language: en

[Confidential: not for distribution. Submitted to IOP Publishing for peer review]

6 June 2010

Search for the 2 + Excitation of the Hoyle State in 12 C Using the 12 C( 12 C,3α) 12 C Reaction

T Muñoz-Britton 1 , M Freer 1 , N I Ashwood 1 , T A D Brown 2 , W N Catford 3 , N Curtis 1 , S P Fox 2 , B R Fulton 2 , C W Harlin 3 , A M Laird 2 , P Mumby-Croft 2 , A St. J Murphy 4 , P Papka 2 , D L Price 1 , K Vaughan 2 , D L Watson 2 and D C Weisser 5
1 School of Physics and Astronomy, University of Birmingham,
Edgbaston, Birmingham, B15 2TT, United Kingdom
2 Department of Physics, University of York,
Heslington, York, YO10 5DD, United Kingdom
3 Department of Physics, Faculty of Engineering & Physical Sciences, University of Surrey,
Guildford, GU2 7XH, United Kingdom
3 School of Physics and Astronomy, The University of Edinburgh,
James Clerk Maxwell Building, Mayfield Road, Edinburgh, EH9 3JZ, United Kingdom
5 The Research School of Physics and Engineering,
Building 60,
The Australian National University,
Canberra, ACT 0200, Australia

Abstract. A search for the 2 + excitation of the Hoyle state in 12 C has been performed using the 12 C( 12 C,3α) 12 C reaction at a beam energy of 101.5 MeV. An angular correlation analysis was used to suppress known contributions to the excitation energy spectrum, enhancing the experimental sensitivity. No strong evidence was found for new states in 12 C between 9 and 11 MeV; rather upper limits for their excitation in the 12 C+ 12 C inelastic scattering reaction are determined.

PACS numbers: 21.10.-k, 23.60.+e, 27.20.+n 1. Introduction