Helsinki JetMET workshop: physics at 100 fb-1

Exactum CK112 (University of Helsinki, Kumpula campus)

Exactum CK112

University of Helsinki, Kumpula campus

Gustaf Hällströmin katu 2, Helsinki, Finland
Hannu Siikonen (Helsinki Institute of Physics (FI)), Henning Kirschenmann (CERN), Jaana Heikkilae (Helsinki Institute of Physics (FI)), Joona Juhani Havukainen (Helsinki Institute of Physics (FI)), Juska Pekkanen (University of Helsinki (FI)), Mikko Voutilainen (University of Helsinki (FI)), Robert Schoefbeck (Hephy Vienna), Santeri Henrikki Laurila (Helsinki Institute of Physics (FI)), Seema Sharma (Indian Institute of Science Education and Research (IN)), Tapio Lampen (Helsinki Institute of Physics (FI)), Tomas Lindén (Helsinki Institute of Physics (FI))

Aceess to internal talks: 

This agenda has been stripped of the internal talks. Please find all material archived in the CMS/physics/JetMET-category of Indico in the cloned conference:


Welcome to the JetMET workshop in Helsinki!

We're now closed for registrations and further room bookings. In case of enquiries, please contact Mikko with JetMET100 in the subject line.The early registration closed March 10th with subsidised registration fees payable by March 20th. The web registration and workshop hotel reservation closed on April 9th with unsubsidised fees due by April 28th.Outline

The LHC is set to collect over 100 fb-1 at 13 TeV by the end of Run 2 in 2018. This will allow unprecedented reach in searches of new physics and precision measurements, such as dijet mass resonances and the top quark mass. The CMS and ATLAS experiments strongly rely on the understanding of the physics objects at the TeV scale and in all their flavors.

This fourth installation of JetMET workshops will review the status of the object performance with 2016 data, and plan for the ultimate precision reachable with full 100 fb-1 and with advanced tools and methods.

The first day of this three-day workshop is open session with representatives from CMS, ATLAS and the theory community, with conference dinner in Suomenlinna in the evening. The second day is internal to CMS, with presentations from JetMET analysers and physics groups and an evening reception at the roof of the campus. The third day will have a wrap-up session and tutorials.

Conference venue

The workshop plenaries are held in the Exactum building on the Kumpula Campus, room CK112. You can enter through the main entrance at Physicum (pictured below) or from adjoining entrances. The conference dinner is held in restaurant Walhalla at the UNESCO World Heritage site of Fortress of Suomenlinna (also pictured below).

Physicum at Kumpula campus        Fortress of Suomenlinna


The web registration is closed. Please contact the organizers at jetmet100 (at) for further information.

Travel Arrangements

By plane: the nearest airport is the Helsinki-Vantaa International airport, which is a European air traffic hub and has regular rail (P) and bus (615) connections to the city center (terminus: Main Railway Station), where the conference hotel is located. You can also hop off the train in Pasila station and take bus 506 to Kumpula campus (direction Viikki, stop at A.I.Virtasen aukio). Total travel time is about an hour.

From city center: the tram #6 from the center (Main Railway Station) to Kumpula campus (direction Arabia, stop at Kyläsaarenkatu) takes about 17 minutes and runs every 10 minutes. You can also use several metro+bus combinations for a bit quicker travel (see below). Reserve about 30 minutes including the final walk up the hill.

Street address: The street address of Kumpula campus is "Gustaf Hällströmin katu 2", for directions and time tables on Google maps or Journey Planner (


We have pre-booked a block of rooms at Hotel Arthur (, pictured below left) with a special university price of 99 EUR/night/single, 119 EUR/night/double. You can get this special price by contacting sales(at) or calling +358-9-173 441 and giving the booking code JETMET100, which is valid until April 9th. The hotel is centrally located near the main railway station and tram line #6. Price includes breakfast.

     Map from Arthur to Kumpula

Another reasonably-priced location is the university guest house Töölö Towers (near tram #8), for around 93 EUR/night/single, 136 EUR/night/double (price confirmed later).

Conference fee

Early registration (open until 10th March): The subsidised conference fee is 120 EUR for a full stay and 80 EUR for 1-day participation only. Accompanying adults coming to the dinner are subject to a 80 EUR fee and the registration form should be filled normally by/for them (public transportation is included in the price).

Late registration: The unsubsidised conference fee is 170 EUR for a full stay and 120 EUR for a 1-day participation or for a dinner companion.

Payment details:

Beneficiary: University of Helsinki, 00014 University of Helsinki, FINLAND

IBAN: FI23 1660 3000 0777 20
Message/reference: H519/3999895/[YOUR NAME HERE]

It is important that you get the message right, so that the payment is pinpointed to this event and your name correctly!

