NUSTAR Neutron Knockout from Intermediate Energy Beams of 26,28 Ne J.R. Terry 1,2, D. Bazin 1, B.A.Brown 1,2, C.M. Campbell 1,2, J.A. Church 1,2, J.M. Cook 1,2, A.D. Davies 1,2, D.C. Dinca 1,2, J. Enders 1, A. Gade 1, T.Glasmacher 1,2, P.G. Hansen 1,2, J.L. Lecouey 1,W.F. Mueller 1,H. Olliver 1,2, B.M. Sherrill 1,2, J.A. Tostevin 3, K. Yoneda 1 1 National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824, USA 2 Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA 3 School of Electronics and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK
NUSTAR Neutron Knockout from Intermediate Energy Beams of 26,28 Ne Direct quantitative observation of negative parity intruder configuration in 28 Ne. First observation of the level structure of 27 Ne. Z N 28 Ne
NUSTAR KNOCKOUT REACTION IN INVERSE KINEMATICS AT ENERGIES OF MeV/nucleon A A-1 EE k A-1 Observables: Cross section of nucleon- removal reaction Population fraction to individual excited states by detection of coincident transition gamma rays Longitudinal momentum distribution of reaction residue Three-body reaction theory based on Sudden and Eikonal approximations: Core-target and nucleon-target S-matrices calculated from Glauber theory Core-nucleon interaction modeled by a two-body Wood-Saxon potential
NUSTAR Be( 26 Ne, 25 Ne)X J.R. Terry, J.L. Lecouey, Nucl. Phys. A734 (2004) E level JπJπ lb [%]σ sp [mb]σ obs [mb]C 2 S obs C 2 S th E th 01/ (7)41.746(7)1.1(2) / (6)21.521(6)1.0(3) / (3)19.320(3)1.0(2)
NUSTAR S800 Spectrograph Segmented Germanium Detector Array SeGA Focal Plane Yellow arrow indicates beam path
NUSTAR Be( 28 Ne, 27 Ne)X Inclusive Cross Section: 66.7(33) mb First observation of excited states in 27 Ne: three gamma transitions: 119(3), 765(5), 885(5) keV. 37.7(20) % of events have no observed coincident transition gamma rays Gamma-gamma analysis 885(5) 48.1(21) 765(5) 14.2(16) 0.830(17) %0.170(17) % E [keV] Branch [%] 119(3) keV keV 9 Be( 28 Ne, 27 Ne)X 765 keV gated 885 keV gated
NUSTAR l=0 l=3 l=2 l=3 l=0 l=2 l=3 765 keV885 keV Events with no coincident transition gamma Momentum Distributions 765 and 885 keV coincident events have momentum distributions characteristic of an l=2 neutron removal Momentum distribution for events with no coincident transition gamma ray is not consistent with any single-l valued distribution. Combination of l=0 and l=3, 12% and 88%, respectively, fits the data. Longitudinal Momentum Distribution [GeV/c]
NUSTAR Results JπJπ l σ partial [mb] σ sp [mb]C 2 S obs (3/2,5/2) (21) (9) (3/2,5/2) (11) (5) 7/ (21)23(1)0.96(10) (1/2 + )(0)3.00(64) (14) 83.0(17) %17.0(17) % (5) 0.885(5) X E [MeV] 27 Ne
NUSTAR Comparison to USD / / / / / JπJπ lC2SC2SJπJπ lC2SC2S (1/2 + )(0)0.068(14) 7/ (10) (3,5)/ (5) (3,5)/ (9) S n =1.43 MeV USDExp
NUSTAR NILSSON DIAGRAM FOR N,Z < 20 a = a = [200]1/2 + 1/2 + [202]3/2 + 3/2 + [330]1/2 - 3/2 - 3/2 + 5/2 + 7/2 - 1/2 - 5/2 - 5/2 +
NUSTAR Comparison of the ( 28 Ne, 27 Ne) f 7/2 Spectroscopic Factor with fp-shell occupancies from the Monte Carlo Shell Model a) a) Y. Utsuno, T. Otsuka, T. Mizusaki and M. Honma, Phys. Rev. C 60, (1999)
NUSTAR Outlook Complete analysis of 28 Ne Angular distributions of de-excitation gamma rays Analyze single-neutron removal from 30,32 Mg 30 Mg 32 Mg
NUSTAR Neutron Knockout from Intermediate Energy Beams of 26,28 Ne J.R. Terry 1,2, D. Bazin 1, B.A.Brown 1,2, C.M. Campbell 1,2, J.A. Church 1,2, J.M. Cook 1,2, A.D. Davies 1,2, D.C. Dinca 1,2, J. Enders 1, A. Gade 1, T.Glasmacher 1,2, P.G. Hansen 1,2, J.L. Lecouey 1,W.F. Mueller 1,H. Olliver 1,2, B.M. Sherrill 1,2, J.A. Tostevin 3, K. Yoneda 1 1 National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824, USA 2 Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA 3 School of Electronics and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK