Quadrupole collectivity in neutron-deficient Sn nuclei: \nuc{104}{Sn} and the role of proton excitations

Abstract

We report on the experimental study of quadrupole collectivity in the neutron-deficient nucleus \nuc{104}{Sn} using intermediate-energy Coulomb excitation. The $B(E2;0_1^{+}\to 2_1^{+})$ value for the excitation of the first $2^{+}$ state in \nuc{104}{Sn} has been measured to be $0.180(37)e^2$b${}^2$ relative to the well-known $B(E2)$ value of \nuc{102}{Cd}. This result disagrees by more than one sigma with a recently published measurement \cite{Gua13}. Our result indicates that the most modern many-body calculations remain unable to describe the enhanced collectivity below mid-shell in Sn approaching $N=Z=50$. We attribute the enhanced collectivity to proton particle-hole configurations beyond the necessarily limited shell-model spaces and suggest the asymmetry of the $B(E2)$-value trend around mid-shell to originate from enhanced proton excitations across $Z=50$ as $N=Z$ is approached.

Accepted for publication as rapid communication in Physical Review C

References in corpus (5)

• Evolution of shell structure in neutron-rich calcium isotopes
• Z=50 shell gap near ${}^{100}$Sn from intermediate-energy Coulomb excitations in even-mass ${}^{106--112}$Sn isotopes
• Orbital dependent nucleonic pairing in the lightest known isotopes of tin
• Living on the edge of stability, the limits of the nuclear landscape
• Production and $\beta$ decay of rp-process nuclei ${}^{96}$Cd, ${}^{98}$In and ${}^{100}$Sn

Cited by in corpus (15)

• Structure of the lightest tin isotopes
• Laser Spectroscopy for the Study of Exotic Nuclei
• Novel shape evolution in Sn isotopes from magic numbers 50 to 82
• Shell-model study of quadrupole collectivity in light tin isotopes
• Pairing-quadrupole interplay in the neutron-deficient tin nuclei: first lifetime measurements of low-lying states in ${}^{106,108}$Sn
• Double-step truncation procedure for large-scale shell-model calculations
• Asymmetric behavior of the B$(E2\uparrow ;0^{+}\to 2^{+})$ values in ${}^{104-130}$Sn and Generalized Seniority
• Electromagnetic Properties of Indium Isotopes Elucidate the Doubly Magic Character of ${}^{100}$Sn
• Shape coexisistence and collective low-spin states in ${}^{112,114}$Sn studied with the $(p,p^{\prime }\gamma )$ DSA coincidence technique
• Quadrupole dominance in the light Sn and in the Cd isotopes
• Isomeric excitation energy for ${}^{99}$In${}^m$ from mass spectrometry reveals constant trend next to doubly magic ${}^{100}$Sn
• Spectroscopy of nuclei around ${}^{100}$Sn populated via two-neutron knockout reactions
• Shape polarization in the tin isotopes near $N=60$ from precision $g$-factor measurements on short-lived $11/2^{-}$ isomers
• Quadrupole dominance in light Cd and Sn isotopes
• Relation between E2 transitions in even--even and odd-mass nuclei