Chiral strings, the sectorized description and their integrated vertex operators

Understand

A chiral string can be seen as an ordinary string in a singular gauge for the worldsheet metric and has the ambitwistor string as its tensionless limit.

• As proposed by Siegel, there is a one-parameter ($\beta$) gauge family interpolating between the chiral limit and the usual conformal gauge in string theory.
• This idea was used to compute scattering amplitudes of tensile chiral strings, which are given by standard string amplitudes with modified ($\beta$-dependent) antiholomorphic propagators.
• Due to the absence of a sensible definition of the integrated vertex operator, there is still no ordinary prescription for higher than $3$-point amplitude computations directly from the chiral model.