DUNE Low Energy and Beyond the Standard Model Physics Studies

DUNE Low Energy and Beyond the Standard Model Physics Studies

Clara Cuesta and Justo Martín-Albo for the DUNE Collaboration XIII CPAN Days, Huelva

March, 22

2022

DUNE

Credit: symmetry magazine

Deep Underground Neutrino Experiment (DUNE)

o New neutrino (n_µor n!_µ) beam facility at Fermilab (LBNF), US.

o A highly capable Near Detector at Fermilab to measure the unoscillated neutrino spectrum and flux constraints.

o 4 x 17 kton liquid argon time-projection chambers (LArTPC) modules deep underground at SURF (Lead, SD, 1300 km baseline).

DUNE aims at answering fundamental questions related to:

• The matter-antimatter asymmetry – Long baseline neutrino oscillations

• The Grand Unification of forces – Physics beyond the Standard Model

• The supernova explosion mechanism – Low energy physics

JINST 15 (2020) T08008 JINST 15 (2020) T08010

EPJC 80 (2020) 978 EPJC 81 (2021) 322 EPJC 81 (2021) 423

Instruments 5 (2021) 31

Long Baseline Neutrino Facility (LBNF)

4

Near Detector (ND)

• Roles:

• Characterization of the beam close to the source.

• Spectral beam monitor.

• Tuning the neutrino interaction model reducing systematics.

• Off-axis beam data to deconvolve beam and cross section models.

• Located 574 m from the ! source.

• Components:

• Highly modular LArTPC (ND-LAR).

• Magnetized gaseous argon TPC (ND-GAr).

• Magnetized beam monitor (SAND).

Fermilab, IL, US

LBNF beam

• 120 GeV main injector proton beam.

• Initial 1.2 MW beam power, upgradable to 2.4 MW.

Far Detector (FD)

Sanford Underground Research Facility in Lead, SD, US (1.48 km

underground)

Construction and operation of 1 kton-scale prototypes at CERN from 2018, critical to demonstrate viability of technology.

ProtoDUNEs LArTPC technology

• Excellent 3D imaging capabilities – few mm scale over large volume detector.

• Excellent energy measurement.

capability – totally active calorimeter.

• Particle ID by dE/dx, range, event topology.

• Combination of information from ionization charge and LAr

scintillation light.

Four 17-kt LAr TPC modules

“2+1+1” model:

• 2 modules horizontal drift

• 1 vertical drift module

• 1 “opportunity” module

Talks by M.A. García Perisand L. Pérez Molina

The DUNE Collaboration

~1400 collaborators from ~200 institutions in >30 countries + CERN

6

DUNE

Collaboration Meeting, CERN

January 2020 CIEMAT, IFAE, IGFAE, IFIC, UGR, UAM

DUNE Collaboration Organization

Physics working groups:

Detector cosntruction consortia:

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Physics beyond the Standard Model (BSM)

Credit: symmetry magazine

The capable DUNE detectors and the powerful LBNF beam enable a rich experimental program of searches for physics beyond the Standard Model (BSM), including:

• Non-standard short-baseline and long-baseline oscillation phenomena.

• Searches for new phenomena and particles at the ND related to the beam and its interactions with the detector.

• Searches for new phenomena and particles at the FD benefitting from its large mass and underground location.

This is a very active and exciting area of collaboration between experimentalists and theorists/phenomenologists. New ideas welcome!

BSM Physics Searches at DUNE

ND FD

!

# !

→ !

Non-standard

Neutrino Oscillations

ND FD

!

# !

→ !

!(#

→ #

) ≠ !(#

→ #

) ⇒ CPviolation

!(#

→ #

) ≠ !(#

→ #

) ⇒ CPTviolation

Projected sensitivity of DUNE to CPT violation for an exposure of 300 kton MW yr and three different values of the θ²³ mixing angle:

maximal mixing, lower octant, and upper octant.

Δ(Δ5₆₇⁸ ) ≡ Δ5₆₇⁸ − Δ5₆₇⁸ < 3.7×10^BCeV⁸ Δ(sin⁸G₈₆) ≡ sin⁸G₈₆ − sin⁸G₈₆ < 0.32

CPT violation

Current experimental bounds:

Barenboim, Ternes Tórtola, Phys. Lett. B 780 (2018) 631

BSM searches at the Near Detector

ND FD

!

# !

→ !

Neutrino trident

• Neutrino trident production is a weak process in which a !, scattering off the Coulomb field of a heavy nucleus,

generates a pair of charged leptons.

• Very rare process: cross section ~7 orders of magnitude smaller than CC one.

• A few tens of events observed in previous experiments.

• A deviation from the event rate predicted by the SM could be an indication of new forces forces mediated by a light vector boson that could explain the muon g–2 anomaly.

Altmannshofer, Gori, M-A, Sousa, Wallbank, Phys. Rev. D 100 (2019) 115029

Heavy neutral leptons (HNL)

• Heavy right-handed singlets predicted in many

extensions of the SM may be produced by the LBNF beam.

• The HNLs could reach the DUNE ND, where they would be detected via their decay products.

• Shown here the sensitivity (90% CL) for a total of 1.32×10²² POT.

14

Ballett, Boschi, Pascoli, JHEP 03 (2020) 111

Low-mass dark matter

• Dark matter particles produced in the decay of light mesons reach the DUNE ND, where they are

detected via electron scattering.

• The main background (neutrino-electron scattering) can be suppressed taking data off-axis (PRISM).

Shown here the sensitivity (90% CL) of DUNE for a 7- year (50% neutrino beam, 50% antineutrino) run.

Production Detection

De Romeri, Kelly, Machado, Phys. Rev. D 100 (2019) 095010

BSM searches at the Far Detector

ND FD

!

# !

→ !

Proton decay

• Grand unified theories extending the SM predict low-energy observables such as nucleon decay, including the decay of the proton into a kaon.

• The DUNE FD has the unique ability to track and identify the kaons produced in those decays.

• A lower limit on the proton lifetime of 1.3×10³⁴ years is expected if no signal is observed in 10

years.

!

K

Example: Photon detection system in dual-phase FD.

NDK t₀ reconstruction efficiency and purity as a function of the nucleon decay vertex position in the drift direction.

J. Soto Otón (CIEMAT) PhD Thesis

Low Energy Physics in DUNE

Credit: symmetry magazine18

Low Energy Physics in DUNE

• The DUNE FD is sensitive to !’s produced by the Sun and in core-collapse supernovae with E ∼ 5-100 MeV.

• Core-collapse supernovae are a huge source of !’s of all flavors in~10 sec.

- 1-3 SN/century in our Galaxy (10 kpc).

- DUNE will participate in SuperNova Early Warning System (SNEWS).

- Measurement of the ! E spectra, flavor composition and time distributions from SN will provide information about:

o Supernova physics: Core collapse mechanism, SN evolution in time, black hole formation.

o Neutrino physics: ! flavor transformation, collective effects, ! absolute mass, other ! properties (sterile !’s, magnetic moments, extra dimensions…).

• Solar and diffuse background supernova !’s are also potentially detectable. Initial studies suggest potential for DUNE to improve the measurement of ∆m²21 as well as observations of the hep and ⁸B solar neutrino flux.

Low energy neutrino signal in LAr

1. Charged-current (CC) interaction on Ar

2. Elastic scattering on electrons (ES) 3. Neutral current (NC) interactions on Ar

!_" + $^% → !_" + $^%

!_' + ⁽⁾*+ → ⁽⁾,^∗ + $^%

!_" + ⁽⁾*+ → !_" + ⁽⁾*+^∗

Dominant interaction '̅! + ⁽⁾*+ → ⁽⁾/0^∗ + $¹

Possibility to separate the various channels by a classification of the associated photons from the K, Cl or Ar deexcitation (specific spectral lines for CC and NC) or by the absence of photons (ES)

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EPJC 81 (2021) 423

Neutrino interactions in LAr

!-e^- ES event (10.25 MeV e^-) !_eCC event (20.25 MeV !)

e^-track

blips from Compton-scattered gammas

EPJC 81 (2021) 423

• CC interactions of !’s from ~5 MeV to tens of MeV create short e- tracks in LAr, potentially accompanied by gamma-ray and other secondary particle signatures.

• DUNE is able to provide pointing information

Low energy neutrino events in DUNE

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Backgrounds will have a minor impact on reconstruction, but can affect triggering

Reconstruction efficiency as a function of neutrino energy for different minimum reconstructed energy

Fractional energy resolution as a function of neutrino energy for TPC tracks and photon detector calorimetry

Energy reconstruction efficiency and energy resolution for low energy events (5-50 MeV)

EPJC 81 (2021) 423

Expected SNB signal in DUNE

!_" flavor dominates.

LAr only future prospect for a large, cleanly tagged SN #_$ sample

40 kton LAr & 10 kpc SN

EPJC 81 (2021) 423

40 kton Garching

Expected SNB signal in DUNE

24

• Number of SN ! interactions scales with mass and inverse square of distance.

• At 10 kpc, DUNE will observe

hundred-thousand events and just a few events for a collapse in the

Andromeda galaxy.

EPJC 81 (2021) 423

• Expected event rates during early stages – the

neutronization burst and early accretion phases

• The effect of different mass orderings is observed.

• It is essential to develop a redundant and highly efficient triggering scheme in DUNE.

• The trigger on a supernova neutrino burst can be done using either TPC or photon detection system information.

• Trigger scheme exploits the time coincidence of multiple signals over a timescale matching the supernova luminosity evolution

• Preliminary trigger designs with maximum fake trigger rate (1/month)

DUNE SN burst event triggering

Example: Photon detection system in dual-phase far detector.

• Real time algorithm provides trigger primitives by searching for PMT hits and optical clusters, based on

time/spatial information.

• >90% efficiency on a SNB at a

distance up to ≥25 kpc, so it would cover the entire Milky Way.

A. Gallego-Ros (CIEMAT) PhD Thesis

Presenter Name | Presentation Title 26

Conclusions

Credit: CERN

Credit: symmetry magazine

Conclusions

The capable DUNE detectors and the powerful LBNF beam enable a rich experimental program of searches for physics beyond the Standard Model (BSM), including CPT violation, heavy neutral leptons, dark matter, and nucleon decay.

We will learn a lot about neutrinos in the next decades and DUNE will be a crucial experiment as well as an enormous challenge.

DUNE will be sensitive to low energy !‘s with about 5 MeV up to several tens of MeV, the regime of relevance for core-collapse supernova burst ν’s. DUNE will have a unique sensitivity to $_% with good sensitivity to the entire Milky Way, and possibly beyond, depending on the $ luminosity of the core-collapse supernova.

Thanks

Credit: Randall Munroe