Google has indexed my sitemap.xml

sitemap.xml appears as first result in serps for my domain

[wrightee]

Searching for [mydomain.com] brings my sitemap.xml page as the first result and homepage as second; obviously, not a good thing.. Silly question - but what should I do.. I can't really block sitemap.xml with robots.txt, can I? Thanks in advance!

[Samizdata]

I haven't faced this situation but my first thoughts would be:

Check there are no links to the file on your site

Remove the file from the index using Google Webmaster Tools

Redirect requests for the file to the homepage (with exceptions for search engines)

...