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Masses of sub- atomic particles

  1. Mar 11, 2009 #1
    does a computer equation exists that can predict the mass of atomic and sub-atomic particles?
     
    Last edited: Mar 11, 2009
  2. jcsd
  3. Mar 11, 2009 #2
    No. One can easily create one by fitting the measured values, but I interpret your question differently, as in "can we compute them from scratch".
     
  4. Mar 11, 2009 #3
    hi..thank you for your reply..!
    i can only say a little at this time..but i believe my father worked on an equation for 45 years that can predict masses of atomic particles. what does this mean if the equation is valid?
     
  5. Mar 11, 2009 #4
    As I said, it is very easy to build such an equation by fitting the data. It is trivial in the sense that it does not explain anything. What must be seen is how you obtain the equation.

    If you obtain the equation by something like "Let's say that the mass of the particle is the vibrational energy of the string. Now the spectrum of possible particles is given by this space-time-gauge structure. When strings propagates in it, I obtain those masses : ...". It's just a semi-dummy example. But basically, we would have replaced the arbitrariness of masses by the arbitrariness of a space-time-gauge structure, which most people would agree is interesting.

    If you obtain the equation by something like "Let me plot the mass as a function of particle number. Now it turns out that mass is approximately A + BxI + C/I + Exp[ pi f(I) ] where A = sqrt[2]/golden ratio ... blablabla ..." that would be boring and most likely useless.

    Both approaches DO have value. The first one is just more likely to lead us somewhere than the second one.
     
  6. Mar 11, 2009 #5
    I guess the point is wether the equation can predict anything that has not yet been measured, so that it can be tested. This could mean

    1.) predicting masses of known particles beyond currently known precision. An experiment with better precision could then test this formula.

    2.) predicting a yet unknown particle, and even better its mass. If its not too high, it could be detected e.g. at the LHC if the formula was correct.

    So I think, in science, it is the predictive power of a theory, and not its explanatory power, that counts. Eventhough I personally find theories that offer a clear, imaginable interpretation of their equations more intriguing - but that is not always the case with modern theoretical physics, as we go way beyond our everyday experiences.
     
  7. Mar 11, 2009 #6
    Is it fair to say that we can calculate hadron properties from QCD? There's a lot fewer parameters in QCD than across the hadrons. I'm not sure how accurate lattice QCD can get yet, or if there are any theoretical reason why lattice QCD wouldn't be able to do the job, in principle.
     
  8. Mar 11, 2009 #7
    Which particles are we referring to?

    if it predicts masses of elementary particles, namely leptons and quarks ... that would be very interesting (if true), because that could give an insight into the next layer above Standard Model.

    If it's hadrons, that would be less exciting - but still that's something we can't do exactly (yet). Lattice QCD allows us to calculate hadron masses from first principles (and conversely, estimate quark masses from known hadron masses), but it's not a "computer equation", it requires supercomputers and enormous amounts of time, and still the best we could come up with is 25-35% precision for light quark masses.
     
  9. Mar 11, 2009 #8
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  10. Mar 12, 2009 #9

    malawi_glenn

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    but there one has to fix the mass of the pion and the kaon in order to get the other masses to work =D
     
  11. Mar 12, 2009 #10
    For sure, but that's just saying that we need the masses of the quarks and the QCD coupling parameter as input to the model. So it's probably fair to say that we can predict the masses of the hadrons given parameters for QCD.
     
  12. Mar 12, 2009 #11

    malawi_glenn

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    Yeah, one has to specify that by saying so. On what level of Ab inito one has.

    Just having an equation that can reproduce or produce masses of stuff without any physics behind it does not mean anything, I would say.
     
  13. Mar 12, 2009 #12
    That's indeed the masses of hadrons, and as you know, we do not have genuine calculations for the masses of fundamental particles. Basically this is the standard model and nothing beyond. It can indeed reproduce quite some stuff...
     
  14. Mar 12, 2009 #13

    malawi_glenn

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    oh yes I know, i just added that to the discussion for the sake of the OP :-)
     
  15. Mar 16, 2009 #14
    gurdjieff1976 here..ok ..guys and girls...!! let me first say..i am a layman...and most of what you are saying in your replys.....goes straight over my head...!!! i'm an artist..
    saying this ..please answer accordly..thanks.... here's the title of the only paper i could find..dealing with the program my father worked on for 45 years " the elementary particle masses" a simple model provides solutions fo the elementary particle masses, including the theoretical mass of the top quark...,author P.B. 1992 ...more to come..>>>> thanks
     
  16. Mar 16, 2009 #15
    Would you mind giving the full citation for the article?
     
  17. Mar 16, 2009 #16
    gurdjieff1976..thanks for the reply.as you probably have guessed..i am alone with the little information i have...scattered notes , one article...(never published)..and this computer program..(equation)..?..my dad passed ..many years ago...without showing me..the in's and out's of the program...the only thing he taught me..was not to show to much...keep it in a black box..never show your complete hand...i will be in contact..and try to show more..how..??...thanks for your patience... P.B. jr.
     
  18. Mar 17, 2009 #17

    malawi_glenn

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    please, he is not serious
     
  19. Mar 17, 2009 #18
    gurdjieff1976 here...ok..i am weary of stating to much info...i am very serious..when it comes to my father's work.!!..i watched him for many years developing it...
    ...my father stated..in his paper..." the model is defined in terms of the kinematic equations of motion describing a rigid rotating body." i was only asking for help..to understand what he had created..and if it was valid....? i am thinking about leaving this quest to my younger brother who has the brains to do so..if you can tolerate..my
    thoughts..i appreciate it...p.b. jr.
     
  20. Mar 17, 2009 #19

    malawi_glenn

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    can a mentor move this thread to independent research forum?

    But since you can't tell us anything, how are we supposed to help you?

    Sounds so sectarian, hiding calculations and articles, not publishing them etc. "keep it in a black box". This is not how the scientific community works.

    If the model is a rigid rotation body, then I see why it has not been published, real physics is much more elegant. Why not spend the time learning real physics instead of this crap?
     
  21. Mar 17, 2009 #20
    gurdjieff1976.hi..it seems some people have their own narrow opinions..without giving a person a chance....i am asking only for help....i dont know my next step..but i dont want
    my father's ideas to be mis-used...that is why i am being safe and cautious...sorry....
    i just need to know the background in this type of research...and see if my dad's ideas are true and valid........i need one person to believe in my dad's work..., and yes...
    i am completely ignorant in high level physics..but i understand the basics.. i think..?? ......thank you... p.b. jr.
     
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