DOCSLIB.ORG

The BESS Program

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The BESS Program The BESS Program Akira Yamamoto (KEK) for the BESS collaboration SpacePart-06, Beijing, April 20, 2006 1 Outline z BESS Experiment and Spectrometer z Recent and New Results z BESS TeV : Precise measurement of cosmic-rays z BESS-Polar I : Search for antiparticle of primary origin z Plan for future z Summary 2 BESS Collaboration As of April, 2006 High Energy Accelerator National Aeronautical and Research Organization(KEK) Space Administration Goddard Space Flight Center BESS The University University of Maryland of Tokyo Collaboration Kobe University University of Denver (Since June 2005) Institute of Space and Astronautical Science/JAXA 3 BESS Balloon-borne Experiment with a Superconducting Spectrometer Search for Primordial Antiparticle antiproton: Novel primary origins (PBH,DM) antihelium: Asymmetry of matter/antimatter Precise Measurement of Cosmic-ray flux: highly precise measurement at < 1 TeV 4 BESS Detector Rigidity measurement JET/IDC SC Solenoid (L=1m, B=1T) Rigidity Min. material (4.7g/cm2) Uniform field TOF Large acceptance β, dE/dx Central tracker (Drift chamber δ ~200μm Z, m measurement R,β --> m = ZeR√ 1/β2-1 dE/dx --> Z 5 BESS-TeV Deflection Resolution MDR 1.4 TV BESS-98 MDR 200 GV 6 BESS-TeV Spectrometer TOF ODC MAGNET JET/IDC 7 Progress of BESS Experiment 1993~ 2000, BESS, North Canada 2002, BESS-TeV 1999, 2001, BESS-Ground, Japan 2001, BESS-TeV, Fort Sumner 2004, BESS-Polar I, Antarctica 10 scientific balloon flights during1993-2004 8 Primary Cosmic-ray Spectra (1998: Bess-98, AMS-I, Caprice) Error: < +/-5 % @ 100 GeV Sanuki et al. ApJ. 545 (2000) 1135 9 Primary Cosmic-ray Spectra (BESS-TeV) Error: < +/-15 % @ 500 GeV Haino et al. PLB 594 (2004) 35 10 BESS-TeV Result Anchor the P and He Spectra in Low Energy (< TeV) φ -γ F = Ek Proton (Ek> 30 GeV) φ = (1.37 ± 0.12)x104 γ = 2.732 ± 0.022 Helium (Ek> 20 GeV) φ = (7.06 ± 1.15)x102 γ = 2.699 ± 0.059 Fitting based on the BESS-TeV results only 11 Low Energy Cosmic-ray Spectra Precisely Measured by BESS 104 BESS Rigidity Measurement -1 Precise spectra sr s GeV) proton (0.2~500 GeV) 2 helium (0.2~250 GeV/n) antiproton (0.2~ 4 GeV) Flux (m Anchor the spectrum in the lowest energy region. 10-28 12 0.1 Energy (GeV) 1012 Search for Antiprotons of Cosmic Origins -1 10 Primary Detectable ) -1 GeV -1 sec -2 -1 10 sr -2 flux (m – p SecondarySecondary 10(+) PBH R=0.5 x 10-2 pc-3 yr-1 SUSY 2 Neutralino mχ = 53.6GeV/c PBH -3 10 -1 10 1 10 Kinetic Energy (GeV) • Most antiprotons are secondary products from nuclear interactions of primary cosmic rays with the ISM. • “Exotic” sources may relatively enhance antiproton flux at energies well below or above secondary peak. 13 Observation of Cosmic-rayAntiprotons in p-bar/p Ratio 1979: First observation (Golden et al) -3 10 Solar minimum in + phase 1979: Russian PM (Bogomolov et al) Solar maximum in + phase 1981: Excess reported (Buffington et al) Solar maximum in - phase 1985: ASTROMAG Study Started 1987: LEAP, PBAR (upper limits) -4 1991: MASS 10 1992: IMAX (16 antiprotons) /p ratio – 1993: BESS (6 antiprotons), TS93 p 1994: CAPRICE94, HEAT-e± -5 1996: Solar minimum 10 Golden et al. Bogomolov et al. 1998: CAPRICE98, AMS-01 Buffington et al. 2000: HEAT-pbar 2004: BESS-Polar -6 10 -1 2006: PAMELA 10 1 10 2007: Solar minimum, BESS-Polar Kinetic Energy (GeV) 2008: AMS-02 Before the BESS Experiment 14 Observation of Cosmic-rayAntiprotons in p-bar/p Ratio 10 1979: First observation (Golden et al) Y. Asaoka et al., Phys. Rev. Lett., in press. BESS(97) 1979: Russian