Searching for long-lived particles at the LHC: Third workshop of the LHC LLP Community

Europe/Zurich
500/1-001 - Main Auditorium (CERN)

500/1-001 - Main Auditorium

CERN

400
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Albert De Roeck (CERN), Brian Shuve (SLAC National Accelerator Laboratory), Giovanna Cottin (National Taiwan University), James Beacham (Ohio State University (US)), José Francisco Zurita (KIT), Juliette Alimena (Ohio State University (US)), Martino Borsato (Universidade de Santiago de Compostela (ES)), Michelangelo Mangano (CERN), Nishita Desai (LUPM, Montpellier), Will Buttinger (CERN), Xabier Cid Vidal (Universidade de Santiago de Compostela)
Description

Following the successes of the LHC Long-Lived Particle (LLP) Workshops in April and October of 2017 -- and continuing the robust and rich tradition defined by prior workshops such as “LHC Searches for Long-Lived BSM Particles: Theory Meets Experiment", at U. Mass, Amherst, in November of 2015; “Experimental Challenges for the LHC Run II", at the Kavli Institute for Theoretical Physics in May of 2016; and the “LHC Long-Lived Particles Mini-Workshop" at CERN in May of 2016 -- the LHC LLP Community, composed of members of the CMS, LHCb, and ATLAS collaborations as well as theorists, phenomenologists and those interested in LLP searches with dedicated LHC detectors such as milliQan, MoEDAL, MATHUSLA, FASER, Codex-b, etc., convenes again to discuss the outcomes presented in the community white paper, assess the state of searches for long-lived particles beyond the Standard Model at the LHC, brainstorm about new ideas for LLP searches, and focus on the future of LLP searches in HEP, both at the LHC and for future detectors and projects.

The format will likely be similar to that of our previous workshops, i.e., a working-workshop, where we focus on discussion and collaboration, with any talks functioning to set the stage for that collaboration.

This workshop is unique, however, because after months of work by our community, the white paper is currently nearing completion.  Thus, while we will definitely feature a component devoted to a review of the content of the white paper, the focus of this workshop will be on the future:

  • What's next for LLP searches at the LHC?
  • What didn't we get to cover in the first white paper?
  • What recommendations for triggers and upgrade studies have arisen since we started this work?
  • How well do we really, quantitatively understand where our searches for prompt objects have sensitivity for LLPs, and how can we encourage the experimental collaborations to address this question comprehensively?
  • What about future detectors?
  • And what about new ideas for thinking critically about the ultimate sensitivity for LLP signatures / benchmark simplified models at the LHC and about what will be learned at future machines?


And yes, of course there will be at least one lightning round!  Please contact the organizers with your proposal or idea.

The first day of the workshop features collaborative sessions with the Re-interpretations workshop concluding that same day, also at CERN.

The agenda is taking shape now, but please register now!

Note that while we hope to see you in person at CERN, remote participation will indeed be available via Vidyo.  Please register whether you will participate in person or remotely and indicate so in your registration.

