117931252
The Properties of $D^{*}_{s1}(2700)^{+}$
The new particle $D^{*}_{s1}(2700)^{+}$ has stimulated many attentions. There are different assignments of its inherent properties. It may be a $2^3S_1$, $1^3D_1$ or the mixture of $2^3S_1-1^3D_1$ $c\bar s$ $1^-$ state. By considering its mass, decay modes, full width, production rate, and comparing with current experimental data, we point out that there is another more reasonable assignment: $D^{*}_{s1}(2700)^{+}$ could be identified as two resonances, one of which is a $2^3S_1$ state, another is a 1D state, and both are $c\bar s$ $1^-$ states. The two states have very close masses, which are around 2700 MeV, and both have broad decay widths. So in experiments, the overlapping of $DK$ or $D^*K$ invariant mass distribution coming from their decays is found, but the current experiments could not distinguish these two resonances and reported one particle.
123145784
OZI-ALLOWED TWO BODY ϒ DECAYS IN THE 3P0 MODEL WITH THE RELATIVISTIC WAVE FUNCTIONS
We combine the Bethe–Salpeter method with the 3P0 model to describe OZI-allowed two body meson decays. In this combined method, the relativistic wave functions defined in the Salpeter equation show up in the decay amplitude of the 3P0 model automatically. We apply the method to OZI-allowed ϒ(4S, 5S, 6S) two body decays. The results are roughly consistent with the experimental data and the predictions of ϒ(6S) decays are given.
14636359
Some low dimensional evidence for the weak gravity conjecture
We discuss a few examples in 2+1 demensions and 1+1 dimensions supporting a recent conjecture concerning the relation between the Planck scale and the coupling strength of a non-gravitional interaction. Unlike those examples in 3+1 dimensions, we do not have to resort to exotic physics such as small black holes. However, the result concerning these low dimensional examples is a direct consequence of the 3+1 dimensional conjecture.
118367171
Static Solutions with Spherical Symmetry in f(T) Theories
The spherically symmetric static solutions are searched for in some f(T) models of gravity theory with a Maxwell term. To do this, we demonstrate that reconstructing the Lagrangian of f(T) theories is sensitive to the choice of frame, and then we introduce a particular frame based on the conformally Cartesian coordinates. In this particular frame, the existence conditions of various solutions are presented. Our results imply that only a limited class of f(T) models can be solved in this frame. For more general models, the search for spherically symmetric static solutions is still an open and challenging problem, hopefully solvable in other frames.
122356377
The use of the discriminant analysis method for e π μ separation in BES
Abstract We use the discriminant analysis method in multivariate statistical theory to handle the e π μ separation in BES, describing the principle of the discriminant analysis method, deriving the unstandardized discriminant functions (responsible for particle separation), giving the discriminant efficiency for e π μ and comparing the results from the discriminant analysis method with those obtained in a conventional way.
119449490
A Rotating Kaluza-Klein black hole with squashed horizons
We find a rotating Kaluza-Klein black hole solution with squashed S-3 horizons in five dimensions. This is a Kerr counterpart of the charged one found by Ishihara and Matsuno [H. Ishihara, K. Matsuno, Kaluza-Klein black holes with squashed horizons. hep-th/0510094] recently. The space-time is geodesic complete and free of naked singularities. Its asymptotic structure is a twisted S' fiber bundle over a four-dimensional Minkowski space-time. We also study the mass and thermodynamics of this black hole. (c) 2006 Elsevier B.V. All rights reserved.
119218213
Four IRAC Sources with an Extremely Red H – [3.6] Color: Passive or Dusty Galaxies at z > 4.5?
We report the detection of four IRAC sources in the GOODS-South field with an extremely red color of H - [3.6] > 4.5. The four sources are not detected in the deep Hubble Space Telescope WFC3 H-band image with H-limit = 28.3 mag. We find that only three types of SED templates can produce such a red H -[3.6] color: a very dusty SED with the Calzetti extinction of A(V) = 16 mag at z = 0.8; a very dusty SED with the SMC extinction of AV = 8 mag at z = 2.0-2.2; and an 1 Gyr SSP with A(V) similar to 0.8 at z = 5.7. We argue that these sources are unlikely dusty galaxies at z 4.5 remains a possible solution for the 4 sources. At z > 4.5, these sources have stellar masses of log(M-*/M-circle dot) = 10.6-11.2. One source, ERS-1, is also a type-II X-ray QSO with L2-8 (keV) = 1.6 x 10(44) er gs(-1). One of the four sources is an X-ray QSO and another one is a HyperLIRG, suggesting a galaxy-merging scenario for the formation of these massive galaxies at high redshifts.