SUSY and other BSM physics with CMS G. Bruno on behalf of the CMS Collaboration Center for Cosmology, Phenomenology and Particle Physics (CP3) Université catholique de Louvain (UCL), Louvain-la-Neuve, Belgium LHC Days in Split Conference 30/9/2014
The Standard Model puzzles Higgs boson discovery has completed the SM Key unanswered questions: Dark matter Matter-antimatter asymmetry Neutrino masses Gravity and “dark energy” Unification of forces Deeper origin of electroweak symmetry breaking Deeper origin of fermion mass hierarchies, flavor mixing, and CP violation BSM Physics that would address these questions is in many cases expected at the TeV scale Split2014 – BSM in CMS
BSM physics ideas Split2014 – BSM in CMS
How to search for BSM physics at the LHC Talks by: J.-P. Sauvan A. Nikitenko F. Pandolfi Scalar sector Precise measurements of Higgs couplings and properties Search for an extended scalar sector Precise measurement of SM observables Few, yet notable, competitive examples Final states with top quarks Strong and ew couplings Rare decays Top squark, vector-like top partners, tt resonances Other direct searches for new physics Inclusive squarks and gluino (and neutralino) searches Compressed SUSY spectra R-parity violating susy searches New vector bosons mono X searches (heavy, strongly interacting states are out of reach) Long-lived particles Talks by C. Grab and E. Gallo Talk by J. Cuevas Maestro Talk by R. Bartek Talk by M. Kazana Split2014 – BSM in CMS
Supersymmetry Split2014 – BSM in CMS
SUSY searches Highly motivated theoretical framework High cross section – gluinos,1st and 2nd generation squarks Multijets + MET w/wo b-jets, leptons, photons Highly motivated theoretical framework Lays the bases for unification of forces Provides a dark matter candidate Can stabilize the Higgs mass Medium cross section – stop and sbottom Multi-jets + MET + b-tags w/w.o. leptons Dedicated searches Low cross section – Charginos, neutralinos, sleptons: 0-4 leptons + METw/w.o. b-tags, jets, W’s, Z’s, h’s Split2014 – BSM in CMS
All-hadronic inclusive search 1402.4770 Gluinos,1st,2nd gen. squarks 36 signal regions in bins of Jet multiplicity (≥3) HT (≥500 GeV) HTmiss (≥200 GeV) Limits in Simplified Model Space (SMS) Split2014 – BSM in CMS
The search for (natural) stops Split2014 – BSM in CMS
Stop search for moderate mass differences Combination of 2 analyses (SUS-14-011): Inclusive search with ETmiss, b-jets w/wo leptons (SUS-13-004) Uses razor variables in several disjoint boxes Exclusive analysis targeting the bb𝑊𝑊 χ 0 χ 0 final state (1308.1586) BDT selection on events with 1 lepton, ≥4 jets (≥1btagged) and Etmiss Limits depend on stop decay BRs Most stringent for BR( 𝑡 →𝑡 χ 0 )=1 Also conservative BR-independent result Split2014 – BSM in CMS
Stop search: filling the gaps Monojet dedicated analysis (SUS-13-009) ISR can induce high ETmiss and relatively soft charm jets Etmiss>250 GeV; pT(j1)>110 GeV Stops from gluinos (1311.4937, 1305.2390) 0/1 leptons, multijets, bjets and ETmiss Stop1 from stop2 (1405.3886) 1-3 leptons, multi-(b)jets and ETmiss optimized for 𝑡 2 → 𝑡 1 𝐻/𝑍 Split2014 – BSM in CMS Stops from gluinos Phys. Lett. B 733 (2014) - CMS-SUS-13-007 (1l multijets and met) ma anche CMS-SUS-14-011 for gluinos Phys. Lett. B 725 (2013) - CMS-SUS-12-024 (0l, multijets,met and bjets)
