Effective field theories are a widely used tool in various branches of physics. This book provides a comprehensive discussion of the foundations and fundamentals of effective field theories of quantum chromodynamics (QCD) in the light quark sector with an emphasis on the study of flavour symmetries and their realizations. In this context, different types of effective field theories pertaining to various energy scales are considered and selected applications are devised. It also covers the formulation of effective field theories in a finite volume and its application in the analysis of lattice QCD data. Effective Field Theories is intended for graduate students and researchers in particle physics, hadron physics and nuclear physics. Exercises are included to help the reader deepen their understanding of the topics discussed throughout, with solutions available to lecturers.

This primer begins with a brief introduction to the main ideas underlying Effective Field Theory (EFT) and describes how nuclear forces are obtained from first principles by introducing a Euclidean space-time lattice for chiral EFT. It subsequently develops the related technical aspects by addressing the two-nucleon problem on the lattice and clarifying how it fixes the numerical values of the low-energy constants of chiral EFT. In turn, the spherical wall method is introduced and used to show how improved lattice actions render higher-order corrections perturbative. The book also presents Monte Carlo algorithms used in actual calculations. In the last part of the book, the Euclidean time projection method is introduced and used to compute the ground-state properties of nuclei up to the mid-mass region. In this context, the construction of appropriate trial wave functions for the Euclidean time projection is discussed, as well as methods for determining the energies of the low-lying excitations and their spatial structure. In addition, the so-called adiabatic Hamiltonian, which allows nuclear reactions to be precisely calculated, is introduced using the example of alpha-alpha scattering. In closing, the book demonstrates how Nuclear Lattice EFT can be extended to studies of unphysical values of the fundamental parameters, using the triple-alpha process as a concrete example with implications for the anthropic view of the Universe. Nuclear Lattice Effective Field Theory offers a concise, self-contained, and introductory text suitable for self-study use by graduate students and newcomers to the field of modern computational techniques for atomic nuclei and nuclear reactions.