Extra Dimensions: From Colliders to Cosmology Large Extra Dimensions (Primordial Black Holes) Universal Extra Dimensions (KK Bino) Warped Extra Dimensions.
Published byModified over 4 years ago
Presentation on theme: "Extra Dimensions: From Colliders to Cosmology Large Extra Dimensions (Primordial Black Holes) Universal Extra Dimensions (KK Bino) Warped Extra Dimensions."— Presentation transcript:
Extra Dimensions: From Colliders to Cosmology Large Extra Dimensions (Primordial Black Holes) Universal Extra Dimensions (KK Bino) Warped Extra Dimensions (KK R ) Michell Symposium 2007 J. Hewett Collider signals & DM properties * * Thanks to T. Tait!
Kaluza-Klein tower of particles E 2 = (p x c) 2 + (p y c) 2 + (p z c) 2 + (p extra c) 2 + (mc 2 ) 2 In 4 dimensions, looks like a mass! p extra is quantized = n/R Small radiusLarge radius Small radius gives well separated Kaluza-Klein particles Large radius gives finely separated Kaluza- Klein particles Tower of massive particles
Large Extra Dimensions Motivation: solve the hierarchy problem by removing it! SM fields confined to 3-brane Gravity becomes strong in the bulk Arkani-Hamed, Dimopoulos, Dvali, SLAC-PUB-7801 Gauss’ Law: M Pl 2 = V M D 2+ , V = R c M D = Fundamental scale in the bulk ~ TeV
Kaluza-Klein Modes in a Detector Indirect SignatureMissing Energy Signature pp g + G n JLH Vacavant, Hinchliffe
Graviton Exchange Modified with Running Gravitational Coupling Insert Form Factor in coupling to parameterize running M * D-2 [1+q 2 /t 2 M * 2 ] -1 Could reduce signal! D=3+4 M * = 4 TeV SM t= 1 0.5 JLH, Rizzo, to appear
Constraints from Astrophysics/Cosmology Supernova Cooling NN NN + G n can cool supernova too rapidly Cosmic Diffuse Rays NN NN + G n G n Matter Dominated Universe too many KK states Neutron Star Heat Excess NN NN + G n becomes trapped in neutron star halo and heats it - Cullen, Perelstein Barger etal, Savage etal Hannestad, Raffelt Hall, Smith Fairbairn Hannestad, Raffelt
Astrophysical Constaints * : M D in TeV = 2 3 4 5 Supernova Cooling 9 0.66 0.01 Cosmic Diffuse -rays Sne 28 1.65 0.02 Sne Cas A 14 1.2 0.02 Neutron Star 39 2.6 0.4 Matter Dominated Universe 85 7 1.5 Neutron Star Heat Excess 700 25 2.8 0.57 Low M D disfavored for ≤ 3 * Can be evaded with hyperbolic manifolds - Starkman, Stojkovic, Trodden Hannestad, Raffelt
Black Hole Production @ LHC: Black Holes produced when s > M * Classical Approximation: [space curvature << E] E/2 b b < R s (E) BH forms Geometric Considerations: Naïve = R s 2 (E), details show this holds up to a factor of a few Dimopoulos, Landsberg Giddings, Thomas
Decay Properties of Black Holes (after Balding): Decay proceeds by thermal emission of Hawking radiation At fixed M BH, higher dimensional BH’s are hotter: N ~ 1/ T higher dimensional BH’s emit fewer quanta, with each quanta having higher energy Harris etal hep-ph/0411022 Multiplicity for n = 2 to n = 6 n determined to n = 0.75 @ 68% CL for n=2-6 from T H and This procedure doesn’t work for large n
p T distributions of Black Hole decays Provide good discriminating power for value of n Generated using modified CHARYBDIS linked to PYTHIA with M * = 1 TeV
Production rate is enormous! 1 per sec at LHC! JLH, Lillie, Rizzo Determination of Number of Large Extra Dimensions
Primordial Microscopic Black Holes Produced in high-energy collisions in early universe Rapid growth by absorption of matter from surrounding plasma Demand: 1.Black Holes not overclose the universe 2.Must not dominate energy density during BBN Mass density determined by T I Conley, Wizansky Excluded Empty Bulk Thermalized Bulk
Universal Extra Dimensions All SM fields in TeV -1, 5d, S 1 /Z 2 bulk No branes! translational invariance is preserved tree-level conservation of p 5 KK number conserved at tree-level broken at higher order by boundary terms KK parity conserved to all orders, (-1) n Consequences: 1.KK excitations only produced in pairs Relaxation of collider & precision EW constraints R c -1 ≥ 300 GeV! 2.Lightest KK particle is stable (LKP) and is Dark Matter candidate 3.Boundary terms separate masses and give SUSY-like spectrum Appelquist, Cheng, Dobrescu
Universal Extra Dimensions: Bosonic SUSY Phenomenology looks like Supersymmetry: Heavier KK particles cascade down to LKP LKP: Photon KK state appears as missing E T SUSY-like Spectroscopy Confusion with SUSY if discovered @ LHC ! Chang, Matchev,Schmaltz Spectrum looks like SUSY !
