Prepared for submission to JCAP Supernova neutrino detection in NOvA The NOvA Collaboration M. A. Acero2 P. Adamson12 G. Agam19 L. Aliaga12 T. Alion40 V. Allakhverdian26 N. Anfimov26 A. Antoshkin26 E. Arrieta-Diaz28 L. Asquith40 A. Aurisano6 A. Back24 C. Backhouse4;45 M. Baird20;40;46 N. Balashov26 P. Baldi25 B. A. Bambah18 S. Bashar44 K. Bays4;19 S. Bending45 R. Bernstein12 V. Bhatnagar33 B. Bhuyan14 J. Bian25;31 J. Blair16 A. C. Booth40 P. Bour9 R. Bowles20 C. Bromberg29 N. Buchanan8 A. Butkevich22 V. Bychkov31 S. Calvez8 T. J. Carroll43;49 E. Catano-Mur24;48 S. Childress12 B. C. Choudhary11 T. E. Coan38 M. Colo48 L. Corwin37 L. Cremonesi45 G. S. Davies32;20 P. F. Derwent12 P. Ding12 Z. Djurcic1 M. Dolce44 D. Doyle8 D. Dueñas Tonguino6 E. C. Dukes46 P. Dung43 H. Duyang36 S. Edayath7 R. Ehrlich46 M. Elkins24 G. J. Feldman15 P. Filip23 W. Flanagan10 J. Franc9 M. J. Frank35 H. R. Gallagher44 R. Gandrajula29 F. Gao34 S. Germani45 A. Giri17 R. A. Gomes13 M. C. Goodman1 V. Grichine27 M. Groh20 R. Group46 B. Guo36 A. Habig30 F. Hakl21 A. Hall46 J. Hartnell40 R. Hatcher12 A. Hatzikoutelis42 K. Heller31 J. Hewes6 A. Himmel12 A. Holin45 B. Howard20 J. Huang43 J. Hylen12 F. Jediny9 C. Johnson8 M. Judah8 I. Kakorin26 D. Kalra33 D. M. Kaplan19 R. Keloth7 O. Klimov26 16 26 27 9 arXiv:2005.07155v3 [physics.ins-det] 29 Jul 2020 L. W. Koerner L. Kolupaeva S. Kotelnikov M. Kubu Ch. Kullenberg26 A. Kumar33 C. D. Kuruppu36 V. Kus9 T. Lackey20 K. Lang43 L. Li25 S. Lin8 A. Lister49 M. Lokajicek23 S. Luchuk22 S. Magill1 W. A. Mann44 M. L. Marshak31 M. Martinez-Casales24 V. Matveev22 B. Mayes40 D. P. Méndez40 M. D. Messier20 H. Meyer47 T. Miao12 W. H. Miller31 S. R. Mishra36 A. Mislivec31 R. Mohanta18 A. Moren30 A. Morozova26 L. Mualem4 M. Muether47 S. Mufson20 K. Mulder45 R. Murphy20 J. Musser20 D. Naples34 N. Nayak25 J. K. Nelson48 R. Nichol45 G. Nikseresht19 E. Niner20;12 A. Norman12 A. Norrick12 T. Nosek5 A. Olshevskiy26 T. Olson44 J. Paley12 R. B. Patterson4 G. Pawloski31 O. Petrova26 R. Petti36 R. K. Plunkett12 F. Psihas20;43 A. Rafique1 V. Raj4 B. Ramson12 B. Rebel12;49 P. Rojas8 V. Ryabov27 O. Samoylov26 M. C. Sanchez24;1 S. Sánchez Falero24 I. S. Seong25 P. Shanahan12 A. Sheshukov26;∗ P. Singh11 V. Singh3 E. Smith20 J. Smolik9 P. Snopok19 N. Solomey47 A. Sousa6 K. Soustruznik5 M. Strait31 L. Suter1;12 A. Sutton46 C. Sweeney45 R. L. Talaga1 B. Tapia Oregui43 P. Tas5 R. B. Thayyullathil7 J. Thomas45;49 E. Tiras24 D. Torbunov31 J. Tripathi33 A. Tsaris12 Y. Torun19 J. Urheim20 P. Vahle48 Z. Vallari4 J. Vasel20 P. Vokac9 T. Vrba9 M. Wallbank6 T. K. Warburton24 M. Wetstein24 D. Whittington41;20 D. A. Wickremasinghe12 S. G. Wojcicki39 J. Wolcott44 A. Yallappa Dombara41 K. Yonehara12 S. Yu1;19 Y. Yu19 S. Zadorozhnyy22 J. Zalesak23 Y. Zhang40 R. Zwaska12 1Argonne National Laboratory, Argonne, Illinois 60439, USA 2Universidad del Atlantico, Carrera 30 No. 8-49, Puerto Colombia, Atlantico, Colombia 3Department of Physics, Institute of Science, Banaras Hindu University, Varanasi, 221 005, India 4California Institute of Technology, Pasadena, California 91125, USA 5Charles University, Faculty of Mathematics and Physics, Institute of Particle and Nuclear Physics, Prague, Czech Republic 6Department of Physics, University of Cincinnati, Cincinnati, Ohio 45221, USA 7Department of Physics, Cochin University of Science and Technology, Kochi 682 022, India 8Department of Physics, Colorado State University, Fort Collins, CO 80523-1875, USA 9Czech Technical University in Prague, Brehova 7, 115 19 Prague 1, Czech Republic 10University of Dallas, 1845 E Northgate Drive, Irving, Texas 75062 USA 11Department of Physics and Astrophysics, University of Delhi, Delhi 110007, India 12Fermi National Accelerator Laboratory, Batavia, Illinois 60510, USA 13Instituto de Física, Universidade Federal de Goiás, Goiânia, Goiás, 74690-900, Brazil 14Department of Physics, IIT Guwahati, Guwahati, 781 039, India 15Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA 16Department of Physics, University of Houston, Houston, Texas 77204, USA 17Department of Physics, IIT Hyderabad, Hyderabad, 502 205, India 18School of Physics, University of Hyderabad, Hyderabad, 500 046, India 19Illinois Institute of Technology, Chicago IL 60616, USA 20Indiana University, Bloomington, Indiana 47405, USA 21Institute of Computer Science, The Czech Academy of Sciences, 182 07 Prague, Czech Republic 22Institute for Nuclear Research of Russia, Academy of Sciences 7a, 60th October Anniversary prospect, Moscow 117312, Russia 23Institute of Physics, The Czech Academy of Sciences, 182 21 Prague, Czech Republic 24Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA 25Department of Physics and Astronomy, University