John A. J. Matthews, Professor Ph.D. 1971, University of Toronto

Research Area: Experimental Particle Physics and Particle Astrophysics
Recent Cosmic Ray and Dark Matter/TeV Gamma-ray Notes+Talks+selected papers:

[-2] 1960s: Decade of Serendipity, TAAS General Meeting, March 23, 2024

[-1] Suggestions for your Talk, Suggestions for better Talks, February 2024

[0] Oct 14, 2023 Eclipse in Farmington, NM, Panel Dsicussion, Farmington Public Library, October 13, 2023

[1] TeV Gamma-ray Astrophysics, Physics and Astronomy Colloquium, UNM, September 28, 2018

[2] Lessons learned from <1 TeV Simulations, HAWC Collaboration Meeting, Cocoyoc, Mexico, October 29 - November 1, 2017

[3] Extreme Universe from 1963 to 2017, Sigma Xi talk, Albuquerque, NM May 15, 2017

[4] Is "gamma coreness" a useful concept for gamma:CR separation (II)?, HAWC Phone Meeting, September 26, 2016

[5] Is "gamma coreness" a useful concept for gamma:CR separation?, HAWC Phone Meeting, August 22, 2016

[6] Measuring 2.4 x 10^26Hz photons and why we do it!, Joint OSE/NUPAC Seminar, April 7, 2016

[7] Dark Matter Searches for Extended Sources, HAWC Collaboration Meeting, UNAM, Mexico City, Mexico, January 7-9, 2016

[8] Indirect Search for Dark Matter, Consortium Seminar, October 12, 2015

[9] Annotated and Abbreviated version of V. Verzi Rapporteur Talk (ICRC 2015) Cosmic Rays: air showers from low to high energies, NUPAC seminar, Physics Department, UNM, September 1, 2015

[10] Indirect Search for Dark Matter, Physics Department Research Seminar, August 28, 2015

[11] Can shower profiles measure more than Xmax and Energy "II"?, Auger Collaboration Meeting, Colorado School of Mines, June 16-20, 2014

[12] What do FD events with well measured Profiles say about Xmax and Xmax RMS?, Auger Collaboration Meeting, Malargue, Argentina, November 11-16, 2013

[13] What are the Highest Energy Cosmic Rays Telling Us?, Invited talk, 4 Corners APS meeting, U. of Denver, October 18-19, 2013; NUPAC seminar, Physics Department, UNM, August 27, 2013

[14] Can shower profiles measure more than Xmax and E?, Auger Collaboration Meeting, Lisbon, Portugal, June 3-7, 2013

[15] HAWC Calibration: Cabling Experience from HAWC30, HAWC Collaboration Meeting, Chiapas, Mexico, Oct 17-19, 2012

[16] Physics of the Extreme Universe, Physics Department Research Seminar, September 6, 2013

..... Physics of the Extreme Universe, Physics Department Research Seminar, August 31, 2012

[17] HAWC Calibration Optimization , HAWC collaboration meeting, Santa Fe, NM, May 30 - June 1, 2012

..... HAWC Calibration: Optical diffusers and float assemblies , HAWC collaboration meeting, Santa Fe, NM, May 30 - June 1, 2012

[18] A Search for Anisotropy in the Arrival Directions of Ulta-high Energy Cosmic Rays Recorded at the Pierre Auger Observatory , Journal of Cosmology and Astro-particle Physics, (2012)

[19] HAWC Calibration: Near Term Goals , HAWC collaboration meeting, Instituto de Fisica, UNAM, Mexico City, Mexico, January 9-11, 2012

[20] HAWC Optical (Laser) Calibration , HAWC DOE/NSF Readiness Review, INAOE, Puebla, Mexico, November 9, 2011

[21] Calibration Plans for HAWC30 , HAWC collaboration meeting, U. of Wisconsin, September 12-14, 2011

[22] HAWC Optical Calibration: Observations from CSU Tests, HAWC collaboration meeting, Tlaxcala, Mexico, June 1-3, 2011

..... Calibration of the HAWC Observatory, to be published in Proc. of 32nd ICRC, Beijing,China, August 11-18, 2011

..... HAWC Optical Calibration: Some Near-term Issues, HAWC collaboration meeting, Tlaxcala, Mexico, June 1-3, 2011

[23] HAWC Optical Calibration: Recent Progress, HAWC collaboration meeting, Guadalajara, October 11-13, 2010

..... HAWC Optical Calibration: Recent Progress at UNM, HAWC Water Cherenkov Detector meeting, Colorado State University, August 18-19, 2010

[24] Staying Sane in an Insane World: Novel Analyses for Cosmic Ray Experiments, Seminar, University of Utah, May 14, 2010

