Nettels, Daniel Hofer, Adrian Moroshkin, Peter Müller-Siebert, Reinhard Ulzega, Simone Weis, Antoine 2005-02-14 We have observed several new spectral features in the fluorescence of cesium atoms implanted in the hcp phase of solid helium following laser excitation to the 6²P states. Based on calculations of the emission spectra using semi empirical Cs-He pair potentials the newly discovered lines can be assigned to the decay of specific Cs*He(n) exciplexes: an apple-shaped Cs(AП(3/2))He₂ and a dumbbell-shaped Cs(AП(1/2))He(n) exciplex with a well-defined number n of bound helium atoms. While the former has been observed in other environments, it was commonly believed that exciplexes with n>2might not exist. The calculations suggest Cs(AП(1/2))He₇ to be the most probable candidate for that exciplex, in which the helium atoms are arranged on a ring around the waist of the dumbbell-shaped electronic density distribution of the cesium atom. application/pdf https://folia.unifr.ch/global/documents/299658 https://folia.unifr.ch/documents/299658/files/1_weis_dds_3.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1103/PhysRevLett.94.063001 info:eu-repo/semantics/openAccess License undefined Physical Review Letters. - 2005, vol. 94, p. 063001 info:eu-repo/classification/udc/53 Discovery of dumbbell-shaped CsHe(n) exciplexes in solid ⁴He http://purl.org/coar/resource_type/c_6501