1,190 research outputs found
Bound state spectra of three-body muonic molecular ions
The results of highly accurate calculations are presented for all twenty-two
known bound and states in the six
three-body muonic molecular ions and
. A number of bound state properties of these muonic molecular ions have
been determined numerically to high accuracy. The dependence of the total
energies of these muonic molecules upon particle masses is considered. We also
discuss the current status of muon-catalysis of nuclear fusion reactions.Comment: This is the final version. All `techical' troubles with the
Latex-file have been resolved. A few misprints/mistakes in the text were
correcte
Gravitational fields with a non Abelian bidimensional Lie algebra of symmetries
Vacuum gravitational fields invariant for a bidimensional non Abelian Lie
algebra of Killing fields, are explicitly described. They are parameterized
either by solutions of a transcendental equation (the tortoise equation) or by
solutions of a linear second order differential equation on the plane.
Gravitational fields determined via the tortoise equation, are invariant for a
3-dimensional Lie algebra of Killing fields with bidimensional leaves. Global
gravitational fields out of local ones are also constructed.Comment: 8 pagese, latex, no figure
A low-voltage retarding-field Mott polarimeter for photocathode characterization
Nuclear physics experiments at Thomas Jefferson National Accelerator
Facility's CEBAF rely on high polarization electron beams. We describe a
recently commissioned system for prequalifying and studying photocathodes for
CEBAF with a load-locked, low-voltage polarized electron source coupled to a
compact retarding-field Mott polarimeter. The polarimeter uses simplified
electrode structures and operates from 5 to 30 kV. The effective Sherman
function for this device has been calibrated by comparison with the CEBAF 5 MeV
Mott polarimeter. For elastic scattering from a thick gold target at 20 keV,
the effective Sherman function is 0.201(5). Its maximum efficiency at 20 keV,
defined as the detected count rate divided by the incident particle current, is
5.4(2) x 10-4, yielding a figure-of-merit, or analyzing power squared times
efficiency, of 1.0(1) x 10-5. The operating parameters of this new polarimeter
design are compared to previously published data for other compact Mott
polarimeters of the retarding-field type.Comment: 9 figure
Status of 174 Mhz RF system for BEP
The new RF system for the BEP storage ring (which is an injector of VEPP-2000 accelerating complex) will increase the particles energy in the BEP from 0.9 to 1 GeV. RF system operates at a frequency of 174 MHz and consists of an accelerating cavity, RF power generator and control system.Новая ВЧ-система накопителя БЭП (являющегося инжектором комплекса ВЭПП-2000) позволит увеличить энергию частиц в БЭП от 0,9 до 1 ГэВ. ВЧ-система работает на частоте 174 МГц и состоит из ускоряющего резонатора, ВЧ-генератора мощности и системы управления.Нова ВЧ-система накопичувача БЕП (що є інжектором комплексу ВЕПП-2000) дозволить збільшити енергію частинок БЕП від 0,9 до 1 ГеВ. ВЧ-система працює на частоті 174 МГц і складається з прискорюючого резонатора, ВЧ-генератора потужності і системи управління
On the Number of Zeros of Abelian Integrals: A Constructive Solution of the Infinitesimal Hilbert Sixteenth Problem
We prove that the number of limit cycles generated by a small
non-conservative perturbation of a Hamiltonian polynomial vector field on the
plane, is bounded by a double exponential of the degree of the fields. This
solves the long-standing tangential Hilbert 16th problem. The proof uses only
the fact that Abelian integrals of a given degree are horizontal sections of a
regular flat meromorphic connection (Gauss-Manin connection) with a
quasiunipotent monodromy group.Comment: Final revisio
Large atom number dual-species magneto-optical trap for fermionic 6Li and 40K atoms
We present the design, implementation and characterization of a dual-species
magneto-optical trap (MOT) for fermionic 6Li and 40K atoms with large atom
numbers. The MOT simultaneously contains 5.2x10^9 6Li-atoms and 8.0x10^9
40K-atoms, which are continuously loaded by a Zeeman slower for 6Li and a
2D-MOT for 40K. The atom sources induce capture rates of 1.2x10^9 6Li-atoms/s
and 1.4x10^9 40K-atoms/s. Trap losses due to light-induced interspecies
collisions of ~65% were observed and could be minimized to ~10% by using low
magnetic field gradients and low light powers in the repumping light of both
atomic species. The described system represents the starting point for the
production of a large-atom number quantum degenerate Fermi-Fermi mixture
Real and Virtual Compton Scattering off the Nucleon
A review is given of the very recent developments in the fields of real and
virtual Compton scattering off the nucleon. Both real and virtual Compton
scattering reactions are discussed at low outgoing photon energy where one
accesses polarizabilities of the nucleon. The real Compton scattering at large
momentum transfer is discussed which is asymptotically a tool to obtain
information on the valence quark wave function of the nucleon. The rapid
developments in deeply virtual Compton scattering and associated meson
electroproduction reactions at high energy, high photon virtuality and small
momentum transfer to the nucleon are discussed. A unified theoretical
description of those processes has emerged over the last few years, which gives
access to new, generalized parton distributions. The experimental status and
perspectives in these fields are also discussed.Comment: 25 pages, 17 figure
Erosion mechanisms and erosion products in tungsten targets exposed to plasma heat loads relevant to ELMS and mitigated disruptions in ITER
Tungsten targets were irradiated by intense plasma streams at plasma gun facilities MK-200UG and QSPA-T. The targets were tested by plasma loads relevant to Edge Localised Modes (ELM) and mitigated disruptions in ITER. Material erosion caused by melt motion and by emission of droplets has been studied.Мишени из вольфрама были подвергнуты воздействию интенсивных потоков плазмы на плазменных ускорителях МК-200UG и КСПУ-Т. Испытания проводились при плазменных нагрузках, характерных для ELMов и ослабленных срывов в ITERe. Исследована эрозия материала, обусловленная движением расплава и капельным разбрызгиванием.Мішені з вольфраму були піддані впливу інтенсивних потоків плазми на плазмових прискорювачах МК-200UG і КСПУ-Т. Іспити проводилися при плазмових навантаженнях, характерних для ELMів і ослаблених зривів в ITERі. Досліджено ерозію матеріалу, що обумовлена рухом розплаву і краплинним розбризкуванням.The work is supported by RFBR grant No 09-02-13562
Measurement of and between 3.12 and 3.72 GeV at the KEDR detector
Using the KEDR detector at the VEPP-4M collider, we have measured
the values of and at seven points of the center-of-mass
energy between 3.12 and 3.72 GeV. The total achieved accuracy is about or
better than at most of energy points with a systematic uncertainty of
about . At the moment it is the most accurate measurement of in
this energy range
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