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The BM@N (Baryonic Matter at Nuclotron) is the first experiment in operation at the NICA-Nuclotron accelerator complex. The BM@N scientific program comprises the study of dense nuclear matter produced in heavy-ion collisions in the intermediate energy range between the SYS-18 and NICA/FAIR facilities. The first experiments were performed with deuteron and carbon beams with kinetic energy ranging from 3.5 to 4.5 GeV per nucleon on fixed targets. An extended configuration of the BM@N setup was realized in the next runs with argon and krypton beams. First preliminary physics results are presented on $$\Lambda $$ hyperon production in carbon–nucleus interactions at a beam kinetic energy of 4 GeV per nucleon. Signals of $$\Lambda $$ hyperons, charged pions, kaons and light nuclear fragments are identified in argon–nucleus interactions. The performance of the upgraded BM@N central tracker is evaluated for the reconstruction of strange particles and hypernuclei in heavy-ion interactions.

In present days the evolution of broad-band laser pulses, propagating in various types of waveguides, has been of a great interest among the scientists. Currently, it is easy for phase-modulated femtosecond pulses the condition Δω≈ω0 to be obtained. It is known that nowadays it is possible also to reach the attosecond region where the spectral bandwidth of the pulse happens to be of order of the carrier frequency also. Light pulses who fulfil this initial condition are called broad-band. On the other hand, the non-fulfilling pulses are the narrow-band ones. In the present paper it is investigated the parametric interaction of two components of one optical pulse by using the Generalized System of Nonlinear Amplitude Equations (GSNAE). GSNAE was analytically solved. A difference in the period of oscillations of the energy exchange between the two components is found.

In the present work the soliton regime of propagation in air of ultra-short long-wavelength infrared laser pulses is investigated. The dispersion of atmospheric air in mid-infrared and long-wavelength infrared shows anomalous group velocity dispersion regions for wavelengths in the ranges of 3.5 to 4.2μm and 9.3 to 13.5μm. In these spectral regions the atmospheric air is transparent. From other hand, the nonparaxiality leads to waveguiding regime of propagation for femtosecond pulses with shape of light disks (the transverse size is much bigger than the longitudinal one). It allows reducing this 3D + 1 task to 1D + 1 problem in the same manner as in optical fibers. The combination between anomalous group velocity dispersion and atmospheric nonlinearity is a base for the observation of optical solitons in the air transparency regions for the indicated wavelengths. The main equation in our research is the 1D + 1 nonlinear nonparaxial amplitude equation, written in Galilean and Laboratory coordinate systems. New analytical solution in the form of bright soliton is found. The critical power, needed for the observation of these solitons is of two orders of magnitudes less than the critical one for self-focusing. That is why there are no conditions for ionization of the media.

In the present work, the formation of vector-type vortex structures in isotropic media is studied. These vortices exist in the electric field components and generate a depolarization in the vector field of the laser spot. Their behavior is governed by a system of amplitude equations. Additionally, new solutions have been found that describe similar types of vortex structures in an optical fiber. The optical vortices admit only amplitude-type singularities. The vortex structures observed within the vector amplitude function have ring-like patterns. The variation of the intensities of the x and y components of the amplitude function along the axis of the fiber is investigated.

In the present paper the parametric interaction between two optical waves, which are propagating in few-mode optical fibers, is investigated. This occurs under the influence of the processes of third harmonic generation, self-phase modulation and cross-phase modulation. The generation of third-harmonic or THz generation in femtosecond region is described by a system of two coupled nonlinear differential equations. A new analytical solution of this system, which characterizes the periodic energy exchange between the two waves, is found. Depending on the wavenumber mismatch Δk, the obtained result can be used for studying different optical processes of generation of signal wave in nonlinear dispersive media. The mentioned effects are strongly related to modern optical sensors, parametric amplifiers and communication systems.

Particle knockout scattering experiments1,2 are fundamental for mapping the structure of atomic nuclei2–6, but their interpretation is often complicated by initial- and final-state interactions of the incoming and scattered particles1,2,7–9. Such interactions lead to reduction in the scattered particle flux and distort their kinematics. Here we overcome this limitation by measuring the quasi-free scattering of 48 GeV c–1 12C ions from hydrogen. The distribution of single protons is studied by detecting two protons at large angles in coincidence with an intact 11B nucleus. The 11B detection suppresses the otherwise large distortions of reconstructed single-proton distributions induced by initial- and final-state interactions. By further detecting residual 10B and 10Be nuclei, we also identified short-range correlated nucleon–nucleon pairs9–13 and provide direct experimental evidence for separation of the pair wavefunction from that of the residual many-body nuclear system9,14. All measured reactions are well described by theoretical calculations that include no distortions from the initial- and final-state interactions. Our results showcase the ability to study the short-distance structure of short-lived radioactive nuclei at the forthcoming Facility for Antiproton and Ion Research (FAIR)15 and Facility for Rare Isotope Beams (FRIB)16 facilities, which is relevant for understanding the structure and properties of nuclei far from stability and the formation of visible matter in the Universe. Initial- and final-state interactions distort the kinematics in particle knockout scattering experiments, complicating their interpretation. These effects are suppressed by detecting 11B nuclei in quasi-free scattering of 12C ions from hydrogen.

We present experimental and theoretical investigation of the first picoseconds of formation of white continuum from 100 fs laser pulse in 0.5 cm BK7 glass. The theory gives an answer to the question of the physical mechanism of asymmetrical ultra-broadening of the pulses in the initial moment of filamentation. The spectra obtained from the experiment are compared with the spectrum profiles of the physical model and are in very good coincidence.

In the present work it is demonstrated two efficient methods of self-compression of femtosecond pulses based on suitable selection of optical elements, parameters of the medium and laser radiation. The basic idea is that the phase modulated pulses more efficiently can be compressed trough nonlinear mechanisms. The first method can be applied for mediums with significant dispersion like fused silica, where the sign of the dispersion of the group velocity is important. We show that the combination of focusing by optical lens and a balance between anomalous dispersion and nonlinearity lead to significant compression from 100fs to~20-30fs of optical pulse. The second method for self-compression is by using only one optical diffraction grating to obtain broadband pulses and the following self-compression in nonlinear regime. In the second case in addition is observed generation of X wave.