scholarly journals Important Influence of Entrance Channel Reorientation Coupling on Proton Stripping

2020 ◽  
Vol 56 (10) ◽  
Author(s):  
N. Keeley ◽  
K. W. Kemper ◽  
K. Rusek
Keyword(s):  
Ground State ◽  
Born Approximation ◽  
Angular Distributions ◽  
Radioactive Beams ◽  
Weakly Bound ◽  
Deformed Nuclei ◽  
Transfer Path ◽  
Coupled Channels ◽  
Spectroscopic Factors ◽  
Transfer Channels

AbstractWhile it is well established that the ground state reorientation coupling can have a significant influence on the elastic scattering of deformed nuclei, the effect of such couplings on transfer channels has been much less well investigated. In this letter we demonstrate that the $$^{208}\hbox {Pb}(^7\hbox {Li},^6\hbox {He})^{209}\hbox {Bi}$$ 208 Pb ( 7 Li , 6 He ) 209 Bi proton stripping reaction at an incident energy of 52 MeV can be well described by the inclusion of the $$^7\hbox {Li}$$ 7 Li ground state reorientation coupling within the coupled channels Born approximation formalism. Full finite-range distorted wave Born approximation calculations were previously found to be unable to describe these data. Addition of coupling to the 0.478-MeV $$1/2^-$$ 1 / 2 - excited state of $$^7\hbox {Li}$$ 7 Li , together with the associated two-step transfer path, has little or no influence on the shape of the angular distributions (except that for stripping leading to the 1.61-MeV $$13/2^+$$ 13 / 2 + level of $$^{209}\hbox {Bi}$$ 209 Bi which is significantly improved) but does affect appreciably the values of the $$^{209}\mathrm {Bi} \rightarrow {^{208}\mathrm {Pb}} + p$$ 209 Bi → 208 Pb + p spectroscopic factors. Implications for experiments with weakly-bound light radioactive beams are discussed.

scholarly journals Excitation of the Ground-State Rotational Band in 28Si by Inelastic Scattering of 25.25 MeV Polarized Protons

1973 ◽  
Vol 51 (12) ◽  
pp. 1293-1299 ◽  
Author(s):  
R. de Swiniarski ◽  
H. E. Conzett ◽  
C. R. Lamontagne ◽  
B. Frois ◽  
R. J. Slobodrian
Keyword(s):  
Inelastic Scattering ◽  
Cross Sections ◽  
Ground State ◽  
Optical Potential ◽  
Great Sensitivity ◽  
Angular Distributions ◽  
Rotational Model ◽  
Coupled Channels ◽  
Polarized Protons ◽  
State Band

Angular distributions of the analyzing power and cross sections have been measured for the elastic and inelastic scattering of 25.25 MeV protons exciting the K = 0+ ground-state band in 28Si. Good agreement with experiment is obtained in the coupled-channels formalism on the basis of the rotational model with a quadrupole deformation β2 = −0.40 (oblate) and a hexadecapole deformation β4 = +0.15. The calculations show the great sensitivity of the experimental results to both the magnitude and sign of the quadrupole and hexadecapole deformations. Equivalent fits of the data were obtained either by keeping the deformation length of the various deformed terms of the optical potential constant (δ0 = β0R0 = βIRI = βLSRLS) or by increasing the deformation of the spin–orbit optical potential relative to the central potential by a factor of 1.5 (βLS = 1.5βcent).

Réaction (3He, α) : validité du modèle optique dans la description de la voie 3He-noyau

1985 ◽  
Vol 63 (7) ◽  
pp. 951-953 ◽  
Author(s):  
L. Potvin ◽  
R. Roy ◽  
P. Bricault ◽  
R. Larue ◽  
C. Rioux ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Ground State ◽  
Born Approximation ◽  
Incident Energy ◽  
Transfer Reaction ◽  
The Other ◽  
Angular Distributions ◽  
State Transitions ◽  
The Real ◽  
Alpha Channel

The transfer reaction (3He, α) on 17O, 29Si and 53Cr nuclei has been studied at 14-MeV incident energy. Complete angular distributions were measured for ground-state transitions and described in the framework of the distorded-wave Born approximation. Parameters have been defined from analysis of the corresponding elastic scattering channels, but avoiding pronounced variations in their values from one nucleus to the other. In addition, the sum of the real depths V for 3He scattering and for the transferred neutron was taken approximately equal to that term in the alpha channel to validate the Born approximation.

