The properties of an extreme state of nuclear matter, the Quark-Gluon Plasma (QGP), are studied in experiments at RHIC and LHC with heavy-ion datasets collected at ultrarelativistic energies. The QGP consists of asymptotically free quarks and gluons which move freely over distances large in comparison to the typical size of a hadron. If the nuclear matter produced in heavy-ion collisions...
The collective expansion of the color-deconfined fireball created in relativistic heavy-ion collisions maps the initial state of the quark-gluon plasma (QGP) to the final-state particle spectrum.
The LHC experiments are completing the flow harmonic measurements at the highest energies to date as well as improving flow harmonic correlation techniques to understand the properties of the QGP and...
The ALICE experiment is designed to study the hot and dense medium, the quark-gluon plasma, produced in ultra-relativistic heavy-ion collisions at the LHC. Measuring the
production of hadrons with large Q2 transfer in these collisions provides the possibility to explore one of the most spectacular effects -- parton energy loss in hot QCD matter. By varying the observables among light- and...
Femtoscopy is an important tool to measure spatial and temporal characteristics of the collision system. In this talk, the results of one-dimensional pion femtscopic analysis performed for d+Au collisions at $\sqrt s_{NN}$ =200 GeV will be shown. We will present various dependences of the invariant radii on pair transverse momentum and particle multiplicity per event. The physics implications...
The $φ$ meson has a small inelastic cross section for interaction with nonstrange hadrons, therefore it is less affected by late hadronic rescattering and better reflects the initial evolution of heavy ion collisions. Small systems, such as $p$+Al, $p$+Au, and $^3$He+Au, can help us understand whether the suppression of hadron yields in the region of intermediate to large transverse momenta is...
The primary goal of the ultra-relativistic heavy-ion collision program at the Large Hadron Collider (LHC) is to study the properties of the Quark-Gluon Plasma (QGP), a novel state of strongly interacting matter which exists in the early universe. Anisotropic flow, which quantifies the anisotropy of the momentum distribution of final state particles, is sensitive to the fluctuating initial...
Using the Gribov–Glauber model for photon–nucleus scattering and a generalization of the vector meson dominance (VMD) model for the hadronic structure of the photon, we make predictions for the cross sections of coherent and incoherent photoproduction of rho-mesons in Pb-Pb ultraperipheral collisions (UPCs) at the LHC. We find that the effect of inelastic nuclear shadowing is significant and...
We argue that $p_T$ distribution data from the LHC on the invariant differential yield of the charged primary particles in Pb–Pb collisions at 2.76 TeV with six centrality bins contains several $p_T$ regions with special properties. These distributions were analyzed by fitting the data with exponential functions. We conclude that the regions reflect features of fragmentation and...
The BESIII experiment, installed at the BEPCII electron positron collider in Beijing, has acquired large data sets at center-of mass energies between 2.0 GeV and 4.6 GeV. One of the main aspects of the BESIII physics program is to test the understanding of QCD at intermediate energies. Applying different experimental techniques, form factors of hadrons are measured. An overview of the recent...
A method is proposed [1] for constructing a model for the interaction of fields of quantum electrodynamics (QED) with two-dimensional materials in the framework of the Symanzik approach [2]. It is based on the modification of the QED Lagrangian by adding to it an additional contribution (the Lagrangian of the defect) concentrated in a two-dimensional region of space. The requirement to comply...
The description of relativistic nuclear interactions in the four velocity space allows to enter the self-similarity parameter. This parameter allows us to describe rather well the ratio of the proton to anti-proton yields in A-A collisions as a function of the energy in a wide range from 10-20 GeV to a few TeV. It is shown that the inclusive spectra of the produced hadrons in hadron-hadron...
The study of continuous (Lorentz transformations) and discrete symmetries of P, T, C, CP, and CPT and their disturbances is one of the important directions in modern quantum field physics. However, the derivation of formulas defining these transformations for spinors still relies heavily on physical considerations, rather than on the algebraic properties of spinors. Initially, in quantum field...
