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 sua taxa de ocorrência 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 : 2
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 : 1
Duração/Datas : 2023-06-01 2023-09-15

Auger muons hands-on
Auger is the Main Cosmic Ray experiment operating in the world. It detects the particles produced in the atmosphere when very high energetic particles hit the top of the atmosphere. Some of these particles reach the ground. Some of them are muons, a heavier lepton than the electron. Lower energetic showers produce a myriad of particles which get attenuated in the atmosphere. Muons, however are capable to survive and a pool of muons can be found at sea level. In the area equivalent to a hand several of them can be detected. In this internship the plan of work is to develop a small detector composed of three detecting planes and to use coincidences to estimate the efficiency of the detector and the flux of muons.

Grupo : Auger
Local : Lisboa
Supervisor(s) : Pedro Assis; Ruben Conceição;
Email : pedjor@lip.pt
Vagas : 1
Duração/Datas : July-Half August

Detecting Neutrino Interactions with the muon system of SND@LHC
SND@LHC is a novel experiment recently installed at CERNs LHC. It has already collected approximately 40 fb-1 worth of data during the ongoing LHC Run3, that is being resumed this summer. The collected dataset has been used to observe the first neutrino candidates through their interactions in the Target system of the detector. In addition, a comparable number of neutrino interactions are predicted to happen in the Muon system (MS). The MS, which doubles as a sampling calorimeter, involves a sandwich of iron blocks and scintillating planes, allowing for the detection of muons and hadronic showers arising from neutrino interactions. The project aims at the observation and analysis of muon neutrino interactions in the MS. It will further allow to narrow down muon-neutrino selection inefficiencies, which range from the implementation of a track to simulation matcher to an in-depth study and improvement of the tracking methods used by the SND@LHC software.

Grupo : SHiP/SND@LHC
Local : Lisboa
Supervisor(s) : Guilherme Soares, Nuno Leonardo, Cristovao Vilela
Email : guilherme.m.s.soares@tecnico.ulisboa.pt
Vagas : 1
Duração/Datas : July-September

Energy calibration of SNO+ with scintillator
SNO+ is a large multi-purpose liquid scintillator based experiment, with the main physics goal of searching for the neutrinoless double-beta decay of 130 Te. Thanks to the low energy threshold and the high purity of the materials selected, additional physics topics include the measurement of solar neutrinos, antineutrinos from reactors and the Earth, supernova neutrinos and the search for other rare events. Since April 2022, SNO+ is taking data using a liquid scintillator target with 2.2 g/L PPO concentration. During this period three calibration campaigns have been performed using an AmBe source which emits neutrons and 4.4 MeV gammas. The student will be involved in the analysis of the acquired calibration data, in order to characterise the response in energy of the detector. The student will also help to understand the detector response to neutrons compared to gammas, electrons and alpha particles.

Grupo : Neutrinos
Local : Lisboa
Supervisor(s) : Valentina Lozza
Email : vlozza@lip.pt
Vagas : 1
Duração/Datas : July to the end of August

Gamma/hadron discrimination through the azimuthal fluctuations of air shower particle distributions at the ground
Wide field-of-view gamma-ray observatories must fight the overwhelming cosmic ray background to identify very high-energy astrophysical gamma-ray events. Recently it has been shown by our group that the measurement of the azimuthal non-uniformity of the particle distributions at the ground can be used as a gamma/hadron discrimination quantity. The above findings constitute a unique opportunity to build a cost-effective gamma-ray observatory, based on water Cherenkov detectors, able to cope with a wide energy range (from hundreds of GeV to many tens of PeV). In this summer internship, we propose to better understand the sensitivity and limitations of the newly introduced quantity, LCm. For that, the student will generate a mock shower footprint dataset to assess, in a controlled environment, the response of LCm to different conditions. Such a study can highly boost the use of LCm both in the future Southern Wide-field Gamma-ray Observatory and the present Pierre Auger Observatory.

Grupo : SWGO
Local : Lisboa
Supervisor(s) : Ruben Conceição, Lucio Gibilisco, Pedro Costa
Email : ruben@lip.pt
Vagas : 0
Duração/Datas : July-September

Identificação de isótopos no fluxo de raios cósmicos usando a construção de templates de massa a partir dos dados
Isótopos de elementos físicos como o hidrogénio, hélio e berílio existem em quantidades pequenas nos raios cósmicos que se detectam no topo da atmosfera terrestre. A sua pequena abundância relativa é indicativo da sua produção ao longo da propagação na galáxia das partículas cósmicas progenitoras produzidas nas fontes (supernovas). Assim, a identificação destes elementos permite um melhor conhecimento dos mecanismos de propagação dos raios cósmicos na galáxia. Neste estágio serão criadas amostras de eventos por técnicas de Monte-Carlo e será desenvolvida a técnica de identificação de isótopos com distribuições de referência de massa obtidas obtidas de forma iterativa a partir dos dados.

Grupo : AMS
Local : Lisboa
Supervisor(s) : Fernando Barão; Miguel Orcinha
Email : barao@lip.pt
Vagas : 2
Duração/Datas : 2a quinzena de Julho, 1a semana de Agosto, 1a quinzena de Setembro

MARTA comissioning monitoring
MARTA is a project based on RPCs to measure muons in Auger. The system prototypes are installed in the Argentinian site. The slow control system developed by LIP Lisboa is monitoring several parameters of the detectors. The work of the candidate will be to analyse the acquired data and correlate with the performance of the detector. Several correlations will be explored that include parameters such as background rate, temperature, pressure, humidity, gas flow, High Voltage. Programming will be necessary but the programming language is flexible.

Grupo : Auger
Local : Lisboa
Supervisor(s) : Pedro Assis
Email : pedjor@lip.pt
Vagas : 2
Duração/Datas : July-Half August

MARTA electronics optimization
MARTA is a project within the Auger collaboration to detect muons under the primary detectors. The detectors to be used are based on RPCs using electronics developed at LIP Lisbon. We have available at LIP a similar system to the one used in the Argentina. The purpose of the internship is to explore the electronics board and program the DAQ to boost the acquisition rate and enable the electronics to acquire all data at high rates. The candidate will have to work with FPGAs, and with DAQ and programming.

