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Isospin influence on the decay of hot and rotating compound systems 118,122Ba⁎ and 118,134Ba⁎ formed in 78,82Kr + 40Ca and 78,86Kr + 40,48Ca reactions at incident energies 5.5 and 10 MeV/A, respectively, has been studied using the dynamical cluster-decay model. Binding energies used in the model have been calculated using semi-empirical mass formula of Davidson et al., where the bulk and asymmetry constants have been adjusted to reproduce the ground state mass excess for all the nuclei which have been added to AME2003 and mass table in Moller et al. 1995 to build AME2016 and FRDM2012 data. The theoretical mass excess is considered only for those cases where experimental mass excess was not available. The shell corrections have been calculated with shell closures at 2, 8, 14, 28, 50, 82, 126, 184 for both protons and neutrons and 258 for neutron only. The influence of isospin and incident energies have been seen on the following: mass and charge distribution of the fragments, de-excitation/evaporation, binary decay/fission processes of the compound system, odd-even staggering, isotopic composition, angular momentum distribution of preformation probabilities and decay cross-sections for evaporation and fission like events. The calculated cross-sections for evaporation and fission like events have been compared with experiments and the role of angular momentum on decay/fission processes have been discussed.

The suitable fission fragments have been predicted to synthesize a doubly magic superheavy element $${}_{126}^{310} X^{184}$$ in the fusion of the fission fragments. This has been done within the framework of fragmentation theory which states that the fragment combinations at/near the minima of various η-regions of the fragmentation potentials are more probable to produce a cool compound nucleus than the combinations away from it. The fragmentation potentials have been calculated for the hot and cold optimized orientations. The binding energies/mass excess used in the fragmentation potentials have been calculated by using the semi-empirical mass formula of Davidson et al. and the bulk and asymmetry constants of it have been readjusted to reproduce the ground state mass excess of AME2016 and FRDM (2012) data. The suitability of the fission fragments at and around various minima of the fragmentation potentials is tested further by comparing the formation yields and the fission barriers.

In this article, the probability tomography imaging method is applied to airborne vertical gravity gradient data to detect anomalies and estimate their depths and locations. First, the subsurface is divided into a 3D regular grid. Then, the probability tomography function is calculated at each grid node, and the obtained grid values are plotted. The zones of the highest values are the most probable areas for the buried bodies. It is noted that the results fall in the range [-1, +1] that represents the mass excess or mass deficit of density relative to the density of the host volume. The approach is applied to a sphere model and a cube model at certain flight altitudes. The results demonstrate that the approximate mass distribution and depth estimation derived from the approach are reliable up to a certain flight altitude.

Background: The neutron-rich $A\ensuremath{\approx}100, N\ensuremath{\approx}62$ mass region is important for both nuclear structure and nuclear astrophysics. The neutron-rich segment of this region has been widely studied to investigate shape coexistence and sudden nuclear deformation. However, the absence of experimental data of more neutron-rich nuclei poses a challenge to further structure studies. The derivatives of the mass surface, namely, the two-neutron separation energy and neutron pairing gap, are sensitive to nuclear deformation and shed light on the stability against deformation in this region. This region also lies along the astrophysical $r$-process path, and hence precise mass values provide experimental input for improving the accuracy of the $r$-process models and the elemental abundances.Purpose: (a) Changes in deformation are searched for via the mass surface in the $A=104$ mass region at the $N=66$ mid-shell crossover. (b) The sensitivity of the astrophysical $r$-process abundances to the mass of Rb and Sr isotopic chains is studied.Methods: Masses of radioactive Rb and Sr isotopes are precisely measured using a Multiple-Reflection Time-of-Flight Mass Separator (MR-TOF-MS) at the TITAN facility. These mass values are used to calculate two-neutron separation energies, two-neutron shell gaps and neutron pairing gaps for nuclear structure physics, and one-neutron separation energies for fractional abundances and astrophysical findings.Results: We report the first mass measurements of $^{103}\mathrm{Rb}$ and $^{103--105}\mathrm{Sr}$ with uncertainties of less than 45 keV/${c}^{2}$. The uncertainties in the mass excess value for $^{102}\mathrm{Rb}$ and $^{102}\mathrm{Sr}$ have been reduced by a factor of 2 relative to a previous measurement. The deviations from the AME extrapolated mass values by more the 0.5 MeV have been found.Conclusions: The metrics obtained from the derivatives of the mass surface demonstrate no existence of a subshell gap or onset of deformation in the $N=66$ region in Rb and Sr isotopes. The neutron pairing gaps studied in this work are lower than the predictions by several mass models. The abundances calculated using the waiting-point approximation for the $r$ process are affected by these new masses in comparison with AME2016 mass values.

The ground-state properties of neutron-rich $^{106}\mathrm{Nb}$ and its $\ensuremath{\beta}$ decay into $^{106}\mathrm{Mo}$ have been studied using the CARIBU radioactive-ion-beam facility at Argonne National Laboratory. Niobium-106 ions were extracted from a $^{252}\mathrm{Cf}$ fission source and mass separated before being delivered as low-energy beams to the Canadian Penning Trap, as well as the X-Array and SATURN $\ensuremath{\beta}$-decay-spectroscopy station. The measured $^{106}\mathrm{Nb}$ ground-state mass excess of $\ensuremath{-}66202.0(13)$ keV is consistent with a recent measurement but has three times better precision; this work also rules out the existence of a second long-lived, $\ensuremath{\beta}$-decaying state in $^{106}\mathrm{Nb}$ above 5 keV in excitation energy. The decay half-life of $^{106}\mathrm{Nb}$ was measured to be 1.097(21) s, which is $8%$ longer than the adopted value. The level scheme of the decay progeny, $^{106}\mathrm{Mo}$, has been expanded up to $\ensuremath{\approx}4\phantom{\rule{4pt}{0ex}}\mathrm{MeV}$. The distribution of decay strength and considerable population of excited states in $^{106}\mathrm{Mo}$ of $J\ensuremath{\ge}3$ emphasizes the need to revise the adopted ${J}^{\ensuremath{\pi}}={1}_{}^{\ensuremath{-}}$ ground-state spin-parity assignment of $^{106}\mathrm{Nb}$; it is more likely to be $J\ensuremath{\ge}3$.

