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Title: A study of. iota. (. eta. (1440)) and E (f sub 1 (1420)) production in two-photon reaction

Miscellaneous ·
OSTI ID:5261731

A study of {iota} ({eta}(1,440)) production in untagged and E (f{sub 1}(1,420)) production in single-tagged two-photon reactions was performed at PEP with colliding e{sup +}e{sup {minus}} beam energies of 14.5 GeV. By observing the reaction {gamma}{gamma} {yields} K{sub s}{sup 0}K{sup {plus minus}}{pi}{sup {minus plus}}, a 95% confidence level limit of {Gamma}{sub {iota}{yields}{gamma}{gamma}}B ({iota} {yields} K{bar K}{pi}) < 1.6 keV for the {iota} meson has been obtained. If the {iota} decays predominantly into K{bar K}{pi}, the resulting {Gamma}{sub {iota}{yields}{gamma}{gamma}} limit appears to conflict with previous assignments of an observed {rho}{gamma} decay to {iota} and also with many analyses of {eta}-{eta}{prime}-{iota} mixing. The contrast of this small {gamma}{gamma} width with the large rate for J/{psi} {yields} {gamma}{iota} provides evidence that {iota} is a glueball with little admixture of q{bar q} states. The observation of the E meson is the first observation of a spin-1 state in two-photon collisions. The final state of the E was identified by detecting K{sup s}{sup 0}K{sup {plus minus}}{pi}{sup {minus plus}} in single-tagged production where one of the photons was quite virtual. The measured mass of the E meson is 1426{sub {minus}7}{sup +11} MeV, the total width is 16{sub {minus}15}{sup +25} MeV, and the E mainly decays through a K{sup {asterisk}}K intermediate state. Production of a spin-1 meson, which cannot be made by two real photons, would fit the observation of the E. The Q{sup 2} dependence of the data in the E mass region agrees with a spin-1 assignment and is incompatible with a spin-O hypothesis. The distributions in energies and angles of the decay particles of E favor positive parity.

Research Organization:
Cambridge City Hospital, MA (United States)
OSTI ID:
5261731
Resource Relation:
Other Information: Thesis (Ph.D.)
Country of Publication:
United States
Language:
English