BOOST 2016: 8th International Workshop on Boosted Object Phenomenology, Reconstruction and Searches in HEP

Europe/Zurich
RAI-H-041 (Zurich)

RAI-H-041

Zurich

University of Zurich Rämistrasse 74 8001 Zürich
Andreas Hinzmann (Universitaet Zuerich (CH)), Ben Kilminster (Universitaet Zuerich (CH)), Charalampos Anastasiou (ETH Zurich), Florencia Canelli (Universitaet Zuerich (CH)), Gino Isidori (Universitaet Zuerich (CH)), Gregor Kasieczka (Eidgenoessische Tech. Hochschule Zuerich (CH)), Guenther Dissertori (Eidgenoessische Tech. Hochschule Zuerich (CH)), Rainer Wallny (Eidgenoessische Tech. Hochschule Zuerich (CH)), Thomas Gehrmann (Univ. Zurich)
Description

BOOST2016 is the eighth of a series of successful joint theory/experiment workshops that bring together the world's leading experts from theory and LHC experiments to discuss the latest progress and develop new approaches on the reconstruction of and use of boosted decay topologies in order to search for new physics. This year, the workshop is jointly hosted by the University of Zurich and ETH Zurich.

Participants
  • Aditya Pathak
  • Aine Kobayashi
  • Alex Christopher Martyniuk
  • Alexander Schmidt
  • Andrea Rizzi
  • Andreas Hinzmann
  • Andreas Sogaard
  • Andrew Hornig
  • Andrew Larkoski
  • Annapaola de Cosa
  • Aparajita Dattagupta
  • Ariel Schwartzman
  • Arthur Bolz
  • Aviv Ruben Cukierman
  • Babis Anastasiou
  • Ben Kilminster
  • Ben Nachman
  • Ben Pecjak
  • Camilla Galloni
  • Chris Pollard
  • Christoph Falk Anders
  • Daniel Hay Guest
  • Daniel Salerno
  • Danilo Enoque Ferreira De Lima
  • Debarati Roy
  • Deborah Pinna
  • Deepak Kar
  • Denys Lontkovskyi
  • dingyu shao
  • Dinko Ferencek
  • Florencia Canelli
  • Francesco De Lorenzi
  • Francesco Rubbo
  • Frank Petriello
  • Frederic Alexandre Dreyer
  • Gavin Salam
  • Giordon Holtsberg Stark
  • Giorgia Rauco
  • Gregor Kasieczka
  • Gregory Soyez
  • Guenther Dissertori
  • Ian Moult
  • Jamal Tildon Rorie
  • Janna Katharina Behr
  • Jennifer Ngadiuba
  • Jesse Thaler
  • John Conway
  • Jonathan Butterworth
  • Joosep Pata
  • Julie Hogan
  • Kevin Connor Nash
  • Kevin Kai Hong Sung
  • Laís Sarem Schunk
  • Lily Asquith
  • Louise Skinnari
  • Luca Brianza
  • Marat Freytsis
  • Marcel Vos
  • Maren Tabea Meinhard
  • Mario Campanelli
  • Mathis Kolb
  • Matteo Negrini
  • Matthew Henry Klein
  • Matthew Schwartz
  • Miaoyuan Liu
  • Michael Russell
  • Mrinal Dasgupta
  • Mykhailo Lisovyi
  • Nhan Viet Tran
  • Nikola Lazar Whallon
  • Nurfikri Norjoharuddeen
  • Oleg Brandt
  • Petar Maksimovic
  • Peter Loch
  • Philip Coleman Harris
  • Qi Zeng
  • Robin Erbacher
  • Roland Jansky
  • Roman Kogler
  • Rosa Simoniello
  • Salvatore Rappoccio
  • Samuel Ross Meehan
  • Shawn Darrell Williamson
  • Shih-Chieh Hsu
  • Simone Marzani
  • Stanislava Sevova
  • Stefan Richter
  • Steven Randolph Schramm
  • Svenja Schumann
  • Takuto Kunigo
  • Tatjana Lenz
  • Thea Aarrestad
  • Thomas Becher
  • Thomas Gehrmann
  • Tobias Kupfer
  • Tobias Lapsien
  • Todd Huffman
  • Torben Schell
  • Trisha Farooque
  • Vieri Candelise
    • 08:00 09:45
      Break: Welcome Coffee + Registration RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 09:45 12:30
      Plenary: Opening + Session I - CALCULATIONS RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Florencia Canelli (Universitaet Zuerich (CH))
      • 09:45
        Welcome 15m
        Speaker: Florencia Canelli (Universitaet Zuerich (CH))
      • 10:00
        Theory Opening 40m

