It has recently been shown that data from 10 GeV/c to 1500 GeV/c lab momenta for the inclusive reactions p p -+ cX (c = v ' , K ', p , 7 ) are consistent with scaling in terms of x , (-2 E / v X ) and P , . In this note, we discuss some elementary consequences of this observation. A straightforward extension of the above scaling property to the semi-inclusive distributions is suggested.It i s now well known that Feynman scaling' of of this l a t e r . ) In Eq. 2, F ( P T 2 + 9 , " i s a universal the inclusive single-particle distributions in hadfunction, the dependence on c coming only through ronic collisions i s badly violated in the central the adjustable p a r a m e t e r $,2 ( s e e Ref. 10): region.? F o r instance, the invariant c r o s s section a , -4 for n ', no 5 for K --7 for 5 for the p r o c e s s pp-$i a t ,\ ( -2 p , , / f i ) fixed and s m a l l r i s e s by almost a n o r d e r of magnitude beetc. , tween plrb"20 GeV/c and ISR Recentwith F(PTL +ac') = (PT%+c2)-4.5 and ly, there have been discussions of scaling in t e r m s of the so-called radial variable5-' fiC2 = 0.86 for n It is remarkable that data from 10 GeV c to 1500 GeV/c lab momenta f o r pp-cX (c = n ' , K 5 , p , p ) a r e consistent with scaling in t e r m s of r, and P,, i.e., d3u rFp/E '~c ( * R 9 P~) 9 ,IR, PT fixed with no explicit dependence on v ' : , the total energy in the center-of-mass system. Clearly, a t extremely high energies w, 2 x and the two f o r m s of scaling a r e identical. Also, if we have early scaling in .xR, the energy a t which Feynman scaling s e t s in is dependent on the t r a n sv e r s e m a s s [= (P,? + n~~~) "~] , namely, the higher the t r a n s v e r s e m a s s of the observed particle, the higher the Feynman scaling energy. Since .I and x, differ most f o r s m a l l x, the deviation from Feynman scaling i s most conspicuous in the cent r a l region, while the limiting behavior in the fragmentation region is attained a t relatively low energies. In Ref. 6 , it i s a s s e r t e d that the invariant c r o s s section f C ( s R , P,) factorizes in xR and P,: (Note, however, that the compilation of Yen7 does not support the factorization of .tc since the d i s t r ibutions in A-, a t low P , and high P, a r e definitely d i s s i m i l a r . W e will d i s c u s s a possible explanation = 1.04 for 6 e t c . We note the following: ( a ) The expression (2) i s formally s i m i l a r to the familiar triple Regge formula f o r singleparticle distributions with E ( 0 ) = 1, and the replacement Comparing (2a) wlth (2), we get n c = 1 -Zu,,,. The general h~e r a r c h y of Regge exchanges is reflected in the value of a,,, ( n~e s o n i c a,,, > baryonic a ,,, >exotic a , , , ) , although the values of a,,, s o obtained a r e too low. A s i m i l a r conclusion has been reached by Chen ct n l "(b) Owing to the factor ( 1 -x,)"~, the average value of the t r a n s v e r s e momentum, P T ) should increase slowly with incomlng energy q;, a trend supported by experiment." Quantitatively, however, the simple...
