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The Great Standard Model (1895 - 2012) Matter"particles" Force"particles" � 2
Two outstanding puzzles in SM Origins of EWSB and Flavor breaking � Fermion Mass) � W/Z Masses � P L G A TeV U N NP T C K 10 3 10 15 10 -9 10 -3 10 0 10 2 10 1 10 19 (GeV) Proton Weak mass scale 1GeV = 10 9 eV t 344000 e � 3
Electroweak Triangle L = ( D µ Φ ) † ( D µ Φ ) − µ 2 Φ † Φ + λ � 2 Φ † Φ � + y f ¯ F L Φ f r + · · · t Flavor breaking Y f H λ , µ g W g Y Symmetry breaking g W g Y W/Z m 2 h = m t × m Z � 4
Electroweak Triangle L = ( D µ Φ ) † ( D µ Φ ) − µ 2 Φ † Φ + λ Spontaneous Electroweak W L can also interact strongly � 2 Φ † Φ � Symmetry Breaking with top quark as + y f ¯ F L Φ f r + · · · v m t = 2 = 174 GeV √ t Goldstone d Massive W -Boson u Flavor g e ff ∼ 1 Equivalence breaking Y f W Theorem L t g b Existence of longitudinal H λ , µ g weak ∼ 1 W -boson W L d g W g Y u Symmetry 2 . 5 breaking W T t g g W g Y Study interaction of b W L W L → W L W L W/Z u t in the TeV region g g s ∼ 1 m 2 u h = m t × m Z t � 4
Electroweak Triangle L = ( D µ Φ ) † ( D µ Φ ) − µ 2 Φ † Φ + λ � 2 Φ † Φ � + y f ¯ F L Φ f r + · · · t Flavor breaking Y f b b Equivalence t t Theorem H λ , µ g W g Y W + φ + g W g Y Symmetry breaking g W g Y W/Z m 2 h = m t × m Z � 4
What can Higgs Boson tell us? HVV coupling HFF coupling Magnitude and CP Relation between MW and MZ (custodial Symmetry) Relation between Higgs-self couplings HVV and HHVV HHH and HHHH couplings The Higgs boson is important not only for EWSB, but also as a WINDOW to NP beyond the SM. � 5
1) Higgs-self Interaction (probing potential at electroweak scale) V ( ϕ ) = − μ 2 ϕ 2 + λ ( μ ) ϕ 4 + κ ( μ ) Λ 2 ϕ 6 + ⋯ Coleman-Weinberg Higgs V ( � ) = � ( � † � ) 2 + ✏ ( � † � ) 2 log � † � µ 2 Pseudo-Goldstone Higgs V ( φ ) = a sin 2 ( φ /f ) + b sin 4 ( φ /f ) � 6
1) Higgs-self Interaction (probing potential at electroweak scale) V ( ϕ ) = − μ 2 ϕ 2 + λ ( μ ) ϕ 4 + κ ( μ ) Λ 2 ϕ 6 + ⋯ Higgs pair production g H t t H H t g g H t t t t H g � 7
• 2) HVV versus HHVV • SM predicts a definite ratio between HVV and HVV couplings 2 M 2 M �� 2 i V g �� 2 i V g v 2 v (tree-level relation) • If the ratio is modified by NP, the unitarity of VV->HH is broken � 8
Higgs Boson Pair Production � 9
Sensitivity to HHH coupling gg->HH: the leading channel � 10 J. Baglio, A. Djouadi et al. JHEP 1304(2013)51
Sensitivity to HHH coupling gg->HH: the leading channel Low-energy theorem (Dawson and Haber, 1989) Strong cancelation � 11
Sensitivity to HHH coupling gg->HH: the leading channel Strong cancelation Low Energy Theorem � 12 J. Baglio, A. Djouadi et al. JHEP 1304(2013)51
