Flavour Physics and Dark Matter Introduction Selected Experimental Results Impact on Dark Matter Searches Conclusion Matthew Herndon University of Wisconsin Dark Side of the Universe 2007, Minneapolis Minnesota

2 Why Beyond Standard Model? Standard Model predictions validated to high precision, however Connection between collider based physics and astrophysics becomes more interesting each year M. Herndon Gravity not a part of the SM What is the very high energy behaviour? At the beginning of the universe? Dark Matter? Astronomical observations of indicate that there is more matter than we see Where is the Antimatter? Why is the observed universe mostly matter? Standard Model fails to answer many fundamental questions DSU 2007 Many of those questions come from Astrophysics and Cosmology

3 Searches For New Physics How do you search for new physics at a collider? Direct searches for production of new particles Particle-antipartical annihilation: top quark Indirect searches for evidence of new particles Within a complex process new particles can occur virtually Rare Decays, CP Violating Decays and Processes such as Mixing Present unique opportunity to find new physics M. Herndon Tevatron is at the energy frontier Tevatron and b factories are at a data volume frontier billions B and Charm events on tape So much data that we can look for some very unusual processes Where to look Many weak processes involving B hadrons are very low probability Look for contributions from other low probability processes – Non Standard Model DSU 2007

4 B Physics Beyond the SM Look at processes that are suppressed in the SM Excellent place to spot small contributions from non SM contributions The Main Players: B s(d) →  μ  μ - SM: No tree level decay b  s  Penguin decay New Players B s Oscillations B   M. Herndon Same particles/vertices occur in both B decay diagrams and in dark matter scattering or annihilation diagrams

5 The B Factories EXCELLENT MUON DETECTION EXCELLENT TRACKING: TIME RESOLUTION EXCELLENT PARTICLE ID CDFD0BABARBELLE

6 b → s  Look at decays that are suppressed in the Standard Model: b → s  Classic b channel for searching for new physics Inclusive decay easier to calculate but still difficult New physics can enter into the loop(penquin) Decay observed Now a matter of precision measurement and precision calculation of the SM rate New calculation by Misiak et. al. NNLO calucation - 17 authors and 3 years of effort BR(b → s  ) = 3.15  0.23 x M. Herndon One of the best indirect search channels at the b factrories PRL DSU 2007

7 b → s  Measure the inclusive branching ratio from the photon spectrum Backgrounds from continuum production and other B decays Continuum backgrounds suppressed using event shapes or reconstruction the other B  o and  reconstructed and suppressed

8 B s(d) → μ + μ - Look at decays that are suppressed in the Standard Model: B s(d) →  μ  μ - Flavor changing neutral currents(FCNC) to leptons No tree level decay in SM Loop level transitions: suppressed CKM, GIM and helicity(m l /m b ): suppressed SM: BF(B s(d) →  μ  μ - ) = 3.5x10 -9 (1.0x ) G. Buchalla, A. Buras, Nucl. Phys. B398,285 New physics possibilities Loop: MSSM: mSugra, Higgs Doublet 3 orders of magnitude enhancement Rate  tan 6 β/(M A ) 4 Babu and Kolda, Phys. Rev. Lett. 84, 228 Tree: R-Parity violating SUSY Small theoretical uncertainties. Easy to spot new physics M. Herndon One of the best indirect search channels at the Tevatron DSU 2007

9 B s(d) → μ + μ - Method M. Herndon Relative normalization search Measure the rate of B s(d) → μ + μ - decays relative to B  J/  K + Apply same sample selection criteria Systematic uncertainties will cancel out in the ratios of the normalization Example: muon trigger efficiency same for J/  or B s  s for a given p T 400pb X 10 7 B + events N(B + )=2225 DSU 2007

10 Discriminating Variables M. Herndon Mass M  CDF: 2.5σ  window: σ = 25MeV/c 2 DØ: 2σ  window: σ = 90MeV/c 2 CDF λ=cτ/cτ Bs, DØ L xy /  Lxy  α : |φ B – φ vtx | in 3D Isolation: p TB /(  trk + p TB ) CDF, λ,  α and Iso: used in likelihood ratio D0 additionally uses B and  impact parameters and vertex probability Unbiased optimization Based on simulated signal and data sidebands 4 primary discriminating variables DSU 2007

CDF 1 B s result: 3.0  B s(d) → μ + μ - Search Results M. Herndon CDF Result: 1(2) B s(d) candidates observed consistent with background expectation Worlds Best Limits! Decay Total Expected Background Observed CDF B s 1.27 ± CDF B d 2.45 ± D0 B s 0.8 ± ± BF(B s   +  - ) < 10.0x10 -8 at 95% CL BF(B d   +  - ) < 3.0x10 -8 at 95% CL D0 Result: First 2fb -1 analysis! BF(B s   +  - ) < 9.3x10 -8 at 95% CL PRD 57, Combined: BF(B s   +  - ) < 5.8x10 -8 at 95% CL

