Searches for high-mass resonances in ATLASpnp.ustc.edu.cn/html/upload/2018/08/29/... ·...

36
Searches for high-mass resonances in ATLAS Zuzana Barnovska-Blenessy USTC Seminar May 4 th , 2018 Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 1 / 35

Transcript of Searches for high-mass resonances in ATLASpnp.ustc.edu.cn/html/upload/2018/08/29/... ·...

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Searches for high-mass resonances in ATLAS

Zuzana Barnovska-Blenessy

USTC Seminar

May 4th, 2018

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 1 / 35

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Outline

1 Standard Model

2 LHC and ATLAS detector

3 Summary of searches

4 X →WW

5 X → γγ

6 General searches

7 Summary and prospects

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 2 / 35

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Standard model of Particle Physics

unified picture of Electroweak and Strong interactionsmatter is build of fermions (leptons, quarks) andforces are carried by bosons (gluons, γ, W±,Z)Higgs field is added to the SM to generate masses of W,Z and fermions

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 3 / 35

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Large Hadron Collider at CERN

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 4 / 35

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ATLAS experiment

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 5 / 35

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ATLAS detector performance

ATLAS steadily collects data

instantaneous luminosity reaching double the desingvalue up to 2.06x1034 cm−2s−1

80 fb−1 of data usable for physics (out of 87 fb−1

recorded)

pile-up reaching up to 70 simultaneous collisions

improved performance wrt Run1: more efficienctb-tagging, new HLT algorigthms, new jet vertex tagger Mean Number of Interactions per Crossing

0 10 20 30 40 50 60 70 80

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= 8 TeVs2012 pp

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= 13 TeVs2016 pp

= 13 TeVs2017 pp

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Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 6 / 35

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Searches in ATLAS - SUSY and EXOTICS

Model e, µ, τ, γ Jets EmissT

∫L dt[fb−1] Mass limit Reference

Incl

usiv

eS

earc

hes

3rdge

n.g

med

.3rd

gen.

squa

rks

dire

ctpr

oduc

tion

EW

dire

ctLo

ng-li

ved

part

icle

sR

PV

Other

qq, q→qχ01 0 2-6 jets Yes 36.1 m(χ0

1)<200 GeV, m(1st gen. q)=m(2nd gen. q) 1712.023321.57 TeVq

qq, q→qχ01 (compressed) mono-jet 1-3 jets Yes 36.1 m(q)-m(χ0

1)<5 GeV 1711.03301710 GeVq

gg, g→qqχ01 0 2-6 jets Yes 36.1 m(χ0

1)<200 GeV 1712.023322.02 TeVg

gg, g→qqχ±1→qqW±χ01 0 2-6 jets Yes 36.1 m(χ0

1)<200 GeV, m(χ±)=0.5(m(χ01)+m(g)) 1712.023322.01 TeVg

gg, g→qq(ℓℓ)χ01

ee, µµ 2 jets Yes 14.7 m(χ01)<300 GeV, 1611.057911.7 TeVg

gg, g→qq(ℓℓ/νν)χ01 3 e, µ 4 jets - 36.1 m(χ0

1)=0 GeV 1706.037311.87 TeVg

gg, g→qqWZχ01 0 7-11 jets Yes 36.1 m(χ0

1) <400 GeV 1708.027941.8 TeVg

GMSB (ℓ NLSP) 1-2 τ + 0-1 ℓ 0-2 jets Yes 3.2 1607.059792.0 TeVgGGM (bino NLSP) 2 γ - Yes 36.1 cτ(NLSP)<0.1 mm ATLAS-CONF-2017-0802.15 TeVgGGM (higgsino-bino NLSP) γ 2 jets Yes 36.1 m(χ0

1)=1700 GeV, cτ(NLSP)<0.1 mm, µ>0 ATLAS-CONF-2017-0802.05 TeVg

Gravitino LSP 0 mono-jet Yes 20.3 m(G)>1.8 × 10−4 eV, m(g)=m(q)=1.5 TeV 1502.01518F1/2 scale 865 GeV

gg, g→bbχ01 0 3 b Yes 36.1 m(χ0

1)<600 GeV 1711.019011.92 TeVg

gg, g→ttχ01 0-1 e, µ 3 b Yes 36.1 m(χ0

1)<200 GeV 1711.019011.97 TeVg

b1b1, b1→bχ01 0 2 b Yes 36.1 m(χ0

1)<420 GeV 1708.09266950 GeVb1

b1b1, b1→tχ±1 2 e, µ (SS) 1 b Yes 36.1 m(χ01)<200 GeV, m(χ±1 )= m(χ0

1)+100 GeV 1706.03731275-700 GeVb1

t1 t1, t1→bχ±1 0-2 e, µ 1-2 b Yes 4.7/13.3 m(χ±1 ) = 2m(χ01), m(χ0

1)=55 GeV 1209.2102, ATLAS-CONF-2016-077t1 117-170 GeV 200-720 GeVt1

t1 t1, t1→Wbχ01 or tχ0

1 0-2 e, µ 0-2 jets/1-2 b Yes 20.3/36.1 m(χ01)=1 GeV 1506.08616, 1709.04183, 1711.11520t1 90-198 GeV 0.195-1.0 TeVt1

