Magnificent CEvNS 2024

Jun 12, 2024, 8:00 AM → Jun 14, 2024, 6:50 PM Europe/Madrid

ADEIT Salón de actos

 

The sixth iteration of the Magnificent CEvNS workshop, focusing on the process of coherent elastic neutrino-nucleus scattering (CEvNS) will be held in Valencia, Spain, from June 12 to June 14, 2024.

The workshop will take place at the University-Enterprise Foundation of the University of Valencia (ADEIT), located in the historic center of the city of Valencia.

Proposed in 1974, but unobserved until 2017, the physics accessible with CEvNS is extensive. Magnificent CEvNS aims to bring together a broad community of researchers working either directly or peripherally on CEvNS to foster enriching discussions, direct the field as it continues to grow, and form and strengthen connections between experimentalists and theorists/phenomenologists. 

 

International Advisory Committee 

Phillip Barbeau
Matthew Green
Janina Hakenmüller
Diane Markoff
Grayson Rich
Kate Scholberg
Raimund Strauss
Louis Strigari
Victoria Wagner

Local Organizing Committee 

Diego Aristizabal (UTFSM, Chile)
Valentina De Romeri (IFIC, CSIC/UV) - Chair
Martín González-Alonso (IFIC, CSIC/UV)
Sergio Palomares-Ruiz (IFIC, CSIC/UV)
Gonzalo Sánchez (IFIC, CSIC/UV)
Mariam Tórtola (IFIC, CSIC/UV)

 

 

 

 

 

 

 

This conference has received funding from the GVA Research Projects CIDEXG/2022/20, CIDEGENT/2018/014 and CNS2023-144124 (MCIN/AEI/10.13039/501100011033 and “Next Generation EU”/PRTR).

 

 

 

Wednesday, June 12

8:30 AM Registration

9:00 AM Welcome

1 Workshop overview

Speaker: Dr Valentina De Romeri (IFIC CSIC/UV (Valencia, Spain))

welcome.pdf

Talks

Convener: Prof. Jose Valle

2 A bird’s eye view: global analysis of nuclear and electroweak properties and the role of CEνNS

Coherent elastic neutrino-nucleus scattering (CEνNS) has been demonstrated to be an essential tool to investigate key electroweak physics parameters and nuclear properties since its first observation in 2017 by COHERENT.
In this presentation, we review the results obtained using the latest COHERENT CsI and Ar and Dresden-II Ge datasets which allow us to achieve a measurement of the neutron distribution radius Rn of 133Cs, 127I, 40Ar and of the weak mixing angle (WMA).
For the first time, we compare and combine the COHERENT data with the atomic parity violation experimental result on Cs and proton-Cs elastic scattering, to obtain the most precise data-driven determination of the low-energy weak mixing angle, independent of the value of the neutron distribution radius. Moreover, we discuss the current agreement between all available determinations of Rn and of the WMA using electroweak and non-electroweak probes, finally performing a global fit of all available determinations.
To conclude, prospects for the future will be reviewed.

Speaker: Matteo Cadeddu

MG7_Valencia_Cadeddu_Matteo.pdf

3 The devil is in the details: the role of the radiative corrections

The quest for increasingly higher precision in the description of EW processes demands the introduction of so-called radiative corrections, due to higher-order vertex contributions to the couplings of interacting particles. In this talk, we will review the radiative corrections of interest for coherent elastic neutrino-nucleus scattering (CEνNS), focusing in particular on the neutrino charge radius, which represents the only non-null neutrino electromagnetic property in the standard model theory. Its value can be predicted with high accuracy and its effect is usually accounted for through the definition of a radiative correction affecting the neutrino couplings to nucleons at low energy, which results effectively in a shift of the weak mixing angle. Exploiting available CEνNS data, there have been many attempts to measure experimentally the neutrino charge radius, enabling one only to put constraints on such a quantity.

In this talk, we will discuss how to properly account for the neutrino charge radius in the CEνNS cross-section including the effects of the non-null momentum transfer in the neutrino electromagnetic form factor, which have been usually neglected when deriving the aforementioned limits. We show the impact of this effect by re-analysing the COHERENT cesium iodide and argon samples and the NCC-1701 germanium data from the Dresden-II nuclear power plant. The size of this correction is such that it will not be possible to neglect it in the analysis of data from future high-precision experiments. Furthermore, we will show how this momentum dependence can be exploited to significantly reduce the allowed values for the neutrino charge radius determination.

Speaker: Francesca Dordei (INFN, Cagliari (IT))

magnificent_cevns_2024.pdf

4 Nuclear structure theory for CEνNS

Speaker: Javier Menéndez Sánchez

menendez_CEvNS.pdf

5 CEvNS phenomenology with reactors

There are several effort in reactor antineutrino experiments to reconfirm the CEvNS signal already detected in pion-decay at rest (pi-DAr) neutrino sources. In this talk I will discuss the implication of such a measurement, paying special attention in the complementary of both reactor and pi-DAR CEvNS measuments.

Speaker: Omar Miranda (Cinvestav Centro de Investigacion y de Estudios Avanzados del IPN)

magnificentVLC_Miranda.pdf

6 CEvNS: Inelastic Exploration

Speaker: Prof. Bhaskar Dutta

CenuNS_dark_dutta.pdf

11:00 AM Coffee

Talks

Convener: Irina Nasteva (Federal University of Rio de Janeiro (BR))

7 The current status of the COHERENT experiment

The COHERENT experiment, located at the Spallation Neutron Source at Oak Ridge National Laboratory, has now made first measurements of CEvNS on three nuclear targets: CsI, Ar, and Ge. A NaI detector has begun taking data. New detectors and detector upgrades are addressing backgrounds and systematics across all COHERENT measurements: CEvNS, inelastic neutrino-nucleus scattering, and dark-matter searches. In this talk, I will survey COHERENT's current status and future prospects.

Speaker: Diana Parno (Carnegie Mellon University)

Parno-COHERENT-Overview-M7s2024.pdf

8 First Measurement of CEvNS on Germanium by COHERENT

P-type Point Contact (PPC) High-Purity Germanium detectors have been a popular choice for CEvNS searches due to their sub-keV energy thresholds and kg-scale masses. Recently, the COHERENT Collaboration constructed Ge-mini: an 18-kg array of Inverted-Coaxial Point Contact (ICPC) PPC detectors. In this talk we will discuss the design, construction and performance and operation of the Ge-mini array. We will discuss analysis of data collected during the summer 2023 SNS run, in which we observe a beam-on excess of 18.4+6.7−5.9 counts with a total exposure of 7.47 GWh-kg and reject the no-CEvNS hypothesis by 3.9 sigma. This result agrees with the predicted standard model of particle physics signal rate within 1sigma.

Speaker: Ryan Bouabid

m7s_rbouabid_upload.pdf

9 Latest results from CONUS

The CONUS experiment was operated inside an optimized shield at the Brokdorf nuclear power plant which provided a reactor antineutrino flux of up to 2.3*10^13/(cm^2 s). The talk will cover the latest results including the final phase of data collection at this site in comparison to the rate predicted by the Standard Model. The talk will also cover limits on new physics which can be derived from these data.

Speaker: Janina Hakenmüller (Duke University)

magnificentcevns2024_conus_jhakenmueller.pdf

10 Status of the NUCLEUS experiment

The first detection of coherent elastic neutrino nucleus scattering (CEvNS) at a nuclear reactor remains to be achieved, especially because the corresponding nuclear recoils lie in the O(100 eV) energy regime which is difficult to measure with conventional detection technologies, and also because of the unfavorable background conditions nuclear power plant environments generally offer. To overcome these obstacles, the NUCLEUS experiment aims to develop an innovative detection system using a 10 g cryogenic detector setup made of CaWO4 and Al2O3 crystals capable of reaching O(10 eV) energy thresholds. These target detectors will be surrounded by a twofold system of instrumented cryogenic vetoes, an external passive shielding and a muon veto to improve the identification and discrimination of backgrounds.

