arXiv subjects

Joachim Spengler

Publications and source records attributed to Joachim Spengler.

2 recordsLinked to original sources

arXiv2005

Search for Pentaquarks with HERA-B

A large data set of proton-nucleus collisions at sqrt(s) =41.6 GeV has been searched for Theta+ and Xi(1862) pentaquark candidates. In 2x10**8 inelastic events we find no evidence for narrow signals (sigma=5 MeV/c**2) in the Theta+ --> pK0s and Xi--(1862) --> Xi- pi- channels. Upper limits on production cross sections at mid-rapidity and on ratios of production cross sections to those of well established resonances are presented.

hep-ex↗

arXiv2004

Quarkonia production with the Hera-B experiment

Measurements of the dependence of the J/Psi production cross section on its kinematic variables as well as on the target atomic numbers for 920 GeV/c protons incident on different targets have been made with the Hera-B detector. The large collected di-lepton sample allows to study the production ratio of Psi(2S) to J/Psi and of Chic to J/Psi . We also report on measurements of the b-bbar and Upsilon production cross section.

hep-ex↗