Accelerating Science and Innovation
Particle Physics Landscape: From Large Hadron Collider to Future Large-Scale Accelerator Projects
1 Maxim Titov, CEA Saclay, France Tyumen, Russia, 16-18 October 2019 Interplay Between Lepton and Hadron Colliders
proton-proton colliders: discovery e+e− colliders: precision machines “broadband” machines direct discovery of access to new physics at high energies new phenomena, i.e. accelerators operating through the precision measurement of at the energy scale of the new particle phenomena at lower scales
Precision measurements of neutral current (i.e. polarized e+d) predicted mW, mZ UA1/UA2 discovered W/Z particles LEP nailed the gauge sector
LEP + SLC + Tevatron led to many success stories: SM test at quantum level, top quark, prediction of Higgs mass
Belle discovery of X(3872) dedicated search at CDF & D0 and independent confirmation
First change of perspective with the Tevatron and revolution with the LHC hadron collider as a PRECISION MACHINE Standard Model Test at the Level of Quantum Fluctuations LEP: indirect determination EW fit: bounds for SM Higgs of the top mass Thanks to radiative corrections: mass before its discovery
With known W, Top and Higgs masses, one can constrain whatever lies beyond the SM!
Precision EW Measurements - SM is still ”Incredibly Healthy”
New ATLAS W mass measurement:
mW = 80.370 ± 0.019 GeV ± 7 MeV statistical ± 11 MeV systematic ± 14 MeV modeling
Consistency of the SM EWK fit:
Good agreement between indirect and direct determinations (global p-value ≈ 20%), l but some Tension between A FB, b A l (LEP & SLD), Ab(SLD) & A FB remains… Precision Measurements vs Direct Observation of New particles
• Observe new particles associated with the theory that cancels large corrections to Higgs mass or explains dark matter…. ….or…. • Measure Higgs couplings and production extremely precisely These approaches typically yield complementary results LEP (Large Electron Positron collider) was installed in LHC tunnel
e+ e- circular collider (27 km) with Ecm=200 GeV
Problem for any ring: 4 2 rec E Synchrotron radiation P = 3 3 (m c2 ) ρ2 Emitted power: scales with o 4 3 E !! and 1/m0 (much less for heavy particles)
This energy loss must be replaced by the RF system !!
particles lost 3% of their energy each turn! LEP HISTORY (1989-2000):
The largest accelerator ever built – 27 km circumference;
Operated at 100 GeV to produce 17 million Z Bosons
Experimental evidence for the existance of three families of quarks and leptons
LHC HISTORY (2010- ~ 2040):
(looooong term projects takes n generations of PhD students, n > 10...)
1983: First LHC proposal, launch of design study 1994: Approval by CERN council 2010: First collisions at 3.5 TeV beam energy 2012: Higgs Boson Discovery 2016: Collisions at design energy, 7 TeV Energy Frontier Colliders: Past, Present, Future
+ - e+e+-eLinear- Linear Colliders Colliders + - HE e+e- Storage Rings HE pp Colliders Previous studies in Italy (ELOISATRON 300km), USA (SSC 87km, VLHC 233km), Japan (TRISTAN-II 94km) ex. ELOISATRON ex. SSC H. Ulrich Wienands, The Supercolliders SSC Low Energy Superdetectors: Booster: Design Proceedings of the 19th and Component and 25th Workshops of Prototypes for the the INFN Eloisatron SSC CDR 1986 First Injector Project Synchrotron, IEEE Press, 1997
ex. VLHC Many aspects of machine design and R&D non-site VLHC Design Study Group specific. Collaboration June 2001 SLAC-R-591, SLAC-R-0591, SLAC-591, Exploit synergies with SLAC-0591, FERMILAB-TM-2149 other projects and previous studies The name of the game of a hadron collider is energy reach
Cf. LHC: factor 3-4 in radius, factor 2 in field factor 7-8 E Future Energy Frontier Hadron Colliders
FCC-hh (alternative) 80 km, 20 T Geneva 100 TeV (c.m.) LHC 27 km, 8.33 T PS FCC-hh (baseline) 14 TeV (c.m.) SPS 100 km, 16 T 100 TeV (c.m.) LHC “HE-LHC” 27 km, 16 T 28 TeV (c.m.)
