Systematical study of beta delayed proton emission energies

Graphs are given of the maximum proton energies in delayed proton emitters. This quantity, equal to the difference of the electron capture decay energy of the precursor and the separation energy of a proton in the daughter, has been calculated in a least squares adjustment of mass spectroscopic data and nuclear decay and reaction energies. The graphs would lead to expect a 950 keV lower maximum proton energy in⁷³Kr(?p)⁷²Se than has been reported from experiments. They can be used to predict new cases for further studies on this subject.     

Unnatural parity levels populated in the 16O(6Li,d)20Ne reaction

The ¹⁶O(⁶Li, d)²⁰Ne reaction to the 2^?, 4.97 MeV, 3^?, 5.63 MeV, and 4^?, 7.01 MeV members of the K^π = 2^? band has been studied. Angular distributions were measured at 32 MeV from 7.5° to 145° (lab). Excitation functions were measured at 15° (lab) and 145° (lab) from 31 to 33 MeV and 31.75 to 32.5 MeV, respectively. Results of multi-step and compound nuclear calculations are compared to the data. At this incident energy, both mechanisms appear to contribute to the population of the unnatural parity levels.     

Search for36Cl in Stripa site groundwaters

Zeitschrift für Physik A Hadrons and nuclei - Four groundwater samples from the Stripa site have been analysed by accelerator mass spectrometry at the University of Rochester. The36Cl...     

Experimental and theoretical results for 21Ne(6Li,d)25Mg

Alpha-particle spectroscopic strengths extracted from ²¹Ne(⁶Li, d) angular distributions agree in both magnitude and multipolarity with predicted strengths. Secondly, strengths calculated using eigenfunctions determined in large shell-model computations are remarkably consistent with pure SU₃ symmetry limit results.     

Alpha-particle strengths from the 16O(6Li,d)20Ne reaction

The ¹⁶O(⁶Li, d)²⁰Ne reaction has been studied at bombarding energies of 20, 32 and 38 MeV. The α-particle spectroscopic strengths have been extracted for levels up to 12.15 MeV in excitation. Nondirect processes appear to contribute significantly to all levels at 20 MeV and to high spin levels (6⁺ and 8⁺) at 32 MeV. Strengths extracted for members of the ground state band assuming (sd)⁴ transfer are unequal at both 32 and 38 MeV, in marked contrast to theoretical predictions. To explain this, particle-hole correlations in ¹⁶O(g.s.), inelastic channel coupling in the reaction and perhaps other effects as well, have to be considered. Strengths extracted for members of excited bands and α-decay reduced widths compare poorly with each other and with simple SU(3) predictions.     

Some Numerical Implications of the Hardy and Littlewood Analysis of the 3-Primes Problem

We explore some of the numerical implications of the famous 1922 paper Some Problems of Partitio Numerorum III: On the Expression of a Number as a Sum of Primes of Hardy and Littlewood. In particular, we prove that if the Generalized Riemann Hypothesis holds, then Hardy and Littlewood's analysis yields that every odd number greater than 1.24 × 10⁵⁰ is a sum of three primes.     

Enveloping semigroups and mappings onto the two-shift

Enveloping semigroups of topological actions of semigroups on compact spaces are studied. For zero dimensional spaces, and under modest conditions on , the enveloping semigroup is shown to be the Stone-\v{C}ech compactification if and only if some Cartesian product has the two-shift as a factor. Examples are discussed showing that, unlike in the measure theory case, positive entropy does not imply the existence of such a factor even if the Cartesian product has large entropy.

     

Isospin impurity of 64Ga ground state

It is well known that the observation of a nonzero Fermi matrix element for a β-transition between states that differ in isospin can provide information about the relative isospin purity of the states involved. We have determined the log ft value for the 0⁺ → 0⁺ (ΔT ≠ 0) β-transition in ${}^{64}\text{Ga}\text{→}{}^{64}\text{Zn}$ decay as 6.516 ± 0.020. From this log ft value, we have deduced |M_F| = (43.4 ± 1.1) × 10^?3, |α| = (21.7 ± 0.6) × 10^?3 and |〈V_CD〉| = 41.7 ± 1.1 keV, where M_F,α² and 〈V_CD〉 represent the Fermi matrix element, isospin impurity and Coulomb matrix element, respectively. The Coulomb matrix element of 41.7 keV found for ⁶⁴Ga is one of the largest known from β-decay experiments. The experimental procedure involved a careful measurement of the intensity of the annihilation radiation relative to that of the other γ-rays from ⁶⁴Ga decay. As a by-product, we have obtained an improved ⁶⁴Ga decay scheme. We have also summarized the existing information on the isospin impurities of nuclear states as deduced from β-decay experiments.     

The 16O(6Li,dγ)20Ne reaction

The discrepancy between observed reaction streghts and those predicted from SU(3) considerations in the ¹⁶O(⁶Li, d) reaction has been studied. The effects of both ¹⁶O ground state correlations and of inelastic couplings on the reaction strengths are included. Particle-gamma angular correlations are presented as a test of the reaction predictions. It is found that inclusion of both the ground state correlations and the inelastic coupling does help to resolve the theoretical- experimental discrepancy, and results in generally improved representations of both cross section and angular correlation data.