It is a holiday and no transactions are being performed on the database. You took a consistent backup of your database without using Recovery Manager (RMAN). How would you make use of this…

RMAN operates exclusively with backups it has created (backup sets or image copies) that are tracked in its repository or recovery catalog. A user-managed consistent cold backup consists of raw OS-level file copies that are not in RMAN's backup set format and are not registered in RMAN's repository, making them incompatible with RMAN restore and recovery operations.

Starting the database again is a standard database operation and has no bearing on whether RMAN can recognize or incorporate a user-managed backup taken outside of RMAN.

The RMAN CATALOG command is used to register RMAN-created backup pieces or image copies that are missing from the catalog, not to import arbitrary OS-level cold backup files created entirely outside of RMAN.

RECOVER CATALOG is an RMAN command used to synchronize a separate recovery catalog database with the target control file, not to import or register external user-managed backup files.

Re-creating the control file rebuilds the database's control file metadata structure but does not enable RMAN to use a backup it did not create and has no record of in its repository.