At present, the experiment is under commissioning in the shallow underground laboratory at the Technical University of Munich (TUM), preparing for the relocation to the Chooz-B nuclear power plant in the French Ardennes later in 2024.

In this talk, I will provide an overview of the experiment’s current status, focusing on the latest developments and milestones achieved.

Speaker: Elisabetta Bossio (CEA Paris Scaly)

NUCLEUS_status_Mag72024_BossioE.pdf

11 MINER Reactor Neutrino Experiment for CENNS and ALP Searches

The Mitchell Institute Neutrino Experiment at Reactor (MINER) experiment at the Nuclear Science Center at Texas A&M University is searching for coherent elastic neutrino-nucleus scattering within close proximity (2-5 meters) of a 1 MW TRIGA nuclear reactor core using phonon mediated low threshold solid state detectors . Given the Standard Model cross section of the scattering process and the proposed experimental proximity to the reactor, as many as 5 to 20 events/kg/day are expected. In this talk we will present an overview of the experiment, the science projections, along with a variety of very low-threshold, low-background detector technologies that are currently deployed in the MINER setup. The MINER experiment also has a new experimental direction for ALP probes via their production by the intense gamma ray flux available from the reactor through Primakoff-like or Compton-like channels. The existing low-threshold detectors in close proximity to the core will have visibility to ALP decays and inverse Primakoff and Compton scattering, providing world-leading sensitivity to the ALP-photon and ALP-electron couplings.

Speaker: Rupak Mahapatra (Texas A&M University)

MINER_Magnificent_CENNS_2024.pptx

1:10 PM Lunch

Talks

Convener: Louis Strigari (Texas A&M)

12 CEvNS in dark matter experiments to constrain neutrino NSI

Direct dark matter detection experiments will soon be sensitive to solar neutrinos through their coherent scattering with the target nuclei, as well as their scattering with electrons. This offers an excellent opportunity to test new physics in this sector. By combining data from the two signatures, direct detection will provide a complementary test of the non-standard neutrino interactions (NSI) landscape to that of spallation sources and neutrino oscillation experiments. To illustrate this, in this talk I will show the constraints on the NSI parameter space from current xenon-based experiments such as LZ, and the potential reach from next generation detectors. This talk is based on arXiv:2302.12846.

Speaker: David Cerdeño (Institute for Theoretical Physics (IFT-UAM/CSIC))

2024-06-CEvNS3.pdf

13 COHERENT bounds on light mediator models

I discuss the constraints on the parameters of several light boson mediator models obtained from the analysis of the current data of the COHERENT CEνNS experiment. Since the COHERENT CEνNS data are well-fitted with the cross section predicted by the Standard Model, the analysis of the data yields constraints for the mass and coupling of the new boson mediator in each model under consideration. These constraints are compared with the limits obtained in other experiments and with the values that could explain the muon g-2 anomaly.

Speaker: Christoph Andreas Ternes

M7_christoph.pdf

14 COHERENT production of a sterile fermion

We consider the possible production of a new MeV-scale fermion at the COHERENT, LZ and XENONnT experiments. The new fermion, belonging to a dark sector, can be produced through the up-scattering process of neutrinos off the nuclei and the electrons of the detector material, via the exchange of a light mediator. We explore the possibility of generalized interactions, that is a scalar, pseudoscalar, vector, axial or tensor mediator. We perform a detailed statistical analysis of the COHERENT, LZ and XENONnT datasets and obtain up-to-date constraints on the couplings and masses of the dark fermion and mediators. Finally, we briefly comment on the stability of the dark fermion.

Speaker: Pablo Muñoz Candela (IFIC (CSIC-Univ. Valencia))

COHERENT_Pablo_M_Candela.pdf

15 Probing neutrino magnetic moments with CEvNS

In this presentation, I will discuss the constraints on the electromagnetic properties, particularly focusing on magnetic moments and millicharge, derived from the most recent measurements of coherent elastic neutrino-nucleus scattering. This will be achieved through a combined analysis of the COHERENT, Dresden-II, and CONUS data.

Based on
https://arxiv.org/abs/2205.09484
https://arxiv.org/abs/2203.16525
and new analysis

Speaker: Prof. Yufeng Li (Institute of High Energy Physics, Beijing)

LI_Yufeng_Magnetic Moments.pdf

LI_Yufeng_Magnetic Moments.pptx

16 Global constraints on non-standard neutrino interactions with quarks and electrons

We derive new constraints on effective four-fermion neutrino non-standard interactions with both quarks and electrons. This is done through the global analysis of neutrino oscillation data and measurements of coherent elastic neutrino-nucleus scattering (CEvNS) obtained with different nuclei. In doing so, we include not only the effects of new physics on neutrino propagation but also on the detection cross section in neutrino experiments which are sensitive to the new physics. We consider both vector and axial-vector neutral-current neutrino interactions and, for each case, we include simultaneously all allowed effective operators in flavour space. To this end, we use the most general parametrization for their Wilson coefficients under the assumption that their neutrino flavour structure is independent of the charged fermion participating in the interaction. The status of the LMA-D solution is assessed for the first time in the case of new interactions taking place simultaneously with up quarks, down quarks, and electrons. One of the main results of our work are the presently allowed regions for the effective combinations of non-standard neutrino couplings, relevant for long-baseline and atmospheric neutrino oscillation experiments.

Speaker: Joao Paulo Pinheiro (Universitat de Barcelona)

document.pdf

17 SMEFT induced neutrino non-standard interactions in the context of CEvNS and neutrino oscillations

The explanation to many puzzles need new degrees of freedom beyond the Standard Model (SM), examples are dark matter and neutrino masses. In this regard, one direction is to introduce specific models and study their phenomenologies, and the other one is to get some possible hint on the new physics model independently by utilizing the SM Effective Field Theory (SMEFT). In this talk, we focus on the latter to minimize any bias in model selection in our study. Realizing that the SMEFT can induce non-standard neutrino interactions at the low scale, we investigate the impact of SMEFT on low-energy neutrino physics like the recent observed CEvNS process and neutrino oscillations.

Speaker: Yong Du (TD Lee Institute)

CEvNS2024-YongDu.pdf

4:30 PM Coffee

Talks

Convener: Gonzalo Sanchez Garcia (Instituto de Física Corpuscular CSIC/UV (Valencia, Spain))

18 The RED-100 results & prospects

RED-100 is a two-phase detector designed and built to study coherent elastic neutrino nucleus scattering (CEvNS) of reactor antineutrinos. In 2022, it was deployed at Kalinin Nuclear Power Plant (Udomlya, Russia) with xenon as a target material. Data collection included both reactor ON and OFF periods. The results of this run such as the sensitivity and the limit on CEvNS on Xe are presented. Various methods of data processing and analysis, including neural networks for background mitigations, are discussed. At the present moment, preparations for the new experiment with argon are underway. Future plans and results of engineering tests and simulations are shown and discussed.

Speaker: Olga Razuvaeva (National Research Nuclear University "MEPhI")

20240612 M7s RED 100 results&prospects.pdf

19 Looking for CEvNS with the νGeN experiment

The νGeN experiment continues to take data with a HPGe PPC detector at the Kalinin Nuclear Power Plant (KNPP) benefiting from the antineutrino flux of $4.4\cdot10^{13}$ cm$^{-2}$ s$^{-1}$ at 11 m from the center of a 3.1 GW reactor core. This talk presents the updated result of the experiment and describes activities aimed to increase the sensitivity of the νGeN detector.

