The Compact Muon Solenoid Experiment. Conference Report. Mailing address: CMS CERN, CH-1211 GENEVA 23, Switzerland. Searches for supersymmetry at CMS

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1 Available on CMS inforaion server CMS CR -26/5 The Copac Muon Solenoid Experien Conference Repor Mailing address: CMS CERN, CH-2 GENEVA 23, Swizerland 2 January 26 Searches for supersyery a CMS Ferdinando Giordano for he CMS Collaboraion Absrac Aong he os proising prospecs for a heory of physics beyond he sandard odel is supersyery. In his alk, he laes resuls fro he CMS experien a he LHC on searches for supersyery produced hrough hrough srong producion and elecroweak producion channels are presened using 2/fb of daa fro he 8 TeV LHC run, wih paricular focus on gluino and sop searches. Presened a SSP25 6h Inernaional Syposiu on Syeries in Subaoic Physics

2 Nonae anuscrip No. (will be insered by he edior) Searches for supersyery a CMS F. Giordano on behalf of he CMS Collaboraion Received: dae / Acceped: dae Absrac Aong he os proising prospecs for a heory of physics beyond he sandard odel is supersyery. In his alk, he laes resuls fro he CMS experien a he LHC on searches for supersyery produced hrough hrough srong producion and elecroweak producion channels are presened using 2/fb of daa fro he 8 TeV LHC run, wih paricular focus on gluino and sop searches. Keywords LHC Run CMS Supersyery PACS.3.Pb 2.6.Jv 4.8.Ly Inroducion The discovery of he Higgs boson [,4] during he firs LHC runs a 7 and 8 TeV was an iporan ilesone in high energy physics (HEP) as i copleed he Sandard Model (SM), noneheless no all he open quesions in HEP have a clever answer wihin he SM fraework. Supersyery (SUSY) [2] offers a clear and elegan soluion o he hierarchy proble and in paricular low-energy hird-generaion squarks (close in ass o he op quark and below he TeV scale) can provide he echanis o cancel quadraically divergen loop correcions o he ass of he SM Higgs boson wihou he well known fine uning proble [2, 4,]. The LHC experiens have a rich search progra for SUSY searches ha, o dae, has only produced null resuls alos reaching he highes possible ass for naural superparners, in spie of his fac here are sill any reasons o keep looking for Naural SUSY as only few and siplified odels have been addressed experienally and any regions of he full phase space have no ye been explored [3]. F. Giordano Via Sana Sofia Caania Ialy Tel.: E-ail: Ferdinando.Giordano@cern.ch

3 2 F. Giordano on behalf of he CMS Collaboraion LSP ass [GeV] g- g producion, CMS Preliinary s = 8 TeV ICHEP 24 Observed SUSY Observed - σ heory Expeced g χ - SUS-3-2 -lep (E T+H T ) 9.5 fb - SUS lep (razor) 9.3 fb SUS-3-7 -lep (n jes - 6) 9.3 fb - SUS lep (OS+b) 9.7 fb - SUS lep (SS+b) 9.5 fb - SUS lep (3l+b) 9.5 fb (gluino) - (LSP) = 2 (op) gluino ass [GeV] Fig. Exclusion plo for gluino pair producion ino four ops, differen analyses have been cobined and superiposed using differen colors in he LSP vs gluino ass plane. In hese proceedings, new resuls fro daa colleced by he Copac Muon Solenoid (CMS) [3] experien during he 22 8 TeV run of he LHC are presened. CMS is a general purpose deecor which ain feaure is a 3.8 T solenoidal agneic field, inside of which here are a silicon verexing and racking syse, a oal absorpion crysal elecroagneic calorieer, and a brass/scinillaor sapling hadronic calorieer, ouside he agne and wihin he iron reurn yoke here is a gaseous uon deecors ha consiss of hree differen sub-deecors o achieve he bes possible perforance as well as good redundancy. Overall, he deecor has a very high efficiency for elecrons, uons, and phoons and explois a novel paricle flow au and je reconsrucion. 2 Gluino searches The srong producion has by far he larger cross-secion a LHC and i is he channel ha has been invesigaed os horoughly, producing ore resuls han any oher channel. Early analyses have already placed srong liis for siplified odels in which gluinos are pair produced and decay sole o op quarks as we can see in Fig., where on he x-axis is ploed he excluded gluino ass and on he y-axis he LSP ass. Given he presence of four op quarks in he final sae, his channel offers a large variey of decay odes and herefore any differen analyses have produced resul using his signal odel, soe uually exclusive channels have also been cobined o increase he exclusion power as he razor search [9] wih he single lepon search [8]. Oher analyses used sae-sign lepons [6] or all hadronic final sae using issing energy (MET) and scalar su of je p T (HT) as discriinaing variables [7]. The large plehora of analyses is needed o boh increase our exclusion power bu also o enhance our discovery chances, reducing false signals since he differen channels populaes differen signal regions. All analyses ake large use of daa-driven background predicions wih Mone Carlo (MC) siulaions used only for inor backgrounds, of course all MC are correced for any isach wih respec o daa as for insance secondary iner-

