249 research outputs found

    Production of Λ6^{6}_{\Lambda}H and Λ7^{7}_{\Lambda}H with the (Kstop^{-}_{stop},π+\pi^+) reaction

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    The production of neutron rich Λ\Lambda-hypernuclei via the (KstopK^-_stop,π+\pi^+) reaction has been studied using data collected with the FINUDA spectrometer at the DAΦ\PhiNE ϕ\phi-factory (LNF). The analysis of the inclusive π+\pi^+ momentum spectra is presented and an upper limit for the production of Λ6^6_\LambdaH and Λ7^7_\LambdaH from 6^6Li and 7^7Li, is assessed for the first time.Comment: 11 pages, 3 figures. Accepted for publication in PL

    A study of the proton spectra following the capture of KK^- in 6^6Li and 12^{12}C with FINUDA

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    Momenta spectra of protons emitted following the capture of KK^- in 6^6Li and 12^{12}C have been measured with 1% resolution. The 12^{12}C spectrum is smooth whereas for 6^6Li a well defined peak appears at about 500 MeV/cc. The first observation of a structure in this region was identified as a strange tribaryon or, possibly, a Kˉ\bar K-nuclear state. The peak is correlated with a π\pi^- coming from Σ\Sigma^- decay in flight, selected by setting momenta larger than 275 MeV/cc. The Σ\Sigma^- could be produced, together with a 500 MeV/cc proton, by the capture of a KK^- in a deuteron-cluster substructure of the 6^6Li nucleus. The capture rate for such a reaction is (1.62\pm 0.23_{stat} ^{+0.71}_{-0.44}(sys))%/K^-_{stop}, in agreement with the existing observations on 4^4He targets and with the hypothesis that the 6^6Li nucleus can be interpreted as a (d+α)(d+\alpha) cluster.Comment: 21 pages, 10 figures. Accepted for publication in NP

    Correlated Λd\Lambda d pairs from the KstopAΛdAK^{-}_{stop} A \to \Lambda d A' reaction

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    Correlated Λd\Lambda d pairs emitted after the absorption of negative kaons at rest KstopAΛdAK^{-}_{stop}A\to \Lambda d A' in light nuclei 6Li^6Li and 12C^{12}C are studied. Λ\Lambda-hyperons and deuterons are found to be preferentially emitted in opposite directions. The Λd\Lambda d invariant mass spectrum of 6Li^6Li shows a bump whose mass is 3251±\pm6 MeV/c2^2. The bump mass (binding energy), width and yield are reported. The appearance of a bump is discussed in the realm of the [Kˉ3N\bar{K}3N] clustering process in nuclei. The experiment was performed with the FINUDA spectrometer at DAΦ\PhiNE (LNF).Comment: 13 pages, 5 figures, accepted for publication in Phys. Lett.

    Systemic chemotherapy with doxorubicin, cisplatin and capecitabine for metastatic hepatocellular carcinoma

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    BACKGROUND: Although numerous chemotherapeutic agents have been tested, the role of systemic chemotherapy for hepatocellular carcinoma (HCC) has not been clarified. New therapeutic strategies are thus needed to improve outcomes, and we designed this study with new effective drug combination. METHODS: Twenty-nine patients with histologically-confirmed, metastatic HCC received a combination chemotherapy with doxorubicin 60 mg/m(2 )and cisplatin 60 mg/m(2 )on day 1, plus capecitabine 2000 mg/m(2)/day as an intermittent regimen of 2 weeks of treatment followed by a 1-week rest. RESULTS: The median age was 49 years (range, 32–64) and 19 patients were hepatitis B virus seropositive. Child-Pugh class was A in all patients and 4 had Zubrod performance status of 2. The objective response rate was 24% (95% CI 9–40) with 6 stable diseases. The chemotherapy was generally well tolerated despite one treatment-related death. CONCLUSION: Combination chemotherapy with doxorubicin, cisplatin and capecitabine produced modest antitumor activity with tolerable adverse effects in patients with metastatic HCC

    First Results on 12Lambda-C production at DAPHNE

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    Lambda-hypernuclei are produced and studied, with the FINUDA spectrometer, for the first time at an e+e- collider: DAPHNE, the Frascati phi-factory. The slow negative kaons from phi(1020) decay are stopped in thin (0.2 g/cm^2) nuclear targets, and Lambda-hypernuclei formation is detected by measuring the momentum of the outgoing pi^-. A preliminary analysis on 12Lambda-C shows an energy resolution of 1.29 MeV FWHM on the hypernuclear levels, the best obtained so far with magnetic spectrometers at hadron facilities. Capture rates for the ground state and the excited ones are reported, and compared with previous experiments.Comment: 15 pages, 5 figures. v2: one reference updated. Accepted for publication in Phys. Lett.

    Search for neutral heavy leptons produced in ZZ decays

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    Weak isosinglet Neutral Heavy Leptons (νm) have been searched for using data collected by the DELPHI detector corresponding to 3.3 × 106 hadronic Z0 decays at LEP1. Four separate searches have been performed, for short-lived νm production giving monojet or acollinear jet topologies, and for long-lived νm giving detectable secondary vertices or calorimeter clusters. No indication of the existence of these particles has been found, leading to an upper limit for the branching ratio BR(Z0 → νmν̄) of about 1.3 × 10-6 at 95% confidence level for νm masses between 3.5 and 50 GeV/c2. Outside this range the limit weakens rapidly with the νm mass. The results are also interpreted in terms of limits for the single production of excited neutrinos. © Springer-Verlag 1997

    Analysis of neural and fuzzy-power electronic control

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