Neutrino Astrophysics

Ryan Nichol UK Input to European Strategy Astrophysics

Ryan Nichol UK Input to European Strategy Highly cited papers • Higgs Discovery (2012) • Z discovery (1983) –1500+ – 8000+ citations –2000+ • SN1987a (1987) • Atmospheric neutrino • Positron excess –1500+ oscillations (1998) [PAMELA] (2008) • Weak neutral current –5000+ citations –1900+ (1973) • Top quark discovery • Reactor neutrino theta_13 –1500+ (1995) (2012) • Charmomium (2003) –3000+ citations –1900+ –1400+ • Solar neutrino oscillations • b-quark discovery (1977) • B-Bbar oscillation (1987) (2002) –1900+ –1300+ –3000+ citations • W-discovery (1983) • nu_mu -> nu_e (2011) • Kaon CP violations (1964) –1800+ –1300+ –3000+ citations • Z width (2005) • Accelerator neutrino • Reactor antineutrino –1700+ oscillation (2002) [KamLAND] (2003) • Proton spin crisis (1989) –1100+ –2000+ citations –1700+ • Muon neutrino discovery • Gravitational Waves • LSND anomaly (2001) (1962) (2016) –1700+ –1100+ –2000+ citations • Parity non conservation • DAMA/Libra (2008-) • c-quark discovery (1974) (1957) –1000+ –2000+ citations –1600+ • Pentaquark [LEPS] (2003) • Solar neutrino • LUX Dark Matter (2013) –1000+ [Homestake] (1968-1998) –1500+ • Neutron EDM (2006) !3 –2000+ • g-2 (2006) –1000+ Highly cited papers • Higgs Discovery (2012) • Z discovery (1983) –1500+ – 8000+ citations –2000+ • SN1987a neutrinos (1987) • Atmospheric neutrino • Positron excess –1500+ oscillations (1998) [PAMELA] (2008) • Weak neutral current –5000+ citations –1900+ (1973) • Top quark discovery • Reactor neutrino theta_13 –1500+ (1995) (2012) • Charmomium (2003) –3000+ citations –1900+ –1400+ • Solar neutrino oscillations • b-quark discovery (1977) • B-Bbar oscillation (1987) (2002) –1900+ –1300+ –3000+ citations • W-discovery (1983) • nu_mu -> nu_e (2011) • Kaon CP violations (1964) –1800+ –1300+ –3000+ citations • Z width (2005) • Accelerator neutrino • Reactor antineutrino –1700+ oscillation (2002) [KamLAND] (2003) • Proton spin crisis (1989) –1100+ –2000+ citations –1700+ • Muon neutrino discovery • Gravitational Waves • LSND anomaly (2001) (1962) (2016) –1700+ –1100+ –2000+ citations • Parity non conservation • DAMA/Libra (2008-) • c-quark discovery (1974) (1957) –1000+ –2000+ citations –1600+ • Pentaquark [LEPS] (2003) • Solar neutrino • LUX Dark Matter (2013) –1000+ [Homestake] (1968-1998) –1500+ • Neutron EDM (2006) !4 –2000+ • g-2 (2006) –1000+ Big Picture (from Johannes Blümer)

!5 Neutrino Universe

!6 arXiv:1111.0507 Tritium β-decay and Neutrino Capture Neutrino capture on Tritium

Tritium β-decay (12.3 yr half-life)

PTOLEMY, Chris Tully !7 https://indico.cern.ch/event/640340 5 Neutrino Universe

!8 arXiv:1111.0507 UK perspective SolarFuture prospectsNeutrinos

22

SJM Peeters, UK Input to the European Particle Physics Strategy Update, Durham, 2018.04.14

!9 Neutrino Universe

!10 arXiv:1111.0507 Aside: Super Nova Neutrinos • SN1987A –24 neutrino events detected by Kamikande-II, IMB and Baksan –Learned about • Supernova collapse mechanisms • Neutrinos feel gravity (similarly to photons) Kamikande-II SN1987A citations • Neutrino mass < 23eV from per year from INSPIRE-HEP time of flight dispersion • Neutrinos are not charged • Limits on non-neutrino weakly interacting particles • Axion bounds • Neutrino mixing and oscillations • Exotic neutrino disappearance!11 * before 2011, excluding solar Neutrino Universe

