scholarly journals Analysis of a Single-Λ Hypernuclear Event in KEK-PS E373 Nuclear Emulsion Experiment

2019 ◽  
Vol 206 ◽  
pp. 09003
Author(s):  
Myo Thandar Aung ◽  
Thida Wint ◽  
Khin Swe Myint ◽  
Kazuma Nakazawa
Keyword(s):  
Nuclear Emulsion ◽  
Alpha Decay ◽  
Energy Relation ◽  
Nucleon Interaction ◽  
Decay Modes ◽  
Mesonic Decay ◽  
Decay Products ◽  
Thorium Series ◽  
Events Data ◽  
Mass Reconstruction

The purpose of this research is to identify a single-Λ hypernucleus and its decay products which support to get more information about hyperon-nucleon interaction. Before performing the analysis of a single-Λ hypernucleus, first, we have deduced the density of emulsion by calibrating the range-energy relation using alpha decay events data from thorium series. It is very important for the mass reconstruction of hypernucleus events in nuclear emulsion. And we have reconstructed a single-Λ hypernucleus event by using the kinematical reconstruction for mesonic and non-mesonic decay modes. From the result of our analysis, we can uniquely identify that single-Λ hypernucleus is $ {}_\Lambda ^9 B $ and decay products are 4He,3He, proton and neutron.

Competition between decay modes of superheavy nuclei 281−310Og

2020 ◽  
Vol 29 (10) ◽  
pp. 2050087
Author(s):  
N. Sowmya ◽  
H. C. Manjunatha ◽  
P. S. Damodara Gupta
Keyword(s):  
Spontaneous Fission ◽  
Potential Model ◽  
Superheavy Element ◽  
Alpha Decay ◽  
Cluster Decay ◽  
Superheavy Nuclei ◽  
Temperature Dependent ◽  
Proximity Potential ◽  
Decay Modes

In this work, we have made an attempt to study the cluster-decay half-lives and alpha-decay half-lives of the superheavy nuclei [Formula: see text]Og by considering the temperature-dependent (TD) and also temperature-independent (TID) proximity potential model. The evaluated half-lives were compared with that of the experiments. To predict the decay modes, we have compared the cluster-decay half-lives and alpha-decay half-lives with that of spontaneous fission half-lives. This work also predicts the decay chains of the superheavy nuclei [Formula: see text]Og and finds an importance in the synthesis of further isotopes of superheavy element Oganesson.

Recent experiments with nuclear emulsions

1964 ◽  
Vol 278 (1374) ◽  
pp. 350-369 ◽  
Keyword(s):  
Spatial Resolution ◽  
Nuclear Emulsion ◽  
High Energy Physics ◽  
High Spatial Resolution ◽  
Bubble Chamber ◽  
High Energy ◽  
Emulsion Technique ◽  
Decay Modes ◽  
Automatic Methods ◽  
The Many

It is unnecessary to stress the many significant contributions made during the past 20 years to nuclear and high-energy physics by means of the nuclear emulsion technique. One needs only to recall the new particles and decay modes that have been first observed with it. With the development of other powerful techniques, however, such as the spark-chamber and bubble-chamber, readily adaptable to automatic methods of analysis and data handling, nuclear emulsion has inevitably tended to fall into the position of a supplementary method. Nevertheless, there are still important experiments for which it is the most convenient, indeed in some cases the only, technique available, and this paper will discuss such experiments, either recently carried out or proposed for the future, using beams of particles from high-energy accelerators. Nuclear emulsion possesses one most significant advantage over all other tech­niques, namely, the extraordinarily high spatial resolution of which it is capable. Other techniques can resolve events separated by tenths of millimetres. Nuclear emulsion can resolve events separated by tenths of micrometres. This high spatial resolution has made possible the measurement of the lifetime of the π 0 -meson (ca.10 -16 s) and is the basis of our confidence that there are no other commonly occurring unstable particles with lifetimes in the range 10 -11 to 10 -16 s. Most of the experiments described in this paper are particularly suited to the nuclear emulsion technique because they make use of this characteristic feature.

