Precision EW Measurements from ATLAS Extracting sin 2 θ eff Introduction Why measure sin 2 θ eff ? New triple-diff l Drell-Yan Cross Sections d 3 σ Systematic Uncertainties Extraction of sin 2 θ eff Measurement of the Drell-Yan triple differential cross section in pp collisions at √ s = 8 TeV HepData tables: http://dx.doi.org/10.1007/JHEP12(2017)059 https://www.hepdata.net/record/ins1630886 arXiv:1710.05167 Eram Rizvi UCL Seminar 26 th October 2018
New Physics Searches ATLAS Exotics Searches* - 95% CL Upper Exclusion Limits ATLAS Preliminary √ s = 8, 13 TeV Status: July 2018 � L dt = (3.2 – 79.8) fb − 1 Jets † E miss ℓ , γ � L dt[fb − 1 ] Model Limit Reference T ADD G KK + g / q 0 e , µ 1 − 4 j Yes 36.1 M D 7.7 TeV n = 2 1711.03301 Extra dimensions ADD non-resonant γγ 2 γ 36.7 M S 8.6 TeV n = 3 HLZ NLO 1707.04147 − − 2 j ADD QBH − − 37.0 M th 8.9 TeV n = 6 1703.09127 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 M th n = 6 , M D = 3 TeV, rot BH − − 3.6 9.55 TeV 1512.02586 RS1 G KK → γγ 2 γ G KK mass − − 36.7 4.1 TeV k / M Pl = 0.1 1707.04147 Bulk RS G KK → WW / ZZ 36.1 G KK mass multi-channel 2.3 TeV k / M Pl = 1.0 CERN-EP-2018-179 1 e , µ ≥ 1 b, ≥ 1 J/2j Yes g KK mass Bulk RS g KK → tt 36.1 3.8 TeV Γ / m = 15% 1804.10823 1 e , µ ≥ 2 b, ≥ 3 j Tier (1,1), B ( A (1,1) → tt ) = 1 2UED / RPP Yes 36.1 1.8 TeV KK mass 1803.09678 SSM Z ′ → ℓℓ Z ′ mass 2 e , µ − − 36.1 4.5 TeV 1707.02424 SSM Z ′ → ττ Z ′ mass 2 τ − − 36.1 2.42 TeV 1709.07242 Gauge bosons V Leptophobic Z ′ → bb Z ′ mass e − 2 b − 36.1 2.1 TeV 1805.09299 T Leptophobic Z ′ → tt Z ′ mass 1 e , µ ≥ 1 b, ≥ 1 J/2j Yes s Γ / m = 1% 36.1 3.0 TeV 1804.10823 3 t W ′ mass n SSM W ′ → ℓν 1 e , µ 1 79.8 − Yes 5.6 TeV ATLAS-CONF-2018-017 i , h W ′ mass 8 SSM W ′ → τν 1 τ Yes 36.1 3.7 TeV − 1801.06992 , M 7 HVT V ′ → WV → qqqq model B V ′ mass 0 e , µ 2 J 79.8 4.15 TeV g V = 3 − ATLAS-CONF-2018-016 = S HVT V ′ → WH / ZH model B V ′ mass s g V = 3 multi-channel 36.1 B 2.93 TeV 1712.06518 √ LRSM W ′ W ′ mass R → tb multi-channel 36.1 o 3.25 TeV CERN-EP-2018-142 t a n d η − CI qqqq 2 j , − − 37.0 Λ 21.8 TeV 1703.09127 s LL e CI l 2 e , µ η − CI ℓℓ qq 36.1 t a − − Λ 40.0 TeV 1707.02424 c LL n e CI tttt ≥ 1 e , µ ≥ 1 b, ≥ 1 j 36.1 | C 4 t | = 4 π Yes Λ 2.57 TeV CERN-EP-2018-174 g l l i o s Axial-vector mediator (Dirac DM) 0 e , µ 1 − 4 j c m med g q =0.25, g χ =1.0, m ( χ ) = 1 GeV Yes 36.1 1.55 TeV 1711.03301 o DM a n Colored scalar mediator (Dirac DM) 0 e , µ 1 − 4 j m med Yes 36.1 1.67 TeV g =1.0, m ( χ ) = 1 GeV 1711.03301 t a , VV χχ EFT (Dirac DM) 0 e , µ 1 J, ≤ 1 j s M ∗ m ( χ ) < 150 GeV Yes 3.2 700 GeV 1608.02372 d n b -1 u Scalar LQ 1 st gen ≥ 2 j 2 e 3.2 β = 1 − LQ mass 1.1 TeV 1605.06035 g LQ Scalar LQ 2 nd gen f ≥ 2 j 2 µ g 3.2 1.05 TeV β = 1 − LQ mass 1605.06035 