Search

With an integrated luminosity of 45 $$\mathrm{ab}^{-1}$$ at $$\sqrt{s} = 91.2$$ GeV, more than $$10^{12}$$ $$\mathrm{Z}$$ bosons will be produced at the Circular Electron Positron Collider (CEPC). As a real $$\mathrm{Z}$$ boson factory, the precise study of $$\mathrm{Z}$$ boson physics can be achieved. In this paper, the relative partial width, $$R_{b}$$ , of $$\mathrm{Z}$$ boson into b quarks, is measured on the CEPC Monte Carlo level. Based on the latest CEPC detector concept, the $$\mathrm{Z}$$ hadronic decay channel is simulated and reconstructed by the CEPC software framework. By using the double-tagging method, $$R_b$$ can be solved from several equations referring to the ratios of b-tagged jet hemispheres in $$\mathrm{Z}$$ hadronic events. With the high performance of the b-tagging algorithm for CEPC, the b-tagging correlation between the two jet hemispheres can be reduced. By carrying out a closure test, the double-tagging method is verified to work well as we expected. We further estimated the dependence of systematic errors on the b-tagging efficiencies of the charm and light jet, as well as the b-tagging correlation between two jet hemispheres. The sources of systematic errors, such as physics modeling and hemisphere correlation, are investigated and studied preliminarily. Several kinds of error sources related to the hemisphere correlation are studied with the characterized variables.

The dwarf musk deer, or Chinese forest musk deer (Moschus berezovskii) is an endangered artiodactyl species native to a narrow region in southern and central China as well as northernmost Vietnam. This species is well known for the habit of male musk deer to secrete musk from the musk gland. Unmated male forest musk deer secrete a greater amount of musk than mated males, which probably allows them to attract a greater number of females. However, transcriptome data for this species are deficient, and the potential transcriptional pathways of musk production remain unknown. In this study, we used RNA-sequencing (RNA-Seq) to perform an in-depth survey of transcriptome data from musk gland and to compare the transcriptome differences between mated- and unmated sexually mature Chinese forest musk deer. There were 13,009 and 12,995 genes were expressed in unmated and mated musk glands tissue. In addition to analyzing these genes, we analyzed the differentially expressed genes in musk gland tissue between mated and unmated Chinese forest musk deer males. One hundred and thirty seven genes were found differentially expressed. We found that some genes in “PPAR signaling pathway”, “PI3K-Akt signaling pathway” and “Thyroid hormone synthesis” pathways may be associated with musk production and the secretion of the musk deer. The annotated genes and differentially expressed genes in this study can be applied in conservation or utilization study of musk deer in the future.

Circular electron positron colliders, such as the CEPC and FCC-ee, have been proposed to measure Higgs boson properties precisely, test the Standard Model, search for physics beyond the Standard Model, and so on. One of the important goals of these colliders is to measure the $W$ boson mass with great precision by taking data around the $W$-pair production threshold. In this paper, the data-taking scheme is investigated to maximize the achievable precisions of the $W$ boson mass and width with a threshold scan, when various systematic uncertainties are taken into account. The study shows that an optimal and realistic data-taking scheme is to collect data at three center-of-mass energies and that precisions of 1.0 MeV and 3.4 MeV can be achieved for the mass and width of the $W$ boson, respectively, with a total integrated luminosity of $\mathcal{L}=3.2$~\mbox{ab}$^{-1}$ and several assumptions of the systematic uncertainty sources., Comment: 12 pages, 10 figures and 4 tables