On the occasion of the centennial of the birth of Sergei Nikolaevich Vernov (1910–1982)

Proceedings of the International Conference “Nucleus 2009: Fundamental Problems and Applications of Nuclear Physics, from Cosmos to Nanotechnologies” (LIX International Conference on Nuclear Spectroscopy and Atomic Nuclear Structure)

On the occasion of the centennial of the birth of Sergei Nikolaevich Vernov (1910–1982)     

How to Determine the Spin of the ξ(2230)

The possibility for increasing the statistics by summing up the events of decaying into two pseudo scalar mesons from the existing data samples is discussed.     

Parameters of the energy spectrum of semiconductive solid solutions of the tetradic system (AlSb)x(HgTe)1−x

From the analysis of the spectra of photoluminescence and transparency in the temperature interval (2–77) K there are determined in the paper, the gap-width and its temperature coefficient as a function of the composition of the melt of (AlSb)_x(HgTe)_1–x. It is shown that for compositions (0.8 x 1) with a lowering of the temperature, the edge of the fundamental absorption is shifted into the domain of large energies, and for compositions (0.05 , x 0.20) with a lowering of temperature, the edge of the fundamental absorption is shifted into the long-wave domain of the spectrum. The dependence of E_g(x, T) has a nonlinear character.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 67–70, April, 1991.     

Measurement of the LT-asymmetry in πelectroproduction at the energy of the Δ(1232)-resonance

The reaction p(e, e'p)π⁰ has been studied at Q² = 0.2 (GeV/c)² in the region of W = 1232MeV. From measurements left and right of , cross-section asymmetries ρ_LT have been obtained in forward kinematics ρ_LT( = 20^°) = (- 11.68±2.36_stat±2.36_sys) and backward kinematics ρ_LT( = 160^°) = (12.18±0.27_stat±0.82_sys) π⁰. Multipole ratios {S₁₊ ^* M₁₊}/| M₁₊|² and {S₀₊ ^* M₁₊}/| M₁₊|² were determined in the framework of the MAID2003 model. The results are in agreement with older data. The unusally strong negative {S₀₊ ^* M₁₊}/| M₁₊|² required to bring also the result of Kalleicher et al. in accordance with the rest of the data is almost excluded.     

Absolute Intensities of the 10-µm Bands of (16)O(3)

Two hundred ninety experimental absolute intensities of nu(1) and nu(3) transitions of ozone have been measured, with good accuracy (<2%). They are used to derive the transition-moment parameters for these bands. The agreement between our observed and calculated line intensities is satisfactory. This work shows that the intensities of these two bands are on average 4% smaller than those used in the literature. In addition, 20 intensities of the nu(2) + nu(3) - nu(2) band confirm this value. Also, 42 line intensities of the 2nu(1)-nu(3) band are reported. Copyright 2001 Academic Press.     

Polarization properties of baryons in the hadronic decays of the Δ(1232) resonance

The angular distribution of the probability for the Δ(1232)-resonance decay Δ(1232) → Nπ versus the polarizations of baryons and the vector of dynamical nucleon polarization are calculated.     

Calculation of vibrations of the H-bonds and electrooptical parameters of the F(HF)2]− complex

The problem of calculating the vibrations of the F(HF)₂]^? complex with hydrogen bonds is considered with allowance for the anharmonicity and interaction of motions in different degrees of freedom. A systematic solution of this problem is proposed which consists in separating the total vibrational system into subsystems, obtaining sufficiently exact vibrational wave functions of subsystems, and expanding the vibrational wave functions of the total system in basis functions constructed from the wave functions of subsystems. At the first stage of our study, the stretching and bending modes of two F...HF hydrogen bonds are considered with the use of an exact kinetic energy operator and a nonempirical three-dimensional potential energy surface. It is shown that these vibrational modes of the complex are characterized by significant mechanical and electric anharmonicities. The calculated values of frequencies of the symmetric and antisymmetric vibrations of hydrogen bonds are in good agreement with the experimental findings.     

Microfacets of the (1 × 2) reconstructed Pt(110) surface seen in the adsorption dynamics of H2

We have detected a strong azimuth dependence of the adsorption dynamics of hydrogen on a Pt(110)(1×2) surface. Adsorption on the (1 ×2) reconstructed surface is found to be governed by the (111) microfacets of the missing row structure. Furthermore we have observed a low temperature α-state in the thermal desorption spectra comparable to the α-states for other fcc (110) surfaces.     

Simulation of the (p,T) phase diagram of the temperature-driven metamagnet α-FeRh

We perform finite-pressure Monte Carlo simulations of an effective spin-analogous model with coupled magnetic and lattice degrees of freedom, which has previously been proposed in order to explain the anomalous temperature driven metamagnetic phase transition in α-FeRh. The results are in reasonable agreement with the experimental (p,?T) phase diagram. The critical behaviour of the system along the transition lines is analysed in detail.     

Effects of the rest mass of the neutrino (antineutrino) on the scattering of ν (\tilde \upsilon ) by6C12

Expressions are obtained for the differential cross sections of the processes +₆C¹² ₇N¹² + e^– and +₆C¹² ₅B¹² + e⁺ for the shell model of the nucleus and the harmonic oscillator model. We analyze the effect of the rest mass of the neutrino (antineutrino) on the degree of longitudinal polarization of the electrons (positrons), the angular electron-neutrino (positron-antineutrino) correlation coefficient, and the charge asymmetry.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 37–43, July, 1988.The authors thank B. K. Kerimov for useful discussions.     

