Dirección: Xabier Cid Vidal e Carlos Vázquez Sierra.

The IGFAE summer fellows that have been staying here during October will make a presentation of their work:

Juan David Hormaza Pantoja | Practical quantum simulation from Ising model to field theory

Summary: I have been working on developing quantum simulation applications to physics using the Qiskit framework. I started with a basic Ising model to get familiarity with quantum computing, and then move on to more advanced real-time simulation of light-front Hamiltonian formalism or quantum field theory. Depending on the student’s interests, we may also focus on other things. Familiarity with quantum mechanics and programming in Python are required. Background in quantum information science would be a plus but not necessary.

Supervisor: Wenyang Qian

Adrián Lambiés Asensio | Desarrollos de diagnósticos y blancos para la aceleración de protones con láseres ultra-intensos

Summary: Los aceleradores láser-plasma permiten alcanzar campos eléctricos superiores a 1012V/m, órdenes de magnitud superiores a los disponibles en aceleradores convencionales, permitiendo el desarrollo de aceleradores compactos para ciencia básica y aplicada. En este proyecto, se plantea desarrollar trabajo experimental asociado al desarrollo necesario para la aceleración láser, en alguna de las líneas de interés en el Laboratorio Láser de Aceleración y Aplicaciones (L2A2), que cuenta con un láser de 50TW para realizar estas medidas. Entre las distintas líneas entre las que podrá elegir la persona candidata, se encuentra el desarrollo de nuevas técnicas de alineamiento para blancos a alta tasa de repetición basadas en técnicas de Machine Learning, así como el desarrollo de nuevos métodos de diagnóstico basados en fibras centelleadoras capaces de caracterizar haces de protones de duración ultra-corta.

Supervisor: Adrián Bembibre Fernández

Luis Miguel Sánchez Sánchez | Electronics for proton therapy

Proton therapy is a type of radiation treatment that uses protons instead of X-rays to treat cancer, allowing for more precise targeting of tumors while minimizing damage to surrounding healthy tissues. IGFAE is involved in designing a novel method for range verification in proton therapy treatments. We developed and tested a first prototype and are currently working on improving it. The student will contribute to the design and verification of PCBs for this project.

Supervisor: Antonio Fernández Prieto

Entanglement is a key feature of quantum mechanics. Usually, it is discussed in the context of two subsystems at a given time. A natural question is whether the notion of entanglement can be extended to subsystems at different times.

I will present a novel family of such entanglement measures. Their key property is providing upper bounds to time-separated correlation functions, akin to the bound on spatially separated correlators in terms of the mutual information. For relativistic quantum field theories our definition agrees with the analytic continuation from space-like to time-likes separated regions. I will discuss the measurement protocols and report explicit computations for Ising chain, free fermions, 1+1 dimensional conformal field theories and holographic theories.

This is a work in progress with Zofia Adamska and John Preskill. 

In this talk I will introduce the main tools to analyse the double-scaled Sachdev-Ye-Kitaev model (DSSYK), which is a specific limit of the SYK model where both the number of fermions and the size of the interaction terms in the Hamiltonian are taken to infinity in a coordinated manner. Such a model is fully analytically solvable thanks to the use of chord diagrams, a combinatorial object that keeps track of Wick contractions in the computation of disorder-averaged observables. Chords may be used to define an effective Hilbert space, together with an algebra of observables, for the averaged theory, which can in turn be interpreted as the gravitational bulk dual. In a suitable limit that focuses on the low-energy regime, such a bulk dual is described by JT gravity on the disk. In recent work, we have made use of this explicit instance of low-dimensional holographic duality in order to build analytically the bulk dual of the Krylov complexity of the thermofield-double state, which is given by the regularised wormhole length in JT gravity with no matter. I will review this result, and I will also discuss some work in progress on the bulk dual of operator Krylov complexity in DSSYK. 

