Research

Master/Bachelor Thesis DUNE

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.

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Master/Bachelor Thesis T2K

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.

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Master Thesis in Detector Development/Simulation

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.

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DUNE

Introduction

DUNE Experiment
The Deep Underground Neutrino Experiment (DUNE) at the Long Baseline Neutrino Facility (LBNF) is a next generation neutrino experiment planning to build a very large scale 40 kt LAr detector to provide unprecedented sensitivity to study neutrinos. The very large detector will be located at the Stanford Underground Research Facility (SURF) at a baseline of 1300 km from the Fermilab neutrino beam. DUNE proposes an immense scientific program and will answer many of the great questions of neutrino physics.

Origin of Matter

Could neutrinos be the reason that the universe is made of matter rather than antimatter? By exploring the phenomenon of neutrino oscillations, DUNE seeks to revolutionize our understanding of neutrinos and their role in the universe.

Unification of Forces

With the world’s largest cryogenic particle detector located deep underground, DUNE can search for signs of proton decay. This could reveal a relation between the stability of matter and the Grand Unification of forces, moving us closer to realizing Einstein’s dream.

Black Hole Formation

DUNE’s observation of thousands of neutrinos from a core-collapse supernova in the Milky Way would allow us to peer inside a newly-formed neutron star and potentially witness the birth of a black hole.
Mainz contributions to DUNE

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.

The process of a neutrino or anti-neutrino interacting with matter can be described by the neutrino exchanging a W- or Z-boson a neutron or proton within the argon nucleus. To understand this process it is not only important to understand the energy/momentum distribution of the argon nucleons, but also on how the particle produced inside the nucleus interact when traversing the nuclear medium of the argon nucleus.

This process will be studied by filling a TPC, a tracking chamber, with argon gas at 10 bar pressure. All, even very low energy charged particles, will leave a curved track in the TPC. Neutral particles like photons and neutrons will be measured with a calorimeter surrounding the TPC. This calorimeter will need to be able to measure the direction and energy of low and high energy photons as well as measuring the velocity of neutrons via their time of flight from the interaction vertex.

We are developing the design, detector technology and electronics for this calorimeter.

DUNE Near Detector

DUNE Near Detector (ND-GAr)

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

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Prof Alfons Weber

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.

Fun facts:

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 am a member of the LHCC advising the CERN management on the LHC experiments concentrating on CMS and the WLCG. I also serve 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.

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Searching for dark matter in all channels

Physicist at many Germany universities and unstitutes have contributed to the analyses in a recently published overview paper about the searches for Dark Matter at the ATLAS experiment. The paper has been accepted for publication by the Journal of High Energy Physics.

News article on ATLAS-FSP103
(Photo: ATLAS)

The question about the nature of Dark Matter stays unanswered. Thr ATLAS collaboration at CERN has summarised the searches for Dark Matter in a summary paper. With the data from proton-proton collisions at the LHC that was taken in 2015 and 2016, more stringent exclusion limits have been set on numerous representative processes. An extensive number of production mechanisms and final states have been covered.

BMBF supports Mainz projects in particle physics

Federal Ministry of Research provides 7 million euros for cooperative research work at CERN. ATLAS experiment and development of scintillator-based particle detectors as one of Mainz's main tasks in the coming years.

University Press Release
(Photo: ETAP/JGU)

Physicists from Johannes Gutenberg University Mainz (JGU) are involved in numerous projects of the international large-scale research institution CERN in Geneva. The Federal Ministry of Education and Research (BMBF) will continue to financially support this work in the coming years. For the three-year funding period until mid-2021, the BMBF provides nearly 7 million euros. "Projects at major research institutions are usually accompanied by a long-term commitment. “We therefore thank the Federal Ministry of Research for its continued support of these tasks with long-term, substantial funding,” says Prof. Dr. med. Georg Krausch, President of Johannes Gutenberg University Mainz. "The grants are also an award for our physicists, who make important contributions to the impressive research at CERN in many areas. We are also pleased that the achievements of the Mainz's physicists have been recently rewarded with the approval of the Cluster of Excellence PRISMA+," says the JGU President. The BMBF funds will be particularly used for Mainz's participation in cooperation projects such as the ATLAS experiment or the NA62 experiment.

One focus of the group Experimental Particle and Astroparticle Physics (ETAP) is the research on the Large Hadron Collider (LHC), the largest particle accelerator in the world, which has been in operation at CERN since 2008. "The Mainz group has taken a great deal of responsibility for the ATLAS experiment at the LHC," explains Prof. Dr. Volker Büscher from ETAP. Prof. Büscher is spokesperson of ATLAS Germany since July 2018, in which the 17 institutions working on the experiment are organised. ATLAS discovered the Higgs boson in 2012 together with another LHC experiment.

An important task of the ATLAS experts from Mainz is to analyze the data collected and recorded when the particles collide - more than 1 gigabyte per second. For this purpose, the Mainz supercomputer MOGON II, one of the fastest high-performance computers in the world, is available at the JGU. In addition, the physicists at Mainz University contribute to the upgrade of the ATLAS detector. They can rely on the infrastructure built up by the PRISMA Cluster of Excellence in Mainz, including the PRISMA Detector Laboratory. By granting the follow-up application for PRISMA+, this support will be secured in the future.

