13,292 research outputs found
Soft Pomerons and the Forward LHC Data
Recent data from LHC13 by the TOTEM Collaboration on and
have indicated disagreement with all the Pomeron model predictions by
the COMPETE Collaboration (2002). On the other hand, as recently demonstrated
by Martynov and Nicolescu (MN), the new datum and the unexpected
decrease in the value are well described by the maximal Odderon
dominance at the highest energies. Here, we discuss the applicability of
Pomeron dominance through fits to the \textit{most complete set} of forward
data from and scattering. We consider an analytic
parametrization for consisting of non-degenerated Regge
trajectories for even and odd amplitudes (as in the MN analysis) and two
Pomeron components associated with double and triple poles in the complex
angular momentum plane. The parameter is analytically determined by
means of dispersion relations. We carry out fits to and data on
and in the interval 5 GeV - 13 TeV (as in the MN
analysis). Two novel aspects of our analysis are: (1) the dataset comprises all
the accelerator data below 7 TeV and we consider \textit{three independent
ensembles} by adding: either only the TOTEM data (as in the MN analysis), or
only the ATLAS data, or both sets; (2) in the data reductions to each ensemble,
uncertainty regions are evaluated through error propagation from the fit
parameters, with 90 \% CL. We argument that, within the uncertainties, this
analytic model corresponding to soft Pomeron dominance, does not seem to be
excluded by the \textit{complete} set of experimental data presently available.Comment: 10 pages, 4 figures, 1 table. Two paragraphs and four references
added. Accepted for publication in Phys. Lett.
Topological Vertex, String Amplitudes and Spectral Functions of Hyperbolic Geometry
We discuss the homological aspects of the connection between quantum string
generating function and the formal power series associated to the dimensions of
chains and homologies of suitable Lie algebras. Our analysis can be considered
as a new straightforward application of the machinery of modular forms and
spectral functions (with values in the congruence subgroup of ) to the partition functions of Lagrangian branes, refined vertex and open
string partition functions, represented by means of formal power series that
encode Lie algebra properties. The common feature in our examples lies in the
modular properties of the characters of certain representations of the
pertinent affine Lie algebras and in the role of Selberg-type spectral
functions of an hyperbolic three-geometry associated with -series in the
computation of the string amplitudes.Comment: Revised version. References added, results remain unchanged. arXiv
admin note: text overlap with arXiv:hep-th/0701156, arXiv:1105.4571,
arXiv:1206.0664 by other author
The small behavior of the gluon structure function from total cross sections
Within a QCD-based eikonal model with a dynamical infrared gluon mass scale
we discuss how the small behavior of the gluon distribution function at
moderate is directly related to the rise of total hadronic cross
sections. In this model the rise of total cross sections is driven by
gluon-gluon semihard scattering processes, where the behavior of the small
gluon distribution function exhibits the power law . Assuming that the scale is proportional to the
dynamical gluon mass one, we show that the values of obtained in this
model are compatible with an earlier result based on a specific nonperturbative
Pomeron model. We discuss the implications of this picture for the behavior of
input valence-like gluon distributions at low resolution scales.Comment: 19 pages, 3 figures; revised version; to appear in Int. J. Mod. Phys.
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