Testing New Physics With Neutrino Astrophysics John Beacom, The Ohio State University John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 1
Plan of the Talk Neutrino astronomy why try? What is IceCube? What has IceCube discovered? What does it mean for particle physics? Concluding perspectives John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 2
Neutrino Astronomy Why Try? John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 3
First Goal: New Astrophysics What happens deep inside astrophysical systems? Use knowledge of subatomic physics listen to theorists Example successes: solar and supernova neutrinos Example searches: GRB neutrinos; CR sources in MW John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 4
Second Goal: New Particle Physics What are the properties of familiar and of unmet particles? Use knowledge of astrophysics listen to theorists Example successes: number of flavors; neutrino mass is small Example searches: neutrino exotica; dark matter John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 5
Third Goal: New Surprises What haven t we thought of? Develop flexible, powerful searches don t listen to theorists Example successes: neutrino mixing; cosmic ray anisotropies Example searches: unknown unknowns! John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 6
What is IceCube? John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 7
The Location John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 8
The Construction John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 9
The Design Needs 86 strings of PMTs buried in 1 km 3 of clear ice John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 10
The Detection Principles Track events Few km in length Planned focus of IceCube Cascade (shower) events Few m in length See Beacom and Candia (2004) e.g., v µ + n µ + p e.g., v e + n e + p v τ + n τ + p John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 11
First Difficulty: Beseeching Nature Requires: sources that reach high energies sources that are luminous sources of different types particles that can reach us particles that can point back particles that can be detected results that can be understood Our part 10 6 ev 10 12 ev 10 18 ev ev kev MeV GeV TeV PeV EeV ZeV atomic nuclear accelerator????????????????????????? John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017
Second Difficulty: Measuring Signals N events ~ 4p. N targets s. T. F ~ 4p. A effective. T. F Volume ~ 1 km 3 A effective ~ 1 m 2 at 100 TeV For many sources, ~ 1 km 3 is the minimum required John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 13
Third Difficulty: Rejecting Backgrounds Atmospheric muons: enormous but greatly reducible background Atmospheric neutrinos: big but reducible (Schonert+ 2008) foreground s -1 sr -1-2 GeV cm dn ν /de ν 2 ν E -3 10 1) AMANDA-II Atmospheric ν µ 1387 d 10-4 -5 10-6 10 10-7 -8 10-9 10 1 14 12 5 2) 3) 4) 5) 6) 7) 6 2 7 AMANDA-II ν µ AMANDA-II ν µ ANTARES ν µ unfolding (2000-2003) 807 d 07-09 Bartol + Naumov RQPM Honda + Enberg Min Waxman Bahcall Prompt GRB Blazars Stecker IC40 Atmospheric ν µ Waxman Bahcall 1998 x 1/2 IC40 Atmo. ν µ IC40 ν µ 375.5 d Unfolding 10 9 8 3 4 Becker AGN Mannheim AGNs 13 11 (8 (9 (10 (11 (12 (13 (14 IceCube 2011: Atm. nu measured up to ~ 200 TeV Astro. nu strong limits at higher energies 2 3 4 5 6 7 8 9 10 log 10 [GeV] John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 14 E ν
What has IceCube Discovered? John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 15
The Pevatrons Uncloak 2011: ~ 1 PeV cascade 2012: ~ 1 PeV cascade Great fortune in finding these events in this search (2013) Many surprised; Laha+ (2013) demystified and showed tests John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 16
Now Comes the Flood 2014 IceCube TeV-PeV search, using 2010 2013 data Declination (degrees) 80 60 40 20 0-20 -40-60 -80 Showers Tracks 10 2 10 3 Deposited EM-Equivalent Energy in Detector (TeV) My opinion: focus above 100 TeV on Clean Dozen events with negligible atmospheric backgrounds Conservative analysis: 37 candidates, ~ 15 background, 5.7s John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 17
What Does the Energy Spectrum Tell Us? Sum of cascade (all flavors), starting track (muon) channels True significance is much higher than reported For Clean Dozen events, ignore the backgrounds shown because cascade channel dominates Easy to see (!): astrophysical neutrinos with spectrum ~ E -2 John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 18
What Does the Angular Distribution Tell Us? First HE neutrino skymap; some caveats for interpretation Isolating Clean Dozen changes picture Only track Easy to see (!): sources mostly isotropic, extragalactic John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 19
