Ground-state binding energy of from high-resolution decay-pion spectroscopy

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• 作者：A1 CollaborationF. Schulz^a ; ¹ ; P. Achenbach^a ; ^{patrick@kph.uni-mainz.de" class="auth_mail" title="E-mail the corresponding author} ; S. Aulenbacher^a ; J. Beričič^b ; S. Bleser^a ; ^c ; R. Bö ; hm^a ; ² ; D. Bosnar^d ; L. Correa^e ; M.O. Distler^a ; A. Esser^a ; H. Fonvieille^e ; I. Fri&scaron ; čić^d ; Y. Fujii^f ; M. Fujita^f ; T. Gogami^f ; ³ ; H. Kanda^f ; M. Kaneta^f ; S. Kegel^a ; Y. Kohl^a ; W. Kusaka^f ; A. Margaryan^g ; H. Merkel^a ; M. Mihovilovič^a ; U. Mü ; ller^a ; S. Nagao^f ; S.N. Nakamura^f ; J. Pochodzalla^a ; A. Sanchez Lorente^a ; ^c ; B.S. Schlimme^a ; M. Schoth^a ; C. Sfienti^a ; S. &Scaron ; irca^b ; M. Steinen^a ; ^c ; Y. Takahashi^f ; L. Tang^h ; M. Thiel^a ; K. Tsukada^f ; ⁴ ; A. Tyukin^a ; A. Weber^a
• 关键词：Hypernuclear mass spectroscopy ; Mesonic weak decay ; Charge symmetry breaking
• 刊名：Nuclear Physics A
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：954
• 期：Complete
• 页码：149-160
• 全文大小：618 K

文摘

A systematic study on the Λ ground state binding energy of hyperhydrogen ${}_{\mathrm{\Lambda }}{}^4\mathrm{H}$ measured at the Mainz Microtron MAMI is presented. The energy was deduced from the spectroscopy of mono-energetic pions from the two-body decays of hyperfragments, which were produced and stopped in a ⁹Be target. First data, taken in the year 2012 with a high resolution magnetic spectrometer, demonstrated an almost one order of magnitude higher precision than emulsion data, while being limited by systematic uncertainties. In 2014 an extended measurement campaign was performed with improved control over systematic effects, increasing the yield of hypernuclei and confirming the observation with two independent spectrometers and two targets of different thicknesses. The analysis of these data is in agreement with the previously published value for the ${}_{\mathrm{\Lambda }}{}^4\mathrm{H}$ binding energy as well as with a consistent re-analysis of the 2012 data. When compared to the ${}_{\mathrm{\Lambda }}{}^4\mathrm{He}$ binding energy from emulsion data, a large charge symmetry breaking effect in the A=4$A=4$ hypernuclear system is confirmed.