Bose-Einstein Condensate in Nuclei, K. Schmidt, Cyclotron Institute Texas A & M University, College Station, Texas USA − Bose-Einstein condensation is known to occur in weakly and strongly interacting systems such as dilute atomic gases and liquid 4He [1].  During the last decade it was theoretically shown that dilute symmetric nuclear matter may also experience Bose particle condensation [2- 4].  More precisely, for low temperatures and densities smaller than one fifth of the nuclear saturation density, nuclear matter organizes itself in α-clusters, while for higher densities deuteron condensation is preferred.  This new possible phase of nuclear matter may have its analog in low-density states of alpha-conjugate lighter nuclei, in the same way as superfluid nuclei are the finite-size counterpart of superfluid nuclear and neutron matter. This means that under some circumstances, the alpha condensation, i.e. bosonic properties, might dominate over the nucleon properties even in finite nuclei [5].  A natural way to pursue this question experimentally is to be to apply experimental techniques developed for the investigation of low density nuclear gases to collisions of nuclei expected to have significant alpha cluster character.  Such nuclei might show a more natural predilection to evolve into a Bose Condensate. We have initiated a search for evidence of Bose Condensates using the NIMROD array. Our experiments employed 10, 25, 35 MeV/u beams of 40Ca and 28Si incident on 40Ca, 28Si, 12C and 180Ta targets.  The first three targets allow an exploration of collisions of alpha conjugate nuclei.  In the 180Ta case the projectile excitation and decay is of primary interest.  The data are currently being analyzed. It is our expectation that a Bose Condensate would manifest itself as an assemblage of alpha conjugate products with particular kinematic correlations.

 

 [1] L. P. Pitaevski and S. Stringari, Bose-Einstein Condensation, Clarendon Press, Oxford, 2003.

[2] G. Röpke, A. Schnell, P. Schuck and P. Nozieres, Phys. Rev. Lett. 80 (1998) 3177.

[3] M. Beyer, S. A. Sofianos, C. Kuhrts, G. Röpke and P. Schuck, Phys. Lett. B448 (2000) 247.

[4] T. Sogo, R. Lazauskas, G. Röpke and P. Schuck, Phys. Rev. C 79 (2009) 051301.

[5] Ad. R. Raduta et al., Physics Letters B705 (2011) 65–70.