QCD: Understanding Leading and Higher Twists

  • Thread starter Thread starter Able
  • Start date Start date
  • Tags Tags
    Qcd
Able
Messages
8
Reaction score
0
Can anyone explain to me what "twist" refers to in the context of QCD? More specifically, I have come across the terms "leading twist" and "higher twist".
 
Physics news on Phys.org
The twist of an operator is its dimensionality minus its Lorentz spin.
 
Thanks Vanadium 50
 
Toponium is a hadron which is the bound state of a valance top quark and a valance antitop quark. Oversimplified presentations often state that top quarks don't form hadrons, because they decay to bottom quarks extremely rapidly after they are created, leaving no time to form a hadron. And, the vast majority of the time, this is true. But, the lifetime of a top quark is only an average lifetime. Sometimes it decays faster and sometimes it decays slower. In the highly improbable case that...
I'm following this paper by Kitaev on SL(2,R) representations and I'm having a problem in the normalization of the continuous eigenfunctions (eqs. (67)-(70)), which satisfy \langle f_s | f_{s'} \rangle = \int_{0}^{1} \frac{2}{(1-u)^2} f_s(u)^* f_{s'}(u) \, du. \tag{67} The singular contribution of the integral arises at the endpoint u=1 of the integral, and in the limit u \to 1, the function f_s(u) takes on the form f_s(u) \approx a_s (1-u)^{1/2 + i s} + a_s^* (1-u)^{1/2 - i s}. \tag{70}...

Similar threads

Replies
38
Views
5K
Replies
1
Views
2K
Replies
3
Views
2K
Replies
5
Views
2K
Replies
2
Views
2K
Replies
8
Views
2K
Replies
5
Views
2K
Back
Top