Description
From the start of the experimental activity of the Large Hadron Collider, Multiple Partonic Interactions (MPI) are experiencing a growing popularity and are widely invoked to account for observations that cannot be explained otherwise. This includes associated hadron production (Underlying Event) in high energy hadronic collisions with jets, the rates for multiple heavy flavor production, the survival probability of large rapidity gaps in hard diffraction, etc. In particular Double Parton Interactions were observed directly and studied by a number of the FNAL and LHC experiments in different reaction channels.
 
At the LHC a new QCD regime has now been reached, where MPIs occur with high rates, in particular in central collisions, where the production of new particles is more likely to take place. Understanding MPIs is therefore crucial, both for their significant contribution to the background of various processes of interest for the search of new physics and because MPIs are an interesting topic of research by itself, allowing to probe high energy - high density QCD dynamics and, as a consequence of the geometrical characteristics of the interaction, to obtain unprecedented information on the correlated structure of the QCD bound states.

The aim of this workshop is to provide an updated view of MPI studies, both experimental and theoretical, and to foster contacts between theoretical and experimental communities active in the field.


TOPICS:

  • Phenomenology of MPI processes and multiparton distributions
  • Considerations for the description of MPI in QCD
  • Measuring multiple partonic interactions
  • Experimental results on inelastic hadronic collisions: underlying event, minimum bias, forward energy flow
  • Monte Carlo development and tuning
  • Connections with low x, diffraction, heavy ion physics and cosmic rays


WORKING GROUPS and CONVENERS:
 


PROCEEDINGS

Proceedings are published in the DESY proceedigs series with report number DESY-PROC-2016-01

