A measurement of $K^{*\pm}$ production in the hyperon beam experiment at CERN

Abstract

We report on a measurement of the differential cross sections of inclusive K ± 890 production in Σ − , π − and neutron beams. A strong leading particle effect was observed for K − 890 production by Σ − . The measured xF -distributions are compared with calculations based on the Lund model (PYTHIA) and the quark-gluon string model. a Supported by Deutsche Forschungsgemeinschaft, contract number DFG 436 RUS 113/465/0-2(R), and Russian Foundation for Basic Research under contract number RFFI 00-02-04018 b Now at TRIUMF,

production in 350 GeV/c π−-N interactions

“…The value we obtain for the ratio of the D cross-section to the D + cross-section is 0 (D )= 0 (D + ) = 1.300.12, showing a relative enhancement o f D production at positive x F . Our value is in good agreement with measurements from WA82 [13] and E769 [14], and is very similar to values found for (D )=(D + ) [2,8,13] (Table 3). The Lund event generator predicts enhanced production of D and D at positive x F , but overestimates the eect by about a factor of 1.7.…”

“…9). An increase of asymmetry with x F is predicted by the Lund event generator and is observed in the case of D and D + [2,13,19,20]. Given the relatively large experimental uncertainties, compatibility b e t w een D =D + asymmetry and D =D + asymmetry is not quite excluded ( As a function of x F and P t 2 , Asym(D ; D ) is also fairly at, with a mean value close to zero (Fig.…”

A study of fluctuations of voids in relativistic ion–ion collisions

“…15,19 The tracks of the secondary particles were identified on the basis of their ionization. 15,16,20 The tracks having ionization, I < 1.4I 0 , where I 0 is the minimum ionization produced by a singly charged relativistic particle, are known as the shower tracks. The tracks having ionization in the range, 1.4I 0 ≤ I ≤ 10I 0 are referred to as grey tracks, whereas those having ionization I > 10I 0 are termed as black tracks.…”

“…[15][16][17][18][19][20] The events lying within 2-5 cm from the edge of the pellicle were considered for various measurements. 15,19 The tracks of the secondary particles were identified on the basis of their ionization. 15,16,20 The tracks having ionization, I < 1.4I 0 , where I 0 is the minimum ionization produced by a singly charged relativistic particle, are known as the shower tracks.…”

“…[15][16][17][18] The events were searched for by along-the-track scanning method, which gives a relative minimum bias sample because of its inherent high detection efficiency. [15][16][17][18][19][20] The events lying within 2-5 cm from the edge of the pellicle were considered for various measurements. 15,19 The tracks of the secondary particles were identified on the basis of their ionization.…”