A Proposal About the Rest Masses of Quarks

In summary, the recommended reading for string theory includes a proposal by Jiao Lin Xu about the rest masses of quarks. The author uses string theory to determine the rest masses of quarks, which are given as u=930, d=930, s=1110, c=2270, b=5530. However, the average rest masses calculated by the Particle Data Group are much smaller, with u=0.003, d=0.00675, s=0.1175, c=1.2, b=4.25 GeV. The conversation then delves into the different definitions of mass for quarks and the challenges in accurately determining their values. One reply mentions Peter Woit's criticism of
  • #1
elas
List of reccomended reading for string theory includes-
'A Proposal About the Rest Masses of Quarks'
by Jiao Lin Xu

Using String Theory the rest mass of quarks is given as-
u=930, d=930, s=1110, c=2270, b=5530

The average rest mass of the figures given by the (international) Particle Data Group are
u=0.003, d=0.00675, s=0.1175, c=1.2, b=4.25 GeV

How do I make a comparison between these two statements?
 
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  • #2
Maybe the problem is how to assign mass to quarks. There are different definitions for what you call mass in the case of quarks, and one must be careful not to speak too loosely about it. Notice that leptons have a very well defined mass, even though it might not be precisely measured (yet).

One definition is the coefficient that appears in the Dirac part of the QCD lagrangian. This results in a renormalized mass, or "running mass", which is usually what one considers as the true mass for the quarks, and is called Standard Model mass.

An other one is furnished by the quark model. This is a classical interpretation, as :
Mass(composite object) = Sum[ Mass(constituents) ] + Binding_Energy (which is negative !)
In my opinion, this is closer to what one determines in String theory. But this is doubtlessly flawed by the fact that the term Binding_Energy is meaningless here, at least on a classical level, because of confinement.

There are still other definitions. In lattice QCD, the mass of the quarks are "bare mass", different from the running MS mass. These parameters are to be determined, so as to produce optimized numerical value for known quantities, such as meson mass.

So, as a conclusion : do not expect anyone to give you a true value for the quark mass, unless first providing a correct definition for this quantity
 
  • #3
humanino

Only one reply but it proves that quality comes in small quantities; many thanks.
Peter Woit's criticism of string theory included an objection to the string theory conclusion that there are an infinite number of fundamental particles. In my latest addition to my development of a vacuum theory, I have added a piece on mass and charge. this not only shows a new way of relating quark masses but also that there is indeed (in theory) an infinite number of fundamental particles. It also shows in practicle terms why they are unlikely to exist in reality.
To do this I have used the average mass for each quark calculated from the figures published by the Particle Data Group. The debate on my proposal is in the Theory Developement forum
 

1. What are quarks?

Quarks are fundamental particles that make up protons and neutrons, which are the building blocks of atoms. They are also responsible for the strong nuclear force that holds these particles together.

2. What is the rest mass of a quark?

The rest mass of a quark is a fundamental property that determines its energy and behavior. It is measured in units of energy, such as electron volts (eV) or kilograms (kg). The rest mass of a quark is incredibly small, with the top quark being the heaviest at approximately 173,000 times the mass of an electron.

3. How are the rest masses of quarks determined?

The rest masses of quarks are determined through experiments, such as particle colliders, where scientists can observe the behavior and interactions of quarks. The Standard Model of particle physics also provides theoretical predictions for the rest masses of quarks.

4. Why is it important to study the rest masses of quarks?

Studying the rest masses of quarks helps us understand the fundamental building blocks of matter and the forces that govern their interactions. It also allows us to test and refine our theories about the nature of the universe and its origins.

5. Can the rest masses of quarks change?

The rest masses of quarks are considered to be constant values, meaning that they do not change over time. However, in certain extreme conditions, such as high-energy collisions or interactions with other particles, the rest masses of quarks can appear to change due to the effects of the strong nuclear force.

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