2,037 research outputs found
Transverse momentum and multiplicity fluctuations in Ar+Sc collisions at the CERN SPS from NA61/SHINE
The NA61/SHINE experiment aims to discover the critical point of strongly
interacting matter and study the properties of the onset of deconfinement. For
these goals a scan of the two dimensional phase diagram (-) is
being performed at the SPS by measurements of hadron production in
proton-proton, proton-nucleus and nucleus-nucleus interactions as a function of
collision energy and system size. In this contribution preliminary results on
transverse momentum and multiplicity fluctuations expressed in terms of
strongly intensive quantities from the Ar+Sc energy scan will be presented.
These fluctuations are expected to be sensitive to the existence of a critical
point. The results are compared with results from the p+p and Be+Be energy scan
as well as with NA49 measurements.Comment: 5 pages, 5 figures, Contribution to the proceedings of the Critical
Point and Onset of Deconfinement 2016, Wroclaw, Poland, May 30th - June 4th,
201
Energy dependence of fluctuations in p+p and Be+Be collisions from NA61/SHINE
The main aims of the NA61/SHINE experiment are to discover the critical point
of strongly interacting matter and to study properties of the onset of
deconfinement. For this goal a two dimensional scan of the phase diagram
(T-) is being performed at the SPS with measurements of hadron
production in proton-proton, proton-nucleus and nucleus-nucleus interactions as
a function of collision energy and system size. It is expected that
fluctuations of various dynamical quantities will increase close to the
critical point. In this contribution recent results of measurements of
fluctuations in p+p and Be+Be collisions at SPS energies are presented as well
as comparisons with model predictions and corresponding data of other
experiments are discussed.Comment: 4 pages, 4 figures, To appear in the proceedings of SQM-201
Recent results from NA61/SHINE
The NA61/SHINE experiment aims to discover the critical point of strongly
interacting matter and study the properties of the onset of deconfinement. For
these goals a scan of the two dimensional phase diagram (T-) is being
performed at the SPS by measurements of hadron production in proton-proton,
proton-nucleus and nucleus-nucleus interactions as a function of collision
energy and system size.
In this contribution intriguing results on the energy dependence of hadron
spectra and yields in inelastic p+p and centrality selected Be+Be collisions
will be presented. In particular, the energy dependence of the signals of
deconfinement, the 'horn', 'step' and 'kink', in p+p interactions will be
presented and compared with the corresponding results from central Pb+Pb
collisions from NA49.Comment: 10 pages, 11 figures, To appear in the proceedings of ICNFP-201
Idling Magnetic White Dwarf in the Synchronizing Polar BY Cam. The Noah-2 Project
Results of a multi-color study of the variability of the magnetic cataclysmic
variable BY Cam are presented. The observations were obtained at the Korean
1.8m and Ukrainian 2.6m, 1.2m and 38-cm telescopes in 2003-2005, 56
observational runs cover 189 hours. The variations of the mean brightness in
different colors are correlated with a slope dR/dV=1.29(4), where the number in
brackets denotes the error estimates in the last digits. For individual runs,
this slope is much smaller ranging from 0.98(3) to 1.24(3), with a mean value
of 1.11(1). Near the maximum, the slope becomes smaller for some nights,
indicating more blue spectral energy distribution, whereas the night-to-night
variability has an infrared character. For the simultaneous UBVRI photometry,
the slopes increase with wavelength from dU/dR=0.23(1) to dI/dR=1.18(1). Such
wavelength dependence is opposite to that observed in non-magnetic cataclysmic
variables, in an agreement to the model of cyclotron emission. The principal
component analysis shows two (with a third at the limit of detection)
components of variablitity with different spectral energy distribution, which
possibly correspond to different regions of emission. The scalegram analysis
shows a highest peak corresponding to the 200-min spin variability, its quarter
and to the 30-min and 8-min QPOs. The amplitudes of all these components are
dependent on wavelength and luminosity state. The light curves were fitted by a
statistically optimal trigonometrical polynomial (up to 4-th order) to take
into account a 4-hump structure. The dependences of these parameters on the
phase of the beat period and on mean brightness are discussed. The amplitude of
spin variations increases with an increasing wavelength and with decreasing
brightnessComment: 30pages, 11figures, accepted in Cent.Eur.J.Phy
The meteor experimental space meteorological system
Soviet meteorological satellite system requirements including Cosmos onboard equipmen
Multiple time scales in cataclysmic binaries. The low-field magnetic dwarf nova DO Draconis
We study the variability of the cataclysmic variable DO Dra, on time-scales
of between minutes and decades.
The characteristic decay time dt/dm=0.902(3) days/mag was estimated from our
3 nights of CCD R observations. The quiescent data show a photometric wave with
a cycle about 303(15)d. We analyzed the profile of the composite (or mean)
outburst. We discovered however, that a variety of different outburst heights
and durations had occurred, contrary to theoretical predictions. With
increasing maximum brightness, we find that the decay time also increases; this
is in contrast to the model predictions, which indicate that outbursts should
have a constant shape. This is interpreted as representing the presence of
outburst-to-outburst variability of the magnetospheric radius. A presence of a
number of missed weak narrow outbursts is predicted from this statistical
relationship. A new type of variability is detected, during 3 subsequent nights
in 2007: periodic (during one nightly run) oscillations with rapidly-decreasing
frequency from 86 to 47 cycles/day and a semi-amplitude increasing from 0.06 to
0. 10, during a monotonic brightness increase from 14. 27 to 14. 13. This
phenomenon was observed only during an unusually prolonged event of about 1 mag
brightening in 2007 (lasting till autumn), during which no (expected) outburst
was detected. We refer to this behaviour as to the transient periodic
oscillations (TPO). To study this new and interesting phenomenon, new regular
photometric and spectral (in a target of opportunity mode) observations are
required.Comment: 12pages, 8figures, accepted in Astronomy and Astrophysic
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