COHERENT Experiment at the SNS Jason Newby for the COHERENT - - PowerPoint PPT Presentation

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COHERENT Experiment at the SNS

Jason Newby for the COHERENT collaboration

CPAD 2019 Workshop December 10, 2019 Madison, Wisconsin

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• J. Newby

Spallation Neutron Source at ORNL

• Superconducting H- LINAC: 1 GeV @ 1.4MW @ 60 Hz
• Storage Ring: 1200 pulses, 1us Period, 350ns FWHM
• Liquid Mercury Target: circulates 20 tons with He gas

injection to mitigate cavitation

• Operation ~5000 hours per year: 25 Terajoules/year
• SNS timing preserves DAR flavor structure
• Mono-energetic 𝜉𝜈 separated from 𝜉e, 𝜉𝜈

“Jet-flow” Target

2.81×1014 𝜉/cm2/flavor/SNSYear @ 20m

2 4 6 8 10 !s 2000 1000 3000

neutrinos cm-2 s-1 ns-1 @ 20m

Neutrino Energy Neutrino Timing Neutrinos via Pion Decay-at-Rest

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• J. Newby

Neutrino Energy (MeV) 5 10 15 20 25 30 35 40 45 50 55 )

2

cm

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Cross-section (10

3

• 10

2

• 10

1

• 10

1 10 NIN total

e

n Pb NIN 1n

e

n Pb NIN 2n

e

n Pb CsI CEvNS Cs CEvNS

133

I CEvNS

127

I CC

127 e

n IBD

• e

e

n

Coherent Elastic neutrino-Nucleus Scattering (CEvNS)

A neutrino scatters on a nucleus via exchange of a Z, and the nucleus recoils as a whole, produce tiny recoils.

CEvNS cross section can be calculated in the Standard Model precisely CEvNS cross-section is large!

a challenge to the gods

𝜏=$%

&'( &

)*

Z 1 − 4sin2θ𝑋 − 𝑂 2𝐺2(𝑅2)

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• J. Newby

The COHERENT Collaboration

21 Institutions (USA, Russia, Canada, Korea)

February 2017 @ SNS

arXiv:1803.09183v2

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• J. Newby

1.4*1023 (~ 0.22g) POT First working, hand held neutrino detector -14kg!!! 16 month of data

Now we have 2.5 times more statistics Plan to publish new result this Winter

CEvNS CEvNS after Form factor Correction First data point

First Detection of CEvNS with CsI detector

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• J. Newby

What were the required elements?

TA-B147 TA-B145 TA-B157 TA-B143 TA-B144 TA-B138 TA-B139

TA-B140 TA-B131 TA-B148

TA-B112 TA-B111 TA-B110 TA-B108 TA-B107 TA-B109 TA-B106

TA-B134 TA-B136 BAY TRUCK

TA-B135 TA-B141 TA-B128 TA-B126 TA-B124

TA-B127

TA-B125 MEN'S TOILETS TA-B117

ROOM LOCKER MEN'S

TA-B118 TA-B113 TA-B142 TA-B104 TA-B105 TA-B114

ROOM LOCKER WOMEN'S

TA-B116 WOMEN'S TOILETS TA-B123 TA-B120

TA-B150 F-3-B TA-B149 TA-B129

TA-B101 TA-B152 TA-B103 TA-B102 TA-B158 TA-B153 UTILITY TUNNEL TA-B137 TA-B159 STAIR NO. 7 TA-B154 TA-B147A TA-B160

BUILDING 8700 - BASEMENT LEVEL (B10) FLOOR PLAN WBS NO. 1.8.3.7

REV 1 ISSUED: 12/10

proton beam Neutron Shielding Neutrino Alley Neutrino Alley is well-shielded from beam related backgrounds

1.8m 20 m 8 m

3.7 m 3.1m 2.5 m

Low Noise Detectors and Background Materials from DM and 0𝜉𝛾𝛾 Detector R&D

Lara Blokland, UTK

Pulsed Timing Structure of Neutrinos constrains systematics on beam related backgrounds. 350 ns FWHM

2 4 6 8 10 !s 2000 1000 3000

neutrinos cm-2 s-1 ns-1 @ 20m

Neutron Flux 105 at surface

• Nucl. Instr. Meth. A773 (2014) 56

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• J. Newby

CPAD 2019 Madison, WI

CEvNS as Probe of New Physics

A new portal to (non)standard parBcle and nuclear physics

... small but multicolor !

