  A significant number of event-related queries are issued in Web search. In
this paper, we seek to improve retrieval performance by leveraging events and
specifically target the classic task of query expansion. We propose a method to
expand an event-related query by first detecting the events related to it.
Then, we derive the candidates for expansion as terms semantically related to
both the query and the events. To identify the candidates, we utilize a novel
mechanism to simultaneously embed words and events in the same vector space. We
show that our proposed method of leveraging events improves query expansion
performance significantly compared with state-of-the-art methods on various
newswire TREC datasets.
