CHARMED MESON PRODUCTION AND DECAY

LBL-6723 CHAR)~D MESON PRODUCTION ~~D DECAY· James E. Wiss Lawrence Berkeley Laboratory University of California, Berkeley, California 94720 ABSTRACT We discuss charmed meson production through two body processes in e+e- annihilation. Evidence for states of charm exci tation beyond the D* is ob~ained through ~n analysi's of the' recoil ,spectrum agains,i: DiS produced at Ecm = 4,.415 GeV. Direct observation of the reaction [1.+.+ 11+0 0 in SPEAR data taken at Ecm exceeding.S GeV will then ~~ discussed. This reaction provides an ex- tremely accurate determination of the 0 +,0 0 mass dif- ference, '(~fO*+ - MOO .. = 145.3 :!: 0.5 MeV/c 2 ) and, a 'new upper limit on '0 0 _DO mix'ing' effect~~: The results of fits to the DO ,[)+ recoi!.vspecuum will then be discussed. These fits provide,considerabl e information on the'masses, pro- duction mechanisms. and decays of chaTDIed mesons. This will be followed by a brief presentati,?n of the kn~n cross 'sections for charmed, m'eson production and decay and an,!lnalysis of possible resonant structure in the decay products of:thePO and 0+. Lastly , we, discuss a bubh Ie chamber D0 candidate submitted br Hagopian eU at., of Florida State Uni versi tr,:...:::., PRESENTATIO:'oj OF' QlARf.1 SIGSALS ~fuch of this talk describes data from the SLAC-LBL coll:Jhora- tion's ,experiment on e+e- annihilation conducted at the Magnetic Detector at SPEAR. Fig. I shows a schematic of the Hagnetic Detec- tor. ~bruentuffi'measurement is afforded bY,system of two prop~rtional ,chambers and four wire spark, chambers which cover, the polar angl e region leosel ' f 0.35-ns over a flight path'of 1.5 to 2.0m. ',UnlesS: 'hthcndse stated, the data sample consists' of 29,000 'hadrciliic events (I. =1830 nb-1)-collectedin anon-uniform scan from 3.9·to'4.6 GeV,cellter-of..;mass energy '(Ecm) IAind :two high statistics, ,monoenergetic samples collected'at Hcm = 4.028 G('V and Ecm = 01.415 GeV of lumjnosity' L ,: 12BO nb- 1 and 1630 nb- 1 respectively. The sClln data was the data set in which charm was originally discov- ered. 1 Subs('lju('ut to that r('sUlt, the SLAC-LBI. collaboration *This work was dnne with support frulD the u.s. Eneq~y Research and Development Administration under th(' auspices of thl' Divisioll of I'hysical Research., DlSTRIRIITION OF THIS DCC ','-