13 research outputs found
On spectral minimal partitions: the case of the sphere
We consider spectral minimal partitions. Continuing work of the the present
authors about problems for planar domains, [23], we focus on the sphere and
obtain a sharp result for 3-partitions which is related to questions from
harmonic analysis, in particular to a conjecture of Bishop
Measurements of higher-order cumulants of multiplicity and net-electric charge distributions in inelastic proton-proton interactions by NA61/SHINE
International audienceThis paper presents the energy dependence of multiplicity and net-electric charge fluctuations in interactions at beam momenta 20, 31, 40, 80, and 158 GeV/. Results are corrected for the experimental biases and quantified with the use of cumulants and factorial cumulants. Data are compared with the Epos1.99 and FTFP-BERT model predictions
Excess of charged over neutral meson production in high-energy collisions of atomic nuclei
International audienceCollisions of atomic nuclei at relativistic velocities produce new particles, predominantly mesons containing one valence quark and one valence anti-quark. These particles are produced in strong interactions, which preserve an approximate symmetry between up () and down () quarks. In the case of meson production, if this symmetry were exact, it would result in equal numbers of charged ( and ) and neutral ( and ) mesons in the final state. In this Letter, we report a measurement of the relative abundance of charged over neutral meson production in collisions of argon and scandium nuclei at a center-of-mass energy of 11.9~GeV per nucleon pair. We find that production of and mesons at mid-rapidity displays a significant excess of relative to that of the neutral mesons. The origin of this unexpected excess remains to be elucidated
Measurements of , , and spectra in Ar+Sc collisions at 13 to 150 GeV/
International audienceThe NA61/SHINE experiment at the CERN Super Proton Synchrotron studies the onset of deconfinement in strongly interacting matter through a beam energy scan of particle production in collisions of nuclei of varied sizes. This paper presents results on inclusive double-differential spectra, transverse momentum and rapidity distributions and mean multiplicities of , , and produced in Ar+Sc collisions at beam momenta of 13, 19, 30, 40, 75 and 150 GeV/. The analysis uses the 10% most central collisions, where the observed forward energy defines centrality. The energy dependence of the / ratios as well as of inverse slope parameters of the transverse mass distributions are placed in between those found in inelastic + and central Pb+Pb collisions. The results obtained here establish a system-size dependence of hadron production properties that so far cannot be explained either within statistical (SMES, HRG) or dynamical (EPOS, UrQMD, PHSD, SMASH) models
Measurements of , , , , and production in 120 GeV/ p + C interactions
International audienceThis paper presents multiplicity measurements of charged hadrons produced in 120 GeV/ proton-carbon interactions. The measurements were made using data collected at the NA61/SHINE experiment during two different data-taking periods, with increased phase space coverage in the second configuration due to the addition of new subdetectors. Particle identification via was employed to obtain double-differential production multiplicities of , , , , and . These measurements are presented as a function of laboratory momentum in intervals of laboratory polar angle covering the range from 0 to 450 mrad. They provide crucial inputs for current and future long-baseline neutrino experiments, where they are used to estimate the initial neutrino flux
Measurements of , and production in 120 GeV/ p + C interactions
This paper presents multiplicity measurements of , , and produced in 120 GeV/ proton-carbon interactions. The measurements were made using data collected at the NA61/SHINE experiment during two different periods. Decays of these neutral hadrons impact the measured , , and multiplicities in the 120 GeV/ proton-carbon reaction, which are crucial inputs for long-baseline neutrino experiment predictions of neutrino beam flux. The double-differential multiplicities presented here will be used to more precisely measure charged-hadron multiplicities in this reaction, and to re-weight neutral hadron production in neutrino beam Monte Carlo simulations
meson production in inelastic p+p interactions at 31, 40 and 80 GeV/c beam momentum measured by NA61/SHINE at the CERN SPS
International audienceMeasurements of meson production via its decay mode in inelastic interactions at incident projectile momenta of 31, 40 and 80 GeV/ ( and GeV, respectively) are presented. The data were recorded by the NA61/SHINE spectrometer at the CERN Super Proton Synchrotron. Double-differential distributions were obtained in transverse momentum and rapidity. The mean multiplicities of mesons were determined to be at 31 GeV/, at 40 GeV/ and at 80 GeV/. The results on production are compared with model calculations (Epos1.99, SMASH 2.0 and PHSD) as well as with published data from other experiments