Grupo : Auger
Local : Lisboa
Supervisor(s) : Pedro Assis
Email : pedjor@lip.pt
Vagas : 2
Duração/Datas : July-Half August

Measuring the neutron capture cross section of Argon - a feasibility study
Argon is largely used as detector material, in particular it is among the main targets for present and future neutrino and dark matter experiments. Nevertheless, alpha and neutron interaction cross sections on Argon have still large uncertainties. In this internship we aim to study the feasibility of measuring and discriminating the neutron capture cross section on natural argon at thermal and resonant energies from the elastic cross section. The goal is to research if there are variables, such as the the gamma energy and their direction of emission, that allow the discrimination among the various interactions.

Grupo : Neutrinos
Local : Lisboa
Supervisor(s) : Sofia Andringa, Valentina Lozza
Email : sofia@lip.pt
Vagas : 1
Duração/Datas : July until the end of August

Optimization of water Cherenkov detector for a next-generation gamma-ray observatory
The Southern Wide-field Gamma-ray Observatory (SWGO) is the next-generation gamma-ray observatory, currently in a three-year R&D phase. The experiment is expected to have a large array of water Cherenkov detectors (WCD) placed at a high elevation (> 4.4 km a.s.l.) in South America. The LIP group is proposing a WCD concept with reduced surface area and height stations comprising three PMTs at the bottom interfaced with advanced machine learning algorithms. Such a concept reduces the cost associated with the transportation of massive amounts of water to high-elevation sites while keeping a high physics performance. In this internship, the student will be using state-of-the-art simulation codes to optimize the station dimensions. Ideally, its volume should be as small as possible without compromising the light collection and signal uniformity.

Grupo : SWGO
Local : Lisboa
Supervisor(s) : Bernardo Tomé, Ruben Conceição, Pedro Costa
Email : ruben@lip.pt
Vagas : 2
Duração/Datas : June-September

Radioactive background analysis with SNO+ scintillator data
SNO+ is a large multi-purpose liquid scintillator based experiment, with the main physics goal of searching for the neutrinoless double-beta decay of 130 Te. Thanks to the low energy threshold and the high purity of the materials selected, additional physics topics include the measurement of solar neutrinos, antineutrinos from reactors and the Earth, supernova neutrinos and the search for other rare events. Since April 2022, SNO+ is taking data using a liquid scintillator target with 2.2 g/L PPO concentration. The student will be involved in the characterisation of the liquid scintillator purity by measuring its radioactive background content (U, Th and 14C) via spectral fits and/or delayed coincidence analysis.

Grupo : Neutrinos
Local : Lisboa
Supervisor(s) : Valentina Lozza
Email : vlozza@lip.pt
Vagas : 1
Duração/Datas : July to end of August

Variabilidade temporal do fluxo de raios cósmicos
Em vários campos da física, a identificação de sinais implica uma análise em tempo e frequência, como é o caso na cosmologia das ondas gravitacionais ou em astroparticulas na análise dos raios cósmicos com carga eléctrica não nula medidos no topo da atmosfera terrestre e modulados pela actividade solar. Neste estágio pretende-se desenvolver uma ferramenta que faça a análise de sinais físicos variáveis no tempo com aplicação aos fluxos raios cósmicos que chegam à Terra.

Grupo : AMS
Local : Lisboa
Supervisor(s) : Fernando Barão; Miguel Orcinha
Email : barao@lip.pt
Vagas : 2
Duração/Datas : 2a quinzena de Julho, 1a e última semana de Agosto, 1a quinzena de Setembro.

Muographying the city
Muography is a technique that uses the large flux of muons created by cosmic rays in the atmosphere to image large objects, giving access to the density of their inner structures. Previously, a muon telescope built at LIP took data in a mine, to characterize an important geological fault at Lousal. Now we want to use that knowledge to see how we could image the city from underground tunnels. We are mostly thinking of tunnels in Lisbon, and it is also possible to do the project in Lisbon.

Grupo : MuTom
Local : Minho
Supervisor(s) : Sofia Andringa, Raul Sarmento
Email : sofia@lip.pt
Vagas : 2
Duração/Datas : Mostly July and some more time to be arranged

Characterization of state-of-the-art instrumentaion 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 : 3
Duração/Datas : July to September

Introdução ao estudo da medida da mobilidade de iões em gases
Nos detetores gasosos de radiação baseados em processos de avalanche, a amplitude do impulso do sinal de saída tem duas componentes, uma devida à deriva dos eletrões, e outra devida à deriva dos iões. Embora a velocidade de deriva dos iões seja muito mais lenta do que a dos eletrões, a sua contribuição para a formação do impulso induzido é frequentemente predominante. Recentemente a utilização da deriva de iões negativos em detetores gasosos, no lugar dos eletrões, com o objetivo de diminuir a difusão tem sido considerada. Deste modo, o conhecimento da mobilidade de iões em gases é muito importante na otimização dos detetores gasosos. O aluno/a será envolvido na medição experimental de mobilidades de iões positivos e negativos presentes em misturas gasosas de gases raros com gases moleculares e na análise e interpretação de resultados obtidos. As medidas de mobilidade serão realizadas para diferentes condições experimentais, nomeadamente diferentes concentrações na mistura, diferentes pressões e para diferentes valores de campo eléctrico reduzido (E/N).

Grupo : GasDet
Local : Coimbra
Supervisor(s) : Filomena Santos/Afonso Marques
Email : filomena.santos@coimbra.lip.pt
Vagas : 1
Duração/Datas : 1/07 até 31/07

Introdução ao estudo de detetores gasosos
Neste estágio, os alunos serão integrados numa equipa de investigação, na área de instrumentação em detectores gasosos. Será feita uma breve introdução/revisão teórica do funcionamento dos diferentes tipos de detetores de radiação (absorção da radiação, conversão, amplificação e recolha do sinal). Os alunos terão contacto com sistemas experimentais de deteção de radiação, essencialmente detetores gasosos. Deste modo, poderão aprender ou reforçar os seus conhecimentos de técnicas de vácuo e manuseamento de gases e de eletrónica nuclear. Espera-se com este trabalho que os alunos adquiram competências na área de espectroscopia de radiação, na recolha de dados e na sua análise para além do estudo dos princípios físicos associados à detecção de radiação.

