09/09/2002Nacho Sevilla Noarbe. AMS.1 Circa 500 BC circa 2000 AD

Search for Dark Matter The AMS Experiment Nacho Sevilla Noarbe. CIEMAT, Madrid.

09/09/2002Nacho Sevilla Noarbe. AMS.3 Outline What is the ´dark matter´problem? What is the AMS experiment? How can AMS help us with dark matter?

09/09/2002Nacho Sevilla Noarbe. AMS.4 Dark matter problem (tentavely) Dark matter: undetected major constituent of the universe which does not seem to emit or absorb any EM radiation, though its gravitational effects are dominant. Observational proof. Candidates.

09/09/2002Nacho Sevilla Noarbe. AMS.5 Dark matter problem: observations Galactic scale: Rotation curves in spirals. X-ray measurements of galactic gas in ellipticals. Lensing events from MACHOs.  m  0.1 Credit: The CHANDRA Collaboration Credit: The MACHO CollaborationCredit: Corbell, Salucci (1999)

09/09/2002Nacho Sevilla Noarbe. AMS.6 Dark matter problem: observations Credit: The CHANDRA CollaborationCredit: HST Cluster scale: Cluster member’s motion. X-ray intergalactic emission. Cluster lensing of background objects.  m 

09/09/2002Nacho Sevilla Noarbe. AMS.7 + Dark matter problem: observations Cosmological scale: Local Group velocity against CMB. Peculiar velocity measurements. Combining latest CMB and high- Z supernovae results.  0  0.3 Credit: The Supernova Cosmology Project and BOOMERANGCredit: COBECredit: The Sc Project

09/09/2002Nacho Sevilla Noarbe. AMS.8 Dark matter problem: observations (some!) Cosmological scale: Combining latest CMB and high-Z supernovae results.  0  1 Cluster lensing of background objects. Cluster scale:Galactic scale:  m  Rotation curves in spirals.  m > Credit: Corbell, Salucci (1999)Credit: HSTCredit: The Supernova Cosmology Project and BOOMERANG Scale: GalacticClusterCosmological

09/09/2002Nacho Sevilla Noarbe. AMS.9  0  1  m   m  0.1 Galactic Cluster Cosmological + Dark matter problem: observations + SCALE OMEGA Galaxy rotation curves Credit: Corbell, Salucci (1999) Gravitational lensing Credit: HST CMB + SNIa observations Credit: BOOMERANG and the SN Cosmology Project

09/09/2002Nacho Sevilla Noarbe. AMS.10 Dark matter problem Theoretical arguments: CMB characteristics are better explained in inflationary models. (Most of) these in turn predict  = 1. If  lum ~  mass it turns out that structure should have formed rapidly requiring unobserved high fluctuations in the CMB. If   1, as we know that  0 ~ 1 now, at Planck time it should have been 1  (  varies quickly if not unity).

09/09/2002Nacho Sevilla Noarbe. AMS.11 Dark matter problem: candidates Baryonic: dwarfs, “planets”, collapsed objects… limited by well-tested BBN observations from MACHO experiments cannot account for all galactic dark matter. Non-baryonic: neutrinos, axions, WIMPs (e.g. supersymmetric particles)...

09/09/2002Nacho Sevilla Noarbe. AMS.12 Dark matter problem: candidates NEUTRINOS They are well-known particles. There is strong indication that they do have mass... …it probably won´t be enough. BUT... DM models based on neutrinos (usually called Hot Dark Matter) are not compatible with observations.

09/09/2002Nacho Sevilla Noarbe. AMS.13 Dark matter problem: candidates NEUTRALINOS (best SUSY candidate) Supersymmetry predicts these particles. The properties of the neutralino are remarkably close to those needed by a hypothetical dark matter particle constituent. Neutralinos (or supersymmetry for that case) has not been observed experimentally yet. BUT... Neutralino dark matter models (Cold Dark Matter) work well in their predictions.

09/09/2002Nacho Sevilla Noarbe. AMS.14 Dark matter problem: candidates Indirect searches for neutralino signatures in cosmic rays can be done from space- borne and balloon experiments. AMS on the International Space Station will do so with unprecedented sensitivity.