!12 arXiv:1111.0507 Atmospheric Neutrinos

13

300 BG after fit Tau after fit 1000 Data 800 200 600

Events 400 100 Oscillations 200 Tau-like Upward 0 0 14 Accepted by PRL -1 -0.5 0 0.5 1 0 0.2 0.4 0.6 0.8 1 1200 a measurement of the cross section. The DONUT mea- termined600 by Super-K atmospheric1000 neutrinos is found to 38 2 800 surement was based on 9 observed charged-current tau be (0.40400 0.08) 10 cm by scaling the measured cross ± ⇥ 600 neutrino events with an estimated background of 1.5 sectionEvents in Eqn. 9 by 41%. This resulting DIS-only cross- events. In DONUT, 800 GeV protons from the Fermilab section200 is comparable and consistent400 with the DONUT 200 Tevatron were used to produce neutrino beam by collid- measurement ofNon the tau-like DIS ⌫⌧ cross section extrapolatedDownward to 0 0 ing with a beam dump, and tau neutrinos were produced lower neutrino-1 -0.5 energy.0 0.5 1 0 0.2 0.4 0.6 0.8 1 NN output via decays of charm mesons. The mean energy of the de- CosΘ tected tau neutrino interactions was estimated to be 111FIG. 14. Fit results, assuming the normal hierarchy, showing binned projections in the NN output and zenith angle distribution for tau-like (NN > 0.5), upward-going [cos ⇥ < 0.2], non-tau-like (NN < 0.5) and downward-going [cos ⇥ > 0.2] events for

)

GeV, an energy at which deep inelastic interactions areboth the two-dimensional2 PDFs and data. The PDFs and data sets have been combined from SK-I through SK-IV. The fitted tau signal is shown in gray.

dominant. Assuming that the DIS charged-current tau cm 10 neutrino cross section had a linear dependence on neu- -38 than 3.5 GeV in the CC ⌫⌧ interactions because of the ) trino energy, DONUT measured the energy-independentenergy threshold, and the expectation of CC ⌫⌧ interac- 2

tions with more than1 70 GeV is less than one in the entire cm slope of the cross section, const, after correcting for the -38 10 10 run period. kinematic e↵ect of tau lepton mass from the standard The flux-averaged theoretical charged-current tau neu-

