How do they measure the mass of the electron in units of MeV/c*c ?

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SUMMARY

The mass of the electron is experimentally determined to be 0.511 MeV/c², derived from the equation E=mc². Modern methods for measuring this value include analyzing the energy and wavelength of gamma rays produced during electron-positron annihilation. While historical methods like Millikan's oil drop experiment and Thomson's charge-to-mass ratios are significant, contemporary techniques focus on high-energy physics experiments that utilize particle accelerators and detectors. Understanding the conversion of mass into energy units, specifically MeV/c², is crucial for interpreting results in particle physics.

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  • Familiarity with gamma radiation and its properties
  • Knowledge of particle accelerators and detection methods
  • Basic grasp of energy-mass equivalence and unit conversions in physics
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  • Research the experimental setups used in high-energy physics, particularly those involving electron-positron annihilation
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What is the experimental system used to determine that an electron has a mass of 0.511 MeV/c*c ?

I'd like to learn about methods other than Millikan's oil drop and Thomson's charge/mass ratios. What is the modern way to generate a value with those units?
 
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You can give some credit to nuclear beta decay.
 
The units come from the equation E =mc^2

If you re-rewite the equation in terms of units eV = kg c^2 and re-arrange it for mass, you get kg = eV/c^2

and so the numerical value for the mass of the electron is equal to the numerical value of its energy/c^2. So we can give mass in terms of eV/c^2
 
I understand what you are saying, but I believe that there is some sort of experimental equipment setup that can and has been used to physically measure the 0.511 MeV or 0.511 MeV/c2 values. It is that info I am after. I would be grateful for any references or links that reveal the nature of that experimental equipment.
Thanks!
 
Observations of the energy/wavelength/frequency of the gammas which result from the annihilation of electrons and positrons?
 
There is no experimental method to single out any system of units. It doesn't matter if you report the measured value of the mass in kilograms, slugs, or dynes/g. You can always convert to MeV/c2.
 
Hello! I'm also confused regarding these units, given the equation E=\gammamc2, i am to show the mass of a proton in the units MeV/C^2, however i have no idea how to convert into these units. Is this form of the display of mass actually a measure of the relativistic energy that the particle has?
 

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