09/09/2002Nacho Sevilla Noarbe. AMS.15 The AMS experiment AMS (Anti-Matter Spectrometer) is a particle physics experiment in space. AMS (Anti-Matter Spectrometer) is a particle physics experiment in space. It will detect and identify huge statistics of primary cosmic rays, up to Z=26. It will detect and identify huge statistics of primary cosmic rays, up to Z=26. Among its physics goals, are anti-matter and dark matter search, cosmic ray propagation studies. Among its physics goals, are anti-matter and dark matter search, cosmic ray propagation studies. It is mostly built in Europe, in close collaboration with NASA. It is mostly built in Europe, in close collaboration with NASA. AMS-01 was tested successfully on shuttle flight STS91 for ten days in AMS-02 will be on the ISS for three years from AMS-01 was tested successfully on shuttle flight STS91 for ten days in AMS-02 will be on the ISS for three years from 2005.

09/09/2002Nacho Sevilla Noarbe. AMS.16 The AMS experiment

09/09/2002Nacho Sevilla Noarbe. AMS.17 a I. Physikalisches Institut, RWTH, D Aachen, Germany b III. Physikalisches Institut, RWTH, D Aachen, Germany c Laboratoire d’Annecy-le-Vieux de Physique des Particules, LAPP, F Annecy-le-Vieux CEDEX, France e Louisiana State University, Baton Rouge, LA 70803, USA d Johns Hopkins University, Baltimore, MD 21218, USA  Center of Space Science and Application, Chinese Academy of Sciences, Beijing, China g Chinese Academy of Launching Vehicle Technology, CALT, Beijing, China h Institute of Electrical Engineering, IEE, Chinese Academy of Sciences, Beijing, China i Institute of High Energy Physics, IHEP, Chinese Academy of Sciences, Beijing, China j University of Bologna and INFN-Sezione di Bologna, I Bologna, Italy k Institute of Microtechnology, Politechnica University of Bucharest and University of Bucharest, R Bucharest, Romania l Massachusetts Institute of Technology, Cambridge, MA 02139, USA m National Central University, Chung-Li, Taiwan n Laboratorio de Instrumentacao e Fisica Experimental de Particulas, LIP, P-3000 Coimbra, Portugal o University of Maryland, College Park, MD 20742, USA p INFN Sezione di Firenze, I Florence, Italy q Max–Plank Institut fur Extraterrestrische Physik, D Garching, Germany r University of Geneva, CH-1211 Geneva 4, Switzerland s Institut des Sciences Nucleaires, F Grenoble, France t Helsinki University of Technology, FIN Kylmala, Finland u Instituto Superior Tecnico, IST, P-1096 Lisboa, Portugal v Laboratorio de Instrumentacao e Fisica Experimental de Particulas, LIP, P-1000 Lisboa, Portugal w Chung–Shan Institute of Science and Technology, Lung-Tan, Tao Yuan 325, Taiwan x Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, CIEMAT, E Madrid, Spain y INFN-Sezione di Milano, I Milan, Italy y INFN-Sezione di Pisa, I Pisa, Italy z Kurchatov Institute, Moscow, Russia aa Institute of Theoretical and Experimental Physics, ITEP, Moscow, Russia ab INFN-Sezione di Perugia and Universita´ degli Studi di Perugia, I Perugia, Italy ac Academia Sinica, Taipei, Taiwan ad Kyungpook National University, Taegu, Korea ae University of Turku, FIN Turku, Finland  Eidgenossische Technische Hochschule, ETH Zurich, CH-8093 Zurich, Switzerland Europe US ASIA

09/09/2002Nacho Sevilla Noarbe. AMS.18 Acceptance: 0.45 m 2 sr The AMS experiment TOF USS II Veto counter Vacuum case Superconducting magnet Silicon Tracker Scintillator system (TOF) Transition Radiation Detector Ring Imaging Cherenkov Detector Electromagnetic Calorimeter ~2 m

09/09/2002Nacho Sevilla Noarbe. AMS.19 The AMS experiment: the superconducting magnet Its purpose is to bend the trajectories of charged particles. It will be the first superconducting magnet to operate in space. It is a system of 12 racetrack coils & 2 dipole coils cooled to 1.85 K by 2.5 m 3 of superfluid helium. BL 2 = 0.86 Tm 2

09/09/2002Nacho Sevilla Noarbe. AMS.20 It will measure the rigidity (momentum/charge) and charge. With over 6 m 2 of active surface, it will be the largest ever built before the LHC. Based on 8 thin layers of double-sided silicon microstrips, a spatial resolution of 10  m will be achieved. This means around 200k channels. The AMS experiment: the Silicon Tracker

09/09/2002Nacho Sevilla Noarbe. AMS.21 The AMS experiment: the Time Of Flight system This sub-detector will measure the velocity of the particle by recording time of passage and position in 4 different planes. Each plane has 8-10 scintillator paddles seen by 2 PMTs on each side. It can measure velocities with 3.6 % relative error (for  =1 protons).

