Other Searches at LEP Sylvie Braibant CERN Moriond QCD week 18-24 March 2001 RPV-SUSY GMSB Technicolor Excited leptons Leptoquarks

Other Searches at LEPSylvie Braibant

CERN

Moriond QCD week18-24 March 2001

On behalf of the LEP experimentsRPV-SUSYGMSBTechnicolor Excited leptonsLeptoquarks

Other Searches at LEP - Moriond 2001 Sylvie Braibant - CERN 2

Searches Variants

• R-parity conserving SUSY(LSP stable missing energy)

• Standard SUSY: neutralino LSP(see T. Alderweireld’s talk)

• GMSB: gravitino LSP G• light G (eV GeV) with possibly long lifetime of slepton or neutralino NLSP: either 1 or l• super-light G (eV)

• R-parity violating SUSY (LSP decays to SM particles)• vast field with very different signatures

• Exotics • Technicolor • Leptoquarks • Excited Leptons

~~

~~ ~0


RPV SUSY: Superpotential


RPV SUSY: R-Parity

• Assumptions • exactly 1 -like coupling different from 0 at the time• mean path of flight < 1 cm > 10-4


RPV SUSY: Production Mechanisms


RPV SUSY:Gaugino Searches


RPV SUSY: Gaugino Searches for

m1 > 40 GeV

~ 0


RPV SUSY: Gaugino Searches for ’

Final states contain many jets and leptons


RPV SUSY: Gaugino Searches for ’’Final states with up to 10 jets

m1 > 38 GeV

~ 0


RPV SUSY: Slepton Searches


RPV SUSY: Slepton Searches - MSSM limits

’’

Similar results for squarks, sneutrinos for RPV , ’, ’’ decays


RPV SUSY: Sneutrino Searches - Resonant Production


RPV SUSY

• Searches for Rp-violating production and decay of SUSY

particles are complementary to searches with Rp-conservation

• Under the assumption of Rp-violation, searches have been

performed for gauginos, sleptons, sneutrinos and squarks for

all Yukawa couplings , ’, ’’

• No evidence for SUSY with Rp-violation

• Exclusion limits are similar to the Rp-conserving case


GMSB SUSY Searches: Light Gravitino Scenarios


GMSB SUSY Searches


GMSB SUSY Searches: Neutralino NLSP

<< LDet

Acoplanar photonsZero Lifetime

~ LDet

Single non-pointing photonNon-zero Lifetime

0


GMSB SUSY Searches: Neutralino NLSPZero LifetimeAcoplanar photons


GMSB SUSY Searches: Neutralino NLSPNon-Zero LifetimeNon-pointing

single photons


GMSB SUSY Searches: Slepton NLSP

Zero LifetimeAcoplanar leptons

Exclusion plots forSleptons in gravity-mediated

Large IP + kinks

Large IP =O(1 mm)-O(40 cm)Kinks =O(10 cm)-O(2 m)

Heavy stable charged particles

dE/dxor

RICH detectors

0


GMSB SUSY Searches: Slepton NLSPCombining searches in various regions of l lifetime

~

Long lifetime:Searches for heavy stable

charged particles

Zero lifetime:Search for prompt decays:

acoplanar lepton search

Intermediate lifetime Searches for large impact parameters+ Searches for kinks


GMSB SUSY Searches: Sgoldstinoe+e-

Depends on m and √ F

Most relevant decays:

(4-11%)gg (96-89%)

M1 M2 M3

1) 200 300 4002) 350 350 350

E =s - m

2 √ s

2


Technicolor• Provides a scheme to generate W/Z masses. EW symmetry broken dynamically by strong interactions of gauge bosons.• Introduces new technifermions

which obey a QCD-like

Interaction with an effective scale TC >> QCD

• At TC , TC interation becomes strong techniquark condensates replace non zero VEV of Higgs field:

<TT> = F ~ 246 GeV

• Extensions are worked out to solve problems:• These extensions call for a large number ND of technidoublets additional scalar (T, ’T) and vector (TT) mesons which can be light enough to be observed at LEP2.

TV

TD

_


Technicolor

e+e- T ff (below WW threshold)

e+e- T W+W- (above WW threshold)

-

T W±T±, T

0

T T -T+

Important decays T+ bc, bu

- -


Technicolor

No significant contribution of technicolor production is observed

95% CL exclusion region in the (MT, MT

) plane


Excited Leptons


Exited Leptons


Excited LeptonsFlavour 95% mass limits (GeV)

e* 102.9* 102.9* 102.8


Leptoquarks

Single Production Pair Production


Leptoquarks

LQ

l

q

ν

q

LQ

Production

BR = β BR = 1 - β

LQ

LQ

LQ

LQ

LQ

LQ

ν

ν

Jet

Jet

Jet

JetJetν


Leptoquarks

Vector Leptoquarks


Leptoquarks

Scalar Leptoquarks


Conclusions• LEP has been a great success until its very end• A broad spectrum of new particle searches have been and are actively pursued… but no indication for Physics beyond the SM• Results are interpreted in various models• Existing limits have been extended:

plenty of preliminary results using all the data collectedat LEPLEP SUSY working group combining results on:

GMSB and RPVLEP exotica working group starting to combine results on:

single top, excited leptons, leptoquarks• We are working towards FINAL LEP results• Apologies for results which were not shown• Many thanks to my LEP colleagues who helped me to prepare thistalk

Documents

Other Searches at LEP Sylvie Braibant CERN Moriond QCD week 18-24 March 2001 RPV-SUSY GMSB Technicolor Excited leptons Leptoquarks