Solutions that satisfy the Klein–Fock–Gordon equation in quasi-Cartesian coordinates of the three-dimensional relativistic Lobachevsky momentum space associated with the horospheres of this space are ...found. The Euclidean plane geometry is realized on these horospheres. This representation of solutions to the Klein–Fock–Gordon equation is closely related to invariant geometric images (horosphere, parallel bundle, and parallel bundle axis) of the three-dimensional Lobachevsky space, in which a part naturally arises associated with the selected direction: the parallel bundle axis orthogonal to horospheres. Such a representation is appropriate for the kinematics of an incident particle in a laboratory system in the processes of particle collisions. The connection of the solutions with the usual coherent states on the horosphere of the Lobachevsky momentum space is established.
A prototype detector based on thin-walled segmented tubes has been developed and its parameters have been studied. The detector contains 360 registration channels with a straw diameter of 4
mm. The ...prototype’ granularity is 4
сm
2 and the length of insensitive region due to straw internal elements is less than 5% of its full sensitive area. Deterioration of the spatial resolution near these elements is observed for 1.0% of the detector sensitive area. The time and spatial parameters of the detector do not differ from those of conventional tracking detectors based on drift tubes.
Spatial resolution of thin-walled high-pressure drift tubes Davkov, V.I.; Gregor, I.; Haas, D. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2011, Letnik:
634, Številka:
1
Journal Article
Recenzirano
A small prototype detector based on high pressure thin-walled tubes (straws) has been developed and its parameters have been studied on a bench at JINR, Dubna, and SPS at CERN. The inner diameter of ...the straws is 9.53
mm. The pressure of the active gas mixture Ar/CO
2 (80/20) was varied from 1 to 5
bar. The best spatial resolution achieved in this pressure range is ∼40
μm. Both the high efficiency and high rate capability are retained.
Photons produced in pp interactions at 450 GeV/c were detected by reconstructing the e+e− pairs of photon conversions in a 1 mm thick lead sheet placed in front of the MWPCs of the OMEGA spectrometer ...at CERN. A soft photon signal 4.1±0.8 times the inner bremsstrahlung prediction was observed in the forward rapidity region (yc.m.s.⩾1.2), thus extending the domain of the anomalous soft photon effect seen already in K+p, π+p and π−p interactions.
The year 2016 marks the 60th anniversary of the Joint Institute for Nuclear Research (JINR) in Dubna, an international intergovernmental organization for basic research in the fields of elementary ...particles, atomic nuclei, and condensed matter. Highly productive advances over this long road clearly show that the international basis and diversity of research guarantees successful development (and maintenance) of fundamental science. This is especially important for experimental research. In this review, the most significant achievements are briefly described with an attempt to look into the future (seven to ten years ahead) and show the role of JINR in solution of highly important problems in elementary particle physics, which is a fundamental field of modern natural sciences. This glimpse of the future is full of justified optimism.
A coupled channel analysis of the centrally produced
K
+
K
−and
π
+
π
−final states has been performed in
pp collisions at an incident beam momentum of 450 GeV/c. The pole positions and branching ...ratios to
ππ and
K
K
of the
f
0(980),
f
0(1370),
f
0(1500) and
f
0(1710) have been determined. A systematic study of the production properties of all the resonances observed in the
π
+
π
−and
K
+
K
−channels has been performed.
The reaction pp -> pf (eta eta) ps has been studied at 450 GeV/c. For the first time a partial wave analysis of the centrally produced eta eta system has been performed. Signals for the f0(1500), ...f0(1710) and f2(2150) are observed and the decay branching fractions of these states are determined.
The CERN cloud technologies (the CernVM project) give a new possibility for the software developers. The participation of the JINR ATLAS TDAQ working group in the software development for distributed ...data acquisition and processing system (TDAQ) of the ATLAS experiment (CERN) involves the work in the condition of the dynamically developing system and its infrastructure. The CERN cloud technologies, especially CernVM, provide the most effective access as to the TDAQ software as to the third-part software used in ATLAS. The access to the Scientific Linux environment is provided by CernVM virtual machines and the access software repository - by CernVM-FS. The problem of the functioning of the TDAQ middleware in the CernVM environment was studied in this work. The CernVM usage is illustrated on three examples: the development of the packages Event Dump and Webemon, and the adaptation of the data quality auto checking system of the ATLAS TDAQ (Data Quality Monitoring Framework) for the radar data assessment.
The reactions
pp→
p
f
(
X
0)
p
s
, where
X
0 is observed decaying to
π
0
π
0
π
0
π
0 ,
π
+
π
−
π
+
π
− and
π
+
π
−
π
0
π
0 , have been studied at 450 GeV/
c. There is evidence for an
a
2(1320)
π ...decay mode of the
η
2(1645) and
η
2(1870) in the
π
+
π
−
π
0
π
0 and
π
+
π
−
π
+
π
− final states. The
f
2(1950) is consistent with being a single resonance with a dominant
f
2(1270)
ππ decay mode. The
f
0(1370) is found to decay dominantly to
ρρ while the
f
0(1500) is found to decay to
ρρ and
σσ.
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