Belle II Germany Meeting 2025

8 Sept 2025, 13:00 → 10 Sept 2025, 21:50 Europe/Berlin

0.056 (ROT building)

Welcome to the Belle II Germany Meeting 2025, which will be hosted at University of Bonn.

The conveners of the parallel sessions on Tuesday are:

• Physics Analysis and Theory: Ana Luisa Moreira de Carvalho, Valerio Bertacchi, Nico Gubernari 
• Hardware and Upgrade: Isabel Haide, Christian Bespin
• Software, Performance and Computing: Stefan Wallner, Patrick Ecker

 

Please contact the conveners above if you would like to give a talk in the parallel session.

Speakapp connection details can be found here.

Please book your accomodation as soon as possible.

Monday 8 September

13:00 → 14:00 Registration

14:00 → 16:15 Plenary Session: Opening Talks: Belle II, LHCb, Theory

14:00 Welcome

14:15 Belle II Status & German Involvement

Speaker: Florian Bernlochner (Belle (SuperKEKB Experiment))

14:45 LHCb Upgrade

Speaker: Klaas Padeken

15:15 Exclusive B decays at the precision frontier (theory)

Speaker: Nico Gubernari

15:45 Precision flavour physics with inclusive penguin decays (theory)

Speaker: Tobias Hurth

16:15 → 16:45 Coffee Break

16:45 → 17:00 Social activities: Belle II Quizz + Karaoke: Belle II Germany Picture

17:00 → 18:00 ECR Session

17:00 → 18:00 PI Meeting

17:00 PXD status and plans

Speaker: Fabian Becherer (BELLE (BELLE Gruppe))

17:15 PT

Speaker: Maren Meinhard

17:30 FSP

Speaker: Veronika Kratzer (not set)

17:45 Sustainability

Speaker: Thomas Kuhr (LMU Munich)

17:55 Next Belle II Germany meeting

18:30 → 20:30 Belle II Germany Dinner

20:30 → 22:00 Social activities: Belle II Quizz + Karaoke

Tuesday 9 September

09:00 → 10:30 Analysis and Theory

09:00 B->K nu nu

Speaker: Caspar Schmitt (Belle (SuperKEKB Experiment))

09:16 B->K nu nu reinterpretation

Speaker: Lorenz Ennio Gaertner (BELLE (BELLE II Experiment))

09:32 Search for B->pi nu nu with tagging methods

Speaker: Boyang Yu (BELLE (BELLE II Experiment))

09:48 Search for B+->K* tau el with hadronic tagging

Speaker: Lara Fuchs (BELLE (BELLE II Experiment))

10:05 Theory talk: B meson fully hadronic decays

Speaker: Marta Burgos (Maastrich)

09:00 → 10:30 Hardware and Upgrade

Conveners: Christian Bespin (Universität Bonn), Isabel Haide (Karlsruhe Institute of Technology)

09:00 PXD Status and Operation

Speaker: Jannes Schmitz (University of Bonn)

09:25 Upgrade of the Belle II Vertex Detector with depleted monolithic CMOS active pixel sensors

Speaker: Yannik Buch ((BELLE (BELLE II Experiment)))

09:50 GNN-ETM - Design and Deployment of a Graph Neural Network Trigger for the ECL

Speaker: Isabel Haide (Karlsruhe Institute of Technology)

09:00 → 10:30 Software/Performance/Computing

09:00 Track finding efficiency in $\mu^+ \mu^- \gamma$ Events

Speaker: Lukas Grussbach (BELLE (BELLE II Experiment))

09:20 Slow pion efficiency

Speaker: Melisa-Melek Akdag (BELLE (BELLE II Experiment))

09:40 Graph Neural Network based Track Finding for SVD and CDC

Speaker: Tristan Brandes (Karlsruhe Institute of Technology (KIT))

10:05 Detector Alignment at Belle II

Speaker: Tadeas Bilka (BELLE (BELLE Gruppe))

10:30 → 11:00 Coffee Break & Institutional Posters

11:00 → 12:30 Analysis and Theory

11:00 Dalitz analysis of B->D pi+ pi

Speaker: Melisa-Melek Akdag (BELLE (BELLE II Experiment))

11:16 tau->3pi nu: integrating background contributions with neural networks in partial wave analysis

Speaker: Miriam Weiskopf (Max Planck Institute for Physics)

11:32 R(D*) with inclusive tagging

Speaker: Fabio Novissimo (BELLE (BELLE II Experiment))

11:48 R(D*) from 1-prong tau decays and tau polarization with hadronic tagging

Speaker: Ilias Tsaklidis

12:04 Theory talk: radiative correction to B-> el nu gamma

Speaker: Max Ferré (Mainz)

11:00 → 12:30 Hardware and Upgrade

Conveners: Christian Bespin (Universität Bonn), Isabel Haide (Karlsruhe Institute of Technology)

