EPJ Web Conf.
Volume 199, 2019MESON 2018 – 15th International Workshop on Meson Physics
|Number of page(s)||4|
|Published online||01 February 2019|
Λ hyperon spin polarization and CP tests at BESIII
Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden
* e-mail: firstname.lastname@example.org
Published online: 1 February 2019
In these proceedings two preliminary results from the BESIII collaboration on polarized Λ and are reported. Both results are first observations and concern the resonant and non-resonant processes and at , respectively. For the relative phase between the electric and magnetic form factors, ΔΦ, has for the first time been determined, . That allows for a simultaneous measurement also of the asymmetry decay parameters , and . The measured value of differs by 17(3)% from the PDG value. The simultaneous measurement for the asymmetry parameters allows for the most precise test of CP violation conducted for Λ decays, ACP = −0.006(12)stat(7)syst. The reaction at is the first complete measurement of the time-like electric (GE) and magnetic (GM) form factor of any baryon as also the ratio R = |(GE/(GM)| and ΔΦ have been determined: R = 0.96(14)(12) and . The obtained cross-section and effective form factor are σ = 119.0(53)stat(51)syst pb and |G| = 0.123(3)stat(3)syst, respectively.
© The Authors, published by EDP Sciences, 2019
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.