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, submitted to Nucl. Instrum. Meth. A (NIMA-D-26-00482, arXiv:2604.22647). Also co-author on the AstroPix silicon-sensor test-beam paper, submitted to Nucl. Instrum. Meth. A (NIMA-D-26-00572). → 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.

Letters from Prof. Beomkyu Kim (SKKU, advisor), Dr. Jaime Norman (Liverpool, ALICE jets), and Prof. Sanghoon Lim (Yonsei, sPHENIX/ePIC) on request. For postdoc inquiries — jbae@cern.ch.

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