Band-mapping of InP (100) along the ΓX-line

We have prepared InP (100) surfaces from wafer-material by cycles of argon ion sputtering and gentle annealing. From these samples normal-emission photoelectron spectra were recorded using photons in the energy range 10eV<h<75eV. From the results we derive the initial-state band disperison along the X-line of the 3-dimensional Brillouin zone. Our results are fully consistent with initial-state bands mapped by other authors along the KX-line. From the good agreement we conclude that the quality of the (100)-surfaces as used in our work is at least adequate for bulk band investigations.     

Observation of the Ξ(b)(0) baryon

The observation of the bottom, strange baryon Ξ(b)(0) through the decay chain Ξ(b)(0)→Ξ(c)(+)π-, where ΞΞ(c)(+)→Ξ- π+ π+, Ξ-→Λπ-, and Λ→pπ-, is reported by using data corresponding to an integrated luminosity of 4.2 fb(-1) from pp collisions at square root(s)=1.96 TeV recorded with the Collider Detector at Fermilab. A signal of 25.3(-5.4)(+5.6) candidates is observed whose probability of arising from a background fluctuation is 3.6×10(-12), corresponding to 6.8 gaussian standard deviations. The Ξ(b)(0) mass is measured to be 5787.8±5.0(stat)±1.3(syst) MeV/c2. In addition, the Ξ(b)- baryon is observed through the process Ξ(b)-→Ξ(c)(0)π-, where Ξ(c)(0)→Ξ- π+, Ξ-→Λπ-, and Λ→pπ-.     

Study of ψ(4415) in the QPC model

Some authors consider the ψ(4415) to be the 4S or 5S excited tate of a cc pair. Starting from this assumption, we study he decays of the ψ(4415) to DD, D^*D^*, D_SD_S, D_S^*D_S^*, and get the corresponding branching ratios in terms of the Quark-Pair-Creation (QPC) model. Compared with the experimental data, we find that the results of 4S state agree much better than those of the 5S state. Therefore, it is more reasonable to assume the ψ(4415) to be a 4S state.     

Structure Analysis of the l/η(1440)

By an amplitudes analysis of the KKπ system in the J/ψ radiative decay to the K⁺K^－π^O and the K⁰_SK^±π⁺ final states, we find that there is one 0^－+ resonance (M=1467±3MeV,Γ=89±6MeV) and two 1⁺⁺ resonances (M=1435±3MeV,Γ=59±5MeV and M=1497±2MeV,Γ=44±7MeV), Which are consistent with the η(1440), the f₁(1420), and the f₁(1510).     

Investigations on the charmless decays of Y(4260)

Apart from the charmful decay channels of Y(4260), the charmless decay channels of Y(4260) also provide us a good platform to study the nature and the decay mechanism of Y(4260). In this paper, we propose to probe the structure of Y(4260) through the charmless decays Y(4260)→VP via intermediate D₁D+c.c. meson loops, where V and P stand for light vector and pseudoscalar mesons, respectively. Under the molecule ansatz of Y(4260), the predicted total branching ratio BR_VP for all Y(4260)→VP processes are about (0.34_-0.23^+0.23)% to (0.75_-0.52^+0.72)% with the cutoff parameter α=2-3. Numerical results show that the intermediate m D₁D+c.c. meson loops may be a possible transition mechanism in the Y(4260)→VP decays. These predicted branching ratios are the same order to that of Y(4260)→Z_c⁺(3900)π^-, which may be an evidence of D₁D molecule and can be examined by the forthcoming BESⅢ data in the near future.     

Estimate of the Δ(1232) component in the 12C nucleus

The cross section for the ¹²C(γ, π⁺ p) reaction was measured in the range of the Δ(1232) isobar. The data were analyzed using the models taking into account the nucleon and isobaric degrees of freedom of the ¹²C nucleus. The conclusion is drawn that in the large-momentum transfer range the π⁺ p pairs are produced in the course of the direct knocking-out of Δ⁺⁺ isobar from the nucleus. The probability of finding the Δ isobar in the ground-state ¹²C nucleus is estimated at 0.018±0.005 Δ isobars per nucleon.     

Calculation of the ground state energy of neutral atoms (Z ≤ 54) by the algebraic variant of the Hartree-Fock method

High-precision calculations of the ground-state energy of atoms He through Xe are performed in the algebraic approximation of the Hartree-Fock method. The orbital exponents of Slater-type basis functions are optimized using the second-order minimization methods, which allows the virial theorem to be fulfilled to within 10^?15–10^?17 for the first time. The energies of atoms calculated with rather limited basis sets are, in terms of accuracy, as good as the results obtained by using the numerical procedure for solving the Hartree-Fock equations.     

Reconstruction of an energy spectrum of fast neutrons (20–60 MeV) of the radex channel (INR) by the inverse problem method

A procedure for and the results from reconstruction of the energy spectrum of a beam of fast neutrons irradiating a plastic scintillator by solving the inverse problem are described. Good agreement between the reconstructed and initial spectra with different shapes of the neutron beam’s energy dependence is obtained. A similar approach can be used to determine the neutron distributions over energies in the beam of the RADEX channel (INR).