title: First direct limits on lightly ionizing particles with electric charge less than e/6.
abstract: While the standard model of particle physics does not include free particles with fractional charge, experimental searches have not ruled out their existence. We report results from the Cryogenic Dark Matter Search (CDMS II) experiment that give the first direct-detection limits for cosmogenically produced relativistic particles with electric charge lower than e/6. A search for tracks in the six stacked detectors of each of two of the CDMS II towers finds no candidates, thereby excluding new parameter space for particles with electric charges between e/6 and e/200.
authors.affiliation: Department of Physics, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: R
authors.initials: R
authors.lastname: Agnese
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Anderson
authors.affiliation: Department of Physics, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: D
authors.initials: D
authors.lastname: Balakishiyeva
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.|Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
authors.forename: R
authors.initials: R
authors.lastname: Basu Thakur
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Bauer
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: J
authors.initials: J
authors.lastname: Billard
authors.affiliation: SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: A
authors.initials: A
authors.lastname: Borgland
authors.affiliation: Department of Physics, Syracuse University, Syracuse, New York 13244, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Bowles
authors.affiliation: SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: D
authors.initials: D
authors.lastname: Brandt
authors.affiliation: SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: P L
authors.initials: PL
authors.lastname: Brink
authors.affiliation: Department of Physics, Syracuse University, Syracuse, New York 13244, USA.|Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA.
authors.forename: R
authors.initials: R
authors.lastname: Bunker
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: B
authors.initials: B
authors.lastname: Cabrera
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106, USA.
authors.forename: D O
authors.initials: DO
authors.lastname: Caldwell
authors.affiliation: Departamento de Física Teórica and Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, 28049 Madrid, Spain.|IPPP, Department of Physics, Durham University, Durham DH1 3LE, United Kingdom.
authors.forename: D G
authors.initials: DG
authors.lastname: Cerdeno
authors.affiliation: School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: H
authors.initials: H
authors.lastname: Chagani
authors.affiliation: Department of Physics, Syracuse University, Syracuse, New York 13244, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA.
authors.forename: J
authors.initials: J
authors.lastname: Cooley
authors.affiliation: Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: B
authors.initials: B
authors.lastname: Cornell
authors.affiliation: Department of Physics, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: C H
authors.initials: CH
authors.lastname: Crewdson
authors.affiliation: School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: P
authors.initials: P
authors.lastname: Cushman
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: M
authors.initials: M
authors.lastname: Daal
authors.affiliation: Department of Physics, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: P C F
authors.initials: PC
authors.lastname: Di Stefano
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: T
authors.initials: T
authors.lastname: Doughty
authors.affiliation: Departamento de Física Teórica and Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Esteban
authors.affiliation: School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: S
authors.initials: S
authors.lastname: Fallows
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: E
authors.initials: E
authors.lastname: Figueroa-Feliciano
authors.affiliation: SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: G L
authors.initials: GL
authors.lastname: Godfrey
authors.affiliation: Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Golwala
authors.affiliation: Pacific Northwest National Laboratory, Richland, Washington 99352, USA.
authors.forename: J
authors.initials: J
authors.lastname: Hall
authors.affiliation: Department of Physics & Astronomy, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: H R
authors.initials: HR
authors.lastname: Harris
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Hertel
authors.affiliation: School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: T
authors.initials: T
authors.lastname: Hofer
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: D
authors.initials: D
authors.lastname: Holmgren
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: L
authors.initials: L
authors.lastname: Hsu
authors.affiliation: Department of Physics, University of Colorado Denver, Denver, Colorado 80217, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Huber
authors.affiliation: Department of Physics & Astronomy, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: A
authors.initials: A
authors.lastname: Jastram
authors.affiliation: Department of Physics, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: O
authors.initials: O
authors.lastname: Kamaev
authors.affiliation: Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA.
authors.forename: B
authors.initials: B
authors.lastname: Kara
authors.affiliation: SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: M H
authors.initials: MH
authors.lastname: Kelsey
authors.affiliation: School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: A
authors.initials: A
authors.lastname: Kennedy
authors.affiliation: Department of Physics, Syracuse University, Syracuse, New York 13244, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kiveni
authors.affiliation: School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: K
authors.initials: K
authors.lastname: Koch
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: A
authors.initials: A
authors.lastname: Leder
authors.affiliation: Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA.
