1 Super-LHC Albert De Roeck CERN & Antwerp University

2 The LHC Machine and Experiments pp collisions at 14 TeV LHCf totem (MOEDAL)

3 The LHC: 22 Years Already! : cms energy TeV Luminosity cm -2 s : cms energy 16 TeV Luminosity cm -2 s -1 Final: cms energy 14 TeV Luminosity cm -2 s -1 /LHC

4 Crucial part: 1232 superconducting dipoles Can follow progress on the LHC dashboard The LHC Progress & Schedule The LHC Schedule (*)  LHC will be closed and set up for beam on 1 September 2007 LHC commissioning will take time!  First collisions expected in November/December 2007 A short pilot run Collisions will be at injection energy ie cms of 0.9 TeV  First physics run in 2008 ~ fb -1 ? 14TeV!  Physics run in … fb -1 /year  100 fb -1 /year (*) eg. M. Lamont et al, September Achtung! Lumi estimates are mine, not from the machine More than 1000 dipoles installed by now

Ramping up the LHC J. Strait 2003: Not an “official” LHC plot If startup is as optimistic as assumed here (10 34 cm -2 s -1 in 2011 already)  After ~3 years the simple continuation becomes less exciting  Time for an upgrade? hypothetical luminosity scenario Statistical error  1/  N Constant luminosity/year 1 year  4 years  16 years to half the stat error Luminosity= #events/cross-section/time

6 The LHC upgrade Higher luminosity ~10 35 cm -2 s -1 (SLHC) –Needs changes of the machine and particularly of the detectors  Start change to SLHC mode some time  Collect ~3000 fb -1 /experiment in 3-4 years data taking.  Discussed in this talk Two options presently discussed/studied Higher energy? (DLHC) –LHC can reach  s = 15 TeV with present magnets (9T field) –  s of 28 (25) TeV needs ~17 (15) T magnets  R&D needed! –Even some ideas on increasing the energy by factor 3 (P. McIntyre) Already time to think of upgrading the machine if wanted in ~10 years Run I  sRun II  sInt Lumi (run I)Int. Lumi (expected/runII) Tevatron1.8 TeV1.96 TeV100 pb~5fb HERA300 GeV320 GeV100 pb~500 pb

7 Machine Upgrade Studies Upgrade in 3 main Phases: Phase 0 – maximum performance without hardware changes Only IP1/IP5, N b to beam beam limit  L = 2.3  cm -2 s -1 Phase 1 – maximum performance while keeping LHC arcs unchanged Luminosity upgrade (  *=0.25m,#bunches,...)  L = 5-10  cm -2 s -1 Phase 2 – maximum performance with major hardware changes to the LHC Energy (luminosity) upgrade  E beam = 12.5 TeV Report on a machine study

8 25 ns nominal and ultimate LHC 12.5 ns 75 ns more & shorter bunches fewer & longer bunches super-bunch baseline upgrade back-up upgrade plus: large luminosity gain with minimal event pile up & impact of  c concern: e-cloud, cryogenic load, LRBB, impedance, collimation, machine protection plus: large luminosity gain with no e-cloud, lower I, easier collimation & machine protection concern: larger event pile up, impedance plus: no e-cloud, lower I concern: event pile up intolerable Bunch schemes for SLHC

9 IP Upgrade Dipole inside end disks? Triplet moves closer to IP Possible scenario: magnets in the detectors

10 Machine Parameters cm -2 s -1 peak luminosity seems possible Bunch crossing somewhere between 12.5  75 ns March 2006

11 Machine Upgrade Studies Studies in the context of the CARE HHH Network HHH = High Energy High Intensity Hadron-Beam facilities in Europe Step 4 requires a new RF system Step 5: upgrade LHC cryogenics, collimation, beam dump systems… Further possible paths: flat beams, dipoles close to IP, crab cavities… Challenging but bigger challenges on the detector side

12 Detectors for SLHC Normalised to LHC values Gy/year R=25 cm LHC SLHC  s 14 TeV 14 TeV Luminosity Bunch spacing  t 25 ns 12.5/75 ns  pp (inelastic) ~ 80 mb ~ 80 mb N. interactions/x-ing ~ 20 ~ 100/600 (N=L  pp  t) dN ch /d  per x-ing ~ 150 ~ 750/4500 charg. particles ~ 450 MeV ~ 450 MeV Tracker occupancy 1 5/30 Dose central region 1 10 In a cone of radius = 0.5  E T ~ 80GeV from pile up. This will make low E t jet triggering and reconstruction difficult. The present detectors need to be upgraded to cope with the higher occupancy and radiation  Detector R&D program Academic training lectures

13 Pile up… H  ZZ   ee event with M H = 300 GeV for different luminosities cm -2 s cm -2 s cm -2 s cm -2 s -1

14 Example of Detector Upgrades Study, detector R&D and production takes time! Possible scenario: Proceed in two steps –Include new layers in the present tracker during the LHC running –Upgrade to full new tracker system by SLHC (8-10 years from LHC Startup)  ATLAS & CMS upgrade workshops since ~two years.. Tracker detector of both CMS & ATLAS will need to be replaced  Occupancy, radiation Include the tracker in the L1 trigger?