t1 t1, t1→cχ01 0 mono-jet Yes 36.1 m(t1)-m(χ0

1)=5 GeV 1711.0330190-430 GeVt1

t1 t1(natural GMSB) 2 e, µ (Z) 1 b Yes 20.3 m(χ01)>150 GeV 1403.5222t1 150-600 GeV

t2 t2, t2→t1 + Z 3 e, µ (Z) 1 b Yes 36.1 m(χ01)=0 GeV 1706.03986290-790 GeVt2

t2 t2, t2→t1 + h 1-2 e, µ 4 b Yes 36.1 m(χ01)=0 GeV 1706.03986320-880 GeVt2

ℓL,R ℓL,R, ℓ→ℓχ01 2 e, µ 0 Yes 36.1 m(χ0

1)=0 ATLAS-CONF-2017-03990-500 GeVℓ

χ+1 χ−1 , χ+1→ℓν(ℓν) 2 e, µ 0 Yes 36.1 m(χ0

1)=0, m(ℓ, ν)=0.5(m(χ±1 )+m(χ01 )) ATLAS-CONF-2017-039750 GeVχ±

1

χ±1 χ∓1 /χ

02, χ+1→τν(τν), χ0

2→ττ(νν) 2 τ - Yes 36.1 m(χ01)=0, m(τ, ν)=0.5(m(χ±1 )+m(χ0

1)) 1708.07875760 GeVχ±1

χ±1 χ02→ℓLνℓLℓ(νν), ℓνℓLℓ(νν) 3 e, µ 0 Yes 36.1 m(χ±1 )=m(χ0

2), m(χ01)=0, m(ℓ, ν)=0.5(m(χ±1 )+m(χ0

1)) ATLAS-CONF-2017-0391.13 TeVχ±1 , χ

02

χ±1 χ02→Wχ0

1Zχ01 2-3 e, µ 0-2 jets Yes 36.1 m(χ±1 )=m(χ0

2), m(χ01)=0, ℓ decoupled ATLAS-CONF-2017-039580 GeVχ±

1 , χ02

χ±1 χ02→Wχ0

1h χ01, h→bb/WW/ττ/γγ e, µ, γ 0-2 b Yes 20.3 m(χ±1 )=m(χ0

2), m(χ01)=0, ℓ decoupled 1501.07110χ±

1 , χ02 270 GeV

χ02χ

03, χ0

2,3 →ℓRℓ 4 e, µ 0 Yes 20.3 m(χ02)=m(χ0

3), m(χ01)=0, m(ℓ, ν)=0.5(m(χ0

2)+m(χ01)) 1405.5086χ0

2,3 635 GeVGGM (wino NLSP) weak prod., χ0

1→γG 1 e, µ + γ - Yes 20.3 cτ<1 mm 1507.05493W 115-370 GeVGGM (bino NLSP) weak prod., χ0

1→γG 2 γ - Yes 36.1 cτ<1 mm ATLAS-CONF-2017-0801.06 TeVW

Direct χ+1 χ−1 prod., long-lived χ±1 Disapp. trk 1 jet Yes 36.1 m(χ±1 )-m(χ0

1)∼160 MeV, τ(χ±1 )=0.2 ns 1712.02118460 GeVχ±1

Direct χ+1 χ−1 prod., long-lived χ±1 dE/dx trk - Yes 18.4 m(χ±1 )-m(χ0

1)∼160 MeV, τ(χ±1 )<15 ns 1506.05332χ±1 495 GeV

Stable, stopped g R-hadron 0 1-5 jets Yes 27.9 m(χ01)=100 GeV, 10 µs<τ(g)<1000 s 1310.6584g 850 GeV

Stable g R-hadron trk - - 3.2 1606.051291.58 TeVgMetastable g R-hadron dE/dx trk - - 3.2 m(χ0

1)=100 GeV, τ>10 ns 1604.045201.57 TeVg

Metastable g R-hadron, g→qqχ01 displ. vtx - Yes 32.8 τ(g)=0.17 ns, m(χ0

1) = 100 GeV 1710.049012.37 TeVg

GMSB, stable τ, χ01→τ(e, µ)+τ(e, µ) 1-2 µ - - 19.1 10<tanβ<50 1411.6795χ0

1 537 GeVGMSB, χ0

1→γG, long-lived χ01 2 γ - Yes 20.3 1<τ(χ0

1)<3 ns, SPS8 model 1409.5542χ01 440 GeV

gg, χ01→eeν/eµν/µµν displ. ee/eµ/µµ - - 20.3 7 <cτ(χ0

1)< 740 mm, m(g)=1.3 TeV 1504.05162χ01 1.0 TeV

LFV pp→ντ + X, ντ→eµ/eτ/µτ eµ,eτ,µτ - - 3.2 λ′311=0.11, λ132/133/233=0.07 1607.080791.9 TeVντ