Grupo : GasDet
Local : Coimbra
Supervisor(s) : Filipa Borges/Alexandre Trindade
Email : filipa.borges@coimbra.lip.pt
Vagas : 1
Duração/Datas : 1/07 até 31/07

Participação no desenvolvimento de uma nova tecnologia de deteção de neutrões
O estágio irá decorrer no grupo “Neutron Detectors”, no LIP em Coimbra, que se dedica ao desenvolvimento de detetores de neutrões, na área de desenvolvimento de detetores para física nuclear e de partículas, tecnologias para ver o invisível. Os alunos selecionados irão participar nos trabalhos de investigação em curso no grupo, envolvendo, simulação de Monte Carlo, otimização de detetores de neutrões, testes experimentais, aquisição e processamento de dados. O Aluno terá a oportunidade de acompanhar o desenvolvimento e testes, de um protótipo, de um novo tipo de detetor para neutrões frios / térmicos, com capacidade de leitura a 4D (XYZ e tempo). Dada a sua notável capacidade de sincronização, elevada eficiência, e alta resolução espacial, este novo tipo de detetor apresenta um elevado potencial para experiências envolvendo imagiologia de neutrões resolvida no tempo e na energia, que têm lugar em reatores nucleares e fontes de espalhamento de neutrões, como por exemplo na ESS - European Spallation Source, a maior infraestrutura científica atualmente em construção na Europa.

Grupo : nDet
Local : Coimbra
Supervisor(s) : Luís Margato and Andrey Morozov
Email : margato@coimbra.lip.pt
Vagas : 2
Duração/Datas : June and jully 2023

Portable cosmic ray telescopes based on RPCs
Timing Resistive Plate Chambers (RPCs) are detectors with good efficiency and excellent timing precision. With proper segmentation (in the readout planes) it is also possible to determine the position with reasonable precision (< cm²). These characteristics associated with their low cost make them suitable for monitoring as well as individual tracking of cosmic rays. These characteristics are useful for accurate cosmic ray flux monitoring (which allows space weather studies) or muon tomography (which allows imaging of large volumes or detection of heavy materials). The RPC group is currently commissioning a series of portable telescopes based on RPCs for cosmic ray monitoring (MINGO project), for muon flux monitoring in one of the LHC tunnels at CERN as part of the SND@LHC experiment, and for muon tomography (MUTOM project). The students will be involved in the commissioning and testing of this series of telescopes performing tasks related to the assembly of the telescopes: acquisition electronics and detectors as well as the analysis software focused on trace reconstruction and characterization of the detector characteristics: efficiency and temporal resolution.

Grupo : RPC
Local : Coimbra
Supervisor(s) : Alberto Blanco
Email : alberto@coimbra.lip.pt
Vagas : 4
Duração/Datas : July to September

Simulação de Monte Carlo da evolução da nuvem de eletrões gerada por Raios-X
Neste estágio, o aluno será integrado numa equipa de investigação, na área de instrumentação em detectores gasosos. O trabalho a realizar é de simulação de Monte Carlo de propriedades dos meios gasosos. Um modelo de Monte Carlo desenvolvido no grupo de investigação permite reproduzir a evolução da nuvem de eletrões produzida por fotoionização de raios-X de baixa energia em alguns meios gasosos, ao longo da sua deriva sob a ação de um campo elétrico, nas condições usuais de um detetor efetivo. Para o efeito, o modelo reproduz todos os processos relevantes na interação da radiação com o meio que resulta na formação da nuvem de eletrões primários. Este modelo está a ser alargado a SF6, um gás eletronegativo que se perspetiva ter grande interesse como aditivo em meio de enchimento de detetores gasosos, cuja investigação carece de aprofundamento nos aspetos relevantes. Pretende-se que o aluno colabore na extensão do modelo, inserindo os dados necessários (já selecionados na quase totalidade) para que os processos físicos que ocorrem em SF6 sejam devidamente reproduzidos. Para validar as secções eficazes de difusão de eletrões em SF6 a usar no Modelo, serão determinados por simulação de Monte Carlo alguns parâmetros de deriva de eletrões em SF6 que serão comparados com dados publicados na literatura. No início, o aluno entrará em contato com o código de Monte Carlo existente, cujo funcionamento bem como os processos físicos envolvidos na simulação lhe serão explicados pelo orientador. Pretende-se ainda estudar o comportamento do meio gasoso contendo SF6 para o caso de raios X linearmente polarizados entre 2 e 15 keV, considerando diferentes valores para a profundidade do detetor e pressão de enchimento, para valores próximos de 1 cm e de 1 atm, respetivamente.

Grupo : GasDet
Local : Coimbra
Supervisor(s) : José Escada
Email : jescada@coimbra.lip.pt
Vagas : 2
Duração/Datas : 1/07 até 31/07

AI for characterization of thin films using RBS
For those interested in applying deep learning techniques to the field of materials science, an internship utilizing Artificial Intelligence (AI) presents an excellent opportunity. One of the methods employed for thin film characterization is Rutherford Back-scattering Spectrometry (RBS), a potent analytical tool that lies on the detection of back-scattered ions from a sample surface, enabling researchers to investigate material composition and properties. However, analyzing RBS data can be a laborious and time-consuming process. The use of AI models can automate this process and make it useful for experimental scenarios. Our group produces thin film targets at the evaporator facility, which are utilized for nuclear physics experiments worldwide. This internship will provide hands-on experience in designing and implementing AI models and, in addition, explore material analysis techniques. Upon completion, you will have developed essential skills and knowledge in the fields of materials science and machine learning, enabling you to contribute to cutting-edge research in this exciting area. We`re looking for a student from physics or engineering physics that really likes to program and enjoys hands-on work, it would be preferable if the student feels comfortable using Python!