15 Modest upgrade of ATLAS, CMS needed for channels with hard jets, , large E T miss Major upgrades (new trackers..) for full benefit of higher L: e  ID, b-tag,  -tag, forward jet tagging, trigger upgrade e.g a tracking trigger… Detectors Upgrades for SLHC Detector Performance Assumed Performance at L = cm -2 s -1 is comparable to that at cm -2 s -1 !! Some know degradations taken into account in individual analyses Integrated Luminosity per Experiment 1000 (3000) fb -1 per experiment for 1 (3) year(s) of at L = cm -2 s -1. Pile-up added Corresponding to 12.5 bunch crossing distance scenario  Study Physics Potential of the LHC

16 Extending the Physics Potential of LHC Electroweak Physics Production of multiple gauge bosons (n V  3) triple and quartic gauge boson couplings Top quarks/rare decays Higgs physics Rare decay modes Higgs couplings to fermions and bosons Higgs self-couplings Heavy Higgs bosons of the MSSM Supersymmetry Extra Dimensions Direct graviton production in ADD models Resonance production in Randall-Sundrum models TeV -1 scale models Black Hole production Quark substructure Strongly-coupled vector boson system W L Z L g W L Z L, Z L Z L scalar resonance, W + L W + L New Gauge Bosons Examples studied in some detail Include pile up, detector… hep-ph/

17 Standard Model Physics Precision measurements of Standard Model processes and parameters  Deviations of expectations can point to new physics or help to understand new observed phenomena WW , Z TGCs Rare top decays Higgs …

18 Triple/Quartic Gauge Couplings Production of multiple gauge bosons: statistics limited at LHC E.g. # events with full leptonic decays, P t >20 GeV/c, |  |<2.5, 90% eff for 6000 fb -1 Typically gain of a factor of 2 in precision Triple gauge couplings: W ,WZ production WW , Z

19 Top Quark Properties SLHC statistics can still help for rare decays searches tqtq t  qZ Results in units of Ideal = MC 4-vector Real = B-tagging/cuts as for cm -2 s -1  -tag = assume only B-tag with muons works at cm -2 s -1 Can reach sensitivity down to ~10 -6 BUT vertex b-tag a must at cm -2 s -1

20 The Higgs at the LHC (SM) First step –Discover a new Higgs-like particle at the LHC, or exclude its existence Second step –Measure properties of the new particle to prove it is the Higgs Measure the Higgs mass Measure the Higgs width Measure cross sections x branching ratios Ratios of couplings to particles (~m particle ) Measure decays with low Branching ratios (e.g H  ) Measure CP and spin quantum numbers (scalar particle?) Measure the Higgs self-coupling (H  HH), in order to reconstruct the Higgs potential Only then we can be sure it is the Higgs particle we were looking for SLHC added value LHC~1 good year of data

21 Channel m H S/  B LHC S/  B SLHC (600 fb -1 ) (6000 fb -1 ) H  Z    ~ 140 GeV ~ 3.5 ~ 11 H   130 GeV ~ 3.5 (gg+VBF) ~ 9.5 (gg) Branching ratio ~ for these channels! Cross section ~ few fb Higgs Decays Modes Channels studied:  H  Z     H   Rare Higgs Decays Higgs Couplings (ratios) Can be improved with a factor of 2: 20%  10% at SLHC g H  /g H  ? g Hff

22 Higgs Self Coupling Measurements ~ v m H 2 = 2 v 2 Once the Higgs particle is found, try to reconstruct the Higgs potential Djouadi et al. /2 < < 3 /2 Difficult/impossible at the LHC Dawson et al.

23 Higgs Self Coupling Limits achievable at the 95% CL. for  =( - SM )/ SM LHC: = 0 can be excluded at 95% CL. SLHC: can be determined to 20-30% (95% CL) Baur, Plehn, Rainwater HH  W + W - W + W -   jj  jj Note: Different conclusion from ATLAS study  no sensitivity at LHC and smaller sensitivity at SLHC. Jury is still out For M H ~ GeV

24 Lower Higgs Masses pp  bb  not useable pp  bb  promising  For m H =120 GeV and 600 fb -1 expect 6 events at the LHC with S/B~ 2 (single b tag)  Potentially interesting measurement at the SLHC (if efficient b-tagging ) m vis Needs accurate prediction of the bb  background rate Experimental checks needed Baur, Plehn, Rainwater

25 SUSY Higgses h,H,A,H  In the green region only SM-like h observable with 300 fb -1 /exp Red line: extension with 3000 fb -1 /exp Blue line: 95% excl. with 3000 fb -1 /exp Heavy Higgs observable region increased by ~100 GeV at the SLHC.

