À descoberta da natureza do neutrino: decaimento beta duplo sem neutrinos
O decaimento beta duplo sem neutrinos é um dos tópicos mais interessantes da física de partículas contemporânea. A sua observação provaria a existência de nova física para além do modelo padrão (SM), e mostraria que o neutrino é uma partícula de Majorana -- isto é, é a sua própria anti-partícula. Provaria ainda a existência de processos que violam a conservação do número leptónico, suportando a ideia de que os leptões podem ter contribuído também para a assimetria entre matéria e anti-matéria observada no Universo. Este decaimento está previsto em extensões do SM que também conseguem explicar a massa extremamente pequena dos neutrinos (6 ordens de grandeza menor que a do electrão). A taxa do decaimento pode ser associada à chamada massa efectiva de Majorana, uma combinação das 3 massas de neutrinos que pode ser usada para determinar se estas massas seguem uma hierarquia normal ou inversa (apesar de não permitir determinar os seus valores absolutos). Várias experiências, entre as quais LUX-ZEPLIN (LZ), procuram este decaimento extremamente raro. O detector LZ, que começou a funcionar no final de 2021, foi desenvolvido com o objectivo principal de procurar interacções directas de matéria escura com o material de detecção (xénon líquido), mas dada a sua grande sensibilidade pode também ser usado para estudar outros processos físicos como o decaimento beta duplo sem neutrinos. O isótopo Xe-136 é um conhecido emissor beta duplo com emissão de neutrinos, e portanto poderá também decair sem emissão de neutrinos, sendo atualmente o isótopo que permite restringir mais fortemente os valores da massa efectiva Majorana. Neste projecto os alunos irão avaliar a sensibilidade de LZ para observar este decaimento no Xe-136 analisando dados da experiência.

Grupo : DarkMatter
Local : Coimbra
Supervisor(s) : Alexandre Lindote / Paulo Brás
Email : alex@coimbra.lip.pt
Vagas : 3
Duração/Datas : July to September

Detecção Directa de Matéria Escura com a Experiência LUX-ZEPLIN
A experiência LUX-ZEPLIN (LZ) tem como objetivo principal responder a um dos maiores enigmas científicos do nosso tempo: o que é a matéria escura. Observações astronómicas como a velocidade radial das galáxias, a radiação cósmica de fundo ou a observação de lentes gravitacionais apontam para que a maior parte da massa do Universo (cerca 85%) seja sob a forma de partículas exóticas, a que se chamou matéria escura por não se conhecer a sua natureza, e cuja probabilidade de interacção com a matéria comum é muito baixa. Com 7 toneladas de xénon líquido como alvo para as partículas de matéria escura, LZ é o maior detector do seu género alguma vez construído. Os resultados preliminares, publicados em 2022, demonstram a sua extrema sensibilidade que é recorde até hoje. As operações de LZ continuarão até ao final da década, tendo a capacidade de detectar pela primeira vez matéria escura. Nesta atividade, vais explorar o detetor LZ, entender o seu princípio de funcionamento, e olhar para os dados a fim de procurar um possível sinal desta matéria misteriosa.

Grupo : DarkMatter
Local : Coimbra
Supervisor(s) : Cláudio Frederico Pascoal da Silva, Paulo Alexandre Brinca da Costa Braz
Email : claudio@coimbra.lip.pt
Vagas : 3
Duração/Datas : 2023-06-01 2023-09-15

Background analysis in recent SNO+ data
The SNO+ detector, located in a mine deep underground in Canada, aims at studying the neutrino properties via the search of the double-beta decay without neutrinos of tellurium-130. This decay, not observed yet, will answer the question if neutrinos are Majorana or Dirac particles. Furthermore, thanks to the low energy threshold and the high purity of the materials selected, it can measure solar neutrinos, antineutrinos from reactors and the Earth, supernova neutrinos and other rare events. In order to fulfill SNO+ goals, it is extremely important to characterize the radioactive background (Uranium and Thorium) of the detector. Since April 2022, SNO+ is taking data using a liquid scintillator target to which it has recently added a secondary wavelength shifter to enhance the emitted light. During this internship the data recently taken by SNO+ will be analysed to identify the main background components of the Uranium chain (Pa234, Bi214, Bi210 and Po210) by comparing data with Monte Carlo simulations.

