Search for Dark Matter Decay of the Free Neutron from the UCNA Experiment: n → χ + e^+e^−

Xiaohui Sun; Edith Adamek; Bruno Allgeier; Matthias A. Blatnik; Thomas J. Bowles; Leah J. Broussard; Matthew A. Brown; Richard Carr; Steven M. Clayton; Chris Cude-Woods; Sonja Currie; Eric B. Dees; Xingxing Ding; Bradley W. Filippone; A. Bello García; Peter Geltenbort; Salajeghe Hasan; Kevin P. Hickerson; J. Todd Hoagland; R. Hong; Gary E. Hogan; Anthony T. Holley; Takeyasu M. Ito; Amanda L. Knecht; Chao-Yu Liu; Jingyang Liu; María Makela; Russel Mammei; J. W. Martin; Dan Melconian; Michael P. Mendenhall; Stephen D. Moore; Charles L. Morris; Sushil Nepal; N. Vahedi Nouri; Robert W. Pattie; A. Pérez Galván; David G. Phillips; Richard H. Picker; Margaret L. Pitt; Blakely A. Plaster; Jana C. Ramsey; R. Barreto Rios; Daniel J. Salvat; Andy Saunders; Walter Sondheim; S. Sjue; Steven Slutsky; Charles Swank; Gyani Swift; E. Tatar; R. Bruce Vogelaar; Brittany VornDick; Z. Wang; Wanchun Wei; J. Wexler; T. Womack; Christopher Wrede; Andrew R. Young; B. A. Zeck

doi:10.1103/PhysRevC.97.052501

Search for Dark Matter Decay of the Free Neutron from the UCNA Experiment: n → χ + e^+e^−

Xiaohui Sun
, Edith Adamek
, Bruno Allgeier
, Matthias A. Blatnik
, Thomas J. Bowles
, Leah J. Broussard
, Matthew A. Brown
, Richard Carr
, Steven M. Clayton
, Chris Cude-Woods
, Sonja Currie
, Eric B. Dees
, Xingxing Ding
, Bradley W. Filippone
, A. Bello García
, Peter Geltenbort
, Salajeghe Hasan
, Kevin P. Hickerson
, J. Todd Hoagland
, R. Hong

Gary E. Hogan, Anthony T. Holley, Takeyasu M. Ito, Amanda L. Knecht, Chao-Yu Liu, Jingyang Liu, María Makela, Russel Mammei, J. W. Martin, Dan Melconian, Michael P. Mendenhall, Stephen D. Moore, Charles L. Morris, Sushil Nepal, N. Vahedi Nouri, Robert W. Pattie, A. Pérez Galván, David G. Phillips, Richard H. Picker, Margaret L. Pitt, Blakely A. Plaster, Jana C. Ramsey, R. Barreto Rios, Daniel J. Salvat, Andy Saunders, Walter Sondheim, S. Sjue, Steven Slutsky, Charles Swank, Gyani Swift, E. Tatar, R. Bruce Vogelaar, Brittany VornDick, Z. Wang, Wanchun Wei, J. Wexler, T. Womack, Christopher Wrede, Andrew R. Young, B. A. Zeck

California Institute of Technology
Indiana University - Bloomington
University of Kentucky
Los Alamos National Laboratory
Humana Military
North Carolina State University
Virginia Tech
University of Washington
Institut Laue-Langevin, France
Tennessee Tech University
Paul Scherrer Institut, Switzerland
Shanghai Jiao Tong University, China
University of Winnipeg, Canada
Southern California Institute of Technology
Texas A&M University
W. K. Kellogg Radiation Laboratory
Triangle Universities Nuclear Laboratory
Idaho State University

Research output: Contribution to journal › Article › peer-review

Abstract

<div class="line" id="line-5"> It has been proposed recently that a previously unobserved neutron decay branch to a dark matter particle ( χ ) could account for the discrepancy in the neutron lifetime observed in experiments that use two different measurement techniques. One of the possible final states discussed includes a single  χ along with an  e + e −  pair. We use data from the UCNA (Ultracold Neutron Asymmetry) experiment to set limits on this decay channel. Coincident electron-like events are detected with  &sim;4 π  acceptance using a pair of detectors that observe a volume of stored ultracold neutrons. The summed kinetic energy ( E e + e − ) from such events is used to set limits, as a function of the  χ  mass, on the branching fraction for this decay channel. For  χ  masses consistent with resolving the neutron lifetime discrepancy, we exclude this as the dominant dark matter decay channel at  &gg;5 σ  level for  100< E e + e − <644 keV . If the  χ + e + e −  final state is not the only one, we set limits on its branching fraction of  <10 −4  for the above  E e + e −  range at  >90%  confidence level. </div>

Original language	American English
Journal	Physical Review C
Volume	97
DOIs	https://doi.org/10.1103/PhysRevC.97.052501
State	Published - May 21 2018
Externally published	Yes