Bilinear RPV CMSSM 2 e, µ (SS) 0-3 b Yes 20.3 m(q)=m(g), cτLS P<1 mm 1404.2500q, g 1.45 TeVχ+1 χ

−1 , χ+1→Wχ0

1, χ01→eeν, eµν, µµν 4 e, µ - Yes 13.3 m(χ0

1)>400GeV, λ12k,0 (k = 1, 2) ATLAS-CONF-2016-0751.14 TeVχ±1

χ+1 χ−1 , χ+1→Wχ0

1, χ01→ττνe, eτντ 3 e, µ + τ - Yes 20.3 m(χ0

1)>0.2×m(χ±1 ), λ133,0 1405.5086χ±1 450 GeV

gg, g→qqχ01, χ0

1 → qqq 0 4-5 large-R jets - 36.1 m(χ01)=1075 GeV SUSY-2016-221.875 TeVg

gg, g→ttχ01, χ0

1 → qqq 1 e, µ 8-10 jets/0-4 b - 36.1 m(χ01)= 1 TeV, λ112,0 1704.084932.1 TeVg

gg, g→t1t, t1→bs 1 e, µ 8-10 jets/0-4 b - 36.1 m(t1)= 1 TeV, λ323,0 1704.084931.65 TeVg

t1 t1, t1→bs 0 2 jets + 2 b - 36.7 1710.07171100-470 GeVt1 480-610 GeVt1

t1 t1, t1→bℓ 2 e, µ 2 b - 36.1 BR(t1→be/µ)>20% 1710.055440.4-1.45 TeVt1

Scalar charm, c→cχ01 0 2 c Yes 20.3 m(χ0

1)<200 GeV 1501.01325c 510 GeV

Mass scale [TeV]10−1 1

√s = 7, 8 TeV

√s = 13 TeV

ATLAS SUSY Searches* - 95% CL Lower LimitsDecember 2017

ATLAS Preliminary√s = 7, 8, 13 TeV

*Only a selection of the available mass limits on new states orphenomena is shown. Many of the limits are based onsimplified models, c.f. refs. for the assumptions made.

Model ℓ, γ Jets† EmissT

∫L dt[fb−1] Limit Reference

Ext

radi

men

sion

sG

auge

boso

nsC

ID

MLQ

Hea

vyqu

arks

Exc

ited

ferm

ions

Oth

er

ADD GKK + g/q 0 e, µ 1 − 4 j Yes 36.1 n = 2 ATLAS-CONF-2017-0607.75 TeVMD

ADD non-resonant γγ 2 γ − − 36.7 n = 3 HLZ NLO CERN-EP-2017-1328.6 TeVMS

ADD QBH − 2 j − 37.0 n = 6 1703.092178.9 TeVMth

ADD BH high∑pT ≥ 1 e, µ ≥ 2 j − 3.2 n = 6, MD = 3 TeV, rot BH 1606.022658.2 TeVMth

ADD BH multijet − ≥ 3 j − 3.6 n = 6, MD = 3 TeV, rot BH 1512.025869.55 TeVMth

RS1 GKK → γγ 2 γ − − 36.7 k/MPl = 0.1 CERN-EP-2017-1324.1 TeVGKK mass

Bulk RS GKK →WW → qqℓν 1 e, µ 1 J Yes 36.1 k/MPl = 1.0 ATLAS-CONF-2017-0511.75 TeVGKK mass

2UED / RPP 1 e, µ ≥ 2 b, ≥ 3 j Yes 13.2 Tier (1,1), B(A(1,1) → tt) = 1 ATLAS-CONF-2016-1041.6 TeVKK mass

SSM Z ′ → ℓℓ 2 e, µ − − 36.1 ATLAS-CONF-2017-0274.5 TeVZ′ mass

SSM Z ′ → ττ 2 τ − − 36.1 ATLAS-CONF-2017-0502.4 TeVZ′ massLeptophobic Z ′ → bb − 2 b − 3.2 1603.087911.5 TeVZ′ massLeptophobic Z ′ → tt 1 e, µ ≥ 1 b, ≥ 1J/2j Yes 3.2 Γ/m = 3% ATLAS-CONF-2016-0142.0 TeVZ′ mass

SSM W ′ → ℓν 1 e, µ − Yes 36.1 1706.047865.1 TeVW′ massHVT V ′ →WV → qqqq model B 0 e, µ 2 J − 36.7 gV = 3 CERN-EP-2017-1473.5 TeVV′ massHVT V ′ →WH/ZH model B multi-channel 36.1 gV = 3 ATLAS-CONF-2017-0552.93 TeVV′ massLRSM W ′

R → tb 1 e, µ 2 b, 0-1 j Yes 20.3 1410.41031.92 TeVW′ massLRSM W ′

R → tb 0 e, µ ≥ 1 b, 1 J − 20.3 1408.08861.76 TeVW′ mass

CI qqqq − 2 j − 37.0 η−LL 1703.0921721.8 TeVΛ

CI ℓℓqq 2 e, µ − − 36.1 η−LL ATLAS-CONF-2017-02740.1 TeVΛ

CI uutt 2(SS)/≥3 e,µ ≥1 b, ≥1 j Yes 20.3 |CRR | = 1 1504.046054.9 TeVΛ

Axial-vector mediator (Dirac DM) 0 e, µ 1 − 4 j Yes 36.1 gq=0.25, gχ=1.0, m(χ) < 400 GeV ATLAS-CONF-2017-0601.5 TeVmmed

