1 / 1

Strangeness Production in p+A Interactions at 920 GeV.

p(p). V 0. Beam p. π ( K ). Ξ ( Ω ). A. π. Δ z / γ. 2. 2. p. p [GeV ]. HERA-B. K 0 S. 3414.6 +/- 2.3 k. t. √ s = 41.6GeV. V 0. -. π. Beam p. Beam 920 GeV/ c protons. Subdetectors used in the present study:. The HERA-B Experiment at DESY. A.

barid
Download Presentation

Strangeness Production in p+A Interactions at 920 GeV.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. p(p) V0 Beam p π(K) Ξ(Ω) A π Δz /γ 2 2 p p [GeV ] HERA-B K0S 3414.6 +/- 2.3 k t √s = 41.6GeV V0 - π Beam p Beam 920 GeV/c protons Subdetectors used in the present study: The HERA-B Experiment at DESY A Acceptance – 15-160(v) resp. 250(h) mrad + + Ξ Ξ and mostly at mid rapidity (xF -0.15 – +0.05) • Silicon vertex detector (SVD) • Tracker (OTR) • RICH High mass resolution spectrometer Δz /γ + Good particle identification Λ Λ Ω K0S 3.0 +/- 0.1 Λ 2.2 +/- 0.1 2.2 +/- 0.1 Ξ- 1.8 +/- 0.2 1.8 +/- 0.2 Ω- 1.7 +/- 0.6 Interactions at: : (GeV/c) 1.7 +/- 0.8 Carbon 76.6 106 Titanium 24.1 106 - HERA-B preliminary Tungsten 71.6 106 The particle ratios measured by the four RHIC collaborations, the statistical model and the HERA-B result (preliminary). K-π+ 410.9 ± 3.0 k K+K- 52.6 ± 0.4 k Strangeness Production in p+A Interactions at 920 GeV. for the HERA-B collaboration Presented by Marko Staric (Marko.Staric@ijs.si ) The Differential p2t spectra The spectra follow a simple exponential law up to nearly 1. GeV/c: Fit function: dσ /dpt2 ∞ (1+pt2/p02)-β valid for the whole pt2 range d σ / dp2t ∞ exp(-Bp2t) and becomes flatter at higher p2t. • Targets: • Feature : works in the beam halo σ • Advantage : different target materials may be used B • 1 kHz data acquisition rate. • Minimum bias trigger • 0.1 interaction per bunch crossing The V0 selection. B β : changes for K* from 3.8 to 4.7 forΦfrom 3.8 to4.2 for C:Ti:W targets <pt> : changes from0.64 to 0.73 for C:Ti:W targets and for all particles Experiment Thermal Model • A thermal model predicts an opposite curvature resp. to the • experimental curve. • The average <p2t> increases with the increase of the mass. Statistics (this analysis) : Λ 705.3 +/- 1.1 k 338.7 +/- 0.8 k Observation of Cronin effect. The particle ratios. Signal per Target - C : Ti : W - 1 : 0.4: 2.2 The Cascade Hyperons Selection. Statistics (this analysis): Ξ- 4778 ± 78 3098 ± 63 444 ± 35 Ω- + 378 ± 27 Ω Signal per Target - C :Ti : W - 1 : 0.3 : 1.9 For each bin, the spectra were fit to the formula: dσpA /dp2t = Aα dσpp /dp2t Statistics (final): The spectra are enhanced at high p2t may be due to multiple scattering inside the nucleus may be ….. K+π- 533.2 ± 3.2 k Signal per Target: C : Ti : W 1. : 0.4 : 1.4 We observed: , for all measured p t , for all measured p t Signal per Target: C : Ti : W 1. : 0.5 : 1.7

More Related