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Single proton knockout from proton-rich 26P nucleus has been investigated theoretically at 65 MeV/n beam energy on 9Be target for stripping and diffraction dissociation mechanisms using Eikonal approximation. The single proton breakup cross sections, longitudinal and transverse momentum distribution of core fragment are calculated using MOMDIS code. Ground as well as recently observed projectile and core excited states are taken into consideration for qualitative examination of their effects on the single proton breakup cross section and full width half maxima (FWHM) width of momentum distribution. The proton breakup cross-section is found decreasing by 9–15% with per MeV core excitation energy and FWHM width of longitudinal momentum distribution is observed increasing by 5–14% with per MeV core excitation energy while the transverse momentum distribution, increases by 4–11% with per MeV core excitation energy. FWHM of longitudinal momentum distributions of different core plus proton bound configuration is used to explore the individual contribution of and states to admixed state of 26P nucleus. The contribution of and state is found 50– 60% and 50–40% respectively. Obtained results are found interesting and shows that inclusion of the core and projectile excited states affects the observables significantly. [ABSTRACT FROM AUTHOR]

We use a numerically solved time-dependent Schrödinger equation for calculating the photoelectron momentum distribution of ground-state hydrogen atoms in the presence of superintense ultrashort high-frequency pulses. It is demonstrated that the dynamic interference effect within a superintense XUV laser beam has the ability to significantly alter the photoelectron momentum distribution. In our work, a clearly visible dynamic interference pattern is observed when hydrogen atoms are exposed to a superintense circularly polarized laser pulse with a photon energy of ℏω = 53.605 eV, which has previously been found for linearly polarized pulses or the weakly bounded model H− system for circularly polarized pulses. Angular-distorted interference arises for linear superintense XUV pulses of similar intensity. The significant differences in photoelectron momentum distributions that have been seen by linearly and circularly polarized XUV pulses are caused by the Coulomb rescattering phenomenon.

The exotic deformed nucleus 31Ne is studied with an approach that combines self-consistent structure and reaction theories. The deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) is utilized to demonstrate that deformation and pairing correlations give rise to a halo structure with a large-amplitude p-wave configuration in 31Ne. Then the valence nucleon wave functions and angle-averaged density distributions of 30Ne from this theory are used as input for the Glauber reaction model to study the observables of neutron-rich neon isotopes to search halo signatures. With NL1 effective interaction, our predictions of the reaction cross sections for these exotic neon isotopes on a carbon target can better reproduce the experimental data than those from the relativistic mean field model for a spherical shape with resonances and pairing correlation contributions, and are roughly 3.3% (∼ 50 mb) larger than those with Gaussian function-fitted densities of the core nuclei. The calculated one-neutron removal cross section at 240 MeV/nucleon, and the inclusive longitudinal momentum distribution of the 30Ne residues from the 31Ne breakup reaction are largely improved over previous theoretical predictions and agree well with data. These reaction evaluations indicate a dilute density distribution in coordinate space and are a canonical signature of a halo structure. Moreover, our predictions with the NL3 and PK1 effective interactions give slightly better descriptions of reaction observables for exotic neon isotopes. [ABSTRACT FROM AUTHOR]

High-momentum components of nuclei are essential for understanding the underlying inter-nucleon correlations in nuclei. We perform the comprehensive analysis for the origin of the high-momentum components of 4He in the framework of Tensor-optimized High-momentum Antisymmetrized Molecular Dynamics (TO-HMAMD), which is a completely variational approach as an ab initio theory starting from the bare nucleon-nucleon interaction. The analytical derivations are provided for the nucleon momentum distribution of the Antisymmetrized Momentum Dynamics (AMD) wave functions, with subtraction of center-of-mass motion. The nucleon momentum distribution for 4He is calculated by applying a new expansion technique to our ab initio wave function, and agrees with the values extracted from experimental data up to the high-momentum region. Fine-grained analysis is performed for the high-momentum components in 4He with respect to different nucleon correlations. Contributions from tensor, central with short-range, and many-body correlations are extracted from the nucleon momentum distributions. The manifestation of tensor correlation around 2 fm−1 region is explicitly confirmed by comparing the momentum distributions predicted using different types of NN interactions with and without the tensor force.

