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C ONTINUUM STATES OF LIGHT NEUTRON - RICH NUCLEI VIA TRANSFER & KNOCKOUT Formless Continuum Jack Haas Example : N=7 structure - 9 He, 10 Li via single-neutron transfer on 8 He [ 9 Li] versus nucleon knockout & fragmentation of fast secondary beams GOAL: Compare and contrast Open issues and questions [ 5 H & 13 Be via proton removal ] NIGEL ORR * * T AL KALANEE, J GIBELIN, H AL FALOU + CHARISSA+DEMON + MUST C OLLABORATIONS Slide 2 toujours la mme chose avec lui mieux vaut peut-tre rester ici avec mon ballon de rouge Slide 3 T HE LIGHT NEUTRON - RICH NUCLEI 10 Li driplines and beyond experimentally accessible via knockout/breakup driplines and beyond experimentally accessible via knockout/breakup neutron transfer 9 He... nuclear structure theory becoming mature (NCSM, ab initio, )... nuclear structure theory becoming mature (NCSM, ab initio, ) Slide 4 N=7 : S TRUCTURAL EVOLUTION WITH ISOSPIN * T Otsuka et al. PRL 2001 T Otsuka et al. PRL 2001 9 He ?? PG Hansen et al. PG Hansen et al. 1/2 + - 1/2 - level inversion * Also input for 3-body models of 10 He, Slide 5 H ISTORICAL I NTERLUDE some cases accessible via heavy-ion multi-nucleon transfer & double-charge exchange from stable targets/beams some cases accessible via heavy-ion multi-nucleon transfer & double-charge exchange from stable targets/beams complex mechanisms, selectivity ( >>0), complex spectra, complex mechanisms, selectivity ( >>0), complex spectra, HMI group, circa 1994 Slide 6 T WO ROADS TO THE CONTINUUM : NEUTRON TRANSFER & FAST BEAM KNOCKOUT / BREAKUP FAST BEAM KNOCKOUT / BREAKUP INVERSE KINEMATICS INVERSE KINEMATICS n (d,p) Si strip beam PID + E B tracking heavy beam-like residue (PID, E, ) CD 2 or Be / C knockout Slide 7 8 He(d,p) SINGLE - NEUTRON TRANSFER 8 He(d,p) SINGLE - NEUTRON TRANSFER 1s 1/2 1p 3/2 1p 1/2 2s 1/2 1d 5/2 N=6 Proton energy and angle E x of recoil B Proton angular distribution, d / d angular momentum transfered by neutron, n angular momentum transfered by neutron, n d / d (expt) = S d / d (reaction theory) 8 He(d,p) 9 He J = 1/2 + 1/2 -, 5/2 +, 3/2 - (iff 8 He gs 2p-2h)* 8 He(d,p) 9 He J = 1/2 + 1/2 -, 5/2 +, 3/2 - (iff 8 He gs 2p-2h)* ppp AA B d d + A p + B n n d=p+n B=A+n neutrons 8 He gs J = 0 + 8 He gs J = 0 + * 8 He(p,d) S(p3/2) 4 8 He(p,t) 2p-2h MUST [ PRC2006, PLB2007 ] * 8 He(p,d) S(p3/2) 4 8 He(p,t) 2p-2h MUST [ PRC2006, PLB2007 ] Slide 8 9 He: SHELL MODEL (p-sd 0 1 ) L Chen et al. PLB (2001) Slide 9 d( 8 He,p) A He @ 15 MEV / NUCLEON d( 8 He,p) A He @ 15 MEV / NUCLEON T Al Kalanee, J Gibelin et al. [MUST2], PRC88 2013 E r =18085 ( =180160) ; 1240120 ( =130 +170 / -130 ) ; 3420780 ( =2900400) keV Slide 10 d( 8 He,p) A He @ 15 MEV / NUCLEON d( 8 He,p) A He @ 15 MEV / NUCLEON T Al Kalanee, J Gibelin et al., PRC88 2013 DWBA & CCBA N Keeley DWBA Optical Potls: d+ 8 He global parameters Daehnick et al p+ 9 He systematics Koning+Delaroche p+ 9 He systematics Koning+Delaroche Form Factors: Woods-Saxon with Weak Binding approx CCBA : d breakup only - d+ 8 He CDCC Slide 11 d( 8 He,p) A He @ 15 MEV / NUCLEON d( 8 He,p) A He @ 15 MEV / NUCLEON T Al