my Rabbinic Thesis:
Meditative and Contemplative Practices of Certain Hasidic Masters
The title fairly describes the content and I hope that you will find it informative and illuminating. Writing it certainly was.
click on this link To read it
Note that there is a considerable amount of Hebrew-language source material in the thesis. Much of it is either translated or summarized in the text that follows. It should be largely accessible to most English-only readers.
Enjoy, thank you, and feel free to correspond.