17 research outputs found
Looking into the matter of light-quark hadrons
In tackling QCD, a constructive feedback between theory and extant and
forthcoming experiments is necessary in order to place constraints on the
infrared behaviour of QCD's \beta-function, a key nonperturbative quantity in
hadron physics. The Dyson-Schwinger equations provide a tool with which to work
toward this goal. They connect confinement with dynamical chiral symmetry
breaking, both with the observable properties of hadrons, and hence provide a
means of elucidating the material content of real-world QCD. This contribution
illustrates these points via comments on: in-hadron condensates; dressed-quark
anomalous chromo- and electro-magnetic moments; the spectra of mesons and
baryons, and the critical role played by hadron-hadron interactions in
producing these spectra.Comment: 11 pages, 7 figures. Contribution to the Proceedings of "Applications
of light-cone coordinates to highly relativistic systems - LIGHTCONE 2011,"
23-27 May, 2011, Dallas. The Proceedings will be published in Few Body
System
Masses of ground and excited-state hadrons
We present the first Dyson-Schwinger equation calculation of the light hadron
spectrum that simultaneously correlates the masses of meson and baryon ground-
and excited-states within a single framework. At the core of our analysis is a
symmetry-preserving treatment of a vector-vector contact interaction. In
comparison with relevant quantities the
root-mean-square-relative-error/degree-of freedom is 13%. Notable amongst our
results is agreement between the computed baryon masses and the bare masses
employed in modern dynamical coupled-channels models of pion-nucleon reactions.
Our analysis provides insight into numerous aspects of baryon structure; e.g.,
relationships between the nucleon and Delta masses and those of the
dressed-quark and diquark correlations they contain.Comment: 25 pages, 7 figures, 4 table
Quantitative conditional quantum erasure in two-atom resonance fluorescence
We present a conditional quantum eraser which erases the a priori knowledge
or the predictability of the path a photon takes in a Young-type double-slit
experiment with two fluorescent four-level atoms. This erasure violates a
recently derived erasure relation which must be satisfied for a conventional,
unconditional quantum eraser that aims to find an optimal sorting of the system
into subensembles with particularly large fringe visibilities. The conditional
quantum eraser employs an interaction-free, partial which-way measurement which
not only sorts the system into optimal subsystems with large visibility but
also selects the appropriate subsystem with the maximum possible visibility. We
explain how the erasure relation can be violated under these circumstances.Comment: Revtex4, 12pages, 4 eps figures, replaced with published version,
changes in Sec. 3, to appear in Physical Review
Recognition by Anti-Fab Antibodies in Rheumatoid Arthritis of Structure(s) Widely Distributed on Human Fab Molecules
Retinoic acid and tumor necrosis factor-α induced monocytic cell gene expression is regulated in part by induction of transcription factor MafB
Randomised observer blind comparative trial of ceftriaxone and penicillin in treating uncomplicated gonorrhoea in men and women.
Spectra of heavy mesons in the Bethe-Salpeter approach
We present a calculation of the spectrum of charmonia, bottomonia and
B_c-meson states with `ordinary' and exotic quantum numbers. We discuss the
merits and limitations of a rainbow-ladder truncation of Dyson-Schwinger and
Bethe-Salpeter equations and explore the effects of different shapes of the
effective running coupling on ground and excited states in channels with
quantum numbers J <= 3. We furthermore discuss the status of the X(3872) as a
potential (excited) quark-antiquark state and give predictions for the masses
of charmonia and bottomonia in the tensor channels with J=2,3.Comment: 9 pages, 8 figures, 1 table. Version to appear in Eur. Phys J.