4,284 research outputs found
Excitation function of elastic scattering from a unitarily extended Bialas-Bzdak model
The Bialas-Bzdak model of elastic proton-proton scattering assumes a purely
imaginary forward scattering amplitude, which consequently vanishes at the
diffractive minima. We extended the model to arbitrarily large real parts in a
way that constraints from unitarity are satisfied. The resulting model is able
to describe elastic scattering not only at the lower ISR energies but also
at 7 TeV in a statistically acceptable manner, both in the
diffractive cone and in the region of the first diffractive minimum. The total
cross-section as well as the differential cross-section of elastic
proton-proton scattering is predicted for the future LHC energies of
8, 13, 14, 15 TeV and also to 28 TeV. A non-trivial, significantly
non-exponential feature of the differential cross-section of elastic
proton-proton scattering is analyzed and the excitation function of the
non-exponential behavior is predicted. The excitation function of the shadow
profiles is discussed and related to saturation at small impact parameters.Comment: Talk by T. Csorgo presented at the WPCF 2014 conference, Gyongyos,
Hungary, August 25-29 201
Parametric Competition in non-autonomous Hamiltonian Systems
In this work we use the formalism of chord functions (\emph{i.e.}
characteristic functions) to analytically solve quadratic non-autonomous
Hamiltonians coupled to a reservoir composed by an infinity set of oscillators,
with Gaussian initial state. We analytically obtain a solution for the
characteristic function under dissipation, and therefore for the determinant of
the covariance matrix and the von Neumann entropy, where the latter is the
physical quantity of interest. We study in details two examples that are known
to show dynamical squeezing and instability effects: the inverted harmonic
oscillator and an oscillator with time dependent frequency. We show that it
will appear in both cases a clear competition between instability and
dissipation. If the dissipation is small when compared to the instability, the
squeezing generation is dominant and one can see an increasing in the von
Neumann entropy. When the dissipation is large enough, the dynamical squeezing
generation in one of the quadratures is retained, thence the growth in the von
Neumann entropy is contained
Protecting, Enhancing and Reviving Entanglement
We propose a strategies not only to protect but also to enhance and revive
the entanglement in a double Jaynes-Cummings model. We show that such
surprising features arises when Zeno-like measurements are performed during the
dynamical process
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