1 / 45

AMS-02 and Dark Matter Search

This article discusses the AMS-02 experiment and its search for dark matter, including the importance of the Time of Flight (TOF) system and evidence for the existence of dark matter.

almar
Download Presentation

AMS-02 and Dark Matter Search

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. AMS-02 and Dark Matter Search NicolòMasi May 2012 Bologna University and INFN

  2. AMS-02, briefly

  3. Matter Anti-Matter Main tasks An Improved Version of AMS-01 Antimatter Astrophysics, Dark Matter The TOF system provides: - the fast trigger to the whole AMS; - the measurement of the time of flight (Δt– better than 180 ps), for the determination of the particle velocity (β), with a resolution of few %; - the distinction from upward and downward going particles at a level of 10-9 necessary to distinguish between matter and antimatter; - the measurement of the absolute particle charge up to Z =15. Strangelets

  4. The AMS-02 TOF • TOF consists of 4 plastic scintillator planes, 2 above and 2 below the magnet. • The counters of adjacent planes are orthogonal. • The number of counters per plane has been reduced to 8, 8, 10, 8 counters to reduce the weight (34 scintillators). • Each TOF counter is composed by: • a plastic scintillator1 cm thick and around 120 cm long (Eljen-Technology type: Ej-200), • read at both ends by 2 independently powered photomultiplier tubes (fine-mesh Hamamatsu R5946 with max spectral response at 420 nm), • connected with transparent light guides. Hamamatsu fine-mesh R5946

  5. AMS-02 Chronology • CERN: Test beam • ESA (Estec): CR Muons • CERN: Permanent Magnet, new test beam and calibration • NASA (Cape Kennedy) - Final Step – CR Muons • On board – Endevour STS-134 • In space on ISS 2008 - 2010 February 2010 May 2010 August 2010 – February 2011 March 2011 May 2011

  6. Lower TOF pre-integration(CERN, Geneva, Switzerland)

  7. AMS at Cape Kennedy 2011 Launches Date: May 9 Mission: STS-134 LaunchVehicle: Space Shuttle Endeavour Launch Site: Kennedy Space Center - Launch Pad 39° STS-134 Description: Space shuttle Endeavourwilldeliver an EXPRESS Logistics Carrier-3 (ELC-3) and the Alpha MagneticSpectrometer (AMS-02) to the ISS ESA Astronaut: Roberto Vittori

  8. Go baby go!

  9. Beyond the SM: Dark Matter

  10. Dark matter: • is inferred to exist since 1934 from gravitational effects on visible matter and background radiation, undetectable by emitted or scattered em radiation. According to observations of structures larger than galaxies, as well as Big Bang cosmology interpreted under the Friedmann equations and the FRW metric, DM accounts for 23% of the mass-energy density of the observable universe. Ordinary matter accounts for only 4.6%. • Local Evidences: • Galactic Rotation Curves • Milky Way warp due to dark satellite galaxies • Dynamics of Galaxy Clusters • X-Ray Cluster Emission • Strong Gravitational Lensing • Anomalous CosmicRayFluxes • Cosmological Evidences: • CMB AcousticPeacks (from WMAP and PLANCK) • StructureFormation and Evolution

  11. Local Galactic Evidences • From the Kepler’s law, for r much larger than the luminous radius, you should have v ∝ r-1/2. • Instead, it is flat or rises slightly. M grav /M vis

  12. Dynamics of galaxy cluster Coma cluster Bullet cluster Virial theorem U = 2K K = i mi vi2 U ~ GM2/R • The Bullet cluster (1E 0657-56) consists of two colliding clusters of galaxies. Studies of the Bullet cluster (August 2006), provide the best evidence for the existence of DM. At a statistical significance of 8σ, it was found that the spatial offset of the center of the total mass from the center of the baryonic mass peaks cannot be explained with an alteration of the gravitational force law. • It provides "evidence against some of the more popular versions of Modified Newtonian Dynamics (MOND)" . • VIRGOHI21 is an extended region of neutral hydrogen (HI) in the Virgo Cluster discovered in 2005. Analysis of its internal motion indicates that it may contain a large amount of DM, as much as a small galaxy, but no stars: the first Dark Galaxy.

  13. X-ray cluster & Lensing Hydrostatic equilibrium: Beta model: But X-ray emission measures the temperature and Mgrav/Mvis = 20 Strong Gravitational Lensing

  14. Cosmological Scale Evidences:WMAP results Universe Curvature Results depend on SNeIaand Hubble parameter Baryon density Matter density

  15. Acoustic peacks: barionic vs non barionic matter mh2=0.135±0.009 m=0.27±0.04 Bh2=0.02±0.002 B =0.04±0.01

  16. Some Clues: PAMELA Positron fraction Exprimental data show that the cosmic ray fluxes of positron, antiprotons and gamma rays are not quite in agreement with SM expectations Nature 458, 607 (2009)

  17. ExoticCandidates Neutralino𝝌 Axion Mass Region: 10 μeV÷1 meV WIMP Mass Region: 100 GeV ÷ 10 TeV (<100 TeV) Statistic: dirac or majorana fermion, boson S= 0,1/2, 1, 3/2, 2

