120528491
Tau-Charm factory project at Beijing
Abstract The Tau-Charm Factory (TCF) is a proposed high luminosity e + e − collider at the threshold region of the production of τ and charm. It could provide many precision measurements and search for new phenomena in the flavor physics. IHEP, Beijing, is an ideal cite to build a TCF. The status of the feasibility study of Beijing Tau-Charm Factory (BTCF) is reported.
138378034
PERFORMANCES OF THE AMS-02 ELECTROMAGNETIC CALORIMETER
198142987
Permanent magnet system of alpha magnetic spectrometer
Alpha magnetic spectrometer (AMS) is the first large magndtic spectrometer in space. Its precursor flioht was completed successfully in June 1998. The key part of AMS is the permanent magnet system, which was built by the lnstitute of Electric Engineering, the institute of High Energy Physics and the Chinese Academy of Launch Vehicle Technology. This system includes a permanent magnet made of high grade NdFeB and a support structure. The unique design of the permanent magnet based on the magic ring fulfills the severe requirements on the magnetic field leakage and the dipole moment for space experiments. The permanent magnet weighs about 2 tons, and provides a geometric acceptance of 0.6 m2 · sr and an analyzing powerBL2 of 0.135 T · m2. It works up to 40°C without demagnetization. The main structure is a thin double shell, which undergoes the strong magnetic force and torque of the permanent magnet, as well as the large load during launching and landing. The permanent magnet system fulfills the requirements from AMS, and satisfies the strict safety standards of NASA.
122972869
Experimental tests of electroweak theories at MARK-J
121288070
A strategy for the precision measurement of MW at the threshold of the W-pair production☆
Abstract A data-driven maximum likelihood scanning strategy (BES method), which has been successfully used to measure the τ mass, is proposed to measure M W near the threshold of the W + W − production at LEP phase II. The Monte Carlo study has shown that with about 45 pb −1 per experiment, and combining the number of W + W − events from the 4 LEP experiments, one could obtain an accuracy on M W of 77 MeV (statistical error only) with the data-driven maximum likelihood search. With the proposed luminosity at the threshold, the statistical error is dominant in the uncertainties of the measurement.
119261928
THz meta-foil: A New photonic material
Seeing sharper or becoming invisible are visions strongly driving the development of THz metamaterials. Strings are a preferred architecture of metamaterials as they extend continuously along one dimension. Here, we demonstrate that laterally interconnecting strings by structural elements that are placed in oscillation nodes such as to not quench electromagnetic resonances enables manufacturing of self-supported free-standing all-metal metamaterials. Upright S-strings, interconnected by rods, form a space-grid which we call meta-foil. In this way, we introduce binding between the "atoms" of the metamaterial, thus doing away with conventional "frozen-in solutions" like matrix embedding or thin films on substrates. Meta-foils are locally stiff, yet globally flexible. Even bent to cylinders of 1 cm radius, they maintain their spectral response, thus becoming true metamaterials on curved surfaces. Exploiting UV/X-ray lithography and ultimately plastic moulding, meta-foils can be cost-effectively manufactured in large areas and quantities to serve as optical elements.
17995666
On the scattering of magnon boundstates
We study the scattering of magnon boundstates in the spin-chain description of planar = 4 SUSY Yang-Mills. Starting from the conjectured exact S-matrix for magnons in the SU(2) sector, we calculate the corresponding S-matrix for boundstates with an arbitrary number of constituent magnons. The resulting expression has an interesting analytic structure with both simple and double poles. We also calculate the semiclassical S-matrix for the scattering of the corresponding excitations on the string worldsheet known as Dyonic Giant Magnons. We find precise agreement with the magnon boundstate S-matrix in the limit of large 't Hooft coupling.
119166024
Heterotic surface defects and dualities from 2d/4d indices
A bstractStarting with the superconformal indices for 4d N=2$$ \mathcal{N}=2 $$ and N=1$$ \mathcal{N}=1 $$ supersymmetric gauge theories, that are related by superpotential deformation, we perform the contour integrations and isolate the residue contributions which can be attributed to the surface defects. These defects can be interpreted as the IR limit of dynamical vortices. Given the 2d N=22$$ \mathcal{N}=\left(2,2\right) $$ and N=02$$ \mathcal{N}=\left(0,2\right) $$ world sheet theories for these surface defects, we then verify this statement by explicitly computing their elliptic genera and identifying their fugacity parameters through superconformal algebras. We show them precisely match, hence extend previous prescriptions for inserting surface defects into 4d supersymmetric partition functions to N=1$$ \mathcal{N}=1 $$ setting. We also study how 4d N=1$$ \mathcal{N}=1 $$ IR dualities descend into the N=02$$ \mathcal{N}=\left(0,2\right) $$ world sheet theories of their surface defects, and extend the N=22$$ \mathcal{N}=\left(2,2\right) $$ triality observed earlier to other N=02$$ \mathcal{N}=\left(0,2\right) $$ surface defects unrelated to dynamical vortices.
15698837
Dyonic giant magnons
We study the classical spectrum of string theory on AdS5 ? S5 in the Hofman-Maldacena limit. We find a family of classical solutions corresponding to Giant Magnons with two independent angular momenta on S5. These solutions are related via Pohlmeyer's reduction procedure to the charged solitons of the Complex sine-Gordon equation. The corresponding string states are dual to BPS boundstates of many magnons in the spin-chain description of planar = 4 SUSY Yang-Mills. The exact dispersion relation for these states is obtained from a purely classical calculation in string theory.
118658279
A simple grand unified relation between neutrino mixing and quark mixing
A bstractIt is proposed that all flavor mixing is caused by the mixing of the three quark and lepton families with vectorlike fermions in $ 5+\bar{5} $ multiplets of SU(5). This simple assumption implies that both VCKM and UM N S are generated by a single matrix. The entire 3 × 3 complex mass matrix of the neutrinos Mv is then found to have a simple expression in terms of two complex parameters and an overall scale. Thus, all the presently unknown neutrino parameters are predicted. The best fits are for θatm ≲ 40°. The leptonic Dirac CP phase is found to be somewhat greater than π.
17544914
Precision test of AdS/CFT in Lunin-Maldacena background
We obtain the solutions and explicitly calculate the energy for a class of two-spin semiclassical string states in the Lunin-Maldacena background. These configurations are the β-deformed versions of the folded string solutions in AdS5 × S5 background. They correspond to certain single trace operators in the = 1 superconformal β deformation of = 4 Yang-Mills. We calculate the one loop anomalous dimension for the dual single trace operators from the associated twisted spin chain with a general two-cut distribution of Bethe roots. Our results show a striking match between the two calculations. We demonstrate the natural identification of parameters on the two sides of the analysis, and explain the significance of the Virasoro constraint associated with the winding motion of semiclassical strings from the perspective of the spin chain solution.