A calculation of the production of pions by 450-MeV protons on nuclei

1968 ◽  
Vol 46 (9) ◽  
pp. 1141-1144 ◽  
Author(s):  
D. McMillin ◽  
P. Bhargava ◽  
L. Lam ◽  
E. W. Vogt
Keyword(s):  
Density Distribution ◽  
Momentum Distribution ◽  
Nucleon Nucleon ◽  
Density Dependent ◽  
Pion Absorption ◽  
Pion Energy ◽  
Nuclear Effects ◽  
Mev Protons

Starting with assumed pion yields in nucleon–nucleon collisions, we consider the influence of the various nuclear effects on the pion yields from the bombardment of various nuclei with 450-MeV protons. In addition to the proton and pion absorption within the nucleus considered by earlier workers, we also include the effects of the momentum distribution and the density distribution of the struck nucleons. The pion absorption, which is density-dependent, is found to dominate the relative yields in various nuclei at these proton energies, using modern densities. We obtain agreement with the measured relative yields as illustrated with the results for pion angle of 21.5° and pion energy of 83 MeV.

ACCURACY OF THE MULTIPOLE EXPANSION OF DENSITY DISTRIBUTION IN THE PRESENCE OF OCTUPOLE DEFORMATION

2011 ◽  
Vol 20 (12) ◽  
pp. 2407-2415
Author(s):  
M. ISMAIL ◽  
M. M. BOTROS ◽  
A. A. WHEIDA
Keyword(s):  
Density Distribution ◽  
Coulomb Barrier ◽  
Orientation Angle ◽  
Multipole Expansion ◽  
Heavy Ion ◽  
Nucleon Nucleon ◽  
Large Error ◽  
Octupole Deformation ◽  
Zero Range ◽  
Density Expansion

The accuracy of multipole expansion of density distribution for deformed nuclei is tested. The interaction potential for a deformed-spherical pair of nuclei was calculated using the folding model derived from zero-range nucleon–nucleon (NN) interaction. We considered two spherical projectiles Ca 40 and Pb 208 scattered on U 238 deformed target nucleus. The error in the heavy ion (HI) potential resulting from using a truncated multipole density expansion is evaluated for each case in the presence of octupole deformation δ3 besides quadrupole δ2. We are interested in the value of error for R ≥ RT (touching distance). We found that for values of |δ3|≤0.1 the error at R = RT reaches reasonable values when six terms expansion is used. For |δ3| = 0.2, we calculated the Coulomb barrier parameters using realistic NN force and found that the large error present in six terms for zero range force decreases strongly to less than 1% when the zero range is added to finite range forces and Coulomb interaction to form the Coulomb barrier. It is noted that the negative value of octupole deformation parameters δ3 = -0.1 produce error at orientation angle θ equal in value to that produced at angle (180°-θ) for the positive values δ3 = 0.1. We also found that the error decreases as the mass number of the projectile nucleus increases.

DENSITY-DEPENDENT CLUSTER MODEL OF α DECAY

2005 ◽  
Vol 19 (15n17) ◽  
pp. 2365-2368 ◽  
Author(s):  
CHANG XU ◽  
ZHONGZHOU REN
Keyword(s):  
Nuclear Physics ◽  
Cluster Model ◽  
Daughter Nucleus ◽  
Nucleon Nucleon ◽  
Nucleon Interaction ◽  
Α Decay ◽  
Density Dependent ◽  
Density Distributions ◽  
Nucleon Nucleon Interaction ◽  
Double Folding

A new cluster model of α decay is proposed where the effective potential between α-cluster and daughter nucleus is obtained from the double folding integral of the renormalized M3Y nucleon-nucleon interaction and of the density distributions of α particle and daughter nucleus. Without introducing any extra adjustment on the potential, the new model (named as the density-dependent cluster model) can successfully reproduce the experimental half-lives of α decay within a factor of 3. The model also works well for new superheavy elements which are the current interests of nuclear physics and chemistry.

scholarly journals Effects of density-dependent scenarios of in-medium nucleon-nucleon interactions in heavy-ion collisions

2020 ◽  
Vol 102 (2) ◽  
Author(s):  
Gao-Feng Wei ◽  
Chang Xu ◽  
Wei Xie ◽  
Qi-Jun Zhi ◽  
Shi-Guo Chen ◽  
...  
Keyword(s):  
Heavy Ion Collisions ◽  
Heavy Ion ◽  
Nucleon Nucleon ◽  
Density Dependent ◽  
Ion Collisions ◽  
Nucleon Interactions ◽  
Effects Of Density

scholarly journals Density-dependent nucleon-nucleon interaction from Urbana UIX three-nucleon force

