9,195 research outputs found

### Estimates for parameters and characteristics of the confining SU(3)-gluonic field in neutral kaons and chiral limit for pseudoscalar nonet

First part of the paper is devoted to applying the confinement mechanism
proposed earlier by the author to estimate the possible parameters of the
confining SU(3)-gluonic field in neutral kaons. The estimates obtained are
consistent with the widths of the electromagnetic decays
$K^0,\bar{K}^0\to2\gamma$ too. The corresponding estimates of the gluon
concentrations, electric and magnetic colour field strengths are also adduced
for the mentioned field at the scales of the mesons under consideration. The
second part of the paper takes into account the results obtained previously by
the author to estimate the purely gluonic contribution to the masses of all the
mesons of pseudoscalar nonet and also to consider a possible relation with a
phenomenological string-like picture of confinement. Finally, the problem of
masses in particle physics is shortly discussed within the framework of
approach to the chiral symmetry breaking in quantum chromodynamics (QCD)
proposed recently by the author.Comment: LaTeX, 16 pages, 2 figure

### Classical Polylogarithms for Amplitudes and Wilson Loops

We present a compact analytic formula for the two-loop six-particle MHV
remainder function (equivalently, the two-loop light-like hexagon Wilson loop)
in N = 4 supersymmetric Yang-Mills theory in terms of the classical
polylogarithm functions Li_k with cross-ratios of momentum twistor invariants
as their arguments. In deriving our result we rely on results from the theory
of motives.Comment: 11 pages, v2: journal version, minor corrections and simplifications,
additional details available at http://goo.gl/Cl0

### Estimates for parameters and characteristics of the confining SU(3)-gluonic field in an $\eta^\prime$-meson

The confinement mechanism proposed earlier by the author is applied to
estimate the possible parameters of the confining SU(3)-gluonic field in an
$\eta^\prime$-meson. For this aim the electric form factor of an
$\eta^\prime$-meson is nonperturbatively computed in an explicit analytic form.
The estimates obtained are also consistent with the width of the
electromagnetic decay $\eta^\prime\to2\gamma$. The corresponding estimates of
the gluon concentrations, electric and magnetic colour field strengths are also
adduced for the mentioned field at the scales of the meson under consideration.Comment: 20 pages, LaTe

### Combined method to extract spectroscopic information

Spectroscopic factors (SF) play an important role in nuclear physics and
astrophysics. The traditional method of extracting SF from direct transfer
reactions suffers from serious ambiguities. We discuss a modified method which
is based on including the asymptotic normalization coefficient (ANC) of the
overlap functions into the transfer analysis. In the modified method the
contribution of the external part of the reaction amplitude, typically
dominant, is fixed and the SF is determined from fitting the internal part. We
illustrate the modified method with $(d,p)$ reactions on ${}^{208}{\rm Pb},
{}^{12}{\rm C}$, and ${}^{84}{\rm Se}$ targets at different energies. The
modified method allows one to extract the SF, which do not depend on the shape
of the single-particle nucleon-target interaction, and has the potential of
improving the reliability and accuracy of the structure information. This is
specially important for nuclei on dripline, where not much is known.Comment: accepted in Phys. Rev. C, 4 pages and 2 figure

### Towards a NNLO calculation in hadronic heavy hadron production

We calculate the Laurent series expansion up to ${\cal O}(\epsilon^2)$ for
all scalar one-loop one-, two-, three- and four-point integrals that are needed
in the calculation of hadronic heavy flavour production. The Laurent series up
to ${\cal O}(\epsilon^2)$ is needed as input to that part of the NNLO
corrections to heavy hadron production at hadron colliders where the one-loop
integrals appear in the loop-by-loop contributions. The four-point integrals
are the most complicated. The ${\cal O}(\epsilon^2)$ expansion of the
four-point integrals contains polylogarithms up to $Li_4$ and the multiple
polylogarithms.Comment: 5 pages, 2 Postscript figure

### Ions in glass forming glycerol: Close correlation of alpha and fast beta relaxation

We provide broadband dielectric loss spectra of glass-forming glycerol with
varying additions of LiCl. The measurements covering frequencies up to 10 THz
extend well into the region of the fast beta process, commonly ascribed to
caged molecule dynamics. Aside of the known variation of the structural alpha
relaxation time and a modification of the excess wing with ion content, we also
find a clear influence on the shallow loss minimum arising from the fast beta
relaxation. Within the framework of mode-coupling theory, the detected
significant broadening of this minimum is in reasonable accord with the found
variation of the alpha-relaxation dynamics. A correlation between
alpha-relaxation rate and minimum position holds for all ion concentrations and
temperatures, even below the critical temperature defined by mode-coupling
theory.Comment: 5 pages, 5 figure

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