Why neutron is heavier than proton

Then, how can we measure such long lifetime? If we can collect many protons and some of them decay, we can estimate proton lifetime unless waiting for so long time. Super-Kamiokande uses 50, tons of pure water and it contains 7x10 33 protons. We are measuring proton lifetime with huge number of protons. Super-Kamiokande has started measurement since and is running more than 10 year, however, we have not observed any evidence of proton decay yet.

What is a neutron? How did James Chadwick contribute to the atomic theory? How do you calculate the density of a neutron? Why did James Chadwick use beryllium? Why did James Chadwick win the Nobel prize? Why is a neutron chargeless? Are protons and neutrons smaller than electrons? How many neutrons are in neon? See all questions in Discovery of the Neutron. Impact of this question views around the world. Why is Neutron Heavier than Proton?

Asked 9 years, 3 months ago. Active 2 years, 10 months ago. Viewed 21k times. Improve this question. Community Bot 1. Further, there is no reason to expect an exact match between the nucleon masses unless isospin is a good symmetry and it is known to be broken. Further still, the neutrino mass differences squared extracted from neutrino beams and solar neutrinos agree with those for the antineutrinos.

Add a comment. Active Oldest Votes. Improve this answer. Matt Reece Matt Reece 7, 2 2 gold badges 25 25 silver badges 47 47 bronze badges. Carlos Carlos 4, 4 4 gold badges 31 31 silver badges 52 52 bronze badges. Jerry Schirmer Jerry Schirmer The proton is already unstable in the standard model, by anomalies, as shown by t'Hooft, but the rate at ordinary energies is vanishing.

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