PM (Bogomolov et al) BESS(99) 1981: Excess reported (Buffington et al) /P ratio BESS(00) ñ P 1985: ASTROMAG Study Started p/p Ratio -4 1987: LEAP, PBAR (upper limits) 10 1991: MASS 1992: IMAX (16 antiprotons) 1993: BESS (6 antiprotons), TS93 1994: CAPRICE94, HEAT-e± -5 1996: Solar minimum 10 Bieber et al, 1999 BESS 10, ( +) ~ 1997 1998: CAPRICE98, AMS-01 solar min. at positive phase 70, ( +) ~ 1999 2000: HEAT-pbar solar max. at positive phase 2004: BESS-Polar 70, ( −) ~ 2000 solar max. at negative phase -6 2006: PAMELA 10 -1 10 1 10 2007: Solar minimum, BESS-Polar Kinetic Energy (GeV) 2008: AMS-02 By the BESS Experiment 15 Low Energy Cosmic-ray Antiprotons in last solar minimum (1995~97) 10-1 Mostly secondary particles BESS(95+97) BESS(93) with specific peak at 2 GeV IMAX CAPRICE ] Study: -1 GeV -1 sec Propagation model -1 sr Solar modulation 10-2 -2 Search for: Novel Primary Origin? Pbar flux [m (PBH, DM) 10-3 Flatter spectrum in low energy 10-1 110 Kinetic Energy (GeV) More Statistics necessary ->> Long-duration Flight16 BESS-Polar Experiment Very precise measurement Low energy Antiprotons Around south-pole, Antarctica Long duration flight High latitude Solar minimum With a new spectrometer Ultimately small material Ultra-thin superconducting solenoid 17 Feature of BESS-Polar Spectrometer BESS-2000 BESS-Polar TOF Upper Coil JET/IDC MTOF 5g/cm2 ACC 18g/cm2 TOF Lower 10g/cm2 Minimize material in spectrometer Energy range extended New detector (Middle TOF) down to 0.1 GeV Low power electronics Long duration flight Solar Power System, Longer life of cryogen, LHe 18 BESS-Polar 2004 8.5 day flight successful 35-37 km in altitude 900 million events recorded - Acceptance limited to ~ 0.2 m2.sr Altitude～38000m Residual air～4g/cm2 Floating 19 Low Energy Antiproton Observed in BESS Polar I (in 2004) Preliminary ～2000 Antiproton Candidates • ~ 2000 antiproton (total) candidate observed • ~ 400 antiprotons below 1 GeV 20 Lowest Energy Events Observed Antiproton RGT -0.4GV event 1/β 2.47 Limit by MTOF Trigger Limit by ★Kinetic Energy ～0.11GeV (@ TOA) BTOF Trigger ★Multi-track events to be further studied 21 Antiprotons Observed (Preliminary) KineticEnergy(@TOA) BESS-97 Polar 4~5 times statistics (than that of 1997), 0.1- 0.18 (GeV) - In Analysis With ~0.2 m2sr (2/3), 0.18-0.28 4 25 8 days flight 0.28-0.40 9 39 0.40-0.56 16 63 18/44 TOF-PMT turned-off 0.56-0.78 31 123 0.78-0.92 19 90 ＰＭＴ－ＨＶ 0.92-1.08 16 92 Both-end Single-end Dead Total (below 1.08 GeV) 95 432 22 Pbar/P Ratio Observation Extended • The measurement consistent with the prediction, Bieber et al. 23 Progress in Antihelium Search • Preliminary Results – The upper limit of antihelium/helium ratio pushed down • ~5 x 10E-7 @ BESS-Polar I – Generally, two order of magnitude lowered by BESS in last ten years. 24 Further Plan for BESS-Polar II z Solar minimum in 2006~07 z Realize further long duration flight of 20 days with two circle around the pole, 4~5 x BESS-Polar I statistics Record at Tiger flight 25 Improvement toward BESS-Polar II Subject (BESS-Polar I) (BESS-Polar II) Magnet Cryogen Life ~ 11 days > 25 days Track detector (JET) gas ~ 10 days > 20 days quality TOF-PMT housing Resin potting Pressurized housing ACC Particle ID Rejection ~ 630 >> 1000 Solar-power gen. 4 stage 900 W 3 stage 675 W Effective Acceptance 0.2 m2sr 0.3 m2sr Observation time 8.5 days > 20 days Statistics 4 x BESS97 20 x BESS97 Data storage 2 of 3.6 TB (recorded) 12 ~ 16 TB 26 BESS Polar II Observation (Expected) -1 10 ) -1 Simulation for secondary only (20 days) Simulation for secondary +PBH (20 days) GeV BESS95+97 real data -1 