Energy of Up & Down Quarks in Joules: What Are They?

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    Energy Joules Quarks
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Discussion Overview

The discussion centers around the energy values of up and down quarks expressed in Joules, exploring the challenges in determining these values and the methods used to estimate quark masses. The scope includes theoretical considerations, experimental challenges, and mathematical conversions between units.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant requests the energy values of up and down quarks in Joules, indicating difficulty finding this information online.
  • Another participant suggests that the energy of quarks is not a well-defined number and questions whether the requester means mass or mass-energy equivalent.
  • A different participant points to the need for conversion from electronvolts to joules and provides a link for reference.
  • A participant shares their calculations for the average mass of the up and down quarks in electronvolts and their conversion to joules, presenting specific numerical values.
  • Some participants note that the estimates for quark masses are challenging due to the inability to isolate quarks as particles, and that there are no theoretical predictions for these values.
  • Discussion includes methods for determining particle masses, such as using Penning traps for charged particles or measuring decay products for unstable particles.
  • Participants express that the methods for measuring quark masses are indirect and complicated due to the nature of quarks.

Areas of Agreement / Disagreement

Participants generally agree on the challenges of determining quark masses and the indirect methods required for measurement. However, there is no consensus on the specific energy values of the up and down quarks, as the discussion includes various estimates and interpretations.

Contextual Notes

The discussion highlights limitations in the measurement of quark masses, including the dependence on indirect methods and the lack of theoretical predictions. The conversion process from electronvolts to joules is acknowledged but not fully resolved in terms of accuracy or significance.

mpolo
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I am using a program that requires the energy of the up quark and down quark be given in Joules. I tried to find these values on the internet but could not find these values. Can someone please tell me what is the energy of the Up and Down Quark in Joules?
 
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That's like asking for the speed of a car. What is the speed of a car?

It depends on where these quarks are, and (unlike for cars) often the energy is not even a well-defined number. Do you mean the mass (or the mass-energy equivalent) of the quarks? The Particle Data Group has numbers.
 
okay here's what I have. Check my math. I simply averaged the min max values for mass in Electron volts for the Up Quark and the Down quark then I converted to Joules.

Up Quark = 2.01 Mev = Average value from standard Model
Up Quark = 3.36457079e-13 Joules Converted to Joules
.000000000000336457079 Joules = Input into ProgramDown Quark = 4.79 Mev = Average value from standard Model
Down Quark = 7.67442575e-13 Joules Converted to Joules
.000000000000767442575 Joules = Input into Program
 
These are estimates for the quark masses. There is no theoretical prediction for them and experimental measurements are very challenging as the quarks cannot occur as isolated particles.

The conversion from MeV to J is right. You can easily round the numbers to 2 significant digits, even the second digit is not very meaningful.
 
Thanks for the confirmation of my calculations. I did not know that there was no theoretical prediction for them. That is interesting. So the estimation that we have are vague. How do we determine the masses of particles that we can isolate? I would be very interested to know that.
 
It depends on the particle. If it lives long enough and has an electric charge, put it in a Penning trap. If it decays, measure the energies of the decay products. The only neutral long-living/stable objects known are atoms, and you can ionize them to put them to give them a charge.

If we can produce it in electron/positron collision, measure the energy where it gets produced.

Neutrino masses are much more complicated.
 
This all seems so indirect. Thanks for the additional info. I will give this information some more thought.
 
mpolo said:
This all seems so indirect.

Indeed. Quarks can't occur as isolated particles, so we can't just put them on a scale or something. We have to resort to complicated, indirect methods to measure their masses.
 

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