Charged Schwarzschild-Levi-Civita Black Hole Via the Hassan-Sen Transformation in Heterotic String Theory

We apply the Hassan-Sen transformation to the Schwarzschild-Levi-Civita vacuum solution and construct its charged generalization within the low-energy effective field theory of heterotic string theory. Starting from a static, axially symmetric seed metric, we obtain an exact Einstein-Maxwell-dilaton black hole in the Einstein frame and verify explicitly that it satisfies the full set of field equations. The resulting spacetime is characterized by a nontrivial dilaton field, an electric Maxwell field, and a strong angular anisotropy inherited from the Schwarzschild-Levi-Civita geometry. A detailed study of null geodesics reveals the impact of the electric field-dilaton-induced deformation on photon propagation, including the absence of circular photon orbits outside the horizon. In the special massless limit, we uncover the charged Levi-Civita spacetime with a line singularity aligned with the symmetry axis, exhibiting pronounced stretching and squashing behavior in different asymptotic regimes. These results demonstrate that the Hassan-Sen transformation provides a powerful mechanism for generating highly anisotropic charged solutions beyond the standard black hole sector of string-inspired gravity.