33,326 research outputs found
Two jets and missing signature to determine the spins of the new particles
We consider the spin determination of new colored particles in the missing
energy plus jets channel at the early stage of LHC. We use a three site moose
model to describe the low energy Lagrangian of all same spin partner (LHT or
UED like) models and check the gauge invariance of the amplitude. For the
benchmark production and decay channel , in contrast to those in supersymmetric models, there
are spin correlations which affect the polar and azimuthal angle distributions
of the quarks from the heavy partner decay. We show such effects
would be visible in the distribution and the
reconstructed azimuthal angle correlation using MAOS reconstruction.Comment: 20 pages, 9 figure
Computer program documentation for a subcritical wing design code using higher order far-field drag minimization
A subsonic, linearized aerodynamic theory, wing design program for one or two planforms was developed which uses a vortex lattice near field model and a higher order panel method in the far field. The theoretical development of the wake model and its implementation in the vortex lattice design code are summarized and sample results are given. Detailed program usage instructions, sample input and output data, and a program listing are presented in the Appendixes. The far field wake model assumes a wake vortex sheet whose strength varies piecewise linearly in the spanwise direction. From this model analytical expressions for lift coefficient, induced drag coefficient, pitching moment coefficient, and bending moment coefficient were developed. From these relationships a direct optimization scheme is used to determine the optimum wake vorticity distribution for minimum induced drag, subject to constraints on lift, and pitching or bending moment. Integration spanwise yields the bound circulation, which is interpolated in the near field vortex lattice to obtain the design camber surface(s)
Frequency-Bin Entanglement with Tunable Phase
We describe a technique to produce narrow-band photon pairs with
frequency-bin entanglement, whose relative phase can be tuned using linear
polarization optics. We show that, making use of the polarization-frequency
coupling effect, the phase of a complex polarizer can be transferred into the
frequency entanglement
Finite-size effect of antiferromagnetic transition and electronic structure in LiFePO4
The finite-size effect on the antiferromagnetic (AF) transition and
electronic configuration of iron has been observed in LiFePO4. Determination of
the scaling behavior of the AF transition temperature (TN) versus the
particle-size dimension (L) in the critical regime 1-TN(L)/TN(XTL)\simL^-1
reveals that the activation nature of the AF ordering strongly depends on the
surface energy. In addition, the effective magnetic moment that reflects the
electronic configuration of iron in LiFePO4 is found to be sensitive to the
particle size. An alternative structural view based on the polyatomic ion
groups of (PO4)3- is proposed.Comment: To be published in Phys. Rev. B - Rapid Communicatio
Gravitational collapse of magnetized clouds II. The role of Ohmic dissipation
We formulate the problem of magnetic field dissipation during the accretion
phase of low-mass star formation, and we carry out the first step of an
iterative solution procedure by assuming that the gas is in free-fall along
radial field lines. This so-called ``kinematic approximation'' ignores the back
reaction of the Lorentz force on the accretion flow. In quasi steady-state, and
assuming the resistivity coefficient to be spatially uniform, the problem is
analytically soluble in terms of Legendre's polynomials and confluent
hypergeometric functions. The dissipation of the magnetic field occurs inside a
region of radius inversely proportional to the mass of the central star (the
``Ohm radius''), where the magnetic field becomes asymptotically straight and
uniform. In our solution, the magnetic flux problem of star formation is
avoided because the magnetic flux dragged in the accreting protostar is always
zero. Our results imply that the effective resistivity of the infalling gas
must be higher by several orders of magnitude than the microscopic electric
resistivity, to avoid conflict with measurements of paleomagnetism in
meteorites and with the observed luminosity of regions of low-mass star
formation.Comment: 20 pages, 4 figures, The Astrophysical Journal, in pres
Dynamic Scoring: Alternative Financing Schemes
Neoclassical growth models predict that reductions in capital or labor tax rates are expansionary when lump-sum transfers are used to balance the government budget. This paper explores the consequences of bond-financed tax reductions that bring forth a range of possible offsetting policies, including future government consumption, capital tax rates, or labor tax rates. Through the resulting intertemporal distortions, current tax cuts can be contractionary. The paper also finds that more aggressive responses of offsetting policies to debt engender less debt accumulation and less costly tax cuts.
Temporal Quantum-State Tomography of Narrowband Biphotons
We describe and demonstrate a quantum state tomography for measuring the
complex temporal waveform of narrowband biphotons. Through six sets of
two-photon interference measurements projected in different polarization
subspaces, we can construct the time-frequency entangled two-photon joint
amplitude and phase functions in continuous-variable time domain. For the first
time, we apply this technique to experimentally determine the temporal quantum
states of narrowband biphotons generated from spontaneous four-wave mixing in
cold atoms, and fully confirm the theoretical predictions.Comment: 5 pages, 5 figure
A Family of Controllable Cellular Automata for Pseudorandom Number Generation
In this paper, we present a family of novel Pseudorandom Number Generators (PRNGs) based on Controllable Cellular Automata (CCA) ─ CCA0, CCA1, CCA2 (NCA), CCA3 (BCA), CCA4 (asymmetric NCA), CCA5, CCA6 and CCA7 PRNGs. The ENT and DIEHARD test suites are used to evaluate the randomness of these CCA PRNGs. The results show that their randomness is better than that of conventional CA and PCA PRNGs while they do not lose the structure simplicity of 1-d CA. Moreover, their randomness can be comparable to that of 2-d CA PRNGs. Furthermore, we integrate six different types of CCA PRNGs to form CCA PRNG groups to see if the randomness quality of such groups could exceed that of any individual CCA PRNG. Genetic Algorithm (GA) is used to evolve the configuration of the CCA PRNG groups. Randomness test results on the evolved CCA PRNG groups show that the randomness of the evolved groups is further improved compared with any individual CCA PRNG
Computing A Glimpse of Randomness
A Chaitin Omega number is the halting probability of a universal Chaitin
(self-delimiting Turing) machine. Every Omega number is both computably
enumerable (the limit of a computable, increasing, converging sequence of
rationals) and random (its binary expansion is an algorithmic random sequence).
In particular, every Omega number is strongly non-computable. The aim of this
paper is to describe a procedure, which combines Java programming and
mathematical proofs, for computing the exact values of the first 64 bits of a
Chaitin Omega:
0000001000000100000110001000011010001111110010111011101000010000. Full
description of programs and proofs will be given elsewhere.Comment: 16 pages; Experimental Mathematics (accepted
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