4 Searches for supersyery a CMS 3 Evens (Daa-Pred.)/Pred CMS, L = 9.5 fb, 5<H <8, 2<H <3 3<H T <45 45<H T <6 H T >6 8<H <, 2<H <3 3<H T <45 45<H T <6 H T >6 <H <25, 2<H <3 Daa 3<H T <45 45<H T <6 H T >6 s = 8 TeV 25<H <5, 2<H <3 3<H T <45 H T >45 H T >5, 2<H T <3 Z (νν)+jes QCD H T >3 5<H <8, 2<H <3 3<H T <45 H T >45 8<H <, 2<H <3 3<H T <45 H T >45 <H <25, 2<H <3 3<H T <45 W/ W/ H T >45 25<H <5, 2<H <3 (e/µ+ν)+jes (τ hadr +ν)+jes Toal uncerainy on background predicion 3<H T <45 H T >45 H T >5, 2<H T <3 H T H T H T >3 [GeV] [GeV] N Jes = 3-5 N Jes = 6-7 N Jes 8 5<H T <8, H T >2 8<H T <, H T >2 <H T <25, H T >2 25<H T <5, H T >2 H T >5, H T >2 Evens / GeV CMS - s = 8 TeV, L = 9.5 fb in Low-p lepons T Daa Rare SM processes Charge isid Non-prop e/µ Toal bkg uncerainy leading p [GeV] T Fig. 2 Suary of he observed nuber of evens in each of he 36 search regions in coparison o he corresponding background predicion. The hached region shows he oal uncerainy of he background predicion [7] (righ). Disribuions of he ransverse oenu of he leading lepon in he low-p baseline region wih N b jes = requireen [6] (lef). acion verices or efficiencies. In hadronic channels Z νν is he os ricky background o address and in order no o rely solely on MC he process Z µµ is used as a proxy for his waned process, afer properly adjused he easured visible paricles by heir efficiencies and accepance. Analyses using lepons are insead osly subjec o iss-lepon(s) or issidenified backgrounds due eiher o evens wih wo genuine lepons, one of which is no reconsruced or even wihou prop lepons bu wih fake ones. Also in his case a series of daa-driven echniques have been developed like he so called fake rae ehod, used o predic lepons no coing direcly fro elecroweak boson decays. For insance in Fig. 2 (righ) we can see ha he iss-idenified background conribues o alos half of o he oal yield of he sae-sign lepon search, so predicing i wih accuracy is fundaenal o clai any discovery, jus as he invisible Z background is iporan in he hadronic channel. Indeed Fig. 2 (lef) shows an excess of daa in a bin doinaed by Z νν and is syseaic uncerainy. 3 Sop searches Anoher proising channel is he direc sop producion. Again we have a broad choice of final saes and we pu in place any analyses o exploi all of he, as before a quick overview can be obained by looking a he suary exclusion plo in Fig. 3. Soe of he searches, as for exaple he razor [9] can be reinerpreed also in he hypohesis of a sop signal and are proven quie effecive, bu again he cobinaion wih dedicaed analyses give he bes exclusion liis. The os sringen lii for high ass sop is given by he razor cobined wih he single lepon analyses [5] ha is able o reach asses of 75 GeV. Again we us sress ha he lii is se on a siplified odel wih few free paraeers. On he righ

