Search for X(3872)      J/  S.K. Choi & S.L. Olsen Properties of X(3872)

Motivation For C=+1, X(3872)      J/  is all via       expect no      since        is forbidden For C=-1, X(3872)      J/  has     expect X       J/   ½      J/  (by ispin)  seeing or not seeing      can determine C

Selection Standard J/   l + l  cuts p 3 (  0 ) >0.15 GeV;  2 (   )<6 (both   s) |M bc -5.28|<0.009 or -0.06<  E<0.03 GeV M(     ) > M(     J/  ) –M(J/  ) –0.2 GeV Mult. entr: Min(  2 =(M  -M  ) 2 /  2 +  E 2 /  2 )

M(  ) cut     J/      J/  M(     ) M(     ) M(     l  l  )-M(l  l  ) (apply same p momentum & M(pp) cuts to     sample)

 ’      J/  signal N ev = 55.4 ±10.2 events M bc

 ’      J/  signal N ev = 742 ± 28 events M bc

X(3872)      J/  signal M bc N ev = 62.6 ±8.3 events

N ev = 0.2 ±2.6 events (< 4.4 evts 90% CL) M bc X(3872)      J/  signal? No signal!!

Br(X      J/  ) limit determination Br(X       J/  ) Br(X      J/  ) = N ev (X       J/  ) N ev (  ’      J/  ) N ev (X       J/  ) N ev (  ’       J/  )  Br(  ’      J/  ) Br(  ’      J/  )  (  ’      J/  )  (X       J/  )  (  ’       J/  )  (X       J/  ) ~1 ± 0.1  < 1.3 Br(  ’      J/  ) Br(  ’      J/  )  reduce by 1 

    J/  summary no sign of X      J/  but sensitivity is still not enough to distinguish between C = + 1 or -1

Other items for BC-0439 shown at previous BGMs & in public Limit on X    c2 Angular dist compared with 1  expectations Limit on X   J/ 

Look for X(3872)   c2 No signal !! M bc M  c2  (X   c2 )  (X      J  ) <1.1 Contrary to expectations for charmonium D states

Fit to (h c ’) is ruled out!  2 =75/9 |cos  J/  

M(  J/  ) B  K  c1 ;  c1   J/  X(3872) ? Br(X   J/  ) Br(X      J/  ) <0.4