YN scattering data: DO66
The experiment:
In the Saclay 81 cm Hydrogen Bubble Chamber which was exposed to a beam
of K- mesons from the Proton-Synchroton at CERN.
Reactions of the produced Σ particles were studied.
200000 pictures have been scanned.
446 Σ- p events and 66
Σ+ p
events were seen.
After applying cut-offs for small angle scattering ( < 14 degrees)
19 Σ+ p events and 59 Σ- p
events are analyzed.
Preliminary results are presented in DO65.
The data:
|
Σ- p → Σ- p
|
total elastic cross section (SGT)
|
|
|
momentum range number of SGT [mb]
[MeV/c] events
135 - 145 ) 207 +/- 85
145 - 155 ) 59 198 +/- 48
155 - 165 ) 189 +/- 32
|
|
|
differential cross section (DSG)
|
|
|
based on 130 events in the range 135 - 165 MeV/c
cos(theta) DSG [mb]
-0.4 - -0.2 90 +/- 20
-0.2 - 0.0 105 +/- 20
0.0 - 0.2 80 +/- 20
0.2 - 0.4 120 +/- 20
0.4 - 0.6 115 +/- 25
0.6 - 0.8 200 +/- 110
|
|
|
Σ+ p → Σ+ p
|
total elastic cross section (SGT)
|
|
|
momentum range number of SGT [mb]
[MeV/c] events
148 - 158 ) 203 +/- 117
158 - 168 ) 19 143 +/- 58
168 - 178 ) 89 +/- 28
|
|
|
differential cross section (DSG)
|
|
|
based on 30 events in the range 148 - 178 MeV/c
cos(theta) DSG [mb]
-0.4 - -0.2 40 +/- 20
-0.2 - 0.0 30 +/- 20
0.0 - 0.2 40 +/- 20
0.2 - 0.4 90 +/- 30
0.4 - 0.6 120 +/- 50
0.6 - 0.8 170 +/- 110
|
Notes:
-
The numbers for the differential cross sections were taken from
PDG (read from a graph).
-
The data are not corrected for Coulomb effects.
-
theta is the angle that the Λ particle makes with the
Σ- beam in the CM system.
-
Corrections are made for undetectable small angle scattering; an
isotropic angular distribution was assumed.
-
For the determination of the differential cross section
different cut-off criteria were used.
