Lucia Garozzo | Searcharxiv

arXiv2024

Effective interactions of the open bosonic string via field theory

We describe a method to extract an effective Lagrangian description for open bosonic strings, at zero transcendentality. The method relies on a particular formulation of its scattering amplitudes derived from color-kinematics duality. More precisely, starting from a $(DF)^2 + \text{YM}$ quantum field theory, we integrate out all the massive degrees of freedom to generate an expansion in the inverse string tension $α^\prime$. We explicitly compute the Lagrangian terms through $\mathcal{O}(α^{\prime 4})$, and target the sector of operators proportional to $F^4$ to all orders in $α^\prime$.

hep-th↗

arXiv2023

Lagrangians Manifesting Color-Kinematics Duality in the NMHV Sector of Yang-Mills

Scattering amplitudes in Yang-Mills theory are known to exhibit kinematic structures which hint to an underlying kinematic algebra that is dual to the gauge group color algebra. This color-kinematics duality is still poorly understood in terms of conventional Feynman rules, or from a Lagrangian formalism. In this work, we present explicit Lagrangians whose Feynman rules generate duality-satisfying tree-level BCJ numerators, to any multiplicity in the next-to-MHV sector of pure Yang Mills theory. Our Lagrangians make use of at most three pairs of auxiliary fields (2,1,0-forms) -- surprisingly few compared to previous attempts of Lagrangians at low multiplicities. To restrict the Lagrangian freedom it is necessary to make several non-trivial assumptions regarding field content, kinetic terms, and interactions, which we discuss in some detail. Future progress likely hinges on relaxing these assumptions.

hep-th↗