Overview of Extra Dimension studies at LHC

1
Overview of Extra Dimension studies at LHC

• Vladimir Litvin, Caltech, CMS

2
Outline

• CMS studies
• RS-1 graviton di-electron decay study (2005)
• RS-1 graviton di-photon decay study (2006)
• Radion decay study (2005)
• ATLAS studies
• Large extra dimension (2001)
• Randall-Sundrum graviton (2001)
• KK boson study (2001)

3
D0 results on Search for Randall-Sundrum
Gravitons in Dilepton and Diphoton Final State
hep-ex/05050189 May 2005
RS-1 Graviton masses up to 785 (250) GeV for c
0.01 (0.1)
4
RS-1 graviton cross-sections and lorentzian widths

RS-1 graviton cross-sections (left) and
lorentzian widths (right). Square markers for the
cross-sections are for qq production, triangle
markers are for gg and circles are for the total
cross-section
5
RS graviton di-electron study

• RS graviton di-electron study
• C. Collard, M-C.Lemaire, Eur. Phys. J. C40
  (2005), Num 5, 15

6
RS graviton di-electron study

• A graviton resonance with a mass of 900 GeV
  (left) and 1.1 TeV (right) and a coupling
  parameter c0.01 is displayed above the Drell-Yan
  background for an integrated luminosity of 10 fb-1

7
RS graviton di-electron study

• The figures present the expected signal above the
  Drell-Yan background for an integrated luminosity
  of 100 fb-1, for different mass hypotheses
  (M1.5, 1.75 and 2 TeV) and c0.01

8
RS graviton di-electron study

• Significance is plotted as a function of the mass
  for different integrated luminosities (from 1 to
  100 fb-1) for c 0.01 (left) and c0.1 (right).
  With 100 fb-1, CMS will be able to detect a
  graviton resonance at 5 sigma up to 1.8 TeV for
  c0.01 and 3.8 TeV for c0.1

9
RS graviton di-electron study

• The figure presents the reach for CMS in the
  (MG,c) plane for different integrated
  luminosities (from 1 to 100 fb-1), based on full
  simulation and reconstruction of CMS. The region
  of interest comes from theoretical constraints on
  the coupling parameter c and the mass MG of the
  first Kaluza-Klein excitation of graviton. With
  an integrated luminosity of 100 fb-1, CMS will
  cover the whole region of interest. Note that for
  the Drell-Yan background a K factor of 1.3 is
  taken into account but no K factor is used for
  the signal

10
RS graviton di-electron study

• We presented preliminary results on the discovery
  potential for RS-1 graviton in the di-electron
  decay mode.
• Confidence Limits for 30 fb-1
• c0.01 MG 1.41 TeV
  c0.1 MG 3.25
  TeV
• Confidence Limits for 10 fb-1
• c0.01 MG 1.21 TeV
• c0.1 MG 2.87 TeV

11
RS-1 graviton di-photon study

• RS-1 graviton di-photon study
• M.-C. Lemaire, V.Litvin, H.Newman, CMS Analysis
  Note 2005/032

12
Requested Datasets

• We have used next datasets for analysis
• Signal (see plot on the next slide)
• c0.01 M1.0, 1.25, 1.5, 1.75, 2.0, 2.25, 2.5
  TeV/c2 1k each
• c0.02 M1.0, 1.5, 2.0, 2.5, 3.0 TeV/c2 1k each
• c0.05 M1.0, 1.5, 2.0, 2.5, 3.0, 3.5 TeV/c2 1k
  each
• c0.075 M2.5, 3.0, 3.5, 4.0 TeV/c2 1k each
• c0.1 M1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5
  TeV/c2 1k each
• There are five backgrounds we need to study
• born (MSEL 0, MSUB 18)
• box (MSEL 0, MSUB 114)
• brem (MSEL 0, MSUB 14,29,115)
• QCD (MSEL 1)
• DY (MSEL 0, MSUB 1, MSTP 43 3). We are
  using PHOTOS radiation for Z boson decay - MSTJ
  41 1 was added.

