Cosmology/DM - II

1. Cosmology/DM - II Konstantin Matchev

2. Outline of the lectures • All lecture materials are on the web: http://www.phys.ufl.edu/~matchev/PiTP2007 • Yesterday: became familiar with MicrOMEGAs. Forgot to mention: • Bug in linking of libraries in case of new models • MicrOMEGAs can compute indirect detection yields • HW from Simulation Practicum at PiTP 2005 still applicable • Earlier today: discussed several new physics models and their respective dark matter candidates • concentrate on WIMPs in SUSY and UED • Now: discuss how collider and astro experiments can • discriminate between alternative models • determine DM properties • Homework exercises throughout today’s lectures

3. Large Hadron Collider CMS Jura Ebunch = 44 kJ ECM = 14 TeV ATLAS CERN

4. The X7 argument Where is the Higgs? How do we know LHC will find anything new or interesting?

5. c c SM c SM SM c c c c SM SM SM c SM SM Avenues for WIMP detection • Potentially observable signals at colliders. • Potentially observable signals of direct DM detection. • Potentially observable signals of indirect DM detection.

6. c c SM SM Dark Matter at colliders: model-independent approach c c SM SM • Relate the WIMP annihilation rate in the early Universe to the WIMP production rate at colliders. Detailed balancing: • Predict the WIMP pair production rate • Known parameters • Unknown parameters • Not an observable signature! What if ? Birkedal,KM,Perelstein 2005

7. Detector Schematics Note the absence of a “Missing energy calorimeter”

8. DM production at colliders • In order to observe the missing energy, the DM particles must recoil against something visible • If some sort of ISR (initial state radiation), model-independent prediction still possible, using soft/collinear factorization • Very challenging experimental signature, does not seem to work • Give up model-independence, look for production of the other, heavier states in the model • At LHC: typically the colored superpartners/KK partners • Problems: • Proliferation of relevant model parameters • Complicated event topologies • Combinatorics confusion • Missing energy is challenging Birkedal,KM,Perelstein 2005

9. Squark gluino production Full Geant4 Detector Simulation 6 hard jets leptons 2 LSPs + 4 ’s SUSY Signature: MET + Jets + …

10. MET Cleaning from Tevatron • MET is very powerful SUSY discriminator • Difficult part is to convince yourself that there is a real excess! • Tevatron teaches us • MET is not easily understood! • Non-collisional backgrounds • Beam halo • Cosmic muons • Detector Effects • Instrumental Noise • Hot/dead channels (DQM) Run II V. Shary CALOR04 e/ Run II junk jets D. Tsybychev, Fermilab-thesis-2004-58

11. Jets Low luminosity Pileup included ET Resolution Stochastic term  125% / √ET Constant term  3% Angular Resolution High ET Jets: better than calo cell size ( x  = 0.087 x 0.087) Missing Transverse Energy Low luminosity Pileup included <MET> from QCD Stochastic term  123% / √ET 1700 GeV ET700 GeV PT dijets  50 GeV observed MET MET  Resolution Low MET : approaches Jet size High MET : approaches calo cell size Jet/MET Reconstruction Performance QCD MET CMS CMS Jets

12. Testing dark matter at colliders • OK, so we see a missing energy signal at the LHC. What next? Is it due to dark matter? • Look for confirmation from dark matter direct detection experiments. Colliders and astroparticle experiments test very different timescales. If signal seen in both, compare • Mass • Interaction strength • Is it a thermal relic? Test the WIMP hypothesis: • Assume a model framework (discriminate look-alikes) • Measure the model parameters • Constrain the annihilation cross-section in the early Universe.

13. mass • Spins differ by 1/2 same as SM same as SM • Higher levels no yes no Supersymmetry or Extra Dimensions?

14. SUSY or UED? Part I • Look for level 2 KK modes of UED Datta,Kong,KM 2005 Datta,Kong,KM 2005

15. q Q q Z 1 1 ( ) ~ ± l near c 0 m l 2 ( ) 1 ~ m l far g m l 1 ~ c 0 1 SUSY or UED? Part II • 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

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

17. 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 Barr 2004

18. 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?