authors.forename: B
authors.initials: B
authors.lastname: Loer
authors.affiliation: Departamento de Física Teórica and Instituto de Física Teórica UAM/CSIC, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Lopez Asamar
authors.affiliation: Department of Physics & Astronomy, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: R
authors.initials: R
authors.lastname: Mahapatra
authors.affiliation: School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: V
authors.initials: V
authors.lastname: Mandic
authors.affiliation: Department of Physics, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: C
authors.initials: C
authors.lastname: Martinez
authors.affiliation: Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: McCarthy
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: N
authors.initials: N
authors.lastname: Mirabolfathi
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Moffatt
authors.affiliation: Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: D C
authors.initials: DC
authors.lastname: Moore
authors.affiliation: Department of Physics, University of California, Santa Barbara, California 93106, USA.
authors.forename: H
authors.initials: H
authors.lastname: Nelson
authors.affiliation: Division of Physics, Mathematics, & Astronomy, California Institute of Technology, Pasadena, California 91125, USA.
authors.forename: R H
authors.initials: RH
authors.lastname: Nelson
authors.affiliation: SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Ogburn
authors.affiliation: Department of Physics, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: K
authors.initials: K
authors.lastname: Page
authors.affiliation: Department of Physics & Astronomy, University of British Columbia, Vancouver, BC V6T 1Z1, Canada.
authors.forename: W A
authors.initials: WA
authors.lastname: Page
authors.affiliation: SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: R
authors.initials: R
authors.lastname: Partridge
authors.affiliation: School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: M
authors.initials: M
authors.lastname: Pepin
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: A
authors.initials: A
authors.lastname: Phipps
authors.affiliation: Department of Physics & Astronomy, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: K
authors.initials: K
authors.lastname: Prasad
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: M
authors.initials: M
authors.lastname: Pyle
authors.affiliation: Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA.
authors.forename: H
authors.initials: H
authors.lastname: Qiu
authors.affiliation: Department of Physics, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: W
authors.initials: W
authors.lastname: Rau
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: P
authors.initials: P
authors.lastname: Redl
authors.affiliation: Department of Physics, University of Evansville, Evansville, Indiana 47722, USA.
authors.forename: A
authors.initials: A
authors.lastname: Reisetter
authors.affiliation: Department of Physics, Queen's University, Kingston, ON, Canada K7L 3N6.
authors.forename: Y
authors.initials: Y
authors.lastname: Ricci
authors.affiliation: School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: H E
authors.initials: HE
authors.lastname: Rogers
authors.affiliation: Department of Physics, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: T
authors.initials: T
authors.lastname: Saab
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.|Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
authors.forename: B
authors.initials: B
authors.lastname: Sadoulet
authors.affiliation: Department of Physics & Astronomy, Texas A&M University, College Station, Texas 77843, USA.|Department of Physics, University of South Dakota, Vermillion, South Dakota 57069, USA.
authors.forename: J
authors.initials: J
authors.lastname: Sander
authors.affiliation: SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: K
authors.initials: K
authors.lastname: Schneck
authors.affiliation: Department of Physics, Syracuse University, Syracuse, New York 13244, USA.|Department of Physics, South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA.
authors.forename: R W
authors.initials: RW
authors.lastname: Schnee
authors.affiliation: Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA.|Karlsruhe Institute of Technology, Institut für Experimentelle Kernphysik, 76128 Karlsruhe, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Scorza
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: B
authors.initials: B
authors.lastname: Serfass
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: B
authors.initials: B
authors.lastname: Shank
authors.affiliation: Department of Physics, University of California, Berkeley, California 94720, USA.
authors.forename: D
authors.initials: D
authors.lastname: Speller
authors.affiliation: Department of Physics & Astronomy, Texas A&M University, College Station, Texas 77843, USA.
authors.forename: S
authors.initials: S
authors.lastname: Upadhyayula
authors.affiliation: School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: A N
authors.initials: AN
authors.lastname: Villano
authors.affiliation: Department of Physics, University of Florida, Gainesville, Florida 32611, USA.
authors.forename: B
authors.initials: B
authors.lastname: Welliver
authors.affiliation: SLAC National Accelerator Laboratory/Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors.forename: D H
authors.initials: DH
authors.lastname: Wright
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: S
authors.initials: S
authors.lastname: Yellin
authors.affiliation: Department of Physics, Stanford University, Stanford, California 94305, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Yen
authors.affiliation: Department of Physics, Santa Clara University, Santa Clara, California 95053, USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Young
authors.affiliation: School of Physics & Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA.
authors.forename: J
authors.initials: J
authors.lastname: Zhang