Narrow-width approximation

  1. Hi all,

    I try to understand the difference which can made by using or not using NWA ..
    I have a process have cross section (p p > x x) ~ 10^-5 pb , where x is a paricle have mass mx = 2 TeV
    and dominant decay channel (x > b b~) with Gamma (x > b b~) ~ 6 * 10^2 GeV ,
    while sigma ( p p > x x , x > b b~) ~ 10^-6 pb (I calculate this with a program not using the NWA)..

    It's clear that if NWA is used sigma ( p p > x x , x > b b~) will just ~ 10^-5 pb since BR (x > b b~) =1,
    so what does mean 10^-5 (NWA) and 10^-6 (non- NWA)

    Is that what meant by that NWA has ## \Gamma/m ## approximation ?

    Last edited: Nov 22, 2013
  2. jcsd
  3. Let me try to understand more.

    Are you pair producing these two new particles? Then looking at the final state of 4 bs?

    And your partial width of x>b bbar is 5% of the mass of x?
  4. Hi,
    I think I get it, thanks.
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