CHEP 2019: Preface to the Proceedings

The 24th International Conference on Computing in High Energy and Nuclear Physics (CHEP) took place at the Adelaide Convention Centre, Adelaide, South Australia from 4–8 November 2019. 525 registered participants took part in the conference, where there were plenary sessions as well as a wide ranging set of ten parallel tracks across all areas of work in the field and allied sciences. The conference hosted 34 plenary presentations, 370 oral presentations in parallel sessions and 131 posters.


Foreword
In November of 2019, the 24 th International Conference on Computing in High Energy and Nuclear Physics (CHEP) was held in Adelaide, South Australia. This signified the first iteration of the conference to be hosted in Australia.
Australia is, by just about anyone's measure of distance, a long way from everywhere else in the world. This is especially true with regards to the focal centres of the high energy and nuclear physics communities. Flying from Adelaide to CERN takes around 24 hours, with a similar time required to reach North America. Even travelling to relatively nearby Asia presents the challenge of sitting on a plane for 10 hours or more.
It was thus a great delight to welcome to Adelaide more than 540 people to participate in CHEP 2019, comprised of scientific delegates and accompanying persons. During the conference, the Adelaide weather of late spring granted long days of sunshine and a comfortable level of warmth, well before the more extreme heat of the Australian summer would commence. This yielded a pleasant atmosphere for delegates to enjoy the organised excursions, choosing to tour either the McLaren Vale wine region or Cleland Wildlife Park. After the completion of the conference, many overseas travellers visited the surrounding regions of South Australia, or journeyed interstate to explore other parts of Australia.
Of course, at the time we did not know that for many this would be the last opportunity for international travel before world events would change everyone's lives. With the onset of the coronavirus pandemic, 2020 presented an entirely new set of challenges to all nations. The CHEP 2019 proceedings catalogue many diverse advances in knowledge, reminding us of the value that is generated by gathering in-person for a conference. This gives all the more reason to look forward to the next face-to-face meeting of the CHEP community in Norfolk, Virginia.

CHEP conference series
The CHEP conference series was established in 1985, and since then has been one of the most important events in the field of computing in high-energy and nuclear physics. The conference covers a broad set of topics such as online, offline and distributed computing; software development, simulation, reconstruction and analysis packages; data handling, data bases and storage solutions; clouds, virtualisation and containers; networking and facilities, including high performance computing. It provides a valuable discussion platform, enabling the exchange of ideas between physicists, computing scientists and software engineers, as well as between renowned experts and young researchers.
Focusing on the achievements, ongoing activities, plans, and trends in the field, the CHEP conference is held every 18 months. The host location is selected on a rotating basis between the geographical regions of Europe, the Americas, and Asia Pacific. The list of past CHEP conferences is shown in Table 1.

Venue
The CHEP 2019 conference was held at the Adelaide Convention Centre (pictured below).

Conference Programme
The programme for CHEP 2019 consisted of plenary sessions and 10 parallel tracks. In the plenary sessions, 18 scientific keynote talks were given covering state-of-the-art developments in HEP (LHC Experiments, Belle II, DUNE, JUNO); other data intensive experiments and systems (SKA, gravitational waves, real-time alert systems, computational chemistry); and key technological and strategic areas (quantum computing, artificial intelligence, cyberthreats and security, European Strategy Update). In addition, two sessions were organised on diversity and inclusivity. There were 10 track highlight talks as well as a presentation from the organisers of the next face-to-face CHEP conference, which will be hosted in Norfolk, Virginia, USA.
In the parallel programme the keywords associated with Tracks 1-9 are shown in Table 2. Track X, so named for being a cross-over track and the tenth parallel track, was specially constructed from papers that had themes of common interest between Tracks 1, 2 and 9. 370 oral presentations were given in the parallel sessions. 131 posters were presented with 2 dedicated poster sessions taking place.  Selected contributions that were identified as of common interest, touching topics between online, offline and exascale computing (Tracks 1, 2 and 9)

Programme Committee
The CHEP 2019 Programme Committee (PC) developed the parallel sessions with appointed track conveners, who provided their expertise to review the papers submitted to the conference. The plenary programme was defined by the conference and PC chairs, in consultation with the International Advisory Committee (IAC). The PC members are listed in Table 3.

International Advisory Committee
The CHEP 2019 International Advisory Committee provided essential strategic advice for the organisation of the event and the members of the IAC are listed in Table 4. The CHEP 2019 IAC met 12 times, including one meeting held after the conference itself.

Local Organisation
The CHEP 2019 conference was chaired by Paul Jackson and Waseem Kamleh. The chairs wish to thank the secretariat, Sharon Johnson and Silvana Santucci, for their tremendous work in ensuring the organisation of the conference ran smoothly. Valuable assistance was provided by the members of the local organising committee, listed in Table 5.