120598852
DECOMPOSITION OF SU(N) CONNECTION AND MASS GAP IN ITS EFFECTIVE THEORY
18661974
Decomposition Theory of Spin Connection and Topological Structure of Gauss-Bonnet-Chern Theorem on Manifold With Boundary
The index theorem of Euler-Poincar\'e characteristic of manifold with boundary is given by making use of the general decomposition theory of spin connection. We shows the sum of the total index of a vector field $\phi $ and half the total of the projective vector field of $\phi $ on the boundary equals the Euler-Poincar\'e characteristic of the manifold. Detailed discussion on the topological structure of the Gauss-Bonnet-Chern theorem on manifold with boundary is given. The Hopf indices and Brouwer degrees label the local structure of the Euler density.
119009381
Generalized structure of hadron-quark vertex function in Bethe-Salpeter framework : applications to leptonic decays of V-mesons
We employ the framework of the Bethe–Salpeter equation under a covariant instantaneous ansatz to study the leptonic decays of vector mesons. The structure of the hadron–quark vertex function Γ is generalized to include various Dirac covariants (other than iγ ⋅ e) from their complete set. They are incorporated in accordance with a naive power counting rule order-by-order in powers of the inverse of the meson mass. The decay constants for ρ, ω and mesons are calculated with the incorporation of leading-order covariants.
53510978
Threshold resummation for the production of a color sextet (antitriplet) scalar at the LHC
We investigate threshold resummation effects in the production of a color sextet (antitriplet) scalar at next-to-next-to-leading logarithmic (NNLL) order at the LHC in the frame of soft-collinear effective theory. We show the total cross section and the rapidity distribution with NLO+NNLL accuracy, and we compare them with the NLO results. Besides, we use recent dijet data at the LHC to give the constraints on the couplings between the colored scalars and quarks.
37649879
LAr TPC Electronics CMOS Lifetime at 300 K and 77 K and Reliability Under Thermal Cycling
A study of hot-carrier effects (HCE) on the 180-nm CMOS device lifetime has been performed at 300 K and 77 K for Liquid Argon Time Projection Chamber (LAr TPC). Two different measurements were used: accelerated lifetime measurement under severe electric field stress by the drain-source voltage Vds, and a separate measurement of the substrate current as a function of 1/Vds. The former verifies the canonical very steep slope of the inverse relation between the lifetime and the substrate current, and the latter confirms that below a certain value of Vds a lifetime margin of several orders of magnitude can be achieved for the cold electronics TPC readout. The low power ASIC design for LAr TPC falls naturally into this domain, where hot-electron effects are negligible. Lifetime of digital circuits (ac operation) is extended by the inverse duty factor 1/(fclockteff) compared to dc operation. This factor is large (> 100) for deep submicron technology and clock frequency needed for TPC readout. As an additional margin, Vds may be reduced by ~ 10%. Extremely low failure rate (incidence) in previous large experiments demonstrates that surface mount circuit board technology withstands very well even multiple abrupt immersion in liquid nitrogen applied in board testing, and that the total failure incidence in continuous operation over time is very low.
46336718
Propagation of field disturbances in Yang-Mills theory
The propagation of field disturbances is examined in the context of the effective Yang-Mills Lagrangian, which is intended to be applied to QCD systems. It is shown that birefringence phenomena can occur in such systems provided some restrictive conditions, as causality, are fulfilled. Possible applications to phenomenology are addressed.
118488945
Current leads for superconducting magnets of ADS injector I
In an ADS injector I, there are five superconducting magnets in each cryomodule. Each superconducting magnet contains a solenoid magnet, a horizontal dipole corrector (HDC), and a vertical dipole corrector (VDC). Six current leads will be required to power the electrical circuits, from room temperature to the 2.1 K liquid helium bath: two leads carry 100 A current for the solenoid magnet while the other four carry 12 A for the HDC and the VDC. This paper presents the principle of current lead optimization, which includes the cooling methods, the choice of material and structure, and the issues for current lead integration.