Volume 149B, number 4,5 PHYSICS LETTERS 20 December 1984 COMMENTS ON THE REACTION rr-p ~ ~b~bnAND GLUEBALLS SJ. LINDENBAUM Brookhaven National Laboratory, Upton, NY, USA and City College of New York, New York, NY, USA and Harry J. LIPKIN Welzmann Institute of Science, Rehovot, Israel Received 4 October 1984 The authors have differed [1,2] as to the interpretation of the observations made in ref. [3] of the reaction lr-p ~ q~n. After personal discussions we have been able to agree on several relevant points. The purpose of this short comment is to present those areas of agreement which are most relevant to the interpretation of the experimental results in lr-p -~¢¢n [3,4]. We agree that: (1) The observation of the reaction of rr-p -->COn is not in itself a sufficient indication for a new type of particle. If the ~ hasJ PC = 0 -+ for example, it could be a radially excited r/or 77' which is produced via the ufi component and decays via the s-~ component. (2) Since the ~ system has been shown [3,4] to be in well-defmed resonances with quantum numbers jPC = 2 ++, this constitutes strong evidence for a new kind of particle (i.e. a gluebaU) which is not a simple quark-antiquark pair. The known tensor mesons f and f' are ideally mixed and it is highly unlikely that higher 2 ++ states would mix like the 77 and r~' especi- ally since there is no known mechanism for such mixing (except a glueball). Ref. [4] gives the arguments, by one of the authors, for the conclusion that these three jPC = 2++ states are produced by 1-3 primary gluebaUs. Ref. [1] gives arguments, by one of the authors, questioning the degree of OZI forbiddenness of the reaction 7r-p ~ ~Cn in the case where there is no re- sonance observed in the q~ system. This case is not relevant to the present discussion because of point 2 above. References [1] H.J. Lipkin, Phys. Lett. 124B (1983) 509; Nucl. Phys. B224 (1984) 147. [2] SJ. Lindenbaum, Phys. Lett. 131B (1983) 221. [3] K. Etkin et al., Phys. Rev. Lett. 49 (1982) 1620. [4] SJ. Lindenbaum, Production of glueballs. Comm. Nucl. Part. Phys. 13, No. 6, to be published. 0370-2693/84/$ 03.00 © Elsevier Science Publishers B.V. (North-Holland Physics Publishing Division) 407

Comments on the reaction π−p→φφn and glueballs

Download PDF Report

Upload
sj-lindenbaum
View
214
Download
0

Embed Size (px)

Citation preview

Page 1: Comments on the reaction π−p→φφn and glueballs

Volume 149B, number 4,5 PHYSICS LETTERS 20 December 1984

COMMENTS ON THE REACTION rr-p ~ ~b~bn AND GLUEBALLS

SJ . LINDENBAUM Brookhaven National Laboratory, Upton, NY, USA and City College o f New York, New York, NY, USA

and

Harry J. LIPKIN Welzmann Institute o f Science, Rehovot, Israel

Received 4 October 1984

The authors have differed [1,2] as to the interpretation of the observations made in ref. [3] o f the reaction l r -p ~ q~n. After personal discussions we have been able to agree on several relevant points. The purpose o f this short comment is to present those areas o f agreement which are most relevant to the interpretation o f the experimental results in l r -p -~¢¢n [3,4].

We agree that: (1) The observation o f the reaction o f rr-p --> COn

is not in itself a sufficient indication for a new type o f particle. I f the ~ h a s J PC = 0 - + for example, it could be a radially excited r /or 77' which is produced via the ufi component and decays via the s-~ component.

(2) Since the ~ system has been shown [3,4] to be in well-defmed resonances with quantum numbers jPC = 2 ++, this constitutes strong evidence for a new kind of particle (i.e. a gluebaU) which is not a simple quark-ant iquark pair. The known tensor mesons f and f ' are ideally mixed and it is highly unlikely that

higher 2 ++ states would mix like the 77 and r~' especi- ally since there is no known mechanism for such mixing (except a glueball).

Ref. [4] gives the arguments, by one of the authors, for the conclusion that these three jPC = 2++ states are produced by 1 -3 primary gluebaUs.

Ref. [1] gives arguments, by one of the authors, questioning the degree o f OZI forbiddenness o f the reaction 7r-p ~ ~Cn in the case where there is no re- sonance observed in the q~ system. This case is not relevant to the present discussion because o f point 2 above.

References

[1] H.J. Lipkin, Phys. Lett. 124B (1983) 509; Nucl. Phys. B224 (1984) 147.

[2] SJ. Lindenbaum, Phys. Lett. 131B (1983) 221. [3] K. Etkin et al., Phys. Rev. Lett. 49 (1982) 1620. [4] SJ. Lindenbaum, Production of glueballs. Comm. Nucl.

Part. Phys. 13, No. 6, to be published.

0370-2693/84/$ 03.00 © Elsevier Science Publishers B.V. (North-Holland Physics Publishing Division)

407