Charmonium production in heavy ion collisions is considered as an important diagnostic probe for studying the phase diagram of strongly interacting matter for potential phase transitions. The ...interpretation of existing data from the CERN SPS is hampered by a lack of knowledge on the properties of open charm particle production in the fireball. Moreover, open charm production in heavy ion collisions by itself is poorly understood. To overcome this obstacle, the NA61/SHINE was equipped with a Small Acceptance Vertex Detector (SAVD), which is predicted to make the experiment sensitive to open charm mesons produced in A-A collisions at the SPS top energy. This paper will introduce the concept and the hardware of the SAVD. Moreover, first running experience as obtained in a commissioning run with a 150
A
GeV/
c
Pb+Pb collision system will be reported.
Charmonium production in heavy ion collisions is considered as an important diagnostic probe for studying the phase diagram of strongly interacting matter for potential phase transitions. The ...interpretation of existing data from the CERN SPS is hampered by a lack of knowledge on the properties of open charm particle production in the fireball. Moreover, open charm production in heavy ion collisions by itself is poorly understood. To overcome this obstacle, the NA61/SHINE was equipped with a Small Acceptance Vertex Detector (SAVD), which is predicted to make the experiment sensitive to open charm mesons produced in A-A collisions at the SPS top energy. This paper will introduce the concept and the hardware of the SAVD. Moreover, first running experience as obtained in a commissioning run with a 150 AGeV/c Pb+Pb collision system will be reported.
Studies on evaluating the tensile strength quality of the sod of single-specific and mixed lawn crops have been carried out on sod–podzolic soils in the Ryazan oblast. An evaluation is given for the ...tensile strength quality of sod in lawn herbage crops over the period of 3 study years. The highest sod tensile strength was recorded in single-specific crops, namely, in creeping red fescue, red fescue, Kentucky bluegrass, and stolon-forming bentgrass; among mixed crops, the highest sod tensile strength was found in the three-component (creeping red fescue, Kentucky bluegrass, and stolon-forming bentgrass) and four-component (stolon-forming bentgrass, red fescue, Kentucky bluegrass, and creeping red fescue) herbage mixture. The lowest tensile strength of the sod was recorded in perennial ryegrass and three-component mixtures (creeping red fescue, sheep fescue, and perennial ryegrass).
Nuclear reactions using proton beams and tin targets are studied in order to obtain antimony radionuclides. A new target system that includes on-line monitoring of target heating is used. To ...determine the parameters of proton beams, experimental studies on nuclear reactions are performed using Ti, Cu and stainless steel targets. Using modern model approximations, cross sections are determined for the formation of radionuclides
119
Sb and
117
Sb in the investigated nuclear reactions.
We present the results from testing Monolithic Active Pixel Sensors of the detector ALPIDE (ALICE Pixel Detector). The purpose of these tests was to measure the pixel threshold and noise ...distributions in each of the four sectors of the detector, as well as the analysis of the hit maps produced by different radioactive sources.
Conducted research on the dynamics of the density of single-species and mixed grass crops on sod-podzolic soils of the Ryazan region. The estimation of the density of turf grass stands in the years ...2012-2014 studies found that the highest density had a single-species crops: Kentucky bluegrass, red fescue, bent grass selenobrachys, and among mixed crops - a three-component grass mixture (red fescue, Kentucky bluegrass, bent grass selenobrachys) and four-component mixture (selenobrachys bent grass, red fescue, Kentucky bluegrass, red fescue). The lowest density of planting was installed at the perennial ryegrass in the second and third years and three-component grass mixture (red fescue, sheep's fescue, perennial ryegrass) in the third year of life of grass. The trend of higher density turf grass stands revealed in experiment 1 for loamy soils compared to sandy loam.
The first evidence of spin alignment of vector mesons ( K*0 and ϕ ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ 00 is measured at ...midrapidity ( | y | < 0.5 ) in Pb-Pb collisions at a center-of-mass energy ( √sNN ) of 2.76 TeV with the ALICE detector. ρ 00 values are found to be less than 1/3 (1/3 implies no spin alignment) at low transverse momentum ( p T < 2 GeV / c ) for K*0 and ϕ at a level of 3 σ and 2 σ , respectively. No significant spin alignment is observed for the K0S meson ( spin = 0 ) in Pb-Pb collisions and for the vector mesons in p p collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.
This work presents new constraints on the existence and the binding energy of a possible Λ–Λ bound state, the H-dibaryon, derived from Λ–Λ femtoscopic measurements by the ALICE collaboration. The ...results are obtained from a new measurement using the femtoscopy technique in ▪ collisions at s=13 TeV and p–Pb collisions at sNN=5.02 TeV, combined with previously published results from ▪ collisions at s=7 TeV. The Λ–Λ scattering parameter space, spanned by the inverse scattering length f0−1 and the effective range d0, is constrained by comparing the measured Λ–Λ correlation function with calculations obtained within the Lednický model. The data are compatible with hypernuclei results and lattice computations, both predicting a shallow attractive interaction, and permit to test different theoretical approaches describing the Λ–Λ interaction. The region in the (f0−1,d0) plane which would accommodate a Λ–Λ bound state is substantially restricted compared to previous studies. The binding energy of the possible Λ–Λ bound state is estimated within an effective-range expansion approach and is found to be BΛΛ=3.2−2.4+1.6(stat)−1.0+1.8(syst) MeV.
Complex experimental studies of the influence exerted by phytoplankton on microwave backscattering from the water surface are carried out. Quantitative data on the concentration and group composition ...of the phytoplankton in the Gorky Reservoir during its eutrophication are obtained. It is established that the velocity of damping of gravity-capillary waves increases as the phytoplankton concentration increases, in which case the rise in the coefficient of damping of gravity-capillary waves is caused by an increase in both the effective viscosity of water and the value of elasticity of surface films related to the phytoplankton. It is established that, under the same weather conditions, the intensity of a radar signal decreases in the areas where the phytoplankton concentration is high. The results of model calculations of contrasts in the spectrum of wind gravity-capillary waves and the intensity of a radar signal are presented with respect to the phytoplankton concentration using the reconstructed values of the effective viscosity of water and the elasticity of films in the eutrophication zones, which describe the observational data satisfactorily.
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