PyHEP 2025 - "Python in HEP" Users Workshop (hybrid), CERN

Session

Plenary Session Monday (1)

27 Oct 2025, 14:00

40/S2-B01 - Salle Bohr (CERN)

Conveners

Plenary Session Monday (1)

• Ianna Osborne (Princeton University)

18. Welcome and workshop overview

Ianna Osborne (Princeton University)

27/10/2025, 14:00

Please join Zulip chat:
https://pyhep2025.zulipchat.com/join/z4trmz2ufs7wqde2bcsy2mph/

24. ROOT's Newest Pythonizations: UHI, RDataFrame and More

Silia Taider (CERN)

27/10/2025, 14:10

Lightning talk

The ROOT software package features automatic and dynamic Python bindings that provide access to its powerful and performant C++ core. With the growing adoption of Python in the HEP community, ROOT continues to evolve to offer a more intuitive and Pythonic user experience.

Recent developments make key components of the framework more accessible and interoperable from Python. This includes...

4. RNTuple and Uproot

Andres Rios-Tascon (Princeton University)

27/10/2025, 14:20

"Standard talk"

RNTuple is a new columnar data storage format with a variety of improvements over TTree. The first stable version of the specification became available earlier this year, so the transition to RNTuples has now begun. The Uproot Python library aims to provide a much better support for reading and writing RNTuples than it did for TTrees, thanks to its modern and simple design. Uproot already...

22. uproot-custom: customize branch data reading in Uproot

Mingrun Li (IHEP, CAS)

27/10/2025, 14:50

Lightning talk

uproot-custom is an extension of Uproot that allows users to define custom behaviors when reading branch data from ROOT files. This capability is particularly useful when handling classes with overloaded Streamer methods or when specific data transformations are required during the reading process. By being implemented in C++ and Python, uproot-custom ensures both high performance and...

7. Simulations, Post-Processing and Visualisations of Detector Cooling Systems

Viren Bhanot (CERN)

27/10/2025, 15:00

"Standard talk"

CO2-based two-phase pumped loop systems are now the de-facto solution for Detector cooling at CERN. The scope of these systems grows ever larger, and with it, so does the complexity of the underlying technology

For the past decade-and-a-half, Matlab has been our one-stop shop for simulations, post-processing, data analyses and data visualisations. Recently, we have begun a piecemeal...

16. ISpy NanoAOD: An event display for the NanoAOD format of the CMS Experiment

Thomas McCauley (University of Notre Dame (US))

27/10/2025, 15:30

Lightning talk

The CMS Experiment introduced a new lightweight format for physics analysis, NanoAOD, during Run 2. Stored as ROOT TTrees, NanoAOD can be read directly with ROOT or with Python libraries such as uproot. Current CMS event displays rely on the larger MiniAOD data tier, which requires CMS-specific software and resources and includes information not available in NanoAOD.
ISpy NanoAOD is a...

20. PyLHE in 2025: New features and improvements

Alexander Puck Neuwirth (UNIMIB & INFN)

27/10/2025, 15:40

Lightning talk

The PyLHE library (Python LHE interface) has seen major improvements since 2024. Recent releases introduced LHE file writing (v0.9.0) and extended event weight support for POWHEG (v0.8.0). Event weights, when available, are now included in the output Awkward Arrays, and systematic tests are performed using LHE files from widely used general-purpose Monte Carlo event generators. In addition to...

13. Coffea schemas modifications

Iason Krommydas (Rice University (US)), Maksym Naumchyk

27/10/2025, 15:50

Lightning talk

This talk explores the results of my recent project as an IRIS-HEP fellow. I was working on improving the coffea schemas by simplifying how they work internally. It eventually transitioned into making a new package that would include all the simplified schemas, separated from coffea. Eventually coffea will use them instead of its old schemas. This new package was given the name 'zipper' and...