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V. F. Dmitriev

Publications and source records attributed to V. F. Dmitriev.

36 records · Page 2Linked to original sources
arXiv2005

Relativistic corrections to the nuclear Schiff moment

Parity and time invariance violating ($P,T$-odd) atomic electric dipole moments (EDM) are induced by interaction between atomic electrons and nuclear $P,T$-odd moments which are produced by $P,T$-odd nuclear forces. The nuclear EDM is screened by atomic electrons. The EDM of a non-relativistic atom with closed electron subshells is induced by the nuclear Schiff moment. For heavy relativistic atoms EDM is induced by the nuclear local dipole moments which differ by 10-50% from the Schiff moments calculated previously. We calculate the local dipole moments for ${^{199}{\rm Hg}}$ and ${^{205}{\rm Tl}}$ where the most accurate atomic and molecular EDM measurements have been performed.

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arXiv2004

Effects of core polarization on the nuclear Schiff moment

Schiff moments were calculated for a set of nuclei with full account of core polarization effects. A finite range P and T violating weak nucleon-nucleon interaction has been used in the calculations. While in the absence of core polarization the Schiff moment depends on one combination of the weak interaction constants, in the presence of core polarization the Schiff moment depends on all three constants separately. The dominant contribution comes from isovector, $ΔT=1$, part of the weak interaction. The effects of core polarization were found to have in general a large effect on the Schiff moments.

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arXiv2004

Two-photon exchange and elastic scattering of electrons/positrons on the proton. (Proposal for an experiment at VEPP-3)

It has been suggested that two-photon exchange corrections could explain the discrepancy between Rosenbluth extractions of the proton form factors and recent polarization transfer measurements. We propose a precise comparison of electron-proton and positron-proton scattering at Q^2=1.6 GeV^2 to determine if two-photon exchange at moderate Q^2 values is in fact able to explain the discrepancy.

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arXiv2003

Schiff moment of the Mercury nucleus and the proton dipole moment

We calculated the contribution of internal nucleon electric dipole moments to the Schiff moment of $^{199}$Hg. The contribution of the proton electric dipole moment was obtained via core polarization effects that were treated in the framework of random phase approximation with effective residual forces. We derived a new upper bound $|d_p|< 5.4\times 10^{-24} e\cdot$cm of the proton electric dipole moment.

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arXiv2003

Cosmological variation of deuteron binding energy, strong interaction and quark masses from big bang nucleosynthesis

We use Big Bang Nucleosynthesis calculations and light element abundance data to constrain the relative variation of the deuteron binding energy since the universe was a few minutes old, $δQ = Q(BBN)-Q(present)$. Two approaches are used, first treating the baryon to photon ratio, $η$, as a free parameter, but with the additional freedom of varying $δQ$, and second using the WMAP value of $η$ and solving only for $δQ$. Including varying $Q$ yields a better fit to the observational data than imposing the present day value, rectifying the discrepancy between the $^4He$ abundance and the deuterium and $^7Li$ abundances, {\it and} yields good agreement with the independently determined $η_{WMAP}$. The minimal deviation consistent with the data is significant at about the 4-$σ$ level; $δQ/Q= -0.019 \pm 0.005$. If the primordial $^4$He abundance lies towards the low end of values in the literature, this deviation is even larger and more statistically significant. Taking the light element abundance data at face-value, our result may be interpreted as variation of the dimensionless ratio $X=m_s/Λ_{QCD}$ of the strange quark mass and strong scale: $δX/X=(1.1 \pm 0.3) \times 10^{-3}$. These results provide a strong motivation for a more thorough exploration of the potential systematic errors in the light element abundance data.

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arXiv2003

P and T odd nuclear moments

We discuss the nuclear anapole moment, a new P odd, T even electromagnetic multipole. Its discovery in the cesium experiment gives a first-rate information on parity-nonconserving nuclear forces. New prospects in the field are considered. Upper limits on the electric dipole moments, which are P odd, T odd multipoles, of elementary particles and atoms are presented, and their physical implications discussed. The atomic experiments are demonstrated to be as informative in this respect as the neutron ones. Tremendous progress in the field can be expected from experiments at ion storage rings and linear electrostatic traps.

