1. Not finding help here? Sign up for a free 30min 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!

Qq- ->qq- differential cross section and mandelstam variables

  1. Nov 17, 2012 #1
    qq- --->qq- differential cross section and mandelstam variables

    1. The problem statement, all variables and given/known data
    for the problem statement please look the attachement


    2. Relevant equations
    The problem is asking to express the mandelstam variables in temrs of the scattering angle θ.I would like to ask the quastion weather there varibles should depend on qq- --->qq- process or they are the same for any process A+B--->A+B ? And then what does it mean massless limit i.e WHICH masses become zero ?
    It is not obvious from where i should start to calculate the mandslestam variables in terms of the scaterring angle.

    3. The attempt at a solution
     

    Attached Files:

    • MV.PNG
      MV.PNG
      File size:
      10.9 KB
      Views:
      86
  2. jcsd
  3. Nov 18, 2012 #2
    Re: qq- --->qq- differential cross section and mandelstam variables

    I think you know about those s,t and u.you may also be aware of fact that only two of it are independent because of the relation
    s+t+u=4m2
    since everything is asked in cm frame,so it is easy.Because in rest frame as you can show
    s=4E2=4(|p|2+m2)
    t=-2|p|2(1-cosθ)
    u=-2|p|2(1+cosθ),since |p|=|p'|
    massless limit is also called high energy limit,in which E>>m,so you can neglect m in comparison to |p|.θ is scattering angle in CM system.
     
  4. Nov 20, 2012 #3
    Re: qq- --->qq- differential cross section and mandelstam variables

    thanks
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Qq- ->qq- differential cross section and mandelstam variables
  1. Mandelstam variable (Replies: 4)

Loading...