Vector mediator (Dirac DM) 0 e, µ, 1 γ ≤ 1 j Yes 36.1 gq=0.25, gχ=1.0, m(χ) < 480 GeV 1704.038481.2 TeVmmed

VVχχ EFT (Dirac DM) 0 e, µ 1 J, ≤ 1 j Yes 3.2 m(χ) < 150 GeV 1608.02372700 GeVM∗

Scalar LQ 1st gen 2 e ≥ 2 j − 3.2 β = 1 1605.060351.1 TeVLQ mass

Scalar LQ 2nd gen 2 µ ≥ 2 j − 3.2 β = 1 1605.060351.05 TeVLQ mass

Scalar LQ 3rd gen 1 e, µ ≥1 b, ≥3 j Yes 20.3 β = 0 1508.04735640 GeVLQ mass

VLQ TT → Ht + X 0 or 1 e, µ ≥ 2 b, ≥ 3 j Yes 13.2 B(T → Ht) = 1 ATLAS-CONF-2016-1041.2 TeVT mass

VLQ TT → Zt + X 1 e, µ ≥ 1 b, ≥ 3 j Yes 36.1 B(T → Zt) = 1 1705.107511.16 TeVT mass

VLQ TT →Wb + X 1 e, µ ≥ 1 b, ≥ 1J/2j Yes 36.1 B(T →Wb) = 1 CERN-EP-2017-0941.35 TeVT mass

VLQ BB → Hb + X 1 e, µ ≥ 2 b, ≥ 3 j Yes 20.3 B(B → Hb) = 1 1505.04306700 GeVB mass

VLQ BB → Zb + X 2/≥3 e, µ ≥2/≥1 b − 20.3 B(B → Zb) = 1 1409.5500790 GeVB mass

VLQ BB →Wt + X 1 e, µ ≥ 1 b, ≥ 1J/2j Yes 36.1 B(B →Wt) = 1 CERN-EP-2017-0941.25 TeVB massVLQ QQ →WqWq 1 e, µ ≥ 4 j Yes 20.3 1509.04261690 GeVQ mass

Excited quark q∗ → qg − 2 j − 37.0 only u∗ and d∗, Λ = m(q∗) 1703.091276.0 TeVq∗ mass

Excited quark q∗ → qγ 1 γ 1 j − 36.7 only u∗ and d∗, Λ = m(q∗) CERN-EP-2017-1485.3 TeVq∗ mass

Excited quark b∗ → bg − 1 b, 1 j − 13.3 ATLAS-CONF-2016-0602.3 TeVb∗ massExcited quark b∗ →Wt 1 or 2 e, µ 1 b, 2-0 j Yes 20.3 fg = fL = fR = 1 1510.026641.5 TeVb∗ massExcited lepton ℓ∗ 3 e, µ − − 20.3 Λ = 3.0 TeV 1411.29213.0 TeVℓ∗ massExcited lepton ν∗ 3 e,µ, τ − − 20.3 Λ = 1.6 TeV 1411.29211.6 TeVν∗ mass

LRSM Majorana ν 2 e, µ 2 j − 20.3 m(WR ) = 2.4 TeV, no mixing 1506.060202.0 TeVN0 massHiggs triplet H±± → ℓℓ 2,3,4 e,µ (SS) − − 36.1 DY production ATLAS-CONF-2017-053870 GeVH±± massHiggs triplet H±± → ℓτ 3 e,µ, τ − − 20.3 DY production, B(H±±

L→ ℓτ) = 1 1411.2921400 GeVH±± mass

Monotop (non-res prod) 1 e, µ 1 b Yes 20.3 anon−res = 0.2 1410.5404657 GeVspin-1 invisible particle mass

Multi-charged particles − − − 20.3 DY production, |q| = 5e 1504.04188785 GeVmulti-charged particle mass

Magnetic monopoles − − − 7.0 DY production, |g | = 1gD , spin 1/2 1509.080591.34 TeVmonopole mass

Mass scale [TeV]10−1 1 10√s = 8 TeV

√s = 13 TeV

ATLAS Exotics Searches* - 95% CL Upper Exclusion LimitsStatus: July 2017

ATLAS Preliminary∫L dt = (3.2 – 37.0) fb−1

√s = 8, 13 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).

→ usually we have exclusions up to 1 TeV, but room still left for discoveries!

