Fusion Excitation Functions Research Articles

Fusion and back-angle quasielastic measurements in Si30+Gd156 near the Coulomb barrier

Background: Advancement in accelerator facilities has opened the door to dig deep to understand the interplay between nuclear reactions and structures. Although the influence of inelastic excitations on nuclear scattering and sub-barrier fusion is somewhat established, a clear understanding of nucleon transfer with a positive-$Q$ value is yet to achieve.Purpose: The objective of this paper is to examine the role of the $2n$-transfer channel with a positive $Q$ value on sub-barrier fusion and back-angle quasielastic (QE) scattering in the $^{30}\mathrm{Si}+^{156}\mathrm{Gd}$ reaction. Furthermore, extraction of barrier distributions (BDs) from fusion and QE scattering to infer their shapes is also a prime goal.Method: The excitation functions (EFs) of fusion and back-angle QE scattering have been measured over a wide range of incident beam energy around the Coulomb barrier using a recoil mass spectrometer. Furthermore, BDs have been extracted using the measured fusion and back-scattered QE data. The underlying findings have been analyzed within the framework of coupled-channel (CC) formalism using ccfull and ecc programs.Results: Fusion enhancement has been observed compared to those predicted from the one-dimensional barrier penetration model at sub-barrier energies. Fusion enhancement and QE EFs are explained by CC predictions considering the collective excitations among the colliding nuclei. The inclusion of $2n$ transfer and collective excitations in ccfull improves the fit to the experimental fusion data in a short span of energy window around the Coulomb barrier, whereas no significant effect has been observed at the sub-barrier region. However, no such effect of $2n$-pickup transfer has been observed from ecc model calculations. Thus, no firm conclusion can be made on the role of $2n$-pickup transfer with a positive $Q$ value in present measurements.Conclusion: Fusion EFs have been successfully explained by the CC calculations using ccfull and ecc model codes. No significant effect of the $2n$-pickup channel with a positive $Q$ value was observed on sub-barrier fusion enhancement. However, QE EFs are reproduced by considering the collective excitations and $2n$-transfer channel couplings. Fusion and QE BDs are similar in shape within the experimental uncertainty. One-dimensional barrier parameters extracted from the measured data agree with the different theoretical models. Also, the present system obeys the systematic based on deformation values after transfer at the exit.

Coherent description of elastic scattering and fusion at near-barrier energies for the Be9+Pb208 and Be9+Au197 reactions

Elastic scattering, total reaction, and fusion cross sections of the systems $^{9}\mathrm{Be}+^{208}\mathrm{Pb}$ and $^{9}\mathrm{Be}+^{197}\mathrm{Au}$ at near-barrier energies, are coherently analyzed into two theoretical contexts. In a phenomenological approach, a BDM3Y1 interaction is used in an optical model potential analysis of the elastic-scattering data and the energy dependence of the potential is mapped around the Coulomb barrier. In a second approach, the elastic scattering is investigated within a four body framework by using the continuum-discretized coupled-channels method. In both scenarios, total reaction cross sections are determined and compared with phenomenological predictions. Moreover, an effective potential is obtained and in a one barrier penetration model analysis, the fusion excitation function is determined and compared with experimental data, further validating our analysis.

Investigation of isotopic dependence on the O + Ni fusion cross section near barrier energies

Fusion excitation functions have been measured for $^{16}\mathrm{O}+^{61}\mathrm{Ni}$ and $^{18}\mathrm{O}+^{61,62}\mathrm{Ni}$ systems around the Coulomb barrier ($\ensuremath{\approx}0.7{V}_{B}$--$1.3{V}_{B}$) using the recoil mass spectrometer, heavy ion reaction analyzer. The ground state $Q$ value for two neutron stripping is positive for both systems with $^{18}\mathrm{O}$ as the projectile. Strong enhancement of the experimental fusion cross sections were observed below the barrier for all the systems compared to that of the predictions of the one-dimensional barrier penetration model. To understand such enhancement, a coupled-channels formalism has been used. A comparative study of these systems indicated that the coupling of two neutron transfer channels with the collective excitations could play the role behind the sub-barrier fusion enhancement for $^{18}\mathrm{O}$ induced reactions. However, the sub-barrier enhancement for $^{16}\mathrm{O} + ^{61}\mathrm{Ni}$ is found to be due to the coupling of quadrupole vibrations of both the interacting nuclei. Also after comparing these systems with other systems of different Ni isotopes, we have found that the signature of the role of coupling to neutron transfer channels due to ground state positive $Q$ value for neutron transfer is ambiguous.

