Search

The pp → ppK+K− reaction was measured near threshold at excess energy Q = 4.5 MeV using the COSY-11 detection system installed at the COSY-Juelich accelerator. Preliminary value of upper limit of the total cross section was determined. This limit indicates that an enhancement of the total cross section close to the threshold, caused by the final state interaction, is smaller than suggested by extrapolation of data measured at higher energies. [ABSTRACT FROM AUTHOR]

The straw tube detectors in the PANDA experiment will work in high particle fluxes reaching up to 25 kHz/cm2. We performed measurement of the gas gain drop in the PANDA straws due to the space charge effect expected at the high particle fluxes. The applied experimental method and obtained results are presented and are compared with calculations of the gas gain drop based on known mobility of positive ions. [ABSTRACT FROM AUTHOR]

A search for the 4He - η bound state via exclusive measurement of the excitation function for the dd → ³Hepπ- reaction, was performed at the Cooler Synchrotron COSY-Jülich with the WASA-at-COSY detection system. The data were taken during a slow acceleration of the beam from 2.185GeV/c to 2.400GeV/c crossing the kinematic threshold for the η production in the dd → 4He η reaction at 2.336 GeV/c. The corresponding excess energy in the 4 He - η system varied from -51.4 MeV to 22 MeV. The shape of the excitation function for the dd → ³Hepπ- was examined. No signal of the 4He - η bound state was observed in the excitation function. [ABSTRACT FROM AUTHOR]

This paper sums up experimental studies of the near threshold production of K+K- pairs at COSY-11. The total cross section of the reaction pp→ppK+K- has been measured at five excess energies below the [lowercase_phi_synonym] production threshold with the magnetic spectrometer COSY-11. The new data show a significant enhancement of the total cross section compared to pure phase space expectations. [ABSTRACT FROM AUTHOR]