$\bf{A.T. D’yachenko^{1,2}}$
$^{1}$Emperor Alexander I Petersburg State Transport University, St.Petersburg, Russia;
$^{2}$NRC "Kurchatov Institute", Petersburg Nuclear Physics Institute, Gatchina, Russia
The transverse momentum distributions for lambda-hyperons are found in the thermodynamic model, which are in agreement with experimental data for proton-proton collisions with energies...
The holographic methods inspired by the gauge/gravity correspondence
from string theory have been actively applied to the hadron spectroscopy in
the last fifteen years. Within the phenomenological bottom–up approach,
the linear Regge-like trajectories for light mesons are naturally reproduced
in the so-called “soft-wall” holographic models. I will give a very short
review of the...
The AdS/QCD models are believed to interpolate between low and high energy sectors of QCD. This claim is usually based on observations that many phenomenologically reasonable predictions follow from bounds imposed at high energies although the hypothetical range of applicability of semiclassical bottom-up holographic models is restricted by the gauge/gravity duality to low energies where QCD...
The strongly intense quantities and robust variances in processes of multi-particle production in pp and AA interactions at LHC energies was studied. The Monte Carlo and analytic modelling of these quantities in the framework of a quark-gluon string model were implies. The string fusion effects were also taken into account by implementing of a lattice (grid) in the impact parameter plane....
The Large Hadron-electron Collider is the proposal of an upgrade of the HL-LHC. An energy recovery linac will provide 50 GeV electrons to collide with the HL-LHC hadrons beams or, later, with the hadron beams at the Future Circular Collider. When combined with the available HL-LHC Pb beams, it will deliver e-Pb collisions with nucleon-nucleon centre-of-mass energies around 0.8 TeV, and per...
Based on the quark-hadron duality concept the hadronization of the deconfined matter arising in high-energy particle collisions is considered. The number of generated hadrons is shown to be entirely determined by the exact non-equilibrium Green's functions of partons in the deconfined matter and the vertex function governed by the probability of the confinement-deconfinement phase...
In a chirally-imbalanced medium we compare some constraints on parameters both in the linear sigma model (LSM) and in the chiral perturbation theory (ChPT) as realizations of low energy quantum chromodynamics (QCD) for light mesons. The relations between the low-energy constants of the chiral Lagrangian and the corresponding constants of the linear sigma model are established as well as the...
The talk is devoted to QCD phase diagram studies, including the region of large baryon density that will be probed at NICA.
Part of the talk is
based on:
Phys.Rev. D95 (2017) no.10, 105010
Phys.Rev. D97 (2018) no.5, 054036
Phys.Rev. D98 (2018) no.5, 054030
Eur.Phys.J. C79 (2019) no.2, 151
JHEP 1906 (2019) 006
Phys. Rev. D 100, 034009 (2019)
Recently It has been shown that in the...
A search for the time-noninvariant (T-odd) interactions is one of the most fundamental not yet resolved problems in physics and, more generally, in nature. In 1950, Purcell and Ramsey [1] suggested that it is equivalent to the search for the electric dipole moment(EDM) of any elementary particle. The existence of EDM violates both P- and T-invariance (P is the space parity). The search for the...
At present the heavy ion accelerator complex NICA is under construction in Dubna, Russia. The Multi-Purpose Detectors (MPD) will operate at NICA to study the properties and phase diagram of strongly interacting matter. The Forward Hadron Calorimeter (FHCal) is one of the basic sub-detectors of MPD and is intended for the detection of the particles in very forward rapidity region, mainly,...
Participating nucleons in collisions of relativistic nuclei are well separated kinematically from spectator nucleons, which propagate forward with the initial beam energy. In central $^{208}$Pb–$^{208}$Pb collisions (0-5% centrality) the nuclear centres are typically separated by less than 3.5 fm [1]. This suggests that only few nucleons in far nuclear periphery escape collisions and move...
