Line shapes in Υ(5S) \to B^{(*)} \bar{B}^{(*)}πwith Z(10610) and Z(10650) using effective field theory

Abstract

The Belle collaboration recently discovered two resonances, $Z_b(10610)$ and $Z_b(10650)$ --- denoted $Z_b$ and $Z_b^{\prime }$ --- in the decays ${\rm Y}(5S)\to {\rm Y}(nS){\pi }^{+}{\pi }^{-}$ for $n$ = 1, 2, or 3, and ${\rm Y}(5S)\to h_b(mP){\pi }^{+}{\pi }^{-}$ for $m=1$ or 2. These resonances lie very close to the $B^{\ast }\bar{B}$ and $B^{\ast }{\bar{B}}^{\ast }$ thresholds, respectively. A recent Belle analysis of the three-body decays ${\rm Y}(5S)\to [B^{(\ast )}{\bar{B}}^{(\ast )}{]}^{\mp }{\pi }^{\pm }$ gives further evidence for the existence of these states. In this paper we analyze this decay using an effective theory of $B$ mesons interacting via strong short-range interactions. Some parameters in this theory are constrained using existing data on ${\rm Y}(5S)\to B^{(\ast )}{\bar{B}}^{(\ast )}$ decays, which requires the inclusion of heavy quark spin symmetry (HQSS) violating operators. We then calculate the differential distribution for ${\rm Y}(5S)\to B^{(\ast )}{\bar{B}}^{(\ast )}\pi$ as a function of the invariant mass of the $B^{(\ast )}{\bar{B}}^{(\ast )}$ pair, obtaining qualitative agreement with experimental data. We also calculate angular distributions in the decay ${\rm Y}(5S)\to Z_b^{(\prime )}\pi$ which are sensitive to the molecular character of the $Z_b^{(\prime )}$.

21 pages, 5 figures

References in corpus (8)

• Observation of anomalous Upsilon(1S)pi+pi- and Upsilon(2S)pi+pi- production near the Upsilon(5S) resonance
• Hadronic Decays of the X(3872) to chi_{cJ} in Effective Field Theory
• Confirming the molecular nature of the $Z_b(10610)$ and the $Z_b(10650)$
• Scalar Resonance Contributions to the Dipion Transition Rates of ${\rm Y}(4S,5S)$ in the re-scattering model
• Decays of Zb(+) and Zb'(+) as hadronic molecules
• $Z_b/Z_b^{\prime }\to {\rm Y}\pi$ and $h_b\pi$ decays in intermediate meson loops model
• Could $Y_b(10890)$ be the P-wave $[bq][\bar{b}\bar{q}]$ tetraquark state?
• Υ(5S) decays into BB and BBπ

Cited by in corpus (29)

• Hadronic molecules
• Chiral perturbation theory for heavy hadrons and chiral effective field theory for heavy hadronic molecules
• An overview of $XYZ$ new particles
• Could the near-threshold $XYZ$ states be simply kinematic effects?
• $Y(4260)$ as the first $S$-wave open charm vector molecular state?
• Interplay of quark and meson degrees of freedom in near-threshold states: A practical parametrisation for line shapes
• The line shapes of the $Z_b(10610)$ and $Z_b(10650)$ in the elastic and inelastic channels revisited
• A practical parametrization for line shapes of near-threshold states
• General considerations on the nature of $Z_b(10610)$ and $Z_b(10650)$ from their pole positions
• The $Z_c$ structures in a coupled-channels model
• Effects of $Z_b$ states and bottom meson loops on ${\rm Y}(4S)\to {\rm Y}(1S,2S){\pi }^{+}{\pi }^{-}$ transitions
• Spin partners $W_{bJ}$ from the line shapes of the $Z_b(10610)$ and $Z_b(10650)$
• Nature of the $Y(4260)$: A light-quark perspective
• Enhanced breaking of heavy quark spin symmetry
• Revisiting $X(3872)\to D^0{\bar{D}}^0{\pi }^0$ in XEFT
• Magnetic dipole moment of $Z_b(10610)$ in light-cone QCD
• Spectroscopic parameters and decays of the resonance $Z_b(10610)$
• Precise determination of the pole position of the exotic $Z_c(3900)$
• Heavy meson thresholds in Born-Oppenheimer Effective field theory
• Production of the $Z_b^{(\prime )}$ states from the ${\rm Y}(5S,6S)$ decays
• The nature of $Z_b$ states from a combined analysis of ${\rm Y}(5S)\to h_b(mP){\pi }^{+}{\pi }^{-}$ and ${\rm Y}(5S)\to B^{(\ast )}{\bar{B}}^{(\ast )}\pi$
• Composite nature of $Z_b$ states from data analysis
• Two-pion exchange for coupled-channel scattering of two heavy mesons
• Predictions of ${\rm Y}(4S)\to h_b(1P,2P){\pi }^{+}{\pi }^{-}$ transitions
• Decays of ${\rm Y}(10860)$ and ${\rm Y}(10753)$ into $\omega {\chi }_{bJ}$
• The nature of near-threshold XYZ states
• Canonical interpretation of $Y(10750)$ and ${\rm Y}(10860)$ in the ${\rm Y}$ family
• Exotic hadrons associated with $b$-quark
• Exotic Quarkonium Spectroscopy: X(3872), Z_b(10610), and Z_b(10650) in Non-Relativistic Effective Theory