Travel guide

Finland has been named one of the top countries in the world for travellers in 2017 by Lonely Planet’s Best in Travel 2017. Finland earned the third position thanks to the host of events planned in every region to celebrate the country’s centenary of independence.

The Official Travel Guide of Finland

For more information on what to see in Helsinki and Finland, you can check out The Official Travel Guide of Finland: (linked above).

Previous workshops

The Helsinki JetMET workshop follows the tradition set by the previous workshops at Fermilab, Vienna and Lyon:

  • Fermilab: (LPC Workshop: JetMET at High Pile-up, Preparation for LHC Run II, 27-28 January 2014)
  • Vienna: (Getting ready for 13 TeV: Vienna workshop on Jets and missing energy, 25-27 August 2014)
  • Lyon: (Lyon JetMET workshop at Run2 restart, 8-10 July 2015)
  • Anastasia Karavdina
  • Andre Hoang
  • Andrey Popov
  • Arne Christoph Reimers
  • Christophe Clement
  • Daniel Spitzbart
  • David Vannerom
  • Engin Eren
  • Fabrice Couderc
  • Gregor Kasieczka
  • Hannu Siikonen
  • Henning Kirschenmann
  • Hugues Lattaud
  • Jaana Heikkilae
  • Jan Kieseler
  • Jim Olsen
  • John Paul Chou
  • Joona Juhani Havukainen
  • Jorma K Tuominiemi
  • Juan Garcia Ferrero
  • Juska Pekkanen
  • Kevin Connor Nash
  • Leonora Vesterbacka
  • Loukas Gouskos
  • Marek Adam Niedziela
  • Martijn Mulders
  • Matthew Schwartz
  • Mikko Voutilainen
  • Milos Dordevic
  • Mrinal Dasgupta
  • Paula Eerola
  • Philip Coleman Harris
  • Robert Schoefbeck
  • Rosa Simoniello
  • Santeri Laurila
  • Satoshi Hasegawa
  • Seema Sharma
  • Simone Gelli
  • Steven Randolph Schramm
  • Tapio Lampen
  • Thomas Berger
  • Tomas Lindén
  • Viola Sordini
  • Yuiko Hasegawa
  • Zeynep Demiragli
    • Registration: By the lecture hall Exactum CK112

      Exactum CK112

      University of Helsinki, Kumpula campus

      Gustaf Hällströmin katu 2, Helsinki, Finland

      Registration for the event in front of the lecture hall.

    • Day 1: Morning session Exactum CK112

      Exactum CK112

      University of Helsinki, Kumpula campus

      Gustaf Hällströmin katu 2, Helsinki, Finland

      Introductory speeches

      • 1
        Welcome to workshop

        Welcome speech by the local organizers.

        Speaker: Mikko Voutilainen (University of Helsinki (FI))
      • 2
        Kick-start talk for physics at 100 fb-1

        Jim Olsen as ex CMS Physics Coordinator gives an overview of what we can expect and should aim in physics at 100 fb-1.

        Speaker: Jim Olsen (Princeton University (US))
      • 3
        Jet flavors at 100 fb-1

        Theoretical and phenomenological challenges in modeling and identifying jet flavors, including top jets and novel approaches such as deep learning for quark and gluon discrimination

        Speaker: Matthew Schwartz
      • 10:45 AM
      • 4
        CMS JetMET overview, public

        Overview talk of CMS state of the art from the JetMET conveners.

        Speakers: Robert Schoefbeck (Ghent University (BE)), Seema Sharma (Indian Institute of Science Education and Research (IN))
      • 5
        ATLAS JetMET overview, public

        Overview of ATLAS state-of-the art in jets and missing ET from one of the ATLAS JetMET conveners.

        Speaker: Christophe Clement (Stockholm University (SE))
    • 12:45 PM
      Day 1: Lunch Dynamicum


      University of Helsinki, Kumpula campus

      Erik Palménin aukio 1

      Lunch at Dynamicum. Directions will be provided

    • Day 1: Afternoon session Exactum CK112

      Exactum CK112

      University of Helsinki, Kumpula campus

      Gustaf Hällströmin katu 2, Helsinki, Finland
      • 6
        Pileup performance at 100 fb-1

        Current status of the best pileup subtraction algorithms, PUPPI and SoftKiller, by the original authors.

