Results and Outlook of The Aluminum Capture Experiment (AlCap)

POSTER

Abstract

Observation of neutrinoless muon-to-electron conversion in the presence of a nucleus would be unambiguous evidence of physics Beyond the Standard Model. Two experiments, COMET at J-PARC and Mu2e at Fermilab, will search for this process in the coming decade. Barring discovery, these experiments will provide upper-limits on this branching ratio up to 10,000 times better than previously published. COMET/Mu2e developed a joint venture, the AlCap Experiment, to measure particle emission spectra from muonic interactions in a number of materials. As a major source of background hits in COMET/Mu2e detectors, AlCap sought to measure the charged particle and neutron spectra following nuclear capture on the candidate target materials aluminum and titanium. Additionally, COMET/Mu2e are exploring normalization schemes via AlCap's measurement of the photon spectra following both atomic and nuclear capture. Over the course of 2013 and 2015, AlCap performed three runs at the Paul Scherrer Institut in Switzerland. The first acquired preliminary data for all spectra, the second run collected only neutron and photon data, and the third primarily charged particle data. Preliminary analyses of the first two runs, already impactful for COMET/Mu2e, is presented along with a summary of the third.

Authors

  • John R. Quirk

    Boston University

  • Ian Shipsey

    Cornell University, Cornell University and University College Dublin, University College Dublin, UC Berkeley, Cal State Univ- Fullerton, Theoretical Astrophysics 350-17, California Institute of Technology, 4Gravitational Wave Physics and Astronomy Center, California State University Fullerton, Syracuse University, Gravitational Wave Physics and Astronomy Center, California State University Fullerton, California Institute of Technology, CITA, Univ of Toronto, California State University, Fullerton, Princeton University, Canadian Institute for Theoretical Astrophysics, Northwestern University, 2016 April Meeting Chair and Oxford University, Rochester Inst of Tech, West Virginia University, Wigner RCP, Budapest, Hungary, Rochester Institute of Technology, Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Univ of California - Davis, University of Texas Brownsville, Department of Physics and Astronomy, Michigan State University, Los Alamos National Laboratory, Boston University, Lock Haven University, Temple University, Dept. of Physics and Space Sciences, Florida Institute of Technology, NSSTC, CSPAR, Univ., of Alabama, Dept. of Physics, Univ., New Hampshire, Royal Institute of Technology, Stockholm, Sweden, Pennsylvania State University, University of Wisconsin-Milwaukee, Univ of Michigan - Ann Arbor, Washington University In Saint Louis, Harvard-Smithsonian Center for Astrophysics, Max Planck Institute for Extraterrestrial Physics, University of Washington, University of California, Santa Cruz, University of California, San Diego, University of Utah, Kavli Institute for Astronomy and Astrophysics, Peking University, Retired, University of Wisconsin-Madison, University of Brussels, Kyoto University, Johann Wolfgang Goethe-Universitat, Massachusetts Inst of Tech-MIT, University of Arizona, Stanford University, New York University, University of Illinois, Urbana-Champaign, MIT & University of Washington, MIT, Tulane U., U. of Waterloo, UNC-Wilmington, University of Tokyo, Ursinus College, Lawrence Berkeley National Laboratory, APS President and University of Michigan, U.S. Naval Academy, Dept. of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA, Dept. di Fisica, Universit\`a di Trento and Istituto Nazionale di Fisica Nucleare and Gruppo Collegato di Trento, I-38123 Trento, Italy, Physics Division, Oak Ridge National Laboratory,Oak Ridge, Tennessee 37831, USA, Racah Institute of Physics, The Hebrew University, Jerusalem 91904, Israel, TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3, Canada, TBD, Hartwick College, Microsoft Research, New York, NY, Amazon, New York, NY, Loyola Marymount University, Parma University, Joint Quantum Institute, Georgia Southern University, Univ of Maryland-College Park, DePaul University, Smithsonian