Line Shapes of the Z(4430)

Abstract

The Belle Collaboration recently discovered the first manifestly exotic meson: Z^+(4430), which decays into psi' pi^+ and therefore has quark content c c-bar u d-bar. The proximity of its mass to the D_1 D-bar^* threshold has motivated the interpretation of the Z^+ as a charm meson molecule whose constituents are an S-wave superposition of D_1^+ D-bar^{*0}$and{D}^{\ast +}D-ba{r}_1^0$. If this interpretation is correct, the small ratio of the binding energy of the Z^+ to the width Gamma_1 of its constituent D_1 can be exploited to predict properties of its line shapes. Its full width at half maximum in the channel psi' pi^+ should be approximately sqrt{3} Gamma_1 = 35 MeV, which is consistent with the measured width of the Z^+. The Z^+ should also decay into D^* D-bar^* pi through decay of its constituent D_1. The peak in the line shape for D^* D-bar^* pi should be at a higher energy than the peak in the line shape for psi' pi^+ by about Gamma_1/sqrt{12} = 6 MeV. The line shape in D^* D-bar^* pi should also be broader and asymmetric, with a shoulder on the high energy side that can be attributed to a threshold enhancement in the production of D_1 D-bar^*.

arXiv comment4 pages, 1 figure

References in corpus (21)

• The Cosmological Parameters 2006
• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• Observation of a New Narrow Charmonium State in Exclusive B+-->K+ pi+pi- J/psi Decays
• Observation of a narrow charmonium-like state in exclusive B+ -> K+ pi+pi- J/psi decays
• Universality in Few-body Systems with Large Scattering Length
• Observation of a resonance-like structure in the pi^+- psi' mass distribution in exclusive B-->K pi^+- psi' decays
• Observation of a Near-threshold $D^0{\bar{D}}^0{\pi }^0$ Enhancement in $B\to D^0{\bar{D}}^0{\pi }^{0}K$ Decay
• Reconciling the X(3872) with the near-threshold enhancement in the D^0\bar{D}^{*0} final state
• Study of Resonances in Exclusive B Decays to Dbar(*)D(*)K
• Line Shapes of the X(3872)
• Is Z^+(4430) a loosely bound molecular state?
• Indications of a Four-Quark Structure for the X(3872) and X(3876) Particles from Recent Belle and BABAR Data
• QCD sum rules study of the meson Z^+(4430)
• The Effects of Charged Charm Mesons on the Line Shapes of the X(3872)
• Properties of the Charmed P-wave Mesons
• Threshold effect and π^\pm ψ(2S) peak
• A Uniform Description of the States Recently Observed at B-factories
• A Precision Determination of the D^0 Mass
• Isospin properties of the X state near the D {\bar D}^{*} threshold
• Partners of Z(4430) and Productions in B Decays
• Bottomed Analog of Z+(4433)

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• Heavy quarkonium: progress, puzzles, and opportunities
• The hidden-charm pentaquark and tetraquark states
• The Physics of the B Factories
• Observation of the resonant character of the $Z(4430{)}^{-}$ state
• New Charmonium States in QCD Sum Rules: a Concise Review
• Exotic Hadrons with Heavy Flavors -X, Y, Z and Related States-
• Four-Quark Hadrons: an Updated Review
• An overview of $XYZ$ new particles
• Heavy hadronic molecules with pion exchange and quark core couplings: a guide for practitioners
• Analysis of the $Z(4430)$ as the first radial excitation of the $Z_c(3900)$
• Treating $Z_c(3900)$ and $Z(4430)$ as the ground-state and first radially excited tetraquarks
• A model-independent confirmation of the $Z(4430{)}^{-}$ state
• Low-energy $D^{\ast +}{D}_1^0$ Scattering and the Resonance-like Structure $Z^{+}(4430)$
• Resolving the puzzling decay patterns of charged $Z_c$ and $Z_b$ states
• Mass spectrum of the scalar hidden charm and bottom tetraquark states
• Mass spectrum of the axial-vector hidden charmed and hidden bottom tetraquark states
• Possible tetraquark states in the ${\pi }^{+}{\chi }_{c1}$ invariant mass distribution
• Recoupling Mechanism for exotic mesons and baryons
• Modifications on parameters of $Z(4430)$ in a dense medium