of California at Irvine, Irvine, California 92697, USA 26Joint Institute for Nuclear Research, Dubna, Moscow region 141980, Russia 27Nuclear Physics and Astrophysics Division, Lebedev Physical Institute, Leninsky Prospect 53, 119991 Moscow, Russia 28Universidad del Magdalena, Carrera 32 No 22 – 08 Santa Marta, Colombia 29Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA 30Department of Physics and Astronomy, University of Minnesota Duluth, Duluth, Minnesota 55812, USA 31School of Physics and Astronomy, University of Minnesota Twin Cities, Minneapolis, Min- nesota 55455, USA 32University of Mississippi, University, Mississippi 38677, USA 33Department of Physics, Panjab University, Chandigarh, 160 014, India 34Department of Physics, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA 35Department of Physics, University of South Alabama, Mobile, Alabama 36688, USA 36Department of Physics and Astronomy, University of South Carolina, Columbia, South Carolina 29208, USA 37South Dakota School of Mines and Technology, Rapid City, South Dakota 57701, USA 38Department of Physics, Southern Methodist University, Dallas, Texas 75275, USA 39Department of Physics, Stanford University, Stanford, California 94305, USA 40Department of Physics and Astronomy, University of Sussex, Falmer, Brighton BN1 9QH, United Kingdom 41Department of Physics, Syracuse University, Syracuse NY 13210, USA 42Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA 43Department of Physics, University of Texas at Austin, Austin, Texas 78712, USA 44Department of Physics and Astronomy, Tufts University, Medford, Massachusetts 02155, USA 45Physics and Astronomy Dept., University College London, Gower Street, London WC1E 6BT, United Kingdom 46Department of Physics, University of Virginia, Charlottesville, Virginia 22904, USA 47Department of Mathematics, Statistics, and Physics, Wichita State University, Wichita, Kansas 67206, USA 48Department of Physics, William & Mary, Williamsburg, Virginia 23187, USA 49Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA ∗Corresponding Author: [email protected] Abstract. The NOvA long-baseline neutrino experiment uses a pair of large, segmented, liquid-scintillator calorimeters to study neutrino oscillations, using GeV-scale neutrinos from the Fermilab NuMI beam. These detectors are also sensitive to the flux of neutrinos which are emitted during a core-collapse supernova through inverse beta decay interactions on carbon at energies of O(10 MeV). This signature provides a means to study the dominant mode of energy release for a core-collapse supernova occurring in our galaxy. We describe the data- driven software trigger system developed and employed by the NOvA experiment to identify and record neutrino data from nearby galactic supernovae. This technique has been used by NOvA to self-trigger on potential core-collapse supernovae in our galaxy, with an estimated sensitivity reaching out to 10 kpc distance while achieving a detection efficiency of 23% to 49% for supernovae from progenitor stars with masses of 9.6 M to 27 M , respectively. Keywords: neutrino: burst, neutrino: supernova, core-collapse supernova, neutrino: detec- tion ArXiv ePrint: 2005.07155 Contents 1 Introduction2 1.1 NOvA Detectors2 1.2 Supernova neutrino signal4 1.3 Detection channels4 1.3.1 Inverse beta decay (IBD)4 1.3.2 Elastic scattering of neutrinos on electrons5 1.3.3 Neutral current scattering on carbon6 2 Simulation chain6 2.1 GenieSNova7 2.2 Detector Simulation8 2.3 Background data overlays9 3 Detection of neutrino interaction candidates9 3.1 Background rejection 10 3.1.1 Atmospheric muons 10 3.1.2 High energy showers 11 3.1.3 Electronics noise in readout channels 11 3.2 Clustering algorithm 13 3.2.1 Position selection 14 3.2.2 Time correction 14 3.3 Candidate selection 15 3.4 Removing time-correlated candidate groups 16 3.5 Selection results 16 4 Trigger system for supernova detection 17 4.1 Data-driven triggering in NOvA 17 4.2 Supernova trigger infrastructure 18 4.3 Triggering delay 19 4.4 Cross-detector triggering 19 4.5 External supernova trigger from SNEWS 20 5 Trigger sensitivity 20 5.1 Results 21 5.2 Probability of detecting the next galactic supernova 23 6 Trigger system commissioning 26 6.1 Partial detector data 26 6.2 Noise channel map updates failure 26 6.3 Triggering rate 26 7 Summary 27 – 1 – 1 Introduction The modeling and understanding of the stellar dynamics involved in core-collapse supernovae (SN) events require knowledge of the complex interplay between different physics processes which transition rapidly during the initial collapse of the star and the explosive expansion phases of the event. The neutrino burst that drives