Observation of a new baryon state in the Λb0π+π− mass spectrum

Research output: Contribution to journalArticle

Authors

  • LHCb Collaboration

Colleges, School and Institutes

External organisations

  • Nikhef National Institute for Subatomic Physics
  • Universität Zürich
  • University of Liverpool
  • Universidad de Santiago de Compostela
  • BRISTOL UNIVERSITY
  • Université Clermont Auvergne
  • University of Michigan, Ann Arbor.
  • Istituto Nazionale di Fisica Nucleare, Sezione di Milano
  • Los Alamos National Laboratory
  • Laboratori Nazionali dell'Infn di Frascati
  • Technische Universität Dortmund
  • European Organization for Nuclear Research (CERN)
  • University of Glasgow
  • Universitat Autònoma de Barcelona
  • Petersburg Nuclear Physics Institute (PNPI)
  • Imperial College London
  • Universidade Federal Do Rio de Janeiro (UFRJ)
  • Université Paris-Saclay
  • Sezione INFN di Firenze
  • Laboratory of Photonics and Interfaces, Department de Chimie, Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne, Switzerland. ahmad@mpip-mainz.mpg.de
  • Sezione INFN di Ferrara
  • Ruprecht-Karls-Universität Heidelberg
  • Institute for High Energy Physics (IHEP)
  • Syracuse University, Syracuse, New York 13244, USA
  • Yandex School of Data Analysis
  • CNRS/IN2P3
  • THE UNIVERSITY OF WARWICK
  • Laboratoire Leprince-Ringuet
  • Institute of Physics

Abstract

A new baryon state is observed in the Λb0π+π− mass spectrum with high significance using a data sample of pp collisions, collected with the LHCb detector at centre-of-mass energies s = 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb−1. The mass and natural width of the new state are measured to be m=6072.3±2.9±0.6±0.2MeV,Γ=72±11±2MeV, where the first uncertainty is statistical and the second systematic. The third uncertainty for the mass is due to imprecise knowledge of the Λb0 baryon mass. The new state is consistent with the first radial excitation of the Λb0 baryon, the Λb(2S)0 resonance. Updated measurements of the masses and the upper limits on the natural widths of the previously observed Λb(5912)0 and Λb(5920)0 states are also reported. [Figure not available: see fulltext.]

Details

Original languageEnglish
Article number136
JournalJournal of High Energy Physics
Volume2020
Issue number6
Publication statusPublished - 23 Jun 2020

Keywords

  • B physics, Hadron-Hadron scattering (experiments), Heavy quark production, Spectroscopy

ASJC Scopus subject areas