We report the first observation of two narrow charmed strange baryons decaying to $\Xi_c^+\gamma$ and $\Xi_c^0\gamma$, respectively, using data from the CLEO II detector at CESR. We interpret the observed signals as the $\Xi_c^{+\prime}(c{su})$ and $\Xi_c^{0\prime}(c{sd})$, the symmetric partners of the well-established antisymmetric $\Xi_c^+(c[su])$ and $\Xi_c^0(c[sd])$. The mass differences $M(\Xi_c^{+\prime})-M(\Xi_c^+)$ and $M(\Xi_c^{0\prime})-M(\Xi_c^0)$ are measured to be $107.8\pm 1.7\pm 2.5$ and $107.0\pm 1.4\pm 2.5 MeV/c^2$, respectively.
The data for two resonances are combined together.
CONST(NAME=EPS) is the parameter of the Peterson fragmentation function (C.Peterson et al., PR D27, 105 (1983)) D(N)/D(Z) = FD(Z) = const * (1/Z)*1/(1 - (1/Z)-CONST(NAME=EPS)/(1-Z))**2. The data for two resonances are combined together.
We present evidence for inclusive F-meson production in B-meson decay. The product branching fraction B(B→FX)B(F+→φπ+) is measured to be 0.0038±0.010. The F momentum spectrum indicates the presence of a large component of two-body final states in the decay B→FX.
No description provided.
DATA SAMPLE CONSISTED OF 77 1/PB. DATA TAKEN ON THE PEAK OF THE UPSI(10575).
CONTINUUM DATA SAMPLE CONSISTED OF 36 1/PB. ENERGY JUST BELOW THE UPSI(10575).
Using data collected by the CLEO II detector, we have observed two states decaying to Λc+π+π−. Relative to the Λc+, their mass splittings are measured to be +307.5±0.4±1.0 and +342.2±0.2±0.5MeV/c2, respectively; this represents the first measurement of the less massive state. These two states are consistent with being orbitally excited, isospin zero Λc+ states.
CONST(NAME=EPS) is the parameter of the Peterson fragmentation function (C.Peterson et al., PR D27, 105 (1983)) D(N)/D(Z) = FD(Z) = const * (1/Z)*1/(1 - (1/Z)-CONST(NAME=EPS)/(1-Z))**2. Charged conjugated states are understood.
Charged conjugated states are understood.
Charged conjugated states are understood.
We have observed Λc baryons in nonresonant e+e− annihilation at energies around s=10.5 GeV through their decay to Λπ+π+π−. We measure the branching fraction to be (2.8 ± 0.7 ± 1.1)%. The momentum spectrum of the Λc is similar to that of charmed mesons, providing a constraint on models of charmed-quark hadronization.
Data are extrapolated over whole x range using the 'Peterson' formula.
Using data collected in the region of the Upsilon(4S) resonance with the CLEO II detector operating at the Cornell Electron Storage Ring CESR, we present the first observation of B mesons decaying into the charmed strange baryons Xi_c0 and Xi_c+. We find 79 +/- 27 Xi_c0 and 125 +/- 28 Xi_c+ candidates from B decays, leading to product branching fractions of BR(Bbar -> Xi_c0 X)BR(Xi_c0 -> Xi- pi+) = (0.144 +/- 0.048 +/- 0.021) x 10~-3 and BR(Bbar -> Xi_c+ X)BR(Xi_c+ -> Xi- pi+ pi+) = (0.453 +/- 0.096 +0.085-0.065) x 10~-3.
Charge conjugated states are included. P(P=4,C=MAX) equals sqrt(Ebeam**2 - m(XI/C)**2). The kinematic limit is : (P(XI/C) / P(P=4,C=MAX)) < 0.5.
Charge conjugated states are included. P(P=4,C=MAX) equals sqrt(Ebeam**2 - m(XI/C)**2). The kinematic limit is : (P(XI/C) / P(P=4,C=MAX)) < 0.5.
We report results on inclusive production of the charmed baryon Λc+ from e+e− annihilations at s=10.5 GeV. Measurements are presented of the inclusive cross section times branching fraction for the continuum production of Λc+ as observed in six different decay modes, and of a new, improved value of the Λc+ mass. The inclusive cross section times the branching fraction into pK−π+ is measured to be 10.0±1.5±1.5 pb summed over all xp. The branching fractions of Λc+ into pK¯0, pK¯0π+π−, Λπ+, Λπ+π−π+, and Ξ−K+π+ relative to that into pK−π+ are measured to be 0.44±0.07±0.05, 0.43±0.12±0.04, 0.18±0.03±0.03, 0.65±0.11±0.12, and 0.15±0.04±0.03, respectively. The Λc+ mass is measured to be 2284.7±0.6±0.7 MeV/c2. The measured momentum distributions for continuum production of Λc+ are compared to analytical fragmentation functions and to other measurements.
No description provided.
No description provided.
No description provided.
In a sample of B mesons from the decay of the ϒ(4S) produced in e+e− collisions at the Cornell Electron Storage Ring, inclusive protons, antiprotons, lambdas, and antilambdas have been observed. Lower limits to the B-to-baryon branching ratios are derived.
NUMERICAL VALUES OF DATA SUPPLIED BY E.H. THORNDIKE. CORRECTED ANTI(PROTON) PRODUCTION FROM UPSI(4S) DECAY.
NUMERICAL VALUES OF DATA SUPPLIED BY E.H. THORNDIKE. CORRECTED ANTI(LAMBDA) PRODUCTION FROM UPSI(4S) DECAY.
Using the CLEO II detector at CESR, we have observed two charmed states, where the higher mass state decays to D 0 π + and to D ∗0 π + , while the lower mass state decays to D ∗0 π + , but not to D 0 π + . The masses and widths were measured to be 2425±2±2 MeV/c 2 and 26 −7−4 +8+4 MeV/c 2 for the lower mass state, and 2463±3±3 MeV/c 2 and 27 −8−5 +11+5 MeV/c 2 for the higher mass state. Properties of these states, including their decay angular distributions and spin-parity assignments have been studied. The results of this analysis support the identification of these states as the charged L = 1 D 1 (2420) + and D 2 ∗ (2460) + , respectively. The isospin mass splittings between these states and their neutral partners have also been measured. This is the first full reconstruction of any decay mode of the D 1 (2420) + and the first observation of the decay of D 2 ∗ (2460) + to D ∗0 π + .
CONST(NAME=EPS) is the parameter of the Peterson fragmentation function (C.Peterson et al., PR D27, 105 (1983)) D(N)/D(Z) = FD(Z) = const * (1/Z)*1/(1 - (1/Z)-CONST(NAME=EPS)/(1-Z))**2. Charged conjugate states are undestood.
We have used the momentum spectrum of leptons produced in semileptonic B-meson decays to set a 90%-confidence-level upper limit on Γ(b→ulν)Γ(b→clν) of 4%. We also measure the semileptonic branching fractions of the B meson to be (12.0±0.7±0.5)% for electrons and (10.8±0.6±1.0)% for muons.
No description provided.
No description provided.
We have observed Σc++ and Σc0 baryons in nonresonant e+e− interactions through their decays to Λc+π± using the CLEO detector. The mass difference M(Σc++)-M(Λc+) is measured to be 167.8±0.4±0.3 MeV; for M(Σc0)-M(Λc+) we find 167.9±0.5±0.3 MeV. Σc decay accounts for (18±3±5)% of Λc+ production.
The cross section ratio is multiplied by a factor of 1.5 to account for theunobserved SIGMA/C(2455)+.
No description provided.