A. A. Volkov

A data acquisition system of the FODS setup

A data acquisition system of the focusing double-arm spectrometer (FODS) setup is described. The information from each recording electronic module is read in response to each trigger by an ЛЭ-74 high-speed controller with a buffer memory and is transmitted by a PCI-7200 extension card to the computer memory at the end of the spill. All crates are read in parallel, ensuring a high speed of operation of the system (8000 events per spill for one spectrometer arm). The system is able to read data from different detectors (drift chambers, proportional chambers, calorimeters, Cherenkov radiation ring spectrometer, etc.), possesses a high flexibility, i.e., ensures readout of information for several types of triggers (inclusive, arm coincidence, two particles in one arm, etc.), and enables calibration of detectors in each spill. The software is based on the MIDAS project with an open initial code and allows one to control operation of all detectors during experiments.

Intensive beam monitors of the FODS spectrometer

A monitoring system comprising ionization and scintillation monitors has been developed to measure the intensity and to control the quality of the beam at the FODS spectrometer. The system has been designed for operation with beam intensities of 104–109 particles/s. The characteristics of the system components are presented.

Hadron calorimeters of the FODS setup

Designs of the hadron calorimeters for the FODS setup and the procedure for their calibration are described. Results of investigations of their characteristics on electron and hadron beams are presented.

Forward particle production in proton–nucleus interactions at momenta of 25 and 50 GeV/с and сarbon–nucleus interactions at an energy of 25 GeV per nucleon

Relative yields of high-xF charged hadrons (π±, К±, р,

Single-spin asymmetry for high-p T charged hadrons at negative x F in proton-nucleus collisions at an energy of 40 GeV

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Single-spin asymmetry for charged hadrons produced in proton-nucleus collisions at 40 GeV for c.m. production angles in the range 40{sup o}-79{sup o}

p¯, and d) in proton–nucleus interactions at incident-proton momenta of 25 and 50 GeV/c were measured at an angle of 0° in the momentum range between 15 and 40 GeV/c. An upper limit on the forward production of two protons in proton–nucleus interactions at 50 GeV/c was estimated. The properties of a carbon beam with an energy of 25 GeV per nucleon and fragment yields in its interaction with nuclear targets were measured within a short exposure.

Observation of multiparton interactions in proton-nucleus collisions at 70 GeV

Cross sections for the production of high-transverse-momentum charged hadrons in proton–nucleus interactions at the incident-proton energy of 50 GeV were measured with the aid of the FODS double-arm spectrometer. Single hadrons (charged pions and protons) emitted at a c.m. angle of about 90° and high-effective-mass pairs of hadrons flying apart at a c.m. angle of 180° were detected simultaneously. Results on the production of single hadrons are presented.

ASYMMETRY MEASUREMENT OF CHARGED HADRON PRODUCTION IN p↑A COLLISIONS AT 40 GeV

AbstractThe transverse single-spin asymmetry was measured for charged hadrons (π±, K±, p, n