sec -1 sr -2 -2 10 Secondary PBH BESS Antiproton Flux (m BESS Polar -3 10 -1 10 1 10 Kinetic Energy (GeV) Antiproton Spectrum Search for Antideuteron and AntiHelium (Search for PBH) 27 BESS-Polar Feature (3 years) (10+20 days) AMS02 PAMELA BESS-Polar realize (3 years) the best sensitivity in lowest energy Acceptance Flight Time Latitude Altitude Launch (m2sr) (km) AMS 0.5 3 years < 51.7 280~500 2008 PAMELA 0.0021 3 years <70.4 350-600 2006 BESS-Polar2 0.3 20 days > 75 36 2007 28 Summary ■ BESS measured: z Precise Cosmic-ray Proton (Helium) spectrum with errors within z 5 % @ 100 GeV, and 15 % @ 500 GeV z with anchoring the spectrum at the lowest energy z Low energy Antiproton spectra at 0.1 - 4 GeV to z Mostly secondaries, z Useful information on cosmic-ray propagation and solar modulation z Search for novel primary origin suchs as PBH, z Antidueteron search with the first upper limit reported, z Antihelium search reaching down to the upper limit ~3 x 10-7 z BESS-Polar II planned, and important for z Ultimately sensitive search for primordial antiparticle with the long duration flight in solar minimum in 2007, and z Further precise measurement of cosmic rays, in a complimentary29 approach to PAMELA and AMS. 30 BESS Deflection Resolution 1993~1998 L B ±δ BESS: dRR-1 Rd/ Max. Det. Rigidity: 200 GV (BL2) Sharp peak of resolution Strong and uniform field 31 BESS-TeV Upgrade 2001~2002 Central Tracker (JET/IDC) improvement BESS-98 BESS-TeV δ = 200 -->150 μm ODC N = 28 --> 52 New detector (ODC) installed L = 0.8 --> 1.6 m JET/IDC ODC MDR: 200 GV --> 1400 GV 32 Charge-Sign-Dependent Solar Modulation p/p Ratio Spanning a Solar Magnetic Field Reversal 10 Y. Asaoka et al., Phys. Rev. Lett., in press. BESS(97) BESS(99) /P ratio BESS(00) ñ P p/p Ratio -4 10 -5 10 Bieber et al, 1999 10, ( +) ~ 1997 solar min.
Load more

Recommended publications
  • BESS-Polar Experiment
    PSB1-0046-02 1 BESS-Polar experiment T. Yoshida1, A. Yamamoto1, J. Mitchell2, K. Abe3, H. Fuke1,3, S. Haino1,3, T. Hams2, N. Ikeda4, A. Itazaki4, K. Izumi1,3, M. H. Lee5, T. Maeno4, Y. Makida1, S. Matsuda3, H. Matsumoto3, A. Moiseev2, J. Nishimura3, M. Nozaki4, H. Omiya1, J. F. Ormes2, M. Sasaki2, E. S. Seo5, Y. Shikaze4, A. Stephens2, R. Streitmatter2, J. Suzuki1, Y. Takasugi4, K. Tanaka1, K. Tanizaki4, T. Yamagami6, Y. Yamamoto3, K. Yamato4, and K. Yoshimura1 1 High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan 2 Goddard Space Flight Center / NASA, Greenbelt, MD 20771, USA 3 The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan 4 Kobe University, Kobe, Hyogo 657-8501, Japan 5 University of Maryland, College Park, MD 20742, USA 6 Institute of Space and Astronautical Science (ISAS), Sagamihara, Kanagawa 229-8510, Japan ABSTRACT For investigating elementary particle phenomena in the early Universe, the BESS-Polar experiment was proposed for highly sensitive studies of the low-energy antiprotons and extensive searches for antinuclei in the cosmic radiations. A new superconducting spectrometer is being developed for long-duration balloon flights. In order to extend detectable energy range of the antiprotons down to 100 MeV, materials along the trajectory of the incident particle is minimized. The spectrometer will be completed in 2003, and the first long-duration flight is planned in 2004. INTRODUCTION Observations of anomalous excess of antiproton ) flux (Bogolomov et al. 1979, Golden et al. 1979, 1 - -1 Buffington et al. 1981), compared to the predictions by V 10 e G the secondary production models, had suggested 1 - c existence of novel processes of the antiproton e s 1 production.
