Master thesis projects 2018/19

List of master thesis projects offered for the 2018/2019 academic year:

Supernova neutrino detection in the liquid argon DUNE experiment

Dr. Inés GIl Botella (CIEMAT) (ines.gil@ciemat.es)

The Deep Underground Neutrino Experiment (DUNE) will pursue a broad program on neutrino physics and astrophysics with a 40 kt liquid argon detector at the Sanford Underground Research Facility (SURF) 1300 km from Fermilab (USA). The size and underground location of the DUNE far detector will allow undertaking not only neutrino oscillations studies leading to measuring the CP violating phase, but also searches for new phenomena and the detection of astrophysical processes involving neutrino emission.

This End-of-Master project will be focused on studying the core-collapse supernova neutrino production, neutrino oscillation effects and their detection in underground experiments. In particular, the DUNE sensitivity to the electron flavor component will be evaluated and the potential information about the neutrino mass ordering and the dynamics and neutronization of a star's central core will be studied.

Light detection analysis with the DUNE (Deep Underground Neutrino Experiment) prototypes at CERN

Dra. Carmen Palomares (CIEMAT) (mc.palomares@ciemat.es), Dra. Clara Cuesta (CIEMAT) (clara.cuesta@ciemat.es)

Future neutrino experiments like DUNE in Fermilab (USA), whose main goal is to measure the CP symmetry violation in the leptonic sector, will consist of liquid argon TPC detectors exposed to neutrino beams. In this context, ProtoDUNE is a 300 ton prototype being built at CERN. As a previous step, a 3x1x1 m3 detector took cosmic ray data also at CERN. The neutrino group at CIEMAT is responsible for the scintillation light collection system of these detectors, which comprises a set of large photomultipliers operating at cryogenic temperature. The tasks proposed in this End-of-Master project include the data analysis of the light signal to study the detection efficiency and the simulation of the processes that will take place in the detector to characterize their scintillation signal.

Analysis of data from dark matter direct search experiments, ArDM and DEAP-3600

Dr. Luciano Romero (CIEMAT), Dr. Vicente Pesudo (CIEMAT) - (DarkMatter@ciemat.es)

The nature of Dark Matter is widely regarded as one of the most important open questions in modern physics. Multiple observations suggest that less than 15% of the universe's matter content is made of ordinary matter, while the greatest contribution is given by non-luminous and non-baryonic matter that manifests itself through its gravitational effects. A possible explanation for the Dark Matter problem lies in the existence of weakly interacting massive particles called WIMPs, remnants of the Big Bang. There are several global projects underway, carried out in underground laboratories, looking for tiny signals produced by WIMP interactions. One of them is the DEAP-3600 experiment, with 3600 kg of liquid argon, which is located in the SNOLAB laboratory (Canada). The CIEMAT-DM group participates in data taking and analysis, developing advanced analysis techniques to optimize the sensitivity of the WIMPs signal, significantly reducing background events. On the other hand, our group participates in the ArMD experiment, installed in the Canfranc Underground Laboratory under the Pyrenees, whose objective is to detect WIMPs with an electroluminescent Time Projection Chamber (TPC) filled with a ton of liquid argon. The purpose of this master's work is to contribute to the analysis of the data currently being taken by the DEAP-3600 and ArDM experiments, to verify the performance of liquid argon detectors and their ability to reject background events. The proposed tasks involve an intense learning of particle physics, nuclear physics and detectors, providing an excellent experience in order to face a thesis in particle physics or astrophysics.

Estudio, construcción y desarrollo de un nuevo detector de argón de doble fase para búsqueda directa de Materia Oscura con el experimento DarkSide-20k.

Dr. Pablo Garcia (CIEMAT), Dr. Roberto Santorelli (CIEMAT) - (DarkMatter@ciemat.es)

