| 1. |
- Adolfsson, Jonatan
(författare)
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Studying particle production in small systems through correlation measurements in ALICE
- 2020
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 14:1, s. 21-27
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Tidskriftsartikel (refereegranskat)abstract
- In these proceedings, measurements of angular correlations between hadron pairs in pp collisions obtained by the ALICE experiment at the LHC are presented and compared with phenomenological predictions. Correlations between particles carrying the same and opposite quantum numbers are studied to understand the hadron production mechanism, and the difference between the same-sign and opposite-sign correlations is used to probe charge-dependent effects in particle production. Correlation measurements dominated by minijet fragmentation agree well with the models, but other results, in particular correlations between baryons and strange hadrons, are not yet understood.
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| 2. |
- Albertsson, M.
(författare)
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Energy dependence of fission-fragment neutron multiplicity in 235U(n, f)
- 2019
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 12:3, s. 499-506
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Tidskriftsartikel (refereegranskat)abstract
- A consistent framework for treating the energy dependence of fission-fragment neutron multiplicities is presented. The shape evolution of the compound nucleus towards scission is treated in the strong damping limit using the Metropolis walk method. The available excitation energy at scission is then divided statistically between the two fragments using microscopic level densities. Deformation energies, which contribute to the excitation energy when the fragments relax to their ground-state shapes, are also computed. From the total fragment excitation energies, the number of emitted neutrons is obtained and illustrated for neutron-induced fission of 235U.
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| 3. |
- Bartoszek, Krzysztof, 1984-, et al.
(författare)
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Influenza differentiation and evolution
- 2010
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Ingår i: Acta Physica Polonica B Proceedings Supplement. ; 3:2, s. 417-452
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Konferensbidrag (refereegranskat)abstract
- The aim of the study is to do a very wide analysis of HA, NA and M influenza gene segments to find short nucleotide regions,which differentiate between strains (i.e. H1, H2, ... e.t.c.), hosts, geographic regions, time when sequence was found and combination of time and region using a simple methodology. Finding regions differentiating between strains has as its goal the construction of a Luminex microarray which will allow quick and efficient strain recognition. Discovery for the other splitting factors could shed lighton structures significant for host specificity and on the history of influenza evolution. A large number of places in the HA, NA and M gene segments were found that can differentiate between hosts, regions, time and combination of time and region. Also very good differentiation between different Hx strains can be seen.We link one of our findings to a proposed stochastic model of creation of viral phylogenetic trees.
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| 4. |
- Baxevani, Anastassia, et al.
(författare)
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Series Decomposition of fractional Brownian motion and its Lamperti transform
- 2009
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 40:5, s. 1395-1435
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Tidskriftsartikel (refereegranskat)abstract
- The Lamperti transformation of a self-similar process is a stationary process. In particular, the fractional Brownian motion transforms to the second order stationary Gaussian process. This process is represented as a series of independent processes. The terms of this series are Ornstein-Uhlenbeck processes if H < 1/2, and linear combinations of two dependent Ornstein-Uhlenbeck processes whose two dimensional structure is Markovian if H > 1/2. From the representation effective approximations of the process are derived. The corresponding results for the fractional Brownian motion are obtained by applying the inverse Lamperti transformation. Implications for simulating the fractional Brownian motion are discussed.
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| 5. |
- Blaschke, David, et al.
