First results for the two-spin parameter ALL in π0 production by 200 GeV polarized protons and antiprotons

D. L. Adams, N. Akchurin, N. I. Belikov, J. Bystricky, P. Chaumette, M. D. Corcoran, J. D. Cossairt, J. Cranshaw, J. Deregel, A. A. Derevschikov, G. Durand, H. En'yo, J. Fabre, K. Fukuda, H. Funahashi, Y. Goto, O. A. Grachov, D. P. Grosnick, D. A. Hill, K. ImaiY. Itow, K. Iwatani, T. Kasprzyk, K. W. Krueger, K. Kuroda, M. Laghai, F. Lehar, A. de Lesquen, D. Lopiano, F. C. Luehring, T. Maki, S. Makino, A. Masaike, Yu A. Matulenko, A. P. Meschanin, A. Michalowicz, D. H. Miller, K. Miyake, T. Nagamine, F. Nessi-Tedaldi, M. Nessi, C. Nguyen, S. B. Nurushev, Y. Ohashi, Y. Onel, D. I. Patalakha, G. Pauletta, A. Penzo, A. L. Read, J. B. Roberts, L. van Rossum, V. L. Rykov, N. Saito, G. Salvato, P. Schiavon, J. Shepard, J. Skeens, V. L. Solovyanov, H. Spinka, R. Takashima, F. Takeutchi, N. Tamura, N. Tanaka, D. G. Underwood, A. N. Vasiliev, A. Villari, J. L. White, S. Yamashita, A. Yokosawa, T. Yoshida, A. Zanetti

Research output: Contribution to journalArticlepeer-review

40 Scopus citations


The two-spin parameter ALL in inclusive π0 productionby longitudinally-polarized protons and antiprotons on a longitudinally-polarized proton target has been measured at the 200 GeV Fermilab spin physics facility, for π0's at xF=0 with 1≤pt≤3 GeV/c. The results exclude, at the 95% confidence level, values of ALL (pp) > 0.1 and < - 0.1 for π0's produced by protons, and values of ALL (pp) > 0.1 and < -0.2 for incident antiprotons. The relevance of ALL (pp) for the gluon spin density is discussed. The data are in good agreement with "conventional", small or zero, gluon polarization.

Original languageEnglish
Pages (from-to)197-200
Number of pages4
JournalPhysics Letters B
Issue number1-2
StatePublished - May 23 1991


Dive into the research topics of 'First results for the two-spin parameter ALL in π0 production by 200 GeV polarized protons and antiprotons'. Together they form a unique fingerprint.

Cite this