    [Show full text]
  • The General Antiparticle Spectrometer (GAPS) - Dark Matter Search Using Cosmic-Ray Antideuterons
    The General Antiparticle Spectrometer (GAPS) - Dark matter search using cosmic-ray antideuterons KAVLI, Stanford University October 2011 Philip von Doetinchem on behalf of the GAPS collaboration Space Sciences Laboratory, UC Berkeley [email protected] T. Aramaki1, N. Bando4, St. Boggs2, W. Craig3, B. Donakowski2, H. Fuke4, F. Gahbauer1,5 , Ch. Hailey1(PI), J. Hoberman2, P. Kaplan1, J. Koglin1, N. Madden1, St. McBride2, I. Mognet6, B. Mochizuki2, K. Mori1, R. Ong6, K. Perez1, D. Stefanik1, M. Lopez-Thibodeaux2, T. Yoshida4, R. Zambelli1, J. Zweerink6 1 Columbia University, 2 UC Berkeley, 3 Lawrence Livermore National Laboratory, 4 Japan Aerospace Exploration Agency 5 University of Latvia, 6 UC Los Angeles Outline Why are antideuterons interesting? How to measure them? cosmic rays antideuteron physics GAPS concept GAPS prototype instrument Ph. von Doetinchem The General Antiparticle Spectrometer (GAPS) Oct. 2011 – p. 2 Cosmic rays in the GeV to TeV range • in general good agreement of models and data • what we already learned: – particle physics – interstellar medium – astronomical objects – … • small fluxes with no primary astronomical source are especially sensitive to new effects Ph. von Doetinchem The General Antiparticle Spectrometer (GAPS) Oct. 2011 – p. 3 Positron fraction & electron flux E. Mocchiutti et al. arxiv:0905.2551 D. Grasso et al. arxiv:0905.0636 pulsar DM: KK SNR DM: SUSY nearby pulsars • unexplained features in positron and electron spectra • proposed theories: – γ-ray pulsars can produce electron and positrons via pair production in the magnetosphere – positrons and electrons can also be accelerated in PWN or SNR shocks – dark matter self-annihilation Ph. von Doetinchem The General Antiparticle Spectrometer (GAPS) Oct.
    [Show full text]
  • V^ " > Proceedings of the 3Rd Workshop on BALLOON-BORNE EXPERIMENTS with SUPERCONDUCTING MAGNET SPECTROMETERS
    KEK-PR0C--92- JP9304099 ^ ,-*.«?* ?*! S-;V^ " > Proceedings of the 3rd Workshop on BALLOON-BORNE EXPERIMENTS WITH SUPERCONDUCTING MAGNET SPECTROMETERS held at National Laboratory for High Energy Physics (KEK) February 24-25, 1992 Edited by Akira Yamamoto [ r National Laboratory for High Energy Physics, 1992 KEK Reports are available from: Technical Information & Library National Laboratory for High Energy Physics 1-1 Oho, Tsukuba-shi Ibaraki-ken, 305 JAPAN Phone: 0298-64-1171 Telex: 3652-534 (Domestic) (0)3652-534 (International) Fax: 0298-64-4604 Cable: KEKOHO II '•J % Foreword The Third Work Shop on Balloon Borne Experiment with a Superconducting Magnet Spectrometer was held at National Laboratory for High Energy Physics (KEK), Tsukuba, Japan on February 24 - 25, 1992. The workshop was supported by a Grant for Joint Research under The Monbusho International Scientific Research Program (No. 02044151). Two invited review talks were presented on " Progress of Measurement of Cosmic Ray Antiprotons and Search for Primordial Antimatter" and on " High Rate Data Acquisition System in Balloon Borne Experiments." The main effort for this workshop was focused on the progress of the BESS (Balloon Borne Experiment with a Superconducting Spectrometer) experiment and on the scope for scientific investigation with the BESS detector. The progress was reviewed and further investigation was discussed for the BESS further scientific collaboration among Univ. of Tokyo, Kobe University, KEK, ISAS and NMSU. The 30 scientists and engineers participated to the workshop and there were extensive discussions to verify and to complete the BESS detector to be launched in Canada, this summer. New technologies for future balloon and space experiments were also discussed on triggering by using Neural Network and on Scientific investigation with Japanese Experimental Module (JEM) on the Space Station.
