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Searches for New Phenomena : Where do we stand …. 5 th Rencontres du VietNam – New Views in Particle Physics Hanoi, 5-11 August 2004. and what we might learn within the coming years …. Emmanuelle PEREZ CEA-Saclay, DSM / DAPNIA / Spp. 10 August 2004. Rencontres du VietNam, Hanoi.

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Emmanuelle perez cea saclay dsm dapnia spp

Searches for New Phenomena :

Where do we stand …

5th Rencontres du VietNam – New Views in Particle Physics

Hanoi, 5-11 August 2004

and what we might learn within the coming years …

Emmanuelle PEREZ

CEA-Saclay, DSM / DAPNIA / Spp

10 August 2004

Rencontres du VietNam, Hanoi


Searches for new physics why where how

Searches for New Physics : why, where, how…

Mechanism of the EW symmetry breaking ?

  •  Higgs (i.e. fundamental scalar) ? Find it…

  •  structure of the Higgs sector ?

  •  solution of the hierarchy problem ?

  • no Higgs ?Dynamical breaking ?( H ~ condensate )

    extra-dimphysics ? ( H ~ Gauge Field|4d )

#doublets, triplets ? CP ?

SUSY  MPl ? “Little Higgs”   10 TeV ?

extra dimensions  no hierarchy ?

In most scenarios, new physics is expected at the TeV scale.

Also hoped for, that NP might answer some of the questions unexplained by the SM.

Various strategies to track new physics, e.g. :

- high precision measurements ( need good theoretical control )

- rare decays (K & B) , LFV processes

- searches for Dark Matter

- searches at high energy colliders Tevatron, HERA

- model driven searches

- exploit at best the experimental knowledge of our detectors

Some complementarities between these different approaches.

Rencontres du VietNam, 08/04


Good performances of our facilities

Good performances of our facilities !

_

H1 &

ZEUS

Tevatron

pp, s = 1.96 TeVCDF & D0

ep, s = 320 GeV

HERA

Run I (92-96) :  110 pb-1 / exp

until summer 2000 : 120 pb-1 / exp

Restart in may 2001   0.6 fb-1 delivered

Serious background problems at the

restart (fall 01)

Tevatron Run II

Required

time,

now solved

2004

1032 cm2 s-1

threshold broken

on July 16th !

1032 cm2s-1

HERA is

now operating

with twice

the 2000

peak lumi

6.1031

HERA-II

Peak lumi

Peak lumi average

(e+ p)

2.1031

2003

2002

Jan 02

Jan 03

Jan 04

HERA-II analyses : up to  50 pb-1

Analyses presented here  200 pb-1

of Run II data (2002 & 2003)

NB: expect several new results in the coming weeks ! some with up to  350 pb-1 !

+ LEP data ! Very relevant constraints on NP ! some final combinations are still to come

Rencontres du VietNam, 08/04


Hunting the sm higgs boson

Hunting the SM Higgs Boson

  • Status :

(LEP EW WG, April 2004)

Direct searches at LEP  MH > 114.4 GeV @ 95% C.L.

EW fits ( latest Mtop = 178.0  4.3 GeV) : MH < 237 GeV

LEP final combination for MSSM Higgs coming soon…

(new Mtop required new databases with , BR etc…)

LEP is finalizing investigations of non-standard

scenarios (invisible h, bosophilic Higgs, CP-violation…)

  • Until the start-up of (physics at) LHC, Higgs searches

  • are in the hands of the Tevatron experiments :

“Light” Higgs, M < 130 GeV :

 ( pb )

a few 10-1 pb

H  bb

gg  H

  • Best S/B in leptonic W/Z decays

  • Large bckgd from W/Z + jets  b tagging !

  • Importance of a good mass resolution !

HW

H bb

“Heavy” Higgs, M > 130 GeV :

H  WW

H  WW(*)

Clean dilepton + ET,miss signature

MH (GeV)

E. Perez


Tevatron searches for a light sm higgs

8.5

4.4 fb-1

Tevatron Searches for a light SM Higgs

WH  bbl with l = e,

First analyses exist !

CDF Run II Prelim., 162 pb-1

Exp. limit

Exploit kinematics and

topology, require

1 (2) b-tag in D0 (CDF)

Obs. limit

(WH) x BR < 5 pb

for MH = 115 GeV

Still a factor ~ 50 larger

than SM predictions !

SM prediction

(also T  WT lbb)

  • Full GEANT simulation, 396 ns, RunIIb Si.

