Neutrino Signals at Dark Matter Direct Detection Experiments Jocelyn Monroe, Royal Holloway, University of London XXIX International Conference on Neutrino Physics and Astrophysics June 30, 2020 Dark Matter Direct Detection Signal: N ➙ N or e- ➙ e- Backgrounds: γ e- ➙γe- N ➙ N N ➙N’ + α, e- νN ➙νN experimental requirements: particle ID for recoil N, e-, alpha, n (multiple)γ final states γ Jocelyn Monroe June 30, 2020 / p. 2 Dark Matter Direct Neutrino Detection Signal: ν N ➙ ν N or ν e- ➙ ν e- ν ν Backgrounds: γ e- ➙γe- N ➙ N N ➙N’ + α, e- N ➙N? very similar requirements! ν (and ideally also measure direction) ν Jocelyn Monroe June 30, 2020 / p. 3 2008: Neutrino Backgrounds to Dark Matter Searches and Directionality Jocelyn Monroe May 30, 2008 2008 2020: Neutrino Backgrounds Signals in Dark Matter Searches (and Directionality) Jocelyn Monroe May 30, 2008 ν Cross Sections 2 2 -44 2 ν-N coherent scattering: ~ A x (Eν/MeV) x 10 cm recoils are O(10 keV) … neutrino floor in DM searches ν ν Z Φ(solar B8 ν) = 5.86 x 106 cm-2 s-1 N N Aprile et al., PhysRevLett 123 (2019) LZ Projected Nuclear Recoil Backgrounds J. Dobson, UCLA DM 2018 circa O(tens) of events/ton-year = 2008 ~ 10-46 cm2 limit JM, P. Fisher, Phys. Rev. D76 (2007) Rev. Phys. Fisher, JM, P. circa An irreducible background,2019 without direction measurement! JM, P. Fisher, Phys. Rev. D 76:033007 (2007) Jocelyn Monroe June 30, 2020 / p. 3 ν Cross Sections 2 2 -44 2 ν-N coherent scattering: ~ A x (Eν/MeV) x 10 cm recoils are O(10 keV) … neutrino floor in DM searches ν ν-e elastic scattering: smaller by ~ (me / Eν) ν but recoils are “high” energy ~ Eν Z and directional! e e LZ Projected Electronic Recoil Backgrounds LZ Projected Nuclear Recoil Backgrounds J. Dobson, UCLA DM 2018 J. Dobson, UCLA DM 2018 J. Dobson, UCLA DM’18 Jocelyn Monroe June 30, 2020 / p. 7 What ν signals can future dark matter detectors see? https://masterclass.icecube.wisc.edu/en/learn/detecting-neutrinos Jocelyn Monroe June 30, 2020 / p. 8 What ν signals can future dark matter detectors see? https://masterclass.icecube.wisc.edu/en/learn/detecting-neutrinos Jocelyn Monroe June 30, 2020 / p. 8 Future Large-Mass Dark Matter Detectors Detector Technology: dual-phase Time Projection Chambers with 4-50 tonne liquid Xe, Ar targets read out primary scintillation: “S1” + proportional gas scintillation from drifted electrons: “S2” • x-y resolution ~cm • z resolution ~mm Goal: zeptobarn -> yoctobarn sensitivity to dark matter! https://lz.slac.stanford.edu/our-research/lz-research Jocelyn Monroe June 30, 2020 / p. 9 2-Phase TPCs: Near(ish) Future XENON-nT: 6 t LXe (active), following XENON-1T (LNGS), from 2020. PandaX-4: 4 t LXe (active), following PandaX (JinPing), from 2020. LZ: 7 t LXe (active), following LUX (SURF), from 2020. DarkSide-20k: 50 t LAr (LNGS), ArDM+DEAP+DS50+MiniCLEAN, from 2023. DARWIN: 40 t LXe (LNGS), following XENON-nT. ARGO: 400 t LAr (SNOLAB?), following DarkSide-20k. 5 cm x 5 cm tiled SiPM Jocelyn Monroe 10 Jan. 23, 2019 Backgrounds N Gamma ray interactions: electron recoil