67 research outputs found
Mjerenje s dobrom statistikom emisije dvaju fotona i dileptona pri proton-proton raspršenju na 190 MeV
The first high-statistics measurement of double-photon and dilepton yields in proton-proton scattering below the pion threshold has been performed. The data obtained will allow a detailed study of the proton-proton interaction.Izveli smo prvo mjerenje s dobrom statistikom emisije dvaju fotona i dileptona pri proton-proton raspršenju na energiji ispod praga za produkciju piona. Dobiveni podaci omogućuju dodatno proučavanje svojstava međudjelovanja protona
Mjerenje s dobrom statistikom emisije dvaju fotona i dileptona pri proton-proton raspršenju na 190 MeV
The first high-statistics measurement of double-photon and dilepton yields in proton-proton scattering below the pion threshold has been performed. The data obtained will allow a detailed study of the proton-proton interaction.Izveli smo prvo mjerenje s dobrom statistikom emisije dvaju fotona i dileptona pri proton-proton raspršenju na energiji ispod praga za produkciju piona. Dobiveni podaci omogućuju dodatno proučavanje svojstava međudjelovanja protona
Strange meson production in Al+Al collisions at 1.9A GeV
The production of K, K and (1020) mesons is studied in Al+Al
collisions at a beam energy of 1.9A GeV which is close or below the production
threshold in NN reactions. Inverse slopes, anisotropy parameters, and total
emission yields of K mesons are obtained. A comparison of the ratio of
kinetic energy distributions of K and K mesons to the HSD transport
model calculations suggests that the inclusion of the in-medium modifications
of kaon properties is necessary to reproduce the ratio. The inverse slope and
total yield of mesons are deduced. The contribution to K production
from meson decays is found to be [17 3 (stat) (syst)]
%. The results are in line with previous K and data obtained for
different colliding systems at similar incident beam energies.Comment: 16 pages, 11 figure
Centrality dependence of subthreshold meson production in Ni+Ni collisions at 1.9A GeV
We analysed the meson production in central Ni+Ni collisions at the
beam kinetic energy of 1.93A GeV with the FOPI spectrometer and found the
production probability per event of . This new data point allows for the first time
to inspect the centrality dependence of the subthreshold meson
production in heavy-ion collisions. The rise of meson multiplicity per
event with mean number of participants can be parameterized by the power
function with exponent . The ratio of to
production yields seems not to depend within the experimental
uncertainties on the collision centrality, and the average of measured values
was found to be .Comment: 9 pages, 5 figure
Measurement of and mesons in Al+Al collisions at 1.9 GeV
New measurement of sub-threshold and production is
presented. The experimental data complete the measurement of strange particles
produced in Al+Al collisions at 1.9 GeV measured with the FOPI detector at
SIS/GSI. The / yield ratio is found to be and is in good agreement with the
UrQMD model prediction. These measurements provide information on in-medium
cross section of - fusion which is the dominant process on
sub-threshold production.Comment: 5 pages, 4 figures, accepted for publication in Phys. Rev.
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