Speaker: Alexey Konovalov (LPI/MEPhI)

nuGeN_M7.pdf

Lightning talks

Convener: Gonzalo Sanchez Garcia (Instituto de Física Corpuscular CSIC/UV (Valencia, Spain))

20 Neutrino Science Opportunities at the High Flux Isotope Reactor

In April 2024, Oak Ridge National Laboratory hosted the Workshop on Neutrino Science and Applications at HFIR to explore opportunities provided by the unique High Flux Isotope Reactor (HFIR) facility to host a world-leading neutrino science experimental program over the next two decades that matches the spirit and utility of its sister laboratory at the Spallation Neutron Source (SNS) at ORNL, Neutrino Alley.  HFIR recently hosted the PROSPECT experiment which, while carrying out its physics program, quantified HFIR background conditions, demonstrated technology for on-surface rare event searches, and established the ability of HFIR facilities to support fundamental neutrino science.  Furthermore, many physics topics including CEvNS that are accessible at a short distance from an intense and well quantified source of MeV-scale electron antineutrinos like HFIR were described in the Snowmass 2021 report and supporting white papers. This workshop focused on identifying fundamental science topics that could be pursued at HFIR in the near-term with the current facility configuration and identifying facility upgrades, such as shielding and overburden, that could unlock additional scientific opportunities in the medium-to-long term. This poster will report on the outcomes of that workshop.

Speaker: Jason Newby

2024M7s_Newby_Flash.pdf

NeutrinosAtHFIR.pdf

21 Exploring the Advantages of an Undoped, Cryogenic CsI Detector for CEvNS Experiments at the SNS with COHERENT

Inorganic crystal scintillators, especially doped alkali-halide scintillators such as NaI[Tl], CsI[Tl] and CsI[Na], play an important role in neutrino experiments. The pioneering achievement of the COHERENT experiment, utilizing CsI[Na] for the initial detection of Coherent Elastic Neutrino-Nucleus Scattering (CEvNS), demonstrated a nuclear recoil detection threshold of approximately 8 keV(nr). However, to advance the capabilities of next-generation neutrino detectors, it is crucial to significantly reduce this detection threshold. Recent studies have illustrated that undoped alkali-halide scintillators, when operated at cryogenic temperatures near 77 K, exhibit a substantial increase in light yield – nearly doubling that of their room-temperature counterparts, alongside diminished afterglow effects. This poster outlines the advantages of adopting undoped, cryogenic CsI as a novel detector material for CEvNS experiments, focusing on its implementation in the COHERENT experiment at the SNS, offering a promising pathway to unlocking new physics through enhanced neutrino detection sensitivity.

Speaker: Charles Prior (Duke University)

M7 Flash Talk.pdf

Poster Submitted.pdf

22 Bounds on new physics with data of the Dresden-II reactor experiment and COHERENT

Coherent elastic neutrino-nucleus scattering was first experimentally established five years ago by the COHERENT experiment using neutrinos from the spallation neutron source at Oak Ridge National Laboratory. The first strong evidence of observation of coherent elastic neutrino-nucleus scattering with reactor antineutrinos has now been reported by the Dresden-II reactor experiment, using a Germanium detector. We present constraints on a variety of beyond the Standard Model scenarios using the new Dresden-II data. In particular, we explore the constraints imposed on neutrino non-standard interactions, neutrino magnetic moments, and several models with light scalar or light vector mediators. We also quantify the impact of their combination with COHERENT (CsI and Ar) data. In doing so, we highlight the synergies between spallation neutron source and nuclear reactor experiments regarding beyond the Standard Model searches, as well as the advantages of combining data obtained with different nuclear targets. We also study the possible signal from beyond the Standard Model scenarios due to elastic scattering off electrons and find more stringent constraints in certain parts of the parameter space than those obtained considering coherent elastic neutrino-nucleus scattering.

Speaker: Leire Larizgoitia (DIPC)

MagnificentJun2024_JHEP05(2022)037.pdf

23 COLINA: Conical liquid noble gas apparatus for CEνNS detection

We recently proposed the development of an innovative single-phase noble liquid time projection chamber (TPC) to detect CEνNS. Two distinct ideas are combined to maximize the potential of the technique. 1) The signal will be amplified through electroluminiscence (EL). 2) The TPC will be shaped as a conical frustum.

Single-phase EL is unaffected by charge trapping which is the major deterrent of dual-phase noble liquid TPCs for CEνNS searches at shallow depths. However, it requires extremely high electric fields. Such fields can be reached by using very thin wires – μm-scale diameter. This is an impediment to produce large amplification regions. Common TPC shapes are thus limited in size and target mass. The conical shape allows to maximize the mass by drifting all charges towards a small amplification region at the smaller circle of the cone. Such scheme appears as cost-efficient as it allows for good coverage with few sensors.

The final goal is to deploy COLINA, a conical TPC capable of holding ∼50 kg of LXe, at the largest spallation neutrino source, the European Spallation Source. Simulations point to a conservative energy threshold as low as ∼0.5 keVnr. The detector will allow for operation with different noble gases. The increase in density of liquid-phase, compared to gaseous-phase, results in large CEνNS interaction rate with rather small detectors. In fact, COLINA will produce the larger CEνNS statistics in all the considered isotopes, Xe, Kr and Ar, and will do so in unexplored energy regions for the process, where the physics relevance is maximal.

In this poster I'll detail the COLINA detection concept as well as highlight its expected performance and physics case.

Speaker: Dr Ander Simón Estévez (Donostia International Physics Center)

COLINA_magnificent2024.pdf

24 Module 2 of the COHERENT D2O Detector

The COHERENT collaboration’s measurements of CEvNS utilize neutrinos produced by the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The uncertainty of the neutrino flux generated from the SNS is on the order of 10% making it one of COHERENT's most dominant systematic uncertainties across all detectors. To address this issue, a heavy water (D2O) detector has been designed to measure the neutrino flux through the well-understood electron neutrino-deuterium interaction which has the potential to lower the uncertainty to 2-3%. The D2O detector is composed of two identical modules designed to detect Cherenkov photons generated inside the target tank with Module 1 containing D2O as the target and Module 2 initially containing H2O for comparison and background subtraction. We also aim to make a measurement of the cross-section of the charged-current interaction between the electron neutrino and oxygen, providing valuable insight for supernova detection in existing and future large water Cherenkov detectors. In this poster, we present construction and commissioning updates for Module 2 of the D2O detector.

Speakers: Gen Li (Carnegie Mellon University), Dr Kirsten McMichael (Carnegie Mellon University)

M7_slides_Gen_Li_D2O.pdf

25 Sensitivity Studies and Experimental Reach for Ge-mini, a COHERENT CEvNS Detector

Ge-mini is a germanium detector subsystem, part of the COHERENT Experiment at Oak Ridge National Lab. Using stopped-pion neutrinos from the Spallation Neutron Source, this ~16 kg array of Ge detectors searches for coherent elastic neutrino-nucleus scattering (CEvNS) on germanium. The low threshold and ultra-low noise nature of the germanium detectors allows for further studies in nuclear physics and physics beyond the standard model, such as measures of neutron skin depth and non-standard neutrino interactions. Following COHERENT's measurement of CEvNS on germanium, we present future experimental sensitivity for CEvNS, as well as the full experimental reach for Ge-mini's planned exposure and subsequent mass upgrades.

Speaker: Emma van Nieuwenhuizen

2024-Flashtalk_vanNieuwenhuizen.pdf

26 A new data analysis tool for NUCLEUS and first results from the commissioning phase

Coherent elastic neutrino nucleus scattering (CEvNS) with its large cross- section allows the study of neutrino interactions with a small target of highly sensitive cryogenic phonon detectors. The NUCLEUS experiment aims for an observation of CEvNS from reactor antineutrinos at recoil energies below 100 eV using gram-scale cryogenic detector crystals with superconductive Transition-Edge Sensors (TES).
In order to understand the response to sub-keV nuclear recoils, a direct energy calibration method is proposed by the CRAB project, detecting the emission of single MeV - gammas following thermal neutron capture.
The full experimental setup is being commissioned this year in the shallow underground lab at the Technical University Munich (Germany), preparing for the relocation of the experiment to the reactor site in Chooz (France).
In this poster, I will introduce a newly developed independent software tool designed for the analysis of NUCLEUS and CRAB data. I will also report on the latest results of the commissioning phase.

Speaker: Lilly Charlotte Peters (Technical University Munich (D))

LightningTalk_LillyPeters.pdf

27 Update on the COHERENT multi-ton, NaI detector array, NaIvETe

NaIvETe, a modular, ton-scale, NaI based neutrino detector is designed to measure the low-energy recoil signals from coherent elastic neutrino nucleus scattering (CEvNS) on sodium nuclei. As part of the suite of CEvNS detectors deployed by the COHERENT collaboration, NaIvETe provides the lightest target material to extend the range of measurements of the CEvNS cross section as a function of neutron number to search for deviations from the standard model prediction. The first of 5 detector modules was deployed in summer 2022 at the ORNL Spallation Neutron Source (SNS), where stopped pion neutrinos are produced as a byproduct of the spallation process. Two more detector modules were deployed in summer 2023. Initial calibration and analysis of data from our 'beta' module along with lessons learned from the additional modules informs how the NaIvETe measurement will be conducted. The collaboration plans to deploy an additional 2 modules in summer 2024 to begin production runs of about 2,300 kg of NaI material. In addition, studies were initiated to determine the sensitivity of the NaI crystals to CEvNS on iodine with a lower recoil energy, or the potential to reach the lower thresholds with minor modifications. Also of interest is the capability for NaIvETe to measure the charged-current inelastic neutrino-nucleus scattering on iodine.

Speaker: Nixon Ogoi (NC Central University)

M7s-conference_20240612_naivete-flash-talk.pdf

28 EFT analysis of the COHERENT experiment with right handed neutrinos

Using an effective field theory approach, we study coherent neutrino scattering on nuclei, in the setup pertinent to the COHERENT experiment. We include non-standard effects in both neutrino production and detection, with an arbitrary flavor structure and all leading Wilson coefficients simultaneously present. We add to previous work with the same formalism the presence of Dirac right-handed neutrinos and all the new operators that this implies. A concise description of the COHERENT event rate is obtained by introducing twelve generalized weak charges that can be associated (in a sense) with the production and scattering of $\nu_e$, $\nu_\mu$ and $\bar{\nu}_\mu$ on the nuclear target and the nuclear currents in detection. Our results present an explicit form of the new charges in terms of all Wilson coefficients.

Speaker: Sergio de la Cruz (IFIC (CSIC/UV))

CruzAlzaga_Magnificent24Beamer-1.pdf

CruzAlzaga_Magnificent24Beamer.pdf

29 Poster Session and Welcome Reception

Thursday, June 13

Talks

Convener: Diana Parno (Carnegie Mellon University)

30 Status of the CONUS+ experiment

The CONUS+ experiment is a new project which aims to detect coherent elastic neutrino-nucleus scattering (CEνNS) of reactor antineutrinos on germanium nuclei in the fully coherent regime, continuing in this way the CONUS physics program. After refurbishment, the four 1 kg point-contact high-purity germanium detector operate at significantly improved energy thresholds and resolutions. In combination with an additional shield optimization, we expect a boost in the sensitivity of the experiment and the detection of a CEvNS signal in CONUS+. The CONUS+ experiment was installed during summer 2023 in the Leibstadt nuclear power plant, Switzerland, at a distance of about 20 m from the 3.6 GWth reactor core. The experiment has been fully operational since October 2023 and it is currently in the physics data taking phase.

The CONUS+ design will be shown, together with the background characterization of the new experimental location. Preliminary data demonstrate the good performance of the upgraded germanium detectors and veto system at reactor place. Finally, the physics potential of the project will be presented.

Speaker: Kaixiang Ni

CONUS Magnificent2024.pdf

31 Measuring coherent elastic neutrino-nucleus scattering in argon with a scintillating bubble chamber

The Scintillating Bubble Chamber (SBC) collaboration is designing and building a bubble chamber to search dark matter and measure coherent elastic neutrino-nucleus scattering utilizing argon as a target material. The bubble chambers excel as exceptional detectors for uncovering rare events like neutrino interactions, owing to their insensitivity to electron recoils and capability to reject backgrounds through acoustic bubble formation and the light signal produced by scintillation. In this talk, an update will be presented on the progress of the SBC scintillating bubble chambers program focusing on studying neutrinos in nuclear reactors. The physics reach of this detector will be introduced, including the sensitivity for an electroweak precision test, a new vector mediator, and the neutrino magnetic moment. Additionally, the sensitivity to other New Physics searches will also be discussed, considering scenarios for sterile neutrinos, unitarity violation, and non-standard interactions.

Speaker: Eric Vazquez-Jauregui

Magnificent_SBC_Eric_Vazquez_Jauregui.pdf

32 Research on Coherent Neutrino Nucleus Elastic Scattering in the TEXONO Program

We will present the latest physics and detector R&D results and plans on the pursuit of neutrino nucleus elastic scattering at the Kuo-Sheng Reactor Neutrino Laboratory in Taiwan, with sub-keV germanium ionization detectors 1. This includes recent efforts in quantifying and studying the quantum-mechanical coherency effects of the interactions [2,3]. Future possibilities to continue and expand the program with reactor laboratories in China and India will be raised.

1. A.K. Soma et al., Nucl. Instrum. Meth. A 836, 67 (2016).
2. S. Kerman et al., Phys. Rev. D 93, 113006 (2016).
3. V. Sharma et al., Phys .Rev. D 103, 092002 (2021).

Speaker: Prof. Henry Wong (Institute of Physics, Academia Sinica, Taiwan.)

nuA-M7-HT_Wong-June24.pdf

33 Current status of the Ricochet experiment

The RICOCHET reactor neutrino observatory aims at measuring the coherent elastic neutrino-nucleus scattering (CEνNS) of antineutrinos at the Institut Laue-Langevin, ILL (Grenoble, France). To that end, RICOCHET employs two cryogenic calorimeter technologies : one based on germanium targets with neutron-transmutation-doped thermistors (the CryoCube)  and one based on superconducting targets and a transition-edge sensor readout (the Q-Array).

The CryoCube exploits a combined readout of phonons and ionization to identify nuclear recoil events and reject other backgrounds (electron recoils). The Q-Array will use pulse shape discrimination related to the different timescales of quasiparticle recombination and phonon relaxation for electron- and nuclear-recoils respectively.

The cryogenic facility was first installed and tested in a surface laboratory before being installed at the end of 2023 at the nuclear reactor. The detector commissioning started in February 2024 with a detector payload of three 40-gram germanium detectors. The results of the surface laboratory tests, the design of the facility, the discovery sensitivity and the first results of the commissioning phase of the Ricochet experiment will be presented in this contribution.

