Comments on “the OZI rule does not apply to baryons”

Volume 234, number 1,2 PHYSICS LETTERS B 4 January 1990

C O M M E N T S O N " T H E O Z I R U L E D O E S N O T A P P L Y T O B A R Y O N S " ~r

S.J. L I N D E N B A U M ~,b and R.S. L O N G A C R E ~

Brookhaven National Laboratory, Upton, NY 11973, USA b City CoLlege, City University o f New York, New York, NY 10031, USA

Received 19 September 1989; revised manuscript received 23 October 1989

We demonstrate that the arguments made by Ellis, Gabathuler and Karliner that meson-baryon couplings could evade the OZI rule are irrelevant to the arguments we have made before. This is so since even if we assume that meson-baryon couplings can violate OZI, we clearly demonstrate that the coupling involved in our r~-p-,g)gm is r~n-~g)9 which does not involve meson-baryon couplings. Thus our arguments that the gr (2010), gr' (2300) and gT" (2340) are naturally explained in the context of QCD by the hypothesis that one to three glueballs are produced in the intermediate state are not affected by arguments made by Ellis et al.

In ref. [ 1 ] the au thors go th rough a n u m b e r o f ar-

gumen t s to conc lude that the O Z l rule does not apply

to baryons , and thus conc lude tha t the O Z I rule can

be e v a d e d for m e s o n - b a r y o n coupl ings .

They then state at the end o f the i r pape r as follows:

" W e conc lude this pape r with a few c o m m e n t s on

g l u o n i u m searches in processes wi th inc iden t bar-

yons. T h e fact that m e s o n coupl ings to ba ryons vio-

late the OZI rule m e a n s tha t the obse rva t i on o f a res-

onance in an O Z I f o r b i d d e n channe l does no t

necessar i ly m e a n that it is a g l u o n i u m state. It could

be an exci ted s~ state. This cau t ion appl ies in par t ic -

ular to the ~)O resonances repor ted in ref. [ 52 }." The i r

ref. [52] is refs. [ 2 - 4 ] o f this c o m m e n t .

In ref. [3] we s ta ted on p. 218: " P i o n exchange re-

ac t ions are cha rac t e r i zed by hav ing only M r = J~ = 0 -

waves present and a t ' - d e p e n d e n c e o f d a / d t ' ~ e x p ( - 10I t ' I ). Thus we conc lude the p roduc t i on o f

09 p roceeds via ~ -exchange . "

In ref. [4] ~ we clear ly state (see p. 570 o f ref.

[ 5 ] ): Fig. 3 shows const . X d~r/dt' p lo t t ed versus I t ' I

for I t ' l < 0 . 3 it is well fit by d a / d t ' = c o n s t . ×

( -9 .50__+0.10) [ t ' l co r r e spond ing to rt-exchange.

Since M ' I = 0 - for all th ree waves it is c lear that the

gv, g~-,, gT" are p roduced by rt-exchange for I t ' l < 0 . 3 . "

This work has been performed under Contract No. DE-AC02- 76CH00016 with the US Department of Energy.

~ Ref. [4 ] has been published as ref. [ 5 I.

A p p r o x i m a t e l y 95% o f our ~)~ da ta is inc luded in the

region I t ' l< 0.3. Wi th in errors all o f our gT, gv', gT"

p r o d u c t i o n is v ia p ion exchange.

Thus as shows in fig. 1 we are clearly p roduc ing the

Q0 via re-exchange at the upper ver tex rc+rc--~0Q

which does not invo lve m e s o n - b a r y o n couplings.

T h e r e f o r e even i f we were to accept the conc lus ion o f

the au thors o f ref. [ 1 ] that m e s o n - b a r y o n coupl ings

can v io la te the O Z I rule, the i r s t a t emen t ( o u r second

pa rag raph ) which effect ively cau t ions us that this

could expla in our obse rved O Z I rule b reakdown is

incorrect . This is so since we are deal ing with a ~rt-~ 99

.... < u

P ) , u . > u n

>d >0

Fig. 1. The Jet=2++ glueball intermediate state in n-p-~O*n. The region of crosshatched lines within the dash-dotted lines in- dicates that we do not know the details of the glueball hadroni- zation into 00- (Fig. 3b ofref. [7]. ).

0370-2693/90/$ 03.50 © Elsevier Science Publishers B.V. ( North-Holland ) 163

Volume 234, number 1,2 PHYSICS LETTERS B 4 January 1990

ve r t ex w h i c h does n o t i n v o l v e m e s o n - b a r y o n

coupl ings . T h u s o u r g lueba l l a r g u m e n t s a n d c o n c l u s i o n s [6 ]

are no t a f f ec t ed by the a r g u m e n t s o f ref. [ 1 ].

References

[ 1 ] J. Ellis, E. Gabathuler and M. Karliner, Phys. Lett. B 217 (1989) 173.

[2] A. Etkin et al., Phys. Rev. Lett. 49 (1982) 1620. [ 3 ] A. Etkin et al., Phys. Lett. B 165 ( 1985 ) 217. [4] A. Etkin et al., Brookhaven preprint BNL 4-716 (December

1987).

[5] A. Etkin et al., Phys. Len. B 201 (1988) 568. [ 6 ] S.J. Lindenbaum and R.S. Longacre, Phys. Lett. B 165 ( 1985 )

2O2; S.J. Lindenbaum, The observation and phenomenology of glueballs, in: Superstrings, supergravity and unified theories, The ICTP Series in Theoretical Physics, Vol. 2 (Trieste, Italy, 1985) pp. 548-593; Glueballs in 2 ++ Q~ final states, in: Proc. BNL Workshop on Glueballs, hybrids, and exotic hadrons (Brookhaven National Laboratory, Upton, NY, August- September 1988), ed. S.U. Chung, American Institute of Physics Conference Proc. No. 185 (AIP, New York) pp. 68- 87.

[7] S.J. Lindenbaum, in: Proc. Second Aspen Winter Particle physics Conf., Vol. 490, Annals of the New York Academy of Sciences (New York, 1986) p. 61.

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