@AmeetSharma I do not think Dasein is reducible to natural kinds, so I do not think Dasein is explainable by physics ... Though natural kinds may be discoverable by science, and physics may involve a valid method of discovering facts about existence, Dasein will never be reducible to what we can discover by any method, because it exists independently of physics and every other science for that matter.
I think Heidegger's positive argument may be operating at a "level above" the debate between dualism and materialism about existence. This debate, perhaps, could be seen as a symptom of Western ontology's attitude of presumption towards existence, that once we have found a way of discovering something about it through science, then the importance of existence itself is reducible to the importance of science for us - whereas, for Heidegger, perhaps this is like looking at existence backwards, through the arbitrary lens of our valuing it according to its "instrumentalisation" value.
One useful thing to remember could be that Dasein is a concept Heidegger apparently uses to critique Western ontology, and though there may be a positive project inherent within it, he is deliberately not buying into already-established debates about the reduction of existence into one thing or another - the-way-things-are-in-the-world is, completely independently of applying our minds to understanding facts about it.
I hope this helps in answer to your response to my first comment!