The direct detection of dark matter is one of the main challenges of modern physics and its discovery would mean an important advance in knowledge both in the fundamental ingredients of the universe and in the role they played in key moments of its early evolution. CIEMAT's Dark Matter group (CIEMAT-DM) specializes in this field of physics and has extensive experience in the design, construction, operation and data analysis of experiments based on liquid argon detectors. We are currently participating in the ArDM (LSC, Canfranc, Spain) and DEAP-3600 (SNOLAB, Canada) experiments. The absence, to date, of the observation of massive particles of dark matter, WIMPs, requires the construction of very massive detectors, whose sensitivity is sufficient to discover particles whose interaction cross sections are well below the current experimental limits. DarkSide-20k will be the largest liquid argon detector for the search of dark matter. With 20 tons of this material, it will have an unprecedented sensitivity to WIMPs signals. This detector will be installed at the Gran Sasso National Laboratory (Italy) and will start taking data in 2022. For DarkSide-20k to achieve its scientific objectives it is essential that its ability to discriminate signal and background (with a system called "veto") works perfectly, that the materials with which it is built are pure from the point of view of natural radioactivity, and that the argon used to record events contains insignificant amounts of the Ar-39 isotope compared to what one finds in atmospheric argon. The objectives of the work can be adapted to the interests of the student, focusing on the optimization of the veto, the impact of the radiopurity of the materials on the sensitivity of the detector or the measurement (in a specific experiment to be carried out in the LSC) of the purity of argon obtained from underground wells. All the proposed tasks entail an intense learning of particle physics, nuclear physics and detectors, providing an excellent experience in order to face a thesis in particle physics or astrophysics.

Study of the associated production of a W boson and jets with b quark content in proton-proton collisions at sqrt(s)=13 TeV with data taken by the CMS experiment at the CERN LHC

Dra. M.Isabel Josa Mutuberría (CIEMAT) (Isabel.Josa@ciemat.es)

The production of W bosons is one of the most copious processes at the LHC. In a small fraction of these events the W boson is produced in association with a jet coming from the hadronization of a b quark. It is interesting to study this type of events as they present the same topology of the events coming from the production of a Higgs boson associated with a W vector boson with the subsequent decay of the Higgs boson in a pair of quark antiquark bbbar. In the Standard Model, the production of a W boson and a b-quark jet arises only from the from the splitting of gluons into bbbar pairs; and this process may not be accurately modeled in the Montecarlo generators most commonly used.

In this work, we propose to study the production of W bosons and jets with b quark content in proton proton collisions at sqrt(s)=13TeV. Data taken by the CMS experiment during 2017 will be analyzed.

Requirement: To be inscribed in the subject “Experimental Particle Physics and Cosmology”

Study on models for cosmic rays propagation using AMS

Dr. Carlos Mañá Barrera (CIEMAT) (Carlos.Mana@ciemat.es), Dr. Jorge Casaus Armentano (CIEMAT) (Jorge.Casaus@ciemat.es). 

After more than 7 years of operation on the International Space Station, the magnetic spectromenter AMS-02 has made precise measurements of the fluxes of cosmic ray electrons, positrons, antiprotons and light nuclei up to few TeV. The deviations observed in all species with respect to the accepted models for their production and propagation may indicate the existence of new phenomena related to the nature of the galactic dark matter. The new AMS-02 measurements of the ratio of light isotopes will provide a complete data set to reduce in a significant manner the uncertainties in the models for cosmic ray propagation. The aim of this TFM is to evaluate the foreseeable impact of the future AMS-02 measurements. 

Study of a calorimeter for direct detection of cosmic rays up to 1 PeV energy

Dr. Javier Berdugo Pérez (CIEMAT) (Javier.Berdugo@ciemat.es), Dr. Jorge Casaus Armentano (CIEMAT) (Jorge.Casaus@ciemat.es).

The direct measurement of the energy spectrum of the most abundant species in cosmic rays (protons, electrons and light nuclei) shows several structures incompatible with a simple power law in energy. These observations suggest the existence of new mechanisms for cosmic ray production that have not been included in current models and may indicate the presence of new physics. Future measurements using large spaceborne experiments in an extended energy range will be required to disentangle the different possibilities. HERD is an experiment aiming to measure cosmic rays up to the PeV, which has been proposed for the projected Chinese Space Station, and will make use of a large calorimeter. The aim of this TFM is to validate the feasibility of this measurement with the simulation and the analysis of the data collected with a prototype of the calorimeter at CERN.

 

Large scale structure of universe using Gold Y1A1 data from Dark Energy Survey

Dr. Aurelio Carnero (CIEMAT) (Aurelio.Carnero@ciemat.es), Dr. Ignacio Sevilla (CIEMAT) (Ignacio.Sevilla@ciemat.es)

In this project we will analyze the Dark Energy Survey year 1 public data in terms of the large scale structure of the Universe. To do so, we will use the galaxy samples built by the collaboration for these objectives, like the BAO sample and the Redmagic sample, both targeting luminous red galaxies. In particular, we will study the baryonic acoustic oscillations signal through the angular correlation function at different redshifts and their cosmological constrains.