Looking to the future, the ETAP Group is developing novel particle detectors with a wide range of potential applications. In the BMBF joint project for research and development on scintillator-based detectors, Prof. Dr. Lucia Masetti, also a physicist of the University of Mainz, is the spokesperson for the joint project. "Scintillator-based particle detectors are ideal for a wide range of applications, the challenges of which we now address together as a community," says the scientist.

"Other activities we are particularly involved in, and funded by the BMBF, include the measurement of extremely rare kaon decays with the NA62 experiment, the search for axion-like particles, and machine learning," adds Büscher. The scientist notes that the LHC accelerator is in a long shutdown for the next two years since early December to carry out major upgrade work. "There is a lot to do for us during this time," says Prof. Büscher. "Then, with the LHC restarting with increased luminosity, we'll go deeper into exploring the smallest particles that make up our matter."

ETAP group part of the network "Innovative Digital Technologies for Universe and Matter Research"

Large-scale experiments in fundamental research require more and more computing and storage resources. In order to gain further scientific insight in the future, physicists from several research institutions have now joined forces in a project funded by the Federal Ministry of Education and Research (BMBF) to develop innovative digital processing methods.

BMBF Press Release

In the context of the framework programme "Erforschung von Universum und Materie – ErUM", the Federal Ministry of Education and Research (BMBF) is funding this network with the name "Innovative Digital Technologies for Research on Universe and Matter" as a pilot project with a total of 3.6 million euros over the next three years. Researchers of the ETAP group are participating in this network together with other researchers from the groups of the Universities of Aachen, Erlangen-Nuremberg, Frankfurt am Main, Freiburg, Hamburg, Munich, Wuppertal and the Karlsruhe Institute of Technology as well as the associated partners DESY (Deutsches Elektronen-Synchrotron), CERN, Forschungszentrum Jülich, Grid Computing Centre Karlsruhe (GridKa), GSI Helmholtzzentrum für Schwerionenforschung and the Universities of Bonn, Göttingen and Münster. Prof. Thomas Kuhr from the LMU coordinates the network.
The participating researchers contribute their diverse experience and knowledge in the fields of distributed computing infrastructures and algorithm development to the project.

Within the next three years, the joined project will develop and test new computing systems. One promising approach is the use of virtualization technologies to tap previously inaccessible resources. The scientists are also thinking about the use of new processor architectures, which are used, for example, in graphics cards and promise better energy efficiency (Green IT). The researchers see an important pillar in the development of improved algorithms and the use of artificial intelligence (AI) for Big Data analyses. Innovative methods of "machine learning" will play an important role here.

"The huge amounts of data are a great challenge for us. Innovative digital methods will be indispensable in the future if fundamental research is to advance decisively," said network coordinator Prof. Thomas Kuhr. However, it is not only physical research that faces the digital challenge. "Sooner or later, other scientific disciplines will also need powerful computing environments and will benefit from the new competences," Kuhr is certain. The joint project offers the participating young scientists an excellent opportunity to acquire comprehensive knowledge in new computing technologies. This means they are well prepared to fill leading positions in science or business in order to drive digital change forward.

The contribution of the ETAP group within this network is the replacement of existing algorithms for the real time detection and reconstruction of physics objects by deep neural networks. The group is targeting a processing rate of up to 40 MHz and a maximum response time of less than a millionth of a second. This will be sufficient to cover a large range of applications within the network. Field Programmable Gate Arrays (FPGAs) are the ideal choice.

The challenge is to optimally adapt the neural networks to the architecture of FPGAs, and the first trigger stage of the ATLAS experiment provides an ideal test environment for this.

Members of the ETAP group receive ATLAS outstanding achievement award

Rosa Simoniello and Eduard Simioni from the ETAP group receive the ATLAS outstanding achievement award for outstanding contributions and dedication in successfully commissioning the Level-1 Topo trigger

ATLAS Press Release
(Photo: E. Ward/CERN)

Two members of the ETAP ATLAS group received the ATLAS outstanding achievement award for the work on the ATLAS Level-1 Topo trigger. They have been awarded the price together with Olga Igonkina, Murrough Landon and Imma Riu.

PRISMA+ Cluster of Excellence selected by the German Research Funding Agency

PRISMA + is the follow-up application for the Cluster of Excellence "Precision Physics, Fundamental Interactions, and Structure of Matter" (PRISMA), which has been successful in the previous Excellence Initiative and has been funded since 2012.

press release by the Germany Resaerch Funding Agency
press release of the university

Today the German Research Funding Agceny (DGF) has announce the selection of the projects that will be funded under the Excellence Initiative. An international committee of experts and the science ministers of the federal and state goverments has selected 57 out of 88 submitted projects.

The PRISMA+ project for precision physics, fundamental interactions and structure of matter which was submitted by the University of Mainz was among the selected projects.

The total amount of the requested funding is expected to be 64 million euro over the next seven years.