Evidence for the positive-strangeness pentaquark ${\Theta }^{+}$ in photoproduction with the SAPHIR detector at ELSA

Abstract

The positive--strangeness baryon resonance ${\Theta }^{+}$ is observed in photoproduction of the $\mathrm{n}{\mathrm{K}}^{+}{\mathrm{K}}_{\mathrm{s}}^0$ final state with the SAPHIR detector at the Bonn ELectron Stretcher Accelerator ELSA. It is seen as a peak in the $\mathrm{n}{\mathrm{K}}^{+}$ invariant mass distribution with a $4.8\sigma$ confidence level. We find a mass ${\mathrm{M}}_{{\mathrm{\Theta }}^{+}}=1540\pm 4\pm 2$ MeV and an upper limit of the width ${\mathrm{\Gamma }}_{{\mathrm{\Theta }}^{+}}<25$ MeV at 90% c.l. From the absence of a signal in the $\mathrm{p}{\mathrm{K}}^{+}$ invariant mass distribution in $\gamma \mathrm{p}\to \mathrm{p}{\mathrm{K}}^{+}{\mathrm{K}}^{-}$ at the expected strength we conclude that the ${\Theta }^{+}$ must be isoscalar.

9 pages, 4 figures

References in corpus (7)

• Evidence for Narrow S=+1 Baryon Resonance in Photo-production from Neutron
• Exotic Anti-Decuplet of Baryons: Prediction from Chiral Solitons
• Observation of an Exotic $S=+1$ Baryon in Exclusive Photoproduction from the Deuteron
• Interpretation of the Theta+ as an isotensor pentaquark with weakly decaying partners
• Radial excitations of low--lying baryons and the $Z^{+}$ penta--quark
• Exotic baryon states in topological soliton models
• K0-Sigma+ Photoproduction with SAPHIR

Cited by in corpus (220)

