4,650 research outputs found
On The S-Matrix of Ising Field Theory in Two Dimensions
We explore the analytic structure of the non-perturbative S-matrix in
arguably the simplest family of massive non-integrable quantum field theories:
the Ising field theory (IFT) in two dimensions, which may be viewed as the
Ising CFT deformed by its two relevant operators, or equivalently, the scaling
limit of the Ising model in a magnetic field. Our strategy is that of collider
physics: we employ Hamiltonian truncation method (TFFSA) to extract the
scattering phase of the lightest particles in the elastic regime, and combine
it with S-matrix bootstrap methods based on unitarity and analyticity
assumptions to determine the analytic continuation of the 2 to 2 S-matrix
element to the complex s-plane. Focusing primarily on the "high temperature"
regime in which the IFT interpolates between that of a weakly coupled massive
fermion and the E8 affine Toda theory, we will numerically determine 3-particle
amplitudes, follow the evolution of poles and certain resonances of the
S-matrix, and exclude the possibility of unknown wide resonances up to
reasonably high energies.Comment: typos corrected, references added, additional comparison with
perturbation theory added. 35 pages, 21 figure
Quantum phase transitions beyond the Landau-Ginzburg paradigm and supersymmetry
We make connections between studies in the condensed matter literature on
quantum phase transitions in square lattice antiferromagnets, and results in
the particle theory literature on abelian supersymmetric gauge theories in 2+1
dimensions. In particular, we point out that supersymmetric U(1) gauge theories
(with particle content similar, but not identical, to those of theories of
doped antiferromagnets) provide rigorous examples of quantum phase transitions
which do not obey the Landau-Ginzburg-Wilson paradigm (often referred to as
transitions realizing "deconfined criticality"). We also make connections
between supersymmetric mirror symmetries and condensed matter particle-vortex
dualities.Comment: 19 page
Constraining Higher Derivative Supergravity with Scattering Amplitudes
We study supersymmetry constraints on higher derivative deformations of type
IIB supergravity by consideration of superamplitudes. Combining constraints of
on-shell supervertices and basic results from string perturbation theory, we
give a simple argument for the non-renormalization theorem of Green and Sethi,
and some of its generalizations.Comment: 9 pages, 2 figures; references ad
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