Minimal UED in CalcHEPCompHEP

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Minimal UED in CalcHEP/CompHEP

• AseshKrishna Datta, Kyoungchul Kong, Konstantin
  Matchev

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Supersymmetry

• Extra dimension, but fermionic (qs anticommute)
• SUSY relates particles and superpartners
• The SM particles and their superpartners have
• Spins differing by ½
• Identical couplings
• Introduce negative R-parity for superpartners
• Forbids dangerous interactions allowing proton
  decay
• Makes the lightest superpartner stable (dark
  matter!)

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Universal Extra Dimensions
Appelquist,Cheng,Dobrescu 2000

• Bosonic extra dimension with a new coordinate y
• An infinite tower of Kaluza-Klein (KK) partners
• for all Standard Model particles
• The SM particles and their KK partners have
• Identical spins
• Identical couplings
• Automatic KK-parity for KK partners
• Makes the lightest KK partner stable (dark
  matter!)

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Supersymmetry or Extra Dimensions?
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Minimal UED Phenomenology

• Dark matter

• Collider signatures
• Missing energy
• Jets
• Leptons

Servant, Tait 2002 Burnell, Kribs 2005 Kong, KM
2005
Cheng,KM,Schmaltz 2002
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Our MUED Implementation

• For details, see the manual (25 pages!) on the
  team web page
• CompHEP/CalcHEP require
• List of particles with masses and widths
• One-loop mass corrections are included
• The 2-body decay widths are implemented
• We also include n2 KK modes
• List of input parameters
• Rinv the inverse radius of the extra dimension
• LR the number of KK levels below the cutoff
  scale
• RG a switch to run gauge coupling RGEs
• scaleN the scale for evaluating the coupling
  constants
• List of interaction vertices (see manual)
• We also include the KK-number violating
  interactions of n2 KK gauge bosons

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SUSY or UED? Part I

• Look for level 2 KK modes of UED

Datta,Kong,KM 2005
Datta,Kong,KM 2005
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SUSY or UED?

• Can we measure the spins? Very difficult

SUSY

UED

• Recently, several proposed methods to measure
  spins
• and thus discriminate SUSY from UED
• Make assumptions what you know and can do
• Propose a measurement
• Interpret

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Measuring spins at a lepton collider
Battaglia,Datta,DeRoeck,Kong,KM 2005

• Find 16 bln dollars, build a 3 TeV CLIC
• Study the processes shown in UED or SUSY
• Compare the angular distributions of the muons in
  the Lab
• Find out if UED or SUSY

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Barr Asymmetry

• Find the right jet among the 8-10 jets in the
  event (all of them look very similar)
• Assume you know the masses of all new particles
• Plot the asymmetry A-
• Find out if UED or SUSY

Kong,KM 2006
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Validation Tests
Datta,Kong,KM 2005
Smillie,Webber 2005

• Asymmetry plots for MUED with Rinv500 GeV and a
  SUSY model with a matching spectrum

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Validation Tests
Datta,Kong,KM 2005
Smillie,Webber 2005

• Invariant mass plots for MUED with Rinv500 GeV
  and a SUSY model with a matching spectrum

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Validation Tests
Datta,Kong,KM 2005
Smillie,Webber 2005

• Invariant mass plots for point SPS1a in SUSY and
  a UED model with a matching spectrum

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Other Validation Tests

• LKP annihilation cross-sections, as well as all
  possible co-annihilation cross-sections
• Servant,Tait 2002 Burnell,Kribs 2005
• KK production cross-sections
• Rizzo 2001 Macesanu,McMullen,Nandi 2002
• KK decay widths and branching fractions
• Cheng,KM,Schmaltz 2002
• Carone,Conroy,Sher,Turan 2003

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Pooh, is this Piglet flying like a kite, or is it
a kite that looks like Piglet?
Pooh, is this SUSY that looks like UED, or is it
UED looking like SUSY?