Fusion Dynamics of 16O + 72,76Ge →88,92Zr Reactions using Skyrme Energy Density Formalism

In the fusion of 16O+72,76Ge→ 88,92Zr reactions the significance of structural and bulk properties of projectile-target combination is investigated at energies across the Coulomb barrier. For the purpose, the role of distinct Skyrme interactions (SIII, SKM*, SGII, RATP, T6, SkP), in conjunction with different surface diffuseness parameter (a=0.45-0.99) and nuclear charge radii i.e. iso-spin dependent and iso-spin independent are examined for the studied reaction. These geometrical parameters have their straight effect on the interaction barrier and the fusion excitation function. Thus, the sensitivity of fusion barrier and the cross sections in the sub barrier region of 88,92Zr Compound systems is carefully explored. The estimations of fusion cross sections are done in the framework of Wong formula and are compared with the respective experimental data. The observations implies that SKM* Skyrme interaction in which nuclear radius derived from polynomial fit gives relatively better result than the considered iso-spin dependent and independent nuclear charge radii. Further, the behaviour in the cross sections of Zr isotopes is investigated in terms of surface diffuseness parameter, which depicts that surface width is higher for neutron rich nucleus and lower for the neutron deficient one.

New Coulomb barrier scaling law with reference to the synthesis of superheavy elements

The synthesis of superheavy elements based on fusion reactions and multinucleon transfer reactions is sensitive to the reaction energies, where the Coulomb barrier plays a crucial role as it must be overcome for the projectile and target to contact each other. The Coulomb barrier cannot be measured directly, and the synthesis of superheavy elements is sensitive to it. In this study, we systematically extract the barrier information from the experimental fusion excitation functions by the empirical cross section formula, which is based on a single-Gaussian distribution of fusion barrier heights. A total of 403 sets of experimental data are fitted, among which 243 sets have good results with ${\ensuremath{\chi}}^{2}/pt$ less than one. The extracted fusion barrier is a dynamical barrier, which includes the overall effect of coupled channels. Different from the prediction of the WKJ formula, the new scaling law proposed in this work is almost identical to the CW76 Coulomb barrier at the $z=170--300$ region and reproduces well the centroid barrier extracted from quasielastic scattering. The comparison to the other 14 bare potential models and exploration of the very large $z$ region is also discussed. It is also remarkable to find that the predictions of the DP2015 potential, including of the contributions of the macroscopic and shell correction terms, are highly consistent with the extracted results in this work and the CW76 potential. The numerical results demonstrated that the dynamical fusion barrier and the centroid barrier extracted from the quasielastic reaction (the reaction threshold) could be the same physical quantity for superheavy reactions. This study could provide important references for the synthesis of superheavy nuclei based on fusion reactions and very heavy multinucleon transfer reactions.

Exploring the effects of breakup couplings for weakly bound projectile 9Be on various targets at around barrier energies

Here, the fusion excitation functions of reactions induced by 9Be on various heavy mass targets, 144Sm, 169Tm, 181Ta, 186W, 187Re, 197Au and 208Pb, at around barrier energies have been studied within the framework of the Continuum Discretized Coupled Channel (CDCC) approach. The inconsistency in the definitions of theoretical and experimental fusion cross section is properly accounted for which results in a fair agreement between data and predictions at near and above barrier energies for all the targets except Tungsten. The difference between the measured and the calculated fusion cross section is found to be independent of the targets.

Evidence of a higher nodal band α+Ca44 cluster state in fusion reactions and α clustering in Ti48

In the nucleus $^{48}$Ti, whose structure is essential in evaluating the half-life of the neutrinoless double-$\beta$ decay ($0\nu\beta\beta$) of $^{48}$Ca, the existence of the $\alpha$ cluster structure is shown for the first time. A unified description of scattering and structure is performed for the $\alpha$+$^{44}$Ca system. By using a global potential, which reproduces experimental $\alpha$+$^{44}$Ca scattering over a wide range of incident energies, $E_\alpha$=18 - 100 MeV, it is shown that the observed $\alpha$+$^{44}$Ca fusion excitation function at $E_\alpha$=9 -18 MeV is described well. The bump at $E_\alpha$=10.2 MeV is found to be due to a resonance which is a $7^-$ state of the higher nodal band with the $\alpha$+$^{44}$Ca cluster structure in $^{48}$Ti. The local potential $\alpha$+$^{44}$Ca cluster model locates the ground band of $^{48}$Ti in agreement with experiment and reproduces the enhanced $B(E2)$ values in the ground band well. This shows that collectivity due to $\alpha$ clustering in $^{48}$Ti should be taken into account in the evaluation of the nuclear matrix element in the $0\nu\beta\beta$ double-$\beta$ decay of $^{48}$Ca.

