Eur. Phys. J. C (2024) 84: 1052
https://doi.org/10.1140/epjc/s10052-024-13423-z

Regular Article

Demonstration of neutron identification in neutrino interactions in the MicroBooNE liquid argon time projection chamber

¹ Argonne National Laboratory (ANL), 60439, Lemont, IL, USA
² Universität Bern, 3012, Bern, Switzerland
³ Brookhaven National Laboratory (BNL), 11973, Upton, NY, USA
⁴ University of California, 93106, Santa Barbara, CA, USA
⁵ University of Cambridge, CB3 0HE, Cambridge, UK
⁶ Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), 28040, Madrid, Spain
⁷ University of Chicago, 60637, Chicago, IL, USA
⁸ University of Cincinnati, 45221, Cincinnati, OH, USA
⁹ Colorado State University, 80523, Fort Collins, CO, USA
¹⁰ Columbia University, 10027, New York, NY, USA
¹¹ University of Edinburgh, EH9 3FD, Edinburgh, UK
¹² Fermi National Accelerator Laboratory (FNAL), 60510, Batavia, IL, USA
¹³ Universidad de Granada, 18071, Granada, Spain
¹⁴ Harvard University, 02138, Cambridge, MA, USA
¹⁵ Illinois Institute of Technology (IIT), 60616, Chicago, IL, USA
¹⁶ Imperial College London, SW7 2AZ, London, UK
¹⁷ Indiana University, 47405, Bloomington, IN, USA
¹⁸ Kansas State University (KSU), 66506, Manhattan, KS, USA
¹⁹ Lancaster University, LA1 4YW, Lancaster, UK
²⁰ Los Alamos National Laboratory (LANL), 87545, Los Alamos, NM, USA
²¹ Louisiana State University, 70803, Baton Rouge, LA, USA
²² The University of Manchester, M13 9PL, Manchester, UK
²³ Massachusetts Institute of Technology (MIT), 02139, Cambridge, MA, USA
²⁴ University of Michigan, 48109, Ann Arbor, MI, USA
²⁵ Michigan State University, 48824, East Lansing, MI, USA
²⁶ University of Minnesota, 55455, Minneapolis, MN, USA
²⁷ Nankai University, Nankai District, 300071, Tianjin, China
²⁸ New Mexico State University (NMSU), 88003, Las Cruces, NM, USA
²⁹ University of Oxford, OX1 3RH, Oxford, UK
³⁰ University of Pittsburgh, 15260, Pittsburgh, PA, USA
³¹ Queen Mary University of London, E1 4NS, London, UK
³² Rutgers University, 08854, Piscataway, NJ, USA
³³ SLAC National Accelerator Laboratory, 94025, Menlo Park, CA, USA
³⁴ South Dakota School of Mines and Technology (SDSMT), 57701, Rapid City, SD, USA
³⁵ University of Southern Maine, 04104, Portland, ME, USA
³⁶ Syracuse University, 13244, Syracuse, NY, USA
³⁷ Tel Aviv University, 69978, Tel Aviv, Israel
³⁸ University of Tennessee, 37996, Knoxville, TN, USA
³⁹ University of Texas, 76019, Arlington, TX, USA
⁴⁰ Tufts University, 02155, Medford, MA, USA
⁴¹ Center for Neutrino Physics, Virginia Tech, 24061, Blacksburg, VA, USA
⁴² University of Warwick, CV4 7AL, Coventry, UK

^bj afurmans@umn.edu

Received: 20 June 2024
Accepted: 25 September 2024
Published online: 14 October 2024

Abstract

A significant challenge in measurements of neutrino oscillations is reconstructing the incoming neutrino energies. While modern fully-active tracking calorimeters such as liquid argon time projection chambers in principle allow the measurement of all final state particles above some detection threshold, undetected neutrons remain a considerable source of missing energy with little to no data constraining their production rates and kinematics. We present the first demonstration of tagging neutrino-induced neutrons in liquid argon time projection chambers using secondary protons emitted from neutron-argon interactions in the MicroBooNE detector. We describe the method developed to identify neutrino-induced neutrons and demonstrate its performance using neutrons produced in muon-neutrino charged current interactions. The method is validated using a small subset of MicroBooNE’s total dataset. The selection yields a sample with $60\%$ of selected tracks corresponding to neutron-induced secondary protons. At this purity, the integrated efficiency is 8.4% for neutrons that produce a detectable proton.