gg->HH: the leading channel Unfortunately, it is not a easy job at the LHC or even at the SppC. 5 D.-Y. Shao, C.-S. Li, H.-T. Li, and J. Wang, HH production JHEP 07 (2013) 169 g NNLL+NLO 4 λ λ / = -1 H t SM ) λ λ / = 0 -1 /dM (TeV t SM H λ λ H 3 / = 1 SM t λ λ / = 2 SM g σ g d H t σ 2 1/ t t 1 t H g 0 300 400 500 600 700 800 900 1000 M (GeV) Not accessible at detector! � 13
gg → HH → b ¯ Too many things involved in b γγ L e ff = − m t c t γ 5 ) th − m t c 2 t γ 5 ) th 2 + α s h µ ν G A,µ ν + ˜ µ ν ˜ ¯ 2 v 2 ¯ 12 π v ( c g G A c g G A G A,µ ν ) t ( c t + i ˜ t ( c 2 t + i ˜ v + α s h 2 m 2 µ ν G A,µ ν + ˜ µ ν ˜ QHC, Li, Yan, Zhang, Zhang, 2 v h 3 , 24 π v 2 ( c 2 g G A c 2 g G A G A,µ ν ) − c 3 h h Phys.Rev. D96 (2017) no.9, 095031 µ hh = A 1 c 2 3 h c 2 g + A 2 c 2 3 h c g c t + A 3 c 2 3 h c 2 t + A 4 c 3 h c g c 2 g + A 5 c 3 h c g c 2 c 2 t + A 6 c 3 h c 2 g c t + A 7 c 3 h c g ˜ t + A 8 c 3 h c 3 c 2 t + A 10 c 2 2 g + A 11 c 2 g c 2 c 2 t + A 13 c 4 t + A 14 c 2 c 2 c 4 t + A 9 c 3 h c t ˜ t + A 12 c g ˜ t ˜ t + A 15 ˜ t + A 16 c 2 c 2 g + A 17 c 2 c t + A 18 c 2 c 2 3 h ˜ 3 h ˜ c g ˜ 3 h ˜ t + A 19 c 3 h ˜ c g ˜ c 2 g + A 20 c 3 h ˜ c g c t ˜ c t + A 21 c 3 h ˜ c 2 g ˜ c t c 2 c t + A 24 c 2 2 t + A 25 c 2 t c 3 h c g + A 26 c 2 t c 3 h c t + A 27 c 2 t c 2 g + A 28 c 2 t c 2 + A 22 ˜ 2 g + A 23 ˜ c 2 g c t ˜ t c 2 c 2 + A 29 c 2 t ˜ t + A 30 c t ˜ c t ˜ c 2 t + A 31 c 3 h ˜ c t ˜ c 2 t + A 32 c 3 h ˜ c g ˜ c 2 t + A 33 ˜ 2 t + A 34 ˜ c g ˜ c 2 t . ✿✿✿✿✿✿ √ s A 1 A 2 A 3 A 4 A 5 A 6 A 7 A 8 A 9 A 10 A 11 A 12 14 TeV 0.138 0.370 0.276 0.640 -0.766 0.821 0.535 -1.35 -6.22 1.37 -1.82 1.58 100 TeV 0.101 0.267 0.208 0.592 -0.569 0.658 0.425 -1.11 -4.79 3.32 -1.30 1.67 √ s A 13 A 14 A 15 A 16 A 17 A 18 A 19 A 20 A 21 A 22 A 23 A 24 14 TeV 2.07 13.9 0.719 0.138 -0.611 0.861 0.640 2.13 -1.24 1.37 4.64 2.55 100 TeV 1.90 11.3 0.680 0.101 -0.428 0.634 0.592 1.53 -0.928 3.32 3.51 2.90 √ s A 25 A 26 A 27 A 28 A 29 A 30 A 31 A 32 A 33 A 34 14 TeV 0.821 1.39 2.44 -4.24 2.30 -18.8 4.04 -1.24 6.19 -3.02 100 TeV 0.658 1.21 2.06 -4.13 2.16 -16.3 3.28 -0.928 6.10 -2.08 � 14
Sensitivity to HHH coupling: 2) VBF and VHH VBF and VHH are sensitive to HHH coupling differently J. Baglio, A. Djouadi et al. JHEP 1304(2013)51 � 15
̂ ̂ ̂ ̂ ̂ ̂ ̂ Sensitive to Triple Higgs Coupling Differently v 2 ( W ) m 2 6 m 2 + 2 m 2 + 4 m 4 λ HHH 1 1 M μν = g μν + ⋯ W H W W + v 2 s − m 2 λ SM v 2 u − m 2 t − m 2 H HHH W Near the threshold of Higgs-boson pairs VBF: v 2 ( − 3 ) g μν + ⋯ M μν ∼ 2 m 2 u = Q 2 < 0 λ HHH t = V λ SM HHH VHH: v 2 ( + 1 ) g μν + ⋯ M μν ∼ 2 m 2 λ HHH V u = Q 2 > 0 t = λ SM HHH � 16
Sensitivity to HHH Coupling v 2 ( − 3 ) g μν + ⋯ M μν ∼ 2 m 2 λ HHH V VBF λ SM HHH v 2 ( + 1 ) g μν + ⋯ M μν ∼ 2 m 2 λ HHH V VHH λ SM HHH � 17
HH and VHH @14 TeV LHC vs >> Cross section: 34 fb Cross section: 0.57 fb � × Br ( bbbb `⌫ ) = 0 . 042 fb Huge backgrounds: Main backgrounds: � 18