Speaker: Nicolas MARTINI (IP2I)

Ricochet Status Mag7 2024 - N. Martini.pdf

34 Current Status of the CONNIE Experiment using Skipper-CCDs

The CONNIE experiment aims to detect CEvNS of reactor antineutrinos off silicon nuclei using thick fully-depleted high-resistivity silicon CCDs. In 2021, two Skipper-CCD sensors with sub-electron readout noise capability were installed at the experiment next to the Angra-2 reactor, marking CONNIE as the first experiment to employ Skipper-CCDs for reactor neutrino detection. Thanks to the remarkably low readout noise of these sensors and thorough data quality analysis, CONNIE achieved a record low detection threshold of 15 eV. In this contribution, we will detail the sensor performance and present the latest results obtained from data collected over 300 days in 2021-2022. The comparison between event rates during reactor-on and off periods reveals no excess, setting upper limits on neutrino interaction rates at a 95% confidence level. These limits align with previous findings from CONNIE using standard CCDs and longer exposure times. Based on these new results, we conducted searches for Physics Beyond the Standard Model, focusing on exploring limits within a simplified model featuring light vector mediators. Additionally, we initiated the first dark matter search by diurnal modulation and further explored the recent search for relativistic millicharged particles produced in reactors. These promising results, achieved with a small-mass sensor, underscore the potential of Skipper-CCDs in investigating rare neutrino interactions and motivate plans for expanding the detector mass by installing a Multi-Chip-Module of Skipper-CCDs.

Speaker: Irina Nasteva (Federal University of Rio de Janeiro (BR))

Nasteva_M7s.pdf

10:40 AM Coffee

Talks

Convener: Diego Aristizabal (Universidad Tecnica Federico Santa Maria (USM))

35 Incoherent solar neutrino scattering off Thalium isotopes

The neutral current neutrino-nucleus scattering process is currently used to probe various nuclear-structure parameters and to constrain physics within and beyond the standard model. Motivated by the observation of coherent elastic neutrino-nucleus scattering (CE$\nu$NS) at the COHERENT experiment, in this article we perform realistic nuclear-structure calculations in the framework of the nuclear shell model. Focusing on the promising $^{203}$Tl and $^{205}$Tl isotopes --which are the detector dopants of CsI[Tl] and NaI[Tl] crystals, currently in use by several experimental collaborations --we present the expected event rates for both the coherent and incoherent neutrino-nucleus scattering channels. We furthermore present the standard neutrino scattering formalism in terms of the nuclear recoil energy for a more convenient comparison of the results with experimental data and compare our event rates with the corresponding results obtained by using phenomenological nuclear form factors.

Speaker: Dr Dimitrios Papoulias (National and Kapodistrian University of Athens)

M7s_2024_Valencia_Papoulias.pdf

36 The neutrino fog

I will review various different ways in which neutrinos represent an important background in upcoming dark matter experiments - encapsulated in the concept known as the neutrino floor, or, to use its recent rebranding: the "neutrino fog".

Speaker: Ciaran O'Hare (Sydney)

nufog.pdf

37 CE$\nu$NS-based Supernova Neutrino Detection with LZ

The LUX-ZEPLIN (LZ) experiment is a low-threshold low-background dark matter detector sensitive to CE$\nu$NS interactions from astrophysical neutrinos. LZ is deployed 4850 feet underground at the Sanford Underground Research Facility in Lead, South Dakota. LZ's central volume is a time projection chamber (TPC) containing 7 tonnes of liquid xenon (LXe) in the active volume. CE$\nu$NS interactions in the LXe deposit $\mathcal{O}(1)$ keV, an energy regime to which LZ is sensitive. LZ will detect CE$\nu$NS interactions with neutrinos emitted from the next galactic core-collapse supernova (CCSN), providing complimentary information to observations by scintillator and water-based detectors.

To model LZ's response to the neutrino signal from a CCSN, we have developed $\nu$ESPER: the Neutrino Engine Simulating the Process of Energetic Recoils. We present the architecture of $\nu$ESPER and discuss the CCSN progenitor models available for simulation. We explore the rate of CE$\nu$NS interactions from a 27~M$_\odot$ CCSN progenitor, and make comparisons to the rate of non-CE$\nu$NS neutrino interactions from this progenitor in LZ's TPC and veto systems.

We study LZ's CE$\nu$NS detection efficiency using $\nu$ESPER and the Noble Element Simulation Technique (NEST), a fast simulation tool which models the TPC response. We examine the response for a variety of CCSN progenitors. Finally, we discuss LZ's participation in the Supernova Neutrino Early Warning System 2.0 (SNEWS2.0) network, and the role of CE$\nu$NS-sensitive liquid noble element detectors in multi-messenger astrophysics.

Speaker: M. Elise McCarthy

MagnificentCEvNS_Valencia2024_CCSNvinLZ.pdf

38 Experimental search for the Migdal Effect in a compact liquid xenon TPC

The “Migdal Effect” is a predicted inelastic process in which a neutral particle scattering with a nucleus results in the excitation or ejection of a bound electron from the recoiling atom. It could enable detection of sub-threshold nuclear recoils, with the potential of dramatically expanding the sensitivity of existing detectors to low-mass dark matter and low-energy CEvNS signals. However, the effect has never been experimentally observed, and should be confirmed and characterized before potential dark matter or CEvNS signals can be discovered. In this talk, we report on a dedicated experimental campaign to search for the Migdal Effect using neutron scattering in a small liquid xenon detector at Lawrence Livermore National Laboratory. Scattered neutrons are detected by a ring of liquid scintillator detectors at fixed angle, providing a high-statistics sample of nuclear recoils. We search for events with an electronic recoil component consistent with atomic excitation from the Migdal Effect. We find no evidence for a signal consistent with predictions, and discuss possible explanations for this discrepancy. Our results, while not yet conclusive, provide important input into future experimental studies of the Migdal Effect.

Speaker: Dr Brian Lenardo (SLAC National Accelerator Laboratory)

M7s 2024 - Lenardo - Experimental search for the Migdal Effect in a compact liquid xenon TPC.pdf

39 The MIGDAL experiment

The Migdal effect has been invoked to extend the sensitivity of dark matter experiments to lighter, sub-GeV mass candidates. However, the Migdal effect has not been observed in nuclear scattering and, given how applications of this effect could impact the DM landscape, an experimental validation of the effect is very much needed. This is the goal of the MIGDAL (Migdal In Galactic Dark mAtter expLoration) experiment at the NILE facility at the Rutherford Appleton Laboratory (RAL). The experiment uses a table-top size low-pressure Optical TPC, which combines information from charge and light readouts to reconstruct 3D ionization tracks produced in the 50 Torr CF$_4$ gas volume. This technology provides a unique and unambiguous detection of the Migdal topology, namely a nuclear and electron recoil sharing an interaction vertex. We present preliminary results from data taken at RAL using an intense beam of fast neutrons from a D-D generator. We also describe the analysis pipeline of data from the various detector subsystems, which includes the use of YOLOv8, a state-of-the-art convolutional neural network that’s trained to simultaneously identify and classify particle tracks observed by the CMOS camera readout.

Speaker: Dinesh Loomba (University of New Mexico)

MIGDAL-DLoomba-Mag7-2024.pdf

12:50 PM Lunch

40 Discussion Panel

Speakers: Prof. Enectali Figueroa-Feliciano (Northwestern University), Janina Hakenmüller (Duke University), Patrick Huber

M7_valencia_2024_datasharing.pdf

4:30 PM Coffee

Talks

Convener: Jason Newby

41 Exploring the Migdal Effect in CEvNS searches at low energies

The search for coherent elastic neutrino-nucleus scattering (CEvNS) from reactor antineutrinos, represents a formidable experimental challenge that has pushed toward a global effort to develop innovative technologies capable of spotting the extremely tiny nuclear recoils produced as a single outcome of this interaction.
Due to the small energies of neutrinos produced at reactors, that extend up to a few MeVs, the CEvNS signal lies in an unexplored low-energy regime where a deep understanding of backgrounds and other compelling signals is crucial. Among them, I will focus on the Migdal effect, which is a yet-to-observed quantum mechanical phenomenon where additional ionization can be emitted after a nuclear recoil.

