Quadrupole Moment of 37K

TL;DR

This paper reports the measurement of the electric quadrupole moment of 37K using nuclear quadrupole resonance, revealing a larger value than shell-model predictions and exploring possible reasons for this discrepancy.

Contribution

First measurement of 37K's quadrupole moment using NQR, providing new data to test nuclear shell-model predictions.

Findings

Measured |Q(37K)| = 10.6 ± 0.4 efm²

Result larger than shell-model predictions

Explored effective charge variations to explain discrepancy

Abstract

The electric quadrupole coupling constant of the ground state of 37K(3/2+, 1.22 s) in a tetragonal KH2PO4 single crystal was measured to be |eqQ/h| = 2.99 +- 0.07 MHz using the beta-ray detecting nuclear quadrupole resonance technique. The electric quadrupole moment of 37K was determined to be |Q(37K)| = 10.6 +- 0.4 efm2, where the known electric quadrupole coupling constant of stable 39K in the KH2PO4 crystal was used as a reference. The present experimental result is larger than that predicted by shell-model calculations in the sd or the sd and fp model spaces. A possible variation of effective charges was explored to explain the discrepancy.