To measure the centrality in heavy ion reactions in the future experiments CBM@FAIR, BM@N, NA61/SHINE@SPS and MPD@NICA the forward hadron calorimeters with transverse and longitudinal segmentations will be used. All these calorimeters have the beam hole in the center. This feature leads to uncertainty in determining the centrality, since in this case the total energy deposition in the...
As the kinetic energy of nuclei grows, studying their fragmentation in collisions with fixed targets becomes an increasingly complicated task. Secondary spectator fragments emitted at small angles close to the beam do not allow the placement of advanced detectors for their registration. This explains the use of nuclear photoemulsion or track detectors at ~1–100 AGeV beam energies [1-3], where...
The BM@N (Baryonic Matter at Nuclotron) is fixed target experiment to study nucleus-nucleus reactions with the ion beams energies up to 4.5 AGeV. It is supposed to perform differential measurements of the energy, charge composition, transverse momentum and other characteristics of the projectile spectators at the BM@N. These observables would be sensitive to the processes in the dense...
The Baryonic Matter at Nuclotron (BM@N) is the fixed target experiment on NICA-Nuclotron acceleration complex in Dubna (JINR). The main goals of experimental data taking in 2016-2018 at the BM@N were measurements of strange and multistrange hyperon productions and searching for the hyper-nuclei in nucleus nucleus collisions. First data with carbon, argon and krypton beams have been taken at...
Centrality is an important concept in a study of strongly interacting matter created in a heavy-ion collision which evolution depends on its initial geometry. Experimentally collisions can be characterized by the measured multiplicities or energy of produced particles at midrapidity or spectator fragments emitted in the forward rapidity region. Relation between collision geometry and...
The experimental determination of event centrality classes is one of the important tasks in studying the properties of strongly interacting matter.
New approaches for event centrality selection in nucleus-nucleus collisions based on the particles charge distributions measured with Forward Wall hodoscope at the HADES experiments will be discussed.
The comparison of experimental charge...
Anisotropic transverse flow is one of the main observables in the study of strongly interacting matter created in nucleus-nucleus collisions. Spatial asymmetry of overlapping region of two ions transforms due to particles interaction into momentum anisotropy of produced hadrons. Comparison of measured azimuthal anisotropy with theoretical calculations allows to extract properties of the...
The relative angle correlation of intermediate mass fragments has been studied for C(22 GeV) + Au collisions at the Dubna Nuclotron with the FASA [1] 4pi detector array. Strong suppression at small angles is observed caused by IMF-IMF Coulomb repulsion. Experimental correlation function is compared to that obtained by the multibody Coulomb trajectory calculations with the various decay time of...
Исследование и применение свойств геометрии Лобачевского для описания релятивистских ядерных реакций. Рассматриваются свойства инклюзивного и множественного рождения частиц, полученных при помощи пузырьковых камер и современных экспериментов в условиях геометрии, близкой к 4π. Рассматривается фундаментальная связь между свойствами пространства Лобачевского и релятивистскими явлениями....
Рассматривается автомодельное описание релятивистских ядерных столкновений. Автомодельный подход иллюстрируются широким набором экспериментальных данных по кумулятивным, подпороговым процессам, а также реакциям с рождением частиц с большими поперечными импульсами. Рассматриваются критерии применимости понятия «элементарная частица». Обсуждается принцип редукционизма и соотношения между...
Deep subthreshold production processes of J/Psi and muon pairs and cold dense baryonic matter are proposed to study at a NICA fixed target experiment FITNEX. Such studies should be very sensitive to cold dense baryonic matter and can be complimentary to upcoming MPD, SPB and BM@N experiments at NICA.
