Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Compute Breit-Wigner for particle decay

  1. Feb 5, 2009 #1
    Hey, Im just woondering if anyone here have computed (numerically) the Breit-Wigner for a particle decay. I have to do some nonlinear fitting of data but I need to compute this, any ideas?

    My case is specific, and Im brand new to particle physics, it's for a tau decay into Kaon, pion and tau neutrino. The expression I have for the Breit-Wigner is posted in: http://mathbin.net/5566 [Broken]

    I still dont understand the math beneath the expression. All Im asked is to compute it, what Im having trouble with is that i on the Breit-Wigner, im not sure if thats the imaginary unit or something different, so if you know please help me compute this. Thanks for the attention.
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Feb 5, 2009 #2
    OK I gave it a second thought and I got it, that BW (for that decay) appears inside a function which is squared, so the imaginary part actually disappears, should have seen this before posting heh, sorry.
  4. Feb 6, 2009 #3


    User Avatar
    Science Advisor

    The Im doesn't disappear, but gets squared in the denominator.
  5. Feb 6, 2009 #4
    OK, thats what I meant by "disappear", sorry the non-technical term. And you are right, it gets squared so that i^2 = -1 and the final result is real which corresponds to the "magnitude" of the complex number.
  6. Feb 6, 2009 #5


    User Avatar
    Science Advisor

    No. You take the complex conjugate so (i)(-i)=+1.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: Compute Breit-Wigner for particle decay
  1. Breit-Wigner formula (Replies: 6)

  2. Breit-Wigner Formula (Replies: 1)

  3. Breit Wigner Formula (Replies: 7)