        40' + 10'

        Speakers: Prof. Frank Petriello (Northwestern University and Argonne National Lab), Frank Petriello Petriello (University of Wisconsin-Madison)
      • 10:50
        Highlights from ATLAS and CMS 40m

        40' + 10'

        Speaker: Robin Erbacher (University of California Davis (US))
      • 11:40
        Factorization and Resummation of Soft Dropped D2 20m

        In experimental studies which use boosted taggers, groomers are typically used to reduce sensitivity to wide angle soft radiation. It is therefore important to understand the behavior of these groomers to all orders in QCD. In this talk, I will discuss the factorization of groomed two prong substructure observables, focusing in particular on the $D_2$ observable. I will show that for a particular groomer, soft drop, this observable can be factorized to all orders in perturbation theory. I will discuss theoretical and experimental advantages and disadvantages of soft dropped $D_2$ as a tagger, as well as present numerical results. This analysis sheds considerable light into the behavior of groomed substructure observables and their calculability.

        Speaker: Ian Moult
    • 12:30 14:00
      Break: Lunch RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 14:00 15:45
      Plenary: Session II - CALCULATION AND MEASUREMENT RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Matthew Schwartz
      • 14:00
        A QCD description of jet shapes for boosted jets 20m

        Jet shapes are commonly used as discriminative variables to tag boosted objects. In this talk, I will present a method to compute jet shapes for boosted objects which retains the dominant contributions coming either from the large boost or, when appropriate, from the smallness of the shape itself. I will mostly focus on the case of 2-subjettiness but will also show that the method can be applied to other observables like N-subjettiness with grooming or Energy-Correlation functions.

        Speakers: Gregory Soyez (CEA Saclay), Gregory Soyez (IPhT, CEA Saclay)
      • 14:25
        Jet Substructure at NNLL 20m

        I will discuss recent advances in precision jet substructure calculations. The soft drop groomed mass has been calculated to next-to-next-to-leading logarithmic accuracy and matched to relative $\alpha_s^2$ fixed-order corrections for jets in $pp\to Z+j$ events. The normalized soft drop mass distribution is insensitive to underlying event and pileup, depends only on collinear physics, and only requires determination of the relative quark and gluon jet fractions from fixed-order calculations. This is the first jet substructure calculation to this accuracy and opens the door to precision theory and data comparisons.

        Speaker: Andrew Larkoski (Harvard University)
      • 14:50
        Measurements of jet properties in CMS 20m

        -

        Speakers: Debarati Roy (Saha Institute of Nuclear Physics (IN)), Debarati Roy (University of the Witwatersrand (ZA))
      • 15:15
        Jet properties at ATLAS 20m

        Jet properties

        Speaker: Ben Nachman (SLAC National Accelerator Laboratory (US))
    • 15:45 16:15
      Break: Coffee RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 16:15 17:55
      Plenary: Session III - TOP TAGGING: PERFORMANCE AND APPLICATION RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Lily Asquith (University of Sussex (UK))
      • 16:15
        Top differential cross section and charge asymmetry at ATLAS 20m RAI-H-041

        RAI-H-041

        Zurich

        University of Zurich Rämistrasse 74 8001 Zürich

        Top differential cross section and charge asymmetry

        Speaker: Matteo Negrini (Universita e INFN, Bologna (IT))
      • 16:40
        Top quark measurements in boosted topologies in CMS 20m RAI-H-041

        RAI-H-041

        Zurich

        University of Zurich Rämistrasse 74 8001 Zürich

        -

        Speaker: Louise Skinnari (Cornell University (US))
      • 17:05
        New massive resonances with boosted top signatures at ATLAS 20m RAI-H-041

        RAI-H-041

        Zurich

        University of Zurich Rämistrasse 74 8001 Zürich

        New massive resonances with boosted top signatures

        Speaker: Aine Kobayashi (University of Tokyo (JP))
      • 17:30
        Search for New Massive Resonances with Boosted Top Signatures at CMS 20m RAI-H-041

