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Probing New Physics a t LHC and Beyond. Hong- Jian He Tsinghua University. HEP Annual Meeting, Wuhan, April 18-22, 2014. SM Structure is complete, but. Recall: situation around 1900 ─ People mis-claimed: Newton Mechanics was complete !
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Probing New Physics at LHC and Beyond Hong-Jian He Tsinghua University HEP Annual Meeting, Wuhan, April 18-22, 2014.
SM Structure is complete, but .... Recall: situation around 1900 ─ People mis-claimed: Newton Mechanics was complete! So physics reached “the End”, but it was just at start of New Revolutions, in 1905 + afterwards ─ SR, GR, QM ....
High Energy Physics at Turning Point LHC New Discovery of H(125GeV) puts leading to New Set of Key Physics Questions
New Set of Key Physics Questions Within SM Structure SM contains 3 kinds of Fundamental Interactions: • 1.Gauge Interactions: via Spin-1 Gauge Bosons • 2.Yukawa Interactions: via Spin-0 Higgs Boson • 3.Higgs Self-Interactions: via h3 and h4 Couplings • LHC only has weak sensitivities to hττ, hbb, htt. ─ All other Yukawa + Self couplings fully unknown!! ─ Origins of Fermion Masses + Higgs Mass Itself ?? • Quantitative Tests of Type 2 + 3 Interactions are Beyond LHC and needs New Colliders
Sensitivity to Higgs Couplings: M.E.Peskin, arXiv:1207.2516 LHC(300/fb) has poor sensitivity to Fermion-Yukawa-Couplings !
Model-Independent: Higgs Anomalous Couplings from Effective dim-6 Operators
New Set of Key Physics QuestionsBeyond SM Structure • SM does not include Gravity Force ! So it cannot explain Dark Energy, Inflation ..... • 85% Matter in the universe is Dark Matter, but SM contains no DM ! • SM with h(125GeV) gives too small Baryon Asymmetry of the universe, in contradiction with observations ! • SM cannot account for Neutrino Mass without adding New Particles. • νMixings fully differ from Quarks. Leptonic CP ?…
High Energy Physics at Turning PointAdditional Remarks • H(125) completes SM spectrum. We enter a New Era where Verification of SM takes 2nd Place to Search for New Forces & Interactions. • A Mystery concerns Higgs Itself: It gives masses to all SM particles -Why is God Particle as simple as this? Why is Higgs mass sensitive to Heavy Particles in UV ? • Higgs itself gives us a New Exp approach: Once SM Higgs is extended, its properties are hardly constrained. It is compelling to tug on this particle until SM breaks !!
What LHC-14 at 300/fb Will Do ? • Increase mass reach by a factor ~2 in most channels. Search glunio to ~2TeV, Z’, t’ above 1TeV, …… • Make 1st measurement on V VVVScattering. • Test h gauge couplings, mass, spin, CP to 10% level. • Give 1st measurement on h-t-t coupling. • Measure MW to precision < 10MeV, Mt to < 600MeV. • Measure t couplings to Z, W, g, γ with sensitivities increased by a factor 2-5 better than today. • Carry out ISR-based searches for DM particles. • Provide data for new generation of PDFs. ………
What HL-LHC at 3/abWill Do ? • Increase mass reach by 20-40% for generic New Particle searches; increase a factor-2 in mass reach via EW force • Make precise measurement on V VVVScattering, to probe Higgs sector resonance. • Test Higgscouplings to 2-10%, 1% for hγγ/hZZ ratio. • Make powerful searches for Extended Higgs Sector. • Measure Rare Decaysh μμ,γZ with100M Higgs bosons. • Measure MW to precision < 5MeV, Mt to < 500MeV. • Search for flavor-changing t couplings with 10B t-quarks. • Follow up an earlier discovery at LHC or in DM searches …