13
Discovery plane for RS-1 graviton
14
RS-1 graviton cross-sections and lorentzian widths

RS-1 graviton cross-sections (left) and
lorentzian widths (right). Square markers for the
cross-sections are for qq production, triangle
markers are for gg and circles are for the total
cross-section
15
Signal backgrounds vs invariant mass
30 fb-1
16
Signal backgrounds vs invariant mass
10 fb-1
17
Significance c0.01 for L30 fb-1
Born k1.5 Box k1.2
with
MG 1.0 TeV/c2 MG 1.25 TeV/c2 MG 1.5 TeV/c2 MG 1.75 TeV/c2 MG 2.0 TeV/c2
Ns 135.8 44.0 17.6 7.3 3.9
Nbkg 15.0 8.8 4.6 1.8 1.2
S 20.6 10.1 5.9 3.9 2.6
18
Significance c0.1 for L 30 fb-1
Born k1.5 Box k1.2
with
MG 2.5 TeV/c2 MG 3.0 TeV/c2 MG 3.5 TeV/c2 MG 4.0 TeV/c2 MG 4.5 TeV/c2
Ns 103.8 31.6 9.9 3.44 1.11
Nbkg 1.11 0.35 0.13 0.06 0.02
S 27.3 15.0 8.2 4.6 2.6
19
Significance vs RS-1 graviton invariant mass
Significance plots are not taking systematic
errors into account
20
Discovery potential
21
Electron and photon discovery potential

22
Limits Uncertainties for 30fb-1

• Hard scale uncertainties
• LHApdf uncertainties
• c0.01 -55 GeV/c2
• c0.1 -152 GeV/c2
• Preselection uncertainty was calculated based on
  2 (QCD) and 1 (brem) upper limit of
  inefficiencies. It propagates to 1-2
  cross-section uncertainties and 0.1-0.15
  uncertainty in the number of background events
• c0.01 -8 GeV/c2
• c0.1 -5 GeV/c2
• Uncertainty due to the fact, that Tevatron has a
  K- factor 2 for born instead of 1.5 (D. Acosta
  et al., CDF Collaboration, PRL 95(2005) 022003)
  as we have here
• c0.01 -50 GeV/c2
• c0.1 -30 GeV/c2

4s 0.25s
C0.01 -62 GeV/c2 56 GeV/c2
C0.1 -47 GeV/c2 42 GeV/c2
23
Conclusion

• We presented preliminary results on the discovery
  potential for RS-1 graviton in the diphoton decay
  mode.
• Various confidence limits systematic
  uncertainties have been estimated hard process
  scale, LHApdf uncertainties for the signal as
  well as for the background. They are changing the
  results from 50 to 150 GeV.
• Confidence Limits for 30 fb-1 c0.01 MG
  1.61 TeV
  c0.1 MG
  3.95 TeV
• Confidence Limits for 10 fb-1 c0.01 MG
  1.31 TeV
• 
  c0.1 MG 3.47 TeV

24
CMS

• Radion study (gg-gtradion-gthh-gt2g2b )
• Left plot gg b j invariant mass for the
  irreducible background and the signal plus
  background after all selections with 30 fb-1.
  Signal was evaluated for the maximal cross
  section times branching ratios point in the
  mixing-scale parameter plane.
• Right plot g g b j invariant mass for the
  irreducible background and the signal plus
  background after all selections with 30 fb-1.
  Signal plus background distribution is shown for
  the point in mixing-scale parameter plane where
  statistical significance 5 is obtained. Dashed
  histograms correspond to the irreducible
  background calculated with the renormalization
  and factorization scales set to 0.5 MZ and 2 MZ

D. Dominici, G. Dewhirst, S. Gennai, L. Fano', A.
Nikitenko, CMS Note 2005/007
25
CMS

• Radion study (gg-gtradion-gthh-gt2g2b )
• The 5 sigma discovery contours for
  gg-gtradion-gthh-gt2gamma2b channel with 30 fb-1.
  Left plot only irreducible background was taken
  into account. Central plot total background was
  taken into account assuming that the ratio of the
  reducible to the total background is 0.4 (from
  the preliminary full simulation of the total
  background for the inclusive h-gtg g study). Right
  plot solid (dashed) line contour present the
  discovery reach without (with) systematical error
  on the background (of 4.7 ) and for the total
  background evaluated as described above.

D. Dominici, G. Dewhirst, S. Gennai, L. Fano', A.
Nikitenko, CMS Note 2005/007
26
CMS

• Radion study (gg-gtradion-gthh-gt2t2b )
• The 5 sigma discovery contours with 30 fb-1 when
  NLO background cross sections were taken at
  maximal and minimal values corresponding to the
  scale variation and PDF uncertainties.
• Left plot stat. error only is taken into
  account. Right plot stat. errors and 5 of the
  syst. uncertainty on the background are taken
  into account.

