CMS overview and prospects Joao Varela CMS Deputy

CMS overview and prospects Joao Varela CMS Deputy Spokesperson LIP Lisbon 19 December 2012 LHC Beam Operation workshop - Evian 2012 3 D event display engraved in glass block. Gift from Elsevier

The CMS Collaboration Some 15% here LHC Evian 2012, CMS overview, J. Varela 2

The LHC luminosity The most precious gift the experiments could get The reality exceeded by far the expectations Thanks LHC! High data taking efficiency CMS recorded 92. 2% of 44/pb in 2010… LHC Evian 2012, CMS overview, J. Varela 3

The LHC luminosity The most precious gift the experiments could get The reality exceeded by far the expectations Thanks LHC! High data taking efficiency CMS recorded 92. 2% of 44/pb in 2010… … then 90. 5% of 6/fb in 2011… LHC Evian 2012, CMS overview, J. Varela 4

The LHC luminosity The most precious gift the experiments could get The reality exceeded by far the expectations Thanks LHC! High data taking efficiency CMS recorded 92. 2% of 44/pb in 2010… … then 90. 5% of 6/fb in 2011… … then 93. 6% of 23/fb in 2012… Overall efficiency 93% LHC Evian 2012, CMS overview, J. Varela 5

Successive challenges • • • The machine set the bar higher at each step Much work to improve Trigger, DAQ, Offline Reconstruction, Computing, Data Validation Detector >95% operational after 3 years Pixels Strips Presho. . . ECAL. . . HCAL. . . muon DT muon. . . 0 50 100 2012 2011 2010 LHC Evian 2012, CMS overview, J. Varela 6

We were ready 6 December 2009 at √s=900 Ge. V 30 March 2010 at √s=7 Te. V 11 March 2011 at √s=7 Te. V LHC Evian 2012, CMS overview, J. Varela 5 April 2012 at √s=8 Te. V 7

… and happy in the end! LHC Evian 2012, CMS overview, J. Varela 8

… and happy in the end! LHC Evian 2012, CMS overview, J. Varela 9

The challenge in 2012 Raw SET~2 Te. V 14 jets with ET>40 Ge. V Estimated PU~50 LHC Evian 2012, CMS overview, J. Varela 10

Pileup in 2012 Peak: 35 pileup events Design value 25 pileup events (L=1034, 25 ns) Pileup distribution in 2012 data sample Average: 21 pileup events LHC Evian 2012, CMS overview, J. Varela 11

Trigger challenges High trigger efficiency for Higgs physics while keeping the trigger rate within budget was one of the biggest challenges in 2012 High Level Trigger CPU time: 8. 5 e 33 @ 50 ns Present limit of HLT farm Trigger Cross-sections: Iso. Mu 24_PFjet 30_PFJet 25_Deta 3_Central. PFJET 25 Particle Flow Jet Energy corrections cured nonlinearities of hadronic triggers Fight against pileup at 50 ns can’t be sustained much further v 3 v 4 Some hadronic trigger rates grow exponentially with PU High PU runs Lumi @ 50 ns: Luminosity mb-1 s-1 LHC Evian 2012, CMS overview, J. Varela 6 E 33 1 E 34 1. 4 E 34 12

Event reconstruction challenges Muon isolation Reconstruction of hard collisions in high pileup environment in CMS exploits: - detectors with very high granularity (tracker) 3. 8 T magnetic field Efficiency is stable in high PU environment Event reconstruction remains robust at PU of 20 -30 events • • • precise jet energy measurement robust missing energy measurement efficient identification of isolated leptons But impact on final physics results (e. g. Higgs) was not (yet) fully assessed for data samples with average PU larger than 20. • • Missing ET resolution H→ 4 l looses 20% efficiency at 50 PU Diphoton mass resolution degrades by 20% at 30 PU LHC Evian 2012, CMS overview, J. Varela 13

Computing challenges From 2011 to 2012, better code allowed to gain: • factor 2. 5 reduction in CPU time • 50% in memory footprint Further gains are not expected without loss for physics ~80 s / evt ~60 s / evt ~30 s / evt Go d Ba In 2012, average at Tier 0 was < 20 s/event od Reconstruction time/event: PU=65 MC sample 50 ns PU=50 PU=35 20 s/event LHC Evian 2012, CMS overview, J. Varela 1034 1. 3 1034 14

A new boson was discovered LHC Evian 2012, CMS overview, J. Varela 15

A new boson was discovered LHC Evian 2012, CMS overview, J. Varela 16

A new boson was discovered LHC Evian 2012, CMS overview, J. Varela 17

Higgs results H→WW H→gg H→ZZ H→bb Mass H→tt H couplings LHC Evian 2012, CMS overview, J. Varela Spin-parity 18

…and many more physics results vector bosons top cross section Zbb top mass New particle : Xb* Jets Heavy ions U suppression LHC Evian 2012, CMS overview, J. Varela ridge p. Pb 19

The standard model and beyond Standard Model The astonishing brain power of a certain ape species At a Crossroad Higgs mass is a huge problem: Miraculous cancelations are needed to keep the Higgs mass < 1 Te. V LHC Evian 2012, CMS overview, J. Varela 20

