NBIA Summer School on Neutrinos: Here, There & Everywhere

11 Jul 2022, 00:00 → 15 Jul 2022, 17:55 Europe/Copenhagen

Auditorium A (Niels Bohr Institute)

Markus Ahlers (NBI), Mauricio Bustamante (Niels Bohr Institute, University of Copenhagen)

 

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Online participation (08/06/2022): In-person registration is closed, but online participation is possible. If you would like to participate of the school online, please complete the Registration form.

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Hotel scam alert (21/04/2022): If you received an e-mail from "Expo Ehotel Services" (possibly from docs[at]email.pandadoc.net or sale[at]ehotelservices.org), please ignore it.  We have not authorized any such service for the summer school and this seems to be a scam.  If you already booked accommodation with them, we strongly suggest that you cancel it right away.  

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The Niels Bohr International Academy (NBIA) invites PhD students and advanced Master students to the International PhD Summer School on Neutrinos: Here, There & Everywhere. This one-week school aims to bring the participants up to date with the latest developments in neutrino physics, from theoretical issues to experimental results, including astrophysical and cosmological aspects.

The deadline for in-person registration is March 31, 2022.  There is no participation fee.

Students will be given topical introductions, along with an overview of the current state of the field and the open questions that confront it. The invited lecturers are internationally renowned experts in their fields. The school participants will gain a broad understanding of current theoretical problems in neutrino physics, state-of-the-art neutrino experiments, and applications of neutrinos in cosmology and astrophysics.

Guest Lectures & Lecturers

Neutrino Cosmology
Olga Mena
Instituto de Física Corpuscular (IFIC), Universidad de Valencia

Neutrino Theory & Phenomenology
Joachim Kopp
Institut für Physik, Johannes Gutenberg-Universität, Mainz

Neutrino Astrophysics & Astronomy
Foteini Oikonomou
Norwegian University of Science and Technology

Local Organizers

Mauricio Bustamante
Markus Ahlers

General instructions

To participate:

• Register as a participant
• Registering is solely an expression of interest; you will later be informed about your admittance to the School by the organizers
• The participation is free of charge and includes catering during coffee and lunch breaks. Students are expected to cover their travel and local expenses.

Financial assistance:

      We have limited funds to cover the accommodation costs of in-person PhD student participants for the duration of the School.  See here for details.

Participation mode:

• The main form of participation of the School will be in person
• In-person participation is limited to 50 students
• Depending on resources available, we might provide options to participate remotely; you may indicate your preference in the registration form, but please be aware that, at this stage, remote participation is not guaranteed
• Priority will be given to in-person participants

COVID-19 and health:

• Please be aware of the health rules regarding COVID-19 to enter Denmark
• These rules may change over time, so please be sure to revisit them close to your travel dates
• The School will be carried out following the health guidelines of the Danish Health Authority
• We ask our participants to follow best health practices at all times

Visa:

• See here for the list of countries with a visa requirement and visa-free countries to enter Denmark
• If you require an invitation letter to apply for a visa, please contact our administrator Michelle Westergaard

Credit:

• Students who wish to receive credit (2.5 ECTS) for the course are required to give a short presentation on their current research project, to attend lectures and discussion sessions, as well as to participate actively in problem classes
• Only in-person participants may receive ECTS (unless there are exceptional circumstances)

Questions: 

      Please contact the local organizers, Markus Ahlers and Mauricio Bustamante

Sponsors

The Leon Rosenfeld Foundation, supporting young scientists

group_photo_cropped.jpg

NBIA_Neutrino_2022.pdf

school_dinner.pdf

Monday, 11 July

09:15 → 09:30 Welcome

PhD_School_welcome.pdf

Video

09:30 → 10:30 Neutrino Astrophysics & Astronomy

09:30 Lecture I

Speaker: Foteini Oikonomou

NBIA_Lectures_Monday_Foteini.pdf

Video

10:30 → 11:00 Coffee

11:00 → 12:00 Neutrino Astrophysics & Astronomy

11:00 Lecture II

Speaker: Foteini Oikonomou

NBIA_Lectures_Monday_Foteini.pdf

Video

12:00 → 13:30 Lunch

13:30 → 14:00 Topical Seminar

13:30 Supernova neutrinos

Speaker: Shashank Shalgar (NBIA)

