Quantum field theory (QFT) is a highly advanced and mathematical subject that typically requires a solid background in undergraduate-level physics and mathematics to fully comprehend. However, if you're looking for an introductory book that starts from scratch and assumes minimal prior knowledge, "Quantum Field Theory for the Gifted Amateur" by Tom Lancaster and Stephen J. Blundell is a highly recommended choice.
"Quantum Field Theory for the Gifted Amateur" is specifically designed for readers with a passion for physics and an interest in delving into the subject of QFT. It introduces the basic concepts and principles of QFT using accessible language, intuitive explanations, and minimal mathematics. The authors take a step-by-step approach, gradually building up the theory and explaining the relevant mathematical tools along the way.
While this book may not provide a fully rigorous treatment of QFT or delve into the advanced mathematical formalism, it serves as an excellent starting point for beginners. It will give you a conceptual understanding of the subject, familiarize you with key ideas, and provide a foundation for further study.
However, it's important to note that eventually, a deeper understanding of the mathematical formalism and advanced concepts will be necessary to grasp QFT fully. As you progress, you may want to supplement your studies with more comprehensive textbooks that cover the subject with greater mathematical rigor, such as "Quantum Field Theory and the Standard Model" by Matthew D. Schwartz or "Quantum Field Theory in a Nutshell" by A. Zee.
Remember, QFT is a challenging subject, and self-studying it without a strong mathematical and physics background can be demanding. It's advisable to approach it with patience, persistence, and a willingness to engage with the material over an extended period. Supplementing your learning with lectures, online resources, and problem-solving will also enhance your understanding.