Enhanced Quadrupole and Octupole Strength in Doubly Magic ^{132}Sn.

Area of Science:

• Nuclear Physics
• Atomic Physics

Background:

• The doubly magic nucleus ^{132}Sn is a key subject for nuclear structure studies.
• Understanding its properties provides insights into nuclear shell structure and forces.

Purpose of the Study:

• To populate and study the first 2^{+} and 3^{-} states in ^{132}Sn.
• To determine reduced transition strengths and verify the double magicity of ^{132}Sn.

Main Methods:

• Utilized safe Coulomb excitation with ^{132}Sn ions at 5.49 MeV/nucleon.
• Employed the HIE-ISOLDE accelerator and the MINIBALL array for gamma-ray detection.
• Measured deexciting gamma rays in coincidence with scattered particles.

Main Results:

• Determined reduced transition strengths for 0_{g.s.}^{+}→2_{1}^{+}, 0_{g.s.}^{+}→3_{1}^{-}, and 2_{1}^{+}→3_{1}^{-} transitions in ^{132}Sn.
• Observed enhanced B(E2;0_{g.s.}^{+}→2_{1}^{+}) strength, consistent with theoretical predictions.
• Provided crucial data on cross-shell configurations.

Conclusions:

• The experimental results align with large-scale shell-model and other theoretical calculations.
• This study offers the first direct experimental verification of the sphericity and double magicity of ^{132}Sn.