Joonsuk Bae ALICE · ePIC
PhD candidate · Sungkyunkwan University

Primary analyzer of the first ALICE Run 3 inclusive charged-particle jet measurement in pp at √s = 13.6 TeV.

Regular speaker in the ALICE jet working group since 2023. Doctoral work centers on the R-dependent cross-section ratio — ALICE Preliminary, presented on behalf of ALICE at EPS-HEP 2025 as the PWG-JE merge talk.

Postdoc-available January – March 2027
ALICE Preliminary: R-dependent charged-particle jet cross-section ratios in pp at √s = 13.6 TeV (ALI-PREL-634701)
ALI-PREL-634701  ·  σ(R=0.2) / σ(R) cross-section ratios vs. Monte Carlo predictions  ·  pp √s = 13.6 TeV, anti-kT, |ηjet| < 0.2  ·  thesis principal result
Modern parton-shower tunes agree with the data above ~40 GeV/c and diverge by up to 30% at low pT and large R.
§1 Doctoral analysis · ALICE Run 3

Full analysis chain, pp 13.6 TeV.

The thesis is the first ALICE Run 3 inclusive charged-particle jet measurement: pp at √s = 13.6 TeV, anti-kT with R = 0.2–0.6, |ηjet| < 0.2. I built the full analysis chain — detector-level QA on continuous-readout data, Run 3-specific cross-section normalization based on the TVX visible cross section, response-matrix construction, Bayesian and SVD unfolding, and a complete systematic-uncertainty program covering tracking-related effects and unfolding stability.

For Hard Probes 2026 I derived the PWG-JE pp charged-particle tracking-efficiency uncertainty at √s = 13.6 and 5.36 TeV (pT-binned, 2022–2024 periods), combining the track-selection component with the ITS–TPC matching component.

The R-dependent ratios shown above are the principal result. PWG-JE preliminary; presented on behalf of ALICE at EPS-HEP 2025 as the PWG-JE merge talk, and shown as a poster at Hard Probes 2026. Paper in preparation.

§2 Next directions

Bias-robust observables in O+O and Pb+Pb.

Radial observables make selection bias directly testable; photon tagging provides a cleaner recoil probe; together they probe medium modification and medium response in O+O and Pb+Pb.

Year 1
Jet shape ρ(r) and fragmentation function D(z) in 2025 O+O.
Radial observables that make selection bias directly testable; the thesis pp measurement provides the baseline for small-system energy-loss searches.
Years 1 – 2
γ-tagged jet-shape measurements in small systems.
The colorless photon trigger as a cleaner probe of medium-induced jet modification; requires full electromagnetic calorimetry coverage.
Years 2 – 3
γ+jet Δφ acoplanarity and γ+jet correlations in Pb+Pb.
Medium-induced kT broadening and the diffusion-wake search proposed in arXiv:2408.08599.
§3 Detector R&D · ePIC Barrel Imaging Calorimeter

Pb/scintillating-fiber calorimeter,
three beam-test campaigns.

Pb/scintillating-fiber prototype, three beam-test campaigns since 2024. CERN PS T10 (July 2025) — lead analyzer for energy response, resolution, and linearity; KEK AF–AR (March 2025) — on-site DAQ shifter, equalization, prompt analysis; CERN PS T10 (August 2024) — module performance characterization. Co-author on the 2024.08 campaign paper, accepted in J. Korean Phys. Soc. (arXiv:2604.22647). Also co-author on the AstroPix silicon-sensor test-beam paper, accepted in Nucl. Instrum. Meth. A (arXiv:2605.07681). → full account

§4 Software, infrastructure & community

O²Physics framework contributions.

I implemented the Run 3 charged-jet cross-section normalization from the ALICE TVX visible cross section, now becoming the standard normalization for Run 3 charged-jet analyses in the group. I also derived the pT-dependent track momentum-resolution smearing profile used in the Run 3 charged-jet corrections and systematics. Contributor to ALICE O²Physics since 2023 — jet-finding and response-matrix tasks, systematic-uncertainty pipelines, particle-level cross-section normalization, and shared track-smearing tools. → full account

Co-mentor of the MSc main analyzer on the ALICE Run 3 O+O charged-jet measurement (SKKU, 2025–present); co-author with W. Ham on the corresponding PWG-JE Analysis Note. Co-organizer and instructor of the KoALICE O²Physics Tutorial (SKKU, January 2024) — a two-day Run 3 analysis-framework tutorial for ~22 Korean ALICE participants. Regular speaker at ALICE PWG-JE meetings since 2023.

§5 Method study · learned reconstruction

Classifier performance at
fixed working points.

Since summer 2026 I have been running a calibration-transfer study on the public sPHENIX TPCpp-10M spacepoint benchmark and the released FM4NPP backbones: classifiers evaluated at fixed working points under a signal-loss budget, differentially in occupancy. A working point calibrated on p+p is exceeded by a factor of roughly thirty at Au+Au-like density. Personal study, not a collaboration deliverable. Data and model checkpoints are public — details.

§6 Trajectory · 2022 → 2027

Path to thesis.

2022.10
Joined ALICE
2024.01
KoALICE O²Physics Tutorial
(co-organizer, instructor)
2025.07
EPS-HEP 2025
PWG-JE merge talk
2026.08
Paper proposal
2026.12
PhD defense
2027.02
Postdoc start
Reach me

Applying for 2027 postdoc positions.

For postdoc inquiries — jbae@cern.ch.

jbae@cern.ch CV (PDF) ↗ INSPIRE-HEP ↗ ORCID ↗ GitHub ↗