Physics Opportunities withSupernova Neutrinos

周 顺中科院高能所理论室

中国科学技术大学交叉学科理论研究中心合肥， 2015-3-26

Outline

Supernova Neutrinos Physics Opportunities Neutrino Mass Scale WDM Sterile Neutrinos Summary and Outlook

Galactic SN 1054Distance: 6500 light years

(2 kpc)Center: Neutron Star

( R~30 km)Progenitor : M ~ 10 solar

masses

Red ： Optical (Hubble)

Blue ： X-Ray (Chandra)

Stellar Collapse and SN Explosion

Hydrogen Burning

Main-sequence star Helium-burning star

HeliumBurning

HydrogenBurning

© Raffelt

Onion structure

Degenerate iron core: r 109 g cm-3

T 1010 K MFe 1.5 Msun

RFe 8000 km

Collapse (implosion)

© RaffeltStellar Collapse and SN Explosion

Neutrino-driven Explosion

© Raffelt

Newborn Neutron Star

50 km

Proto-Neutron Star

r rnuc = 3 1014 g cm-3

T 30 MeV

Stellar Collapse and SN Explosion

Newborn Neutron Star

50 km

Proto-Neutron Star

r rnuc = 3 1014 g cm-3

T 30 MeV

Neutrino cooling by diffusion

Gravitational binding energy

Eb 3 1053 erg 17% MSUN c2

This shows up as 99% Neutrinos 1% Kinetic energy of explosion (1% of this into cosmic rays) 0.01% Photons, outshine host galaxy Neutrino luminosity

Ln 3 1053 erg / 3 sec

3 1019 LSUN

While it lasts, outshines the entire visible universe

© RaffeltStellar Collapse and SN Explosion

Raffelt, 1996

Kitaura, Janka & Hillebrandt astro-ph/0512065

Supernova Neutrinos: Theoretical Prediction

Supernova 1987A23 February 1987

Sanduleak - 69 202

Large Magellanic Cloud SN 1987A

Distance ： 165 000 light yrs (50 kpc)

Center ： Neutron Star (expected, but not

found)Progenitor ： M ~ 18 solar

masses

Supernova Neutrinos: SN 1987A

Hirata et al., PRD 38 (1988) 448

Arnett et al.,ARAA 27 (1989)

Kamiokande-II (Japan): Water Cherenkov (2,140 ton) Clock Uncertainty ± 1 min

Irvine-Michigan-Brookhaven (US): Water Cherenkov (6,800 ton) Clock Uncertainty ±50 ms

Baksan LST (Soviet Union): Liquid Scintillator (200 ton) Clock Uncertainty +2/-54 s

Mont Blanc: 5 events, 5 h earlier

Supernova Neutrinos: SN 1987A

E b [1

053 e

rgs]

Spectral anti-νe Temperature [MeV]

Jegerlehner, Neubig & Raffelt astro-ph/9601111

Assumptions:

Thermal Equipart.

Conclusions: Collapse Ave.Ener. Duration

Problems ： 24

events by

chance

Supernova Neutrinos: SN 1987A

Supernova Neutrinos: Astrophysics & Astronomy

Explosion Mechanism ： Neutrino-driven Explosion

The prompt shock halted at 150 km,

by disintegrating heavy nuclei

Neutrinos deposit their energies via

interaction with matter; 1 % neutrino

energy leads to successful explosion

Simulations in 1D & 2D for different

progenitor masses observe explosions

3D simulation has just begun; but no

clear picture (resolution, progenitors)for a review, Janka, 1211.1378

For Optical Observations ： SuperNova Early Warning System (SNEWS)

Arnett et al.,ARAA 27 (1989)

Super-K IceCube

LVD Borexino

http://snews.bnl.gov/

Alert @BNL

Neutrinos arrive several hours before photons

To alert astronomers several hours in advance

Supernova Neutrinos: Astrophysics & Astronomy

Gravitational waves from SN Explosions Locate the SN via neutrinos

Bounce

GWs from asymmetricneutrino emission

GWs from convective mass flows

ee

nepe

Müller, Rampp, Buras, Janka,& Shoemaker, astro-ph/0309833

“Towards gravitational wave signals from realistic core collapse supernova models”

