Simplify the following text for a Grade 11 native English-speaking person.
Original: It is possible that the neutrino and antineutrino are in fact the same particle , a hypothesis first proposed by the Italian physicist Ettore Majorana . The neutrino could transform into an antineutrino ( and vice versa ) by flipping the orientation of its spin state .
Simplified: Each neutrino has an antiparticle , called an antineutrino .