The short answer . You can not.
Long answer . An attribute value cannot contain several special characters, such as '<', '>'and '&'.
If they are present, they run as '<', '>'and '&'.
These characters can be created if the output method is “text,” which is not your case.
, , : : '<', '>' '&'.
, node, CDATA. :
<xsl:stylesheet version="1.0"
xmlns:xsl="http://www.w3.org/1999/XSL/Transform" >
<xsl:output cdata-section-elements="t"
omit-xml-declaration="yes" indent="yes"/>
<xsl:template match="/">
<t> < & ></t>
</xsl:template>
</xsl:stylesheet>
XML- ( ), :
<t><![CDATA[ < & >]]></t>