Изучение образования протонов в адрон- и ядро-ядерных соударениях при высоких энергиях позволяет получить ценную информацию о вкладах различных механизмов их происхождения. Особый интерес представляет сравнительный анализ различных характеристик протонов в изотопически сопряженных реакциях – в рС- и nC-соударениях при одинаковых энергиях. Такое сравнение позволяет, в частности, изучить...
Since the production and hadronisation of heavy-flavour quarks is well-separated within the evolution of a high-energy particle collision, the resulting yields and kinematics of heavy-flavoured hadrons are valuable signals to gain insight in the underlying processes and dynamics of a hadronic collision.
In this contribution, an overview of recent results on heavy-flavour hadron production...
The excitation of nucleon resonances (N*) by real and virtual photons is an important source of information on the structure of excited nucleon states and dynamics of the nonperturbative strong interaction underlying the resonance generation from quarks and gluons [1, 2]. This information has already become available from the nucleon resonance electroexcitation amplitudes ($\gamma_v p N^*$...
BM@N is a really working fixed target experiment considered as a first step towards a fulfil realization of physics program at the NICA accelerator complex (Dubna, Russia). It has an extensive physics program to be investigated. Estimation of yields of strange particles in the BM@N energy range ($E_{lab} = 2 - 6$ AGeV) is considered as a point of utmost importance due to lack of measurements....
Dressed quarks with dynamically generated masses shape the structure of the ground and excited nucleon states (N*) as their active constituents. The generation of >98% of hadron mass and the emergence of quark-gluon confinement are encoded in the momentum dependence of dressed quark mass. Experimental studies of electroexcitation amplitudes of prominent nucleon resonances in a broad range of...
The e+e- -> n+anti-n cross section has been measured in the experiment at the VEPP-2000 e+e- collider with the SND detector. The technique of the time measurements in the multichannel NaI(Tl) electromagnetic calorimeter is used to select n+anti-n events. The measured value of the cross section in the energy range from the threshold up to 2 GeV is of order of 0.5 nanobarn, what corresponds to...
Relativistic heavy-ion collision experiments are aimed to study the properties of nuclear matter under extreme conditions, i.e. high baryon density and/or temperature, and to understand the underline mechanism of transition from quark-gluon to hadron matter. The phase transition may leave imprints on space and time characteristics of particle-emitting source that can be measured using...
The future heavy-ion collider NICA (JINR, Dubna) will provide a variety of beam species in the energy range of 4 – 11 GeV. New experimental data on strangeness production and event-by-event fluctuations from NICA allow addressing important QCD properties such as the nature of the deconfinement phase transition and existence of the Critial End Point (CEP). Heavy-ion collisions at NICA will be...
We estimate the yields of particles at central rapidities and large transverse momenta in the region outside NN-kinematics (the so-called cumulative region) in AuAu collisions, which in principle may be observed by MPD and SPD detectors at the NICA collider facility. We suppose that particles is this kinematical region are produced due to scattering from the clusters of cold dense quark-gluon...
Inclusive differential cross sections for the forward production of charged hadrons and nuclei are measured in $CC$-interactions depending on their momentum at beam energy 20.5 GeV/nucleon ($\sqrt{S_{NN}}=$6.3 GeV). The measurements have been performed at the U-70 Accelerator Complex (Protvino) using a combined spectrometer on base of beamline 22. Particle selection was carried out by...
Although the start-up of the MPD experiment is still ahead, the work on the preparation and physics validation of the future detector upgrade program has already been initiated.
As one of the possible MPD upgrade steps, an Inner Tracking System (ITS) based on the next generation silicon pixel detectors is being considered to be installed between the beam pipe and the Time Projection...
Charged pion momentum spectra in 12C fragmentation at a laboratory angle of 3.5o on Be target were measured in the FRAGM experiment at ITEP TWA heavy ion facility. Carbon beam energy was 3.2 GeV/nucleon. Positive pions were identified on severe proton background by TOF and Cherenkov counters. Yields of positive and negative pions have been measured up to 5.2 GeV/c momentum, which is...