D. Dominici, G. Dewhirst, S. Gennai, L. Fano', A.
Nikitenko, CMS Note 2005/007
27
CMS

• Radion study (gg-gtradion-gthh-gt4b )
• b b j j invariant mass for the signal and
  background after all selections with 30 fb-1. NLO
  cross sections for the signal and LO for the
  background were used. Fast simulation for the
  signal and background. Background can be
  normalized in the signal free region of the
  four-jet invariant mass (assuming that radion
  mass will be known from the other channels) and
  extrapolated then to the region of the signal. To
  have 5 sigma discovery at the maximal cross
  section times branching ratios point in
  mixing-scale plane the uncertainty of the
  extrapolation should be less than 0.1 .

D. Dominici, G. Dewhirst, S. Gennai, L. Fano', A.
Nikitenko, CMS Note 2005/007
28
ATLAS

• ATLAS studies
• Large extra dimension (2001)
• Randall-Sundrum graviton (2001)
• KK boson study (2001)

29
ATLAS

• Large extra dimension, jet ETmiss (ISAJET
  AtlFast)
• Signal direct Graviton 1 jet production
• Main background jet Z(W) Z ? nn,W?ln

L.Vacavant, I. Hinchliffe (J. Phys. G Nucl.
Part. Phys. 27 (2001) 1839-1850)
30
ATLAS

• Large extra dimension, di-photon and di-lepton
  decays

pp ? ll-- X
pp ? gg X
100 fb-1
All channels combined
Kabachenko, Miagkov, Zenin (ATL-PHYS-2001-012)
10 fb-1
31
ATLAS

• Randall-Sundrum graviton di-electron decay study
  (1)

gg (qq) ? G ? ee-
B.C. Allanach, K. Odagiri, M.A. Parker, B.R.
Weber (JHEP 09 (2000) 019 ATL-PHYS-2000-029)
32
ATLAS

• Randall-Sundrum graviton di-electron decay study
  (2)

gg (qq) ? G ? ee-
HELAS has been modified to work with spin-2
particles
B.C. Allanach, K. Odagiri, M.A. Parker, B.R.
Weber (JHEP 09 (2000) 019 ATL-PHYS-2000-029)
33
ATLAS

• Radion studies

100fb-1, ? 0, ?? 1(10) TeV ? ? ??
S/?B10(.1) for 80ltm?lt160 GeV/c2 ? ? ZZ()
S/?B100(1) for 200ltm?lt600 GeV/c2
?-gthh-gtbb??
??max4.6 TeV for m? 300 GeV/c2 and ??max5.7
TeV for m? 600 GeV/c2
?-gthh-gtbb??
Require a minimum of 10 evts and
S/?B?5 ??max1.05 TeV for m? 300 GeV/c2
et ??max1.4 TeV for m? 600 GeV/c2
G.Azuelos,D.Cavalli,L.Vacavant,H.Przysiezniak
(Les Houches Workshop 2001 Proc.)
34
ATLAS

• Scenario TeV-1 (Search for KK boson decay,
  through g and Z, in ee- and mm- channels)

• Search for KK boson decays through g and Z,
  pp?ee-X or pp?µµ-X
• Cuts
• Mllgt1 TeV
• Ptlgt 20 GeV and hlt2.5
• For 100 fb-1, Mc5.8 TeV
• sgt5, Ngt10

G. Azuelos, G. Polesello, EPJ Direct C (2004)
10.1140/epjcd/s2004-02-001-y
35
ATLAS

• Scenario TeV-1 (Search for KK boson decay,
  through g and Z, with W )

• Search for KK boson decay, through g and Z, with
  W pp?e/-nX or pp?µnX (W1?l/-n)
• Backgrounds tt (semi-leptonic), WW, ZZ, WZ
• Cuts
• 1 isolated lepton (Elt10 GeV, DR0.2)
• Ptlgt 200 Gev and hlt2.5
• Ptmissgt 200 GeV
• Mtlngt 1000 GeV

G. Polesello, M. Prata, EPJ Direct, C 32 Sup.2
(2004) pp.55-67