Table of contents

Classical novae are fascinating stellar explosions at the crossroads of stellar astrophysics, nuclear physics, and cosmochemistry. In this review, we briefly summarize 30 years of nucleosynthesis studies, with special emphasis on recent advances in nova theory (including multidimensional models) as well as on experimental efforts to reduce nuclear uncertainties affecting critical reaction rates. Among the topics that are covered, we outline the interplay between nova outbursts and the galactic chemical abundances, the synthesis of radioactive nuclei of interest for γ-ray astronomy, such as ⁷Li, ²²Na or ²⁶Al, and the potential discovery of presolar meteoritic grains likely condensed in nova shells.

The LIT method has allowed ab initio calculations of electroweak cross sections in light nuclear systems. This review presents a description of the method from both a general and a more technical point of view, as well as a summary of the results obtained by its application. The remarkable features of the LIT approach, which make it particularly efficient in dealing with a general reaction involving continuum states, are underlined. Emphasis is given on the results obtained for electroweak cross sections of few-nucleon systems. Their implications for the present understanding of microscopic nuclear dynamics are discussed.

We report the first measurements of inclusive W and Z boson cross-sections times the corresponding leptonic branching ratios for collisions at TeV based on the decays of the W and Z bosons into electrons and muons. The data were recorded with the CDF II detector at the Fermilab Tevatron and correspond to an integrated luminosity of 72.0 ± 4.3 pb⁻¹. We test e-μ lepton universality in W decays by measuring the ratio of the W → μν to W → eν cross sections and determine a value of 0.991 ± 0.004(stat.) ± 0.011(syst.) for the ratio of W − ℓ − ν couplings (g_μ/g_e). Since there is no sign of non-universality, we combine our cross-section measurements in the different lepton decay modes and obtain nb and pb for dilepton pairs in the mass range between 66 GeV/c² and 116 GeV/c². We compute the ratio R of the W → ℓν to Z → ℓℓ cross sections taking all correlations among channels into account and obtain R = 10.84 ± 0.15(stat.) ± 0.14(syst.) including a correction for the virtual photon exchange component in our measured γ*/Z → ℓℓ cross section. Based on the measured value of R, we extract values for the W leptonic branching ratio, Br(W → ℓν)= 0.1082 ± 0.0022; the total width of the W boson, Γ(W)= 2092 ± 42 MeV; and the ratio of W and Z boson total widths, Γ(W)/Γ(Z)= 0.838 ± 0.017. In addition, we use our extracted value of Γ(W) whose value depends on various electroweak parameters and certain CKM matrix elements to constrain the V_cs CKM matrix element, |V_cs| = 0.976 ± 0.030.

We examine the N_pN_n scheme based on a recently proposed simple empirical formula, which is highly valid for the excitation energy of the first excited natural parity even multipole states in even–even nuclei. We demonstrate explicitly that the N_pN_n scheme for the excitation energy emerges from the separate exponential dependence of the excitation energy on the valence nucleon numbers N_p and N_n together with the fact that only a limited set of numbers is allowed for the N_p and N_n of the existing nuclei.

We present the numerical investigation of the fermionic two-body decays of squarks in the minimal supersymmetric standard model with complex parameters. In the analysis, we particularly take into account the cosmological bounds imposed by Wilkinson Microwave Anisotropy Probe data. We find that the phase dependences of the decay widths of the third family squarks, as well as those of the first and second families, are quite significant which can provide viable probes of additional CP sources. We plot the CP-phase dependences for each fermionic two-body decay channel of squarks (i = 1, 2, q = u, d, c, s, t, b) and speculate about the branching ratios and total (two-body) decay widths.

The target excitation dependence of higher order correlation of the pions is investigated in the present work using the data of ¹⁶O–AgBr interactions at 2.1 and 60 A GeV and ³²S–AgBr interactions at 200 A GeV. The data are divided into different sets of n_g which correspond to different degrees of the target excitation. The target excitation dependence was evident at the lower projectile energy—at the higher projectile energy no target excitation dependence was revealed by the data.

