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Stephane Coutu

Stephane Coutu

Main Content

  • Professor of Physics and of Astronomy & Astrophysics
303H Osmond
Email: coutu [ AT ] phys [ DOT ] psu [ DOT ] edu
Phone: (814) 865-2015

Education

  1. McGill University (B.Sc. Physics, First Class Honours), 1987
  2. California Institute of Technology (M.S., Physics), 1989
  3. California Institute of Technology (Ph.D., Physics), 1993
  4. University of Michigan (Post-doctoral Fellow, Particle Astrophysics), 1997

Specialties:

Particle Astrophysics
  • Experimental
Particles & Fields
  • Experimental

Honors and Awards

  • 2016 APS Fellow
  • 2012 Antarctica Service Medal of the National Science Foundation
  • 2009, 2011 Penn State Residence Life freshman teaching awards
  • 2006 NASA Group Achievement Award for CREAM Science Mission
  • 2001 – 2007 Presidential Early Career Award for Scientists and Engineers
  • 1998/99 Research Innovation Award, Research Corporation;
  • 1987-1991 1967 Science and Engineering Scholarship, NSERC (Natural Sciences and Engineering Research Council of Canada);
  • 1987/88 R.A. Millikan Fellowship, California Institute of Technology;
  • 1987 Horace Watson Medal for Physics, McGill University;
  • 1987 Robert E. Bell Prize for Physics, McGill University;
  • 1987 Moyse Travelling Scholarship, McGill University;
  • 1986/87 president, McGill Student Physics Society;
  • 1985, 1986, 1987 NSERC Summer Research Awards;
  • 1986 John Foster Scholarship, McGill University;
  • 1984-1986 William MacDonald Scholarship, McGill University;
  • 1985 Garnet Woonton Prize for Physics, McGill University