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 7 / 35

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X → WW → eνµν

Search for heavy resonances decaying into WW in the eνµν channel in pp collisions at√s = 13 TeV with the ATLAS detector

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 8 / 35

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X→ WW - Introduction

many BSM models predict new resonances

sensitive mass range: 200-4000 GeV

Heavy Higgs models:Higgs with a Narrow Width approximation (NWA) Γ ≈ 4 MeVHiggs with a Large Width assumption (LWA) Γ = 5%, 10% and 15% of mH

new heavy resonance models:Georgi-Machacek (GM) model (VBF GM)Heavy Vector Triplet (HVT): includes qqF and VBFbulk Randall-Sundrum graviton model with spin-2 Graviton (RS-G*)spin-2 signal in the VBF production (spin-2 VBF)

Model Resonance spin Production modeggF qqA VBF

NWA Spin-0 x x2HDM x xLWA x xGM xHVT Spin-1 x x

Bulk RS Spin-2 xELM x

g

X

g

WW,Z

W,Z W

q

W +

W q

qW+

Wq

+

__

X

_

X

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 9 / 35

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X→ WW - Data and Main backgrounds

→ using data collected by ATLAS at√s = 13 TeV, total of 36.1 fb−1

→ Monte Carlo events used for signal modelling and background estimations

Main backgrounds:

top quark: single t and tt

diboson production: WW , WZ and ZZ

Z+jets

W+jets

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 10 / 35

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X→ WW - Event selection

Signal regions

VBF 1-jet: Njet = 1, ηjet > 2.4,min(|∆ηl ,jet |) > 1.75

VBF 2-jet: Njet ≥ 2, mjj > 500 GeV,|∆yjj | > 4

these are excluded from thequasi-inclusive ggF signal region

Control regions - cut definition

|η``|(m``) defines the WW CR, alsoimproves sensitivity in SR

max(mWT ) and psubleadT reduce Wjets and

Zjets contributions

cuts in VBF 1jet phase space are used togain sensitivity

psubleadT also improves WW puritySRggF SRVBF1J SRVBF2J

Common selectionsNb-tag = 0|∆η``| < 1.8m`` > 55GeV

p`,leadT > 45GeV

p`,subleadT > 30GeV

veto if p`,otherT > 15GeVmax(mW

T ) > 50GeVggF phase space VBF1J phase space VBF2J phase space

Inclusive in Njet but excluding Njet = 1 and Njet ≥ 2 andVBF1J and VBF2J phase space |ηj | > 2.4, min(|∆ηj`|) > 1.75 mjj > 500GeV, |∆yjj | > 4

SRggF SRVBF1J SRVBF2J

Common selectionsNb-tag = 0|∆η``| < 1.8m`` > 55GeV

p`,leadT > 45GeV

p`,subleadT > 30GeV

veto if p`,otherT > 15GeVmax(mW

T ) > 50GeVggF phase space VBF1J phase space VBF2J phase space

Inclusive in Njet but excluding Njet = 1 and Njet ≥ 2 andVBF1J and VBF2J phase space |ηj | > 2.4, min(|∆ηj`|) > 1.75 mjj > 500GeV, |∆yjj | > 4

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 11 / 35

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X→ WW - Analysis strategy

discriminating variable: transverse mass

mT =√

(E ``T + EmissT )2 − |p``T + Emiss

T |2, where

E ``T =√|p``T |2 + m2

``

both normalization and shape of mT have to beestimated

shape: modelled using MC events

top and WW normalizations are determined froma simultaneous fit to the data in mT binneddistributions in the SR and total event yields in CR

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 12 / 35

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X→ WW - Leading lepton pT correction

normalization of the top-quark background is determined in the Top CR (ggF)

one b-tagged jet, 97% purity of background in this CR

leading lepton pT disagreement between data and MC

correction proposed: linear reweighting of 4-10% for 50-200 GeV

Eve

nts

/ GeV

3−10

2−10

1−10

1

10

210

310

410

510 Data stat)⊕SM(sys

Top x 0.99 Other VV

WW x 1.15 ggF NWA 700

W+jets ggF NWA 2000

Z+jets

ATLAS-1 = 13 TeV, 36.1 fbs

ggF Top CRνµν e→WW→X

[GeV]Tm200 400 600 800 1000 1200

Dat

a / S

M

0.5

1

1.5E

vent

s / G

eV

3−10

2−10

1−10

1

10

210

310

410

510 Data stat)⊕SM(sys

Top x 0.99 Other VV

WW x 1.15 ggF NWA 700

W+jets ggF NWA 2000

Z+jets

ATLAS-1 = 13 TeV, 36.1 fbs

ggF Top CRνµν e→WW→X

[GeV]Tm200 400 600 800 1000 1200

Dat

a / S

M

0.5

1

1.5

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 13 / 35

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X→ WW - Post-fit distributionsE