19. HW PRECISION SUSY @ LHC • Next, measure the model parameters • Only mass differences directly measurable @ LHC: need to overconstrain the system • Couplings are even more difficult • The “inverse problem” is tough! Weiglein et al. (2004)

20. Contributions to NeutralinoWIMP Annihilation Jungman, Kamionkowski, Griest (1995)

21. What do we know? • Winning entry in the 2003 annual “Foot in mouth” award by the Plain English Campaign: • “As we know, there are known knowns; there are things we know we know.” • “We also know there are known unknowns; that is to say we know there are some things we do not know.” • “But there are also unknown unknowns - the ones we don't know we don't know.”

22. Testing the WIMP Hypothesis Birkedal,KM 2004 • SUSY parameters • Relevant for DM • Irrelevant for DM • … but also • Measured* • Unknown • Consider all possible allowed variations of the “unknowns”

23. LHC/ILC determination of relic densities has now been studied by many groups. Allanach, Belanger, Boudjema, Pukhov (2004) Moroi, Shimizu, Yotsuyanagi (2005) Baltz, Battaglia, Peskin, Wizansky (2006) Bottom line: LHC results are not always good, but ILC removes degeneracies How well can one do? Baltz, Battaglia, Peskin, Wizansky (2006)

24. IDENTIFYING DARK MATTER Are Whep and Wcosmo identical? Calculate the new Whep Yes No Yes Which is bigger? Congratulations! You’ve discovered the identity of dark matter and extended our understanding of the Universe to T = 10 GeV, t = 1 ns (Cf. BBN at T = 1 MeV, t = 1 s) Did you make a mistake? Yes Wcosmo Whep No Yes Does it decay? No No Can you discover another particle that contributes to DM? Yes Are you sure? No Can you identify a source of entropy production? Yes No No Yes Think about the cosmological constant problem No Does it account for the rest of DM? Can this be resolved with some wacky cosmology? Yes Courtesy of J.Feng, inspired by my T-shirt, IAS Princeton 2005

25. Several DM species? Kination domination SuperWIMPS gravitino, KK graviton SuperWIMPS inherit the WIMP miracle, but relic abundance is reduced by SM NLSP G̃ Discrepancies are interesting! Salati 2002 Chung,Everett,Kong,KM 2007 Feng,Rajaraman,Takayama 2003

26. c c SM c SM SM c c c c SM SM SM c SM SM Avenues for WIMP detection • Potentially observable signals at colliders. • Potentially observable signals of direct DM detection. • Potentially observable signals of indirect DM detection.

27. Direct Detection • Expected signal rates all over the place • (Coherent) spin-independent scattering most promising for most WIMP candidates • Theorists: cq scattering Experimentalists: c nucleus scattering Compromise: cp scattering • MicrOMEGAs does not compute this, but DarkSUSY can.

28. Indirect Detection Dark Matter Madlibs! Dark matter annihilates in ________________ to a place __________ , which are detected by _____________ . particlesan experiment

29. Dark Matter annihilates in the galactic center to a place photons , which are detected by GLAST, HESS, … . some particlesan experiment HESS COLLIDERS ELIMINATE PARTICLE PHYSICS UNCERTAINTIES, ALLOW ONE TO PROBE ASTROPHYSICAL DISTRIBUTIONS Very sensitive to halo profiles near the galactic center Particle Physics Astro- Physics

30. Dark Matter annihilates in the halo to a place positrons , which are detected by AMS on the ISS . some particlesan experiment Cheng,Feng,KM 2002

31. Dark Matter annihilates in the center of the Sun to a place neutrinos , which are detected by AMANDA, IceCube . some particlesan experiment n m (km-2 yr-1) AMANDA in the Antarctic Ice Feng,KM,Wilczek 2000

32. Final project • Implement your (advisor’s) favorite dark matter model as CalcHEP model files • Use MicrOMEGAs to calculate the relic density • Use MicrOMEGAs to estimate the indirect detection rates • Use CalcHEP to estimate the size of the collider signals at LHC/ILC