  • experience from current data (bckgd, (Mbb))

Updated sensitivity study

(impact of cancellation of Si. upgrades still to be assessed)

Fermilab-Pub-03/320-E

Challenging anyway !

End 2008 :

between

4 & 8 fb-1

No “golden” channel …

10

8.5

Integrated Lumi (fb-1)

(reasonably)

optimistic

5

4.4

conservative

Combining

WH & ZH,

D0 & CDF

09

05

06

07

08

Rencontres du VietNam, 08/04


Tevatron searches for a heavy sm higgs

e

Tevatron Searches for a Heavy SM Higgs

Final states investigated : ee + ET,miss, e + ET,miss,  + ET,miss

(combined ll + ET,miss in the CDF analysis)

( H  WW* )

L 160 – 200 pb-1

Backgrounds from W + jet(s), Z/DY, WW

Exploit spin correlations : leptons small

No excess w.r.t. SM predictions…

x-section enhanced

w.r.t. SM via heavy

4th generation quarks

in the ggH loop

Will soon be sensitive …

Higgs = condensate RtL

(H) x BR(H  WW) < 5.6 pb

for MH = 160 GeV

i.e. a factor ~ 20 larger than SM predictions

SM Higgs : need ~ 4 fb-1 for sensitivity @ 95% CL

Rencontres du VietNam, 08/04

E. Perez


Susy non standard higgses

SUSY & Non standard Higgses

  • Higgs in SUSY models : extended Higgs sector h, H, A, H 

MSSM constraints

Mh < 135 GeV

Two free parameters, e.g. MA and tan = vu/vd

  • Often : one Higgs  looks like HSM

  • Else : low (W+Higgs) but (Higgs+bb)

  • enhancedat large tan  4b !

  • Difficult cases : SM = H heavy, orbb

  • look for A  , use partially reco’ed mass

 95% CL sensitivity over the allowed M range

_

  e/ + had.

_

For tan = 30,

sensitivity

still a factor

~ 10 away

from MSSM

  • Doubly charged Higgses :

D0, hep-ex/0404015

CDF, hep-ex/0406073

CDF Run II

240 pb-1

H++ appear in e.g. L- R symmetric models :

SU(2)L x SU(2)R broken by Higgs triplet

(or extended Higgs sector by a triplet with Y=2).

Might explain small (Majorana)  masses.

136 GeV

Evidence of 0 at the Heidelberg-Moscow experiment ?

H++ couples to fermions via unknown Yukawa couplings, not related

to masses. SUSY L–R models predict low H++ masses, below  1 TeV

113 GeV

  • Search for (high mass) same-sign dileptons

(CDF also searched for quasi-stable H++ , M > 134 GeV)

Rencontres du VietNam, 08/04


H and the hera multilepton events

expt

H1 ( 115 pb-1)

selection

2e, M12 > 100 GeV

3 / 0.30  0.04

3e, M12 > 100 GeV

3 / 0.23  0.04

H++ and the HERA multilepton events

Events with  2 leptons in final state. Mainly produced via 

H1 data 94-00 : excess of 2e+3e events at

high M12 = mass of two highest PT e

No such

excess

seen in

ZEUS

data

obs. / exp.

H1 94-00 data

The H1 evts

are not

consistent

with

(different angular

ranges in both

analyses)

H1,EPJ C31 (2003) 17

e  H++ (e)  ee(e)

H1 analysis extended to include 45 pb-1 of 03-04 data

163 pb-1

H1 Prelim.,

HERA I+II

Extended to other 2l & 3l topologies :

ee, , e, eee, e, ee

  • no new 2e / 3e evt at M12 > 100 GeV

  • (but one high mass 3e event …)

  • one e event at M > 100 GeV

Altogether, at PT > 100 GeV :

Nobs = 4, Nexp = 0.61  0.11

2l + 3l

e

Rencontres du VietNam, 08/04

E. Perez


Hunting supersymmetry

Hunting Supersymmetry…

For the last  20 years, SUSY has been “the standard non-standard theory”…

  • Provides a technical solution for the “hierarchy” problem

  • The only symmetry which prevents to add a mass term m2 H+H

  • Unification of couplings : works well with SM + SUSY

  • Possibly provides an additional source of CP

Different models and phenomenology depending on :

- the SUSY breaking mechanism(gravity mediated, or gauge interactions, anomalies ?)

