Optimizing the relativistic energy density functional with nuclear ground state and collective excitation properties

We introduce a new relativistic energy density functional constrained by the ground state properties of atomic nuclei along with the isoscalar giant monopole resonance energy and dipole polarizability in $^{208}$Pb. A unified framework of the relativistic Hartree-Bogoliubov model and random phase approximation based on the relativistic density-dependent point coupling interaction is established in order to determine the DD-PCX parameterization by $\chi^2$ minimization. This procedure is supplemented with the co-variance analysis in order to estimate statistical uncertainties in the model parameters and observables. The effective interaction DD-PCX accurately describes the nuclear ground state properties including the neutron-skin thickness, as well as the isoscalar giant monopole resonance excitation energies and dipole polarizabilities. The implementation of the experimental data on nuclear excitations allows constraining the symmetry energy close to the saturation density, and the incompressibility of nuclear matter by using genuine observables on finite nuclei in the $\chi^2$ minimization protocol, rather than using pseudo-observables on the nuclear matter, or by relying on the ground state properties only, as it has been customary in the previous studies.Comment: 6 pages, 3 figures, submitted to Physical Review

Large-scale calculations of supernova neutrino-induced reactions in Z=8-82 target nuclei

Background: In the environment of high neutrino-fluxes provided in core-collapse supernovae or neutron star mergers, neutrino-induced reactions with nuclei contribute to the nucleosynthesis processes. A number of terrestrial neutrino detectors are based on inelastic neutrino-nucleus scattering and modeling of the respective cross sections allow predictions of the expected detector reaction rates. Purpose: To provide a self-consistent microscopic description of neutrino-nucleus cross sections involving a large pool of Z = 8 - 82 nuclei for the implementation in models of nucleosynthesis and neutrino detector simulations. Methods: Self-consistent theory framework based on relativistic nuclear energy density functional is employed to determine the nuclear structure of the initial state and relevant transitions to excited states induced by neutrinos. The weak neutrino-nucleus interaction is employed in the current-current form and a complete set of transition operators is taken into account. Results: We perform large-scale calculations of charged-current neutrino-nucleus cross sections, including those averaged over supernova neutrino fluxes, for the set of even-even target nuclei from oxygen toward lead (Z = 8 - 82), spanning N = 8 - 182 (OPb pool). The model calculations include allowed and forbidden transitions up to J = 5 multipoles. Conclusions: The present analysis shows that the self-consistent calculations result in considerable differences in comparison to previously reported cross sections, and for a large number of target nuclei the cross sections are enhanced. Revision in modeling r-process nucleosynthesis based on a self-consistent description of neutrino-induced reactions would allow an updated insight into the origin of elements in the Universe and it would provide the estimate of uncertainties in the calculated element abundance patterns.Comment: 25 pages, 12 figures, submitted to Physical Review

Inclusive charged-current neutrino-nucleus reactions calculated with the relativistic quasiparticle random phase approximation

Inclusive neutrino-nucleus cross sections are calculated using a consistent relativistic mean-field theoretical framework. The weak lepton-hadron interaction is expressed in the standard current-current form, the nuclear ground state is described with the relativistic Hartree-Bogoliubov model, and the relevant transitions to excited nuclear states are calculated in the relativistic quasiparticle random phase approximation. Illustrative test calculations are performed for charged-current neutrino reactions on $^{12}$C, $^{16}$O, $^{56}$Fe, and $^{208}$Pb, and results compared with previous studies and available data. Using the experimental neutrino fluxes, the averaged cross sections are evaluated for nuclei of interest for neutrino detectors. We analyze the total neutrino-nucleus cross sections, and the evolution of the contribution of the different multipole excitations as a function of neutrino energy. The cross sections for reactions of supernova neutrinos on $^{16}$O and $^{208}$Pb target nuclei are analyzed as functions of the temperature and chemical potential.Comment: 28 pages, 8 figures, 2 tables, submitted to Phys. Rev.

Neutron star structure and collective excitations of finite nuclei

We study relationships between properties of collective excitations in finite nuclei and the phase transition density $n_t$ and pressure $P_t$ at the inner edge separating the liquid core and the solid crust of a neutron star. A theoretical framework that includes the thermodynamic method, relativistic nuclear energy density functionals and the quasiparticle random-phase approximation is employed in a self-consistent calculation of $(n_t,P_t)$ and collective excitations in nuclei. The covariance analysis shows that properties of charge-exchange dipole transitions, isovector giant dipole and quadrupole resonances and pygmy dipole transitions are correlated with the core-crust transition density and pressure. A set of relativistic nuclear energy density functionals, characterized by systematic variation of the density dependence of the symmetry energy of nuclear matter, is used to constrain possible values for $(n_t,P_t)$. By comparing the calculated excitation energies of giant resonances, energy weighted pygmy dipole strength, and dipole polarizability with available data, we obtain the weighted average values: $n_t = 0.0955 \pm 0.0007$ fm$^{-3}$ and $P_t = 0.59 \pm 0.05$ MeV fm$^{-3}$.Comment: 4 pages, 3 figures, paper submitted for publicatio

