Recursive Construction of Higgs-Plus-Multiparton Loop Amplitudes: The Last of the Phi-nite Loop Amplitudes

We consider a scalar field, such as the Higgs boson H, coupled to gluons via the effective operator H tr G_{mu nu} G^{mu nu} induced by a heavy-quark loop. We treat H as the real part of a complex field phi which couples to the self-dual part of the gluon field-strength, via the operator phi tr G_{SD mu nu} G_{SD}^{mu nu}, whereas the conjugate field phi^dagger couples to the anti-self-dual part. There are three infinite sequences of amplitudes coupling phi to quarks and gluons that vanish at tree level, and hence are finite at one loop, in the QCD coupling. Using on-shell recursion relations, we find compact expressions for these three sequences of amplitudes and discuss their analytic properties.Comment: 63 pages, 7 figures; v2 references added; v3 minor typos corrected and note added; v4 fixed error in eq. (7.11) (lower limit of sum should be l=2, not l=3), also affecting eqs. (7.14), (8.20), (8.21), (8.27) and (8.28

The Step-Harmonic Potential

We analyze the behavior of a quantum system described by a one-dimensional asymmetric potential consisting of a step plus a harmonic barrier. We solve the eigenvalue equation by the integral representation method, which allows us to classify the independent solutions as equivalence classes of homotopic paths in the complex plane. We then consider the propagation of a wave packet reflected by the harmonic barrier and obtain an expression for the interaction time as a function of the peak energy. For high energies we recover the classical half-period limit.Comment: 19 pages, 7 figure

Quantum relative positioning in Hilbert space

A new class of state transformations that are quantum mechanically prohibited is introduced. These can be seen as the generalization of the universal-NOT transformation which, for all pure inputs state of a given Hilbert space produces pure outputs whose projection on the original state is fixed to a value smaller than one. The case of not pure output states is also addressed. We give an application of these transformations in the context of separability criteria.Comment: 5 pages, 1 figure; new material added: in particular we present an application of quantum movers in the context of separability criteria. Typos corrected. Phys. Rev. A, accepted for publicatio

The Automobile Industry and The Mexico-Us Free Trade Agreement

This paper considers the likely effect on the automobile industry of a free trade agreement between the U.S. and Mexico. As there are currently large restrictions on imports into Mexico, one important outcome of a free trade agreement would be the opening of the Mexican market to U.S. producers. This is consistent with the history of the international auto industry and the fact that the U.S.-Canada Auto Pact opened a new, large market to U.S. manufacturers. The current state of the Mexican auto industry is considered in great detail, suggesting that the Mexican industry will continue to prosper, increasing output but also relying heavily on production from U.S. owned plants and on inputs imported from the U.S. and Canada. However, much of the existing domestically oriented industry is likely to be replaced by other North American producers. Finally, an econometric demand analysis implies that economic growth together with declines in prices to world levels could rapidly expand the size of the Mexican auto market. The free trade agreement represents an opportunity for product diversification and rationalization in the auto industry.

Fast Spherical Harmonic Analysis: a quick algorithm for generating and/or inverting full sky, high resolution CMB Anisotropy maps

We present a fast algorithm for generating full sky, high resolution ($\sim 5'$) simulations of the CMB anisotropy pattern. We also discuss the inverse problem, that of evaluating from such a map the full set of $a_{\ell m}$'s and the spectral coefficients $C_\ell$. We show that using an Equidistant Cylindrical Projection of the sky substantially speeds up the calculations. Thus, generating and/or inverting a full sky, high resolution map can be easily achieved with present day computer technology.Comment: 13 pages, LaTex, 5 PostScript figures included, 1 colour plate available (PostScript version, 1.6 Mb) at http://itovf2.roma2.infn.it/natoli

Degradability of Bosonic Gaussian channels

The notion of weak-degradability of quantum channels is introduced by generalizing the degradability definition given by Devetak and Shor. Exploiting the unitary equivalence with beam-splitter/amplifier channels we then prove that a large class of one-mode Bosonic Gaussian channels are either weakly degradable or anti-degradable. In the latter case this implies that their quantum capacity Q is null. In the former case instead, this allows us to establish the additivity of the coherent information for those maps which admit unitary representation with single-mode pure environment.Comment: 7 pages, 1 figure, 1 table (minor editing

Efficiency of quantum controlled non-Markovian thermalization

We study optimal control strategies to optimize the relaxation rate towards the fixed point of a quantum system in the presence of a non-Markovian dissipative bath. Contrary to naive expectations that suggest that memory effects might be exploited to improve optimal control effectiveness, non-Markovian effects influence the optimal strategy in a non trivial way: we present a necessary condition to be satisfied so that the effectiveness of optimal control is enhanced by non-Markovianity subject to suitable unitary controls. For illustration, we specialize our findings for the case of the dynamics of single qubit amplitude damping channels. The optimal control strategy presented here can be used to implement optimal cooling processes in quantum technologies and may have implications in quantum thermodynamics when assessing the efficiency of thermal micro-machines.Comment: 7 pages, 3 figure

Local-channel-induced rise of quantum correlations in continuous-variable systems

It was recently discovered that the quantum correlations of a pair of disentangled qubits, as measured by the quantum discord, can increase solely because of their interaction with a local dissipative bath. Here, we show that a similar phenomenon can occur in continuous-variable bipartite systems. To this aim, we consider a class of two-mode squeezed thermal states and study the behavior of Gaussian quantum discord under various local Markovian non-unitary channels. While these in general cause a monotonic drop of quantum correlations, an initial rise can take place with a thermal-noise channel.Comment: 6 pages, 4 figure

Multivalent glycan arrays

Glycan microarrays have become a powerful technology to study biological processes, such as cell–cell interaction, inflammation, and infections. Yet, several challenges, especially in multivalent display, remain. In this introductory lecture we discuss the state-of-the-art glycan microarray technology, with emphasis on novel approaches to access collections of pure glycans and their immobilization on surfaces. Future directions to mimic the natural glycan presentation on an array format, as well as in situ generation of combinatorial glycan collections, are discussed