A generalized empirical formula for half-lives of alpha-decay fine structure

2019 ◽  
Vol 28 (08) ◽  
pp. 1950067
Author(s):  
I. Sreeja ◽  
M. Balasubramaniam
Keyword(s):  
Experimental Data ◽  
Fine Structure ◽  
Ground State ◽  
Empirical Formula ◽  
Daughter Nucleus ◽  
Alpha Decay ◽  
Parent Nucleus ◽  
State Formula ◽  
Model Independent ◽  
Proton Radioactivity

A model-independent and [Formula: see text]-dependent four parameter formula has been recently proposed for the studies of one proton and two proton radioactivity. The same form of the formula with different parameter sets worked well for 1p and 2p emission indicating the fact that the similar phenomenological law is able to successfully reproduce both 1p as well as 2p emission half-lives suggesting the identical descriptions of these phenomena. Retaining the same form of the formula, its applicability is studied in this work for calculating the ground state as well as excited state [Formula: see text] emission. For this study, we consider 22 odd–odd nuclei, 31 odd–even nuclei, 52 even–odd nuclei, 88 even–even nuclei with the parent nucleus charge numbers in the range of [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text], respectively. For each of these subsets the emission of [Formula: see text] with different angular momentum values are considered. The general formula with four different parameter sets is proposed and the obtained results are compared with the experimental data. The study reveals that the general form of the proposed empirical formula is suitable for calculating the half-lives of 1p, 2p and [Formula: see text]-emission with different [Formula: see text]-values. With very minimal input like [Formula: see text]-values, and charge number of the daughter nucleus, this formula can be used as a handy tool for a systematic study as well as to plan new experiments.

SPECTRUM AND STRUCTURE OF THE FREE HNCN RADICAL

1963 ◽  
Vol 41 (2) ◽  
pp. 286-298 ◽  
Author(s):  
G. Herzberg ◽  
P. A. Warsop
Keyword(s):  
Fine Structure ◽  
Ground State ◽  
Electronic Transition ◽  
Flash Photolysis ◽  
Geometrical Structure ◽  
Transition Moment ◽  
Lower State ◽  
State Formula ◽  
Exact Position

A widely spaced perpendicular band at 3440 Å observed in the flash photolysis of diazomethane is ascribed to the free HNCN radical. The study of the fine structure of this band for HNCN, DNCN, and HNC13N has yielded information about the geometrical structure of the molecule in both the upper and lower (ground) state. For the lower state[Formula: see text]The N—C—N group is very nearly linear, but the exact position of the C atom on this line could not be determined. The electronic transition is of the type 2A′–2A″, the transition moment being perpendicular to the plane of the molecule.

ALPHA-DECAYS TO MEMBERS OF GROUND-STATE ROTATIONAL BAND OF HEAVY EVEN-EVEN NUCLEI

2008 ◽  
Vol 17 (supp01) ◽  
pp. 29-36 ◽  
Author(s):  
CHANG XU ◽  
ZHONGZHOU REN
Keyword(s):  
Experimental Data ◽  
Angular Momentum ◽  
Rotational Band ◽  
Ground State ◽  
Daughter Nucleus ◽  
Branching Ratios ◽  
Decay Energy ◽  
Α Decay ◽  
Barrier Penetration ◽  
Excitation Probability

We apply a simple barrier penetration approach to calculate α-decay branching ratios to members of ground-state rotational band of heavy even-even nuclei. The influence of α-decay energy, the angular momentum of α-particle, and the excitation probability of the daughter nucleus is taken into account in our calculations. The theoretical branching ratios of α-transitions are found to agree with the available experimental data well.

scholarly journals Pseudo-Riemannian universe from Euclidean bulk

2018 ◽  
Vol 33 (17) ◽  
pp. 1850104
Author(s):  
Milovan Vasilić
Keyword(s):  
Ground State ◽  
Conservation Equation ◽  
Action Functional ◽  
Physical Measurements ◽  
Effective Metric ◽  
Bulk Stress ◽  
State Formula ◽  
Klein Gordon ◽  
Minkowski Signature ◽  
Model Independent

I develop the idea that our world is a brane-like object embedded in Euclidean bulk. In its ground state, the brane constituent matter is assumed to be homogeneous and isotropic, and of negligible influence on the bulk geometry. The analysis of this paper is model independent, in the sense that action functional of bulk fields is not specified. Instead, the behavior of the brane is derived from the universally valid conservation equation of the bulk stress tensor. The present work studies the behavior of a 3-sphere in the five-dimensional Euclidean bulk. The sphere is made of bulk matter characterized by the equation of state [Formula: see text]. It is shown that stability of brane vibrations requires [Formula: see text]. Then, the stable brane perturbations obey Klein–Gordon-like equation with an effective metric of Minkowski signature. The argument is given that it is this effective metric that is detected in physical measurements. The corresponding effective Universe is analyzed for all the values of [Formula: see text]. In particular, the effective metric is shown to be a solution of Einstein’s equations coupled to an effective perfect fluid. As an illustration, one simple choice of the brane constituent matter is studied in detail.

