Open LHCb Workshop on semileptonic exclusive $b\rightarrow c$ decays

Europe/Rome
Bruno Touschek Auditorium (INFN - Laboratori Nazionali di Frascati)

Bruno Touschek Auditorium

INFN - Laboratori Nazionali di Frascati

Marta Calvi (Istituto Nazionale di Fisica Nucleare), Patrizia de Simone (Istituto Nazionale di Fisica Nucleare), Anna Lupato (PD), Marcello Rotondo (Istituto Nazionale di Fisica Nucleare), Mark Smith (CERN)
Description

The semileptonic decays of heavy hadrons are a rich source of observables sensitive to SM and NP paramaters. Despite the efforts from both experimental and theoretical sides, the measurements of the CKM parameter $|V_{cb}|$ from inclusive and exclsuive decays, remain in significant tension. Moreover, the measurements of the ratios $R=BF(B\rightarrow D^{(*)}\tau\nu_{\tau})/ BF(B\rightarrow D^{(*)}\ell\nu_{\ell})$ have gained in the last decade a lot of interests because of the intriguing discrepancies with their precise SM expectations. Even if the tension with the SM seems reduced with the accumulation of more measurements, more precise measurements and solid SM predictions would be welcome. If confirmed, the discrepancy would be a clear sign of violation of Lepton Universality (LU).

The main goal of the workshop is to enlarge the potential of these measurements at LHCb, with a critical comparison with the results from B-Factories and prospects from Belle II.  The measurements of $|V_{cb}|$ and the predictions of the ratios R from exclusive $b\to c$ decays, require crucial input from non perturbative calculations of the Form Factors. New observables, accessibile from detailed studies of final state angular distributions, are very sensitive to NP models and can also constrain the shape of the Form Factors.

Another topic that will be discussed is related to common systematic uncertainties that affect measurements both at LHCb and B-Factories. For example the production of excited charm-hadrons in semileptonic decays, that is a source of physical background. Moreover there are common tools that could be shared between the various experiments to speed up the analysis process and for better understanding of common systematics.

Finally, these analyses require improvements  in external inputs from both theory and experiment. Some of these inputs would need dedicated measurements from other facilities, as BESIII. A coordination accross experiments would be beneficial for many analyses.

All of this will be discussed during the first two days of the workshop between the LHCb community, the theorists of flavour physics and the experimentalists from other heavy flavour facilities. Friday morning will be dedicated to internal discussions of the LHCb collaboration.


The Workshop will be held in the "Bruno Touschek" Auditorium (Bldg. 36). Participants will access from the LNF secondary entrance in Via E. Fermi, 60 (see map).

 

Registration
Registration form
Participants
  • Abhijit Mathad
  • Adlene Hicheur
  • Alejandro Vaquero Avilés-Casco
  • Alessandra Gioventù
  • Andrew MORRIS
  • Anna Lupato
  • Anton Poluektov
  • Antonio Romero Vidal
  • Barbara Sciascia
  • Benjamin Stefanek
  • Biljana Mitreska
  • Blaise Delaney
  • Bogdan Kutsenko
  • Chen Chen
  • Davide Fazzini
  • Dorothea vom Bruch
  • Elisa Minucci
  • Emi Kou
  • Federico Manganella
  • Florian Bernlochner
  • Florian Reiss
  • Francesca Acanfora
  • Frank Meier
  • Fulvia De Fazio
  • Gaya Benane
  • Giulio Mezzadri
  • Greg Ciezarek
  • Guy Wormser
  • Havva Hasret Nur
  • Ho Yin Derek Yeung
  • Lopamudra Mukherjee
  • Lorenzo Paolucci
  • Lucia Grillo
  • Ludovico Vittorio
  • Marcello Rotondo
  • Maria Cristina D'Amato
  • Mark Smith
  • Markus Prim
  • Marta Calvi
  • Martin Jung
  • Martina Ferrillo
  • Michael Hedges
  • Michel De Cian
  • monica pepe altarelli
  • Nico Gubernari
  • Oliver Witzel
  • Olivier Leroy
  • Patrick Owen
  • Patrizia De Simone
  • Philipp Horak
  • Ricardo Vazquez Gomez
  • Rizwaan Mohammed
  • Scott Ely
  • Silvano Simula
  • Stefania Vecchi
  • Suzanne Klaver
  • Tejhas Kapoor
  • Vlad Dedu
    • 14:30 15:30
      General Seminar on Flavour Physics "The Flavor Puzzle as a Hint for Light New Physics in the Third Family" 1h Bruno Touschek Auditorium

      Bruno Touschek Auditorium

      INFN - Laboratori Nazionali di Frascati

      Speaker: Benjamin Stefanek (University of Zurich)
    • 15:30 16:00
      coffee break 30m Bruno Touschek Auditorium

      Bruno Touschek Auditorium

      INFN - Laboratori Nazionali di Frascati

    • 16:00 18:00
      Exclusive b->c semileptonic transitions Bruno Touschek Auditorium

      Bruno Touschek Auditorium

      INFN - Laboratori Nazionali di Frascati

      Current status of transition form factor calculations for b-hadrons decays: open questions and prospects. Status of measurements of $|V_{cb}|$ from exclusive decays: experimental techniques, source of systematic uncertainties.