In this presentation, I will discuss the most recent result from the NCC-1701 germanium detector located about 10 meters away from the Dresden-II reactor site, which stands as the only experiment that has been able to find an excess compatible with CEνNS from reactor antineutrinos.
The Dresden-II observation relies on an enhancement of the measured quenching factor at low energies with respect to the theoretical prediction and the Migdal effect has been considered as a possible explanation for this unexpected behaviour. In this presentation, I will present the impact of the Migdal contribution on top of the standard CEvNS signal and I will compare it with the experimental data [1].

[1] ArXiv: 2307.12911

Speaker: Mattia Atzori Corona (University of Cagliari; INFN of Cagliari)

M7_Valencia_CEvNS_Migdal.pdf

M7_Valencia_CEvNS_Migdal.pdf

M7_Valencia_CEvNS_Migdal.pptx

42 Characterization and Optimization of Cryogenic Pure CsI Detector for CLOVERS Experiment

In this study, we conducted a comprehensive characterization and optimization of a cryogenic pure CsI (pCsI) detector. Achieving a notable light yield of 35.2PE/keVee and a world-leading energy resolution of 6.9% at 60keV, we utilized a 2cm cubic crystal coupled with a HAMAMATSU R11065 photomultiplier tube (PMT). Additionally, we measured the scintillation decay time of pCsI, which proved to be significantly faster than that of CsI(Na) at room temperature. Furthermore, we investigated the impact of temperature, surface treatment, and crystal shape on the light yield. Notably, the light yield peaked at approximately 20K and remained stable within the range of 70-100K. We observed that the light yield of polished crystals was approximately 1.5 times greater than that of ground crystals, while the crystal shape exhibited minimal influence on the light yield. These results are crucial for the design of the 10kg pCsI detector for the future CLOVERS (Coherent eLastic neutrinO(V)-nucleus scattERing at China Spallation Neutron Source (CSNS)) experiment.

Speaker: Chenguang Su (University of Chinese Academy of Sciences)

M7s_CryoCsI.pdf

43 Ultra-high light yield scintillation crystal detector based on low-temperature CsI and SiPMs for CEνNS detection

The first experimental measurement of coherent elastic neutrino-nucleus scattering (CEνNS) was successfully conducted using a CsI(Na) scintillation crystal detector. Recognizing that a higher light yield in scintillation crystal detectors correlates with greater physical sensitivity for CEνNS detection, we introduced a novel low-temperature CsI detector design employing SiPMs readout. This design capitalizes on the exceptional brightness of low-temperature CsI crystals combined with the ultra-high photon detection efficiency of SiPMs, thereby significantly improving the light yield and elevating CEνNS detection sensitivity to unprecedented levels. Positioned as a formidable contender for forthcoming CEνNS experiments, this innovative approach has been substantiated by our experimental group's development of a kilogram-scale low-temperature CsI detector [1]. This detector, notable for its leading international standards in light yield and energy resolution, serves as a preliminary proof of concept for the technical feasibility of our proposed scheme. This presentation delineates the detector scheme's characteristics, elucidating the principal prototype's performance metrics, including light yield, energy resolution, and the influence of SiPMs noise and optical crosstalk on detector performance.

Speaker: Chenguang Su (University of Chinese Academy of Sciences)

Ultra-high light yield scintillation crystal detector based on low-temperature CsI and SiPMs for CEνNS detection to UCAS.pdf

Ultra-high light yield scintillation crystal detector based on low-temperature CsI and SiPMs for CEνNS detection to UCAS.pptx

44 Q-Array: R&D towards superconducting targets for Cevns detection with Ricochet

Ricochet is an experiment based at the Institut Laue-Langevin (ILL) reactor in Grenoble aimed at detecting coherent elastic neutrino-nucleus scattering. Ricochet is designed to be a milliKelvin platform supporting multiple technologies, each differentiating between electronic recoils, nuclear recoils, and heat-only events. One such technology —CryoCube— uses an array of germanium crystals, while the other —Q-Array— uses superconducting metallic absorbers. Three CryoCube detectors have been deployed at ILL and started taking reactor data earlier this year.

This talk will give an overview of the recent progress of Ricochet's Q-Array concept.
Q-array pursues neutrino detection inside centimetre-scale superconducting crystals. Interactions inside the crystal create Bogoliubov quasi-particles and phonons that can be collected and converted into a heat signal within a trapping layer.

Currently, detector prototypes are measuring pulses at MIT and in the shallow underground NEXUS facility at Fermilab. The crystals are read out using Manganese-doped Aluminium transition-edge sensors (TES) fabricated at Argonne National Lab. The TES current signal is amplified using commercial DC-SQUID readout or multiplexed and upconverted using custom-designed RF-SQUID multiplexers fabricated at Lincoln Laboratories.

Speaker: Dr Wouter Van De Pontseele (Massachusetts Institute of Technology)

202406_M7s_qarray.pdf

8:30 PM Social dinner at restaurant Submarino

Friday, June 14

Talks

Convener: Francesca Dordei (INFN, Cagliari (IT))

45 Status of NEON

Since the observation of CEνNS by the COHERENT collaboration in 2017, interest in CEνNS has increased and there have been many global efforts to observe reactor neutrinos through CEνNS. NEON, neutrino elastic scattering observation with NaI(Tl), was also launched in 2019 to observe CEνNS of reactor neutrinos. Following the successful development of a high-light-yield NaI(Tl) detector, data acquisition has begun in 2022 with the detector installed at the tendon gallery of the Hanbit Nuclear Power Plant Unit 5 in Yeonggwang, South Korea. This talk will cover the overall status of the NEON experiment, including the detector configuration and operation, as well as the detector's performance and recent analysis results.

Speaker: Dr Young Ju Ko (Institute for Basic Science)

20240614_yjko.pdf

46 Imaging Nuclear Recoils in Argon

Tracking capabilities for Nuclear Recoils (NRs) from CEvNS interactions would allow measurements of the recoil energy and direction, enabling an expansive physics program which leverages the kinematics of the neutrino's coherent scattering interaction. This talk will present the status of experimental efforts aimed at imaging the ionization charge produced by NRs in argon. These efforts consist both of attempts to obtain direct charge amplification in liquid, as well as NR tracking in gas. We present progress in R&D devoted to developing tip-like geometries for micron-scale charge amplification, and simulation work aimed at exploring the experimental limitations and physics prospects of a physics program centered around CEvNS NR tracking.

Speaker: Prof. David Caratelli (UC Santa Barbara)

LArCADe_NR_imaging.pdf

47 CEvNS at the ESS.

The recent detection of the coherent elastic neutrino-nucleus scattering (CEνNS) opens the possibility to detect neutrinos with small-size detectors and with different techniques, opening a new window to explore possible BSM physics.
The CEνNS process generates signals at the few-keV level, requiring sensitive detection technologies for its observation. The European Spallation Source (ESS) has been identified as the best possible site for the exploration this CEνNS process.
Within the NuESS program, two different detector approaches are currently under development at Donostia International Physics Center (DIPC). The GanESS project, a high-pressure gaseous time projection chamber (TPC) and the CoSI project, which employs cryogenic undoped CsI crystals.
These next-generation technologies will be capable of observing the process with lower energy threshold and better energy resolution than current detectors. In addition, the combination of these detectors will allow for a complete phenomenological exploitation of the CEνNS signal. In particular, these measurements will not be statistically limited due to the synergy between larger neutrino fluxes at the ESS and these improved detectors.
I will give an overview of the current status of NuESS with a focus on its short-term plans.

