The Spin Physics Detector is one of two large setups at the NICA collider under construction at JINR (Dubna). The ultimate goal of the studies at SPD is the measurement of different spin observables in polarized proton-proton and deuteron-deuteron collisions sensitive to the polarized gluon structure of the nucleon at the luminosity up to 10$^{32}$ $cm^{-2}\cdot s^{-1}$ and $\sqrt{s}$ up to 27 GeV. SPD will consist of the superconducting magnetic system, silicon tracker, straw mini-drift tubes tracker, time-of-flight system, electromagnetic"shashlyk"- type calorimeter, muon (range) and local-polarimetry systems. The high performance free-streaming DAQ system will be able to operate at the collision rate up to 4 MHz.

Obtaining new data on the polarization observables is the important part of the nucleon–nucleon scattering models’ development. For this purpose, the polarized deuteron beam and the detection setup at the Nuclotron internal target station were used. Counters were mounted in according to pp -elastic scattering kinematics. Relevant events were selected using time and amplitude information from the counters. The polyethylene target was used as the main target. Auxiliary carbon target was used to remove the background. This article presents the results of the vector analyzing power measurement for the proton–proton quasi-elastic scattering at the deuteron beam energies of 200, 500, 550, 650 MeV/nucleon. The obtained results are in a good accordance with the data of other experiments and the partial wave analyzis SP07 SAID predictions.

The Spin Physics Detector collaboration proposes to install a universal detector in the second interaction point of the NICA collider under construction (JINR, Dubna) to study the spin structure of the proton and deuteron and other spin-related phenomena using a unique possibility to operate with polarized proton and deuteron beams at a collision energy up to 27 GeV and a luminosity up to 10^32 cm^-2 s^-1. As the main goal, the experiment aims to provide access to the gluon TMD PDFs in the proton and deuteron, as well as the gluon transversity distribution and tensor PDFs in the deuteron, via the measurement of specific single and double spin asymmetries using different complementary probes such as charmonia, open charm, and prompt photon production processes. Other polarized and unpolarized physics is possible, especially at the first stage of NICA operation with reduced luminosity and collision energy of the proton and ion beams. This document is dedicated exclusively to technical issues of the SPD setup construction.

The Spin Physics Detector is an experiment at NICA designed to study the spin structure of the proton and deuteron and the other spin-related phenomena using polarized beams. The collision energy is up to 27 GeV and the luminosity is up to 10 ^32 cm ^-2 s ^-1 in pp mode. Two scintillator-based detectors, Beam–Beam Counters (BBC), will be installed upstream and downstream the interaction point and will serve as a tool for beam diagnostics including local polarimetry. In this paper, we present the design of the BBC prototype based on the tiles with green WLS and SensL SiPM readout. FERS-5200 is used as the front-end readout system. The amplitude and timing resolutions for different tiles using radioactive source and cosmic rays are obtained.

The deuteron beam vector polarization was obtained at the Nuclotron Internal Target Station using the proton–proton quasielastic scattering on the polyethylene target at the beam energies of 200, 500, 550, and 650 MeV/nucleon. The selection of useful events was performed using the time and amplitude information from the scintillation counters. The asymmetry on hydrogen was obtained by the subtraction of the carbon background. The obtained values are compared with the data obtained using the deuteron–proton elastic scattering at the beam energy of 135 MeV/nucleon.

At an experiment on acceleration of a polarized proton beam up to an energy at 13 GeV , the possibility of crossing the transition energy at 5.7 GeV by a jump is considered. The scheme of crossing by a rapid change of transition energy, assumes the longitudinal movement in Barrier Bucket RF near the zero value of the slip-factor. The jump itself is carried out in the absence of an RF field. The paper presents the influence of the above features on the dynamics of a polarized beam.