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Slide from opening plenary talk by Eligio Lisi at NuInt 2018 https://indico.cern.ch/event/703880/

The COHERENT experiment has demonstrated the scientific potential

• f a CEvNS program using the intensity, timing structure, and

hermetic shielding at the Spallation Neutron Source. Renewed Interest in the CEvNS community

• Magnificent CEvNS Workshops, 2018 Chicago, 2019 Chapel Hill
• Second Target Station Science Workshops, July 2019, Dec 2019

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• J. Newby

CPAD 2019 Madison, WI

COHERENT “First Light” CEvNS Program

10 20 30 40 50 60 70 80 90

Neutron Number

1 10

2

10

3

10

)

2

cm

40

• Cross section (10

Na Ar Ge I Cs 68% CL 90% CL

16 kg PPC HPGe 500-600 CEvNS/yr Installation 2020 3.4 ton NaI 3𝞽 CEvNS/yr Installation 2020

• 22 kg Fiducial Mass
• Single Phase
• TPB CVD Teflon
• TPB Coated PMTs
• Kr83m Calibrations
• 4.5 p.e. per keVee
• ~20 keVnr threshold
• 6.12 GWhrs
• 130 predicted CEvNS

Neutrino Alley Germanium Sodium (NaI) Argon

• D. Akimov et al. Phys. Rev. D 100, 115020

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• J. Newby

CPAD 2019 Madison, WI

COHERENT Future Initiatives for a Precision Program

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• 750kg LAr
• Single phase
• Light Collection Options
• 3” PMT TPB
• SiPM, Xenon Doping, …
• ~3000 CEvNS/yr

Kate Scholberg

Reduction in allowed NSI D2O 1.3 ton

H2O

Darryl Dowling, ORNL

Concept: Yuri Efremekno

Precise Flux Normalization High Statistics CEvNS

Walt Fox, IU

• Deuteron Charged Current
• 2-3% Accuracy*
• Single phase, light only
• 2.5% Statistical in 2 yrs

𝜉< + 𝑒 → 𝑞 + 𝑞 + 𝑓B

*S.Nakamura et. al. Nucl.Phys. A721(2003) 549

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• J. Newby

CPAD 2019 Madison, WI

COHERENT Physics Overview

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Topic CsI Ar NsI Ge Nubes D2O

Non-standard neutrino interactions ✓ ✓ ✓ ✓ Weak mixing angle ✓ ✓ ✓ ✓ Accelerator-produced dark matter ✓ ✓ ✓ ✓ Sterile oscillations ✓ ✓ ✓ ✓ Neutrino magnetic moment ✓ ✓ ✓ Nuclear form factors ✓ ✓ ✓ ✓ Inelastic CC/NC cross-section for supernova ✓ ✓ ✓ Inelastic CC/NC cross-section for weak physics ✓ ✓ ✓ ✓ The sum is greater than the individual measurements All measurements benefit from neutrino flux normalization

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• J. Newby

An ORNL Perspective on the Future of Neutrinos at the SNS

PPU project: Double the power of the existing accelerator structure

• First Target Station

(FTS) is optimized for thermal neutrons

• Increases the

brightness of beams

• f pulsed neutrons
• Provides new

science capabilities for atomic resolution and fast dynamics

• Provides a platform

for STS

STS project: Build the second target station with initial suite of beam lines

• Optimized for cold

neutrons

• World-leading

peak brightness

• Provides new

science capabilities for measurements across broader ranges of temporal and length scales, real-time, and smaller samples

Slide from Ken Herwig, Workshop on Fundamental Physics at the Second Target Station (FPSTS18)

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• J. Newby

2028 after STS

PPU and STS upgrades will ensure SNS remains the world’s brightest accelerator-based neutron source

