共查询到20条相似文献,搜索用时 31 毫秒
1.
The amt2/m2w order supersymmetric electroweak corrections arising from loops of chargino, neu tralino and squark to top quark pair production by gg fusion at LHC are calculated in the minimal supersymmetric model. We found that the corrections amount about a few percent. 相似文献
2.
We studied the leading supersymmetric contribution to top–antitop threshold production using the NRQCD framework. The one-loop matching to the potential and the Wilson coefficient of the leading 3S1 production current were considered. We point out that the leading correction to the potential is zero due to SU(3)c gauge invariance. This is true in general for any new physics that enters above the electroweak scale. The shape of the top quark pair production cross section is therefore almost unaffected near threshold, allowing a precise determination of the top quark mass based on the Standard Model calculations. The supersymmetric correction to the Wilson coefficient c1 of the production current decouples for heavy super particles. Its contribution is smaller than the Standard Model next-to-next-leading-log results. 相似文献
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We present the analytical and numerical investigations of chargino-pair productions via Drell-Yan process a t proton-proton collider in the frame of minimal supersymmetric extension at tree level. For the χi+χj-(i,j= 1,2) pair productions at the LHC, the cross section is in the order of 3~2.5 ×10-3 pb. We find that the cross sections of all kinds of chargino-pair production processes are strongly related to the SUSY Lagrangian parameters M2 and μ. 相似文献
4.
从有效性、稳定性和可行性三个方面, 对基于标记配对相干态光源的诱骗态量子密钥分配的性能进行了全面分析. 采用四组实验数据对基于标记配对相干态光源的三强度诱骗态方案的密钥生成效率、量子比特误码率和最优信号态强度与安全传输距离之间的关系进行了仿真和分析; 考虑到光源涨落, 对方案的稳定性进行了讨论和仿真; 并对基于标记配对相干态光源设计简单易实现方案的可行性进行了分析. 结论表明: 基于标记配对相干态光源的诱骗态方案性能在安全传输距离和密钥生成效率两方面都优于现有基于弱相干态光源和预报单光子源的诱骗态方案; 在光源强度涨落相同条件下, 标记配对相干态光源的稳定性逊于预报单光子源, 而优于相干态光源. 但是标记配对相干态光源在有效性上的优势可弥补其在稳定性上的不足; 且标记配对相干态光源的双模特性为设计简单易实现的被动诱骗态方案提供了条件.
关键词:
量子光学
量子密钥分配
标记配对相干态光源
性能 相似文献
5.
We study the N=2 supersymmetric E6 models on the 6-dimensional space–time where the supersymmetry and gauge symmetry can be broken by the discrete symmetry. On the space–time M4×S1/(Z2×Z2′)×S1/(Z2×Z2′), for the zero modes, we obtain the 4-dimensional N=1 supersymmetric models with gauge groups SU(3)×SU(2)×SU(2)×U(1)2, SU(4)×SU(2)×SU(2)×U(1), and SU(3)×SU(2)×U(1)3 with one extra pair of Higgs doublets from the vector multiplet. In addition, considering that the extra space manifold is the annulus A2 and disc D2, we list all the constraints on constructing the 4-dimensional N=1 supersymmetric SU(3)×SU(2)×U(1)3 models for the zero modes, and give the simplest model with Z9 symmetry. We also comment on the extra gauge symmetry breaking and its generalization. 相似文献
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7.
We calculate Wigner function, tomogram of the pair coherent state by using its Sehmidt decomposition in the coherent state representation. It turns out that the Wigner function can be seen as the quantum entanglement (QE) between two two-variable Hermite polynomials (TVHP) and the tomogram is further simplified as QE of two single-variable Hermite polynomials. The Husimi function of pair coherent state is also calculated. 相似文献
8.
We show that no radiative masses are acquired by the Goldstone pion supermultiplet in supersymmetric QCD. Thus, in contrast to ordinary QCD, the mass difference mπ2+−mπ20 remains zero even after electromagnetism is turned on. Bound state Goldstone supermultiplets obey a nonrenormalization theorem analogous to that obeyed by elementary chiral superfields. 相似文献
9.
FAN Hong-Yi 《理论物理通讯》2008,50(4):935-937
We propose a new two-fold integration transformation in p-q phase space
∫∫-∞∞(dp dq/π)e2i(p-x)(q-y)f(p,q)≡G( x,y),
which possesses some well-behaved transformation properties. We apply this
transformation to the Weyl ordering of operators, especially those Q-P
ordered and P-Q ordered operators. 相似文献
10.
S.Y. Choi B.C. Chung J. Kalinowski Y.G. Kim K. Rolbiecki 《The European Physical Journal C - Particles and Fields》2006,46(2):511-520
Neutralinos
in supersymmetric theories, the spin–1/2 Majorana–type superpartners of the U(1) and SU(2) neutral electroweak gauge bosons
and SU(2) neutral Higgs bosons, are expected to be among light supersymmetric particles so that they can be produced copiously
via direct pair production and/or from cascade decays of other sparticles such as sleptons at the planned Large Hadron Collider
and the prospective International Linear Collider. Considering the prospects of having both highly polarized neutralinos and
possibility of reconstructing their decay rest frames, we provide a systematic investigation of the three–body leptonic decays
of the neutralinos in the minimal supersymmetric standard model and demonstrate alternative ways for probing the Majorana
nature of the neutralinos and CP violation in the neutralino system. 相似文献
11.