Circular e+e- Higgs Factory at 240GeV • Offer 10 times higher Luminosity than ILC(240), improve Higgs Coupling measurements by factor 3, and provide Multiple Detectors working at the same time. • Make better measurementsthan ILC by factor-4 in sin2θeff, a factor-4 in MW, and a factor-10 inMZ. • Search for rare top coupling via ee t c, t u . • Offer possible improvement of αs by a factor-5 over Giga-Z, to <0.1% precision. • TLEP350 measures top mass more precisely to ±100MeV. • …………
Circular pp Collider at 50-100TeV • Give high rates for gghh production, and measure h3 coupling to 8% atpp(100TeV) with 3/ab luminosity. • Sensitively search New Higgs bosons of extended Higgs sector in multi-TeVrange. • Significantly improve sensitivity to WW Scattering and multi-weak-boson production. • Search for WIMP DM Particle up to TeV mass range. • Follow up any discovery at LHC or DM & flavor searches, with further probes for related higher-mass particles. Both energy + luminosity matter! • ………… Brock & Peskin, Snowmass-Summary-Rept
Circular e+e- : Precision Higgs Machine • e+e- Higgs Factory (240GeV) can more precisely measure Higgs properties than LHC: Mass, JPC, Couplings, especially h-Z-Z, h-b-b, h-τ-τ, h-g-g couplings, and invisible decays . It can also measure h-c-c Coupling, which cannot be carried out at LHC. • Most of important Precision-Higgs-Tests can be already done at HF(240GeV) , without ILC500. Higgs self-couplings’ll be probed at Super pp(50-100TeV). M. E. Peskin, arXiv:1207.2516 ILC1(250GeV) & HF(240-250) can do well !
Collider Reach for New Physics Upper Limits on New Particles Reaches at 95%CL Snowmass-Summary-2013
Testing Higgs Self-Couplings LHC(14TeV) vs pp(50-100TeV) • pp hh + X bbγγ • LHC(14TeV, 3/ab) probe h3 coupling with50% accuracy. • HE-LHC(33TeV, 3/ab) probe h3 coupling with20% accuracy. • pp(100TeV, 3/ab) probe h3 coupling with8% accuracy. • W. Yao, Snowmass-2013 (arXiv:1308.6302)
Can Circular ee+ (240) Probe h3 Coupling? • TLEP(240GeV) can measure σ[Zh] to 0.4% . Estimate: Can probe h3 to 28%. • Recall: HL-LHC probes h3 to 50%. ILC500 probes h3 to 83%. M. Mcullough, arXiv:1312.3322
Higgs Gauge Couplings via WW ScatteringLHC(14TeV) vs pp(50-100TeV)
Higgs Gauge Couplings via WW Scattering LHC(14TeV) vs pp(50-100TeV)
Higgs Gauge Couplings via WW Scattering LHC(14TeV, 300/fb) Sensitivity: |Δκ| < 0.2 (2σ level) For recent study, Y.Cui & Z.Han, arXiv:1304.4599
Unitarity Bound on Higgs-Gravity Coupling Bound with Φ = v Bound with large Φ Ren, Xianyu, He, arXiv:1404.4627[gr-qc]
Probe Higgs-Gravity Coupling at pp CollidersW+W+ W+W+ • for WW Energies at pp(50-100TeV) for WW energies at LHC(14TeV) • Ren, Xianyu, He, arXiv:1404.4627
Higgs Inflation:ModerateHiggs-Gravity Coupling ξ = O(104 ─10) ξ = 104 (conventional) ξ = 10(BICEP2) • Ren, Xianyu, He, arXiv:1404.4627[gr-qc]
Origins of Fermion Masses: Probing Yukawa ! • All spin-1/2 matter particles have • Masses∝Arbitrary Yukawa Couplings: (in SM) • New Physics enters fermion mass generation, so the SM Yukawa Couplings are modified ! • Model-independent parametrization: • Yff ( 1 + Δκf ) • Can be directly probed via High Energy Scattering: • f f n VL (n ≥ 2)
PP(50-100TeV): Direct Probe of b & c Yukawa Couplings • J. Ren & HJH
Probing New Heavy Higgs States Higgs WG Rept - SppC
Current WG Report (~200pp) 6 Sub-Reports Very Preliminary
We need: Good Colliders +Good Ideas ! CooperateExp & Theory ! Beyond Higgs Boson(125) ?!!
Sensitivity to Higgs Couplings: M.Kluteetal, arXiv:1301.1322 HL-LHC(3/ab) does not improve much on Yukawa Couplings !