        RAI-H-041

        Zurich

        University of Zurich Rämistrasse 74 8001 Zürich

        -

        Speakers: Kevin Connor Nash (Rutgers, State Univ. of New Jersey (US)), Kevin Connor Nash (Rutgers, State Univ. of New Jersey (US))
      • 17:50
        How to get to the Apero 5m
        Speaker: Gregor Kasieczka (Eidgenoessische Tech. Hochschule Zuerich (CH))
    • 19:00 20:30
      Break: Welcome Apero Dozentenfoyer (ETH Zurich)

      Dozentenfoyer

      ETH Zurich

    • 09:00 10:45
      Plenary: Session IV - FLAVOR RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Alexander Schmidt (University of Hamburg)
      • 09:00
        Identification of b jets in boosted event topologies with CMS 20m

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        Speaker: Dinko Ferencek (Institute Rudjer Boskovic (HR))
      • 09:25
        Identification of b jets in boosted event topologies at ATLAS 20m

        Identification of b jets in boosted event topologies

        Speaker: Nikola Lazar Whallon (University of Washington (US))
      • 09:50
        X-> bbbar tagging ATLAS 20m

        X-> bbbar tagging ATLAS

        Speaker: Qi Zeng (SLAC National Accelerator Laboratory (US))
      • 10:15
        Tagging $b$ quarks at extreme energies without tracks 20m

        Many of the most exciting searches for new physics beyond the Standard Model,
        as well as further studies of the Standard Model itself, benefit from being
        able to identify high-energy jets containing $b$ quarks (``$b$-jets'').
        Examples include Higgs pair production and decay via
        $HH\rightarrow b\overline{b}b\overline{b}$, sensitive to Higgs trilinear
        couplings~\cite{Behr:2015oqq}; graviton and radion decays to heavy fermions
        and bosons in warped extra dimension models~\cite{Gouzevitch:2013qca}; third-generation
        superpartners in supersymmetry~\cite{Alwall:2008ag}; and indeed any new
        physics with preferential couplings to heavy Standard Model particles or
        third-generation fermions in particular.

        One of the most distinctive features of a $b$-jet is the relatively long life
        (on the order of 1.5~ps) of the $B$ hadron, resulting in charged particle
        tracks displaced from the primary interaction vertex. For this reason, almost
        all modern collider-based particle physics experiments deploy several layers of
        high-granularity silicon detectors near the interaction point, and algorithms
        for distinguishing $b$-jets from jets originating from lighter quarks rely on
        the ability to reconstruct high-resolution tracks in these finely grained
        subsystems.

        However, with increasingly stringent limits placed on the energy scale for new physics,
        distinguishing displaced tracks within increasingly energetic jets
        becomes simultaneously more important and more challenging. Two effects in
        particular make $b$-tagging in TeV-scale jets difficult: First,
        more tracks are collimated into a small angle, resulting in a higher hit
        density and a more ambiguous association of hits with tracks.
        A single mis-assignment can steer a track off-course and produce an
        erroneous impact parameter. Second, at extreme energies, an increasing
        fraction of $B$ hadrons will decay after crossing the innermost layers of the
        silicon detector: in the best case scenario, this situation merely reduces the
        number of hits available for reconstruction and thus degrades the impact
        parameter resolution of the track. A worse scenario is that the track picks up
        a spurious hit in the densely populated inner layer.

        Results on conventional $b$-tagger efficiencies from the LHC experiments typically
        are limited to momenta transverse to the beam ($p_T$) below roughly
        500 GeV. Early simulation
        results indicated a falling tagging efficiency beyond approximately 150 GeV.
        Even with considerable optimization, results remain
        consistent with a falling efficiency at high energies, though obscured somewhat
        by the restricted momentum range published.

        This article investigates a new method which, by relying only on Si detector hits rather
        than the reconstructed tracks, better maintains its efficiency at extreme energies,
        by which we mean energies of at least 300 GeV, above which conventional
        $b$-tagging performance degrades rapidly.

