Kenji Kume

Formation of Deeply Bound 1s Pionic States of Intermediate Mass Nuclei in (d,3He) Reactions

We study the formation cross sections of the deeply bound 1s pionic states in (d,He) reactions at intermediate energies. We investigate the reaction spectra for the three target nuclei Xe, Sn and Cd, which involve the (s1/2)n neutron orbit in outer shell. We conclude that the (d,He) reactions at Td = 500 MeV with Xe and Sn targets are the best candidates to observe the deepest 1s pionic states with very high accuracy.

Residual interaction effects on deeply bound pionic states in Sn and Pb isotopes

We have studied the residual interaction effects theoretically on the deeply bound pionic states in Pb and Sn isotopes. We need to evaluate the residual interaction effects carefully to deduce the nuclear medium effects for pion properties, which are believed to provide valuable information on nuclear chiral dynamics. The s- and p-wave {pi}N interactions are used for the pion-nucleon residual interactions. We show that the complex energy shifts are around [(10-20) + i(2-7)] keV for 1s states in Sn, which should be taken into account in the analyses of the high precision data of deeply bound pionic 1s states in Sn isotopes.

Asymmetry and energy spectrum of high-energy neutrons emitted in polarized muon capture by nuclei

Abstract Formulas for the asymmetry and energy spectrum of high-energy neutrons emitted in polarized muon capture by nuclei are given in the theory of allowed and forbidden transitions, with the small components of lepton wave functions. The neutron asymmetry is explicitly given by the interferences between two transitions whose forbiddennesses differ by one unit. A large asymmetry of the neutrons and its strong energy dependence in 40Ca experiments are successfully explained by taking into account a realistic reaction mechanism with the effect of channel coupling.

MULTIDIMENSIONAL EXTENSION OF SINGULAR SPECTRUM ANALYSIS BASED ON FILTERING INTERPRETATION

Singular spectrum analysis is a nonparametric spectral decomposition of a time series. The singular spectrum analysis can be viewed as the two-step filtering with the complete set of eigenfilter adaptively constructed from the original time series. Based on this viewpoint, we present a flexible and quite simple algorithm for the singular spectrum analysis which can be applied to the multidimensional data series with arbitrary dimension. We have carried out the decomposition of two-dimensional image data, and the optimally constructed filters are found to be the smoothing or the edge enhancement filters of various type. We have also examined a simple example for the decomposition of 3D data.

Nuclear quadrupole effects in deeply bound pionic atoms

Abstract We have studied nuclear quadrupole deformation effects in deeply bound pionic atoms theoretically. We have evaluated the level shifts and widths of the hyperfine components using the first order perturbation theory and compared them with the effects of neutron skin. We conclude that the nuclear quadrupole deformation effects for deeply bound 1s and 2p states are very difficult to observe and that the effects could be observed for 3d states. We also conclude that the deformation effects are sensitive to the parameters of the pion-nucleus optical potential.

Excitation of stretched 2p1h states in near-threshold (p, π−) reaction

Abstract We have studied the cross section and the analyzing power for the pion production reactions 88 Sr(p, π − ) 89 Zr( 25 2 + :4.2 MeV ) and 88 Sr(p, π − ) 89 Zr( 21 2 + :3.8 MeV ) within the model. It is shown that the two-body process with the final protons coupled to spin singlet state p + n → (p + p) S = 0 + π − dominates the reaction cross section, while the analyzing power is affected appreciably by the transition to the spin-triplet proton pair p + n → ( p + p ) S = 1 + π − . The main features of the measured angular distributions of the cross section and the analyzing power are explained within the present model.

Photon Absorption on a Neutron-Proton Pair in 3He and 4He

We have developed a phenomenological quasi-deuteron model to describe photodisintegration reactions of

Near-threshold (p, π−) reaction on 48Ca

^3

Pion-nucleus potential parameters and quadrupole effect in deeply bound pionic atom

He and

An Adaptive Orthogonal SSA Decomposition Algorithm for a Time Series

^4