How to distinguish SUSY from UED I: Observe KK states in e + e - annihilation Measure their spin via: Threshold production, s-wave vs p-wave Distribution of decay products However, could require CLIC energies... JLH, Rizzo, Tait Datta, Kong, Matchev
How to distinguish SUSY from UED II: Observe higher level (n = 2) KK states: –Pair production of q 2 q 2, q 2 g 2, V 2 V 2 –Single production of V 2 via (1) small KK number breaking couplings and (2) from cascade decays of q 2 Discovery reach @ LHC Datta, Kong, Matchev
How to distinguish SUSY from UED III: Measure the spins of the KK states @ LHC – Difficult! Decay chains in SUSY and UED: Form charge asymmetry: Works for some, but not all, regions of parameter space Smillie, Webber
Identity of the LKP Boundary terms (similar to SUSY soft-masses) –Induced @ loop-level (vanish @ cut-off) –Determine masses & couplings of entire KK tower 1 ≪ 2 ≪ 3 –Smallest corrections to U(1) KK state –NLKP is e R (1) M ~ 1/R > v –LKP is almost pure Bino KK B (1) Bino-Wino mass matrix, n=1
Thermal Production and Freeze Out Assume LKP in thermal equilibrium in early universe Falls out of equilibrium as universe expands Below freeze-out, density of LKP WIMPS per co-moving volume is fixed For 1 TeV KK, T f = 40 TeV
Co-annihilation e R (1) may substantially affect relic density if it is close in mass to B (1) e R (1) has same interaction efficiency – freeze-out temp is unaffected e R (1) left after freeze-out –Eventually e R (1) e (0) + B (1) Net relic density of B (1) is increased
Relic Density = scaled mass splitting between e R (1) and B (1) = 0.05 = 0.01 h 2 = 0.11 0.006 yields for R: Tait, Servant … 1 flavor … 5 flavors 5d range of 600-900 GeV 6d range of 425-625 GeV B (1) alone
More Complete Calculations WMAP Kong, MatchevBurnell, Kribs Quasi-degenerate KK e L (1) Quasi-degenerate KK quarks and gluons = 0.01 solid 0.05 dashed
Add Gravity in the Bulk m G1 > m B1 m G1 < m B1 KK graviton decays into B (1) (m WG = KK scale from relic density without graviton) Shah, Wagner Super-WIMPS! Feng, Rajaraman, Takayama
Direct Detection of LKP LKP – nucleon scattering: Tait, Servant
Localized Gravity: Warped Extra Dimensions Randall, Sundrum Bulk = Slice of AdS 5 5 = -24M 5 3 k 2 k = curvature scale Naturally stablized via Goldberger-Wise Hierarchy is generated by exponential!
Number of Events in Drell-Yan @ LHC For this same model embedded in a string theory: AdS 5 x S Kaluza-Klein Modes in a Detector: SM on the brane Davoudiasl, JLH, Rizzo Unequal spacing signals curved space
Kaluza-Klein Modes in a Detector: SM off the brane Fermion wavefunctions in the bulk: decreased couplings to light fermions for gauge & graviton KK states gg G n ZZ @ LHC gg g n tt @ LHC Agashe, Davoudiasl, Perez, Soni - Lillie, Randall, Wang
Issue: Top Collimation Lillie, Randall, Wang gg g n tt - g 1 = 2 TeV g 1 = 4 TeV
Warped Extra Dimension with SO(10) in the bulk Splits families amongst 16 of SO(10) with different Z 3 charges: Baryon symmetry in bulk Lightest Z-odd particle, R ’ KK state, is stable Agashe, Servant Gives correct relic density for wide range of masses Bold-face particles have zero-modes