Grupo : Neutrinos
Local : Lisboa
Supervisor(s) : Valentina Lozza
Email : vlozza@lip.pt
Vagas : 1
Duração/Datas : June and July

Bi207 source: looking for energetic peaks
Análise de séries temporais.

Grupo : AMS
Local : Lisboa
Supervisor(s) : Fernando Barao
Email : fernando.barao@tecnico.ulisboa.pt
Vagas : 2
Duração/Datas : 15/June - 31/July + 01/Sep-10/Sep

Improving Neutrino Detection at the Pierre Auger Observatory through Vertical Events
The detection of ultra-high-energy cosmogenic neutrinos is eagerly sought by the scientific community as they could bring light to the origin and propagation of ultra-high-energy cosmic rays, the highest energy particles known to humanity. However, the searches in large observatories such as the Pierre Auger Observatory, are usually bounded to the detection of very inclined showers, undermining the sky observation capabilities and attainable fluxes. At the Auger-LIP group, we are pursuing a novel possibility: to detect neutrino events also using vertical shower events (theta < 60 deg) by exploring the balance between shower muonic and electromagnetic signals. The students participating in this project will use state-of-the-art shower and detector simulations to investigate this possibility and develop an experimental analysis to be applied to the Pierre Auger Observatory data.

Grupo : Auger
Local : Lisboa
Supervisor(s) : Ruben Conceição, Pedro J. Costa
Email : ruben@lip.pt
Vagas : 2
Duração/Datas : Mid June to the beginning of September (dates to be arranged between students and supervisors)

Investigating Gamma/Hadron Discrimination Features to Augment Gamma-Ray Observatory Physics Capabilities
The detection of the faint fluxes of ultra-high-energy gamma rays is connected to the ability of ground-based observatories to discriminate the gamma-induced showers from the overwhelming cosmic ray background. The Auger-LIP group has developed several discriminators in recent years that have the potential to boost the capabilities of the gamma-ray observatories that are being planned, namely the Southern Wide-field Gamma-ray Observatory. In this project, students will work on a dedicated simulation framework to further explore the features of these novel variables to further understand their behavior and enhance their discrimination power.

Grupo : SWGO
Local : Lisboa
Supervisor(s) : Ruben Conceição, Lucio Gibilisco
Email : ruben@lip.pt
Vagas : 2
Duração/Datas : Mid June to the beginning of September (dates to be arranged between students and supervisors)

Neutrino observatory for geosciences
Due to their different properties, each elementary particle is useful for getting different information. The SNO+ detector in Canada measures neutrinos produced by the Uranium and Thorium decays in the Earth crust and mantle, as done previously only from Japan and Italy. SNO+ is located 2000 m underground to avoid noise from cosmic ray muons, but still a few muons can reach it every hour, which can be used to map the shielding between the detector and the surface. Based on simple models and inspired by read data, we want to explore what neutrinos and muons are telling us about the rocks surrounding and how much time we need to understand their messages about the Earth.

Grupo : Neutrinos
Local : Lisboa
Supervisor(s) : Sofia Andringa
Email : sofia@lip.pt
Vagas : 2
Duração/Datas : mostly June, July

Testing new detectors with muography
Muography is an imaging technique similar to radiography but useful for much larger scales. LIP develops muon telescopes for several uses and built on different detector technologies: one built on a new concept of sealed RPCs has been recently installed at the LHC tunnel at CERN. Before that, its operational parameters were tested in LIP’s laboratory for several months. In this project, we want to further test its capabilities by constructing and comparing images of the building obtained in each configuration, leaving the tools ready for the test of the muon telescopes being now built.