        Speaker: Philip Coleman Harris (CERN)
      • 7

        (pruning, soft drop, theory), + W,top,H tagging, boosted (theory)

        Speakers: Mrinal Dasgupta (University of Manchester (GB)), Mrinal Dasgupta (Unknown)
      • 8
        Top mass aspirations at 100 fb-1

        What would it take experimentally to get the top quark mass uncertainty to 0.2 GeV with 100 fb-1? Advanced NLOxPS generators, better PS model such as Vincia, new methods, Z+b response? Data-based flavor responses, better use of W->qq' mass peak, 3D R_bq from ATLAS?

        Speaker: Martijn Mulders (CERN)
      • 3:45 PM


      • 9
        Top quark mass: what is it and should it be?

        Review on what are we measuring with the top quark mass (MC mass), how it is related to theory (pole mass, MSbar mass), and how we could strengthen the link between theory and experiment when experimental precision reaches 0.2 GeV.

        Speaker: Andre Hoang (University of Vienna)
      • 10
        IML: Inter-Experimental LHC Machine Learning Working Group

        Introduction to the work and goals of IML, and how this ties to JetMET work.

        Speaker: Steven Randolph Schramm (Universite de Geneve (CH))
      • 11
        DeepFlavour: deep neural network for all flavors

        State-of-the art in quark (and gluon) flavor discrimination with deep neural networks at CMS.

        Speaker: Jan Kieseler (CERN)
    • 6:00 PM
      Transportation to the dinner Exactum -> Kauppatori -> Suomenlinna

      Exactum -> Kauppatori -> Suomenlinna

      We will have bus leaving Kumpula at 18:00 and arrive to harbour at 18:20, to take a ferry to Suomenlinna at 18:35. From there it is 20 min walk to the Walhalla restaurant through the World Heritage site of Suomenlinna Sea Fortress.

    • 7:30 PM
      Dinner at Restaurant Walhalla, in Suomenlinna Sea Fortress Suomenlinna


      We will jointly take a charter bus from Kumpula to Kauppatori at 18:00 to catch the 18:40 ferry to Suomenlinna. We also have planned to take a private boat from King's Gate next to Restaurant Walhalla back to Kauppatori at 22:30 (tickets will be provided).

      If you go by yourself, the ferry trip from Kauppatori takes roughly 20 minutes. You can see the full timetable here:

      Ferries to Suomenlinna from Kauppatori: 18.00, 18.40 and 19.20 (next ones are 20.20 and 21.00, so don't be late!).

      Ferries back from Suomenlinna to Kauppatori 18.20, 19.00, 19.40, 20.40, 21.20, 22.00, 23.00, 23.40, 0.20, 1.00, 2.00.

    • 10:30 PM
      Ferry back from Suomenlinna Sea Fortress Exactum CK112

      Exactum CK112

      University of Helsinki, Kumpula campus

      Gustaf Hällströmin katu 2, Helsinki, Finland

      We will take a boat ride back from Suomenlinna by the King's Gate (next to restaurant Walhalla). Enjoy the scenic sunset tour!

    • Day 2: Morning session Exactum CK112

      Exactum CK112

      University of Helsinki, Kumpula campus

      Gustaf Hällströmin katu 2, Helsinki, Finland
      • 12
        Phase 1 Upgrade
        Speaker: Milos Dordevic (Vinca Institute, University of Belgrade)
      • 13
        HCAL & GEANT
        Speaker: John Paul Chou (Rutgers, State Univ. of New Jersey (US))
      • 14
        ECAL & EGamma
        Speakers: Fabrice Couderc (CEA/IRFU,Centre d'etude de Saclay Gif-sur-Yvette (FR)), Fabrice Couderc
      • 10:30 AM
      • 15
        JEC Overview
        Speakers: Anastasia Karavdina (Hamburg University (DE)), Henning Kirschenmann (CERN)
      • 16
        JEC 1: MC Truth Improvements and High-Pt Extrapolation

        More advanced NLOxPS generators for MC truth, jet flavor responses and their uncertainties with various MC, and how to tune single pion response for high pT extrapolation a la D0.

        Speaker: Alexx Perloff (Texas A & M University (US))
      • 17
        JEC 2: Forward Calibration

        Relative calibration from dijet events. Challenges, limitations, and ways forward.

        Speaker: Arne Reimers (Hamburg University (DE))
      • 18
        JEC3: Z+jet
        Speaker: Thomas Berger (KIT - Karlsruhe Institute of Technology (DE))
      • 19
        JEC 4: Gamma+Jet
        Speaker: Hugues Lattaud (Universite Claude Bernard-Lyon I (FR))
      • 20
        JEC5: Multijet
        Speaker: Andrey Popov (Institut de Physique Nucléaire de Lyon (FR))
      • 21
        JEC 6: Resolution
        Speaker: Marek Adam Niedziela (Hamburg University (DE))
      • 22
        JEC7: Composition studies and flavor

        PF Jet composition, flavor definitions (past, present, future), NLO

        Old (Jet flavors from data) State-of-the art in extracting jet flavors from data. What do we know and what should we do to get light quarks, gluons, charm and bottom jets nailed down.

