Kavli Affiliate: Hsiao-Mei (Sherry) Cho
| First 5 Authors: [#item_custom_name[1, [#item_custom_name[2, [#item_custom_name[3, [#item_custom_name[4, [#item_custom_name[5| Summary:Using data samples collected by the Belle and Belle II experiments at the $Υ(4S)$ resonance with integrated luminosities of 571 fb$^-1$ and 365 fb$^-1$, respectively, we measure the pseudoscalar $B$-meson mass difference to be $m(B^0)-m(B^+) = (0.495pm0.024pm0.005)$ MeV/c$^2$. The results are based on a simultaneous fit to the variable $tildeM_bc$, which is related to the $B$ momentum, for $B^0$ and $B^+$ candidates; and to the energy dependence of $cal R=σ(e^+e^-to B^0barB^0) / σ(e^+e^-to B^+B^-)$, which is measured using changes in the average center-of-mass energy over the data taking periods. The phase-space hypothesis $cal R=(p_B^0/p_B^+)^3$, upon which previous measurements rely, is strongly disfavored by our fit; the measured mass-difference value for the phase-space hypothesis also differs significantly from our measurement. We constrain $cal R$ in a broader energy range than covered by the direct measurement and extract the energy dependence of $cal R$ in the range from the $BbarB$ threshold up to 10.59 GeV. We interpret the results using a phenomenological model and constrain the parameters of the $BbarB$ potential in the isovector channel.| Search Query: arXiv Query: search_query=au:Cho OR all:Hsiao-Mei&id_list=&start=0&max_results=3Read More