Astrophysical Observatory, Minnesota State University-Mankato, Department of Pure and Applied Physics, Ladoke Akintola University of Technology, Ogbomoso, Department of Science Laboratory Technology, Osun state polytechnic, Iree, LAL, Universit e Paris-Sud, IN2P3/CNRS, F-91898 Orsay, France, Massachusetts Institute of Technology, Univ of Kansas, Paul Scherrer Institute, Hartnell Community College, Astronomy & Meteorology Department, Faculty of Science, A l-Azhar University., Lawrence Berkeley National Lab, University of Tennessee, Florida Atlantic University, Millikin University, Univ of Colorado - Boulder, University of Maine, Colorado State Univ, Univ of Florida - Gainesville, Louisiana State University, University of Florida, Montana State University, (College of William \& Mary, Jefferson Lab, North Carolina A&T State Univ, Departament d'Estructura i Constituents de la Mat{\`e}ria and Institut de Ci{\`e}nces del Cosmos, Universitat de Barcelona, Avinguda Diagonal 647, E-8, Department of Physics, Washington University, St. Louis, Missouri 63130, USA, Department of Physics, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, Surrey GU2 7XH, United Kingdom, U of Guelph, Caltech, Allegheny College, LBNL, RIT, WSU, Michigan State U. Dept of Physics and Astronomy, National Superconducting Cyclotron Laboratory, National Superconducting Cyclotron Laboratory, Michigan State U. Dept of Chemistry, National Superconducting Cyclotron Laboratory, University of Illinois, Jefferson National Laboratory, Fermi National Laboratory, Argonne National Laboratory, Thomas Jefferson National Accelerator Laboratory, JPL-Caltech, UC Berkeley-SSL, CRESST-UMCP-GSFC, CRESST-UMBC-GSFC, WUSL, CRESST-USRA-GSFC, NASA-GSFC, School of Physics and Astronomy, The Univ of Birmingham, Universidad Nacional Autonoma de Mexico, Texas A\&M University, Oak Ridge National Laboratory, Lawrence Livermore National Laboratory, University of Kentucky, University of Richmond, Australian National University, U.S. Army Research Laboratory, University of Birmingham, ICTS-TIFR, IISER Kolkata, Idaho State Univ, University of California (Davis), Lawrence Livermore National Lab, Nazarbayev University, Univ of Washington, AEI Potsdam, Montana State Univ, University of Mississippi, Max-Planck-Institut f\"ur Gravitationsphysik, LIGO Livingston Observatory, University of Texas Rio Grande Valley, Aarhus University, University of Michigan, University of Notre Dame, RIKEN Nishina Center, National Superconducting Cyclotron Laboratory / Michigan State University, Gonzaga University, National Superconducting Cyclotron Laboratory/Michigan State University, Harvard University, University of California, Berkeley, University of Connecticut, H3D, Royal Holloway University, University of Chicago, Yale University, Columbia University, Tufts University, Bard Coll, CITA, University of Toronto, NCSA, University of Illinois at Urbana-Champaign, Washinton State University, University of Parma, Albert Einstein Institute, Jet Propulsion Lab, California Institute of Technology, NASA Goddard Space Flight Center, Busek Co. Inc., Department of Physics & Astronomy, University of Utah, Vanderbilt University, Florida State University, Indiana University, Indiana Univ - Bloomington, Geophysics Res. Group, Dept. of Physics, Sch. of Sci. and Eng. Ateneo de Manila University, Christopher Newport University, Jefferson Laboratory, Florida International University, Washington University in Saint Louis, 300 below Inc., 300 Below, Inc., Tennessee Tech University, Kanazawa University, Wentworth Institute of Technology, MIT Lincoln Laboratories, Paul Scherrer Institut, Hartnell College, Rutgers University, Harvard, Frankfurt University, University of Illinois at Urbana-Champaign, Universidad Industrial de Santander, Univ of Trento, Universitat de les Illes Ballears, Brigham Young University, Perimeter Institute for Theoretical Physics, University of New Hampshire, Department of Chemistry, Smalley-Curl Institute and Laboratory for NanoPhotonics, Rice University, Georg-August-Universitaet Goettingen, Ohio State Univ - Columbus, Cyclotron Institute, Texas A\&M University, Cyclotron Institute, Texas A\&M University, College Station, Texas