Isolated mixed-symmetry 2+ state of the radioactive neutron-rich nuclide Te132

The <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mi>M</a:mi><a:mn>1</a:mn></a:mrow></a:math> transition strengths between excited <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:msup><b:mn>2</b:mn><b:mo>+</b:mo></b:msup></b:math> states of the neutron-rich, radioactive nuclide <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mmultiscripts><c:mi>Te</c:mi><c:mprescripts/><c:none/><c:mn>132</c:mn></c:mmultiscripts></c:math> was studied through direct lifetime measurements using the Doppler-shift attenuation method in a two-neutron transfer reaction on a <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"><d:mmultiscripts><d:mi>Te</d:mi><d:mprescripts/><d:none/><d:mn>130</d:mn></d:mmultiscripts></d:math> target. An unambiguous identification of the lowest-lying mixed-symmetry <e:math xmlns:e="http://www.w3.org/1998/Math/MathML"><e:msup><e:mn>2</e:mn><e:mo>+</e:mo></e:msup></e:math> state was achieved on the basis of the large <f:math xmlns:f="http://www.w3.org/1998/Math/MathML"><f:mrow><f:mi>B</f:mi><f:mrow><f:mo>(</f:mo><f:mi>M</f:mi><f:mn>1</f:mn><f:mo>;</f:mo><f:msubsup><f:mn>2</f:mn><f:mn>2</f:mn><f:mo>+</f:mo></f:msubsup><f:mspace width="0.16em"/><f:mo>→</f:mo><f:mspace width="0.16em"/><f:msubsup><f:mn>2</f:mn><f:mn>1</f:mn><f:mo>+</f:mo></f:msubsup><f:mo>)</f:mo></f:mrow><f:mo>=</f:mo><f:mn>0.18</f:mn><f:mrow><f:mo>(</f:mo><f:mn>2</f:mn><f:mo>)</f:mo></f:mrow><f:mspace width="0.16em"/><f:msubsup><f:mi>μ</f:mi><f:mrow><f:mi mathvariant="normal">N</f:mi></f:mrow><f:mn>2</f:mn></f:msubsup></f:mrow></f:math> transition strength. Results are compared to the shell model, and the analysis of both data and calculations unambiguously identifies the second-excited <k:math xmlns:k="http://www.w3.org/1998/Math/MathML"><k:msup><k:mn>2</k:mn><k:mo>+</k:mo></k:msup></k:math> state of <l:math xmlns:l="http://www.w3.org/1998/Math/MathML"><l:mmultiscripts><l:mi>Te</l:mi><l:mprescripts/><l:none/><l:mn>132</l:mn></l:mmultiscripts></l:math> as the one-quadrupole phonon mixed-symmetry state of this isotope. A lowering of the energy and <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"><m:mrow><m:mi>B</m:mi><m:mo>(</m:mo><m:mi>M</m:mi><m:mn>1</m:mn><m:mo>;</m:mo><m:msubsup><m:mn>2</m:mn><m:mi>ms</m:mi><m:mo>+</m:mo></m:msubsup><m:mo>→</m:mo><m:msubsup><m:mn>2</m:mn><m:mn>1</m:mn><m:mo>+</m:mo></m:msubsup><m:mo>)</m:mo></m:mrow></m:math> strength within the <n:math xmlns:n="http://www.w3.org/1998/Math/MathML"><n:mi>N</n:mi><n:mo>=</n:mo><n:mn>80</n:mn></n:math> isotones toward the <o:math xmlns:o="http://www.w3.org/1998/Math/MathML"><o:mi>Z</o:mi><o:mo>=</o:mo><o:mn>50</o:mn></o:math> shell closure is observed, which occurs along with the lowering of the <p:math xmlns:p="http://www.w3.org/1998/Math/MathML"><p:mrow><p:mi>E</p:mi><p:mn>2</p:mn></p:mrow></p:math> collectivity approaching the magic proton shell.