Of course some, actually many, scientists believe there is life after death—see. But questions about reincarnation, heaven, or hell, are outside the realm of conventional science. They fall, to some degree, within the province of the science of parapsychology. For that in connection with the reincarnation part, see: . For the heaven hell aspects of your question, see S .
The consensus about heaven and hell is that the reality has little correspondence with religious teachings. Hell is not something imposed by God on wayward souls and heaven is not something granted only to the faithful of some religion. Rather, heaven is a natural phenomena and a state of consciousness that is the ultimate destination for all. Also it is much better than religious imaginations have depicted. Hell is just a very temporary and rather illusory self-created problem. More specifically, hell is a self-created state of temporary consciousness characterized by failure to express harmlessness in thoughts, words, and actions, and is operative in Earth life as well as in the afterlife. Heaven, in its many grades demonstrates as the dimensions of life based on love, and is also operative in Earth life as well as in the afterlife.
Though no words can capture “heaven,” here is a very good try: