UED Observables at the LHC

UED Observables at the LHC?

• Level 1 Discovery Potential– 4 leptons + missing energy – Neutral LKP escapes detection

• Level 2 Discovery Potential– f0 f0 → Z** → l +l -

• Dijet Production enhancement at high ECM

– Exchange of gluon excitations g(2n)

TE 4 l

UED Level 1 Discovery• 4 leptons + missing energy

– Q* pair production each decaying to V+j– WWjj, WZjj, ZZjj– ZZjj most promising with 4 charged leptons in

final state

• Each jet carries a LKP escaping detection, carrying away readily discernible missing energy

Level 1 Discovery Diagrams

• pp collider → gluon fusion strongest channel for high PT events

Existing Analysis for

• hep-ph/0205314 Matchev, Cheng, and Schmaltz provide some analysis results

TE 4 l

Discovery Reach

hep-ph/0205314 Matchev, Cheng, and Schmaltz

• LHC can resolve with 5σ statistics missing ET events if R < 1 TeV after the first year (low luminosity = 10 fb-1)

• LHC will be able to 5σ resolve missing ET events after 2nd year (@ high luminosity) if R<1.5 TeV

TE 4 l

UED Level 2 Signature Z(2)→l +l -

• 2nd KK level excitation should still be accessible at LHC with mass ~2 TeV

• KK parity conservation allows pair production through even /Z excitations

• f0 f0 → Z(2) → l +l -

Dijet Production

• At high ECM, gluon excitations enhance jet production through virtual gluon exchange

• Polessello, Laforge, Ferrag, Escalier, Balazs (hep-ph/0402295 pg. 95) have performed a PYTHIA simulation of these processes

Dijet Production

• Left: Number of dijets vs. transverse momentum Pt• Right: KK contribution to the cross section

Servant, Tait

• Hep-ph/0206071

Prediction for ΩB(1)h2

• hep-ph/0206071• Graph plotted in 2002

– slightly outdated• Lower band should

span 0.09 to 0.13 corresponding to m = 750 - 950 GeV, using latest WMAP results