• NJL-model analysis of dense quark matter
• Exotics: Heavy Pentaquarks and Tetraquarks
• Baryon spectroscopy
• Observation of an Exotic S = -2, Q = -2 Baryon Resonance in Proton-Proton Collisions at the CERN SPS
• Observation of an Exotic Baryon with S=+1 in Photoproduction from the Proton
• Evidence for a narrow |S|=1 baryon state at a mass of 1528 MeV in quasi-real photoproduction
• Quark-model study of few-baryon systems
• Evidence for a narrow baryonic state decaying to K0s-p and K0s-pbar in deep inelastic scattering at HERA
• Evidence for a narrow resonance at 1530 MeV/c2 in the K0 p - system of the reaction pp --> Sigma+ K0 p from the COSY-TOF experiment
• Pentaquark hadrons from lattice QCD
• Evidence for a Narrow Anti-Charmed Baryon State
• K+ nucleon scattering and exotic S=+1 Baryons
• New results on the Roper resonance and the P_{11} partial wave
• Experimental Limits on the Width of the Reported Theta(1540)+
• Evidence of the Θ^+ in the γd \to K^+K^-pn reaction
• Nonstrange and other unitarity partners of the exotic Theta+ baryon
• One-pion-exchange final-state-interaction and the pbar p near threshold enhancement in J/psi -> gamma pbar p decays
• Detailed Analysis of the Tetraquark Potential and Flip-Flop in SU(3) Lattice QCD
• Search for the Pentaquark State in $\psi (2S)$ and $J/\psi$ Decays to $K_S^{0}p{K}^{-}\bar{n}$ and $K_S^0\bar{p}{K}^{+}n$
• Experimental Search for Pentaquarks
• A schematic model for pentaquarks based on diquarks
• A study of pentaquarks on the lattice with overlap fermions
• Group-theoretical construction of extended baryon operators in lattice QCD
• Search for ${\Theta }^{+}(1540)$ pentaquark in high statistics measurement of $\gamma p\to {\bar{K}}^0{K}^{+}n$ at CLAS
• First Study for the Pentaquark Potential in SU(3) Lattice QCD
• Is Theta+(1540) a Kaon--Skyrmion Resonance?
• Limits for the central production of Theta^+ and Xi^{--} pentaquarks in 920 GeV pA collisions
• Pentaquarks in high-energy colliding experiments: perspectives from HERA
• Where are the missing members of the baryon antidecuplet?
• Unitary coupled channel analysis of the $\Lambda (1520)$ resonance
• The Evidence for a Pentaquark Signal and Kinematic Reflections
• Search for the ${\Theta }^{+}$ pentaquark in the reactions $\gamma p\to {\bar{K}}^0{K}^{+}n$ and $\gamma p\to {\bar{K}}^0{K}^{0}p$
• Search for the ${\bar{\Theta }}^{-}\to$ K${}^{-}$ $\bar{n}$ with PHENIX
• Parity of ${\Theta }^{+}$(1540) from QCD sum rules
• Exotic Theta^+ baryon production induced by a photon and a pion
• Penta-quark baryon in anisotropic lattice QCD
• Pentaquark baryon production at the Relativistic Heavy Ion Collider
• The pentaquark in K-plus-d total cross section data
• Two-Hadron-Irreducible QCD Sum Rule for Pentaquark Baryon
• Heavy pentaquark spectroscopy in the diquark model
• Search for Theta^+ and Xi^{--}_{3/2} pentaquarks in HERA-B
• High Statistics Search for the Theta+(1.54) Pentaquark State
• Resonating group method study of kaon-nucleon elastic scattering in the chiral SU(3) quark model
• Elliptic flow of resonances at RHIC: probing final state interactions and the structure of resonances
• Light-Front Approach for Heavy Pentaquark Transitions
• Spectroscopy of pentaquark states
• Evidence for the B0->ppbarK*0 and B+->eta_cK*+ decays and Study of the Decay Dynamics of B Meson Decays into ppbarh Final States
• Exotic and nonexotic magnetic transitions in the context of the SELEX and GRAAL experiments
• Pentaquark Theta^+(1540) production in gamma N --> K Anti-K N
• Search for Theta+ via pi- p --> K- X reaction near production threshold
• The static tetraquark and pentaquark potentials
• Search for the Theta+ pentaquark in the gamma d -> Lambda n K+ reaction measured with CLAS
• Anti-charmed pentaquark ${\Theta }_c(3099)$ from QCD sum rules
• Search for a narrow charmed baryonic state decaying to D^*+/- p^-/+ in ep collisions at HERA
• Search for the possible S=+1 Pentaquark states in Quenched Lattice QCD
• Observation of narrow baryon resonance decaying into $p{K}_s^0$ in pA-interactions at $70GeV/c$ with SVD-2 setup
• Search for the exotic ${\Xi }^{--}(1860)$ Resonance in 340GeV/c ${\Sigma }^{-}$-Nucleus Interactions
• New study of the isotensor pi-pi interaction
• Pentaquark baryons in SU(3) quark model
• Study of $Thet{a}^{+}(udud\bar{s})$ in lattice QCD with exact chiral symmetry
• Determining the ${\Theta }^{+}$ quantum numbers through the $K^{+}p\to {\pi }^{+}{K}^{+}n$ reaction
• Study the exotic ${\Theta }^{+}$ with polarized photon beams
• How to measure the parity of the ${\Theta }^{+}$ in $\vec{p}\vec{p}$ collisions
• Coherent Theta^+ and Lambda(1520) photoproduction off the deuteron
• Baryon Exotics in the Quark Model, the Skyrme Model and QCD
• Improved study of a possible Theta+ production in the pp -> p K0 sigma+ reaction with the COSY-TOF spectrometer
• On the Existence of Heavy Pentaquarks: The large Nc and Heavy Quark Limits and Beyond
• Strange Pentaquark Hadrons in Statistical Hadronization
• Experimental Review on Pentaquarks
