The near detector complex at the DUNE long-baseline neutrino oscillation experiment will use the PRISM approach: Some of the near detectors will be movable to different off-beam-axis angles to measure neutrino interaction event rates in different neutrino flux distributions. A linear combination of the event rate distributions at the different angles can then be used to predict the event rates at the far detector for different assumed values of oscillation parameters, with a reduced dependence on (and thus reduced systematic uncertainty caused by) neutrino-interaction models. The event rates measured at different angles can also be used to measure neutrino cross section as a function of neutrino energy, without having to rely on interaction models to reconstruct the energy on an event-by-event basis. This is a novel statistical approach that promises to allow measurements that simply were not possible to do in a model-independent way before. While it should work in principle, many question regarding the practical application of this methods remain and need to be investigated. A thesis in this topic would involve studying this method using simulated data, especially in regard to the question how it performs under realistic conditions.

Neutrino Cross-section Measurements at the Near Detector of the T2K Experiment

Cross sections of neutrino interactions with matter are an important input into other neutrino experiments, like oscillation analyses. Unfortunately, our current models of neutrino-nuclear interactions are not able to describe the data in the 1 GeV neutrino energy region well. Cross-section measurements are thus a crucial tool to constrain systematic uncertainties for experiments working in these energy ranges (e.g. T2K, HyperK, DUNE). The AG Weber offers Bachelor and Master thesis topics investigating aspects of these measurements. This can include but is not limited to studies about different neutrino interaction models and how they compare to the data, sensitivity studies for future measurements, development of data selections at the T2K near detector for cross-section measurements, and investigation of statistical methods to extract the cross sections from the measured event rates.

Neutrino physics is a captivating field dedicated to studying the characteristics of lightweight, electrically neutral particles with fascinating properties. Due to their weak interactions, detecting neutrinos is challenging, but their study provides valuable insights into astrophysical phenomena, such as stellar processes and the early universe. Fundamental research on neutrinos has yielded groundbreaking discoveries, including their mass and flavor-changing abilities. This field expands our understanding of the universe and finds practical applications in nuclear reactor monitoring and particle astrophysics.

This master thesis will be conducted within the Alfons Weber group in Mainz, as part of the LiquidO consortium. The group actively contributes to globally significant neutrino oscillation experiments like T2K and DUNE.

LiquidO (since 2016) is a novel detection technology for fundamental research and innovation, exploring the possibilities of light detection in opaque madia. Through active exploration of LiquidO's scientific potential, we uncover a multitude of new projects and experiments. The development of LiquidO entails extensive R&D and prototyping, fine-tuning its performance for ultra-sensitive particle detection, especially in the neutrino research field.

The thesis will specifically focus on the first LiquidO-based neutrino experiment, known as the CLOUD experiment. After the CHOOZ and Double Chooz experiments, CLOUD opens the third generation of experiments at Chooz power plant (France), the most powerful European site for reactor neutrino research.

One of the first goal of the thesis will be to concentrate on modeling and simulating the detector, which is a crucial phase in the development of the experiment. This work will contribute to shaping the future design of the detector within the collaboration.

The Mainz group is contributing to the near detectors of the DUNE complex, which are essential to understand the properties of the neutrino beam and how neutrinos interact with argon. We are involved in the development of the TMS near detector design and reconstruction algorithms, as well as the development of analyses using the PRISM approach of the near detector complex.

TMS is a muon spectrometer which will be positioned behind the liquid argon detector ND-LAr. Its job is to "catch" nigh energetic muons that leave ND-LAr and determine their energy and charge. The muons are detected by layers of scintillator bars. In between the scintillation layers, there are layers of magnetized steel. The steel serves to bend the tracks slightly, so their charge can be measured. The thick steel layers also absorb a lot of energy, stopping the muons in the detector. The muon energy is inferred from the total length of the muon track.

In the PRISM approach, the near detector is made movable, allowing us to take data at different angles w.r.t. the beam axis, and thus in different neutrino energy spectra. Using the same detector in different beams allows us to disentangle the effects of beam uncertainties and interactions uncertainties, which usually are very hard to distinguish in a single detector in a single beam. By building linear combinations of the data taking in different fluxes, one can create "virtual measurements" in virtual fluxes that correspond to the same linear combination. This can then be used to "simulate" the oscillated beam at the far detector, or to do cross section measurements in different virtual beams.

Please have a look here for Bachelor, Master and PhD theses in the ETAP group.

I hold a joint professorship at the University of Mainz and Fermilab and am a visiting professor at the University of Oxford. My main research interest is in neutrino physics, but I am also active in developing electronics and novel detectors.

Contact:
I can be reached via email email, phone (+49 6131 39 24175) or our secretariat. Additional contact information can be found here.

Fun facts:

• My Erdös Number is at most 4. Thanks to Phil Rodrigues for pointing this out and providing the connection.
• My Academic Family Tree can be found here.

Research

I started my career in physics doing a diploma thesis in phenomenology, looking into novel way of detecting relict neutrinos from the big bang, or solar and accelerator neutrinos. After this more theoretical start at the RWTH-Aachen, I switched to experimental physics and did my Ph.D. and first post-doc at the L3 experiment at the LEP collider at CERN. I searched for new particles (but didn't find any) and made precision measurements of the W-boson mass.

I returned to neutrino, when I came to Oxford in 1999. I started to lead the Oxford MINOSgroup, who looks into the phenomenon of neutrino oscillations at Fermilab. We made a precision measurements using muon neutrinos from the NuMI beam line. More information can be found at the Fermilab MINOS page.

Later I joint the T2K experiment in Japan, which looks for electron neutrino appearance in a muon neutrino beam. We were awarded the Breakthrough Prize in Fundamental Physics for the measurement of neutrino oscillations and even found the first indication that neutrinos and anti-neutrinos don't oscillate in the same way. This process may eventually hold the key to understand why there is more matter than anti-matter in the universe. We need a new generation of experiments to really unlock the secret of the neutrino.

The DUNE Experiment is exact this. This very long baseline neutrino oscillation experiment is located in a neutrino beam that goes from Fermilab for 1300 km to the Sanford Underground Research Facility (SURF). The DUNE far detector will consist of 70,000 tons of liquid argon and will have an unprecedented sensitivity to measure neutrino oscillation. Its main aim is not only to study the matter anti-matter asymmetry, but to look for neutrino from supernova explosions or for the decay of the proton. I was the UK PI of the project and also leading a team to design the near detector, which is an essential component of the experiment to study the neutrino beam composition and the details of the neutrino interactions. I am the chair of the Institute Board of the International DUNE Collaboration.

I have also developed a novel detector for neutrino and neutron detection. These activities lead to the creation of the SoLid experiment, which searches for sterile neutrinos at the research reactor BR2 in Mol, Belgium.

Committees

I was serving on the STFC Science Board that provides advice to STFC Council and the executive on all aspects of STFC's science and technology programme.

I was on the Executive Committee of the MINOS and NOvA Experiments and was the chair of the institutional board and a member of the Executive Committee of the LAGUNA-LBNO design study. I am now the chair of DUNE's Institute board. I also served on the HyperK PAC advising the University of Tokio and KEK in Japan on the progress of the HyperK Experiment.

I am a member of the LHCC advising the CERN management on the LHC experiments concentrating on CMS and the WLCG. I also served on the HyperK PAC advising the University of Tokio and KEK in Japan on the progress of the HyperK Experiment.

Master Thesis

Please get in contact with me, if you are interested in master thesis in my area of research. There are many options how you can make a difference in our research. One topic is listed below.

• Master Thesis in Detector Development/Simulation