In this seminar, I will present the analysis of data collected from an Optical Time Projection Chamber (OTPC) based on an argon gas mixture, aimed at evaluating its performance for potential integration into the DUNE near detector to improve control over systematic errors. The study focuses on the identification and analysis of ionization profiles from alpha particles and cosmic muons. A dedicated software tool was developed to characterize the OTPC\'s performance, specifically estimating its optical gain, which is critical for understanding the detector’s measurement capabilities. Notably, this work includes the first successful reconstruction of cosmic muon tracks using an argon-gas OTPC.

After a perturbation, black holes emit gravitational radiation at certain characteristic frequencies corresponding to their quasinormal modes (QNMs). These modes depend on the underlying gravitational dynamics and hence their detection in gravitational wave experiments provides an excellent test to look for deviations to Einstein gravity. In the case of Kerr black holes in General Relativity (GR), the study of QNMs is made possible by the Teukolsky equation. However, the study of perturbations of rotating black holes in theories beyond GR is a very challenging problem that has remained elusive for a long time. In this talk I will present a resolution to this problem by introducing (and solving) a "universal" Teukolsky equation that holds in modifications of GR. I will use this equation to obtain the QNM frequencies of black holes with substantial angular momentum in higher-derivative extensions of GR. I will also discuss the case of near-extremal black holes, which poses additional challenges and is the subject of ongoing investigations.

Esta sesión especial estará organizada en colaboración co Art.Lab do Instituto Galego de Física de Altas Enerxías (IGFAE) a partir da súa exposición Instrumentos de Visión, do artista Armin Linke e comisariada por Mónica Bello desde Arts at CERN. A actividade contará coa participación do físico teórico Carlos Salgado, director do IGFAE; Luísa Martínez, Responsable de Cultura Científica de CSIC-Galicia e o investigador e artista sonoro, Xoán-Xil. A conversa partirá do traballo exposto por Linke para facer unha analoxía entre os instrumentos da visión científica e as ferramentas da visión e da filmación e, a partir de aí, afondar nas analoxías e diverxencias dos métodos de investigación artística e científica.

Nos últimos anos, o IGFAE impulsou o programa ArtLab, un espazo de diálogo entre a arte e a ciencia desenvolvida neste centro de investigación, que fomenta as interaccións entre ambas áreas do coñecemento. Neste marco, e en relación á recente exposición organizada polo IGFAE, o centro súmase á programación de Curtocircuito, co obxectivo de explorar as analoxías entre os instrumentos de visión científica e as ferramentas da filmación, e afondar nos vínculos e diverxencias entre os métodos de investigación científica e artística.

The formation of short-range correlated nucleon-nucleon pairs (SRCs), primarily composed of neutron-proton pairs [1], appears to be a universal feature in atomic nuclei [2]. Interestingly, measurements in electron scattering indicate that protons become significantly more correlated in asymmetric nuclei as a function of neutron excess. This has potential implications for the description of cold dense nuclear matter as for neutron stars. However, available data are limited to stable nuclei which have maximum neutron excess of ~1.6 and, at the same time as they become more neutron-rich, they also become more heavy. To overcome these limitations, we performed a pilot experiment at the R³B setup at GSI-FAIR [3] as part of the FAIR Phase-0 experimental program to measure SRC in the most neutron-rich nucleus yet, 16C. We employ hard proton knockout reactions in inverse kinematics of 16C beam at 1.25 GeV/nucleon, as well as 12C beam as reference, to study SRC behavior. In this talk, I will discuss the results of this SRC investigation in neutron-rich nuclei and prospects for the follow-up research program at FAIR.

[1] R. Subedi, R. Shneor, Science, 1156675, 2008.

[2] M. Duer et al. (CLAS Collaboration), Nature, 560:617, 2018.

[3] https://www.gsi.de/work/forschung/nustarenna/nustarenna_divisions/kernreaktionen/activities/r3b.

An important question in heavy-ion collisions is how the initial far-from-equilibrium medium evolves and thermalizes while it undergoes a rapid longitudinal expansion. In this presentation, I will show how to use the two-particle irreducible (2PI) effective action to address this question, focusing on phi^4 scalar theory truncated at three loops. I will present numerical results for quantities such as the occupation number, the thermal mass, and the number density.