Beacom & Vogel, astro-ph/9811350

SK

SK 30

90 %None

7.8° 3.2°

1.4° 0.6°

95% CL half-coneopening angle

Tomàs et al., hep-ph/0307050

n-tagging efficiency

Supernova Neutrinos: Astrophysics & Astronomy

Neutrino Mass Bound ： Time delay of massive particles

22

eV 10

MeV 10

kpc 50 s 57.2

m

E

Dt

G. Zatsepin, 1968

Kamiokande-II data

IMB data

Estimate:

Take the first event A: (tA, EA)

Take the last event B: (tB, EB)

ABAB ttmEtmEt ),(),(

IMB eV 37

II-Kam eV 22

m

m

Assumptions: Instant.

emission Diff. only from

m

Schramm, CNPP 17 (1987) 239

Supernova Neutrinos: Elementary Particle Physics

Flavor Conversion & Matter Effects: Source ─ Prop. ─ Detector

Neutrino sphere

-310 cm g 10

High Matter Density:

High interaction rate

Flavors conserved

Vacuum MSW Collective

Wolfenstein, 78Mikheyev&Smirnov, 85Pantaleone, 92

Matter Effects:

Envelope

Shock wave

Earth matter

Mass ordering

Supernova Neutrinos: Elementary Particle Physics

Flavor Conversion: collective effects (accretion phase)

Duan, Fuller&Qian, 1011.2799

Fogli, Lisi, Marrone&Mirizzi, 0707.1998

Left:Sketch of

Collective

effects

Bottom:Inverted

+ Accretion

Supernova Neutrinos: Elementary Particle Physics

NH

IH

Dasgupta, Mirizzi, Tamborra&Tomàs, 1002.2943

Note: compare between accretion

and cooling results

Supernova Neutrinos: Elementary Particle Physics

Flavor Conversion: collective effects (cooling phase)

NH IH

Dighe & Smirnov, hep-ph/9907423

L – Resonance Res. for neutrinos Always adiabatic

12221 θ ,Δm H – Resonance

Res. for neutrinos (NH)

Res. for antineutrinos (IH)

13231 θ ,Δm

Adiabatic for

a ‘large’ 13

Supernova Neutrinos: Elementary Particle Physics

Flavor Conversion: MSW effects in the SN envelope

for

for

for

0eF

0eF0xF

e

e ,,,

00 )1( xee FpFpF 00 )1( xee FpFpF

000

4

1

4

1

4

2

4

1eexx F

pF

pF

ppF

Normal

Inverted

sin2(213)

≳ 10-3

Mass ordering

sin2(12)

0 cos2(12)

0

Case

A

B

Survival probabilities

)for(p e )for(p e

Dighe & Smirnov, hep-ph/9907423 Dighe, Kachelriess, Raffelt & Tomàs, hep-ph/0311172

Primary fluxes (+ collective)

Leaving the SN (+ Collective & MSW effects)

Supernova Neutrinos: Elementary Particle Physics

Flavor Conversion: MSW effects in the SN envelope

survival

02

02 )1( xeeee FPFPF

02

02 )1( xeeee FPFPF

L

E

mP

mmm

e12

122212

121212122

2 2sin4

2sinsin)22sin(2sinsin

L

E

mP

mmm

e12

122212

121212122

2 2sin4

2sinsin)22sin(2sinsin

Dighe&Smirnov, hep-ph/9907423Lunardini & Smirnov, hep-ph/0106149

NH:Matter Effects

-antineutrinos

Mass Ordering sin2 13 survival

NH

IH ≳ 10-3 cos2 12

e Earth matter e

Yescos2 12

0 No

Yes

Collective Neutrino Oscillations (accretion phase)

No Yes

IH:Matter Effects

- neutrinos

If IH is determined from oscillation experiments ， Earth matter effects indicate collective effects.

Earth matter

Supernova Neutrinos: Elementary Particle Physics

Flavor Conversion: including Earth Matter Effects

for a ‘large’ 13

Extra energy-loss channels: Bound on particle physics models

50 km

Proto-Neutron Star

r rnuc = 3 1014 g cm-3

T 30 MeV

Cooling via Neutrino Emission

Exotic weakly-interacting particles

If exotic particles can be produced and escape from the SN core, then the energy carried awayby them should be at least smaller than that by neutrinos. Otherwise, the SN neutrino signal would be significantly reduced.