NBIAschool2022.pdf

Video

14:00 → 15:00 Student Talks

14:00 Deciphering Cosmic Neutrinos

High-energy neutrino astronomy is rapidly evolving: After the discovery of a largely diffuse astrophysical TeV-PeV neutrino flux, the IceCube Neutrino Observatory has more recently found indications of associations between blazar emission and high-energy neutrinos. However, different analyses show that blazars are only expected to make up a subdominant contribution to the total observed diffuse flux. We are thus in the remarkable situation that we have firmly detected a diffuse astrophysical neutrino flux but at the same time, we have so far no (well-established) neutrino point sources. Neutrinos are produced along with $\gamma$-rays in the interactions of Ultra High-Energy Cosmic Rays (UHECRs) and radiation and gas. But as with UHECRs, the sources of the high-energy neutrinos are as yet unknown. The close relations between the emission of the different messengers: cosmic rays, neutrinos and gamma-rays make it possible to study the neutrino flux with a multi-messenger approach. Our work investigates the viable source populations responsible for the high-energy largely diffuse neutrino flux that IceCube has observed. Using multi-messenger data, we seek to derive a set of necessary conditions on neutrino source candidates. Once we have the resulting candidate neutrino source populations, the aim is to test them in an IceCube data analysis.

Speaker: Kathrine Mørch Groth (Niels Bohr Institute, University of Copenhagen)

Kathrine_NBIA_11-07-2022.pdf

Video

14:12 Lepto-hadronic modelling of TXS0506+056 blazar

TXS0506+056 is the first-ever known blazar having coincidence with IceCube neutrino alert 170922A, this source has been observed in multi-wavelengths during different epochs. Multi-wavelengths study of this source during different epochs with electron synchrotron and proton synchrotron using the GAMERA package has been presented.

Speaker: Sunanda . (Indian Institute of Technology Jodhpur, Rajasthan India)

2022-07-11_Sunanda.pdf

Video

14:24 IceCube Search for High-Energy Neutrinos from Obscured Sources in the Great Observatories All-Sky LIRG Survey (GOALS)

Tension between the diffuse multimessenger observations of both neutrinos and gamma rays hints that the contribution of gamma-ray bright objects to the observed astrophysical neutrino flux is limited. This initiated the interest in gamma-ray dim objects, obscured by large amounts of dust and gas. In this work we investigate for the first-time ultra-and luminous infrared galaxies (U/LIRGs) within the Great Observatories All-Sky LIRG Survey (GOALS) as candidate neutrino sources. GOALS objects are among the brightest infrared sources in the Universe, powered by highly obscured starburst and AGN activity. These key features make GOALS objects excellent gamma-ray dim neutrino source candidates that can contribute to the neutrino flux measured by IceCube. A neutrino-production framework for U/LIRGs is developed with special focus on electromagnetic observables that can be linked to neutrino production. This phenomenological model will then be tested with a dedicated IceCube analysis on the GOALS sample.

Speaker: Yarno Merckx (Vrije Universiteit Brussel)

(U)LIRGs_with_GOALS_and _IceCube_Yarno_Merckx.pdf

Video

14:36 Rapid Response to Extraordinary Events: the Gamma-Ray Follow Up (GFU) platform for IceCube

The IceCube discovery of an astrophysical flux of high-energy neutrinos is a milestone in multi-messenger astronomy. Time-integrated searches for point-like neutrino sources have failed so far because of large backgrounds and weak signals. The IceCube capability of observing the sky with a full duty cycle enables the search for transient neutrino emissions and provides alerts to the community to encourage searches for electromagnetic counterpart of rapidly fading sources.
In this talk, we will present the Gamma-Ray Follow Up platform, created to identify good muon neutrino candidates used to generate and send alerts to the astrophysical community. Results will be presented of the most significant neutrino flares recorded so far.

Speaker: Caterina Boscolo Meneguolo

gfu_NBIA_Boscolo.pdf

Video

14:48 Constraining very high energy diffuse gamma (and neutrino) emission with Tibet AS$\gamma$ data.