(författare)
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Accessibility of color superconducting quark matter phases in heavy-ion collisions
- 2010
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Ingår i: Acta Physica Polonica B Proceedings Supplement. - 1899-2358 .- 2082-7865. ; 3:3, s. 741-745
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Tidskriftsartikel (refereegranskat)abstract
- We discuss a hybrid equation of state (EoS) that fulfills constraints for mass-radius relationships and cooling of compact stars. The quark matter EoS is obtained from a Polyakov-loop Nambu-Jona-Lasinio (PNJL) model with color superconductivity, and the hadronic one from a relativistic mean-field (RMF) model with density-dependent couplings (DD-RMF). For the construction of the phase transition regions we employ here for simplicity a Maxwell construction. We present the phase diagram for symmetric matter which exhibits two remarkable features: (1) a "nose"-like structure of the hadronic-to-quark matter phase border with an increase of the critical density at temperatures below T \sim 150 MeV and (2) a high critical temperature for the border of the two-flavor color superconducting (2SC) phase, Tc >160 MeV. We show the trajectories of heavy-ion collisions in the plane of excitation energy versus baryon density calculated using the UrQMD code and conjecture that for incident energies of 4 . . . 8 A GeV as provided, e.g., by the Nuclotron-M at JINR Dubna or by lowest energies at the future heavy-ion collision experiments CBM at FAIR and NICA at JINR, the color superconducting quark matter phase becomes accessible.
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| 6. |
- Csörgő, T., et al.
(författare)
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Lévy imaging of elastic hadron–hadron scattering : Odderon and inner structure of the proton∗
- 2019
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 12:4, s. 779-785
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Tidskriftsartikel (refereegranskat)abstract
- A novel model-independent Lévy imaging method is employed for reconstruction of the elastic pp and pp¯ scattering amplitudes at low and high energies. The four-momentum transfer t-dependent elastic slope B(t), the nuclear phase φ(t) as well as the excitation function of the shadow profile P(b) have been extracted from data at ISR, Tevatron and the LHC energies. We found qualitative differences in properties of B(t) and φ(t) between pp and for pp¯ collisions that indicate an odderon effect. A proton substructure has also been identified and found to have two different sizes, comparable to that of a dressed quark at the ISR and a dressed diquark at the LHC energies, respectively.
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| 7. |
- Csörgő, Tamás, et al.
(författare)
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MODEL-INDEPENDENT ODDERON RESULTS BASED ON TOTEM DATA ON ELASTIC PROTON-PROTON SCATTERING AT 8 TeV
- 2023
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 16:5
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Tidskriftsartikel (refereegranskat)abstract
- We complete the model-independent analysis of the scaling properties of the differential cross section of elastic proton-proton cross sections, including new TOTEM data published in 2022 at √s = 8 TeV. We separate the signal and background regions with a new gating method. In the signal region, we find that the statistical significance of the Odderon exchange from the combined 7.0 and 8.0 TeV pp data of TOTEM and the 1.96 TeV pp̄ data of D0 is at least 7.32σ. In the background region, the scaling functions of elastic proton-proton data at 7 and 8 TeV, and that of elastic proton-antiproton scattering data at 1.96 TeV agree with a statistical significance not larger than 1.93σ.
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| 8. |
- Gustafson, Gösta
(författare)
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Small x, Saturation, and Diffraction in Collisions with Electrons, Protons and Nuclei
- 2013
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Ingår i: International Symposium on Multiparticle Dynamics. - 1899-2358. ; 6:2, s. 621-627
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Konferensbidrag (refereegranskat)abstract
- The Lund dipole model DIPSY is based on BFKL evolution and saturation. It can be applied to collisions between electrons, protons, and nuclei. In this paper, I present some recent results for exclusive final states in inelastic collisions, a method to generate final states in diffractive excitation, and some results for collisions with nuclei.
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| 9. |
- Kudaibergenova, E., et al.
