Observation of New Resonances in the Λ b 0 π + π − System
Name
PhysRevLett.123.152001.pdf
Description
Published version
Size
445.81 KB
Format
Unknown
Checksum (MD5)
90da11507849f4c7fd7abca7331c820b
Author(s)
The LHCb Collaboration
Boettcher, Thomas Julian
Craik, Daniel C
Weisser, Constantin
Williams, Michael
Date Issued
2019
Journal
Physical Review Letters
Publisher
American Physical Society (APS)
Version
Final published version
Abstract
© 2019 CERN. We report the observation of a new structure in the Λb0π+π- spectrum using the full LHCb data set of pp collisions, corresponding to an integrated luminosity of 9 fb-1, collected at s=7, 8, and 13 TeV. A study of the structure suggests its interpretation as a superposition of two almost degenerate narrow states. The masses and widths of these states are measured to be mΛb(6146)0=6146.17±0.33±0.22±0.16 MeV,mΛb(6152)0=6152.51±0.26±0.22±0.16 MeV,ΓΛb(6146)0=2.9±1.3±0.3 MeV,ΓΛb(6152)0=2.1±0.8±0.3 MeV,with a mass splitting of Δm=6.34±0.32±0.02 MeV, where the first uncertainty is statistical, the second systematic. The third uncertainty for the mass measurements derives from the knowledge of the mass of the Λb0 baryon. The measured masses and widths of these new excited states suggest their possible interpretation as a doublet of Λb(1D)0 states.
MIT Department
Massachusetts Institute of Technology. Department of Physics
Massachusetts Institute of Technology. Laboratory for Nuclear Science
Terms of Use
Creative Commons Attribution 4.0 International license
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1103/PHYSREVLETT.123.152001
