Captures and Molecules Sandrine Courtin Institut Pluridisciplinaire Hubert

Captures and Molecules … Sandrine Courtin Institut Pluridisciplinaire Hubert Curien, Département des Recherches Subatomiques and Université Strasbourg I Sandrine Courtin Atelier de l’ESNT Saclay, Feb. 4 -6 / 2008

Now 11. 8 -9. 32 AME 03 -LMD, P. Van Isacker et A. E. L. Dieperink, Int. J Mod. Phys. E 15, 1371(2006) 82 126 50 82 28 50 20 8 8 28 20 N-rich around N = 20 – 28 How ? Transfer reactions transfer process / nucleon-nucleon spectroscopy Ex 40 Ar : Where ? Collaboration : Theory : Sandrine Courtin (ELab = 255 Me. V) + 208 Pb (11/2007) n-rich Ar Legnaro (Prisma-Clara), GANIL IPHC, Univ. Zagreb (S. Szilner et al. ), Univ. Torino, LNL Legnaro (L. Corradi et al. ), Univ. of West Scotland (R. Chapman et al. ) G. Pollarolo (Univ. Torino), E. Caurier, F. Nowacki (IPHC) Atelier de l’ESNT Saclay, Feb. 4 -6 / 2008

Now Clustering in light heavy-ions How ? Ex : Where ? Narrow ‘molecular’ resonances, fragment, particle, g decay (24 Mg-24 Mg) resonances in 48 Cr 12 C - 12 12 C) resonances in 24 24 Mg (12 12 C - 16 16 O) resonances in 28 28 Si (12 Legnaro (Prisma-Clara), Berkeley (Gammasphere), Triumf (Dragon + BGO), Argonne (Gammasphere+FMA) Molecules Deformation g-decay Collaboration : IPHC, Univ. York (D. Jenkins et al. ), Triumf (D. Hutcheon et al. ) Radiative Capture Reactions : recent results ANL (C. Lister et al. ), Univ. of West Scotland (R. Chapman et al. ) Theory : Sandrine Courtin J. Dudek (IPHC), K. Pomorski (Lublin) LSD Model S. Ohkubo. K. Yamashita (Univ. Kochi) a. CM D. Baye and P. Descouvemont (ULB) GCM J. Cseh and G. Lévaì (Atomki, Debrecen) ACM Atelier de l’ESNT Saclay, Feb. 4 -6 / 2008

12 C(12 C, )24 Mg and 12 C(16 O, )28 Si Setting the stage Resonances ? NOC (F. Haas and Y. Abe, Phys. Rev. Lett. 46 (1981) 1667) Narrow Resonances (150 ke. V), DEDt ~ h molecules Radiative Capture : Light Particles vs Heavy-Ions Light heavy-ions : 12 C+12 C 24 Mg, 12 C+16 O 28 Si Sandorfi et al. (BNL, ~ 1980) Narrow resonances @ Bc No recoil, decay to g. s. Sandrine Courtin Atelier de l’ESNT Saclay, Feb. 4 -6 / 2008

Results on 12 C(12 C, )24 Mg and 12 C(16 O, )28 Si Measurements ON- and OFF resonance @ BC D. A. Hutcheon et al. , NIM A 498, 190 (2003). First Stage Second Stage ISAC I : RNBs / Stable (OLIS) gas/solid target system 0° spectrometer Tof on 17 m Beam rejection 1013 Acceptance : cone half angle 20 mrad recoil detectors (DSSSD, …) BGO array ( = 50 % @ 5 Me. V) Sandrine Courtin Atelier de l’ESNT Saclay, Feb. 4 -6 / 2008

Results on 12 C(12 C, )24 Mg and 12 C(16 O, )28 Si 2+ → 0+ 4+ → 2+ 25 Me. V 12 C+16 O Gamma spectrum (28 Si) ~14 Me. V 3+, 0+, 3 - 20 Me. V ~ 11 Me. V 28 Si ~ 10 Me. V ~ 14 Me. V ~ 10 Me. V 12 C+16 O Highest energy -ray 24 Mg 0 Me. V 12 C+12 C Highest energy -ray S. C. et al. , Fusion 06, San Servolo, AIP Conf. Proc. 853 (2006), S. C. et al. , Journal of Physics G, London (2008). Sandrine Courtin Atelier de l’ESNT Saclay, Feb. 4 -6 / 2008

