Physics of Atomic Nuclei最新文献

We generalize the concept of holography for the color superconductivity (CSC) phase by considering (d)-dimensional Anti de Sitter (AdS) space instead of the traditional 6 dimensions. The corresponding dual field theory is a gauge theory with (SU)((N_{c})) symmetry defined in ((d-1))-dimensions that, despite lacking a confinement phase, retains characteristics consistent with quantum chromodynamics (QCD) CSC. We then use a holographic model based on Einstein–Maxwell gravity and the standard Maxwell interaction in (d)-dimensional AdS space to investigate this phenomenon for the number of colors (N_{c}geq 2) without confinement phase, identifying the dimensions where the model remains valid for (N_{c}=2).

During the LHC Run 2 several methods to identify charged (Sigma) have been developed by ALICE. The main challenge of (Sigma) measurements is the reconstruction of (anti-)neutrons, neutral mesons and soft photons produced in the decays using the electromagnetic calorimeter and photon conversion method. A novel method to detect anti-neutrons in the Photon Spectrometer (PHOS) was proposed, allowing the (bar{Sigma}^{pm}rightarrowbar{n}pi^{pm}) decays to be reconstructed. We present the transverse momentum spectra of (bar{Sigma}^{pm}) in minimum bias pp and p–Pb collisions at (sqrt{s}=5.02) TeV compared with predictions from state-of-the-art Monte Carlo models. Also, results related to (Sigma^{+}rightarrow ppi^{0}) and (Sigma^{0}rightarrowgammaLambda) spectra and integrated yields measurements in Run 2 are presented.

({}^{7})Li elastic scattering and the lithium-induced reaction of one-nucleon transfers from ({}^{10})B(({}^{7})Li, ({}^{6})Li)({}^{11})B have been measured at (E_{textrm{LAB}})(({}^{7})Li) = 58 MeV using U-400 accelerator beam of the FLNR JINR, Dubna. Angular distribution for reaction ({}^{10})B(({}^{7})Li, ({}^{6})Li)({}^{11})B with excitation of the 3.56 MeV state (({}^{6}textrm{Li}^{*})) is presented for the first time. The ‘‘Finite Range Distorted Wave Born Approximation’’ (FRDWBA) analysis of the differential cross section of the ({}^{10})B(({}^{7})Li, ({}^{6})Li)({}^{11})B ground state (g.s.) transition and excited ((J^{pi}=0^{+}), (T=1), (E=3.56) MeV) state of ({}^{6})Li transition was performed. Phenomenological approach based on solving an approximate equation for the reaction form factor was used to determine its radial dependence and empirical values of asymptotic normalization coefficient (ANC). The obtained values of ANC for the ({}^{6})Li({}_{textrm{g.s}}) and ({}^{6}textrm{Li}^{*})(3.56 MeV) states are in agreement with the literature ones. Comparison of the radial dependences of form factors shows that the wave function of the ({}^{6})Li nucleus in excited ((J^{pi}=0^{+}), (T=1), (E=3.56) MeV) state has increased spatial dimension compared to the ground state. This result is an argument in favor of a halo existence in ({}^{6}textrm{Li}^{*})(3.56 MeV) state, while the question of a halo in ({}^{6})Li({}_{textrm{g.s.}}) still stays open.

At the electrostatic accelerator at the Institute of Nuclear Physics, the differential cross-sections of nuclear reactions with deuteron and proton beams on light nuclei in the energy range of 0.3–2.2 MeV were measured by (alpha)-detector.

Free and interacting fixed points of the renormalization group play an important role in particle and statistical physics. High energy fixed points such as in asymptotic freedom or asymptotic safety are crucial for a fundamental definition of quantum field theory. Low energy fixed points relate to (quantum) phase transitions and critical phenomena. In this contribution, we explain the arising of weakly interacting fixed points in general 4d QFTs. This covers necessary and sufficient conditions for existence, and explicit examples. In addition, we also review the last progress in calculation of beta functions, anomalous dimensions up to four loop in the gauge and three loop in the Yukawa and scalar couplings. Moreover, we will overview the status of functional renormalization group and its implications for gravity.

The fluctuation of the number of charged particles in a given rapidity interval of observation was studied. Analytical expressions and the Monte Carlo modelling in the framework of a quark–gluon string model were used to calculate scaled and robust variance of the multiplicity in the case with string fusion and without it. The used distribution of primary strings in the transverse plane is consistent with the Regge approach. The string fusion effects were taken into account by implementing of a lattice (grid) in the impact parameter plane. The scaled and robust multiplicity variance for pp collisions is calculated at three initial energies: 0.9, 2.76 and 7 TeV, and it is shown that the results obtained with string fusion included are in better agreement with the experimental values of the ALICE collaboration at CERN than those without string fusion. It is also demonstrated that for pp collisions at LHC energies, fluctuations in the number of particles from a given string cluster, due to the presence of short-range correlations between particles, significantly exceed the Poisson ones.

To optimize the radiation processing planning process, the software ‘‘DosePreview by IRT’’ has been developed, which calculates depth dose distributions based on the specified energy spectrum of the electron beam. This software is built on a database of depth dose distributions from monoenergetic electrons, covering energy levels from 0.1 to 20 MeV and calculated using the Geant4 simulation toolkit. The created tool can make the planning of radiation processing easier and faster. This will help to make the use of electron beam technology for food processing more accessible and contribute to food security.

The experiment demonstrating the break-up in the Cu foil of some fraction of fragments from binary fission of ({}^{252})Cf(sf) is discussed. One of the features of this new effect is that at least one of the break-up products shows magic nucleon composition. The possible link of the effect with fission modes is analyzed.

The light mesons tend to cluster near certain values of mass. As was noticed some time ago, the emergent degeneracy is of the same type as the dynamical (O(4))-symmetry of the Coulomb potential in the hydrogen atom. The meson mass spectrum can be well approximated by the linear Regge trajectories of the kind (M^{2}=al+bn_{r}+c), where (l) and (n_{r}) are angular momentum and radial quantum numbers and (a), (b), (c) are parameters. Such a spectrum arises naturally within the hadron string models. Using 2024 data from the Particle Data Group, various fits for (M^{2}(l,n_{r})) were performed. Our analysis seems to confirm that (aapprox b) in the light non-strange mesons, i.e., their masses depend on the sum (l+n_{r}) as prescribed by the hydrogen-like (O(4))-symmetry. Using the semiclassical approximation, we discuss which kind of hadron string models are more favored by the experimental data.

Obtaining new data on the polarization observables is the important part of the nucleon–nucleon scattering models’ development. For this purpose, the polarized deuteron beam and the detection setup at the Nuclotron internal target station were used. Counters were mounted in according to (pp)-elastic scattering kinematics. Relevant events were selected using time and amplitude information from the counters. The polyethylene target was used as the main target. Auxiliary carbon target was used to remove the background. This article presents the results of the vector analyzing power measurement for the proton–proton quasi-elastic scattering at the deuteron beam energies of 200, 500, 550, 650 MeV/nucleon. The obtained results are in a good accordance with the data of other experiments and the partial wave analyzis SP07 SAID predictions.