Grupo : NUC-RIA
Local : Lisboa
Supervisor(s) : Tomás Sousa, Francisco G. Barba e Ricardo Pires
Email : tsousa@lip.pt
Vagas : 1
Duração/Datas : 01/07 - 06/08 & 21/08 - 08/09

AI for thin film characterization using AEL
- A student from physics or engineering physics that really likes to program and enjoys hands-on work. - For those interested in applying deep learning techniques to the field of materials science, an internship utilizing Artificial Intelligence (AI) presents an excellent opportunity. Alpha Energy Loss (AEL) is one of the methods employed for thin film characterization, a potent analytical tool that enables researchers to investigate material composition and properties by detecting the energy loss of alpha particles as they pass through a sample. However, analyzing AEL data can be a laborious and time-consuming process. The use of AI models can automate this process and make it useful for experimental scenarios. Our group produces thin film targets at the evaporator facility, which are utilized for nuclear physics experiments worldwide. This internship will provide hands-on experience in designing and implementing AI models and exploring material analysis techniques, specifically in AEL. Upon completion, you will have developed essential skills and knowledge in the fields of materials science and machine learning, enabling you to contribute to cutting-edge research in this exciting area.

Grupo : NUC-RIA
Local : Lisboa
Supervisor(s) : Raquel Nunes, Pamela Teubig e Tomás Sousa.
Email : pteubig@lip.pt
Vagas : 1
Duração/Datas : 01/07 - 06/08 até 21/08 - 08/09

Biophysical Modeling of the Ionizing Radiation Influence on Cells
Living organisms are complex systems characterized by an unpredictable behavior. However, using appropriate methods, it is possible to create models that can provide a good approximation to reality. The way human cells respond to ionizing radiation continues to be of significant research interest, and therefore this internship will be focused on the biophysical modelling of the cellular damages induced by ionizing radiation. The work will be developed using TOPAS, an advanced Monte Carlo simulation code that extends the Geant4 Simulation Toolkit to describe interactions of primary particles, secondary particles, and radiolysis products within the cell.

Grupo : NUC-RIA
Local : Lisboa
Supervisor(s) : Carina Marques Coelho and Pamela Teubig
Email : cmcoelho@lip.pt
Vagas : 1
Duração/Datas : 01/07 - 06/08 until 21/08 - 08/09

Developing a GUI for thin film characterization
- If you’re a student looking to learn more about the experimental ways in nuclear physics then come join a very fun group during the summer and contribute to create a tool that will improve our process of work whilst developing thin films! - Our target engineering group is developing and producing targets used in national and international facilities worldwide. The characterization of these targets prior to their use in experimental campaigns is of vital importance for the scientific outcome. The trainee will get experience in material characterization and developing easy-to-use GUI that will run a Python script automating the process of determining the thickness of the target. Furthermore, time permitting the simulation of the set-up using Geant4 or TOPAS will be included.

Grupo : NUC-RIA
Local : Lisboa
Supervisor(s) : Raquel Nunes, Tomás Sousa, Pamela Teubig
Email : pteubig@lip.pt
Vagas : 1
Duração/Datas : July - September

Electronics adaptation for scintillation dosimeter
The growing interest in charged particle therapy (protons, ions) has motivated the development of projects at LIP that aim to the application of the know-how about particle physics to radiotherapy. In this context, the Dosimetry group at LIP is developing a detector to explore the capabilities of plastic scintillation detectors to perform dosimetric measurements for Radiobiology studies and Machine Quality Assurance. The detector consists of an array of scintillating plastic optical fibres (SCSF-78) inserted inside an irradiation box that keeps it in a light-tight environment. The signal produced by the optical fibres is readout using a multi-anode photomultiplier (MAPMT H8500, 64 channels). The usage of the Trigger and Readout Board (TRB) of the HADES experiment for the 64 channels readout needs to be validated. The successful candidate will be testing the coupling of the TRB with the detector, perform acquisitions with these electronics and explore the adaption of the TRB to an external clock in order to circumvent the acquisition rate limitations. A candidate who is interested in experimental measurements, data acquisition, electronics and software is the perfect match. The expected start is the beginning of July. A large availability during July is necessary for the laboratory work. Earlier contact with the internship supervisors is welcomed.

Grupo : RADART
Local : Lisboa
Supervisor(s) : Duarte Guerreiro, João Gentil, Jorge Sampaio
Email : dguerreiro@lip.pt
Vagas : 1
Duração/Datas : June - July

Flash beam monitoring
Monitoring of RT beams play a very important role. Moreover in applications with high rate, feedback to the machine is of the utmost importance for dose delivery control. The candidate will work in simulation exploring different possibilities. Simulation with Geant4 or similar is expected to be used. The purpose is to explore conceptual designs for beam monitors.

Grupo : RADART
Local : Lisboa
Supervisor(s) : Pedro Assis
Email : pedjor@lip.pt
Vagas : 1
Duração/Datas : May-Half August

Identifying relevant reactions for Nuclear Astrophysics
The origin of all the chemical elements in the Universe is a fundamental study of Nuclear Astrophysics. To understand how the elements are formed in stars, nuclear reaction experiments are performed in dedicated facilities using particle accelerators. The feasibility of these experiments depends on technical factors as well as nuclear physics factors. This internship will aim to identify relevant reactions for Nuclear Astrophysics that can be performed in facilities used by NUCRIA. You will learn the key features of nuclear reactions, benchmark previously performed reactions, compare different nuclear models that need to be verified and select reactions to be performed in the future. With this internship, not only will you have the opportunity to gain skills in Python and Linux by performing different calculations to study the characteristics of a reaction but also deepen your knowledge about Nuclear Physics, shredding some light on what the future experiments must be!

Grupo : NUC-RIA
Local : Lisboa
Supervisor(s) : Margarida Paulino, Francisco G. Barba, Daniel Galaviz Redondo
Email : fgbarba@lip.pt
Vagas : 1
Duração/Datas : 01/07 - 06/08 até 21/08 - 08/09

Portable muon detection system with a scintillator-PMT based setup
If you open your hand, you’ll get around 400 highly energetic muons per minute. Emerging technology like muon tomography or radiography have gained a lot of traction, and the use of these particles for engineering purposes is becoming more prominent. This internship focuses on the construction of a portable muon detection system that allows for the measurement of cosmic muon flux, angle and energy at different altitudes. This work includes simulations with TOPAS and Geant4, as well as instrumentation work. This internship is intended for candidates in the area of physics or engineering physics from the 3rd year or masters.

