Physics Performance Report for PANDA Strong Interaction Studies with Antiprotons

To study fundamental questions of hadron and nuclear physics in interactions of antiprotons with nucleons and nuclei, the universal PANDA detector will be build. Gluonic excitations, the physics of strange and charm quarks and nucleon structure studies will be performed with unprecedented accuracy thereby allowing high-precision tests of the strong interaction. The proposed PANDA detector is a state-of-the-art internal target detector at the HESR at FAIR allowing the detection and identifcation of neutral and charged particles generated within the relevant angular and energy range. This report presents a summary of the physics accessible at PANDA and what performance can be expected

Contributions to the study of Austism Spectrum Brain conectivity

164 p.Autism Spectrum Disorder (ASD) is a largely prevalent neurodevelopmental condition with a big social and economical impact affecting the entire life of families. There is an intense search for biomarkers that can be assessed as early as possible in order to initiate treatment and preparation of the family to deal with the challenges imposed by the condition. Brain imaging biomarkers have special interest. Specifically, functional connectivity data extracted from resting state functional magnetic resonance imaging (rs-fMRI) should allow to detect brain connectivity alterations. Machine learning pipelines encompass the estimation of the functional connectivity matrix from brain parcellations, feature extraction and building classification models for ASD prediction. The works reported in the literature are very heterogeneous from the computational and methodological point of view. In this Thesis we carry out a comprehensive computational exploration of the impact of the choices involved while building these machine learning pipelines

Multi-wavelength investigation of energy release and chromospheric evaporation in solar flares

For a comprehensive understanding of the energy release and chromospheric evaporation processes in solar flares it is necessary to perform a combined multi-wavelength analysis using observations from space-based and ground-based observatories, and compare the results with predictions of the radiative hydrodynamic (RHD) flare models. Initially, the case study of spatially-resolved chromospheric evaporation properties for an M 1.0-class solar flare (SOL2014-06-12T21:12) using data form IRIS (Interface Region Imaging Spectrograph), HMI/SDO (Helioseismic and Magnetic Imager onboard Solar Dynamics Observatory), and VIS/GST (Visible Imaging Spectrometer at Goode Solar Telescope), demonstrate a complicated nature of evaporation and its connection to the magnetic field topology. Following this study, the Interactive Multi-Instrument Database of Solar Flares (IMIDSF) is designed for efficient search, integration, and representation of solar flares for statistical studies. Comparison of the energy release and chromospheric evaporation properties for seven solar flares simultaneously observed by IRIS and RHESSI (Reuven Ramaty High Energy Solar Spectroscopic Imager) with predictions of the RHD electron beam-heating flare models reveals weak correlations between deposited energy fluxes and Doppler shifts of IRIS lines for observations and strong fore models, together with other quantitative discrepancies. Statistical analysis of properties of Soft X-Ray (SXR) emission, plasma temperature (T), and emission measure (EM), derived from GOES (Geostationary Operational Environmental Satellite) observations demonstrate that flares form two groups, “T-controlled” and “EM-controlled”, distinguished by different contribution of T and EM to the SXR peak formation and presumably evolving in loops of different lengths. Also, the modeling of the SDO/HMI line-of-sight observables for RHD flare models highlights that for relatively high deposited energy fluxes (≥ 5.0 x 1010 erg cm-2 s-1) the sharp magnetic transients and Doppler velocities observed during the solar flares by HMI/SDO should be interpreted with caution. Finally, problems of the solar flare prediction and the role of the magnetic field Polarity Inversion Lines (PIL) in the initiation and development of flares are considered. In particular, the possibility to enhance the daily operational forecasts of M-class flares by considering jointly PIL and other magnetic field and SXR characteristics is demonstrated, with corresponding Brier Skill Scores (BSS = 0.29 ± 0.04) higher than for the SWPC NOAA operational probabilities (BSS = 0.09 ± 0.04)

Measurement of the W → ev cross section with early data from the CMS experiment at CERN

The Compact Muon Solenoid (CMS) is a general purpose detector designed to study proton-proton collisions, and heavy ion collisions, delivered by the Large Hadron Collider (LHC) at the European Laboratory for High Energy Physics (CERN). This thesis describes a measurement of the inclusive W → ev cross section at 7 TeV centre of mass energy with 2:88 ± 0:32 pb-1 of LHC collision data recorded by CMS between March and September 2010. W boson decays are identified by the presence of a high-pT electron that satisfies selection criteria in order to reject electron candidates due to background processes. Electron selection variables are studied with collision data and found to be in agreement with expectations from simulation. A fast iterative technique is developed to tune electron selections based on these variables. Electron efficiency is determined from simulation and it is corrected from data using an electron sample from Z decays. The number of W candidates is corrected for remaining background events using a fit to the missing transverse energy distribution. The measured value for the inclusive W production cross section times the branching ratio of the W decay in the electron channel is: σ(pp → W+X)xBR(W → ev) = 10.04±0.10(stat)±0.52(syst)±1.10(luminosity) nb; which is in excellent agreement with theoretical expectations

Physics at BES-III

This physics book provides detailed discussions on important topics in $\tau$-charm physics that will be explored during the next few years at \bes3 . Both theoretical and experimental issues are covered, including extensive reviews of recent theoretical developments and experimental techniques. Among the subjects covered are: innovations in Partial Wave Analysis (PWA), theoretical and experimental techniques for Dalitz-plot analyses, analysis tools to extract absolute branching fractions and measurements of decay constants, form factors, and CP-violation and \DzDzb-oscillation parameters. Programs of QCD studies and near-threshold tau-lepton physics measurements are also discussed.Comment: Edited by Kuang-Ta Chao and Yi-Fang Wan

