scholarly journals Experimental study of (p, 2p) reactions at 392 MeV on 12C, 16O, 40Ca and 208Pb nuclei leading to low-lying states of residual nuclei

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Tetsuo Noro ◽  
Tomotsugu Wakasa ◽  
Takashi Ishida ◽  
Hidetomo P Yoshida ◽  
Masahiro Dozono ◽  
...  
Keyword(s):  
Cross Sections ◽  
Impulse Approximation ◽  
Bound State ◽  
Present Measurement ◽  
Analyzing Powers ◽  
Spectroscopic Factors ◽  
Careful Treatment ◽  
Distorted Wave Impulse Approximation ◽  
State Potential ◽  
Standard Calculation

Abstract We have measured the differential cross-sections and analyzing powers for ($p,2p$) reactions at an incident energy of 392 MeV on $^{12}$C, $^{16}$O, $^{40}$Ca, and $^{208}$Pb nuclei, leading to discrete states of the residual nuclei. The data are compared with two kinds of distorted-wave impulse approximation (DWIA) calculations, a standard calculation using a global optical potential and a calculation using wave functions generated in a relativistic Hartree model. The spectroscopic factors deduced from these two calculations agree with those determined in ($e,e'p$) studies mostly within 15% in the case of the lighter three target nuclei. However, those for the $^{208}$Pb target are overestimated compared with the ($e,e'p$) results. In the heavy target case, the DWIA results are very sensitive to the radius parameter of the bound-state potential and thus a careful treatment is required. Regarding the analyzing powers of the present measurement, we confirmed that the $j$-dependence is sufficient for practical spectroscopic use.

Studies of the (p,n) reaction at medium energies

1987 ◽  
Vol 65 (6) ◽  
pp. 566-573 ◽  
Author(s):  
J. W. Watson ◽  
B. D. Anderson ◽  
R. Madey
Keyword(s):  
Cross Sections ◽  
Differential Cross ◽  
Giant Resonance ◽  
Impulse Approximation ◽  
Differential Cross Sections ◽  
Analyzing Powers ◽  
Dipole Resonance ◽  
Spin Flip ◽  
Distorted Wave Impulse Approximation ◽  
Gamow Teller

We measured differential cross sections, analyzing powers, and the polarization-transfer coefficient [Formula: see text] for 135 MeV (p,n) reactions on 40Ca and 48Ca. The observed shapes for the analyzing-power angular distributions are in good overall agreement with distorted-wave-impulse-approximation calculations, and are more sensitive to nuclear structure than to whether or not spin transfer is involved. Measured spin-flip probabilities for [Formula: see text] combined with a multipole analysis of differential cross sections reveal that at 0°, the apparent continuum under and adjacent to the Gamow–Teller giant resonance is also primarily 1+ strength. A comparison of [Formula: see text] and [Formula: see text] shows no discernable signature of Gamow–Teller strength in the region –30 < Q(MeV) < –45. Utilizing information from high-resolution cross-section measurements and spin-flip probabilities, we decompose the spin-dipole resonance of 40Sc into its 0−, 1−, and 2− components.

Analyzing powers for theC12(p→,p′)C12reaction at 120 MeV and a test of the distorted-wave impulse approximation

1981 ◽  
Vol 24 (5) ◽  
pp. 1834-1843 ◽  
Author(s):  
J. R. Comfort ◽  
G. L. Moake ◽  
C. C. Foster ◽  
P. Schwandt ◽  
C. D. Goodman ◽  
...  
Keyword(s):  
Impulse Approximation ◽  
Distorted Wave ◽  
Analyzing Powers ◽  
Distorted Wave Impulse Approximation

scholarly journals The 12C(p,2p)11B Reaction at 100 MeV

1979 ◽  
Vol 32 (4) ◽  
pp. 323 ◽  
Author(s):  
DW Devins ◽  
DL Friesel ◽  
WP Jones ◽  
AC Attard ◽  
ID Svalbe ◽  
...  
Keyword(s):  
Ground State ◽  
Impulse Approximation ◽  
Intermediate Step ◽  
Distorted Wave ◽  
Giant Resonances ◽  
Angular Correlations ◽  
Spectroscopic Factors ◽  
Distorted Wave Impulse Approximation ◽  
Reaction Processes ◽  
Multistep Reaction

The 12C(p,2p)l1B reaction has been measured at 100 MeV in both symmetric and asymmetric geometries. Distorted wave impulse approximation calculations were used to obtain spectroscopic factors for all states of l1B below 7 MeV excitation. From these spectroscopic factors and the shapes of the measured angular correlations, it is concluded that (i) no large 1f components are present in the wavefunction of the ground state of 12C and (ii) this experiment gives no evidence for the formation of giant resonances as the intermediate step in multistep reaction processes to the 4�44 MeV (5/2-) and 6�74 MeV (7/2-) states of 11B.

