S. Triambak

The He-3 + He-4 ---> Be-7 astrophysical S-factor

We present precision measurements of the 3He + 4He --> 7Be reaction in the range ECM = 0.33 to 1.23 MeV using a small gas cell and detection of both prompt gamma rays and 7Be activity. Our prompt and activity measurements are in good agreement within an experimental uncertainty of several percent. We find S(0) = 0.595 +/- 0.018 keV b from fits of the Kajino theory to our data. We compare our results with published measurements, and we discuss the consequences for Big Bang Nucleosynthesis and for solar neutrino flux calculations.

Electron-capture branch of {sup 100}Tc and tests of nuclear wave functions for double-{beta} decays.

We present a measurement of the electron-capture branch of {sup 100}Tc. Our value, B(EC) = (2.6 {+-} 0.4) x 10{sup -5}, implies that the {sup 100}Mo neutrino absorption cross section to the ground state of {sup 100}Tc is roughly 50% larger than previously thought. Disagreement between the experimental value and QRPA calculations relevant to double-{beta} decay matrix elements persists. We find agreement with previous measurements of the 539.5- and 590.8-keV {gamma}-ray intensities.

The 3He + 4He --> 7Be Astrophysical S-factor

We present precision measurements of the 3He + 4He --> 7Be reaction in the range ECM = 0.33 to 1.23 MeV using a small gas cell and detection of both prompt gamma rays and 7Be activity. Our prompt and activity measurements are in good agreement within an experimental uncertainty of several percent. We find S(0) = 0.595 +/- 0.018 keV b from fits of the Kajino theory to our data. We compare our results with published measurements, and we discuss the consequences for Big Bang Nucleosynthesis and for solar neutrino flux calculations.

ft value of the 0{sup +}{yields}0{sup +} {beta}{sup +} decay of {sup 32}Ar: A measurement of isospin symmetry breaking in a superallowed decay

We determined the absolute branch of the T=2 superallowed decay of {sup 32}Ar by detecting the {beta}{sup +}-delayed protons and {gamma} decays of the daughter state. We obtain b{sub SA}{sup {beta}}=(22.71{+-}0.16)%, which represents the first determination of a proton branch to better than 1%. Using this branch along with the previously determined {sup 32}Ar half-life and energy release, we determined ft=(1552{+-}12) s for the superallowed decay. This ft value, together with the corrected Ft value extracted from previously known T=1 superallowed decays, yields a measurement of the isospin symmetry breaking correction in {sup 32}Ar decay {delta}{sub C}{sup exp}=(2.1{+-}0.8)%. This can be compared to a theoretical calculation {delta}{sub C}=(2.0{+-}0.4)%. As by-products of this work, we determined the {gamma} and proton branches for the decay of the lowest T=2 state of {sup 32}Cl, made a precise determination of the total proton branch and relative intensities of proton groups that leave {sup 31}S in its first excited state and deduced an improved value for the {sup 32}Cl mass.

{sup 3}He+{sup 4}He {yields} {sup 7}Be astrophysical S factor

We present precision measurements of the {sup 3}He+{sup 4}He {yields} {sup 7}Be reaction in the range E{sub c.m.}=0.33 to 1.23 MeV using a small gas cell and detection of both prompt {gamma} rays and {sup 7}Be activity. Our prompt and activity measurements are in good agreement within the experimental uncertainty of several percent. We find S(0)=0.595{+-}0.018 keV b from fits of the Kajino theory to our data. We compare our results with published measurements, and we discuss the consequences for Big Bang Nucleosynthesis and for solar neutrino flux calculations.

He3+He4→Be7astrophysicalSfactor

We present precision measurements of the 3He + 4He --> 7Be reaction in the range ECM = 0.33 to 1.23 MeV using a small gas cell and detection of both prompt gamma rays and 7Be activity. Our prompt and activity measurements are in good agreement within an experimental uncertainty of several percent. We find S(0) = 0.595 +/- 0.018 keV b from fits of the Kajino theory to our data. We compare our results with published measurements, and we discuss the consequences for Big Bang Nucleosynthesis and for solar neutrino flux calculations.

Mass of the lowest T = 2 state of 32S

We determined the mass of the lowest T = 2 state in 32S with unprecedented accuracy and precision (ΔM/M ≈ 10−5). The state was produced via the 31P(p,γ) reaction and the energies of the de‐excitation γ rays measured with high accuracy. This, together, with a recent measurement of the mass of 32Ar provides a stringent test of the Isobaric Multiplet Mass Equation (IMME) for the A = 32 multiplet. A significant violation of the IMME is observed.