        Speaker: Todd Brian Huffman (University of Oxford (GB))
      • 10:35
        Social Program 5m
        Speaker: Ben Kilminster (Universitaet Zuerich (CH))
    • 10:45 11:15
      Break: Coffee RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 11:15 12:30
      Plenary: Session V - W/Z TAGGERS RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Andreas Hinzmann (Universitaet Zuerich (CH))
      • 11:15
        Thinking outside the ROCs: Designing Decorrelated Taggers (DDT) for jet substructure 20m

        We explore the scale-dependence and correlations of jet substructure observables to improve upon existing techniques in the identification of highly Lorentz-boosted objects. Modified observables are designed to remove correlations from existing theoretically well-understood observables, providing practical advantages for experimental measurements and searches for new phenomena. We study such observables in W jet tagging and provide recommendations for observables based on considerations beyond signal and background efficiencies.

        Speaker: Salvatore Rappoccio (State University of New York (US))
      • 11:40
        Boosted W/Z-tagging at ATLAS 20m

        Boosted W/Z-tagging

        Speakers: Aparajita Dattagupta (University of Oregon (US)), Aparajita Dattagupta (Indiana University (US))
      • 12:05
        Boosted W/Z tagging in CMS 20m

        -

        Speaker: Luca Brianza (Universita & INFN, Milano-Bicocca (IT))
    • 12:30 14:00
      Break: Lunch RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 14:00 15:45
      Plenary: Session VI - TOP: CALCULATION AND MEASUREMENT RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Conveners: Thomas Gehrmann (Univ. Zurich), Thomas Gehrmann
      • 14:00
        QCD resummation for boosted top production 20m

        The LHC is starting to study the regime where top-quark pairs are produced with energies much larger than the top mass. In this "boosted regime", large QCD corrections can arise both from soft-gluon emissions and from emissions collinear to the energetic top quarks, which become singular in the boosted limit. In this talk I discuss a theoretical framework which can be used to resum both types of potentially large corrections in the boosted regime, and compare some of its numerical predictions for differential cross sections with LHC data.

        Speaker: Ben Pecjak
      • 14:25
        Kinematic Extraction of Short Distance Top Mass at the LHC 20m

        The top quark mass is one of the most important standard model parameters. The most precise method for top mass extraction comes from kinematic extraction. However, there's an O(1) GeV theory uncertainty associated with the fact these methods rely on Monte Carlo simulations which do not have a fully specified field theoretic mass scheme definition. I will describe our proposal for using a 2-jettiness variable with a boosted top sample to extract the top mass at the LHC. This variable obeys a factorization theorem which allow the associated cross section to be calculated with a well defined top mass scheme, and has the same strong sensitivity as the currently used template method.

        Speaker: Aditya Pathak (Massachusetts Institute of Technology)
      • 14:50
        Boosted top tagging in CMS 20m

        -

        Speaker: Roman Kogler (Hamburg University (DE))
      • 15:15
        Boosted top-tagging at ATLAS 20m

        Boosted top-tagging

        Speaker: Christoph Falk Anders (Ruprecht-Karls-Universitaet Heidelberg)
    • 15:45 16:15
      Break: Coffee RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 16:15 17:30
      Plenary: Session VII - FUTURE RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Jesse Thaler (MIT)
      • 16:15
        Detectors for Superboosted Jet Substructure at Future Circular Colliders 20m

        We study the detector performance with an emphasis on jet substructure variables for extremely boosted objects at very high energy proton colliders using Geant4 simulation. We focus on the calorimeter performance and study hadronically-decaying W bosons with transverse momentum in the multi-TeV range (5-20 TeV). The calorimeter segmentation is benchmarked in order to understand the impact of granularity and resolution on boosted boson discrimination.

        Speaker: Nhan Viet Tran (Fermi National Accelerator Lab. (US))
      • 16:40
        Jet reconstruction at future e+e- colliders 20m

        Abstract: The linear collider experiments require excellent performance of jet clustering algorithms in high-energy electron-positron with non-negligible gamma gamma -> hadrons background. The ILC and CLIC detector concepts have studied the performance of several algorithms under realistic conditions and with a detailed model of the detector response. Results on jet energy and substructure response are presented for several key benchmark processes. The identification of boosted objects in TeV electron-positron collisions is also discussed.

