Searches for Heavy Stable Charged Particles at the LHC Loïc Quertenmont on behalf of CMS and ATLAS 12 November 2015
What are we talking about ? Appears in many scenarios and in various forms…. SUSY EXOTIC +++ other more exotic models/particles (monopoles, quirks, dyons, etc.) arXiv:hep-ph/0611040 Fairbairn et al. Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 2
What are we talking about ? A rich phenomenology, dictating the experimental signature • Heavy • Stable • Charged Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 3
What are we talking about ? A rich phenomenology, dictating the experimental signature • Heavy Slow particle β<1 • Stable • Charged Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 4
What are we talking about ? A rich phenomenology, dictating the experimental signature • Heavy Slow particle β<1 • Stable Long-lived cτ > O(0.1)m 1) Reach the tracker cτ > O(10)m 2) Escape the detector 3) Stop in Asynchronous decay cτ > O(100)m • Charged Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 5
What are we talking about ? A rich phenomenology, dictating the experimental signature • Heavy Slow particle β<1 • Stable Long-lived cτ > O(0.1)m 1) Reach the tracker cτ > O(10)m 2) Escape the detector 3) Stop in Asynchronous decay cτ > O(100)m • Charged lepton-like Electric |Q|<<e, |Q|<e, |Q|=e, |Q|>e, |Q|>>e hadron-like R-hadron properties ?! Color (gluinoball, charge flip, interaction w/ matter, etc.) Magnetic monopoles, dyons quirks, … Exotic Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 6
What are we talking about ? A rich phenomenology, dictating the experimental signature • Heavy Slow particle β<1 • Stable Long-lived cτ > O(0.1)m 1) Reach the tracker cτ > O(10)m 2) Escape the detector 3) Stop in Asynchronous decay cτ > O(100)m • Charged lepton-like Electric IONIZATION |Q|<<e, |Q|<e, |Q|=e, |Q|>e, |Q|>>e hadron-like R-hadron properties ?! Color (gluinoball, charge flip, interaction w/ matter, etc.) Magnetic monopoles, dyons quirks, … Exotic Terminology : HSCP=SMP=ChaMP=CmLLP =… Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 7
Experimental Signature IONIZING SLOW dE/dx Time Of Flight with δ t = delay Magnetic charge g D Q ~ 68.5e β resolution improves dE/dx resolution improves with time resolution ( δ t) with #layers, sensor and with lever arm (L) thickness and readout Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 8
Experimental Signature IONIZING SLOW dE/dx Time Of Flight with δ t = delay STOPPED Magnetic charge g D Q ~ 68.5e Decay asynchronously w.r.t LHC bunch If dE/dx is (high) comparable to the kinetic energy β resolution improves dE/dx resolution improves The particle may with time resolution ( δ t) with #layers, sensor stop in the detector and with lever arm (L) thickness and readout and decay later Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 9
ATLAS/CMS Detectors for HSCP Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 10
ATLAS/CMS Detectors for HSCP Time of Flight Muon Chambers Muon Chambers MDT + RPC DT + CSC Calorimeter Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 11
ATLAS/CMS Detectors for HSCP dE/dx Time of Flight Calorimeter Muon Chambers Pixel Muon Chambers MDT + RPC Pixel tracker DT + CSC tracker Strip Calorimeter tracker Calorimeter Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 12
ATLAS/CMS Detectors for HSCP dE/dx Time of Flight Calorimeter* Calorimeter Muon Chambers MDT* Pixel Muon Chambers MDT + RPC Pixel tracker DT + CSC tracker Strip Calorimeter tracker TRT* Calorimeter tracker * = only if dEdx>> O(1) GeV * = only in special stream Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 13
ATLAS/CMS Detectors for HSCP • π 0 R-Hadron charge can flip due to nuclear interaction p + • Many possible R-Hadron interaction models some predicts that flipping to neutral is more likely R 0 R + • Gluino ball fraction (f) is also unknown (even if 10% in pythia) Stay charge Charged in Charged in all along tracker only muon syst. only R + R 0 R + R + R 0 R + Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 14