[25] HAWC Optical Calibration: Getting Serious!, HAWC collaboration meeting, Benemerita Universidad Autonoma de Puebla, February 4-5, 2010

[26] A Parametrization of Cosmic Ray Shower Profiles Based on Shower Width, Auger Collaboration Meeting, Malargue Argentina, November 14-20, 2009

[27] HAWC Optical Calibration: 900 --> 300 Tanks, HAWC Collaboration Meeting, U. of Maryland, November 6-7, 2009

[28] A Three-point (Shape Strength) Cosmic Ray Anisotropy Search Method , Workshop on Exotic Physics in Cosmic Rays, Universidade Tecnica de Lisboa, Lisbon, 3-6 July 2009

[29] Update on HAWC Optical Calibration System , HAWC Collaboration Meeting, U. of Maryland, May 7-8, 2009

..... HAWC Timing Calibration, to be published in Proc. 31st ICRC, Lodz , Poland, July 2009

[30] Why are we still studying cosmic rays? (Pierre Auger Observatory: Past, Present, Future) , UNM Physics and Astronomy Colloquium, April 3, 2009

[31] Milagro Magic Paint: Does it Work? , Auger North Meeting, Colorado State U., Feb. 17-19, 2009

[32] Selected Physics Results from the Pierre Auger Southern Observatory , HEP Seminar(s) at: CalTech (2/9/2009), Universidat Complutense de Madrid, Madrid, Spain (1/16/2009), Harvard (11/14/2008), SLAC (3/11/2008)

[33] Milagro Tank Temperature Study: w/ and w/o Tank Insulation , Auger North Meeting, LPNHE, Paris, March 13-14, 2008

[34] Evidence for Correlation of the Highest Energy Cosmic Rays and Extra-galactic Objects (AGNs)? , 23rd Annual New Mexico Symposium, NRAO, Socorro, Oct 19, 2007

..... Correlation of the Highest Energy Cosmic Rays with Nearby Extragalactic Objects, Science, 9 November 2007

[35] Temperature Measurements in a Milagro Outrigger Detector, Auger North Design Meeting, Karlsruhe, Feb 26-28, 2007 / Auger North R&D Meeting, Colorado State University, February 12-13, 2007

[36] Power Laws and the Cosmic Ray Energy Spectrum, published in Astroparticle Physics (2007)

[37] Search for Correlations between Nearby AGNs and Ultra-high Energy Cosmic Rays, published in Astroparticle Physics (2007)

[38] Lessons Learned from Milagro Outrigger Detectors, Auger North R&D Meeting, University of Colorado, February 10, 2006

[39] Status Report on Fluorescence Detector Xmax Composition Analysis, Auger Collaboration Meeting, Malargue Argentina, November 16, 2005

[40] HAWC Sensitivity from BOE Showers , HAWC/Milagro Collaboration Meeting, Michigan State U., June 25, 2004

[41] Highest Energy Cosmic Rays: Probe of the Extreme Universe, colloquium, Texas Tech University, January 29, 2004

[42] Cosmic Ray Composition and Muon Counters, talk, Telescope Array Collaboration meeting, October 25, 2003

..... Are We Serious About Cosmic Ray Composition?, updated talk, Auger South Upgrade Meeting, Karlsruhe, Germany, Feb 24-25, 2005

[43] Atmospheric Monitoring with Tunable Lasers, talk, T.A. Japan Meeting, January 29, 2004

[44] How Well Do We Know Rayleigh Cross Sections?, Auger GAP-2003-059, August 20, 2003

[45] APF Light Sources for the Auger Southern Observatory, poster, 28th ICRC, July 31 - August 7, 2003

[46] Atmospheric Monitoring Systems for the Auger Southern Observatory, talk, Astroparticles and Atmosphere Workshop, College de France, Paris, May 2003

.... Monitoring the Aerosol Phase Function with the Coihueco Fluorescence Detector, talk, Astroparticles and Atmosphere Workshop, College de France, Paris, May 2003

[47] APF Light Sources for the Auger Southern Observatory, May 2003, 28th ICRC, July 31 - August 7, 2003

[47a] APF Light Source Status, Auger Collaboration Meeting, Malargue, Argentina, April 28, 2003

[48] Composition below 10^19 eV, talk, US Auger Collaboration Meeting, Colorado State University, February 28, 2003

[48a] New Mexico Hardware Responsibilities, US Auger Collaboration Meeting, Colorado State U, February 28, 2003

[49] Optical Relative Calibration and Stability Monitoring for the Auger Fluorescence Detector, 29th ICRC, Pune India 2005

.... Optical Calibration of the Auger Fluorescence Telescopes, Auger GAP_02_029, SPIE Conference "Astronomical Telescopes and Instrumentation", August 22-28, 2002 __(Revised: Aug 20, 2002)

