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Supersymmetry: Lecture 3 Superpartners in Action

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Supersymmetry: Lecture 3 Superpartners in Action Supersymmetry: Lecture 3 superpartners in action Yael Shadmi Technion gauge bosons (s=1) + gauginos (s=1/2) photon + photino gluon + gluinos W + wino Z + zino 2 Yael Shadmi Technion ESHEP2014 fermions + sfermions (scalars) quark + squark electron + selectron .. neutrino + sneutrino 2x( Higgs (s=0) + Higgsino (s=1/2) ) 3 Yael Shadmi Technion ESHEP2014 each superpartner: same charges as SM particle GAUGE + YUKAWA INTERACTIONS COMPLETELY DICTATED by SUSY + SM 4 Yael Shadmi Technion ESHEP2014 electron photon + electron selectron selectron photino photon electron selectron superpartners appear in pairs R-parity: SM fielDs = even superpartners=odD 5 Yael Shadmi Technion ESHEP2014 the only freedom is in: spectrum (DetermineD by soft terms) [+ interactions: – are there R-parity breaking couplings or not? – are gaugino-scalar-fermion couplings flavor diagonal or not? ] 6 Yael Shadmi Technion ESHEP2014 spectrum (soft terms): many possibilities (depend on the mediation of SUSY breaking) so: don`t listen to theorists … .. if they tell you they know what the superpartner masses are 7 Yael Shadmi Technion ESHEP2014 where can we observe superpartners? • virtual corrections: electric and magnetic dipole moments flavor violating processes widths of known particles • direct production: LHC 8 Yael Shadmi Technion ESHEP2014 virtual corrections: most relevant for LHC searches: flavor violating processes: eg KK00− bs→ γ µ→ eγ ... let’s talk about sleptons (easier) 9 Yael Shadmi Technion ESHEP2014 relevant parameters: ɶɶ eg R-sleptons: ll13, .. , • 3 masses: mm12,, m 3 • mixings: li gaugino ∝≠ Kijij l j 10 Yael Shadmi Technion ESHEP2014 ɶ l 1 <5.7⋅ 10−13 (MEG) µ e χ0 ɶ l 2 essentially constrains: µ e χ0 2 ɶ ∆ m ij K ij l 3 δ ij = 2 µ e m χ0 ESHEP2014 Yael Shadmi Technion 11 ɶ l 1 <5.7⋅ 10−13 (MEG) µ e χ0 ɶ l 2 essentially constrains: µ e χ0 2 ɶ ∆ m ij K ij l 3 δ ij = 2 µ e m χ0 Kij →→0 Br 0 2 * ∆mij →→0 : KK12j j = 0 (super-GIM) Br 0 12 Suppressing SUSY Flavor Violation 3 obvious approaches: 2 ∆ m ij K ij (or combination) δ = ij m 2 small mass splittings degeneracy 13 Yael Shadmi Technion ESHEP2014 Suppressing SUSY Flavor Violation 3 obvious approaches: 2 ∆ m ij K ij (or combination) δ = ij m 2 small mixings: alignment slepton mass matrix “aligned” with lepton mass matrix: approximately diagonal together 14 Yael Shadmi Technion ESHEP2014 Suppressing SUSY Flavor Violation 3 obvious approaches: 2 ∆ m ij K ij (or combination) δ = ij m 2 3. increase masses: taken care of by ATLAS anD CMS .. 15 Yael Shadmi Technion ESHEP2014 Suppressing SUSY Flavor Violation 3 obvious approaches: 2 ∆ m ij K ij (or combination) δ = ij m 2 there are viable models of each type 3. increase masses: taken care of by ATLAS anD CMS .. 16 Yael Shadmi Technion ESHEP2014 LHC SEARCHES 17 Yael Shadmi Technion ESHEP2014 supersymmetry is NOT a single model so: rather than a model based approach use a signature baseD approach (both CMS and ATLAS!) 18 Yael Shadmi Technion ESHEP2014 the only freedom is in: spectrum (DetermineD by soft terms) [+ interactions: – are there R-parity breaking couplings or not? – are gaugino-scalar-fermion couplings flavor diagonal or not? ] 19 Yael Shadmi Technion ESHEP2014 general considerations: interactions: R-parity conservation • production: superpartners produced in pairs • decay: superpartner superpartner + SM • the lightest superpartner (LSP) is stable 20 Yael Shadmi Technion ESHEP2014 R-parity violating coupling(s) (RPV): • production: single superpartner (resonant) production is possible • decay: a superpartner can decay to SM (jets, leptons) (see below) 21 Yael Shadmi Technion ESHEP2014 R-parity violating coupling(s) (RPV): if small: • production: single superpartner (resonant) production is possible competitive with gauge couplings because of kinematics • decay: a superpartner can decay to SM (jets, leptons) only the LSP decays via the RPV coupling 22 Yael Shadmi Technion ESHEP2014 general considerations: interactions: flavor mixing li gaugino ∝≠ K ij i j l j mainly affects decay 23 Yael Shadmi Technion ESHEP2014 general considerations: spectrum: gluino coloreD vs non-coloreD: squarks generically: sleptons sneutrinos coloreD heavier (factor of few-10) charginos neutralinos (* don’t know LSP squark vs gluino ?? sleptons vs neutralinos??) 24 Yael Shadmi Technion ESHEP2014 general considerations: spectrum: gluino coloreD vs non-coloreD: squarks generically: sleptons sneutrinos coloreD heavier (factor of few-10) charginos neutralinos (* don’t know LSP squark vs gluino ?? expect: squark gluino production dominates sleptons vs neutralinos??) 