Characterisation of Kr-85 background in SNO+ scintillator data
Overview The project will be developed within the field of neutrino physics. Neutrinos are tiny neutral particles which interact very little with matter via the weak force. They are the most abundant particle with mass in the Universe. Neutrinos are produced in the nuclear reactions in the Sun and the Earth, as well as in accelerator experiments. SNO+ is an underground multi-purpose neutrino detector located in a mine in Sudbury, Canada. It is the successor of the Sudbury Neutrino Observatory (SNO), that has demonstrated that neutrinos do have mass, leading to the 2015 Nobel Prize in Physics. The main goal of SNO+ is the search for neutrinoless double-beta decay using Te-130, a very rare nuclear process that will happen only if neutrinos are their own antiparticle (Majorana type particles). It will help us to understand the neutrinos nature and will contribute to the measurement of the value of the neutrino masses. This is one of the most active and competitive areas of research in modern particle physics. Other physics topics of SNO+ include reactor neutrino oscillations, solar and geo-neutrino detection. As of April 2022, the detector is filled with about 800 tons of liquid scintillator, LAB, and 2.2 g/L PPO, enclosed in a spherical acrylic vessel. A secondary wavelength shifter added in late 2023, boosted the light yield in preparation for the tellurium loaded phase. The light emitted by particles interacting with the scintillator is detected by 9300 photomultiplier tube (PMTs) at 8.5 m distance from the center. The double-beta decay phase is foreseen to start in 2026 with the loading of the scintillator with several tons of Tellurium. In July 2025, the SNO+ collaboration did the first internal calibration of the scintillator phase using an AmBe (neutrons emitting) source. The LIP group has several responsibilities within the SNO+ experiment being involved both in calibration and physics analyses. At the present date, we focus on the backgrounds, antineutrino, solar physics and preparation of the tellurium phase. Proposed topic: The characterisation of the radioactive backgrounds in SNO+ is a crucial element for the various physics goals. Kr-85 (beta-decay, Q-value of 0.69 MeV), naturally present in air, in particular is a background for the low energy solar neutrino measurements. Measuring this background with precision, including its evolution with time, is the goal of this project. The candidate will analyse SNO+ data acquired between May 2022 and July 2025 and will develop cuts to isolate these events from the rest of the data. In particular classifier to separate alpha and beta events will be used to try to isolate this type of decay. Monte Carlo simulation will be used to estimate the efficiency of the cuts to isolate these events. Finally, the events that will pass the cuts will be fit to extract the activity. A basic knowledge of coding (C++ or python) is required.

Grupo : Neutrinos
Local : Lisboa
Supervisor(s) : Valentina Lozza
Email : vlozza@lip.pt
Vagas : 1
Duração/Datas : Project duration about two months. First available start date: January 2026

Characterisation of surface radioactive backgrounds in SNO+ scintillator data
Overview The project will be developed within the field of neutrino physics. Neutrinos are tiny neutral particles which interact very little with matter via the weak force. They are the most abundant particle with mass in the Universe. Neutrinos are produced in the nuclear reactions in the Sun and the Earth, as well as in accelerator experiments. SNO+ is an underground multi-purpose neutrino detector located in a mine in Sudbury, Canada. It is the successor of the Sudbury Neutrino Observatory (SNO), that has demonstrated that neutrinos do have mass, leading to the 2015 Nobel Prize in Physics. The main goal of SNO+ is the search for neutrinoless double-beta decay using Te-130, a very rare nuclear process that will happen only if neutrinos are their own antiparticle (Majorana type particles). It will help us to understand the neutrinos nature and will contribute to the measurement of the value of the neutrino masses. This is one of the most active and competitive areas of research in modern particle physics. Other physics topics of SNO+ include reactor neutrino oscillations, solar and geo-neutrino detection. As of April 2022, the detector is filled with about 800 tons of liquid scintillator, LAB, and 2.2 g/L PPO, enclosed in a spherical acrylic vessel. A secondary wavelength shifter added in late 2023, boosted the light yield in preparation for the tellurium loaded phase. The light emitted by particles interacting with the scintillator is detected by 9300 photomultiplier tube (PMTs) at 8.5 m distance from the center. The double-beta decay phase is foreseen to start in 2026 with the loading of the scintillator with several tons of Tellurium. In July 2025, the SNO+ collaboration did the first internal calibration of the scintillator phase using an AmBe (neutrons emitting) source. The LIP group has several responsibilities within the SNO+ experiment being involved both in calibration and physics analyses. At the present date, we focus on the backgrounds, antineutrino, solar physics and preparation of the tellurium phase. Proposed topic: The characterisation of the radioactive backgrounds in SNO+ is a crucial element for the various physics goals. Bi-210 (beta-decay, Q-value of 1.2 MeV) and Po-210 (alpha-decay, Q-value of 5.4 MeV), from the U-238 natural radioactive chain, present on the vessel surface, in particular are a background for the low energy solar neutrino measurements as well as the reactor and geo-neutrino ones. Measuring this background with precision, including its evolution with time, is the goal of this project. The candidate will analyse SNO+ data acquired between May 2022 and July 2025 and will develop cuts to isolate these events from the rest of the data. Monte Carlo simulation will be used to estimate the efficiency of the cuts. Finally, the events that will pass the cuts will be fit to extract the activity. A basic knowledge of coding (C++ or python) is required.

