PoS(ICHEP2016)788 http://pos.sissa.it/ Nhan Viet b FERMILAB-CONF-16-684-CD-PPD Lindsey Gray, c -leptons at Future τ -leptons with transverse momentum in the TeV range. τ Sergei Chekanov, -lepton identification variables at very high energy proton -lepton discrimination. τ τ b a, d Ashutosh Kotwal, a , ∗ and Shin-Shan Yu b Speaker. Calorimeters are benchmarked ingranularity various and configurations resolution on in boosted order to understand the impact of We study the detector performance of colliders. We study hadronically-decaying ∗ 38th International Conference on High Energy3-10 Physics August 2016 Chicago, USA © Copyright owned by the author(s)Attribution-NonCommercial-NoDerivatives 4.0 under International the License terms (CC of BY-NC-ND the 4.0). Creative Commons Department of Physics, National Central University, Chung-Li, Taiwan E-mail: ,[email protected], [email protected],[email protected] ,[email protected] [email protected],[email protected] Circular Colliders Tran, Department of Physics, Duke University, DurhamFermi NC, National USA Accelerator Laboratory, Batavia IL,High USA Energy Physics Division, Argonne National Laboratory, Argonne IL, USA Sourav Sen Detectors for Superboosted c a b d This manuscript has been authored by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the U.S. This manuscript has been authored by Fermi Research Alliance, LLC under Contract Department of Energy, Office of Science, Office of High Energy Physics. PoS(ICHEP2016)788 ). I 2 cm 100 TeV Sourav Sen , branching = lepton is the 0 s τ nπ √ + jets, the Hadronic τ ν T p  leptons (referred here 65%) and leptonically 8. These samples were τ jets are more collimated 3π decay. jets [6] against QCD back- → had had τ τ -decay products has been de- had had τ τ -leptons predominantly decay via MADGRAPH τ 6/ Monte-Carlo events were used to model ¯ q q PYTHIA → -leptons τ 21%) or 3-prong (τ 1 ∼ 5 cm scintillator pixels. The cylindrical barrel extends (1 TeV) 0 -identification performance study. Z τ 3]. The detectors should therefore be able to detect the super- and 777 GeV. The hadronically decaying ττ radiation lengths. In order to contain high 0 → , branching ratio: 35X 0 7. The total diameter of the detector is 19 m. ∼ nπ 1. + (1 TeV) = τ 0 | ν Z η  | π jets, distinguishing them from QCD jets as follows: (i) -leptons at FCC → τ 500 GeV) using a full GEANT4-based simulation of the FCC-hh detector. had had τ 70%) channels; and (iii) presence of secondary vertex in the leptons in their final states [2, ) have QCD jets as their major background. A high-granularity silicon-tungsten calorimeter ∼ -leptons being color-neutral decay via the weak interaction. This inhibits quark & gluon ra- τ τ As a starting point, we repurposed the basic design of the Silicon Detector (SiD)[4] of the Future experiments like FCC-hh (proton-proton collider at very high energy For this study, jets (∼ had 35%) due to its heavy mass of 1. τ had diation in the signal and background processessamples respectively. were The obtained generator-level from (referred aevents, to public HepSim as], [5 repository where truth-level) for they were High produced Energyprocessed using through Physics the Monte SiFCC Carlo detector simulated simulation.background events, Owing the to Durham the Jet di-jet Algorithm topologyjets. was of These used both jets to signal are cluster and then the passed final-state on particles to into the two 4. Identification of hadronically-decaying with sufficient radiation and interaction lengths to contain all the as signed. Since the granularityrequired is insights very into high, the detector aτ design. fast Here simulation we study present would the not detector be response to able super-boosted to give the silicon pixels, providing Calorimeter (HCAL) consists of 64The HCAL layers active of material consists steel of absorber, 5 cm× giving 11.3 interaction lengths (λ and isolated; (ii) low1-prong track (τ (charged-particle) multiplicity as 2. Detector design International Linear Collider, because oftracker its and high calorimeters. solenoid This made field theThe (5 detector Tesla) Electromagnetic silicon and Calorimeter sensor-based, the hence (ECAL) highly it has is granular named 32 "SiFCC". layers of tungsten absorber with 2 cm× to pseudorapidity 3. Event simulation and reconstruction Superboosted 1. Introduction [1]) would probe Beyond Standardhave Model channels involving heavyboosted resonances, final states many in of order which tomost reconstruct difficult these charged heavy lepton resonances. to Additionally, identify, the (∼ and it decays both hadronically (∼ ratio: Based on these features, we use a set of variables to discriminate ground. We set the axis of a jet as the direction of the vector sum of momenta of its constituents. PoS(ICHEP2016)788 4, < 0. ∆R < 1, where jets at the ∆R Sourav Sen 0. had ≤ τ 4 (i.e, core and 0. < ∆R (3 prong) iso N (b) identification variables. 