Precision Higgs Measurements at Higgs factories LianTao Wang - PowerPoint PPT Presentation

Precision Higgs Measurements at Higgs factories LianTao Wang University of Chicago ICTP . Sept. 8, 2016 A first glance beyond the energy frontier

24 Present ATLAS Exotics Searches* - 95% CL Exclusion ATLAS Preliminary √ s = 8, 13 TeV Status: August 2016 � L dt = (3.2 - 20.3) fb − 1 Jets † E miss Model ℓ , γ � L dt[fb − 1 ] Reference Limit T ADD G KK + g / q ≥ 1 j Yes 3.2 M D 6.58 TeV n = 2 1604.07773 − 2 e , µ M S ADD non-resonant ℓℓ − − 20.3 4.7 TeV n = 3 HLZ 1407.2410 Extra dimensions 1 e , µ 1 j ADD QBH → ℓ q − 20.3 M th 5.2 TeV n = 6 1311.2006 ADD QBH 2 j 15.7 M th 8.7 TeV n = 6 ATLAS-CONF-2016-069 − − ADD BH high � p T ≥ 1 e , µ ≥ 2 j M th n = 6 , M D = 3 TeV, rot BH − 3.2 8.2 TeV 1606.02265 ADD BH multijet ≥ 3 j − − 3.6 M th 9.55 TeV n = 6 , M D = 3 TeV, rot BH 1512.02586 RS1 G KK → ℓℓ 2 e , µ 20.3 G KK mass 2.68 TeV 1405.4123 − − k / M Pl = 0.1 RS1 G KK → γγ 2 γ G KK mass − − 3.2 3.2 TeV k / M Pl = 0.1 1606.03833 1 e , µ Bulk RS G KK → WW → qq ℓν 1 J Yes 13.2 G KK mass 1.24 TeV k / M Pl = 1.0 ATLAS-CONF-2016-062 Bulk RS G KK → HH → bbbb 4 b 13.3 G KK mass 360-860 GeV ATLAS-CONF-2016-049 − − k / M Pl = 1.0 Bulk RS g KK → tt 1 e , µ ≥ 1 b, ≥ 1 J/2j Yes g KK mass 20.3 2.2 TeV BR = 0.925 1505.07018 1 e , µ ≥ 2 b, ≥ 4 j Tier (1,1), BR( A (1,1) → tt ) = 1 2UED / RPP Yes 3.2 KK mass 1.46 TeV ATLAS-CONF-2016-013 SSM Z ′ → ℓℓ Z ′ mass 2 e , µ 13.3 4.05 TeV − − ATLAS-CONF-2016-045 Gauge bosons Z ′ mass SSM Z ′ → ττ 2 τ − − 19.5 2.02 TeV 1502.07177 Leptophobic Z ′ → bb Z ′ mass − 2 b − 3.2 1.5 TeV 1603.08791 SSM W ′ → ℓν W ′ mass 1 e , µ Yes 13.3 4.74 TeV − ATLAS-CONF-2016-061 HVT W ′ → WZ → qq νν model A W ′ mass 0 e , µ g V = 1 1 J Yes 13.2 2.4 TeV ATLAS-CONF-2016-082 HVT W ′ → WZ → qqqq model B W ′ mass − 2 J − 15.5 3.0 TeV g V = 3 ATLAS-CONF-2016-055 HVT V ′ → WH / ZH model B V ′ mass multi-channel 3.2 2.31 TeV g V = 3 1607.05621 W ′ mass LRSM W ′ R → tb 1 e , µ 2 b, 0-1 j Yes 20.3 1.92 TeV 1410.4103 LRSM W ′ R → tb 0 e , µ ≥ 1 b, 1 J W ′ mass − 20.3 1.76 TeV 1408.0886 CI qqqq 2 j 15.7 19.9 TeV η LL = − 1 − − Λ ATLAS-CONF-2016-069 CI CI ℓℓ qq 2 e , µ η LL = − 1 − − 3.2 Λ 25.2 TeV 1607.03669 CI uutt 2(SS)/ ≥ 3 e , µ ≥ 1 b, ≥ 1 j Yes 20.3 Λ 4.9 TeV | C RR | = 1 1504.04605 Axial-vector mediator (Dirac DM) 0 e , µ ≥ 1 j 3.2 m A g q =0.25, g χ =1.0, m ( χ ) < 250 GeV Yes 1.0 TeV 1604.07773 DM Axial-vector mediator (Dirac DM) 