Full LHC exploitation:
15 TeV = 2 x7.5 TeV (ultimate energy, dipoles at 9 T -93% of intrinsic limit)
Beyond ultimate energy (replacing 1 out of 3 LHC dipoles with 11 T HiLumi dipoles unlikely, big change/difficult operation L. Rossi Storage Rings or Linear Collides for Future e+e- Accelerator
Energy tends to be the cost driver: hadrons - high-field magnets; e+e- - high-gradient RF
Circular collider: high-luminosity from Z peak to top threshold Linear colliders: extendability to high energies / beam polarization LHC machine <100 MW
×ECM drives the MWatts (at least for leptons): it’s all about COST per GeV | inv fb Linear vs. Circular Higgs Factory: ℒ Parameter Comparison Where are the acceptable limits? (not the technical limits)
High running costs may need to be shared (global project)
R&D needed in increasing efficiencies and/or recovering the energy
Linear Collider provides power efficient luminosity for > 250 GeV Future Electron-Positron Colliders: “ Higgs Factory” Linear colliders: ILC, CLIC (technical extendability to TeV regime)
arXiv: 1812.07987 arXiv: 1901.09829 arXiv: 1812.07986 arXiv: 1901.09825
International Linear Collider (ILC): Compact Linear Collider (CLIC): Japan (Kitakami) CERN √s = 250 - 500 GeV, 1 TeV √s = 380 GeV, 1.5 TeV, 3 TeV Length: 21 km - 31 km (50 km) Length: 11 km, 29 km, 50 km Circular colliders: CEPC, FCC-ee
arXiv: 1901.03169 http://fcc-cdr.web.cern.ch/ arXiv: 1901.03170
Circular Electron-Positron Collider (CEPC): Future Circular Collider (FCC-ee): China CERN √s = 90 - 240 GeV √s = 90 - 350 GeV Circumference: 100 km Circumference: ~100 km 2023 2030
“Expression of interest” by Japanese government to host International Linear Collider in Japan is expected by the end of 2018 ILC ACCELERATOR
Staged Running Program:
Start with a Higgs Factory 250 GeV Technical extendibility of energy staging to ~ TeV regime has to be secured The International Linear Collider: from GDE to LCC The International Linear Collider Design Overview Ring to Main Linac Damping Rings Polarised Electron Source (including bunch compressors (reduce emittance (deliver stable beam current) reduce σz to eliminate hourglass smaller transverse effect at IP) IP size achievable) e+ Main Linac
Polarized e+ Source (use e- to pair-produce e+ on target)
Beam Delivery/Final Focus System e- Main Linac (demagnify and collide)
20km
Key ILC Technologies ILC PHYSICS: « Higgs Factory »
Baseline running scenario: Deviations Patterns to Reveal New Physics via Nature of Higgs
Precision has always been a window to new discoveries
Different BSM models predict different deviation patterns
=> Help discriminate between different Higgs models based on new physics possibilities beyond SM
The ILC250 has the capability to tell the nature of the BSM from its deviation pattern! Higgs “Golden Channel” at 250 GeV e+e- Collider
Recoil mass measurement: detecting the Higgs boson without using its decay !
