Observation of the ^1P_1 State of Charmonium

Abstract

The spin-singlet P-wave state of charmonium, hc(1P1), has been observed in the decay psi(2S) -> pi0 hc followed by hc -> gamma etac. Inclusive and exclusive analyses of the M(hc) spectrum have been performed. Two complementary inclusive analyses select either a range of energies for the photon emitted in hc -> gamma etac or a range of values of M(etac). These analyses, consistent with one another within statistics, yield M(h_c) =[3524.9 +/- 0.7 (stat) +/- 0.4 (sys)]MeV/c^2 and a product of the branching ratios B_psi(psi(2S) -> pi0 hc) x B_h(hc -> gamma etac) = [3.5 +/- 1.0 (stat) +/- 0.7 (sys)] x 10^{-4}. When the etac is reconstructed in seven exclusive decay modes, 17.5 +/- 4.5 hc events are seen with an average mass M(hc) = [3523.6 +/- 0.9 (stat) +/- 0.5 (sys)] MeV/c^2, and B_psi x B_h = [5.3 +/- 1.5 (stat) +/- 1.0 (sys)] x 10^{-4}. Because the inclusive and exclusive data samples are largely independent they are combined to yield an overall mass M(hc) = [3524.4 +/- 0.6 (stat) +/- 0.4 (sys)]MeV/c^2 and product of branching ratios B_psi x B_h = [4.0 +/- 0.8 (stat) +/- 0.7 (sys)] x 10^{-4}. The hc mass implies a P-wave hyperfine splitting Delta M_{HF}(1P) \equiv M(1^3P)-M(1^1P_1) = [1.0 +/- 0.6 (stat) +/- 0.4 (sys)] MeV/c^2.

arXiv comment38 pages postscript,also available through http://www.lns.cornell.edu/public/CLNS/2005/, Submitted to PRD

References in corpus (24)

• PYTHIA 6.4 Physics and Manual
• PYTHIA 6.2 Physics and Manual
• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• Rigorous QCD Analysis of Inclusive Annihilation and Production of Heavy Quarkonium
• High-Energy-Physics Event Generation with PYTHIA 6.1
• Properties of heavy quarkonia and B_c mesons in the relativistic quark model
• Rigorous QCD Predictions for Decays of P-Wave Quarkonia
• Charmonium Spectrum from Quenched Anisotropic Lattice QCD
• Observation of h_c(^1P_1) State of Charmonium
• Observation of eta_c^{prime} Production in gamma gamma Fusion at CLEO
• Measurements of the mass and width of the eta_c meson and of an eta_c(2S) candidate
• Construction, Pattern Recognition and Performance of the CLEO III LiF-TEA RICH Detector
• Measurement of Absolute Hadronic Branching Fractions of D Mesons and e^+e^- --> D barD Cross Sections at E_cm = 3773 MeV
• Production of singlet P-wave $c\bar{c}$ and $b\bar{b}$ states
• New precision measurement of the $J/\psi$- and ${\psi }^{\prime }$ -meson masses
• Photon Transitions in ψ(2S) Decays to χ_{cJ}(1P) and η_c(1S)
• S-D Mixing and Searching for the psi(1P1) State at the Beijing Electron-Positron Coolider
• Heavy Quarkonium Potential Model and the ${}^1{P}_1$ State of Charmonium
• Branching Fractions for psi(2S) to J/psi Transitions
• Sea Quark Effects on Quarkonia
• Heavy Quarkonium
• Masses of light mesons in the relativistic quark model
• The Lost Tribes of Charmonium
• Search for ${\eta }_c^{{}^{\prime }}$ and $h_c{(}^1{P}_1)$ states in the $e^{+}{e}^{-}$ annihilations

Cited by in corpus (51)

• Heavy quarkonium: progress, puzzles, and opportunities
• Glueballs, Hybrids, Multiquarks. Experimental facts versus QCD inspired concepts
• Heavy-flavour and quarkonium production in the LHC era: from proton-proton to heavy-ion collisions
• The New Heavy Mesons: A Status Report
• The Exotic XYZ Charmonium-like Mesons
• Quarkonia and their transitions
• Exotic hadrons: review and perspectives
• Radiative Transitions in Charmonium from Lattice QCD
• New states above charm threshold
• Bottomonium Mesons and Strategies for Their Observation
• Measurements of h_c(^1P_1) in psi' Decays
• Canonical Charmonium Interpretation for Y(4360) and Y(4660)
• Precision Measurement of the Mass of the h_c(1P1) State of Charmonium
• Search for excited charmonium states in $e^{+}{e}^{-}$ Annihilation at $\sqrt{s}=10.6$ GeV
• Hadron Spectroscopy: Theory and Experiment
• Charm as a domain wall fermion in quenched lattice QCD
• Recent Results in Bottomonium
• Study of B-meson decays to eta_c K^(*), eta_c(2S) K^(*) and eta_c gamma K^(*)
• Potential description of charmonium and charmed-strange mesons from lattice QCD
• Status of quarkonia - like negative and positive parity states in a relativistic confinement scheme
• Heavy Quark Spectroscopy -- Theory Overview
• Inclusive $h_c$ production at $B$ factories
• Search for the h_c meson in B^+- ->h_c K^+-
• Lh_c
• Evidence for Decays of h_c to Multi-Pion Final States
• h_c Production at Hadron Colliders
• Charmonium spectrum with a Dirac potential model in the momentum space
• QCD and Relativistic $O({\alpha }_s{v}^2)$ Corrections to Hadronic Decays of Spin-Singlet Heavy Quarkonia $h_c,h_b$ and ${\eta }_b$
• First observations of $h_c\to$ hadrons
• Higher ${\eta }_c(nS)$ and ${\eta }_b(nS)$ mesons
• Scalar and axial-vector mesons
• Branching fractions for Y(3S) -> pi^0 h_b and psi(2S) -> pi^0 h_c
• Masses of the η_c(nS) and η_b(nS) mesons
• Renormalized Quarkonium
• Inclusive Production of $h_c(h_b)$ States via $e^{+}{e}^{-}$ Annihilation
• Inclusive $h_c$ production and energy spectrum from $e^{+}{e}^{-}$ annihilation at Super $B$ factory
• Heavy Hadron Spectroscopy
• New Studies of XYZ States at PANDA
• Detecting h_c(^1P_1) at the LHC
• Calculation of the Branching Ratio of $B^{-}\to h_c+K^{-}$ in PQCD
• Probing the charm-Higgs Yukawa coupling via Higgs boson decay to $h_c$ plus a photon
• Predictions for $h_c$ and $h_b$ production at the LHC
• An introduction to the quark model
• Hadronic Transition chi(c1)(1P) to eta(c) plus two pions at the Beijing Spectrometer BES and the Cornell CLEO-c
• Search for New Hadronic Decays of $h_c$ and Observation of $h_c\to K^{+}{K}^{-}{\pi }^{+}{\pi }^{-}{\pi }^0$
• Hadronic Physics and Exotics
• Observation of the Electromagnetic Dalitz Transition $h_c\to e^{+}{e}^{-}{\eta }_c$
• Observation of the decay $h_c\to 3({\pi }^{+}{\pi }^{-}){\pi }^0$
• Measurements of the branching fractions of the $P$-wave charmonium spin-singlet state $h_c{(}^1{P}_1)\to h^{+}{h}^{-}{\pi }^0/\eta$
• Charmonium Review
• Search for $h_c\to {\pi }^{+}{\pi }^{-}J/\psi$ via $\psi (3686)\to {\pi }^0{h}_c$