Relativistic heavy-ion collisions provide a unique opportunity to study nuclear matter under
extreme density and temperature. The study of the strangeness production is of particular interest. Since strange hadrons are initially not present but created during the heavy-ion collision, the strangeness is one among the most sensitive probes for the deconfinement phase transition as
well as for...
First data on the high pt cumulative K+/- and anti-proton particles produced at angle of 40 deg. (lab.syst.) in proton-nucleus interaction are presented. The anti-proton, pion and K-meson inclusive cross-sections in proton interactions with C, Al, Cu and W targets at 50 GeV/c were investigated. The available pt range 0.6 < pt <2.7 GeV/c exceeds free proton – nucleon kinematic limit (2.3 GeV/c...
The Multi-Purpose Detector(MPD) is being constructed to study the properties of extremely dense nuclear matter formed in relativistic nucleus-nucleus collisions at the NICA collider energies.The yields of strange and charmed particles are the important observables sensitive to critical phenomena in phase transitions of the QGP-matter at high net-baryon density. Highly efficient registration of...
Baryonic Matter at Nuclotron (BM@N) is a fixed target experiment at the NICA - Nuclotron accelerator complex (JINR). It is aimed at studies of nuclear – nuclear (up to gold-gold) collisions at high densities. The Nuclotron provides heavy ion beams with energies from 2.3 to 3.5 GeV, which is suitable for studies of strange mesons and multi–strange hyperons produced in nucleus-nucleus...
Search for new dibaryons was carried out in [1, 2]. It was found that the data of two independent experiments [3, 4] might give an affirmative answer to this question. Furthermore, the data from [1] and [2] are in a so striking agreement that their incidental coincidence should be considered as a marvel. On this basis, it is reasonable to assume existence in an excited neutron-proton system a...
The local canonical growth of gravitational 3 dimensinal commuting space dependent
gauge fields is shown to be constructable in a canonical way which can well be chosen to include all gaugefield pertaining to gravity in a unique way comptible with renormqlizable structure, which however necessarily contqin nonperturbqtive regions, not easily displying excludively perturbative approximation
We study the important role of magnetic field on one of the indirect signature of quark gluon plasma as equation of state. The magnetic field plays an important role in producing the equation of state of QGP using simple phenomenological model. The results are significant at RHIC and LHC.
The event of astroparticle collision at high energy was detected in 1975 during
the balloon flight in the stratosphere. The hundred particle tracks in x-ray films have been re-analyzed in the style of LHC experiments: rapidity distributions of charged particles and transverse mass spectra of multiparticle production have been built. The comparison of rapidity-and-transverse-mass histograms...
Spin amplitudes of pp- and pn elastic scattering contain important information on the dynamics of the NN interaction. Systematic information on these amplitudes is accumulated in the SAID data base [1] and available up to kinetic energy 3 GeV for pp and 1.2 GeV for pn scattering. At higher energies there are only non-complete data on pp scattering, whereas information about the pn amplitudes...
The HERMES experiment has collected a wealth of data using the 27.6 GeV polarized HERA lepton beam and various polarized and unpolarized gaseous targets. This allows for a series of unique measurements of observables sensitive to the multidimensional (spin) structure of the nucleon, in particular semi-inclusive deep-inelastic scattering (SIDIS) measurements, for which the HERMES dual-radiator...
The main goal of study the relativistic heavy-ion collisions at energies of accelerator facility NICA (4−11 GeV) is to explore the QCD phase diagram in the region of high net baryon chemical potential and moderate temperatures. The anisotropic collective flow is one of the important observables sensitive to transport properties of strongly interacting matter created in such collisions. The MPD...
We present the first measurements of diffraction in $\sqrt{s_{NN}}=8.16$ TeV proton-lead collisions with CMS. The very large angular coverage of CMS is used to tag rapidity gaps on both the proton-going and lead-going sides and to identify both pomeron-lead and pomeron-proton topologies. Since the previous highest energy measurement of these processes was at $\sqrt{s_{NN}}=30$ GeV, the current...