  18. Cosmology: Primordialsoup Thermal production – where do they come from? Cosmology 2 Thermally averaged cross section Boltzmann Equation on FRW background Condition of Departure from Equilibrium: Freeze out Relativisticlimit Non-relativisticlimit Yield

  19. Cosmology Boltzmann Equation in Yield DM densityparameter DM particledensity Neutralino Nonthermal Production: from Oscillating Field on Cosmological Background

  20. Detection Two basic ways to detect WIMP dark matter which is present in the halo of our Galaxy 1) Direct detection: the possibility to detect the recoil energy of the nuclei of a low–background detector as a consequence of their elastic scattering with a WIMP. One possible signal arises if the solar system itself is moving relative to the stationary halo of WIMP as it orbits around the Milky Way center. 2) Indirect detection: to detect products of the annihilation of DM particles, either in the galactic halo or in celestial bodies (namely the Earth and the Sun): the signal can consists of photons, neutrinos and antimatter (positrons, antiprotons and antideuterons)

  21. Direct Detection Scattering Rate Anything above the blue lines is now excluded • This recoil can be detected in some ways : • Electric charges released (ionization detector) • Flashes of light produced (scintillation detector) 1000 • Vibrations produced (phonon detector)

  22. Low energy effective Lagrangian for WIMP-quark interaction scalar interaction spin-dep. interaction q q q q • The other terms are velocity-dependent contributions and can be • neglected in the non-relativistic limit for the direct detection. • The scalar interaction scales with the atomic weight and • almost always dominates for nuclei with A > 30.

  23. Neutralino

  24. MSSM: Neutralino • The exact properties of each neutralino will depend on the details of the mixing but they tend to have masses in the order of 300-600 GeV and couple to other particles with strengths characteristic of the weak interaction. • In this way they are phenomenologically similar to neutrinos. In fact they are Majorana fermions and not directly observable in particle detectors at accelerators. Some MSSM Parameters In the basis : ratio of vev of the two neutral Higgs : Bino, Wino mass parameters SUSY dependence : Higgsino mass parameter Upper bounds now enlarged by LHC results

  25. Neutralino: Indirect Detection • Neutralino Annihilation channels Gaugino Higgsino Mixed And antideuteron

  26. Signatures of SUSY DM in the Cosmic Ray Spectra: positrons and antiprotons PAMELA results on the Cosmic-Ray Antiprotons and positrons Fluxes Clear Signal! Channels: bb, tt, gg No Dark Matter Signal!

  27. Secondary Signatures: photons and antideuterons Since EGRET Gamma Excess

  28. e+ Primaryfluxes: DM vs astrophysicalsources ● CR sources and astrophysical primary sources of positrons are confined to the Galactic Disc, while the DM component has a spherical distribution ● The ratio of DM signal vs CR/astrophysical signal in the diffuse emission is clear enhancedatmid-high latitudes: No excess=No DM origin Diffuse emission

  29. Antideuteron M = 0.1 TeV MIN, MED, MAX propagation sets M = 1 TeV M = 10 TeV MED propagation and NFW profile Background secondary flux Lowenergyrange Light Dark Matter Not Light Dark Matter

  30. AMS Challenges

  31. Primary CR Positron from Dark Matter

  32. And alsoHigh Energy Antiprotons Total Flux High Energy Antiproton High Energy Signal from KK particle

  33. An example: Antideuteronfluxfrom neutralino, KK Photon and right-handed neutrino LZP Light LZP provides measurable fluxes for AMS-02 SUSY Wino, Little Higgs, KK Theory, PBH, Singlet Scalar, Minimal DM, Technicolor… With e+, antiproton and lowenergyantideuteronwe can probe

  34. Facenda… Censorship! Wehave 1 year data @ CNAF = 15 billionsparticles = a lot of fun! Kinetic Energy (GeV)

  35. Which DM candidate?

  36. Table - DM Candidatesproperties HS: Hidden Sector Also leptophilic models may produce antip by EW corrections Wrong relics Light candidates GHP: most relevant Scalar, vector, Dirac fermion, Majorana fermion, Rarita-Schwinger fermion

  37. A bit of detergent

  38. Strong CP problem NeutronElectricDipole Moment Theta is a new particlefield

  39. The Lagrangian EM Anomaly Kinetic term From Goldstone Theorem: QCD Instanton Sector Pseudo Nambu-Goldstone Boson of the PQSB: its vev remove the anomaly, through a potential minimum

  40. Maxwell-Chern-Simons theory and Primakoff effect Currents Maxwell-Chern-Simons Equations Light shining through walls experiments

  41. From CDM to BEC Axionsrethermalize and reach TBEC a a a a Galactic Halos: Tidal Torque Theory

  42. Conclusions Conclusions • Dark Matteris the simplest and mostclever way to deal with astrophysical and cosmologicalproblems: DM has to exist! • Exoticscandidates • SUSY candidates • SUSY antagonist • Weprefer: minimal scalar and Majorana-likesolution, from a strong or EW Simmetry Breaking • AMS will soon demonstrate the presence or absence of WIMPs annihilation products

More Related