Measurement of the Zero Crossing in a Feshbach Resonance of Fermionic 6-Li

We measure a zero crossing in the scattering length of a mixture of the two lowest hyperfine states of 6-Li. To locate the zero crossing, we monitor the decrease in temperature and atom number arising from evaporation in a CO2 laser trap as a function of magnetic field B. The temperature decrease and atom loss are minimized for B=528(4) G, consistent with no evaporation. We also present preliminary calculations using potentials that have been constrained by the measured zero crossing and locate a broad Feshbach resonance at approximately 860 G, in agreement with previous theoretical predictions. In addition, our theoretical model predicts a second and much narrower Feshbach resonance near 550 G.Comment: Five pages, four figure

Measurement of anomalous muon pair production in electron-positron annihilations

We have observed 16 events of the type μ+μ-+(missing energy and momentum) from e+e- annihilations at center-of-mass energies between 6.4 and 7.4 GeV. Taking into account QED backgrounds, we find an excess of 11 anomalous dimuon events. If these are attributed to the production and subsequent decay of a pair of heavy leptons L±, we obtain the muonic braching ratio B((L+→μ+νμν̄L)(L+→all))=0.22-0.08+0.07. © 1978 The American Physical Society

Long-term efficacy, safety and neurotolerability of MATRix regimen followed by autologous transplant in primary CNS lymphoma: 7-year results of the IELSG32 randomized trial

219 HIV-negative adults ≤70 years with primary CNS lymphoma (PCNSL) were enrolled in the randomized IELSG32 trial. Enrolled patients were randomly assigned to receive methotrexate-cytarabine (arm A), or methotrexate-cytarabine-rituximab (B), or methotrexate-cytarabine-thiotepa-rituximab (MATRix; arm C). A second randomization allocated patients with responsive/stable disease to whole-brain irradiation (WBRT) or carmustine-thiotepa-conditioned autologous transplantation (ASCT). First results, after a median follow-up of 30 months, showed that MATRix significantly improves outcome, with both WBRT and ASCT being similarly effective. However, sound assessment of overall survival (OS), efficacy of salvage therapy, late complications, secondary tumors, and cognitive impairment requires longer follow-up. Herein, we report the results of this trial at a median follow-up of 88 months. As main findings, MATRix was associated with excellent long-lasting outcome, with a 7-year OS of 21%, 37%, and 56% respectively for arms A, B, and C. Notably, patients treated with MATRix and consolidation had a 7-year OS of 70%. The superiority of arm B on arm A suggests a benefit from the addition of rituximab. Comparable efficacy of WBRT and ASCT was confirmed. Salvage therapy was ineffective; benefit was recorded only in patients with late relapse re-treated with methotrexate. Eight (4%) patients developed a second cancer. Importantly, MATRix and ASCT did not result in higher non-relapse mortality or second tumors incidence. Patients who received WBRT experienced impairment in attentiveness and executive functions, whereas patients undergoing ASCT experienced improvement in these functions as well as in memory and quality of life