The alpha-decay chains and decay mode predictions of the nuclei Z = 118, 119 and 120

2020 ◽  
Vol 29 (07) ◽  
pp. 2050053
Author(s):  
F. Koyuncu ◽  
A. Soylu
Keyword(s):  
Decay Mode ◽  
Half Life ◽  
Spontaneous Fission ◽  
Theoretical Models ◽  
Alpha Decay ◽  
Quantization Condition ◽  
Experimental Investigations ◽  
Universal Curve ◽  
Wkb Method ◽  
Decay Modes

The alpha decay (AD) chains of the nuclei having [Formula: see text], 119 and 120 have been investigated in terms of different theoretical models. Decay mode results that are presented in this study have been probed over the possible isotopes of the aforementioned nuclei. In the decay mode predictions, the formula of Bao et al. and the formula proposed by Soylu have been used to calculate the spontaneous fission (SF) half-lives. The AD half-lives have been computed by using the Denisov and Khuedenko, Royer, Horoi, the universal decay law (UDL), the Viola–Seaborg–Sobiczewski (VSS), the universal curve (UNIV) formulas and Wentzel–Kramers–Brillouin (WKB) approximation with Bohr–Sommerfeld quantization condition for the nuclei that have the measured experimental half-lives. Therefore, the rms values of the results of the related expressions and WKB method have been determined, in this way, AD half-life calculations of the [Formula: see text], 119 and 120 nuclei have been performed. According to the obtained results, SF half-life values for Bao et al. and Soylu are quite different from one approach to another, the predictions on decay modes of the [Formula: see text], 119 and 120 nuclei show differences. The decay modes produced by using different models used in this study would be important for the predictions of the future experimental investigations.

EXPERIMENTAL STUDIES OF ANTIKAON MEDIATED BOUND NUCLEAR SYSTEMS

2007 ◽  
Vol 16 (03) ◽  
pp. 905-918 ◽  
Author(s):  
PAUL KIENLE
Keyword(s):  
Phase Transitions ◽  
Experimental Studies ◽  
Dense Matter ◽  
Nucleon Interaction ◽  
Decay Modes ◽  
Density Distributions ◽  
Nuclear Systems ◽  
Nuclear Clusters ◽  
Experimental Approaches ◽  
Cold Dense Matter

Recent experimental studies of the synthesis and properties of deeply bound antikaon mediated nuclear systems are reviewed. Following a brief introduction in the basic properties of the antikaon–nucleon interaction which may lead to cold and dense antikaonic nuclear systems, we review the results of very first experiments which give indications of the existence of such exotic clusters of matter. Then ongoing efforts to substantiate the early findings are presented and future experimental approaches which will allow a very detailed study of the decay modes, the sizes and density distributions of these kaonic nuclear clusters are discussed including their relevance for possible phase transitions in cold dense matter.

Systematic study of alpha-decay of super-heavy isotopes with Z = 120–126

2021 ◽  
pp. 2150033
Author(s):  
S. A. Seyyedi
Keyword(s):  
Spontaneous Fission ◽  
Alpha Decay ◽  
Nucleon Nucleon ◽  
Decay Modes ◽  
Nucleon Nucleon Interaction ◽  
Fragmentation Potential ◽  
Double Folding ◽  
Semi Empirical ◽  
Empirical Approaches ◽  
Good Agreement