Grupo : MuTom
Local : Lisboa
Supervisor(s) : Sofia Andringa
Email : sofia@lip.pt
Vagas : 2
Duração/Datas : mostly June, July

Calibração de um detetor do Observatório Pierre Auger
O estudo de raios cósmicos de energia extrema com o Observatório Pierre Auger pretende fornecer respostas sobre a natureza, a origem e os mecanismos físicos de produção e aceleração destas partículas. A Fase-2 do programa de pesquisas do observatório teve início, recentemente, com a conclusão da instalação de novos instrumentos de deteção no terreno. Estes incluem detetores que medem a componente de rádio emitida em chuveiros atmosféricos extensos, a luz de cintilação criada pelas partículas dos chuveiros à superfície e o número de muões que atingem alguns metros abaixo do solo. O estabelecimento de procedimentos precisos e robustos para a calibração dos novos detetores, objecto deste projeto de investigação, garante uma interpretação física correta dos dados obtidos e fornece uma base para as análises efetuadas sobre os mesmos.

Grupo : Auger
Local : Minho
Supervisor(s) : Raul Sarmento
Email : raul@lip.pt
Vagas : 2
Duração/Datas : Junho e/ou Julho

Characterization of state-of-the-art instrumentation for timing RPCs detectors
Timing Resistive Plate Chambers are large area detectors with good efficiency and excellent timing precision. They are capable to timing tag charged particles with a precision down to around 50 ps. To exploit this precision the Front End Electronic (FEE) and Data Acquisition System (DAQ), should contribute significantly less in order to do not degrade the timing precision. In this internship, we will characterize, mainly in term of timing precision, a state or the art DAQ (http://trb.gsi.de/), which incorporate FPGA-TDC based technology, and different high resolution FEE used in different RPC setups. At the end of the internship, we will characterize a working setup. A small four-plane RPC telescope, designed for precise cosmic ray measurements, equipped with the aforementioned DAQ and one of the FEEs under study. The students will become familiar and in close contact with the necessary instrumentation (oscilloscopes, multimeters, power supplies, TDCs, ....) and software (daq control, data unpackers, calibration).

Grupo : RPC
Local : Coimbra
Supervisor(s) : Alberto blanco
Email : alberto@coimbra.lip.pt
Vagas : 2
Duração/Datas : July

Detectores gasosos R&D
No grupo de detectores R&D trabalhamos com detectores gasosos com o intuito de melhorar as suas características ou adaptar as existentes a necessidades especificas. Com a criação de experiências de grandes dimensões, frequentes em Colaborações Internacionais, novas solicitações têm surgido relativamente ao desempenho dos contadores gasosos. É com este tema genérico que vimos propor o nosso estágio de verão. Concretizando, o/a aluno vai contactar e aprender técnicas de vazio, manuseamento de gases, recolha e tratamento de dados, montagem de detectores, ou seja, técnicas experimentais relacionadas com detectores gasosos, bem como apoio teórico sobre o tema em estudo e o objectivo do trabalho. O/a estagiário/a será também incitado e ajudado a fazer alguma pesquisa autónoma sobre os assuntos em estudo. Pretende-se familiarizar o/a estagiário/a com técnicas laboratoriais realçando também a formação e pesquisa teóricas.

Grupo : GasDet
Local : Coimbra
Supervisor(s) : Filomena Santos e Afonso Marques
Email : filomena.santos@coimbra.lip.pt
Vagas : 1
Duração/Datas : Junho a Setembro (a combinar)

Development and characterization of a power supply for amplifier electronics
In this internShip, we will design and implement a switching power supply for powering state of the art electronics used in RPC type particle detectors. The power supply should be compact, low noise and with high current capability. First we will learn the basic principles of this type of power supply and then we will build a prototype for which it will be necessary to learn how to solder. Finally we will characterize the noise of the power supply and its impact on the amplifier electronics it powers.

Grupo : RPC
Local : Coimbra
Supervisor(s) : Alberto blanco
Email : alberto@coimbra.lip.pt
Vagas : 2
Duração/Datas : July