    Proceedings of the 3Rd Workshop on BALLOON-BORNE EXPERIMENTS with SUPERCONDUCTING MAGNET SPECTROMETERS" class="panel-rg color-a">[Show full text]
  • CP Violation and Baryogenesis
    PITHA 02/08 CP VIOLATION and BARYOGENESIS 1 Werner Bernreuther Institut f. Theoretische Physik, RWTH Aachen, 52056 Aachen, Germany Abstract: In these lecture notes an introduction is given to some ideas and attempts to un- derstand the origin of the matter-antimatter asymmetry of the universe. After the discussion of some basic issues of cosmology and particle theory the scenarios of electroweak baryogenesis, GUT baryogenesis, and leptogenesis are outlined. 1 Introduction arXiv:hep-ph/0205279v1 24 May 2002 CP violation has been observed so far in the neutral K meson system, both in ∆S = | | 2 and ∆S = 1 processes, and recently also in neutral B meson decays. These phenomena| | are very probably caused by the Kobayashi-Maskawa (KM) mechanism, that is to say by a non-zero phase δKM in the coupling matrix of the charged weak quark currents to W bosons. CP violation found so far in these meson systems does not catch the eye: either the value of the CP observable or/and the branching ratio of the associated mesonic decay mode is small. However, the interactions that give rise to these subtle effects may have also been jointly responsible for an enormous phenomenon, namely for the apparent matter-antimatter asymmetry of the universe. In this context it has been a long-standing question whether or not CP violation in 1Lectures given at the International School on CP Violation and Related Processes, Prerow, Germany, October 1 - 8, 2000, and at the workshop of the Graduiertenkolleg Elementarteilchen- physik of Humboldt Universit¨at, Berlin, April 2 - 5, 2001. 1 0 0 K K¯ mixing, i.e.
    [Show full text]
  • A Thin Superconducting Solenoid Magnet for Ballon Experiments in Space Science
    A THIN SUPERCONDUCTING SOLENOID MAGNET FOR BALLON EXPERIMENTS IN SPACE SCIENCE Akira Yamamoto KEK, High Energy Accelerator Research Organization, Tsukuba, 305-0801, Japan Abstract A very thin and transparent superconducting solenoid magnet is being developed to investigate cosmic-ray antiparticles in the Universe. The uniform magnetic field is provided in a cosmic-ray particle detector system, BESS-Polar, for high-altitude long duration ballooning at Antarctica. The coil is wound with high-strength aluminum stabilized superconductor which has been recently much advanced in mechanical strength while keeping electrical resistivity low enough for the coil stability. The progress of the high-strength aluminum stabilized superconductor and the development of the thin solenoid magnet are described. 1. INTRODUCTION The Balloon-borne Experiment with a Superconducting Solenoid Magnet Spectrometer, BESS, has been carried out, as a US-Japan space science cooperation program, since 1993 [1-2]. Figure 1 shows a picture just before launching of the BESS spectrometer, in northern Canada, 2002. It aims at highly sensitive search for cosmic-ray antiparticle and for the novel primary origins such as evaporation of Primordial Black Holes (PBH) initiated in the early history of the Universe [3.4]. The search for antihelium to investigate the asymmetry of particle/antiparticle composition in the Universe is also a major fundamental question in the history of the Universe [5]. Fig. 1 Balloon launching of the BESS superconducting magnet spectrometer. It provides a central magnetic field of 1T maintained constant in persistent mode. TOF Counters Solenoid Jet chamber Middle TOF Inner DC Silica Aerogel 00.51m Cherenkov TOF Counters Fig.
