what are the names of the scientists who are involved in the discovery of this negative charge?
J. J. Thomson
Electron
J. J. Thomson and his team of British physicists identified it as a particle in 1897. 
what is the exact mass of an electron Approximately 1/1836 that of the proton is the electron a positive charge or a negative charge or is it neutral? Negative charge can you describe any experiment in short where this charge can be produced? UNANSWERABLE
wiki:1606622
Electron [SEP] Introduction
J. Thomson and his team of British physicists identified it as a particle in 1897. Electrons can also participate in nuclear reactions, such as nucleosynthesis in stars, where they are known as beta particles. Electrons can be created through beta decay of radioactive isotopes and in high-energy collisions, for instance when cosmic rays enter the atmosphere. The antiparticle of the electron is called the positron; it is identical to the electron except that it carries electrical and other charges of the opposite sign. When an electron collides with a positron, both particles can be annihilated, producing gamma ray photons.