32 research outputs found
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
Influence of mesons on negative kaons in Ni+Ni collisions at 1.91A GeV beam energy
and K mesons from Ni+Ni collisions at the beam energy of 1.91A GeV
have been measured by the FOPI spectrometer, with a trigger selecting central
and semi-central events amounting to 51% of the total cross section. The phase
space distributions, and the total yield of K, as well as the kinetic
energy distribution and the total yield of mesons are presented. The
\K ratio is found to be , meaning that about 22% of K mesons originate from the
decays of mesons, occurring mostly in vacuum. The inverse slopes of
direct kaons are up to about 15 MeV larger than the ones extracted within the
one-source model, signalling that a considerable share of gap between the
slopes of K and K could be explained by the contribution of
mesons to negative kaons.Comment: 8 pages, 6 figure
Dynamic Grouping of Hippocampal Neural Activity During Cognitive Control of Two Spatial Frames
Hippocampal neurons represent two concurrent streams of spatial information by transiently organizing into subpopulations of coactive neurons and can reflect the most behaviorally relevant information at any given time