Resonance recombination of spin-polarized atomic hydrogen at low temperatures

1988 ◽  
Vol 66 (5) ◽  
pp. 405-413 ◽  
Author(s):  
M. W. Reynolds ◽  
W. N. Hardy
Keyword(s):  
Cross Section ◽  
Dissociation Energy ◽  
Born Approximation ◽  
Atomic Hydrogen ◽  
Proton Exchange ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Weakly Bound ◽  
Coupled Channels ◽  
Spin Polarized

In sufficiently large magnetic fields, the weakly bound levels of H2 acquire finite lifetimes owing to hyperfine predissociation and become manifest as scattering resonances in spin-polarized atomic hydrogen (H↓). In this work we investigate in detail the contribution to the reaction kinetics in H↓ due to the resonance, denoted [Formula: see text], arising from the predissociation of the (v,J) = (14,4) level of H2. To characterize the formation and disintegration of [Formula: see text], we calculate the predissociation as a function of both the applied magnetic field and the dissociation energy, D, of the level. Recombination occurs when [Formula: see text] is stabilized in collisions that cause transitions to lower molecular levels. For low H↓, densities, collisions with atoms of the saturated 4He vapour dominate; we calculate the cross section in the distorted wave Born approximation and also use a coupled-channels approach. At higher densities, stabilization occurs in collisions with H↓ as well; the effect of proton exchange between the atom and the molecule is derived. Previous experiments, analyzed neglecting proton exchange, are reanalyzed including this; the dissociation energy D is not as well determined by the data as was previously thought. Prospects for future experiments are discussed.

A PANORAMA OF CDCC CALCULATIONS FOR DEUTERON INDUCED REACTIONS: FROM ELASTIC CROSS SECTIONS TO INELASTIC AND TRANSFER ONES

2011 ◽  
Vol 20 (04) ◽  
pp. 953-957 ◽  
Author(s):  
P. HUU-TAI CHAU
Keyword(s):  
Experimental Data ◽  
Cross Sections ◽  
Deformed Nuclei ◽  
Coupled Channels ◽  
The Continuum

An overview of calculations performed within the Continuum Discretized Coupled Channels (CDCC) approach for deuteron induced reactions is given. We briefly present an extension of the CDCC formalism which accounts for the target excitations allowing us to determine ( d , d ') cross sections off deformed nuclei. We compare some calculated inelastic cross sections with experimental data. Then it is shown that the CDCC formalism can also be a useful tool to determine ( d , p ) cross sections. This point is illustrated with 54 Cr ( d , p )55 Cr reactions.

Analysing powers and differential cross sections of (3He,p) reactions on 6Li and 7Li at low energy

1995 ◽  
Vol 73 (1-2) ◽  
pp. 74-84 ◽  
Author(s):  
D. Baddou ◽  
C. Rioux ◽  
R. J. Slobodrian ◽  
J. M. Nelson
Keyword(s):  
Cross Sections ◽  
Differential Cross ◽  
Born Approximation ◽  
Low Energy ◽  
Angular Distributions ◽  
Differential Cross Sections ◽  
Distorted Wave ◽  
Distorted Wave Born Approximation ◽  
Nucleon Transfer ◽  
Cluster Transfer

Angular distributions of the differential cross sections and analysing powers were measured at an energy of 4.6 MeV. The results are compared with the distorted wave Born approximation predictions for two-nucleon transfer and for a deuteron-cluster transfer. The agreement is qualitative at best, and a discussion of alternatives to improve it is presented.

Stabilization and rovibronic spectra of the T-shaped and linear ground-state conformers of a weakly bound rare-gas–homonuclear dihalogen complex: He⋯Br2

2005 ◽  
Vol 123 (10) ◽  
pp. 104312 ◽  
Author(s):  
David S. Boucher ◽  
David B. Strasfeld ◽  
Richard A. Loomis ◽  
John M. Herbert ◽  
Sara E. Ray ◽  
...  
Keyword(s):  
Ground State ◽  
Rare Gas ◽  
Weakly Bound ◽  
Rovibronic Spectra

scholarly journals Study of sub-barrier fusion of 36S+50Ti,51V systems

2019 ◽  
Vol 223 ◽  
pp. 01013
Author(s):  
Giulia Colucci ◽  
Giovanna Montagnoli ◽  
Alberto M. Stefanini ◽  
Kouichi Hagino ◽  
Antonio Caciolli ◽  
...  
Keyword(s):  
Experimental Data ◽  
Comparative Study ◽  
Excitation Function ◽  
Ground State ◽  
Weak Coupling ◽  
Coupling Scheme ◽  
Excitation Functions ◽  
Coupled Channels ◽  
Barrier Distribution ◽  
Good Agreement

A detailed comparative study of the sub-barrier fusion of the two near-by systems 36S+50Ti,51V was performed at the National Laboratories of Legnaro (INFN). Aim of the experiment was the investigation of possible effects of the non-zero spin of the ground state of the 51V nucleus on the sub-barrier excitation function, and in particular on the shape of the barrier distribution. The results sh w that the two measured excitation functions are very similar down to the level of 20 - 30 μb. The same is observed for the two barrier distributions. Coupled-channels calculations have been performed and are in good agreement with the experimental data. This result indicates that the low-lying levels in 51V can be interpreted in the weak-coupling scheme, that is, 51V(I) = 50Ti(2+)⊗ p(1 f7/2).

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