New physics searches with Z(ll) + X + ET

miss final state

N. Panikashvili and D. Harper

University of Michigan, US

General Gauge Mediation (GGM) - motivation• effort to formulate gauge mediation in the

model independent way• there is no hierarchy between M of colored

states (squarks, gluinos) and uncolored states (wino, bino, higgsinos, sleptons). The discovery of GGM becomes possibile even with early LHC data in regions of parameter space not probed by any Tevatron searches

• At gauge mediation• LSP is gravitino• NLSP is lightest neutralino, stau ….

• Neutralino is mixture of bino, wino and higgsinos

• If Neutralino is higgsino like, it decays to ~X1 Z + ~G or ~X1 h + ~G and leads to the final states such asZZ+MET, Zh+MET …

• We concentrate on the final state: Z(ll) + jets + MET

Thanks to Shih/Ruderman ArXiv 0911.4130

Tevatron limits:

Z(ll) + jets + METJets + MET

GGM higgsino – like neutralino grid production

• 40 points (50K each one) which cover M(gluino) from 300GeV to 700GeV and M(higgsinos) from 110GeV up to 690GeV

• Parameters of production:

• EF: at least one Zll• Details of the grid:

• Mass spectrum, LO cross sections, filter efficiency, details of production:

https://twiki.cern.ch/twiki/bin/view/AtlasProtected/GGMHiggsinoZGrid

M1 1TeV

M2 1TeV

vary, >0

tan() 1.5

c NLSP 0.1mm

Thanks to Shih/Ruderman ArXiv 0911.4130

GGM grid – different production mechanism

• We investigated the kinematics of the following points we selected 4 points:• M(~g) =300GeV, M(~h)=120GeV• M(~g) =700GeV, M(~h)=120GeV• M(~g) =300GeV, M(~h)=290GeV

• M(~g) =700GeV, M(~h)=690GeV

M(~g)

M(higgsino)

300GeV

120GeV

700GeV

120GeV

300GeV

290GeV

700GeV

690GeV

Electro

weak

f+fbar ~chi1 + ~chi2

<10%

17%

0 <2%f+fbar ~chi+-1 +~chi-+1 18.2%

q+qbar' ~chi1 +~chi+-1 34.4%

q+qbar' ~chi2 +~chi+-1 28.6%

Strongq + qbar -> ~g + ~g  12.9%

<2%14% 33%

g + g -> ~g + ~g 78.6% 86% 65.8%

Dominant production:strong

qqbar~g~g, gg~g~g

Dominant production:electroweak

MC signal cross - section

Fraction of the gluino-gluino pair production

0

0.2

0.4

0.6

0.8

1

1.2

100 200 300 400 500 600 700 800

M(higgsino) GeV

Fra

ctio

n

M(~g) = 300GeV

M(~g) = 400GeV

M(~g) = 500GeV

M(~g) = 600GeV

M(~g) = 700GeV

Fraction of strong vs. weak production for M(~g) = 600 GeV

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

50 100 150 200 250 300 350 400 450 500 550 600 650

M(higgsino) GeV

Fra

ctio

n

gg

total weak prod

neutralino-neutralino

chargino-chargino

neutralino-chargino

NLO cross section

0.01

0.1

1

10

100

0 100 200 300 400 500 600 700 800

M(higgsino) GeV

NL

O c

ross

se

ctio

n *

filt

er

(pb

)

M(~g)=300GeV

M(~g)=400GeV

M(~g)=500GeV

M(~g)=600GeV

M(~g)=700GeV

• Prospino 2

• NLO was calculated using 4 different processes

Event Selection (need an update for 1fb-1)• We are using Standard SUSY di-lepton selection• In addition we require 81GeV < M(ll) < 101GeV, which defines our preselection

• Electrons (1fb-1)

• Muons (689.3pb-1)

Data

Total SM

Z+jets

DrellYan

W+jets

Ttbar

Single top

Dibosons

EE 238389 236541.5 ± 151.5 232709.5±11.7 932.8±37.2 1588.0±37.9

764.1±6.4

78.0±1.0

469.1±3.4

OS

227955 228863.6 ± 147.2 225861.8±139.6

887.9±36.1 900.8±28.5 703.9±6.1 70.35±0.96

438.8±3.3

M>12GeV

226416

228731.8 ± 146.1

225856.9±139.6

782.9±31.4 887.6±28.4

703.90±6.1369.58±0.95

438.8±3.3

Signal leptons

160166 148397.2 ± 115.8 147067.9±112.8

507.4±26.1

21.96±3.08

703.9±6.1 39.6±0.7

438.8±3.3

Z(ee)

136732 129205 ± 154.08 128949 ±155.23

- 4.1 ± 0.9 72.96 ± 2.58 6.4 ± 0.4 172.8±1.6

Data

SM Z+jets

DrellYan

W+jets

Ttbar

Single top

Dibosons

345773

284155.9 191.9 272271.3 153.2

10007.5113.7 303.019.0

914.2 7.0

102.8 1.2

556.23.7

OS

343829

284011.5 191.7

272260.0 153.2

10000.7113.7

224.116.4

883.6 6.9

97.8 1.1

545.23.7

M>12GeV 312151 282916.4 182.9 272248.8153.2

8943.3 98.3

215.016.0

871.8 6.8

96.2 1.1

541.33.7

Signal leptons

299183

275800.6 180 265502.3 151.3

8783.2 97.6

85.4 10.2

820.4 6.6

85.63 523.7 3.6

Z() 240947 225372. 192.2224961.0 193.6

-3.3 0.7

107.9 2.9

12.4 0.5 287.8 1.9

pre-selection results: efficiency of the MC signal

OS EE tight + ISO + mass (17% - 45%) OS MM tight + ISO + mass (6% - 45%)

• Different efficiencies due to different pT spectra

• Different pT cuts: pT = 8GeV/10 GeV, pTleading = 20GeV/25 GeV muons/electrons

Efficien

cy (%)

Efficien

cy (%)

pre-selection results (MET)

• MET depends on the mass of NLSP, the lower mass the lower MET

Large MET region

Signal region 1: MET > 200GeV + inclusive leptons

Efficiency (%)S/√B

• Significance S/√B

Z(ee)+MET>150GeVN(data) = 5N(SM) = 3.1 0.2

pre-selection results (N jets)

• Not optimal variable for the GGM searches with dominant weak production mechanism: M(~g) = 700GeV and M(~h) =120GeV

Leading jet pT

Sub-leading jet pT

Signal region 2: MET > 100GeV, Njets>3

• Improve of the significance in certain regionS/√BEfficiency (%)

Z(ee)+MET>100GeVN jets>3N(data) = 20N(SM) = 13.6 0.5

• N(SM) – is from MC only: ttbar, dibosons, single top, inclusive Z• Errors are statistical only

pre-selection results (HT)

• HT is useful for points with high M(NLSP) and M(~g)

Signal region3: MET>150GeV HT>350GeV

N(data) = 7N(SM) = 4.1 0.2

Effective Mass

Leading lepton pT

N of leptons

Plans

• Background estimation - • Systematic • Enlarge GGM parameter space for the case of Wino

• submitted