The modified path integral representation of Wigner functions and the new Monte Carlo approach has been suggested to account for the impact of the interparticle interaction on the Pauli exclusion principle of fermions. This approach also allows to calculate the momentum distribution functions and to reduce the “sign problem” that is inaccessible to the standard path integral Monte Carlo methods. The obtained pair electron–electron distribution functions for the “uniform electron gas” demonstrate the short-range quantum ordering of electrons associated with exchange-correlation excitons. The exchange-correlation exciton is caused by the interaction of electrons with positively charged exchange holes and the excluded volume effect. The developed approach allows one to study the density–temperature range of the exciton arising, existence, and decay. Using the potential of the mean force and semiclassical Bohr–Sommerfeld quantization condition, we have demonstrated the existence of bound states disturbing the Maxwellian distribution and estimated their average energy levels. The exchange-correlation excitons have not been observed earlier in the standard path integral Monte Carlo simulations.

The internuclear distance (R) dependence of the correlated electron dynamics in strong-field nonsequential double ionization (NSDI) of parallel aligned diatomic molecules has been investigated. Results show the correlated electron momentum distribution (CEMD) is almost uniformly spread in the four quadrants for R = 4 a.u., while for larger R it is mainly located in the first and third quadrants. Classifying NSDI events into recollision and internal-collision processes demonstrates the CEMD of internal-collision induced NSDI is strongly dependent on R, which changes from a uniform distribution to a back-to-back emission pattern, and finally to a side-by-side emission pattern as R increases. Back analyzing of the classical trajectories shows it originates from the R dependent time delay between double ionization and collision times. When R increases, more and more internal-collision induced NSDI events occur immediately after collision, resulting in the enhanced dominance of the electron emission in the same hemisphere. [ABSTRACT FROM AUTHOR]

We investigate the universal properties of mass-imbalanced highly polarized Fermi gases in one-dimensional scenarios. By treating the mass ratio as a parameter, we delve into the binding energy, quasiparticle residue, and correlation functions of the systems. We provide a thorough momentum distribution for impurities and spin-up atoms within the Fermi sea. When the impurity mass is infinite, we discover that the quasiparticle residue approaches to zero and the systems exhibit the signature of the Anderson orthogonality catastrophe in strong coupling regime. We observe an increase in Tan contact under large mass ratios and study density correlations by applying Fourier transform. Crucially, we demonstrate the existence of the molecular state in one-dimensional polaron system with strong attractive interactions, unlike previous conclusions. • We demonstrate the existence of molecular states in a one-dimensional polaron system. • We study the one-dimensional polaron system with infinite impurity mass. • We provide a thorough momentum distribution for impurities and spin-up atoms within the Fermi sea. [ABSTRACT FROM AUTHOR]

We consider the non-overlapping wave function paradox of Aharanov et al., wherein the relative phase between two wave functions cannot be measured by the moments of position or momentum. We show that there is an unlimited number of other expectation values that depend on the phase. We further show that the Wigner distribution is M-indeterminate, that is, a distribution whose moments do not uniquely determine the distribution. We generalize to more than two non-overlapping functions. We consider arbitrary representations and show there is an unlimited number of M-indeterminate distributions. The dual case of non-overlapping momentum functions is also considered. [ABSTRACT FROM AUTHOR]

In classical statistics, the momentum distribution functions are Maxwellian in the state of thermodynamic equilibrium. However, quantum effects can change it to non‐Maxwellian through two mechanisms. The first mechanism is an exchange interaction between identical particles, leading to the Fermi distribution. The second mechanism is the Heisenberg's principle: an interaction of a particle with others reduces the volume available to it, which leads to uncertainty in the momentum and results in an increased probability of having a higher momentum. In this paper, the momentum distribution functions of a two‐component Coulomb system are computed using the Monte Carlo method. It is shown that the momentum distribution functions have high‐momentum “tails” in the regime of strong coupling. [ABSTRACT FROM AUTHOR]

Momentum flux is the physical property that deeply affects the evolution of jets and sprays. A sensor able to measure the spatial distribution of momentum in micro-jets and automotive diesel sprays has been designed and critically analysed. The idea behind the sensor is that of deriving the momentum flux profile of a jet/spray impinging against a flat surface by reconstructing the impact pressure distribution. The latter is realized from a set of line integrals of the impact pressure distribution along different directions and by applying the Filtered Back Projection algorithm. The performances of the sensor have hence been theoretically compared to those of a sensor that punctually measures the pressure distribution. The proposed sensor proved to be able to capture a higher frequency content of the momentum under investigation. Finally, the sensor has been employed to investigate the momentum flux of an under-expanded supersonic jet and the corresponding expected characteristic patterns of the impact pressure distribution have been obtained. [ABSTRACT FROM AUTHOR]