Relativistic Energy States of the A-Particle in Hypernuclei Using Gaussian Potentials

1990 ◽  
Vol 45 (1) ◽  
pp. 14-16
Author(s):  
C. G. Koutroulos

Abstract The Dirac equation with scalar potential and fourth component of vector potential of the Gaussian form is solved numerically for potential parameters obtained by a least squares fitting of the ground state binding energies of the A in a number of hypernuclei. The binding energies in the ground and excited states for various hypernuclei are determined. The spacings between the various levels are also given

1989 ◽  
Vol 44 (12) ◽  
pp. 1234-1238 ◽  
Author(s):  
C. G. Koutroulos

Abstract The relativistic Dirac equation with a scalar potential and the fourth component of a vector potential of the Woods-Saxon shape is solved numerically for potential parameters obtained by a last squares fitting procedure of the ground state binding energies of the Λ in a number of hypernuclei and its binding energies in the ground and excited states (as well as the relevant spacings) for various hypcrnuclei are determined. The results are in very good agreement with the preliminary experimental ones given by Chrien on the basis of the (π+, K+) reaction on nuclei.


2010 ◽  
Vol 25 (33) ◽  
pp. 2849-2857 ◽  
Author(s):  
GUO-HUA SUN ◽  
SHI-HAI DONG

In this work we solve the Dirac equation by constructing the exact bound state solutions for a mixing of scalar and vector spherically asymmetrical singular oscillators. This is done provided that the vector potential is equal to the scalar potential. The spinor wave functions and bound state energy levels are presented. The case V(r) = -S(r) is also considered.


2006 ◽  
Vol 21 (07) ◽  
pp. 581-592 ◽  
Author(s):  
A. D. ALHAIDARI

We introduce coupling to three-vector potential in the (3+1)-dimensional Dirac equation. The potential is noncentral (angular-dependent) such that the Dirac equation separates completely in spherical coordinates. The relativistic energy spectrum and spinor wave functions are obtained for the case where the radial component of the vector potential is proportional to 1/r. The coupling presented in this work is a generalization of the one which was introduced by Moshinsky and Szczepaniak for the Dirac-oscillator problem.


2020 ◽  
Vol 5 ◽  
pp. 125
Author(s):  
G. J. Papadopoulos ◽  
C. G. Koutroulos ◽  
M. E. Grypeos

The root mean square radii of the Λ-particle orbits in hypemuclei are calculated semi-analytically for every bound state, using the Dirac equation with a scalar potential Us{r) and the fourth component of a vector potential Uv{f) in the case of rectangular shapes of these potentials with the same radius R.ln addition an analytic expression of the expectation value of the corresponding potential energy operator is derived. For the above quantities, expressions of the energy eigenvalues in terms of the potential parameters are needed and approximate formulae may be used, in certain cases. The variation of these quantities with the mass number is also investigated and numerical calculations are performed.


2007 ◽  
Vol 22 (18) ◽  
pp. 3123-3130
Author(s):  
V. V. BONDARCHUK ◽  
I. M. SHVAB ◽  
A. V. KATERNOGA

The ground state wave function and the energy term of a relativistic electron moving in the field of two fixed centers, when interaction of this particle with centers is described by two Coulomb and two Coulomb-like scalar potentials are calculated analytically by the LCAO method. Dependence of electron binding energy from value of scalar coupling constant was investigated using obtained analytic results.


2020 ◽  
Vol 4 ◽  
pp. 41
Author(s):  
M. E. Grypeos ◽  
C. G. Koutroulos ◽  
G. J. Papadopoulos

The Dirac equation with scalar potential Us(r) and fourth component of vector po­ tential Uv(r) is considered in the case of the rectangular shapes of these potentials with the same radius R and approximate analytic expressions are derived for the single-particle energy of bound states in certain cases. The results obtained with these expressions are compared with the corresponding "exact" results obtained by solving the eigenvalue equa­ tion numerically.It is found that very good results are obtained for the ground state and for quite a wide range of values of R with one of the proposed expressions. Even the corresponding non-relativistic version of this expession, has not been derived before, to our knowledge.


2016 ◽  
Vol 31 (23) ◽  
pp. 1650132 ◽  
Author(s):  
K. Saeedi ◽  
S. Zarrinkamar ◽  
H. Hassanabadi

We study the motion of relativistic fermions in a time-dependent electromagnetic field within the framework of Dirac equation. We consider the time-dependent scalar potential of the exponential form and the vector potential of linear form. We obtain the eigenfunctions and eigenvalues.


1993 ◽  
Vol 48 (11) ◽  
pp. 1102-1106 ◽  
Author(s):  
H. Hartwig ◽  
H. Dreizler

Abstract The rotational spectrum of 2,2-dimethylthiirane (isobutylene sulfide) has been assigned for the ground and torsionally excited states. The rotational and centrifugal distortion constants, as well as the potential parameters V3 and V´1 2 are determined. The ground state spectra of the 13C and 34S isotopomers were assigned in natural abundance and heavy atom structure parameters are given.


2019 ◽  
Vol 3 ◽  
pp. 20
Author(s):  
C. G. Koutroulos ◽  
G. J. Papadopoulos

The root mean square radii of the Λ-particle orbits in hypernuclei are calculated in the ground and first excited states using the Dirac equation with scalar and vector potentials of orthogonal shape. An exact analytic and also approximate expressions are derived for the root mean square ra-' dius of the Λ orbit in its ground state. It is shown that <r >  2 1/2 1/3 ' varies linearly with A ' for the higer mass hypers 1/2 ^ nuclei, Our results in the ground state are compared with the results of Rayet and also with those of Daskaloyannis et. al.


2019 ◽  
Author(s):  
Matthew M. Brister ◽  
Carlos Crespo-Hernández

<p></p><p> Damage to RNA from ultraviolet radiation induce chemical modifications to the nucleobases. Unraveling the excited states involved in these reactions is essential, but investigations aimed at understanding the electronic-energy relaxation pathways of the RNA nucleotide uridine 5’-monophosphate (UMP) have not received enough attention. In this Letter, the excited-state dynamics of UMP is investigated in aqueous solution. Excitation at 267 nm results in a trifurcation event that leads to the simultaneous population of the vibrationally-excited ground state, a longlived <sup>1</sup>n<sub>O</sub>π* state, and a receiver triplet state within 200 fs. The receiver state internally convert to the long-lived <sup>3</sup>ππ* state in an ultrafast time scale. The results elucidate the electronic relaxation pathways and clarify earlier transient absorption experiments performed for uracil derivatives in solution. This mechanistic information is important because long-lived nπ* and ππ* excited states of both singlet and triplet multiplicities are thought to lead to the formation of harmful photoproducts.</p><p></p>


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