Learning and reasoning with physical, structural, and symbolic priors

General purpose neural network models such as transformers have achieved remark- able success in solving complicated tasks across multiple domains and modalities. However, in many applications, the need for domain-specific models remains evident. Moreover, large-scale general-purpose models often demand an excessive amount of data to achieve satisfactory generalization. This PhD research aims to address these challenges by focusing on several application domain settings and improving model generalization through the integration of domain-specific priors into the learning and reasoning process. To accomplish this goal, we explore four distinct computational domains: traffic light control, graph cold start recommendation, program synthesis, and optimizer learning. For traffic light control, we tackle the task by incorporating the delayed propagation physical prior into the model architecture. We introduce the Delayed Propagation Transformer (DePT), a transformer-based model that leverages a cone-shaped spatial-temporal attention prior. DePT enables global modeling of CPS by considering the immutable constraints from the physical world, resulting in improved generalization performance compared to state-of-the-art expert methods. In the context of graph cold start recommendation, we address the limitations of Graph Neural Networks (GNNs) under cold start scenarios. Specifically, we introduce Cold Brew, a teacher-student distillation approach that incorporates neighborhood message passing, and quantified the behavior of inductive GNNs through the feature contribution ratio. For program synthesis, we focus on the challenge of generating high-quality code solutions by integrating structured thought processes. We propose ChainCoder, a program synthesis language model that progressively generates Python code in multiple passes, reflecting the “outline-then-detail" paradigm. By decomposing source code into layout frame components and accessory components, ChainCoder incorporates hierarchical generation, syntactic structure priors, and a tailored transformer architecture. In the domain of optimizer learning, we leverage the symbolic regression tool to overcome scalability and interpretability challenges in Learning to Optimize (L2O) models. By introducing a holistic symbolic representation and analysis framework for L2O, we gain insights into learnable optimizers and explicitly develop optimizers in symbolic form. This approach eliminates the scalability limitations associated with numerical rule representation in L2O models and provides interpretability and comparability among different L2O models. This PhD research has explored and developed methods to integrate domain-specific priors into the learning process, both by incorporating them into neural network architecture and by explicitly leveraging symbolic representations. By incorporating these physical, structural, and symbolic priors, we have improved generalization with less data requirements, and demonstrated the potential for more efficient and generalizable learning and reasoning systems.Electrical and Computer Engineerin

SELF-ORGANIZATION IN MICROWAVE FILAMENTARY DISCHARGES

We studied the self organising phenomena im filamntary microwave discharge at various pressures and excitation types

Searches for doubly charmed Baryons at LHCb

The results of two separate searches for the doubly-charmed Ξcc++ particle through the Ξcc++ → Λc+K−π+π+ and Ξcc++ → D+pK−π+ decay modes are presented in this thesis. Both analyses examine proton-proton collision data collected by the LHCb detector at the European Laboratory for Particle Physics. The Ξcc++→ Λc+K−π+π+ analysis resulted in the first-ever observation of a doubly-charmed baryon, namely the Ξcc++ state. Using data recorded in 2016 at LHCb, the mass of the Ξcc++ state was measured to be m(Ξcc++) = 3621.40 ± 0.72 (stat) ± 0.27 (syst) ± 0.14 (Λc+) MeV/c2, where the first and second uncertainties are statistical and systematic, respectively, and the last uncertainty is due to the limited knowledge on the mass of the Λc+ baryon. The signal was determined to be compatible with a weak decay. The second Ξcc++ analysis did not yield any evidence of the Ξcc++→ D+pK−π+ decay within the data recorded in 2016 so, instead, the following branching fraction ratio upper limit is set B(Ξcc++→ D+pK−π+)/B(Ξcc++ →Λc+K−π+π+) < 1.7 (2.1) × 10−2 at the 90% (95%) confidence level and at the measured mass of the Ξcc++ particle from the Ξcc++→Λc+K−π+π+ analysis. No signal is observed in the mass range 3300−3800MeV/c2. Additionally, a new multivariate-based trigger line was developed for reconstructing Ξc+→ pK−π+ decays at LHCb. The new trigger makes use of the Bonsai Boosted Decision Tree method and is designed with searches for doubly-charmed particles in mind. This trigger gives a 36% increase in the signal yield of potential Ξc+ particles compared to an original trigger line that was designed for the similar purposes. Aside from searches for doubly-charmed baryons, a short study is conducted into the calibration of the Ring Imaging Cherenkov (RICH) subdetectors at the LHCb detector. A method was successfully developed to obtain high momentum tracks without any knowledge of the magnetic field, which will be used in the future to test the hypothesis that the magnetic field is causing discrepancies seen between data and simulation for the RICH-1 Cherenkov angle resolution

Technical Design Report for PANDA Electromagnetic Calorimeter (EMC)

This document presents the technical layout and the envisaged performance of the Electromagnetic Calorimeter (EMC) for the PANDA target spectrometer. The EMC has been designed to meet the physics goals of the PANDA experiment. The performance figures are based on extensive prototype tests and radiation hardness studies. The document shows that the EMC is ready for construction up to the front-end electronics interface