1,779,901 research outputs found
Three-Loop Contribution to Hyperfine Splitting in Muonium: Polarization Corrections to Light by Light Scattering Blob
We calculate corrections of order to hyperfine
splitting in muonium generated by the gauge invariant set of diagrams with
polarization insertions in the light by light scattering diagrams. This
nonrecoil contribution turns out to be -2.63 Hz. The total contribution of all
known corrections of order is equal to -4.28 Hz.Comment: 12 pages, 3 figure
A New Class of Path Equations in AP-Geometry
In the present work, it is shown that, the application of the Bazanski
approach to Lagrangians, written in AP-geometry and including the basic vector
of the space, gives rise to a new class of path equations. The general equation
representing this class contains four extra terms, whose vanishing reduces this
equation to the geodesic one. If the basic vector of the
AP-geometry is considered as playing the role of the electromagnetic
potential, as done in a previous work, then the second term
(of the extra terms) will represent Lorentz force while the fourth term gives
a direct effect of the electromagnetic potential on the motion of the charged
particle. This last term may give rise to an effect similar to the
Aharanov-Bohm effect. It is to be considered that all extra terms will vanish
if the space-time used is torsion-less.Comment: 11 pages, LaTeX fil
NEW CORRECTIONS OF ORDER AND TO THE LAMB SHIFT
Two corrections to the Lamb shift, induced by the polarization operator
insertions in the external photon lines are calculated.Comment: 4 pages, revtex, no figure
Radiative-Recoil Corrections to Hyperfine Splitting: Polarization Insertions in the Muon Factor
We consider three-loop radiative-recoil corrections to hyperfine splitting in
muonium due to insertions of one-loop polarization operator in the muon factor.
The contribution produced by electron polarization insertions are enhanced by
the large logarithm of the electron-muon mass ratio. We obtained all
single-logarithmic and nonlogarithmic radiative-recoil corrections of order
generated by the diagrams with electron and muon
polarization insertions.Comment: 10 pages, 4 figure
Three-Loop Radiative-Recoil Corrections to Hyperfine Splitting Generated by One-Loop Fermion Factors
We consider three-loop radiative-recoil corrections to hyperfine splitting in
muonium generated by diagrams with one-loop radiative photon insertions both in
the electron and muon lines. An analytic result for these nonlogarithmic
corrections of order is
obtained. This result constitutes a next step in the implementation of the
program of reduction of the theoretical uncertainty of hyperfine splitting
below 10 Hz.Comment: 11 pages, 3 figures, 1 tabl
Soft and hard processes in QCD
QCD equations for the generating functions are applied to separate soft and
hard jets in -processes of multiparticle production. The dependence of
average multiplicities and higher moments of multiplicity distributions of
particles created in a "newly born" soft subjets on the share of energy devoted
to them is calculated in fixed coupling gluodynamics. This dependence is the
same as for the total multiplicity up to a constant factor if soft jets are
defined as those carrying out a fixed share of initial energy at all energies.
The constant factor depends on this share in a non-trivial way. Other
definitions are also proposed. The relation between these quantities for soft
and hard processes is discussed.Comment: 6 pages, no Figures, LATEX, more detailed discussion of definitions
and proposals for experiment is give
Lifetimes of Heavy-Flavour Hadrons -- Whence and Whither?
A theoretical treatment for the weak decays of heavy-flavour hadrons has been
developed that is genuinely based on QCD. Its methodology as it applies to
total lifetimes and the underlying theoretical issues are sketched. Predictions
are compared with present data. One discrepancy emerges: the beauty baryon
lifetime appears to be significantly shorter than expected. The ramifications
of those findings are analyzed in detail.Comment: 15 pages, no figures, LATEX, two references added and new information
concerning a lower charm content in B decays incorporate
Electron self-trapping and fluctuation density-of-states tail at the critical point
We consider electron self-trapping due to its interaction with
order-parameter fluuctuations at the second-order phase-transition or critical
point (for example, at the Curie temperature in magnetic or ferroelectric
semiconductors). Using Feynman path integral approach the autolocalization
energy and the size of the self-trapped state (fluctuon) are estimated. It is
shown that the fluctuon states are connected with the Lifshitz tail of the
electron density-of-states, the parameters of this tail being determined by the
critical exponents.Comment: 4 pages, revtex4, Phys. Rev. B, accepte
The two types of Cherenkov gluons at LHC energies
Beside comparatively low energy Cherenkov gluons observed at RHIC, there
could be high energy gluons at LHC, related to the high energy region of
positive real part of the forward scattering amplitude. In both cases they give
rise to particles emitted along some cone. The characteristics of the cones
produced by these two types of gluons are different. Therefore different
experiments are needed to detect them. The cosmic ray event which initiated
this idea is described in detail.Comment: 6 pages, talk at IWCF2006, Hangzhou, Chin
High E jets and double scattering
The recently found excess of high E jets over current QCD predictions is
attributed to gluon radiation at double scattering process inside a nucleon.
The order of magnitude estimate of the cross section fits experimental findings
rather well. The specific features of the process are discussed. Various
similar hadronic effects related to the short radiation length are described.Comment: 6 pages, plain LaTe
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