VBF and WHH @14 TeV LHC Huge vs backgrounds >> Cross section: 2.01 fb Cross section: 0.57 fb � × Br ( bbbb `⌫ ) = 0 . 042 fb > Isolated weak boson fusion? � 19 M. J. Dolan et al, Eur.Phys.J.C75(2015)8,387
WHH and ZHH Productions QHC, Liu, Yan, Phys.Rev. D95 (2017) no.7, 073006 The discovery potential of triple Higgs coupling in VHH production is comparable to other channels. 0 . 5 ≤ κ ≤ 2 . 2 Nordstrom and Papaefstathiou (arXiv:1807.01571) include full detector effects and show that measuring HHH coupling via WHH and VHH channels is very challenging. � 20
Higgs as a pseudo Nambu-Goldstone The Signature of Pseudo Nambu - Goldstone Higgs Boson in its Decay Ling-Xiao Xu � ��� � School of Physics, Peking University Collaborate with Qing-Hong Cao, Bin Yan, Shou-hua Zhu, to appear Aug ??, 2018 @ Tianjin � 1 � 21
3) Higgs-Fermion Interaction First observation of Higgs-Top coupling tH = 1 . 26 +0 . 31 µ t ¯ − 0 . 26 CMS: PRL120,231801 (2018) Lianliang MA ����� Shandong University Observation of ttH at CMS June 20-24, 2018@Shanghai Huaqiao Zhang (IHEP) 1 ��������� 2018 � 6 � 19-24 � ��
Good News: Higgs-Bottom Coupling July 9th, ICHEP18, Seoul � 23
Sizing Up Top Quark’s Interaction with Higgs Four-top production arXiv:1710.10614 -1 CMS t 35.9 fb (13 TeV) g ) (fb) t ¯ Obs. upper limit 60 H t t Obs. cross section t (t Predicted cross section, σ off-shell t 50 Phys. Rev. D 95 (2017) 053004 g off-shell ¯ t 40 QHC, Chen, Liu PRD95 (2017) 053004 CMS 30 No assumption on Higgs decay 20 10 tth associated production t 0 g 0.5 1 1.5 2 2.5 SM | y / y | ������������ h t t y t /y SM ���������� ≤ 2 . 1 on-shell t g ¯ t � 24
The CP property of Htt coupling QHC, Xie, Zhang Goncalves,Kim, Kong in preparation t t arXiv:1804.05874 g γ g 0.15 Normalized Distribution h h 0.10 g γ g ¯ t ¯ t 0.05 0.00 0.0 0.5 1.0 1.5 angle need top-quark After cuts Hadron level CS-frame reconstruction After cuts 0.10 Hadron level Normalized Distribution 0.08 0.06 0.04 0.02 0.00 0.0 0.5 1.0 1.5 angle no need to reconstruct top quark � 25
Interim Summary ℒ = ( D μ Φ ) † 2 ( D μ Φ ) − μ 2 Φ † Φ + λ ( Φ † Φ ) + y f ¯ F L Φ F R + ⋯ t Flavor breaking Y f d u Equivalence H λ , µ Theorem W L Symmetry t g breaking b g W g Y g e ff ∼ 1 W/Z More accurate knowledge of Higgs boson might shed lights on NP. � 26
� What if NP knew nothing about Higgs? Higgs boson discovery the END of the era of SM P L A G N U See- C T Saw TeV K 10 3 10 15 10 -9 10 -3 10 0 10 2 10 1 10 19 GeV Q1. Why are light quarks so light? Top quark and W/Z bosons are naturally around the weak scale. Q2. Heavy NP particles cannot achieve mass mainly from Higgs. NP scale = New Resonance Mass ~ 2TeV � 27
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