(författare)
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MEASUREMENTS OF THE REACTION CROSS SECTIONS OF NEUTRON-RICH Sn ISOTOPES AT THE R3B SETUP
- 2024. - 3
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Ingår i: XXXVII MAZURIAN LAKES CONFERENCE ON PHYSICS : PROBING FUNDAMENTAL PROPERTIES OF MATTER WITH RARE ISOTOPES - PROBING FUNDAMENTAL PROPERTIES OF MATTER WITH RARE ISOTOPES. - 1899-2358. ; 17
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Konferensbidrag (refereegranskat)abstract
- A fundamental framework to describe nuclear matter as a function of pressure and nuclear isospin asymmetry is the nuclear Equation of State (EoS). Constraining the parameters of the EoS is one of the central issues in nuclear physics, especially since the slope parameter L has not yet been constrained well experimentally. It has been identified that a precise determination of the neutron-removal cross section in neutron-rich nuclei, which correlates with the neutron-skin thickness, would provide a more precise constraint on L. To this end, an experiment was performed at the R3B setup in the GSI Helmholtzzentrum für Schwerionenforschung GmbH as a part of the FAIR Phase-0 program. The reactions are studied in inverse kinematics with neutron-rich tin isotopes in the mass range of A = 124–134 on carbon targets of different thicknesses. The reaction products have been measured at beam energies of 400–900 MeV/u in a kinematically complete manner. In this communication, the analysis of124Sn+12C at 900 MeV/u is presented. The charge-exchange reactions, resulting processes, and their role in the calculation of other reaction cross sections are discussed. © 2024 Jagiellonian University. All rights reserved.
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| 10. |
- Lihtar, I., et al.
(författare)
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RELATIVISTIC COULOMB EXCITATION OF 124 Sn
- 2024
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 17:3
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Tidskriftsartikel (refereegranskat)abstract
- The Coulomb excitation of 124, 128, 130, 132, 134Sn isotopes in the electric field of a Pb target have been studied using the R3B setup as a part of the FAIR Phase-0 program. The experiment was motivated by the possibility of using the nuclear dipole response to infer valuable information on the slope of the symmetry energy of the nuclear equation of state. Measurements were performed in inverse kinematics at relativistic energies of 750 MeV/u and 904 MeV/u. The analysis method and preliminary results for the decay channel with a single outgoing neutron for 124Sn are reported.
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| 11. |
- Lihtar, I., et al.
(författare)
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RELATIVISTIC COULOMB EXCITATION OF 124Sn
- 2024. - 3
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Ingår i: XXXVII MAZURIAN LAKES CONFERENCE ON PHYSICS : PROBING FUNDAMENTAL PROPERTIES OF MATTER WITH RARE ISOTOPES - PROBING FUNDAMENTAL PROPERTIES OF MATTER WITH RARE ISOTOPES. - 1899-2358. ; 17
-
Konferensbidrag (refereegranskat)abstract
- The Coulomb excitation of 124, 128, 130, 132, 134Sn isotopes in the electric field of a Pb target have been studied using the R3B setup as a part of the FAIR Phase-0 program. The experiment was motivated by the possibility of using the nuclear dipole response to infer valuable information on the slope of the symmetry energy of the nuclear equation of state. Measurements were performed in inverse kinematics at relativistic energies of 750 MeV/u and 904 MeV/u. The analysis method and preliminary results for the decay channel with a single outgoing neutron for 124Sn are reported. © 2024 Jagiellonian University. All rights reserved.
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| 12. |
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| 13. |
- Nahrgang, M., et al.
(författare)
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Nonequilibrium effects in dynamic symmetry breaking
- 2012
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 5:4, s. 1191-1196
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Tidskriftsartikel (refereegranskat)abstract
- We study the evolution of the sigma field fluctuations in a scenario featuring a critical point and a first order phase transition using the model of nonequilibrium chiral fluid dynamics (NχFD).
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| 14. |
- Rasmussen, Christine O.
(författare)
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Hard diffraction in PYTHIA8
- 2015
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 8:4, s. 849-854
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Tidskriftsartikel (refereegranskat)abstract
- We present an overview of the options for diffraction implemented in the general-purpose event generator PYTHIA8. We review the existing model for low- and high-mass soft diffraction and present a new model for hard diffraction in pp and pp¯ collisions. Both models use the Pomeron approach pioneered by Ingelman and Schlein, factorising the single diffractive cross section into a Pomeron flux and a Pomeron PDF. The model for hard diffraction is implemented as a part of the multiparton interactions framework, thereby introducing a dynamical rapidity gap survival probability that explicitly breaks factorisation.