    [Show full text]
  • Search for Primordial Antiparticle in Cosmic Rays with the BESS
    SearchSearch forfor AntiparticleAntiparticle inin CosmicCosmic RaysRays withwith BESSBESS Akira Yamamoto (KEK) for the BESS Collaboration RESCEU symposium, held at U. Tokyo, Nov. 11-14, 2008 1 BESS Collaboration High Energy Accelerator National Aeronautical and Research Organization(KEK) Space Administration Goddard Space Flight Center BESS The University University of Maryland of Tokyo Collaboration Kobe University University of Denver (Since June 2005) Institute of Space and Astronautical Science/JAXA Balloon-borne Experiment with a Superconducting Spectrometer 2 BESSBESS CollaborationCollaboration (as of Nov., 2008) •KEK M. Hasegawa, A. Horikoshi, Y.Makida, M. Nozaki, R. Orito, J.Suzuki, K.Tanaka, A. Yamamoto*, K.Yoshimura, S. Haino •NASA/Goddard Space Flight Center T. Hams, J.W .Mitchell*, M. Sasaki, R.E. Streitmatter •The University of Tokyo J.Nishimura, K. Sakai •Kobe University A. Kusumoto •Univ. of Maryland K. Kim, M.H. Lee, E.S. Seo •ISAS/JAXA H. Fuke, T. Yoshida, T. Yamagami •University of Denver J. Ormes, N. Thakur 3 Cosmic-Ray Antiproton Chronology 1979: First Antiproton Report (Golden et al.) 2004: BESS-Polar I 1979: Russian PM (Bogomolov et al.) 2006: PAMELA 1981: Low-energy excess (Buffington et al.) 2007: Solar minimum 1985: ASTROMAG Study Started BESS-Polar II 1986: HEAO Antinucleus upper limits 2010+: AMS-02 1987: LEAP, PBAR (upper limits) BESS proposed (by Orito) 1991: MASS 1992: IMAX (16 mass-resolved antiprotons) 1993: BESS (6 mass-resolved antiprotons) 1994: CAPRICE94 1998: CAPRICE98, AMS-01 2000: HEAT-pbar 4 SearchSearch
    [Show full text]
  • BESS- Polar Acceptance 0.0021 0.5 0.3 3 Years (M2•Sr) MDR (GV) 740 ~1000 150
    Searching for Cosmological Antimatter Bob Streitmatter For the BESS Collaboration (KEK / NASA-GSFC / Tokyo / Kobe / Maryland / ISAS) Outline • Briefly: (TEE), Theory Explained by Experimentalist • Review History of Experimental Search for CAM • Instruments, Techniques and measurements • BESS Program • Current Status of Data •The Future In the Beginning … •Dirac, in 1928, was the first to realize that the physics of relativity and quantum mechanics taken together required the existence of matter whose additive quantum numbers (e.g. charge, baryon number, lepton number, spin) were the negative of “normal” matter. (Proc. R. Soc. London, A, 117, (1928), 610) •Positron discovered, August 2, 1932. Positron produced by cosmic radiation seen in a cloud chamber. (Anderson, Phys. Rev. (1933) 491) Baryon Symmetric Universe “We must regard it rather as an accident that the Earth and presumably the whole Solar System contains a preponderance of negative electrons and positive protons. It is quite possible that for some of the stars it is the other way about” -- Dirac, 1933 Noble acceptance speech Antimatter Miscellanea • 1955: Antiprotons are “manufactured” at Bevatron - Chamberlain et al. Phys. Rev. 100 (1955) 947 • Experimental evidence that antimatter is normal in the gravitational sense - High and Holzschieter Phy. Rev. Lett. 66 (1991) 854 • Contrary to popular myth among Trekkies, the 1908 Tunguska meteor was not antimatter - Cowan, Atluri and Libby, Nature, May 29, 1965 But: Simple Big Bang BSU Fatal Problems •The “Annihilation Catastrophe” - not enough baryons •SBB predicts baryon/photon ratio ≈ 10-18 at freezeout •Observed baryon/photon raio ≈ 10-9 •How did the matter and antimatter get separated? •Fluctuations won’t do it •e.g.
