neutrino (electron neutrino)

https://doi.org/10.1351/goldbook.N04115
An elementary particle of negligible mass and zero electric charge. There are also a muon neutrino and tau neutrino.
Source:
Green Book, 2nd ed., p. 93 (https://dev.goldbook.iupac.org/files/pdf/green_book_2ed.pdf)