Videoconference Rooms
LHC_LLP_Workshop_v1
Name
LHC_LLP_Workshop_v1
Description
LHC_LLP_Workshop_v1
Extension
10714087
Owner
James Beacham
Auto-join URL
Useful links
Phone numbers
Registration
Registration for the third workshop of the LHC LLP Community
Participants
  • Aayush Anand
  • Abhigyan Dasgupta
  • Akshansh Singh
  • Albert De Roeck
  • Alberto Escalante Del Valle
  • Alberto Mariotti
  • Alexander Josef Grohsjean
  • Alexandre Arbey
  • Alice Morris
  • Alicia Calderon Tazon
  • Amber Roepe
  • Ana Maria Rodriguez Vera
  • Andrea Giammanco
  • Anthony Lionti
  • Antonio Policicchio
  • Arnaud Dubreuil
  • Atsushi Mizukami
  • Basile Vermassen
  • Bibhuti Parida
  • Bingxuan Liu
  • Biplab Dey
  • Brian Shuve
  • Bryan Zaldivar
  • Carlos Munoz
  • Carlos Vazquez Sierra
  • Charlie Young
  • Chris Hill
  • Christian Ohm
  • Christopher Blake Martin
  • Claudia Gemme
  • Colleen Treado
  • Cristiano Alpigiani
  • Cristiano Sebastiani
  • Daniel E. LOPEZ-Fogliani
  • Daniele Trocino
  • David Curtin
  • David Cutts
  • David Sabonis
  • Deepak Kumar
  • Dominik Krauss
  • Ece Akilli
  • Edgar Fernando Carrera Jarrin
  • Egor Antipov
  • Elena Dall'Occo
  • Emanuele Angelo Bagnaschi
  • Emma Sian Kuwertz
  • Emma Torro Pastor
  • Erez Etzion
  • Fabrizio Nesti
  • Federico Leo Redi
  • Felix Kling
  • Francesca Ricci-Tam
  • Gail Hanson
  • Geng-Yuan Jeng
  • Georgios Zacharis
  • Gilson Correia Silva
  • Giovanna Cottin
  • Giuliano Gustavino
  • Goran Popara
  • Greg Landsberg
  • Gregor Kasieczka
  • Haifa Rejeb Sfar
  • Heather Russell
  • Henning Keller
  • Hidetoshi Otono
  • Hideyuki Oide
  • Igor Kostiuk
  • Iñaki Lara
  • Jackson Carl Burzynski
  • James Beacham
  • James Pinfold
  • Jamie Boyd
  • Jan Heisig
  • Jennifer Kathryn Roloff
  • Jessica Prisciandaro
  • Jike Wang
  • Jingyu Luo
  • John Stupak
  • Jonathan Feng
  • Jong Soo Kim
  • Jose Miguel No
  • José Francisco Zurita
  • Juan Carlos Helo
  • Judita Mamuzic
  • Juhi Dutta
  • Juliette Alimena
  • Jyothsna Rani Komaragiri
  • Karri Folan Di Petrillo
  • Katherine Pachal
  • Kerstin Hoepfner
  • Kin Ho Lo
  • Laura Lopez Honorez
  • Lawrence Lee Jr
  • Leonardo Rossi
  • Lesya Horyn
  • Lisa Benato
  • Livia Soffi
  • Louie Dartmoor Corpe
  • Mai Elsawy
  • Malgorzata Kazana
  • Manfredi Ronzani
  • Margaret Susan Lutz
  • Mario Campanelli
  • Martina Vit
  • Martino Borsato
  • Mason Proffitt
  • Matthew Strassler
  • Matthieu Marinangeli
  • Maurizio Pierini
  • Melissa Yexley
  • Michael Werner
  • Michele Papucci
  • Miha Nemevsek
  • Mohamed Darwish
  • Mohammed Mahmoud Mohammed
  • Monica D'Onofrio
  • Nishita Desai
  • Nora Emilia Pettersson
  • Oliver Fischer
  • Paolo Camarri
  • Pavel Fileviez Perez
  • Philippe Mermod
  • Praveen Chandra Tiwari
  • Riccardo Manzoni
  • Rinaldo Santonico
  • Sascha Mehlhase
  • SEBASTIAN TROJANOWSKI
  • Sergio Grancagnolo
  • Simon Knapen
  • Slava Krutelyov
  • Sophie Renner
  • Stefan Vogl
  • Stefania Gori
  • Stefano Giagu
  • Steven Lowette
  • Swagata Mukherjee
  • Tamas Almos Vami
  • Tao Huang
  • Thomas Mastrianni Perry
  • Toshiaki Kaji
  • Varvara Batozskaya
  • Vasiliki Mitsou
  • Viktor Kutzner
  • Wen-Yi Song
  • Wendy Taylor
  • Will Buttinger
  • Wouter Hulsbergen
  • Xabier Cid Vidal
  • Yongbin Feng
  • Yury Smirnov
  • Zach Marshall
  • Zhen Liu
    • 09:00 09:30
      Introduction to the LLP Community and Whitepaper 30m 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
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      Speakers: Brian Shuve (Harvey Mudd College), James Beacham (Ohio State University (US))
    • 09:30 10:00
      Long-lived particles at the LHC: A theorist's perspective 30m 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
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      Speaker: Brian Shuve (Harvey Mudd College)
    • 10:00 10:30
      Coffee 30m 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
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    • 10:30 11:30
      LLP search snapshots 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
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    • 11:30 12:45
      Material for re-interpretation - I 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
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      • 11:30
        Re-interpretation of long-lived particle searches: Whitepaper recommendations 30m
        Speaker: Nishita Desai (LUPM, Montpellier)
      • 12:00
        Fast detector simulation for LLPs: Delphes and MA5 25m
        Speakers: Eric Conte (Universite de Haute Alsace (FR)), Eric Conte (Laboratoire de Physique Corpusculaire (LPC))
      • 12:25
        Update on public tools for LLP recasts: Checkmate / Gambit discussion 20m
        Speakers: Anders Kvellestad (Nordita), Jong Soo Kim (IFT Madrid)
    • 12:45 14:00
      Lunch 1h 15m 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
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    • 14:00 15:30
      Material for re-interpretation - II 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
      Show room on map
    • 15:30 16:00
      Coffee 30m 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
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    • 16:00 18:00
      Contributed Talks 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
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      • 16:00
        Dark photon interpretation of LHCb search 20m
        Speaker: Wei Xue (CERN)
      • 16:20
        Reinterpretation of long-lived particles searches within SModelS 20m
        Speaker: Jan Heisig (RWTH Aachen University)
      • 16:40
        Freeze-in and LLPs 20m
        Speaker: Mr Bryan Zaldivar (LAPTh, Annecy)
      • 17:00
        Recasting the scotogenic FIMP 20m
        Speaker: Stefan Vogl (Max Planck Institute for Nuclear Physics)
      • 17:20
        Novel signatures for long-lived particles at the LHC 20m
        Speaker: Ms Swagata Mukherjee (Rheinisch Westfaelische Tech. Hoch. (DE))
      • 17:40
        Long-lived neutrinos in the left-right symmetric model 20m
        Speaker: Goran Popara
    • 18:00 19:00
      DIY welcome drink in CERN Restaurant 1 1h 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
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    • 09:00 09:45
      Top-down theory overview and simplified models yielding LLPs 45m 40/S2-C01 - Salle Curie

