Lifetime measurements of the first 2+ states in Te116,118

The lifetimes of the first 2⁺ states in 116,118Te were measured by means of the recoil distance Doppler-shift technique with the CIAE-plunger coupled to a HPGe array via ¹⁰⁷Ag(¹²C,3n) and ¹¹⁰Pd(¹²C,p3n) reactions, respectively. The spectra are analyzed using the differential decay curve method. An improved precision for the lifetime of the 2₁⁺ state in ¹¹⁸Te was obtained, τ(2₁⁺)=8.2(5) ps, as well as a first measurement of the 2₁⁺ state in ¹¹⁶Te, τ(2₁⁺)=5.1(3) ps. The lifetime values complete the systematic data near midshell and contribute to the understanding of how quadrupole collectivity evolves in this mass region. The resulting B(E2,0₁⁺→2₁⁺) transitions strength are discussed in relation to the systematics of the previously reported B(E2,0₁⁺→2₁⁺) values in the Te isotopes and compared to the predictions of several models.