final states rate ~ Ne x (gamma flux), O(1E7) events/(kg day) mis-identified electrons mimic nuclear recoils … part-per-billion level particle ID! Ajaj et al, Phys.Rev..D100 (2019) Contamination: modified from Malling, UCLA DM’16 238U and 232Th decays, recoiling progeny and 2009 mis-identified alphas, betas mimic nuclear recoils Neutrons: 2019 Nuclear recoil final state. (alpha,n), U, Th fission, DEAP, +PSD cosmogenic spallation pp solar neutrinos μ μ γ N* N D. Malling, UCLA DM’16 n D. Malling, UCLA DM’16 Jocelyn Monroe June 30, 2020 / p. 11 Backgrounds N Gamma ray interactions: electron recoil final states rate ~ Ne x (gamma flux), O(1E7) events/(kg day) mis-identified electrons mimic nuclear recoils … part-per-billion level particle ID! Ajaj et al, Phys.Rev..D100 (2019) Contamination: modified from Malling, UCLA DM’16 238U and 232Th decays, recoiling progeny and 2009 mis-identified alphas, betas mimic nuclear recoils Neutrons: 2019 Nuclear recoil final state. (alpha,n), U, Th fission, DEAP, +PSD cosmogenic spallation pp solar neutrinos μ μ γ N* N D. Malling, UCLA DM’16 n D. Malling, UCLA DM’16 Amaudruz et al, Phys.Rev.Lett. 121 (2018) no.7, 071801 Jocelyn Monroe June 30, 2020 / p. 11 Backgrounds N Gamma ray interactions: electron recoil final states rate ~ Ne x (gamma flux), O(1E7) events/(kg day) mis-identified electrons mimic nuclear recoils … part-per-billion level particle ID! Ajaj et al, Phys.Rev..D100 (2019) Contamination: modified from Malling, UCLA DM’16 238U and 232Th decays, recoiling progeny and 2009 mis-identified alphas, betas mimic nuclear recoils Neutrons: 2019 Nuclear recoil final state. (alpha,n), U, Th fission, DEAP, +PSD cosmogenic spallation pp solar neutrinos μ μ γ N* N D. Malling, UCLA DM’16 n D. Malling, UCLA DM’16 Jocelyn Monroe June 30, 2020 / p. 11 Backgrounds N Gamma ray interactions: electron recoil final states rate ~ Ne x (gamma flux), O(1E7) events/(kg day) mis-identified electrons mimic nuclear recoils … part-per-billion level particle ID! Ajaj et al, Phys.Rev..D100 (2019) Contamination: modified from Malling, UCLA DM’16 238U and 232Th decays, recoiling progeny and 2009 mis-identified alphas, betas mimic nuclear recoils Neutrons: 2019 Nuclear recoil final state. (alpha,n), U, Th fission, DEAP, +PSD cosmogenic spallation pp solar neutrinos μ μ γ N* N D. Malling, UCLA DM’16 n D. Malling, UCLA DM’16 + large, active veto detectors Jocelyn Monroe June 30, 2020 / p. 11 12 ) 10 -1 11 pp 10 7 What ν signals can bin Be -1 10 13 s 10 N -2 future dark matter detectors see? 109 15O 17 108 F 8B 107 Flux (cm hep ν 106 105 Solar 104 103 102 10-1 1 10 Neutrino Energy (MeV) https://masterclass.icecube.wisc.edu/en/learn/detecting-neutrinos Jocelyn Monroe June 30, 2020 / p. 12 Prospects for Solar ν-N Coherent Scattering European Strategy for Particle Physics, Physics Briefing Book (2019) DarkSide-20k ESPP 2019 Jocelyn Monroe June 30, 2020 / p. 13 12 ) 10 -1 Solar ν-e Event Rates 11 pp 10 7 ν bin Be ν -1 10 13 s 10 N example event rates -2 109 15O of solar neutrino-electron Z, W 17 108 F