Grupo : NUC-RIA
Local : Lisboa
Supervisor(s) : Tomás Sousa, Prof. Daniel Galaviz e Diogo Miguel
Email : tsousa@lip.pt
Vagas : 1
Duração/Datas : 01/07 - 06/08 & 21/08 - 08/09

Radiobiological phantom characterization
The irradiation of any biological system generates a succession of processes, and their effects are the main concern in any radiobiological study. To perform experiments on in vitro biological models it is important to create a system that allows us to perform the desired measures and that is also reproducible, easy to assemble and fast to set up. A phantom for the irradiation of cells at radiotherapy facilities was designed and needs to be characterized. This internship will focus in the validation of the phantom using Monte Carlo simulations and resourcing to TOPAS, a Geant4-based Monte Carlo tool.

Grupo : NUC-RIA
Local : Lisboa
Supervisor(s) : Carina Marques Coelho and Pamela Teubig
Email : cmcoelho@lip.pt
Vagas : 1
Duração/Datas : 01/07 - 06/08 until 21/08 - 08/09

Target production
Every nuclear physics experiment needs a target! The Target Group offers an internship of the preparation of targets using thermal evaporation at the evaporator laboratory situated at FCUL. Important target aspects are properties like thickness, mechanical stability and composition. The produced targets will be characterized using alpha particle E-loss transmission and/or Rutherford Backscattering Spectrometry techniques. The experimental results from the characterization will be compared to simulation codes. The internship has a duration of two months.

Grupo : NUC-RIA
Local : Lisboa
Supervisor(s) : Margarida Paulino, Ricardo Matoza Pires, Pamela Teubig
Email : pteubig@lip.pt
Vagas : 1
Duração/Datas : July - September

TOPAS Automator
Creating a TOPAS Automator with Python means building a fantastic program that helps researchers run simulations more easily. TOPAS is a powerful tool for studying how particles like protons, electrons, and neutrons move through different materials like tissues, organs, and detectors. However, manually setting up and running simulations can take a long time. With a TOPAS Automator, researchers can give the program some instructions and let it do the hard work, like creating input files, running the simulations, and analysing the results. This program can save researchers time and energy and help them study medical physics, radiation therapy, and nuclear engineering. Only students who like physics and programming should choose this topic.

Grupo : NUC-RIA
Local : Lisboa
Supervisor(s) : Carolina Felgueiras and Daniel Galaviz
Email : ccfelgueiras@lip.pt
Vagas : 1
Duração/Datas : July to September

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, Guiomar Evans, Luís Gurriana
Email : agomes@lip.pt
Vagas : 1
Duração/Datas : duration ~1 month, from the beginning of July with some flexibility

Anomaly detection as a tool for discovery the unexpected at colliders
The Standard Model of particle physics describes the elementary constituents of matter and provides a model for the fundamental interactions between them. This is a model with enormous success in describing experimental measurements but which does not provide answers to important evidence such as the existence of dark matter or the asymmetry of matter and anti-matter. There is a panoply of new physics proposals beyond the standard model that attempt to explain the open questions, and it is impossible to test all of them at the LHC. In this work, Artificial Intelligence will be used to distinguish potential new physics events in a generic way using anomaly detection techniques.

Grupo : SimBigDat
Local : Minho
Supervisor(s) : Nuno Castro, Rute Pedro, Miguel Caçador, Gabriela Oliveira
Email : nuno.castro@cern.ch
Vagas : 0
Duração/Datas :

Quantum machine learning in HEP
Quantum computing has been gaining prominence as an alternative computing paradigm, and is currently a very active field of research. In this project several applications of quantum computation to experimental particle physics will be explored, including the simulation of physical phenomena and the use of quantum circuits in machine learning.

Grupo : SimBigDat
Local : Minho
Supervisor(s) : Nuno Castro, Miguel Caçador, Gabriela Oliveira
Email : nuno.castro@cern.ch
Vagas : 0
Duração/Datas :

Visualization of 3D muography
The muon tomography technique has been applied at the Lousal mine using a RPC telescope. The idea of this project is to build an interactive display that will offer an intuitive visualization of the muography data, in particular the 3D density map of the soil. Additional possible features include the visualization of the detector model, the underground mine gallery based on laser mappings, the surface profile from photogrammetry images and the inclusion of explanatory materials. The project will be concluded with the development of a prototype exhibitor with an holographic-type projection of the display image.

Grupo : MuTom
Local : Minho
Supervisor(s) : Henrique Carvalho, Sofia Andringa, Raul Sarmento
Email : raul@lip.pt
Vagas : 3
Duração/Datas : July

Higgs Physics at Future Colliders
The Higgs boson is unique among all known particles, and intimately connected to the breaking of electroweak symmetry that shaped the fundamental forces in the Universe today. The study of its properties and interactions may give us invaluable clues to what new physics is behind the Standard Model (SM) of particle physics. In this project, the student will study the production of Higgs bosons at the LHC and at the Future Circular Collider (FCC), a giant collider being planned at CERN to reach even higher energy than the LHC. The study will involve learning how to run a Monte Carlo simulation of the collisions and how to analyze the results. Good programming skills, basic knowledge of particle physics, enthusiasm and curiosity will be important assets in this work.