Speaker: Francesc Monrabal

Magnificent.pdf

48 CEvNS Detection via 12C Recoils in Large Scale Liquid Scintillation Detectors - Prospects, R&D and Challenges -

In the coming year, two next-generation neutrino detectors, JUNO and JUNO-TAO, will start taking data. These neutrino observatories will realize unprecedented energy resolution and linearity in the field of liquid scintillator technology. Both detectors have a very broad physics
program, with a focus on the precise spectroscopy of reactor anti-electron neutrinos via the inverse beta decay of a proton in their scintillating target media based on hydrocarbon compounds. A successful observation of CEvNS from carbon nuclei in JUNO would open a new detection channel for the experiment’s supernova and atmospheric neutrino studies. Nevertheless, the detection of recoils on 12C nuclei is very challenging due to the low energy transfer and the high scintillation quenching of these heavy ions. In order to better evaluate this potential with neutron induced 12C recoils two beamlines at the INFN-LNL accelerator complex in Legnaro (Italy) were modified and equipped with dedicated targets in such a way that both quasi-monoenergetic neutrons up to 4 MeV and neutrons with a broad spectrum up to approx. 100 MeV can be generated for the irradiation of scintillator samples. Detailed studies of the typical quenching factors as well as the pulse shape of proton recoils in liquid scintillators have already been carried out in several beamtimes. While the available data sets for the detection media of JUNO and JUNO-Tao are currently being analyzed for indications of visible 12C recoils, the used detectors are being upgraded to allow lower energy thresholds and fixed neutron scattering angles. Within this talk we review the status of these facilities for the study of nuclear recoils in detectors, the yet available data and the potential and challenges for enriching the detection channels in large-scale LS detectors with CEvNS.

Speaker: Dr Hans Theodor Josef Steiger (Physics Department, Technical University of Munich)

ValenciaSteiger2024_2.pdf

49 CEvNS detection in XENONnT

Dual phase Xenon time projection chambers for Weakly Interacting Massive Particles (WIMP) dark matter (DM) detection strongly suppress electronic recoil background, making the detection of astro-neutrinos via coherent elastic scattering with Xe nucleus (CE$\nu$SN) possible. The sensitivities of New generation ton-scale WIMP DM detectors are approaching the named 'neutrino fog' formed by several sources of cosmic neutrinos: solar, atmospheric and from diffuse supernova background. With 5.9 tons of LXe, XENONnT is expected to detect for the first time CE$\nu$SN induced by $^8 $B neutrinos produced in the sun. In this talk, efforts ongoing to their detection will be overviewed, particularly the lowering of the detection threshold and the reduction of the background crucial to this purpose. Finally, simulation studies concerning CE$\nu$SN from the next galactic Core Collapse Supernova Neutrino (CCSN), as well as, charged current interactions induced from the last in the water muon and neutron vetos will be presented.

Speaker: L D. García

MAgnificience_140624_LDaniel.pdf

11:00 AM Coffee

Talks

Convener: Eric Vazquez-Jauregui

50 Quenching factors and new physics searches

I will present first results on how poorly constrained quenching factors can severely limit the ability to search for new physics in reactor experiments.

Speaker: Patrick Huber

M7s-2024.v2.pdf

51 Neutrino flux normalization to enable precise CEvNS analysis

COHERENT Collaboration has the first heavy-water Cherenkov detector deployed in the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL), in the same location where CEvNS events have been observed in cesium iodine, argon, and germanium. This detector, in combination with the second module (light water), has the goal of lowering the neutrino flux uncertainty at the SNS from 10% to only 2-3%, which will impact data analysis from COHERENT detectors from past, present, and future. Precise knowledge of the neutrino flux is crucial to enable more precisely testing the Standard Model, probing non-standard neutrino interactions (NSI), and searches for new physics. This detector will continue to collect data for many more years. In this talk, I will present initial results of commissioning of this detector.

Speaker: Igor Bernardi (University of Tennessee Knoxville)

Bernardi-M7s.pdf

52 Estimation of (particle) backgrounds at sub-keV energies for the NUCLEUS CEvNS experiment

The NUCLEUS experiment aims to detect reactor anti-neutrinos through coherent elastic neutrino-nucleus scattering (CEvNS) at the Chooz nuclear power plant in France using a 10-g cryogenic detection system made of CaWO4 and Al2O3 target crystals featuring unprecedented low energy thresholds of 20\,eV. Although being exposed to a high neutrino flux of $1.7\times10^{12}\,\text{s}^{-1}\text{cm}^{-2}$, the NUCLEUS experimental site exhibits challenging background conditions for CEvNS detection.
With a 3 meters water equivalent overburden, secondary cosmic-rays and gammas from natural radioactivity are expected to be the main contributors to the backgrounds in the region of interest, below 100\,eV, where most of the expected CEvNS signal in NUCLEUS lies in. To suppress these backgrounds to a sufficiently low level and achieve a signal-over-background ratio greater than 1, a combination of passive and active shieldings has to be erected around the cryogenic target detectors.
This talk will present the results of extensive Monte Carlo simulation studies of the NUCLEUS setup combined to dedicated on-site background measurements for both optimizing the design of the shielding and for achieving a first background prediction at sub-keV energies.

Speaker: Chloé Goupy (Commissariat à l'énergie atomique et aux énergies alternatives (CEA Saclay))

Mag7_NUCLEUS_Bckg_CGoupy.pdf

53 Plans and Preparation Status of the Sanmen Reactor Neutrino Laboratory

The Sanmen Reactor Neutrino Laboratory is currently being under construction as the CEvNS experimental platform, which is located at the Sanmen nuclear power plant in Zhejiang, China. In this laboratory, two different detector technologies: high-purity germanium detector technology and liquid xenon detector technology, will be used to jointly measure the reactor neutrino CEvNS at multiple experimental sites. The far site is located at about 22 m distance from the 3.4 GWth reactor core, while the near site has a distance about 10 m. This means the advantage of large neutrino flux and the convenience of operation brought by being located outdoors for the far site. This talk will introduce the plans and preparation status of the Sanmen Reactor Neutrino Laboratory.

Speaker: Dr Litao Yang (Tsinghua University)

M7s-Sanmen-Litao Yang.pdf

54 The First Search for Neutrino-Induced Nuclear Fission

For over 53 years, it was predicted that the neutrino, the smallest particle in the universe, is capable of splitting the atom. This phenomenon of neutrino-induced nuclear fission, or nuFission, is a portal between the weak and strong interactions and may lead to a new method for nuclear reactor monitoring. However, before these use cases can be leveraged, the central question must be meted out–is it possible to split an atom with a neutrino? To investigate, we turn to Oak Ridge National Laboratory’s Spallation Neutron Source (SNS) which is an intense source of neutrinos that stream isotropically outwards where the COHERENT Collaboration has established a basement corridor facility called “Neutrino Alley” in close proximity to the accelerator target (the neutrino source) while boasting a sharp decrease in beam-related backgrounds.

At Neutrino Alley, a new neutrino detector subsystem called “NuThor” was commissioned and deployed in the summer of 2022 where it is currently amassing data. NuThor is a bespoke neutron counting apparatus (or neutron multiplicity meter) that envelops a 52 kg thorium metal target. The neutrinos occasionally burrow straight through the outer shielding and active detectors in NuThor to interact with the inner thorium mass where there is a probability of inducing nuclear fission. The nuclear fission events will be accompanied by an outflow of neutrons. NuThor then counts these neutron detections in time with the neutrino beam’s onset.

With the accelerator currently in a sustained down period for upgrades and maintenance, the NuThor analysis is rapidly progressing through a multi-tier pipeline optimized for this experiment’s science goal.