• Magnetic moments of antidecuplet pentaquarks
• Are There Diquarks in the Nucleon?
• Pentaquark and diquark-diquark clustering: a QCD sum rule approach
• Have Pentaquark States Been seen?
• Light hadron and diquark spectroscopy in quenched QCD with overlap quarks on a large lattice
• Reviewing the Evidence for Pentaquarks
• Theta^+ baryon production in KN and NN reactions
• Observation of a narrow structure in p(gamma,K_s)X via interference with phi-meson production
• Properties of baryon anti-decuplet
• Exotic states of matter in heavy meson decays
• Search for Theta+ via K+p -> pi+X reaction with a 1.2 GeV/c K+ beam
• Search for pentaquarks decaying to Xi-pi in deep inelastic scattering at HERA
• Search for an exotic S=-2, Q=-2 baryon resonance at a mass near 1862 MeV in quasi-real photoproduction
• CKM Results From CLEO
• Pentaquark Searches in Electron-Positron Annihilations and Two-Photon Collisions at LEP
• Dynamical study of the pentaquark antidecuplet
• Pentaquark ${\Theta }^{+}$ production from the reaction $\gamma p\to {\pi }^{+}{K}^{-}{\Theta }^{+}$
• The 27-plet Baryons from Chiral Soliton Models
• Width of the J^P=1/2^+ pentaquark in the quark-diquark model
• Pentaquark searches at FOCUS
• Instanton induced quark dynamics and the pentaquark
• Prediction of Narrow $J^{\pi }=1/2^{+}$, $3/2^{+}$, and $3/2^{-}$ states of ${\Theta }_{+}$ in a Quark model with Antisymmetrized Molecular Dynamics
• Pentaquark Decay Width in QCD Sum Rules
• 1/N Expansion for Exotic Baryons
• Spin 3/2 Penta-quarks in anisotropic lattice QCD
• Search for a strongly decaying neutral charmed pentaquark
• Prospects for Pentaquark Production at Meson Factories
• Present status on experimental search for pentaquarks
• Comment on the ${\Theta }^{+}$-production at high energy
• QCD sum rules for the anti-charmed pentaquark
• Pentaquark ${\Theta }^{\ast }$ States in {27} Baryon Multiplet from Chiral Soliton Model
• Spin observables and the determination of the parity of ${\Theta }^{+}$ in photoproduction reactions
• Pentaquarks: review of the experimental evidence
• "Super-radiance" and the width of exotic baryons
• A lattice study of the pentaquark states
• Triquark correlations and pentaquarks in a QCD sum rule approach
• The effect of the in-medium ${\Theta }^{+}$ pentaquark on the kaon optical potential
• Negative-Parity Heavy Pentaquark States in 1/N_c
• KKbar photoproduction from protons
• Negative parity pentaquarks in large Nc QCD and quark model
• Light-Front Approach for Pentaquark Strong Decays
• Isospin Mixing of Narrow Pentaquark States
• Search for a pentaquark decaying to p K_S^0
• A comprehensive search for the Θ^+ pentaquark on the lattice
• A QCD Sum Rule Study of ${\Theta }^{+}$ in Nuclear Matter
• Photoproduction of ${\Theta }^{+}$ and other pentaquark states
• Pentaquark state in pole-dominated QCD sum rules
• Even Parity $\Theta$-Pentaquark and Stable Strange Nuclear Matter
• A Phenomenological Lagrangian Approach to Two Kaon Photoproduction and Pentaquark Searches
• Axial vector tetraquark with S=+2
• Theta+ formation in inclusive gamma D -> pK- X
• An Experimental Review of the ${\Theta }^{+}$ Pentaquark
• Investigating the parity of the exotic Theta^+ baryon from the kaon photoproduction
• Search for the pentaquark candidate ${\Theta }^{+}$(1540) in the hyperon beam experiment WA89
• Spin-3/2 pentaquark in the QCD sum rule
• Search for ${\Theta }^{++}$ Pentaquarks in the Exclusive Reaction $\gamma p\to K^{+}{K}^{-}p$
• Photoproduction of the Theta^+ resonance on the nucleon in a Regge model
• Further study on 5q configuration states in the chiral SU(3) quark model
• ${\Theta }^{+}$ hypernuclei in relativistic mean field model
• Decay constants of the pseudoscalar charmonium and bottomonium
• Pentaquark baryon production from photon-neuteron reactions
• Search for the Charmed Pentaquark Candidate Theta_c(3100) in e+e- Annihilations at sqrt(s)=10.58 GeV
• High Energy Photoproduction
• Spin asymmetries in gamma + N --> K*bar + Theta^+
• Comparative Regge analysis of $\Lambda ,{\Sigma }^0,\Lambda (1520)$ and ${\Theta }^{+}$ production in $\gamma p$, $\pi p$ and $pp$ reactions
• Search for Exotic Baryons in 800 GeV pp (rtarrow) pXiPiX
• Soft-core meson-baryon interactions. II. $\pi N$ and $K^{+}N$ scattering
• A possibility to determine the P-parity of the ${\Theta }^{+}$ pentaquark in the $pn\to {\Lambda }^0{\Theta }^{+}$ reaction
• Production of Theta+ in gamma + D -> Lambda + Theta+ and gamma + D -> Sigma + Theta+ reactions
• Photoproduction of pentaquark cascades from nucleons
• Search for Higher Flavor Multiplets in Partial Wave Analyses
• Understanding penta quark with various quark models
• Resonances, and mechanisms of Theta-production
• Pentaquarks in a relativistic quark model and nature of Theta-states
• Effects of Instanton Induced Interaction on the Pentaquarks
• Magnetic moment of the pentaquark ${\Theta }^{+}(1540)$ with QCD sum rules
• Magnetic moment of the pentaquark ${\Theta }^{+}(1540)$ with light-cone QCD sum rules