        Speaker: Rosa Simoniello (CERN)
      • 17:05
        Boosted tops and the time-structure of the hot dense-medium of heavy-ion collisions 20m

        -

        Speaker: Gavin Salam (CERN)
    • 19:30 21:30
      Public Evening Event HG-F30 (Audimax) (ETH Zurich)

      HG-F30 (Audimax)

      ETH Zurich

      Raemistrasse 101
    • 09:00 10:20
      Plenary: Session VIII - PILE UP AND CALCULATIONS RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Ariel Gustavo Schwartzman (SLAC National Accelerator Laboratory (US))
      • 09:00
        Factorization and resummation of non-global logarithms 20m

        In this talk I will introduce our recent work about factorization and resummation for jet processes. From a detailed analysis of Sterman-Weinberg cone-jet cross sections in effective field theory, we obtain novel factorization theorems which separate the physics associated with different energy scales present in such processes. The relevant low-energy physics is encoded in Wilson lines along the directions of the energetic particles inside the jets. This multi-Wilson-line structure is present even for narrow-cone jets due to the relevance of small-angle soft radiation. We discuss the renormalization-group equations satisfied by these operators. Their solution resums all logarithmically enhanced contributions to such processes, including non-global logarithms. Such logarithms arise in many observables, in particular whenever hard phase-space constraints are imposed, and are not captured with standard resummation techniques. Our formalism provides the basis for higher-order logarithmic resummations of jet and other non-global observables. As a nontrivial consistency check, we use it to obtain explicit two-loop results for all logarithmically enhanced terms in cone-jet cross sections and verify those against numerical fixed-order computations. This talk is based on arXiv:1508.06645, arXiv:1605.02737 and some recent progress about numerical results.

        Speaker: Dr dingyu shao
      • 09:25
        Pile-up mitigation techniques at ATLAS 20m

        Pile-up mitigation techniques

        Speaker: Matthew Henry Klein (Columbia University (US))
      • 09:50
        Using wavelets for pile-up mitigation in hadron collisions 20m

        Measuring inclusive quantities, both global (missing and sum transverse energy) and local (jet mass and substructure), after the high luminosity LHC upgrade will be extremely challenging, and will require new pile-up mitigation techniques that correct more than local jet energies. To this end, one can use the fact that pile-up has no angular structure while hard processes are characterised by small-angle emissions and are therefore highly sparse in the frequency domain. Using wavelet functions, intermediates between a standard pixel basis and a Fourier basis, which are localised in position ($y - \phi$) as well as frequency (angular) space, we can naturally and efficiently perform an event-wide classification of signal and pile-up particles by filtering in the frequency domain. In this talk, we will motivate the use of wavelets in high energy physics, describe the procedure behind a wavelet analysis, and present a few concrete methods and results. In particular, using a generator-level overlay of signal and pile-up events, we demonstrate that, using wavelet techniques, a significant improvement in e.g.~missing transverse energy reconstruction may be possible even up to $\langle\mu\rangle$ of 300 or beyond.

        Speaker: Andreas Sogaard (University of Edinburgh (GB))
    • 10:20 10:50
      Break: Coffee RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 10:50 12:10
      Plenary: Session IX - SEARCHES RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Ben Kilminster (Universitaet Zuerich (CH))
      • 10:50
        Search for Higgs-boson production in association with a top-quark pair at CMS 10m

        -

        Speakers: Shawn Darrell Williamson (KIT - Karlsruhe Institute of Technology (DE)), Shawn Darrell Williamson (KIT - Karlsruhe Institute of Technology (DE))
      • 11:05
        Search for light Z' to qq produced in association with a jet in CMS 10m

        -

        Speaker: Nhan Viet Tran (Fermi National Accelerator Lab. (US))
      • 11:20
        Search for beyond the Standard Model Higgs boson decaying to a pair of new light bosons in boosted dimuon final states in CMS 10m

        -

        Speakers: Jamal Rorie (University of Hawaii at Manoa), Jamal Tildon Rorie (Rice University (US)), Jamal Tildon Rorie (Rice University (US))
      • 11:35
        Jet mass response ATLAS 20m

        Jet mass response ATLAS

        Speakers: Roland Jansky (University of Innsbruck (AT)), Roland Wolfgang Jansky (University of Innsbruck (AT))
    • 12:10 13:00
      Break: Sandwich Lunch RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 13:00 15:00
      Plenary: Mid-Week Session RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Marcel Vos (IFIC Valencia (ES))
    • 15:15 18:30
      Break: Excursions RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 09:00 10:45
      Plenary: Session X - SEARCHES RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Andrea Rizzi (Universita di Pisa & INFN (IT))
      • 09:00
        SUSY using boosted techniques at ATLAS 20m

