Study of $B_c(1P{)}^{+}$ states in the $B_c^{+}\gamma$ mass spectrum

Abstract

The study of a wide peaking structure in the $B_c^{+}\gamma$ mass spectrum is reported using a data sample of proton-proton collisions collected by the LHCb detector at center-of-mass energies of $7$, $8$, and $13\text{TeV}$, corresponding to an integrated luminosity of $9{\text{fb}}^{-1}$. The observed structure is consistent with the lowest excited $P$-wave $B_c^{+}$ states and exhibits a statistical significance exceeding seven standard deviations relative to the background-only hypothesis. A two-peak model serves as an effective description of the data, with various theory-constrained models further explored to provide physical interpretation. Based on the predictions for the $B_c(1P{)}^{+}$ spectrum, the relative production cross-section of the overall $B_c(1P{)}^{+}$ states with respect to the $B_c^{+}$ ground state with the transverse momentum $p_{\text{T}}$ and rapidity $y$ of $B_c^{+}$ mesons in the regions $p_{\text{T}}<20\mathrm{Ge}\mathrm{V}/c$ and $2.0<y<4.5$ at $\sqrt{s}=13\text{TeV}$ is measured to be $0.20\pm 0.03\pm 0.02\pm 0.03$, where the uncertainty terms represent statistical, systematic, and uncertainties related to the choice of theoretical models, respectively. The results provide a test of theoretical models and deepen our understanding of quantum chromodynamics.

arXiv commentAll figures and tables, along with any supplementary material and additional information, are available at https://lbfence.cern.ch/alcm/public/analysis/full-details/4137 (LHCb public pages)

References in corpus (54)

• A Brief Introduction to PYTHIA 8.1
• LHCb Detector Performance
• Properties of heavy quarkonia and B_c mesons in the relativistic quark model
• Mesons with Beauty and Charm: Spectroscopy
• Decay Chain Fitting with a Kalman Filter
• Trial factors for the look elsewhere effect in high energy physics
• Observation of the B_c Meson in p-bar p Collisions at sqrt{s} = 1.8 TeV
• Measurement of the track reconstruction efficiency at LHCb
• Observation of B_c Mesons in p-bar p Collisions at sqrt{s} = 1.8 TeV
• Spectroscopy of B_c Mesons in the Relativized Quark Model
• $B_c$ spectroscopy
• Heavy Mesons In A Relativistic Model
• Selection and processing of calibration samples to measure the particle identification performance of the LHCb experiment in Run 2
• Precise heavy-light meson masses and hyperfine splittings from lattice QCD including charm quarks in the sea
• Precise predictions of charmed-bottom hadrons from lattice QCD
• Observation of an Excited $B_c^{\pm }$ Meson State with the ATLAS Detector
• Prospects for the Bc Studies at LHCb
• BCVEGPY: An Event Generator for Hadronic Production of the B_c Meson
• Observation of two excited B${}_{\mathrm{c}}^{+}$ states and measurement of the B${}_{\mathrm{c}}^{+}$(2S) mass in pp collisions at $\sqrt{s}=$ 13 TeV
• On Hadronic Production of the $B_c$ Meson
• $Q\bar{Q}$ ($Q\in \{b,c\}$) spectroscopy using Cornell potential
• Phenomenological prediction of the properties of the B_{C} system
• Mass of the B_c Meson in Three-Flavor Lattice QCD
• Performance of the Muon Identification at LHCb
• Mesons with Beauty and Charm: New Horizons in Spectroscopy
• Measurement of the ratio of prompt ${\chi }_c$ to $J/\psi$ production in $pp$ collisions at $\sqrt{s}=7$ TeV
• BCVEGPY2.0: A upgrade version of the generator BCVEGPY with an addendum about hadroproduction of the $P$-wave $B_c$ states
• $B_c$ Spectroscopy from Lattice QCD
• Observation of an excited $B_c^{+}$ state
• Measurement of the cross-section ratio $\sigma ({\chi }_{c2})/\sigma ({\chi }_{c1})$ for prompt ${\chi }_c$ production at $\sqrt{s}=7$ TeV
• Comparative Study of the Hadronic Production of $B_c$ Mesons
• Bc spectroscopy in a quantum-chromodynamic potential model
• The excited bottom-charmed mesons in a nonrelativistic quark model
• Hadronic production of S- and P-wave states of (b-bar c)-quarkonium
• The Color-Octet Contributions to $P$-wave $B_c$ Meson Hadroproduction
• Measurement of the relative rate of prompt ${\chi }_{c0}$, ${\chi }_{c1}$ and ${\chi }_{c2}$ production at $\sqrt{s}=7$TeV
• Hadronic production of the $P$-wave excited $B_c$-states ($B_{cJ,L=1}^{\ast }$)
• Analysis of the vector and axialvector $B_c$ mesons with QCD sum rules
• Measurement of the ${\chi }_b(3P)$ mass and of the relative rate of ${\chi }_{b1}(1P)$ and ${\chi }_{b2}(1P)$ production
• The mass spectrum and wave functions of the $B_c$ system
• A Trick to Improve the Efficiency of Generating Unweighted $B_c$ Events from BCVEGPY
• A non-perturbative calculation of the mass of the Bc
• $B_c$ Meson Spectrum Via Dyson-Schwinger Equation and Bethe-Salpeter Equation Approach
• BCVEGPY2.2: A Newly Upgraded Version for Hadronic Production of the Meson $B_c$ and Its Excited States
• Towards the discovery of novel $B_c$ states: radiative and hadronic transitions
• Radiative decays of Bc mesons in a Bethe-Salpeter model
• Spectroscopic survey of higher-lying states of $B_c$ meson family
• Scaling of P-wave excitation energies in heavy-quark systems
• $B_c$ excitations at LHC experiments
• Precision measurement of the $B_c^{+}$ meson mass
• Higher states of the $B_c$ meson family
• Observation of the $B_c^{+}\to J/\psi {\pi }^{+}{\pi }^0$ decay
• BCVEGPY and GENXICC for the hadronic production of the doubly heavy mesons and baryons
• Observation of orbitally excited $B_c^{+}$ states

Cited by in corpus (1)

• Observation of orbitally excited $B_c^{+}$ states