38 2 1 1 Events per Bin trino cross section is calculated to be 0.64 10 cm model calculation: -1 10 NEUT CC ν cross⇥ section NEUT CC ν cross section between 3.5 GeV and 70 GeV, and thusτ the measured τ Cross-sections -1 -1 flux-averagedCross Section (10 charged current tau neutrino cross section: 10 10 (E)= E K(E), (10) Cross Section (10 const DONUT CC ντ cross section DONUT CC ντ cross section · · -2 -2 -2 10 38 2 10 10 (0.94 0.20) 10 cm . (9) ± ⇥ where (E) is the charged-current cross section per nu- SK measured CC tau cross section The measured cross section is shown together with the 10-3 10-3 cleon as a function of neutrino energy, const is the 0 20 40 60 theoretical cross10-3 sections and the MC simulations in Neutrino Energy (GeV) !13 asymptotic slope which is constant in /E for deepFig. 15. The measured0 and theoretical20 cross section val-40 60 inelastic scattering, and K(E) is the kinematic e↵ectues are consistent at the 1.5 level. NeutrinoFIG. Energy 15. Measured (GeV) flux-averaged charged-current tau neu- trino cross section (black), together with theoretical di↵eren- of tau lepton mass. DONUT measured const to be tial cross sections (⌫⌧ in red and⌫ ¯⌧ in blue), flux-averaged theoretical cross section (dashed gray) and tau events after 38 2 1 C. ComparisonsFIG. 16. Comparison of charged-current of tau the neutrino Super-K measured (marker with (0.39 0.13 0.13) 10 cm GeV in their final re- selection in MC simulations (gray histogram). The horizontal cross section measurement with previously reported ± ± ⇥ bar of the measurement point shows the 90% range of tau error bars) andresults expected tau neutrino cross sections (solid sults paper[40]. DONUT was incapable of distinguishing neutrino energies in the simulation. the charge of the ⌧ lepton, therefore, the measurement is lines) with (E) inferred from DONUT (dashed lines). The BecauseDONUT of the di crossculties section in tau neutrino considers production only DIS, and is is digitized an average of the ⌫ and⌫ ¯ cross sections assuming equal ⌧ ⌧ and detection,from[40]. charged-current tau neutrino cross sec- number of ⌫ and⌫ ¯ in the neutrino flux. tions have not been well measured. DONUT[14] and directly observed charged-current tau neutrino interac- ⌧ ⌧ OPERA[15] are the only two experiments that have tions, and DONUT is the only experiment that reported We wish to compare the ⌫⌧ cross section measured with atmospheric neutrinos by Super-K at relatively low energies to that measured by DONUT with a neutrino beam at higher energies. We recalculate the DONUT VII. CONCLUSION value of (E) from Eqn. 10 with the kinematic cor- rection K(E) integrated over neutrino energies between Using 5,326 days of atmospheric neutrino data in SK-I 3.5 GeV and 70 GeV and weighted to the world av- through SK-IV, Super-K measured the tau normalization erage ratio of cross sections between ⌫ and⌫ ¯ [37]. to be 1.47 0.32, excluding the hypothesis of no-tau- µ µ ± The calculated DONUT value of (E)isthenfurther appearance with a significance of 4.6. A flux-averaged weighted by the predicted ⌫⌧ and⌫ ¯⌧ flux ratio of 1.11 charged current tau neutrino cross section is measured to 38 2 for atmospheric neutrino tau appearance at Super-K. be (0.94 0.20) 10 cm for neutrino energy between ± ⇥ The resulting (E) is shown in Fig. 16. The charged- 3.5 GeV and 70 GeV in Super-K, to be compared with 38 current tau neutrino DIS cross section inferred from the the flux-averaged theoretical cross section of 0.64 10 ⇥ DONUT published number and rweightd to lower en- cm2. Our result is consistent with the previous DONUT 38 2 ergy is (0.37 0.18) 10 cm . This is smaller than result, and is consistent with the Standard Model predic- ± ⇥ 38 2 our measurement of (0.94 0.20) 10 cm ,butthe tion to within 1.5. measurements are not yet directly± ⇥ comparable. DONUT measured the cross section with a neutrino beam that had a much higher average energy than that of the tau ACKNOWLEDGMENTS neutrinos in the atmospheric neutrino flux at Super-K. Quasi-elastic scattering and resonant pion production is a We gratefully acknowledge the cooperation of the small component of the DONUT measurement and was Kamioka Mining and Smelting Company. The Super- neglected in their calculations. However, the tau neu- Kamiokande experiment has been built and operated trino flux at Super-K has a large component of neutri- from funding by the Japanese Ministry of Education, nos below 10 GeV, where CCQE and resonant pion pro- Culture, Sports, Science and Technology, the U.S. De- duction makes a significant contribution to the detected partment of Energy, and the U.S. National Science Foun- event rate. We complete the comparison using the pre- dation. Some of us have been supported by funds from dicted CC DIS fraction in the Super-K sample. Accord- the National Research Foundation of Korea NRF-2009- ing to our Monte Carlo simulation, the fraction of DIS 0083526 (KNRC) funded by the Ministry of Science, ICT, events in Super-K CC tau neutrino sample is estimated and Future Planning, the European Union H2020 RISE- to be 41%. Therefore, the ⌫⌧ DIS-only cross section de- GA641540-SKPLUS, the Japan Society for the Promo- Neutrino Universe

!14 arXiv:1111.0507 • 20% of the Universe is opaque to the EM spectrum • non-thermal Universe powered by cosmic accelerators • probed by gravity waves, neutrinos and cosmic rays !15 IceCube

• IceCube detected 5th PeV “Ernie” “Big Bird” cascade cascade “Bert” 1.0 PeV 2.0 PeV “?????” neutrino (name: ?????) cascade track –Cascade type 1.1 PeV 2.6 PeV –~2.7 PeV (the highest energy) –unlikely to be cosmogenic neutrino

Yoshida, ICRC2017 • They are selling new IceCube Preliminary IC170922 t-shirts –Point source candidate? –Blazar coincidence?

!16 Future: IceCube-Gen2

IceCube-Gen2 covers particle physics from MeV to EeV with real discovery potential

PINGU (GeV) Askaryan Radio Array (EeV) - ~20m spacing dense array - GZK neutrinos - neutrino mass ordering Main array (TeV-PeV) - 120 new strings, 80 DOMs per string - 240m separation to cover x8 volume - x2 QE PMTs, and/or new photo-sensors

Teppei Katori, Queen Mary University of London 2017/07/21 !17 Physics of IceCube-Gen2

Argüelles et al, PRL2015 Astrophysical neutrino flavour - very sensitive to new physics such as neutrino decay, non-standard interaction, quantum gravity, etc

Lepton unitarity triangle - High statistics τ appearance to test of lepton unitarity

Kowalski, IPA2017

Unlimited list of science! - low mass dark matter - neutrino mass ordering - multi-messenger astronomy, etc Teppei Katori, Queen Mary University of London 2017/07/21 !18 Manchester: J. Evans, S. Söldner-Rembold, S. Wren Oxford: S. Sarkar IceCube-Gen2 in UK Queen Mary: T. Katori, S. Mandalia

IceCube data analysis - Mass ordering analysis on DeepCore - Test of quantum gravity