Speaker: Tyler Johnson

MagCEVNS_2024_TJohnson.pdf

1:00 PM Lunch

Talks

Convener: David Cerdeño (Institute for Theoretical Physics (IFT-UAM/CSIC))

55 Dark Sector Searches with Coherent CAPTAIN-Mills

The Coherent CAPTAIN-Mills (CCM) experiment is a 10 ton liquid argon scintillation and Cherenkov detector at the Los Alamos Neutron Science Center. The detector is located 90deg off-axis and 23m away from the Lujan Facility's stopped pion source which will receive 2.25 10^22 POT in the ongoing 3 year run cycle. The short duration 290ns proton pulse and delayed arrival time of spallation neutrons allows CCM to probe rare processes with very low backgrounds. The high-rate of pion production and intense flux of other particles at the Lujan source allow CCM to probe a wide variety of dark sector models, including possible explanations to the short-baseline neutrino anomalies and MeV-scale Axion-Like-Particles. In this talk I present the latest work from CCM as well as projections for its full 3yr run cycle.

Speaker: Austin Schneider (LANL / MIT)

CCM | Magnificent CEvNS | 2024-06-14.pdf

56 Long-Lived Particles at Spallation Neutron Sources

The Japanese Spallation Neutron Source (JSNS) at J-PARC can provide an intense source of light new particles. We study the sensitivity of existing neutrino detectors to the decay in flight of light scalars, axion-like particles, and heavy neutral leptons. Detection sites include the magnetized gaseous argon near detector of the T2K experiment, ND280, the liquid-scintillator detectors of the JSNS$^2$ experiment, and the KOTO electromagnetic calorimeter. The combination of these setups has the potential to improve existing limits by over an order of magnitude in some regions of parameter space, encouraging further study on data acquisition and background rejection by the experimental collaborations.

Speaker: Matheus Hostert

mh_cevns.pdf

57 Toward the low-mass dark matter searches with DarkSide-20k: the solar neutrino and the argon-39 backgrounds

DarkSide-20k will have a 50-tonne total (20-tonne fiducial) dual-phase argon Time Projection Chamber, currently under construction at Hall C of LNGS.
The detector is specifically designed for the direct detection of Weakly Interacting Massive Particles (WIMPs) with masses exceeding 10 GeV/c^2. However, as demonstrated with the previous DarkSide-50 detector, the experiment has a significant potential for discovering light dark matter particles (1-10 GeV/c^2).
The search for low-mass dark matter particles presents many experimental challenges, such as the loss of discrimination power, the selection of few-electron events and the need to have control over the various background components. Among them, the signals due to solar neutrino interactions, which represent an irreducible background for the DarkSide-20k detector, and the beta decay of argon-39, an unstable argon isotope, are rather relevant and need to be well characterized.
I will discuss the latest calculations of the expected CEvNS and neutrino-electron event rates for the DarkSide-20k Low Mass searches as well as the importance of reducing the argon-39 content by extracting argon from underground sources (Urania program) and purifying it by cryogenic distillation (Aria project).

Speaker: Nicola Cargioli

Cargioli_Mag7_2024.pdf

58 Detecting Charged-Current Neutrino-Nucleus Interactions on Oxygen in a Heavy-Water Cherenkov Detector

At Oak Ridge National Laboratory (ORNL), the COHERENT collaboration has built a heavy-water Cherenkov detector to measure the neutrino flux coming from the Spallation Neutron Source (SNS) via the scattering of neutrinos on deuterium nuclei, with the primary aim of improving the precision of past and future CEvNS measurements. The detector was fully completed and began taking measurements in the summer of 2023. Although this heavy-water Cherenkov detector was built primarily to measure the SNS neutrino flux, it can also be used to measure the cross section of neutrino-nucleus charged-current interactions on $^{16}\textrm{O}$ nuclei. Charged-current $^{16}\textrm{O}(\nu_e,e^-)\textrm{X}$ reactions produce $e^-$ that will emit Cherenkov radiation within the detector. The SNS is the most powerful pulsed source of accelerator-based neutrinos in the world, which also happens to produce $\nu_e$ in a similar energy range to supernova neutrinos. Thus the measurement of this charged-current neutrino reaction in oxygen has implications for supernova neutrino detection. This neutrino-oxygen interaction has also never been experimentally measured, and thus its measurement can be a test of nuclear models. This presentation describes methodology for detecting and measuring the cross section and event rate of this charged-current interaction between $\nu_e$ and $^{16}\textrm{O}$ nuclei.

Speaker: Eli Mygatt Ward

Magnificent CEvNS 2024 Presentation.pdf

59 Optimizing the directional detection of low-energy electron recoils

Modern high-definition gaseous time projection chambers (TPCs) enable us to not only measure the energy but also the direction of low-energy nuclear and electron recoils. This capability is highly sought after for a range of applications, including directional coherent elastic neutrino-nucleus scattering (CEvNS) measurements, dark matter searches within the neutrino fog, and studying solar neutrinos. Historically, the emphasis within the directional recoil detection community has been on nuclear recoils for dark matter detection. Recently, the directional detection of electron recoils has re-emerged as a potential avenue for probing solar neutrinos. We introduce a methodology for predicting the angular resolution of electrons in gas, which can be used to optimize the parameters of directional detectors for electron scattering. Furthermore, we discuss a novel deep learning model capable of analyzing 3D data to probabilistically predict direction. Tested on simulated electron recoil data, this model significantly surpasses conventional approaches in performance and offers accurate estimates of directional uncertainty. Although our primary focus is on directional electron scattering, the methodologies discussed are widely applicable to directional detection experiments.

Speaker: Majd Ghrear

MagnificentCEvNS.pdf

60 Exploring DSNB bossted Sub-GeV Dark Matter through Electron and Nuclear Recoil Signal at XENONnT and LUX-ZEPLIN Experiments

Conventional direct Dark Matter (DM) detection experiments primarily explore the DM parameter space within the GeV-TeV mass range. However, recently, interest in exploring sub-GeV DM has increased. However, their low momenta make detection challenging, as they fail to induce recoils above the thresholds of conventional direct detection experiments. Even strongly interacting DM within this mass range has been suggested to elude all observational bounds. We explore a scenario where sub-GeV cold DM particles are accelerated to semi-relativistic velocities through their scattering with the diffuse supernova neutrino background (DSNB) in the galaxy |1|. This mechanism introduces a high-energy DM component capable of interacting with both electrons and nuclei in the detector, triggering a detectable recoil signal. We analyse data from the most advanced direct detection facilities in the contemporary world, namely the XENONnT |2| and LUX-ZEPLIN (LZ) |3| experiments, to derive constraints on the scattering cross sections of sub-GeV-boosted DM with both electrons and nucleons. Additionally, we emphasise the imperative nature of considering Earth’s attenuation effects for both electron and nuclei interactions. Lastly, we present a comparison of our findings with existing constraints, illuminating the complementarity and significance of the LZ and XENONnT data in probing the sub-GeV DM parameter space.

References:
|1| V. De Romeri, A. Majumdar, D. K. Papoulias, and R. Srivastava, "XENONnT and LUX-ZEPLIN constraints on DSNB-boosted dark matter," arXiv:2309.04117 [hep-ph].

|2| E. Aprile et al., "First Dark Matter Search with Nuclear Recoils from the XENONnT Experiment," Phys. Rev. Lett. 131 (2023) no.4, 041003.

|3| J. Aalbers et al., "First Dark Matter Search Results from the LUX-ZEPLIN (LZ) Experiment," Phys. Rev. Lett. 131 (2023) no.4, 041002.

Speaker: Mr Anirban Majumdar (Indian Institute of Science Education and Research - Bhopal)

Magnificent_CEvNS_2024_Slides_Anirban_Majumdar.pdf

61 Summary talk - Theory

Summary talk for the theory session

Speaker: Pilar Coloma (Instituto de Fisica Teorica UAM-CSIC)

pcoloma_magnificent.pdf

62 Summary talk - Experiments

Speaker: Matthew Green (NC State University)

2024_06_Mag7s_Exp_Summary.pdf

5:00 PM Final Remarks

63 Closing

Closing_session.pdf