It has long been believed that small colliding systems (
p
+Au,
d
+Au,
3
He + Au) are can only be used to study the collective effects of cold nuclear matter. However, recent studies on the RHIC and ...LHC accelerators indicate there are flowlike collective effects characterized by the high multiplicity of charged particles produced in these collisions. Whether these effects result from the hydrodynamic expansion of a dense and hot thermalized medium or are caused by the initial state remains an open question. This work reports the results from measuring flow characteristics in
d
+ Au and
3
He + Au collisions at an energy of 200 GeV in the PHENIX experiment on the RHIC collider. Attempts to describe the results theoretically are discussed.
—
This paper presents the results of estimating the changes in the yields and spectral properties of hadronic resonances in heavy ions collisions at NICA energies by the example of short-lived ...resonances
and
. The results of studying the feasibility of detecting hadronic resonances at the MPD detector in collisions of bismuth nuclei at an energy of 9.2 GeV are also presented.
An asymmetric system of colliding copper and gold nuclei (Cu + Au) has a specific overlap geometry when compared to symmetric systems (Au + Au, Cu + Cu). Studying asymmetric heavy systems allows us ...to obtain additional restrictions for existing models and more accurate descriptions of the processes of parton energy loss in hot and dense QCD matter produced in collisions of heavy nuclei. This work reports nuclear modification factors for neutral pions in Cu + Au, Сu + Cu, and Au + Au collisions at an energy of 200 GeV, measured in the PHENIX experiment on the RHIC.
Initial results are presented from studying the possibility of measuring different resonances on the experimental setup of the MPD spectrometer of the NICA accelerator, along with the first ...assessments of the impact the hadron phase has on the properties of resonances in heavy ion collisions at NICA energies.
Investigations of light vector mesons allow us to understand the mechanisms of hadron production in more detail and to investigate the properties of the dense and hot medium formed in central ...collisions of heavy ultrarelativistic nuclei. One of the most useful objects for investigations are φ-mesons, since their properties are sensitive to such effects as strangeness enhancement, the restoration of chiral symmetry, and the loss of parton energy that accompanies a phase transition. To investigate these phenomena, meson production must be measured not only in collisions of heavy nuclei but in proton-proton and proton-nuclear collisions as well. Measurements in elementary nucleon-nucleon collisions are used as the basis for comparison to heavier interacting systems. The collision of light and heavy nuclei allows us to evaluate the effects of cold nuclear matter and to interpret the effects of a hot nuclear medium more precisely. Invariant differential production spectra of φ-mesons were measured in the ALICE experiment as a function of transverse momenta in
p
+
p
,
p
+ Pb, and Pb + Pb interactions. The distributions of the nuclear modification factors were constructed for φ-mesons on the basis of these data.
Collisions between asymmetric nuclei (Cu–Au) differ significantly in their nuclear overlap geometry from those of symmetric nuclei (Cu–Cu, Au–Au). This results in a number of consequences that allow ...us to obtain more comprehensive and accurate information about the fundamental properties of matter under extreme conditions. The High Energy Proton–Proton Collider Experiment (PHENIX) at the Relativistic Heavy Ion Collider (RHIC) measured the nuclear modification factors of π-mesons in Cu+Au collisions at an energy of 200 GeV. New experimental data from measurements of light hadron flows of different orders (ν
1
, ν
2
) in Cu + Au collisions at an energy of 200 GeV are discussed.
A 64-channel readout and data-acquisition module is described in detail. It consists of an H12700 multianode photomultiplier tube, four PADIWA preamplifier boards, and a TRB v3 card that perform the ...functions of a time-to-digital converter and a data concentrator. The software modules that are necessary for operation of the prototype are described. The inter-channel delays are calibrated. The drift of individual delays does not exceed 0.5 ns for the entire measurement time. The spectra of the “time over threshold” (ToT) are investigated. The influence of periodic noise pickups and the need to improve circuit designs are revealed. The timing properties of the wavelength shifter and its effect on the detection efficiency for Cherenkov rings are investigated. The most intense component is characterized by a decay time of 1.1 ns and there are components with characteristic times of 3.8 and 45 ns. The influence of single-electron spectrum features on the detection efficiency for photoelectrons and the probability of false hits are determined. The total time resolution of 131 channels is 1.1 ns (FWHM). The results make it possible to use the investigated system of readout and data acquisition in the CBM experiment. Nevertheless, the elimination of the revealed shortcomings will provide the efficiency margin and improve the reliability of the system during long-term operation.
The motivation for quark-gluon plasma studies at beam energies of 20–100 GeV are the detailed exploration of the phase diagram of QCD matter and the search for the critical point of deconfinement ...transition. The PHOENIX experiment on the RHIC measures nuclear modification factors for protons, π
0
and φ mesons in heavy-ion collisions at
6 = 2.4 GeV. The possibility of obtaining the electromagnetic signatures of quark-gluon plasma measurements with an innovative HBD detector is discussed.
The latest physics results obtained in the PHENIX experiment by studying
d
Au, CuCu, and AuAu collisions at various interaction energies are reviewed. Attention is given primarily to the energy loss ...of hard-scattered partons and to the production of soft and high-transverse-momentum direct photons.
Investigations of light vector mesons allow us to understand the mechanisms of hadron production in more detail and to investigate the properties of the dense and hot medium formed in central ...collisions of heavy ultrarelativistic nuclei. One of the most useful objects for investigations are Φ-mesons, since their properties are sensitive to such effects as strangeness enhancement, the restoration of chiral symmetry, and the loss of parton energy that accompanies a phase transition. To investigate these phenomena, meson production must be measured not only in collisions of heavy nuclei but in proton-proton and proton-nuclear collisions as well. Measurements in elementary nucleon-nucleon collisions are used as the basis for comparison to heavier interacting systems. The collision of light and heavy nuclei allows us to evaluate the effects of cold nuclear matter and to interpret the effects of a hot nuclear medium more precisely. Invariant differential production spectra of Φ-mesons were measured in the ALICE experiment as a function of transverse momenta in p + p, p + Pb, and Pb + Pb interactions. The distributions of the nuclear modification factors were constructed for Φ-mesons on the basis of these data.
