates the sensitivity to the D/S-wave ratio in the ³He and ³H wave functions in the energy range of the experiment. Data on T ₂₀ for the ³Hen channel are in agreement with those for the ³Hp channel within the experimental errors.     

Proposal of the experiment on the investigation of the (d, p) reaction at the extracted deuteron beam of the U-70 accelerator

The experiment on the investigation of the A(d, p)X reaction at the extracted deuteron beam created at the Serpukhov U-70 accelerator is proposed. Precise measurements of the momentum spectra of protons emitted in the (d, p) reaction at an initial deuteron momenta of 20–40 GeV/c can give unique information on the deuteron short-range structure. A manifestation of contribution of nonnucleonic degrees of freedom in the deuteron is entirely possible over this energy range. The text was submitted by the authors in English.     

Detection equipment for investigating dp elastic scattering at internal target of nuclotron in the framework of DSS project

A complex of detection equipment based on scintillation detectors for investigating dp elastic scattering at the internal target of the Nuclotron developed in the framework of the Deuteron Spin Structure (DSS) project is presented. The results of optimizing scintillation detectors and the results of test measurements of a deuteron beam of the Nuclotron are given.     

Measurement of the vector A y and tensor A yy , A xx , A xz analyzing powers for the dd → 3H p reaction at 200 MeV

The data on the vector A _y and tensor A _yy , A _xx , A _xz analyzing powers for the d → ³H p reaction have been obtained at the energy of the initial deuteron of 200MeV in the angular range of 0–95 degrees in the c.m.s. The calculations performed within one-nucleon exchange model with the use of the standard three-nucleon bound state wave functions fail to reproduce the data on the tensor analyzing powers.     

Measurement of the tensor analyzing power Ayy in the inelastic scattering of deuterons in the vicinity of excitation of baryonic resonances

The tensor A_yy and vector A_y analyzing powers in the inelastic scattering of deuterons with a momentum of 4.5 GeV/c on beryllium at an angle of 80 mr in the vicinity of baryonic resonances excitation have been measured. The A_yy data being in good agreement with the previous results obtained at a zero angle demonstrate an approximate t scaling up to - 0.9 (GeV/c)². The results of the experiment are compared with the predictions of the multiple-scattering and -meson exchange models. Received: 20 April 2000 / Accepted: 29 May 2000     

Calibration procedure of the Δ<Emphasis Type="Italic">E</Emphasis>–<Emphasis Type="Italic">E</Emphasis> detectors for <Emphasis Type="Italic">dp</Emphasis> breakup investigation at nuclotron

Calibration procedure of ΔE ? E detectors used in dp breakup reaction measurement in the framework of DSS project is discussed. Time information from all PMTs along with amplitude information and known energy values of pp quasi elastic reaction are used to find calibration coefficients for ΔE and E detectors. Calibration coefficients are used to recover deposited particle energies. ΔE vs. E plots, energies and missing mass spectra are compared with geant4 Monte Carlo simulation. Missing mass for particular physical configuration is calculated as a test of the calibration procedure quality.     

Cathode strip chamber for CMS ME1/1 endcap muon station

Seventy-six serial ME1/1 cathode strip chambers have been produced in Dubna. These chambers are the coordinate detectors of the first muon station of the CMS detector at CERN. This paper describes the design of the chamber, its main mechanical parameters, and the results of the cosmic ray test. The text was submitted by the authors in English.