Introdução ao estudo de detetores de radiação
Neste estágio, os alunos irão ser integrados numa equipa de investigação, na área de instrumentação para o espaço. A equipa de investigação está, neste momento, fortemente envolvida num projeto europeu com a ESA numa missão em que um /vai-vém/ espacial não tripulado – Space Rider, colocará em órbita no ano de 2025, um dos nossos detetores de radiação de estado sólido. Os trabalhos ao longo deste estágio incluirão a utilização de detetores de radiação: gasosos e de estado sólido. Depois de uma introdução/revisão teórica do funcionamento dos diferentes tipos de detetores de radiação, os alunos irão ter a oportunidade operar alguns destes tipos de detetores. O trabalho prossegue para a utilização de um detetor de estado sólido com características semelhantes ao que vai ser usado na missão e, através do qual, os alunos irão aprender a identificar a radiação incidente bem como a avaliar a energia, natureza e direção de incidência, através dos dados recolhidos pelo detetor. Além das competências adquiridas com a utilização dos detetores, no decorrer do estágio os alunos irão também aprender ou reforçar os seus conhecimentos de técnicas de vácuo, manuseamento de gases e de eletrónica nuclear.

Grupo : i-Astro
Local : Coimbra
Supervisor(s) : Alexandre Trindade
Email : alexandre.trindade@coimbra.lip.pt
Vagas : 2
Duração/Datas : 1 mês - Julho

The nRPC-4D neutron detector: experimental study of its sensitivity to gamma rays
The internship will take place in the Neutron Detectors Group, at LIP in Coimbra, Portugal. The group main activity involves the development of neutron detectors, in the area of detectors for nuclear and particle physics. Currently, we are developing a neutron detection technology that combines Resistive Plate Chambers (RPC) and solid-state neutron converters, recently introduced by us. The results of our previous studies demonstrated that it has high potential for the design of high precision neutron detectors, both in time and position. Our research has two goals. First, we want to advance the RPCs technology for neutron imaging detectors demonstrating both high spatial accuracy and timing capability satisfying the requirements of modern applications at neutron facilities. Second, we also intend to explore the possibility to apply this technology for the detection of epithermal and fast neutrons. Students will participate in the groups ongoing research activities, and will be involved in both the simulation work (Monte Carlo simulations in Geant 4), and in experimental tests. It is expected that students will learn to independently perform Monte Carlo simulations (ANTS3 and Geant4), conduct experimental work, and perform data acquisition and processing. Students are also expected to report on their work at the end of the internship. They will be encouraged to present their achievements at the LIP Summer Student Internship Workshop and write an internal note that will be available at the LIP website.

Grupo : nDet
Local : Coimbra
Supervisor(s) : Luís Margato and Andrey Morozov
Email : margato@coimbra.lip.pt
Vagas : 1
Duração/Datas : From 1 June to 31 Jully

Metrology of the fibre optic arrays of a dosimeter for radiotherapy applications
The quality assurance of radiotherapy treatments is secured by different methodologies including the instruments that can describe the accurate dose distribution of the radiation field. In the RADART group, a dosimeter is being developed based on scintillating optical fibres for radiotherapy. The fibres are placed in arrays of juxtaposed fibres that need to go through metrology measurements that can identify defects not discernible by the direct observation of the naked eye. Confocal microscopy was used to produce detailed images of the fibre planes. The images have been analysed using the connected components labelling method which runs over the pixels of the produced images and discriminates between clusters (fibres) and unfilled spaces. In the current trials to extract the metrology the current limitations are present: the fibre image must be broken into sections for the measurement and not all the fibres/clusters are identified correctly. The proposed project requests the student to revisit and revalidate the used clustering methodology. The student will also be invited to visit other algorithms used for image and pattern recognition that could be used for the same purpose. The current version is implemented in MatLab but implementation in Python, C++ or other programming languages can be options to circumvent the current limitations.

Grupo : RADART
Local : Lisboa
Supervisor(s) : Joao Gentil, Duarte Guerreiro, Jorge Sampaio
Email : gentil@lip.pt
Vagas : 1
Duração/Datas : July, 1st to August, 9th (an earlyer start can be discussed)

Production and characterization of cell-level passive dosimeters
A detailed description of radiation fields at the cellular level can be achieved through the use of a specific type of dosimeters that record the tracks generated by charged ionizing particles. However, the current solution, which utilizes an alumina single-crystal matrix doped with carbon and magnesium (Al2O3:C, Mg), has limitations in its sensitivity to low-mass particles and neutrons. Nevertheless, a proper choice of the adequate dopant combination is expected to result in an improvement in the performance of these passive dosimeters. During this internship, the student will follow and participate in the whole process, from crystal growth, to test samples preparation and characterization. The crystals will be grown using the flux method, followed by impregnation in an epoxy matrix to produce laminated test samples. The test samples will be in the first place irradiated using an Am-241 alpha source. Subsequently, they will be characterized using wide-field and confocal microscopy techniques. Another important task will involve identifying dopants and their concentrations, which can be done using a combination of X-ray, PIXE, and RBS techniques. This proposal arises from a collaboration between LIP and C2TN, leveraging the expertise available in both research units.

