Jing Ren University of Toronto ACFI Workhop September 19, 2015 - - PowerPoint PPT Presentation
Probing New Physics of Cubic Higgs Interaction Jing Ren University of Toronto ACFI Workhop September 19, 2015 Based on H.J. He (Tsinghua), JR, W. Yao (LBNL), 1506.03302 1 Outline Motivation New physics v.s. Higgs self-interactions
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Based on H.J. He (Tsinghua), JR, W. Yao (LBNL), 1506.03302
Strong first order electroweak phase transition (SFOEWPT) Higgs non-minimal gravitational interaction
Effective theory with dim=6 operators Higgs pair production on hadron collider
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We now have the 125GeV SM-like Higgs with LHC Run1 But no convincing evidence from new physics search
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ATLAS and CMS Collaborations RRL 114, 191803 (2015)
We now have the 125GeV SM-like Higgs with LHC Run1 But no convincing evidence from new physics search
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ATLAS and CMS Collaborations RRL 114, 191803 (2015)
QM gravity Self- coupling
Baryon Asymm etry Inflation
Higgs as the window for new physics
EWSB: 𝜈2, 𝜇 fixed by 𝑤 = 246GeV, 𝑁ℎ = 125GeV EWPT: far from first order, (~cross-over) Self-couplings: 𝜇3 = 3𝑁ℎ
2/𝑤, 𝜇4 = 3𝑁ℎ 2/𝑤2
Dihiggs production to probe 𝜇3
~ 50% accuracy on HL-LHC
~ 27% accuracy on ILC @500GeV ~ 35% accuracy on CEPC5 (careful!)
TriHiggs production to probe 𝜇4: much more challenging
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[Snomass Higgs Working Group Report, arXiv:1310.8361] [Plehn, Rauch, PRD 72 (2005) 053008]
[arXiv:1506.05992] [McCullough, arXiv:1312.3322]
[See Jianming Qian’s talk]
Correlation between SFOEWPT and cubic Higgs coupling
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“Quantum” >20% [See M. Perelstein’s talk] “Non-renormalizable” can be both >0 & <0 [See C. Wagner’s talk] [See P . Winslow’s talk] “Singlet”
Correlation between SFOEWPT and cubic Higgs coupling Resonance dihiggs production
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“Quantum” >20% [See M. Perelstein’s talk] “Non-renormalizable” can be both >0 & <0 [See C. Wagner’s talk] [See P . Winslow’s talk] “Singlet” [See C. Chen’s talk]
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Δ𝑀6 = 3𝜇
Λ𝜊1
2 (𝜖𝜈𝐼†𝐼)2+ 4
Λ𝜊2
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𝜇 𝐼†𝐼
3 + ⋯ , Λ𝜊1 = 𝑁𝑄𝑚 𝜊ℎ ≪ Λ𝜊2 = 𝑁𝑄𝑚 𝜊ℎ , if 𝜊ℎ ≫ 1 Einstein frame transformation
Ω2 = 1 + 2𝜊ℎ𝐼†𝐼 𝑁𝑄𝑚
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Higgs rescaling induced by graviton-Higgs kinetic mixing New derivative Higgs self-couplings: ℎ𝜖𝜈ℎ𝜖𝜈ℎ Higgs inflation: extreme flat potential at large field
