DRAFT Supernova Burst Physics At DUNE Alex Friedland University - - PowerPoint PPT Presentation

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DRAFT Supernova Burst Physics At DUNE Alex Friedland University - - PowerPoint PPT Presentation

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DRAFT Supernova Burst Physics At DUNE Alex Friedland University of Tokyo, Feb 12, 2017 Wednesday, February 8, 17 1 Outline DUNE Experiment and Collaboration Core collapse supernova: overview Things to observe: Stages of the explosion in

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Supernova Burst Physics At DUNE

Alex Friedland

University of Tokyo, Feb 12, 2017

DRAFT

1 Wednesday, February 8, 17
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Outline

DUNE Experiment and Collaboration Core collapse supernova: overview Things to observe: Stages of the explosion in neutrinos Oscillations effects Particle and Nuclear physics effects Detection issues

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About DUNE

Deep Underground Neutrino Experiment Neutrino beam from Fermilab to a large liquid argon detector 1,300 km away in South Dakota

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DUNE Collaboration

As of today: 945 collaborators from 161 institutions in 30 nations

Armenia, Brazil, Bulgaria, Canada, CERN, Chile, China, Colombia, Czech Republic, Finland, France, Greece, India, Iran, Italy, Japan, Madagascar, Mexico, Netherlands, Peru, Poland, Romania, Russia, South Korea, Spain, Sweden, Switzerland, Turkey, UK, Ukraine, USA 60 % non-US 4 Wednesday, February 8, 17
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DUNE Timeline

Looking ahead: Strategic Goals

  • DUNE is committed to delivering:
  • Two large-scale engineering prototype detectors (protoDUNE-SP
and protoDUNE-DP) operational at CERN in 2018
  • DUNE TDR for the CD-2/3B and LBNC Reviews in 2019
  • 20-kt (fiducial mass) Far Detector ready for beam in 2026
  • Two 10-kt detector modules (not necessarily the same design)
  • Near detector system(s) operational in time for first beam

Ultimate plan is for 40 kton of LAr far detector four modules of 10 kton each

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Why SNB neutrinos at DUNE?

Unique characteristics make is a very important, complementary machine to SuperK/HyperK Sensitivity primarily to electron neutrinos Energy resolution Time snapshots of all stages of the explosion Different side of the Earth: Earth matter effect!

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What happens when all fuel is exhausted?

The star can be supported by the electron degeneracy pressure only when electrons are non-relativistic M❊ ~ (MPl/MN)2 MPl ~ 1.4 M⊙!! Chandrasekhar mass. (We live in an amazing universe!) When the Iron core reaches this mass, gravity at last wins The Fe core collapses in free fall, at v ~c/4, until reaching (supra)nuclear densities, 1010 g/cm3 → 1014 g/cm3 7 Wednesday, February 8, 17
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Gravity-powered neutrino bomb

The gravitational binding energy GNM2/R ~ 3*1053 ergs (~10% of rest mass!) is initially stored mostly in the Fermi seas of electrons & electron neutrinos Photons are hopelessly stuck. Neutrinos diffuse out

  • easier. The weak interactions mean free path: λ~(GF2 E2

n)-1 ~ a few cm

t ~ R2/cλ ~ 1012 cm2/(3 cm 3*1010cm/s) ~ 10 s For comparison, solar luminosity is 3.8*1033 ergs/s. A core- collapse supernova shines in neutrinos as bright as 1020

  • Suns. Instantaneously outshines the visible universe.
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60-year-old problem. Why should we care?

Origin of stuff: Supernovae synthesize and disperse heavy
  • elements. (“Theory of everything”)
BBN created hydrogen and helium. Chemical elements around us were once inside a star Supernova “feedback” is crucial to understanding the universe around us (galaxy). Conditions not reproducible on Earth make them unique laboratories for particle and nuclear physics. E.g.: Flavor oscillations in dense neutrino gas The final state is one big nucleus Sterile neutrinos, axions, Majorons, dark photons, etc, etc 9 Wednesday, February 8, 17
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Evolution of the explosion is reflected in neutrinos

Neutronization burst, accretion and cooling phases can all be seen in neutrinos. All stages are extremely important!! Signal depends on the progenitor star

0.2 0.4 0.6 0.8 1 0.1 0.2 0.3 0.4 0.5 8.8 solar mass Time After Bounce [s] Lν [1053 erg/s] νe anti−νe 0.2 0.4 0.6 0.8 1 0.1 0.2 0.3 0.4 0.5 10.8 solar mass Time After Bounce [s] Lν [1053 erg/s] νe anti−νe Fig from Fischer, Whitehouse, Mezzacappa, Thielemann, Liebendörfer, arXiv: 0908.1871 10 Wednesday, February 8, 17
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Cooling Accretion

(no2oscillations)

CC NC

≈“Shock2 Revival”

We may see something like this (illustration from Messer)

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Basics of detection

Eνe > 7.48 MeV
  • Elastic scattering (ES) on electrons
  • Charged-current (CC) interactions
  • n Ar
  • Neutral current (NC) interactions
  • n Ar

Low-energy neutrino signal in LAr

νe + 40Ar → 40K* + e- νe + 40Ar → 40Cl* + e+

ν + e- → ν + e- ν + 40Ar → ν + 40Ar*

Eνe > 1.5 MeV Eν > 1.46 MeV

_

_ 31 SN ν cross sections on Ar hep-ph/0307222 JCAP 10 (2003) 009 JCAP 08 (2004) 001 I.G-B & A.Rubbia 12 Wednesday, February 8, 17
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Predicted signal, for a reference SN model

