Prospects for TeV ScaleNew Physics at LHC

Prospects for TeV ScaleNew Physics at LHC

Reisaburo Tanaka(Okayama University)

On behalf of ATLAS-Japan

KEK Theory Meeting 2006March 2-4, 2006

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Prospects for TeV Scale New Physics at LHC 22006.03.04

Large cross section via strong interaction

Easy discovery M~1TeV within 1 month ?

˜ q ̃ q , ˜ q ̃ g , ˜ g ̃ g

3pb for m(˜ q , ˜ g ) 1 TeV

100 events/day@1033cm 2s 1

4. Supersymmetry4. SupersymmetrySUSY Scale

２０％ accuracy （ L=10fb-1, mSUGRA ）Missing ET is important （ calibrate with Z→ll+jets)

MSUSY min(m( ˜ q ),m( ˜ g ))

Missing ET + high pt jets + Leptons

(Model indep. Analysis, R-parity conserv.)

Meff ETmiss pT

jet

Signal

MSUSY

J.G. Branson et al., Eur.Phys.J.direct C4(2002)N1

Prospects for TeV Scale New Physics at LHC 32006.03.04

SUSY event topology (Gravity- mediation + R-parity) 　

Gluino/squark are produced copiously,“Cascade decay” follows after.

E T High PT leptons+ multi-jets + b-jets τ-jets

(1) ETmiss should be controlled in multi-jets

topology (N>=4).(2) High Pt multi-jets are important to estimate

SM background contributions and SUSY reconstruction.

HighStop,sbottom --->

Prospects for TeV Scale New Physics at LHC 42006.03.04

No EWSB

1 year run (L=10fb-1) M2TeV

High Lum. 3 year run (L=300fb-1) M2.5TeV

LEP & Tevatron region

Cold Dark Matter1 week run is enough.

1 month run (L=1fb-1)　　　 〜 1.5TeV 5 discovery

m( ˜ q , ˜ g )

WMAP 0.0094<Ωmh2<0.129

mSUGRA discovery potential

Prospects for TeV Scale New Physics at LHC 52006.03.04

ME-PS Matching

1. Collinear and soft regions are covered with Parton Shower Pythia(6.2). Pt ordering is applied.

2. ME-PS matching is performed to remove double counts:

No-Shower branching probability is given by pQCD: 　 Sudakov factorΔ:

Two major methods exist: (A) CKKW: Events is reweight with Sudakov fa

ctor (product of Δ for all line) (B) MLM: veto is applied after shower evolut

ion

F. Krauss et al., Phys.Rev.D70(2004)114009

PS(Pythia)

PS

Prospects for TeV Scale New Physics at LHC 62006.03.04

No lepton mode 　　　　　　　　 One Lepton modeC

ount

/40

0GeV

/10f

b-1

m( ˜ g , ˜ q ) ~ 1TeV

Effective Mass(GeV) = mET + ΣPT(4jets)

(1) Background increases by factor 2-4 than the PS prediction depending on Meff.

(2) Slope becomes more gentle, and similar to the signal <-- important Point

S.Asai et al., ATLAS Preliminary

(1) One lepton mode gives clean discovery.(2) Top is dominant background. 　

Prospects for TeV Scale New Physics at LHC 72006.03.04

Detector Material

∑Et (GeV)

ATLAS preliminaryT.Sasaki (U.Tokyo) et al.

Crack +20% worseAll eta

(G

eV

)

Tile barrel Tile extended barrel

LAr forward calorimeter (FCAL)

LAr hadronic end-cap (HEC)

LAr EM end-cap (EMEC)

LAr EM barrel

Lots of materialsCrack ||=1.4-1.6

Missing Ex resolution

Prospects for TeV Scale New Physics at LHC 82006.03.04

Mass Reconstruction　 kinematical endpoint

˜ g

q

˜ q

˜ 20

q

˜ R

˜ 10

Bottomup Reconstruction

Sharp Edge Mll

max

Mmax m( ˜ 2

0 ) 1m(˜ R

)

m( ˜ 20 )

2

1m( ˜ 1

0 )

m(˜ R)

2

1. Generally under-constrained. Determine mass with help of models.

2. Can determine model independently if 2-body decay chain continues 3 times.

3. Large tanβ means more cascade and , b.

4. Strong model dependence.5. Mass uncertainty mostly from LSP’

s momentum.6. Determination of spin or Br are dif

ficult. 　

B.C. Allanach et al., JHEP 0009(2000)004

Prospects for TeV Scale New Physics at LHC 92006.03.04

Synergy between LHC and ILC

HiggsHiggs

sleptonslepton

neutralinocharginoneutralinochargino

squarksquark

Typical mSUGRA scenario

LHC

ILC

Split supersymmetry: R-hadrons in ATLASA.C. Kraan et al., hep-ex/0511014

Universal Extra-Dimension scenario

H-C.Cheng et al., Phys.Rev.D66(2002)036005, ibid. 056006

B.C.Allanach et al., Eur.Phys.J.C25(2002)113

LHC - Higgs, squark/gluinoILC - Higgs, neutralino/chargino, slepton

Use spin !

Prospects for TeV Scale New Physics at LHC 102006.03.04

Testing the underlying theoryTesting the underlying theory

• Determination of SUSY model parametresC.G. Lester, M.A. Parker, M.J. White, JHEP 0601(2006)080

• SUSY “inverse map” LHC signatures theoretical models

N. Arkani-Hamed et al., hep-ph/0512190

InclusiveSignature

ExclusiveSignature

Cross sections

Meff

Nlepton

…

Kinematics

Endpoints(mass)

Easy for theory

Markov chain sampling technique

1808 LHC observables15 dimensional parametrization

Prospects for TeV Scale New Physics at LHC 112006.03.04

7. Summary7. Summary• Discovery first !• LHC is capable to find new particles (SUSY, ED, Z’ etc. )

up to 2-3 TeV (up to ~10TeV with interference effect).• Model discrimination / parametre determination under stu

dy.• Experimental issues: commissioning/calibration• Needs to understand SM bkg from data and tuned MC.• Tools: t, b, W/Z and even Higgs!

• We do hope major breakthrough in HEP (SUSY, ED etc.)• Important decision in 2010 about HEP’s future…