QED evolution LO

[scarlehoff]

What Marek and Alan asked for more than one year ago :P

[felixhekhorn]

https://arxiv.org/abs/1911.12040 might be a good starting place or eventually a possible comparison ...

[scarrazza]

Yes, in fact this should be exactly what people want so see

[scarlehoff]

Mm, I missed this. I wonder whether this means they don't need us anymore :_

[scarrazza]

Yes and no. They do not release an LHAPDF set, but for sure if you ask them we could get it...

[scarrazza]

Anyway, they are working on that since I left CERN.

[felixhekhorn]

talk by Paolo N in the seminar https://indico.cern.ch/event/918896/

[felixhekhorn]

until we do, I use this place to collect references: https://arxiv.org/pdf/2007.14300.pdf seems like it is an active filed of research

[felixhekhorn]

https://arxiv.org/pdf/2008.02895.pdf "Factorized approach to radiative corrections for inelastic lepton-hadron collisions"

[felixhekhorn]

https://arxiv.org/pdf/2009.12220.pdf "Parton distributions in radiative corrections to the crosssection ofelectron-proton scattering"

[felixhekhorn]

Hi,

During our last meeting we briefly discussed QED evolution equations, and I believe what we'll need are the DGLAP equations

• in the complex-mass scheme [1], with

• alpha set according to the Gmu scheme [2], i.e.

  alpha = sqrt(2)/pi * Gmu * | MW^2 * (1 - MW^2 / MZ^2) |

where

MW^2 = mw^2 - i * gw * mw
MZ^2 = mz^2 - i * gz * mz

are complex parameters using the real pole masses mw/mz, and widths gw/gz.

That's at least what we use in our theory calculations.

Do you already have a timeline for this feature?

Best,
Christopher

[1] https://arxiv.org/abs/1912.06823, sec. 6.6
[2] https://arxiv.org/abs/1912.06823, sec. 5

[alecandido]

Updated references on DGLAP QED solution:

• section 2.2.3 in @scarrazza thesis
• section 2 of photon PDF from LHC data
• appendix A in APFEL's lepton PDF

[felixhekhorn]

A comparison between LuxQED and DGLAP: https://indico.bnl.gov/event/9726/contributions/46331/
https://www.youtube.com/watch?v=wvvVMiHFfnI&list=PLSU3NGiXqGfkDc4pQOmfqQj1qc3LlqMKX&index=4 starting ~ 01:05:00

[juanrojochacon]

https://inspirehep.net/literature/1840369 Calculation of photon-induced Drell-Yan by means of the structure function approach

[felixhekhorn]

https://arxiv.org/abs/1911.12040 might be a good starting place or eventually a possible comparison ...

https://github.com/gstagnit/ePDF