Reality → Energy → Particles → Mass-energy equivalence
Einstein’s formula E = m c2 is used to express both energy and mass of particles in electronvolt. It allows to determine rest energy, kinetic energy, rest mass, and relativistic mass of particles in accelerator experiments that include transformation of mass into energy, of energy into mass, as well as annihilation and creation of particles. Mass-energy is conserved in all transformations, as are momentum, charge and some other quantities as defined in conservation laws [1] .
Conservation in quantum mechanics includes baryon and lepton quantum numbers (baryons are particles that include 3 quarks, leptons are elementary particles without any quarks). Baryons and leptons get the quantum number 1, their antiparticles the number -1, and particles that are neither baryon nor lepton get the number 0. The sum of all baryon quantum numbers is conserved, as is the sum of all lepton quantum numbers. The counting and balancing of properties of matter and force carrier particles before and after an experiment contribute to a better understanding of particle and nuclear reactions.