Software development - Atmospheric flux systematics Evans et al, PRD95(2017)023012 - Hadronization systematics Katori et al, JPhysG42(2015)115004 - PINGU fast oscillation analysis code paper in preparation

Hardware - FEB firmware development

- DOM Fermilab beam test paper in preparation

Analysis coordination - Gen2 low E convener (Justin Evans)

On top of these, there is a large theory contribution from Oxford (Subir Sarkar)

LHCb for prompt-ν production, JHEP02(2016)130 High energy neutrino cross section, JHEP08(2011)042 etc

Teppei Katori, Queen Mary University of London 2017/07/21 !19 IceCube-Gen2 phase I

Staged approach - Phase I includes 7 close strings to focus on

ντ appearance (unitarity triangle) - Proposal submitted to NSF, received with favor

PINGU: A vision for neutrino and particle physics at the South Pole arXiv:1607.02671,JPhysG44(2017)054006 IceCube-Gen2: A vision for the future arXiv:1412.5106

Thank you for your attention!

Teppei Katori, Queen Mary University of London 2017/07/21 !20 !21 Neutrino Universe

!22 arXiv:1111.0507 ANITA

Photo: H. Schoorlemmer , University of Hawaii Concept

!24 Cosmin Deaconu (UChicago/KICP) ANITA ARENA16 4 / 26 Concept

!25 Cosmin Deaconu (UChicago/KICP) ANITA ARENA16 4 / 26 Concept

Photo: H. Schoorlemmer , University of Hawaii Cosmin Deaconu (UChicago/KICP) ANITA ARENA16 4 / 26 Concept

Photo: H. Schoorlemmer , University of Hawaii Cosmin Deaconu (UChicago/KICP) ANITA ARENA16 4 / 26 ANITA Flights

ANITA-1 ANITA-2 (2006-2007) (2008-2009) 35 days 30 days

ANITA-3 ANITA-4 (2014-2015) (2016) 22 days 30 days

!28 L. Cremonesi 10 “UHE neutrinos and ANITA” ANITA-3 Results • New diffuse neutrinos searchWhat’s left? •fromOne ANITA-3 V-POL candidate –arXiv 1803.02719 +0.5 • Background estimate: 0.7 -0.3 per polarisation • No known human activity within 260km

Event Location Coherently-Deconvolved 200 VPol ANITA 0.1 0 HPol Northing (km) Mirny (RUS) E-Field (arb) 0.05 200 Event 0 400 83139414 0.05 Edgeworth 600 David (AUS) 0.1

1800 2000 2200 2400 2600 2800 0 5 10 15 20 25 30 35 40 Easting (km) time (ns) !29

L. Cremonesi 15 “UHE neutrinos and ANITA” interferometric Not to scale, payload angles don't reflect reality UHECR

ANITA1: 16 UHECR

14 reflected + 2 direct direct UHECR Askaryan reflected UHECR ANITA-2: 2 UHECR Askaryan geomagnetic + H-pol trigger was off geomagnetic + emission ANITA-3: 25 UHECR emission ANITA-4: analysis in progress Ice Askaryan 3 emission ~EeV ν

30 ANITA3 ANITA1 20

10

0

reflected CRs geomagnetic -10 anomalous CR direct CRs measured plane of polarization, deg. -20 -20 -10 0 10 20 30 PRL 105, 151101 (2010) expected plane of polarization, deg. FIG. 4: Plane of polarization of UHECR events compared to the an- gle of the magnetic field local to the event, with the red line indicating arXiv:1803.05088 [astro-ph.HE] the expectation for the Lorentz force. The reflected events are cor- rected for their surface Fresnel coefficients, and angles aremeasured from the horizontal. !30 L. Cremonesi 17 “UHE neutrinos and ANITA” larity of our radio pulses, as well as their robust correlation to geomagnetic parameters, suggests that ANITA’s observations, which are at much greater distance and higher frequency than prior and current air-shower geosynchrotron observations,are less susceptible to near-field fluctuations of radio strengthand plane of polarization. Such issues have been problematic in this field throughout most of its history. Our data represent the first broadband measurements of geosynchrotron emission in the UHF frequency range. The average observed radio-frequency spectral flux density of the above- and below-horizon events, shown in Fig. 3 (Bottom) is consistent with an exponential decrease with frequency. The FIG. 3: Top: overlay of the 16 UHECR event Hpol pulse shapes, lack of any statistically significant difference in the spectra showing the inverted phase for the 14 reflected events (in blue) com- for the direct and reflected events indicates that ice rough- pared to the two direct events (in red). Inset: Average pulse pro- file for all events. Bottom: Flux density for both the averageddi- ness is unimportant for the average surface reflection. To es- rect and averaged reflected events. In each case the data are con- timate the electric field amplitude at the source of these emis- sistent with an exponential decrease with frequency: the fitted co- sions, we model the surface reflection using standard physical- efficients of decrease with frequency are (180 ± 13 MHz)−1,and optics treatments developed for synthetic-aperture radar anal- (197 ± 15 MHz)−1,consistentwitheachotherwithinfiterrors.Er- ysis. Such models use self-affine fractal surface parame- rors at low frequency (high SNR) are primarily due to systematic ters [23] and Huygens-Fresnel integration over the specular uncertainty in the antenna gains, and to thermal noise statistics at reflection region to estimate both amplitude loss and phase higher frequencies. distortion from residual slopes or roughness. In our case, we used digital-elevation models from Radarsat [24] to esti- mate surface parameters for each of the event reflection points, originates in the earth’s atmosphere and which involves elec- known to a few km precision. In most cases the surface pa- trical current accelerating transverse to the geomagnetic field. rameters are found to be smooth, yielding only modest effects Such observations are in every way consistent with predic- on the reflection amplitude; in a minority of the events, sur- tions of geosynchrotron emission from cosmic-ray air show- face parameters were estimated to be rougher, but still within ers. In addition, the inherent spectral and time-domain simi- the quarter-wave-rms Rayleigh criterion for coherent reflec- And ANITA-3 mystery event

