80 research outputs found
Chiral symmetry breaking in confining theories and asymptotic limits of operator product expansion
The pattern of spontaneous chiral symmetry breaking (CSB) in confining
background fields is analyzed. It is explicitly demonstrated how to get the
inverse square root large proper time asymptotic of the operator product
expansion which is needed for CSB.Comment: LaTeX, 20 pages; minor revision
A molecular dynamics study on the equilibrium magnetization properties and structure of ferrofluids
We investigate in detail the initial susceptibility, magnetization curves,
and microstructure of ferrofluids in various concentration and particle dipole
moment ranges by means of molecular dynamics simulations. We use the Ewald
summation for the long-range dipolar interactions, take explicitly into account
the translational and rotational degrees of freedom, coupled to a Langevin
thermostat. When the dipolar interaction energy is comparable with the thermal
energy, the simulation results on the magnetization properties agree with the
theoretical predictions very well. For stronger dipolar couplings, however, we
find systematic deviations from the theoretical curves. We analyze in detail
the observed microstructure of the fluids under different conditions. The
formation of clusters is found to enhance the magnetization at weak fields and
thus leads to a larger initial susceptibility. The influence of the particle
aggregation is isolated by studying ferro-solids, which consist of magnetic
dipoles frozen in at random locations but which are free to rotate. Due to the
artificial suppression of clusters in ferro-solids the observed susceptibility
is considerably lowered when compared to ferrofluids.Comment: 33 pages including 12 figures, requires RevTex
Decomposition of the QCD String into Dipoles and Unintegrated Gluon Distributions
We present the perturbative and non-perturbative QCD structure of the
dipole-dipole scattering amplitude in momentum space. The perturbative
contribution is described by two-gluon exchange and the non-perturbative
contribution by the stochastic vacuum model which leads to confinement of the
quark and antiquark in the dipole via a string of color fields. This QCD string
gives important non-perturbative contributions to high-energy reactions. A new
structure different from the perturbative dipole factors is found in the
string-string scattering amplitude. The string can be represented as an
integral over stringless dipoles with a given dipole number density. This
decomposition of the QCD string into dipoles allows us to calculate the
unintegrated gluon distribution of hadrons and photons from the dipole-hadron
and dipole-photon cross section via kT-factorization.Comment: 43 pages, 14 figure
Mass spectra of doubly heavy Omega_QQ' baryons
We evaluate the masses of baryons composed of two heavy quarks and a strange
quark with account for spin-dependent splittings in the framework of potential
model with the KKO potential motivated by QCD with a three-loop beta-function
for the effective charge consistent with both the perturbative limit at short
distances and linear confinement term at long distances between the quarks. The
factorization of dynamics is supposed and explored in the nonrelativistic
Schroedinger equation for the motion in the system of two heavy quarks
constituting the doubly heavy diquark and the strange quark interaction with
the diquark. The limits of approach, its justification and uncertainties are
discussed. Excited quasistable states are classified by the quantum numbers of
heavy diquark composed by the heavy quarks of the same flavor.Comment: 14 pages, revtex4-file, 3 eps-figures, 5 tables, typos correcte
Double volume reflection of a proton beam by a sequence of two bent crystals
The doubling of the angle of beam deflection due to volume reflection of protons by a sequence of two bent silicon crystals was experimentally observed at the 400 GeV proton beam of the CERN SPS. A similar sequence of short bent crystals can be used as an efficient primary collimator for the Large Hadron Collider
Analysis on the Issue of East Financial Integration
在1997年金融危机发生后,东亚各国和地区意识到过分依赖外国的资金存在着巨大的风险。因此,为了避免对外国资金的过分依赖防止危机再次发生,东亚各国和地区通过完善金融体系,加强金融合作以推进金融一体化。 在此背景下,本文对东亚金融的一体化程度做出分析。本文对东亚各国和地区金融一体化的必要前提:东亚货币金融合作,东亚各国和地区资本市场放松管制情况、各国和地区的资本流动以及各国和地区股票及债券市场的发展进行了定性分析和描述,同时对各国投资与储蓄的相关性、各国消费者通过金融市场分散风险的程度、各国股票市场以及各国债券市场与两大国际市场间的联系,对东亚各国和地区金融市场一体化程度进行了实证分析。本文的研...East Asia has realized that it has great risk to depend on the foreign capital, after 1997 financial crisis. East Asia tried to improve the financial system and strengthen financial cooperation, so as to avoid the recurrence of financial crisis. This thesis tries to address the issue of the financial integration of East Asia. First of all, the basis of financial integration of East Asia was anal...学位:经济学博士院系专业:经济学院国际贸易系_世界经济学号:2005140292
Measurement of the branching ratio Γ(Λb⁰ → ψ(2S)Λ0)/Γ(Λb⁰ → J/ψΛ0) with the ATLAS detector
An observation of the decay and
a comparison of its branching fraction with that of the decay has been made with the ATLAS detector in
proton--proton collisions at TeV at the LHC using an integrated
luminosity of fb. The and mesons are
reconstructed in their decays to a muon pair, while the decay is exploited for the baryon reconstruction. The
baryons are reconstructed with transverse momentum GeV and pseudorapidity . The measured branching ratio of
the and decays is , lower than the expectation from the
covariant quark model.Comment: 12 pages plus author list (28 pages total), 5 figures, 1 table,
published on Physics Letters B 751 (2015) 63-80. All figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/BPHY-2013-08
АЛГОРИТМ РЕШЕНИЯ ЗАДАЧИ ОПТИМИЗАЦИИ ДЛЯ ЦИКЛИЧЕСКИХ РАСПИСАНИЙ С ПРЕРЫВАНИЯМИ
In this paper, we consider a model of the problem to determine the characteristics of the time-step computation process in hard real-time systems. We proposed a formal description of the timestep computation with preemption and its existence conditions. A necessary condition for the feasibility of the schedule was determined. We took into account the behavior of the function graphs to optimize the schedule. We analyzed the mathematical model features including the objective function and the constraints. In the paper we determined the upper and lower limits of total function variation. The possible approaches to solving the optimization problem were introduced. We proposed to solve that task by the branch and bound method. In the proposed approach the objective function is represented as the set or branches included in the method tree. We developed the algorithm to determine characteristics of the time-step computation process and give a detailed description. The performance of the algorithm was shown by test case.Анотаці
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