Calculation of β-decay rates in a relativistic model with momentum-dependent self-energies

The relativistic proton-neutron quasiparticle random phase approximation (PN-RQRPA) is applied in the calculation of β-decay half-lives of neutron-rich nuclei in the Z≈28 and Z≈50 regions. The study is based on the relativistic Hartree-Bogoliubov calculation of nuclear ground states, using effective Lagrangians with density-dependent meson-nucleon couplings, and also extended by the inclusion of couplings between the isoscalar meson fields and the derivatives of the nucleon fields. This leads to a linear momentum dependence of the scalar and vector nucleon self-energies. The residual QRPA interaction in the particle-hole channel includes the π+ρ exchange plus a Landau-Migdal term. The finite-range Gogny interaction is employed in the T=1 pairing channel, and the model also includes a proton-neutron particle-particle interaction. The results are compared with available data, and it is shown that an extension of the standard relativistic mean-field framework to include momentum-dependent nucleon self-energies naturally leads to an enhancement of the effective (Landau) nucleon mass, and thus to an improved PN-QRPA description of β^ -decay rates

Effect of inhalation anesthetics on cerebral blood flow

Primarni cilj anestezije je održavanje fiziološke homeostaze. To zahtijeva monitoring i tretman kardiovaskularnih, respiratornih, neuroloških i bubrežnih funkcijskih promjena tokom perioperativnog perioda kako bi se minimizirali neželjeni ishodi. Optimiziranje fiziologije pacijenta u intraoperativnom periodu može ubrzati oporavak i pružiti protekciju organskih sustava. Znanje o utjecaju anestetika na moždani protok krvi i metabolizam je potrebno kako bi se pacijentu osigurala sigurna anestezija. Jaki halogenirani inhalacijski anestetici uzrokuju vazodilataciju moždanog krvožilja ovisno o dozi. Unatoč tome što smanjuju metabolizam mozga, povećavaju moždani protok krvi kroz mozak ovisno o dozi gubitkom sveze protokmetabolizam. Međutim, potpuni gubitak te sveze se ne događa. Moždana autoregulacija se mijenja ovisno o dozi. Smanjenje moždanog metabolizma uzrokuje smanjenje protoka krvi, no tome se suprotstavlja direktni vazodilatacijski učinak inhalacijskih anestetika. Održavanje odgovarajuće razine intrakranijalnog tlaka je izuzetno bitno za neurokirurške pacijente. Stupanj do kojeg jaki halogenirani inhalacijski agensi povećavaju moždani protok krvi, te tako i intrakranijalni tlak ovisi o zbroju posrednog vazokonstrikcijskog i izravnog vazodilatacijskog učinka. Dušični oksidul povećava moždani protok krvi, kao i moždani metabolizam. Ksenon povećava moždani protok krvi.The primary goal of anesthesia is the maintenance of physiologic homeostasis. This includes monitoring and treatment of cardiovascular, pulmonary, neurologic and kidney functions changes during the perioperative period to minimize adverse outcomes. Optimizing intraoperative physiology may help speed recovery and provide for perioperative organ system protection. Knowledge of the influence of anesthetics on cerebral blood flow and metabolism is important for safe anesthesia practice.The potent halogenated inhalation anesthetics are all dosedependent cerebral vasodilators. While they reduce cerebral metabolic rate (CMR), they can blunt cerebral autoregulation by uncoupling cerebral blood flow (CBF) and metabolism and subsequently increase CBF. However, total uncoupling of the CBF and metabolism does not happen. Cerebral autoregulation is dose-dependently altered. Brain metabolism decreases which causes a decrease in CBF. That is counteracted by the direct vasodilatation of brain blood vessels by volatile anesthetics. Maintaining adequate ICP levels is crucial for neurosurgical patients. The degree to which the potent halogenated inhalation agents increase CBF and therefore intracranial pressure (ICP) depends on sum of the mediated vasoconstriction and the direct vasodilatation . Nitrous oxide gas increases cerebral metabolism and cerebral blood flow. Xenon increases cerebral blood flow as well

Primjena relativističkih funkcionala gustoće u procesima slabog međudjelovanja u atomskim jezgrama

