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ATGC study in ZmumuGamma channel

L. Han, L.HE, Suen.H, M.Liu, H.SongIPAS&USTC

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Generation of ATGC samples- BAUR NLO

• With BAUR NLO package, we generate 61 sample with H30(ϒ) from -0.03 – 0.03 with step 0.001 pt(γ) > 45GeV, |η(ϒ)|<2.37 ; pt(l) > 25GeV, |η(l)|<2.47 ; pt(jet)>20GeV, |η(jet)|<3.0 ; dR(l,ϒ) > 0.7 ; M(llϒ)>100GeV; =2TeV efract =0.5 used pdf: cteq6m

• Data: period D-H(~ 1 fb-1) using tag p605 use exactly the same event selection except: pt_gamma >45GeV M(μμϒ)>100GeV

Use H30(ϒ) for an example

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BinningWe binned pT_ϒ to 2 bins- 45GeV to 60 GeV and 60GeV above.

We use 45GeV<pT_ϒ<60GeV as normalization

We use pT_ϒ>60GeV to fit with data

Use H30(ϒ) for an example

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Normalization – 45GeV<pT_ϒ<60GeVUse H30(ϒ) for an example

H30(ϒ)

σ(ATGC)/σ(SM) in 45GeV<pT_ϒ<60GeV

1. SM dominate in 45GeV to 60GeV2. εϒ in (45GeV,60GeV) and (>60GeV) region almost sameWe normalize MC’s 45GeV – 60GeV bin to data.

Likelihood Fitting method

Vtot: expected eventsni: observed events in ith bin

We calculate the likelihood of data and MC in pT_ϒ>60GeV with different H30(ϒ). when a polynomial is fitted to the array of negative logarithmic likelihood values

1

( , ) ( , )N

tot tot toti

Log L Log L

σ changes little with different H30ϒ parameter in 45 GeV- 60 GeV. We can negalect ATGC in this region.

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H30_ϒResult of H30_ϒ:

-0.029<h30(ϒ)<0.030With 95%CL

H30(ϒ)

σ(ATGC)/σ(SM) in 45GeV<pT_ϒ<60GeV

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H30_ZResult of H30_Z:

-0.023<h30(Z)<0.024With 95%CL

H30(Z)

σ(ATGC)/σ(SM) in 45GeV<pT_ϒ<60GeV

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*10-3

H40_ϒResult of H40_ϒ:

-0.00061<h40(ϒ)<0.00064With 95%CL

H40(ϒ)

σ(ATGC)/σ(SM) in 45GeV<pT_ϒ<60GeV

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H40_ZResult of H40_Z:

-0.00050<h40(Z)<0.00051With 95%CL

H40(Z)

σ(ATGC)/σ(SM) in 45GeV<pT_ϒ<60GeV

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95% C.L. D0 1.01/fb ATLAS 1.02/fb

H30_ϒ ( -0.085 , 0.084 ) ( -0.029 , 0.030 )

H30_Z ( -0.083 , 0.082 ) ( -0.023 , 0.024 )

H40_ϒ ( -0.0053 , 0.0054 ) ( -0.00061 , 0.00064 )

H40_Z ( -0.0053 , 0.0054 ) ( -0.00050 , 0.00051 )

Comparison of D0 and ATLAS result

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Summary

1. Our frame-work for ATGC study is ready;

2. We have got a preliminary result which is much better than D0 1.02/fb result.