Grupo : FCC
Local : Coimbra
Supervisor(s) : Ricardo Gonçalo, Filipe Veloso
Email : jgoncalo@lip.pt
Vagas : 2
Duração/Datas : from 16/6/2023 to 28/7/2023

Comparison of Machine Learning algorithms applied to the search for rare processes in the LHC CMS data
The CERN Large Hadron Collider (LHC) is a particle collider located near the boarder between Switzerland and France. The LHC accelerates protons beams up to very high energies, with the protons travelling at nearly the speed of light. The protons are made to collide against each other and in this process they produce events which reproduce the conditions of the primordial universe. In this way we are able to study physics processes and particle which only exist in this energy regime. This internship will focus on the use of advanced Machine Learning (ML) methods to distinguish between events representing well known physics processes, the so-called background, and signal events of rare processes. The main interest will be in the use of neural networks in innovative approaches, however the chosen candidates will be free to suggest and explore other ML algorithms. In an initial stage the project will focus on the search for the supersymmetric top, a particle foreseen to exist in some supersymmetric models. The supersymmetric models are extensions to the Standard Model (SM) which introduce a whole new range of supersymetric particles. Supersymmetry is a model which provides particle candidates for Dark Matter and also allows to solve the Hierarchy Problem. In a later stage and if time allows, the studies ML algorithms will be applied to other physics processes such as the supersymmetric tau and the pair production of Higgs bosons. Candidates should have a good understanding of the python programming language, which is the language of choice for ML applications and Artificial Intelligence, and some knowledge of the C++ programming language will also be an asset. During the internship the candidates will further deveop their competences in the domains of ML, programming and particle physics. These skills are sought after not only in the research environment but also in the business world. The work will be overseen by researchers of the LIP CMS group and the results will contribute towards defining the future development of this project.

Grupo : CMS
Local : Lisboa
Supervisor(s) : Cristóvão Beirão da Cruz e Silva
Email : cbeiraod@lip.pt
Vagas : 2
Duração/Datas : July and September (to be agreed upon)

Development of safety algorithms for the ATLAS-HGTD
The High Granularity Timing Detector (HGTD) is a new detector of the ATLAS experiment, foreseen to operate during the high luminosity Phase-II of the LHC. The HGTD is designed to measure the arrival time and position of particles in the forward region with an unprecedented time resolution of 30 ps. The two sides of the HGTD are located at 3.5 m from the interaction point (IP). The HGTD Interlock System is a standalone safety system that protects the detector against a variety of risks. The central part of the Interlock System contains an FPGA, which defines the interlock matrix. In addition to temperature data, signals related to risks due to general infrastructure failures or security issues will be transmitted to this interlock matrix. The student will map the correspondence between the input interlock signals (from NTC sensors and from the ATLAS Detector Safety System) and the corresponding power supply channels that must be switched off, and other interlock actions, e.g. delays between signals.

Grupo : ATLAS
Local : Lisboa
Supervisor(s) : Helena Santos
Email : helena@lip.pt
Vagas : 1
Duração/Datas : at least 3 weeks between 2023-06-01 2023-07-31

Estudo de processos de produção exclusiva no LHC através de algoritmos de Machine Learning.
O LHC (Large Hadron Collider) é um acelerador de partículas situado na fronteira entre a Suíça e a França, nas instalações do CERN. O LHC tem o papel de acelerar pacotes de protões até alcançarem uma velocidade próxima à da luz. Logo, os protões interagem e os produtos da interação são estudados através de detetores de partículas. A energia alcançada pelos protões reproduz o conteúdo energetico do universo primordial. Portanto, explorar este tipo de processos permite, em principio, estudar a física dos primeiros momentos da vida do nosso universo. Mais especificamente, este estágio foca-se no estudo da produção central exclusiva de pares tau/tau, utilizando técnicas de Machine Learning. O tau é uma partícula muito pesada do modelo padrão, que pertence à família dos leptões carregados. Contudo, a massa do tau é milhares de vezes maior das outras partículas da mesma família. O processo estudado permitirá verificar se as propriedades do tau são efetivamente em linha com as previsões do modelo padrão, ou seja a teoria que, à data de hoje, descreve o nosso universo. Para mais informações, podem entrar em contacto comigo. É de referir que este estágio oferece aos candidatos a oportunidade de reforçar as próprias competências informáticas e, para além disso, introduzirá os estudantes ao mundo da inteligência artificial, uma competência muito apreciada tanto no mundo da investigação, quanto nas empresas. Enfim, gostaria de sublinhar que o trabalho será supervisionado pela equipa de investigação da experiência CMS do CERN e, sendo o trabalho em fase avançada, os resultados contribuirão significativamente ao desenvolvimento do projeto.

Grupo : CMS
Local : Lisboa
Supervisor(s) : Matteo Pisano
Email : pisano.matteo96@gmail.com
Vagas : 2
Duração/Datas : (1 Julho - 31 Julho) + (1 Setembro - 30 Setembro)

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 end of June or beginning of July, to beginning of September

Novel probes of the primordial plasma
At the LHC, we recreate droplets of the primordial medium that permeated the universe microseconds after the big bang. Heavy-flavor particles are highly sensitive &ldquo;hard probes&rdquo; of the properties of this hot and dense soup of quarks and gluons (the quark-gluon plasma, QGP). The decays of these heavy particles are being reconstructed for the first time ever in such a challenging and busy collision environment by the CMS experiment at the LHC. The goal of this project is to study and reconstruct B meson signals produced in lead and proton collisions to study critical properties of the QGP. This will be achieved by exploring PbPb and pp datasets collected by the CMS experiment in the most recent LHC run. The exploration of these meson signals will facilitate unique information about the underlying properties of the QGP medium.

Grupo : CMS
Local : Lisboa
Supervisor(s) : Henrique Legoinha, Nuno Leonardo
Email : nuno.leonardo@cern.ch
Vagas : 1
Duração/Datas : July-September

Observing and measuring the first LHC neutrinos
Neutrinos are very feebly interacting particles. Although they are copiously produced at the LHC, collider neutrinos had not ever been detected. SND@LHC is the most recent LHC experiment at CERN, which has been designed to measure neutrinos at yet unexplored high energies and to search for other feebly interacting particles beyond the standard model. It uses the large flux of neutrinos at the LHC to make measurements that will be impactful in topics ranging from the flavor structure of the standard model to the structure of protons. The experiment started taking physics data in 2022, having acquired a sizeable dataset that is being currently analyzed. More recently, the experiment has just reported first collider neutrino candidates. The participants in this project will gain familiarity with analysis tools and become involved in the effort to identify neutrino events, which are outnumbered by background events by a factor of a few billion. Having identified neutrino candidates, a next crucial task will be to measure their energy. Students will acquire a qualitative understanding of the physics pertinent to neutrino interactions and proton-proton collisions. They will also gain a basic understanding of how the SND@LHC detector functions and the role of its sub-components in the analysis of neutrino data. Students will be able to have an impactful contribution to the first robust observation and measurement of LHC neutrinos, using the unique dataset collected by SND@LHC.