0 n Scalar LQ 3 rd gen 1 e , µ ≥ 1 b, ≥ 3 j 6 Yes 20.3 640 GeV β = 0 LQ mass 1508.04735 i k r o e Heavy quarks VLQ TT → Ht / Zt / Wb + X m multi-channel 36.1 T mass 1.37 TeV SU(2) doublet ATLAS-CONF-2018-032 v O s VLQ BB → Wt / Zb + X multi-channel 36.1 B mass 1.34 TeV SU(2) doublet ATLAS-CONF-2018-032 o VLQ T 5 / 3 T 5 / 3 | T 5 / 3 → Wt + X 2(SS)/ ≥ 3 e , µ ≥ 1 b, ≥ 1 j T 5 / 3 mass B ( T 5 / 3 → Wt ) = 1, c ( T 5 / 3 Wt ) = 1 Yes 36.1 1.64 TeV CERN-EP-2018-171 N √ 1 e , µ ≥ 1 b, ≥ 1 j VLQ Y → Wb + X Yes 3.2 Y mass 1.44 TeV B ( Y → Wb ) = 1, c ( YWb ) = 1 / 2 ATLAS-CONF-2016-072 ≥ 1 b, ≥ 1 j VLQ B → Hb + X 0 e , µ , 2 γ 79.8 κ B = 0.5 Yes B mass 1.21 TeV ATLAS-CONF-2018-024 1 e , µ ≥ 4 j VLQ QQ → WqWq Yes 20.3 Q mass 690 GeV 1509.04261 Excited fermions Excited quark q ∗ → qg q ∗ mass only u ∗ and d ∗ , Λ = m ( q ∗ ) 2 j 37.0 6.0 TeV 1703.09127 − − Excited quark q ∗ → q γ q ∗ mass only u ∗ and d ∗ , Λ = m ( q ∗ ) 1 γ 1 j − 36.7 5.3 TeV 1709.10440 Excited quark b ∗ → bg b ∗ mass 1 b, 1 j − − 36.1 2.6 TeV 1805.09299 ℓ ∗ mass Excited lepton ℓ ∗ 3 e , µ − − 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 Type III Seesaw 1 e , µ ≥ 2 j N 0 mass Yes 79.8 560 GeV ATLAS-CONF-2018-020 LRSM Majorana ν 2 e , µ 2 j N 0 mass 20.3 2.0 TeV m ( W R ) = 2.4 TeV, no mixing 1506.06020 − Higgs triplet H ±± → ℓℓ H ±± mass 2,3,4 e , µ (SS) 36.1 870 GeV DY production 1710.09748 − − Other Higgs triplet H ±± → ℓτ H ±± mass DY production, B ( H ±± 3 e , µ , τ → ℓτ ) = 1 − − 20.3 400 GeV 1411.2921 L Monotop (non-res prod) 1 e , µ a non − res = 0.2 1 b Yes 20.3 spin-1 invisible particle mass 657 GeV 1410.5404 Multi-charged particles multi-charged particle mass DY production, | q | = 5 e − − − 20.3 785 GeV 1504.04188 Magnetic monopoles 7.0 monopole mass DY production, | g | = 1 g D , spin 1 / 2 − − − 1.34 TeV 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. † Small-radius (large-radius) jets are denoted by the letter j (J). 2 Eram Rizvi UCL Seminar − 26 th October 2018
The Standard Model Standard Model Total Production Cross Section Measurements Status: July 2018 σ [pb] 500 µ b − 1 10 11 ATLAS Preliminary 80 µ b − 1 Theory Run 1,2 √ s = 7,8,13 TeV LHC pp √ s = 7 TeV 10 6 Probing EW and QCD sector of Standard Model over 12 orders of magnitude! Data 4.5 − 4.6 fb − 1 LHC pp √ s = 8 TeV 10 5 Data 20.2 − 20.3 fb − 1 10 4 LHC pp √ s = 13 TeV These measurements Data 3.2 − 79.8 fb − 1 10 3 10 2 total 10 1 2.0 fb − 1 VBF VH 1 t ¯ tH 10 − 1 pp t¯ t¯ tW t¯ tZ tZj t t W Z WW H Wt WZ ZZ t t -chan s -chan 3 Eram Rizvi UCL Seminar − 26 th October 2018