Alpha-decay half-lives of the even–even superheavy isotopes with proton numbers [Formula: see text] have been calculated within the cluster model. The alpha-daughter potential was constructed by employing the density-dependent double-folding model with a realistic nucleon–nucleon interaction whose exchange part has a finite range approximation. The half-lives were calculated using Wentzel–Kramers–Brillouin (WKB) approximation with the alpha preformation factor. The results have shown that the computed alpha-decay half-lives were in good agreement with their counterpart calculated by different semi-empirical approaches. The obtained results have also shown a negative linear relationship between the logarithm of the preformation factor and the fragmentation potential for the understudy isotopes. Also, the calculated results have shown that isotopes [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] had longer half-lives than their adjacent isotopes, which indicates that the corresponding neutron or proton numbers have a magical or semi-magical properties. Furthermore, we have studied the competition between alpha-decay and spontaneous fission to predict possible decay modes from the even–even isotopes [Formula: see text]. The results revealed that the isotopes [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] had alpha-decay as a predominant mode of decay and the nuclei [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] could not survive from the spontaneous fission. We hope that the theoretical prediction could be helpful for future investigation in this field.

SUPER-ASYMMETRIC COLD FISSION AND EXOTIC CLUSTER-DECAY

1994 ◽  
Vol 03 (01) ◽  
pp. 195-218 ◽  
Author(s):  
SATISH KUMAR ◽  
RAJ K. GUPTA ◽  
WERNER SCHEID
Keyword(s):  
Experimental Data ◽  
Mass Region ◽  
Cluster Decay ◽  
Model Calculations ◽  
Decay Modes ◽  
Cluster Radioactivity ◽  
Decay Products ◽  
Text Fragment ◽  
Mechanical Fragmentation ◽  
Cold Fission

Cold fission of radioactive nuclei is studied in the super-asymmetric mass region of exotic cluster radioactivity, using the quantum-mechanical fragmentation theory (QMFT) based saddle-point fission (SPF) model for calculating the decay half-life times. The calculations show that cold fission also prefers light fragments like 24–26Ne, 28,30Mg, 32,34,36Si, 37P 38S, 46Ar and 48,50Ca, some of which are observed in exotic cluster radioactivity. The predictions of the SPF model calculations are compared with the available exotic cluster-decay experimental data and the calculations based on the preformed-cluster model (PCM). The SPF model calculations show large disagreements with both the PCM and cluster-decay experimental data. For clusters of mass A2<46, the predicted half-lives for the SPF model are much smaller than for the PCM, which apparently means predicting the cold fission as a more probable process than the cluster-decay. The cold fission predicts some new decay modes which are far more probable (smaller log10 T1/2-values) as cold fission fragments than as cluster-decay products. For heavier clusters (A2≥46), the two models (SPF and PCM) make nearly identical predictions, which means predicting an overlap of two processes (cold fission and cluster-decay) for A2>46. Also, cold fission is found to be more probable than hot fission and a new fission mode (known as bimodel fission) is identified in the neighbourhood of the doubly magic [Formula: see text] fragment. Our calculations are made for 234U, 238Pu, 241Am and 252Cf.

(γ, p + α) REACTIONS PRODUCED IN PHOTOGRAPHIC EMULSIONS

1956 ◽  
Vol 34 (2) ◽  
pp. 216-222 ◽  
Author(s):  
D. L. Livesey
Keyword(s):  
Cross Section ◽  
Nuclear Emulsion ◽  
Maximum Energy ◽  
Energy Relation ◽  
Lithium Ions ◽  
Sharp Drop ◽  
Electron Synchrotron ◽  
Most Probable Mode ◽  
Integrated Cross Section ◽  
Photographic Emulsions

Ilford C.2 plates were exposed to bremsstrahlung of maximum energy 70 Mev. from the electron synchrotron at Queen's University, and 82 stars produced in the emulsion have been attributed to the reaction:[Formula: see text]The excitation function of the reaction shows a sharp drop near 40 Mev. and the integrated cross-section up to this limit has been estimated. In addition 23 stars have been identified as being due to the reaction:[Formula: see text]In both reactions the most probable mode of disintegration is by the initial emission of an alpha-particle. The range measurements in the carbon stars have been used to derive an accurate range–energy relation for lithium ions in nuclear emulsion.

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