        Speaker: Hannu Siikonen (Helsinki Institute of Physics (FI))
      • 23
        JEC8: Sneek-peek at regression using DNN
        Speaker: Joona Juhani Havukainen (Helsinki Institute of Physics (FI))
    • 12:45 PM
      Day 2: Lunch Dynamicum


      University of Helsinki, Kumpula campus

      Erik Palménin aukio 1

      Held at Dynamicum.

    • Day 2: Afternoon session Exactum CK112

      Exactum CK112

      University of Helsinki, Kumpula campus

      Gustaf Hällströmin katu 2, Helsinki, Finland
      • 24
        MET Overview
        Speakers: Loukas Gouskos (Univ. of California Santa Barbara (US)), Zeynep Demiragli (Massachusetts Inst. of Technology (US)), Zeynep Demiragli (Brown University)
      • 25
        MET 1: MET at high pileup

        Study of MET performance in high pile up events

        Speaker: Leonora Vesterbacka (Eidgenoessische Technische Hochschule Zuerich (CH))
      • 26
        MET 2: MET significance algorithm

        Overview of the MET significance algorithm and implemented improvements

        Speaker: Daniel Spitzbart (Austrian Academy of Sciences (AT))
      • 27
        MET 3: Dead cell recovery with regression

        New regression techniques to recover the energy of the dead cells using near by crystals in calorimeters and tracking information

        Speakers: David Vannerom (Universite Libre de Bruxelles (BE)), David Vannerom (U)
      • 28
        Trigger Overview
        Speaker: Milos Dordevic (Vinca Institute, University of Belgrade)
      • 29
        DQM Overview
        Speaker: Viola Sordini (Universite Claude Bernard-Lyon I (FR))
      • 3:45 PM
      • 30
        JMAR Overview
        Speakers: Gregor Kasieczka (Eidgenoessische Technische Hochschule Zuerich (CH)), Kevin Connor Nash (Rutgers, State Univ. of New Jersey (US))
      • 31
        JMAR: Heavy resonances (W/Z/H/top)
        Speakers: Gregor Kasieczka (Eidgenoessische Technische Hochschule Zuerich (CH)), Kevin Connor Nash (Rutgers, State Univ. of New Jersey (US)), Simone Gelli (Sapienza Universita e INFN, Roma I (IT))
      • 32
        JMAR: Pileup (PUPPI and PU JetID)
        Speaker: Satoshi Hasegawa (Fermi National Accelerator Lab. (US))
      • 33
        JMAR: JetID and QGL

        Jet identification and quark/gluon likelihood

        Speaker: Eirini Tziaferi (National and Kapodistrian University of Athens (GR))
      • 34
        Physics highlight: rainbow of jets

        CMS has already measured cross sections of inclusive jets and inclusive b-jets. What tools would be needed take to push this forward at 100 fb-1 and also measure inclusive gluon jets, inclusive light quark jets, inclusive charm jets and inclusive top jets, to have full view of flavor universality at the TeV scale?

        Speaker: Engin Eren (Deutsches Elektronen-Synchrotron (DE))
    • 6:00 PM
      Reception outside CK112 (changed from the Exactum rooftop due to bad weather) Exactum rooftop

      Exactum rooftop

      University of Helsinki, Kumpula campus

      Gustaf Hällströmin katu 2, Helsinki Finland

      Drinks and light snacks will be provided

    • Day 3: Morning session Exactum CK112

      Exactum CK112

      University of Helsinki, Kumpula campus

      Gustaf Hällströmin katu 2, Helsinki, Finland
      • 35
        Coordination meeting - plan for the rest of the year A315 (Physicum)



      • 36
        Future planning session A315 (Physicum)



      • 10:45 AM
        Coffee A315, Physicum (University of Helsinki, Kumpula)

        A315, Physicum

        University of Helsinki, Kumpula

        Gustaf Hällströmin katu 2, Helsinki, Finland
      • 37
        Future planning session continued A315 (Physicum)



      • 38
        Training session A315 (Physicum)



        Informal training on JEC global fit. Instructions to run are attached.

        Speaker: Mikko Voutilainen (University of Helsinki (FI))
    • 12:45 PM
      Day 3: Lunch Dynamicum


      University of Helsinki, Kumpula campus

      Erik Palménin aukio 1

      Held at Dynamicum.