Keywords

Dark Matter
Decay
Free Neutron
UCNA Experiment

Disciplines

Physics
Nuclear

Access to Document

10.1103/PhysRevC.97.052501License: Unspecified

Search for dark matter decay.pdfFinal published version, 498 KBLicense: Unspecified

Cite this

Sun, X., Adamek, E., Allgeier, B., Blatnik, M. A., Bowles, T. J., Broussard, L. J., Brown, M. A., Carr, R., Clayton, S. M., Cude-Woods, C., Currie, S., Dees, E. B., Ding, X., Filippone, B. W., García, A. B., Geltenbort, P., Hasan, S., Hickerson, K. P., Hoagland, J. T., ... Zeck, B. A. (2018). Search for Dark Matter Decay of the Free Neutron from the UCNA Experiment: n → χ + e^+e^−. Physical Review C, 97. https://doi.org/10.1103/PhysRevC.97.052501

Sun, X, Adamek, E, Allgeier, B, Blatnik, MA, Bowles, TJ, Broussard, LJ, Brown, MA, Carr, R, Clayton, SM, Cude-Woods, C, Currie, S, Dees, EB, Ding, X, Filippone, BW, García, AB, Geltenbort, P, Hasan, S, Hickerson, KP, Hoagland, JT, Hong, R, Hogan, GE, Holley, AT, Ito, TM, Knecht, AL, Liu, C-Y, Liu, J, Makela, M, Mammei, R, Martin, JW, Melconian, D, Mendenhall, MP, Moore, SD, Morris, CL, Nepal, S, Nouri, NV, Pattie, RW, Galván, AP, Phillips, DG, Picker, RH, Pitt, ML, Plaster, BA, Ramsey, JC, Rios, RB, Salvat, DJ, Saunders, A, Sondheim, W, Sjue, S, Slutsky, S, Swank, C, Swift, G, Tatar, E, Vogelaar, RB, VornDick, B, Wang, Z, Wei, W, Wexler, J, Womack, T, Wrede, C, Young, AR & Zeck, BA 2018, 'Search for Dark Matter Decay of the Free Neutron from the UCNA Experiment: n → χ + e^+e^−', Physical Review C, vol. 97. https://doi.org/10.1103/PhysRevC.97.052501

@article{4485a179c8314a3883ca2ecba680791a,

title = "Search for Dark Matter Decay of the Free Neutron from the UCNA Experiment: n → χ + e\textasciicircum{}+e\textasciicircum{}−",

abstract = " It has been proposed recently that a previously unobserved neutron decay branch to a dark matter particle ( \χ ) could account for the discrepancy in the neutron lifetime observed in experiments that use two different measurement techniques. One of the possible final states discussed includes a single\  \χ along with an\  e + e \− \ pair. We use data from the UCNA (Ultracold Neutron Asymmetry) experiment to set limits on this decay channel. Coincident electron-like events are detected with\  \&sim;4 \π \ acceptance using a pair of detectors that observe a volume of stored ultracold neutrons. The summed kinetic energy ( E e + e \− ) from such events is used to set limits, as a function of the\  \χ \ mass, on the branching fraction for this decay channel. For\  \χ \ masses consistent with resolving the neutron lifetime discrepancy, we exclude this as the dominant dark matter decay channel at\  \&gg;5 \σ \ level for\  100< E e + e \− <644 keV . If the\  \χ + e + e \− \ final state is not the only one, we set limits on its branching fraction of\  <10 \−4 \ for the above\  E e + e \− \ range at\  >90\% \ confidence level. ",

keywords = "Dark Matter, Decay, Free Neutron, UCNA Experiment",

author = "Xiaohui Sun and Edith Adamek and Bruno Allgeier and Blatnik, \{Matthias A.\} and Bowles, \{Thomas J.\} and Broussard, \{Leah J.\} and Brown, \{Matthew A.\} and Richard Carr and Clayton, \{Steven M.\} and Chris Cude-Woods and Sonja Currie and Dees, \{Eric B.\} and Xingxing Ding and Filippone, \{Bradley W.\} and Garc{\'i}a, \{A. Bello\} and Peter Geltenbort and Salajeghe Hasan and Hickerson, \{Kevin P.\} and Hoagland, \{J. Todd\} and R. Hong and Hogan, \{Gary E.\} and Holley, \{Anthony T.\} and Ito, \{Takeyasu M.\} and Knecht, \{Amanda L.\} and Chao-Yu Liu and Jingyang Liu and Mar{\'i}a Makela and Russel Mammei and Martin, \{J. W.\} and Dan Melconian and Mendenhall, \{Michael P.\} and Moore, \{Stephen D.\} and Morris, \{Charles L.\} and Sushil Nepal and Nouri, \{N. Vahedi\} and Pattie, \{Robert W.\} and Galv{\'a}n, \{A. P{\'e}rez\} and Phillips, \{David G.\} and Picker, \{Richard H.\} and Pitt, \{Margaret L.\} and Plaster, \{Blakely A.\} and Ramsey, \{Jana C.\} and Rios, \{R. Barreto\} and Salvat, \{Daniel J.\} and Andy Saunders and Walter Sondheim and S. Sjue and Steven Slutsky and Charles Swank and Gyani Swift and E. Tatar and Vogelaar, \{R. Bruce\} and Brittany VornDick and Z. Wang and Wanchun Wei and J. Wexler and T. Womack and Christopher Wrede and Young, \{Andrew R.\} and Zeck, \{B. A.\}",

year = "2018",

month = may,

day = "21",

doi = "10.1103/PhysRevC.97.052501",

language = "American English",

volume = "97",

journal = "Physical Review C",

}

TY - JOUR

T1 - Search for Dark Matter Decay of the Free Neutron from the UCNA Experiment: n → χ + e^+e^−

