2025 Belle II Physics Week

6 Oct 2025, 08:30 → 10 Oct 2025, 19:00 Asia/Tokyo

Kobayashi Hall (KEK)

Florian Bernlochner (Belle (SuperKEKB Experiment)), James Frederick Libby (BELLE (BELLE II Experiment)), Karim Trabelsi (TYL - KEK)

 

We are pleased to announce that Belle II Physics Week 2025 will take place from October 6-10, 2025, at KEK, directly following the autumn Belle II General Meeting.

 

The theme of this year’s Physics Week is:

 

Rare decays of beauty and charm hadrons with missing energy

 

This workshop will continue the successful tradition of focused physics discussions and community building, building on the momentum of the 2024 and 2025 editions.

 

We are very happy to confirm an exciting line-up of invited speakers:

 

• Wolfgang Altmannshofer
• Chris Bouchard
• Claudia Cornella
• Hector Gisbert
• Jack Jenkins
• Hajime Nanjo
• Michael Schmidt
• Olcyr Sumensari
• Dayong Wang

 

The organizing committee consists of:

 

• Belle II: Karim Trabelsi, Gianluca Inguglia, Sally Stefkova, Toru Iijima-san, Florian Bernlochner, Carlos Marinas, Soeren Prell, and Jim Libby
• KEK Theory: Motoi Endo-san

 

Registration fee:

 

The registration fee will be 8,000 JPY covering coffee breaks and a social activity on Tuesday. For those who does not join the social activity, a reduced registration fee of 2,500 JPY will be applied. An invoice will be sent to registrants' email address, according to the information given at the registration.

 

B2_PW_Poster.pdf

Monday 6 October

09:00 → 09:10 Welcome

Speaker: Slavomira Stefkova (Bonn)

Introduction_Physics_Week_SStefkova.pdf

09:10 → 11:10 School

Belle II Physics Week School

09:10 EWP B decays with missing energy in the SM

Speaker: Wolfgang Altmannshofer (University of California, Santa Cruz)

altmannshofer_Belle_II.pdf

10:10 New Physics in EWP B decays with missing E

Speaker: David Marzocca (INFN Trieste)

NP_BKnunu.pdf

11:10 → 11:30 Coffee Break

11:30 → 12:30 School

Belle II Physics Week School

11:30 Charm tagging

Speaker: Luka Santelj (Jozef Stefan Institute)

charmFullEvent1.pdf

12:30 → 14:00 Lunch Break

14:10 → 16:00 Conference

14:10 Missing Energy decays @ Belle II + Public Likelihood

Speakers: Gaetano de Marino (Jožef Stefan Institute), Lorenz Ennio Gaertner (BELLE (BELLE II Experiment))

phywee_GdM_LG.pdf

14:50 Interplays with $B \to K \tau \tau, B \to \tau \tau$, and $K \to \pi \nu \bar{\nu}$

Speaker: Claudia Cornella (CERN)

Cornella_kek.pdf

15:30 HFLAV news

Speaker: Mirco Dorigo (INFN Trieste)

HFLAV_news_physics_week_2025.pdf

quiz - access during the talk

16:00 → 16:30 Coffee Break

16:30 → 18:30 Conference

16:30 LQCD results for rare B-decays with missing energy

Speaker: Chris Bouchard (University of Glasgow)

Bouchard_BelleIIPW_KEK_2025.pdf

17:10 Unitarity Bounds for Hadronic Form Factors

Speakers: Danny Van Dyk (Durham University), Danny van Dyk

dvandyk-ub-v3.pdf

Tuesday 7 October

09:00 → 11:00 School

Belle II Physics Week School

09:00 Full Event Interpretation (FEI)

Speaker: Karim Trabelsi (TYL - KEK)

belle2_kt_20251007.pdf

10:00 Fully-inclusive B reconstruction

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

Inclusive tagging (1).pdf

11:00 → 11:30 Coffee Break

11:30 → 12:30 School

Belle II Physics Week School

11:30 Charm decays with missing energy (NP and SM)

Speaker: Hector Gisbert

School_charm_HGisbert.pdf

12:30 → 13:30 Lunch Break

13:30 → 14:00 Ask you favourite question to theorist

14:00 → 15:50 Conference

14:00 Introduction to $c \to u \nu \bar{\nu}$ decays

Speaker: Hector Gisbert (Universidad Europea de Valencia)

Charm_HGisbert.pdf

14:40 Introduction to $b \to d \nu \bar{\nu}$ decays

Speaker: Hector Gisbert (Universidad Europea de Valencia)

Beauty_HGisbert.pdf

15:20 Missing Energy B-Decays @ LHCb

Speaker: Abhijit Mathad (CERN)

Abhijit_BelleII_PhysicsWeek.pdf

16:00 → 16:30 Coffee Break

16:30 → 18:30 Conference

16:30 Missing Energy Decays @ BESIII

Speaker: Dayong Wang (Peking University)

20251007_BelleIIPhysicsWeek_wangdy.pdf

17:10 Missing Energy Decays @ KOTO & NA62

Speaker: Hajime Nanjo (Osaka University)

