Publications [#249264] of Ying Wu

Papers Published
  1. Zimmerman, WR; Ahmed, MW; Bromberger, B; Stave, SC; Breskin, A; Dangendorf, V; Delbar, T; Gai, M; Henshaw, SS; Mueller, JM; Sun, C; Tittelmeier, K; Weller, HR; Wu, YK, Unambiguous Identification of the Second 2(+) State in C-12 and the Structure of the Hoyle State, Physical Review Letters, vol. 110 no. 15 (April, 2013), pp. 152502 [Gateway.cgi], [doi] .

    The second J ¼ 2þ state of 12C, predicted over 50 years ago as an excitation of the Hoyle state, has been unambiguously identified using the 12Cð;0 Þ8Be reaction. The alpha particles produced by the photodisintegration of 12C were detected using an optical time projection chamber. Data were collected at beam energies between 9.1 and 10.7 MeVusing the intense nearly monoenergetic gamma-ray beams at the HIS facility. The measured angular distributions determine the cross section and the E1-E2 relative phases as a function of energy leading to an unambiguous identification of the second 2þ state in 12C at 10.03(11) MeV, with a total width of 800(130) keVand a ground state gamma-decay width of 60(10) meV; BðE2 : 2þ 2 ! 0þ 1 Þ ¼ 0:73ð13Þe2 fm4 [or 0.45(8) W.u.]. The Hoyle state and its rotational 2þ state that are more extended than the ground state of 12C presents a challenge and constraints for models attempting to reveal the nature of three alpha-particle states in 12C. Specifically, it challenges the ab initio lattice effective field theory calculations that predict similar rms radii for the ground state and the Hoyle state.