2011 ◽  
Vol 336 ◽  
pp. 012016 ◽  
Author(s):  
Alessandro Lovato ◽  
Omar Benhar ◽  
Stefano Fantoni ◽  
Alexey Yu Illarionov ◽  
Kevin E Schmidt
Keyword(s):  
Nucleon Nucleon ◽  
Nucleon Interaction ◽  
Nucleon Force ◽  
Density Dependent ◽  
Nucleon Nucleon Interaction

Semimicroscopic Optical Potential with Effective Density-Dependent Nucleon-Nucleon Interaction

1998 ◽  
Vol 07 (04) ◽  
pp. 465-483 ◽  
Author(s):  
S. M. Kravchenko ◽  
V. I. Kuprikov ◽  
A. P. Soznik
Keyword(s):  
Optical Potential ◽  
Particle Density ◽  
Nucleon Nucleon ◽  
Effective Density ◽  
Potential Influence ◽  
Density Dependent ◽  
Nucleus Scattering ◽  
Scattering Phase ◽  
Scattering Phase Shifts ◽  
Nucleon Nucleon Interaction

An expression for the optical potential is obtained in the nuclear matter approximation while taking into account the rearrangement potential for the generalized two-particle density-dependent Skyrme forces. The rearrangement potential influence on the nucleon-nucleus scattering is investigated. It is shown that two- and three-particle Skyrme forces are not equivalent in calculating the imaginary part of the optical potential. The intensity of the optical potential (both its real and imaginary parts) appears to be decreased considerably when the rearrangement potential is taken into account. As a result the dependence of scattering phase shifts on the incident nucleons energy is changed markedly.

Study of event mixing for Bose–Einstein correlations in reactions with ππ X final states around 1 GeV

2017 ◽  
Vol 32 (23) ◽  
pp. 1750118
Author(s):  
Q. H. He
Keyword(s):  
Correlation Function ◽  
Momentum Distribution ◽  
Final States ◽  
Relative Momentum ◽  
Final State ◽  
Numerical Tests ◽  
Pion Energy ◽  
Simulation Results ◽  
Bose Einstein ◽  
Good Agreement

We present a new event mixing cut condition, named energy sum (ES) cut, aiming to investigate two-pion Bose–Einstein correlations (BEC) in reaction with only two identical pions among three final state particles. Unlike the previous proposed pion energy cut, which rejects original events with either pion’s energy beyond a given level, this cut does not eliminate any original events and hence improves the statistics of both original events and mixed events. It selects mixed events in terms of a weight proportional to the two-pion energy sum distribution of original events. Numerical tests using the [Formula: see text] events are carried out to verify the validity of the energy sum cut. Simulation results show this cut is able to reproduce the relative momentum distribution of the original events in the absence of BEC effects. Its ability to observe BEC effects and to extract correct BEC parameters is verified using event sample in the presence of BEC effects. It is found that the BEC effects can be obviously observed as an enhancement in the correlation function and the BEC parameters extracted by this event mixing cut are in good agreement with input values.

Alpha decay and spontaneous fission in superheavy isotopes, Z = 124, using a density-dependent cluster model

2020 ◽  
pp. 2050096
Author(s):  
S. A. Seyyedi
Keyword(s):  
Empirical Formula ◽  
Half Life ◽  
Cluster Model ◽  
Spontaneous Fission ◽  
Alpha Decay ◽  
Nucleon Nucleon ◽  
Empirical Formulas ◽  
Density Dependent ◽  
Double Folding ◽  
Semi Empirical

Alpha decay (AD) and spontaneous fission (SF) half-lives of superheavy nuclei [Formula: see text] have been studied within the density-dependent cluster model. The alpha-nucleus potentials were calculated using the double-folding model with the realistic M3Y nucleon–nucleon interaction. To calculate nuclear half-lives, several semi-empirical formulas were used in addition to the Wentzel–Kramers–Brillouin (WKB) approximation. The calculated AD half-lives agree well with the values computed by the analytical formulas of Royer, the semi-empirical formula of Poenaru et al. and the Viola–Seaborg systematic. To identify the mode of decay of these nuclei, the SF half-lives were calculated using the semi-empirical formula given by Xu et al. The results show that among the isotopes studied, isotopes [Formula: see text] can be survived from the SF and have a half-life greater than [Formula: see text][Formula: see text](s). The study predicts [Formula: see text] chains from isotopes [Formula: see text], [Formula: see text] chains from isotopes [Formula: see text], [Formula: see text] chains from isotopes [Formula: see text] and an AD from [Formula: see text]. These isotopes have a half-life long enough to be synthesized in the laboratory. Also, in the decay chains of these isotopes, it is observed that the nuclei [Formula: see text] have higher half-lives than their neighbors. The neutron numbers corresponding to these isotopes are [Formula: see text] indicating the magical or semi-magical behavior of these numbers, which is in good agreement with the research results.

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