- whether or not the LSP (Lightest Supersymmetric Particle) is stable

 Typical signatures with ET,miss , or , or large multiplicities or etc…

HERA

LEP

Tevatron

Mass bounds  100 GeV

NB: no model independent

bound on the LSP mass

SUSY might also manifest itself in precision measurements,

rare decays, Dark Matter searches etc…

Rencontres du VietNam, 08/04


Susy gmsb at the tevatron

Run I

SUSY : GMSB at the Tevatron

Gauge Mediated SUSY Breaking :

- naturally avoids large unwanted FCNC

- revival of interest in GMSB following “the” CDF Run I event

NB : LEP analyses made the GMSB interpretation unlikely

- LSP = gravitino G ( < keV), pheno. depends on NSLP

(10-6 expected !)

~

~

When NLSP = Neutralino : 01  G

Inclusive search for  + ET,miss – might come from 02 1 production

(no spectacular eeET,miss event observed so far in Run II data)

Large instrumental background(jets faking a ), determined from the data.

NB : Tevatron will provide very relevant data for

the jet 0 fragmentation… cf H   @ LHC !!

Interpretation within

a “minimal” GMSB

model :

185 pb-1

(D0 Prelim, 185 pb-1)

M(01) > 105 GeV

M(1) > 192 GeV

01 mass (GeV)

Similar results from CDF

World best limit !

Rencontres du VietNam, 08/04

E. Perez


Sugra like susy at the tevatron

~

D0 : pair production of squarks, q  q 01

Z () + jets

Large bckgd

from multijet prod. !

search domain

~

q > 292 GeV,

g > 333 GeV

~

~

(roughly,   g, sleptons +   squarks )

SUGRA-like SUSY at the Tevatron

LSP usually the 01. RPC  ET,miss

~

~

  • Pair production of q / g

  • large , Signature jets + ET,miss

Interpretation

within mSUGRA:

(for some values

of parameters)

D0 Run II, Prelim., 85 pb-1

Better than in Run I… but still stronger LEP

bounds in this very constrained model !

CDF : light sbottom squarks (156 pb-1)

g pair production, g  bb1

~

~

~

D0 Prelim., 147 – 250 pb-1

  • Chargino + Neutralino production ( 02 1 )

  •  trilepton final states

  • Low  x BR but clean signatures

eel + el + l +

same-sign 

Need high L and combined analyses

Getting close to the unexplored mSUGRA region !

NB : importance of  id. at large tan 

Rencontres du VietNam, 08/04

E. Perez


New physics searches in rare decays examples

tan 

New Physics Searches in rare decays (examples)

  • b  s 

 stops + charginos

BR (SM) = (3.70  0.30) x 10 –4

Good agreement with CLEO & Belle :

BR (exp) = (3.34  0.68) x 10-4

i.e. not much room for SUSY here …

Note: SUSY constraints are model-dependent

(mixing in the down squark sector)

J/

  • Bd,s +-

SM  (3.4  0.5) x 10 -9

SM signal

X 106

SUSY :  (tan )6 could reach 10-6 !

 (1S,2S,3S)

’

M (GeV)

_

Tevatron :  (bb)  100 b  sensitivity !

For Bd0 :

Slightly

better

than

Belle 2003 !

New CDF upper bounds on BR( Bs,d  ) :

hep-ex/0403032

Submitted to PRL

Br(Bd ) < 1.5 x 10-7

Br(Bs ) < 5.8 x 10-7

Similar sensitivity from D0

Rencontres du VietNam, 08/04


The muon anomalous magnetic moment

from    had

from e+e- had

  • Summer 03: revised analysis of CMD-2 data better agree with , but still…

  • exp. measurement of E821 using- : average value goes up a bit

(+ & - combined) 0.5 ppm !

aexp = 11 659 208 (6) x 10-10

The muon anomalous magnetic moment

(g-2) sensitive probe to New Physics …

aHAD ?

