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O. L. Fedin

Publications and source records attributed to O. L. Fedin.

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Precision studies of neutron decay, left-right asymmetry model of weak interaction, CP-violation and baryon asymmetry of the Universe

An analysis of the latest, most accurate experimental data on neutron decay points to the need to extend the Standard Model by introducing a right vector boson admixture $W_R$. A left-right asymmetry model of the weak interaction is presented, in which the sign of the mixing angle $W_R$ and $W_L$ is reversed upon transition from $W^-$ to $W^+$. In this model, CP violation occurs due to the presence of a right vector boson admixture. The model parameter, the mixing angle, $ζ$=-(2.7$\pm$0.9)$\cdot$10$^{-3}$ is derived from neutron decay - lifetime and decay asymmetries - as well as from studies of proton decay in nuclei, the so-called superallowed $0^+$-$0^+$ transitions. An estimate for the mass $W_R$ $M_{W_R}$=(340$\pm$60) GeV is given by the relation: from the parameter $δ$=(5.5$\pm$1.8)$\cdot$10$^{-2}$, which is the ratio of the squares of the mass states of vector bosons. The possibility of describing CP-violation effects in neutral meson oscillations within the left-right asymmetry weak interaction model with parameters $δ$ and $ζ$ is investigated. It is shown that within this model, CP violation effects in the decays of $K^0$-mesons, $D^0$-mesons, $B^0$-mesons, and $B^0_s$-mesons can be successfully described. Moreover, the sign of CP violation is opposite for particles and antiparticles, i.e., the CP violation phase is equal to $\pmπ$/2, which corresponds to 100% CP violation. The results of calculations within the left-right asymmetry model with parameters $δ$ and $ζ$ are confirmed by experimental results with neutral mesons. The formation of baryon asymmetry in the Universe is considered in a left-right asymmetry model of weak interaction with an admixture of a right vector boson with different signs of the mixing angle with $W^-$ and $W^+$.

hep-ph

Conceptual design of the Spin Physics Detector

The Spin Physics Detector, a universal facility for studying the nucleon spin structure and other spin-related phenomena with polarized proton and deuteron beams, is proposed to be placed in one of the two interaction points of the NICA collider that is under construction at the Joint Institute for Nuclear Research (Dubna, Russia). At the heart of the project there is huge experience with polarized beams at JINR. The main objective of the proposed experiment is the comprehensive study of the unpolarized and polarized gluon content of the nucleon. Spin measurements at the Spin Physics Detector at the NICA collider have bright perspectives to make a unique contribution and challenge our understanding of the spin structure of the nucleon. In this document the Conceptual Design of the Spin Physics Detector is presented.

hep-ex