Observation of two new ${\Xi }_b^{-}$ baryon resonances

Abstract

Two structures are observed close to the kinematic threshold in the ${\Xi }_b^0{\pi }^{-}$ mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb${}^{-1}$ recorded by the LHCb experiment. In the quark model, two baryonic resonances with quark content $bds$ are expected in this mass region: the spin-parity $J^P={\frac{1}{2}}^{+}$ and $J^P={\frac{3}{2}}^{+}$ states, denoted ${\Xi }_b^{\prime -}$ and ${\Xi }_b^{\ast -}$. Interpreting the structures as these resonances, we measure the mass differences and the width of the heavier state to be $m({\Xi }_b^{\prime -})-m({\Xi }_b^0)-m({\pi }^{-})=3.653\pm 0.018\pm 0.006$ MeV$/c^2$, $m({\Xi }_b^{\ast -})-m({\Xi }_b^0)-m({\pi }^{-})=23.96\pm 0.12\pm 0.06$ MeV$/c^2$, $\Gamma ({\Xi }_b^{\ast -})=1.65\pm 0.31\pm 0.10$ MeV, where the first and second uncertainties are statistical and systematic, respectively. The width of the lighter state is consistent with zero, and we place an upper limit of $\Gamma ({\Xi }_b^{\prime -})<0.08$ MeV at 95% confidence level. Relative production rates of these states are also reported.

17 pages, 2 figures

References in corpus (38)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• A Brief Introduction to PYTHIA 8.1
• Big-Bang Nucleosynthesis
• PHOTOS Monte Carlo: a precision tool for QED corrections in Z and W decays
• The LHCb Trigger and its Performance in 2011
• Performance of the LHCb RICH detector at the LHC
• Baryon spectroscopy
• Efficient, reliable and fast high-level triggering using a bonsai boosted decision tree
• Charmed bottom baryon spectroscopy from lattice QCD
• Performance of the LHCb muon system
• Measurement of the track reconstruction efficiency at LHCb
• Evidence for CP violation in time-integrated D0 -> h-h+ decay rates
• Towards an understanding of heavy baryon spectroscopy
• Experimental constraints on the spin and parity of the Z(4430)+
• Masses of heavy baryons in the relativistic quark model
• The Quark Model and $b$ Baryons
• Bottom Baryons
• Direct observation of the strange b baryon Xi_b^{-}
• Experimental Constraints on the Spin and Parity of the Lambda_c(2880)
• Observation and Mass Measurement of the Baryon ${\Xi }_b^{-}$
• Measurement of the Λ_b^0, Ξ_b^- and Ω_b^- baryon masses
• Precision measurement of D meson mass differences
• Observation of a new Xi(b) baryon
• Search for the doubly charmed baryon Xi_cc^+
• Analysis of the ${\frac{3}{2}}^{+}$ heavy and doubly heavy baryon states with QCD sum rules
• Heavy baryon spectroscopy in QCD
• Observation of the Omega_b^- and Measurement of the Properties of the Xi_b^- and Omega_b^-
• Bottom baryons from a dynamical lattice QCD simulation
• Precision measurement of the mass and lifetime of the ${\Xi }_b^0$ baryon
• Studies of beauty baryon decays to $D^{0}p{h}^{-}$ and ${\Lambda }_c^{+}{h}^{-}$ final states
• Model-Independent Bottom Baryon Mass Predictions in the 1/N Expansion
• Precision measurement of the mass and lifetime of the Xi_b^- baryon
• Measurement of the D*(2010)+ meson width and the D*(2010)+ - D0 mass difference
• Mass and lifetime measurements of bottom and charm baryons in $p\bar{p}$ collisions at $\sqrt{s}= 1.96 TeV
• Observation of the Xi_b^0 Baryon
• Measurement of the D*(2010)+ natural line width and the D*(2010)+ - D0 mass difference
• Heavy quark spectroscopy and prediction of bottom baryon masses

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