root file for NLO calculation

Hi,

Could you specify your question? I'm a bit confused about it. Which output file are you discussing?
Which type of NLO computation are you speaking about (fixed order NLO or NLO+PS).
If it is NLO+PS all output file before running Parton-Shower are not physical (since you need to run the PS to made them physical)

Cheers,

Olivier

> On 24 Jul 2017, at 09:14, abulikim2011 <email address hidden> wrote:
>
> New question #652278 on MadGraph5_aMC@NLO:
> https://answers.launchpad.net/mg5amcnlo/+question/652278
>
> hello Expertes
> i have quotation about NLO calculation output file , after finished run the output format not root , i hear even though the format is root ,this root file is unmusical , if we using this root file , it is not okay . the root output file is available when how we do this ?
>
> --
> You received this question notification because you are an answer
> contact for MadGraph5_aMC@NLO.

I am sorry about that , my means that in fixed order NLO calculation how do we can gain the physical root out put file that induced all the information about particles (four momentum and so on ) ,before i calculated fixed order NLO calculation, but in this calculation i modify the HWu.f file where located on FixedOrderAnalysis file , and in this calculation i divided different bins for some physical observables , but this time i don't need to divide bins , only after finishing calculation , according to my needs , i want to analysis like LO calculation .

Hi,

We are not able to generate unweighted events at fix order NLO.
If you want to have access to (nearly) all the weighted events used during the computation, then you can ask to have the LHE output mode. (this is a quite new output format introduced in 2.5.3)
 This will create a (typically huge) lhe file. That you can convert to root file if you want.
Note that a lot of information are set to wrong value on that file since such file can ONLY be used for plotting and can not be passed to any parton-shower.

Cheers,

Olivier

thanks you answer Olivier.
in the NLO level calculation there are not produced lhe file, just appear call hep file , iuse ExROOTAnalaysis can convert to root file , this file indeed huge as you say , but this file is not non-physical that is right? one more question a lot of information are set to wrong value on that file , what is mean this clause? , for example in this process which I want to calculate , only we need to modify set scale , no other requirements.

What is the name of your hep events?

at fix order NLO, you should not have any of those files.
if this is NLO+PS then you should have an unphysical lhe file plus another output depending of your choice of parton-shower.
(stdhep or hepmc)
Those files are physical.

Cheers,

Olivier