Study of high multiplicity events in proton-proton (nucleus) interactions is carried out at U-70 accelerator of IHEP, Protvino. These events are extremely rare. Usually, MC codes underestimate ...topological cross sections in this region. Gluon dominance model has been offered to describe them. Some collective phenomena can be observed in high multiplicity events. SVD-2 Collaboration has obtained the evidence of pion condensate formation at high total multiplicity. Our future program is aimed at studying soft photon yield puzzle at U-70 and Nuclotronfacility at JINR, Dubna.
Study of high multiplicity events in proton-proton interactions is carried out at the U-70 accelerator (IHEP, Protvino). These events are extremely rare. Usually, Monte Carlo codes underestimate ...topological cross sections in this region. The gluon dominance model (GDM) was offered to describe them. It is based on QCD and a phenomenological scheme of a hadronization stage. This model indicates a recombination mechanism of hadronization and a gluon fission. Future program of the SVD Collaboration is aimed at studying a long-standing puzzle of excess soft photon yield and its connection with high multiplicity at the U-70 and Nuclotron facility at JINR, Dubna.
•The classical logistic and Gompertz models are used to interpret the first wave of COVID-19 pandemic in 23 countries.•The models describe properly the growth in the number of confirmed cases with ...time.•The Gompertz model demonstrates better fit of official statistics data compared to the classical logistic equation in all considered countries except Japan.•Employment of the Gompertz model with delay did not reveal any effect of the delay time in providing better fit of the official statistics.
The paper reports on application of the Gompertz model to describe the growth dynamics of COVID-19 cases during the first wave of the pandemic in different countries. Modeling has been performed for 23 countries: Australia, Austria, Belgium, Brazil, Great Britain, Germany, Denmark, Ireland, Spain, Italy, Canada, China, the Netherlands, Norway, Serbia, Turkey, France, Czech Republic, Switzerland, South Korea, USA, Mexico, and Japan. The model parameters are determined by regression analysis based on official World Health Organization data available for these countries. The comparison of the predictions given by the Gompertz model and the simple logistic model (i.e., Verhulst model) is performed allowing to conclude on the higher accuracy of the Gompertz model.
An extension of the QED “return to resonance” mechanism to light meson emission (π, ρ) in (anti)proton collisions with a hadronic target (nucleon or nucleus) is proposed. The cross section and the ...multiplicity distributions are calculated. The collinear emission (along the beam direction) of a charged meson may be used to produce high energy (anti)neutron beams. Possible applications at existing and planned facilities are considered.
First results of the study of a soft photon yield in nucleus-nucleus collisions at 3.5 GeV per nucleon at Nuclotron (LHEP, JINR) are presented. These photons are registered by an BGO electromagnetic ...calorimeter built by the SVD-2 Collaboration. The obtained spectra confirm the excessive yield in the energy region less than 50 MeV in comparison with theoretical estimations and agree with previous experiments at high-energy interactions.
Proton interactions with high multiplicity Kokoulina, E. S.; Nikitin, V. A.; Petukhov, Y. P. ...
Physics of atomic nuclei,
06/2012, Letnik:
75, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Project Thermalization is aimed to study the proton-proton interaction with high multiplicity of secondary particles. The region of high multiplicity is especially actual at present. We expect the ...manifestation of the secondary particle collective behavior at this region. The experimentally measured topological cross section was corrected for apparatus acceptance and detection efficiency. These data are in good agreement with gluon dominance model. The comparison with other models is also done and shows no essential deviations. There is evidence that Bose-Einstein condensation can formed at high total multiplicity region.
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