X
This method yields absolute measurements of all σ(ZH) x BR and model- independent determination of the total Higgs width / cross section (e.g. invisible Higgs, H cc, modes undetectable at LHC) and Higgs couplings
This would be a boon to entire Higgs effort, as it feeds into hadron-collider Higgs measurements to break redundancies and maximise impact Large quantitative and qualitative improvement over the HL-LHC HL-LHC & ILC Comparison (Model-Dependent)
S1, current projection model-dependent S2, improved model-dependent (HL-LHC adopted)
arXiv: 1903.01629
Model-dependent projections assume:
Higgs boson has no decay modes beyond those predicted by the SM Higgs boson WW & ZZ couplings modified only by rescaling New Physics Interpretation of Higgs: EFT Approach Test various example BSM points – all chosen such that no hint for new physics at HL-LHC Illustrates the ILC’s discovery potential - complementary to the HL-LHC
The only probe would be precision measurements of the Higgs couplings
→ Different new physics models predict different deviation patterns
→ We can discriminate the models! Discrimination power in σs: arXiv: 1710.07621
> 3σ sensitivities to many models @ 250 GeV > 5σ sensitivities to almost all models @ 500 GeV EXFEL @ DESY: an Ultimate Integrated System Test (10%) for ILC The currently longest super-conducting accelerator in the world ILC Site Candidate Location in Japan: Kitakami Area Establish a site-specific Civil Engineering Design - map the (site independent) TDR baseline onto the preferred site - assuming “Kitakami” as a primary candidate
Proposed by JHEP community High-way Endorsed by LCC
Earthquake-proof stable bedrock of granite. No faults cross the line Ofunato Oshu
Express- Rail
Kesen-numa Sendai Ichinoseki
IP Region Need to finalize: - IP / Linac orientation and length - Access points and IR infrastructure - Conventional Facilities and Siting (CFS) 2023 2030
2025 2033 CHINA: CepC/SppC study, CepC CDR – 2018 e+e- collisions ~2030-2035; pp collisions > 2050 Qinhuangdao (秦皇岛）
CepC, SppC
54 km
easy access 300 km from Beijing 70 km 3 h by car 1 h by train “Chinese Toscana”
Yifang Wang N. Walker, 2014 ICHEP What is Next at CERN ?
Beyond HL-LHC:
It’s good to have choices Compact Linear Collider (CLIC) Concept Superconducting SRF cavities have lower gradient (50 MV/m) with longer RF pulse
Normal conducting cavities have higher gradient (100 MV/m) with shorter RF pulse length
No conventional RF source able to produce power for the CLIC accelerator (12 GHz) two-beam accelerator scheme
High-current low-energy drive beam serves as an RF power source for the low-current high-energy main beam large power transformer. CERN energy consumption 2012: 1.35 TWh
Challenge: accelerator energy consumption close to the socially acceptable limit
Currently the only option to multi- TeV e+e- if physics case requires 2727 ILC vs CLIC: Superconducting vs Normal RF
ILC: CLIC:
. Higher Power Efficiency (31-35 MV/m) . Higher Gradient (70-100 MV/m) . Lower RF Frequency (1.3 GHz) . Higher RF Frequency (12 GHz): relaxed tolerances & smaller emittance dilution more accuracy required 10 . High-Q (Q0 =10 ): . Ordinal-Q0 . Larger aperture / better beam quality . Smaller aperture / better accuracy . Long beam pulses (~ 1 ms or CW) . Short beam pulses (µs pulse) . Cryogenics . Water cooling
The LC (ILC/CLIC) can be pursued for construction starting-up in about 5 years aiming for operation by ~ 2030-2035 CLIC Energy Staging and Physics Potential
Wider applicability than only SUSY searches:
reconstructed particles can be classified as states of given mass, spin and quantum numbers Technology Challenges for Future Energy-Frontier Colliders Future Circular Collider (FCC)
FCC Study: 4-volume CDR released on 15 Jan. 2019
Also studied: HE-LHC: √s=27 TeV using FCC-hh 16 T magnets in LHC tunnel; L~1.6x1035 15 ab -1 F. Gianotti for 20 years operation
Sequential implementation, FCC-ee followed by FCC-hh, would enable: variety of collisions (ee, pp, PbPb, eh) comprehensive breadth of programme, 6++ experiments building stepwise at each stage on existing accelerator complex and technical infrastructure
Purely technical schedule assuming green light to preparation work in 2020 A 70 years programme Accelerator Magnet Technologies: International Collaboration Need 16 T (14.3 m long dipoles) to reach 50 TeV /beam Full-size successful (5.5 m) 11 T dipole prototypes - move from NbTi (LHC technology) to Nb3Sn (also 5.5m long coil at Bc > 12 T): Nb3Sn international R&D programme Several EU countries and US LARP & its successor
Magnet is key cost driver (improve cable performance, reduce cable cost, improve fabrication of magnet, ...) Training quench is still a critical issue can we improve training of Nb3Sn magnets ? How do we manage the forces and stresses in a 16T accelerator magnet ? Can we improve the manufacturing processes ?
