Quasi-Frozen Spin Structures at the NICA Collider As an Option to Search for the Electric Dipole Moment of Deuterons and Axion Dark Matter

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