Kalanee, J Gibelin et al., PRC88 2013 [ sp (=0) 2700 keV] [ sp ( =0) 2700 keV] [ sp (=1) 2400 keV] [ sp ( =1) 2400 keV] [ sp (=2) 3000 keV] [ sp ( =2) 3000 keV] DWBA: * No reliable form factor for =0 using WBEA Uncertainty dominated by form factor ** Barker (2004) R-Matrix < 0.1 Uncertainty dominated by form factor ** Barker (2004) R-Matrix < 0.1 * a s ~ - 12 fm ** Slide 12 K NOCKOUT & B REAKUP nucleon removal via knockout or breakup of projectile ( 0.3) with known structure + in-flight decay fragment n FSI VfVf VnVn V f - V n target Proj. A Z A-1 Z + n Slide 13 A PPROX. S ELECTION R ULES (i) 1 & 2-proton knockout n 0 proj. valence neutron config. C( 11 Be, 9 Li+n)X,C( 11 Be, 8 He+n)X s 1/2 [ 11 Be C 2 S ( s 1/2 ) 0.8 ] well adapted to probing low-lying (s-wave strength) (ii) fragmentation (-xp,-yn) population via neutron-decay of N+1,2, systems following proton removal C( 14 B, 9 Li+n)X, C( 14 B, 8 He+n)X, C( 11 Li, 8 He+n)X, s 1/2 + p 1/2 + CAVEAT: decay of narrow resonances in N+1,2, systems C( 14 B, 9 Li+n)X, C( 14 B, 8 He+n)X, C( 11 Li, 8 He+n)X, s 1/2 + p 1/2 + CAVEAT: decay of narrow resonances in N+1,2, systems Slide 14 N=7 : S TRUCTURAL EVOLUTION WITH ISOSPIN Brida e at al.,. NUPA (2006) 10 Li * PG Hansen et al. PG Hansen et al. s 1/2 - p 1/2 level inversion s 1/2 - p 1/2 level inversion p 1/2 s 1/2 ; p 3/2 2 -,1 - ; 2 +,1 + Slide 15 S CATTERING /V IRTUAL S - WAVE STATES a s = 0 fm no FSI ; a s H ISTORICAL I NTERLUDE some cases accessible via heavy-ion multi-nucleon transfer & double-charge exchange from stable targets/beams some cases accessible via heavy-ion multi-nucleon transfer & double-charge exchange from stable targets/beams complex mechanisms, selectivity ( >>0), complex spectra, complex mechanisms, selectivity ( >>0), complex spectra, Slide 29 9 He : d( 8 He,p) @ 15 MeV/nucleon S Fortier et al., AIP Conf Proc 912 (2007) Slide 30 d( 8 He,p) A He @ 15 MEV / NUCLEON d( 8 He,p) A He @ 15 MEV / NUCLEON T Al Kalanee, J Gibelin et al. [MUST2], PRC88 2013 Slide 31 17 O : d( 16 O,p) @ 15 MEV / NUCLEON T Al Kalanee, J Gibelin et al., PRC88 2013 Slide 32 d( 16 0/ 8 He,p) 17 O/ 9 He @ 15 MEV / NUCLEON : RESOLUTION d( 16 0/ 8 He,p) 17 O/ 9 He @ 15 MEV / NUCLEON : RESOLUTION T Al Kalanee, PhD Thesis LPC-Caen (2010) Slide 33 9 He: S UMMARY T Al Kalanee, J Gibelin et al., PRC88 2013 Slide 34 9 He: AB INITIO THEORY P Navratil ECT* Nov 2013 Slide 35 I NVARIANT MASS SPECTROSCOPY : LIGHT NUCLEI @ ~40 MeV/u 9 Li+n 12 Be+n Slide 36 Resolution E XPERIMENTAL RESPONSE FUNCTION Efficiency FWHM ~ 0.3 E d 1/2 nnnn JL Lecouey LPCC 04-03 JL Lecouey LPCC 04-03 model distributions must be filtered through the simulation model distributions must be filtered through the simulation Slide 37 I NITIAL S TATE D EPENDENCE OF U NBOUND S TATES G Bertsch et al., PRC (1998), L Chen et al. PLB (2001) sudden approximation sudden approximation neutron configuration of projectile preserved ( n = 0 ) neutron configuration of projectile preserved ( n = 0 ) Initial bound state Final unbound state DecayEnergySimulation Comparison to data ( 2 ) Slide 38 I NITIAL S TATE D EPENDENCE OF V IRTUAL S -S TATES a s = 0 fm no FSI ; a s