Measurements of WZ production in pp collisions at a center-of-mass energy of 13 TeV are presented. The data were collected in 2015 and 2016 by the ATLAS experiment at the Large Hadron Collider, and correspond to an integrated luminosity of 36.1 f⁻¹. The WZ candidate events are reconstructed using leptonic decay modes into electrons and muons of the gauge bosons. The measured inclusive cross...
We discuss the prospects of the observation of double heavy baryons $\Xi_{cc}$, $\Omega_{cc}$ with excited diquark (S and P excitations) in experiments at LHC. P-wave excitations of a diquark in double charmed baryons are supposed to be quite narrow since their decay into the ground state is highly suppressed. Relative yields of S-wave and P-wave excitations have been estimated within pQCD for...
Supersymmetric black holes play an important role in string theory. It is natural to ask whether they are classically stable or not, i.e. does a small initial perturbation remain small with time evolution?
In supergravity from the fact that supersymmetric solution staurates BPS-bound does not imply classical stability. For example, anti-de-Sitter spacetime is a supersymmetric solution of...
The recent CMS results on B^0_s spectroscopy are presented. The search for exotic state X(5568) decaying into B^0_s pi^{+-} is reported together with the studies of P-wave B_s meson states Bs1(5830)0 and Bs2(5840)0, including the observation of the Bs2(5840)0 -> B0 K0s decay. The results are based on the data sample collected by the CMS experiment at the LHC in proton-proton collisions at...
We consider (1+1)-dimensional Yukawa theory with a massless real scalar field. We study the response of the production of fermion pairs to an external coordinate-dependent scalar field.
DANSS is a one cubic meter highly segmented solid scintillator detector. It consists of 2500 scintillator strips, covered with gadolinium loaded reflective coating and read out with SiPMs via wavelength shifting fibers. DANSS is placed under a 3 GW industrial reactor at the Kalinin NPP (Russia) on a movable platform. The distance from the reactor core center is varied from 10.7 m to 12.7 m...
We consider 1+1 Yukawa model in the strong background field (namely, linearly growing scalar field). We derive exact harmonics, calculate the fermionic current and find that it grows logarithmically. We reproduce this result by integrating out the fermion degrees of freedom in the effective action. Finally, we calculate loop corrections to the scalar and fermion propagators and observe that...
In this talk the phase structure of the dense baryonic/quark matter has been investigated in the presence of baryon, isospin, chiral and chiral isospin chemical potentials in the framework of Nambu--Jona-Lasinio model. It has been shown that in the large-Nc limit there exist several dualities of the phase portrait. One of the key conclusions of our studies is the fact that chiral imbalance...
The talk will showcase some of the Machine Learning (ML) methods being applied in B physics spectroscopy. Using the data collected with the CMS experiment and the Bs→psi(2S) phi decay as a playground several most commonly used algorithms will be examined and compared while searching for a well-known intermediate psi(2S) resonance. The main emphasis will be given to a proper understanding of...
Detection of rare neutrino interactions requires a large target mass. One of commonly used solutions is a detector composed of liquid scintillator surrounded by an array of photo-multiplier tubes. Its large dimensions and a variety of optical effects lead to non-uniformity of light collection, which significantly complicates deriving the neutrino energy from the raw photo-multiplier signals....
The analysis of flavor changing neutral currents (FCNC) is one of the best tools to look for new physics in High Energy Experiments, since these are highly suppressed in the Standard Model (SM), which makes both contributions from NP and from the SM to affect the decays at the same level.
Moreover, the $B \rightarrow K\ell\overline{\ell}$ decay (governed by the transition $b \rightarrow...
The Analog Hadronic Calorimeter AHCAL is a highly granular sampling calorimeter developed by the CALICE collaboration for the future International Linear Collider (ILC). It is designed in accordance with the requirements of particle flow algorithms to achieve a good jet energy resolution. The AHCAL technological prototype consists of $\sim22000$ channels equipped with $3\times3\ cm^2$ ...
Resently new inhomogeneous field configurations similar to kinks in the Gross-Neveu model were found in the CP(N-1) model in the large N limit. We will discuss properties of the solutions. In particular, energy of the inhomogeneous states is lower then energy of the homogeneous one. Thus the question about the true ground state of the model arises. In context of this question we discuss...
Two-phase argon detector is being developed in the Laboratory of Cosmology and Particle physics of the Novosibirsk State University jointly with the Budker Institute of Nuclear Physics. One of the main purpose of this detector is to measure the ionization yield and scintillation efficiency of nuclear recoils, which is of paramount importance for the energy calibration in rare-event experiments...
The DANSS experiment aims to search for sterile neutrinos. It is a compact neutrino spectrometer located at the Kalinin NPP close to the core of an industrial power reactor. Detection of the reactor antineutrino is based on the Inverse Beta-Decay (IBD) reaction. The detector records about 5000 events per day after subtracting the background. The significant contribution to background events is...
Measurement of electroweak (EWK) component of associated $Z\gamma$ production is a precise test of the electroweak theory and a probe of BSM theories that predict anomalous vector boson self-couplings. However, recognition of it in the presence of QCD $Z\gamma$ production component on hadron collider experiment is a very challenging task due to identical final states and higher cross section...
It is suggested that Primordial Black Holes (PBHs) could be one of the plausible constituents of Massive Compact Halo Objects (MACHOs). It is likely that such PBHs were produced after the completion of inflation (or more specifically, during the epoch of reheating). We follow a particular scenario of PBH formation which is based on the Affleck-Dine mechanism of baryogenesis. It was predicted...
The Drell-Yan process in which a lepton pair is produced in hadron-hadron collisions is one of the most extensively studied reactions. The precision measurements of dilepton angular coefficients at various energies were presented over the past years. However, the values of angular coefficients strongly depend on the choice of a reference frame. That is why an adequate comparison between...
An initial study of neutron detection in the near detector ND280 of T2K was done. Monte Carlo data simulated for muon antineutrino interactions on a CH active target with energies about 0.6 GeV was analysed. Kinematics of quasi-elastic scattering was reconstructed using time-of-flight technique. Efficiency of neutron detection, kinematics of secondary particles were measured and energy...
The production of Z bosons in association with a high energy photon (Zγ production) is studied in the neutrino decay channel of the Z boson using pp collisions at √s=13 TeV. The analysis uses a data sample with an integrated luminosity of 36.1 fb−1 collected by the ATLAS detector in 2015 and 2016. Zγ events with invisible decays of the Z boson are selected by requiring significant missing...
There is a problem of overproduction of gammas in decay or annihilation of dark matter (DM) while trying to explain cosmic positron data. We consider the specific models where DM particle decays to e+ e- and e+ e+. These modes can have different physical reasons of final state radiation (FSR) suppression, which is the subject of our investigation.
We study restrictions imposed on the parameters of the Kaluza-Klein extra space supplied by the standard inflationary models. It is shown that the size of the extra space cannot be larger than $\sim 10^{-27}$cm and the $D$-dimensional Planck mass should be larger than $\sim 10^{13}$GeV. The validity of these estimates is discussed.
We also study creation of stable excitations of scalar field...
We look the reinforcement learning dynamics. As the dynamics is a stochastic process, the adequate mathematical tool is the master equation. We introduce the probability distributions for the actions and value functions, then get a master equation, describing the reinforcement learning process. We derived a Hamilton-Jacobi equation for the latter equation. We verify a unique feature of the...
We consider Feynman propagators between two different $\alpha-$states in global de Sitter space and in Poincare patch. Then we separately consider $\alpha-\alpha$, in-in and in-out Feynman propagators. They are used to find the imaginary contribution to the effective actions.
