so we just need another tune to fit the data, don’t we?
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So we just need another tune to fit the data, don’t we?. Zoltan Nagy. So we just need another tune to fit the data, don’t we?. Zoltan Nagy. MPI kernel : NLO → Need to consider NLO and colour-subleading contributions to standard shower. - PowerPoint PPT PresentationTRANSCRIPT
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
So we just need another tune to fit the data, don’t we?
Zoltan Nagy
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
So we just need another tune to fit the data, don’t we?
Zoltan Nagy
MPI kernel : NLO → Need to consider NLO and
colour-subleading contributions to standard shower
St. Andrews, 26/8/11
![Page 3: So we just need another tune to fit the data, don’t we?](https://reader035.vdocument.in/reader035/viewer/2022062517/56813167550346895d97de00/html5/thumbnails/3.jpg)
Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
So we just need another tune to fit the data, don’t we?
Zoltan Nagy
MPI kernel : NLO → Need to consider NLO and
colour-subleading contributions to standard shower
St. Andrews, 26/8/11
![Page 4: So we just need another tune to fit the data, don’t we?](https://reader035.vdocument.in/reader035/viewer/2022062517/56813167550346895d97de00/html5/thumbnails/4.jpg)
Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
So we just need another tune to fit the data, don’t we?
Zoltan Nagy
Colour reconnection effects are
important when comparing MC
predictions to data
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
So we just need another tune to fit the data, don’t we?
Zoltan Nagy
Colour reconnection effects are
important when comparing MC
predictions to data
St. Andrews, 26/8/11
![Page 6: So we just need another tune to fit the data, don’t we?](https://reader035.vdocument.in/reader035/viewer/2022062517/56813167550346895d97de00/html5/thumbnails/6.jpg)
Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
Do we have a good understanding of MPIs and mPDFs?
Jo GauntBattlefield restricted to Double Parton Scattering
Assumption:
“dPDF framework”, used in phenomenology→ longitudinal-transverse factorization also in MCs
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
Jo Gaunt
Evolution equations for dPDFs known, would give contributions to DPS cross sections of the sort:
According to dPDF the diagram should contribute a DGLAP log but well known box diagram contributions, e.g. for gg→ZZ, are finite!
Do we have a good understanding of MPIs and mPDFs?
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
Jo Gaunt
Evolution equations for dPDFs known, would give contributions to DPS cross sections of the sort:
According to dPDF the diagram should contribute a DGLAP log but well known box diagram contributions, e.g. for gg→ZZ, are finite!
In general, all diagrams with the “DPS-singularity” give only integrable contributions to the cross section: this is a correction to a single scattering process
The apparent inconsistency due to the transverse-longitudinal factorization assumption: the dPDF framework breaks down!
Do we have a good understanding of MPIs and mPDFs?
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
Jo GauntEvolution equations for dPDFs known
According to dPDF the diagram should contribute a DGLAP log but the well known box diagram contributions are finite!
In general, all diagrams with the “DPS-singularity” give only integrable contributions to the cross section: this is a correction to a single scattering process
The apparent inconsistency due to the transverse-longitudinal factorization assumption: the dPDF framework breaks down!
Do we have a good understanding of MPIs and mPDFs?
Impact on phenomenology – definition of DPS cross section?
DPS at high pT will be measured: another test of MPI models in MCs
mPDFs and mPDFs running in MC?
Interference effects in flavour, spin and colour?
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
What is the impact of soft QCD corrections on jet physics?
Mrinal Dasgupta
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
What is the impact of soft QCD corrections on jet physics?
Mrinal Dasgupta
Soft QCD corrections to jets
Hadronization <δpt>h~ -1/R
Underlying Event <δpt>UE~ R2
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
An example of measurement particularly sensitive to UE
modelling?But beware, difficult
measurement! (track jets?)
Mrinal Dasgupta
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
What would be the impact of soft QCD effects on (feasibility of some) LHC searches?
Simone MarzaniJet-pull method: identification of hard subprocess from studying colour flow
Expect:
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
What would be the impact of soft QCD effects on (feasibility of some) LHC searches?
Simone MarzaniJet-pull method: identification of hard subprocess from studying colour flow
Expect:
But get: b
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
The DIPSY alternativeDIPSY = Dipole Event Generator Gösta Gustafson
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
The DIPSY alternativeGösta Gustafson
Fair description of exclusive final states: MB and UE
The DIPSY alternative
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
Gösta Gustafson
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
Gösta Gustafson
from DIPSY
St. Andrews, 26/8/11
€
σ eff−1 = d2∫ b F(b,..)F(b,..)
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
Summary of the soft QCD working group
Within this working group:
Proposed: new measurements
Emphasized: need to compare data with various available MC models* / identify measurements which cannot be well described by all MCs/tunes
Highlighted: many theoretical issues / open questions in the description of soft QCD
The real big question:
Are we happy with the current status? Is tuning the end of the story?
Certainly not satisfactory from the theory point of view…
*i.e. Sherpa
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
Summary of the soft QCD working group cntd.
Open call to both theory and experiment:
Is there a need for more measurements? Can we come up with measurements sensitive to particular aspects of soft QCD (hadronization, MPI, non-perturbative)?
Proposals need to be made now!
St. Andrews, 26/8/11
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Anna Kulesza (RWTH Aachen) Summary of soft QCD WG part 2
Summary of the soft QCD working group
Open call to both theory and experiment:
Is there a need for more measurements? Can we come up with measurements sensitive to particular aspects of soft QCD (hadronization, MPI, non-perturbative)?
Proposals need to be made now!
Many thanks to all the speakers and contributors!
St. Andrews, 26/8/11