Grupo : Neutrinos
Local : Lisboa
Supervisor(s) : Valentina Lozza
Email : vlozza@lip.pt
Vagas : 1
Duração/Datas : Project duration about two months. First available start date: January 2026

Electron Neutrino observation at the LHC
Copious amounts of neutrinos are produced in the Large Hadron Collider (LHC) at CERN, and they were undetected until recently. In 2023, two experiments, SND@LHC and FASER, announced the first direct detection of the muon neutrino at the LHC. This result is a milestone in experimental particle physics, opening the door to a rich new program of neutrino measurements at colliders. The most recent LHC experiment, SND@LHC, will be impactful in topics ranging from the flavour structure of the standard model to the structure of the proton. The experiment began physics data taking in 2022, and in 2023 we reported the first observation of collider neutrinos. This marks a milestone in experimental particle physics: the dawn of neutrino physics at colliders. The student will integrate the research team in Lisbon. The proposed project will focus primarily on advancing the analysis effort towards the observation of the electron neutrino at the LHC. The student will have an impactful contribution to the first robust measurements of neutrinos at the previously unprobed LHC energies. The student will be specifically working on developing the statistical inference method with Python packages widely used in the high-energy physics. The student will work with standard tools used in high energy physics, learning how to use ROOT and writing C++ and/or Python data analysis code. They will become acquainted with the physics pertinent to neutrino interactions and proton-proton collisions. The student will also become familiar with the basic functioning of the SND@LHC detector and the role of its sub-components in analyzing neutrino data.

Grupo : SHiP/SND@LHC
Local : Lisboa
Supervisor(s) : R. Biswas, C.Vilela, N.Leonardo
Email : nuno.leonardo@cern.ch
Vagas : 1
Duração/Datas : 1.1.2026 --

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 real data, we want to explore what neutrinos and muons are telling us about the surrounding rocks 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 : Any dates starting in January 2026, assuming around 2 months of work

Building a network of LLM agents to test hypotheses in social physics
In the Social Physics and Complexity research group (SPAC) we use digital data to understand human behaviour and develop tools that benefit society https://socialcomplexity.eu/. Experimentation involving humans poses several risks and difficulties and therefore much of our research relies on natural experiments (e.g., by observing patterns before and after large events such as the Covid-19 pandemic) and simulations. For the past two or three years, large language models (LLMs) have been increasingly used in computational social science (https://direct.mit.edu/coli/article/50/1/237/118498), and specifically in understanding specific aspects of human interaction (e.g. https://proceedings.neurips.cc/paper_files/paper/2024/hash/1cb57fcf7ff3f6d37eebae5becc9ea6d-Abstract-Conference.html, https://www.science.org/doi/full/10.1126/sciadv.adu9368). Although LLMs are not expected to behave the same way as humans, we can observe their textual outputs and compare them with empirical observations. Unlike with traditional agent-based models, we do not have to parameterize all aspects of their interactions, allowing us to test more complex hypotheses. At SPAC, we want to build an artificial social network where we are able to fully customize agent behaviour as well as adapt it to use different model architectures. The students participating in this internship will create a functional prototype of this network and run a pilot experiment.