Grupo : RADART
Local : Lisboa
Supervisor(s) : Joao Gentil, Antonio Gonçalves (C2TN), Cristiana Rodrigues
Email : gentil@lip.pt
Vagas : 1
Duração/Datas : July, 1st to August, 9th (an earlyer start can be discussed)

Study of new plastic scintillator materials for future detectors
Organic scintillators with novel polymeric substrates are being developed in a collaboration between LIP and the Institute for Polymers and Composites of the Minho University towards the design of detectors for future collider experiments. Radiation hardness and large scintillation light output of the materials are key points to optimize since these properties determine the lifetime and applicability of the scintillators. This project will focus on the optical characterisation of the produced scintillator samples, such as the light response and emission spectrum. Additionally, it also includes the development of new test systems to characterise the light output of the scintillators. The work will be carried out at LIPs Laboratory of Optics and Scintillating Materials.

Grupo : LOMaC
Local : Lisboa
Supervisor(s) : Rudnei Machado and Rute Pedro
Email : rute@lip.pt
Vagas : 2
Duração/Datas : Junho e Julho

Upgrade of the ATLAS Tile Calorimeter High Voltage System
The upgrade of the ATLAS detector to work at the high-luminosity LHC (HL-LHC) implies the replacement of all the electronics of the Tilecal hadronic calorimeter, including the high voltage (HV) system that feeds the 10000 Tilecal photomultipliers, as the existing HV system is not able to survive in the radiation environment predicted for the HL-LHC. The new high voltage system will be located outside the detector in an area not exposed to radiation, and consists of high voltage regulator and distributor cards and high voltage DC-DC converter cards that produce the primary HV (HV supplies). To take the HV to the detector, cables of about 100 meters in length will be used, and inside the detector the HV will be distributed by Hvbus distribution cards. The new HV system is being developed at LIP. The last prototype boards and cables will be tested on the crate prototypes, using specific software developed for the respective control and monitoring. At this project, the performance of the various prototypes will be evaluated.

Grupo : ATLAS
Local : Lisboa
Supervisor(s) : Agostinho Gomes, Luis Gurriana, Guiomar Evans
Email : agomes@lip.pt
Vagas : 2
Duração/Datas : flexible from June to early September

Construção de um acelerador de partículas
O acelerador de partículas é uma das instrumentos fundamentais para o estudo dos elementos mais básicos da natureza. Neste estágio iremos construir aceleradores de pequenas esferas metálicas, que serão operados manualmente e de forma cooperativa e competitiva, e automaticamente usando microcontroladores do tipo arduino, para depois serem usados em exposições e demonstrações científicas para explicar ao grande público como funcionam estas máquinas.

Grupo : ECO-AT
Local : Minho
Supervisor(s) : Henrique Carvalho
Email : hcarvalho@lip.pt
Vagas : 2
Duração/Datas : Junho e/ou Julho

High-precision fully differential predictions for top-pair production at the LHC in perturbative QCD
The asymptotic freedom is a feature of QCD, the theory of the strong interaction, which makes the coupling constant of theory small at high energies. As such, a perturbative approach to the quantum field theory of QCD is applicable and has been successful in the computation of cross sections for many final states produced in proton-proton collisions at the LHC. In this project the student will obtain, using state-of-the art Monte Carlo generators, fully differential theoretical predictions for top-pair production at the LHC in QCD. The goal is to test the theoretical accuracy of these calculations and assess quantitatively their agreement with recent experimental measurements of this process at the LHC.

