[PPT] - Distributions for Higgs + Jet at Hadron Colliders: MSSM vs SM PowerPoint Presentation

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Distributions for Higgs + Jet at Hadron Colliders: MSSM vs SM Oliver Brein

Institute for Particle Physics Phenomenology, University of Durham in collaboration with W. Hollik

[see also 0705.2744 [hep-ph]; hep-ph/0305321] e-mail: Oliver.Brein@durham.ac.uk

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utline :
Higgs + jet in the Standard Model
Higgs + jet in the MSSM
MSSM results

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LHC/CMS 5σ discovery contours for the MSSM Higgs bosons

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Higgs + jet in the Standard Model

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Higgs + jet in the Standard Model

– Higgs production @ the LHC SM Higgs production @ LHC mainly via gluon fusion:

g g

H Detection (mH ≈ 100 − 140GeV): mainly via the rare decay H → γγ. → difficult ! huge background

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[ Higgs + jet in the SM ]

– Higgs + jet suggestion: study Higgs events with a high-pT hadronic jet

[R.K. Ellis et al. ’87; Baur, Glover ’89] (LO) [de Florian, Grazzini, Kunszt ’99] (NLO QCD)

advantage: * richer kinematical structure compared to inclusive Higgs production. → allows for refined cuts → better S/B ratio disadvantage: * lower rate than inclusive Higgs production () NLO signal prediction has still sizable theoretical uncertainty (≈ 20%) () background only partly known at NLO accuracy → theoretical uncertainties larger than in the fully inclusive case (so far)

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[ Higgs + jet in the SM, Higgs + jet ]

SM H+jet, partonic processes (mostly loop-induced):

gg → Hg (≈ 50 - 70 % of total rate)
qg → Hq, ¯

qg → H¯ q (≈ 30 - 50 % of total rate)

b b b b

q¯

q → Hg (rate small)

b b b b

recently simulated: pp → H + jet, H → γγ [Abdullin et al. ’98 & ’02; Zmushko ’02] pp → H + jet, H → τ+τ− → l+l−pT /

[Mellado et al. ’05]

result: H + jet production (e.g. with pT,jet ≥ 30 GeV , |ηjet| ≤ 4.5) is a promising alternative (supplement) to the inclusive SM Higgs production for mH ≈ 100 − 140GeV.

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[ Higgs + jet in the SM, Higgs + jet ]

available codes:

Higgsjet [de Florian, Grazzini, Kunszt ’99]

NLO QCD cross section for pp → H + jet also: soft gluon resummation [de Florian, Kulesza, Vogelsang ’05]

HqT [Bozzi, Catani, de Florian, Grazzini ’03 & ’06]

pT-distribution for pp → H + X at NLL + LO and NNLL + NLO QCD accuracy (large effects at small pT resummed)

MC@NLO [Frixione, Webber ’02; Frixione, Nason, Webber ’05]

contains pp → H + X event generation at NLO QCD accuracy

FEHiP [Anastasiou, Melnikov, Petriello ’05]

NNLO QCD differential cross section for pp → H + X

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Higgs + jet in the MSSM

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Higgs + jet in the MSSM

[OBr, Hollik ’03; ’07] (full MSSM), [Field, Dawson, Smith ’04] (MSSM, no superpartners), [Langenegger et al. ’06] (MSSM with soft-gluon resummation, no superpartners)

– differences to the SM Motivation: * promising simulation results in the SM case * process loop-induced → potentially large effects from virtual particles partonic processes similar to the SM:

gluon fusion gg → h0g, quark-gluon scattering q(¯ q)g → h0q(¯ q), q¯ q annihilation q¯ q → h0g

but: * different Higgs Yukawa-couplings gSM

q¯ qH=

e 2sw mq mW −

→ gMSSM

q¯ qh0 =

e 2sw mq mW fq(α,β),

fuI(α,β)=cos α/ sin β fdI(α,β)=− sin α/ cos β

→ change of overall rate * additional superpartner-loops (even additional topologies) → also angular distribution changed

