Search

Neural networks are currently used in various fields of science and technology, as well as in experiments related to particle physics. DarkSide-50 is a two-phase (liquid and gas) argon TPC which has two main signals: scintillation in LAr (S1 signal) and electroluminescence in GAr (S2 signal) [1]. In the low-mass dark matter search only the more energetic second signal is used for position reconstruction [2]. As a result only events detected by seven central photomultiplier tubes are used for the analysis. Here we attempt to improve reconstruction using the convolutional neural networks (CNN).

Study of the event classification in liquid noble gas detectors is presented. The discrimination between different events usually done by prompt light fraction. To tackle this task we adopt the neural net classifier and use pulse shape as an input feature. The main difficulty comes from low-energy events that are difficult to separate. This is important because these events provide a background for dark matter searches. We find that neural networks are suitable for this task.

A model describing the formation of protogalaxies is developed. Compact supermassive clusters of primordial black holes assumed to act as a nuclei for the galaxy formation. The mechanism of PBH formation based on a collapse of massive walls of scalar field due to second order phase transition. Mass spectra of PBH are obtained analytically and shown possibility of the formation of PBH clusters with a total mass of ~ 105 – 108 M ⊙, having a size of ~ 10 parsec, in an amount of ~ 1011, which corresponds to observational data on the value of galaxies on the visible Universe. The primary fractal structure of galaxies is naturally explained through the mechanism. Proposed approach is the cornerstone for a principally new scenario of the galaxy formation in the early Universe.

We propose a unified model of primordial black holes and soliton dark matter formation. Dynamic of spherically symmetric clumps of scalar field is considered in Newtonian approximation. The formation of hidden mass of the Universe is discussed. Numerical solution of the system of interacting scalar and gravitational fields is used to obtain the mass of a clumps.

Fermions are considered in a multidimensional space with two extra dimensions. Fermion Lagrangian contains coupling to a metric of deformed extra space. We show that the point-like defect on a space with topology of sphere leads to fermion interaction with such defect and calculate cross section of a fermion scattering on such defect.