Grupo : Pheno
Local : Lisboa
Supervisor(s) : João Pires
Email : jnpires@lip.pt
Vagas : 1
Duração/Datas : At least 4 weeks from beginning of July until first week of September

Investigating the Flavour Anomalies with Machine Learning at LHC
While the Standard Model (SM) is very successful to describe the properties of the elementary particles and their interactions, a set of experimental measurements of B-hadron decays is found to be in tension with the SM predictions. These are the so-called Flavour Anomalies. One of the most interesting types of measurement, among the ones composing the Flavour Anomalies, is the Lepton Flavour Universality (LFU) test, i.e. the comparison of the probability of a B-hadron decaying in channels involving different lepton flavours (electron, muon, tau). These measurements are very powerful tools to investigate the existence of new physics beyond the SM. In this project the student will analyse data collected by the Compact Muon Solenoid experiment, at the Large Hadron Collider, to reconstruct the decay of the B0 meson into a K*0 and two leptons, which is one of the most promising decay channels for the study of LFU in B decays. The analysis will be carried out on a dedicated dataset, which has been collected during the Run-2 data taking. By making use of novel data-acquisition techniques, this dataset contains an enormous set of B-hadron decays without any requirement on the final state, allowing to explore the decay channels containing any lepton flavour. Machine Learning techniques will be developed to reconstruct the candidates and optimize the rejection of background events. Finally, the student will use a fitting procedure to estimate the number of signal events in the dataset, which is the main ingredient of the lepton universality tests.

Grupo : CMS
Local : Lisboa
Supervisor(s) : Alessio Boletti, Nuno Leonardo
Email : alessio.boletti@cern.ch
Vagas : 2
Duração/Datas : From June to begin of September (exact dates to be agreed before beginning the project)

Study of generative machine learning for future collider calorimeter optimisation
In this project we will explore machine-learning surrogate methods such as generative adversarial networks (GAN) combined with GEANT4 for performing calorimeter design optimization. The work will start with an ATLAS-like calorimeter and study its energy response to single particles at various energies. A GAN will be employed to parameterise its performance as a function of design choices.

Grupo : FCC
Local : Lisboa
Supervisor(s) : Inês Ochoa
Email : miochoa@lip.pt
Vagas : 1
Duração/Datas : Junho, Julho, Setembro

Study of quark hadronization at the LHC
The project that will be developed concerns one of the hallmarks of quantum chromodynamics (QCD), namely, hadronization, the mechanism through which quarks combine with other quarks to form hadrons (colorless states). The student will carry out the study of B mesons produced in proton-proton (pp) collisions as function of the mesons kinematic (momentum, rapidity) and environment (multiplicity) variables. Employing state-of-the-art data analysis methods (likelihood fitting and machine learning techniques), recent pp collision data collected by the CMS experiment at the LHC will be explored. As part of the final results we aim to measure the b quark fragmentation fractions, i.e. the relative fractions the b quark hadronizes into different B hadron species, as well as their ratios and dependencies. Such studies can then be extended to nuclear collisions (PbPb), with the goal of understanding how the quark-gluon plasma (QGP) affects the quark hadronization process.

Grupo : CMS
Local : Lisboa
Supervisor(s) : Henrique Legoinha, Nuno Leonardo
Email : h.legoinha@cern.ch
Vagas : 2
Duração/Datas : 1 June to 15 September (Flexible)

Tracking muons from ongoing LHC collisions
Muons are highly penetrating particles that traverse large amounts of matter. A muon telescope, designed and built at LIP, has just been installed last month in the LHC tunnel. It will allow us to measure the flux of muons produced in the LHC collisions, that occur 500m away at ATLAS. The unique measurement that will be performed will not only allow to improve the physics simulations of the LHC collision products, but is also key for detecting neutrinos at the LHC – a milestone that has been only recently achieved for the first time, with the most recent CERN experiment, SND@LHC. (Refs: https://www.lip.pt/?section=press&page=news-details&id=1687; https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.031802)

Grupo : SHiP/SND@LHC
Local : Lisboa
Supervisor(s) : N.Leonardo, C.Vilela, A.Blanco
Email : nuno.leonardo@cern.ch
Vagas : 2
Duração/Datas : May-September (flexible)

Searching for new physics phenomena in ATLAS data using machine learning
The Standard Model of particle physics covers the elementary constituents of matter and describes the fundamental interactions between them. It is a model that has been extremely successful in describing experimental measurements but does not provide an answer to important evidence such as the existence of matter or the asymmetry of matter/anti-matter. There is a panoply of new physics proposals beyond the standard model that try to explain the open questions, all of which are impossible to test at the LHC. In this project, advanced data analysis techniques will be exploited to analysing data to identify new physics phenomena. These techniques will be applied to data from LHC/CERN proton-proton collisions acquired by the ATLAS experiment.

