EXOTICS

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EXOTICS Atlas-IFAE meeting Dec 21-22 Volpi Matteo
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• Exotics
• This group studies any model of a new physics,
  excluding the Standard Model (SM) and the Super
  Symmetry theory (SUSY).
• These studies can be divided into following main
  lines
• Compositeness
• New particles
• Dynamical Symmetry Breaking
• Extra Dimensions
• Others (not to be covered in this overview)

Exotics Group Convenors Samir FERRAG (University
of Oslo) Georges AZUELOS (University of
Montreal)
Group Resources http//atlas.web.cern.ch/Atlas/GR
OUPS/PHYSICS/EXOTICS/
List of very active institutions in the
group University of Montreal Columbia University
University of Oslo Hampton University .
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Compositeness physics (CT)

• Excited Leptons and Quarks (3 more notes)
• Production of Excited Neutrinos at the LHC
  SN-ATLAS-2004-047
• Excited Quarks at LHC W/ZJet Channel
• ATL-PHYS-2000-030 (to be shown)
• Excited Quarks at LHC Double Jets Channel
• ATL-PHYS-99-024 (to be shown)
• Search for Excited Electrons with ATLAS at LHC
  Z,W decay ATL-PHYS-2002-014
• Quark substructure (to be shown) Activities in
  progress
• High PT jet production and their angular
  distributions
• in quark-lepton compositeness model
• Quark-lepton compositeness
• Searching for quark-lepton compositeness at LHC
  ATL-PHYS-94-038
• High PT jet production and quark-lepton
  compositeness -- note in preparation
• Diquarks
• Resonance Production of Diquarks at the CERN LHC
• Phys. Rev. D59 (1998) 015008-1-015008-5

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CT Excited Quarks at LHC W/ZJet Channel
Double Jets Channel (jj)
Resonant production of excited quarks (q) at the
CERN LHC by the quark gluon fusion process and
their subsequent decay to ordinary quarks and
weak gauge bosons W and Z.
q-gtqW
q -gtqZ
2000 analysis
2000 analysis
Distributions of the reconstructed mass of jet
lepton neutrino system for the backgrounds and
for the excited quark mass of 1 TeV (qW and qZ
decay), with main cuts indicated. (f is the
couplings determined by the compositeness
dynamics).
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1999 analysis
2000 analysis
q -gtqZ q-gtqW
q-gtjj
5s with 100 pb-1
Excited quark signal significance for q-gtqW
(solid lines left),q-gtqZ (dashed lines left)
and q-gtjj (in the right) at the integrated
liminosity of 100pb-1. The red lines shows the
5s event.
The mass reaches is about 3.7 TeV for qW, is
about 2TeV for qZ and about 3.2 Tev for jj
channels are achieved.
The CDF and D0 Collaborations have excluded the
mass region (2000 analysis) -below 540GeV for
both photonjet (j) and Wjet ( Wj ) decay
channels -the mass region 80 lt m lt 570 GeV
using the dijet ( jj ) channel. -mass ranges
200lt m lt 520 GeV and 580 lt m lt 760 GeV ( for
excited quarks in the double jets channel, by
CDF). -the mass region 200 lt m lt 720 GeV for
all channels (by D0).
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Quark substructure I (CT)
One can describe effects of quark
compositeness by analogy of Fermi theory.
Tevatron up to ? ? 2 TeV no quark structure
seen.
Two jets with the highest pT were chosen (?1,?2)
Dijet angular distribution
2005 analysis
To cut on chi distribution (on the plot)
a Way to quantify difference between SM QCD and
QCDCT
(Lukas Pribyl ,FZU,Prague 13 December 2005)
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Quark substructure II (CT)
Values of integral luminosity to reach R1 5
(significance) for various compositeness scales
No systematic errors included.
To spot small compositeness scales (5 TeV), an
integrated luminosity 15 pb-1 of
data-taking should be enough. The systematic
errors (PDF uncertainties, calorimeter
non-linearity) are not included (analysis in
progress). Discovery limits are still not
definitive.
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(Lukas Pribyl ,FZU,Prague 13 December 2005)
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New particles physics

