Dirac phenomenological analyses for the proton scatterings from nickel isotopes

2018 ◽  
Vol 96 (12) ◽  
pp. 1304-1308 ◽  
Author(s):  
Sugie Shim
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Rotational Band ◽  
Ground State ◽  
Optical Potential ◽  
Intermediate Energy ◽  
Channel Coupling ◽  
Optical Potentials ◽  
Nickel Isotopes ◽  
Coupled Channel

Relativistic Dirac coupled channel analyses are performed phenomenologically using an optical potential model for the intermediate energy proton inelastic scatterings from nickel isotopes, 58Ni and 60Ni. The first-order rotational collective model is used for the transition optical potentials to describe the low-lying excited collective states of the ground state rotational band. The complicated Dirac coupled channel equations are solved phenomenologically by varying the optical potential and the deformation parameters to reproduce the experimental data, using a computer program that uses a sequential iteration method. The channel-coupling effects of the multistep transition process for the excited states of the ground state rotational band are found to be strong and lead the calculation results to better agreement with the experimental data when the channel coupling between the excited states is added in the calculation. The Dirac equations are reduced to the second-order differential equations to obtain the Schrödinger equivalent effective central and spin–orbit optical potentials, and the obtained effective potentials are analyzed.

SYSTEMATIC DIRAC ANALYSES OF PROTON INELASTIC SCATTERINGS FROM AXIALLY SYMMETRIC DEFORMED NUCLEI

2012 ◽  
Vol 21 (12) ◽  
pp. 1250098 ◽  
Author(s):  
SUGIE SHIM ◽  
MOON-WON KIM
Keyword(s):  
Excited States ◽  
Ground State ◽  
Vector Model ◽  
Axially Symmetric ◽  
Deformed Nuclei ◽  
Dirac Equations ◽  
Optical Potentials ◽  
Deformed Nucleus ◽  
Sequential Iteration ◽  
Coupled Channel

Relativistic Dirac coupled channel analyses using optical potential model are performed for the 800 MeV proton inelastic scatterings from 26 Mg and the results are compared with those from several other axially symmetric deformed nuclei for the systematic Dirac analyses. Employing scalar-vector model, scalar and time-like vector optical potentials in Lorentz covariant form are calculated phenomenologically by solving Dirac coupled channel equations using sequential iteration method. Dirac equations are reduced to second-order differential equations to obtain Schrödinger equivalent effective central and spin-orbit optical potentials and it is found that the heavier deformed nucleus has the larger effective central potential strength. Using the first-order rotational collective model to describe the low-lying excited states of ground state rotational band in the deformed nuclei, deformation parameters for the excited states are calculated and it is observed that the lighter deformed nucleus has the larger deformation parameter for the lowest lying excited 2+ state at the 800 MeV proton inelastic scattering, indicating the stronger coupling to the ground state compared to that of heavier nucleus.

1s hole excited states of Be: partial autoionization rates compared with recent experimental data

1991 ◽  
Vol 69 (5) ◽  
pp. 603-605
Author(s):  
D. Petrini ◽  
J. A. Tully
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Cross Section ◽  
Ground State ◽  
Photoionization Cross Section ◽  
Recent Experimental Data ◽  
Auger Decay ◽  
Close Coupling ◽  
University College London ◽  
The University

Auger decay following inner-shell photoexcitation of atomic beryllium is studied using the University College London close-coupling codes. We reproduce some of the features observed experimentally by Krause and co-workers. The vastly predominant decay mode of Be 1s2s2np1P° is to Be+ 1s2np rather than the ground state of Be+ and the theoretical np/2s ratio agrees with the experimental value. The peak observed in the partial photoionization cross section for formation of 1s(2s2p3P) 2P° is due to photoexcitation of 1s2s(3s3p3P) 1P° followed by autoionization. Our theoretical result reproduces this feature. Strong configuration interaction effects limit the accuracy we can achieve for the radiationless decay width.

