35 research outputs found
Charm production nearby threshold in pA-interactions at 70 GeV
The results of the SERP-E-184 experiment at the U-70 accelerator (IHEP,
Protvino) are presented. Interactions of the 70 GeV proton beam with C, Si and
Pb targets were studied to detect decays of charmed , ,
, mesons and baryon near their production threshold.
Measurements of lifetimes and masses are shown a good agreement with PDG data.
The inclusive cross sections of charm production and their A-dependencies were
obtained. The yields of these particles are compared with the theoretical
predictions and the data of other experiments. The measured cross section of
the total open charm production ( = 7.1
2.3(stat) 1.4(syst) b/nucleon) at the collision c.m. energy
= 11.8 GeV is well above the QCD model predictions. The
contributions of different species of charmed particles to the total cross
section of the open charm production in proton-nucleus interactions vary with
energy.Comment: 4 pages, 6 pages, 38th International Conference on High Energy
Physics 3-10 August 2016, Chicago, US
Search for Collective Phenomena in High Multiplicity Events at Nuclotron and U-70
More than ten-year experimental search for collective phenomena in high multiplicity events has been carried out at the Laboratory of high energy physics at JINR. We present main results, which have been received at the U-70 accelerator (IHEP, Protvino) in the proton collisions and at Nuclotron ( JINR, Dubna) in the nuclear interactions. Fo
Comparison of the In-plane Thermal and Electrical Conductivities and Transverse Pull Strengths of Various Pyrolytic Graphite Materials
Different pyrolytic graphite materials were produced varying the annealing parameters such as temperature, pressure and time. These variations should alter the product properties in a systematic way. The coefficient of in-plane thermal conductivity, C_KT, the coefficient of electrical conductivity, and the pull strength S of these samples were measured. Results for the different materials and correlations are reporte
Observation of narrow baryon resonance decaying into in pA-interactions at with SVD-2 setup
SVD-2 experiment data have been analyzed to search for an exotic baryon
state, the -baryon, in a decay mode at on IHEP
accelerator. The reaction with a limited multiplicity was
used in the analysis. The invariant mass spectrum shows a resonant
structure with and . The statistical significance of this peak was estimated to be of . The mass and width of the resonance is compatible with the recently
reported - baryon with positive strangeness which was predicted as an
exotic pentaquark () baryon state. The total cross section for
production in pN-interactions for was estimated to be
and no essential deviation from A-dependence for inelastic
events was found.Comment: 8 pages, 7 figures, To be submitted to Yadernaya Fizika. v3-v5 - Some
references added, minor typos correcte
Collective phenomena in hadron and nuclear interactions at high multiplicity
Multiparticle production is described in the language of quarks and gluons. In the experiment the real hadrons are registered. For transfer from quarks and gluons to observed hadrons, various phenomenological models are used. In order to describe the high multiplicity region, we have developed a gluon dominance model. It represents a convolution of two stages. First stage is described by QCD. For second one (hadronisation), the phenomenological model is used. The description of topological cross sections in p
collisions within of our model testifies that in hadron collisions the mechanism of hadronisation is being replaced by the recombination one. At that point, gluons play an active role in the multiparticle production process, and valence quarks are passive. They stay in the leading particles, and only the gluon splitting is responsible for the region of high multiplicity. The model with inclusion of intermediate quark charged topologies describes topological cross sections in annihilation. We observe the significant growth of a scaled variance of number of neutral pions with increasing of the total multiplicity at U-70 accelerator at IHEP (Protvino). The following experiment with 3.5 A GeV deuteron, lithium and carbon beams of the Nuclotron (JINR, Dubna) falling at a carbon target is carried out at the NIS-GIBS setup. The noticeable excess yield of soft photons(pT < 50 MeV/c) is observed. The existing models based on Monte Carlo simulation and theoretical estimations predict a lower yield. Our Collaboration plans to study excess of soft photon yield and other phenomena at the SPD (Spin Physics Detector) setup at JINR, Dubna with polarised beams of proton and light nuclei up to 25 GeV
Collective phenomena in hadron and nuclear interactions at high multiplicity
Multiparticle production is described in the language of quarks and gluons. In the experiment the real hadrons are registered. For transfer from quarks and gluons to observed hadrons, various phenomenological models are used. In order to describe the high multiplicity region, we have developed a gluon dominance model. It represents a convolution of two stages. First stage is described by QCD. For second one (hadronisation), the phenomenological model is used. The description of topological cross sections in p
p
¯
collisions within of our model testifies that in hadron collisions the mechanism of hadronisation is being replaced by the recombination one. At that point, gluons play an active role in the multiparticle production process, and valence quarks are passive. They stay in the leading particles, and only the gluon splitting is responsible for the region of high multiplicity. The model with inclusion of intermediate quark charged topologies describes topological cross sections in annihilation. We observe the significant growth of a scaled variance of number of neutral pions with increasing of the total multiplicity at U-70 accelerator at IHEP (Protvino). The following experiment with 3.5 A GeV deuteron, lithium and carbon beams of the Nuclotron (JINR, Dubna) falling at a carbon target is carried out at the NIS-GIBS setup. The noticeable excess yield of soft photons(pT < 50 MeV/c) is observed. The existing models based on Monte Carlo simulation and theoretical estimations predict a lower yield. Our Collaboration plans to study excess of soft photon yield and other phenomena at the SPD (Spin Physics Detector) setup at JINR, Dubna with polarised beams of proton and light nuclei up to 25 GeV