The entry in Inspire is http://inspirehep.net/record/1456006


PREVIOUS MEETINGS

MPI@LHC'08 Perugia, Italyhttp://www.pg.infn.it/mpi08/
MPI@LHC'10 Glasgow, Scotlandhttp://www.mpi2010.physics.gla.ac.uk/
MPI@LHC'11 DESY Hamburg, Germanyhttp://mpi11.desy.de/
MPI@LHC'12 CERN Geneva, Switzerlandhttp://indico.cern.ch/conferenceDisplay.py?confId=184925
MPI@LHC'13 Antwerp, Belgium: http://indico.cern.ch/event/231843/
MPI@LHC'14 Krakow, Poland: https://indico.cern.ch/event/305160/
Go to day
  • Monday, 23 November 2015
    • 08:30 - 09:10
      • 08:30 Registration & Administrative Formalities 30' ( Leonardo Building - Lobby )
      • 09:00 Welcome 10' ( Leonardo Building - Budinich Lecture Hall )
        Speaker: G. Villadoro (ICTP)
    • 09:10 - 14:25 Minimum Bias and Underlying Event
      Location: Leonardo Building - Budinich Lecture Hall
      • 09:10 Introduction by Convener 15'
      • 09:25 Recent measurement of underlying events 25'
        Speaker: W.Y. Wang (CMS)
        Material: Slides
      • 09:50 Charged-particle multiplicities at different pp interaction centre-of-mass energies measured with the ATLAS detector at the LHC 25'
        Speaker: R. Iuppa (ATLAS)
        Material: Slides
      • 10:15 Studies of the underlying event and particle production with the ATLAS detector 25'
        Speaker: J. Robinson (ATLAS)
        Material: Slides
      • 10:40 Coffee Break 20' ( Leonardo Building - Lobby )
      • 11:00 Treating jet correlations in high pile-up at hadron colliders 25'
        Speaker: H. Van Haevermaet (Antwerp)
        Material: Slides
      • 11:25 Min Bias WG Phase Space 15'
        Speaker: D. Kar (CMS/ATLAS/ALICE)
        Material: Slides
      • 11:40 Exploring the Underlying Event and Hadronization Using Dijets at STAR 25'
        Speaker: B. Page (STAR)
        Material: Slides
      • 12:05 Charged particle production in proton-proton collisions at \sqrt{s} = 13 TeV, with ALICE at the LHC 25'
        Speaker: P. Palni (ALICE)
        Material: Slides
      • 12:30 Lunch 1h30' ( Leonardo Building - Cafeteria )
      • 14:00 Evaluation of the Underlying Event in pp collisions at a center of mass energy of 500 GeV at STAR 25'
        Speaker: G. Webb (STAR)
        Material: Slides
    • 14:25 - 16:40 Monte Carlo Development and Tuning
      Location: Leonardo Building - Budinich Lecture Hall
      • 14:25 Introduction by Convener 15'
      • 14:40 CMS underlying event and double parton scattering tunes 25'
        Speaker: D. Sunar-Cerci (CMS)
        Material: Slides
      • 15:05 Monte Carlo Tuning at ATLAS 25'
        Speaker: S. Jiggins (ATLAS)
        Material: Slides
      • 15:30 Coffee Break 20' ( Leonardo Building - Lobby )
      • 15:50 Recent Pythia 8 developments: hard diffraction, colour reconnection and photon-photon collisions 25'
        Speaker: I. Helenius (Lund)
        Material: Slides
      • 16:15 SHRIMPS 25'
        Speaker: H. Schulz (Durham)
        Material: Slides
    • 16:40 - 18:05 Double Parton Scattering
      Location: Leonardo Building - Budinich Lecture Hall
      • 16:40 Introduction by Convener 15'
        Material: Slides
      • 16:55 Double parton scattering in same sign W pairs 25'
        Speaker: D. Ciangottini (CMS)
        Material: Slides
      • 17:20 Coffee Break 20' ( Leonardo Building - Lobby )
      • 17:40 Study of high pT particle production from Double Parton Scatterings 25'
        Speaker: P. Gunnellini (CMS)
        Material: Slides
    • 18:05 - 18:30 Minimum Bias and Underlying Event
      Location: Leonardo Building - Budinich Lecture Hall
      • 18:05 Underlying events and flow in EPOS 3 25'
        Speaker: T. Pierog (Karsruhe)
        Material: Slides
    • 19:00 - 20:30 Dinner
      Location: Adriatico Guest House - Cafeteria
      • 19:00 1h30'
  • Tuesday, 24 November 2015
    • 09:00 - 16:25 Double Parton Scattering
      Location: Leonardo Building - Budinich Lecture Hall
      • 09:00 Momentum conservation factor in DPS 25'
        Speaker: A. Snigirev (Moscow)
        Material: Slides
      • 09:25 Studies of double parton interactions with the ATLAS detector 25'
        Speaker: O. Gueta (ATLAS)
        Material: Slides
      • 09:50 A Comment on Multi-Gluon Amplitudes and DPIs 25'
        Speaker: D. Treleani (Trieste)
        Material: Slides
      • 10:15 Effects of double-parton scattering in four-jet production at the LHC 25'
        Speaker: R. Maciula (Cracow)
        Material: Slides
      • 10:40 Coffee Break 20' ( Leonardo Building - Lobby )
