English

Observation of Spin-Dependent Charge Symmetry Breaking in $\Lambda N$ Interaction: Gamma-Ray Spectroscopy of $^4_{\Lambda }$He

Nuclear Experiment 2015-12-02 v1 Nuclear Theory

Abstract

The energy spacing between the ground-state spin doublet of Λ4^4_\Lambda He(1+^+,0+^+) was determined to be 1406±2±21406 \pm 2 \pm 2 keV, by measuring γ\gamma rays for the 1+0+1^+ \to 0^+ transition with a high efficiency germanium detector array in coincidence with the 4^4He(K,π)(K^-,\pi^-) Λ4^4_\Lambda He reaction at J-PARC. In comparison to the corresponding energy spacing in the mirror hypernucleus Λ4^4_\Lambda H, the present result clearly indicates the existence of charge symmetry breaking (CSB) in ΛN\Lambda N interaction. It is also found that the CSB effect is large in the 0+0^+ ground state but is by one order of magnitude smaller in the 1+1^+ excited state, demonstrating that the ΛN\Lambda N CSB interaction has spin dependence.

Keywords

Cite

@article{arxiv.1508.00376,
  title  = {Observation of Spin-Dependent Charge Symmetry Breaking in $\Lambda N$ Interaction: Gamma-Ray Spectroscopy of $^4_{\Lambda }$He},
  author = {T. O. Yamamoto and M. Agnello and Y. Akazawa and N. Amano and K. Aoki and E. Botta and N. Chiga and H. Ekawa and P. Evtoukhovitch and A. Feliciello and M. Fujita and T. Gogami and S. Hasegawa and S. H. Hayakawa and T. Hayakawa and R. Honda and K. Hosomi and S . H. Hwang and N. Ichige and Y. Ichikawa and M. Ikeda and K. Imai and S. Ishimoto and S. Kanatsuki and M. H. Kim and S. H. Kim and S. Kinbara and T. Koike and J . Y. Lee and S. Marcello and K. Miwa and T. Moon and T. Nagae and S. Nagao and Y. Nakada and M. Nakagawa and Y. Ogura and A. Sakaguchi and H. Sako and Y. Sasaki and S. Sato and T. Shiozaki and K. Shirotori and H. Sugimura and S. Suto and S. Suzuki and T. Takahashi and H. Tamura and K. Tanabe and K. Tanida and Z. Tsamalaidze and M. Ukai and Y. Yamamoto and S. B. Yang},
  journal= {arXiv preprint arXiv:1508.00376},
  year   = {2015}
}