3,076 research outputs found
First Results of a Detailed Analysis of p+p Elastic Scattering Data from ISR to LHC Energies in the Quark-Diquark Model
First results of a detailed analysis of p+p elastic scattering data are
presented from ISR to LHC energies utilizing the quark-diquark model of protons
in a form proposed by Bialas and Bzdak. The differential cross-section of
elastic proton-proton collisions is analyzed in detailed and systematic manner
at small momentum transfers, starting from the energy range of CERN ISR at
GeV, including also recent TOTEM data at the present LHC
energies at TeV. These studies confirm the picture that the size
of protons increases systematically with increasing energies, while the size of
the constituent quarks and diquarks remains approximately independent of (or
only increases only slightly with) the colliding energy. The detailed analysis
indicates correlations between model parameters and also indicates an
increasing role of shadowing at LHC energies.Comment: Proceeding from conference material, which was presented by F. Nemes
at the Wilhelm and Else Heraeus SummerSchool on Diffractive and
Electromagnetic Processes at High Energies, Heidelberg, Germany, September
5-9, 201
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
Semiclassical analysis of defect sine-Gordon theory
The classical sine-Gordon model is a two-dimensional integrable field theory,
with particle like solutions the so-called solitons. Using its integrability
one can define its quantum version without the process of canonical
quantization. This bootstrap method uses the fundamental propterties of the
model and its quantum features in order to restrict the structure of the
scattering matrix as far as possible. The classical model can be extended with
integrable discontinuities, purely transmitting jump-defects. Then the quantum
version of the extended model can be determined via the bootstrap method again.
But the outcoming quantum theory contains the so-called CDD uncertainity. The
aim of this article is to carry throw the semiclassical approximation in both
the classical and the quantum side of the defect sine-Gordon theory. The CDD
ambiguity can be restricted by comparing the two results. The relation between
the classical and quantum parameters as well as the resoncances appeared in the
spectrum are other objectives
Perturbed kepler problem in general relativity with quaternions
The motion of binary star systems is re-examined in the presence of perturbations from the theory of general relativity. To handle the singularity of the Kepler problem, the equation of motion is regularized and linearized with quaternions. In this way first-order perturbation results are derived using the quaternion-based approach. </jats:p
Elastic scattering of protons from sqrt{s}=23.5 GeV to 7 TeV from a generalized Bialas-Bzdak model
The Bialas-Bzdak model of elastic proton-proton scattering is generalized to the case when the real part of the parton-parton level forward scattering amplitude is non-vanishing. Such a generalization enables the model to describe well the dip region of the differential cross-section of elastic scattering at the ISR energies, and improves significantly the ability of the model to describe also the recent TOTEM data at sqrt{s} = 7 TeV LHC energy. Within this framework, both the increase of the total cross-section, as well as the decrease of the location of the dip with increasing colliding energies, is related to the increase of the quark-diquark distance and to the increase of the "fragility" of the protons with increasing energies. In addition, we present and test the validity of two new phenomenological relations: one of them relates the total p+p cross-section to an effective, model-independent proton radius, while the other relates the position of the dip in the differential elastic cross-section to the measured value of the total cross-section
Stern-Gerlach Entanglement in Spinor Bose-Einstein Condensates
Entanglement of spin and position variables produced by spatially
inhomogeneous magnetic fields of Stern-Gerlach type acting on spinor
Bose-Einstein condensates may lead to interference effects at the level of
one-boson densities. A model is worked out for these effects which is amenable
to analytical calculation for gaussian shaped condensates. The resulting
interference effects are sensitive to the spin polarization properties of the
condensate.Comment: 9 pages, 2 figure
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