1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Quark content of particles

  1. Apr 3, 2014 #1
    1. The problem statement, all variables and given/known data

    Write down the quark content of the following particles, made of (u; d; s) and their antiquarks:

    (a) A meson with strangeness S = 1, and isospin component I3 = 1/2

    (b) An antibaryon with strangeness S = 0, and isospin I3 = -3/2



    3. The attempt at a solution

    a) A meson consists of one quark and one antiquark. The strangeness comes from an anti-strange quark and an up quark satisfies the isospin So we have [itex]u\bar{s}[/itex]

    b) The antibaryon must have three antiquarks and in this case none can be strange. In order to have isospin of -3/2 we must have three antiup quarks, ie [itex]\bar{u}\bar{u}\bar{u}[/itex]

    My answer for a) is correct and b) seems ok.

    Here is the given solution to b).

    "An antibaryon contains three antiquarks. There can be no strange antiquarks if S=0 Also,
    isospin component I3 = -3/2 tell us there must be three antiup quarks. So the answer is [itex]\bar{d}\bar{d}\bar{d}[/itex]."

    This is just a typo at the end, right?
     
    Last edited: Apr 3, 2014
  2. jcsd
  3. Apr 4, 2014 #2

    lightgrav

    User Avatar
    Homework Helper

    If they had wanted a (regular) baryon, it would have been ddd , right?
    I'll bet the question WAS originally (previous edition) for a baryon with I3 = - 3/2
    When they changed the problem (for the new edition), the editor changed the (regular) to anti-,
    but didn't notice that he also needed to negate the isospin projection (or change d to u in the solution).
     
  4. Apr 4, 2014 #3
    Thanks. I just wanted to make sure as this stuff is new to me.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Quark content of particles
  1. Quark content (Replies: 2)

Loading...