1,282 research outputs found
The International Linear Collider beam dumps
The ILC beam dumps are a key part of the accelerator design. At Snowmass
2005, the current status of the beam dump designs were reviewed, and the
options for the overall dump layout considered. This paper describes the
available dump options for the baseline and the alternatives and considers
issues for the dumps that require resolution.Comment: Prepared for 2005 International Linear Collider Physics and Detector
Workshop and 2nd ILC Accelerator Workshop, Snowmass, Colorado, 14-27 Aug 200
Spin-glass-like behavior of Ge:Mn
We present a detailed study of the magnetic properties of
low-temperature-molecular-beam-epitaxy grown Ge:Mn dilute magnetic
semiconductor films. We find strong indications for a frozen state of
Ge_{1-x}Mn_{x}, with freezing temperatures of T_f=12K and T_f=15K for samples
with x=0.04 and x=0.2, respectively, determined from the difference between
field-cooled and zero-field-cooled magnetization. For Ge_{0.96}Mn_{0.04}, ac
susceptibility measurements show a peak around T_f, with the peak position T'_f
shifting as a function of the driving frequency f by Delta T_f' / [T_f' Delta
log f] ~ 0.06, whereas for sample Ge_{0.8}Mn_{0.2} a more complicated behavior
is observed. Furthermore, both samples exhibit relaxation effects of the
magnetization after switching the magnitude of the external magnetic field
below T_f which are in qualitative agreement with the field- and
zero-field-cooled magnetization measurements. These findings consistently show
that Ge:Mn exhibits a frozen magnetic state at low temperatures and that it is
not a conventional ferromagnet.Comment: Revised version contains extended interpretation of experimental dat
Hyperons in neutron-star cores and two-solar-mass pulsar
Recent measurement of mass of PSR J1614-2230 rules out most of existing
models of equation of state (EOS) of dense matter with high-density softening
due to hyperonization or a phase transition to quark matter or a boson
condensate.
We look for a solution of an apparent contradiction between the consequences
stemming from up-to-date hypernuclear data, indicating appearance of hyperons
at 3 nuclear densities and existence of a two-solar-mass neutron star.
We consider a non-linear relativistic mean field (RMF) model involving baryon
octet coupled to meson fields. An effective lagrangian includes quartic terms
in the meson fields. The values of the parameters of the model are obtained by
fitting semi-empirical parameters of nuclear matter at the saturation point, as
well as potential wells for hyperons in nuclear matter and the strength of the
Lambda-Lambda attraction in double-Lambda hypernuclei.
We propose a non-linear RMF model which is consistent with up-to-date
semiempirical nuclear and hypernuclear data and allows for neutron stars with
hyperon cores and M larger than 2 solar masses. The model involves
hidden-strangenes scalar and vector mesons, coupled to hyperons only, and
quartic terms involving vector meson fields.
Our EOS involving hyperons is stiffer than the corresponding nucleonic EOS
(with hyperons artificially suppressed) above five nuclear densities. Required
stiffening is generated by the quartic terms involving hidden-strangeness
vector meson.Comment: 7 pages, 5 figures. Main results of this paper were already presented
at the MODE-SNR-PWN Workshop in Bordeaux, France, November 15-17, 2010, and
in a poster at the CompStar 2011 Workshop in Catania, Italy, May 9-12, 2011.
The paper is being submitted to Astronomy & Astrophysic
Synthesis and Biodistribution of N- [(2RS, 3RS)-1-Benzyl-2-Methyl-3-Pyrrolidinyl]-5-Chloro-2-Methoxy-4-[11C]Methylaminobenzamide, [11C]YM-09151-2: A New in Vivo Ligand for Dopamine D2 Receptors
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The extended, relativistic hyperon star model
In this paper an equation of state of neutron star matter which includes
strange baryons in the framework of Zimanyi and Moszkowski (ZM) model has been
obtained. We concentrate on the effects of the isospin dependence of the
equation of state constructing for the appropriate choices of parameters the
hyperons star model. Numerous neutron star models show that the appearance of
hyperons is connected with the increasing density in neutron star interiors.
Various studies have indicated that the inclusion of delta meson mainly affects
the symmetry energy and through this the chemical composition of a neutron
star. As the effective nucleon mass contributes to hadron chemical potentials
it alters the chemical composition of the star. In the result the obtained
model of the star not only excludes large population of hadrons but also does
not reduce significantly lepton contents in the star interior.Comment: 22 pages, revtex4, 13 figure
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