China: starting the development of HTS high-field magnets (may increase field to 20T) for SppC Physics Case for a 100 TeV Collider Focus on understanding why 100 TeV region: Rare processes: ttH/ttZ - probe of top Yukawa coupling down to sub-% precision What are origins of mass scales 14 <Λ< 100 TeV ? “Sort of” no-lose BSM scenarios at 100 TeV ? Scale: Rare processes important to explore at 100 TeV ? Interplay with other probes available 30 years PDF: from now (e.g. cosmos, e+e- collider) ? M. Mangano Projecting the discovery reach F. Gianotti http://cern.ch/collider-reach (Salam, & Weiler)
arXiv: 1309.1688 arXiv: 1311.6480 Z’
Squarks/gluinos
Expected Sensitivity (Λ ):
Rule of thumb: at fixed Luminosity, Compositeness: 120 TeV discovery reach scales like 2/3 Ebeam Z’: 50 TeV => x 5 from 14 to 100 TeV Squarks/gluinos: 15 TeV
Muon Colliders: Extending High Energy Frontier Multi-TeV lepton collider No beamstrahlung superb energy resolution Muon accelerator Program (MAP) No synchrotron radiation created in 2010: http://map.fnal.gov/ relatively small footprint (but no damping!) Possibilities for cost and MW savings N. Walker, 2014 ICHEP
Plasma Wakefield Acceleration “Dream”: GeV per m
Fundamental “blue skies” research:
- understanding / demonstrating the acceleration process - benchmarking computer simulation models - Experiments: AWAKE [CERN], FACET & FACET 2 [SLAC], FLASHforward [DESY]
Main Driver for PWFA: Linear Collider
ILC “upgrade” :
1 GeV/m 10 TeV L~1035
PAC ~500 MW Summary and Outlook Discussed in this talk: There are many other opportunities:
• B-Factories – SuperKEKB (KEK)
• Heavy ion colliders – LHiC (CERN), FAIR (GSI), – RHIC (BNL), NICA (JINR) • ep colliders – FCC-he (CERN), ENC (GSI), – ELIC (JLAB), eRHIC (BNL)
• Neutrino physics – Many! (LBNE – PIP @ FNAL)
• Gamma-gamma colliders – a natural extension to LC
What will the road look like in 10 years time? – Exciting times ahead of us
The real challenge is GETTING THE FUNDING!
BUT THE SCIENCE IS COMPELLING! Instead of Summary: Particle Physicist – Opportunities for Young People
Conception and realization of accelerator Electronics, mechanics… with strong link with engineers Conception and realization of detectors Electronics, mechanics… with strong link with engineers Simulation
Acquisition and data taking with strong link with engineers in informatics Data analysis Software, statistical analysis, mathematical methods.. Phenomenology link with theory Meeting and work in team (very international, trips...)
Communication of results scientific paper, large public… 40 If you are interested – Join High Energy Physics School in Siberia BACK-UP SLIDES B. List, L. Hagge (Implemented into ILC-EDMS (Engineering Data Management): in cooperation with DESY/FNAL) EDMS will have a 3D system model of all ILC technical areas in a structured way (design integration, accelerator layout, Kitakami geology, tunnel/cavern requirements, civil engineering …)