arXiv subjects

CLEO collaboration

Publications and source records attributed to CLEO collaboration.

5 recordsLinked to original sources

arXiv2000

Study of chi_{c1} and chi_{c2} meson production in B meson decays

Using a sample of 9.7 million B meson pairs collected with the CLEO detector, we study inclusive B meson decays to the chi_c1 and chi_c2 charmonia states. We measure the branching fraction for the inclusive chi_c1 production in B decays to be Br(B->chi_c1 X)=(4.14+-0.31+-0.40)*10^-3, where the first uncertainty is statistical and the second one is systematic. We obtain the branching fractions for direct chi_c1 and chi_c2 production in B decays by subtracting the contribution from the decay chain B->psi(2S)X with psi(2S)->chi_c1,2 gamma. We measure Br(B->chi_c1[direct] X)=(3.83+-0.31+-0.40)*10^-3. No statistically significant signal for chi_c2 production is observed in either case. We determine the 95% C.L. upper limits to be Br(B->chi_c2 X)<2.0*10^-3, Br(B->chi_c2[direct] X)<1.7*10^-3, and Br(B->chi_c2[direct] X)/Br(B->chi_c1[direct] X)<0.44. All quoted results are preliminary.

hep-ex↗

arXiv2000

Observation of the Omega_c Charmed Baryon at CLEO

The CLEO detector at the CESR collider has used 13.7 fb^{-1} to search for the production of Omega_c (css-ground state) in e^{+}e^{-} collisions at sqrt{s} = 10.6 GeV The modes used to study the Omega_c are Omega- pi+, Omega- pi+ pi0, Xi- K- pi+ pi+, Xi0 K- pi+, and Omega- pi+ pi+ pi-. We observe 40.4 +- 9.0(stat) combined events at a mass of 2694.6 +- 2.6(stat) +- 2.4(syst) MeV. We have also measured the σ* Br of the above modes for xp > 0.5 to be 11.3 +- 3.9 +- 2.3 fb, 47.6 +- 18.0 +- 2.8 fb, 45.1 +- 23.2 +- 4.1 fb, 18.2 +- 10.6 +- 3.8 fb, and <5.1 fb @ 90 % CL, respectively.

hep-ex↗

arXiv2000

Observation of New States Decaying into Lambda_c^+pi-pi+

Using 13.7 fb^{-1} of data recorded by the CLEO detector at CESR, we investigate the spectrum of charmed baryons which decay into Lambda_c^+ pi^- pi^+ and are more massive than the Lambda_{c1} baryons. We find evidence for two new states: one is broad and has an invariant mass roughly 480 MeV above that of the Lambda_c^+; the other is narrow with an invariant mass of 596 +- 1 +- 2 MeV above the Lambda_c^+ mass. These results are preliminary.

hep-ex↗

arXiv2000

Evidence of New States Decaying into Xi_c^{prime} pi

Using 13.7 fb^{-1} of data recorded by the CLEO detector at CESR, we report preliminary evidence for two new charmed baryons; one decaying into Xi_c^{0\prime} pi^+ with the subsequent decay Xi_c^{0\prime} to Xi_c^0 gamma, and its isospin partner decaying into Xi_c^{+\prime} pi^- followed by Xi_c^{+\prime} to Xi_c^+ gamma. We measure the following mass differences for the two states: M(Xi_c^0 gamma pi^+)-M(Ξ_c^0)=318.4+-1.5+-2.9 MeV, and M(Xi_c^+ gamma pi^-)-M(Xi_c^+)=323.9+-pm1.4+-pm3.0 MeV. We interpret these new states as the J^P = (1/2)^-1 Xi_{c1} particles, the charmed-strange analogues of the Lambda_{c1}^+(2593).

hep-ex↗

arXiv2000

Determination of the B -> D^*+l-nu Decay Width and |V_{cb}|

We determine the CKM matrix element |Vcb| using a sample of 3.33 million BBbar events in the CLEO detector at CESR. We determine the yield of reconstructed B --> D*+ l nu decays as a function of w = v_B . v_D*, and from this we obtain the differential decay rate dΓ/dw. By extrapolating the differential decay rate to w=1, the kinematic point at which the D* is at rest relative to the B, we extract the product |Vcb| F(1), where F(1) is the form factor at w=1 and is predicted accurately by theory. We find |Vcb| F(1) = 0.0424 +- 0.0018(stat.) +- 0.0019(syst.). We also integrate the differential decay rate over w to obtain B(B --> D*+ l nu) = (5.66 +- 0.29 +- 0.33)%. All results are preliminary.

hep-ex↗