    [Show full text]
  • Search for Cosmic-Ray Antiproton Origins and for Cosmological Antimatter with BESS
    Available online at www.sciencedirect.com Advances in Space Research 51 (2013) 227–233 www.elsevier.com/locate/asr Search for cosmic-ray antiproton origins and for cosmological antimatter with BESS A. Yamamoto a,⇑, J.W. Mitchell b, K. Yoshimura a, K. Abe c,1, H. Fuke d, S. Haino a,2, T. Hams b,3, M. Hasegawa a, A. Horikoshi a, A. Itazaki c, K.C. Kim e, T. Kumazawa a, A. Kusumoto c, M.H. Lee e, Y. Makida a, S. Matsuda a, Y. Matsukawa c, K. Matsumoto a, A.A. Moiseev b, Z. Myers b,4, J. Nishimura f, M. Nozaki a, R. Orito c,5, J.F. Ormes g, K. Sakai f, M. Sasaki b,6, E.S. Seo e, Y. Shikaze c,7, R. Shinoda f, R.E. Streitmatter b, J. Suzuki a, Y. Takasugi c, K. Takeuchi c, K. Tanaka a, T. Taniguchi a,8, N. Thakur g, T. Yamagami d, T. Yoshida d, BESS Collaboration a High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan b National Aeronautics and Space Administration, Goddard Space Flight Center (NASA/GSFC), Greenbelt, MD 20771, USA c Kobe University, Kobe, Hyogo 657-8501, Japan d Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 229-8510, Japan e IPST, University of Maryland, College Park, MD 20742, USA f The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan g University of Denver, Denver, CO 80208, USA Available online 29 July 2011 Abstract The balloon-borne experiment with a superconducting spectrometer (BESS) has performed cosmic-ray observations as a US–Japan cooperative space science program, and has provided fundamental data on cosmic rays to study elementary particle phenomena in the early Universe.
    [Show full text]
  • High Precision Particle Astrophysics As a New Window on the Universe with an Antimatter Large Acceptance Detector in Orbit (Aladino)
    High Precision Particle Astrophysics as a New Window on the Universe with an Antimatter Large Acceptance Detector In Orbit (ALADInO) A White Paper submitted in response to ESA’s Call for the VOYAGE 2050 long-term plan Contact Person: Roberto Battiston Address: Dipartimento di Fisica, Via Sommarive 14, 38123 Trento E-mail: [email protected] Telephone: +39 366 687 2527 Core Team members O.Adriani1,2, G.Ambrosi3, , B. Baoudoy4, R.Battiston5,6, B.Bertucci7,3, P.Blasi8, M.Boezio9, D.Campana10, L. Derome11, I. De Mitri8, V. Di Felice12, F. Donato13, M.Duranti3, V.Formato12, D. Grasso14, I. Gebauer15, R. Iuppa5,6, N. Masi17, D. Maurin11, N.Mazziotta17, R. Musenich18, F. Nozzoli6, P.Papini2, P. Picozza19,12, M.Pierce20, S.Pospíšil21, L. Rossi22, N.Tomassetti6,3, V. Vagelli23, X.Wu24 1) University of Florence, Italy (IT) 2) INFN-Florence, Italy (IT) 3) INFN-Perugia, Italy (IT) 4) CEA Saclay Irfu/SACM, France (FR) 5) University of Trento, Italy (IT) 6) INFN-TIFPA, Trento, Italy (IT) 7) University of Perugia, Italy (IT) 8) Gran Sasso Science Institute, Italy & INFN-Laboratori Nazionali del Gran Sasso, Italy (IT) 9) INFN-Trieste, Italy (IT) 10) INFN-Napoli, Italy (IT) 11) Universitè Grenoble Alpes and IN2P3 LSPC, France (FR) 12) INFN-Roma Tor Vergata, Italy (IT) 13) University & INFN Torino, Italy (IT) 14) INFN Pisa, Italy (IT) 15) KIT, Karlsruher Institut für Technologie, Germany (DE) 16) University and INFN Bologna, Italy (IT) 17) INFN-Bari, Italy (IT) 18) INFN-Genova, Italy (IT) 19) University of Roma Tor Vergata, Italy (IT) 20) KTH Royal
    [Show full text]
  • BESS-Polar Experiment
    Advances in Space Research 33 (2004) 1755–1762 www.elsevier.com/locate/asr BESS-polar experiment T. Yoshida a,*, A. Yamamoto a, J. Mitchell b, K. Abe c, H. Fuke a,c, S. Haino a,c, T. Hams b, N. Ikeda d, A. Itazaki d, K. Izumi a,c, M.H. Lee e, T. Maeno d, Y. Makida a, S. Matsuda c, H. Matsumoto c, A. Moiseev b, J. Nishimura c, M. Nozaki d, H Omiya a, J.F Ormes b, M. Sasaki b, E.S. Seo e, Y. Shikaze d, A. Stephens b, R. Streitmatter b, J. Suzuki a, Y. Takasugi d, K. Tanaka a, K. Tanizaki d, T. Yamagami f, Y. Yamamoto c, K. Yamato d, K. Yoshimura a a High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan b Goddard Space Flight Center/NASA, Greenbelt, MD 20771, USA c The University of Tokyo, Bunkyo, Tokyo 113-0033, Japan d Kobe University, Kobe, Hyogo 657-8501, Japan e University of Maryland, College Park, MD 20742, USA f Institute of Space and Astronautical Science (ISAS), Sagamihara, Kanagawa 229-8510, Japan Received 19 October 2002; received in revised form 28 April 2003; accepted 2 May 2003 Abstract In order to investigate elementary particle phenomena in the early Universe, the BESS-polar experiment is proposed. It will study low-energy antiprotons and search for antinuclei in the galactic cosmic rays at the constant altitude maintained by a scientific balloon. A new superconducting spectrometer is being developed for long-duration balloon flights. In order to extend the detectable energy range of antiprotons down to 100 MeV, the thickness of materials along the trajectory of the incident particle is minimized.