-1-333new scmerg1003 . E

The energy-loss argument has been applied to the SN 1987A, and restrictive bounds on particle physics models have been obtained: Axion ， Majoron ， keV sterile neutrino ，……

Supernova Neutrinos: Elementary Particle Physics

SN Detection: present and future experiments

Super-Kamiokande (104)KamLAND (400)

MiniBooNE(200)

LVD (400)Borexino (100)

IceCube (106)

Baksan (100)

Water / Ice

Cherenkov

Liquid

Scintillator

JUNO (104)

SN @10 kpc

Memphys

Hyper-K

DUSELLBNE

Megaton-scalewater Cherenkov

5-100 ktonliquid Argon

100 kton scale scintillator

LENAJUNOHanoHano

SN Detection: present and future experiments

Key Problem: where and When?

© Raffelt

(1) Estimate from SN statistics in other galaxies; (2) Only massive stars produce 26Al (with a half-life 7.2 105 years); (3) Historical SNe in the Milky Way; (4) No neutrino bursts observed by Baksan since June 1980

Key Problem: where and When?

SN Candidate: The Red Supergiant Betelgeuse (Alpha Orionis ）

Distance: 425 ly (130 pc)

Type ： Red Supergiant

Mass ： ~ 18 solar masses

Expected to end its life as SN explosion

@ Super-K: 6 107 events

Detection of SN Neutrinos @JUNO

Main Channels in LSD

2015/1/10, Jiangmen, Guangdong

Goal: to pin down mass ordering

A typical SN @ 10 kpc

Neutrino Mass Bound: SN ModelKamiokande-II Data IMB Data Baksan Data

(1)Use the SN 1987A observations to extract the SN model param.

(2)Use all the information (ti Ei i )

Maximum likelihood

eeiieii

N

i

tRdttRfdEEGcEtR

BeeL di )(),,(

2

dd

1

)()(

d

Pagliaroli, Vissani, Costantini & Ianni, 0810.0466

Kam, IMB & Baksan

Every Event

Loredo & Lamb, astro-ph/0107260

Signal Events

eee dE

dEEEtE

d

dNEtR

e

)()(cos),()cos,(cos

)cos,,( ddIBD

p

Neutrino Flux Parametrization

Pagliaroli, Vissani, Costantini & Ianni, 0810.0466

)()(1)()( aca ttjtt ke

Accretion PhaseMa : initial mass

Ta : initial e+ temp.

a : accretion time

Cooling PhaseRc : -sphere

rad.Tc : initial

temp.c : cooling

time

e

Fit SN Model Parameters

s 55.0 s 7.4

MeV 4.2 MeV 6.4

22.0 km 16

58.017.0a

7.12.1c

6.04.0a

7.06.0c

sun68.015.0a

95c

TT

MMR

(1) Cooling: Thermal distr. of anti-e ， and exp. decay of luminosity;

(2) Accretion: Anti-e only from e+ +n ， and thermal distr. of positrons

Neutrino Mass Bound: SN Model

Neutrino Mass Bound: Events @JUNO

JUNO: 20 kt (12% p) liquid scintillator

),(ˆ)(),( IBDp EtENEtRe

)()(1)(1)(ˆaca

/ r ttjtet k

t

e

Best-fit values for SN model & r=100 ms

IBD events @JUNO: N = 4300

1. Generate n pairs of (t i , E

i) according to R (t , E)

Nn

en

NNnP

!),(

2. Denote e+ as (t i , Ee

i) corresponding to (t i , E

i)

1ttt ii ie

ie

ie EEE /03.0/

3. Label event by a relative time t i and energy Ee

i

2

2

ii

E

m

c

Dt

4. Extract SN model parameters and m from data

Pagliaroli, Rossi-Torres &Vissani 1002.3349

MeV 5.6th E

EEE /41.0023.0/

1987A SNfor CL @95% eV 8.5m

SN kpc 10 afor CL @95% eV 8.0m

@Super-K

Better ? @JUNO

Neutrino Mass Bound: Simulations

Neutrino Mass Bound @ JUNOFit for one single experiment

Jia-Shu Lu, Jun Cao, Yu-Feng Li, S.Z., 1412.7418

3000 simulations

for JUNO

3000 simulations

for Super-K

(1) Include numerical models, - systematic errors;

(2) Simulate a large number of experiments - stat. errors;

(3) Low-E, Early-t events help

Robust evidence for Dark Matter

Moore et al., 99’

Abundance of Cosmic Substructure

Cold or Warm DM ?