Clusters ? Shell Model ? 16 O, doubly magic …, 0+ , 2+, 4+ …B(E 2) (2+ 0+) = 27 W. u. , B(E 2) (4+ 2+) = 65 W. u. 2 8 Be, 9 Be, 10 Be 12 C (0+, Hoyle) … Model Space … Cluster Models ? CM (Abe & Uegaki), ex : 24 Mg-24 Mg resonances in 48 Cr. GCM, (Baye & Descouvemont), deformed structures, rotational bands. AMD ? Ab initio (Horiuchi, Kanada En’yo) 24 Mg, 28 Si, 32 S, 36 Ar, 40 Ca, 28 Mg Deformed structures, SD, clusters … Clusters in n-rich nuclei Sandrine Courtin Atelier de l’ESNT Saclay, Feb. 4 -6 / 2008

Results on 12 C(12 C, )24 Mg and 12 C(16 O, )28 Si Theory What is the structure of those states ? 24 Mg(12 C-12 C) P. Descouvemont and D. Baye, Phys. Lett. 169 B (1986) 143. 28 Si(12 C-160) Ohkubo and Yamashita, Phys. Lett. B 578 (2004) 304. Links between low-lying members of these cluster bands ? Sandrine Courtin Atelier de l’ESNT Saclay, Feb. 4 -6 / 2008

Results on 12 C(12 C, )24 Mg and 12 C(16 O, )28 Si 2+ resonance ? (Ecm = 6 Me. V) 12 C+12 C simulation experiment 12 C+16 O D. G. Jenkins, S. Courtin et al. , Phys. Rev. C (in press) Resonances strongly correlated to 24 Mg and 28 Si states Large part of the flux via doorway states around 10 -11 Me. V. (a threshold = 9. 3 Me. V and 10. 0 Me. V) 2 scenarii 1 - States with a specific structure ? 2 - Decay via T = 1 states through DT = 1 M 1 allowed transitions may be favoured in this N = Z nucleus … Sandrine Courtin Atelier de l’ESNT Saclay, Feb. 4 -6 / 2008

Lower energies ? What happens below BC and down to Eastro … ? Medium mass systems fusion X-sections, hindrance … Ex : 64 Ni +64 Ni, incompressibility, CC calc. 36 S+48 Ca, LNL, Legnaro, 10/2007 (20% below B ) C 12 C + 12 C, 12 C + 16 O C. L. Liang, K. E. Rehm, B. B. Back and R. V. F. Janssens, PRC 75, 015803 (2007), 16 O and 12 C induced fusion. S extrapolated to low energies … 12 C(a, ) 16 O R → 6. 05 E R → g. s. R → 6. 9 6. 09 → g. s. C(a, g) 16 O, Dragon data 12 Sandrine Courtin Atelier de l’ESNT © H. Esbensen, S. Misicu Reaction rate, s = 0. 01 fb @ EGamow Direct kin. (Stuttgart, M. Assuncao et al. , PRC 73 (2006) 055801), no recoil Inverse kin. (Triumf, C. Matei et al. PRL 97 (2006) 242503) recoil with Dragon, new path … Saclay, Feb. 4 -6 / 2008

Next move Identify the doorway states Giant resonances & molecular resonances … ? N-rich clusters ? new generation of scintillators (La. Br 3(Ce)) + state-of-the-art spectro … Shell model and mean field, a kind of unified view TDHF, reaction mechanism at Bc and below as a function of the reacting time … E 12 C + 12 C, why ? Sandrine Courtin Atelier de l’ESNT Saclay, Feb. 4 -6 / 2008

12 C+16 O et 12 C+12 C Breakup reactions 28 Si 12 C+16 O, 24 Mg 12 C+12 C RC RC • 12 C+16 O breakup states to 45 Me. V. C. J. Metelko et al. , J. Phys. G 29 (2003), 697 • Reaction 12 C(20 Ne, 12 C 16 O) @ ANL Sandrine Courtin • 12 C+12 C breakup states to 50 Me. V C. J. Metelko et al. , Phys. Rev. C 68 (2003) 0544321 • Reaction 12 C(16 O, 12 C) Atelier de l’ESNT Saclay, Feb. 4 -6 / 2008

Multinucleon transfer, far from stability (collab. L. Corradi, LNL) n-pairs transfers in n-rich nuclei sfus very @ low E. SPIRAL 2 Nuclear Molecules resonances and doorway states EM transitions between resonant states Gammasphere+FMA, AGATA, PARIS SPIRAL 2 PARIS Sandrine Courtin Atelier de l’ESNT 24 Si detectors @ 45° + highly efficient -array Saclay, Feb. 4 -6 / 2008