        SUSY using boosted techniques

        Speaker: Giordon Holtsberg Stark (University of Chicago (US))
      • 09:25
        SUSY searches using boosted techniques at 13 TeV in CMS 20m

        -

        Speaker: Miaoyuan Liu (Fermi National Accelerator Lab. (US))
      • 09:50
        Search for New Resonances Decaying to Boosted Higgs Signatures at CMS 20m
        Speakers: Vieri Candelise (Universita di Roma I "La Sapienza"-Universita & INFN, Roma I), Vieri Candelise (National Central University (TW)), Vieri Candelise (National Central University (TW))
      • 10:15
        New resonances decaying to boosted Higgs signatures at ATLAS 20m

        New resonances decaying to boosted Higgs signatures

        Speakers: Chris Pollard (University of Glasgow (GB)), Christopher Samuel Pollard (Duke University)
    • 10:45 11:15
      Break: Coffee RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 11:15 12:30
      Plenary: Session XI - SEARCHES AND TAGGING RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Jonathan Butterworth (University College London (UK))
      • 11:15
        Search for New Resonances Decaying to Boosted Diboson Signatures at CMS 20m

        -

        Speaker: Petar Maksimovic (Johns Hopkins University (US))
      • 11:40
        New resonances decaying to boosted diboson signatures at ATLAS 20m

        New resonances decaying to boosted diboson signatures (no abstract received)

        Speaker: Francesco De Lorenzi (Iowa State University (US))
      • 12:05
        Resolved Top Tagger in CMS 20m
        Speaker: Stanislava Sevova (Northwestern University (US))
    • 12:30 14:00
      Break: Lunch RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 14:00 15:45
      Plenary: Session XII - TAGGING RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Gavin Salam (CERN)
      • 14:00
        Jet Images with Deep Learning 20m

        Building on the jet-image based representation of high energy jets, we develop computer vision based techniques for jet-tagging through the use of Deep Neural Networks. Jet-images enabled the connection between jet substructure and tagging with the fields of computer vision and image processing. We show how applying such techniques using Deep Neural Networks can improve the performance to identify highly boosted W bosons with respect to state-of-the-art substructure methods. In addition, we explore new ways to extract and visualize the discriminating features of different classes of jets, adding a new capability to understand the physics within jets and to design more powerful jet tagging methods.

        Speakers: Ben Nachman (SLAC National Accelerator Laboratory (US)), Michael Aaron Kagan (SLAC National Accelerator Laboratory (US))
      • 14:25
        Deep Learning for Boosted Objects 20m

        Deducing whether the substructure of an observed jet is due to a low-mass single particle or due to multiple decay objects of a massive particle is an important problem in the analysis of collider data. Traditional approaches have relied on expert features designed to detect energy deposition patterns in the calorimeter, but the complexity of the data make this task an excellent candidate for the application of machine learning tools. The data collected by the detector can be treated as a two-dimensional image, lending itself to the natural application of image classification techniques. In this work, we apply deep neural networks with a mixture of locally-connected and fully-connected nodes. Our experiments demonstrate that without the aid of expert features, such networks match or modestly outperform the current state-of-the-art approach for discriminating between jets from single hadronic particles and overlapping jets from pairs of collimated hadronic particles, and that such performance gains persist in the presence of pileup interactions.

        In addition, we will present initial studies on using deep networks to perform b-tagging inside boosted objects.

        Speaker: Daniel Hay Guest (University of California Irvine (US))
      • 14:50
        New Multivariate Approach to Tagging Highly Boosted Top Quarks, Higgs Bosons, and W and Z Bosons 20m

        We present a new approach for efficiently and selectively identifying high-momentum, hadronically decaying top quarks, Higgs bosons, and W and Z bosons, distinguishing them from jets from light quarks and gluons in proton-proton collisions at the LHC or future colliders. This technique yields variables that can be combined with those from current approaches to boosted particle tagging in multivariate classifiers such as deep neural networks or boosted decision trees to yield estimators which can be used in a broad range of analyses in which such highly boosted particles play a role. The technique is capable of identifying subjets which overlap strongly in the tracking and calorimetry systems, allowing good performance even in the multi-TeV regime. The performance of the method is studied in various scenarios and shows promise for actual use at the LHC experiments.