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6𝑤2 Λ𝜊1
2 ≲ 𝑃 0.1 ⇒ 𝜊ℎ ≲ 1015 (LHC bound)
Λ𝑉𝑊 ≾ Λ𝜊1 (Unitarity bound) Slow roll: 𝑜𝑡 ≃ 1 − 2/𝑂, 𝑠
𝑡 ≃ 12/𝑂2 V(h)
Δ𝑀6 = 3𝜇
Λ𝜊1
2 (𝜖𝜈𝐼†𝐼)2+ 4
Λ𝜊2
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𝜇 𝐼†𝐼
3 + ⋯ , Λ𝜊1 = 𝑁𝑄𝑚 𝜊ℎ ≪ Λ𝜊2 = 𝑁𝑄𝑚 𝜊ℎ , if 𝜊ℎ ≫ 1 Einstein frame transformation
Ω2 = 1 + 2𝜊ℎ𝐼†𝐼 𝑁𝑄𝑚
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[Bezrukov, Shaposhnikov, Phys.Lett. B 659 (2008) 703]
Dim=6 operators for Higgs self-interactions:
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[Corbett, Eboli, Gonzalez-Fraile, Gonzalez-Garcia, Phys. Rev. D 87, 015022 (2013)]
Dim=6 operators for Higgs self-interactions:
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[Corbett, Eboli, Gonzalez-Fraile, Gonzalez-Garcia, Phys. Rev. D 87, 015022 (2013)]
Violate custodial symmetry, negligible for collider study
Dim=6 operators for Higgs self-interactions:
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[Corbett, Eboli, Gonzalez-Fraile, Gonzalez-Garcia, Phys. Rev. D 87, 015022 (2013)]
Violate custodial symmetry, negligible for collider study Eliminated by EOM
Dim=6 operators for Higgs self-interactions: The 2d Parameter Space: (𝑦2, 𝑦3)
Higgs-SM couplings rescaled by 𝜂 = (1 + 𝑦2)−1/2 Cubic Higgs coupling 𝜇3
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[Corbett, Eboli, Gonzalez-Fraile, Gonzalez-Garcia, Phys. Rev. D 87, 015022 (2013)]
Effective cutoff
Violate custodial symmetry, negligible for collider study Eliminated by EOM
Dim=6 operators for Higgs self-interactions: The 2d Parameter Space: (𝑦2, 𝑦3)
Higgs-SM couplings rescaled by 𝜂 = (1 + 𝑦2)−1/2 Cubic Higgs coupling 𝜇3
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[Corbett, Eboli, Gonzalez-Fraile, Gonzalez-Garcia, Phys. Rev. D 87, 015022 (2013)]
Effective cutoff
Violate custodial symmetry, negligible for collider study Eliminated by EOM
Treat 𝑠 , 𝑦 as two free inputs
measurement
“cubic” correlation broken down
h h h h h h h h h
Gluon fusion production
Vector boson fusion production
Top-pair associated production
𝒕 (T eV) 𝒒𝒒 → 𝑰𝑰 𝒒𝒒 → 𝑰𝑰𝒌𝒌 𝒒𝒒 → 𝒖 𝒖𝑰𝑰 𝒒𝒒 → 𝑿𝑰𝑰 𝒒𝒒 → 𝒂𝑰𝑰 8 8.73 0.479 0.177 0.214 0.130 14 34.8 2.017 0.981 0.565 0.356 100 1186 79.6 87.8 7.90 5.18
NLO cross section in unit of fb
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Frederix, et al, Phys. Lett. B 732 (2014) 142]
→ ℎℎ 𝑞𝑞 → ℎℎ𝑘𝑘 𝑞𝑞 → 𝑢𝑢 ℎℎ
(dash, solid, dot) for 𝑠 = (−1,0,1)
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→ ℎℎ → ℎℎ 𝑞𝑞 → 𝑢𝑢 ℎℎ 𝑞𝑞 → ℎℎ𝑘𝑘 (VBF)
𝑠 = 0 𝑦 = −1 𝑠 = 0 𝑠 = 0
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HXWG meeting, Michael Spannowsky, 2014-11
HL-LHC with 3𝑏𝑐−1 𝑇/ 𝐶 = 1.3𝜏
[ATL-PHYS-PUB-2014-019]
Search in tthh and VBF channel,