12 B s → μ + μ -  Physics Reach Strongly limits specific SUSY models: SUSY SO(10) models Allows for massive neutrino Incorporates dark matter results BF(B s   +  - ) < 5.8x10 -8 at 95% CL Excluded at 95% CL (CDF result only) BF(B s   +  - ) = 1.0x10 -7 Dark matter constraints L. Roszkowski et al. JHEP A close shave for the theorists Typical example of SUSY Constraints However, large amount of recent work specifically on dark matter DSU 2007

13 B Physics and Dark Matter B Physics constraints impact dark matter in two ways Dark matter annihilation rates Interesting for indirect detection experiments Annihilation of neutralinos Dark matter scattering cross sections Interesting for direct detection experiments Nucleon neutralino scattering cross sections Models are (n,c)MSSM models with constraints to simplify the parameter space: Key parameters are tanβ and M A as in the flavour sector along with m 1/2 Two typical programs of analysis are performed Calculation of a specific property: Nucleon neutralino scattering cross sections Constraints from B s(d) →  μ  μ - and b  s  as well as g-2, lower bounds on the Higgs mass, precision electroweak data, and the measured dark matter density. General scan of allowed SUSY parameter space from which ranges of allowed values can be extracted M. Herndon Results can then be compared to experimental sensitivities DSU 2007

14 SUSY and Dark Matter M. Herndon Informs you about what types of dark matter Interactions are interesting H. Baer et. al. What’s consistent with the constraints? There are various areas of SUSY parameter space that are allowed by flavour, precision electroweak and WMAP Stau co-annihilation Funnel Bulk Region Low m 0 and m 1/2, good for LHC Focus Point Large m 0 neutralino becomes higgsino like Enhanced Higgs exchange scattering diagrams Disfavoured by g-2, but g-2 data is controversial TeV

15 Flavour Constraints on m  New analysis uses all available flavour constraints B s →  μ  μ -, b  s ,B s Oscillations, B   Later two results only 1 year old CMSSM - constrained so that SUSY scalers and the Higgs and the gauginos have a common mass at the GUT scale: m 0 and m 1/2 respectively M. Herndon J. Ellis, S. Heinemeyer, K. Olive, A.M Weber and G. Weiglein hep-ph/ Focus Point Stau co-annihilation Definite preferred neutralino masses ~ This region favoured because of g-2

16 B s → μ + μ - and Dark Matter B s →  μ  μ - correlated to dark matter searches CMSSM supergravity model B s →  μ  μ - and neutralino scattering cross sections are both a strong functions of tanβ In high tanβ(tanβ ~ 50), positive μ, CDM allowed Current bounds on B s →  μ  μ - exclude parts of the parameter space for direct dark matter detection M. Herndon More general scan in m 0, m 1/2 and A 0, allowed region S. Baek, D.G. Cerdeno Y.G. Kim, P. Ko, C. Munoz, JHEP , 2005 CDF Paper Seminar 2007 R. Austri, R. Trotta, L. Roszkowski, hep-ph/

17 B Physics and Dark Matter Putting everything together including most recent theory work on b  s  M. Herndon R. Austri, R. Trotta, L. Roszkowski, hep-ph/ Current experiments starting to probe interesting regions Analysis shows a preference for the Focus Point region, g-2 deweighted Higgsino component of Neutralino is enhanced. Enhances dominant Higgs exchange scattering diagrams Interesting relative to light Higgs searches at Tevatron and LHC Probability in some regions has gone down However… DSU 2007 S. Baek, et.al.JHEP , 2005

18 Current Xenon 10 Results Liquid Xenon detector Multiple modules M. Herndon Xenon 10 Preliminary R. Austri, R. Trotta, L. Roszkowski Current best limits Excluding part of the high probability region - 60 live day run! Excluded by new B s →  μ  μ -

19 Dark Matter Prospects From dmtools.brown.edu Just considering upgrades of the two best current experiments and LUX. Prospects for dark matter detection look good in CMSSM models constrained by collider data! M. Herndon Perhaps find both Dark Matter and B s → μ + μ - DSU 2007 Excluded by new B s →  μ  μ -

20 Conclusions Collider experiments are providing a wealth of data on Flavour physics as well as direct searches and precision electroweak data These data can be used to constrain the masses and scattering cross sections of dark matter candidates Constrained MSSM models indicate that dark matter observation may be within reach for current or next generation experiments! If B s →  μ  μ - is there as well. M. Herndon A simulations observation of direct(or indirect) evidence for new physics at a collider and Cold Dark Matter would reveal much about the form of the new physics DSU 2007