Selected Publications

  1. P. Abreu et al. (Auger Collaboration), “Measurement of the proton-air cross-section at sqrt(s) = 57 TeV with the Pierre Auger Observatory,” Phys. Rev. Lett. 109, 062002 (2012).
  2. P. Abreu et al. (Auger Collaboration), “Search for point-like sources of ultra-high energy neutrinos at the Pierre Auger Observatory and improved limit on the diffuse flux of tau neutrinos,” ApJ 755, L4 (2012).
  3. P. Abreu et al. (Auger Collaboration), “A Search for Point Sources of EeV Neutrons,” ApJ 760, 148 (2012).
  4. P. Abreu et al. (Auger Collaboration), "Large scale distribution of arrival directions of cosmic rays detected above 10^18 eV at the Pierre Auger observatory," ApJ Suppl. 203, 34 (2012).
  5. P. Abreu et al. (Auger Collaboration), “Constraints on the origin of cosmic rays above 10^18 eV from large scale anisotropy searches in data of the Pierre Auger observatory,” ApJL 762, L13 (2013).
  6. S. Coutu, “Positrons Galore,” Physics 6, 40 (2013) (invited Viewpoint article by APS on the release in PRL of the first AMS results: “First Results from the Alpha Magnetic Spectrometer on the International Space Station: Precision Measurement of the Positron Fraction in Primary Cosmic Rays of 0.5-350 GeV”).
  7. P. Abreu et al. (Auger Collaboration), “The Interpretation of the Depths of Shower Maximum of Extensive Air Showers Measured by the Pierre Auger Observatory,” JCAP 02, 026, 1-19 (2013).
  8. M.W.E. Smith et al. (AMON Collaboration), “The Astrophysical Multimessenger Observatory Network (AMON),” Astropart. Phys. 45, 56-70 (2013).
  9. P. Abreu et al. (Auger Collaboration), “Bounds on the density of sources of ultra-high energy cosmic rays from the Pierre Auger Observatory,” JCAP 05, 009, 1-18 (2013).
  10. A. Aab et al. (Auger Collaboration), “Probing the radio emission from cosmic-ray-induced air showers by polarization measurements,” Phys. Rev. D 89, 052002, 1-18 (2014).
  11. A. Aab et al. (Auger Collaboration), “A search for point sources of EeV photons,” ApJ 789, 160-171 (2014).
  12. A. Aab et al. (Auger Collaboration), “A Targeted Search for Point Sources of EeV Neutrons,” ApJL 789, L34-40 (2014).
  13. A. Aab et al. (Auger Collaboration), “Muons in air showers at the Pierre Auger Observatory: measurement of atmospheric production depth,” Phys Rev D 90, 012012, 1-15 (2014).
  14. A. Aab et al. (Auger and TA Collaborations), “Searches for Large-Scale Anisotropy in the Arrival Directions of Cosmic Rays Detected above Energy of 1019 eV at the Pierre Auger Observatory and the Telescope Array,” ApJ 794, 172, 1-15 (2014).
  15. A. Aab et al. (Auger Collaboration), “Depth of Maximum of Air-Shower Profiles at the Pierre Auger Observatory. I. Measurements at Energies above 1017.8 eV,” Phys Rev D 90, 122005, 1-25 (2014).
  16. A. Aab et al. (Auger Collaboration), “Depths of Maximum of Air-Shower Profiles at the Pierre Auger Observatory. II. Composition Implications,” Phys Rev D 90, 122006, 1-12 (2014).
  17. A. Aab et al. (Auger Collaboration), “Muons in air showers at the Pierre Auger Observatory: Mean number in highly inclined events,” Phys Rev D 91, 032003, 1-12 (2015).
  18. A. Aab et al. (Auger Collaboration), “Large scale distribution of ultra high energy cosmic rays detected at the Pierre Auger Observatory with zenith angles up to 80 degrees,” ApJ 802, 111 (2015).
  19. A. Aab et al. (Auger Collaboration), “Searches for Anisotropies in the Arrival Directions of the Highest Energy Cosmic Rays Detected by the Pierre Auger Observatory,” ApJ 804, 15 (2015).
  20. H.J. Hyun et al. (ISS-CREAM Collaboration), “Performances of photodiode detectors for top and bottom counting detectors of ISS-CREAM experiment,” NIM A 787, 134-139 (2015).
  21. A. Aab et al. (Auger Collaboration), “An improved limit to the diffuse flux of ultra-high energy neutrinos from the Pierre Auger Observatory,” Phys. Rev. D 91, 092008 (2015); featured on the PRD homepage as a PRD Editor’s Suggestion.
  22. A. Aab et al. (Auger Collaboration), “Search for patterns by combining cosmic-ray energy and arrival directions at the Pierre Auger Observatory,” European Phys. J. C 75, 269 (2015).
  23. A. Aab et al. (Auger Collaboration), “Measurement of the cosmic ray spectrum above 4x1018 eV using inclined events detected with the Pierre Auger Observatory,” JCAP 08, 049 (2015).
  24. A. Aab et al. (Auger Collaboration), “The Pierre Auger Cosmic Ray Observatory,” Nucl. Inst. & Meth. A 798, 172-213 (2015).
  25. Y.S. Hwang et al. (ISS-CREAM Collaboration), “Construction and Testing of a Top Counting Detector and a Bottom Counting Detector for the Cosmic Ray Energetics And Mass Experiment on the International Space Station,” JINST 10, P07018 (2015).
  26. M.G. Aartsen et al. (IceCube, Auger and TA Collaborations), “Search for correlations between the arrival directions of IceCube neutrino events and ultrahigh-energy cosmic rays detected by the Pierre Auger Observatory and the Telescope Array,” JCAP01, 037, 1-33 (2016).
  27. A. Aab et al. (Auger Collaboration), “Nanosecond-level time synchronization of autonomous radio detector stations using a reference beacon and commercial airplanes,” JINST 11, P01018, 1-30 (2016).
  28. A. Aab et al. (Auger Collaboration), “Azimuthal asymmetry in the risetime of the Surface Detector signals of the Pierre Auger Observatory,” Phys. Rev. D 93, 072006, 1-16 (2016).
  29. A. Aab et al. (Auger Collaboration), “The prototype muon module for the AMIGA project of the Pierre Auger Observatory,” JINST 11, P02012, 1-26 (2016).
  30. F.G. Schröder et al. (Auger Collaboration), “Radio detection of high-energy cosmic rays with the Auger Engineering Radio Array,” Nucl. Inst. & Meth. A 824, 648-651 (2016).
  31. A. Aab et al. (Auger Collaboration), “Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory,” Phys. Rev. D 93, 122005, 1-15 (2016).
  32. A. Aab et al. (Auger Collaboration), “Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy,” PRL 116, 241101, 1-9 (2016).
  33. G. Snow et al. (Auger Collaboration), “AugerPrime looks to the highest energies,” CERN Courier (cover article), 56, 29-31 (2016).
  34. L. Collica et al. (Auger Collaboration), “Measurement of the Muon Production Depths at the Pierre Auger Observatory,” Eur. Phys. J. Plus 131, 301 (2016).
  35. A. Aab et al. (Auger Collaboration), “Search for Ultra-relativistic Magnetic Monopoles with the Pierre Auger Observatory,” PRD 94, 082002, 1- 12 (2016); selected as editor’s suggestion.
  36. A. Aab et al. (Auger Collaboration), “Testing hadronic interactions at ultrahigh energies with air showers measured by the Pierre Auger Observatory,” PRL 117, 192001, 1-9 (2016); selected as editor’s highlight.