But uncertainties on the SM prediction :

Disagree…

Recent developments :

  • underestimation of isospin breaking corrections to the  data due to -0 mass

  • splitting? … controversial …

(Davier, hep-ex/0312065; Ghozzi & Jegerlehner, DESY 03-155)

  • reevaluation of part of aLBL

  • would shift the expected value by ~ + 50 10-11

(Melnikov & Vainshtein,

hep-ph/0312226)

1.4

2.7

  • e+e- 4 at BaBar using ISR photons :

  • somehow in-between e+e- & , closer to  data …

  • (e+e-  ) by KLOE at DANE (s  1 GeV) :

  • confirms the other e+e- measurements …

Winter 04

hep-ex/

0407048

Still puzzling… but new data from BaBar and KLOE might help understand…

Rencontres du VietNam, 08/04


Emmanuelle perez cea saclay dsm dapnia spp

Encroaches on the “trileptons” domain of the Tevatron

SUSY Searches and a

In any case, aSUSY cannot be too large !

e.g. aSUSY < 80 x 10-10

(very conservative)

aSUSY > 0

| aSUSY |  tan  / m2SUSY

Martin & Wells,

PRD67, 015002 (2003)

 > 0

500

tan  = 50

M ( smuon )

tan  = 20

At large tan  :

difficult to have chargino & sleptons both light

0

0

1000

M ( chargino )

Baltz & Gondolo, PRD67, 06503 (2003)

If aSUSY“signal” is confirmed :

 (p) (pb)

10-6

- upper bounds on M(chargino) & M(sleptons)

 encouraging for collider searches

although ’s and l might be too heavy for Tevatron…

- encouraging fordirect0 CDM searches

~

10-10

(squarks & Higgs not too heavy i.e. (p) not too small)

NB : however can have large (p) while aSUSY  0 …

CDMS II,

Edelweiss II

M ( LSP )

e.g. if aSUSY > 11 x 10-10

Rencontres du VietNam, 08/04

100

1000


Constraints sensitivities on msugra

 from Sun

(Antares, Icecube)

 from Sun

100

100 fb-1

LHC 10 fb-1

LHC 10 fb-1

1 x 10-8

Bs  < 2 x 10-8

Run II

3-leptons

CDMS II,

Edelweiss II

CDMS II,

Edelweiss II

Tri

leptons

Run II

Constraints & Sensitivities on mSUGRA

If DM = 01 : 2 bounds from WMAP 0.095 < LSP < 0.13

Very precise !!

White domains allowed if 01 is only a part of the CDM

“funnel”,

  A

“focus point”,   WW

tan  = 10

tan  = 55

1000

LSP

too

large

1000

m0 (Gev)

m0 (Gev)

100

  • sfermion

  • exchange

  • - l

    coannihil.

&

~

10

100

100

1000

100

1000

m1/2 (GeV)

m1/2 (GeV)

~

  • -  co-annihilation

  • Requires m  O(10 GeV)

aSUSY not too large

Plots from L. Roszkowski hep-ph/0404052; bounds from V. Bertin et al. hep-ph/0204135, Run II Workshop hep-ph/0003154


Beyond minimal sugra

  • Relaxing universality : constraints on LSP much more easily fulfilled

e.g. increase M1 or decrease M3 m( ) decreases  co-annihilation  

Lower M3 q & g searches at the Tevatron not so severely constrained by LEP…

~

~

  • In some cases, might expect stable  or t

Beyond Minimal SUGRA…

mSUGRA is becoming very tightly constrained… But (examples of way-outs) :

Belanger et al.,

hep-ph/0407218

~

~

  • SO(10) SUSY Grand Unified Theories

Large interest, e.g. in view of neutrino masses !

Minimal models not so severely constrained by LSP (lighter A)

Yt = Yb = Y = Y

1st & 2nd gene. sfermions are heavy ! i.e. no effect on (g-2)

Large tan  sensitivity of Bs  at the Tevatron !

Direct DM searches :   10-9 – 10-7 pb, i.e. encouraging

May see   e in the difficult “funnel” region !

m2atm  m2t / MGUT

e.g. Masiero & Vempati, hep-ph/0407325

  • DM mainly consists of something else …

(axions, gravitinos, axinos, Kaluza-Klein states,…)

Stable stop

above  100 GeV

Search for charged slowly moving particles (TOF)

 0  DM if Rparity = (-1)3B+L+2S is not conserved …

Might affect rare decays e.g. K 

For neutrinos : mechanism to generate (Majorana) mass terms

At colliders : single production of SUSY particles, less Emiss

Rencontres du VietNam, 08/04


R p and the hera events with lepton p t miss

_

e

PTX

  • (W prod)

     1 pb

’131 = 0.3

M(sbottom) (GeV)

H1 Collab.,

hep-ex/0405070

M(stop) (GeV)

  • Data not consistent

  • with t production (3 chan)

  • Other interpretations

  • considered e.g. FCNC top

~

Rp and the HERA events with lepton + PT,miss

Rp

Example : resonant stop production at HERA via ’131

Assume heavy gauginos & light sbottom.