The interpretation of extensive air shower measurements often requires a comparison with shower simulations in the atmosphere. These calculations rely on hadronic interaction models which have to extrapolate into kinematical and energy regions not explored by present-day collider experiments. The KASCADE experiment with its large hadron calorimeter and the detector array for the electromagnetic and muonic components provides experimental data to check such interaction models. For the simulations the program CORSIKA is used, which has several hadronic event generators embedded. For high-energy interactions the models DPMJET, , QGSJET and SIBYLL have been used. Low-energy interactions have been treated by GHEISHA and FLUKA. Different hadronic observables are investigated as well as their correlations with the electromagnetic and muonic shower components up to primary energies of about 40 PeV. Although the predictions of the more recent models are to a large extent compatible with the measured data within the range given by proton and iron primary particles, there are still significant differences between the individual models.

The 90° problem of cosmic-ray transport theory is revisited in this paper. By using standard forms of the wave spectrum in the solar wind, the pitch-angle Fokker–Planck coefficient and the parallel mean free path are computed for different resonance functions. A critical comparison is made of the strength of 90° scattering due to plasmawave effects, dynamical turbulence effects and nonlinear effects. It is demonstrated that, only for low-energy cosmic particles, dynamical effects are usually dominant. The novel results presented here are essential for an effective comparison of heliospheric observations for the parallel mean free path with the theoretical model results.

Experimental data of nuclear β⁻-decay half-lives are systematically analyzed and investigated. We have discovered an exponential law between β⁻-decay half-life and the nucleon number (Z, N) of parent nuclei far from the β-stable line. Based on the exponential law, we have proposed new formulae in which the shell effects are included to describe the β⁻-decay half-lives of nuclei far from the β-stable line. Experimental data are well reproduced by the formula. In addition, we have systematically studied the shell effects on β⁻-decay half-lives for nuclei far from stability. The correlation between the major shell or subshell closures and β⁻-decay half-lives is discussed. This correlation provides the feasibility of obtaining information about the major shell or subshell closures of nuclei far from the β-stable line according to the exponential law.

We derive the pair-production probability in a constant electric field in Rindler coordinates in a quasi-classical approximation. Our result is different from the pair-production probability in an inertial frame (Schwinger formula). In particular, it exhibits non-trivial dependence on rapidity and deviation from Gaussian behavior at small transverse momenta. Our results can be important for analysis of particle production in heavy-ion collisions.

The neutral-current neutrino-nucleus scattering is calculated through the neutrino-induced knocked-out nucleon process in the quasielastic region by using a relativistic single particle model for the bound and continuum states. The incident energy range between 500 MeV and 1.0 GeV is used for the neutrino (antineutrino) scattering on the ¹²C target nucleus. The effects of the final state interaction of the knocked-out nucleon are studied not only on the cross section but also on the asymmetry due to the difference between neutrinos and antineutrinos, within a relativistic optical potential. We also investigate the sensitivity of the strange quark contents in the nucleon on the asymmetry.

A new approach to the calculation of the vacuum pressure difference between the Nambu phase and the Wigner phase is proposed, which accommodates both temperature and baryon chemical potential appropriately. Based on this treatment, a continuum model study of a QCD phase structure is conducted within the framework of the Dyson–Schwinger equation and a phase diagram in the T–μ plane is consequently obtained. A comparison between our method and an earlier one on the calculation of vacuum pressure difference is given.

The ¹²¹Sb(p,t)¹¹⁹Sb reaction has been measured in a high-resolution experiment at an incident energy of 21 MeV. Accurate measurement of the (p,t) reaction angular distributions for the transitions to the levels of ¹¹⁹Sb allows us to determine energies of 59 levels, 23 of which have been identified for the first time, and to assign the angular momentum transfer values and a well-defined range for the J values. DWBA analysis has been performed in a finite-range approximation, assuming a dineutron cluster pickup mechanism, by using conventional Woods–Saxon potentials for the entrance proton and exit triton channel. The present (p,t) data have been supplemented by microscopic calculations in the framework of the quasiparticle–phonon model, giving a reasonably good description of the experimental fragmentation of the integrated cross sections and the absence of (p,t) strength above 2.9 MeV.

