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  Strong first order electroweak phase transition (SFOEWPT)  Higgs non-minimal gravitational interaction  Probing new cubic Higgs interactions on hadron collider  Effective theory with dim=6 operators  Higgs pair production on hadron collider 1

Higgs Discovery  We now have the 125GeV SM-like Higgs with LHC Run1 ATLAS and CMS Collaborations RRL 114, 191803 (2015)  But no convincing evidence from new physics search 2

Higgs Discovery  We now have the 125GeV SM-like Higgs with LHC Run1 ATLAS and CMS Collaborations RRL 114, 191803 (2015)  But no convincing evidence from new physics search Self- coupling  Higgs as the window for new physics QM Higgs gravity Baryon Asymm etry Inflation 2

Less Known Higgs Potential SM Higgs potential 𝑊 𝐼 = −𝜈 2 𝐼 † 𝐼 + 𝜇(𝐼 † 𝐼) 2  EWSB: 𝜈 2 , 𝜇 fixed by 𝑤 = 246 GeV, 𝑁 ℎ = 125 GeV  EWPT: far from first order, (~cross-over) 2 /𝑤 , 𝜇 4 = 3𝑁 ℎ 2 /𝑤 2  Self-couplings: 𝜇 3 = 3𝑁 ℎ  Higgs self-couplings measurement  Dihiggs production to probe 𝜇 3  ~ 50% accuracy on HL-LHC [Snomass Higgs Working Group Report, arXiv:1310.8361]  ~ 27% accuracy on ILC @500GeV [See Jianming Qian’s talk] [arXiv:1506.05992]  ~ 35% accuracy on CEPC5 (careful!) [McCullough, arXiv:1312.3322]  TriHiggs production to probe 𝜇 4 : much more challenging [Plehn, Rauch, PRD 72 (2005) 053008]  Higgs self-interactions as the window to new physics 3

New Physics v.s. Higgs Self- Interactions

Strong first order EWPT (SFOEWPT) Case 3:  Correlation between SFOEWPT and cubic Higgs coupling “Quantum” “Non - renormalizable” “Singlet” can be both >0 & <0 >20% [See M. Perelstein’s talk] [See C. Wagner’s talk] [See P . Winslow’s talk ]  5

Strong first order EWPT (SFOEWPT) Case 3:  Correlation between SFOEWPT and cubic Higgs coupling “Quantum” “Non - renormalizable” “Singlet” can be both >0 & <0 >20% [See M. Perelstein’s talk] [See C. Wagner’s talk] [See P . Winslow’s talk ]  Resonance dihiggs production [See C. Chen’s talk] 5

Higgs non-minimal gravitational interaction Case 3: Joint effective action for SM and GR: 6

Higgs non-minimal gravitational interaction Case 3: Joint effective action for SM and GR: Ω 2 = 1 + 2𝜊 ℎ 𝐼 † 𝐼 Einstein frame 𝑀 2 𝑁 𝑄𝑚 transformation 3 + ⋯ , Λ 𝜊1 = 𝑁 𝑄𝑚 Δ𝑀 6 = 3𝜇 2 (𝜖 𝜈 𝐼 † 𝐼) 2 + 4 𝜊 ℎ ≪ Λ 𝜊2 = 𝑁 𝑄𝑚 𝜇 𝐼 † 𝐼 𝜊 ℎ , if 𝜊 ℎ ≫ 1 2 Λ 𝜊1 Λ 𝜊2 6

Higgs non-minimal gravitational interaction Case 3: Joint effective action for SM and GR: Ω 2 = 1 + 2𝜊 ℎ 𝐼 † 𝐼 Einstein frame 𝑀 2 𝑁 𝑄𝑚 transformation 3 + ⋯ , Λ 𝜊1 = 𝑁 𝑄𝑚 Δ𝑀 6 = 3𝜇 2 (𝜖 𝜈 𝐼 † 𝐼) 2 + 4 𝜊 ℎ ≪ Λ 𝜊2 = 𝑁 𝑄𝑚 𝜇 𝐼 † 𝐼 𝜊 ℎ , if 𝜊 ℎ ≫ 1 2 Λ 𝜊1 Λ 𝜊2  Higgs rescaling induced by graviton-Higgs kinetic mixing 6𝑤 2 2 ≲ 𝑃 0.1 ⇒ 𝜊 ℎ ≲ 10 15 (LHC bound) Λ 𝑉𝑊 ≾ Λ 𝜊1 (Unitarity bound) Λ 𝜊1  New derivative Higgs self-couplings: ℎ𝜖 𝜈 ℎ𝜖 𝜈 ℎ  Higgs inflation: extreme flat potential at large field 𝑡 ≃ 12/𝑂 2 Slow roll: 𝑜 𝑡 ≃ 1 − 2/𝑂 , 𝑠 V(h) 6 [Bezrukov, Shaposhnikov, Phys.Lett. B 659 (2008) 703]

