Currently, I am a master's student at a Swiss university, and my degree requires me to complete a master's thesis. Unfortunately, no professors at my university are experts in the concentration that I am interested in, and I found a professor in the United States who has close interests and backgrounds with mine. If possible, I plan to stay at that U.S. university for an entire year. Please note that while I am writing my thesis in the U.S., I am not enrolled to that university, nor will I receive any formal accreditation there, and I have no intention to do that, either. I will still be enrolled in my Swiss university and receive the credit for thesis from that university.
I have a valid B1/B2 visa, but I know that I can't stay in the U.S. for that long with this visa. So which type of visa should I have? The first thing that comes to my mind is J-1, but I'm not sure.
I appreciate any insights. Thank you so much for your help.