Towards the discovery of novel $B_c$ states: radiative and hadronic transitions

Abstract

The properties of the $B_c$-meson family ($c\bar{b}$) are still not well determined experimentally because the specific mechanisms of formation and decay remain poorly understood. Unlike heavy quarkonia, i.e. the hidden heavy quark-antiquark sectors of charmonium ($c\bar{c}$) and bottomonium ($b\bar{b}$), the $B_c$-mesons cannot annihilate into gluons and they are, consequently, more stable. The excited $B_c$ states, lying below the lowest strong-decay $BD$-threshold, can only undergo through radiative decays and hadronic transitions to the $B_c$ ground state, which then decays weakly. As a result of this, a rich spectrum of narrow excited states below the $BD$-threshold appear, whose total widths are two orders of magnitude smaller than those of the excited levels of charmonium and bottomonium. In a different article, we determined bottom-charmed meson masses using a non-relativistic constituent quark model which has been applied to a wide range of hadron physical observables, and thus the model parameters are completely constrained. Herein, continuing to our study of the $B_c$ sector, we calculate the relevant radiative decay widths and hadronic transition rates between $c\bar{b}$ states which are below $BD$-threshold. This shall provide the most promising signals for discovering excited $B_c$ states that are below the lowest strong-decay $BD$-threshold. Finally, our results are compared with other models to measure the reliability of the predictions and point out differences.

13 pages, 9 tables. arXiv admin note: text overlap with arXiv:1601.05093

References in corpus (22)

• Heavy quarkonium: progress, puzzles, and opportunities
• Constituent quark model study of the meson spectra
• Excited and exotic charmonium spectroscopy from lattice QCD
• Excited and exotic charmonium, $D_s$ and $D$ meson spectra for two light quark masses from lattice QCD
• 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
• A New Hadron Spectroscopy
• Mesons with Beauty and Charm: New Horizons in Spectroscopy
• Observation of an excited $B_c^{+}$ state
• The excited bottom-charmed mesons in a nonrelativistic quark model
• Charmonium resonances in the 3.9 GeV/$c^2$ energy region and the $X(3915)/X(3930)$ puzzle
• Canonical description of the new LHCb resonances
• Spectroscopy of ${\mathbf{B}}_{\mathbf{c}}$ mesons and the possibility of finding exotic ${\mathbf{B}}_{\mathbf{c}}$-like structures
• Charmed-strange Meson Spectrum: Old and New Problems
• Exotic to standard bottomonium transitions
• Doubly Charmed Pentaquarks
• The $\mathbf{sQ}\bar{\mathbf{q}}\bar{\mathbf{q}}$ $(\mathbf{q}=\mathbf{u},\mathbf{d};\mathbf{Q}=\mathbf{c},\mathbf{b})$ tetraquarks in the chiral quark model
• $QQ\bar{s}\bar{s}$ tetraquarks in the chiral quark model
• Puzzles in hadronic transitions of heavy quarkonium with two pion emission
• $B_c$ Meson Spectrum Via Dyson-Schwinger Equation and Bethe-Salpeter Equation Approach
• Excited and exotic bottomonium spectroscopy from lattice QCD
• The $Z_b$ structures in a constituent quark model coupled-channels calculation
• Can the hyperfine mass splitting formula in heavy quarkonia be applied to the $B_c$ system?

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• Three-loop matching coefficients for heavy flavor-changing currents and the phenomenological applications
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• M1 Radiative and spin-nonflip $\pi \pi$ transitions of $B_c$ states in the Cornell potential model
• Observation of orbitally excited $B_c^{+}$ states
• Parton distribution functions of ground state mesons composed of $c$ or $b$ quarks
• In-medium mass shift of two-flavored heavy mesons, $B_c$, $B_c^{\ast }$, $B_s$, $B_s^{\ast }$, $D_s$ and $D_s^{\ast }$
• Spectra and Decay Properties of Higher Lying $B_C$ Meson States
• Study of $B_c(1P{)}^{+}$ states in the $B_c^{+}\gamma$ mass spectrum
• Chromopolarizability of charm-beauty quarkonium from $B_c(2S)\to B_c\pi \pi$ transition
• Study of the two-body nonleptonic $B_c(2S)$ weak decays with the QCD factorization approach