We present results on the system size dependence of high transverse momentum di-hadron correlations at sNN=200 GeV as measured by STAR at RHIC. Measurements in d+Au, Cu+Cu and Au+Au collisions reveal ...similar jet-like near-side correlation yields (correlations at small angular separation –Δϕ∼0, Δη∼0) for all systems and centralities. Previous measurements have shown that the away-side (Δϕ∼π) yield is suppressed in heavy-ion collisions. We present measurements of the away-side suppression as a function of transverse momentum and centrality in Cu+Cu and Au+Au collisions. The suppression is found to be similar in Cu+Cu and Au+Au collisions at a similar number of participants. The results are compared to theoretical calculations based on the parton quenching model and the modified fragmentation model. The observed differences between data and theory indicate that the correlated yields presented here will further constrain dynamic energy loss models and provide information about the dynamic density profile in heavy-ion collisions.
Heavy ion collisions at RHIC create a hot and dense medium that exhibits novel properties. Study of these properties and hadronization mechanisms of the medium requires identified particle results ...over wide transverse momentum (
p
T
) range. We present STAR results of identified charged pions, protons and antiprotons up to transverse momentum of
12
GeV
/
c
in Au+Au,
pp and d+Au collisions at the
s
N
N
=
200
GeV
. Spectra, ratios, and nuclear modification factors, and their comparisons to jet fragmentation, partonic energy loss, and coalescence/recombination models are discussed.
Extensive particle identification with TPC and TOF at the STAR experiment Shao, Ming; Barannikova, Olga; Dong, Xin ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2006, Letnik:
558, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Particle identification (PID) capabilities are studied by using the Time Projection Chamber (TPC) and a Time-Of-Flight (TOF) detector together at STAR. The identification capability of charged ...hadrons is greatly extended compared with that achieved by TPC and TOF separately. Particle spectra from
p
+
p
,
d
+
Au
collisions at
s
NN
=
200
GeV
and
Au
+
Au
collisions at
s
NN
=
62.4
GeV
are used to develop the methods. The transverse momentum (
p
T
) ranges of
π
, and
p
(
p
¯
)
identification are from
∼
0.3
GeV
/
c
to
∼
10
GeV
/
c
. The high
p
T
reach is limited by statistics in current data sets. An important conceptual advance was developed to identify electrons by using a combination of
d
E
/
d
x
in TPC and velocity information from the TOF detectors, which is important for future low-mass dilepton program at STAR.
METHOD OF INCREASING COMBINE HARVESTER MAINTAINABILITY Yury A. Tsarev; Sergey V. Filobok; Olga O. Barannikova
Vestnik Donskogo gosudarstvennogo tehničeskogo universiteta (Online),
07/2018, Letnik:
12, Številka:
1-1
Journal Article
Recenzirano
Odprti dostop
The solution to the problem connected with increasing the service reliability of the combine harvesters at the expense of cutting time on the delivery of spare parts to the field is offered.
The acoustic emission following the salt solution processes is investigated. It is educed that the acoustic emission parameters depend on the substance chemistry. It is stated that irrespective of ...the crystal purity degree with their dissolution the total count of signals increases logarithmically, and activity of the acoustic emission decreases exponentially. It is shown that the occluded gases liberation is a crucial element of the acoustic emission under the crystal dissolution.
We study the beam-energy and system-size dependence of ϕ meson production (using the hadronic decay mode ϕ→K+K−) by comparing the new results from Cu+Cu collisions and previously reported Au+Au ...collisions at sNN=62.4 and 200 GeV measured in the STAR experiment at RHIC. Data presented in this Letter are from mid-rapidity (|y|<0.5) for 0.4<pT<5 GeV/c. At a given beam energy, the transverse momentum distributions for ϕ mesons are observed to be similar in yield and shape for Cu+Cu and Au+Au colliding systems with similar average numbers of participating nucleons. The ϕ meson yields in nucleus–nucleus collisions, normalized by the average number of participating nucleons, are found to be enhanced relative to those from p+p collisions. The enhancement for ϕ mesons lies between strange hadrons having net strangeness =1 (K− and Λ¯) and net strangeness =2 (Ξ). The enhancement for ϕ mesons is observed to be higher at sNN=200 GeV compared to 62.4 GeV. These observations for the produced ϕ(ss¯) mesons clearly suggest that, at these collision energies, the source of enhancement of strange hadrons is related to the formation of a dense partonic medium in high energy nucleus–nucleus collisions and cannot be alone due to canonical suppression of their production in smaller systems.
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