Brief annotation and scientific rationale: 

The study of properties of the lightest hypernuclei is actual, has high significance and the Nuclotron beam is suitable place to investigate these tasks. The study of properties of light neutron-rich hypernuclei is of great interest, first of all, to clarify the theory of the intranuclear nucleon-nucleon interactions: the neutron halo, ΛN interaction including ΛN – ΣN conversion and the spin-dependent ΛN interaction etc. The special interest to this investigation is because of absence of reliable data on ⁶_ΛН properties and theoretical predictions that are strongly depend on model and controversial. Simultaneously, the lifetimes and production cross sections of ⁴_ΛН and ³_ΛН will be studied in the same experiment. The  and  measurement scan be used as “reference points” to confirm the production and decay of ⁶_ΛН.

Expected results upon completion of the activity: 

1. Experimental conclusion about the existence of the hypernucleus ⁶_ΛН.
2. New experimental data on the properties of the lightest hypernuclei and experimental verification of corresponding theoretical models for these hypernuclei.
3. New experimental data on the drip-line location for loosely bound light hypernuclei with high neutron excess, necessary for the development of the theory of neutron-rich hypernuclei and models of their production in non-central nucleus-nucleus interactions.
   
4. New experimental data on the production of strangeness and vector mesons (including those, containing strange quarks) by polarized photons (close to the relevant thresholds).

Expected results of the activity this year:   

1. Data taking for ⁶_ΛH search using beam of ⁷Li nuclei. Analysis of the first experimental data for the ⁶_ΛH search and for the measurements of hyperhydrogen isotopes ⁶_ΛH and ⁴_ΛH lifetimes.
   
2. Upgrade of the HyperNIS magnetic spectrometer (tracking system) by adding the planes of GEM detectors. These detectors, which have already been (partially) purchased and are being tested at the HyperNIS setup by staff, will be integrated into this setup to improve accuracy of the hypernucleus decay vertex determination. Preparation of a project for joint experiments with SRC, integration of detectors, development of a technical design for a spectrometer with two magnets (installations of a second magnet, supply of communications, supports for detectors), common data acquisition systems (design and tests), MC for the optimal geometry of joint detectors.
3. Within the collaboration with Japan: data taking at LEPS/LEPS2 setups on the production of strangeness and vector mesons (including those, containing strange quarks) by polarized photons (close to the relevant thresholds); analysis of data on such reactions, taken before.
4. Preparing the new combined HyperNIS and SRC project.

Brief annotation and scientific rationale: 

In high energy physics, events are usually analyzed for which the deviation from the average multiplicity does not exceed two average values. Events with a higher multiplicity occur extremely rarely, so it is difficult to collect large statistics for them, in addition, there are difficulties in processing them. When planning any experiment, simulations are performed, but despite the fact that the number of Monte Carlo generators increases every year, their predictions deviate significantly in the region of high multiplicity. Setting their parameters at the given energy stops working when moving to a higher energy. All this indicates a significant misunderstanding of the mechanism of multiple production. The study of events with the production of a large number of secondary particles will allow a deeper understanding of strong interactions, including the hadronization stage. In the region of high multiplicity, a series of collective phenomena with a quantum nature are predicted, such as the formation of a pion (Bose-Einstein) condensate, an excess soft photon (less than 50 MeV) yield, Cherenkov radiation of gluons by quarks, and others. In this region, the longitudinal component of the momentum approaches the transverse component, reaching it. This indicates the disappearance of the leading effect, and in the same region, apparently, the formation of a condensate begins. These and other collective manifestations in the behavior of secondary particles can be studied at the future NICA collider in the SPD project, since it is planned to register events in the absence of any trigger. This project is aimed at studying the gluon component of the nucleon. The study of processes with high multiplicity in the model of gluon dominance developed at JINR will provide additional knowledge about the gluon component of the nucleon and its contribution to hadronization.

Expected results upon completion of the activity: 

1. Preparation of a physics program for the study of collective phenomena in the region of high multiplicity in proton and deuterium interactions at the SPD facility at the NICA collider.
2. Development of the gluon dominance model for the collective behavior study of secondary particles in high multiplicity events at the energies of the future NICA collider at the SPD facility. Estimates of the contribution of gluon bremsstrahlung by quarks and gluon fission as dominant elementary QCD processes in this region. Estimatesof hadronization parameters for different kinds of hadrons.
3. Designing of a stand-alone multichannel spectrometer-calorimeter for detecting soft photons and using it to measure the polarization by the SPILER polarimeter at the output of a spin polarization source (SPI).
4. Determination of the critical region of multiplicity, at which the longitudinal and transverse components of the momentum become the same (the disappearance of the leading particle) and the establishment of its connection with the region of the pionic condensate formation.

Expected results of the activity this year:

1. Designing of electronics for reading and controlling silicon photomultipliers (SiPM) of a stand-alone multichannel spectrometer-calorimeter for detecting soft photons and using it to measure the polarization of the SPILER polarimeter at the output of a spin polarization source (SPI).
2. Manufacture of a spectrometer-calorimeter prototype together with colleagues from Belarus.
3. The detailed simulation of the deuteron-deuteron interaction at the planing beam energy.
4. Manufacture of scintillation counters based on vacuum PMTs, and, further, as a development of the workable concept, based on solid-state PMTs (SiPM). Reading control and presentation of the received information will be carried out directly at the source control panel workstation. Testing the prototype on the PNPI beam.
5. Participation in the development of a physics program at the future SPD facility with unpolarized and polarized beams of light nuclei and protons to study the behavior of multiplicity. Simulation of pp (dd, pd) interactions at energies up to 27 GeV.
6. Preparation of a physics program aimed at searching for collective phenomena in events with a large (exceeding average) multiplicity, in particular, the pion (Bose-Einstein) condensate discovered at the U-70 accelerator, excess soft photon yield, Cherenkov radiation of gluons by quarks, disappearance of the leading particle effect.
7. Detailed study of the parameters of the hadronization stage for charged and neutral mesons and baryons in the gluon dominance model.
8. Preparing the NEMAN project instead of activity.