s = 28 TeV upgrade

1. L = 1035 upgrade “SLHC = Super-LHC” vs s = 28 TeV upgrade Easier for machine Challenging and expensive for machine Major changes to detectors for Modest changes to detectors full benefit, very difficult environment Smaller physics potential: Larger physics potential: -- mass reach 20-30% higher than LHC -- mass reach ~1.5 higher than LHC -- precision measurements possible but -- many improved measurements (e.g. Higgs) -- with significant detector upgrades -- higher statistics than LHC -- challenging due to environment -- LHC-like environment Cost : ~ 25% of LHC project ? ??? More powerful than L upgrade but benefit/cost ratio should be better understood … wait for LHC data Maximum exploitation of existing tunnel, machine, detectors …  good physics return for “modest” cost ? Question : do we want to consider also the energy upgrade option or only the luminosity upgrade ? Fabiola Gianotti, 14/10/2003

2. If bunch crossing 12.5 ns LVL1 trigger (BCID) • tracker (occupancy) must work at 80 MHz L = 1035 : experimental challenges and detector upgrades • ~ 120 minimum-bias per crossing (compared to ~ 25 at LHC) • occupancy in tracker ~ 10 times larger than at LHC (for same granularity and response time) • pile-up noise in calorimeters ~ 3 times larger (for same response time) • Trackers : need to be replaced(radiation, occupancy, response time) • -- R > 60 cm : development of present Si strip technology ~ ok • -- 20 < R < 60 cm : development of present Pixel technology ~ ok • -- R < 20 cm : fundamental R & D required (materials, concept, etc.) • -- channel number ~ 5 larger (occupancy)  R&D needed for low cost • Calorimeters : mostly ok (radiation resistance of CMS end-cap ECAL ?) • Muon spectrometers : mostly ok • -- increase forward shielding  acceptance reduced to ||< 2 • -- space charge effects, aging ? • -- some trigger chambers (e.g. ATLAS TGC) too slow for 12.5 ns Cost : ~ 300 MCHF (material only) ? • Electronics and trigger : large part to be replaced • -- new LVL1 trigger electronics for 80 MHz • -- R&D needed for e.g. tracker electronics (fast, rad hard) • -- most calorimeter and muon electronics ~ ok (radiation resistance ?) Fabiola Gianotti, 14/10/2003

3. Units are TeV (except WLWL reach) Ldt correspond to 1 year of running at nominal luminosity for 1 experiment PROCESS LHCSLHC VLHCVLHC LC LC 14 TeV14 TeV 28 TeV 40 TeV 200 TeV 0.8 TeV 5 TeV 100 fb-11000 fb-1 100 fb-1 100 fb-1100 fb-1 500 fb-1 1000 fb-1 Squarks 2.534 5200.4 2.5 WLWL24 4.5 7 18 6 90 Z’ 56811 358†30† Extra-dim (=2) 91215 25 655-8.5† 30-55† q* 6.57.5 9.5 13 750.8 5  compositeness 3040 40 50100 100 400 † indirect reach (from precision measurements) Summary of reach and comparison of various machines Only a few examples …. In many cases numbers are just indications …. Most important issues (my view …): -- measurement of Higgs self-coupling and H -- strong EWSB -- coverage of MSSM Higgs sector vs TESLA-like LC Approximate mass reach of LHC and upgrades: s = 14 TeV, L=1034 (LHC) : up to  6.5 TeV s = 14 TeV, L=1035 (SLHC) : up to  8 TeV s = 28 TeV, L=1034 : up to  10 TeV Fabiola Gianotti, 14/10/2003