Bøker i Springer Theses-serien

This thesis describes two groundbreaking measurements in the precision frontier at the LHC: the first ever differential measurement of the Z-associated single top quark (tZq) production, and the luminosity measurement using Z boson production rate for the first time in CMS. Observed only in 2018, the tZq process is of great importance in probing top quark electroweak couplings. These couplings are natural places for new phenomena to happen in the top quark sector of the standard model. Yet, they are the least explored directly. One has to obtain a firm understanding of the modeling of sensitive distributions to new top-Z interactions. The present analysis marks a major milestone in this long-term effort. All distributions relevant for new phenomena, and/or modeling of tZq, are studied in full depth using advanced Machine Learning techniques.The luminosity and its uncertainty contributes to every physics result of the experiment. The method minutely developed in this thesis provides a complementary measurement that results in a significant overall reduction of uncertainties.

Time, space and entanglement are the main characters in this book. Their nature is still a great mystery in physics and we study here the possibility that these three phenomena are closely connected, showing how entanglement can be at the basis of the emergence of time and space within closed quantum systems. We revisit and extend the Page and Wootters theory that was originally introduced in order to describe the emergence of time through entanglement between subsystems in a globally static, quantum Universe. In the book, after providing a complete review of the salient aspects of the theory, we establish a connection with recent research on the foundations of statistical mechanics and we provide a new understanding of the thermalization process. Furthermore, we generalize the framework in order describe the spatial degree of freedom and we provide a model of 3+1 dimensional, quantum spacetime emerging from entanglement among different subsystems in a globally "timeless" and "positionless" Universe. Finally, via the Page and Wootters theory, the evolution of quantum clocks within a gravitational field is treated and a time dilation effect is obtained in agreement with the Schwarzschild solution.

In recent decades, twistor theory has grown into an irreplaceable tool for the study of scattering amplitudes in gauge theory and gravity. This book introduces the reader to cutting-edge advances in twistor theory and its applications to general relativity. The problem of graviton scattering in four dimensions is shown to be dual to dramatically simpler computations in a two-dimensional CFT known as a twistor sigma model. Twistor sigma models are the first step toward a holographic description of gravity in asymptotically flat space-times. They underpin the infinitely many asymptotic symmetries of flat space physics discovered in celestial holography, and extend them to exciting new arenas like curved space-times. They also yield intrinsically mathematical results in the field of hyperkähler manifolds. This volume will be of broad interest to students and researchers looking for an accessible entry point into twistor geometry, scattering amplitudes, and celestial holography. It will also provide an invaluable reference for specialists by bringing together results from a host of different disciplines.

One of the main unanswered question of modern Physics is "How does gravity behave at small scales?". The aim of this thesis is to illustrate in a comprehensive but accessible way how to look for deviations from Einstein's theory of General Relativity in this regime, looking at the simplest celestial bodies: static and spherically symmetric ones.With a conservative and bottom-up approach, at smaller scales the first corrections to the action of General Relativity are generally considered to be terms quadratic in the curvature tensors; while these modifications do not cure the inconsistency between gravity and quantum mechanics, the solutions of this theory are plausible candidates to be the first-order corrections of the classical ones.Even with such simple modifications, a striking picture emerges from the study of isolated objects: the unique Schwarzschild solution of General Relativity is only a rare bird in the set of solutions, with non-Schwarzschild black holes, wormholes and naked singularities appearing as possible substitutes.Tailored to graduate students and researchers entering this field, this thesis shows how to construct these new solutions from action principles, how to characterize their metric, how to study their physical properties, such as their stability or Thermodynamics, and how to look for phenomenological signatures.