      40/S2-C01 - Salle Curie

      CERN

      27
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      Speaker: Prof. David Curtin (University of Toronto)
    • 09:45 10:00
      White paper chapter 3 -- Experimental coverage of LLP signatures 15m 40/S2-C01 - Salle Curie

      40/S2-C01 - Salle Curie

      CERN

      27
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      Speaker: José Francisco Zurita (KIT)
    • 10:00 10:30
      Elevator pitch session: Your idea goes here 40/S2-C01 - Salle Curie

      40/S2-C01 - Salle Curie

      CERN

      27
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      Convener: Will Buttinger (CERN)
    • 10:30 10:45
      Coffee 15m 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
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    • 10:45 11:45
      Lightning round: Session 1 40/S2-C01 - Salle Curie

      40/S2-C01 - Salle Curie

      CERN

      27
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      • 10:45
        Neutrino reinterpretation and particle masses with displaced vertices 15m
        Speaker: Giovanna Cottin (National Taiwan University)
      • 11:00
        Singlet-Doublet Dark Matter Freeze-in: LHC displaced signatures 15m
        Speaker: Alberto Mariotti (VUB Brussels)
      • 11:15
        Discerning the left sneutrino LSP with displaced-vertex searches 15m
        Speaker: Iñaki Lara Pérez (UAM-CSIC)
      • 11:30
        Long lived right-handed neutrinos, oscillations and leptogenesis 15m
        Speaker: Oliver Fischer (Unibas)
    • 11:45 12:10
      White paper chapter 5 -- Triggers and detector upgrades 25m 40/S2-C01 - Salle Curie

      40/S2-C01 - Salle Curie

      CERN

      27
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      Speaker: Yangyang Cheng (Cornell University (US))
    • 12:10 13:40
      Lunch 1h 30m 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

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    • 13:40 15:00
      Dedicated LLP experiments: Session 1 503/1-001 - Council Chamber

      503/1-001 - Council Chamber

      CERN

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      • 13:40
        MATHUSLA 20m
        Speaker: Mason Proffitt (University of Washington (US))
      • 14:00
        SHiP 20m
        Speaker: Federico Leo Redi (EPFL - Ecole Polytechnique Federale Lausanne (CH))
      • 14:20
        SeaQuest 20m
        Speakers: Stefania Gori (University of Cincinnati (US)), Stefania Gori (Perimeter Institute/Cincinnati University)
      • 14:40
        MilliQan 20m
        Speaker: Chris Hill (Ohio State University (US))
    • 15:00 15:20
      Coffee 20m 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

      400
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    • 15:20 17:30
      Breakout working group sessions: Parallel and hands-on
      • 15:20
        Breakout #1 2h 10m 42/R-402

        42/R-402

        CERN

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        Name
        LHC_LLP_Workshop_B1
        Description
        LHC LLP Breakout #1
        Extension
        107140871
        Owner
        Will Buttinger
        Auto-join URL
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        Geant4, Pythia, and the challenges of LLP simulation(-over-beers)

        Speaker: Will Buttinger (CERN)

