1.

NA61/SHINE

A.I. Malakhov
Deputies:
A.V. Dmitriev
A.A. Zajtsev

02-1-1087-1-2012/2024

Brief annotation and scientific rationale:

The main physics goals include: search for the second-order critical end-point in the temperature versus baryon-chemical potential phase diagram (looking for nonmonotonic behavior of critical point signatures, such as transverse momentum and multiplicity fluctuations, intermittency signal, etc., when system freezes out close to the critical point), study the properties of the onset of deconfinement (search for the onset of the horn, kink, step, and dale structures in collisions of light nuclei). In recent years, the program has been extended by Pb+Pb collisions where the open charm production, as well as collective effects are studied. Based on the obtained results, few years ago NA61/SHINE introduced a concept of two onsets in nucleus-nucleus collisions at the CERN SPS energies: onset of deconfinement (beginning of QGP formation – collision energy threshold for deconfinement) and onset of fireball (beginning of formation of a large cluster which decays statistically – system-size threshold for creation of statistical system). The strong interactions program is based on beam momentum scans (13A-158A·GeV/c) with light and intermediate mass nuclei (from p+p to Xe+La).

Expected results upon completion of the project:

Data analysis of the NA61/SHINE experiment (SPS, CERN). Studies of the birth of hadrons in hadron-nuclear interactions. The study of the formation of charmed hadrons (mainly D-mesons) during the interaction of heavy ions in order to obtain new data on the average number of charmed quark-antiquark pairs and to understand the mechanism of the birth of open charm. Obtaining data for precision calculation of neutrino spectra and fluxes in accelerator experiments for the study of neutrino oscillations. Completion of the modernization of the TOF system.

Expected results of the project this year:

Processing and analysis of experimental data obtained at the NA61/SHINE installation on p+p, Be+Be, Ar+Sc, O+O, Pb+Pb collisions. Conducting experimental studies on a beam of relativistic lead nuclei. Investigation of anti-core formation in Ar+Ca and Xe+La collisions. The study of the formation of enchanted hadrons in the interaction of heavy ions in order to understand the mechanism of the birth of an open charm.

Expected results at the end of the activity:

Search and study of the Hoyle state and more complex nuclear-molecular States in the dissociation of light nuclei. Analysis of the isotopic composition of the fragmentation of heavy nuclei. Use of automated microscopes, as well as improvement of the NE technology.

Expected major results in the current year:

Analysis of exposures to Xe (NICA/Nuсlotron) and Kr (GSI) nuclei to study ⁸Be decays and the Hoyle state and accompanying α-ensembles and search for the 4α-condensate. Estimation of the parameters of accompanying neutrons. Mastering identification by multiple scattering of He and H isotopes on a motorized microscope. Search for ⁸Be and ⁹B isobar-analogue states in the ⁹Be and ¹⁰C exposures. Mastering the identification of ensembles of stopped α-particles in the fragmentation of nuclei from the composition of the emulsion under the action of relativistic particles.

Expected results at the end of the activity:

Analysis of the experimental data on the processes of the multiple emission of intermediate mass fragments on the beams of relativistic light ions using a 4-π PHASE-3 setup for the registration of nuclear fragments. Performing data analysis to determine the mechanism of multifragmentation and to obtain new information about the nuclear phase transitions "liquid-fog" and "liquid-gas". Investigation of properties of hot nuclei formed in the collisions of light relativistic ions with heavy targets. Production of the detector system  for the registration of the decay of hypernuclei.

Expected major results in the current year:

Debugging of the QUARTUS CAEN program at the  PHASE spectrometer for registration of nuclear fragments. Analysis of experimental data in the framework of statistical and dynamic models. Preparation of a new project.

Expected results at the end of activity:

Upgrade of the SCAN setup. Analysis of the experimental data on the behavior of nucleon resonances and nucleon fluctuations in nuclei, on the search and study of properties of the bound state-meson in nuclear matter.

Expected major results in the current year:

Testing of a three-beam magnetic spectrometer SCAN. Conducting a technical session on the internal beam of the nuclotron to adjust the detectors and debug the data collection program. Analysis of experimental data.

Expected results at the end of the topic or project stages:

Collection, processing and digitization of the film information obtained using bubble chambers and in electronic experiments with fixed targets under the conditions of registration of multiple birth of particles in the energy range of 1-300 GeV. Preparation of a education programme for highly qualified students for the NICA project.

Expected major results in the current year:

Analysis of bubble chamber data, search and research of new phenomena based on the JINR LIT supercomputer. Replenishment of the experimental data base in the field of relativistic nuclear physics.

 Refinement of the results obtained on a propane two-meter chamber, and analysis of data on the results of the NA61/SHINE experiment.

Expected results at the end of the activity:

Updating the Marusya installation for conducting the experimental studies with the extracted Nuclotron beams. Investigation of A-dependences of rare subthreshold and cumulative processes of the formation of pions, kaons and antiprotons depending on the type and energy of the incoming nuclei, the momentum and angle of the detected particles. Carrying out correlation experiments with registration of groups of particles in the final state, one of which is cumulative.

Expected major results in the current year:

Reconstruction of the experimental zone of the channel spectrometer in focus F4. Creation of a new installation data collection system. Commissioning of track detectors. Development and creation of a neutron detector. Testing of the Cherenkov detector.

Expected results at the end of the activity:

Use of heavy and light ions for applied research.

Expected results at the end of the activity:

Replacement of target operation control electronics from the KAMAK system to modern industrial standards. Creating software for new electronics. Production of a target based on the carbon isotope ¹³C.

Expected major results in the current year:

Preparing the station for operation in the spring Nuclotron Run.

Expected results at the end of the activity:

Creation of a detector and development of algorithms for configuring beam reduction in the NICA collider.

Expected major results in the current year:

Preparation of a technical project for luminosity measurement at the NICA collider.

Production of two planes for the luminosity measurement detector.

Expected results at the end of the activity:

Preparation of a project to study spin asymmetries at the LHEP accelerator complex.

Expected major results in the current year:

Processing of experimental data obtained on a ¹²⁴Xe beam with an energy of 3 GeV/nucleon.

Expected results at the end of the activity:

Search and investigation of a  charged particle in the 2-120 MeV mass range.

Expected major results in the current year:

Addition of existing results with new data.

Expected results at the end of the activity:

Development of secondary particle detectors for collider experiments.

Study of mechanisms of electromagnetic interactions and regularities of generation of electromagnetic radiations, including controllable generation of THz radiation.

Development of a test bench for registration of neutron spectra with time of flight energy measurement system.

Expected major results in the current year:

Development and beam tests of particle detectors based on fast scintillators.

Registration of GHz radiation from active targets irradiated by relativistic electron beams.

Development of a test bench for registration of secondary neutrons.