The SO(7) limit of the fermion dynamical symmetry model (FDSM) is discussed. Using the vector coherent state theory (VCST), we construct the matrix elements of quadruple pair (D+) and quadrupole (P2) operators explicitly, then obtain a selection rule for E2 transition and a formula for the E2 transition rates of the SO(7) limit. As an experimental evidence of the FDSM's SO(7) limit, the B(E2) values for the Pd-Ru region in this way are calculated,and the predicted results are in good agreement with the experimental data. 相似文献
12.
Pair coherent state, is a state of a two-mode radiation field that is known as a state with non-gaussian wave function. In this paper, study on the pair coherent state, we notice that with superposition of two first terms of this states, one two-qubits formed. Because of the importance of two-qubits in theory of quantum entanglement, with two different measures with the title of concurrence and D-concurrence, we have studied the amount of entanglement and
discussed its details. At the end, we describe these measures for pair coherent states as a function of the amplitude of the SU(2) coherent states. 相似文献
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We firstly give a nonlocal method for generating pair coherent state with two traveling wave fields in distinct districts. The experimental scheme proposed is based on a two-mode photon number matching process, which employs weak cross-Kerr media and on/off detection. Then we discuss the details for implementing this scheme, showing that it is robust against the low quantum efficiency of photon detectors and offers nearly perfect pair coherent states. Finally, we show how a two-mode Schrödinger cat state and a generalized two-mode correlated photon number state can be prepared via this matching process. 相似文献
15.
The muon number violating (μ−, e−) conversion in the presence of nuclei is investigated. The effective operators resulting from various mechanisms, both photonic and non-photonic, are expressed in terms of nuclear coordinates: (i) for intermediate neutrino models, and (ii) for supersymmetric theories. Using these operators the (A, Z) dependence of the corresponding widths is discussed throughout the periodic table. For the coherent process the dependence of the conversion rate on the nuclear parameters is given in terms of the elastic nuclear form factors, which are obtained in the context of shell model, taking into account finite nucleon-size effects. For the inclusive μ−e conversion process the total rates are calculated for closed-shell nuclei. The method of calculation utilizes microscopic non-energy-weighted sum rules (closure). The isospindependent part of the total (μ−, e−) rate is also related to that of the total (μ−, vμ capture rate, the latter being calculated with Primakoff's phenomenological method. The agreement between the two provides a good test of the reliability of the shell-model closure calculations. For non-closed-shell nuclei the relevant rates can be obtained by interpolation techniques from the functions obtained in the present work for closed-shell nuclei. Finally the experimentally interesting ratio of the coherent to the total μ−e conversion rate is discussed. 相似文献
16.
Francesco Toppan 《Czechoslovak Journal of Physics》2004,54(11):1387-1392
This paper presents report of the joint work with Z. Popowicz, which appeared in J. Phys. A, concerning the construction of a manifestly N = 2 supersymmetric heavenly equation in 2 + 1 dimensions. Its integrability properties have been derived from an N = 2 supersymmetric Lax pair, based on the n limit of the sl(n;n + 1) superalgebra series. The superhydrodynamical type of restrictions to 1+1 dimensions have been analyzed. 相似文献
17.
The Schwinger representation of the SO(8) fermion pair algebra in terms ofd and quasispin vector (u, s, v) bosons is used in deriving a microscopic boson coherent state having both particle-hole and pair excitations. The coherent
state is the exact boson image of the HFB variational solution. We can study the shape phase transition and pairing behaviour
of the nuclear ground states using the coherent states. 相似文献
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采用关联表象变分波函数方案, 介入三个非经典关联效应, 求解有限温度双能态自旋-晶格声子耦合量子隧道系统的非经典态, 着重研究化解由于粒子自旋-单声子相互作用引起的量子涨落导致双能态系统的退相干性量子耗散. 这三个非经典关联效应是: 1) 声子位移-粒子自旋 (σz)间强非绝热关联; 2) 声子压缩态效应及其伴随发生的单声子相干态-声子压缩态两过程相干效应; 3) 由关联表象导致的声子位移(UD)与声子压缩(US)的表象关联非绝热修正. 结果表明: 由于引入粒子自旋-双声子相互作用, 大幅度地增强了声子场压缩态, 特别是更进一步极大幅度地增强了非经典压缩-相干态效应. 因此, 由粒子自旋-单声子相互作用产生的Debye-Walle相干弹性散射效应导致量子隧道项(-Δ0σx)的强烈指数衰减及其伴随严重的量子相干损失的极大幅度的抑制, 并且自旋-晶格声子耦合量子隧道系统的非经典态能量大幅度降低.
关键词:
非经典能态
量子隧穿相干损失
自旋-双声子相互作用
压缩相干态效应 相似文献