[Rivet] Born and dressed level in Rivet

[Andy Buckley]

Yep: at the moment, at least, there is no guarantee of how photon
radiation from leptons is to be represented. It could appear as a vertex
correction on the photon production, as a set of emissions from the
lepton line, or something totally mysterious. Until there's some
standard format, a complementary approach that chooses what *not* to
accept is safest.

Did the study of clustering all non-hadronic photons in an infinite cone
(except for a near-beam cut) into a Z definition ever produce any plots?
I was told earlier in the week that this "failed" but I would really
like to know how it went wrong!

By the way, the definition of a particle from a hadron/tau decay used in
Rivet is the one here:

https://rivet.hepforge.org/trac/browser/src/Core/Particle.cc#L19

Note that we use the PID::isHadron() function rather than enumerating
"all" hadrons. This is equivalent to the function of the same name
provided in HepPID.

Andy


On 07/11/13 17:52, Ulla Blumenschein wrote:
> Hi Holger,
> 
> Exactly, this is one of the reasons I  want to advertise your option
> as a SM base line ;-)
> Do you have this comparative study somewhere in indico? I would like
> to send a link to Jan and Pierluigi..
> 
> Many thanks in advance,
> Ulla
> 
> 
> On Thu, Nov 7, 2013 at 5:46 PM, Holger Schulz
> <hschulz at physik.hu-berlin.de> wrote:
>> On 07/11/13 17:35, Ulla Blumenschein wrote:
>>> Hi Holger,
>>>
>>> Many thanks, this sound like a good start. I hope I will soon be able
>>> to compare this definition with the currently used definition in SM
>>> where we request the photons to come from the W/Z/lepton, depending on
>>> the generator..
>>>
>>> Cheers, Ulla
>>>
>>>
>>>
>> No problem.
>> I did a similar comparison and found (IIRC) no difference between the two
>> methods.
>>
>> Concerning the method where you ask for photons radiated off of leptons,
>> does anyone
>> have a feeling how future-proof this would be?
>> What if at some point in the future there is a generator which does
>> NLO photon radiation, shouldn't that dressing method have an intrinsic
>> problem?
>>
>> Cheers,
>> Holger
> 
> 
> 


-- 
Dr Andy Buckley, Royal Society University Research Fellow
Particle Physics Expt Group, University of Glasgow / PH Dept, CERN