5 F. Giordano on behalf of he CMS Collaboraion - producion, χ / c χ W = = W χ - = 5 - χ 2 BF( χ ) =.7 BF( χ ) =.6 BF( χ ) =.5 2 = 3 χ 25 SUS-3-5 (hadronic sop) 9.4 fb- χ SUS-4- -lep (Razor) + -lep (MVA) 9.3 fb- SUS-3-9 (onoje sop) 9.7 fb- ( c χ ) BF( χ ) =. BF( χ ) =.9 BF( χ ) =.8 unpolarized op SUS-4- -lep + -lep + 2-lep (Razor) 9.3 fb- Observed liis pp *, χ BDT analysis 35 SUS-3- -lep (MVA) 9.5 fb Expeced - Observed 6 s = 8 TeV, Ld = 9.5 fb- CMS CMS Preliinary s = 8 TeV ICHEP 24 7 χ [GeV] LSP ass [GeV] sop ass [GeV] [GeV] Fig. 3 On he lef he suary exclusion plo for sop pair producion decaying ino op and neuralino (% branching fracion BF), differen analyses have been cobined and superiposed using differen colors in he LSP vs sop ass plane. On he righ he assupion on he BF is relaxed and he plo shows how he exclusion can degrade wih he sop does no decay always ino op, he reference is he SUS-3- analysis on he lef. Fig. 4 Disribuions of 23 /3 je versus arcan 3 /2 for siulaed QCD ulije processes evens (lef) and for siulaed processes evens (righ) in he ulije -agged search []. of Fig. 3 i is shown how his lii changes as we ove away fro he assupion ha he sop decays always o he op quark, he reducion in he exclusion power is clearly visible even when BF( χ )=9%. As he high ass region searches reurned null resuls he effor was oved back o low ass, in paricular in he diagonal region in Fig. 3, where he difference beween he sop ass and he op (or W ) is sall, hence he signal is SMlike and ore difficul o exrac. To increase our sensiiviy in his copressed specra region new echniques have been recenly developed such as op-agging o discriinae QCD jes fro signal-like jes. This ype of op agging is based on ass easureens of jes ha are closely spaced, where he relaive raios of he je asses are hen used o build a discriinaor as shown in Fig. 4, where QCD on he lef is copared o on he righ. This hadronic analysis in cobinaion wih he onoje search is very effecive in looking for copressed signal near he enioned diagonal as we can see in Fig. 5

6 Searches for supersyery a CMS 5 Fig. 5 Various observed 95% CL ass exclusion lii curves for op-squark pair producion, assuing differen branching fracions of he wo op squark decays χ and b χ ±. The ass difference beween he χ ± and χ is aken o be 5 GeV. A branching fracion (B) of. iplies all decays are via χ and conversely, B =. iplies all decays proceed hrough b χ ±. The cobined resuls fro he dije b-agged and ulije -agged searches and he resul fro he onoje search are displayed separaely. where i is shown he phase space region cover by his hadronic analysis on he usual LSP vs sop ass plane. References. ATLAS collaboraion. Observaion of a new paricle in he search for he Sandard Model Higgs boson wih he ATLAS deecor a he LHC. Phys. Le. B, 76: 29, Riccardo Barbieri and Duccio Pappadopulo. S-paricles a heir nauralness liis. JHEP, 6, CMS collaboraion. The CMS experien a he CERN LHC. JINST, 8, CMS collaboraion. Observaion of a new boson a a ass of 25 GeV wih he CMS experien a he LHC. Phys. Le. B, 76:3 6, CMS collaboraion. Search for op-squark pair producion in he single-lepon final sae in pp collisions a s = 8 TeV. EPJ C, 73, CMS collaboraion. Search for new physics in evens wih sae-sign dilepons and jes in pp collisions a s = 8 TeV. JHEP, 63, CMS collaboraion. Search for new physics in he ulije and issing ransverse oenu final sae in proon-proon collisions a s = 8 TeV. JHEP, 55, CMS collaboraion. Search for supersyery in pp collisions a s = 8 TeV in evens wih a single lepon, large je ulipliciy, and uliple b jes. Phys. Le. B, 733: , CMS collaboraion. Search for supersyery using razor variables in evens wih b- agged jes in pp collisions a s = 8 TeV. Phys. Rev. D, 9, 25.. CMS collaboraion. Searches for hird-generaion squark producion in fully hadronic final saes in proon-proon collisions a s = 8 TeV. JHEP, 6, 25.. Savas Diopoulos and Howard Georgi. Sofly broken supersyery and SU(5). Nuclear Physics B, 93:5 62, Sephen P. Marin. A Supersyery prier. Adv.Ser.Direc.High Energy Phys., 2: 53, Michele Papucci, Joshua T. Ruderana, and Andreas Weiler. Naural SUSY endures. JHEP, 9, Edward Wien. Dynaical breaking of supersyery. Nuclear Physics B, 88(3):53 554, 98.