ANITA-III UHECR Air Showers ° ° 15717147, -35 27142546, -5.5 1 A Hpol B Hpol 1 Vpol Vpol 0.5

0 0

-0.5 -1 anomalous atmosphere-skimming field strength, mV/m -1 upward air shower field strength, mV/m air shower -2 -10 0 10 20 30 40 50 -10 0 10 20 30 40 50 time, ns time, ns ° ° 39599205, -3.6 68298837, -36.7 0.6 1 C Hpol D Hpol Vpol 0.4 Vpol Direct Cosmic Rays

0 0.2

0 -1

atmosphere-skimming -0.2 normal, reflected field strength, mV/m field strength, mV/m Reflected Cosmic Rays air shower air shower -2 -0.4 -10 0 10 20 30 40 50 -10 0 10 20 30 40 50 time, ns time, ns Chord length: 5500-7000 km (20-30,000km NEW PHYSICS ? water equivalent) 1600km SM interaction length @ 1 EeV

Background estimate < 10-2 !31 L. Cremonesi 18 “UHE neutrinos and ANITA” The ExaVolt Antenna (EVA): FutureConcept Radio and Development

Deployed ARA DEPLOYMENTSta:on ARA6 OF ANALOG PHASED ARRAYEVA Instrumenta:on Carl Pfendner deployment in 17 / 18. Site / road prepara:on 4 South in 16 / 17. Pole IceCube Poten:al if support is available South Pole 3 1 Sta:on WT3 Hang Test 5 2 6 2 km Skiway Wallops Flight Facility, September 2014

THEGreenland PHASED Neutrino ARRAY ObservatoryTECHNIQUE Phased Array Lowers Trigger Threshold: ARENA 2016 2016-06-1030m$ 30m$ 1 22 June 2016 8 Ice$Surface$ Coherent Signal increases N Incoherent Noise increased by √(N)

➤ Beamforming: for a given incident

direction, calculate the system delay 30m$ Pointing$ required between antennas to see the Array$ Trigger$ (Both$ signal in-phase in all the antennas Array$ $Polarizations)$ 0.5m$ (Vertical$ ➤ The signal is correlated between Polarization)$

antennas and noise is uncorrelated: 30m$ increase the SNR as ~√N 1/20th scale model balloon. Dual-polarized sinuous Balloon and feed ➤ Create many beams at once to cover the !32 antenna feeds. system. solid angle of interest ➤ Analog or digital

➤ Can be combined with outrigger antenna ARENA 2016 19 2016-06-10 14 strings with longer baselines for pointing 4 Vieregg, Bechtol, Romero-Wolf JCAP 2016 arXiv:1504.08006v1 Questions? • What consensus / conflicts (on what should be done in longer term European HEP) are there in this area? • What are the experimental possibilities? Are different scenarios already envisaged? –IceCube is a tremendous success, the science case for IceCube-Gen2 (both the high and low energy extensions) are clear –Some version of KM3NeT will exist –Small experiments (i.e. ANITA) have discovery potential –Hard to disentangle politics • What are the choices for the strategy? What can the UK agree to input? –Astroparticle physics should be mentioned • What are the potential developments in this field? How do they relate to fundamental physics questions? !33