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

The γp→p η ′ reaction was investigated with the 4 π magnetic spectrometer SAPHIR at ELSA with tagged photons in the energy range from 0.9 to 2.6 GeV. On the basis of six million hadronic events 250 events with five tracks due to the reaction chain γp→p η ′→p π + π − η→p π + π − π + π − π 0 were sele...

Full description

Saved in:

Bibliographic Details
Published in:	Physics letters. B Vol. 444; no. 3; pp. 555 - 562
Main Authors:	Plötzke, R, Barth, J, Braun, W, Burgwinkel, R, Ernst, J, Glander, K.H, Goers, S, Hannappel, J, Joepen, N, Jüngst, H.G, Kalinowsky, H, Kirch, U, Klein, F, Klein, F.-J, Klempt, E, Kozela, A, Lawall, R, Link, J, Menze, D, Neuerburg, W, Ostrick, M, Paganetti, M, Paul, E, van Pee, H, Schulday, I, Schwille, W.J, Smyrski, J, Thoma, U, Tiator, L, Tran, M.Q, Wehnes, F, Wiegers, B, Wieland, F.W, Wißkirchen, J
Format:	Journal Article
Language:	English
Published:	Elsevier B.V 24-12-1998
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	The γp→p η ′ reaction was investigated with the 4 π magnetic spectrometer SAPHIR at ELSA with tagged photons in the energy range from 0.9 to 2.6 GeV. On the basis of six million hadronic events 250 events with five tracks due to the reaction chain γp→p η ′→p π + π − η→p π + π − π + π − π 0 were selected. The strong rise of the cross section at threshold and its steep decrease with γ-energy indicate dominant resonance production. The linear forward rise of the η ′ CMS angular distribution is consistent with a coherent excitation of two resonances S 11 and P 11. Assuming dominance of resonance production, the following masses and widths are determined: S 11(M,Γ)=(1.897±0.050 +0.030 −0.002,0.396±0.155 +0.035 −0.045) GeV and P 11(M,Γ)=(1.986±0.026 +0.010 −0.030,0.296±0.100 +0.060 −0.010) GeV , where the first error is of statistical nature while the second represents the systematic error.
ISSN:	0370-2693 1873-2445
DOI:	10.1016/S0370-2693(98)01444-0