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[ Higgs + jet in the MSSM ]

– Feynman graphs gluon fusion, gg → h0g quark loops

h0 g qi qi qi h0 qi qi qi h0 qi qi qi h0 qi qi qi qi h0 qi qi qi qi h0 qi qi qi qi

superpartner loops

h0 ˜ qs

i

˜ qs

i

˜ qs

i

h0 ˜ qs

i

˜ qs

i

h0 ˜ qs

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˜ qs

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˜ qs

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h0 ˜ qs

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˜ qs

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h0 ˜ qs

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˜ qs

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˜ qs

i

h0 ˜ qs

i

˜ qs

i

h0 ˜ qs

i

˜ qs

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˜ qs

i

˜ qs

i

h0 ˜ qs

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˜ qs

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˜ qs

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h0 ˜ qs

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˜ qs

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˜ qs

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˜ qs

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h0 ˜ qs

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˜ qs

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˜ qs

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h0 ˜ qs

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˜ qs

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˜ qs

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˜ qs

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h0 ˜ qs

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˜ qs

i

˜ qs

i

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[ Higgs + jet in the MSSM, Feynman graphs ]

quark gluon scattering, qg → h0q quark loops

h0 qi qi qi

superpartner loops

h0 ˜ qs

i

˜ qs

i

˜ qs

i

h0 ˜ qs

i

˜ qs

i

h0 ˜ qs ˜ g ˜ qt h0 ˜ qs ˜ g ˜ qt h0 ˜ qs ˜ g ˜ qs ˜ qt h0 ˜ g ˜ qs ˜ qt ˜ qt h0 ˜ g ˜ qs ˜ g ˜ qt

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[ Higgs + jet in the MSSM, Feynman graphs ]

quark anti-quark annihilation, q¯ q → h0g quark loops

h0 qi qi qi

superpartner loops

h0 ˜ us

i

˜ us

i

˜ us

i

h0 ˜ us

i

˜ us

i

h0 ˜ us ˜ g ˜ ut h0 ˜ us ˜ g ˜ ut h0 ˜ g ˜ us ˜ ut ˜ us h0 ˜ g ˜ us ˜ ut ˜ ut h0 ˜ g ˜ us ˜ g ˜ ut

b-quark processes: bg scattering, bg → h0b, b¯ b annihilation, b¯ b → h0g

b b b b [ partonic processes calculated using FeynArts/FormCalc, see : www.feynarts.de ]

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MSSM results

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[ MSSM results ]

– total cross section

total hadronic cross section @ LHC

σ(pp → h0 + jet + X) applying the cuts pT,jet ≥ 30 GeV and |ηjet| ≤ 4.5

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[ MSSM results, total cross section ]

mA- and tan β-dependence :

10 100 400 300 200 100 90 SM MSSM, full MSSM, no SP MSSM, no b MSSM, no b, no SP

σ(pp→h0+jet) [pb]

tan β=30 MSUSY=400 GeV

mh-max

mA [GeV]

⇑

high mA

10 5 10 15 20 25 30 SM MSSM, full MSSM, no SP MSSM, no b MSSM, no b, no SP

σ(pp→h0+jet) [pb]

mA=400 GeV MSUSY=400 GeV

mh-max

tan β

⇑

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[ MSSM results, total cross section ]

mA- and tan β-dependence :

10 100 400 300 200 100 90 SM MSSM, full MSSM, no SP MSSM, no b MSSM, no b, no SP

σ(pp→h0+jet) [pb]

tan β=30 MSUSY=400 GeV

mh-max

mA [GeV]

⇑

low mA

10 100 5 10 15 20 25 30 SM MSSM, full MSSM, no SP MSSM, no b MSSM, no b, no SP

σ(pp→h0+jet) [pb]

mA=100 GeV MSUSY=400 GeV

mh-max

tan β

⇑

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[ MSSM results, total cross section ]

MSUSY -dependence :

2 4 6 8 10 12 300 400 500 600 700 800 900 1000 no-mixing no-mixing, no SP mh-max mh-max, no SP