In Nuclotron, there are no intrinsic spin resonances for protons up to 3.5 GeV/c, and in this momentum range beam depolarization is associated with the crossing of integer spin resonances. Correction dipoles are used to deliberately increase the resonance strength due to controlled deflection of the closed synchrotron orbit. When the closed orbit is deflected up to 10 mm and the field ramp rate in arch dipoles is 0.6 T/s, almost all integer resonances will cross adiabatically without loss of polarization, with the exception of the first two resonances at energies of 108 and 631 MeV. Adiabatic crossing of these resonances can be provided by introducing a weak longitudinal field with an integral of 50 mT m. Conserving polarization by the proposed method will allow the injection of protons into the NICA collider up to 3.5 GeV/c, as well as experiments on external targets.

The study of spin effects in elastic proton–proton and antiproton–proton scattering in the SPASCHARM experiment at U-70 accelerator facility (Institute for High Energy Physics, National Research Centre Kurchatov Institute, Protvino, Moscow oblast) is discussed. Polarized beams or a polarized target of the experiment will be used to measure the analyzing power A_N of elastic scattering of protons and antiprotons. The possibility of using two different types of the detectors to register recoil particles of elastic scattering of protons is analyzed. In the first case, it is proposed to use scintillation counters, the second option is a detector based on proportional chambers. A comparison of the registration efficiency of elastic pp scattering for two configurations of the experimental setup is carried out, and the required measurement time is determined.

The study of spin effects in elastic proton-proton and antiproton-proton scattering in the SPASCHARM experiment at U-70 accelerator facility (Institute for High Energy Physics, National Research Centre Kurchatov Institute, Protvino, Moscow oblast) is discussed. Polarized beams or a polarized target of the experimentwill be used to measure the analyzing powerAN of elastic scattering of protons and antiprotons. The possibility of using two different types of the detectors to register recoil particles of elastic scattering of protons is analyzed. In the first case, it is proposed to use scintillation counters, the second option is a detector based on proportional chambers. A comparison of the registration efficiency of elastic pp scattering for two configurations of the experimental setup is carried out, and the required measurement time is determined.

A possible magneto-optical structure of the Nuclotron is considered, which could provide the conditions for an experiment to measure the electric dipole moment of the deuteron. To this end, it was necessary to solve four problems for eight superperiodic structures: implement the concept of “quasi-frozen spin” in the proposed optics, increase the lengths of the straight sections between arcs, ensure zero dispersion in the straight sections, and, as far as it is possible, preserve the length of the accelerator ring, taking into account accommodation of the required equipment. In addition, the transition to a magneto-optical structure with superperiodicity N = 16 is considered, which will bring the properties of the “quasi-frozen” structure closer to those of the “frozen” structure by reducing the beam rotation angle on each arc. At such angles for deuterons, the feasibility of searching for the electric dipole moment of the proton is also considered.

The np → npπ^ + π^ - reaction is investigated at the incident neutron momenta P_0 = 3.83 and 5.20 GeV/c. Contributions of different diagrams to the reaction cross section are calculated at the momenta from the threshold to 12 GeV/c. It is shown that the main contributions to the np → npπ^ + π^ - reaction at momenta above P_0 > 3 GeV/c come from diagrams of the reggeized π -meson exchange model (OPER).To study spin effects, the reaction np → npΔ^ + + Δ^ - was separated. It is shown that description of the spin density matrix [ ρ_ij ] requires taking into account the ρ-meson exchange diagram. The reaction np → npρ^0 is separated by background subtraction method. The investigation has shown that ρ^0 -meson production is described by suspended diagrams of the OPER model.

This paper investigates the influence of space charge impedances, as well as RF resonators, on longitudinal dynamics during transition energy crossing with a jump. One distinctive feature is the use of the Barrier Bucket RF as a result a specific distribution of the beam in the phase space, different from the classical one formed by harmonic RF.

The values of the analyzing power in quasi-elastic proton-proton (pp) scattering are obtained at the Nuclotron Internal Target Station using a polarized deuteron beam at an energy of 500 MeV/nucleon and the polyethylene target. The selection of useful events has been performed using the time and amplitude information from scintillation counters. Asymmetry by protons has been obtained by the subtraction of the carbon background from the data accumulated on polyethylene. The analyzing power values are compared with predictions of SAID partial-wave analysis and the data of other experiments.