.... Optical Calibration of the Auger Fluorescence Telescopes, SPIE Conference TALK, August 22, 2002

[50] Proposal for a Remote Vertical Laser System for the Auger Fluorescence Detector, June 25, 2002; updated to "Central Laser Facility", International Workshop on Calibration and Atmospheric Monitoring for the Fluorescence Detector of the Pierre Auger Observatory, Gran Sasso Laboratory, January 9-12, 2003

[50a] Piece by Piece FD Calibration Future Plans, Auger Collaboration Meeting, Malargue, Argentina, November 11, 2002

[51] AAS talk: New Results on the Highest Energy Cosmic Rays , June 3, 2002

.... UPDATED talk with latest HiRes data , LANL Colloquium, October 17, 2002

[51a] FD Atmospheric Absorption Corrections: Overview and Issues, Auger Event Reconstruction Workshop, U. of Chicago, October 2, 2002

[51b] Aerosol Phase Function Monitoring "I", Auger Collaboration Meeting, Malargue, Argentina, April 23, 2002

[51c] Summary of FD Calibration Session, Auger Collaboration Meeting, Malargue, Argentina, April 24, 2002

[51d] Aerosol Phase Function Monitoring "II", Auger Collaboration Meeting, Malargue, Argentina, April 26, 2002

[52] An Absolute Calibration of the Bay-4 Telescope using Remote Laser Shots, Auger GAP-2002-010, March 16, 2002

[52a] Fluorescence Detector Calibration, Auger Collaboration Meeting, October 24, 2001

[53] Klett Inversion of Simulated LIDAR Signals, Auger GAP-2001-051, October 15, 2001

[54] Lessons from a Toy LIDAR Simulation, Auger GAP-2001-046, October 1, 2001

[55] ICRC2001: Atmospheric Monitoring for the Auger Fluorescence Detector -- talk, August 1, 2001

.... ICRC2001: Atmospheric Monitoring for the Auger Fluorescence Detector, Auger GAP-2001-029, May 25, 2001

[56] Air Fluorescence Detector Site Elevation Issues, Auger GAP-2000-054, December 20, 2000

[56a] Physics, Instrumentation and Fluorescence Energy Measurement, Auger Collaboration Meeting, Malargue, Argentina, Novemeber 14, 2000

[57] Fluorescence Detector Optical Calibration Source Test, Auger GAP-2000-050, October 16, 2000

[58] Fluorescence Detector Optical Calibration and Atmospheric Monitoring for the Pierre Auger Experiment, Auger GAP-2000-033, June 30, 2000/Rev. January 5, 2001

[59] Analysis of Time Variant Molecular Atmosphere for the Purpose of Air Fluorescence Measurements, Auger GAP-1999-037, October 11, 1999

[59a] Update on Atmospheric Monitoring in Utah, Telescope Array Meeting, U.C.L.A. , August 28, 1999

[60] A Preliminary Analysis of the Optical Properties of the Atmosphere in Millard County, Auger GAP-1999-026, July 26, 1999

[61] ICRC1999: OG 4.5.6 Time Variation of the Vertical Profile of the Atmosphere ..., May 14, 1999

....ICRC1999: OG 4.5.18 Measurement of the Aerosol Differential Scattering Cross Section ..., May 14, 1999

....ICRC1999: OG 4.5.19 Atmospheric Monitoring for Transmission Corrections ..., May 14, 1999

[62] Proposed Atmospheric Monitoring for the HiRes Experiment, December 1998

[63] The Standard Atmosphere, the Moliere Radius, and Ground Array Systematic Errors, Auger GAP-1998-002, January 1998

....Original Kamata and Nishimura paper

[64] Study of Ground Array Performance using Parametric Showers, Auger GAP-1997-071, November 1997

[66] Notes on the Biggest Showers, Auger GAP-1997-019, April 1997

[66] Back of the Envelope Insights into Shower Energy Measurements by Sparse Ground Arrays, Auger GAP-1997-018, April 1997


Brief Description of Research:

My present research focuses on the study of the highest energy gamma rays with the HAWC experiment near Puebla Mexico and on the study of the highest energy cosmic rays with the Pierre Auger experiment in Argentina. Part of my Auger research involved R\&D on atmospheric monitoring and detector calibration for fluorescence experiments with the High Resolution Fly's Eye experiment in Utah. Atmospheric monitoring uses various light sources including laser beams. I am a co-leader of the atmospheric monitoring and fluorescence detector calibration group in the Pierre Auger experiment. The next generation of ultra-high energy experiments, using fluorescence light from the extensive air showers in the atmosphere to measure the properties of the cosmic rays, will need to measure the air showers at unprecedented distances, 20 to 40km, from the fluorescence detectors. Thus the success of these experiments hinges on reliable atmospheric monitoring as well as precision fluorescence detector calibration.

