HonexComb meeting #7

53/R-044 (CERN)



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Attendance = 28 

There will be the annual STRONG2020 meeting (14-15 October),
everybody welcome to join : https://indico.in2p3.fr/event/20784/  
Amendment has been submitted, very close to to being approved (and then post-doc hiring procedure will start)
Barbara announce that they work on a 6-month extension 
Next meetings, back to last Tue of the month: Oct 27th (if contributions), Nov 24th 

Marco presents some slides : 
Jet RAA saturates - DeltaE/E constant?
Hadron RAA raises - DeltaE/E decreasing?
Two identified areas of possible common work 
a/ Extending the pt reaches (low pt in Alice, high pt in ATLAS/CMS)
b/ Understanding the tension in fragmentation functions 

Comments (non-exhaustive, nor in order) 
- Matt suggests contacting Chris McGinn about jet spectra, ex-CMS, now in ATLAS
- Matt says that difference in FF at high z may be due to unfolding (done in ATLAS); also to check if the pp is smeared (forward folding ?). The migration in “z” will change after the unfolding procedure is applied. 
- Alex S says we should work on pp
- Alex S says he will talk to Martin Spousta
- Alex K asks which models are able to simultaneously predict the jet and single hadron RAA and Marco answers that mostly event generator based models are able to do this right now
- Giulia asks about pPb ; it is important to probe fragmentation functions only in the mid- rapidity region, in the forward (i.e. LHCb coverage) we can probe nuclear modification effects and shadowing but not the points above. However, it would be nice to have a measurement of RpPb for charged particles in the forward (work in progress)
- General: it would be nice to make a sort of table where the definition of the variables are used, I noted: 
    - what is a “jet” in the different experiments; same for charged particle (pt cut, quality requirements, min energy in the cone of … etc) 
    - what is “z” ? Pz?
- Alice results in red in a zoomed box maybe to see the low-pt region? (s.5)

a/ Interest in combining the results, not that easy for jet because of the different definitions, easier for spectra than RAA…  
b/ Interest in comparing the fragmentation functions, need to bring experts in the same room

Open charm
The Open charm sub-group welcomed the new components and gave a summary of the status. Achim mentioned the ideawould be to produce combined results similar to what was done in the Conference Note describing tbe combination of the 7 TeV results of LHCb and ALICE. A more complete presentation is expected for the next meeting. 
Meetings are on Friday afternoons if you want to join you are welcome! 

Johanna : it would be important to have differential results (i.e. dSigma / dy ) as well as integrated ones.
Matt : Open charm modes did not include  Lambda-c, would be nice to include it (remember: only published results can be used)
Achim similar to what was done by Alice and LHCb for J/psi in pPb at 5 TeV : https://cds.cern.ch/record/1639617/files/LHCb-CONF-2013-013.pdf    


There are minutes attached to this event. Show them.
    • 3:00 PM 3:10 PM
      Welcome 10m
      Speakers: Alexander Philipp Kalweit (CERN) , Giulia Manca (Universita` degli studi di Cagliari and INFN, Cagliari, IT) , Iwona Grabowska-Bold (AGH University of Science and Technology (PL)) , Raphael Granier De Cassagnac (Centre National de la Recherche Scientifique (FR))
    • 3:10 PM 3:30 PM
      Interest for cross-experiment jet activities? [NA3 input] 20m

      NA3-Jet-QGP is another work package of Strong 2020 with whom we could collaborate...

      Speakers: Dr Guilherme Milhano (LIP-Lisbon & CERN TH) , Marco Van Leeuwen (Nikhef National institute for subatomic physics (NL))
    • 3:30 PM 3:50 PM
      Interest for cross-experiment jet activities? [personal input] 20m
      Speaker: Alexandre Shabetai (Centre National de la Recherche Scientifique (FR))
    • 3:50 PM 4:10 PM
      Charm cross section [update] 20m
      Speakers: Achim Geiser (Deutsches Elektronen-Synchrotron (DE)) , Gian Michele Innocenti (CERN) , Jiayin Sun (Tsinghua University)