Experiments with polarized beams for EDM search in the NICA accelerator complex implies the design of an additional ByPass channels. Such alternative channels will make possible to use NICA as a storage ring and get enough statistical data.

The deuteron beam vector polarization was obtained at the Nuclotron Internal Target Station using proton-proton quasielastic scattering on the polyethylene target at the beam energies of 200, 500, 550, and 650 MeV/nucleon. The proton beam polarization was obtained at the beam energy of 500 MeV. The selection of useful events was performed using the time and amplitude information from the scintillation counters and the subtraction of the carbon background, both for the deuteron and proton beams.

The Spin Physics Detector is an experiment at NICA designed to study the spin structure of the proton and deuteron and other spin-related phenomena using polarized beams. Two Beam-Beam Counters (BBCs) will be installed symmetrically aside from the interaction point in the end-cups of SPD setup and will serve as a tool for beam diagnostics including local polarimetry. The outer part of the BBC wheel is based on fast scintillator tiles and cover the polar angels between 60 and 500 mrad. Different material configurations for the BBC prototype based on scintillator tiles were tested. The light collection depends on material combinations—fiber (Saint Gobain BCF91AS, BCF92S, and Kuraray Y-11), tile surface cover (Matted and double covered with Tyvek sheets tiles), and optical cement (CKTN mark E, OK-72). SensL 1 × 1 mm2 and 3 × 3 mm2 SiPMs were used as photosensors in the prototype tiles. The studies were performed with a cosmic rays test setup equipped with CAEN FERS-5200 readout system.

The article presents the results of the pp -scattering simulation at the total energy up to 27 GeV for the SPD Technical Design Report version of the Beam–Beam Counter. In the SPDRoot framework the simulation has been performed using the event generators: FRITIOF, Pythia8, and Pluto. The results have been compared with the differential cross section of the existing experimental data. The first estimations of the inclusive charged particle production asymmetries with Beam–Beam Counter have been obtained.

The original program of the NICA (Nuclotron based Ion Collider fAcility) accelerator complex is focused on a heavy ion and polarized deuteron and proton collider physics and did not include precision searches for the electric dipole moments (EDM) and the galactic axion condensate. It is of importance to note the approaches to the search for the EDM of deuterons usually discussed by CPEDM and srEDM collaborations only envision the development of a dedicated ring corresponding to the “frozen spin” mode with spin pointing all the time along the momentum due to using special deflectors with crossed electric and magnetic fields. Taking advantage of the smallness of the magnetic anomaly of deuterons, we propose to use in the NICA collider the “quasi-frozen spin” mode, when the precession of spin away from momentum in arcs is compensated by Wien filters in straight sections. The simplest technical solution at the NICA collider currently under construction is to create bypasses at the collider equipped with Wien filters, which make it possible to explore the deuteron EDM without affecting any infrastructure of the MPD and SPD detectors. Concurrently, modulation of the spin precession by Wien filters in bypasses will make NICA a broadband axion antenna. The new role of the bypass as an axion antenna, in addition to searching for the EDM of protons and deuterons, will significantly enhance the potential of the NICA complex as a unique platform for precision tests of basic symmetries in elementary particle physics

The Spin Physics Detector is an experiment at NICA designed to study the spin structure of the proton and deuteron and the other spin-related phenomena using polarized beams. Two endcap detector wheels of scintillator-based Beam-Beam Counters (BBCs) will be installed symmetrically aside from the interaction point and will serve as a tool for beam diagnostics including local polarimetry. The selection of material combinations for BBC is presented using scintillation tiles with different material combinations of the BBC prototype. The influence of the light collection was studied using matted and covered with Tyvek tiles. Different fibers (Saint-Gobain Crystals BCF91AS, BCF92S, and Kuraray Y-11), as well as different optical cements (CKTN type E, OK-72) were used. The prototypes were tested with cosmic rays and radioactive source using SensL SiPM readout.