We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m χ) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m χ are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ SI χN at 90% confidence level are derived as 2 × 10 −32 ∼ 7 × 10 −35 cm 2 for TI analysis at m χ ∼ 50-180 MeV=c 2 , and 3 × 10 −32 ∼ 9 × 10 −38 cm 2 for AM analysis at m χ ∼ 75 MeV=c 2-3.0 GeV=c 2 .

No abstract

No abstract

No abstract

The Breit-Wheeler process which produces matter and anti-matter from photon collisions is investigated experimentally through the observation of 6085 exclusive electron-positron pairs in ultraperipheral Au+Au collisions at √ s N N = 200 GeV. The measurements reveal a large fourth-order

We report constraints on the dark photon effective kinetic mixing parameter (κ) with data taken from two p-type point-contact germanium detectors of the CDEX-10 experiment at the China Jinping Underground Laboratory. The 90% confidence level upper limits on κ of solar dark photon from 205.4 kg-day exposure are derived, probing new parameter space with masses (m V) from 10 to 300 eV=c 2 in direct detection experiments. Considering dark photon as the cosmological dark matter, limits at 90% confidence level with m V from 0.1 to 4.0 keV=c 2 are set from 449.6 kg-day data, with a minimum of κ ¼ 1.3 × 10 −15 at m V ¼ 200 eV=c 2 .

No abstract

In relativistic heavy-ion collisions, the light nuclei production is sensitive to the baryon density fluctuations and can be used to probe the QCD phase transition. Based on the coalescence production of light nuclei, we can extract the neutron density fluctuation from the yield ratio of proton (p), deuteron (d) and triton (t), Np × Nt/N 2 d . In this work, we studied the production of proton, deuteron, triton in Au+Au collisions at √200 GeV from a transport model (JAM model). We presented the energy dependence of rapidity density dN/dy, particle ratios (d/p, t/p, and t/d), and the yield ratio of Np × Nt/N 2 d . We found the energy dependence of the yield ratio is flat and cannot describe the non-monotonic trend observed by STAR experiment. This study can be used as a baseline to search for the QCD critical point and/or first order phase transition with light nuclei production in heavy-ion collisions.