3,587 research outputs found
On AGT conjecture
In these notes we consider relation between conformal blocks and the Nekrasov
partition function of certain SYM theories proposed recently by
Alday, Gaiotto and Tachikawa. We concentrate on theory,
which is the simplest example of AGT relation.Comment: References adde
Multipoint correlation functions in Liouville field theory and minimal Liouville gravity
We study n+3-point correlation functions of exponential fields in Liouville
field theory with n degenerate and 3 arbitrary fields. An analytical expression
for these correlation functions is derived in terms of Coulomb integrals. The
application of these results to the minimal Liouville gravity is considered.Comment: Contribution to the proceedings of the International Workshop on
Classical and Quantum Integrable Systems, Dubna, Russia, January 22-25, 2007,
18 page
Coupling of two conformal field theories and Nakajima-Yoshioka blow-up equations
We study the conformal vertex algebras which naturally arise in relation to
the Nakajima-Yoshioka blow-up equations.Comment: 23 pages v2. 24 pages, references added, proofs in section 3 are
expanded, many typos correcte
Isochronicity Correction in the CR Storage Ring
A challenge for nuclear physics is to measure masses of exotic nuclei up to
the limits of nuclear existence which are characterized by low production cross
sections and short half-lives. The large acceptance Collector Ring (CR) at FAIR
tuned in the isochronous ion-optical mode offers unique possibilities for
measuring short-lived and very exotic nuclides. However, in a ring designed for
maximal acceptance, many factors limit the resolution. One point is a limit in
time resolution inversely proportional to the transverse emittance. But most of
the time aberrations can be corrected and others become small for large number
of turns. We show the relations of the time correction to the corresponding
transverse focusing and that the main correction for large emittance
corresponds directly to the chromaticity correction for transverse focusing of
the beam. With the help of Monte-Carlo simulations for the full acceptance we
demonstrate how to correct the revolution times so that in principle
resolutions of dm/m=1E-6 can be achieved. In these calculations the influence
of magnet inhomogeneities and extended fringe fields are considered and a
calibration scheme also for ions with different mass-to-charge ratio is
presented.Comment: 6 figures, recised version May 201
Hyperfine-induced effects on the linear polarization of the K emission from helium-like ions
The linear polarization of the characteristic photon emission from
few-electron ions is studied for its sensitivity with regard to the nuclear
spin and magnetic moment of the ions. Special attention is paid, in particular,
to the K (1s 2p_{3/2} ^{1,3}P_{1,2} \to 1s^2 ^1S_0) decay of
selected helium-like ions following the radiative electron capture into
initially hydrogen-like species. Based on the density matrix theory, a unified
description is developed that includes both, the many-electron and hyperfine
interactions as well as the multipole-mixing effects arising from the expansion
of the radiation field. It is shown that the polarization of the K
line can be significantly affected by the mutipole mixing between the leading
and hyperfine-induced components of 1s2p ^3P_2, F_i \to 1s^2 ^1S_0,
F_f transitions. This - mixing strongly depends on the nuclear
properties of the considered isotopes and can be addressed experimentally at
existing heavy-ion storage rings
Sensor Explosive Concentrations of Hydrogen
The article describes a resistive sensor explosive concentrations of hydrogen with a response time of about 0.1 s is completely selective for hydrogen
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