BSM is an umbrella term, covering a large literature. The Lattice allows to explore otherwise inaccessible regimes in specific models.Recovering phenomenologically relevant information is, in many cases, highly non-trivial. This unit discusses three different topics: Composite Higgs Models, Large-N and Axions.
Essentials of Lattice Field Therory. Further specific prerequisites are enlisted with the different topics.
Motivation: naturalness problem, origin of EWSB.
Statement of the Composite Higgs solution:
Mimic QCD: New strongly-coupled sector at high energy scale.
At a suppressed scale, spontaneous breaking of chiral symmetry.
The Higgs is pNG boson, radiatively generated potential.
Use of the Lattice:
Only with the lattice can we explore the non-perturbative regime. ❖Define the model in the UV in isolation, "simulate" it.
Compute masses and decay constants from correlation functions.
Connect with continuum EFTs (beware of chiral/continuum limit!)
Difficulty: Intermediate
Prerequisites:
Renormalization group, EFTs
Simulation of gauge theories with different groups G (and Nc) (ex. SU(N), Sp(2N)).
Fermions in multiple representations (and Nf).
Hadron spectrum calculations.
Scale Setting.
Related:
Composite Dark Matter
Location of Conformal Window
Peskin-Takeuchi parameters
Chiral lattice fermions
Motivation: Gain a better understanding of YM theories, make predictions of phenomenological relevance
Statement of Strategy:
Gauge theories simplify as N goes to ∞
Compute at large-N.
Obtain results for lower N in powers of 1/N.
Use of the Lattice:
Only with the lattice can we explore the non-perturbative regime.
Calculate at different values of (largish)-N.
Extrapolate to N=∞ and obtain the leading 1/N dependence
Prerequisites:
Perturbative YM
Simulation of gauge theories with different groups G (and Nc) (ex. SU(N), Sp(2N)).
Fermions in multiple representations (and Nf).
Hadron spectrum calculations.
Scale Setting.
Related:
Witten-Veneziano
BSM models
Holography/Strings
Universality in YM theories
Motivation: Strong-CP problem
Statement of Peccei-Quinn Strategy:
Introduce a new (broken) U(1) symmetry
Its pNG is the Axion
CP violations can then be strongly suppressed
Use of the Lattice:
Theta-term is genuinely non-perturbative
Lattice can explore complex theta and finite T
Axion mass squared proportional to topological susceptibility
Prerequisites:
Renormalization, Anomalies
Simulation of SU(3) with fundamental fermions.
Calculation of Topological charge.
Scale Setting.
Related:
Theta dependence in gauge theories
Axion (relic) Dark Matter
Witten-Veneziano
Universality in YM theories
Tasi 2009 lectures: The Higgs as a Composite Nambu-Goldstone Boson – R. Contino
The Composite Nambu-Goldstone Higgs – G. Panico, A. Wulzer
Video Lectures @ICTP – A. Wulzer
Seminal papers by Kaplan, Weinberg, Georgi,...
David Tong's notes on gauge theories
Coleman's "Aspects of symmetry"
Lectures on QFT by John Preskill
Coleman's "Aspects of symmetry"
"Theta dependence of SU(N) gauge theories in the presence of a topological term" – E. Vicari, H. Panagopoulos
Schulman's "Techniques and applications of Path integration"
Lectures on QFT by John Preskill
R. Peccei's - "The Strong CP Problem and Axions" - hep-ph/0607268