Fusion studies in O16+Nd142,150 reactions at energies near the Coulomb barrier

Background: Enhancement in fusion cross sections over one-dimensional barrier penetration model (1D-BPM) predictions has been observed at sub-barrier energies owing to the coupling of various internal degrees of freedom to the relative motion. On the other hand, hindrance in fusion is noticed at energies well above the barrier in a few cases.Purpose: The purpose is to probe the dynamics of heavy ion fusion at energies below and well above the Coulomb barrier.Methods: Fusion excitation functions for the $^{16}\mathrm{O}+^{142,150}\mathrm{Nd}$ reactions are measured using the Heavy Ion Reaction Analyzer (HIRA) at IUAC, New Delhi. Measurements have been performed in the range $12%$ below to $50%$ above the Coulomb barrier for both systems. The measured fusion cross sections are compared with coupled channels calculations using ccfull code. The cross sections are also compared with reactions using $^{16}\mathrm{O}$ beams with other isotopes of Nd to explore the systematic behavior of fusion.Results: Compared with 1D-BPM predictions, fusion enhancement is observed in both $^{16}\mathrm{O}+^{142}\mathrm{Nd}$ and $^{16}\mathrm{O}+^{150}\mathrm{Nd}$ reactions at below-barrier energies, with the latter reaction showing a higher enhancement. Coupled channels calculations incorporating the collective excitations of the target nuclei reproduce the fusion cross sections in both reactions. The collective excitations of the projectile nucleus do not seem to contribute to the observed fusion enhancement. Calculations using Aky\"uz-Winther potential parameters fail to reproduce the fusion cross sections at energies well above the barrier.Conclusions: Fusion enhancement is observed in both reactions studied. Degree of enhancement of sub-barrier fusion cross section is larger for the reaction using $^{150}\mathrm{Nd}$ target. Fusion hindrance is observed in both reactions at very high energies. The hindrance seems to increase with increasing beam energy. Larger value of diffuseness parameter compared with the value consistent with elastic-scattering measurements is required to reproduce the fusion excitation function at energies well above the barrier. This could be a strong indication of dynamical effects in fusion at very high energies.

Fusion dynamics of 12C with 92Zr and 194,198Pt targets at energies lying in the neighbourhood of Coulomb barrier

This work theoretically analyzed the role played by intrinsic degrees of freedom of the colliding partners and/or nucleon transfer channel in the fusion dynamics of [Formula: see text]C + [Formula: see text]Zr and [Formula: see text]C + [Formula: see text]Pt reactions. The theoretical calculations for the chosen reactions have been done by using symmetric–asymmetric Gaussian barrier distribution (SAGBD) model, coupled channel code CCFULL and one-dimensional Wong formula. The fusion excitation functions for these reactions are enhanced at energies lying in the sub-barrier regions with respect to calculations based on one-dimensional Wong formula. Such enhancement can be ascribed to the involvement of the low-lying inelastic surface excitations of the colliding systems and some other favored channels. The CCFULL calculations consider the couplings to low lying vibrational states of target isotopes and hence intimate the dominance of the collective excitations associated with the fusing partners. For all the studied reactions, the SAGBD model adequately addresses the sub-barrier fusion dynamics and thus the impacts of nuclear structure degrees of freedom associated with the collision partners are intrinsically incorporated via single Gaussian type of weight function. In the SAGBD approach, the nuclear structure effects are analyzed in terms of channel coupling parameter [Formula: see text] and percentage reduction of effective fusion barrier [Formula: see text] with reference to the Coulomb barrier. The larger values for [Formula: see text] and [Formula: see text] imply that the channel couplings due to internal structure of participants are significant at below barrier energies. The CCFULL calculations and SAGBD predictions consistently explain the fusion dynamics of chosen systems and hence reveal that both models have almost similar predictive power with respect to reported fusion data.

