G. Aad, Erlend Aakvaag, B. Abbott, Sara Abdelhameed, K. Abeling, Nils Julius Abicht, S. H. Abidi, Mohammed Aboelela, A. Aboulhorma, H. Abramowicz, Yiming Abulaiti, B. S. Acharya, Anke Ackermann, C. Adam Bourdarios, L. Adamczyk, Sagar Addepalli, Matthew John Addison, J. Adelman, Aytul Adiguzel, T. Adye, A. A. Affolder, Yoav Afik, M. N. Agaras, A. Aggarwal, C. Agheorghiesei, F. Ahmadov, Sudha Ahuja, X. Ai, G. Aielli, A. Aikot, M. Ait Tamlihat, Brahim Aitbenchikh, M. Akbiyik, T. P. A. Åkesson, A. V. Akimov, D. Akiyama, Nilima Nilesh Akolkar, S. Aktas, G. L. Alberghi, J. Albert, Una Helena Alberti, P. Albicocco, Guillaume Lucas Albouy, S. Alderweireldt, Z. L. Alegria, Martin Aleksa, I. N. Aleksandrov, C. Alexa, Theodoros Alexopoulos, Fabrizio Alfonsi, Malte Algren, M. Alhroob, B. Ali, Hanadi Ali, S. Ali, Samuel William Alibocus, M. Aliev, G. Alimonti, W. Alkakhi, C. Allaire, Benedict Allbrooke, Jonny Allen, Julia Frances Allen, P. P. Allport, Alberto Aloisio, F. Alonso, C. Alpigiani, Zainab Mohammad K Alsolami, A. Álvarez Fernández, Mario Alves Cardoso, M. G. Alviggi, M. Aly, Y. Amaral Coutinho, A. Ambler, Christoph Amelung, M. Amerl, C. G. Ames, Thiziri Amezza, D. Amidei, Baktash Amini, Kyle Amirie, Artem Amirkhanov, S. P. Amor Dos Santos, K. R. Amos, Dimitra Amperiadou, Shiwen An, C. Anastopoulos, T. Andeen, J. K. Anders, Adam Campbell Anderson, A. Andreazza, S. Angelidakis, A. Angerami, A. V. Anisenkov, A. Annovi, C. Antel, E. Antipov, Mario Antonelli, Fabio Anulli, M. Aoki
A search for the resonant production of a heavy scalar $X$ decaying into a lighter scalar $S$ and a Higgs boson, through the process $X \rightarrow S (\rightarrow b \bar{b})H ( \rightarrow γγ)$, where the two photons are consistent with the Higgs boson decay, is performed. The search is conducted using integrated luminosities of 140 and 59 fb$^{-1}$ of proton-proton collision data at centre-of-mass energies of 13 and 13.6 TeV, respectively, recorded with the ATLAS detector at the LHC. The search is performed over the mass ranges of 170 $\leq$ $m_{X}$ $\leq$ 1000 GeV and 15 $\leq$ $m_{S}$ $\leq$ 500 GeV. No significant excess over the Standard Model background prediction is observed and limits at 95% confidence level are set on the product of cross section and branching fraction for the process $X \rightarrow S (\rightarrow b \bar{b})H ( \rightarrow γγ)$ at 13 TeV, ranging from 9 fb to 0.06 fb.