    [Show full text]
  • Lecture 9 CPT Theorem and CP Violation
    Lecture 9 CPT theorem and CP violation Emmy Noether's theorem (proved 1915, published 1918) •Any differentiable symmetry of the action of a physical system has a corresponding conservation law. The action of a physical system is the integral over time of a Lagrangian function (which may or may not be an integral over space of a Lagrangian density function), from which the system’s behavior can be determined by the principle of least action. •Energy, momentum and angular momentum conservation laws are consequences of symmetries of space. eg, if a physical system behaves the same regardless of how it is oriented in space -> Lagrangian is rotationally symmetric -> angular momentum of the system must be conserved •We have seen that although both charge conjugation and parity are violated in weak interactions, the combination of the two CP turns left-handed antimuon onto right-handed muon, that is exactly observed in nature. •There is another symmetry in nature – time reversal T (winding the film backward). •Charge conjugation, C, together with parity inversion, P, and time reversal, T, are connected into the famous CPT theorem. •CPT theorem is one of the basic principles of quantum field theory. It states that all interactions are invariant under sequential application of C, P and T operations in any order. Any Lorentz invariant local quantum field theory with a Hermitian Hamiltonian must have CPT symmetry. •It is closely related to the interpretation that antiparticles can be treated mathematically as particles moving backward in time. Ernst Stueckelberg (1905-1984) Should have received several Noble prizes • 1934 - First developer of fully Lorentz-covariant theory for quantum field • 1935 - Developed vector boson exchange as theoretical explanation for nuclear forces.
    [Show full text]
  • Symmetries and CP Violation Thanks to a Hocker and M
    FYST17 Lecture 2 Symmetries and CP violation Thanks to A Hocker and M. Bona 1 Today’s topics • Symmetries – Broken symmetries • Neutral kaon mixing • CP violation – Matter / anti-matter asymmetry • The CKM matrix 2 3 Continuous Symmetries and Conservation Laws In classical mechanics we have learned that to each continuous symmetry transformation, which leaves the scalar Lagrange density invariant, can be attributed a conservation law and a constant of movement (E. Noether, 1915) Continuous symmetry transformations lead to additive conservation laws No evidence for violation of these symmetries seen so far 4 Continuous Symmetries and Conservation Laws In general, if U is a symmetry of the Hamiltonian H, one has: H, U 0 H U† HU fHi UfHUi fUHUi† fHi Accordingly, the Standard Model Lagrangian satisfies local gauge symmetries (the physics must not depend on local (and global) phases that cannot be observed): Conserved additive quantum numbers: Electric charge (processes can move charge between quantum fields, but the sum of all charges is constant) Similar: color charge of quarks and gluons, and the weak charge Quark (baryon) and lepton numbers (however, no theory for these, therefore believed to be only approximate asymmetries) → evidence for lepton flavor violation in “neutrino oscillation” 5 Discrete Symmetries Discrete symmetry transformations lead to multiplicative conservation laws The following discrete transformations are fundamental in particle physics: Parity P (“handedness”): In particle physics: Reflection of space around
    [Show full text]