Abstract
Negatively charged pions from two-body decays of stopped _Lambda^4H hypernuclei were studied in 2012 at the Mainz Microtron MAMI, Germany. The momenta of the decay-pions were measured with unprecedented precision by using high-resolution magnetic spectrometers. A challenge of the experiment was the tagging of kaons from associated K^+∧ production off a Be target at very forward angles. In the year 2014, this experiment was continued with a better control of the systematic uncertainties, with better suppression of coincident and random background, improved particle identification, and with higher luminosities. Another key point of the progress was the improvement in the absolute momentum calibration of the magnetic spectrometers.
Highlights
The structure of light Λ-hypernuclei and the precise determination of Λ binding energies has been the focus of recent experimental and theoretical programs
Was investigated in 2012 by high-resolution spectroscopy at the Mainz Microtron MAMI, Germany [1]. In this experiment the binding energy of 4ΛH was determined from the two-body charged decay mode with an unprecedented ±10 keV statistical uncertainty and ±90 keV systematic uncertainty to be BΛ =
The statistical uncertainty for the binding energies in light hypernuclei with the emulsion method ranged from a minimum of 20 keV for the most abundant hypernuclei 5ΛHe to more than keV
Summary
The structure of light Λ-hypernuclei and the precise determination of Λ binding (separation) energies has been the focus of recent experimental and theoretical programs. H was investigated in 2012 by high-resolution spectroscopy at the Mainz Microtron MAMI, Germany [1]. In this experiment the binding energy of 4ΛH was determined from the two-body charged decay mode with an unprecedented ±10 keV statistical uncertainty and ±90 keV systematic uncertainty to be BΛ =. This value is 80 keV different from emulsion data, the most complete compilation of which found BΛ = 2.04 ± 0.04 MeV using only three-body charged decay modes [2]. The new method of decay-pion spectroscopy has the potential to allow binding energy measurements of several light hypernuclei with a precision comparable or better than with the emulsion technique. The control of systematic uncertainties, the improvements in background suppression, and the extensive calibrations are discussed which reduced the systematic error for the binding energy extraction and yielded a more accurate absolute calibration of the magnetic spectrometers
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