MuSIC@Indiana: An effective tool for accurate measurement of fusion with low-intensity radioactive beams

The design, construction, and characterization of the Multi-Sampling Ionization Chamber, MuSIC@Indiana, are described. This detector provides efficient and accurate measurement of the fusion cross-section at near-barrier energies. The response of the detector to low-intensity beams of 17,18O, 19F, 23Na, 24,26Mg, 27Al, and 28Si at Elab=50–60 MeV was examined. MuSIC@Indiana was commissioned by measuring the 18O+12C fusion excitation function for 11 < Ecm< 20 MeV using CH4 gas. A simple, effective analysis cleanly distinguishes proton capture and two-body scattering events from fusion on carbon. With MuSIC@Indiana, measurement of 15 points on the excitation function for a single incident beam energy is achieved. The resulting excitation function is shown to be in good agreement with literature data.

Study of breakup induced fusion mechanisms for 9Be+181Ta system at around barrier energies

The excitation functions for total, complete and incomplete fusion (TF, CF and ICF) mechanisms have been investigated for 9Be + [Formula: see text]Ta system at near and above barrier energy region. The calculations are performed by employing the code FRESCO based on continuum discretized coupled channel (CDCC) method. An enhancement is observed in the TF excitation function with respect to the data when breakup couplings are taken into account. Further, the CF and ICF probabilities, defined as the ratio of CF (ICF) cross-sections to the TF cross-sections, are also calculated. The dominance of breakup induced fusion is noticed at near barrier energies.

Assessing the impact of valence sd neutrons and protons on fusion

Experimental above-barrier fusion cross-sections for $^{17}$F + $^{12}$C are compared to the fusion excitation functions for $^{16,18}$O, $^{19}$F, and $^{20}$Ne ions on a carbon target. In comparing the different systems both the differing static size of the incident ions and changes in fusion barrier are accounted for by examining the reduced fusion cross-section. Remaining trends of the fusion cross-section above the barrier which reflect the sensitive interplay of the sd protons and neutrons are observed. The experimental data are also compared to both a widely-used analytical model of near-barrier fusion, as well as a time-dependent Hartree-Fock model. Both models fail to describe the trends observed.

Experimental study of the F17+C12 fusion reaction and its implications for fusion of proton-halo systems

The halo nature of the low-lying $1/2$+ first excited state of the exotic weakly-bound proton drip-line nucleus $^{17}$F has long been hypothesized. The structure of such a halo nucleus would imply special nuclear properties including, possibly, an enhancement in its fusion cross section above the barrier. The total fusion cross section of $^{17}$F + $^{12}$C near the Coulomb barrier was studied using the newly developed "Encore" active-target detector at Florida State University. Total fusion cross sections for the stable counterpart systems $^{16}$O + $^{12}$C and $^{19}$F + $^{12}$C were also measured to enable a systematic comparison. No influence of the halo nature of the $^{17}$F $1/2$+ first excited state on its fusion excitation function was observed when compared with the stable counterpart systems.

Direct fusion measurement of the 8B proton-halo nucleus at near-barrier energies

Direct measurements of the total fusion cross section for B8+40Ar were achieved with the active target technique. The fusion excitation function was extracted at energies near the Coulomb barrier. The cross section is well described by a coupled reaction channels calculation. The data were compared with previous B8 fusion experiments on Si28 and Ni58 targets. No evidence of striking enhancement of the total fusion cross section at near the Coulomb barrier, that was previously reported for the B8+58Ni system, was observed in these direct measurements. The present data are systematically consistent with the results for B8+28Si at higher energies and with other weakly-bound systems at near-barrier energies.

Progress on reaction mechanisms of the proton drip-line nucleus &amp;lt;sup&amp;gt;17&amp;lt;/sup&amp;gt;F at energies around the Coulomb barrier