The Tibet AS$\gamma$ experiment provided the first measurement of the total diffuse gamma-ray emission from the Galactic disk in the sub-PeV energy range.
This measurement can be used to constrain the cosmic-rays (CRs) space and energy distribution and consequently the gamma-neutrino Galactic diffuse emission, produced by the interaction of CRs with the interstellar medium.
The interpretation of Tibet AS$\gamma$ observational data might be not straightforward because of the presence of a non-negligible contribution from faint unresolved sources that adds up to the truly diffuse emission produced by CRs, shaping the energy and space dependence of the total (i.e. truly diffuse + unresolved) observed gamma-ray flux.
Based on analysis of the TeV sources included in the HGPS catalog, we predict the expected contribution of unresolved pulsar-powered sources in the two angular windows of the Galactic plane observed by Tibet AS$\gamma$.
We show that, with the inclusion of this additional diffuse component due to unresolved sources, the Galactic diffuse emission well saturates the Tibet data, without the need to introduce a progressive hardening of the CR spectrum toward the Galactic center. Under this condition, one obtains a prediction of the Galactic neutrino diffuse emission above 100 TeV showing that they can contribute at most to $5\%$ of the total neutrino flux observed by IceCube.

Speaker: Vittoria Vecchiotti

Presentazione Tibet Copenhagen.pdf

Video

15:00 → 15:30 Coffee

15:30 → 16:30 Exercises

astro_exercises.pdf

astro_exercises_data_OJ287_data.txt

astro_exercises_solutions.pdf

nu_cosmology_exercise_1_2.png

nu_cosmology_exercise_3.png

theory_pheno-exercises.pdf

16:30 → 17:30 Discussion

17:30 → 19:00 Reception

Tuesday, 12 July

09:30 → 10:30 Neutrino Theory & Phenomenology

09:30 Lecture I

Speaker: Joachim Kopp (CERN and JGU Mainz)

lecture-notes-1.pdf

Video

10:30 → 11:00 Coffee

11:00 → 12:00 Neutrino Theory & Phenomenology

11:00 Lecture II

Speaker: Joachim Kopp (CERN and JGU Mainz)

lecture-notes-2.pdf

Video

12:00 → 13:30 Lunch

13:30 → 14:00 Topical Seminar

13:30 Neutrino oscillation with IceCube (IceCube-DeepCore)

Speaker: Tom Stuttard (Niels Bohr Institute, IceCube)

NeutrinoOscillationsIceCube_TomStuttard.pdf

Video

14:00 → 15:00 Student Talks

14:00 Prospects of neutrino oscillation physics with JUNO

The Jiangmen Underground Neutrino Observatory (JUNO) is a 20$\,$kt multi-purpose experiment under construction in southern China, expecting to begin data taking in 2023. JUNO will detect electron antineutrinos generated from the beta decays of fission products inside nuclear reactors and is located at about 53$\,$km from two nuclear power plants to maximize the effect of neutrino oscillations. JUNO is expected to determine the neutrino mass ordering with a $3\sigma$ significance in 6 years of data-taking, and to measure three oscillation parameters, $\Delta m^2_{21}$, $\Delta m^2_{31}$, and $\sin^2 \theta_{12}$, with sub-percent precision.

JUNO is expected to reach these physics goals thanks to its large active volume, a total photo-coverage of 78$\,$%, an effective energy resolution of 3$\,$% at 1$\,$MeV, and by keeping energy-related systematic uncertainties below 1$\,$%. In light of the recent results from short-baseline experiments, proper modeling of the electron antineutrino spectrum from nuclear reactors is also required to take into account both the reactor antineutrino anomaly and the spectral distortion at 5$\,$MeV.

This contribution will focus on the neutrino oscillation analysis with JUNO.

Speaker: Beatrice Jelmini (Università degli Studi di Padova & INFN Padova)

jelmini_JUNOphysics_NBIASchool2022_final.pdf

Video

14:12 Impact of Wave Packet Separation in Low-Energy Sterile Neutrino Searches

Analyses of neutrino oscillations experiments usually rely on the standard probability formula, which assumes that neutrino wave functions can be approximated by plane waves and neglects any decoherence effect. This expression is valid in most regimes, or at least it is in the three neutrino paradigm.
In this talk, we will re-examine this assumption in the context of sterile neutrino oscillations and check that reactor and nuclear decay experiments must not blindly use the standard formula. Instead, it is necessary to acknowledge the phenomenological implications of a possible dampening of the sterile neutrino oscillations. Furthermore, we will see how the tension between reactor and nuclear decay experiments can be slightly relaxed by this effect, which does not necessarily introduce any other new physics.
This talk is based on 2201.05108.