09/09/2002Nacho Sevilla Noarbe. AMS.22 The TRD is based on the radiation emitted by a moving charged particle when it traverses two different media. It will perform hadron/lepton separation. There are 20 layers of foam separated by drift tubes. h/e rejection of 10 2 – 10 3 in the range 3 – 300 GeV. The AMS experiment: the Transition Radiation Detector

09/09/2002Nacho Sevilla Noarbe. AMS.23 The AMS experiment: the RICH detector Makes use of the Cherenkov light emitted in the radiator by relativistic charged particles. We can obtain the velocity and absolute charge of incoming particles. 3 cm thick aerogel radiator; 680 multianode photomultipliers. We can achieve velocity measurements with a 0.1 % relative error for protons. CIEMAT is a major partner in this effort. reflector PMT plane radiator

09/09/2002Nacho Sevilla Noarbe. AMS.24 The AMS experiment: the Electromagnetic Calorimeter The ECAL registers electromagnetic showers initiated by the particles. Thus we can measure the energy of the primary. It consists of 9 superlayers of scintillator/lead connected to 324 multianode photomultipliers. Energy is measured with a 3 % error at 100 GeV.

09/09/2002Nacho Sevilla Noarbe. AMS.25 The AMS experiment: AMS/  AMS will also be able to operate as a gamma ray detector! TRD + structure provide 0.25Xo for electron-positron conversion. Tracker and Calorimeter can measure the e - e + pairs. The Calorimeter alone can register unconverted photons. TOF USS II Veto counter Vacuum case

09/09/2002Nacho Sevilla Noarbe. AMS.26 The AMS experiment: AMS-01 on STS-91 AMS

09/09/2002Nacho Sevilla Noarbe. AMS.27 The AMS experiment: AMS-01 on STS-91 AMS had a successful operation in space during a 10-day flight in Precise physics results were obtained: * New limit for nuclear antimatter (N He/He < 1.1·10 -6 ). * Charged CR spectra (p,e ,D,He). * Measurement of geomagnetic effects on CR.

09/09/2002Nacho Sevilla Noarbe. AMS.28 The AMS experiment: energy ranges p up to several TeV p GeV e up to O(TeV) e GeV He,….C 1 up to several TeV anti – He…C 1 up to O(TeV) Light Isotopes 1-10 GeV/nucleon  GeV

09/09/2002Nacho Sevilla Noarbe. AMS.29 Searching for neutralinos Direct detection via inelastic scattering (DAMA, CDMS, UKDMC…). Indirect detection: *Coannihilation in Earth/Sun    *Coannihilation in galactic halo  ANOMALIES IN CR SPECTRA

09/09/2002Nacho Sevilla Noarbe. AMS.30 Searching for neutralinos Gamma photons: –They are originated either from coannihilation into a final state containing a photon (line signal) or from the decay of other primary coannihilation products (continuum signal). Positrons: –They come from the decay of gauge bosons (e.g.,W + ) as primary coannihilation products. Antiprotons and antideuterons: –Direct production in WIMP annihilations. Possible detectable products from:  xx Balloons  ray telescopes and satellites AMS

09/09/2002Nacho Sevilla Noarbe. AMS.31 Searching for neutralinos Gamma rays Many experiments will be covering the GeV range in the next decade. Gamma ray output from neutralino annihilation is highly model-dependent. Credit: Battiston (2002)

09/09/2002Nacho Sevilla Noarbe. AMS.32 Searching for neutralinos Positrons The relative fluxes of electrons and positrons are very uncertain at energies above 10 GeV. An excess of positron fraction is claimed by the HEAT balloon experiment, maybe hinting to neutralinos? Credit: Battiston (2002)

09/09/2002Nacho Sevilla Noarbe. AMS.33 Searching for neutralinos Antiprotons They seem to follow expected spectrum from CR interaction with ISM. However there are large uncertainties above 10 GeV and below 1 GeV. Credit: Battiston (2002)

09/09/2002Nacho Sevilla Noarbe. AMS.34 Summing up Recent research points to a non-baryonic component of dark matter. Neutralinos are one of the best candidates to date.Recent research points to a non-baryonic component of dark matter. Neutralinos are one of the best candidates to date. AMS will be a multipurpose detector in space that will look for signatures of neutralino coannihilation in the galactic halo.AMS will be a multipurpose detector in space that will look for signatures of neutralino coannihilation in the galactic halo. It will make use of high statistics, outstanding particle identification capabilities and multichannel observations.It will make use of high statistics, outstanding particle identification capabilities and multichannel observations.

09/09/2002Nacho Sevilla Noarbe. AMS.35