vent

s / G

eV

3−10

2−10

1−10

1

10

210

310

410

510 Data stat)⊕SM(sys

WW x 1.14 Other VV

Top x 0.96 ggF NWA 700

Z+jets ggF NWA 2000

W+jets

ATLAS-1 = 13 TeV, 36.1 fbs

ggF SRνµν e→WW→X

[GeV]Tm210 310

Dat

a / S

M

0.5

1

1.5

Eve

nts

/ GeV

3−10

2−10

1−10

1

10

210

310

410

Data stat)⊕SM(sys

WW x 1.00 Other VV

Top x 1.12 VBF NWA 700

Z+jets VBF NWA 2000

W+jets

ATLAS-1 = 13 TeV, 36.1 fbs

+ 1 jet VBF SRνµν e→WW→X

[GeV]Tm210 310

Dat

a / S

M

0.5

1

1.5

Eve

nts

/ GeV

3−10

2−10

1−10

1

10

210

310Data stat)⊕SM(sys

Top x 1.12 W+jets

WW x 1.00 VBF NWA 700

Z+jets VBF NWA 2000

Other VV

ATLAS-1 = 13 TeV, 36.1 fbs

2 jets VBF SR≥ + νµν e→WW→X

[GeV]Tm210 310

Dat

a / S

M

0.5

1

1.5

Signal yields in data and MC →

SRggF Top CRggF WW CRggF

WW 11 500 ± 800 820 ± 120 3 360 ± 220Top quark 11 800 ± 600 52 550 ± 330 2 610 ± 180Z/γ* 1 420 ± 110 111 ± 20 20.9 ± 2.0W+jets 1 180 ± 320 710 ± 190 280 ± 70V V 866 ± 34 101 ± 12 250 ± 11Background 26 740 ± 170 54 290 ± 250 6 510 ± 80Data 26 739 54 295 6 515

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 14 / 35

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X→ WW - Systematic uncertainties

→ dominant uncertainties: jet energy scale, resolution and b-tagging→ for VBF 2-jet, uncertainty on MC modelling is comparable to exp. uncertainties

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 15 / 35

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X→ WW - Results (NWA)

95% CL upper limits computed using modified frequentist method CLS

test statstic qµ, signal strength µ defined asratio of the measured σX × B(X →WW ) to the prediction

qµ = −2 ln(L(µ;θµ)L(µ;θ)

)

Limits:

[GeV]H m

500 1000 1500 2000 2500 3000 3500 4000

WW

) [p

b]→

B(H

× Hσ

2−10

1−10

1

10Observed 95% CL

Expected 95% CL

σ 1±

σ 2± (ggF, NWA)νµν e→ WW→H

ATLAS-1 = 13 TeV, 36.1 fbs

[GeV]H m

500 1000 1500 2000 2500 3000 W

W)

[pb]

→ B

(H×

2−10

1−10

1

10Observed 95% CL

Expected 95% CL

σ 1±

σ 2± (VBF, NWA)νµν e→ WW→H

ATLAS-1 = 13 TeV, 36.1 fbs

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 16 / 35

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X→ WW - Results (NWA)

95% CL upper limits computed using modified frequentist method CLS

test statstic qµ, signal strength µ defined asratio of the measured σX × B(X →WW ) to the prediction

qµ = −2 ln(L(µ;θµ)L(µ;θ)

)

Exclusion regions (for a 200 GeV 2HDM signal):

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

ATLAS = 13 TeVs

-136.1 fb

=200 GeV±H=mA=mHWW m→H2HDM Type I

Observed 95% CL σ1±Expected 95% CL σ2±Excluded

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

ATLAS = 13 TeVs

-136.1 fb

=200 GeV±H=mA=mHWW m→H2HDM Type II

Observed 95% CL σ1±Expected 95% CL σ2±Excluded

)α-βcos(

0.8− 0.6− 0.4− 0.2− 0 0.2 0.4 0.6 0.8

βta

n

1−10

1

10

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 17 / 35

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X→ WW - Results (NWA)

95% CL upper limits computed using modified frequentist method CLS

test statstic qµ, signal strength µ defined asratio of the measured σX × B(X →WW ) to the prediction

qµ = −2 ln(L(µ;θµ)L(µ;θ)

)

Exclusion regions as a function of mX :

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10ATLAS

= 13 TeVs-136.1 fb

) = -0.1α-βWW cos (→H2HDM Type I

Observed 95% CL σ1±Expected 95% CL σ2±Excluded

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10ATLAS

= 13 TeVs-136.1 fb

) = -0.1α-βWW cos (→H2HDM Type II

Observed 95% CL σ1±Expected 95% CL σ2±Excluded

[GeV]Hm

200 220 240 260 280 300 320 340 360 380 400

βta

n

1−10

1

10

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 18 / 35

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X→ WW - Results (LWA ggF - left, VBF -right)