Grupo : SHiP/SND@LHC
Local : Lisboa
Supervisor(s) : Cristovao Vilela, Nuno Leonardo, Guilherme Soares
Email : c.vilela@cern.ch
Vagas : 2
Duração/Datas : July-September

Obtaining high-precision predictions for hadronic final states 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, theoretical predictions for the processes of jet and top-pair production at the LHC. The goal is to test the theoretical accuracy of these calculations and assess quantitatively their agreement with recent experimental measurements of these processes at the LHC.

Grupo : Pheno
Local : Lisboa
Supervisor(s) : João Pires
Email : jnpires@lip.pt
Vagas : 2
Duração/Datas : At least 4 weeks from beginning of July until first week of September

Studying Higgs production at the LHC and at future colliders
The Higgs boson was the last unobserved particle of the Standard Model of Particle Physics. It is crucial to the self-consistency of the model and in explaining the observed breaking between electromagnetic and weak interactions. The Higgs mechanism, which includes the Higgs boson, is mandatory to render the Standard Model into a predictive theory. The experimental observation of the Higgs boson was one of the key goals of the LHC physics programme. With its discovery, the focus shifts from discovery to detailed measurements of its properties, and their interpretation in the light of the Standard Model and of theories beyond it. In this project the student will perform a theoretical study in perturbative QCD of Higgs production at the LHC and future hadron colliders via the gluon-fusion mechanism, and compare the obtained results with the latest measurements from the LHC experiments.

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

Search for unexpected ATLAS events in fully hadronic events using anomaly detection techniques
In this project the use of anomaly detection techniques based on a semi-supervised machine learning approach will be explored and applied to the analysis of data collected by the ATLAS experiment. Fully hadronic topologies with missing transverse energy will be considered and the sensitivity to different new physics models will be tested.

Grupo : ATLAS
Local : Minho
Supervisor(s) : Nuno Castro, Rute Pedro
Email : nuno.castro@cern.ch
Vagas :
Duração/Datas :

Deciphering Jet Quenching Effects with Novel Analysis Tools
Heavy ion collisions (HICs) allow to study the most extreme regimes of the strong interaction. In these experiments, conducted at the LHC and RHIC, a novel state of matter called Quark-Gluon Plasma (QGP) is generated. This is an almost perfect fluid made up of quarks and gluons - elementary particles described by one of the building blocks of the Standard Model: Quantum Chromodynamics (QCD). Due to the extremely short lifespan of the QGP, physicists have to observe and quantify its properties indirectly through the analysis of secondary particles. Some of these appear in the detectors in the form of jets: collimated sprays of hadrons that emerge from a cascade of fundamental particles originally emitted by a single quark or gluon. When traversing a medium, these particle showers interact with it, giving rise to jets with different properties than those that develop in the vacuum. This phenomenon - called jet quenching - is one of the most notorious sources of information about the QGP. In this internship, the selected students will use novel analysis techniques to extract physical properties of jets such as their mass, opening angle, or formation time; and use this information to assess their sensitivity to medium-induced modifications.

Grupo : Pheno
Local : Lisboa
Supervisor(s) : Pablo Guerrero Rodríguez, Liliana Apolinário
Email : pguerrero@lip.pt
Vagas : 2
Duração/Datas : July, August

Elastic scattering off radioactive nuclei at relativistic energies
Do you like experimental nuclear physics, but think that an internship is too short to make an experiment and would like to put already your hands on data? Would you like to learn more about data analysis with tools like ROOT? Then this is your internship! In this context you will work on the analysis of data measured in reactions on light stable and radioactive ion beams at relativistic energies. Elastic scattering reactions induced by CH2, C and Pb targets were performed at the GSI/FAIR laboratory in Darmstadt (Germany). The analysis of the elastic scattering channel is a fundamental quantity of strong relevance in the determination of other reaction channels, but so far has not been carefully studied. The reconstruction and analysis of the trajectories of charged ions through various detections systems will be the core of the analysis. Some knowledge on basic nuclear concepts is desirable, although not fully necessary.

Grupo : NUC-RIA
Local : Lisboa
Supervisor(s) : Daniel Galaviz, Manuel Xarepe, Diogo Miguel
Email : galaviz@lip.pt
Vagas : 1
Duração/Datas : 01/07 - 06/08 and 21/08 - 08/09

Experimental Data Analysis at ATLAS-LHC
Ultra-relativistic nucleus-nucleus collisions at the Large Hadron Collider (LHC) provide a unique opportunity to recreate the Quark-Gluon Plasma (QGP) in the laboratory energy frontier. This plasma of quarks and gluons, which is known to behave as a nearly perfect liquid, was the prevailing state of the Universe shortly after the Big Bang. The capabilities of ATLAS, namely large acceptance and high granularity calorimeters, afford excellent handles for QGP studies. Jets, collimated sprays of particles produced in the LHC collisions, are excellent probes to infer the properties of the QGP. The main goal of this project is to perform crucial validation studies of jet reconstruction in the ATLAS calorimeter using data collected during the Pb+Pb pilot run in 2022. The student will have the opportunity to work in an international team and is expected to present the results in the ATLAS Heavy Ion Jet group meetings. \ Working plan: - Introduction to the problem, software and documentation. - Development of the software algorithm. -Validation studies. \ Required skills - some experience in programming is desirable. Skills learned - Software programming (python, C++, ROOT), data analysis techniques. \ Recommendations - The student should get familiar with the ATLAS Experiment: https://atlas.cern/ . Registration in ATLAS will be needed to access the repository, documentation and software tools. In order to save time, the student should register in the week before starting the project.

