$\alpha$ cluster states in $^{44, 46, 52}$Ti

TL;DR

This study investigates alpha decaying states in titanium isotopes using specific nuclear reactions, discovering new alpha cluster states in $^{44}$Ti and $^{46}$Ti, and assigning their spin-parities, thus advancing understanding of nuclear clustering phenomena.

Contribution

The paper reports the first observation and spin-parity assignment of alpha cluster states in $^{44}$Ti and $^{46}$Ti using angular correlation measurements, highlighting differences in alpha clustering among isotopes.

Findings

New alpha cluster states identified in $^{44}$Ti and $^{46}$Ti.

A $J^ ext{pi}=7^-$ state found at 11.95 MeV in $^{44}$Ti.

No alpha cluster states detected in $^{48}$Ca.

Abstract

$\alpha$ decaying states of $^{44, 46, 52}$Ti were investigated with angular correlation functions between $t$ and $\alpha$ with the $^{40, 42, 48}$Ca($^7$Li, $t\alpha$)$^{40, 42, 48}$Ca reactions at E = 26.0 MeV. Many $\alpha$ cluster states were newly observed in the 10 - 15 MeV excitation energy of $^{44}$Ti and their spin-parities were assigned, in which $J^\pi=7^-$ state was found at 11.95 MeV as a candidate for the member of the $K=0_1^-$ negative parity band. In $^{46}$Ti many $\alpha$ cluster states were also found in the 11 - 17 MeV excitation energy with the $^{42}$Ca($^7$Li, $t\alpha$)$^{42}$Ca reaction, though its strength is weak compared to $^{44}$Ti. No $\alpha$ cluster states were detected for the $^{48}$Ca($^7$Li, $t\alpha$)$^{48}$Ca reaction, in which the number of coincidence events decaying from $^{48}$Ca was very small.