Exotics Convener

Some big news in this post! I can now officially say that I’ve been appointed to be the ATLAS experiment’s next Exotics Convener, starting October 1st 2024. To the un-initiated, this may sound like I am going to become some kind of unusual fruit collector. But in reality, this is an important scientific leadership role within the largest scientific collaboration in the world.

ATLAS and CMS (and most other large particle physics collaborations) organise their leadership in terms of so-called “conveners”: people who convene meetings on particular topics and coordinate the activities of the researchers on those topics. In ATLAS you could say there are five levels:

• Analysis contacts, who are responsible for organising analysis teams (~ up to dozen people) working towards a particle publication. I’ve served in that role for several papers including my most recent measurement.
• Subgroup conveners, who organise a team of analyses on closely-related topics. This usually means a group of up to a dozen analyses, so some 50-100 people. Between 2021 and 2023, I was subgroup convener for the “Unusual Signatures” subgroup, one of the main group looking for long-lived particles. In that role I was in charge of coordinating the activities of around 70 researchers. Under my leadership, the subgroup published its first ever official summary plots, and we saw six searches published and 6 new searches initiated, including the first Run3 searches. Earlier (2019-2021) I held a subgroup convenership in a technical group responsible for incorporating/maintaining Event Generation/Simulation software in the ATLAS software suite.
• Group conveners, who organise whole swathes of the ATLAS physics programme, encompassing multiple subgroups and the work of some 500 people. Exotics is one of those groups, and represents about 20 % of the whole ATLAS physics programme (alongside Higgs physics, Top quark physics, measurements of the Standard Model, and another search group including SUSY and diboson signatures. There are also groups for heavy ion physics and b-physics.) There are also group conveners for technical activities such as reconstructing and calibrating jets, electrons/photons, muons, taus and identifying b-hadrons, and for developing and preparing simulations.
• Physics coordinators, who coordinate the activities of al the physics and performance groups and are responsible for the entire physics output of the collaboration.
• The spokesperson and their deputies, who coordinate physics activities, operations and detector maintenance and upgrades. Basically the CEO of ATLAS.

At each level, (except spokesperson), the role is usually shared between two people with staggered fixed-term (usually 2 years) tenures. This may remind some of you of the “cursus honorum” of ancient Rome, and for sure there are some similarities (although thankfully the top role is not called dictator).

In my case, from October 1st and for two years, I will be in charge of about half of the ATLAS searches for new particles, including:

• exotic states decaying to or involving leptons, such as Z’ and W’ (pronounced Z- and W-prime) particles, lepto-quarks, or other models which predict lepton flavour violation;
• new physics leading to extra jets and missing energy, such as dark matter, or other new invisible particles which recoil invisibly against Standard Model activity;
• heavy quark searches, looking for new partners of the 6 quarks we know about. This for example includes “vector-like quark” models and “composite Higgs” models;
• unusual signatures, such as long-lived particles, heavily ionising particles and “weird” jets: my old patch as a subgroup convener;
• combinations of results from different subgroups.

My job in all this will be one of project management and smooth delivery of the papers, checking the physics of all the analyses (and eventually signing off on them), coordinating the use of person-power within the group, liaising with theorists and organising workshops . It’s a full time activity: that means my own research will take a back seat for that time (although it will continue via my PhD students and post-doc!). It’s a true honour to take up this role, and it will be a wild ride for the next few years. But if ATLAS discovers any new fundamental particles between now and 2027, you’ll know there is a faire chance that I was knee-deep in bringing that result to fruition.