Speaker
Daniel Gazda
(Nuclear Physics Institute, Czech Academy of Sciences)
Description
Charge symmetry in hadron physics is broken in QCD by the up-down quark mass difference and electromagnetic interactions. In $\Lambda$ hypernuclei, charge symmetry breaking (CSB) manifests itself in a sizable charge dependence of $\Lambda$ separation energies of light mirror hypernuclei. The large value of CSB was recently reaffirmed by precision measurements of A = 4 hypernuclei [1, 2] and until recently it could not be reproduced in any *ab initio* 4-body calculation.
In this contribution, I will report on our *ab initio* no-core shell model calculations of ${}\_\Lambda^4$He and ${}\_\Lambda^4$H using realistic nucleon-nucleon, three-nucleon and hyperon-nucleon interactions derived from chiral effective field theory plus a CSB $\Lambda-\Sigma^0$ mixing vertex [3, 4]. Our calculations provide, for the first time, microscopic understanding of the sizable CSB in $A = 4$ hypernuclei.
[1] T.O. Yamamoto *et al.* (J-PARC E13 Collaboration), Phys. Rev. Lett. 115, 222501 (2015).
[2] A. Esser *et al.* (A1 Collaboration), Phys. Rev. Lett. 114, 232501 (2015).
[3] D. Gazda, A. Gal, Phys. Rev. Lett. 116, 122501 (2016).
[4] D. Gazda, A. Gal, Nucl. Phys. A 954, 161 (2016).
Primary author
Daniel Gazda
(Nuclear Physics Institute, Czech Academy of Sciences)