Speaker: Toni Bertólez Martínez (Institute of Cosmic Sciences, Universitat de Barcelona)

IfPowerDoesNotWork.pdf

NBIA - PW vs WP.pptx

Video

14:24 HNL Searches in IceCube: Current Status and Future Opportunities

Heavy Neutral Leptons (HNLs) are GeV-scale right-handed (sterile) neutrinos which have been posited as a possible explanation for light neutrino masses via the seesaw mechanism. HNL production from tau neutrinos and the HNL's subsequent decay would produce a unique double-bang signature in the IceCube detector, enabling a novel search for GeV-scale HNLs at atmospheric neutrino energies. Currently, event reconstruction of these double-bangs is adapted from the astrophysical tau neutrino reconstruction, and does not address the difficulty of reconstructing low-light events more common at these lower energies. The HNL signal in IceCube is therefore currently limited to an excess of cascade-like events, rather than a clear double-bang signal. In this talk, I address the opportunities and challenges of searching for this double-bang signal, and suggest how updated reconstruction and event selection techniques, along with the IceCube upgrade, enhance future opportunities for HNL searches.

Speaker: Julia Book (Harvard University)

NBIA Presentation v2.pdf

Video

14:36 Dark Matter decay to neutrinos

Dark matter (DM) particles are predicted to decay into Standard Model particles which would produce signals of neutrinos, gamma-rays, and other secondary particles. Neutrinos provide an avenue to probe astrophysical sources of DM particles. We review the decay of dark matter into neutrinos over a range of dark matter masses from MeV/c2 to ZeV/c2. We examine the expected contributions to the neutrino flux at current and upcoming neutrino and gamma-ray experiments, such as Hyper-Kamiokande, DUNE, CTA, TAMBO, and IceCube Gen-2. We consider galactic and extragalactic signals of decay processes into neutrino pairs, yielding constraints on the dark matter decay lifetime that ranges from tau ∼ 1.2×10^21 s at 10 MeV/c2 to 1.5x10^29 s at 1 PeV/c2.

Speaker: Diyaselis Delgado (Harvard University)

DarkMatterDecay_NBIA2022.pdf

Video

14:48 Reparameterisations of the neutrino mixing matrix in long-baseline analysis

Tokai to Kamioka (T2K) is a long-baseline neutrino experiment based in Japan, which has provided some of the strongest constraints for the $\theta_{23}$ and $\delta_{CP}$ parameters of the neutrino mixing matrix. I will discuss the role of remparameterisations of the phase space of the Pontecorvo-Maki-Nakagawa-Sakata matrix in testing the robustness of T2K's Bayesian analysis framework MaCh3, and the motivation behind T2K's plans for reporting measurements of parameterisation invariants such as $J_{CP}$ and $|U_{\alpha i}|$.

Speaker: Andres Lopez Moreno (King's College London)

Talk_2_NBIA 2022 presentation Andres Lopez Moreno_full.pdf

Video

15:00 → 15:30 Coffee

15:30 → 16:30 Exercises

astro_exercises.pdf

astro_exercises_data_OJ287_data.txt

astro_exercises_solutions.pdf

nu_cosmology_exercise_1_2.png

nu_cosmology_exercise_3.png

theory_pheno-exercises.pdf

16:30 → 17:30 Discussion

Wednesday, 13 July

09:30 → 10:30 Neutrino Cosmology

09:30 Lecture I

Speaker: Dr Olga Mena

Olga_Mena_slides.pdf

Video

10:30 → 11:00 Coffee

11:00 → 12:00 Neutrino Astrophysics & Astronomy

11:00 Lecture III

Speaker: Foteini Oikonomou

Astro_lecture_3.pdf

Video

12:00 → 13:30 Lunch

13:30 → 14:00 Topical Seminar

13:30 Neutrino emission from starburst galaxies

Speaker: Enrico Peretti (Niels Bohr Institute)

Starburst_Peretti.pdf

Video

14:00 → 15:00 Student Talks

14:00 Self-confinement of low-energy cosmic rays around supernova remnants

Supernova Remnants have long been considered as promising candidate sources for cosmic rays. However, modelling the transport around these sources is difficult due to its nonlinear nature. The strong overdensity in the near source region leads to the production of plasma turbulence, upon which the particles scatter. To calculate this mechanism, called self-confinement, requires the numerical solution of two coupled differential equations describing the transport of particles and waves, most ofthen done in the flux tube approximation. Here, this formalism is extended to energies below $10\,GeV$, where energy losses become relevant. Particles around $100\,MeV$ are found to be confined for in between $300\,kyr$ and $1\, Myr$, depending on the interstellar medium. The diffusion coefficient is initially suppressed by up to two orders of magnitude. Interestingly, the spectrum outside the supernova flattens below $1\,GeV$ at later times, similar to the spectral behavior observed by Voyager. Furthermore, the grammage accumulated in the near source region is found to be non-negligible, which could be important for precision fitting cosmic ray spectra.

