scholarly journals Role of consistent parameter sets in an assessment of the α -particle optical potential below the Coulomb barrier

2019 ◽  
Vol 99 (4) ◽  
Author(s):  
V. Avrigeanu ◽  
M. Avrigeanu
Keyword(s):  
Coulomb Barrier ◽  
Optical Potential ◽  
Consistent Parameter

Estimating a model of sportfishing trip expenditures using a quasi-maximum likelihood approach

2016 ◽  
Vol 23 (2) ◽  
pp. 448-459 ◽  
Author(s):  
Richard T. Melstrom
Keyword(s):  
Maximum Likelihood ◽  
Exponential Model ◽  
Parameter Estimates ◽  
Maximum Likelihood Approach ◽  
Likelihood Approach ◽  
Quasi Maximum Likelihood ◽  
Species Preferences ◽  
The Impact ◽  
Consistent Parameter

This article presents an exponential model of tourist expenditures estimated by a quasi-maximum likelihood (QML) technique. The advantage of this approach is that, unlike conventional OLS and Tobit estimators, it produces consistent parameter estimates under conditions of a corner solution at zero and heteroscedasticity. An application to sportfishing evaluates the role of socioeconomic demographics and species preferences on trip spending. The bias from an inappropriate estimator is illustrated by comparing the results from QML and OLS estimation, which shows that OLS significantly overstates the impact of trip duration on trip expenditures compared with the QML estimator. Both sets of estimates imply that trout and bass anglers spend significantly more on their fishing trips compared with other anglers.

The role of off-shell scattering in the pion optical potential

1974 ◽  
Vol 231 (3) ◽  
pp. 445-454 ◽  
Author(s):  
R.H. Landau ◽  
F. Tabakin
Keyword(s):  
Optical Potential

RADIAL SENSITIVITY OF THE ELASTIC SCATTERING AROUND THE COULOMB BARRIER ENERGIES FOR WEAKLY-BOUND AND HALO NUCLEI

2012 ◽  
Vol 27 (21) ◽  
pp. 1250118
Author(s):  
Y. SERT ◽  
T. CANER ◽  
O. BAYRAK ◽  
I. BOZTOSUN
Keyword(s):  
Elastic Scattering ◽  
Cross Section ◽  
Coulomb Barrier ◽  
Optical Potential ◽  
Theoretical Calculations ◽  
Fusion Cross Section ◽  
Halo Nuclei ◽  
Weakly Bound ◽  
Medium Mass ◽  
Good Agreement

The radial sensitivity of the elastic scattering of the weakly-bound 6 Li and halo 6 He nuclei on medium-mass 64 Zn target and heavy target 208 Pb is examined around the Coulomb barrier energies. We present that very good agreement between theoretical and experimental results have been obtained with small χ2/N values. The fusion cross-section and volume integrals of the potentials have been deduced from the theoretical calculations for all studied systems at relevant energies. We have also analyzed the elastic scattering of the 6 He +208 Pb system at E lab = 14, 16, 18, 22, 27 MeV in order to investigate whether there is a dispersion relation between the real and imaginary parts of the optical potential.

Role of second-order optical potential in pion-oxygen scattering

1979 ◽  
Vol 19 (1) ◽  
pp. 129-134 ◽  
Author(s):  
L. C. Liu ◽  
C. M. Shakin
Keyword(s):  
Optical Potential ◽  
Second Order

THE ROLE OF ANTIKAON CONDENSATES IN THE ISOSPIN ASYMMETRY OF NEUTRON STARS

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1553-1556
Author(s):  
A. MESQUITA ◽  
M. RAZEIRA ◽  
C. A. Z. VASCONCELLOS ◽  
F. FERNÁNDEZ
Keyword(s):  
Phase Transition ◽  
Optical Potential ◽  
Mean Field ◽  
Field Approximation ◽  
Mixed Phase ◽  
Hadronic Matter ◽  
Mean Field Approximation ◽  
Isospin Asymmetry ◽  
Nucleon Matter

We study the effects of the scalar-isovector light mesons on the isospin asymmetry and phase transition of hadronic matter to hadronic matter with a condensate of antikaons, using an effective model with derivative couplings. In our formalism, nucleons interact through the exchange of σ, ω, ϱ, δ, and ς mesons in the presence of electrons and muons to accomplish electric charge neutrality and beta equilibrium. The phase transition to the antikaons condensate was implemented through the Gibbs conditions combined with the mean-field approximation, giving rise to a mixed phase of coexistence between nucleon matter and the condensed antikaons. As expected, our results indicate that the scalar-isovector mesons increase the range of the mixed phase–space, they operate for restoring isospin symmetry and they reduce the value of the effective nucleon mass, independently of the depth of the optical potential for antikaons. Also as expected the increase of the depth of optical potential favors the population of antikaons. Our results predict the density threshold of birth of the K-antikaons. The most expressive result of our calculation is the abrupt change in the isospin asymmetry due to the presence of the condensate. Moreover, we have found that scalar-isovector mesons increase the fraction of protons and reduced the fraction of neutrons in the system, since these mesons couple with the conserved isovector current of baryons and thus the minimum in the energy of the system corresponds to saturated isospin states (symmetric in isospin). Finally, we have found as expected that these mesons produce the stiffness of the EoS.

scholarly journals Role of breakup processes in fusion enhancement of drip-line nuclei at energies below the Coulomb barrier

2000 ◽  
Vol 61 (3) ◽  
Author(s):  
K. Hagino ◽  
A. Vitturi ◽  
C. H. Dasso ◽  
S. M. Lenzi
Keyword(s):  
Coulomb Barrier ◽  
Drip Line

scholarly journals The [sup 6]He Optical Potential at energies around the Coulomb barrier

2010 ◽  
Author(s):  
J. P. Fernández-García ◽  
M. Rodríguez-Gallardo ◽  
M. A. G. Alvarez ◽  
A. M. Moro ◽  
J. A. Caballero ◽  
...  
Keyword(s):  
Coulomb Barrier ◽  
Optical Potential
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