The interplay between electronic charge density wave (CDW) order, magnetic excitations and superconductivity in cuprates has been a subject of wide debate. In this talk, I will describe our resonant elastic and inelastic x-ray scattering investigation of electronic CDW and paramagnons in a wide range of hole dopings x = 0.05 to x = 0.50 in La2-xCaxCuO4 (LCCO). LCCO is unique due to the remarkable persistence of superconductivity up to a hole doping level x = 0.50, allowing us to explore the interplay of CDW and magnetic excitations with superconductivity in the extremely overdoped regime. We find that while electronic CDW persists only up to a doping of x = 0.20, lattice superstructures, most likely associated with oxygen vacancy ordering, persists to dopings at least as large as x = 0.50. Furthermore, in the doping range where they overlap, the electronic CDW and the lattice superstructure are observed to lock into each other, suggesting a strong interplay between electronic and lattice energetics in LCCO. In addition, the investigation of magnetic excitations reveals that while the paramagnon signal persists up to x = 0.50, a strong cross over from collective to partially incoherent spin-flip excitations is observed at x = 0.15, in agreement with prior work on other overdoped cuprates. I will discuss the general implications of these findings [1,2].

[1] S. Hameed et al., Phys. Rev. B 112, L161114 (2025)

[2] S. Hameed et al., arXiv:2509.06680 (2025)