<p indent=0mm>The reaction mechanism of proton drip-line nuclear systems at energies around the Coulomb barrier is one of the most popular topics in the field of nuclear physics. The present status of reactions induced by ¹⁷F at energies around the Coulomb barrier is reviewed in this paper. To make a further investigation of the reaction mechanisms of ¹⁷F, our group performed the measurements of elastic scattering of ¹⁷F+¹²C, ⁸⁹Y and ²⁰⁸Pb, as well as the complete kinematics of ¹⁷F+⁵⁸Ni at energies around the Coulomb barrier. For the elastic scattering, the excitation to the first excited state of ¹⁷F cannot be distinguished, hence the results have to be considered as the quasi-elastic scattering. The continuum-discretized coupled-channels (CDCC) calculations were performed to investigate the couplings to the continuum states on the elastic scattering. Both the calculations with and without the couplings to the continuum states can describe the quasi-elastic scattering data properly. The results indicate that, in a wide target-mass range, the couplings to the continuum states of ¹⁷F are not significant. For the breakup mechanism, breakup fragments of ¹⁷F+⁵⁸Ni and ²⁰⁸Pb were measured at energies above the Coulomb barrier. CDCC calculation could reproduce the breakup angular distribution of ¹⁷F+⁵⁸Ni well. However, it significantly overestimated the results of ¹⁷F+²⁰⁸Pb. The possible reason is that the excitation of the core, ¹⁶O, was not taken into account in the calculation. However, the underlying physics needs a further study. Within the energy region close to the Coulomb barrier, the breakup reactions of ¹⁷F+⁵⁸Ni were measured in single and in coincidence. The CDCC and the newly developed three-body model (the IAV model) were adopted to analyze the breakup data. The coincident data could be described well by the CDCC calculations. The sum of CDCC and IAV, which is referred to be as the total breakup, can reproduce properly the angular distributions of ¹⁶O. Moreover, the results also indicate that the non-elastic breakup dominates the ¹⁶O production. For the fusion measurement, only the results of ¹⁷F+⁵⁸Ni and ²⁰⁸Pb have been reported so far. The total fusion cross section of ¹⁷F+⁵⁸Ni was derived by measuring the fusion-evaporated protons and alphas. Compared with ¹⁶O+⁵⁸Ni, an obvious enhancement was observed at the energy below the Coulomb barrier. CDCC calculation indicates that such an enhancement is mainly due to the couplings to the continuum states. While for ¹⁷F+²⁰⁸Pb, the total fusion cross section was deduced by measuring the fusion-fission fragments in coincidence. The fusion excitation function of ¹⁷F+²⁰⁸Pb is almost identical with the stable system ¹⁹F+²⁰⁸Pb, indicating that the weakly bound nature of ¹⁷F does not play an important role in the fusion of ¹⁷F+²⁰⁸Pb. The underlying physics of the difference between ¹⁷F+⁵⁸Ni and ²⁰⁸Pb strongly deserves a further investigation. Furthermore, to establish the systematics of the reaction dynamics of ¹⁷F, reaction measurements of ¹⁷F on a range of targets at energies around and below the Coulomb barrier will be valuable. The results of ¹⁷F further indicate that the complete kinematics measurement could be the only promising approach to understand the reaction mechanisms of weakly bound nuclear systems comprehensively and provide the convincing data to promote the development of nuclear reaction theory.

Study of neutron-rich nuclei reaction using ImQMD ‎model

In the present study, the fusion reactions induced by neutron-rich nuclei have been investigated using the improved quantum molecular-dynamics (ImQMD) model. First, the accuracy of the results was determined by using a set of parameters IQ3a for 16O+92Zr, 40Ca+46Ti and 16O+154Sm fusion excitation functions. The obtained results revealed that the measured fusion excitation function can be reasonably well reproduced. A comparison was also performed with the theoretical results based on the coupled-channel calculations. Then, the time evolution of densities for the 16O+59Co and 32S+92Zr reactions in which the target nuclei were neutron-rich were studied and the fusion cross sections were calculated dynamically. It was found that the fusion cross sections of these reactions at energies around the Coulomb barrier can be well reproduced by using the ImQMD modle.

Effect of increasing neutron-excess on the fusion cross-section in 12−15C + 12C at above-barrier energies

Fusion excitation functions at energies above the fusion barrier for 12−15C + 12C are examined. From these excitation functions the average fusion cross-section, <σF>, is calculated. For this isotopic chain, the measured dependence of <σF> on neutron excess is compared with static barrier penetration models. The more rapid increase observed for the experimental cross-sections above the geometric increase predicted by the static models suggests that the stronger dependence on neutron-excess measured may be attributable to dynamics. Calculations with a time-dependent Hartree-Fock model also fail to describe the observed trend suggesting that for neutron-rich nuclei, neutron dynamics may play a larger role than is presently accounted for.

