New Resonances at Belle B. Golob University of Ljubljana,
Slovenia Belle Collaboration B. Golob, Belle Cracow Epiphany
Conference, 2005 Experimental environment D sJ s and their
properties X(3872)......and also Y(3940) cc recoil spectrum
pentaquarks? Conclusion Slide 2 B. Golob, Belle Cracow Epiphany
Conference, 2005 Experimental environment KEKB asymmetric B factory
~1 km in diameter Mt. Tsukuba KEKB Belle (4s) e+e+ e-e- B B Ldt =
255 fb -1 on reson. 30 fb -1 off reson. ~280 M BB > 900 pb -1
/day (~1 M BB/day) Integrated luminosity May 99 Oct 04 Slide 3 B.
Golob, Belle Cracow Epiphany Conference, 2005 Experimental
environment combined particle ID (K )~85% ( K ) B. Golob, Belle
Cracow Epiphany Conference, 2005 D sJ states Production in
continuum backup slide reconstruction: D s K + K - D s * D s p(D sJ
)>3.5 GeV D sJ + (2317) D s + 0 D s side band 0 side band D s *+
(2112) also D s + (2460) D s *+ 0 ; lost (MC) D sJ + (2460) D s *+
0 D s * side band D s + (2317) D s + 0 +random D sJ + (2460) D s +
D s side band M(D sJ (2317))=2317.2 0.5 0.9 MeV M(D sJ
(2460))=2456.5 1.3 1.3 MeV (D sJ (2317)) B. Golob, Belle Cracow
Epiphany Conference, 2005 Y(3940) B K J/ backup slide Main syst.
uncertainty: fit using S-wave BW or Lorentzian shape for resonance;
linear or 3rd order polynomial for bckg.; largest deviation +38%
possible non- 3 contribution; -28% Significance: integral of fitted
phase space in first 3 bins of M( J/ ) 16.81.4 total number of
events: 55.6 significance > 9 > 8 Slide 49 cc recoil backup
Slide 50 B. Golob, Belle Cracow Epiphany Conference, 2005 J/ X e-e-
e+e+ Reconstruct J/ l + l - Calculate recoil mass (mass of X):
backup slide calibrate with e + e - (2S) (2S) J/ + - B. Golob,
Belle Cracow Epiphany Conference, 2005 Isotriplet of charmed
baryons c + - final state: 4 excited charmed baryons lower two
orbital excitations of c + upper two ? c + final state: c (2455)
ground state c (2520) spin excitation c orbital excitations? c-c-
c0c0 c+c+ side band Fit: D-wave BW + feed-down + comb. backg.
backup slide feed-down c + (2880) c + + - through c (2455) 0, c
(2455) ++ feed-down not seen due to lower ( 0 ) Full recon. of c +
(2880) c + + - for signal events in bins of M( c )-M( c ) to
determine the amount of feed-down 2.24x10 3 1.54x10 3 2.81x10 3 x p
>0.7 Slide 56 B. Golob, Belle Cracow Epiphany Conference, 2005
Isotriplet of charmed baryons backup slide M( c )-M( c ) full
region: c (2455) 0 c (2520) 0 estimation of syst. uncertainty: -
change of signal descr. (L=0,1) - change of comb. bckg. descr. -
change of down-feed contrib. - change of x p and other selection
criteria c pK - + c pK S c + c (2800)/ c yield ratio cross-check:
Slide 57 c p structure backup Slide 58 B. Golob, Belle Cracow
Epiphany Conference, 2005 c + p structure 3-body baryon production
in B decays: baryon-antibaryon system peaked near treshold B - c +
p - c + pK - +,pK S, +, pK S + -, + + - p - 26420 evts. c (2455) 0
c (2520) 0 (1600) (2420) Fits to E in mass bins BW peak + feed down
from B - c + M = 3.35 0.02 GeV 50 10 evts.(5.6 ) ~70 MeV 152M
BB,hep-ex/0409005 Slide 59 B. Golob, Belle Cracow Epiphany
Conference, 2005 c + p structure c (2455) 0 p c + (1232) c + (1600)
c + (2420) c + p simultaneous fit to 6 E distrib.; N i = j ij Y j
Br(B - c (2455) 0 p)=(3.67 +0.74 -0.66 0.36 0.95)10 -5 Br(B - ( c +
p) - )=(3.87 +0.77 -0.72 0.43 1.01)10 -5 due to Br( c + pK - + )
M=3.35 +0.01 -0.02 0.02 GeV =0.07 +0.04 -0.03 0.04 GeV from
different bkgd. param.