Ewkino searches Inclusive multileptons, ETmiss w/wo jets search (1405.7570) 2/3/4 leptons + ETmiss 2 SS leptons + Etmiss W(jj)/Z(jj)+Z(ll) + Etmiss W(lυ)H + ETmiss Interpretation in several specific SMS Search targeting hh / hZ / hW + ETmiss (1409.3168) ℎ→𝑏 𝑏 , 𝛾𝛾,𝑍𝑍 Interpretation in scenarios with 𝜒 1 0 𝜒 1 ± higgsino or gauginos Split2014 – BSM in CMS
M(l+l-) kinematic edge search SUS-12-019 Generic search for a kinematic endpoint in the invariant mass distribution of OS-SF lepton pairs (e or μ) in events with ETmiss and jets E.g. 𝜒 2 0 →𝑙 𝑙 → 𝜒 1 0 𝑙 + 𝑙 − Two search regions: central (2l in |η|<1.4) and forward (1l in1.6<|η|<2.4) Background estimated from OS-OF lepton pairs Fit the observed distribution with B-only and S+B models Also cut & count analysis in signal region 20<M( 𝑙 + 𝑙 − )<70 GeV OS-SF OS-OF Cut&Count Split2014 – BSM in CMS
DARK MATTER Split2014 – BSM in CMS
Dark Matter (DM) searches DM-nucleon scattering (LUX, CDMS, XENON, …) DM annihilation or decay (Fermi, PAMELA, AMS, IceCube, …) DM production at colliders Particularly competitive at low DM masses DM produced in cascade decays from heavier particles: Supersymmetry, Higgs portal Direct DM production Detectable if accompanied by additional objects (e.g. ISR) Interpretation in terms of Effective Field Theories Key parameters: DM mass mDM Mediator mass M Interaction type (scalar, vector, axial-vector, tensor) Couplings 𝑔 𝑞, 𝑔 χ Split2014 – BSM in CMS
Mono-X searches Mono-jet (1408.3583) Mono-γ (EXO-12-047) Mono-𝑡 𝑡 𝑝 𝑇 𝑗 >110 GeV | η 𝑗 |<2.4 𝐸 𝑇 𝑚𝑖𝑠𝑠 >250 GeV strongest limits on vector and axial-vector interactions Also on ADD G, unparticles Mono-γ (EXO-12-047) 𝐸 𝑇 𝛾 >145 GeV | η γ |<1.44 𝐸 𝑇 𝑚𝑖𝑠𝑠 >145 GeV Mono-𝑡 𝑡 Semileptonic (B2G-14-004) and dileptonic analyses (B2G-13-004) Strongest limit on scalar interaction (strength ∝ 𝑚 𝑞 𝑀 ∗ 3 ) Mono-𝑡 (B2G-12-022) Requires FCNC or Baryon number / R-parity violation Limits set on scalar and vector boson DM produced via FCNC Split2014 – BSM in CMS
Limits on DM MONO-JET: vector (𝑞𝑞χχ) and scalar (ggχχ) interaction MONO-JET: axial-vector (𝑞𝑞χχ) interaction MONO-tt: scalar interaction (𝑞𝑞χχ) Invisible Higgs: scalar, fermion and vector DM Split2014 – BSM in CMS
Mono-W (DM-DM-W production) If u and d quarks couples differently to DM, interference can make mono-W the dominant process ξ= λ 𝑢 λ 𝑑 is the relevant parameter Standard lepton(e or μ) + ETmiss search in the MT spectrum (1408.2745) Sets limits on SSM W’, CI, UED W(n)KK, as well as model-independent ones Split2014 – BSM in CMS
EXTRA-DIMENSIONS, COMPOSITENESS and new BOSONS Split2014 – BSM in CMS
Theoretical context Extra dimensions Compositeness Address hierarchy problem by extending space-time dimensions (4+δ in ADD variant) 𝑀 𝑃𝑙 ≈ 𝑀 𝐷 δ+2 𝑅 δ (δ dimensions compactified over multidim torus of radius 𝑅) RS variant: 1 ED and warped space-time Gravity propagates in all dimensions and appears weak in 4 dim space time KK excitations of all known SM particles Can provide dark matter candidates ADD: non-resonant enhancement RS: distinct resonant production Compositeness Known fermions would be composed of more fundamental constituents interacting via a new strong gauge interaction At energies smaller than the new interaction scale Λ, it manifests as a contact interaction giving event rate enhancements Most sensitive searches: di-fermions and mono-X Split2014 – BSM in CMS