Speaker: Hanno Jacobs (TTK RWTH-Aachen)

NBIA_talk_Hanno_Jacobs.pdf

Video

14:12 Collective Effect in Supernova Neutrinos

Due to neutrino-neutrino forward scattering, the neutrino flavor conversion inside a supernova is still an open question. This type of interaction leads to a non-linear evolution of neutrino states and is strongly dependent on their angular distribution. Thus, the peculiarities of the supernovae's innermost environment impose a number of complexities on an accurate calculation of the neutrino evolution towards the outside of the star. Unquestionably, a comprehensive understanding of the neutrino flavor conversion mechanisms is essential to extract astrophysical information from future detections of supernovae neutrinos. Therefore, in this talk, we present some preliminary results for this problem, in which we have adopted a numerical solution approach. First, we discuss an isotropic neutrino gas and its connection to simpler systems, such as a pendulum. Then, we show the results of modeling the supernova neutrino emission as a sphere (Bulb-Model), which has connections with the isotropic scenario when considering a single-angle emission approximation. Finally, we explain the limitations of this model and the next steps toward a more detailed calculation. It is worth emphasizing that the numerical implementation of the code is public (open-source), and is already available for users interested in studies of neutrino collective effects.

Speaker: Pedro Dedin Neto (Unicamp - University of Campinas)

Link

NBIA___Neutrino_International_Summer_School___2022_Pedro_Dedin_Neto.pdf

14:24 Exploiting a future galactic supernova to probe neutrino magnetic moments

A core-collapse supernova (SN) offers an excellent astrophysical laboratory to
test non-zero neutrino magnetic moments. In particular, the neutronization burst
phase, which lasts for few tens of milliseconds post-bounce, is dominated by electron neutrinos and can offer exceptional discovery potential for transition magnetic
moments. We simulate the neutrino spectra from the burst phase in forthcoming
neutrino experiments like the Deep Underground Neutrino Experiment (DUNE),
and the Hyper-Kamiokande (HK), by taking into account spin-flavour conversions
of supernova neutrinos caused by interactions with ambient magnetic fields. We
find that the neutrino transition magnetic moments which can be explored by these
experiments for a galactic SN are an order to several orders of magnitude better
than the current terrestrial and astrophysical limits. Additionally, we also discuss
how this realization might provide light on three important neutrino properties: (a)
the Dirac/Majorana nature, (b) the neutrino mass ordering, and (c) the neutrino
mass-generation mechanism.

Speaker: Yago Philippe Porto Silva (Universidade Estadual de Campinas)

NBIA-yago-slides.pdf

Video

14:36 CORSIKA simulation for massive quarks in hadronic showers

We simulated hadronic showers at PeV-EeV energy with CORSIKA to study the massive quark production and decay modes. In this regard, we specifically studied charm meson production and their decay channels with SYBILL and QGSJet models. This understanding would possibly help implement bottom quark production and their decay in these models. The massive quark decays contribute to the atmospheric high-energy gamma-rays and neutrinos. Hence, this study would be essential to significantly observe high-energy gamma rays and neutrinos fluxes from astrophysical objects.

Speaker: Bhanu Pant (Indian Institute of Technology Jodhpur)

NBIA_Bhanu_130722.pdf

Video

14:48 Machine-learning aided experimental design for P-ONE

The Pacific Ocean Neutrino Experiment (P-ONE) is a collaboration of Ocean Networks Canada (ONC) and Universities from Germany, Canada, and the USA to build a large volume neutrino telescope in the Pacific Ocean. Similar to other neutrino telescopes, P-ONE wants to instrument the ocean with photosensors deployed on vertical cables (lines) to detect high-energy neutrino interactions by the Cherenkov light emitted from secondary particles.
The design of such telescopes has a variety of free parameters, such as the sensor spacing and sensor density, trigger algorithms and thresholds, or hardware used for signal digitization. These parameters directly impact the physics potential of the telescope and need to be optimized under external constraints (cost, bandwidth, site limitations). These optimization studies typically require expensive Monte-Carlo simulations that limit the explorable parameter phase space.
This talk presents a framework that uses graph-neural networks and multi-parameter optimization to comprehensively explore the parameter phase space while reducing the simulation time. The framework facilitates a data-driven decision process for the design of P-ONE, maximizing the physics potential while minimizing the expenses.

