By Thomas Becher, Alessandro Broggio and Andrea Ferroglia
Springer
Also available at the CERN bookshop
The volume provides an essential and pedagogical introduction to soft-collinear effective field theory (SCET), one of the low-energy effective field theories (EFTs) of the Standard Model developed in the last two decades. EFTs are used when the problem that is tackled requires a separation of the low-energy contributions from the high-energy part, to be solved.
SCET has already been applied to a large variety of processes, from B-meson decays to jet production at the LHC. As a consequence, the need was felt for a self-contained text that could make this subject easily accessible to students, as well as to researchers who are not experts in the subject. Nevertheless, a background in quantum field theories and perturbative QCD is a prerequisite for the book.
The basics of the construction of effective theory are presented in detail. The expansion of Feynman diagrams describing the production of energetic particles is described, followed by the construction of an effective Lagrangian, which produces the different terms that contribute to the expanded diagrams. The case of a scalar theory is considered first, then the construction is extended to the more complex case of QCD.
To show the method at work, the authors have included some collider-physics example applications (the field where, in the last few years, SCET has been applied the most). In particular, the soft-gluon resummation for the inclusive Drell–Yan cross-section in proton–proton collisions is discussed, and SCET formalism is used to perform transverse-momentum resummation. In addition, the application of SCET methods to a process with high energetic particles in many directions is analysed, and the structure of infrared singularities in n-point gauge-theory amplitudes derived.
