Double Chooz 实验中的正电子素观测
仪器与探测器
2014-10-08 v2 高能物理 - 实验
摘要
Double Chooz 实验通过探测反应堆 的逆衰变来测量中微子混合角 。正电子与中子的时空符合性可实现大幅度的本底抑制，尽管如此，若在大型探测器中可行，液闪探测器若能进行正电子/电子鉴别，将有助于抑制剩余本底。由于两种粒子质量相同，基于液闪中光子发射时间剖面依赖性的标准粒子识别方法无法使用。然而，正电子湮灭有时会因形成亚稳态的正电子素 (ortho-positronium, o-Ps) 而延迟，这会引发脉冲形状畸变，从而可用于正电子识别。本文报告了首次在大型液闪探测器中基于单事例脉冲形状分析观测到正电子素的形成。我们测量了 o-Ps 的形成份额及其寿命，发现其值分别为 44 12 (sys.) 5 (stat.) 和 ns 0.17ns (sys.) 0.15ns (stat.)，与专用正电子湮灭寿命谱仪装置获得的结果一致。
引用
@article{arxiv.1407.6913,
title = {Ortho-positronium observation in the Double Chooz Experiment},
author = {Y. Abe and J. C. dos Anjos and J. C. Barriere and E. Baussan and I. Bekman and M. Bergevin and T. J. C. Bezerra and L. Bezrukov and E. Blucher and C. Buck and J. Busenitz and A. Cabrera and E. Caden and L. Camilleri and R. Carr and M. Cerrada and P. -J. Chang and E. Chauveau and P. Chimenti and A. P. Collin and E. Conover and J. M. Conrad and J. I. Crespo-Anadon and K. Crum and A. S. Cucoanes and E. Damon and J. V. Dawson and J. Dhooghe and D. Dietrich and Z. Djurcic and M. Dracos and M. Elnimr and A. Etenko and M. Fallot and F. von Feilitzsch and J. Felde and S. M. Fernandes and V. Fischer and D. Franco and M. Franke and H. Furuta and I. Gil-Botella and L. Giot and M. Goger-Neff and L. F. G. Gonzalez and L. Goodenough and M. C. Goodman and C. Grant and N. Haag and T. Hara and J. Haser and M. Hofmann and G. A. Horton-Smith and A. Hourlier and M. Ishitsuka and J. Jochum and C. Jollet and F. Kaether and L. N. Kalousis and Y. Kamyshkov and D. M. Kaplan and T. Kawasaki and E. Kemp and H. de Kerret and D. Kryn and M. Kuze and T. Lachenmaier and C. E. Lane and T. Lasserre and A. Letourneau and D. Lhuillier and H. P. Lima and M. Lindner and J. M. Lopez-Castano and J. M. LoSecco and B. Lubsandorzhiev and S. Lucht and J. Maeda and C. Mariani and J. Maricic and J. Martino and T. Matsubara and G. Mention and A. Meregaglia and T. Miletic and R. Milincic and A. Minotti and Y. Nagasaka and Y. Nikitenko and P. Novella and L. Oberauer and M. Obolensky and A. Onillon and A. Osborn and C. Palomares and I. M. Pepe and S. Perasso and P. Pfahler and A. Porta and G. Pronost and J. Reichenbacher and B. Reinhold and M. Rohling and R. Roncin and S. Roth and B. Rybolt and Y. Sakamoto and R. Santorelli and A. C. Schilithz and S. Schonert and S. Schoppmann and M. H. Shaevitz and R. Sharankova and S. Shimojima and D. Shrestha and V. Sibille and V. Sinev and M. Skorokhvatov and E. Smith and J. Spitz and A. Stahl and I. Stancu and L. F. F. Stokes and M. Strait and A. Stuken and F. Suekane and S. Sukhotin and T. Sumiyoshi and Y. Sun and R. Svoboda and K. Terao and A. Tonazzo and H. H. Trinh Thi and G. Valdiviesso and N. Vassilopoulos and C. Veyssiere and M. Vivier and S. Wagner and N. Walsh and H. Watanabe and C. Wiebusch and L. Winslow and M. Wurm and G. Yang and F. Yermia and V. Zimmer},
journal= {arXiv preprint arXiv:1407.6913},
year = {2014}
}
备注
17 pages, 5 figures