11:00 First Studies of a GNN based ECL Trigger on Versal-FPGAs for the Belle II Upgrade

Speaker: Thomas Gideon Lobmaier (BELLE (BELLE II Experiment))

11:25 Upgrade of the Belle II First-Level Neural Track Trigger by Three-Dimensional Hough Finding and Deep Neural Networks on FPGAs

Speaker: Simon Hiesl (BELLE (BELLE II Experiment))

b2germany_2025_3dhough_hiesl.pdf

11:50 Design of the OBELIX Monolithic Active Pixel Sensor for the Belle II VTX Upgrade

Speaker: Alexander Walsemann (BELLE (BELLE II Experiment))

11:00 → 12:30 Software/Performance/Computing

11:00 Advancements in Analysis-Level Particle Identification through Machine Learning Techniques at Belle II

Speaker: Martin Bartl (Max Planck Institute for Physics)

11:30 Development and Testing of a Neutron Identification Algorithm for Belle II

Speaker: Georgios Alexandris (BELLE (BELLE II Experiment))

11:50 Photon efficiency calibration for MC16

Speaker: Sebastiano Raiz (BELLE (BELLE II Experiment))

12:10 Low-energy efficiency studies in $\tau^-\to \pi^- \pi^0\nu_\tau$ decays

Speaker: Dr Mengchuan Du (BELLE (BELLE II Experiment))

14:00 → 16:00 Analysis and Theory

14:00 Forward-backward asymmetry in B->X el nu

Speaker: Raynette van Tonder (BELLE (BELLE II Experiment))

14:16 Differential branching fraction and angular distributions in B->Xc el nu

Speaker: Ms Rajeshwari Roy (BELLE (BELLE II Experiment))

14:32 Theory talk: B->K+a decays: which framework leads to consistent exclusion plots?

Speaker: Xiyuan Gao (KIT)

14:57 Search for a new spin 0 mediator in B->K S

Speaker: Luc Brandl (Karlsruhe Institute of Technology)

15:13 Search for ALPs produced via photon-fusion

Speaker: Frederik Schmitt (Karlsruhe Institute of Technology (KIT))

15:29 Theory talk: B mixing

Speaker: Zachary Wüthrich (Siegen)

14:00 → 16:00 Hardware and Upgrade

Conveners: Christian Bespin (Universität Bonn), Isabel Haide (Karlsruhe Institute of Technology)

14:00 All-silicon detector modules for the inner pixel layers of the VTX upgrade

Speaker: Andreas Ulm (BELLE (BELLE II Experiment))

14:25 PXD Emergency Shutdown Investigation

Speaker: Paula Scholz (University of Bonn)

14:50 DePFET X-ray Irradiation Studies

Speaker: Georgios Giakoustidis (University of Bonn)

15:15 Challenges Of Hardware-Software Co-Design Of A Graph Neural Network For The ECL Trigger

Speaker: Frank Michael Baptist (BELLE (BELLE II Experiment))

14:00 → 16:00 Software/Performance/Computing

14:00 Data production and skims

Speaker: Valerio Bertacchi (University of Bonn)

14:25 SysVar: A new tool for enhancing consistency in the treatment of systematics

Speakers: Agrim Aggarwal (BELLE (BELLE II Experiment)), Ilias Tsaklidis

14:50 The Belle II Document Server

Speaker: David Koch (BELLE (BELLE II Experiment))

15:15 Computing for Belle II at DESY

Speaker: Andreas Gellrich (BELLE (BELLE Gruppe))

15:40 b2luigi for amplitude analysis

Speaker: Godo Kurten (Max Planck Institute for Physics)

16:00 → 16:30 Coffee Break & Institutional Posters

16:30 → 18:00 PI Meeting: PI meeting II

16:30 Strategie für die nächste Förderperiode (PXD, Upgrade, Software, Computing, Analysen, FSP, Theorie)

17:00 Sprecher in der nächsten Förderperiode

17:10 ECR issues

16:30 → 18:00 Poster Session

19:00 → 21:00 ECR Session: ECR dinner

19:00 → 21:00 PI Dinner

Wednesday 10 September

09:00 → 09:45 FTD tour (Markus Ball)

09:50 → 11:00 Plenary Session

09:50 ML in Particle Physics

Speaker: Nicole Hartman (Munich)

10:30 Outreach

Speaker: Veronika Kratzer (not set)

11:00 → 11:30 Coffee break (FTD)

11:30 → 13:10 Plenary Session: Summaries

11:30 ECR news

Speakers: Ana Luisa Moreira de Carvalho (BELLE (BELLE Gruppe)), Lorenz Ennio Gaertner (BELLE (BELLE II Experiment))

11:50 Summary: Theory and Analysis

12:10 Summary: Hardware and Upgrade

12:30 Summary: Software and Performance

12:50 Close-out

Speaker: Thomas Kuhr (LMU Munich)