You don't delete a database from SQL Server Browser, that's just a service If you deleted the database itself, you need to restore it again.
If you have a .bak backup, open SQL Server Management Studio → right click Databases → Restore Database → select your .bak file and restore it.
If you don't have a backup, then unfortunately that database is gone and you'll need to re-import or recreate it.
Also make sure your SQL Server (not just Browser) is running