DUNE: 40 kton LAr (SN @10 kpc)

Time-dependent signal Expected event spectrum integrated over time 13 Wednesday, February 8, 17
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ances$adiabaLc,$small$enough$to$ignore$mixing$$

ls$

Or maybe the signal suddenly stops, a black hole forms (O’Connor)

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Neutronization burst

Thompson, Burrows, Pinto, astro-ph/0211194

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Update from Oak Ridge

100 200 300 400 500 time [ms] 500 1000 1500 2000 events νe + 40Ar ➝ e
  • +
40K *

2D - νe total counts vs. time

shock lift-off accretion-powered evolution rapid shock expansion - Si-Si/O C15-2D, angle-averaged, SNOwGLoBES Ar17kt, 10 kpc Messer, Devotie, et al. In prep. 16 Wednesday, February 8, 17
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Oscillations!

In the normal hierarchy, almost the entire neutronization burst would oscillate away! Why?

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Sun: 2-state oscillations

In the Sun, the density scale height is Rsun/10, while losc is comparable to the width of Japan (KamLAND) -> The evolution is adiabatic (no level jumping)

P2(νe → νe) = sin2 θ sin2 θ + cos2 θ cos2 θ cos2 θ sin2 θ cos2 θvac sin2 θvac

Vacuum Core 18 Wednesday, February 8, 17
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SN ν oscillations: 2 MSW densities

ν-sphere “regular MSW” νe νμ ντ νe νμ ντ _ _ _ 19 Wednesday, February 8, 17
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SN MSW transformations, schematics

➡ Given the scale height in the progenitor, the MSW evolution is very adiabatic ➡ the adiabaticity of the atmospheric resonance is controlled by theta13 ➡ Prediction for the nue signal during the neutronization burst is critically dependent
  • n the sign of mass
hierarchy ➡ One of 3-4 different ways of determining hierarchy from the SN signal (redundancy!)

sin2 θ cos2 θ

sin2 θ13 F(νµ,τ) F(νe) F(νµ,τ)

sin2 θ cos2 θ

sin2 θ13 F(νµ,τ) F(νe) F(νµ,τ)
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SN ν: very rich physics

ν-sphere Collective turbulence front shock “regular MSW” νe νμ ντ νe νμ ντ _ _ _ 21 Wednesday, February 8, 17
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SLIDE 22 * See LBNE science document, 1307 .7335

WC LAr

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Another smoking-gun feature. Tracking the shock in real time

The neutrino spectrum is modulated, but not antineutrinos (simultaneously observed by SK/HK)

multiangle collective

  • scillations +

moving shock

Figure 7–5: Observed spectra in 34 kton of LAr for a 10 kpc core collapse, representing

LBNE science document arXiv:1307 .7335v3

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Observations

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νeCC final states: de-excitation γs

  • Lack of precision models of low energy
neutrino argon reactions
  • No measurements are available
  • Some efforts to study this problem with indirect
beam sources and small-scale experiments
  • Fermi transition to 4.38 MeV IAS
40K
  • σ precisely known < 1%
  • Raghavan, PRD 34 (1986) 2088
  • GT transitions of various
40K: Experimental data of β-decay of the mirror nucleus 40Ti
  • Ormand et al., Rhys. Lett. B 345 (1995)
343-350
  • Trinder et al., Phys. Lett. B 415 (1997) 211-216
  • Bhattacharya et al., Phys. Rev. C 58 3677
(1998) 32 25 Wednesday, February 8, 17
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MARLEY: Model of Argon Reaction Low-Energy Yields

  • e–
  • e
40Ar 40K
  • e–
  • e
40Ar 40K

Goal: determine whether “every 40K∗ e– little thing gonna be all right” for SN neutrino physics in LArTPCs

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Gammas, neutrons, protons at high Eν

40 18Ar 0+ 1460.859 2+ 11 1460.830 E2 stable 1.12 ps 40 19K ≈ 0.048% 21.03 10.67% 11.61 4– 1.277×109 y QEC=1504.9 10.72% 40K γ 39Ar 39K Sp Sn p n
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Notice that theory and experiment don’ t match at all

  • K* Excitation Energy (MeV)
40 10 20 30 40 50 60 Integrated B(GT) 2 4 6 8 10 12 14 16 18 Ar 40
  • n
e ν Integrated Gamow-Teller Strength for CC et al. (1998) Ti Decay Data from Bhattacharya, 40 QRPA from Cheoun, et al. (2012) et al. (2009) (p,n) Data from Bhattacharya, Ti data 40 MARLEY B(GT) based on MARLEY B(GT) based on (p,n) data Ar 40
  • n
e ν Integrated Gamow-Teller Strength for CC
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Spectral distortion at high

  • energy. (Not collective oscillations!)
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e– + γs Event

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Neutron ejected

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In Summary

The next supernova will allow us to look inside the core collapse, observing the engine in real time Hyperk-K and DUNE are perfectly complementary. Will help unravel the explosion mechanism, while also presenting a laboratory for particle and nuclear physics unavailable on earth But we need to be prepared! Events in LAr are complicated and missing photons and gammas could be a big problem Measurements of cross sections and robust DAQ design now would pay off handsomely when SN2029a goes off 32 Wednesday, February 8, 17