118068874
Topological Defects in 3-d Euclidean Gravity
By making use of the complete decomposition of SO(3) spin connection, the topological defect in 3-dimensional Euclidean gravity is studied in detail. The topological structure of disclination is given as the combination of a monopole structure and a vortex structure. Furthermore, the Kac-Moody algebra generated by the monopole and vortex is discussed in three dimensional Chern-Simons 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.
15957415
The topological structure of the space–time disclination
The space–time disclination is studied by making use of the decomposition theory of gauge potential in terms of the antisymmetric tensor field and φ-mapping method. It is shown that the self-dual and anti-self-dual parts of the curvature compose the space–time disclinations which are classified in terms of topological invariants—winding number. The projection of space–time disclination density along an antisymmetric tensor field is quantized topologically and characterized by Brouwer degree and Hopf index.
120598852
DECOMPOSITION OF SU(N) CONNECTION AND MASS GAP IN ITS EFFECTIVE THEORY
115465221
OPERA Collaboration have observed phase speed of neutrino wave function, while advanced time displacement is mainly due to finite life time of pion
First we call the attention that velocity defined by ratio between some intervals of space and time respectively is sometimes ambiguous, in the framework of quantum theory. Velocity in general is not possible to be well defined as some generator of certain space-time symmetry operation. Then in section 3 by analyzing the OPERA experiment we show that the OPERA Collaboration may have measured the phase speed of the neutrino wave function. Employing a very (maybe too) simple model which is just a reproduction from Brillouin's classical book, we demonstrate the phase velocity and group velocity. These are just a qualitative illustration rather than aiming to quantitively explain the OPERA data. However, how to rigorously define the phase containing the particle production ordering information as a space-time distribution observable in QFT needs more investigations. Due to the finite life time of the pions (w.r.t. its flying time in the 1 km long tunnel) which decay to the muon neutrinos, the wave form for neutrinos recorded by OPERA is deformed from that of the proton. Such an effect is estimated to lead to an advanced time displacement of the order of 100ns, which coincides with the measured. Such an effect can only be significant when measuring phase speed and the recorded neutrino events per extraction of proton smaller than one, as the OPERA case.
47538620
VMM1 - An ASIC for micropattern detectors
We present VMM1, the first prototype of a family of front-end ASICs designed for the ATLAS muon upgrade. The ASIC will operate with MICRO MEG AS and TGC detectors providing charge and timing measurements along with a number of features including sub-hysteresis discrimination, address of the first event in real time, and digital output per channel for Time-over-Threshold measurements. The shaper, designed using the concept of Delayed Dissipative Feedback (DDF), allows analog dynamic ranges in excess of 10,000. With a capacitance of 200 pF and a nominal peaking time of 25 ns it can provide charge and timing resolution below 1 fC and Ins respectively, for input charges up to 2 pc. Designed in a commercial 130 nm technology it dissipates about 4.5 mW per channel.
118680063
Search for a doubly charmed hadron at B factories
The doubly charmed hadron production at B factories is of special importance for the study of the hadron structure and the color connections before hadronization. To suppress the combination background fluctuations of the reconstructed hadron mass spectra, we suggest a three-jet event shape trigger. After these three jets are identified by their energy and angular distributions, it is found that: 1) The background process $e^+ e^- \to c\bar {c} \to h's$ in consideration of the final hadron system $\Lambda_c^+K^-\pi^+ +X$ are significantly suppressed. 2) For the selected events, about half of the particles, $\Lambda_c^+$, $K^-$, $\pi^+$, which obviously can not belong to the decay products of doubly charmed hadron, can be vetoed. The relevant hadronization is investigated.
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.
118740978
Constraints on Randall-Sundrum model from the events of dijet production with QCD next-to-leading order accuracy at the LHC
We study the dijet production in Randall-Sundrum model at the LHC with QCD next-to-leading(NLO) order accuracy. Our results show that the QCD NLO corrections can increase the total cross sections by more than $80\%$ and reduce the scale dependence. We also explore in detail several important kinematic distributions at the NLO level. Moreover, we discuss the upper limits of the KK graviton excluded mass range and the allowed parameter space for the coupling constant and KK graviton mass, using the experiment data.