25 Yael Shadmi Technion ESHEP2014 general considerations: spectrum: gluino coloreD vs non-coloreD: squarks if larger hierarchy (colored masses go up) EWK production sleptons sneutrinos more important (slepton, neutralino, charginos neutralinos chargino production) LSP 26 Yael Shadmi Technion ESHEP2014 general considerations: spectrum: gluino identity of LSP squarks neutral or charged? sleptons sneutrinos (usually: neutralino or slepton) charginos neutralinos missing energy or LSP something else main Distinguishing 27 Yael Shadmi Technion feature of SUSYESHEP2014 general considerations: spectrum: gluino small mass differences squarks soft decay products long lifetimes sleptons sneutrinos charginos neutralinos LSP 28 Yael Shadmi Technion ESHEP2014 general considerations: spectrum: gluino extreme case: squarks squished spectrum soft decay products LSP sleptons sneutrinos little missing energy charginos neutralinos 29 Yael Shadmi Technion ESHEP2014 general considerations: spectrum: gluino flavor depenDent or not? squarks up squark=charm squark? d squark= s squark? sleptons sneutrinos smuon=selectron? charginos neutralinos LSP 30 Yael Shadmi Technion ESHEP2014 production: colored vs EWK p qɶ squark pair strong: or squark gluino or gluino gluino p qɶ p lɶ EWK: slepton pair chargino pair … p lɶ relative importance depends on colored masses vs EWK masses 31 Yael Shadmi Technion ESHEP2014 production: flavor dependence p qɶ strong: squark pair or squark gluino p qɶ or gluino gluino qɶ some channels flavor blind: eg: gg to squark anti-squark q q qɶ some channels g flavor sensitive larger for q qɶ u-squark, d-squark 32 Yael Shadmi Technion ESHEP2014 production: with R-parity violating coupling in principle p single squark qɶ or slepton p coupling may be small but kinematics can win 33 Yael Shadmi Technion ESHEP2014 decay: (with no RPV coupling) LSP = neutralino e e q wino ɶ selectron q LSP=DM? qɶ LSP=DM? missing energy 34 Yael Shadmi Technion ESHEP2014 decay: (with no RPV coupling) LSP = slepton (stau?) e q wino qɶ slepton qɶ 35 Yael Shadmi Technion ESHEP2014 LSP = neutralino • stable, neutral: good DM candidate (WIMP) • LHC: transverse momentum imbalance: ``missing ET ” • main handle against SM bgnds: – squark mass (or other mother particle) goes up: missing ET goes up (LSP more boosted) – LSP mass goes up missing ET goes down (LSP less boosted) efficiency goes Down with mass Difference 36 Yael Shadmi Technion ESHEP2014 LSP = charged slepton cosmology ?? ruled out if the slepton is stable but it can be metastable: gluino squarks sleptons sneutrinos charginos neutralinos slepton = NLSP 37 Yael Shadmi Technion ESHEP2014 LSP = charged slepton cosmology ?? ruled out if the slepton is stable but it can be metastable: remember the gravitino? gluino squarks sleptons sneutrinos charginos neutralinos slepton = NLSP 38 Yael Shadmi Technion gravitino = LSP ESHEP2014 • lifetime only depends on SB scale ( gravitino mass) and slepton mass • a whole range • in particular: slepton can exit detector: looks like a muon • if it’s seen: how do we know it’s not a muon? • but will it be seen? • it`s slow: β <1 trigger? reconstruction? usually assume β =1 39 Yael Shadmi Technion ESHEP2014 {this is a good example of a ``practical application” of thinking about SUSY (other BSM) models you coulD say (shoulD say?) we will have this amazing machine why not look for long-liveD chargeD particles (regardless of any BSM) } arXiv:1211.1597 low beta: is it lost (forever..)? high beta: fake muon? by now: good coverage in beta muon detector (ATLAS) TOF inner detector (CMS) dE/dx 40 Yael Shadmi Technion ESHEP2014 apply to the simplest process: Drell-Yan slepton proDuction with ``zero SM bgnd”.. 41 Yael Shadmi Technion ESHEP2014 completely model independent: (almost) any long-lived scalar with charges of slepton (old result) 42 Yael Shadmi Technion ESHEP2014 this is our first example of possible SUSY signatures it’s the simplest: just DY production no SM bgnd IF you identify the long-lived slepton let’s move to harder examples in the process: – see how the different considerations we listed come into play – learn about different handles for distnguishing signal from bgnd: usually the main challenge 43 Yael Shadmi Technion ESHEP2014 Drell-Yan slepton proDuction: but LSP=neutralino final state: opposite sign (OS) leptons + missing ET 44 Yael Shadmi Technion ESHEP2014 • efficiency goes Down with mass difference • flavor: l=e, mu what if not degenerate? 45 Yael Shadmi Technion ESHEP2014 • flavor: l=e, mu what if not degenerate? Calibbi Galon Masiero Paradisi YS in progress 46 Yael Shadmi Technion ESHEP2014 • more info: separate info on selectron, smuon 47 Yael Shadmi Technion ESHEP2014 squark/gluino pair proDuction (neutralino LSP) e+ e− q 0 qɶ χ qɶ χ 0 missing energy 48 Yael Shadmi Technion ESHEP2014 or a shorter squark Decay q 0 qɶ χ gluino decay q q 0 qɶ χ gɶ costs another jet 49 Yael Shadmi Technion ESHEP2014 squark/gluino pair proDuction (neutralino
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