elastic scattering at LNGS, 8B 107 per tonne-year of CF4 Flux (cm hep e e ν 106 105 Solar 104 103 102 10-1 1 10 Neutrino Energy (MeV) e.g. for Ar target: DarkSide-20k estimates 10k solar neutrino- electron elastic scatters above threshold per 100 tonne-yrs Aalseth, et al. Eur.Phys.J.Plus 133 (2018) Jocelyn Monroe June 30, 2020 / p. 14 Statistics even allow solar oscillation physics! Solar ν-e Event Rates ν ν example event rates of solar neutrino-electron Z, W elastic scattering at LNGS, per tonne-year of CF4 e e Aalbers, et al. arXiv:2006.03114 e.g. for Ar target: DarkSide-20k estimates 10k solar neutrino- electron elastic scatters above threshold per 100 tonne-yrs Aalseth, et al. Eur.Phys.J.Plus 133 (2018) Jocelyn Monroe June 30, 2020 / p. 15 Statistics even allow solar oscillation physics! Solar ν-e Event Rates ν ν example event rates of solar neutrino-electron Z, W elastic scattering at LNGS, per tonne-year of CF4 e e Aalbers, et al. arXiv:2006.03114 e.g. for Ar target: DarkSide-20k estimates 10k solar neutrino- electron elastic scatters above threshold per 100 tonne-yrs Aalseth, et al. Eur.Phys.J.Plus 133 (2018) Jocelyn Monroe June 30, 2020 / p. 15 Solar ν-Electron Scattering Via neutrino-electron elastic scattering, LAr dark matter experiments can measure CNO (via spectral deformation), and CNO vs. Be-7 +with O(500 t-y), study the “solar metallicity problem”. Franco et al., JCAP 1608 (2016) 08 Cerdeno, Davis, Fairbairn, Vincent, JCAP 1804 (2018) 37 big opportunities: 1) distinguish exclusion betweendetection high vs. low metallicity. *Xe-136 background makes LXe CNO more challenging Baudis et al., JCAP 1401 (2014) 044, Baudis et al., 2006.03114 Jocelyn Monroe June 30, 2020 / p. 16 C. Boehm et al., 2006.11250 Solar ν-Electron Scattering Via neutrino-electron elastic scattering, LAr dark matter experiments can measure CNO (via spectral deformation), and CNO vs. Be-7 Xenon1T data +with O(500 t-y), study the “solar metallicity problem”. Franco et al., JCAP 1608 (2016) 08 Cerdeno, Davis, Fairbairn, Vincent, JCAP 1804 (2018) 37 big opportunities: 1) distinguish exclusion betweendetection high vs. low metallicity. 2) study non- standard solar neutrino interactions? *Xe-136 background makes LXe CNO more challenging Aprile et al., 2006.09721 Baudis et al., JCAP 1401 (2014) 044, Baudis et al., 2006.03114 Boehm et al., 2006.11250 Jocelyn Monroe June 30, 2020 / p. 17 Lang et al., Phys. Rev. D 94 (2016) What neutrino signals can Arnaud et al., Phys.Rev.D.65.033010 future dark matter detectors see? (if lucky!) for a supernova at 10 kPc, expect 300-500 ν-N events in near-future experiments. • measure all flavors via NC 40 - 40 • measure νe Ar e K* • multi-messenger observation: sub-eV mass ordering? https://masterclass.icecube.wisc.edu/en/learn/detecting-neutrinos Jocelyn Monroe May 3, 2018 / p. 7 Lang et al., Phys. Rev. D 94 (2016) What neutrino signals can Arnaud et al., Phys.Rev.D.65.033010 future dark matter detectors see? (if lucky!) for a supernova at 10 kPc, expect 300-500 ν-N events in near-future experiments.