Observation of new states decaying into Lambda+(c)pi(-)pi(+)

Using 13.7 fb(-1) of data recorded by the CLEO detector at the Cornell Electron Storage Ring, we investigate the spectrum of charmed baryons which decay into Lambda+(c)pi(-)pi(+) and are more massive than the Lambda+(c)(2625) baryon. We find evidence for two new states: one is broad and has an invariant mass roughly 480 MeV above that of the Lambda+(c) baryon; the other is narrow with an invariant mass of 596+/-1+/-2 MeV above the Lambda+(c) mass.     

{\Xi} Hypernucler States Predicted by the New Interaction Model ESC08c

The features of the new interaction model ESC08c in ${\Lambda N}$ , ${\Sigma N}$ and ${\Xi N}$ channels are demonstrated single hyperon potentials ${U_Y(Y=\Lambda, \Sigma, \Xi)}$ in nuclear matter on the basis of the G-matrix theory. (K ^?, K ⁺) productions of ${\Xi}$ hypernuclei are studied with ${\Xi}$ -nucleus folding potentials.     

On Decaying Rate of Quantum States

The survival amplitude of a quantum state (wave function) under the Schrödinger evolution can be expressed as the Fourier transform of the probability density induced by the wave function in the energy representation. In particular, the first zero of the survival amplitude is a fundamental quantity in characterizing the decaying rate of the quantum state. A basic problem in quantum mechanics is to study how fast the survival amplitude can fall. We present a general estimation of the decaying rate of a quantum state in terms of a moment of any order. The result is established by integrating an inequality which involves controlling trigonometric sums by power functions. This inequality is of independent interest in estimating exponential sums.     

Observation of new states decaying into Lambda(c)(+)Kappa(-)pi(+) and Lambda(c)(+)Kappa(0)/(s)pi(-)

We report the first observation of two charmed strange baryons that decay into Lambda(c)(+)Kappa(-)pi(+). The broader of the two states is measured to have a mass of 2978.5+/-2.1+/-2.0 MeV/c2 and a width of 43.5+/-7.5+/-7.0 MeV/c2. The mass and width of the narrow state are measured to be 3076.7+/-0.9+/-0.5 MeV/c;{2} and 6.2+/-1.2+/-0.8 MeV/c2, respectively. We also perform a search for the isospin partner states that decay into Lambda(c)(+)Kappa(0)/(s)pi(-) and observe a significant signal at the mass of 3082.8+/-1.8+/-1.5 MeV/c2. The data used for this analysis were accumulated at or near the Upsilon(4S) resonance, using the Belle detector at the e+ e- asymmetric-energy collider KEKB. The integrated luminosity of the data sample used is 461.5 fb(-1).     

Measurement of the branching fractions of exclusive _B-->D(*)(pi)l-_nu l decays in events with a fully reconstructed B meson

We report a measurement of the branching fractions for _B-->D(*)(pi)l- _nu(l) decays based on 341.1 fb(-1) of data collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC PEP-II e+ e- storage rings. Events are tagged by fully reconstructing one of the B mesons in a hadronic decay mode. We obtain B(B- -->D(0)l-_nu(l)=(2.33+/-0.09(stat)+/-0.09(syst)%, B(B- -->D(*0)l-_nu(l)=(5.83+/-0.15(stat) +/-0.30(syst) %, B(_B(0)-->D+l-_nu(l)=(2.21+/-0.11(stat) +/-0.12(syst)%, B(_B(0)-->D(*)l-_nu(l)=(5.49+/-0.16(stat)+/-0.25(syst)%, B(B- -->D+pi-l-_nu(l)=(0.42+/-0.06(stat)+/-0.03(syst)%, B(B- -->D(*)+pi-l-_nu(l)=(0.59+/-0.05(stat)+/-0.04(syst)%, B(_B(0)-->D(0)pi+l-_nu(l)=(0.43+/-0.08(stat)+/-0.03(syst)%, and B(_B(0)-->D(*0)pi+l-_nu(l)=(0.48+/-0.08(stat)+/-0.04(syst)%.     

Dynamics of the pi(-)p-->pi(0)pi(0)n reaction for p(pi(-))<750 MeV/c

Data are presented for the reaction pi(-)p-->pi(0)pi(0)n in the range from threshold to p(pi(-))=750 MeV/c. The systematics of the data and multipole analyses are examined for sensitivity to a f(0)(600) ("sigma") meson. A one-pion-exchange mechanism is found to be very weak, or absent. The reaction appears to become dominated by sequential pi(0) decays through the Delta(1232) resonance as the beam momentum increases, along with substantial interference effects from several competing mechanisms.     

Observation of B-->K(0)(S)pi(+)pi(-) and Evidence for B-->K(*+/-)pi(-/+)

We report on a search for charmless hadronic B decays to the three-body final states K(0)(S)h(+)pi(-), K(+)h(-)pi(0), K(0)(S)h(+)pi(0) (h(+/-) denotes a charged pion or kaon), and their charge conjugates, using 13.5 fb(-1) of integrated luminosity produced near sqrt[s]=10.6 GeV, and collected with the CLEO detector. We observe the decay B-->K0pi(+)pi(-) with a branching fraction (50(+10)(-9)(stat.)+/-7(syst.))x10(-6) and the decay B-->K(*+)(892)pi(-) with a branching fraction (16(+6)(-5)(stat.)+/-2(syst.))x10(-6).     

Evidence for the decay D0-->K(-)pi(+)pi(-)e(+)nu(e)

Using a 281 pb{-1} data sample collected at the psi(3770) with the CLEO-c detector, we present the first absolute branching fraction measurement of the decay D0-->K(-)pi(+)pi(-)e(+)nu(e) at a statistical significance of about 4.0 standard deviations. We find 10 candidates consistent with the decay D0-->K(-)pi(+)pi(-)e(+)nu(e). The probability that a background fluctuation accounts for this signal is less than 4.1 x 10{-5}. We find B(D0-->K(-)pi(+)pi(-)e(+)nu(e)) = [2.8{-1.1}{+1.4}(stat)+/-0.3(syst)]x10{-4}. By restricting the invariant mass of the hadronic system to be consistent with K1(1270), we obtain the product of branching fractions B(D{0}-->K{1}{-}(1270)e{+}nu{e})xB(K1-(1270)-->K{-}pi{+}pi{-})=[2.5{-1.0}{+1.3}(stat)+/-0.2(syst)]x10{-4}. Using B(K1-(1270)-->K{-}pi{+}pi{-})=(33+/-3)%, we obtain B(D{0}-->K{1}{-}(1270)e{+}nu{e})=[7.6{-3.0}{+4.1}(stat)+/-0.6(syst)+/-0.7]x10{-4}. The last error accounts for the uncertainties in the measured K1-(1270)-->K{-}pi{+}pi{-} branching fractions.     

Interference study of the chi c0(13P0) in the reaction -pp-->pi0pi0

Fermilab experiment E835 has observed (-)pp annihilation production of the charmonium state chi(c0) and its subsequent decay into pi(0)pi(0). Although the resonant amplitude is an order of magnitude smaller than that of the nonresonant continuum production of pi(0)pi(0), an enhanced interference signal is evident. A partial wave expansion is used to extract physics parameters. The amplitudes J=0 and 2, of comparable strength, dominate the expansion. Both are accessed by L=1 in the entrance (-)pp channel. The product of the input and output branching fractions is determined to be B((-)pp-->chi(c0))xB(chi(c0)-->pi(0)pi(0))=(5.09+/-0.81+/-0.25)x10(-7).