Grupo : SPAC
Local : Lisboa
Supervisor(s) : Lilia Perfeito
Email : lperfeito@lip.pt
Vagas : 2
Duração/Datas : From December 2025

Desenho de um detetor de fibras para radioterapia com minifeixes
Neste projeto, pretende-se que o aluno desenhe um detector baseado em fibras cintiladoras para uso em dosimetria numa técnica emergente: a radioterapia com minifeixes. Dependendo da disponibilidade de tempo, poderá também ser realizada a simulação da resposta do sistema projectado a feixes clínicos com base em programas de Monte Carlo

Grupo : RADART
Local : Lisboa
Supervisor(s) : Jorge Sampaio ou João Gentil
Email : jsampaio@lip.pt
Vagas : 1
Duração/Datas : Starting from 01.05.2026 (2 months)

Precision timing detector for the next-generation neutrino experiment for HL-LHC
The first direct detection of neutrinos produced in proton-proton collisions was recently announced by the SND@LHC and FASER experiments at CERN’s Large Hadron Collider (LHC). These results are a milestone in experimental particle physics, opening the door to a rich new program of neutrino measurements in proton colliders. The high-luminosity LHC (HL-LHC) is the next phase of the LHC, which will start after an upgrade that will increase the number of collisions by a factor of 10. The HL-LHC will provide an opportunity for high-precision measurements using neutrinos from proton collisions, which will test assumptions of standard model (SM) of particle physics and search for new particles. Neutrino experiments at the HL-LHC will have a chance to discover the only particle in the SM which has not been observed so far: the tau antineutrino. To achieve these goals, advanced detector technologies will need to be developed that can deal with the high rates of backgrounds, while at the same time having enough precision to identify the three neutrino flavours. AdvSND is a next-generation experiment that is being prepared for the HL-LHC. It has been approved for construction in 2025. At its core is a Silicon vertex detector: it will be the first use of this technology in neutrino experiments; along with a precision timing detector: a critical component in the challenging HL-LHC environment. The research project is focused on the analysis of dedicated test-beam data collected recently at CERN using a prototype of the precision timing detector. The student will acquire familiarity with state-of-the-art analysis tools employed in high-energy physics and will have a chance to contribute substantially to the design of a future experiment.

Grupo : SHiP/SND@LHC
Local : Lisboa
Supervisor(s) : T. Camporesi (CERN/LIP), C.Vilela, N.Leonardo
Email : nuno.leonardo@cern.ch
Vagas : 1
Duração/Datas : 1.1.2026 --

Proposta de Estágio em Engenharia Física (FCUL): Avaliar kit da Experiência Franck-Hertz.
Proposta de Estágio em Engenharia Física (FCUL): Avaliar kit da Experiência Franck-Hertz. À medida que o mundo avança para a comunicação quântica segura, a computação quântica e a deteção quântica, torna-se cada vez mais importante reforçar a intuição quântica dos futuros engenheiros. A experiência de Franck-Hertz, realizada em 1914 (um ano depois de Bohr ter proposto o seu modelo atómico), demonstrou a quantização da energia nos átomos. Franck e Hertz mostraram que os eletrões, ao colidirem com átomos, só podem transferir energia em quantidades fixas, revelando a estrutura discreta dos níveis atómicos. O Departamento de Física da FCUL tem um conjunto de equipamentos didáticos (kit) que permite reproduzir a experiência de Franck-Hertz. Este “kit” carece de avaliação. Objetivo do estágio: aprimorar os dotes analíticos e experimentais dos futuros engenheiros físicos, isto é, contribuir para formar engenheiros capazes de pensar de forma rigorosa e crítica, mas também de pôr as mãos na massa, testando e experimentando, tendo como meta transformar teoria em tecnologia. Tarefas: perceber como Franck e Hertz conceberem a ideia da experiência e como efetivamente realizaram experiência para testar o modelo atómico de Bohr; fazer a avaliação dos componentes do kit, testar o kit e verificar se funciona conforme esperado e cumpre os objetivos pedagógicos que permitam a utilização futura, por exemplo, na disciplina de Física Experimental III. Domínios: instrumentação, eletrónica, aplicação do método científico Orientadores: José Figueiredo e Luís Peralta Grupo: RADART LIP: Lisboa Período: maio a julho

Grupo : RADART
Local : Lisboa
Supervisor(s) : José Figueiredo
Email : jmfigueiredo@ciencias.ulisboa.pt
Vagas : 1
Duração/Datas : maio a julho