Speaker: Janik Prottung (Technical University Munich)

220712 NBIA Talk - Machine-learning aided experimental design for P-ONE.pdf

220712 NBIA Talk - Machine-learning aided experimental design for P-ONE.pptx

Video

15:00 → 15:30 Coffee

15:30 → 19:00 Free Afternoon

19:00 → 21:00 School Dinner

Thursday, 14 July

09:30 → 10:30 Neutrino Theory & Phenomenology

09:30 Lecture III

Speaker: Joachim Kopp (CERN and JGU Mainz)

anomalies.pdf

nu-mass.pdf

Video

10:30 → 11:00 Coffee

11:00 → 12:00 Neutrino Cosmology

11:00 Lecture II

Speaker: Dr Olga Mena

Olga_Mena_slides.pdf

Video

12:00 → 13:30 Lunch

13:30 → 14:00 Topical Seminar

13:30 Neutrinos in the early Universe

Speaker: Rasmus Hansen (Niels Bohr Institute)

NuEarlyUniverse.pdf

Video

14:00 → 15:00 Student Talks

14:00 Can Neutrinos 'save' Early Dark Energy?

Early dark energy (EDE) alleviates the $H_0$ tension at the cost of increasing the clustering amplitude and worsening the $S_8$ discrepancy. Motivated by massive neutrinos' ability to suppress structure, we study their impact on EDE combining Planck and BOSS full-shape clustering data. A Bayesian analysis returns no evidence for a non-zero neutrino mass sum $M_{\nu}$ ($<0.15,{\rm eV}$ at 95%~C.L.), with limits driven primarily by shifts in the BAO scale. A frequentist profile likelihood analysis reveals a correlation between $M_{\nu}$ and the EDE fraction $f_{\rm EDE}$, which keeps $H_0$ fixed as $M_\nu$ increases. Compared to the best-fit baseline EDE model ($M_\nu = 0.06,{\rm eV}$), a model with $M_\nu=0.15,{\rm eV}$ maintains the same $H_0$(km/s/Mpc)=(70.08, 70.12, respectively) whilst decreasing $S_8$=(0.837, 0.831 respectively), whilst still representing a better fit ($\Delta \chi^2=-3.1$) relative to $\Lambda$CDM. Our results indicate that an EDE+$M_{\nu}$ model can keep the $H_0$ tension at the same level as baseline EDE while mitigating the enhanced clustering issue. Further analysis of this model and neutrino mass measurements in general require the careful addition of extra datasets. I will present preliminary work on building a pipeline for combining probes on the map-level with both auto- and cross-correlations of different datasets. This pipeline is promising to obtain strong constraints on the LCDM model and several extensions.

Speaker: Alexander Reeves (ETHZ)

NBI_talk_Reeves.pdf

Video

14:12 Neutrino Masses, Leptogenesis and Dark Matter from a Scotogenic Model with two Higgs doublets

For a scotogenic model (i.e. with radiatively generated neutrino masses
through dark matter) with two additional Higgs doublets and a single
Majorana fermion, we explore the possibility of explaining neutrino
masses, Leptogenesis and dark matter all at once. To this end, we apply
the Leptogenesis mechanism described in
(https://arxiv.org/abs/1201.5126) to the model proposed in
(https://arxiv.org/abs/1208.3162). This offers an alternative to the
usual seesaw and Leptogenesis mechanisms relying on the mixing of at
least two Majorana fermions and a Higgs doublet.

Speaker: Edward Wang (TUM)

Scotogenic.pdf

Video

14:24 Sensitivity of the T2K Near Detector Upgrade to constrain CCQE uncertainties in the Spectral Function model

A substantial fraction of systematic uncertainties in neutrino oscillation experiments stems from the lack of precision in modeling the nucleus when describing neutrino-nucleus interactions. Reducing these uncertainties is crucial for present and next-generation long baseline experiments. The T2K experiment is preparing for its second phase with the upgrade of its near detector starting next year. The capabilities of full polar angle acceptance, lower proton tracking threshold as well as reconstruction of neutron kinematics with this upgrade will open the door to explore new physics with unprecedented precision thanks to new observables.