AU - Sun, Xiaohui

AU - Adamek, Edith

AU - Allgeier, Bruno

AU - Blatnik, Matthias A.

AU - Bowles, Thomas J.

AU - Broussard, Leah J.

AU - Brown, Matthew A.

AU - Carr, Richard

AU - Clayton, Steven M.

AU - Cude-Woods, Chris

AU - Currie, Sonja

AU - Dees, Eric B.

AU - Ding, Xingxing

AU - Filippone, Bradley W.

AU - García, A. Bello

AU - Geltenbort, Peter

AU - Hasan, Salajeghe

AU - Hickerson, Kevin P.

AU - Hoagland, J. Todd

AU - Hong, R.

AU - Hogan, Gary E.

AU - Holley, Anthony T.

AU - Ito, Takeyasu M.

AU - Knecht, Amanda L.

AU - Liu, Chao-Yu

AU - Liu, Jingyang

AU - Makela, María

AU - Mammei, Russel

AU - Martin, J. W.

AU - Melconian, Dan

AU - Mendenhall, Michael P.

AU - Moore, Stephen D.

AU - Morris, Charles L.

AU - Nepal, Sushil

AU - Nouri, N. Vahedi

AU - Pattie, Robert W.

AU - Galván, A. Pérez

AU - Phillips, David G.

AU - Picker, Richard H.

AU - Pitt, Margaret L.

AU - Plaster, Blakely A.

AU - Ramsey, Jana C.

AU - Rios, R. Barreto

AU - Salvat, Daniel J.

AU - Saunders, Andy

AU - Sondheim, Walter

AU - Sjue, S.

AU - Slutsky, Steven

AU - Swank, Charles

AU - Swift, Gyani

AU - Tatar, E.

AU - Vogelaar, R. Bruce

AU - VornDick, Brittany

AU - Wang, Z.

AU - Wei, Wanchun

AU - Wexler, J.

AU - Womack, T.

AU - Wrede, Christopher

AU - Young, Andrew R.

AU - Zeck, B. A.

PY - 2018/5/21

Y1 - 2018/5/21

N2 - It has been proposed recently that a previously unobserved neutron decay branch to a dark matter particle ( χ ) could account for the discrepancy in the neutron lifetime observed in experiments that use two different measurement techniques. One of the possible final states discussed includes a single  χ along with an  e + e −  pair. We use data from the UCNA (Ultracold Neutron Asymmetry) experiment to set limits on this decay channel. Coincident electron-like events are detected with  &sim;4 π  acceptance using a pair of detectors that observe a volume of stored ultracold neutrons. The summed kinetic energy ( E e + e − ) from such events is used to set limits, as a function of the  χ  mass, on the branching fraction for this decay channel. For  χ  masses consistent with resolving the neutron lifetime discrepancy, we exclude this as the dominant dark matter decay channel at  &gg;5 σ  level for  100< E e + e − <644 keV . If the  χ + e + e −  final state is not the only one, we set limits on its branching fraction of  <10 −4  for the above  E e + e −  range at  >90%  confidence level.

AB - It has been proposed recently that a previously unobserved neutron decay branch to a dark matter particle ( χ ) could account for the discrepancy in the neutron lifetime observed in experiments that use two different measurement techniques. One of the possible final states discussed includes a single  χ along with an  e + e −  pair. We use data from the UCNA (Ultracold Neutron Asymmetry) experiment to set limits on this decay channel. Coincident electron-like events are detected with  &sim;4 π  acceptance using a pair of detectors that observe a volume of stored ultracold neutrons. The summed kinetic energy ( E e + e − ) from such events is used to set limits, as a function of the  χ  mass, on the branching fraction for this decay channel. For  χ  masses consistent with resolving the neutron lifetime discrepancy, we exclude this as the dominant dark matter decay channel at  &gg;5 σ  level for  100< E e + e − <644 keV . If the  χ + e + e −  final state is not the only one, we set limits on its branching fraction of  <10 −4  for the above  E e + e −  range at  >90%  confidence level.

KW - Dark Matter

KW - Decay

KW - Free Neutron

KW - UCNA Experiment

U2 - 10.1103/PhysRevC.97.052501

DO - 10.1103/PhysRevC.97.052501

M3 - Article

VL - 97

JO - Physical Review C

JF - Physical Review C

ER -