When you delete an artifact definition and all its versions, it is not possible to recreate it with the same name. Also, please note that Artifact Definitions cannot be renamed once created.
Please see the following product documentation page for more information: Manage Artifacts and Artifact Packages
Release Automation 5.5 and above
The deleted artifact definition still lives in the database but is archived.
You can cleanup the artifacts tables by the SQL statements as listed in:
Delete artifact definition that has been deployed
Make sure you have a valid backup of the database, just as a precaution.
When you delete an artifact, it is archived with no supported way to restore it afterwards. This is something that many customers dislike and enhancement requests have been raised to have this change. Have a look at:
Idea - Restore archived artifact
and
Idea - Need ability to completely remove and rename artifact versions