~

~

Dominant decay : t  b W  jet + P T,miss + W

H1 Collab.,PLB 561,

241 (2003)

Main bckd when W  l :

HERA-I, 105 pb-1 :

No such excess in ZEUS

(but candidates in  channel)

(HERA-I)

HERA I & II, e & 

H1 in HERA-II data

(45 pb-1) :

8 new events,

3 at PTX > 25 GeV

At PTX > 25 GeV :

Nobs = 14

Nexp = 5.1  1.0

H1 Prelim.,

163 pb-1

(includes e-p HERA-I data)

 Stay tuned !!!


Emmanuelle perez cea saclay dsm dapnia spp

e e

ZEUS e+p

94-00

Lepton + Quark Resonances : Leptoquarks

cf Rp squarks

Apparent symmetry between the lepton & quark sectors ?

Exact cancellation of QED triangular anomaly ?

  • LQs appear in many extensions of SM

  • (enlarged gauge structure, compositeness, technicolor…)

  • Connect lepton & quark sectors

  • Scalar or Vector color triplet bosons

  • Carry both L and B, frac. em. charge

 (unknown) Yukawa coupling lepton-quark-LQ

ej channel at HERA

jj channel at Tevatron

ZEUS, PRD68 052004 (2003)

CDF Run II Prelim.,

191 pb-1

Not an easy channel !

Look for a resonant peak in M spectra

 reduced background

Large bckgd, but well controled


Constraints on 1 st 2 nd generation leptoquarks

Constraints on 1st & 2nd generation Leptoquarks

(LP’03)

e = BR( LQ  eq )

D0 Run II + Run I :

M > 253 GeV for =1

 = BR (LQ  eq)

  • Tevatron probes

  • large masses for large

  • e independently of 

  • HERA better probes LQs with small  provided

  • that  not too small

 Complementarity of both facilities

CDF II Prelim,

198 pb-1

MLQ (GeV)

NB : at HERA, e+ / e- +

polarisation could help in disentangling

the LQ quantum nbs

2nd gene,  = 1

2nd (and 3rd ) generation LQs also

looked for at the Tevatron.

For LQ  j, similar sensitivity as

for LQ  ej.

M(LQ2) > 241 GeV

Rencontres du VietNam, 08/04

E. Perez


Searches for new resonances dilepton

Searches for new resonances : dilepton

  • New heavy gauge boson Z ’, e.g. L-R models, or E6 GUT inspired, Little HiggsZ’…

  • Kaluza-Klein gravitons in some extra-dim. models

  • (Color-singlet) technirho in Technicolor models …

D0 & CDF searched for ee &  resonances :

Main bckgds @ high M :



200 pb-1

q

cotan 

“Little

Higgs”

_

q

ZH

Z’ Run II direct

bounds between

570 & 780 GeV

CDF II Prelim, 200 pb-1

Z’ Bounds

D0 Run II Prelim.

For E6 inspired models,

already competitive

with indirect LEP

bounds (430-670 GeV)

SM couplings

E6, 

Z’H ee

E6, 

E6, 

ee

First constraints

(direct) on “Little

Higgs” models !

780 GeV

(although “minimal”

models predict

heavier ZH, 2-6 TeV)

95% CL

200 pb-1

E. Perez


Emmanuelle perez cea saclay dsm dapnia spp

G(k) heavy, G(1) TeV

Coupling of G(k) to SM fields  TeV

(determined by some model param, k/MPl 0.1)

Kaluza-Klein Gravitons

Why is the gravity so weak, i.e. MPl >>> MEW ?

All attempts  higher dim. space, with n compactified extra dimensions

  • “Localized gravity” on a “brane” at d  0 from our brane; propagation of gravity

  • in the extra dim is exponentially damped due to the (tuned) space-time metric

Randall & Sundrum models; “usual” version : n=1, Rc Planck length

PRL 83 (1999) 3370;

PRL 83 (1999) 4690

  • “Strong gravity” ; fundamental scale ~ TeV; gravity appears weaker in 4d because flux lines

  • are “diluted” in large extra dim. Large Rc 0.1 mm. Not excluded by gravity measurements

  • Arkani-Hamed, Dimopoulos, Dvali, PLB 429 (1998) 263 revived ideas from Antoniadis, PLB 246 (1990) 377.