2024 after PPU Today

1.4 MW 1 GeV 25 mA 60 Hz

FTS 2 MW 45 pulses/sec

2.8 MW 1.3 GeV 38 mA 60 Hz 2.0 MW 1.3 GeV 27 mA 60 Hz

STS 0.7 MW 15 Hz FTS 1.4 MW 60 Hz FTS 2 MW 60 Hz

The choice of 15 Hz and 0.7 MW resulted from a detailed analysis of STS design (reviewed by a panel of experts in 2017) and optimizes performance of STS without impacting performance of FTS

• 900 users
• Materials at atomic

resolution and fast dynamics

• 1000+ users
• Enhanced capabilities
• 2000+ users
• Hierarchical materials, time-

resolution and small samples

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• J. Newby

Power Upgrade and STS Facilities create new opportunities …

Ton-Scale Argon Calorimetry

• CEvNS studies
• Dark Matter searches
• Limits on quark-lepton couplings for DUNE mass
• rdering degeneracy
• Supernovae neutrino cross sections for DUNE

COHERENT “First Light” Program

• Heavy Water Flux Normalization of FTS
• CEvNS with HPGe, NaI
• Low Threshold Detector R&D: Quantum

Enhanced Light Collection, Xenon Doping, SiPM Ton-Scale Directionality with Low Threshold Detector R&D Heavy Water Ring Imaging Design

• Improved Flux Normalization
• Neutrino oxygen Interactions for Super-K,

Hyper-K Argon Detector R&D for STS

• Simultaneous Low threshold Light and

Time Projection Readout of Charge 750 kg Ar Ar TPC

2.3 m 2 . 3 m

1.3 ton D2O

H2O Darryl Dowling, ORNL Acrylic

2021 2022 2023 2024 2025

10 ton Ar TPC HEP Program at STS Argon TPC

• Dark Matter searches
• Precision CEvNS studies
• Precision Ar cross sections for DUNE
• Weak Mixing Angle
• Neutrino EM properties

Heavy Water Ring Imaging

• Flux Normalization of STS
• Precision oxygen cross sections for

Super-K, Hyper-K

2.3 m 2 . 3 m

D2O

H2O Darryl Dowling, ORNL Acrylic

FTS STS Calorimetry Directionality Discovery Scale

Walt Fox IU Walt Fox IU

Exact time evolution of program to be determined by the collaboration

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• J. Newby

Dark Matter Possibilities at the SNS

The ability to measure delayed CEvNS key to control systematics of prompt CEvNS “background”. Scalar DM excluded for all α′ < 1 for 5 < 𝑛χ < 100

deNiverville et al., Phys Rev D92 095005 (2015)

Portal particles would be produced mainly through π0/η0 → 𝑊γ and the hidden sector particles may interact within our detectors in Neutrino Alley

See D. Pershey’s talk from M7s arXiv:1911.06422 First Target Station Second Target Station

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• J. Newby

CPAD 2019 Madison, WI

Summary

• The Spallation Neutron Source is currently the cleanest, most intense stopped pion

neutrino source with stable operation planned for decades.

• Multiple targets (Ar, Ge, Na, Cs, I, D) deployed (or planned) by the COHERENT

collaboration in neutrino alley has created a rich neutrino physics program.

• SNS Power Upgrades and Second Target Station Operations provide new opportunities

for precision neutrino measurements and DM searches.

• Maintaining CEvNS sensitivity at 10-ton scale while operating with “surface” backgrounds

critical to competitive DM searches.

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We are grateful for logistical support and advice from SNS (a DOE Office of Science facility). Much of the background measurement work was done using ORNL SEED funds, as well as Sandia Laboratories Directed Research and Development (LDRD) and NA-22 support. LAr detector deployment is supported by ORNL LDRD funds and the CENNS-10 detector is on loan from Fermilab. We thank Pacific Northwest National Laboratory colleagues and Triangle Universities Nuclear Laboratory for making resources for various detector components available. COHERENT collaborators are supported by the U.S. Department of Energy Office of Science, the National Science Foundation, NASA, and the Sloan Foundation.

Acknowledgements