To model quasi-elastic interactions, T2K uses the Benhar Spectral Function (SF) model which offers significant improvements with respect to the more commonly used Fermi gas-based models. Based on constraints from electron scattering experiments, we develop a set of parameters that can alter the occupancy of the nuclear shells and the distribution of the nucleon momentum within each shell. In addition, the contribution of short-range correlations and the effect of Pauli blocking can also be modified. With such freedoms, uncertainties on the input models can be estimated for neutrino oscillation analyses.

In this talk, we will first show how this parameterisation can improve the SF model agreement with available cross section measurements of the muon momentum and direction as well as the transverse momentum imbalance from T2K and MINERvA. Then we will present the sensitivity of the upgraded T2K near detector to these parameters for the statistics expected during this second phase of T2K.

Speaker: Jaafar Chakrani (Laboratoire Leprince-Ringuet (LLR))

20220714_NBIASummerSchool_JaafarChakrani.pdf

Video

14:36 Characterisation of Germanium Detectors for LEGEND-200

The LEGEND Collaboration is searching for neutrinoless double beta ($0\nu\beta\beta$) decay in Germanium-76 ($^{76}$Ge) via a phased approach. The first of two phases, LEGEND-200 (L200), will use 200 kg of enriched High Purity Germanium (HPGe) detectors, submerged in a liquid argon active shield, in order to target a half life sensitivity of 10$^{27}$ years. It is currently being commissioned at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy and the first physics data is expected later this year. Inverted Coaxial Point Contact (ICPC) detectors are a new type of HPGe detector that will be utilised in L200. Their unique geometry enables them to maintain a large detector mass whilst achieving both superior energy resolution and strong discrimination of signal against background. These detectors must be comprehensively characterised before their deployment at LNGS in order to verify their performance and behaviour. This characterisation process is performed in the underground laboratories of HADES in Belgium and SURF in the US. This talk will focus on the characterisation activities of LEGEND, with a particular emphasis on the active volume determination of ICPC detectors. Active volume determination is a crucial characterisation task required for $0\nu\beta\beta$ analyses directly affecting the measured half-life sensitivity.

Speaker: Abigail Alexander (University College London)

NBIA_AbigailAlexander.pdf

Video

14:48 Background modeling in GERDA

Since 2011, the GERmanium Detector Array (GERDA) collaboration has searched for the double-beta decay without neutrinos ($0\nu\beta\beta$) of $^{76}$Ge by operating bare germanium detectors, enriched in $^{76}$Ge, in liquid argon.
The technological challenge of GERDA was to operate in a “background-free” regime in the region of interest (ROI) after analysis cuts for the full 100 kg$\cdot$yr target exposure of the experiment.
A precise knowledge of background intensity and distribution is essential to search for faint signals.
The background model obtained by studying the PhaseII data was able to well describe the data and the results were compatible with the expectations from material screening measurements.
The background event distribution in the ROI around Q$_{\beta\beta}$ (~2039 keV) could be well approximated with a constant function.
Since 2018, a lower energy threshold has been applied, and a background model in the new range is fundamental because it enables more sensitive signal searches. Furthermore, the next-generation experiment LEGEND will perform new signal searches at low energy.
This talk will focus on background modeling in GERDA, with a particular emphasis on the low energy range.

Speaker: Valentina Biancacci

VBiancacci_Background modelling in Gerda.pdf

Video

15:00 → 15:30 Coffee

15:30 → 16:30 Exercises

astro_exercises.pdf

astro_exercises_data_OJ287_data.txt

astro_exercises_solutions.pdf

nu_cosmology_exercise_1_2.png

nu_cosmology_exercise_3.png

theory_pheno-exercises.pdf

16:30 → 17:30 Discussion

Friday, 15 July

09:30 → 10:30 Neutrino Cosmology

09:30 Lecture III

Speaker: Dr Olga Mena

Olga_Mena_slides.pdf

Video

10:30 → 11:00 Coffee

11:00 → 11:30 Topical Seminar

11:00 Decaying dark matter

Speaker: Damiano Francesco Fiorillo (Niels Bohr Institute)

SlidesDarkMatter.pdf

Video

11:30 → 11:40 Farewell

school_farewell.pdf

Video

11:40 → 12:10 Guided Tour by Niels Bohr Archive

12:10 → 13:40 Lunch