      Convener: Oliver Witzel (University of Siegen)
      • 16:00
        Measurements of exclusive B semileptonic decays at Belle II 30m
        Speaker: Philipp Horak (HEPHY Vienna)
      • 16:30
        Recent results from Lattice QCD 30m
        Speaker: Alejandro Vaquero (Universidad de Zaragoza)
      • 17:00
        Results with unitarity based DM approach 30m
        Speaker: Ludovico Vittorio (Istituto Nazionale di Fisica Nucleare)
      • 17:30
        Exclusive semileptonic measurements and prospects at LHCb 30m
        Speaker: Ricardo Vazquez Gomez (Universitat de Barcelona)
    • 09:30 12:00
      Status of LFU tests in b->c decays Bruno Touschek Auditorium

      Bruno Touschek Auditorium

      INFN - Laboratori Nazionali di Frascati

      Current SM predictions for $R(D)$ and $R(D^*)$ and analogous ratios for other b-hadrons. Implications and prospects on these calculations.
      Review of the current ratio measurements, focusing on experimental techniques used by BaBar and LHCb, challenges and source of systematic uncertainties. Opportunities with "other" b-hadron semileptonic decays and spectroscopy.

      Convener: Anna Lupato (Università di Padova)
      • 09:30
        SM predictions on LFU and implications 30m
        Speaker: Nico Gubernari (Siegen University)
      • 10:00
        Current status of R(D(*)) measurements in LHCb 30m
        Speaker: Gregory Ciezarek (CERN)
      • 10:30
        Measurements of LFU in B->D(*)lnu at B-Factories 30m
        Speaker: Michael Hedges (Purdue University)
      • 11:00
        coffee break 30m
      • 11:30
        Opportunities with Bc semileptonic decays 30m
        Speaker: Fulvia De Fazio (Istituto Nazionale di Fisica Nucleare)
    • 12:00 13:30
      Angular b->c analyses Bruno Touschek Auditorium

      Bruno Touschek Auditorium

      INFN - Laboratori Nazionali di Frascati

      Results of angular analysis of semileptonic decays: techniques employed at BFactories and LHCb. Experimental sensitivity at Belle II and LHCb on New Physics searches and discussion about observables not fully explored yet.

      Convener: Stefania Vecchi (Istituto Nazionale di Fisica Nucleare)
      • 12:00
        Measurements and prospects for B->D*l nu angular analysis at B-Factories 30m
        Speaker: Florian Bernlochner (University of Bonn)
      • 12:30
        Exclusive 𝑏→𝑐ℓ𝜈 transitions in and beyond the Standard Model 30m
        Speaker: Emi Kou (IJCLab)
    • 13:30 14:30
      lunch break 1h LNF canteen

      LNF canteen

      LNF canteen
    • 14:30 15:00
      angular b->c analysis Bruno Touschek Auditorium

      Bruno Touschek Auditorium

      INFN - Laboratori Nazionali di Frascati

      Convener: Stefania Vecchi (Istituto Nazionale di Fisica Nucleare)
      • 14:30
        Prospect on angular analysis at LHCb 30m
        Speaker: Lucia Grillo (University of Glasgow)
    • 15:00 16:40
      Complementary Information and Measurements (external inputs and background) Bruno Touschek Auditorium

      Bruno Touschek Auditorium

      INFN - Laboratori Nazionali di Frascati

      Some of the measurements of ratios $R$ are limited by present knowledge of external parameters: what should be improved?
      Systematic uncertaines can be reduced only with dedicated measurements: semileptonic decays into excited c-hadron states, precise measurement of charm hadron decays at BESIII, and of fully hadronic $B$ decays from LHCb and Belle.

      Convener: Marta Calvi (Istituto Nazionale di Fisica Nucleare)
      • 15:00
        Charm decays @ BESIII 30m
        Speaker: Giulio Mezzadri (Istituto Nazionale di Fisica Nucleare)
      • 15:30
        B->D** decays experimental status @ Belle 30m
        Speaker: Frank Meier (Duke University)
      • 16:00
        Double charm B-decays @ LHCb and b-factories 30m
        Speaker: Anton Poluektov (University of Warwick / BINP)
      • 16:30
        FLAG updates 10m
        Speakers: Alejandro Vaquero (Universidad de Zaragoza), Silvano Simula (Istituto Nazionale di Fisica Nucleare)
    • 16:40 16:50
      coffee break 10m Bruno Touschek Auditorium

      Bruno Touschek Auditorium

      INFN - Laboratori Nazionali di Frascati

    • 16:50 18:20
      Common issues/tools Bruno Touschek Auditorium

      Bruno Touschek Auditorium

      INFN - Laboratori Nazionali di Frascati

      Open dicussion on issues and tools common to all measurements/experiments.
      The focus will be on: generators, fitting and reweighting tools, unfolding and impact of QED corrections.

      Convener: Marcello Rotondo (Istituto Nazionale di Fisica Nucleare)
      • 16:50
        EvtGen model for $B\rightarrow D^{*}\ell\nu$ with New Physics 20m
        Speaker: Lopamudra Mukherjee (Nankai University)
      • 17:10
        Fitting tools: RooFit, HistFactory, HAMMER 20m
        Speaker: Patrick Owen (University of Zurich)
      • 17:30
        MC reweighting tools and Unfolding 20m
        Speaker: Markus Prim (University of Bonn )
      • 17:50
        QED corrections 20m
        Speaker: Suzanne Klaver (VU Amsterdam)
    • 20:00 22:00
      Social Dinner 2h Frascati downtown

      Frascati downtown

      Frascati downtown
    • 09:30 12:30
      LHCb closed session 3h Bruno Touschek Auditorium

      Bruno Touschek Auditorium

      INFN - Laboratori Nazionali di Frascati