Light-by-light (LbyL) scattering is a quantum-mechanical process that is forbidden in
the classical theory of electrodynamics. This LbyL scattering proceeds at lowest order via virtual one-loop box diagrams, involving charged fermions/W bosons. In ultra-relativistic heavy-ion collisions, one can expects higher rates of gamma + gamma processes through the interaction of the large electromagnetic fields of the nuclei, which can maximises the cross-section of LbyL scattering. I will talk about the observation of the LbyL scattering using the 2018 Pb+Pb data with the ATLAS detector and some of the recent results of the search for Axion Like Particle using full Run II data. Moreover, I will briefly talk about the ongoing measurement of the topquark
pair production in proton-lead collisions using lepton+jets and dilepton channels. Since
top quarks are produced and decays much before the possible formation of Quark Gluon Plasma (QGP), this process can provide novel insight into the time structure of the QGP. Secondly, the tt-bar cross-section measurements can be used to put constraints on nuclear Parton Distribution Functions (nPDFs).
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