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In this article, the molecular permanent electric dipole moments and components of static dipole polarizabilities for the electronic ground state of singly charged aluminum monohalides are reported. The coupled-cluster method by considering single and double excitations (CCSD) together with relativistic Dyall basis sets have been used to carry out these molecular property calculations. The contribution from triple excitations are incorporated through perturbative triples (CCSD(T)). The results from a series of progressively larger basis sets are extrapolated to the complete basis set limit. Further, the role of correlation and relativistic effects, and also the effect of augmentation over the considered basis sets on the valence molecular properties are studied. Our results are compared with those available in the literature., Comment: 13 pages, 8 figures, 6 tables

The quantum-classical hybrid Variational Quantum Eigensolver (VQE) algorithm is recognized to be the method of choice to obtain ground state energies of quantum many-body systems in the noisy intermediate scale quantum (NISQ) era. This study not only extends the VQE algorithm to the relativistic regime, but also calculates a property other than energy, namely the molecular permanent electric dipole moment (PDM). We carry out 18-qubit quantum simulations to obtain ground state energies as well as PDMs of single-valence diatomic molecules, ranging from the light BeH to the heavy radioactive RaH molecule. We investigate the correlation trends in these systems as well as access the precision in our results. Furthermore, we measure the PDM of the moderately heavy SrH and SrF molecules on the optimized unitary coupled cluster state, using the state-of-the-art IonQ Aria-I quantum computer in an active space of 6 qubits. The associated quantum circuits for these computations were extensively optimized in view of limitations imposed by NISQ hardware. To that end, we employ an array of techniques, including the use of point group symmetries, integrating ZX-Calculus into our pipeline-based circuit optimization, and energy sort VQE procedure. Through these methods, we compress our 6-qubit quantum circuit from 280 two-qubit gates to 37 two-qubit gates (with a marginal trade-off of 0.33 and 0.31 percent in the PDM for SrH and SrF in their respective 6-spin orbital active spaces). We anticipate that our proof-of-concept demonstration lays the groundwork for future quantum hardware calculations involving heavy atoms and molecules.

Charm and beauty are heavy quarks with observed masses of 1.28 GeV/$\textit{c}^2$ and 4.18 GeV/$\textit{c}^2$ respectively. They are produced in initial hard scattering processes. Due to their small formation time ($\Delta t \sim0.1 fm/\textit{c}$) as compared to the formation time of QGP ($\Delta t \sim0.3 fm/\textit{c}$) at the LHC, they experience all the stages occuring during the time evolution of the hot and dense medium produced in heavy-ion collisions. Therefore, the measurement of open charm and beauty production allows probing QGP properties and investigating the color charge and mass dependence of the parton in-medium energy loss. Moreover, due to their large masses ($m_c , m_b \gg \Lambda_{QCD}$ ) their pp production cross-sections are calculable within the domain of perturbative QCD constituting an excellent test of pQCD calculations. The aim of this study is to understand the processes involved in the production of charm quarks through the productions of D$^+$, D$^0$, D$^+_s$ and $\Lambda_c^+$ hadrons. Further to investigate the possibility of hadronization of the charm quarks, ratios like $\Lambda_c^+$/$D^+$, $D_s^+$/$D^+$, $\Lambda_c^+$/$D^0$ and $D_s^+$/$D^0$ are also measured. For the current analysis, the events are generated by using PYTHIA 8 for pp collisions at $\sqrt{s}$ = 13 TeV. PYTHIA 8 has proved to be quite successful in explaining the heavy-flavor particle production at the LHC energies., Comment: additional work required