The (K−,π−) and (π+, K+) Reactions and Λ-Hypernuclear Polarization

1994 ◽  
Vol 117 ◽  
pp. 17-53 ◽  
Author(s):  
K. Itonaga ◽  
T. Motoba ◽  
M. Sotona
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Cross Sections ◽  
Ground State ◽  
Weak Decay ◽  
Angular Distributions ◽  
Theoretical Studies ◽  
Excitation Functions ◽  
Unnatural Parity ◽  
Natural Parity

The theoretical studies of (K−, π−) and (π+, K+) reactions on p-shell targets are presented in the DWIA framework with use of the elementary spin-nonflip and spin-flip amplitudes. Calculations can explain the available experimental data of excitation functions and angular distributions of the (K−, π−) reactions at pK−=800 MeV/c and the (π+, K+) reactions at pπ+ = 1.04 GeV/c. Characteristic and distinguished features of the excitation functions and cross sections are exhibited. Especially it is demonstrated that the (K−, π−) reactions at pK−=1.1 GeV/c and 1.5 GeV/c can excite the unnatural parity states with comparable strength to the natural parity ones. Further interesting is that the (π+, K+) and (K−, π−) reactions with ∼1 GeV/c incident beams can be shown to produce very large polarizations of the produced hypernuclear states. Taking the subsequent deexcitation processes of the excited states into account, we have evaluated the hypernuclear polarization and Λ-spin polarization of the ground state and/or the ground-doublet states at the hypernuclear weak-decay stage, which would play a role in the hypernuclear coincidence experiment.

scholarly journals Relativistic Dirac analyses of polarized proton scatterings to the 2+ gamma vibrational band in 24Mg and 26Mg

2017 ◽  
Vol 95 (4) ◽  
pp. 317-321 ◽  
Author(s):  
Sugie Shim
Keyword(s):  
Excited States ◽  
Optical Potential ◽  
Vibrational Band ◽  
Collective Models ◽  
Channel Calculation ◽  
Vector Potentials ◽  
Deformation Parameters ◽  
Polarized Proton ◽  
Coupled Channel ◽  
Gamma Vibrational Band

Relativistic Dirac analyses are performed phenomenologically for the high-lying excited states that belong to the 2+ gamma vibrational band at the 800 MeV polarized proton inelastic scatterings from the s-d shell nuclei, 24Mg and 26Mg. Optical potential model is used and scalar and time-like vector potentials are considered as direct potentials. First-order vibrational collective models are used to obtain the transition optical potentials to accommodate the high-lying excited vibrational collective states. The complicated Dirac coupled channel equations are solved phenomenologically to reproduce the differential cross section and analyzing power data by varying the optical potential and deformation parameters. It is found that the relativistic Dirac coupled channel calculation could describe the high-lying excited states of the 2+ gamma vibrational band at the 800 MeV polarized proton inelastic scatterings from s-d shell nuclei 24Mg and 26Mg reasonably well, showing mostly better agreement with the experimental data compared to the results obtained from the nonrelativistic calculations. Calculated deformation parameters for the excited states are analyzed and compared with those of nonrelativistic calculations.

ALPHA-DECAYS TO MEMBERS OF GROUND-STATE ROTATIONAL BAND OF HEAVY EVEN-EVEN NUCLEI

2008 ◽  
Vol 17 (supp01) ◽  
pp. 29-36 ◽  
Author(s):  
CHANG XU ◽  
ZHONGZHOU REN
Keyword(s):  
Experimental Data ◽  
Angular Momentum ◽  
Rotational Band ◽  
Ground State ◽  
Daughter Nucleus ◽  
Branching Ratios ◽  
Decay Energy ◽  
Α Decay ◽  
Barrier Penetration ◽  
Excitation Probability

We apply a simple barrier penetration approach to calculate α-decay branching ratios to members of ground-state rotational band of heavy even-even nuclei. The influence of α-decay energy, the angular momentum of α-particle, and the excitation probability of the daughter nucleus is taken into account in our calculations. The theoretical branching ratios of α-transitions are found to agree with the available experimental data well.

scholarly journals Pairing and (9/2)n configuration in nuclei in the 208Pb region

2018 ◽  
Vol 177 ◽  
pp. 03004
Author(s):  
M. Stepanov ◽  
L. Imasheva ◽  
B. Ishkhanov ◽  
T. Tretyakova
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Ground State ◽  
Exotic Nuclei ◽  
Low Energy ◽  
Energy Spectra ◽  
Pairing Energy ◽  
Multiplet Splitting ◽  
Wide Range ◽  
Nuclear Masses

Excited states in low-energy spectra in nuclei near 208Pb are considered. The pure (j = 9/2)n configuration approximation with delta-force is used for ground state multiplet calculations. The multiplet splitting is determined by the pairing energy, which can be defined from the even-odd straggering of the nuclear masses. For the configurations with more than two valence nucleons, the seniority scheme is used. The results of the calculations agree with the experimental data for both stable and exotic nuclei within 0.06-6.16%. Due to simplicity and absence of the fitted parameters, the model can be easily applied for studies of nature of the excited states in a wide range of nuclei.