This book provides a comprehensive overview of Nuclear Magnetic Resonance (NMR) theory, its applications, and advanced techniques to improve the quality and speed of NMR data acquisition. In this book, the author expands his outstanding Ph.D. thesis and provides a valuable resource for researchers, professionals, and students in the field of NMR spectroscopy.The book covers quantum mechanics basics, and topics like density operators, pulse sequences, 1D pulse acquisition, INEPT (Insensitive nuclei enhancement by polarization transfer), product operators, and 2D NMR principles. It also explores innovative experiments like States HSQC (Heteronuclear Single Quantum Coherence) and echo-antiecho HSQC with gradients.In the subsequent chapters, the author discusses Pure Shift NMR, including PSYCHE (Pure Shift Yielded by Chirp Excitation) and its optimizations, such as waveform parameterization and time-reversal methods. The 'Discrete PSYCHE' approach and Ultrafast PSYCHE-iDOSY (Diffusion-ordered spectroscopy) are also highlighted.This book presents the POISE (Parameter Optimisation by Iterative Spectral Evaluation) software for real-time NMR experiment optimization, including pulse width calibration and Ernst angle optimization, and demonstrates applications across various NMR experiments.Lastly, the book examines accelerated 2D NMR data collection and the NOAH (NMR by Ordered Acquisition using 1H detection) supersequences, emphasizing automated pulse program creation using GENESIS (GENEration of Supersequences In Silico). Covered NMR experiments include 13C sensitivity-enhanced HSQC, 15N HMQC (Heteronuclear Multiple Quantum Coherence), dual HSQC, HSQC-TOCSY (Total Correlation Spectroscopy), HMBC (Heteronuclear Multiple Bond Correlation), and ADEQUATE (Adequate Sensitivity Double-Quantum Spectroscopy).

This thesis describes how the rich internal degrees of freedom of molecules can be exploited to construct the first ¿clock¿ based on ultracold molecules, rather than atoms. By holding the molecules in an optical lattice trap, the vibrational clock is engineered to have a high oscillation quality factor, facilitating the full characterization of frequency shifts affecting the clock at the hertz level. The prototypical vibrational molecular clock is shown to have a systematic fractional uncertainty at the 14th decimal place, matching the performance of the earliest optical atomic lattice clocks. As part of this effort, deeply bound strontium dimers are coherently created, and ultracold collisions of these Van der Waals molecules are studied for the first time, revealing inelastic losses at the universal rate. The thesis reports one of the most accurate measurements of a molecule¿s vibrational transition frequency to date. The molecular clock lays the groundwork for explorations into terahertz metrology, quantum chemistry, and fundamental interactions at atomic length scales.

This book describes the development of novel protein¿RNA-binding assays and their applications in a high-throughput manner for the identification of small-molecule modulators of protein¿RNA interactions to treat cancer and COVID-19.Modulating protein¿RNA interactions with small molecules is expected to provide novel biological insights of the interrelation of diseases with the protein¿RNA interactome. The modulations may also be exploited therapeutically. For these reasons, the development of a simple, reliable, and sensitive protein¿RNA-binding assay is necessary for high-throughput screening to discover new effective chemical entities capable of acting on diverse protein¿RNA interactions. This book discusses the discovery of small-molecule modulators targeting protein¿RNA interactions that are potentially valuable to treat cancer and COVID-19 by constructing novel high-throughput screening methods. The results of this dissertation provide valuable insights into the regulation of protein¿RNA interactions in chemical biology and drug development.

This thesis outlines the principles, device physics, and technological applications of electronics based on the ultra-wide bandgap semiconductor aluminum nitride. It discusses the basic principles of electrostatics and transport properties of polarization-induced two-dimensional electron and hole channels in semiconductor heterostructures based on aluminum nitride. It explains the discovery of high-density two-dimensional hole gases in undoped heterojunctions, and shows how these high conductivity n- and p-type channels are used for high performance nFETs and pFETs, along with wide bandgap RF, mm-wave, and CMOS applications. The thesis goes on to discuss how the several material advantages of aluminum nitride, such as its high thermal conductivity and piezoelectric coefficient, enable not just high performance of transistors, but also monolithic integration of passive elements such as high frequency filters, enabling a new form factor for integrated RF electronics.