• Leptoquarks (3 more notes)
• Leptoquark Single and Pair production at LHC with
  CalcHEP/CompHEP in the complete model
  ATL-COM-PHYS-2005-004
• Prospects for Scalar Leptoquark Discovery at the
  LHC ATL-COM-PHYS-2004-071
• Leptoquarks CompHep Atlfast study (activities
  in progress)
• New gauge bosons and gauge symmetries (6 notes
  more)   
• Z' studies in full simulation (to be shown)
• Prospects for the Search for a Doubly-Charged
  Higgs in the Left-Right Symmetric
• Model with ATLAS SN-ATLAS-2005-049
• Z' asymmetries and distinguishing models
  (activities in progress)
• Z' ? t t Z coupling to third family
  (activities in progress)
• Heavy quarks and leptons (1 note more)
• Charged Heavy Lepton Pair Production in ATLAS
  /Detecting Exotic Heavy Leptons at the LHC
  ATL-PHYS-2003-014
• Sensitivity Study for a Z' boson decaying into
  two right-handed Majorana neutrinos at LHC in the
  ATLAS detector ATL-PHYS-2000-034
• Majorana neutrinos in Left-Right Symmetric model
  (activities in progress)
• Z,gamma,Z' --gt LL-  --gt 6 e-'s (activities in
  progress)

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New particles physics
New gauge bosons and gauge symmetries
A large variety of theories beyond the Standard
Model predict additional gauge bosons, or new
states of the already know gauge bosons. The
Z-gt e e- channel is the most studied because it
benefits from the high detector resolution of
Atlas for electrons while the decay channel is
very clean. The potential of the Atlas detector
to measure the total decay width and the leptonic
forward backward asymmetry in several Z models
has been studied. These two variables were found
to be correctly measured with a realistic
integrated luminosity 100 pb-1 and to bring
informations on the underlying model. (Z' -gt ee-
studies in full simulation (DC1) Schäfer, M
Ledroit, F Trocmé, Benjamin ATL-COM-PHYS-2005-026
) By the Z rapidity distribution study to
extract the coupling constant to quarks involved
in the initial state . (M.Dittmar,A.Nicollerat,A.D
jouadi, Phys. Lett. B583 (2004) 111) Also the
forward backward asymmetry as a function of the
Z rapidity is another way to probe the quark
couplings constant. (J.L.Rosner, Phys. Rev. D35
(1987) 2244 M.Schafer , Diploma Thesis
(September 2004),LPSC-04-59)

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Dynamical Symmetry Breaking

• Search for hadronic decays of ZH and WH in the
  Little Higgs model
• ATL-COM-PHYS-2005-001
• Characteristic decays Z'/W'--gtZ/WH in the Little
  Higgs model
• ATL-COM-PHYS-2004-032
• Vector Boson Scattering in the Chiral Lagrangian
  Model- ATL-PHYS-99-006
• Search for Technicolor Signals with the ATLAS
  Detector- ATL-PHYS-99-020
• Exploring Little Higgs Models at the LHC
• SN-ATLAS-2004-038 (in details)
• Search for hadronic decays of ZH and WH in the
  Little Higgs model ATL-COM-PHYS-2005-001
• Measuring the rate of non-resonant high mass
  longitudinal gauge boson pairs in ATLAS -
  ATL-PHYS-99-023
• WZ resonance in full simulation (activities in
  progress)
• Other projects
• models with singlet quark , B. A. Dobrescu and C.
  T. Hill,  hep-ph/9712319
• topgluons hep-ex/9809022
• colorons in dijet mass spectrum hep-ph/9809472
• Z'  ? t t    resonance in topcolor model
  hep-ph/9911288  
• Z' ? t t Z coupling to third family
  hep-ph/0007286
• more on little higgs, with T-Parity,
  hep-ph/0308199, hep-th/0403036

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Exploring Little Higgs Models at the LHC
Littlest Higgs models have been proposed as
possible solutions to the hierarchy problem of
the Standard Model. In this model, a new charge
2/3 quark, T, which is an electroweak singlet is
predicted. T-quark mixes with the top quark and
hence decays to Wb, th and tZ final states. The
theory constrain is mT lt 2Tev x (mh/200Gev)2.
All the analysis is at integrated luminosity of
300 fb-1 - long one
2004 analysis
T-gtZt
bcgd
Reconstructed mass of the Z and t . The signal T
-gtZt is shown for a mass of 1000 GeV.
Accessible regions for 5s discovery of the
neutral gauge bosons AH and ZH as a function of
the scale f.
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Using the ATLAS can be to reveal the
characteristic particles of the Little Higgs
models
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Extra Dimensions I

• Large Extra Dimensionsjets Etmiss
• Signals of Models with Large Extra Dimensions in
  ATLAS SN-ATLAS-2001-005
• Large extra dimensions Virtual Graviton Exchange
• Sensitivity of the ATLAS detector to extra
  dimensions in di-photon and di-lepton production
  processes - ATL-PHYS-2001-012 (to be shown)
• Narrow Graviton Resonances
• Exploring Small Extra Dimensions at the LHC
  ATL-PHYS-2002-031
• Coupling Unification
• Testing extra-dimensions by RGE - Sept.
  2001 hep-ph/0110217Radion
  