The DANSS detector is located under a commercial reactor core at the Kalinin Nuclear Power Plant. DANSS position below industrial reactor core provides overburden about 50 m. w. e. in vertical direction. So in terms of cosmic rays it occupies an intermediate position between surface and underground detectors. The core of the detector is a cubic meter of plastic scintillator with fine...
Short range correlated (SRC) NN pairs play an important role in structure of atomic nuclei and are studied in many nuclear centers using electron beams [1]. A new step was done at BM@N in JINR [2] where the reaction $^{12}$C+p→$^{10}$A+pp+N is studied using the $^{12}$C beam at energy of 4 GeV/nucleon at kinematics providing interaction of the hydrogen target with the SRC pair in the...
The production of heavy flavor mesons in pp and p-Pb collisions at LHC energy is considered in the Monte Carlo model [1,2] with the string fusion. In the model, the elementary partonic collisions are implemented as interactions of color string, and the particle production is implemented using a string mechanism. The particle differentiation is implemented according to the Schwinger mechanism...
The SPD and BM@N detectors of the Nuclotron-NICA accelerator complex at JINR are designed to operate at relatively high luminosities, which potentially significantly expands their physical program. The presented report is intended to stimulate the development of models and the development of experiments that are adequate to these capabilities. The report discusses the influence of...
The PHENIX experiment aims to study the hot and dense state of strongly interacting matter produced in high energy heavy ion collisions, the quark-gluon plasma (QGP). Measurements of proton production, when contrasted with light meson production, provide excellent opportunities to study the constituent quark number dependence of certain observables. In this talk, we present a systematic study...
The Compressed Baryonic Matter experiment (CBM) at FAIR aims to study the area of the QCD phase diagram at high net baryon densities and moderate temperatures using collisions of heavy ions at center-of-mass energies of a few GeV per nucleon. Anisotropic transverse flow is among the key observables to study the properties of matter created in such collisions. The CBM performance for charged...
The NA61/SHINE experiment at the CERN SPS has recently extended its
program for the energy scan with Pb ions. In the past, the NA49
experiment, which preceded NA61/SHINE, also recorded data for
Pb-Pb collisions at different energies. Together, the two experiments
cover a wide range of beam energies provided by the CERN SPS in the range 13 - 150 A GeV/c. Analysis of the new NA61/SHINE data...
A central goal of current relativistic heavy-ion experiments is to study the properties of the hot and dense QCD matter. Such studies can give provide on the QCD phase diagram, as well as the transport coefficients of the strongly-coupled Quark Gluon Plasma (sQGP). Anisotropic flow measurements of identified particles play an essential role in such studies.
We report on the results of the...
The future MPD experiment at the NICA collider is going to explore the dense hadronic matter produced in heavy-ion collisions in the energy range 4-11 GeV and search for signs of the phase transition to the deconfined quark-gluon plasma state. Measurements of soft thermal photon spectra via photon conversions can significantly extend the physics program of the MPD experiment, allowing one to...
The short-lived resonances have always played an important role in the physical programs of heavy-ion experiments. The resonances measured in the hadronic decay channels probe the strangeness production, the hadronization mechanisms at intermediate and high transverse momenta, rescattering and regeneration effects in the hadronic phase of nucleus-nucleus collisions at various energies....
One of the first proposed signatures of quark-gluon plasma (QGP) formation in heavy ion collisions was strangeness enhancement [1]. Due to its strange quark content, the $K^*$ meson is a good probe for the study of the QGP formed in heavy-ion collisions. $K^*$-meson production was previously measured by PHENIX [2] in symmetric Cu+Cu collisions at $\sqrt{s_{NN}}$ = 200 GeV [3]. To continue the...
