# Other values of mass of the electron and the charge of the electron?

Are there whatever experimental data other than Millikan Oil Droplet experiments data and Stoney calculations from electrolysis low, or some experimental indications pointed on the possibility that the mass of the electron and the charge of the electron can be larger than we known from textbooks ? And, we are not consider moving electron in SRT.

• well the values that are on the textbooks are the values that have been experimentally measured... The charge of the electron actually depends on the energy at which you are probing it though, as the higher the energy the more non-negligible terms you have in the Feynman diagram expansion (more energy => creates more virtual particles, that "shield" the bare charge of the electron and effectively reduce it, if you are looking from outside this virtual cloud. With high energy, you can 'break through' and you see a smaller charge). – SuperCiocia Nov 21 '15 at 21:53
• As far as the mass is concerned, there is something called the effective mass, which can be very different from the nominal mass of the electron. It basically comes from incorporating into Newton II the interaction between the electron (of well known mass m) with its surroundings (e.g. a crystal), which results in an artifical 'm' term, called the effective mass. Is the kind of things that you are looking for, or is your question aiming at a different answer? What's SRT? Special Relaitity...? – SuperCiocia Nov 21 '15 at 21:55
• @SuperCiocia, I am looking for pure experimental evidences, not theoretical. Yes, special relativity. My expectation is to have some evidence that these two parameters can be larger. – VYT Nov 21 '15 at 22:04
• I don't understand the question. Our knowledge of these properties comes from experiments, not books. – Javier Nov 21 '15 at 22:45
• No questions about the charge to mass ratio, this value was determined independently on the charge and mass (by Thompson, first). Charge of electron came from the Millikan Oil Droplet experiment and Stoney calculations from electrolysis low. Mass was calculated from the charge to mass ratio and the charge from the Millikan’s value. So, my question is on measurements of the charge and reliability of Millikan experiments data. I need other experiments on electron charge than from Millikan and Stoney. Some more examples ? – VYT Nov 21 '15 at 23:02

People have certainly measured the electron's charge and mass more than once in the last 100 years. See for example this table from the Particle Data Group, where you can find the constants you want to around 8 significant digits, much more than what was possible for Millikan. For comparison, Wikipedia claims that Millikan and Fletcher measured $e$ to be $1.5924(17) \times 10^{-19}\ \mathrm{C}$, while the table I linked gives a value of $1.602\, 176\, 565(35)\times 10^{-19}\ \mathrm{C}$, around 0.6% higher. Rest assured that any data you find in textbooks is very likely to contain relatively recent measurements, unless the textbook was written a century ago.