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| 15. |
- Schönning, Karin, 1978-
(författare)
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Hyperon structure at BESIII
- 2023
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - : Jagiellonian University Press. - 1899-2358 .- 2082-7865. ; 16:3
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Tidskriftsartikel (refereegranskat)abstract
- By dedicated off-resonance energy scans, the BESIII experiment pro-vides unique information on the time-like structure of strange and single -charm hyperons. In particular, exploiting polarised and entangled hyperon- antihyperon pairs, has enabled the first complete measurement of the time -like structure of a baryon at a single energy. From this, we gain new insights into the strong interaction forming visible matter.
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| 16. |
- Sharov, P.G., et al.
(författare)
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FOUR-NEUTRON DECAY CORRELATIONS
- 2021
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 14:4, s. 749-753
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Tidskriftsartikel (refereegranskat)abstract
- The mechanism of simultaneous non-sequential four-neutron emission (or “true” four-neutron decay) has been considered in the phenomenological five-body approach. It is demonstrated that four-neutron decay fragments should have specific energy and angular correlations reflecting strong spatial correlations of “valence” nucleons orbiting in their four-neutron precursors. Due to the Pauli exclusion principle, the valence neutrons are pushed to the symmetry-allowed configurations in the four-neutron precursor structure, which causes a “Pauli focusing” effect. Prospects of the observation of the Pauli focusing have been considered for the hydrogen-7 nucleus. Fingerprints of its nuclear structure or/and decay dynamics are predicted.
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| 17. |
- Vary, J. P., et al.
(författare)
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Basis light-front quantization : a new approach to non-perturbative scattering and time-dependent production processes
- 2013
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358 .- 2082-7865. ; 6:1, s. 257-262
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Tidskriftsartikel (refereegranskat)abstract
- Hamiltonian light-front quantum field theory constitutes a framework for deriving invariant masses, correlated parton amplitudes of self-bound systems and time-dependent scattering amplitudes. By choosing the lightfront gauge and adopting an orthonormal basis function representation, we obtain a large, sparse, Hamiltonian matrix for mass eigenstates that is solvable by adapting ab initio no-core methods of nuclear many-body theory. In the continuum limit, the infinite matrix limit, we recover full covariance. There is considerable freedom in the choice of the orthonormal and complete set of basis functions with key considerations being convenience and convergence properties. We adopt a two-dimensional harmonic oscillator basis for transverse modes that corresponds with eigensolutions of the soft-wall anti-de Sitter/quantum chromodynamics (AdS/QCD) model obtained from light-front holography. We outline our approach and present preliminary results for non-linear Compton scattering, evaluated non-perturbatively, where a strong (possibly time-dependent) laser field excites an electron that emits a photon.
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| 18. |
- Ward, D., et al.
(författare)
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Fission dynamics with microscopic level densities
- 2017
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - 1899-2358. ; 10:1, s. 201-209
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Tidskriftsartikel (refereegranskat)abstract
- We present a consistent framework for treating the energy and angularmomentum dependence of the shape evolution in the nuclear fission. It combines microscopically calculated level densities with the Metropolis-walk method, has no new parameters, and can elucidate the energy-dependent influence of pairing and shell effects on the dynamics of warm nuclei.
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| 19. |
- Yaneva, A., et al.
(författare)
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FAST-TIMING MEASUREMENT IN 96Pd: IMPROVED ACCURACY FOR THE LIFETIME OF THE 4+1 STATE
- 2023
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Ingår i: Acta Physica Polonica B, Proceedings Supplement. - : Jagiellonian University. - 1899-2358 .- 2082-7865. ; , s. 1-1
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Konferensbidrag (refereegranskat)abstract
- Direct lifetime measurements via γ–γ coincidences using the FATIMA fast-timing LaBr3(Ce) array were performed for the excited states below previously reported isomers. In the N = 50 semi-magic 96Pd nucleus, lifetimes below the Iπ = 8+ seniority isomer were addressed as a benchmark for further analysis. The results for the Iπ = 2+ and 4+ states confirm the published values. Increased accuracy for the lifetime value was achieved for the 4+ state.
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