分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: We list all possible dimension-six CP-conserving SUc(3)×SUL(2)×UY(1)SUc(3)×SUL(2)×UY(1)SU_c(3)\times SU_L(2) \times U_Y(1) invariant operators involving the third-family quarks which could be generated by new physics at a higher scale. Expressions for the
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: We discuss single top quark production via u^i+\bar d^j \to t+\bar b at the Fermilab Tevatron in the minimal supersymmetric model with R-parity violation. We find that within the allowed range of coupling constants, the lepton-number violating couplings c
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: The dimension-six CP-violating SU_L(2)\times U_Y(1) invariant operators involving the tau lepton are studied. The constraints from the available experimental data on tau dipole moments are derived. Under the current constraints, the induced CP-violating e
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-16
摘要: We discuss single top quark production via u(i) (d) over bar(j)-->t (b) over bar at the Fermilab Tevatron in the minimal supersymmetric model with R-parity violation. We find that within the allowed range of coupling constants, the lepton-number-violating couplings can give rise to observable effects when the slepton mass lies in a specific narrow range. For the baryon number-violating couplings, the contribution to the production rate can be quite large in the presently allowed range of the coupling constants. We show that the measurement of single top quark production at the upgraded Tevatron can be used to constrain a linear combination of products of the R-parity-violating couplings.
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-16
摘要: We list all possible dimension-six CP-conserving SUc(3)xSU(L)(2)xU(Y)(1)-invariant operators involving the third-family quarks which could be generated by new physics at a higher scale. Expressions for these operators after electroweak gauge symmetry breaking and the induced effective couplings Wt(b) over bar, Xb(b) over bar, and Xt(t) over bar (X = Z, gamma,g, H) are presented. Analytic expressions for the tree level contributions of all these operators to the observables R-b and A(FB)(b) at CERN LEP I, sigma(e(+)e(-) --> ) and A(FB)(b) at LEP II, sigma(e(+)e(-) --> ) and A(FB)(t) at the Next Linear Collider (NLC). as well as sigma( --> + X) at the Fermilab Tevatron upgrade, are provided. The effects of these operators on different electroweak observables are discussed and numerical examples presented. Numerical analyses show that in the coupling region allowed by R-b and A(FB)(b) at LEP I, some of the new physics operators can still have significant contributions at LEP II, the Tevatron, and the NLC.
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: We investigate the ability of single top quark production via qq'-> squark->tb and q \bar q'->slepton->t\bar b at the LHC and Tevatron to probe the strength of R-parity violating couplings in the minimal supersymmetric model. We found that given the exist
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: We study in the effective Lagrangian approach the possibility of probing anomalous top quark charged current couplings in the single top production at a high energy e\gamma collider. We analyzed all possible dimension-six CP-conserving operators which can
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: We investigate the possibility of observing the exotic decay mode of the top quark into the lightest stop (t~1t~1\tilde t_1) and neutralino (χ~01χ~10\tilde\chi^0_1) in the minimal supersymmetric standard model with R-parity at the upgraded Tevatron. First
分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-05-16
摘要: This talk is a review of the recent studies on probing new physics through single top quark processes and probing exotic top quark decays at the upgraded Tevatron.
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: This talk is a brief review of the recent studies on probing new physics through single top quark processes and probing exotic top quark decays at the upgraded Tevatron.
分类: 动力与电气工程 >> 工程热物理学 提交时间: 2017-06-22 合作期刊: 《热科学学报》
摘要: Effects of the uneven circumferential blade space on static characteristics and aerodynamic noise of a small axial flow fan are studied in this work. The blade angle modulation is adopted to design a series of unequally spaced fans, which have different maximum of modulation angular displacement. The steady flow is simulated by the calculations of Navier-Stokes equations coupled with RNG k-epsilon turbulence model, while the unsteady flow is computed with large eddy simulation. According to theoretical analysis, a fan with a maximum of modulation angular displacement of 6 is regarded as the optimal unequally spaced fan. The experiment of static characteristic is carried out in a standard wind tunnel and the aerodynamic noise of both fans is tested in a semi-anechoic room. Then, performances of the optimal unequally spaced fan are compared with those of the prototype fan. The results show that there is reasonable agreement between the simulation results and the experimental data. It is found that the discrete noise of the optimal unequally spaced fan is lower than that of the prototype fan at the near field monitoring point. This can be explained that the total pressure fluctuation of the optimal unequally spaced fan is much more regular than that of the prototype fan.
分类: 分类: 物理学 >> 基本粒子与场物理学 提交时间: 2016-12-28
摘要: We discuss the prospects of a very long baseline neutrino oscillation experiment from HIPA to Beijing. The current understanding of neutrino oscillations, both theoretically and experimentally, are summarized. The figure of merits for interested physics m
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: Engineered pillars, pits and grooves spaced 3, 6, 9 and 12 m apart were fabricated on siloxane modified acrylic resin films. The effect of feature size, geometry, and wettability on the settlement of different algae was evaluated. These films showed various antifouling performances to Ulothrix, Closterium and Navic- ula. For Navicula (length: 10–12 m), the feature size and geometry displayed a substantial correlation with the antifouling properties. The film with pillars spaced 3 m reduced Navicula settlement by 73% compared to the control surface. For Closterium (length: 45–55 m), their responses were governed by the same underlying thermodynamic principles as wettability, the largest reduction in Closterium, 81%, was obtained on the surface with grooves spaced 12 m apart. For Ulothrix (length: 5–8 mm), the surface also showed the best antifouling performance, the reduction ratio of the settlement on the surface with grooves spaced 12 m apart could even reach 92%. At last, physical fouling deterrent mechanisms for the films with various textures were analyzed in detail. The feature size and geometry display a substantial correlation with the antifouling properties when the size of fouling algae is close to the textures. With the increasing size for algae, antifouling performance was getting better on surface with pillars or grooves because the algae are bridged between two or more features other than stabilizing its entire mass on one single feature or able to settle between features.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-05-02
摘要: We obtained a single phase BLS:Eu2+, Ce3+, Mn2+ phosphor by solid-state reactions. Eu2+, Ce3+, and Mn2+ gives rise to the blue, green, and red emission, respectively. The Mn2+ red emission can be effectively enhanced via energy transfers from both Eu2+ and Ce3+. Thus a tunable full color emission from 410 to 750 nm was realized in this single phosphor. The Eu2+ ! Mn2+ energy transfer mechanism was investigated by the fluorescence decay curves. This single phosphor exhibits an efficient excitation band covering from 390 to 410 nm, which matches well with the emission light of the efficient NUV chips. The optimized BLS:Eu2+, Ce3+, Mn2+ phosphor shows a high quantum efficient of $62% and a good color stability. When this single phosphor was combined with a 395 nm NUV-chip, an ideal white LED with a high color render index (CRI) of 85 and a correlated color temperature (CCT) of 6300 K was obtained. This demonstrates the promising application of the BLS:Eu2+, Ce3+, Mn2+ single phosphor for the NUV-based white LEDs.