Proposta de Estágio em Engenharia Física (FCUL): Efeito de túnel
Proposta de Estágio em Engenharia Física (FCUL): Efeito de túnel Efeito de túnel: da fusão nuclear aos circuitos quânticos e neuromórficos. À medida que o mundo avança para a comunicação quântica segura, a computação quântica e a deteção quântica, e computação neuromórfica, torna-se importante reforçar a intuição quântica dos futuros engenheiros. A observação em tempo real do comportamento quântico da matéria não é exclusiva dos grandes laboratórios (CERN, IBM, Google, Microsoft, EUA, China, Europa, etc.). Podes fazê-lo à temperatura ambiente, embora de forma mais modesta, no laboratório, usando o díodo de efeito de túnel e o díodo de efeito de túnel ressonante. Estes dois dispositivos trazem a mecânica quântica do reino da abstração para realidades que os engenheiros podem construir, medir e compreender. Objetivo do estágio/projeto: aprimorar os dotes analíticos e experimentais dos futuros engenheiros físicos, isto é, contribuir para formar engenheiros capazes de pensar de forma rigorosa e crítica, mas também de pôr as mãos na massa, testando e experimentando, tendo como meta transformar teorias em tecnologias. Tarefas: familiarização com a física do efeito túnel, da fusão nuclear aos circuitos quânticos, explorar em laboratório o comportamento de circuito eletrónicos e optoelectrónicos contendo dispositivos cujo funcionamento depende do efeito de túnel e do efeito de túnel ressonante, incluindo a geração de sinais periódicos, aperiódicos e de sinais caótico, e a aplicações destes circuitos em computação neuromórfica. O estágio irá permitir verificar como conceitos abstratos de mecânica quântica se tornam reais e relevantes na ciência e na engenharia. Em laboratório, irás manusear realidades quânticas com os dedos e aumentar a tua intuição quântica várias ordens de grandeza. Domínios: mecânica quântica, instrumentação, eletrónica, aplicação do método científico Grupo: RADART LIP: Lisboa Período: maio a julho

Grupo : RADART
Local : Lisboa
Supervisor(s) : José Figueiredo
Email : jmfigueiredo@ciencias.ulisboa.pt
Vagas : 1
Duração/Datas : maio a julho

Proposta de Estágio em Engenharia Física (FCUL): Emular comportamentos quânticos usando a luz
Proposta de Estágio em Engenharia Física (FCUL): Emular comportamentos quânticos usando a luz Uma das regras fundamentais que regem a física quântica é que observar (i.e., medir/caracterizar) o estado de um fotão ou partícula provoca a “alteração” desse estado. Partindo deste pressuposto, será possível ver (i.e., medir a presença de) um objeto sem interagir com ele? Neste estágio irás compreender como se interligam conceitos centrais que impulsionam as tecnologias quânticas, através de experiências de ótica ondulatória que permitem emular fenómenos e comportamentos quânticos, só possíveis de serem observados num punhado de laboratórios do nosso universo. Objetivo do estágio/projeto: aprimorar os dotes analíticos e experimentais dos futuros engenheiros físicos, isto é, contribuir para formar engenheiros capazes de pensar de forma rigorosa e crítica, mas também de pôr as mãos na massa, testando e experimentando, tendo como meta transformar teorias em tecnologias. Tarefas: compreender o funcionamento de componente optoelectrónicos e fotónicos, e fazer as montagens que permitem emular (reproduzir de forma análoga) as experiências da borracha quântica (“delayed-choice quantum eraser”), do teste de bombas (problema de Elitzur-Vaidman), e de demonstração de criptografia quântica. O estágio irá permitir verificar como conceitos abstratos de mecânica quântica se tornam reais e relevantes na ciência e na engenharia. Em laboratório, irás manusear entidades quânticas com os dedos e aumentar a tua intuição quântica. Domínios: mecânica quântica, instrumentação, fotónica, aplicação do método científico Grupo: RADART LIP: Lisboa Período: maio a julho

Grupo : RADART
Local : Lisboa
Supervisor(s) : José Figueiredo
Email : jmfigueiredo@ciencias.ulisboa.pt
Vagas : 1
Duração/Datas : maio a julho

