Hi everyone, I am doing a final project on the title " fundamentals of neutrino physics". I wanted to raise some issues with neutrino which makes it the possible way to the physics beyond standard model. I am myself doing some research on these topics but at some points the math bugs me out. Anyway, i have some questions which answers themselves confounded me due to the complicated math. Some pf them are: 1. Why wouldnt there be a mirror image of a neutrino? Is it because they are chargeless? They are still in the lepton family but unlike electrons, muons and tau, they are not right handed. I know this is the major source of cp violation but still I couldn't find a better explanation. In fact I looked up at what means left handedness and right handedness. According to a site called quantum-diary ( i guess), that depends upon the perception. The same electron might be left handed or right handed depending upon the frame of reference. I got that but this really bugged me out. What property of neutrino keeps it from having mirror image? 2. I looked at the issue of whether the neutrinos are dirac fermions or majarona fermions. But i couldnt get why would neutrino be majarona? 3. This question is really stupid but somehow I saw a lot of topics on theta 13 but no one seemed to describe it properly. They are explained using variables like A and B. Can anybody explain what it really means in simplest term? Like are there theta12, theta23, theta21 mixing angles? And if so, is theta 12 equal to theta21 ( i had a thought that since mixing angles depend upon the square of mass difference between two types of neutrinos, they should be equal.) 4. And one last thing, what makes neutrino a good candidate for dark matter, its negligible interaction with matter and EM force? Since neutrinos are nearly massless, does our current calculations, like the total neutrinos produced from stars in milky way galaxy all this time will equal the mass of dark matter that slows down our galaxy? I think it is extremely impossible given the low interaction of neutrinos with mass? It is a lot of questions to ask in a single thread but any kind of insight on any of these topics will be highly appreciated. And its not a hw problem. They are the topics i came across when i was doing my research on this topic. Thanks a lot.