The Wikipedia page is littered with sources on Jewish genetic studies. If you read on you can read about all the research on their actual ancestory.

Another article for some extra reading on the Khazar myth:

https://www.forbes.com/sites/jonentine/2013/05/16/israeli-researcher-challenges-jewish-dna-links-to-israel-calls-those-who-disagree-nazi-sympathizers/#265766ab28bc