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Supernova Neutrinosin DUNEAnd other questions we weren’t askedSammy Valder James Pillow Kenny Vetter Sander Breur Olexiy DvornikovSLAC Summer Institute 2019

The QuestionA star, ten times the mass of the sun, went supernovanear the galactic core; a neutron star, two times themass of the sun, was left behind. Thankfully, DUNE’sFar Detector was up and running and ready to takedata.How many events should DUNE expect to record?The delay of the neutrino arrivals was determined tobe 5 seconds past the gamma-ray time-tag.What could you learn about neutrinos from thismeasurement?22/08/2019Supernova Neutrinos in DUNE2

DUNE“And I say: ‘Look! I have hands!’ But the people all around me say: ‘What are hands?’” - Frank Herbert, Dune, 1965The Deep Underground Neutrino Experiment will be thelargest LArTPC ever built, with 4 individual TPC modulesleading to a total fiducial mass of 40kt.The state of the art TPCs will allow for highprecision on particle position and energy,allowing for extremely detailed images.It will incorporate a large physics program,from pinning down the mass hierarchy tobeing ready to record supernova neutrinosand more.22/08/2019Supernova Neutrinos in DUNEProtoDUNE-SP: chronicles of an endeavor3

Type II Supernova Star burns until Fe core is present.As density increases neutrinos get trapped in the coreOnce the core mass reaches 1.4M , the core collapses undergravity at free fallCollapse halted by nuclear force and a shockwave bouncesback𝜈e are produced in huge numbers through electron captures onfree protons behind the shock frontShock breaks out into neutrino transparent layers, producesflash of 𝜈eAccretion and cooling phases release further neutrinos of allflavours22/08/2019Supernova Neutrinos in DUNE4

Type II Supernova NeutrinosMC Mass of the coreRNC Radius of neutron coreEnergy losses: 1%Almost all of the energy is takenby neutrinos! That’s 1053 erg22/08/2019Supernova Neutrinos in DUNE5

Well that was easy(ish)22/08/2019Supernova Neutrinos in DUNE6

Well that was easy(ish)DUNE VolumeDUNE DensityNumber ofArgon AtomsNeutrino Flux at EarthNeutrino Cross Sectionwith ArgonNeutrino Interaction Rate22/08/2019Supernova Neutrinos in DUNE7

Sanity checks: Rate @ DUNE“About 3000 events would be expected in a40 kt fiducial mass liquid argon detector fora supernova at a distance of 10 kpc.”(DUNE TDR)22/08/20191804.01877v1Supernova Neutrinos in DUNESource: Kate Scholberg8

What can we learn about the Neutrinos? Neutrino Mass Ordering Neutrino Mass bounds Oscillation parameter Shape of Earth22/08/2019Supernova Neutrinos in DUNE9

Neutrino Mass OrderingThe measurable neutrino flavor spectrum,starting with electron neutrinos produced bythe SN, is influenced by three differentneutrino oscillation effects:1.2.3.Evolution due to vacuum oscillationsMSW potential term (matter effect)Neutrino self interaction in dense matterHow does NH and IH effect the measurableneutrino flavor spectrum differently ?22/08/20192.3.Supernova Neutrinos in DUNE10

Neutrino Mass Ordering“Oscillations and supernova: a non trivial story.” Kate Scholberg @ SSI 201922/08/2019Supernova Neutrinos in DUNE1804.01877v1 11

Neutrino Mass Bound22/08/2019Supernova Neutrinos in DUNE12

Neutrino OscillationsOur Toy Model: Right-skewed energy distributionwith mean neutrino energy of 10 MeVProbability of oscillation using sin2 (2ϴ12) 0.846Note: True energy distribution doesn’t matter solong as it is narrow-band22/08/2019Supernova Neutrinos in DUNE13

Neutrino OscillationsSmearing Effect on OscillationProbability at Large DistancesProbability of oscillation becomes fixedfor large distances due to “smearing”Since Δm2 and the mixing angles arewell-known, deviations from expectedvalues would imply that neutrino profile ofcurrent supernova models are incorrect.22/08/2019Supernova Neutrinos in DUNE14

