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•Conformational analysis on quinoline-7-carboxaldehyde reveals two stable conformers.•Their optimized geometry parameters were investigated at HF and B3LYP levels.•Their experimental ...vibrational and UV–Vis spectra were analyzed with calculations.
Spectroscopic properties of quinoline-7-carboxaldehyde (Q7C) have been studied in detail both experimentally and theoretically. The FT-IR (4000–50cm−1), FT-Raman (4000–50cm−1), dispersive-Raman (3500–50cm−1), and UV–Vis (200–400nm) spectra of Q7C were recorded at room temperature (25°C). Geometry parameters, potential energy surface about CCH(O) bond, harmonic vibrational frequencies, IR and Raman intensities, UV–Vis spectrum, and thermodynamic characteristics (at 298.15K) of Q7C were computed at Hartree–Fock (HF) and density functional B3LYP levels employing the 6-311++G(d,p) basis set. Frontier molecular orbitals, molecular electrostatic potential, and Mulliken charge analyses of Q7C have also been performed. Q7C has two stable conformers that are energetically very close to each other with slight preference to the conformer that has oxygen atom of the aldehyde away from the nitrogen atom of the quinoline.
Strange hadron production in pp collisions at \(\sqrt{s}= 7\) TeV is studied with PYTHIA 8 and EPOS event generators via the two-particle correlation method. After pairing charged particles as ...trigger particles with associated strange hadrons \((\mathrm{K}^{0}_{S}\) and \((\Lambda/\overline{\Lambda})\) , the strange baryon to meson per trigger yield ratios \({Y_{\Delta\varphi}^{\mathrm{h}-(\Lambda+\overline{\Lambda})}}\)/\(/{2Y_{\Delta\varphi}^{\mathrm{h}-\mathrm{K}^{0}_{S}}}\) dependent on transverse momentum (\(p_{T})\) are investigated within the near- and away-side jet region as well as the underlying event (UE) region. The modified string fragmentation effects of color reconnection and string shoving mechanisms implemented in PYTHIA 8 and the final state evolution effects built in EPOS are compared in this study. It is found that \(p_{T}\) dependence of the \(\Lambda/\mathrm{K}^{0}_{S}\) per trigger yield ratio in UE is similar to that in the inclusive measurements while the in-jet result is smaller. We also show that the \(\Lambda/\mathrm{K}^{0}_{S}\) ratio at both near- and away-side jet region in the intermediate \(p_{T}\) region decreases significantly with trigger \(p_{T}\), which suggests the hard process effects might contribute to the strange baryon to meson enhancement at intermediate \(p_{T}\). The much higher \(\Lambda/\mathrm{K}^{0}_{S}\) ratio in UE and the striking difference between the near and away side of the in-jet results with low trigger \(p_{T}\) predicted by the EPOS model indicate that the soft process effects induced by the final state evolution further increase the strange baryon production and can be still effective in a higher \(p_{T}\) region compared to the string fragmentation type models.
The Large Hadron Collider (LHC) aims to inject oxygen (\({}^{16}O\)) ions in the next run into its experiments. This include the anticipated one-day physics run focusing on \(OO\) collisions at ...center-of-mass energy \sqrt{s_{\mathrm{NN}} = 7 Tev. In this study, we have used recently developed version of the EPOS model (EPOS4) to study the production of identified particles (\(\pi^\pm\), \(K^\pm\) and \(p(\overline{p})\)) in \(OO\) collisions at 7 Tev. Predictions of transverse momentum (\(p_T\)) spectra, \(\langle p_T \rangle\), integrated yield (dN/dy) for different centrality classes are studied. To provide insight into the collective nature of the produced particles, we look into the \(p_T\)-differential particle ratios (\(K/\pi\) and \(p/\pi\)) and \(p_T\)-integrated particle ratios to (\(\pi^++\pi^-\)) as a function of charge particle multiplicity. The shape of the charge particle multiplicity (\(dN/d\eta\)) and \(\langle p_T \rangle\) is well described by the EPOS4. The EPOS4 model predictions for the ratios of \(K/\pi\) and \(p/\pi\) exhibit a systematic overestimation compared to the observed trends as a function of charged-particle multiplicity. Interestingly, the \(OO\) results of \(p_T\)-integrated particle ratios shows a clear final state multiplicity overlap with \(pp\), \(p-Pb\) and \(Pb-Pb\) collisions. EPOS4 mimics signs of collectivity and is one of the suitable candidates to study ultra-relativistic heavy-ion collisions. Furthermore, the foreseen data from \(OO\) collisions at the LHC, when available, will help to better understand the heavy-ion-like behavior in small systems as well as help to put possible constraints on the model parameters.
The measurement of the production of charm jets, identified by the presence of a D$^{0}$ meson in the jet constituents, is presented in proton–proton collisions at centre-of-mass energies of $ ...\sqrt{s} $ = 5.02 and 13 TeV with the ALICE detector at the CERN LHC. The D$^{0}$ mesons were reconstructed from their hadronic decay D$^{0}$ → K$^{−}$π$^{+}$ and the respective charge conjugate. Jets were reconstructed from D$^{0}$-meson candidates and charged particles using the anti-k$_{T}$ algorithm, in the jet transverse momentum range 5 < p$_{T,chjet}$< 50 GeV/c, pseudorapidity |η$_{jet}$| < 0.9 − R, and with the jet resolution parameters R = 0.2, 0.4, 0.6. The distribution of the jet momentum fraction carried by a D$^{0}$ meson along the jet axis $ \left({z}_{\Big\Vert}^{\textrm{ch}}\right) $ was measured in the range 0.4 <$ {z}_{\Big\Vert}^{\textrm{ch}} $< 1.0 in four ranges of the jet transverse momentum. Comparisons of results for different collision energies and jet resolution parameters are also presented. The measurements are compared to predictions from Monte Carlo event generators based on leading-order and next-to-leading-order perturbative quantum chromodynamics calculations. A generally good description of the main features of the data is obtained in spite of a few discrepancies at low p$_{T,chjet}$. Measurements were also done for R = 0.3 at $ \sqrt{s} $ = 5.02 and are shown along with their comparisons to theoretical predictions in an appendix to this paper.graphic not available: see fulltext
