Disappeared from Google

Even though using Google Sitemaps.

[future]

Hi Guys

We have a url which we changed. Neither our old or new url are now in google.
They have vanished.
we tried the cache.www.domain.com and its just not there.
The new site is in yahoo but not in google.
we have the google xml site map in there and we use google adwords.
Please can you help?
Many thanks