scholarly journals INFRARED ABSORPTION LINES IN BORON-DOPED SILICON

1963 ◽  
Vol 41 (11) ◽  
pp. 1801-1822 ◽  
Author(s):  
Konrad Colbow
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Ground State ◽  
Half Width ◽  
Stark Broadening ◽  
Boron Doped ◽  
Doped Silicon ◽  
Spectrometer Slit ◽  
Proper Allowance ◽  
Internal Strains

In boron-doped silicon, optical absorption takes place through the excitation of bound holes from the ground state to excited states. This leads to a line spectrum. Because of a lack of sufficient resolution and a failure to make proper allowance for line distortion by the finite spectrometer slit width, previous authors gave a misleading picture of the low-temperature half-width, the temperature dependence of this half-width, and the onset of concentration broadening at low temperatures.New experimental data are presented and explained by introducing the mechanism of statistical Stark broadening due to ionized impurities, and by modifying Baltensperger's (1953) theory for concentration broadening. At low impurity concentration the width is attributed to phonon broadening (Barrie and Nishikawa 1963) and internal strains (Kohn 1957).

DESCRIPTION OF E1 TRANSITION IN DOUBLY EVEN WELL-DEFORMED NUCLEI

1994 ◽  
Vol 03 (04) ◽  
pp. 1227-1250 ◽  
Author(s):  
V.G. SOLOVIEV ◽  
A.V. SUSHKOV ◽  
N. YU. SHIRIKOVA
Keyword(s):  
Experimental Data ◽  
Excited States ◽  
Ground State ◽  
Transition Probabilities ◽  
Wave Functions ◽  
Radial Dependence ◽  
Nuclear Model ◽  
Transition Rates ◽  
Deformed Nuclei ◽  
Dipole Interactions

One-phonon states with Kπ=0− and 1− are calculated within the RPA taking the isoscalar and isovector particle-hole and particle-particle octupole and isovector particlehole dipole interactions into account. General equations of the Quasiparticle-Phonon Nuclear Model are modified. The energies and wave functions of the nonrotational states below 2.3 MeV in 160Gd calculated within this model are in good overall agreement with experimental data. The E1 transition rates in several doubly even well-deformed nuclei are calculated. The influence of the radial dependence of the dipole and octupole interactions on E1 and E3 transition probabilities is investigated. It is shown that the fragmentation of one-phonon states below 2.3 MeV weakly affects the E1 transition rates from 1− states to the ground state. The fragmentation of one- and two-phonon states strongly affect B(E1) values of the transitions from 1− states with energy above 2.5 MeV to the ground states and between excited states. The results of calculating the E1 transition rates are compared with the relevant experimental data.

NEW 5− AND 6+ STATES IN Ne20

1964 ◽  
Vol 42 (3) ◽  
pp. 477-488 ◽  
Author(s):  
J. A. Kuehner ◽  
J. D. Pearson
Keyword(s):  
Excited States ◽  
Rotational Band ◽  
Ground State ◽  
Negative Parity ◽  
Alpha Particles ◽  
Excitation Energies ◽  
Angular Correlations ◽  
Fourth Member

Excited states of Ne20 at excitation energies of 8.46 Mev and 8.79 Mev have been identified and assigned spin and parity values of 5− and 6+, respectively. The excited states were produced in the C12(C12, α)Ne10 reaction and the spin assignments were made on the basis of angular correlations of the decay alpha particles from these states leaving O16 in its ground state. It is postulated that the 5− state is the fourth member of a K = 2 negative-parity rotational band based on the 2– 4.97-Mev state and that the 6+ state is the fourth member of a K = 0 rotational band based on the 0+ ground state of Ne20.

OBSERVATION OF THE SPIN 20 LEVEL IN THE GROUND STATE ROTATIONAL BAND OF 158Dy

1971 ◽  
Vol 32 (C6) ◽  
pp. C6-289-C6-290
Author(s):  
P. THIEBERGER ◽  
A. W. SUNYAR ◽  
P. C. ROGERS ◽  
N. LARK ◽  
O. C. KISTNER ◽  
...  
Keyword(s):  
Rotational Band ◽  
Ground State
Sign in / Sign up

Export Citation Format

Share Document