        Simulating travelling rhadrons

        - 2 grids in the Whitepaper where the LLP carries SM (except weak) charge. We need to know how to simulate these.
        - Important to let G4 interact the rhadron because it can hadronize as it goes through all the material (travels through more than a bhadron because of lifetime) so cannot decide how to decay it before g4 does its thing (unlike bhadrons, as is done in evtgen, where assumption that bhadron wont change state is reasonable given lifetime/material).
        - G4 can decay slepton, but not things like rhadrons ...  need to use pythia.
        - Have been technical issues in being able to reinitialize pythia after G4 runs and make it decay an rhadron that’s given to it (Reported by Jennifer, Somewhat resolved by Steve?).
        - How do we pass configuration information from pythia->G4->pythia in this chain ... ATLAS moving away from HepMC, making it harder to do this in a unified way, each collaboration just deals with it themself?
        - The current mass spectrum ("generic" or "intermediate") used by ATLAS for rhadrons is a hacked-together incoherent(?) mess. Its a choice. Last update was 5 years ago, before that was 15 years ago. Store deltas (are masses relative to the input gluino state). Rather than adding up the constituent quark masses to get Rhadron mass in pythia, we should just specify the masses for each Rhadron. 
        - Regge model determines hadronic interactions - is what is in use in ATLAS atm. Not the same as “regge model” mass spectrum that is used in pythia6. CMS uses the "cloud model" for the hadronic interactions, which we hope is the same thing.
        - At the moment spin correlations are completely neglected - nobody can think of an important case where it matters.

        Simulating stopping rhadrons

        - At the moment ATLAS uses a simple stopping threshold criteria (Beta < A^(-2/3)). This doesnt simulate the deceleration of stopping rhadrons, which would occur as they drag ions along. 

        - Concern that efficiencies measured in stopping particle searches are overestimated (by factors of maybe 2, not 10-100). Would like to be able to simulate these correctly.

        Simulating quirks

        - Chris Hill made his argument for why quirks are basically non-existent (all but shortest string lengths were killed by fractional charge search).
        - Could reinterpret Heavy Stable Charged Particle searches in terms of (short length) quirks if we had a reliable simulation. But it's going to be driven by best effort, and effort seems lacking.

        Fast simulation

        - There was reasonable interest in understanding how far validity of fast simulation can go when it comes to LLPs (non-pointing tracks/photons etc).

         

        Action items

        - It is very important that each simplified model in the white paper that features long-lived interacting (SM-charged) particles should come with a corresponding description of the interaction model. Experts should be assembled to define/document for each case (rhadrons, HIP, monopole, ..) where relevent:

           - Particle mass spectrum
           - Particle fragmentation function
           - G4 interaction model
           - Other relevant parameters of the model (e.g. initial qluino/gluon fraction)

        - At very least there needs to be effort to compare/contrast what is currently done by ATLAS and CMS and LHCb to check for differences

        - Would like to call for studies on both sides that compare fast and full sim in LLP scenarios to try to quantify geometric/phase space where fast sim is reasonable

         

        Participants in discussion

        Zach Marshall (ATLAS)
        Larry Lee (ATLAS)
        Chris Hill (CMS)
        Steve Mrenna (CMS/Pythia)
        Jennifer Roloff (ATLAS)
        ...

      • 15:20
        Breakout #2 2h 10m 4/3-001 - New Capacity following HSE rules about COVID: 5

        4/3-001 - New Capacity following HSE rules about COVID: 5

        CERN

        5
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        Name
        LHC_LLP_Workshop_B2
        Description
        LHC LLP Breakout session #2
        Extension
        107140872
        Owner
        Philippe Mermod
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        Heavy Neutral Leptons

        Speakers: Carlos Vazquez Sierra (Nikhef National institute for subatomic physics (NL)), Daniele Trocino (Ghent University (BE)), Oliver Fischer (Unibas), Philippe Mermod (Universite de Geneve (CH))
      • 15:20
        Breakout #3 2h 10m 503/1-001 - Council Chamber

        503/1-001 - Council Chamber

        CERN

        162
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        Name
        LHC_LLP_Workshop_B3
        Description
        LHC LLP breakout #3
        Extension
        107140873
        Owner
        James Beacham
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        Blue-Sky Thinking / Go-Nuts / Brainstorming-Over-Beers / No-Idea-Too-Crazy

        Speaker: José Francisco Zurita (KIT)
    • 19:30 21:30
      Workshop dinner 2h 500/1-001 - Main Auditorium

      500/1-001 - Main Auditorium

      CERN

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