[Liu, Zhang, 1410.1855] [Dolan et al,, 1506.08008] [Li, Li, Yan, Zhao, 1503.07611] [Baur, Plehn, Rainwater, PRL 89, 151801 (2002)]
(0.26%) (7.3%) (25%) (33%) (4.7%)
𝑋𝑋∗𝑋𝑋∗
(3𝑚3𝜑𝑘𝑘,2𝑚±2𝜑4𝑘) 𝑇/ 𝐶~1.5𝜏 (3𝑚3𝜑𝑘𝑘)
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Signal: include finite mt effect Background: include up to one extra parton with MLM matching Detector simulation based on ATLAS responses
Use anti-kT for jets with Δ𝑆 = 0.5 b-tagging efficiency: 75%, 18.8%, and 1% for bottom, charm, and light
Photon identification efficiency: roughly 80% for photons with 𝐹𝑈 >
Jet-faking-photon background: a faking probability of
𝑔
𝑘 = 0.0093exp
(−𝐹𝑈/27) as a function of jet 𝐹𝑈 in GeV, and scale the
Events selection
2 bjets and b photon Kinematic cuts
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Background: 𝑐𝑐 𝛿𝛿, 𝑐𝑐 ℎ 𝛿𝛿 , Z 𝑐𝑐 ℎ 𝛿𝛿 , 𝑢 𝑢ℎ 𝛿𝛿 , 𝑘𝑘𝛿𝛿 (mis-tagging 𝑐 or 𝑐 ) 𝑢 𝑢𝛿𝛿, 𝑐𝑐 𝑘𝛿, 𝑐𝑐 𝑘𝑘, 𝑢 𝑢𝛿 (jet-faking-photon)
(Higgs decay angle)
[W. Yao, arXiv:1308.6302 [hep-ph]]
Comparison:
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[Bar et al, JHEP 1502 (2015) 016, arXiv:1412.7154]
16.5 𝑇/ 𝐶
[Azatov et al, arXiv:1502.00539]
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𝒔 , 𝒚 = (0,0)
Degenerate direction
around origin
Exclusive analysis
breaks degenerate direction
1d sensitivity:
δ𝑠 ~13% 4% , δ𝑦 ~5%(1.6%)
The weakest 2d
sensitivity:
δ𝑠 ~25% 8% , δ𝑦 ~10%(3%)
dash: 3ab−1 solid: 30ab−1
Exclusive analysis translated as probe of the effective cutoffs Tow cases: 𝑦2𝑦3 > 0 (red), 𝑦2𝑦3 < 0 (blue) 1d sensitivity: Λ
Weakest 2d sensitivity: Λ
dash: 3ab−1 solid: 30ab−1
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Sensitivity contours qualitatively different
Benchmark B: non-minimal gravitational coupling.
𝑠 , 𝑦 = (0, 0.2) (B1), 𝑠 , 𝑦 = (0, 0.5) (B2), sensitivity contour and
Benchmark C: CW potential in classical scale invariant model.
𝑠 , 𝑦 = (2/3, 0), similar to the SM.
Benchmark B1 Benchmark B2 Benchmark C
Higgs self-interactions as the window for new physics, important
Probing new physics of Higgs self-couplings based on effective
Dihiggs production alone can probe both cubic Higgs couplings
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Goldstone boson equivalence theorem: Coupled channel analysis: 2 → 2 scattering Unitarity analysis for Higgs inflation
𝐹 < 8𝜌 3 𝑁𝑄𝑚 𝜊ℎ
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𝐹2 < 16𝜌𝑤2 1 − 𝜂2 1 + 1 + 3𝜂4
Puzzle: go beyond
Unitarity bound depends on background
The strongest bound from 𝜌+𝜌− → 𝜌0𝜌0
[JR, Z. Z. Xianyu, H.J. He,1404.4627]
T
Gluon fusion production Vector fusion production
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dim=6: dim=6: dim=6: 𝐼†𝐼𝑋𝑏𝜈𝜉𝑋
𝜈𝜉 𝑏 , 𝐼†𝐼 𝐸𝜈𝐼 †(𝐸𝜈𝐼)
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