[GeV]H m

500 1000 1500 2000 2500 3000 3500 4000

WW

) [p

b]→

B(H

× Hσ

2−10

1−10

1

10Observed 95% CL

Expected 95% CL

σ 1±

σ 2± (ggF, 15% LWA)νµν e→ WW→H

ATLAS-1 = 13 TeV, 36.1 fbs

[GeV]H m

500 1000 1500 2000 2500 3000

WW

) [p

b]→

B(H

× Hσ

2−10

1−10

1

10Observed 95% CL

Expected 95% CL

σ 1±

σ 2± (VBF, 15% LWA)νµν e→ WW→H

ATLAS-1 = 13 TeV, 36.1 fbs

[GeV]H m

500 1000 1500 2000 2500 3000 3500 4000

WW

) [p

b]→

B(H

× Hσ

2−10

1−10

1

10 Obs. 5% LWA

Exp. 5% LWA

Obs. 10% LWA

Exp. 10% LWA

Obs. 15% LWA

Exp. 15% LWA

95% CL limits

(ggF , LWA)νµν e→ WW→H

ATLAS-1 = 13 TeV, 36.1 fbs

[GeV]H m

500 1000 1500 2000 2500 3000

WW

) [p

b]→

B(H

× Hσ

2−10

1−10

1

10 Obs. 5% LWA

Exp. 5% LWA

Obs. 10% LWA

Exp. 10% LWA

Obs. 15% LWA

Exp. 15% LWA

95% CL limits

(VBF , LWA)νµν e→ WW→H

ATLAS-1 = 13 TeV, 36.1 fbs

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 19 / 35

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X→ WW - Results - other models

[GeV]X m

200 300 400 500 600 700 800 900 1000

WW

) [p

b]→

B(X

× Xσ

2−10

1−10

1

10=0.4HθGM, sin

Observed 95% CL

Expected 95% CL

σ 1±

σ 2±

(VBF, GM)νµν e→ WW→X

ATLAS-1 = 13 TeV, 36.1 fbs

[GeV]X m

200 300 400 500 600 700 800 900 1000

Hθ s

in

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

=0.4HθGM, sinObserved 95% CLExpected 95% CL

σ 1±σ 2±

(VBF, GM)νµν e→ WW→X

ATLAS-1 = 13 TeV, 36.1 fbs

[GeV]X m

1000 2000 3000 4000 5000

WW

) [p

b]→

B(X

× Xσ

2−10

1−10

1

10 =1v

HVT, g

Observed 95% CL

Expected 95% CL

σ 1±

σ 2±

(qqA, HVT)νµν e→ WW→X

ATLAS-1 = 13 TeV, 36.1 fbs

[GeV]X m

300 400 500 600 700 800 900 1000

WW

) [p

b]→

B(X

× Xσ

1−10

1

10=0

F=1, c

vHVT, g

Observed 95% CL

Expected 95% CL

σ 1±

σ 2±

(VBF, HVT)νµν e→ WW→X

ATLAS-1 = 13 TeV, 36.1 fbs

[GeV]X m

0 1000 2000 3000 4000 5000

WW

) [p

b]→

B(X

× Xσ

2−10

1−10

1

10

210 = 1.0PlMBulk RS, k/

Observed 95% CL

Expected 95% CL

σ 1±

σ 2±

(ggF, Bulk RS)νµν e→ WW→X

ATLAS-1 = 13 TeV, 36.1 fbs

[GeV]X m

0 1000 2000 3000 4000 5000

WW

) [p

b]→

B(X

× Xσ

2−10

1−10

1

10

210 = 0.5PlMBulk RS, k/

Observed 95% CL

Expected 95% CL

σ 1±

σ 2±

(ggF, Bulk RS)νµν e→ WW→X

ATLAS-1 = 13 TeV, 36.1 fbs

[GeV]X m

200 300 400 500 600 700 800 900 1000

WW

) [p

b]→

B(X

× Xσ

1−10

1

10=1i

ELM, f

Observed 95% CL

Expected 95% CL

σ 1±

σ 2±

(VBF, ELM)νµν e→ WW→X

ATLAS-1 = 13 TeV, 36.1 fbs

→ unfortunately, no excess is observed, but significant portions of the phase space areexcluded in some models

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 20 / 35

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X→ WW - Conclusions and prospects

no significant excess has been found

exclusions:

narrow width above 6.5 pb at mH = 200 GeV, above 0.008 pb at 4 TeV for ggF

VBF: above 1.3 pb at mH = 200 GeV and above 0.006 pb at 4 TeV

heavy vector triplet model excluded below 1.3 TeV

Randall-Sundrum graviton with k/MPl = 1 excluded below 1.1 TeV

Randall-Sundrum graviton with k/MPl = 0.5 excluded below 750 GeV

analysis will be soon repeated with new 2018 data

STAY TUNED!

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 21 / 35

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X → γγ

Search for new phenomena at high-mass in the diphoton final state at√s = 8 and 13 TeV

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 22 / 35

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X→ γγ - Introduction (8 TeV Run1)

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 23 / 35

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X→ γγ - Signal modelling (8 TeV Run1)

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 24 / 35

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X→ γγ - Results (8 TeV Run1)

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 25 / 35

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X→ γγ - Run 2, 13 TeV analysis

Changes wrt Run1 analysis:

36.7 fb−1 13 TeV ATLAS data

selection split to two categories - optimized spin 0 and spin 2 selection

spin 0: relative photon pT cuts of EγT > 0.4mγγ leading (0.3 subleading) photon,background functional form

spin 2: EγT > 55 GeV, backround: NLO prediction of spectrum shape

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 26 / 35

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X→ γγ - mγγ distributions for spin-0 and spin-2 selection

