xsection parton - hadronic level

[cakir@cern.ch]

Hi all,

I am gonna ask xsections for parton and hadron level differences Sherpa-1.1.2 with respect to Alpgen-2.13 (Pythia). I attached my generation cards which it is used for this generations. The question related to this case is about Drell-Yan,1,2,3 jets rate according to the total xsection when you compare Alpgen and other generators. For example , Alpgen(Pythia) gives moreless same total hadronic-xsection around ~966.4 pb (Sherpa ~947pb) but the rate of the jet generation in Alpgen(Pythia) is for Drell_Yan (Alpgen(Pythia)%74 --Sherpa~%59) , first Jet Alpgen(Pythia)~%17 -- Sherpa ~%24 , second Jet Alpgen(Pythia)~%5 -- Sherpa ~15 , and third jet Alpgen(Pythia)~%1-2 -- Sherpa ~%9 respectively. In Sherpa, this rates are quite different than Alpgen(Pythia) xsections. According to the validation works with Sherpa vs Alpgen , xsection is moreless the same at least up to third jet and we know that third jet slightly bigger than Alpgen xsections. As far as i seen from generation , these differences in Sherpa is quite high according the Alpgen(Pythia) hadronic and partonic xsections and automatically effects distributions according to the JetET and so on. Does anybody can explain xsection for parton and hadronic level differences according to these generation. Does wieghted -unweighted effeciency differences effect so much ? Why Drell_yan xsections in Sherpa is very less than Alpgen ?

best,

Altan

[anonymous]

second and third jets differences in Sherpa are %11 and %5 repectively . sorry for typo error

Replying to cakir@cern.ch:

Hi all,

I am gonna ask xsections for parton and hadron level differences Sherpa-1.1.2 with respect to Alpgen-2.13 (Pythia). I attached my generation cards which it is used for this generations. The question related to this case is about Drell-Yan,1,2,3 jets rate according to the total xsection when you compare Alpgen and other generators. For example , Alpgen(Pythia) gives moreless same total hadronic-xsection around ~966.4 pb (Sherpa ~947pb) but the rate of the jet generation in Alpgen(Pythia) is for Drell_Yan (Alpgen(Pythia)%74 --Sherpa~%59) , first Jet Alpgen(Pythia)~%17 -- Sherpa ~%24 , second Jet Alpgen(Pythia)~%5 -- Sherpa ~15 , and third jet Alpgen(Pythia)~%1-2 -- Sherpa ~%9 respectively. In Sherpa, this rates are quite different than Alpgen(Pythia) xsections. According to the validation works with Sherpa vs Alpgen , xsection is moreless the same at least up to third jet and we know that third jet slightly bigger than Alpgen xsections. As far as i seen from generation , these differences in Sherpa is quite high according the Alpgen(Pythia) hadronic and partonic xsections and automatically effects distributions according to the JetET and so on. Does anybody can explain xsection for parton and hadronic level differences according to these generation. Does wieghted -unweighted effeciency differences effect so much ? Why Drell_yan xsections in Sherpa is very less than Alpgen ?

best,

Altan

[Frank Siegert]

Solved in email communication.

[Stefan Hoeche]

Milestone old deleted