In this thesis, the author proposes "metal-responsive base pair switching" of ligand-modified nucleobases as a novel tool for stimuli-responsive control of DNA assemblies. It is written to demonstrate broad applicability of the base pair switching in dynamic DNA nanotechnology and inspire researchers to use this technique. Based on specific interactions between ligand-type nucleobases and target metal ions, in this volume, DNA hybridization was dynamically controlled through strand displacement reactions. The base pair switching was further applied to develop metal-dependent DNA molecular machines. This novel strategy for stimuli-responsive regulation of DNA assemblies will greatly expand the scope of dynamic DNA nanotechnology. This volume uniquely features importance of elaborate molecular design based on chemistry for imparting stimuli responsiveness to DNA assemblies.

This book describes the development of two kinds of continuous-flow transformation using heterogeneous catalysts, and explains how they can be applied in the multistep synthesis of active pharmaceutical ingredients. It demonstrates and proves that fine chemicals can be synthesized under continuous-flow conditions using heterogeneous catalysis alone. Importantly, the book also proposes a general concept and strategy for achieving multistep flow synthesis and developing heterogeneous catalysts, and shows that commercially available anion exchange resin can be used as a water-tolerant strong base catalyst for various types of continuous-flow aldol-type reaction. Reviewing the state of the art in heterogeneous catalysis in flow chemistry - a "e;hot topic"e; and rapidly developing area of organic synthesis - the book will provide readers with a deeper understanding of fine chemical flow synthesis and its future prospects. 

This thesis makes significant advances in the use of microspheres in optical traps as highly precise sensing platforms. While optically trapped microspheres have recently proven their dominance in aqueous and vacuum environments, achieving state-of-the-art measurements of miniscule forces and torques, their sensitivity to perturbations in air has remained relatively unexplored. This thesis shows that, by uniquely operating in air and measuring its thermally-fluctuating instantaneous velocity, an optically trapped microsphere is an ultra-sensitive probe of both mass and sound. The mass of the microsphere is determined with similar accuracy to competitive methods but in a fraction of the measurement time and all while maintaining thermal equilibrium, unlike alternative methods. As an acoustic transducer, the air-based microsphere is uniquely sensitive to the velocity of sound, as opposed to the pressure measured by a traditional microphone. By comparison to state-of-the-art commercially-available velocity and pressure sensors, including the world¿s smallest measurement microphone, the microsphere sensing modality is shown to be both accurate and to have superior sensitivity at high frequencies. Applications for such high-frequency acoustic sensing include dosage monitoring in proton therapy for cancer and event discrimination in bubble chamber searches for dark matter. In addition to reporting these scientific results, the thesis is pedagogically organized to present the relevant history, theory, and technology in a straightforward way.

This book describes a detailed multi-scale approach integrating nano- (active site), meso- (porous catalyst architecture) and macroscale (reactor) efforts, to address the challenges of producing a better epoxidation catalyst. It contains an in-depth study of the design and synthesis of gold nanoparticles and their application as a catalyst for direct gas phase propylene epoxidation. "e;Direct"e; means using only hydrogen and oxygen in one step, which is key for sustainable manufacturing, as opposed to commercialised, more complex production routes requiring multiple steps, or integration with another chemical plant. The insights gained can be used for rational design for stable and selective catalysts for other reactions. It also details the step-by-step process to build an epoxidation reactor system with a focus on safety aspects, which can be used as a guidebook for undergraduate and graduate students in chemical engineering. Beyond heterogeneous catalysis, the new, easily accomplished methodology for synthesising atomically precise nanoparticles is shown to be relevant to electrocatalysis and to healthcare applications, such as anti-microbial surfaces.This book will be of interest to researchers, engineers and experts in the related areas of chemical engineering, chemistry, material science and electrochemistry.