Photoproduction of positive pions from 16O at medium energies

1980 ◽  
Vol 58 (8) ◽  
pp. 1151-1162 ◽  
Author(s):  
V. Devanathan ◽  
V. Girija ◽  
G. N. Sivarama Prasad
Keyword(s):  
Experimental Data ◽  
Nuclear Structure ◽  
Cross Sections ◽  
Impulse Approximation ◽  
Wave Functions ◽  
Fair Agreement ◽  
Free Nucleon ◽  
Distorted Wave ◽  
Distorted Wave Impulse Approximation ◽  
Γ Ray

The reaction 16O(γ,π+)16N has been studied in the distorted wave impulse approximation (DWIA) using the free-nucleon photopion amplitude. The nuclear distortion effects on the emitted pion and also the effect of nuclear structure are investigated in detail. The effect of nuclear distortion is found to be small at lower energies but is of great importance resulting in large absorption of pions around the (3,3) resonance. Using realistic nuclear wave functions, it is found that the DWIA yields cross sections in fair agreement with the experimental data at γ-ray energies above 230 MeV but higher values at lower energies.

CONTRIBUTION OF THE PARITY DEPENDENT POTENTIAL IN HEAVY ION TRANSFER REACTIONS

1994 ◽  
Vol 03 (01) ◽  
pp. 219-238 ◽  
Author(s):  
AHMED OSMAN ◽  
A.A. FARRA
Keyword(s):  
Cross Sections ◽  
Bound State ◽  
Heavy Ion ◽  
Transfer Reactions ◽  
Ion Transfer ◽  
Ion Interactions ◽  
Spectroscopic Factors ◽  
Dependent Potential ◽  
Good Agreement ◽  
Dependent Interaction

The theory of heavy ion reactions with particle transfer is considered in the framework of the exact finite-range distorted wave Born approximation (EFR-DWBA). Modified Woods-Saxon potentials which include a parity dependent interaction and an angular momentum absorptive term have been used as the ion-ion interactions in the initial and final channels. The bound state interactions are represented by nucleus-nucleus inter-actions which include repulsive and attractive Yukawa type components. The present numerical calculations of the differential cross-sections are in good agreement with the experimental measurements. The distorting parity dependent potentials are found very important in reproducing the cross-sections at backward as well as at intermediate angles. The obtained extracted values of the spectroscopic factors are reasonable.

Multipole decomposition of Gamow–Teller strength

1987 ◽  
Vol 65 (6) ◽  
pp. 660-665 ◽  
Author(s):  
Murray A. Moinester
Keyword(s):  
Charge Exchange ◽  
Cross Sections ◽  
Present Report ◽  
Random Phase ◽  
Impulse Approximation ◽  
General Importance ◽  
Least Squares Fit ◽  
Distorted Wave Impulse Approximation ◽  
One Step ◽  
Gamow Teller

Doubly differential continuum cross sections from the 90Zr(p, n)90Nb reaction have been analyzed via a multipoledecomposition technique. No quasi-free charge-exchange background has been subtracted, following the assumption that the observed cross sections are primarily due to one-step charge-exchange leading to 1p–1h states of all multipolarities to all excitations. The theoretical shapes of the differential cross sections for each Jπ multipole have been taken from random-phase approximation (RPA)–distorted-wave impulse approximation (DWIA) calculations. The experimental dσ/dΩ, for each 1 MeV excitation-energy bin have been decomposed into different multipole components by a least squares fit. This RPA-based analysis should determine the Jπ = 1+ cross sections with different, and also fewer, assumptions than usual for describing the underlying background. It can be of general importance in determining the extent of possible quenching of Gamow–Teller (GT) strength. The present decomposition accounts for all the theoretically predicted GT strength. The purpose of the present report is to illustrate an analysis based on RPA–DWIA shapes rather than to present final-decomposition results.

scholarly journals ASSOCIATED HYPERON–KAON PRODUCTION VIA NEUTRINO–NUCLEUS SCATTERING

2011 ◽  
Vol 20 (12) ◽  
pp. 2475-2503 ◽  
Author(s):  
G. B. ADERA ◽  
B. I. S. VAN DER VENTEL
Keyword(s):  
Cross Sections ◽  
Mean Field ◽  
Impulse Approximation ◽  
Born Term ◽  
Bound State ◽  
Kaon Production ◽  
Plane Wave Impulse Approximation ◽  
Relativistic Mean Field ◽  
Associated Production ◽  
Nuclear Effects

We present the investigation of the neutrino-induced strangeness associated production on nuclei in the relativistic plane wave impulse approximation (RPWIA) framework at the intermediate neutrino energies. In this study, the elementary hadronic weak amplitudes are embedded inside the nuclear medium for the description of the exclusive channels of neutrino–nucleus interactions. These amplitudes are extracted using a model-dependent evaluation of the hadronic vertex using the Born term approximation in which the application of the Cabibbo V–A theory and SU(3) symmetry are assumed to be valid. The nuclear effects are included via the bound state wave functions of the nucleon obtained from the relativistic mean field (RMF) models. Two kinematics settings are used to examine various distributions of the differential cross-section in the rest frame of the target nuclei. The numerical results are obtained for the neutrino-induced charged-current (CC) K +Λ-production on bound neutrons in 1s1/2 and 1p3/2 orbitals of 12 C . The angular distributions are forward peaked under both kinematic settings, whereas under the quasifree setting, the cross-sections tend to mimic the missing momentum distribution of the bound nucleon inside the nucleus.

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