Sterile Neutrinos of keV Masses

Production of sterile neutrinos:Low matter density: neutrino flavor oscillations with matter

effectsHigh matter density: production & absorption via scattering processes

Occupation-number formalism:

jiij

ijij

dd

bb

Diagonal terms: just the usual occupation numbersNon-diagonal terms: encode the phase information

Equations of motion:

],[ ppp i Mass terms and matter potentials

n

i

ii

iii III

1

,2

1,

2

1pppp AP

h.c.)1(h.c.)1()2(2

13

3

aaaaaa

a

GGGGd

pppppppp

p

WW

Sterile Neutrinos in a SN Core

Two-flavor mixing case ],[ ppp i τPppp n

2

1

τBppp E2

1

ppp PBP

BpPp

z

yx

eff

22

2cos2

,0,2sin2

VE

m

E

m pB

Flavor polarization vectors rotate around magnetic fields

Matter EffectsWolfenstein, 78’; Mikheyev, Smirnov, 85’

22

2

,2

/)(2cos2sin

2sin2sin

rEE

where the resonant energy is

eff

2

2V

mEr

maximal mixing if E ~ Er cos 2θ

Sterile Neutrinos in a SN CoreWeak-damping

limit 24

2osc

keV10

2sin

10

MeV 30cm7.0~

4

sm

E

m

E

31423

Bmfp

cm g10MeV 30cm10

1

EN N

Oscillation length

Mean free path

BpPp

z

yx

Bp

z

yx

Pp

Neutrinos oscillate many times before a subsequent collision with nucleons

mfposc

Sterile Neutrinos in a SN CoreIn the weak-damping

limit τBBP ppppp ˆˆ

2

1~ n averaged over a period of oscillation

01

10

2

1

0

0~ppp

p

pp tff

f

f ss

Two independent parameters:occupation numbers fα

p & fsp

Simplified equations of motion:

a

sasaasss ffffd

gffsf )1()1()2(

)1(4

13

322

pppppppppppppp

pWWAP

further simplification if sterile neutrinos escape from the SN core

a

aas fd

gsf

pppppp

pWP

3

322

)2(4

1 set fsp = 0

Lepton-number-loss rate Energy-loss rate sf

dp

p 3

3

L2

N

ss fE

dp

p 3

3

2E

Sterile Neutrinos in a SN Core

Tau-sterile neutrino mixing

04212

BF

YYYNG

Vee

Initial conditions: Ye = 0.3, Yνe = 0.07, Yνμ

=Yντ=0

22

2

,2

/2cos2sin

2sin2sin

rEE

1. the MSW resonance occurs in the antineutrino channel;

2. asymmetry between tau neutrinos and antineutrinos.

Simple bound in the ‘vacuum limit’: Er >> E

Energy-loss rate

262

FB0

22FB2

2

2

42sin4

1

1/exp22

TGNdE

EGN

TE

EEs

E

Supernova Bound-1-333262

FB scmerg10034 .TGNs EE 82 10

Energy-loss Rate and SN Bound

*

G. Raffelt, S.Z., 1102.5124

Follow the time evolution of η and calculate the energy loss

Summary and Outlook

Neutrinos from next nearby supernova cannot be missed (a once-in-a-lifetime opportunity!)

Physics opportunities with SN neutrinos: stellar collapse, explosion mechanism, collective flavor conversion, matter effects, neutrino mass ordering, absolute neutrino mass,…

104 neutrino events @ JUNO for a typical galactic SN; to improve neutrino mass bound, & other possibilities; A lot of theoretical works to do while waiting for a real SN