I have tried text box as form control type and it didn't work for "xxx & xxxx". So looking for suggestions if it is with Form control type or something else.If yes, please do let me know to fix it.
Smart Search (i.e.Lucene) supports escaping special characters that are part of the query syntax. The special characters are: + - && || ! ( ) { } [ ] ^ " ~ * ? : \ /
. To escape these characters use the \
before the character. So try "xxx \& xxxx"
and see if it works.