ATLAS/CMS Searches *= apply to g D ≠0 yes no R-Hadron ? Stopped in ? Q/g d charge ? |Q|<1 |Q|=1 ± Charge ? 0 |Q|>1* Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 15
ATLAS/CMS Searches *= apply to g D ≠0 yes no R-Hadron ? Stopped in ? Q/g d charge ? |Q|<1 |Q|=1 ± Charge ? 0 |Q|>1* 0 ± 0 0 ± ± ± 0 |Q|~1/2 |Q|<<1 |Q|>>1* |Q|<8 |Q|=1 Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 16
ATLAS/CMS Searches *= apply to g D ≠0 yes no R-Hadron ? Stopped in ? Q/g d charge ? |Q|<1 |Q|=1 ± Charge ? 0 |Q|>1* 0 ± 0 0 ± ± ± 0 |Q|~1/2 |Q|<<1 |Q|>>1* |Q|<8 |Q|=1 CMS : TK arXiv:1305.0491 pT + dEdx Not covered But proposal for LHC exp. arXiv:1410.6816 Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 17
Selected Results on: Q<1 The search in a nutshell • Challenges: • Small energy loss LHC detectors and DAQ designed for Q=1 • Out-of-time particles (cosmics/ghost) also lead to low dE/dx • Advantage: • Tracking: high reco pT (=pT True / Q) signature Background (ABCD) Limits Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 18
ATLAS/CMS Searches *= apply to g D ≠0 yes no R-Hadron ? Stopped in ? Q/g d charge ? |Q|<1 |Q|=1 ± Charge ? 0 |Q|>1* 0 ± 0 0 ± ± ± 0 |Q|~1/2 |Q|<<1 |Q|>>1* |Q|<8 |Q|=1 CMS : TK arXiv:1305.0491 pT + dEdx Not covered But proposal for LHC exp. arXiv:1410.6816 Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 19
ATLAS/CMS Searches *= apply to g D ≠0 yes no R-Hadron ? Stopped in ? Q/g d charge ? |Q|<1 |Q|=1 ± Charge ? 0 |Q|>1* 0 ± 0 0 ± ± ± 0 |Q|~1/2 |Q|<<1 |Q|>>1* |Q|<8 |Q|=1 CMS : TK+MS CMS : TK arXiv:1305.0491 arXiv:1305.0491 pT + dEdx dEdx + TOF ATLAS: arXiv:1504.04188 dEdx PIX,TRT,MDT ATLAS: TRT+EM Not covered arXiv1509.08059 But proposal 10<Q<60 & 0.5<g D <1.5 for LHC exp. arXiv:1102.0459 arXiv:1410.6816 6<Q<17 Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 20
Selected Results on: 1<Q<10 The search in a nutshell • Challenges: • Tracking: smaller reco pT (=pT True / Q) trigger & background rate • Solutions: • Requires it to reach MS (many redundant measurements dE/dx or TOF) • Keep track pT threshold as low as possible (40GeV) Comparable Limits CMS/ATLAS Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 21
Selected Results on: Q>>1 or g D ≠0 The search in a nutshell • Challenges: • Tracking: small reco pT (=pT True / Q) or track bending for g D ≠0 • Huge energy loss: not reach outer detector (+ possible DAQ issues) • Solutions: Dedicated trigger + no tracking + only inner detectors (TRT and EM) TRT info EM info Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 22
ATLAS/CMS Searches *= apply to g D ≠0 yes no R-Hadron ? Stopped in ? Q/g d charge ? |Q|<1 |Q|=1 ± Charge ? 0 |Q|>1* 0 ± 0 0 ± ± ± 0 |Q|~1/2 |Q|<<1 |Q|>>1* |Q|<8 |Q|=1 CMS : TK+MS CMS : TK arXiv:1305.0491 arXiv:1305.0491 pT + dEdx dEdx + TOF ATLAS: arXiv:1504.04188 dEdx PIX,TRT,MDT ATLAS: TRT+EM Not covered arXiv1509.08059 But proposal 10<Q<60 & 0.5<g D <1.5 for LHC exp. arXiv:1102.0459 arXiv:1410.6816 6<Q<17 Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 23
ATLAS/CMS Searches *= apply to g D ≠0 yes no R-Hadron ? Stopped in ? Q/g d charge ? |Q|<1 |Q|=1 ± Charge ? 0 |Q|>1* 0 ± 0 0 ± ± ± 0 |Q|~1/2 |Q|<<1 |Q|>>1* |Q|<8 |Q|=1 CMS : TK+MS CMS : TK arXiv:1305.0491 arXiv:1305.0491 pT + dEdx dEdx + TOF ATLAS: arXiv:1504.04188 dEdx PIX,TRT,MDT CMS: CALO ATLAS: TRT+EM Not covered arXiv:1501.05603 arXiv1509.08059 But proposal 10<Q<60 & 0.5<g D <1.5 for LHC exp. arXiv:1102.0459 ATLAS: CALO arXiv:1410.6816 6<Q<17 arXiv:1310.6584 Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 24
Selected Results on: Stopped HSCP The search in a nutshell • Signature: Energetic jet w/o pp collisions • Backgrounds: cosmics, beam halo, det. noise gluino stop sbottom Loic.Quertenmont@cern.ch 12/11/2015 - Searches for HSCP at the LHC 25
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