A visual query language for HEP analysis

Pheasant is the first proposal for a declarative domain specific visual query language for HEP data analysis. It has been designed based on our experience dealing with Hera-B event data and query patterns. Its main goal is to allow the physicist to describe the decay selection queries by means of visual operators, to be run against the experiments' existing storage bases and analysis frameworks. Our visual language aims to be a simple-to-use tool with which a user can express complex decay queries in an easy way with reduced programming efforts. Indeed, the user does not have to deal with intricacies like physical storage details. In our communication we will describe how we determined the visual primitives by looking at the query patterns. We will also describe our language in an informal manner in terms of syntax, semantics, and example queries.