Thermal analysis for the ATLAS/LHC/CERN High Granularity Timing Detector
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 in the forward region with an unprecedented time resolution of 35 ps. The two sides of the HGTD are located at ±3.5 m from the interaction point (IP). Each side consists of two double-sided layers of Low-Gain Avalanche Detectors (LGAD), mounted on two large cooling plates inside an hermetic vessel. The Portuguese team is strongly involved in the design and construction of the detector, namely in the development of the HGTD Interlock System, which is a standalone safety system that protects the detector against a variety of threads. A key analysis is the assessment of thermal risks during the LHC beam pipe bake-out, in the hypothetical event of a cooling-system failure. Since bake-out procedures involve elevated and time-varying temperatures, understanding the resulting thermal load on HGTD components is essential for defining safe operating conditions. The project focuses on performing this assessment through a finite-element analysis (FEM). The inputs will be the HGTD geometry and material/thermal properties. The goals are: Definition of the bake-out scenario, including the temperature evolution of the beam pipe, cooling-failure assumptions, and thermal boundary conditions. Establish risk criteria, such as maximum safe temperatures for LGAD sensors, ASICs, and the bump-bonded system. Carry out FEM simulations to evaluate heat propagation and identify potential failure modes. Document and interpret the results, contributing to the safety specifications of the HGTD Interlock System. This is an international project. The student will work as member of the ATLAS Portuguese group and will work closely with the ATLAS-HGTD team, gaining experience in detector engineering, thermal modelling, and experimental physics operations.

Grupo : ATLAS
Local : Lisboa
Supervisor(s) : Helena Santos
Email : helena@lip.pt
Vagas : 1
Duração/Datas : January-June 2026

Filtering for Discovery: Studying Jet Trigger Efficiency in ATLAS
At the forefront of human discovery, the ATLAS experiment at the Large Hadron Collider (LHC) probes the fundamental building blocks of our universe. As the most energetic particle collider ever built, the LHC collides bunches of protons at a staggering rate of 40 million times per second, producing an average of 60 proton-proton collisions in every crossing. The results of the bunch crossings, called events, are registered by the ATLAS detector. However, recording this huge event rate for future analysis is physically impossible, and only only 1500 events per second can be stored. This is where the ATLAS Trigger System performs its critical role. Acting as the experiments intelligent, real-time selection system, it must make a very fast decision on which collisions are interesting for future physics analysis. This sophisticated system employs a sequence of hardware and software filters, searching for generic signatures such as highly energetic particles. An excellent performance of the trigger system is paramount, as any data rejected at this stage is lost forever. This internship project focuses the performance studies of an important component of this system: the Jets Software Triggers. Jets are the experimental signatures of quarks and gluons, the fundamental constituents of matter governed by the strong force. When these particles are produced in collisions, they instantly transform into narrow, collimated sprays of hadrons that we detect as jets. The accurate and efficient identification of high transverse momentum jets is the key that unlocks a vast physics programme, from precision tests of Quantum Chromodynamics (QCD) to the direct search for new particles and exotic interactions. The mission of this project is to ensure that this trigger is both robust and efficient. The student will undertake a hands-on performance study using the real data collected by the ATLAS detector, complemented by simulated Monte Carlo samples. The core of the work will involve producing detailed performance plots, such as trigger efficiency and energy resolution, as a function of various relevant physical variables. This analysis will be conducted across different periods of the ongoing LHC Run 3 (2022-2026), providing essential feedback on the triggers stability and performance over time. The successful candidate will become an integral part of our international team, gaining invaluable experience in data analysis and detector performance in high-energy physics. The findings of this research will be presented at the relevant ATLAS Trigger meetings, offering a unique opportunity to contribute directly to the operational success of one of the worlds most ambitious scientific endeavors.

Grupo : ATLAS
Local : Lisboa
Supervisor(s) : Patricia Conde Muíño
Email : pconde@lip.pt
Vagas : 1
Duração/Datas : 2-3 months project

Tracking muons from ongoing LHC collisions
Muons are highly penetrating particles that traverse large amounts of matter. A muon telescope, based on an innovative technology (sRPC), designed and built at LIP, has been installed in 2024 in the LHC tunnel, and has already successfully accumulated one year worth of data. The new detector allows us to measure the flux of muons produced in the LHC collisions, that occur 500m away at ATLAS. These unique measurements 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 LHC 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). The project involves the analysis of the collected data towards the measurement (and publication) of the LHC muonic flux.

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