Higher energy after LS 1 • Increased sensitivity for new physics at the ~Te. V mass scale Ratios of parton luminosities – probe SUSY up to m(gluino) ~ 2 Te. V • At the mass scale of 2 Te. V, the cross section for pair production of new particles is ~103 times higher at 13 Te. V relative to 8 Te. V A new particle observed at 5 s with 150 fb-1 (up to LS 2), would give a 2 -2. 5 s hint with 25 -30 fb-1 in the first year LHC Evian 2012, CMS overview, J. Varela 21

Higgs couplings with 300 fb-1 With 300 fb-1 the uncertainties of the Higgs couplings are expected in the range: σ (κV ) ~ 3 -6% σ (κb ) ~ 7 -15% 300 fb-1 14 Te. V, Scenario 1 300 fb-1 14 Te. V, Scenario 2 LHC Evian 2012, CMS overview, J. Varela 22

Upgrade phases LS 1 Projects: • Completes muon coverage (ME 4) • Improve muon trigger (ME 1), DT electronics • Replace HCAL photo-detectors in Forward (new PMTs) and Outer (HPD → Si. PM) LS 1 LS 2 Phase 1 Upgrades: • • New Pixels, HCAL Si. PMs and electronics, and L 1 -Trigger Preparatory work during LS 1: • new beam pipe • test slices of new systems LHC Evian 2012, CMS overview, J. Varela LS 3 Phase 2 Upgrades: scope to be defined in Technical Proposal (2014) • • • Tracker Replacement Forward Calorimetry and Muons Further Trigger upgrade: Track Trigger 23

Activities in LS 1 • Tracker cooling able to operate at target -25 o. C • Install 45 mm beam-pipe and make provision for pixel upgrade before LS 2 • Complete DAQ upgrade • Installation of optical splitters on CSCs and Calorimeters for the L 1 -Trigger upgrade parallel commissioning • Consolidation of magnet, power, cooling, electrical and dry gas systems • Complete muon upgrade (ME 1/1, DTSC, YE 4, ME 4/2, RE 4) • Complete first stage of HCAL photo-sensor upgrade (HO, HF) • Correct detector faults affecting physics performance LHC Evian 2012, CMS overview, J. Varela 24

Post-LS 1 beam conditions • LHC pileup conditions at 8 Te. V, that CMS succeeded to sustain: – peak: ~35 pileup events (limited by L 1 trigger and HLT at 40 PU) – average over fill: ~20 pileup events (limited by computing, physics) – Note that at 13 Te. V particle multiplicities are slightly higher (10 -20%) • In 2015, CMS prefers to run at 25 ns as soon as stable beams are feasible • Leveling above 20 PU events stresses computing and physics – As of today it is not demonstrated that CMS can run above leveled 20 PU events (4 1033 cms-2 s-1 @ 50 ns) – Additional studies are needed for a better estimation of the CMS limit • Trigger and pixel upgrades in 2016 -17 were designed to sustain ~ 2 1034 cms-2 s-1 @ 25 ns LHC Evian 2012, CMS overview, J. Varela 25

Outlook • LHC achieved an astonishing performance in the first 3 years of operation • CMS succeeded in meeting all pileup challenges, and to produce an unprecedented wave of physics results (> 200 papers) • As of today, the new particle is compatible with the SM Higgs boson • Bright prospects for physics at LHC with higher energy and luminosity. We are just at the beginning. LHC Evian 2012, CMS overview, J. Varela 26

Thanks LHC! LHC Evian 2012, CMS overview, J. Varela 27

Thanks LHC! LHC Evian 2012, CMS overview, J. Varela 28

BACKUP LHC Evian 2012, CMS overview, J. Varela 29

LHC projections 50 ns 25 ns HL-LHC 25 ns Luminosityleveled at 5 x 1034 Hz/cm 2 7 x 1033 Hz/cm 2 30 fb-1 2 x 1034 Hz/cm 2 300 fb-1 LS 1 CMS Upgrades: Phase 1 Upgrade LHC Evian 2012, CMS overview, J. Varela 1035 Hz/cm 2 3000 fb-1 LS 3 Phase 2 Upgrade 30

Spin-parity: H→ ZZ, WW, gg with 30 fb-1 • Simplified generator study – – ZZ S. Bolognesi et al. , ar. Xiv: 1208. 4018 ZZ: likelihood discriminator WW feature: angle between leptons gg: production angle For 5+30 fb-1: WW γγ • Up to 4σ separation possible in 2012 – for both odd parity and spin-2 – ATLAS+CMS combined LHC Evian 2012, CMS overview, J. Varela 31

HL-LHC: Higgs couplings with 3 ab-1 • With 3 ab-1 the Higgs couplings can possibly be determined with high precision (1 -3%) • The decay H→μμ can be observed with a significance of 5 sigma • measurement of the Hμμ coupling with a precision of ~10%. • Measurement of multiple Higgs boson production is possible • The SM cross section for di-Higgs boson production is 33 fb at 14 Te. V. • Measurement of the Higgs potential LHC Evian 2012, CMS overview, J. Varela Scenario 1: • 2012 systematics Scenario 2: • theory syst: scaled by a factor ½ • other systematics scaled by 1/√L 32

Search for super symmetry Simplified models: Stop from gluino decays CMS searches have excluded light squarks and gluinos up to ~ 1 Te. V LHC Evian 2012, CMS overview, J. Varela 33

Long Lived Resonances CMS Exotica 95% CL Exclusion Limits Lepto. Quarks Contact Interaction Compositeness 4 th Generation LHC Evian 2012, CMS overview, J. Varela Sh. Rahatlou Black Holes 342