1. had 2 τ Fraction of transverse momentum of the hardest as- ) track between an associated track inside the core region and the f Number of associated tracks in the isolation region (Fig.1b). ∆R ) Fraction of transverse energy deposited inside the region iso track ) cent f -weighted distance of the associated tracks within (1 prong) Maximum T discrimination variables in the SiFCC detector about the jet axis) which contains 90% of the jet energy, and the "isolation 4) which forms the periphery of the jet. The discriminating variables are: p 2 ) Figure 1: Distributions of τ cent Invariant mass calculated using all the associated tracks within ) f 0. ) mass for each track. ) max < ∆φ  (a) track π track (∆R + ( ∆R -leptons at FCC 2 τ ) < ∆R 1 ∆η ( 05 (i.e., half of the core radius) with respect to the total transverse energy deposited in the assuming 0. core region1a). (Fig. sociated track inside the corethe region core with region. respect to the total transverse energy deposited in jet axis. isolation region combined) from the jet axis. p The discrimination variables worked well in capturing the salient features of Due to sufficient granularity of the SiFCC detector design, the super-boosted final state par- = 5. Performance of truth-level as well as detector-level, as shown in Fig. Superboosted We divide the region containing∆R the jet intoregion" two (0. parts viz. the "core region"Central energy (∆R fraction ( Number of isolation tracks (N ticles could be resolvedexceptional and agreement between reconstructed the with truth and hightion detector-level variables efficiency. distributions for (Fig.1) both of This signal the and can discrimina- background. be This high inferred reconstruction from efficiency also the bolsters the Leading-track momentum fraction ( Maximum Track radius (R Track mass (M PoS(ICHEP2016)788 -lepton τ Sourav Sen leptons with the channel from τ 3 -lepton identification provides an important physics 8 TeV." The European Physical Journal C 75.7 (2015): τ = s √ collisions at pp -leptons at the FCC-hh energy scale using the current detector design. τ -leptons at FCC τ 1-33. Collier Workshop, CERN, Geneva Switzerland. 2014. resonances in longitudinal vector boson scattering(2015): at 114018. a 100 TeV collider." Physical Review D 91.11 Frontier." Physical Review D 94.03 (2016): 035022. Detectors." arXiv preprint arXiv:1306.6329 (2013). Advances in High Energy Physics 2015 (2015). ATLAS experiment in The good performance of super-boosted This research was performed using resources provided by the Open Science Grid, which is sup- [1] Benedikt, Michael. "Future Circular Collider (FCC) study-status." Proceedings of 1st Future[2] Hadron Kotwal, A. V., S. Chekanov, and M. Low. "Double Higgs boson production in the 4τ [3] Kotwal, Ashutosh V., et al. "Singlet-Catalyzed Electroweak Phase Transitions in the 100[4] TeV Behnke, Ties, et al. "The International Linear Collider Technical Design Report-Volume 4: [5] Chekanov, S. V. "HepSim: a repository with predictions for high-energy physics experiments." [6] Aad, Georges, et al. "Identification and energy calibration of hadronically-decaying benchmark for the granularity and sizevariables of are the applicable SiFCC at detector. the It also FCC-hhemploy shows energy multivariate methods that scales. like the Boosted For discrimination Decision further Tree optimization, (BDT) to we improve are super-boosted planning to ported by the National Science Foundation andArgonne the National U.S. Laboratory’s Department work of was Energy’s Office supportedScience of under by Science. contract the DE-AC02-06CH11357. U.S. Department Themilab) of Fermi is Energy, National Office operated Accelerator of by Laboratory Fermi (Fer- with Research the Alliance, United States LLC Department under of Contract Energy. No. DE-AC02-07CH11359 References Superboosted performance of the discrimination variables at theare detector clearly level. separated The signal and and even backgroundwith a events good simple background cut-based rejection. selection Thus, can thehadronically-decaying give discrimination a variables are high efficient yield in of identification signal of events, 6. Conclusion and further plans identification at FCC-hh in the near future. 7. Acknowledgements