• Search for the Randall Sundrum Radion using the
  ATLAS SN-ATLAS-2002-019
• Other Bulk Scalars
• A full simulation analysis of the graviscalar
  discovery potential ATL-PHYS-PUB-2005-008
• Dimensionless Coupling of Bulk Scalars at the
  LHC  SN-ATLAS-2004-044
• Gauge Excitations
• KK excitation of the W boson SN-ATLAS-2003-036
• Singlet Neutrino
• The hadronic tau decay of a heavy charged Higgs
  in models with singlet neutrino in large extra
  dimensions ATL-PHYS-2001-019
• TransPlanckian Elastic Collisions (in progress)

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Sensitivity of the ATLAS to extra dimensions in
gg and ll production processes
The processes of photon and lepton pair
production are studied in models where gravity
can propagate in large extra dimensions. The
signal and backgrounds are simulated with ATLFAST
program.
In this scenario a new fundamental mass scale MS
of gravity in (4n)D space appears
Where R is the radius of n additional dimensions
2001
gg ll production maximal reach at 5s level
in the scale MS as a function of critical cut on
the invariant mass Mmin. Solid lines are for L
10 fb-1, dashed for L100 fb-1(integrated)
2001
Gravity with extra dimensions could be probed up
to a scale Msmax

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Extra Dimensions II

• Black Holes (to be show)
• Exploring Higher Dimensional Black Holes at the
  LHC ATL-PHYS-2004-033
• Study of Black Holes with the ATLAS detector at
  the LHC -- ATL-PHYS-2003-037
• Singlet Neutrino
• The hadronic tau decay of a heavy charged Higgs
  in models with singlet neutrino in large extra
  dimensions ATL-PHYS-2001-019
• Universal Extra Dimensions
• Dijets and Missing Energy in ATLAS from a
  Universal Extra Dimension ATL-PHYS-PUB-2005-003
• Gravity-mediated UED and the two-photon channel
  (activities in progress)
• Dark energy
• Dark Energy Signals (activities in progress)
• tt spin correlations
• Effect of Graviton on Top-Antitop Spin
  Correlations at LHC in Extradimensional Theory
  (activities in progress)
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  Other projects
• Calculation of process of production of pair of
  KK gluons and/or quarks signal di-jets
• ETmiss (assume KK states decay) hep-ph/0201300
• Single Kaluza Klein Production in Universal Extra
  Dimensions hep-ph/0407253
• .

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Black Holes (BH) I
In some extra dimension theories with a TeV
fundamental Planck scale, black holes could be
produced in LHC collider.
Micro Black hole events were simulated using the
Cambridge based MC program Charybdis.
BH decay by Hawking evaporation q and g (72)
leptons (11) Z and W (8) n and G (6) H (2).
Ratio hadron lepton is (5 1) accounting for
t, W, Z and H decays.
Decay of 6.1 TeV Black Hole High multiplicity
events
Due to their high mass, black hole decays are
very spectacular events with a large visible
transverse energy
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Black Holes (BH) II
Integrated luminosity with which discovery is
achieved in (MP,n) plane. Where MP the
fundamental scale Planck and n the number of
extra dimensions
2003 analysis
We find an excess of events from the SM
backgrounds for the integrated luminosity of 1
fb-1 if MP lt 5 TeV and with the integrated
luminosity of 100 pb-1 if MP lt 4 TeV.
New technique determine the model parameters.
2004 analysis
We conclude that in this case the Planck mass can
be determined to 15 and the number of extra
dimensions to 0.75, with strongly correlated
errors
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Summary

• The LHC has to open window at the world of the
  new physics, but the number of speculations on
  what this window might be, is big.
• Wide variety of topics is studied in the exotic
  WG,
• I only reported the status of some analyses,
  rather personally chousen.
• I think the more realist model is the
  compositeness for the continuity of the discovery
  in history of physics.
• The trigger studies are those that, in my
  personal opinion, logically has to be done now in
  the EWG.
• At the moment Atlfast studies are validated with
  full simulation.

Most useful references
CURRENT STATUS AND FUTURE PLANS Rome Workshop
talks
http//atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/EXOT
ICS/
Exotics Wiki (With Links to Privately Produced
Samples)
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https//uimon.cern.ch/twiki/bin/view/Atlas/Exotics
WorkingGroup