Grupo : ATLAS
Local : Minho
Supervisor(s) : Nuno Castro
Email : nuno.castro@cern.ch
Vagas : 2
Duração/Datas : June-July

Dressed quark mass function in the Covariant Spectator Theory
Dynamical chiral-symmetry breaking is the phenomenon of Quantum Chromodynamics (QCD) that is responsible for the bulk of the proton and neutron mass, and therefore for more than 98% of mass of ordinary matter in the Universe. Quarks, the constituents of hadrons such as protons and neutrons, interact with themselves through the strong interaction which generates a momentum-dependent or “running” quark mass. This dressed quark mass function is of particular interest as it provides the connection between the current quark masses from the Higgs mechanism and the constituent quark masses inside hadrons. The dressed quark mass function is calculated by solving an integral equation in momentum space, the so-called “gap equation” with an interaction kernel that describes the strong force. In this more theory-oriented internship the selected candidate(s) will numerically study and solve the integrals involved in the calculation of the quark mass function within the framework of the Covariant Spectator Theory. Candidates should have a decent knowledge of quantum mechanics and some familiarity with the Dirac equation. Some programming experience is also required, in languages like Mathematica, Fortran, C++ or Python.

Grupo : NPStrong
Local : Lisboa
Supervisor(s) : Elmar Biernat, Alfred Stadler
Email : elmar@lip.pt
Vagas : 2
Duração/Datas : Dates are flexible. We could start sometime in June and continue until the end of July in person at LIP. Occasional remote meetings during August would also be possible, if needed.

Hunting for kaons and Lambdas at AMBER
AMBER is a new fixed-target experiment at CERN devoted to studies of hadron physics. In 2023 the first measurement was performed, aiming at the antiproton production cross section from proton on helium collisions, at beam energies ranging from 50 to 250 GeV. The abundant production of kaons and Lambdas allows to use these strange hadron decays for quality controls of the collected data and infer on the correctness of the spectrometer alignment. The project will consist in a selection of kaons and Lambdas from real data taken at different stages of the Run, and the investigation of their measured properties.

Grupo : P&QCD
Local : Lisboa
Supervisor(s) : Catarina Quintans
Email : quintans@lip.pt
Vagas : 2
Duração/Datas : period to be defined with the students

Hyperfine interactions in heavy quarkonia and heavy-light mesons
Hadrons are composite systems of quarks and antiquarks that interact through the strong interaction, which is mediated by the exchange of gluons. This interaction is so strong that single quarks cannot be separated from other quarks, a phenomenon known as confinement. It is not yet known how exactly confinement arises from the fundamental quark and gluon interactions, but one can study effective models to learn about its properties. The objective of this internship project is to investigate the spin structure of the confining interaction. Relativistic models for the confining interaction with different Lorentz structures, which determine the spin structure and behavior under Lorentz transformations, will be approximated by keeping only the dominant central potential and first-order spin-dependent relativistic corrections, known as hyperfine interactions. A Schrödinger-type equation for different quark-antiquark systems will then be solved to obtain the meson masses and wave functions, and the solutions will be compared to the ones obtained with a more exact relativistic equation where the full potential is used. This allows us not only to assess the quality of nonrelativistic calculations with first-order relativistic corrections, but also to study the effects that the various spin-dependent interactions have in the meson systems. This is a theory project with a strong computational component, so experience with programming in languages like Mathematica, Fortran, C++ or Python is necessary. Candidates should also have a decent knowledge of quantum mechanics, including the quantum treatment of spin and orbital angular momentum, as well as of special relativity. Familiarity with the Dirac equation would be a plus.