What can we learn about the Neutrinos? Neutrino Mass Ordering Neutrino Mass bounds Oscillation parameters Shape of Earth22/08/2019Supernova Neutrinos in DUNE15

What can we learn about the Neutrinos? Neutrino Mass Ordering Neutrino Mass bounds Oscillation parameters Shape of the Earth22/08/2019Supernova Neutrinos in DUNE16

Is the Earth Flat?We’ve made a crude assumption on the shape of our Earth“Modern flat Earth belief originated with the English writer Samuel Rowbotham (1816–1884). He later expanded intoa book ‘Earth Not a Globe’, proposing the Earth is a flat disc, .Rowbotham further held that the "cosmos" was 3,100miles (5,000 km) above the Earth. https://en.m.wikipedia.org/wiki/Modern flat Earth societies 22/08/2019If Earth is flat, DUNE would expect the same relative number of 𝞶e asall other experiments due to no differences in MSW contribution.Supernova Neutrinos in DUNE17

Is the Earth Flat?We’ve made a crude assumption on the shape of our Earth“Modern flat Earth belief originated with the English writer Samuel Rowbotham (1816–1884). He later expanded intoa book ‘Earth Not a Globe’, proposing the Earth is a flat disc, .Rowbotham further held that the "cosmos" was 3,100miles (5,000 km) above the Earth. https://en.m.wikipedia.org/wiki/Modern flat Earth societiesOur universe:R 1022 cm 22/08/2019Flat Earth:R 108 cmFlux increase @ DUNE by 1028If Earth is flat, DUNE would expect the same relative number of 𝞶e asall other experiments due to no differences in MSW contribution.Furthermore, DUNE would expect to measure the energy of a 10gigaton blast deposited by neutrinos from the SN.Supernova Neutrinos in DUNE18

Is the Earth Flat?We’ve made a crude assumption on the shape of our Earth“Modern flat Earth belief originated with the English writer Samuel Rowbotham (1816–1884). He later expanded intoa book ‘Earth Not a Globe’, proposing the Earth is a flat disc, .Rowbotham further held that the "cosmos" was 3,100miles (5,000 km) above the Earth. https://en.m.wikipedia.org/wiki/Modern flat Earth societiesOur universe:R 1022 cm Flat Earth:R 108 cmFlux increase @ DUNE by 1028If Earth is flat, DUNE would expect the same relative number of 𝞶e asall other experiments due to no differences in MSW contribution.Furthermore, DUNE would expect to measure the energy of a 10gigaton blast deposited by neutrinos from the SN.That is equivalent to 20 times the total energy released by all nucleartesting as of 1996. (i.e pretty bad)- Evidence for shape of the Earth22/08/2019Supernova Neutrinos in DUNE19

Summary DUNE will see 4000 neutrinos Our order of magnitude calculation agrees with the literature From the time spectrum, we can infer the mass hierarchy. Difference in arrival time gives us a bound on the mass Unless the Earth is Flat. Then we’ll die. Sorry!Samy Valder Jamy Pillow Keny Vetter Sandy Breur Lexy DvornikovSLAC Summer Institute 201922/08/2019Supernova Neutrinos in DUNE20

BACKUPS22/08/2019Supernova Neutrinos in DUNE21

Sanity Checks: LuminosityJanka HT. (2017)22/08/2019Supernova Neutrinos in DUNE22

Sterile Neutrinos1712.0383622/08/2019Supernova Neutrinos in DUNE23

Disproving the Flat Earth?We’ve made a crude assumption on the shape of the Earth“Modern flat Earth belief originated with the English writer Samuel Rowbotham(1816–1884). Based on conclusions derived from the Bedford Level experiment,Rowbotham published a pamphlet Zetetic Astronomy. He later expanded into a book EarthNot a Globe, proposing the Earth is a flat disc, centred at the North Pole and boundedalong its southern edge by a wall of ice, Antarctica.From: https://en.m.wikipedia.org/wiki/Modern flat Earth societies22/08/2019Supernova Neutrinos in DUNE24

22/08/2019 Supernova Neutrinos in DUNE The Question A star, ten times the mass of the sun, went supernova near the galactic core; a neutron star, two times the mass of the sun, was left behind. Thankfully, DUNE's Far Detector was up and running and ready to take data. How many events should DUNE expect to record?