• Absence of evidence for pentaquarks on the lattice
• Recent Results on Searches for Pentaquark States from STAR at RHIC
• Heavy Quark Analogues of the Theta and Their Excitations
• Some aspects of ${\Theta }^{+}$ parity determination in the reaction $\gamma N\to {\Theta }^{+}\bar{K}\to NK\bar{K}$
• Chiral perturbation theory for pentaquark baryons and its applications
• Variational Monte Carlo study of pentaquark states
• Regge Trajectories of Exotic Hadrons in the Flux Tube Model
• Production of Pentaquark States in pp Collisions within the Microcanonical Ensemble
• K+N scattering data and exotic Z+ resonances
• Mixing of Pentaquark and Molecular States
• Flavored exotic multibaryons and hypernuclei in topological soliton models
• Search for Exotic S=-2 Baryons in proton-antiproton Collisions at sqrt(s) = 1.96 TeV
• Phenomenological constraints on the Jaffe-Wilczek model of pentaquarks
• Photoproduction of Pentaquark in Feynman and Regge Theories
• Experimental Outlook for the Pentaquark
• Search for the exotic ${\Theta }^{+}$ resonance in the NOMAD experiment
• Theta++ from QCD sum rule
• Pentaquarks in the Chiral Symmetry Limit
• The Experimental Search for Pentaquark
• Kaon-Soliton Bound State Approach to the Pentaquark States
• A Selection Rule for Multiquark Decays
• Search for Pentaquarks in the Hadronic Decays of the Z Boson with the DELPHI Detector at LEP
• Relativistic five-quark equations and u, d- pentaquark spectroscopy
• Parity of Anti-Decuplet Baryons Revisited from Chiral Soliton Models
• Stable Pentaquarks from Strange Chiral Multiplets
• The Chiral Soliton Model for Arbitrary Colors and Flavors
• Polarization Observables in $\gamma N\to K\bar{K}N$
• Physics at ELSA, achievements and future
• Search for a Theta++ Pentaquark State
• Possibility of determinig the parity of the pentaquark ${\Theta }^{+}$ from photoproduction near threshold
• Calculating loops without loop calculations: NLO computation of pentaquark correlators
• Positive parity pentaquark towers in large Nc QCD
• SU(6), Triquark states, and the pentaquark
• The 35-plet Baryons from Chiral Soliton Models
• Relativistic five-quark equations and negative parity pentaquarks
• What Can we Learn about $\Theta$ Baryon from Unified Picture for Hadron Spectra
• Structure and reactions of pentaquark baryons
• Principles for a unified picture of fermions
• Tetraquark and Pentaquark Systems in Lattice QCD
• Relativistic five-quark equations and exotic baryons with isospin I=5/2
• Magnetic moments of S-shell pentaquarks in the constituent quark model
• Quarkonia & Pentaquarks
• The SELEX Measurements in the Unified Picture for Hadron Spectra
• Structure and decay width of Θ^+ in a one-gluon exchange model
• Some (further) Comments on the Theta(1540) Pentaquark
• Beyond CP violation: hadronic physics at BaBar
• Photoproduction of Pentaquark ${\Theta }^{+}$ and Chiral Symmetry Restoration in Hot and Dense Medium
• Search for exotic baryons in double radiative capture on pionic hydrogen
• The pentaquark ${\Theta }^{+}(1540)$ in the string model
• Antikaon angular distributions in the reaction $\gamma d\to K^{-}{\Theta }^{+}p\to K^{-}{K}^{+}np$ near the threshold and the parity of the ${\Theta }^{+}$ pentaquark
• In-medium Properties of ${\Theta }^{+}$ as a K$\pi$N structure in Relativistic Mean Field Theory
• Pentaquark Masses in Chiral Perturbation Theory
• Effective mass and decay of ${\Theta }^{+}$ in nuclear matter in quark-meson coupling model
• Effect of Chiral Symmetry Restoration on Pentaquark ${\Theta }^{+}$ Mass and Width at Finite Temperature and Density
• Spin correlations in the reaction "pi \vec D --> \vecΣΘ^+" and the parity of Theta^+
• Reanalysis the pentaquark ${\Theta }^{+}(1540)$ in the framework of QCD sum rules approach with direct instantons
• $P$-parity of charm and strange particles in electroproduction processes, in collinear regime
• Constraints on narrow exotic states from K+p and K0_Lp scattering data
• Decay Probability Ratio of Pentaquark Theta^+ State
• Relativistic Calculation of the Width of the Theta (1540) Pentaquark
• Pentaquarks in the medium in the quark-meson coupling model
• Low-lying $s=+1$ Pentaquark states in the Inherent Nodal Structure Analysis
• Diquarks and pentaquark nature
• Review of Recent Jlab Results
• Heavy Pentaquarks in the Diquark Model and the Large N_c Expansion
• Representation Mixing and Exotic Baryons in the Skyrme Model
• Magnetic Moment of the Pentaquark THETA+ State
• Kinematic selection criteria in a new resonance searches: Application to pentaquark states
• Theta^+ baryon production from gamma N and NN scattering
• Chiral Soliton Model vs Pentaquark Structure for Θ(1540)
• The Skyrme Model Revisited: An Effective Theory Approach and Application to the Pentaquarks
• The Nucleon and Delta Baryons in the Unified Picture for Hadron Spectra
• Angular distribution and azimuthal asymmetry for pentaquark production in proton-proton collisions
• Width of Theta - pentaquarks in relativistic quark model