      • 11:00 Double parton scattering effects in kt-factorisation for 4-jets production 25'
        Speaker: M. Serino (Cracow)
        Material: Slides
      • 11:25 Double parton scattering in the ultraviolet: addressing the double counting problem 25'
        Speaker: M. Diehl (DESY)
        Material: Slides
      • 11:50 Study of DPS processes at LHCb. 25'
        Speaker: V. Belyaev (LHCb)
        Material: Slides
      • 12:15 The effective cross section of double parton scattering in a Light-Front quark model 25'
        Speaker: M. Rinaldi (Perugia)
        Material: Slides
      • 12:40 Lunch 1h20' ( Leonardo Building - Cafeteria )
      • 14:00 Dynamical approach to MPI four-jet and Wjj/Zjj production in Pythia 25'
        Speaker: B. Blok (Technion)
        Material: Slides
      • 14:25 Cancellation of Glauber gluon exchange in the double Drell-Yan process 25'
        Speaker: J. Gaunt (DESY)
        Material: Slides
      • 14:50 Study of Observables for the measurement of MPI using Z + Jet process 25'
        Speaker: R. Kumar (Panjab)
        Material: Slides
      • 15:15 Constraining the double gluon distribution by the single gluon distribution 25'
        Speaker: K. Golec-Biernat (Cracow)
        Material: Slides
      • 15:40 Coffee Break 20' ( Leonardo Building - Lobby )
      • 16:00 Single and double parton production of $c \bar c c \bar c$ - a new idea 25'
        Speaker: A. Szczurek (Cracow)
    • 16:25 - 18:40 MPI & Small x & Diffraction
      Location: Leonardo Building - Budinich Lecture Hall
      • 16:25 Introduction by Convener 15'
      • 16:40 Measurement of the elastic, inelastic and total pp cross section at 7 TeV and 13 TeV with the ATLAS detector 25'
        Speaker: P. Puzo (ATLAS)
        Material: Slides
      • 17:05 Colour Dipole Cascades, parton correlations, and colour coherence at small x 25'
        Speaker: G. Gustafson (Lund)
        Material: Slides
      • 17:30 Coffee Break 20' ( Leonardo Building - Lobby )
      • 17:50 Multi-jet production at CMS 25'
        Speaker: G. Safronov (CMS)
        Material: Slides
      • 18:15 MPI and UE corrections to jet measurements and influence on PDF determination and alphas 25'
        Speaker: S. Cerci (CMS)
        Material: Slides
    • 19:30 - 21:00 Reception
      Location: Adriatico Guest House - Cafeteria
      • 19:30 1h30'
  • Wednesday, 25 November 2015
    • 09:00 - 10:05 High Multiplicities and Interactions with Nuclei
      Location: Leonardo Building - Budinich Lecture Hall
      • 09:00 Introduction by Convener 15'
      • 09:15 Two Component model for hadroproduction: from pp to heavy-ion collisions 25'
        Speaker: A. Bylinkin (Moscow)
        Material: Slides
      • 09:40 Multi-Parton interactions in p-Pb collisions at sqrt(s_{NN})=5.02 TeV with ALICE 25'
        Speaker: C. Oppedisano (ALICE)
        Material: Slides
    • 10:05 - 15:00 MPI & Small x & Diffraction
      Location: Leonardo Building - Budinich Lecture Hall
      • 10:05 Relating low-x DIS structure functions to hadronic total cross sections 25'
        Speaker: L. Jenkovszky (Kiev)
      • 10:30 Coffee Break 20' ( Leonardo Building - Lobby )
      • 10:50 Dynamic color rescattering model using kT factorization for DDIS 25'
        Speaker: D. Werder (Uppsala)
        Material: Slides
      • 11:15 Inclusive three jet production at the LHC as a new BFKL probe 25'
        Speaker: G. Chachamis (Madrid)
        Material: Slides
      • 11:40 Improved TMD factorization for forward di-jet production in pA collisions 25'
        Speaker: E. Petreska (Compostela)
        Material: Slides
      • 12:05 Gauge-invariant gluon TMDs from large- to small-x in the coordinate space 25'
        Speaker: I. Cherednikov (Antwerpen)
        Material: Slides
      • 12:30 Lunch 1h30' ( Leonardo Building - Cafeteria )
      • 14:00 The story of UE measurements 1h0'
        Speaker: R. Field (Florida)
        Material: Slides
    • 15:15 - 22:30 Excursion & Dinner
      • 15:15 Guided Tour of Trieste 3h0'
      • 19:30 Dinner at HARRY'S GRILL 3h0'
  • Thursday, 26 November 2015
    • 09:00 - 11:25 Monte Carlo Development and Tuning
      Location: Leonardo Building - Budinich Lecture Hall
      • 09:00 On the impact of nonperturbative parton correlations on the rate of double parton scattering 25'
        Speaker: S. Ostapchenko (Frankfurt)
      • 09:25 Multiple scattering in EPOS: Implications for charm production 25'
