Data obtained from emulsion plates exposed to a 24-GeV/c proton beam are presented in a manner suitable for observation from all Lorentz frames, following an idea presented in a recent paper by Biswas. The convenience of such a plot is discussed.In recent years a great deal of activity in nuclear emulsion techniques has involved the study of highenergy events.' Analysis of secondary emission from the nucleon-nucleon and nucleon-nucleus interactions in emulsion has proved t o be a quite successful method for determining the underlying mechanism. Several processes for the secondary production, e.g. pionization, fragmentation2 (both target and projectile fragmentation), pulverization, etc. have been suggested to be effective depending upon the magnitude of the longitudinal and transverse momenta of the particle produced. It i s necessary to view the secondary particles in a number of reference frames. F o r viewing particles lying in some specific region of p and p , (respectively denoting the longitudinal and transverse momenta of a secondary), one i s compelled to go from one Lorentz frame to the other, so that a simultaneous study in both frames of reference becomes impossible. In our present report we apply the idea presented in Ref.3 using data f r o m interactions of a 24-GeV/c proton beam in emulsion.The pellicles of nuclear emulsion used f o r m a stack consisting of 24 plates of Nikfi-R type and a r e 10 c m x 10 cmx400 pm in size. This stack was exposed to a 24-GeV/c proton beam of the CERN proton synchrotron. The scanning of the nuclear emulsion plates was performed on a Leitz-Wetzler microscope provided with a Brower traveling ~t a g e .~* P l a t e s were scanned using an oil-immersion 53.1 x objective in conjunction with a 16.8xocular. All events were scanned by the "along-the-track" method. A sample of 220 events, which were clear (having no blob at the point of production), was selected for analysis. To ensure the best approximation for a nucleon-nucleon collision, the events with iV,s 3 and 92,s 18 were taken. All the secondary tracks with a grain density g* : 1.4gmln were taken a s pions. In practice the momentum of the secondaries was determined from the individual range measurement of the tracks. Space angles of these were also observed in the laboratory system. The system was then transformed to the center-of-mass frame, so t h a t p * and E * (the c.m. longitudinal momentum and the c.m. energy of secondary pions) were computed.Let us denote the center-of-mass momentum of the beam and the target, respectively, of mass y and M, to b e p and -p with energies E, and E,, Also denote the energy and longitudinal momentum of a secondary in the c.m. frame by E* a n d p t .Furthermore, p ,(p) a n d p ( t ) a r e respectively the longitudinal momenta in the projectile and target rest frame. Now, so that a relation independent of the transverse momenta of the secondaries. Also from (1) one can obtain contours of constant p: in the ~p , , ( p ) and ~Wp,,(t) plane. These two sets of lines divide the whole re...
