So we just need another tune to ﬁt the data, don’t we? › event › 311 › ... · Anna Kulesza (RWTH Aachen) Summary of so QCD WG part 2 St. Andrews, 26/8/11 What is the impact

Sowejustneedanothertunetofitthedata,don’twe?

ZoltanNagy

St.Andrews,26/8/11AnnaKulesza(RWTHAachen)SummaryofsoFQCDWGpart2


ZoltanNagy

MPIkernel:NLO→NeedtoconsiderNLOandcolour‐subleadingcontribu:ons

tostandardshower



ZoltanNagy

MPIkernel:NLO→NeedtoconsiderNLOandcolour‐subleadingcontribu:ons

tostandardshower



ZoltanNagy

Colourreconnec:oneffectsare

importantwhencomparingMC

predic:onstodata



ZoltanNagy

Colourreconnec:oneffectsare

importantwhencomparingMC

predic:onstodata


DowehaveagoodunderstandingofMPIsandmPDFs?

JoGauntBaBlefieldrestrictedtoDoublePartonScaBering

Assump:on:

“dPDFframework”,usedinphenomenology→longitudinal‐transversefactoriza:onalsoinMCs


JoGaunt

Evolu:onequa:onsfordPDFsknown,wouldgivecontribu:onstoDPScrosssec:onsofthesort:

AccordingtodPDFthediagramshouldcontributeaDGLAPlogbutwellknownboxdiagramcontribu:ons,e.g.forgg→ZZ,arefinite!



JoGaunt

Evolu:onequa:onsfordPDFsknown,wouldgivecontribu:onstoDPScrosssec:onsofthesort:

AccordingtodPDFthediagramshouldcontributeaDGLAPlogbutwellknownboxdiagramcontribu:ons,e.g.forgg→ZZ,arefinite!

  Ingeneral,alldiagramswiththe“DPS‐singularity”giveonlyintegrablecontribu:onstothecrosssec:on:thisisacorrec:ontoasinglescaBeringprocess

  Theapparentinconsistencyduetothetransverse‐longitudinalfactoriza:onassump:on:thedPDFframeworkbreaksdown!



JoGauntEvolu:onequa:onsfordPDFsknown

AccordingtodPDFthediagramshouldcontributeaDGLAPlogbutthewellknownboxdiagramcontribu:onsarefinite!

  Ingeneral,alldiagramswiththe“DPS‐singularity”giveonlyintegrablecontribu:onstothecrosssec:on:thisisacorrec:ontoasinglescaBeringprocess

  Theapparentinconsistencyduetothetransverse‐longitudinalfactoriza:onassump:on:thedPDFframeworkbreaksdown!


  Impactonphenomenology–defini:onofDPScrosssec:on?

  DPSathighpTwillbemeasured:anothertestofMPImodelsinMCs

  mPDFsandmPDFsrunninginMC?

  Interferenceeffectsinflavour,spinandcolour?


Whatistheimpactofso[QCDcorrec:onsonjetphysics?

MrinalDasgupta


Whatistheimpactofso[QCDcorrec:onsonjetphysics?

MrinalDasgupta

So[QCDcorrec:onstojets

Hadroniza:on<δpt>h~‐1/R

UnderlyingEvent <δpt>UE~R2


Anexampleofmeasurementpar:cularlysensi:vetoUE

modelling?Butbeware,difficult

measurement!(trackjets?)

MrinalDasgupta


Whatwouldbetheimpactofso[QCDeffectson(feasibilityofsome)LHCsearches?

SimoneMarzaniJet‐pullmethod:iden:fica:onofhardsubprocessfromstudyingcolourflow

Expect:


Whatwouldbetheimpactofso[QCDeffectson(feasibilityofsome)LHCsearches?

SimoneMarzaniJet‐pullmethod:iden:fica:onofhardsubprocessfromstudyingcolourflow

Expect:

Butget: b


TheDIPSYalterna:ve

DIPSY=DipoleEventGenerator GöstaGustafson


TheDIPSYalterna:veGöstaGustafson

Fairdescrip:onofexclusivefinalstates:MBandUE

TheDIPSYalterna:ve


GöstaGustafson


GöstaGustafson

fromDIPSY


€

σ eff−1 = d2∫ b F(b,..)F(b,..)

Summaryoftheso[QCDworkinggroup

Withinthisworkinggroup:

  Proposed:newmeasurements

  Emphasized:needtocomparedatawithvariousavailableMCmodels*/iden:fymeasurementswhichcannotbewelldescribedbyallMCs/tunes

  Highlighted:manytheore:calissues/openques:onsinthedescrip:onofso[QCD

  Therealbigques:on:

Arewehappywiththecurrentstatus?Istuningtheendofthestory?

Certainlynotsa0sfactoryfromthetheorypointofview…

*i.e.Sherpa


Summaryoftheso[QCDworkinggroupcntd.

Opencalltoboththeoryandexperiment:

Isthereaneedformoremeasurements?Canwecomeupwithmeasurementssensi:vetopar:cularaspectsofso[QCD(hadroniza:on,MPI,non‐perturba:ve)?

Proposalsneedtobemadenow!


Summaryoftheso[QCDworkinggroup

Opencalltoboththeoryandexperiment:

Isthereaneedformoremeasurements?Canwecomeupwithmeasurementssensi:vetopar:cularaspectsofso[QCD(hadroniza:on,MPI,non‐perturba:ve)?

Proposalsneedtobemadenow!

Manythankstoallthespeakersandcontributors!


Documents

So we just need another tune to ﬁt the data, don’t we? › event › 311 › ... · Anna Kulesza (RWTH Aachen) Summary of so QCD WG part 2 St. Andrews, 26/8/11 What is the impact