500 1000 1500 2000 2500

Eve

nts

/ 20

GeV

1−10

1

10

210

310

410

510ATLAS

Spin-0 Selection-1 = 13 TeV, 36.7 fbs

Data

Background-only fit

[GeV]γγm500 1000 1500 2000 2500

Dat

a -

fitte

d ba

ckgr

ound

10−

5−0

5

10

15500 1000 1500 2000 2500

Eve

nts

/ 20

GeV

1−10

1

10

210

310

410

510ATLAS

Spin-2 Selection-1 = 13 TeV, 36.7 fbs

Data

Background-only fit

[GeV]γγm500 1000 1500 2000 2500

Dat

a -

fitte

d ba

ckgr

ound

10−

5−0

5

10

15

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 27 / 35

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X→ γγ - 2D p-value scan

→ scanning the mass of a new resonance and as well as the width or k/MPl parameter

[GeV]Xm500 1000 1500 2000 2500

[%]

Xm/

0

2

4

6

8

10

]σ [ 0Lo

cal p

0

0.5

1

1.5

2

2.5

3

Spin-0 Selection-1 = 13 TeV, 36.7 fbs ATLAS

[GeV]G*m500 1000 1500 2000 2500

Pl

M/k

0.05

0.1

0.15

0.2

0.25

0.3 ]σ [ 0Lo

cal p

0

0.5

1

1.5

2

2.5

3

Spin-2 Selection-1 = 13 TeV, 36.7 fbs ATLAS

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 28 / 35

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X→ γγ - p-value

→ famous bump at 700-750 GeV in the resonance search- almost a discovery, until new data came - just a fluctuation :(

[GeV]Xm

0 500 1000 1500 2000 2500

Lo

ca

l p-v

alu

e

5−10

4−10

3−10

2−10

1−10

1

ATLAS-1= 13 TeV, 36.7 fbs

Spin-0 Selection

= 10%Xm/X

Γ, γγ→X

)-12015 (3.2 fb

)-12016 (33.5 fb

Combination

σ0

σ1

σ2

σ3

σ4

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 29 / 35

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X→ γγ - exclusion limits

[GeV]Xm

500 1000 1500 2000 2500

B [f

b]×

fidσ95

% C

L U

pper

Lim

it on

1−10

1

10

210Spin-0 Selection

= 4 MeV)XΓNWA (

ATLAS-1 = 13 TeV, 36.7 fbs

limitsObserved CL limit

sExpected CL

σ 1±Expected σ 2±Expected

[GeV]G*m500 1000 1500 2000 2500 3000 3500 4000 4500 5000

B [f

b]× σ

95%

CL

Upp

er L

imit

on

2−10

1−10

1

10

210

310 limitsObserved CL limit

sExpected CL

σ 1±Expected σ 2±Expected

γγ→G*→pp limitsObserved CL

from pseudo-exp. limit

sExpected CLfrom pseudo-exp.

Spin-2 Selection = 0.10PlM/k, γγ→G*

ATLAS-1 = 13 TeV, 36.7 fbs

→ STAY TUNED for new analysis coming out very soon - low mass result! (USTC ATLASgroup is taking part - work lead by Yanwen Liu and Asma Hadef)

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 30 / 35

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Next level - automation:General Searches

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 31 / 35

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General search

preliminary result with 3.2 fb−1, full 13 TeV dataset paper coming out soon!ATLAS developed an algorithm to look for excesses - a framework that classifies dataevents, compares to MC and provides results as p-values or standard deviationslooking at invariant or effective mass (depends on channel)639 final states investigated (up to 700 for the upcoming paper)

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810Data 2015 3-/4-top Higgs +Z/W/WWtt γ+tt single top

di-/triboson )γ(γZ/W+ +jetstt )+jetsγ(γ Z/W+jets multijets

ATLAS Preliminary-1 = 13 TeV, 3.21 fbs

dijet and multijet

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 32 / 35

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General search

How many excesses should we see?

probability that a deviation of a given sizeoccurs is modeled by pseudo-experiments

fraction of pseudo-experiments that predict atleast one, two or three event classes withdeviations below a given p-value in the scan ofminv and meff

lowest p-value found for 1m1e4b2j channel(5.10−4)

consistent at 70% level with SM expectationfrom pseudo experiment study

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ATLAS Preliminary-1 = 13 TeV, 3.21 fbs

invvariable: m

pseudo experiments 1 class≥ 2 classes≥ 3 classes≥

Data

pseudo experiments SM-onlyincluding syst. correlations

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 33 / 35

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Summary and plans

ATLAS continues to collect data, 2018 data-taking just started

the collaboration works tirelessly on ensuring detector safety andpublishing physics analyses

more searches coming out very soon!personal plan:

repeat the H → WW search with new dataworking on a generic Z+X search, where Z serves as a tag, and X can beanything - many channels investigated

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 34 / 35

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Thank you for your attention :)

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 35 / 35

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BONUS

→ a 3.6σ excess in ZZ

Zuzana Barnovska-Blenessy (USTC, ATLAS) High-mass searches in ATLAS May the 4th be with you 36 / 35