        Speaker: K. Werner (Nantes)
        Material: Slides
      • 09:50 Developments in MC tuning techniques 25'
        Speaker: A. Buckley (Durhams)
        Material: Slides
      • 10:15 Towards Diffraction in Herwig 25'
        Speaker: F. Loshaj (Karsruhe)
        Material: Slides
      • 10:40 Coffee Break 20' ( Leonardo Building - Lobby )
      • 11:00 Quark/gluon jets and colour reconnection 25'
        Speaker: A. Siodmok (CERN)
        Material: Slides locked
    • 11:25 - 14:25 MPI & Small x & Diffraction
      Location: Leonardo Building - Budinich Lecture Hall
      • 11:25 Multi(3)-particle production in DIS at small x 25'
        Speaker: J. Jalilian-Marian (New York)
        Material: Slides
      • 11:50 Double scattering contribution to small-x processes 25'
        Speaker: L. Szymanowski (Warsaw)
        Material: Slides
      • 12:15 Application and calculation of amplitudes with off-shell partons 25'
        Speaker: A. van Hameren (Cracow)
        Material: Slides
      • 12:40 Lunch 1h20' ( Leonardo Building - Cafeteria )
      • 14:00 Results of the LHCf experiment so far and future prospect 25'
        Speaker: K. Kasahara (LHCf)
        Material: Slides
    • 14:25 - 14:50 Minimum Bias and Underlying Event
      Location: Leonardo Building - Budinich Lecture Hall
      • 14:25 Particle Spectra in Minimum Bias events at 13 TeV 25'
        Speaker: J.M. Grados Luyando (CMS)
        Material: Slides
    • 14:50 - 19:15 High Multiplicities and Interactions with Nuclei
      Location: Leonardo Building - Budinich Lecture Hall
      • 14:50 Jet effects in high multiplicity pp events 25'
        Speaker: A. Ortiz Velasquez (Mexico)
        Material: Slides
      • 15:15 Two-particle correlation measurements in p-Pb collisions at \sqrt{sNN} = 5.02 TeV 25'
        Speaker: M. Floris (ALICE)
        Material: Slides
      • 15:40 Coffee Break 20' ( Leonardo Building - Lobby )
      • 16:00 Measurement of the long-range azimuthal correlations in 2.76 and 13 TeV pp collisions with the ATLAS detector at the LHC 25'
        Speaker: A. Buckley (ATLAS)
        Material: Slides
      • 16:25 First measurements of long-range near-side angular correlations in √sNN = 5TeV proton-lead collisions in the forward region 25'
        Speaker: A. Dosil (LHCb)
        Material: Slides
      • 16:50 Multiparticle production in small systems from the Color Glass Condensate 25'
        Speaker: P. Tribedy (BNL)
        Material: Slides
      • 17:15 Measurement of long-range near-side two-particle correlations in pp collisions at 13 TeV 25'
        Speaker: A. Moraes (CMS)
        Material: Slides
      • 17:40 Coffee Break 20' ( Leonardo Building - Lobby )
      • 18:00 Study of collective effects in high-energy hadron-nucleus collisions measured with ALICE 25'
        Speaker: E. Fragiacomo (ALICE)
        Material: Slides
      • 18:25 Color fluctuations in the high energy hadron and photon - nucleus collisions 25'
        Speaker: M. Strikman (Pennstate)
        Material: Slides
      • 18:50 The leading particle spectra as a tool to tune the Color reconnection models 25'
        Speaker: G. Paic (Mexico)
        Material: Slides
    • 19:15 - 20:15 Dinner
      Location: Leonardo Building - Cafeteria
      • 19:15 1h0'
  • Friday, 27 November 2015
    • 09:00 - 11:25 High Multiplicities and Interactions with Nuclei
      Location: Leonardo Building - Budinich Lecture Hall
      • 09:00 Measurements of Bose-Einstein correlations with the ATLAS detector 25'
        Speaker: O. Zenin (ATLAS)
        Material: Slides
      • 09:25 Measurement of identified hadron production as a function of event multiplicity in pp collisions at $\sqrt{s} = 7$ TeV with the ALICE experiment 25'
        Speaker: B.A. Hess (ALICE)
        Material: Slides
      • 09:50 Measurements of heavy-flavour production dependence with charged-particle multiplicity in pp and p-Pb collisions with ALICE 25'
        Speaker: Z. Conesa del Valle (ALICE)
        Material: Slides
      • 10:15 Rapidity distributions of final state hadrons in DIS in pQCD 25'
        Speaker: B. Blok (Technion)
      • 10:40 Coffee Break 20' ( Leonardo Building - Lobby )
      • 11:00 The Transverse Proton Polarization Dependence of Forward Neutral Pion Production in p-Au Collisions at  in STAR 25'
        Speaker: S. Heppelmann (STAR)
        Material: Slides
    • 11:25 - 12:05 End of Workshop Discussion
      Location: Leonardo Building - Budinich Lecture Hall
      • 11:25 40'