Previous to this my research focused on the collider physics program at Fermilab and in particular the CDF experiment, and the the study of the top quark and the search for the Higgs boson. Both top and Higgs physics depend on the efficient detection of b-quark jets using a silicon vertex detector; I have been a leader in CDF and a world expert in this technology.

During my collider physics "phase", I was involved with major discoveries with the Mark II and CDF experiments. The Mark II experiment emphasized the first measurements of the properties of the Z vector boson using high energy colliding beams. The most significant result of this experiment was the first measurement of the number of types of low mass neutrinos to be 3. Thus we now know that there are only three types of low mass neutrinos: , and . The CDF experiment at the Fermilab Tevatron collider is one of the two highest energy collider experiments until the LHC begins operation in 2006. Thus the primary focus of the CDF experiment has been the search for new physics including new quarks. One example is our recent discovery of the t-quark. The t-quark is unusual in that it is much more massive than any previous fundamental fermion! Our measured mass of the t-quark is 176.1 +/- 6.6 GeV/c2 or almost the same mass as a gold nucleus! As elementary fermions appear to group in generations, where a generation consists of 2 quarks, one lepton and one neutrino, the t-quark discovery and the measurement of 3 generations of neutrinos, could imply that we have discovered all the fundamental fermions!

(Sorry ... very old) Sample Publications:

  • Correlation of the highest-energy cosmic rays with the positions of nearby active galactic nuclei, J. Abraham et al., Astropart. Phys. 29 188 (2008) [arXiv: 0712.2843]

  • Correlation of the highest energy cosmic rays with nearby extragalactic objects, J. Abraham et al., Science 318 938 (2007) [arXiv: 0711.2256]

  • Observation of the GZK Cutoff by the HiRes Experiment, R. Abbasi et al., Phys. Rev. Lett. 100 101101 (2008) [astro-ph/0703099]

  • Observation of the suppression of the flux of cosmic rays above $4 \times 10^{19}$eV, J. Abraham et al., Phys. Rev. Lett. 101 061101 (2008) [arXiv:0806.4302]

  • Monocular Measurement of the Spectrum of UHE Cosmic Rays by the FADC Detector of the HiRes Experiment, T. Abu-Zayyad et al., Astropart. Phys. 23 157 (2005) [astro-ph/0208301]

  • A Three-Point Cosmic Ray Anisotropy Method, J.D. Hague, B.R. Becker, M.S. Gold, J.A.J. Matthews, to be pub. in Journal Phys. G (2009) [arXiv:0905.4488]

  • Statistical Methods for Investigating the Cosmic Ray Energy Spectrum, J.D. Hague, B.R. Becker, M.S. Gold, J.A.J. Matthews, Proc. 30th I.C.R.C. (2007) [arXiv:0710.3600]

  • Power Laws and the Cosmic Ray Energy Spectrum, J.D. Hague, B.R. Becker, M.S. Gold, J.A.J. Matthews, Astropart. Phys. 27 455 (2007) [astro-ph/0610865]

  • Observation of Top Quark Production in Collisions, with the CDF Collaboration, F. Abe, et al, Phys. Rev. Lett. 74, 2626-2631 (1995)

  • Evidence for Top Quark Production in Collisions at TeV, with the CDF Collaboration, F. Abe, et al, Phys. Rev. D50, 2966-3026 (1994)

  • Bulk Radiation Damage in Silicon Detectors and Implications for LHC Experiments, J.A.J. Matthews, et al., Nucl. Instr. Meth. A381, 338 (1996)

  • The Silicon Vertex Detector of the Collider Detector at Fermilab, D. Amidei, et al., Nucl. Instr. Meth. A350, 73-130 (1994)

  • Temperature Dependence of the Radiation Induced Change of Depletion Voltage in Silicon PIN Detectors, H.J. Ziock, et al, Proceedings of the International Symposium on the Development and Application of Semiconductor Tracking Detectors, Hiroshima, Japan, May 22, 1993, Nucl. Instr. Meth. A342 96-104 (1994)

  • Silicon Tracker for the Super-conducting Super-collider, J. Hylen et al, 2nd London Conf. on Position Sensitive Detectors, London, England Sept 4-7, 1990, Nucl. Instr. and Meth. A310, 497 (1991)

  • Measurements of Z Boson Resonance Parameters in Annihilation, with Mark II Collaboration, G. S. Abrams et al, Phys. Rev. Lett. 63, 2173 (1989)


    J.A.J. Matthews
    Most updated regularly ...