K. Kampf

collaborators

4 papers

hep-th2026

A Surface Integrand for the Inverse KLT Kernel

Christoph Bartsch, Karol Kampf, JiÅÃ NovotnÃ½ +1

We propose a loop-level generalization of the inverse string theory Kawai-Lewellen-Tye (KLT) kernel: the planar inverse KLT integrand. The integrand is defined constructively via a…

hep-th2026

Positive Geometry for Stringy Scalar Amplitudes

Christoph Bartsch, Karol Kampf, David Podivin +1

We introduce a new positive geometry, the associahedral grid, which provides a geometric realization of the inverse string theory KLT kernel. It captures the full $I^\pm^{'}$ -dependence…

hep-ex2025

Searches for hidden sectors using $K^{+} \to I ¨ ^{+} X$ decays

NA62 Collaboration

Results from the study of the rare decays $K^{+} \to I ¨ ^{+} I^½ I^ˉ ½$ , $K^{+} \to I ¨ ^{+} I^¼^{+} I^¼^{-}$ and $K^{+} \to I ¨ ^{+} I^^{3} I^^{3}$ at the NA62 experiment at CERN are interpreted…

hep-th2025

Soft Factor Structure of MHV Amplitudes for Massless Charged Particles

Christoph Bartsch, Karol Kampf, David PodivÃn

We present a simple derivation of MHV amplitudes in massless spinor and scalar electrodynamics. Working with permutationally invariant amplitudes, we show that they are fully deter…

A Surface Integrand for the Inverse KLT Kernel

Positive Geometry for Stringy Scalar Amplitudes

Searches for hidden sectors using K+→I¨+X decays

Soft Factor Structure of MHV Amplitudes for Massless Charged Particles

Searches for hidden sectors using $K^{+} \to I ¨ ^{+} X$ decays