Using density functional theory,we investigate the vibrational properties and polarization-resolved Raman spectra ofα-PtO_(2) and obtain the Raman tensor and angle-dependent Raman intensity of α-PtO_(2).It is found ...Using density functional theory,we investigate the vibrational properties and polarization-resolved Raman spectra ofα-PtO_(2) and obtain the Raman tensor and angle-dependent Raman intensity of α-PtO_(2).It is found that the polar plot of A_(1g)mode in parallel polarization configuration is useful in identifying the orientation of the crystal.The Raman intensity of the E_(g) mode is about five times stronger than that of the A_(1g) mode.The Raman intensity is about three times stronger when the wave vector of the incident light is in x or y direction than in z direction.Our work will help the material scientists to characterize the α-PtO_(2) and to identify its orientation by comparing the experimental spectra with our result.展开更多
Type Ⅱ seesaw leptogenesis simultaneously explains the origin of neutrino masses,the baryon asymmetry of our universe,and inflation.The Large Hadron Collider(LHC)provides an opportunity to directly test type Ⅱ seesa...Type Ⅱ seesaw leptogenesis simultaneously explains the origin of neutrino masses,the baryon asymmetry of our universe,and inflation.The Large Hadron Collider(LHC)provides an opportunity to directly test type Ⅱ seesaw leptogenesis by looking for the predicted triplet Higgs.In this paper,we perform an analysis of the detection prospect for the triplet Higgs at the LHC through multi-electron channels.We find that due to the contribution of the pp→H^(±±)H^(∓) process,the sensitivity of multi-electron channels searching for doubly-charged Higgs pair production can be improved.We also investigate the 3e+E_(T)^(miss) signals to probe pp→H^(±±)H^(∓) production and find that the future high luminosity LHC could probe a triplet Higgs around 1.2 TeV at the 2σlevel.展开更多
Dark matter(DM)direct detection experiments have been setting strong limits on the DM-nucleon scattering cross section at the DM mass above a few GeV,but leave large parameter spaces unexplored in the low mass region....Dark matter(DM)direct detection experiments have been setting strong limits on the DM-nucleon scattering cross section at the DM mass above a few GeV,but leave large parameter spaces unexplored in the low mass region.DM is likely to be scattered and boosted by relativistic cosmic rays in the expanding universe if it can generate nuclear recoils in direct detection experiments to offer observable signals.Since low energy threshold detectors using Germanium have provided good constraints on ordinary halo GeV-scale DM,it is necessary to re-analyze102.8 kgxday data in the CDEX-10 experiment assuming that DM is boosted by cosmic rays.For the DM mass range 1 keV<m_(χ)<1 MeV and the effective distance within 1 kpc,we reach an almost flat floor limit at8.32×10^(-30) cm^(2) for the spin-independent DM-nucleon scattering cross section,at a 90%confidence level.The CDEX-10 result is able to close the gap unambiguously in the parameter space between the MiniBooNE and XENON IT constraints,which were partially hindered by the Earth attenuation effect.We also quantitatively calculate the expected neutrino floor on searching for CRBDM in future direct detection experiments using Germanium.展开更多
基金Project supported by the Key-Area Research and Development Program of Guang Dong Province,China(Grant No.2019B030330001)the National Key R&D Program of China(Grant No.2016YFA0202000)+2 种基金the Natural Science Foundation of Guangdong Province,China(Grant No.2018B030311045)the National Natural Science Foundation of China(Grant No.11704419)the Physical Research Platform(PRP)in School of Physics,SYSU。
文摘Using density functional theory,we investigate the vibrational properties and polarization-resolved Raman spectra ofα-PtO_(2) and obtain the Raman tensor and angle-dependent Raman intensity of α-PtO_(2).It is found that the polar plot of A_(1g)mode in parallel polarization configuration is useful in identifying the orientation of the crystal.The Raman intensity of the E_(g) mode is about five times stronger than that of the A_(1g) mode.The Raman intensity is about three times stronger when the wave vector of the incident light is in x or y direction than in z direction.Our work will help the material scientists to characterize the α-PtO_(2) and to identify its orientation by comparing the experimental spectra with our result.
基金C.H.is supported by the Sun Yat-Sen University Science Foundation,and the Fundamental Research Funds for the Central Universities,Sun Yat-sen University(23qnpy58)。
文摘Type Ⅱ seesaw leptogenesis simultaneously explains the origin of neutrino masses,the baryon asymmetry of our universe,and inflation.The Large Hadron Collider(LHC)provides an opportunity to directly test type Ⅱ seesaw leptogenesis by looking for the predicted triplet Higgs.In this paper,we perform an analysis of the detection prospect for the triplet Higgs at the LHC through multi-electron channels.We find that due to the contribution of the pp→H^(±±)H^(∓) process,the sensitivity of multi-electron channels searching for doubly-charged Higgs pair production can be improved.We also investigate the 3e+E_(T)^(miss) signals to probe pp→H^(±±)H^(∓) production and find that the future high luminosity LHC could probe a triplet Higgs around 1.2 TeV at the 2σlevel.
基金Supported in part by Guangdong Basic and Applied Basic Research Foundation (2019A1515012216)National Undergraduate Innovation and Entrepreneurship Training Program (20201023)the CAS Center for Excellence in Particle Physics (CCEPP)。
文摘Dark matter(DM)direct detection experiments have been setting strong limits on the DM-nucleon scattering cross section at the DM mass above a few GeV,but leave large parameter spaces unexplored in the low mass region.DM is likely to be scattered and boosted by relativistic cosmic rays in the expanding universe if it can generate nuclear recoils in direct detection experiments to offer observable signals.Since low energy threshold detectors using Germanium have provided good constraints on ordinary halo GeV-scale DM,it is necessary to re-analyze102.8 kgxday data in the CDEX-10 experiment assuming that DM is boosted by cosmic rays.For the DM mass range 1 keV<m_(χ)<1 MeV and the effective distance within 1 kpc,we reach an almost flat floor limit at8.32×10^(-30) cm^(2) for the spin-independent DM-nucleon scattering cross section,at a 90%confidence level.The CDEX-10 result is able to close the gap unambiguously in the parameter space between the MiniBooNE and XENON IT constraints,which were partially hindered by the Earth attenuation effect.We also quantitatively calculate the expected neutrino floor on searching for CRBDM in future direct detection experiments using Germanium.