We investigate decay and production mechanisms of the resonance X(1812) recently observed in the at BESII. The decay widths of X(1812) → ηη', ηη, ωϕ, K⁺K⁻, ρ⁺ρ⁻, ωω, K*⁺K*⁻ and π⁺π⁻ are evaluated based on the scenario of the X(1812) as a candidate of the molecule. It turns out that the quark exchange mechanism plays an important role in the understanding of the large decay width for the X(1812) → ωϕ. It is also found that the decay widths for X(1812) → ηη' and ηη are enhanced by the quark exchange mechanism. These channels are suggested to be the tools to test the molecular scenario in experiment. The branching fraction of Br(X → ωϕ) is evaluated to be about 4.60%. Searches for additional evidence about the X(1812) in radiative decays are reviewed. In the molecular scenario, the X(1812) production rate is also evaluated to be , which is close to the measured value 2.83 ± 0.92.

Inclusion of turbulent cascade cut-offs in wavenumber space for the fast- and slow-magnetosonic modes is shown to have a profound effect on estimates of heating rates for the interstellar medium from the two wave types. Using a generalization of the Goldreich–Sridhar cut-off procedure, this paper shows that the effect of the turbulent cut-offs is to lower the previous estimates of interstellar heating rates (which were about 10–11 orders of magnitude higher than cooling rate estimates) to precisely the level of the cooling rate estimates. Thereby a major discordance is removed between heating and cooling rate estimates that had persisted for over a quarter of a century. The electron number density calculated in this paper which follows a roughly k^−5/3 rule over at least 8–10 orders of magnitude, is in accord with observed spectra in the interstellar medium. Application of the same sort of turbulent wavenumber cascade cut-off to an anisotropic wave spectrum (proposed by Lerche and Schlickeiser as a possible candidate to achieve balance between the interstellar heating and cooling rates) is shown to modify that spectrum so that it more closely mimics the wave power spectra derived by Goldreich and Sridhar using turbulent MHD arguments. The wavenumber cut-offs are shown to have a power index different than the canonical value of 1/3 suggested by Goldreich and Sridhar and are closer to 1. Numerical turbulent cascade calculations in the framework of a particle kinetic picture rather than an MHD procedure would likely be required to improve the understanding of wave cut-offs from a purely theoretical perspective.

We perform a fully correlated study of ⁶_ΛΛHe hypernucleus with two- and three-baryon potentials. We investigate the role of every strength of the strange-sector potentials on the energy breakdown and present a clear understanding of their interplay. The investigation determines the strength of the simulated Nijmegen ΛΛ potential, phenomenologically. We note that the consistency of calculations between ⁵_ΛHe and ⁶_ΛΛHe depends on the ΛN space-exchange strength only, which incidentally determines it. This study is a step forward to pin down all the strengths, to resolve A = 5 anomaly and to search for recently conjectured ⁴_ΛΛH in an authentic way. The study also suggests that the medium effect on strange-sector potentials often written as a repulsive three-body force may be well adapted at two-body level.

Inspired by the recent measurement of the B(E2; 0⁺₂ → 2⁺₁) and B(E0; 0⁺₂ → 0⁺₁) values in ¹²Be, we give an interpretation of available spectroscopic data on both ¹²Be and ¹¹Be, using a simple model which contains the essential feature of these two nuclei: the presence of weakly bound neutron(s) in deformed potentials. The agreement of the calculated results with observed data is surprisingly good, including well-known strong E1 transitions in both nuclei.

The BEC of charged pions is investigated in the framework of an O(N) linear sigma model. By using Cornwall–Jackiw–Tomboulis formalism, we have derived the gap equations for the effective masses of the mesons at finite temperature and finite isospin density. The BEC is discussed in chiral limit and non-chiral limit at a large N approximation.

Vertex fitting frequently has to deal with both mis-associated tracks and mis-measured track errors. A robust, adaptive method is presented that is able to cope with contaminated data. The method is formulated as an iterative re-weighted Kalman filter. Annealing is introduced to avoid local minima in the optimization. For the initialization of the adaptive filter a robust algorithm is presented that turns out to perform well in a wide range of applications. The tuning of the annealing schedule and of the cut-off parameter is described using simulated data from the CMS experiment. Finally, the adaptive property of the method is illustrated in two examples.

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