26 Beyond the Standard Model SupersymmetryExtra dimensions New physics expected around the TeV scale  Stabelize Higgs mass, Hierarchy problem, Unification of gauge couplings, CDM,… +… + a lot of other ideas… Split SUSY, Little Higgs models, new gauge bosons, technicolor, compositness,..

27 Supersymmetry Reach: LHC and SLHC CMS tan  =10 5  contours Impact of the SLHC Extending the discovery region by roughly 0.5 TeV i.e. from ~2.5 TeV  3 TeV This extension involved high E T jets/leptons and missing E T  Not compromised by increased pile-up at SLHC

28 SLHC: tackle difficult SUSY scenarios Squarks: TeV Gluino: 2.5 TeV Can discover the squarks at the LHC but cannot really study them signal Inclusive: M eff > 4000 GeV S/B = 500/100 (3000 fb -1 ) Exclusive channel qq  1 0  1 0 qq S/B =120/30 (3000fb -1 ) Measurements of some difficult scenarios become possible at the SLHC P t >700 GeV & E t miss >600 GeV P t of the hardest jet ~~ eg. Point K in hep-ph/ Higgs in  2 decay  2  1 h becomes Visible at 3000 fb -1

29 Extra Dimension Signals at the LHC Graviton production! Graviton escapes detection Large (ADD) type of Extra Dimensions Signal: single jet + large missing ET About 25% increase in reach escape! example

30 SLHC: KK gravitons Randall Sundrum model  Predicts KK graviton resonances  k= curvature of the 5-dim. Space  m 1 = mass of the first KK state SLHC 100  1000 fb -1: Increase in reach by 25% TeV scale ED’s  KK excitations of the ,Z Direct: LHC/600 fb -1 6 TeV SLHC/6000 fb TeV Interf:SLHC/6000 fb TeV T.Rizzo 95% excl. limits

31 New gauge bosons  SLHC 1000 fb - 1  LHC 100 fb -1 Gain in reach ~ 1.0 TeV i.e % in going from LHC to SLHC ~ 1.0 TeV LHC reach ~ 4.0 TeV with 100 fb -1

32 Spin analysis (Z’  RS gravitons) Luminosity required to discriminate a spin-1 from spin-2 hypothesis at the 2  level  May well be a case for the SLHC  Also: SUSY particle spin analysis (Barr, Webber, Smiley) need > 100 fb -1

33 Strongly Coupled Vector Boson System If no Higgs, expect strong V L V L scattering (resonant or non-resonant) at q q q q VLVL VLVL VLVL VLVL Could well be difficult at LHC. What about SLHC? degradation of fwd jet tag and central jet veto due to huge pile-up BUT : factor ~ 10 in statistics  5-8  excess in W + L W + L scattering  other low-rate channels accessible

34 WZ vector resonance in VB scattering Vector resonance (ρ-like) in W L Z L scattering from Chiral Lagrangian model M = 1.5 TeV  300 fb -1 (LHC) vs 3000 fb -1 (SLHC) At SLHC: S/  B ~ 10 At LHC: S = 6.6 events, B = 2.2 events These studies require both forward jet tagging and central jet vetoing! Expected (degraded) SLHC performance is included lepton cuts: p t1 > 150 GeV, p t2 > 100 GeV, p t3 > 50 GeV; E t miss > 75 GeV

35 Indicative Physics Reach Approximate mass reach machines:  s = 14 TeV, L=10 34 (LHC) : up to  6.5 TeV  s = 14 TeV, L=10 35 (SLHC) : up to  8 TeV  s = 28 TeV, L=10 34 (DLHC) : up to  10 TeV Units are TeV (except W L W L reach)  Ldt correspond to 1 year of running at nominal luminosity for 1 experiment † indirect reach (from precision measurements) PROCESS LHC SLHC DLHC VLHC VLHC LC LC 14 TeV 14 TeV 28 TeV 40 TeV 200 TeV 0.8 TeV 5 TeV 100 fb fb fb fb fb fb fb -1 Squarks W L W L 2  4  4.5  7  18  6  90  Z’ † 30 † Extra-dim (  =2) † † q*  compositeness TGC (  ) Ellis, Gianotti, ADR hep-ex/ updates

36 Summary: LHC Upgrade In general: SLHC gives a good physics return for “modest” cost, basically independent of the physics scenario chosen by Nature  It is a natural upgrade of the LHC  It will be a challenge for the experiments!  Needs detector R&D starting now: Tracking, electronics, trigger, endcaps, radiation, shielding…  CMS and ATLAS have working groups/workshops on SLHC The LHC luminosity upgrade to cm -2 s -1 The energy upgrade DLHC is certainly more costly and up in the future  Extend the LHC discovery mass range by 25-30% (SUSY,Z’,EDs,…)  Higgs self-coupling measurable with a precision of (20-30%)  Rear decays accessible: H ,  Z, top decays…  Improved Higgs coupling ratios by a factor of 2,…  TGC precision measurements…