G. Aad, Erlend Aakvaag, Braden Keim Abbott, Sara Abdelhameed, Kira 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, Anamika 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, Daiya Akiyama, Nilima Nilesh Akolkar, S. Aktas, G. L. Alberghi, J. Albert, Una Helena Alberti, Pietro Albicocco, Guillaume Lucas Albouy, S. Alderweireldt, Z. L. Alegria, M. Aleksa, I.N. Aleksandrov, C. Alexa, T. Alexopoulos, Fabrizio Alfonsi, Malte Algren, M. Alhroob, B. Ali, H. M. J. 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, Yara Do Amaral Coutinho, A. Ambler, Christoph Amelung, Maximilian 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, Christos Anastopoulos, T. Andeen, J. K. Anders, Adam Campbell Anderson, Attilio Andreazza, S. Angelidakis, A. Angerami, A. V. Anisenkov, A. Annovi, Claire Antel, E. Antipov, M. Antonelli, Fabio Anulli, Masato Aoki
A search for Higgs boson pair production in the $b \overline{b} γγ$ final state is performed. The proton-proton collision dataset in this analysis corresponds to an integrated luminosity of 308 fb$^{-1}$, consisting of two samples, 140 fb$^{-1}$ at a centre-of-mass energy of 13 TeV and 168 fb$^{-1}$ at 13.6 TeV, recorded between 2015 and 2024 by the ATLAS detector at the CERN Large Hadron Collider. In addition to a larger dataset, this analysis improves upon the previous search in the same final state through several methodological and technical developments. The Higgs boson pair production cross section divided by the Standard Model prediction is found to be $μ_{HH} = 0.9^{+1.4}_{-1.1}$ ($μ_{HH} = 1^{+1.3}_{-1.0}$ expected), which translates into a 95% confidence-level upper limit of $μ_{HH}<3.8$. At the same confidence level the Higgs self-coupling modifier is constrained to be in the range $-1.7 < κ_λ< 6.6$ ($-1.8 < κ_λ< 6.9$ expected).