Narrow resonances (EXO-12-061) Dilepton searches Narrow resonances (EXO-12-061) Shape analysis in the full unbinned di-μ and di-e inv. mass spectra Enhancement in di-lepton event rates at high mass (EXO-12-027, EXO-12-031, EXO-12-020) Count events beyond mass threshold EXO-12-061 EXO-12-027 Split2014 – BSM in CMS
Dilepton searches - limits Limits from peak search w.r.t. previous 5+5 fb-1 paper (1212.6175): Z’SSM : 2.59 TeV 2.96 TeV KK graviton ( 𝑘 𝑀 𝑃𝑙 =0.1): 2.39 TeV t.b.u. Limits on MSvs nED in the ADD ED Limits in the LLIM variant of CI For both destructive and constructive interference with DY production Limits on HnCM from “mono-W” search Split2014 – BSM in CMS
FINAL STATES WITH TOP QUARKS Split2014 – BSM in CMS
ttbar invariant mass distribution 1309.2030 Combines semi-leptonic and all-hadronic analyses All-hadronic: 2 back-to-back top-tagged CA8 jets with pT>400 GeV Semileptonic: has both resolved (1l,≥4j) and boosted (1l wo isolation, ≥2j) event categories (transition at 𝑀 𝑡 𝑡 ~1TeV ) Subjet identification in boosted category Background control with 0 btag selection Results from simultaneous fit to the different 𝑀 𝑡 𝑡 distributions Split2014 – BSM in CMS
Rare top decays FCNC (1312.4194): 𝑡→𝑍𝑞 SM decay BR of order (10-14) occurring via loop diagrams. RPV susy, warped ED and others predict enhancements up to 10-4 -10-5 with large model parameter dependence Search for 𝑡 𝑡 →𝑍𝑞𝑊𝑏 with leptonic (e or μ) decay for W and Z BR(𝑡→𝑍𝑞)>5× 10 −4 excluded at 95% CL BNV (1310.1618): 𝑡→ 𝑏 𝑐 μ + (𝑡→ 𝑏 𝑢 𝑒 + ) Baryon Number (BN) is a conserved quantity in the SM BN violation necessary condition for matter-antimatter asymmetry in the Universe. Predicted in RPV susy, and grand unification models Recent theory paper has noted that the above decay could occur at relatively high rates, preserving proton stability search for 𝑡 𝑡 →𝑙𝑏𝑏𝑗𝑗𝑗 in electron and muon channel BR(𝑡→ 𝑏 𝑢 𝑒 + )>1.6× 10 −3 excluded at 95% CL (and similar for muon channel) Split2014 – BSM in CMS
NEUTRINOS Split2014 – BSM in CMS
Search for RH heavy neutrino and W 1407.3683 Search guided by Left-right symmetric SM extensions Predicts heavy RH W/Z and Majorana neutrinos, explaining neutrino masses through see-saw Signature with SF leptons: Shape analysis in the lljj invariant mass spectrum No distinction between OS and SS leptons First limits on WR beyond the th. lower limit MWR >2.5 TeV (from KL-KS mass diff.) 2.8 σ local excess in electron channel (only 1 SS pair out of 14 events and no deviation in muon channel) Split2014 – BSM in CMS
Huge spectrum of BSM physics searches performed by CMS Conclusions Huge spectrum of BSM physics searches performed by CMS Overview and personal selection, with some physics guidance, presented in this talk Ground prepared for the RUNII data analysis Split2014 – BSM in CMS
BACK-UP Split2014 – BSM in CMS
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Conclusions Split2014 – BSM in CMS