Graviton propagate in extradim  Kaluza-Klein modes

In localized gravity :

Spin 2

resonance



Coupling k/MPl



345 pb-1

For k / MPl = 0.1 : masses below

690 GeV ruled out at 95% C.L.

ee

Most stringent

collider bounds

so far.

(also D0 Prelim, ee final states)

G(1) mass (GeV)


Emmanuelle perez cea saclay dsm dapnia spp

m2 = 0 = ( E2-p4d2 )-qT2

 m4d2 = qT2

Kaluza-Klein Gravitons in Large Extra Dim

Very different phenomenology if “large” extra dimensions.

G(k) with quantized momentum qT = k/R in extra dim :

R  0.1 mm i.e. 1/R  1 meV  Mass “continuum”,

“first” states very light !!

ADL Prelim., Summer 04

Coupling of G(k) to SM fields  1 / MPl  G(k) stable !

e+e-  G (k)

  • Direct production at colliders

n=2 : MD > 1.6 TeV

n=4 : MD > 0.9 TeV

compensated by huge multiplicity of states

1 / MPl

  • Indirect effect on SM aplitudes due to virtual exchange :

D0 Run II Prelim.

200 pb-1

ee & 

SM + MS = 1.1 TeV

Effective coupling : A  / MS4

QCD

“fake”

D0 Run II + Run I, ee &  : MS > 1.43 TeV

Most stringent collider bound

Tevatron 2 fb-1 MS up to  2 TeV

Rencontres du VietNam, 08/04

E. Perez


Conclusions

Conclusions

The search for new physics is a very active field.

Tevatron & HERA are working very well, the experiments might “see” something

in the near future !

Constraints set on many models, often the most stringent up to date.

The example of SUSY searches shows the nice complementarity between

different experimental approaches :

direct searches, rare decays, precision measurements, Dark Matter searches …

“Searches” is a very rich field of physics.

It is likely to remain the case – even more ? – after direct evidence for

New Physics at (e.g.) the LHC

( if SUSY : consistent value for LSP, additional CP phases, mixing in the

squark sector, possible relations with the  mixing etc …)

No doubt that using most of the experimental data to reach the understanding

we aim at will be fun !

Rencontres du VietNam, 08/04


Backup divers

Backup & Divers…

Rencontres du VietNam, 08/04


Emmanuelle perez cea saclay dsm dapnia spp

-j-

“Signature Based” Searches for NP

Pionnered by DZero with

the full Run I sample

  • (Quasi) “model-independent” search for new physics :

  • definition of objects (e, , , , jet, W, Z, …)

  • look at data vs SM in all “channels” with > 1 object

  • in each channel, find the part of  space with largest deviation (e.g. in M,  pT )

  • quantify the agreement using “Gedanken” (Mock, MC) expts

D0, PRD64, 012004 (2001)

# Events

Applied recently to the full sample of H1 data

H1, contrib paper #195

H1 Prelim

2B

45 pb-1

  • overall very good agreement H1 data / SM

  • retrieves the “lepton-jet-ET,miss” and

  • “multi-electron” anomalies

  • (dedicated analyses might be more sensitive)

3B

HERA-II

Requires a very good understanding of

detector & backgrounds !

4B

Rencontres du VietNam, 08/04


Emmanuelle perez cea saclay dsm dapnia spp

Excited quarks & other j-j resonances

  • Dijet resonances predicted in various models

Narrow

resonances

compared to

(Mjj)  10% Mjj

  • New fermions, e.g. excited quarks

  •  expect signal in q /Z, q W depending on fs vs f & f’

  • new gauge bosons, Z’, W’(but signal mainly in the dilepton channels)

  • new massive colored bosons, e.g. SU(3)1 x SU(3)2 SU(3)QCD

  • ( chiral color, colorons, topgluons…)

q

q

q*

g

g

fs / 

  • Look for a narrow resonance in the di-jet spectrum : use a simple background

  • parametrization for d/dM and search for bumps  resolution

CDF Run II, 75 pb-1, Prelim.

 X BR (pb)

  • Axigluon & (flavor univ.) colorons :

assuming

(qqg) = (qqG)

M > 1130 GeV

First direct bound > 1 TeV !!

10

  • Excited quarks :

1

M > 760 GeV

(f=f’=fs=1,  = M)

Resonance mass (GeV)

200

1100

Rencontres du VietNam, 08/04


Emmanuelle perez cea saclay dsm dapnia spp

HERA events with isolated lepton + PT,miss

HERA I data

HERA I

Rencontres du VietNam, 08/04


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