Relativistic density functionals are employed in a study of weak-interaction processes in atomic nuclei. The approach is based on the relativistic Hartree-Bogoliubov (RHB) model that is used to compute the self-consistent nuclear ground state, and collective excited states are modeleld with the relativistic quasiparticle random phase approximation (RQRPA).The focus of the study is the calculation of β-decay half-lives of neutron-rich nuclei that are predicted to play a role in r-process nucleosynthesis, and their comparison to available experimental values. The model is also applied to the description of charged lepton capture and neutrino capture. This study provides a microscopic description of weak-interaction processes in nuclei, based of modern nuclear energy density functional concepts, and results contribute to a better understanding of the origin of elements heavies than iron.Relativistički funkcionali gustoće upotrijebljeni su za proučavanje procesa slabog međudjelovanja u atomskim jezgrama. Pristup se temelji na relativističkom Hartree-Bogoljubov (RHB) modelu koji daje samosuglasno osnovno stanje jezgre, a kolektivna pobuđenja modelirana su sa relativističkom kvazičestičnom aproksimacijom slučajnih faza (RQRPA). Središnja tema rada je proračun vremena poluživota pri β raspadu jezgara bogatih neutronima za koje je predviđeno da sudjeluju u r-procesu nukleosinteze, te njihova usporedba sa dostupnim eksperimentalnim vrijednostima. Model je također primijenjen na opis uhvata nabijenog leptona i uhvata neutrina. Ova radnja predstavlja mikroskopski opis procesa slabog međudjelovanja u jezgrama, temeljen na modernim konceptima funkcionala gustoće energije, a rezultati doprinose boljem razumijevanju porijekla elemenata težih od željeza

Effect of inhalation anesthetics on cerebral blood flow

Primarni cilj anestezije je održavanje fiziološke homeostaze. To zahtijeva monitoring i tretman kardiovaskularnih, respiratornih, neuroloških i bubrežnih funkcijskih promjena tokom perioperativnog perioda kako bi se minimizirali neželjeni ishodi. Optimiziranje fiziologije pacijenta u intraoperativnom periodu može ubrzati oporavak i pružiti protekciju organskih sustava. Znanje o utjecaju anestetika na moždani protok krvi i metabolizam je potrebno kako bi se pacijentu osigurala sigurna anestezija. Jaki halogenirani inhalacijski anestetici uzrokuju vazodilataciju moždanog krvožilja ovisno o dozi. Unatoč tome što smanjuju metabolizam mozga, povećavaju moždani protok krvi kroz mozak ovisno o dozi gubitkom sveze protokmetabolizam. Međutim, potpuni gubitak te sveze se ne događa. Moždana autoregulacija se mijenja ovisno o dozi. Smanjenje moždanog metabolizma uzrokuje smanjenje protoka krvi, no tome se suprotstavlja direktni vazodilatacijski učinak inhalacijskih anestetika. Održavanje odgovarajuće razine intrakranijalnog tlaka je izuzetno bitno za neurokirurške pacijente. Stupanj do kojeg jaki halogenirani inhalacijski agensi povećavaju moždani protok krvi, te tako i intrakranijalni tlak ovisi o zbroju posrednog vazokonstrikcijskog i izravnog vazodilatacijskog učinka. Dušični oksidul povećava moždani protok krvi, kao i moždani metabolizam. Ksenon povećava moždani protok krvi.The primary goal of anesthesia is the maintenance of physiologic homeostasis. This includes monitoring and treatment of cardiovascular, pulmonary, neurologic and kidney functions changes during the perioperative period to minimize adverse outcomes. Optimizing intraoperative physiology may help speed recovery and provide for perioperative organ system protection. Knowledge of the influence of anesthetics on cerebral blood flow and metabolism is important for safe anesthesia practice.The potent halogenated inhalation anesthetics are all dosedependent cerebral vasodilators. While they reduce cerebral metabolic rate (CMR), they can blunt cerebral autoregulation by uncoupling cerebral blood flow (CBF) and metabolism and subsequently increase CBF. However, total uncoupling of the CBF and metabolism does not happen. Cerebral autoregulation is dose-dependently altered. Brain metabolism decreases which causes a decrease in CBF. That is counteracted by the direct vasodilatation of brain blood vessels by volatile anesthetics. Maintaining adequate ICP levels is crucial for neurosurgical patients. The degree to which the potent halogenated inhalation agents increase CBF and therefore intracranial pressure (ICP) depends on sum of the mediated vasoconstriction and the direct vasodilatation . Nitrous oxide gas increases cerebral metabolism and cerebral blood flow. Xenon increases cerebral blood flow as well