arXiv subjects

V. A. Andreev

Publications and source records attributed to V. A. Andreev.

28 records · Page 2Linked to original sources

arXiv2009

Tomographic probability representation for quantum fermion fields

Tomographic probability representation is introduced for fermion fields. The states of the fermions are mapped onto probability distribution of discrete random variables (spin projections). The operators acting on the fermion states are described by fermionic tomographic symbols. The product of the operators acting on the fermion states is mapped onto star-product of the fermionic symbols. The kernel of the star-product is obtained. The antisymmetry of the fermion states is formulated as the specific symmetry property of the tomographic joint probability distribution associated with the states.

quant-ph↗

arXiv2007

Measurement of the Rate of Muon Capture in Hydrogen Gas and Determination of the Proton's Pseudoscalar Coupling $g_P$

The rate of nuclear muon capture by the proton has been measured using a new experimental technique based on a time projection chamber operating in ultra-clean, deuterium-depleted hydrogen gas at 1 MPa pressure. The capture rate was obtained from the difference between the measured $μ^-$ disappearance rate in hydrogen and the world average for the $μ^+$ decay rate. The target's low gas density of 1% compared to liquid hydrogen is key to avoiding uncertainties that arise from the formation of muonic molecules. The capture rate from the hyperfine singlet ground state of the $μp$ atom is measured to be $Λ_S=725.0 \pm 17.4 s^{-1}$, from which the induced pseudoscalar coupling of the nucleon, $g_P(q^2=-0.88 m_μ^2)=7.3 \pm 1.1$, is extracted. This result is consistent with theoretical predictions for $g_P$ that are based on the approximate chiral symmetry of QCD.

nucl-ex↗

arXiv2007

Cost Effective Electronics for Proportional and Drift Chambers of 'EPECUR' Experiment

'EPECUR' experiment setup is under construction at the beam line 322 of the ITEP proton synchrotron. The experiment requires several large area drift chambers to provide reasonable acceptance and fine pitch proportional chambers for beam particle tracking with total number of electronic channels of about 7000. New compact and cost effective readout system for these gaseous detectors was designed, prototyped and tested in the latest two years based on the modern technologies in analog and digital electronics, as well as in data transfer protocols. Mass production of the proportional chamber electronics is close to the end, while the boards for the drift chambers are manufactured in the amount to equip one 8-plane module. The paper presents the functional description of the whole DAQ system and its main parts together with some of the test results as an illustration of the excellent performance of the system. The appendix contains specific information which may be useful for the system users or code developers.

physics.ins-det↗

arXiv2006

Search for Two-Particle Muon Decay to Positron and Goldstone Massless Boson (FAMILON)

The experimental test of possible expansion for the Higgs sector is proposed. The lepton family violation will be studied. To reach this goal we are going to carry out the search for the scalar Goldstone boson in the neutrinoless muon decay mu+ to e+ and alpha. The asymmetry of the muon decay near the high energy edge of Michel spectrum is to be measured. To examine previous TRIUMF data the experiment FAMILON is prepared at the surface muon beam of JINR (Dubna) accelerator. The setup consist of the precision magnetic spectrometer and the device for muSR - analysis.

hep-ex↗

arXiv2006

5-Dimensional Extended Space Model

We put forward an idea that physical phenomena have to be treated in 5-dimensional space where the fifth coordinate is the interval S. Thus, we considered the (1+4) extended space G(T;X,Y,Z,S). In addition to Lorentz transformations (T;X), (T;Y), (T;Z) which are in (1+3)-dimensional Minkowski space, in the proposed (1+4)d extended space two other types of transformations exist in planes (T,S); (X,S), (Y,S), (Z,S) that converts massive particles into massless and vice versa. We also consider energy-momentum-mass 5-d space which is conjugated to the time-coordinates-interval (T;X,Y,Z,S) space. The mass in above mentioned 5-d energy-momentum-mass space corresponds to the interval S in 5-d space (T,X,Y,Z,S). Well known energy-momentum 4-vector P(1+3)=(E/c; px,py,pz) in the Minkowski (T;X,Y,Z) space is transformed to the the 5-vector - P(1+4)=(E/c; px,py,pz,mc) in the extended space G(T;X,Y,Z,S) and becomes isotropic for 5-vectors of the massive as well as for the massless particles.

physics.gen-ph↗

arXiv2005

Mechanism of the Dark Matter and Condensed Bubble Objects Formation in the Model of Extended Space

Within the framework of Extended Space Model (ESM) the processes connected to birth of photons in a gravitational field are studied. These photons have a nonzero mass. It can be both positive, and negative, and photon's energy and strength of the gravitational field determine its absolute value. It is shown that in ESM model formation of bubble gravitational structures is possible. In the frame of ESM one can obtain the follow physical picture. Bubble gravitational objects have a halo formed by dark matter generated by photons with a positive mass. The photons with a negative mass are throw away in free deep space and create there antigravitating vacuum with negative pressure. The comparison ESM bubble structures with similar objects of a type "gravastar", existing in a General Theory of Relativity (GR) is made.

physics.gen-ph↗

arXiv2004

Optic-Mechanical Analogy and Gravitational Effects in the Extended Space Model

New approach to the description of a gravitation using analogy between the optical and mechanical phenomenon is advanced. For this purpose in extended (1+4)-dimensional space G(1,4) the gravitational effects are considered: the speed of escape, red shift, radar echo, deviation light and perihelion precession of Mercury. It is shown, that methods of the Extended Space Model (ESM) give the same outcomes, as General Theory of Relativity (GR). The various ways of introduction of refraction index are discussed, which appropriate to the gravitational field.

physics.gen-ph↗

arXiv2003

Lienard-Wiechert Potentials for Model of Extended Space

In the extended (1 + 4) -dimensional space (T;X,Y,Z,S)-(time-space-interval) it is considered a model joining electromagnetic and gravitational fields. For the equations circumscribing these fields, the exact solutions appropriated to dot moving sources are found. Such solutions express through potentials Lienard-Wiechert in the extended space. Their properties are analyzed.

physics.gen-ph↗

arXiv2002

Precise Measurement of Muon Capture on the Proton

The aim of the MuCap experiment is a 1% measurement of the singlet capture rate Lambda_S for the basic electro-weak reaction mu + p -> n + nu_mu. This observable is sensitive to the weak form-factors of the nucleon, in particular to the induced pseudoscalar coupling constant g_P. It will provide a rigorous test of theoretical predictions based on the Standard Model and effective theories of QCD. The present method is based on high precision lifetime measurements of mu^- in hydrogen gas and the comparison with the free mu^+ lifetime. The mu^- experiment will be performed in ultra-clean, deuterium-depleted H_2 gas at 10 bar. Low density compared to liquid H_2 is chosen to avoid uncertainties due to ppmu formation. A time projection chamber acts as a pure hydrogen active target. It defines the muon stop position in 3-D and detects rare background reactions. Decay electrons are tracked in cylindrical wire-chambers and a scintillator array covering 75% of 4 pi.

nucl-ex↗

arXiv2001

Structure of Extended Space

In present work the generalization of Einstein's special theory of relativity on 5-dimentional space is considered, in which as fifth coordinates we consider the interval s of a particle. 5-dimentional vectors in this space are isotropic both for mass, and for massless of particles. In extended space, offered by the authors, there is a possibility in addition with usual Lorentz transformations, to enter two new transformations, therefore massive and massless of a particle can reversible converted to each other.

gr-qc↗