hong-jian he tsinghua university probing new physics at lhc and beyond hep annual meeting, wuhan,...

Hong-Jian HeTsinghua University

Probing New Physics at LHC and Beyond

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 ....

LHC Status

High Energy Physics at Turning Point

New Set of Key Physics Questions

LHC New Discovery of H(125GeV) puts

leading to

New Set of Key Physics Questions

Within SM Structure SM contains 3 kinds of Fundamental Interactions:1. Gauge Interactions: via Spin-1 Gauge Bosons2. Yukawa Interactions: via Spin-0 Higgs Boson3. 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

Higgs Anomalous Coupling from Models

New Set of Key Physics Questions

Beyond SM StructureSM 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.

ν Mixings fully differ from Quarks. Leptonic CP ?…

High Energy Physics at Turning Point Additional 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 V V V Scattering.

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/ab Will 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 V V V Scattering,

to probe Higgs sector resonance.

Test Higgs couplings to 2-10%, 1% for hγγ/hZZ ratio.

Make powerful searches for Extended Higgs Sector.

Measure Rare Decays h μμ,γZ with 100M 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 measurements than ILC by factor-4 in sin2 θeff,

a factor-4 in MW , and a factor-10 in MZ .

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 gg hh production, and measure

h3 coupling to 8% at pp(100TeV) with 3/ab luminosity.

Sensitively search New Higgs bosons of extended Higgs sector in multi-TeV range.

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 PhysicsUpper Limits on New Particles Reaches at

95%CL

Snowmass-Summary-2013

Higgs Production @ Higgs Factory

Testing Higgs Self-Couplings LHC(14TeV) vs pp(50-100TeV)

pp hh + X bbγγ

LHC(14TeV, 3/ab) probe h3 coupling with 50% accuracy. HE-LHC(33TeV, 3/ab) probe h3 coupling with 20% accuracy. pp(100TeV, 3/ab) probe h3 coupling with 8% 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 Scattering

LHC(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

Modify Effective hWW/hZZ Couplings in Einstein Frame:

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 LHC(14TeV) for WW Energies at pp(50-100TeV)

Ren, Xianyu, He, arXiv:1404.4627

Higgs Inflation:Moderate Higgs-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:

Yf f ( 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

Higgs WG Rept - SppC

Higgs WG Rept - SppC

Higgs WG Rept - SppC

Current WG Report

(~200pp)

6 Sub-ReportsVery Preliminary

Beyond Higgs Boson(125) ?!!

We need: Good Colliders + Good Ideas ! Cooperate Exp & Theory !

Sensitivity to Higgs Couplings: M.Klute etal, arXiv:1301.1322

HL-LHC(3/ab) does not improve much on Yukawa Couplings !