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.     

Observation of an isotriplet of excited charmed baryons decaying to lambda+c pi

We report the observation of an isotriplet of excited charmed baryons, decaying into Lambda(+)(c)pi(-), Lambda(+)(c)pi(0), and Lambda(+)(c)pi(+). We measure the mass differences M(Lambda(+)(c)pi)-M(Lambda(+)(c)) and widths to be 515.4(+3.2+2.1)(-3.1-6.0) MeV/c(2), 61(+18+22)(-13-13) MeV for the neutral state; 505.4(+5.8+12.4)(-4.6-2.0) MeV/c(2), 62(+37+52)(-23-38) MeV for the charged state; and 514.5(+3.4+2.8)(-3.1-4.9) MeV/c(2), 75(+18+12)(-13-11) MeV for the doubly charged state, where the uncertainties are statistical and systematic, respectively. These results are obtained from a 281 fb(-1) data sample collected with the Belle detector near the Upsilon(4S) resonance, at the KEKB asymmetric energy e(+)e(-) collider.     

Observation of a narrow meson state decaying to D(+)(s)pi(0) at a mass of 2.32 GeV/c(2)

We have observed a narrow state near 2.32 GeV/c(2) in the inclusive D(+)(s)pi(0) invariant mass distribution from e(+)e(-) annihilation data at energies near 10.6 GeV. The observed width is consistent with the experimental resolution. The small intrinsic width and the quantum numbers of the final state indicate that the decay violates isospin conservation. The state has natural spin-parity and the low mass suggests a J(P)=0(+) assignment. The data sample corresponds to an integrated luminosity of 91 fb(-1) recorded by the BABAR detector at the SLAC PEP-II asymmetric-energy e(+)e(-) storage ring.     

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).     

Evidence of New States Decaying into Xi(*)(c)pi

Using 13.7 fb(-1) of data recorded by the CLEO detector at Cornell Electron Storage Ring, we report evidence of two new charmed baryons: one decaying into Xi(0')(c)pi(+) with the subsequent decay Xi(0')(c)-->Xi(0)(c)gamma, and its isospin partner decaying into Xi(+')(c)pi(-) followed by Xi(+')(c)-->Xi(+)(c)gamma. We measure the following mass differences for the two states: M(Xi(0)(c)gammapi(+))-M(Xi(0)(c)) = 318.2+/-1.3+/-2.9 MeV and M(Xi(+)(c)gammapi(-))-M(Xi(+)(c)) = 324.0+/-1.3+/-3.0 MeV. We interpret these new states as the J(P) = 1 / 2(-) Xi(c1) particles, the charmed-strange analogs of the Lambda(+)(c1)(2593).     

Observation of a narrow baryon resonance decaying to pK

Data from the SVD-2 experiment that were obtained at the IHEP accelerator in 70-GeV/c proton-nucleus interactions are analyzed with the aim of searches for an exotic Θ⁺ baryon that decays through the pK _S ⁰ channel. The reaction pN → pK _S ⁰ + X characterized by a bounded multiplicity of charged secondaries is used for this analysis. A resonance of mass M = 1526 ± 3(stat.) ± 3(syst.) MeV/c ² and width Γ < 24 MeV/c ² is observed in the invariant-mass spectrum of the pK _S ⁰ system at a statistical significance of 5.6σ. The mass and the width of this resonance correspond to the recently found positive-strangeness Θ⁺ baryon, which was predicted to be an exotic baryon consisting of five quarks (pentaquark), . The total cross section for the production of a Θ⁺ baryon in pA interactions is estimated at a value within the range 30–120 μb for x _F ≥ 0. An analysis of the A dependence of the cross section for Θ⁺-baryon production does not reveal a significant deviation from the A dependence for inelastic events (∼A ^0.7). __________ Translated from Yadernaya Fizika, Vol. 68, No. 6, 2005, pp. 1012–1019. Original Russian Text Copyright ? 2005 by Aleev, Amaglobeli, Ardashev, Balandin, Basiladze, Berezhnev, Bogdanova, Boguslavsky, Vasiliev, Vischnevskaya, Volkov, Vorobiev, Voronin, Golovnya, Golubkov, Gorokhov, Gorkov, Gramenitsky, Grishin, Grishkevich, Egorov, Ezhov, Ermakov, Ermolov, Zhidkov, Zakamsky, Zapolsky, Zverev, Zmushko, D. Zotkin, S. Zotkin, Karmanov, Kiryakov, V. Kozlov, Yu. Kozlov, Kokoulina, Korotkov, Kosarev, Kramarenko, Kubarovsky, Kuznetsov, N. Kuzmin, V. Kuzmin, Kurchaninov, Lanshikov, Larichev, Levitsky, Leflat, Lyutov, Maiorov, Merkin, Minaenko, Mitrofanov, Moiseev, Murzin, Nikitin, Nomokonov, Oleinik, Orfanitsky, Parakhin, Petrov, Pilavova, Pleskach, Popov, Rudenko, Rufanov, Riadovikov, Senko, Sidorov, Soldatov, Tikhonova, Topuria, Furmanec, Kholodenko, Tsyupa, Shalanda, Shafranov, Yukaev, Yakimchuk.     

Observation of a narrow hyperon state of mass 3.17 GeV

We present evidence for a narrow Y¹ with a mass of 3.17 GeV and a width ? 20 MeV decaying to ΣKK? + pions, ΛKK? + pions and ΞK + pions. The data come from two high statistics K^?p bubble chamber experiments with a sensitivity of ≈100 eV/μbat 8.25 GeV/c and ≈ 45 eV/μbat 6.5 GeV/c.