Antonio,
I would try loading your own version jQuery first, and then calling jQuery's noConflict(), as done below.
<script type="text/javascript" src="http://example.com/jquery-1.1.3.js"></script><script type="text/javascript">
var jQuery_1_1_3 = $.noConflict(true);
</script><script> …other scripts loaded by Orbeon Forms …
And of course, this is something that Orbeon Forms should do itself, and we have an RFE for this:
https://github.com/orbeon/orbeon-forms/issues/1155Alex
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