NA62andKOTO.pdf

19:00 → 20:30 Social Activity: Party

Wednesday 8 October

09:00 → 11:00 School

Belle II Physics Week School

09:00 Global combinations

Speaker: Marcella Bona (BELLE (BELLE II Experiment))

bona-globalfits.pdf

10:00 Non-EWP decays with missing energy

Speaker: Markus Prim (BELLE (BELLE II Experiment))

B2PhysicsWeek_Non-EWP decays with missing energy.pdf

11:00 → 11:30 Coffee Break

11:30 → 12:30 School

Belle II Physics Week School

11:30 Status and future potential of Belle II analyses (incl. systematic uncertainties)

Speaker: Elisa Manoni (BELLE (BELLE II Experiment))

EWPMiss_PhysWeek20251.pdf

14:00 → 15:50 Conference

14:00 $B \to K^{(*)} \nu \bar{\nu}$ in SM and observables beyond rate

Speaker: Olcyr Sumensari (IJC Lab)

belle2-sumensari.pdf

14:40 $B \to X_{s} \nu \bar{\nu}$ in SM

Speaker: Jack Jenkins (University of Siegen)

belleII2025.pdf

15:20 Probing CP Violation in $b \to s \nu \bar{\nu}$ decays

Speaker: Martin Novoa-Brunet (Valencia)

CP-Asymmetries in Semileptonic neutrino Decays.pdf

16:00 → 16:30 Coffee Break

16:30 → 18:30 Conference

16:30 BSM for $B \to K \nu \bar{\nu} $ & related anomalies

Speaker: Michael Schmidt (New South Wales University)

BelleIIPhysicsWeek-Michael_Schmidt_v2.pdf

17:10 Impact of new particles on missing energy $B$ decays

Speaker: Patrick Bolton (Jozef Stefan Institute)

patrickbolton_talk_KEK.pdf

19:00 → 20:30 Social Activity: Posters and Sake

Thursday 9 October

09:00 → 11:00 School

Belle II Physics Week School

09:00 Tracking (detectors and performance)

Speaker: Bianca Scavino (BELLE (BELLE II Experiment))

2025Oct9_PW_Tracking_final.pdf

10:00 ECL, photons and extra energy

Speaker: Eldar Ganiev (Institute Jozef Stefan)

ECL_talk_v2.pdf

09:15 → 10:35 Social Activity: Visit of Belle II Detector

11:00 → 11:30 Coffee Break

11:30 → 12:30 School

Belle II Physics Week School

11:30 Particle ID (detectors and performance)

Speaker: Alessandro Gaz (University of Padova & INFN)

PID_physics_week_ale_v2.pdf

12:30 → 13:15 Lunch Break

13:15 → 14:00 Ask you favourite question to theorist

14:00 → 16:00 Conference

14:00 Belle II @ ESPP

Speaker: Thibaud Humair (BELLE (BELLE Gruppe))

2025-10-09-EPS-thumair.pdf

14:40 Panel Discussion: opportunities with $c \to u$ + $b \to d$ + missing energy for Belle II

Speaker: Luka Santelj (Jozef Stefan Institute)

Panel discussion-1.pdf

recording(2).webm

15:20 Panel Discussion: opportunities for $b \to s$ missing energy for Belle II

Speaker: Elisa Manoni (BELLE (BELLE II Experiment))

Opportunities for b → s missing energy for Belle II.pdf

recording(3).webm

16:00 → 16:30 Coffee break

16:30 → 18:00 Conference

16:30 Panel Discussion: Missing energy decays @ other experiments and interplay with Belle II

Speaker: Abhijit Mathad (CERN)

recording(5).webm

17:10 Panel Discussion: Outlook for SM and NP calculations & form factors

Speakers: Chris Bouchard (University of Glasgow), Lorenz Ennio Gaertner (BELLE (BELLE II Experiment))

Panel_Theory_calc_outlook_Belle2_PW-2025.pdf

recording(6).webm

18:10 → 19:40 Cabinetry Validation (mini hands-on challenge)

https://github.com/igartiy/2025B2PW-cabinetry-tutorial

18:10 Cabinetry

Speaker: Igor Prudiev (None)

2025B2PW-cabinetry-tutorial

Friday 10 October

09:00 → 11:00 School

Belle II Physics Week School

09:00 State of the art ML tools and methods

Speaker: Adrian Bevan (BELLE (BELLE II Experiment))

StateOfTheArtMLToolsAndMethods.pdf

10:00 Fitting and limit setting (incl. combinations of measurements & likelihoods)

Speaker: Diego Tonelli (BELLE (BELLE II Experiment))

B2G-limits-DT.pdf

11:00 → 11:30 Coffee Break

11:30 → 12:30 School

Belle II Physics Week School

11:30 Physics Week Summary Theory

Speaker: Wolfgang Altmannshofer (University of California, Santa Cruz)

altmannshofer_theory_summary.pdf

12:00 Physics Week Summary Experiment

Speaker: Akimasa Ishikawa (KEK)

20251010PhysicsWeek_ishikawa_v1.2.pdf

12:30 → 13:00 Closeout + Picture

Speakers: Florian Bernlochner (Belle (SuperKEKB Experiment)), Soeren Prell (Iowa State University)

PhysicsWeek_Closing.pdf

13:00 → 14:00 Lunch Break