Calculating a Proton’s Mass

Calculating the mass of a proton has been stumping scientists for the longest time now. Only recently they were able to discover what exactly makes up the heft of this subatomic particle. Early findings suggest that only nine percent of the mass of a proton come from the mass of its quarks.

Determining the mass of a proton is not as simple as adding up all its parts. It is a well-known fact that protons are made up of smaller particles called quarks. And usually, when calculating mass, it is enough to add up the mass of all the parts and get the end result. As stated before, only nine percent of the mass of the proton comes from quarks, the rest is a result of complicated effects that are occurring inside the particle.


Using a technique called lattice QCD were able to calculate the protons exact mass which measures about 938 million electron volts of mass. The lattice QCD works by breaking up space and time where the quarks are located into a grid.

Scientists were able to calculate the mass of the proton before, but they have only recently discovered where from exactly does this mass come from. Aside from the nine percent that comes from the quarks, 32 percent comes as a result of the energy produced when those same quarks move around. Gluons, the particles that hold the quarks together add another 36 percent. Finally, the remaining 23 percent is a result of the quantum effects as the quarks and the gluons interact within the proto.

The results of this study come as no surprise. It has long been speculated by researchers that these particles and their interactions are responsible for the mass of the proton. The difference is that scientists now have the scientific knowledge to back these claims up.

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