The positive-strangeness baryon resonance Θ+ is observed in photoproduction of the nK+K0s final state with the SAPHIR detector at the Bonn ELectron Stretcher Accelerator ELSA. It is seen as a peak in the nK+ invariant mass distribution with a 4.8σ confidence level. We find a mass MΘ+=1540±4±2 MeV and an upper limit of the width ΓΘ+<25 MeV at 90% c.l. The photoproduction cross section for K0Θ+ is in the order of 300 nb. From the absence of a signal in the pK+ invariant mass distribution in γp→pK+K− at the expected strength we conclude that the Θ+ must be isoscalar.

Pentaquark

Isoscalar

Invariant mass

10.1016/j.physletb.2003.08.019

Cite

Citations (297)

Low-energy photoproduction of $\omega$ -mesons

The European Physical Journal A (2003)

J. Barth Wolfgang Braun J. Ernst K.-H. Glander J. Hannappel

Helicity

10.1140/epja/i2003-10061-y

Cite

Citations (78)

Erratum to: Study of the reaction gammap --> K+Lambda(1520) at photon energies up to 2.65 GeV

F. W. Wieland J. Barth K.-H. Glander J. Hannappel N. Jöpen

Source

Cite

Citations (0)

Photoproduction of η′-mesons with the 4π-detector SAPHIR

Physics Letters B (1998)

R. Plötzke J. Barth Wolfgang Braun R. Burgwinkel J. Ernst

Photon energy

Vector meson dominance

10.1016/s0370-2693(98)01444-0

Cite

Citations (63)

Table 5 ; Measurement of the reaction $γ p \to K^ + Λ(1520)$ at photon energies up to 2.65 GeV

F. W. Wieland J. Barth K.-H. Glander J. Hannappel N. Jöpen

Table (database)

Source

Cite

Citations (0)

First results on η′ photoproduction with SAPHIR

Nuclear Physics A (1998)

J. Ernst H. Jüngst H. Kalinowsky E. Klempt J. M. Link

10.1016/s0375-9474(98)00276-0

Cite

Citations (0)

Measurement of the reaction γp → K0Σat photon energies up to 2.6 GeV⋆

The European Physical Journal A (2005)

R. Lawall J. Barth C. Bennhold K.-H. Glander S. Goers

Isobar

Photon energy

10.1140/epja/i2005-10002-x

Cite

Citations (92)

Strangeness photoproduction with the SAPHIR detector

J. Barth M. Bockhorst Wolfgang Braun R. Burgwinkel K.-H. Glander

Statistically improved data of total cross sections and of angular distributions for differential cross sections and hyperon recoil polarizations of the reactions γp→K+Λ and γp→K+Σ0 have been collected with the SAPHIR detector at photon energies between threshold and 2.0 GeV. Here total cross section data up to 1.5 GeV are presented. The opposite sign of Λ and Σ polarization and the change of sign between forward and backward direction could be confirmed by higher statistics. A steep threshold behaviour of the K+Λ total cross section is observed.

10.1063/1.54376

Cite

Citations (0)

New results on η and η′ photoproduction with SAPHIR at ELSA

Nuclear Physics A (2001)

J. Barth C. Bennhold Wolfgang Braun J. Ernst K.-H. Glander

10.1016/s0375-9474(01)01059-4

Cite

Citations (5)