0 e , µ , 1 γ 1 j m A g q =0.25, g χ =1.0, m ( χ ) < 150 GeV Yes 3.2 710 GeV 1604.01306 ZZ χχ EFT (Dirac DM) 0 e , µ 1 J, ≤ 1 j Yes 3.2 M ∗ 550 GeV m ( χ ) < 150 GeV ATLAS-CONF-2015-080 Scalar LQ 1 st gen ≥ 2 j β = 1 2 e − 3.2 LQ mass 1.1 TeV 1605.06035 LQ Scalar LQ 2 nd gen 2 µ ≥ 2 j − 3.2 LQ mass 1.05 TeV β = 1 1605.06035 Scalar LQ 3 rd gen 1 e , µ ≥ 1 b, ≥ 3 j Yes 20.3 LQ mass 640 GeV β = 0 1508.04735 VLQ TT → Ht + X 1 e , µ ≥ 2 b, ≥ 3 j Yes 20.3 T mass 855 GeV T in (T,B) doublet 1505.04306 1 e , µ ≥ 1 b, ≥ 3 j VLQ YY → Wb + X Yes 20.3 Y mass 770 GeV Y in (B,Y) doublet 1505.04306 Heavy quarks VLQ BB → Hb + X 1 e , µ ≥ 2 b, ≥ 3 j Yes 20.3 B mass 735 GeV isospin singlet 1505.04306 VLQ BB → Zb + X 2/ ≥ 3 e , µ ≥ 2/ ≥ 1 b − 20.3 B mass 755 GeV B in (B,Y) doublet 1409.5500 1 e , µ ≥ 4 j VLQ QQ → WqWq Yes 20.3 Q mass 690 GeV 1509.04261 VLQ T 5 / 3 T 5 / 3 → WtWt 2(SS)/ ≥ 3 e , µ ≥ 1 b, ≥ 1 j Yes 3.2 T 5 / 3 mass 990 GeV ATLAS-CONF-2016-032 Excited quark q ∗ → q γ q ∗ mass only u ∗ and d ∗ , Λ = m ( q ∗ ) 1 γ 1 j − 3.2 4.4 TeV 1512.05910 fermions Excited quark q ∗ → qg q ∗ mass only u ∗ and d ∗ , Λ = m ( q ∗ ) Excited − 2 j − 15.7 5.6 TeV ATLAS-CONF-2016-069 Excited quark b ∗ → bg b ∗ mass 1 b, 1 j 8.8 2.3 TeV − − ATLAS-CONF-2016-060 Excited quark b ∗ → Wt 1 or 2 e , µ 1 b, 2-0 j b ∗ mass f g = f L = f R = 1 Yes 20.3 1.5 TeV 1510.02664 Excited lepton ℓ ∗ 3 e , µ ℓ ∗ mass − − 20.3 3.0 TeV Λ = 3.0 TeV 1411.2921 ν ∗ mass Excited lepton ν ∗ 3 e , µ , τ 20.3 1.6 TeV Λ = 1.6 TeV − − 1411.2921 LSTC a T → W γ 1 e , µ , 1 γ a T mass − Yes 20.3 960 GeV 1407.8150 2 e , µ N 0 mass LRSM Majorana ν 2 j − 20.3 2.0 TeV m ( W R ) = 2.4 TeV, no mixing 1506.06020 Higgs triplet H ±± → ee H ±± mass 2 e (SS) 13.9 DY production, BR( H ±± → ee )=1 − − 570 GeV ATLAS-CONF-2016-051 L Other Higgs triplet H ±± → ℓτ 3 e , µ , τ H ±± mass DY production, BR( H ±± → ℓτ ) =1 − − 20.3 400 GeV 1411.2921 L 1 e , µ Monotop (non-res prod) 1 b Yes 20.3 spin-1 invisible particle mass 657 GeV a non − res = 0.2 1410.5404 Multi-charged particles 20.3 multi-charged particle mass DY production, | q | = 5 e − − − 785 GeV 1504.04188 Magnetic monopoles − − − 7.0 monopole mass 1.34 TeV DY production, | g | = 1 g D , spin 1 / 2 1509.08059 √ s = 8 TeV √ s = 13 TeV 10 − 1 1 10 Mass scale [TeV] *Only a selection of the available mass limits on new states or phenomena is shown. Lower bounds are specified only when explicitly not excluded. - No “early” discovery. - Next?

