If you want to migrate the application then for BSO one of the best ways is to use the Maxl command "archive to file" and "restore from file"
More details - Alter Database and Using Backup and Restore for Block Storage Databases
Copying just the index and pag files is not enough to migrate the database, you need also the tct and esm files and still that might not work depending on the environment and is not really the supported method, I suggest looking at the MaxL command.
Copy the index file and pag file to the database folder and check whether the installation path of Dev and UAT are same.
If the installation path is same you will be able to see the data. If both env path are not same then change the path of kernel file(*.esm) file in UAT.
And restart the application. If issue still persists keep posted on this.
JohnGoodwin answer is the better one. Other things you could do
1. Use LCM to export the application and import onto the new server
2. After copying the outline do a data export in native format (either level 0 or all data depending on the size of the DB) then import it into the prod server
As juhn said, just copying the .pag and .ind files is not enough, there are other files that are required for the data to be recognized
If you want to move data, you could do a level zero export in your source and load to target. That should be easier. Though you would then need to run your agg scripts and other calculations (if required).