Probing New Cubic Higgs Interactions

EFT: Dim=6 Operators  Dim=6 operators for Higgs self-interactions: [Corbett, Eboli, Gonzalez-Fraile, Gonzalez-Garcia, Phys. Rev. D 87, 015022 (2013)] 8

EFT: Dim=6 Operators  Dim=6 operators for Higgs self-interactions: [Corbett, Eboli, Gonzalez-Fraile, Gonzalez-Garcia, Phys. Rev. D 87, 015022 (2013)] Violate custodial symmetry, negligible for collider study 8

EFT: Dim=6 Operators  Dim=6 operators for Higgs self-interactions: [Corbett, Eboli, Gonzalez-Fraile, Gonzalez-Garcia, Phys. Rev. D 87, 015022 (2013)] Violate custodial symmetry, negligible for collider study Eliminated by EOM 8

EFT: Dim=6 Operators  Dim=6 operators for Higgs self-interactions: [Corbett, Eboli, Gonzalez-Fraile, Gonzalez-Garcia, Phys. Rev. D 87, 015022 (2013)] Violate custodial symmetry, negligible for collider study Eliminated by EOM  The 2d Parameter Space: (𝑦 2 , 𝑦 3 ) Effective cutoff  Higgs-SM couplings rescaled by 𝜂 = (1 + 𝑦 2 ) −1/2  Cubic Higgs coupling 𝜇 3 8

EFT: Dim=6 Operators  Dim=6 operators for Higgs self-interactions: [Corbett, Eboli, Gonzalez-Fraile, Gonzalez-Garcia, Phys. Rev. D 87, 015022 (2013)] Violate custodial symmetry, negligible for collider study Eliminated by EOM  The 2d Parameter Space: (𝑦 2 , 𝑦 3 ) Effective cutoff  Higgs-SM couplings rescaled by 𝜂 = (1 + 𝑦 2 ) −1/2  Cubic Higgs coupling 𝜇 3 Treat 𝑠 , 𝑦 as two free inputs Accidental cancelation with other • operators in single higgs measurement Nonlinear realization: “quadratic” & • “cubic” correlation broken down 8

Dihiggs Production on Hadron Collider Gluon fusion production  A. Djouadi, Phys. Rept. 457 (2008) 1 [arXiv:hep-ph/0503172] h h h h h Vector boson fusion production  h h Top-pair associated production  h Frederix, et al, Phys. Lett. B 732 (2014) 142] h 𝒕 (T 𝒒𝒒 → 𝑰𝑰 𝒒𝒒 → 𝑰𝑰𝒌𝒌 𝒒𝒒 → 𝒖 𝒖𝑰𝑰 𝒒𝒒 → 𝑿𝑰𝑰 𝒒𝒒 → 𝒂𝑰𝑰 eV) NLO cross 8 8.73 0.479 0.177 0.214 0.130 section in 14 34.8 2.017 0.981 0.565 0.356 unit of fb 100 1186 79.6 87.8 7.90 5.18 9

Dihiggs Production on Hadron Collider  𝑕𝑕 → ℎℎ  𝑞𝑞 → ℎℎ𝑘𝑘  𝑞𝑞 → 𝑢𝑢 ℎℎ (dash, solid, dot) for 𝑠 = (−1,0,1) 10

Kinematic distributions @100T eV 𝑠 = 0 𝑦 = −1 𝑕𝑕 → ℎℎ 𝑕𝑕 → ℎℎ 𝑠 = 0 𝑠 = 0 𝑞𝑞 → 𝑢𝑢 ℎℎ 𝑞𝑞 → ℎℎ𝑘𝑘 (VBF) 18 11

