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Search for X(3872) J/ S.K. Choi & S.L. Olsen Properties of X(3872)
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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
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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 )
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M( ) cut J/ J/ M( ) M( ) M( l l )-M(l l ) (apply same p momentum & M(pp) cuts to sample)
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’ J/ signal N ev = 55.4 ±10.2 events M bc
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’ J/ signal N ev = 742 ± 28 events M bc
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X(3872) J/ signal M bc N ev = 62.6 ±8.3 events
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N ev = 0.2 ±2.6 events (< 4.4 evts 90% CL) M bc X(3872) J/ signal? No signal!!
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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
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J/ summary no sign of X J/ but sensitivity is still not enough to distinguish between C = + 1 or -1
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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/
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Look for X(3872) c2 No signal !! M bc M c2 (X c2 ) (X J ) <1.1 Contrary to expectations for charmonium D states
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Fit to 1 +- 1 +- (h c ’) is ruled out! 2 =75/9 |cos J/
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M( J/ ) B K c1 ; c1 J/ X(3872) ? Br(X J/ ) Br(X J/ ) <0.4
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