Long lived photo excitations in (6, 5) carbon nanotubes C. Sciascia, J. Crochet, T. Hertel and G. Lanzani Eur. Phys. J. B, 75 2 (2010) 115-120 Published online: 03 November 2009 DOI: 10.1140/epjb/e2009-00374-1