Evaporation residue cross section in the Cl37+Zn68 fusion reaction near the Coulomb barrier

Background: The measured subbarrier fusion cross sections in heavy-ion reactions are found to be significantly large as compared with those expected from the one-dimensional barrier penetration model (1d-BPM). Although attempts have been made to comprehend the enhancement in terms of different intrinsic degrees of freedom of the colliding nuclei, a clear understanding of the same is yet to come.Purpose: The objectives of this study is to understand the interplay of the channel coupling effect on fusion excitation function and explore the decay dynamics of the excited compound nucleus in the sub-and-near barrier region.Method: Fusion excitation function has been measured at energies from 7% below to 38% above the Bass barrier using a recoil mass spectrometer. Furthermore, cross sections of the different evaporation residues, such as 98, 99, 100, and 101 u, have been extracted.Results: The observed enhancement in the subbarrier fusion cross sections over the 1d-BPM predictions has been explained by considering the low-lying inelastic excitations among the interacting partners using ccfull code and by the barrier modification using the dynamical cluster-decay model (DCM). The cross sections of individual residual mass fractions (98, 99, 100, and 101 u) have been compared with the Hauser-Feshbach model.Conclusion: Coupled-channel calculations and DCM have successfully explained the total fusion cross sections data. The measured total fusion cross section ${\ensuremath{\sigma}}_{\mathrm{fus}}$ was found to be approximately equal to the sum of various residual mass fractions ($\mathrm{\ensuremath{\Sigma}}{\ensuremath{\sigma}}_{\mathrm{ER}}$) at energies above the Bass barrier. One-dimensional barrier height and radius parameters extracted from the measured data are in good agreement with the Bass model and DCM parameters.

Microscopic description of fusion hindrance in symmetric Ni+Ni and asymmetric C12+Pt198 systems

Hindrance at deep subbarrier energies for the symmetric $^{58}\mathrm{Ni}+^{58}\mathrm{Ni}, ^{64}\mathrm{Ni}+^{64}\mathrm{Ni}$, and asymmetric $^{12}\mathrm{C}+^{198}\mathrm{Pt}$ systems is investigated using microscopic energy and the density-dependent $G$-matrix effective interaction. The proton and neutron density distributions of target and projectile are derived from Skyrme-Hartree-Fock calculations. A fair agreement with the data of the fusion excitation functions and astrophysical $S$ factors have been obtained without any fitting parameters. Hindrance is naturally reproduced at deep subbarrier energies, which is consistent with experimental observations.

Role of neutron transfer in the sub-barrier fusion cross section in O18 + Sn116

Background: In heavy-ion-induced fusion reactions, cross sections in the sub-barrier region are enhanced compared to predictions of the one-dimensional barrier penetration model. This enhancement is often understood by invoking deformation and coupling of the relative motion with low-lying inelastic states of the reaction partners. However, effects of nucleon transfer on fusion below the barrier, especially for the systems having positive $Q$ value neutron transfer (PQNT) channels, are yet to be disentangled completely.Purpose: We intend to study the role of the PQNT effect on the sub-barrier fusion of the $^{18}\mathrm{O} + ^{116}\mathrm{Sn}$ system having positive $Q$ value for the two-neutron stripping channel. Also we reflect on the interplay of couplings involved in the system around the Coulomb barrier.Method: The fusion excitation function was measured at energies from $11%$ below to $46%$ above the Coulomb barrier for $^{18}\mathrm{O} + ^{116}\mathrm{Sn}$ using a recoil mass spectrometer, viz., the Heavy-Ion Reaction Analyser (HIRA). Fusion barrier distributions were extracted from the data. Results from the experiment were analyzed within the framework of the coupled-channels model.Results: Fusion cross sections at energies below the Coulomb barrier showed strong enhancement compared to predictions of the one-dimensional barrier penetration model. The fusion process is influenced by couplings to the collective excitations with coupling to single- and two-phonon vibrational states of the target and the projectile respectively. Inclusion of the two-neutron transfer channel in the calculation along with these couplings could reproduce the data satisfactorily.Conclusions: The significant role of PQNT in enhancing the sub-barrier fusion cross section for the chosen system is not observed. It simply reduced the sub-barrier fusion cross section. Therefore, a consistent link between PQNT and sub-barrier fusion enhancement could not be established vividly while comparing the fusion excitation function from this work with the same from other $^{16,18}\mathrm{O}$-induced reactions. This clearly points to the need for more experimental as well as theoretical investigation in this field.