        Speaker: John Conway (University of California, Davis)
      • 15:15
        A new tagger for hadronically decaying heavy particles at the LHC 20m

        We present a new algorithm developed for the identification of boosted heavy particles at the LHC, the Heavy Object Tagger with Variable R (HOTVR). The algorithm is based on jet clustering with a variable distance parameter $R$ combined with a mass jump condition. The variable $R$ approach adapts the jet size to the transverse momentum $p_T$, resulting in smaller jets for increasing values of $p_T$, making the jet mass less susceptible to radiation. Two and three prong decays are identified using subjets, formed by the mass jump condition. The resulting algorithm combines the jet clustering, subjet finding and rejection of soft clusters in one step, making it robust and simple. We present performance tests for the identification of boosted top quarks, which show that the HOTVR algorithm has similar or better performance over a large range in $p_T$ compared to other algorithms commonly used at the LHC.

        Speaker: Tobias Lapsien (Hamburg University (DE))
    • 15:45 16:15
      Break: Coffee RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 16:15 17:57
      Plenary: Session XIII - PERFORMANCE RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Peter Loch (University of Arizona (US))
      • 16:15
        Jet performance in Run 2 at CMS 20m

        -

        Speaker: Giorgia Rauco (Universitaet Zuerich (CH))
      • 16:40
        Jet performance in Run 2 at ATLAS 20m

        Jet performance in Run 2

        Speaker: Takuto Kunigo (Kyoto University (JP))
      • 17:05
        Tau identification in boosted topologies in CMS 20m

        -

        Speaker: Camilla Galloni (Universitaet Zuerich (CH))
      • 17:30
        Y-splitter with grooming as an effective boosted object tagger 20m

        It has recently been shown that the Y-splitter method with trimming is a very effective method for tagging boosted electroweak bosons, outperforming several standard taggers at high pt. Here we analytically investigate this observation and explain the performance of Y-splitter with a range of grooming techniques from first principles of QCD. We also suggest modifications that considerably simplify the analytical results, thereby increasing robustness, and make the results largely independent of the details of grooming.

        Speaker: Laís Sarem Schunk (IPhT, CEA - Saclay)
      • 17:55
        How to get to the Dinner 2m
        Speaker: Gregor Kasieczka (Eidgenoessische Tech. Hochschule Zuerich (CH))
    • 18:30 22:30
      Break: Conference Dinner
    • 09:15 10:30
      Plenary: Session XIV - SEARCHES AND TAGGING RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Salvatore Rappoccio (State University of New York (US))
      • 09:15
        Splitting function in pp and PbPb collisions at 5 TeV in CMS 20m

        Heavy Ion z-fragmentation measurement in pp and PbPb

        Speaker: Marta Verweij (CERN)
      • 09:40
        Massive vector-like quarks using boosted particle reconstructions ATLAS 20m

        Massive vector-like quarks using boosted particle reconstructions

        Speaker: Trisha Farooque (Universitat Autònoma de Barcelona (ES))
      • 10:05
        Search for Massive Vector-like Quarks using Boosted Particle Reconstruction in CMS 20m

        -

        Speaker: Julie Hogan (Brown University (US))
    • 10:30 11:00
      Break: Coffee RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
    • 11:00 14:00
      Plenary: Closing RAI-H-041

      RAI-H-041

      Zurich

      University of Zurich Rämistrasse 74 8001 Zürich
      Convener: Gregor Kasieczka (Eidgenoessische Tech. Hochschule Zuerich (CH))
      • 11:00
        Experimental summary 40m
        Speaker: Philip Coleman Harris (CERN)
      • 11:50
        Theory summary 40m
        Speaker: Simone Marzani (University of Durham (GB))
      • 12:40
        Open discussion 20m
      • 13:00
        BOOST 2017 15m
        Speaker: Salvatore Rappoccio (State University of New York (US))
      • 13:15
        Farewell 5m
        Speaker: Gregor Kasieczka (Eidgenoessische Tech. Hochschule Zuerich (CH))
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