Certainties, Probabilities, Mysteries Signal origin: definitely observed extraterrestrial neutrinos likely no UHE, Galactic, or exotic sources Energy spectrum: E 2 F ~ 10^-8 GeV cm -2 s -1 sr -1 shape E^-2 with cutoff or a bit steeper Angular distribution: likely isotropic with Earth attenuation no obvious clustering or correlations Flavor ratios: maybe consistent with 1:1:1, but a little weird where are the muon tracks at high energy? Time distribution: appears to be constant, not bursty John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 20
What Does it Mean for Particle Physics? John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 21
Dark Matter Annihilation DM likely should annihilate with a predicted cross section First use of neutrinos to probe halo DM by Beacom+ (2006) IceCube bb νν W + W - νν Super-K νν µ + µ - Fermi (γ) natural scale expectation for DM as thermal relic P. Mijakowski, Super-K preliminary 2012 IceCube 2014 John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 22
Dark Matter Decay DM may decay (slowly), but there is no predicted lifetime Excitement that DM decay may explain Galactic Center peak and spectrum dip Feldstein+ (2013); Esmaili+ (2013); Bai+ (2013); Ema+ (2014); Bhattacharya+ (2014) Re-examination is needed using new IceCube data, care with other neutrino, gamma-ray cascade limits Murase, Beacom (2012); Ibarra+ (2013) John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 23
Spectrum Distortions from Secret Interactions New test: n+n à n+n (Ng, Beacom 2014; Ioka, Murase 2014; Cherry+ 2014) Must include attenuation, regeneration, multiple scattering E 2 J [10-8 GeV cm -2 s -1 sr -1 ] 1 0.5 0 1 0.5 0 1 0.5 Line spectrum injection 1 PeV line w/ SFR w/ regeneration w/o regeneration E res = 5 PeV E res = 0.5 PeV E res = 0.05 PeV 0 0 10 3 10 4 10 5 10 6 10 3 10 4 10 5 10 6 10 7 10 8 Ng, Beacom (2014) Ng, Beacom (2014) E [ GeV ] E 2 J [10-8 GeV cm -2 s -1 sr -1 ] Continuum spectrum injection no-interaction Model A Model B Model C Model D E [ GeV ] John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 24 2 1
Parameter Space for Secret Interactions Must take care to separate mass, coupling of new mediator G=10 +7 GeV -2 G=10 +1 GeV -2 G=10-5 GeV -2 g 10 0 10-1 SN1987A BBN Non-perturbative regime CMB τ(0.01 PeV)=1 τ(0.1 PeV)=1 τ(1 PeV)=1 A g ατ Z-decay C B 10-2 D g αµ g αe 10-3 10-2 10-1 10 0 10 1 10 2 10 3 10 4 10 5 Ng, Beacom (2014) M [ MeV ] IceCube sensitivity is complementary to other constraints John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 25
Flavor Composition of Mass Eigenstates Neutrino mixing angles are all large, well known (and similar for both hierarchies) Bustamante, Beacom, Winter (2015, PRL) John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 26
Flavor Ratios No New Physics For no new neutrino physics beyond standard mixing: The full space of flavor ratios at Earth is tightly restricted for all initial ratios Bustamante, Beacom, Winter (2015, PRL) John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 27
Flavor Ratios Broad Class of New Physics For new neutrino physics that only incoherently mixes mass eigenstates: The full space of flavor ratios at Earth is also tightly restricted for all initial ratios Bustamante, Beacom, Winter (2015, PRL) John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 28
Flavor Ratios All Possibilities of New Physics To fill the remainder of the space, the new physics must preserve coherence and/or change the mixing parameters Arguelles, Katori, Salvado (2015, PRL) John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 29
Concluding Perspectives John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 30
The Time for Neutrino Astronomy is Now Neutrino Astronomy MeV GeV n Efforts: HK and more Targets: Solar, SN, more Surprises TeV PeV n Efforts: IceCube and more Targets: GRBs, AGN, more Surprises EeV ZeV n Efforts: ANITA and more Targets: GZK process Surprises Neutrino astronomy must be broad John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 31
The Time for Neutrino Science is Now Neutrino Science Laboratory n Cosmology n Astronomy n Efforts: Fermilab and more Context: Precision Physics, BSM reach Efforts: CMB and more Context: Precision Cosmology, BSM reach Efforts: IceCube and more Context: Transient Astronomy, Multi-messenger Neutrinos are multi-frontier science John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 32
TeVPA 2017 tevpa2017.osu.edu I August 7 11, Columbus, OH I Registration and abstract submission are open I Pre-meeting mini-workshops on Sunday, August 7 John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 33
Center for Cosmology and AstroParticle Physics Columbus, Ohio: 1 million people (city), 2 million people (city+metro) Ohio State University: 56,000 students Physics: 55 faculty, Astronomy: 20 faculty CCAPP: 20 faculty, 10 postdocs from both departments Placements: In 2014 alone, 12 CCAPP alumni got permanent-track jobs Recent faculty hires: Antonio Boveia, Linda Carpenter, Chris Hirata, Adam Leroy, Laura Lopez, Annika Peter Recent postdoc hires: Ami Choi, Alexia Lewis, Niall MacCrann, Tuguldur Sukhbold, Michael Troxel, Ying Zu, Francesco Capozzi ccapp.osu.edu John Beacom, The Ohio State University Baryon and Lepton Number Violation, Case Western, May 2017 34