Grupo : NPStrong
Local : Lisboa
Supervisor(s) : Alfred Stadler, Elmar Biernat
Email : stadler@lip.pt
Vagas : 2
Duração/Datas : Dates are flexible. We could start sometime in June and continue until the end of July in person at LIP. Occasional remote meetings during August would also be possible, if needed.

Studying the Primordial Fluid with Deep Generative Learning
The Quark-Gluon Plasma (QGP), produced in heavy-ion collisions at the LHC and RHIC, once was the only state of matter present in our universe. Forming, dissipating and condensing into hadrons, very early in the history of our universe - long before the Cosmic Microwave Background was emitted - this primordial fluid has been studied at a rather large degree of detail, through classical methods, over the past decades. Today Deep Generative Learning (DGL) as transformed our world through the advent of Variational AutoEncoders (VAEs), Generative Adversarial Models (GANs) and Generative Pretrained Transformers (GPTs), with very interesting new models starting to show promise, such as Normalizing Flows and Difusion Models. These models show significant promise in capturing the underlying effect - the generative process - that the QGP has on a high-energy jet, produced in the same collision, as it transverses the fluid - all the effects the QGP has on the jet we call Jet Quenching. The student or students are given several paths to follow: 1 - Optimizing our prior knowledge on VAEs, where the students are expected to take a simple VAE code with a gaussian prior, and test this model with different prior distributions, such as an exponential or multivariate gaussian. If time and other resources are available, constructing an optimization code to find the optimal prior or mixture of priors for the problem. Finding an optimal mixture of priors for these models, would significantly further our understanding of the QGP. 2 - Making a GPT from the Particle Transformer (ParT), where the students are expected to train a Particle Transformer model, from the github code and datasets provided in the ParT paper, later using transfer learning to train this model further on samples from heavy-ion collisions, building the first GPT for Jet Quenching. 3 - Capturing the Quenching effect in the HYBRID Jet Quenching model, with Normalizing Flows and Difusion Models, where the students will generate small samples with the HYBRID model and apply these Generative models.

Grupo : Pheno
Local : Lisboa
Supervisor(s) : João A. Gonçalves
Email : jgoncalves@lip.pt
Vagas : 3
Duração/Datas : 01/07/2024- 31/09/2024

Studying the Primordial Fluid with Deep Learning
The Quark-Gluon Plasma (QGP), produced in heavy-ion collisions at the LHC and RHIC, once was the only state of matter present in our universe. Forming, dissipating and condensing into hadrons, very early in the history of our universe - long before the Cosmic Microwave Background was emitted - this primordial fluid has been studied at a rather large degree of detail, through classical methods, over the past decades. Today Deep Learning (DL) as transformed our world through the advent of deeper and deeper neural networks, taking these models to headlines around the world over the past decades as well. More and more physics aware models have been appearing such as Energy Flow Networks (EFNs) Lorenz Networks and others. These models show significant promise in outranking other, more classical models, in distinguinshing between jets coming from proton-proton collisions (pp) and jets coming from led-led collisions (PbPb) where the QGP is expected to form and interact with the jet - all the effects the QGP has on the jet we call Jet Quenching. This is an interesting and very hard to solve problem because we expect a significant fraction of jets in PbPb to be the same as in pp, due to the fact that some jets, for one reason or another, do not interact significantly with the medium, they are not quenched. The student or students are given several paths to follow: 1 - Extending EFNs with particle interactions, where the students are expected to add particle-particle information to the EFN model for pp vs PbPb jet discrimination. 2 - Exploring Hierarchical EFNs, where the students are expected to study this variation of the EFNs on pp vs PbPb discrimintation. 3 - Exploring Moment EFNs, where the students are expected to study this very promising varitaion of the EFN for explainability and interpretability of these models. 4 - Exploring Other Models. All paths have supporting starter code and nothing stops a single student to follow all three paths in this project, although preference is given to understanding over exploration.

Grupo : Pheno
Local : Lisboa
Supervisor(s) : João A. Gonçalves
Email : jgoncalves@lip.pt
Vagas : 2
Duração/Datas : 01/07/2024- 31/09/2024