In-Medium Cluster Binding Energies and Mott Points in Low Density Nuclear Matter K. Hagel WPCF 2013 Acireale, Italy 7-Nov-2013 Clustering and Low Density Nuclear Matter

Outline Experimental Setup Clusterization of alpha conjugate nuclei – Alpha like multiplicities – Origin of alpha particles from different breakup channels – Correlation functions – Geometry/proximity effects Clusterization and observables in low density nuclear matter. Summary

3 14 Concentric Rings degrees Silicon Coverage Neutron Ball S. Wuenschel et al., Nucl. Instrum. Methods. A604, 578–583 (2009). Beam Energy: Reactions: NIMROD beam 35 MeV/u 40 Ca + 40 Ca 35 MeV/u 28 Si + 28 Si

Alpha clustering in nuclei Ikeda diagram (K. Ikeda, N. Takigawa, and H. Horiuchi, Prog. Theor. Phys. Suppl. Extra Number, 464, 1968.) Clusterization of low density nuclear matter in collisions of alpha conjugate nuclei Role of clusterization in dynamics and disassembly. Estimated limit N = 10 α for self- conjugate nuclei( Yamada PRC 69, ) 40 Ca + 40 Ca 28 Si + 40 Ca 40 Ca + 28 Si 28 Si + 28 Si 40 Ca + 12 C 28 Si + 12 C 40 Ca Ta 28 Si Ta Data Taken 10, 25, 35 MeV/u Focus on 35 MeV/u 40 Ca + 40 Ca and 28 Si + 28 Si analysis for now

Alpha-like multiplicities Large number of events with significant alpha conjugate mass for both systems Larger contribution of alpha conjugate masses than AMD would predict. odd-odd odd-even even-even BjBj Expt AMD 35 MeV/u 40 Ca + 40 Ca 35 MeV/u 28 Si + 28 Si Ca+Ca

V parallel vs A max Observe mostly PLF near beam velocity for low E* More neck (4-7 cm/ns) emission of α-like fragments with increasing E*

Heavy partner is near beam velocity alphas originate from neck emission Origin of alpha conjugate clusters

Source Frame study of Origin of clusters

Origin of alpha conjugate clusters (continued)

Source Frame Origin of clusters (continued)

Experimental Correlation Functions Correlation functions exhibit peak near Hoyle state of 7.64 MeV. 3α events

Effects of neck geometry and/or proximity effects Sphericity analysis shows significant rod like emission patterns 3 α Energy Dalitz plot shows difference depending on whether emission from neck or PLF. Sphericity Coplanarity Rod-like NeckPLF

arXiv v1 22 April 2013 Slater Determinants

Clustering in Low Density Matter PRL 108 (2012) PRL 108 (2012) Evolution of the system Systems studied – 47 MeV/u 40 Ar + 112,124 Sn Use NIMROD as a violence filter – Take 30% most violent collisions Coalescence analysis to extract densities and temperatures – Equilibrium constants (tests of Astrophysical EOS calculations) – Mott points

Summary Clusterization of alpha conjugate nuclei – Large production of α-like nuclei in Ca + Ca – Neck emission of alphas important – Proximity and geometry effects Clusterization in low density nuclear matter – Equilibrium constants to test Astrophysical EOS models – Density dependence of Mott points

Outlook and near future Disassembly of alpha conjugate nuclei – Analysis on 40 Ca+ 40 Ca and 28 Si+ 28 Si continues – Several other systems nearly calibrated Low density nuclear matter – We have a set of 35 MeV/u 40 Ca+ 181 Ta and 28 Si+ 181 Ta

Collaborators J. B. Natowitz, K. Schmidt, K. Hagel, R. Wada, S. Wuenschel, E. J. Kim, M. Barbui, G. Giuliani, L. Qin, S. Shlomo, A. Bonasera, G. Röpke, S. Typel, Z. Chen, M. Huang, J. Wang, H. Zheng, S. Kowalski, M. R. D. Rodrigues, D. Fabris, M. Lunardon, S. Moretto, G. Nebbia, S. Pesente, V. Rizzi, G. Viesti, M. Cinausero, G. Prete, T. Keutgen, Y. El Masri, Z. Majka, and Y. G. Ma