Set up your lucene instructions in collection.xconf so that you're using the standard analyzer instead of the whitespace analyzer (which is the rather inflexible default). Here's what's inside my lucene structure:

<analyzer id="sa" class="org.apache.lucene.analysis.standard.StandardAnalyzer"/>
<analyzer id="ws" class="org.apache.lucene.analysis.WhitespaceAnalyzer"/>
<text qname="tei:div" analyzer="sa"/>