55,393 research outputs found
Pomeron pole plus grey disk model: real parts, inelastic cross sections and LHC data
I propose a two component analytic formula
for scattering at energies
,where denote squares of c.m. energy and momentum
transfer.It saturates the Froissart-Martin bound and obeys
Auberson-Kinoshita-Martin (AKM) \cite{AKM1971} scaling. I choose as given by Particle Data Group (PDG) fits to
total cross sections. The PDG formula is extended to non-zero momentum
transfers using partial waves of and motivated by
Pomeron pole and 'grey disk' amplitudes . is deduced from real
analyticity: I prove that for with
fixed, and apply it to .Using also the forward slope fit by
Schegelsky-Ryskin , the model gives real parts,differential cross sections for
, and inelastic cross sections in good agreement with data at
and . It predicts for inelastic cross
sections for or , at and
at in agreement with Totem experimental values
and respectively, and with Atlas values
and respectively. The predictions at
and also agree with experimental results of Abe et al
\cite{Abe} at and .
The model yields for , with PDG2013 total cross sections ,
and Schegelsky-Ryskin slopes as input, where is in Comment: 6 pages, 5 figures, 2 table
Contextual Deterministic Quantum Mechanics
We present a simple proof of quantum contextuality for a spinless particle
with a one dimensional configuration space. We then discuss how the maximally
realistic deterministic quantum mechanics recently constructed by this author
and V. Singh can be applied to different contexts.Comment: 7 pages,latex,no fig
Marginal distributions in -dimensional phase space and the quantum marginal theorem
We study the problem of constructing a probability density in 2N-dimensional
phase space which reproduces a given collection of joint probability
distributions as marginals. Only distributions authorized by quantum mechanics,
i.e. depending on a (complete) commuting set of variables, are considered.
A diagrammatic or graph theoretic formulation of the problem is developed. We
then exactly determine the set of ``admissible'' data, i.e. those types of data
for which the problem always admits solutions. This is done in the case where
the joint distributions originate from quantum mechanics as well as in the case
where this constraint is not imposed. In particular, it is shown that a
necessary (but not sufficient) condition for the existence of solutions is
. When the data are admissible and the quantum constraint is not
imposed, the general solution for the phase space density is determined
explicitly. For admissible data of a quantum origin, the general solution is
given in certain (but not all) cases. In the remaining cases, only a subset of
solutions is obtained.Comment: 29 pages (Work supported by the Indo-French Centre for the Promotion
of Advanced Research, Project Nb 1501-02). v2 to add a report-n
Froissart Bound on Total Cross-section without Unknown Constants
We determine the scale of the logarithm in the Froissart bound on total
cross-sections using absolute bounds on the D-wave below threshold for
scattering. E.g. for scattering we show that for c.m. energy
, where .Comment: 6 page
Froissart Bound on Inelastic Cross Section Without Unknown Constants
Assuming that axiomatic local field theory results hold for hadron
scattering, Andr\'e Martin and S. M. Roy recently obtained absolute bounds on
the D-wave below threshold for pion-pion scattering and thereby determined the
scale of the logarithm in the Froissart bound on total cross sections in terms
of pion mass only. Previously, Martin proved a rigorous upper bound on the
inelastic cross-section which is one-fourth of the
corresponding upper bound on , and Wu, Martin,Roy and Singh
improved the bound by adding the constraint of a given . Here we
use unitarity and analyticity to determine, without any high energy
approximation, upper bounds on energy averaged inelastic cross sections in
terms of low energy data in the crossed channel. These are Froissart-type
bounds without any unknown coefficient or unknown scale factors and can be
tested experimentally. Alternatively, their asymptotic forms,together with the
Martin-Roy absolute bounds on pion-pion D-waves below threshold, yield absolute
bounds on energy-averaged inelastic cross sections. E.g. for
scattering, defining ,we show that for c.m. energy ,
where . This bound is
asymptotically one-fourth of the corresponding Martin-Roy bound on the total
cross section, and the scale factor is one-fourth of the scale factor in
the total cross section bound. The average over the interval (s,2s) of the
inelastic cross section has a bound of the same form with
replaced by .Comment: 9 pages. Submitted to Physical Review
Exact Solutions of the Caldeira-Leggett Master Equation: A Factorization Theorem For Decoherence
Exact solutions of the Caldeira-Leggett Master equation for the reduced
density matrix for a free particle and for a harmonic oscillator system coupled
to a heat bath of oscillators are obtained for arbitrary initial conditions.
The solutions prove that the Fourier transform of the density matrix at time t
with respect to (x + x')/2, where x and x' are the initial and final
coordinates, factorizes exactly into a part depending linearly on the initial
density matrix and a part independent of it. The theorem yields the exact
initial state dependence of the density operator at time t and its eventual
diagonalization in the energy basis.Comment: 8 pages, late
Hadronic components of EAS by rigorous saddle point method in the energy range between 10(5) and 10(8) GeV
The study of hadronic components in the high energy range between 10 to the 5 and 10 to the 8 Gev exhibits by far the strongest mass sensitivity since the primary energy spectrum as discussed by Linsley and measured by many air shower experimental groups indicates a change of slope from -1.7 to 2.0 in this energy range. This change of slope may be due to several reasons such as a genuine spectral feature of astrophysical origin, a confinement effect of galactic component or a rather rapid change of mass, a problem which we have attempted to study here in detail
- …