Research Interests

My research interests lie in the study of high-energy particles in the cosmic-ray flux, as windows on fundamental processes and laws governing the Universe. I am involved in a number of collaborative efforts, with colleagues at Penn State and elsewhere, in the following areas. 

1. The properties of cosmic rays, namely their nuclear composition, origin, acceleration and propagation, are studied with a number of different approaches:

• Direct measurements are made with balloon-borne instruments (e.g., the HEAT, CREST, CREAM and HELIX payloads), or with a space-borne instrument (the ISS-CREAM payload, to be deployed on the Space Station in 2017).

• Indirect studies are conducted with large instruments buried deep underground (e.g., MACRO experiment), or arrays of instruments scattered on the ground surface (e.g., the EAS-TOP and Pierre Auger air shower arrays).

Of interest are the relative proportions of various elements in the cosmic-ray flux (e.g., nuclei such as H, He, C, Fe, etc., and electrons, positrons and antiprotons), their differential energy spectra and arrival directions. All of these parameters can be used to infer possible creation/acceleration scenarios for these particles, and properties of their propagation through the Galaxy and beyond. We are planning a new study of isotopic abundances of cosmic-ray nuclei (e.g., 10Be/9Be) in a new energy regime (up to 10 GeV/n), which provides a complementary view of Galactic propagation (the HELIX project).

 2. Particle physics candidates are sought for the dark matter that is known to dominate the mass of the Universe, but whose identity remains elusive. This is done by studying the antimatter content of the cosmic-ray flux: antimatter particles could be created in the annihilation of dark matter particles (such as supersymmetric Weakly Interacting, Massive Particles, or WIMPs). The HEAT instrument was used for these studies, and for a decade represented the state-of-the-art in cosmic positron and antiproton measurements (until the advent of the PAMELA and AMS space-borne instruments). Another approach is the study of neutrinos, which could reveal dark matter gravitationally accumulated at the core of the Sun. Such neutrinos are detected deep underground (e.g., with the MACRO instrument). Complementary neutrino studies come from measurements of atmospheric muons (e.g., with the HEAT balloon payload), whose production is closely coupled to that of neutrinos.

 3. The highest energy particles in the Universe, at energies beyond 10^19 eV, are very rare and a complete puzzle, as there is no known mechanism that satisfactorily accounts for their existence. They can only be studied with sufficient statistics by huge detectors. With the Pierre Auger Observatory, such particles are measured with enough accuracy that important clues are obtained to help resolve the mystery of their origin. At these energies, particle deflections by magnetic fields may be small enough that for the first time particle astronomy becomes possible, and point sources of these objects can be identified. Of special interest is the possibility that the highest energy cosmic rays contain a neutrino, gamma ray or neutron component. By revealing them through the study of horizontal air showers (neutrinos), air showers with a different structure (gamma rays) or hadronic showers pointing to an excess from a Galactic source (neutrons), the Auger Observatory opens new frontiers. 

     

    Group Members

    Former graduate students

    • Tyler Anderson
    • Sanjeevi Atulugama
    • Nick Conklin
    • Matt Geske
    • Sai Im
    • Steve Minnick
    • Isaac Mognet

     

    Former post-doctoral fellows

    • Jose Bellido
    • Mike DuVernois
    • Stephanie Jaminion
    • Foteini Oikonomou
    • Mike Roberts
    • Ralph Ulrich
    • Ben Whelan

     

     Current graduate students

    • Jamyang Phuntsok

     

    Current postdocs and research engineer

    • Tyler Anderson
    • Isaac Mognet

     

    Current and recent undergraduate students

    • Joe Berlin
    • George Filippatos
    • Allen Foster
    • Michael Grinshpon
    • Amar Paul
    • Justin Powell
    • Mike Spitz
    • Tyler White
    • Zhiyu Yin