Dihiggs Decay Channels HL-LHC with 3𝑏𝑐 −1 𝑇/ 𝐶 = 1.3𝜏 [ATL-PHYS-PUB-2014-019] (0.26%) (7.3%) (25%) Search in tthh and VBF channel, [Liu, Zhang, 1410.1855] [Dolan et al,, 1506.08008] (33%) 𝑋𝑋 ∗ 𝑋𝑋 ∗ [Li, Li, Yan, Zhao, 𝑇/ 𝐶~1.5𝜏 1503.07611] ( 3𝑚3𝜑𝑘𝑘 , 2𝑚 ± 2𝜑4𝑘 ) ( 3𝑚3𝜑𝑘𝑘 ) [Baur, Plehn, Rainwater, PRL 89, 151801 (2002)] (4.7%) 12 HXWG meeting, Michael Spannowsky, 2014-11

𝜹𝜹 @100T Fast Simulation of 𝒄𝒄 eV Events generation: Madgraph5, Pythia 6.2, Delphes 3  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 favor jets in the central region  Photon identification efficiency: roughly 80% for photons with 𝐹 𝑈 > 50 GeV and 𝜃 < 2.5 (HL-LHC: 𝐹 𝑈 > 80 GeV)  Jet-faking-photon background: a faking probability of (−𝐹 𝑈 /27) as a function of jet 𝐹 𝑈 in GeV, and scale the 𝑔 𝑘 = 0.0093exp⁡ jet energy by 0.75 ± 0.12 as the photon energy 13

𝜹𝜹 @100T Fast Simulation of 𝒄𝒄 eV  Background: 𝑐𝑐 𝛿𝛿 , 𝑐𝑐 ℎ 𝛿𝛿 , Z 𝑐𝑐 ℎ 𝛿𝛿 , 𝑢 𝑢ℎ 𝛿𝛿 , 𝑘𝑘𝛿𝛿 (mis-tagging 𝑐 or 𝑐 ) 𝑘𝛿 , 𝑐𝑐 𝑘𝑘 , 𝑢 𝑢𝛿 (jet-faking-photon) 𝑢 𝑢𝛿𝛿, 𝑐𝑐  Events selection [W. Yao, arXiv:1308.6302 [hep-ph]]  2 bjets and b photon  Kinematic cuts (Higgs decay angle) 14

Results eV) with 𝑀 = 3𝑏𝑐 −1 Signal and background at pp(100T 16.5 𝑇/ 𝐶 Comparison : -- 𝑇/ 𝐶 = 8.4 , conservative (photon identification) efficiency [Bar et al, JHEP 1502 (2015) 016, arXiv:1412.7154] -- 𝑇/ 𝐶 = 15.2 , comparable efficiency [Azatov et al, arXiv:1502.00539] 15

Discrimination of T wo Operators  Utilize distribution in reconstructed 𝑁 ℎℎ bins 16

Sensitivity on (𝒔 , 𝒚 ) Plane: SM , 𝒚 = (0,0) 𝒔 dash: 3ab −1  solid: 30ab −1  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%) Dihiggs measurements alone can probe both 𝒔 , 𝒚 ⁡ to a good accuracy 17

Sensitivity on (𝒔 , 𝒚 ) Plane: SM dash: 3ab −1 solid: 30ab −1  Exclusive analysis translated as probe of the effective cutoffs  Tow cases: 𝑦 2 𝑦 3 > 0 (red), 𝑦 2 𝑦 3 < 0 (blue) 2 , Λ 3 ≳ 1 2 TeV  1d sensitivity: Λ 2 , Λ 3 ≳ 0.75 1.4 TeV  Weakest 2d sensitivity: Λ 18

Sensitivity for Generic (𝒔 , 𝒚 )  Sensitivity contours qualitatively different  Benchmark B: non-minimal gravitational coupling. = (0, 0.2) (B1), 𝑠 , 𝑦 = (0, 0.5) (B2), sensitivity contour and 𝑠 , 𝑦 degenerate direction strongly depend on the explicit 𝑦 .  Benchmark C: CW potential in classical scale invariant model. = (2/3, 0) , similar to the SM. 𝑠 , 𝑦 Benchmark B2 Benchmark C Benchmark B1 19