σ(pp→h0+jet) [pb] MSUSY[GeV]

mA=200 GeV tan β=6

no-mixing mh-max

1 2 3 4 5 6 7 8 400 500 600 700 800 900 1000 large-mu large-mu, no SP

σ(pp→h0+jet) [pb] MSUSY[GeV]

[Xt=−900 GeV,mmax h =124 GeV]

mA=200 GeV tan β=6

large-µ

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[ MSSM results, total cross section ]

relative difference δ = (σMSSM − σSM)/σSM) :

1000 800 600 400 200 50 10 1

32
30
28
26
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mh-max scenario, MSUSY=400 GeV

tan β

−26% <δ< −24% δ[%]

mA [GeV]

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[ MSSM results ]

– differential cross section

differential hadronic cross sections @ LHC/Tevatron

dσ(S,pT,jet) dpT,jet

, dσ(S,ηjet)

dηjet

, d2σ(S,pT,jet,ηjet)

dpT,jet dηjet

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[ MSSM results, differential cross section ]

pT,jet- and ηjet-dependence, low-mA case Tevatron, mh-max scenario, MSUSY = 400 GeV, mA = 110 GeV, tan β = 30

6 8 10 12 14 16 18 20 22 24

δ [1]

5

5 10 15 20 25 30 35

δ [1]

0.1 0.2 0.3 0.4 0.5

4
3
2
1

1 2 3 4

dσ/dη3 [pb] η3 all gg qg q¯ q

100

dσ/dpT [pb/GeV] pT [GeV]

10−1 10−2 10−3 10−4 10−5 10−6

pT,jet ≥ 30 GeV |ηjet| ≤ 4.5 thick lines: MSSM thin lines: SM

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[ MSSM results, differential cross section ]

pT,jet- and ηjet-dependence, low-mA case LHC, mh-max scenario, MSUSY = 400 GeV, mA = 110 GeV, tan β = 30

8 10 12 14 16 18 20 22 24 26 28

δ [1]

5

5 10 15 20 25 30 35 40

δ [1]

5 10 15 20 25 30 35 40

4
3
2
1

1 2 3 4

dσ/dη3 [pb] η3 all gg qg q¯ q

100 1000

dσ/dpT [pb/GeV] pT [GeV]

10 1 10−1 10−2 10−3 10−4 10−5 10−6

pT,jet ≥ 30 GeV |ηjet| ≤ 4.5 thick lines: MSSM thin lines: SM

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[ MSSM results, differential cross section ]

pT,jet- and ηjet-dependence, high-mA case LHC, mh-max scenario, MSUSY = 400 GeV, mA = 400 GeV, tan β = 30

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δ [%]

30
28
26
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δ [%]

0.2 0.4 0.6 0.8 1 1.2

4
3
2
1

1 2 3 4

dσ/dη3 [pb] η3 all gg qg q¯ q

100 1000

dσ/dpT [pb/GeV] pT [GeV]

10−1 10−2 10−3 10−4 10−5 10−6

pT,jet ≥ 30 GeV |ηjet| ≤ 4.5 thick lines: MSSM thin lines: SM

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[ MSSM results, differential cross section ]

pT,jet- and ηjet-dependence, high-mA case LHC, no-mixing(700) scenario, MSUSY = 700 GeV, mA = 500 GeV, tan β = 35

8 7 6 5 4

δ [%]

2 4 6 8 10 12 14 16 18

δ [%]

0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

4
3
2
1

1 2 3 4

dσ/dη3 [pb] η3 all gg qg q¯ q

100 1000

dσ/dpT [pb/GeV] pT [GeV]

10−1 10−2 10−3 10−4 10−5 10−6

pT,jet ≥ 30 GeV |ηjet| ≤ 4.5 thick lines: MSSM thin lines: SM

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[ MSSM results, differential cross section ]

pT,jet- and ηjet-dependence, high-mA case LHC, small-αeff scenario, mA = 400 GeV, tan β = 30

