We present an automatized bibliometric investigation applied to the field of fundamental research in physics. We briefly describe the scientific context motivating this study and the statistical method used for analyzing the data. We discuss in more detail how we adapted our investigation to the questions motivating this study, namely the identification of relevant groups working in a well defined subfield of physics. We next present the results of our investigation. We particularly focus on an analysis of Index and Free terms, as obtained from the INSPEC data base we used for performing the bibliometric investigation. We discuss the relevance of Index and Free terms by means of a separation between “Noise”, “Interesting” and “Trivial” entries. We show that Index and Free terms exhibit somewhat different behaviors when considered as distributions in terms of frequencies of occurrence in the references. We show the particular relevance of Free terms in this analysis. This may be connected to the emerging nature of the subfield of physics under consideration. This shed an interesting light on the respective importance of Index and Free terms, as entries of data bases, in particular in the case of rapidly evolving scientific domains.