Before we go on, I want to make something clear. The issue here is if one has the knowledge and understanding of how hard disks/SSDs and partitions actually work, knows about the file system structure ( I assume NTFS in this case), and how partition and recovery tools work. If you do know, you may have a chance to recover the disk, tho it depends on the reason that this happened (power failure, bad sectors, virus, etc). If not, you may damage the disk even more, and it would be better to ask for help from someone who knows depending of course how valuable your files are. To understand a disk being raw can happen because of several reasons and each one has a different method of approach. Also, a lot depends if the disk is a spinner or SSD and so many other variables which makes it hard to just say "Use this tool and you will be ok"
Now it's important to use a boot cd/usb stick and not the OS of your system because, in its effort to read the raw disk, it might make things worse. Try Hiren's boot cd or Sergei Strelec's boot cd (both can be found here) and try their recovery options, starting from partition managers. See if they do recognize the missing partition and if they can recover it. If that doesn't work, try one of the hard disk recovery tools. After that, all will depend on the feedback you will get from the software. Try to google whatever the software tells you is the cause so you can read about your options. I do hope and wish best of luck in recovering the files.
@pleiadians What you described is one major problem with SSD and NVMe disks. The TRIM command. TRIM is a "service" that cleans the SSD from deleted data to keep the cells and disk in optimal conditions but with the negative effect that once a TRIM is issued, your deleted data are wiped clean and there is no possible recovery to my knowledge. The moment you lose files you should power off the PC to avoid making windows using TRIM, and access it from a Bootable USB and run recovery software. The sooner the better.
Hope it helped.