Electroweak Precision Observables - sin 2 θ eff GFitter 2018 With known m h EW sector of SM is over-constrained Global EW fit of all precision data • m Z = 91.1876 GeV • G µ = 1.16637 x 10 -5 GeV -2 • α QED (0) = 1/137.035 M 0.0 H • … . several others … . M -1.5 W Γ 0.1 W M 0.3 Z Γ -0.2 sin 2 θ W is a fundamental SM parameter of the SM Z 0 σ Specifies the mixing between EM and weak fields -1.5 had 0 Relates the Z and W couplings g Z and g W (and their masses) R -1.0 lep 0,l A -0.9 FB A (LEP) 0.1 l sin 2 θ W = 1 − g 2 = 1 − m 2 A (SLD) W W At leading order -2.1 l g 2 m 2 lept 2 sin (Q ) Θ -0.7 Z Z eff FB lept 2 sin (Tevt.) 0.1 Θ eff 0,c A 0.8 FB Higher order EW corrections modify this 0,b 2.4 A e ff = (1 − m 2 FB sin 2 θ f to an effective mixing angle W ) · (1 + ∆ r ) A 0.0 c m 2 dependent on fermion flavour f A Z 0.6 b 0 R 0.0 c 0 R -0.7 b m EW scheme dependent 0.5 t (5) 2 corrections incorporated into ∆ α (M ) -0.2 had Z 2 Δ r → Δ r(m H , m top , … ) (M ) α 1.3 s Z − 3 − 2 − 1 0 1 2 3 (O O ) / − σ meas meas fit 4 Eram Rizvi UCL Seminar − 26 th October 2018
Electroweak Precision Observables - sin 2 θ eff e ff = (1 − m 2 sin 2 θ f W ) · (1 + ∆ r ) m 2 Z In context of EFT extension to SM EW scheme dependent EW oblique parameters S, T, U, Y, W corrections incorporated into incorporate new BSM dim-6 operators Δ r → Δ r(m H , m top , new physics) in self-energy terms Measurement of one observable can predict the other m W ⇔ sin 2 θ W πα (0) 1 m 2 W = 2 G µ sin 2 θ W √ 1 − ∆ r m W and sin 2 θ eff allows self-consistency check of SM New physics hidden in the higher order corrections ?? Valuable test in absence of direct BSM signals GFitter 2014 Final Precision on sin 2 θ eff LEP: ± 29 x10 -5 2 SLD: ± 26 x10 -5 CDF+D0: ± 35 x10 -5 First LHC results on sin 2 θ eff sin 2 θ eff precision ± 50x10 -5 equivalent to ± 25 MeV in m W CMS(7TeV): ± 320 x10 -5 ATLAS(7TeV): ± 120 x10 -5 5 Eram Rizvi UCL Seminar − 26 th October 2018
Electroweak Precision Observables - m W arXiv:1701.07240 New ATLAS measurement of m W reaches ±19 MeV precision ATLAS approaches precision of combined LEP + Tevatron measurement Theory prediction from EW fit has uncertainty ±8 MeV 6 Eram Rizvi UCL Seminar − 26 th October 2018
Electroweak Precision Observables - sin 2 θ eff Physics Reports 427 (2006) 257–454 0,l A 0.23099 ± 0.00053 fb Previous generation of sin 2 θ W measurements LEP/SLD A l (P τ ) 0.23159 ± 0.00041 Several different observables and asymmetries used A l (SLD) 0.23098 ± 0.00026 A l = polarisation L/R asymmetry at SLD 0,b A FB = forward/backward asymmetry in Z → bb 0,b A 0.23221 ± 0.00029 fb 0,c A 0.23220 ± 0.00081 Long-standing 3.2 σ discrepancy between LEP and SLD fb had Q 0.2324 ± 0.0012 fb Average 0.23153 ± 0.00016 χ 2 /d.o.f.: 11.8 / 5 10 3 m H [ GeV ] 10 2 = 0.02758 ± 0.00035 ∆α ∆α m = 178.0 ± 4.3 GeV 0.23 0.232 0.234 lept sin 2 θ eff 7 Eram Rizvi UCL Seminar − 26 th October 2018
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