New empirical formula for α-decay calculations

2018 ◽  
Vol 27 (08) ◽  
pp. 1850068 ◽  
Author(s):  
Dashty T. Akrawy ◽  
Ali H. Ahmed
Keyword(s):  
Experimental Data ◽  
Angular Momentum ◽  
Orbital Angular Momentum ◽  
Ground State ◽  
Empirical Formula ◽  
State Transitions ◽  
Α Decay ◽  
O Isotopes

A set of empirical formulae have been proposed to calculate the [Formula: see text]-decay half-lives from ground state to ground state transitions of 356 nuclei classified to different set of e–e, e–o, o–e and o–o isotopes. Within these formulae, modification of the previous set of Royer expressions were done by introducing three different physical terms, including the orbital angular momentum and isobaric asymmetry factors. The predicted [Formula: see text]-decay half-lives compared with those adopted by former proposed models for the depended experimental data, and significant improvements were noticed for all the studied sets of isotopes.

Fine structure in the photoneutron spectra from praseodymium-141 and lead

1970 ◽  
Vol 48 (8) ◽  
pp. 950-953 ◽  
Author(s):  
K. G. McNeill ◽  
J. W. Jury ◽  
J. S. Hewitt
Keyword(s):  
Fine Structure ◽  
Excited State ◽  
Energy Spectrum ◽  
Cross Section ◽  
Ground State ◽  
Giant Dipole Resonance ◽  
Daughter Nucleus ◽  
State Transitions ◽  
Dipole Resonance ◽  
Section Curve

Careful measurements of the energy spectrum of photoneutrons ejected from praseodymium and from natural lead show that there are peaks on top of the expected smooth spectrum. Comparison with the recent cross-section studies, which indicate structure on the giant dipole resonance for these nuclei, shows agreement between the energies of the peaks found in the present work and the energies En = E−Qi where E corresponds to a peak in the cross-section curve and Qi is the threshold for producing a given state in the daughter nucleus. Only ground state transitions (for Pr) or ground state and the first two excited state transitions (for Pb) need be invoked.

Partial alpha-decay half-life of 178Hfm2 isomer

2021 ◽  
pp. 2150036
Author(s):  
O. A. P. Tavares ◽  
E. L. Medeiros ◽  
M. L. Terranova
Keyword(s):  
Ground State ◽  
Half Life ◽  
Alpha Decay ◽  
Parent Nucleus ◽  
Calculation Model ◽  
Quantum Mechanical ◽  
Ground State Band ◽  
Tunneling Mechanism ◽  
State Band ◽  
Semi Empirical

A simple, semi-empirical, one-parameter calculation model based on the quantum mechanical tunneling mechanism through a potential barrier has been used to estimate the partial [Formula: see text]-decay half-life, [Formula: see text], of [Formula: see text] isomer. Alpha-transitions to levels of the ground-state band [Formula: see text] of [Formula: see text] have been considered, and the contributions to [Formula: see text] due to overlapping, Coulomb, and centrifugal barriers have been detailed in each case. Results have indicated a [Formula: see text]-value of [Formula: see text] and a predominance [Formula: see text] of [Formula: see text]-particles populating the level [Formula: see text], compatible with results by other authors. Besides, a single, universal-like formula to estimate half-life of alpha transitions, whatever [Formula: see text]-value and the characteristics of the parent nucleus (e-e, e-o, o-e and o-o nuclei, whether in the ground or isomeric states), has been envisaged.

HALF-LIVES WITH YUKAWA PROXIMITY POTENTIAL FOR ALPHA-DECAY PROCESS

2012 ◽  
Vol 21 (11) ◽  
pp. 1250094 ◽  
Author(s):  
E. JAVADIMANESH ◽  
H. HASSANABADI ◽  
A. A. RAJABI ◽  
H. RAHIMOV ◽  
S. ZARRINKAMAR
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Potential Model ◽  
Alpha Decay ◽  
Decay Process ◽  
Proximity Potential ◽  
Good Agreement

We intend to study the alpha-decay half-lives of some nuclei from ground state to ground state. We consider a potential model with Yukawa proximity potential. We see that the results are in good agreement with the experimental data.

PROPERTIES OF ALPHA DECAY TO ROTATIONAL BANDS OF HEAVY NUCLEI

2010 ◽  
Vol 19 (10) ◽  
pp. 1961-1971 ◽  
Author(s):  
Y. Z. WANG ◽  
J. Z. GU ◽  
J. M. DONG ◽  
B. B. PENG
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Liquid Drop ◽  
Alpha Decay ◽  
Branching Ratios ◽  
Heavy Nuclei ◽  
Liquid Drop Model ◽  
Α Decay ◽  
Rotational Bands ◽  
Good Agreement

In the framework of the generalized liquid drop model (GLDM) and improved Royer's formula, we investigate the branching ratios and half-lives of α-decay to the members of the ground-state rotational bands of heavy even–even Fm and No isotopes. The calculated results are in good agreement with the available experimental data and some useful predictions are provided for future experiments.

scholarly journals Rotational Ground-State Bands of ¹⁶⁸Hf Nucleus

2021 ◽  
Vol 3 (5) ◽  
pp. 34-36
Author(s):  
I. Hossain ◽  
Hewa Y. Abdullah ◽  
M. A. Saeed ◽  
M. O. Alzanbaqi ◽  
Fadhil I. Sharrad
Keyword(s):  
Experimental Data ◽  
Ground State ◽  
Empirical Formula ◽  
Remarkable Degree ◽  
Experimental Values ◽  
Semi Empirical

This paper has been explained to study the rotational arrangement of even-even 168Hf isotope using the phenomenological fitting, Sood’s semi-empirical formula. The rotational energies from the calculated values were compared to the experimental data. The result shows that in 168Hf, calculated energies fit the experimental values to a remarkable degree of accuracy.

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