You are going to have a very tough time "proving" your thesis friend!!! Abandon this idea before you spend too much time on it. The more you ask around, the more you will find that this is a silly claim!
"Better" is a very subjective term in audio.
I have yet to hear a digital delivery system, at any bit depth or sampling rate that sounds as good as 2" tape running at 15ips with dolby SR. I would wager that the finest sounding recordings (in your opinion) that you have heard were recorded in this format. I have not discussed this with ANY engineer who's ears I trust who would disagree that 2" analog tape has a certain ear friendly sound that digital currently does not have, and that sound is favored.
At the same time, I have heard some digital delivery systems that sound incredible! The versatility that digital offers in editing and archiving is simply incredible and cannot be duplicated in analog. There is no way to dispute this! Digital recordings rule in the department of providing versatility in what you can do with it after is was recorded.
So, if you want "the sound", you would favor analog.
If you want "the versatility to edit/copy/encode to other digital formats", you would favor digital.
Digital recording has a very bright future indeed. It will not be that long before most everything you hear will be digitally recorded (in the multi track stage of things). But, that time is not here yet. I could elaborate on the how's and why's of this, but that would be a lengthy process. Count this post as being my .2 cents worth on the subject.
I hope Shailat, John Sayers, Harvey Gearst, Tom Cram chime in here. I would find it incredible if any of them would disagree with the above (and by the way, there are many others on this BBS who I know would agree too, sorry you guys were not named).
A better approach to your paper might be in addressing how currently, both analog and digital recording mediums are being used closely together to allow the best overall sound with the most versatility in editing and archiving. If you approached a paper in that way, and formed questions based on that, I think you will find many quality engineers willing to discuss in more detail the why's of this.
Please don't take this as a rebuke. It is rather a wake up call.
Ed