This talk - Focus on longer term future. - Higgs measurements at Higgs factories and what we can learn from it. Assuming no LHC discovery. - General picture. (brief) - A couple of new studies.

Higgs factories - FCC-ee, CEPC, ILC, CLIC. - Physics case relatively independent of the outcome of the LHC. Reach further than the LHC. Address questions that LHC can’ t answer.

Probing NP with precision measurements - CEPC: clean environment, good for precision. - We are going after deviations of the form δ ' c v 2 M NP : mass of new physics c: O( 1) coefficient M 2 NP - Take for example the Higgs coupling. LHC precision: 5-10% ⇒ sensitive to M NP < TeV However, M NP < TeV largely excluded by direct NP searches at the LHC. To go beyond the LHC, need 1% or less precision.

Higgs factory processes e + e + e + ¯ ν e e + H W ∗ Z ∗ Z ∗ H H W ∗ Z ∗ e − Z e − e − ν e e − 250 CEPC Preliminary 200 Total Nevents in 5 ab − 1 Process Cross section Higgs boson production, cross section in fb 150 (fb) e + e − → ZH 1 . 06 × 10 6 HZ 212 e + e − → νν H 3 . 36 × 10 4 6.72 σ 100 e + e − → eeH 3 . 15 × 10 3 0.63 1 . 10 × 10 6 Total 219 50 HZ( ) → ν ν WW H → 0 200 250 300 350 400 - + e e f f H [GeV] →

Zh cross section CEPC Preliminary ∫ -1 → + - Z ; Ldt = 5 ab µ µ 3000 � CEPC Simulation Entries/0.2 GeV S+B Fit � Signal Background 2000 h e + e − 1000 Z f 0 120 125 130 135 140 - + µ µ M [GeV] ¯ f zero momentum: recoil recoil = ( √ s − E ff ) 2 − p 2 √ s + m 2 M 2 ff = s − 2 E ff ff and are, respectively, the total energy, momentum a Can use recoil mass to identify Zh process, independent of Higgs decay ⇒ inclusive measurement of Zh cross section

Higgs width. Unique capability of lepton colliders. Z Z* Γ H ∝ Γ ( H → ZZ ∗ ) σ ( ZH ) BR( H → ZZ ∗ ) ∝ h BR( H → ZZ ∗ ) e + e − Z Main channel at 250 GeV. f Needs statistics ¯ f e − W b Γ H ∝ Γ ( H → bb ) σ ( νν H → νν bb ) BR( H → bb ) ∝ h BR( H → bb ) · BR( H → WW ∗ ) ¯ b W e + Needs to go beyond 250.

Higgs factories Measured Higgs-X coupling κ X = Standard Model Higgs-X coupling Precision of Higgs couplingmeasurement ( Contrained Fit ) 1 Projected precision of Higgs coupling and width (model-independent fit) % 10 18% 20% HL - LHC wi / wo theo. uncertainty -1 -1 -1 ILC 500 GeV, 500 fb 350 GeV, 200 fb 250 GeV, 500 fb ⊕ ⊕ 9 % -1 -1 -1 ILC 500 GeV, 4000 fb ⊕ 350 GeV, 200 fb ⊕ 250 GeV, 2000 fb CEPC 250 GeV at 5 ab - 1 wi / wo HL - LHC ( with HL - LHC theo. uncertainty ) -1 ILC ⊕ HL-LHC 3000 fb combination % 8 0.1 Relative Error % 7 6 % 5 % 10 - 2 % 4 % 3 % 2 10 - 3 � b � c � g � W � � � Z � � 1 % 0 % Γ (CL95%) κ κ κ κ κ Γ κ κ κ κ g tot γ c t µ invis Z W b τ Highlights: HZ coupling to sub-percent level. Many couplings to percent level. Model independent measurement of total width. Sensitive to the triple Higgs coupling: 20-30%

Higgs factories Measured Higgs-X coupling κ X = Standard Model Higgs-X coupling Precision of Higgs couplingmeasurement ( Contrained Fit ) 1 Projected precision of Higgs coupling and width (model-independent fit) % 10 18% 20% HL - LHC wi / wo theo. uncertainty -1 -1 -1 ILC 500 GeV, 500 fb 350 GeV, 200 fb 250 GeV, 500 fb ⊕ ⊕ 9 % -1 -1 -1 ILC 500 GeV, 4000 fb ⊕ 350 GeV, 200 fb ⊕ 250 GeV, 2000 fb CEPC 250 GeV at 5 ab - 1 wi / wo HL - LHC ( with HL - LHC theo. uncertainty ) -1 ILC ⊕ HL-LHC 3000 fb combination % 8 0.1 Relative Error % 7 6 % 5 % 10 - 2 % 4 % 3 % 2 10 - 3 � b � c � g � W � � � Z � � 1 % 0 % Γ (CL95%) κ κ κ κ κ Γ κ κ κ κ g tot γ c t µ invis Z W b τ Highlights: HZ coupling to sub-percent level. Many couplings to percent level. Model independent measurement of total width. Sensitive to the triple Higgs coupling: 20-30%