Grupo : ATLAS
Local : Lisboa
Supervisor(s) : Helena Santos
Email : helena@lip.pt
Vagas : 1
Duração/Datas : at least 4 weeks between 2023-06-01 2023-07-31

Gamma spectroscopy of radioactive nuclei
Do you like experimental nuclear physics, but think that an internship is too short to make any experiment and would like to put already your hands on data? Would you like to learn more about data analysis with tools like ROOT? Then this is your internship! In this context you will work on the analysis of data measured in reactions on a 31S radioactive ion beam at relativistic energies. Breakup reactions induced by a CH2 target are connected to the emission of photons, boosted by the Doppler effect due to the high velocity of the remaining nucleus. The reconstruction and analysis of photons measured with High Purity Germanium detectors, in coincidence with other charged particle systems, will be the core of the analysis. Some knowledge on basic nuclear concepts is desirable, although not fully necessary.

Grupo : NUC-RIA
Local : Lisboa
Supervisor(s) : Daniel Galaviz, Pamela Teubig
Email : galaviz@lip.pt
Vagas : 1
Duração/Datas : 01/07 - 06/08 and 21/08 - 08/09

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 computational component. Candidates should have a decent knowledge of quantum mechanics, including the quantum treatment of spin and orbital angular momentum, as well as 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) : Alfred Stadler, Elmar Biernat
Email : stadler@uevora.pt
Vagas : 2
Duração/Datas : At least 3 weeks in July at LIP in person, then until first week of September remotely, if needed.

Predicting COMPASS/AMBER acceptance using Neural Netowrks
Experiments in high-energy particle physics often use Monte Carlo simulations to predict how a given set of particles will be reconstructed in reality after they pass a detector system. These simulations often take quite some time. For example in the COMPASS experiment at CERN generating a set of given particles takes about hundreds of microseconds per event. However, their reconstruction already takes 2-3s per event, while statistics between millions and a billion are needed. Often the interesting question is if a particle at all will be detected. It can be lost due to reinteraction in target/detector material, the reconstruction algorithm may fail, or particle simple points to the space where detectors are inactive or absent. In a bit simplified manner this reconstruction probability we call acceptance. The idea of the project is to train Neural Networks to predict COMPASS acceptance on a set of existing MCs. With the aim of usage obtained acceptance on another MC, where only generated set of particles exists. The project can be extended. For example, one can not only predict the acceptance but how well different parameters (Energy, angles) will be reconstructed. One can even try to replace the whole Monte Carlo chain with NN. In these cases, one would use some generative adversarial networks. The expected project timeline is about 3 weeks for basic acceptance studies, and about 6 weeks for a somewhat extended version.

Grupo : P&QCD
Local : Lisboa
Supervisor(s) : Marcin Stolarski
Email : mstolars@lip.pt
Vagas : 1
Duração/Datas : June-September (to be agreed)

The combinatorial background of muon pairs in COMPASS
The COMPASS experiment measured in 2018 the pion-induced Drell-Yan process. In this process, a quark-antiquak annihilation produces a virtual photon that decays into a pair of muons of opposite charge. The experiment detects any pair of muons produced. Those pairs with invariant masses M>4 GeV/c² provide a relatively pure Drell-Yan sample. Nevertheless, other physics mechanisms have significant contribution at lower masses. The combinatorial background of uncorrelated muon pairs is a contaminant to the Drell-Yan and J/psi production. Usually it is evaluated from the like-sign muon pairs recorded simultaneously. The latter technique has the disadvantage of limited statistics. The present topic of research proposes an alternative method, making use of event mixing. The real data collected in 2018 by COMPASS will be used in order to build a model of combinatorial background out of uncorrelated muons originating from different events, capable of firing the dimuon trigger and resulting in a viable vertex inside target. This model will be compared with the estimated from like-sign muon pairs, in order to validate it.

Grupo : P&QCD
Local : Lisboa
Supervisor(s) : Catarina Quintans
Email : quintans@lip.pt
Vagas : 1
Duração/Datas : June to September (to be agreed)

The hidden charm in the COMPASS and AMBER experiments at CERN
Charm-anticharm mesons are produced abundantly in pion-nucleon collisions as those occurring in the COMPASS and AMBER experiments at CERN. The data collected by COMPASS in 2018 will be used to study the properties of the two observable charmonium resonances, Jpsi and Psi(2S). The event selection will be optimized in order to obtain the best signal to background ratio. A Monte-Carlo simulation of charmonium events will be used to extract acceptances in kinematic bins. Finally, the ratios of yields Psi(2S)/Jpsi from data corrected by acceptance will be compared with the expectation. Charmonium is also one of the main topics in the new fixed-target experiment AMBER at CERN.

Grupo : P&QCD
Local : Lisboa
Supervisor(s) : Catarina Quintans
Email : quintans@lip.pt
Vagas : 2
Duração/Datas : June to September (to be agreed)

Validation studies of Monte Carlo generators at ATLAS-LHC
Ultra-relativistic nucleus-nucleus collisions at the Large Hadron Collider (LHC) provide a unique opportunity to recreate the Quark-Gluon Plasma (QGP) in the laboratory energy frontier. This plasma of quarks and gluons, which is known to behave as a nearly perfect liquid, was the prevailing state of the Universe shortly after the Big Bang. The capabilities of ATLAS, namely large acceptance and high granularity calorimeters, afford excellent handles for QGP studies. Jets, collimated sprays of particles produced in the LHC collisions, are excellent probes to infer the properties of the QGP. The project concerns crucial validation studies of Monte Carlo generators (SHERPA vs POWHEG + PYTHIA samples) using jets. The student will have the opportunity to work in an international team and is expected to present the results in the ATLAS Heavy Ion Jet group meetings. \\\ Working plan: - Introduction to the problem, software and documentation. - Development of the software algorithm. -Validation studies. \\\ Required skills - some experience in programming is desirable. Skills learned - Software programming (python, C++, ROOT), data analysis techniques. \\\ Recommendations - The student should get familiar with the ATLAS Experiment: https://atlas.cern/ . Registration in ATLAS will be needed to access the repository, documentation and software tools. In order to save time, the student should register in the week before starting the project.

Grupo : ATLAS
Local : Lisboa
Supervisor(s) : Helena Santos
Email : helena@lip.pt
Vagas : 1
Duração/Datas : At least 4 weeks between 01/06 and 31/07