Understanding how Madgraph handles the ttgamma syntax
Dear Madgraph authors,
We are currently working on a ttgamma analysis and when reviewing again our process cards, we want to make sure we understand the syntax correctly:
import model sm-ckm_no_b_mass
define p = p b b~
define j = j b b~
define part = ve vm vt e- mu- ve~ vm~ vt~ e+ mu+ ta- ta+
generate p p > t t~ a, t > b part part, t~ > b~ part part @1
add process p p > t t~, t > b part part a, t~ > b~ part part @2
add process p p > t t~, t > b part part , t~ > b~ part part a @3
As you can see, the goal is to have a 2->7 ttgamma process, where the photon could be emitted by the top, ISR or the top decay products. Now, if we would look at the produced diagrams, you would see that some diagrams appear in both @1 and @2, and similar for @1 and @3. Indeed, also in @2 and @3, the photon could still be emitted from the top quarks.
Therefore we want to make sure there is no risk of double counting here. We do not know how exactly Madgraph handles these situations, though I would assume double counting is avoided. Can you confirm this?
Thanks,
Tom
Question information
- Language:
- English Edit question
- Status:
- Answered
- Assignee:
- No assignee Edit question
- Last query:
- Last reply:
Can you help with this problem?
Provide an answer of your own, or ask Tom Cornelis for more information if necessary.