13
12
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δ [%]

30
25
20
15
10
5

δ [%]

0.2 0.4 0.6 0.8 1 1.2

4
3
2
1

1 2 3 4

dσ/dη3 [pb] η3 all gg qg q¯ q

100 1000

dσ/dpT [pb/GeV] pT [GeV]

10−1 10−2 10−3 10−4 10−5 10−6

pT,jet ≥ 30 GeV |ηjet| ≤ 4.5 thick lines: MSSM thin lines: SM

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[ MSSM results, differential cross section ]

1st Question : Can we detect such 2 %-ish differences in the η or pT distribution ? → No ! → absolute cross section measurement : systematic uncertainties too large ! 2nd Question : Can we do better than that ? → Yes → larger differences occur in the η-pT plane → define suitable ratios of cross sections

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[ MSSM results, differential cross section ]

LHC,

d2σ dpT,jetdηjet : MSSM − SM relative and absolute difference

100

4
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2
1

1 2 3 4 100

4
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1

1 2 3 4

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100

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1 2 3 4

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1 2 3 4

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1 2 3 4

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1 2 3 4

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1 2 3 4

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1 2 3 4

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pT [GeV] ηjet

relative difference in % : contour lines —– absolute difference :

:

5 - 10 fb/GeV

:

1 - 5 fb/GeV

: 0.5 - 1 fb/GeV : 0.1 - 0.5 fb/GeV

LHC, mh-max scenario, MSUSY = 400 GeV, mA = 400 GeV, tan β = 30

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[ MSSM results, differential cross section ]

LHC,

d2σ dpT,jetdηjet : MSSM − SM relative and absolute difference

100

4
3
2
1

1 2 3 4 100

4
3
2
1

1 2 3 4

28
27
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25
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100

4
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1 2 3 4

28
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1 2 3 4

28
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1 2 3 4

28
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1 2 3 4

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1 2 3 4

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pT [GeV] ηjet

relative difference in % : contour lines —– absolute difference :

:

5 - 10 fb/GeV

:

1 - 5 fb/GeV

: 0.5 - 1 fb/GeV : 0.1 - 0.5 fb/GeV

→ consider ratio :

R = σ

  

pT > 70 GeV |η| < 1.5

  

σ

  

pT ∈ [30, 50] GeV |η| > 1.5

  

LHC, mh-max scenario, MSUSY = 400 GeV, mA = 400 GeV, tan β = 30

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[ MSSM results, differential cross section ]

example: ratio R = σ

|η| < 1.5, pT > 70 GeV
σ
|η| > 1.5, pT ∈ [30, 50] GeV
for the above mh-max scenario at the LHC (mA = 400 GeV, tan β = 30):

quantity SM MSSM σ

|η| < 1.5, pT > 70 GeV
1.448 pb

1.096 pb σ

|η| > 1.5, pT ∈ [30, 50] GeV
1.419 pb

1.031 pb R 1.020 1.063

→ ∆ = RMSSM−RSM

RSM

= 4.2%

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FORTRAN code HJET to calculate the MSSM (and SM) cross sections, σtotal

hadronic,

dσhadronic d √ ˆ s , dσhadronic dpT,jet , dσhadronic dηjet , d2σhadronic dpT,jet dηjet ˆ σtotal

partonic,

dˆ σpartonic dΩ , dˆ σpartonic dˆ t , dˆ σpartonic dyjet , dˆ σpartonic dpT,jet , will be available on request → oliver.brein@durham.ac.uk

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summary

SM simulations show: Higgs + high-pT jet production is a promising

alternative to the inclusive production.

difference between MSSM and SM Higgs + jet production

also extends to the shapes of differential distributions. − if b-quark processes dominate (low mA): * much larger cross sections and softer pT spectrum − if loop-induced processes dominate (high mA): * large effect on total cross section due to (rather light) virtual squarks * mild but possibly measurable deviations in differential distributions with non-trivial variation in the whole η-pT plane

more precise predictions are needed in order to be useful for experimental