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arXiv2003

P- and T-violating Schiff moment of the Mercury nucleus

The Schiff moment of the $^{199}$Hg nucleus was calculated using finite range P- and T-violating weak nucleon-nucleon interaction. Effects of the core polarization were considered in the framework of RPA with effective residual forces.

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arXiv2003

Anapole moment of an exotic nucleus

We demonstrate that there is no appreciable enhancement of the anapole moment of $^{11}$Be. The effect of small energy intervals is compensated for by a small overlap of the halo neutron wave function with core.

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arXiv2001

Nuclear magnetization distribution and hyperfine splitting in Bi$^{82+}$ ion

Hyperfine splitting in Bi$^{82+}$ and Pb$^{81+}$ ions was calculated using continuum RPA approach with effective residual forces. To fix the parameters of the theory the nuclear magnetic dipole moments of two one- particle and two one-hole nuclei around $^{208}$Pb were calculated using the same approach. The contribution from velocity dependent two-body spin- orbit residual interaction was calculated explicitly. Additionally, the octupole moment of $^{209}$Bi and the hfs in muonic bismuth atom were calculated as well in the same approach. All the calculated observables, except the electronic hfs in $^{209}$Bi, are in good agreement with the data. We argue for more accurate measurement of the octupole moment and the muonic hfs for $^{209}$Bi.

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arXiv2001

Do Hadronic Charge Exchange Reactions Measure Electroweak L = 1 Strength?

An eikonal model has been used to assess the relationship between calculated strengths for first forbidden beta decay and calculated cross sections for (p,n) charge exchange reactions. It is found that these are proportional for strong transitions, suggesting that hadronic charge exchange reactions may be useful in determining the spin-dipole matrix elements for astrophysically interesting leptonic transitions.

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arXiv1999

Many-body corrections to the nuclear anapole moment II

The contribution of many-body effects to the nuclear anapole moment were studied earlier in [1]. Here, more accurate calculation of the many-body contributions is presented, which goes beyond the constant density approximation for them used in [1]. The effects of pairing are now included. The accuracy of the short range limit of the parity violating nuclear forces is discussed.

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arXiv1996

Many Body Corrections to Nuclear Anapole Moment

The many body contributions to the nuclear anapole moment of $^{133}$Cs, $^{205}$Tl, $^{207,209}$PB, and $^{209}$Bi from the core polarization are calculated in the random-phase approximation with the effective residual interaction. Strong reduction of a valence nucleon contribution was found provided by the core polarization effects. The contribution of the core particles to the anapole moment compensates this reduction to large extent keeping the magnitude of nuclear anapole moment close to its initial single particle value.

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arXiv1994

Nuclear Magnetic Quadrupole Moments in Single Particle Approximation

A static magnetic quadrupole moment of a nucleus, induced by T- and P-odd nucleon-nucleon interaction, is investigated in the single-particle approximation. Models are considered allowing for analytical solution. The problem is also treated numerically in a Woods-Saxon potential with spin-orbit interaction. The stability of results is discussed.

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arXiv1994

Nuclear Anapole Moments in Single Particle Approximation

Nuclear anapole moments of $\;^{133}$Cs, $\;^{203,205}$Tl, $\;^{207}$Pb, $\;^{209}$Bi are treated in the single-particle approximation. Analytical results are obtained for the oscillator potential without spin-orbit interaction. Then the anapole moments are calculated numerically in a Woods-Saxon potential which includes spin-orbit interaction. The results obtained demonstrate a remarkable stability of nuclear anapole moment calculations in the single-particle approximation.

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arXiv1992

The Nuclear Response in Delta-Isobar Region in the ($^3\!$He,t) Reaction

The excitation of a $Δ$-isobar in a finite nucleus in charge--exchange ($^3\!$He,t) reaction is discussed in terms of a nuclear response function. The medium effects modifying a $Δ$- and a pion propagation were considered for a finite size nucleus. The Glauber approach has been used for distortion of a $^3\!$He and a triton in the initial and the final states. The effects determining the peak positions and its width are discussed. Large displacement width for the $Δ$ - h excitations and considerable contribution of coherent pion production were found for the reaction on $^{12}$C.

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