Background: The quadratic isobaric multiplet mass equation (IMME) has been very successful at predicting the masses of isobaric analog states in the same multiplet, while its coefficients are known to follow specific trends as functions of mass number. The Atomic Mass Evaluation 2016 [Chin. Phys. C 41, 030003 (2017)] $^{44}\mathrm{V}$ mass value results in an anomalous negative $c$ coefficient for the IMME quadratic term; a consequence of large uncertainty and an unresolved isomeric state. The $b$ and $c$ coefficients can provide useful constraints for construction of the isospin-nonconserving Hamiltonians for the $pf$ shell. In addition, the excitation energy of the ${0}^{+},T=2$ level in $^{44}\mathrm{V}$ is currently unknown. This state can be used to constrain the mass of the more exotic $^{44}\mathrm{Cr}$.Purpose: The aim of the experimental campaign was to perform high-precision mass measurements to resolve the difference between $^{44}\mathrm{V}$ isomeric and ground states, to test the IMME using the new ground state mass value and to provide necessary ingredients for the future identification of the ${0}^{+}$, $T=2$ state in $^{44}\mathrm{V}$.Method: High-precision Penning trap mass spectrometry was performed at LEBIT, located at the National Superconducting Cyclotron Laboratory, to measure the cyclotron frequency ratios of [${^{44g,m}\mathrm{VO}]}^{+}$ versus [${^{32}\mathrm{SCO}]}^{+}$, a well-known reference mass, to extract both the isomeric and ground state masses of $^{44}\mathrm{V}$.Results: The mass excess of the ground and isomeric states in $^{44}\mathrm{V}$ were measured to be $\ensuremath{-}23\phantom{\rule{4pt}{0ex}}804.9(80)$ keV/${c}^{2}$ and $\ensuremath{-}23\phantom{\rule{4pt}{0ex}}537.0(55)$ keV/${c}^{2}$, respectively. This yielded a new proton separation energy of ${S}_{p}=1\phantom{\rule{4pt}{0ex}}773(10)$ keV.Conclusion: The new values of the ground state and isomeric state masses of $^{44}\mathrm{V}$ have been used to deduce the IMME $b$ and $c$ coefficients of the lowest ${2}^{+}$ and ${6}^{+}$ triplets in $A=44$. The ${2}^{+}\phantom{\rule{4pt}{0ex}}c$ coefficient is now verified with the IMME trend for lowest multiplets and is in good agreement with the shell-model predictions using charge-dependent Hamiltonians. The mirror energy differences were determined between $^{44}\mathrm{V}$ and $^{44}\mathrm{Sc}$, in line with isospin-symmetry for this multiplet. The new value of the proton separation energy determined, to an uncertainty of 10 keV, will be important for the determination of the ${0}^{+}$, $T=2$ state in $^{44}\mathrm{V}$ and, consequently, for prediction of the mass excess of $^{44}\mathrm{Cr}$.

RIBLL Collaboration: et al., The mass of 27P is expected to impact the X-ray burst (XRB) model predictions of burst light curves and the composition of the burst ashes, but large uncertainties and inconsistencies still exist in the reported 27P masses. We have used the β-decay spectroscopy of 27S to determine the most precise mass excess of 7P to date to be −659(9)keV, which is 63 keV (2.3σ) higher and a factor of 3 more precise than the value recommended in the 2016 Atomic Mass Evaluation. Based on the new 27P mass, the 26Si(p, γ)27P reaction rate and its uncertainty were recalculated using Monte Carlo techniques. We also estimated the previously unknown mass excess of 27S to be 17678(77) keV, based on the measured β-delayed two-proton energy and the Coulomb displacement energy relations. The impact of these well-constrained masses and reaction rates on the modeling of the explosive astrophysical scenarios has been investigated by post-processing XRB and hydrodynamic nova models. Compared to the model calculations based on the masses and rates from databases, the abundance of A =26 in the burst ashes is increased by a factor of 2.4, while no substantial change was found in the XRB energy generation rate or the light curve. Our calculation also suggests that 27S is not a significant waiting point in the rapid proton capture process, and the change of the 26Si(p, γ)27P reaction rate is not sufficiently large to affect the conclusion previously drawn on the nova contribution to the synthesis of galactic 26Al., This work is supported by the Ministry of Science and Technology of China under the National Key R&D Programs Nos. 2018YFA0404404 and 2016YFA0400503, and the National Natural Science Foundation of China under Grants Nos. 11635015, 11805120, U1632136, 11705244, U1432246, 11775316, U1732145, 11705285, U1867212, 11805280, 11825504, 11675229, and 11490562, and the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No. 2019406, and the Continuous Basic Scientific Research Project under Grant No. WDJC-2019-13, and the China Postdoctoral Science Foundation under Grants Nos. 2017M621442 and 2017M621035, and the Office of China Postdoctoral Council under the International Postdoctoral Exchange Fellowship Program (Talent-Dispatch Program) No. 20180068. Jordi José acknowledges funding from the Spanish MINECO grant AYA2017-86274-P, by the E.U. FEDER funds, and by the AGAUR/Generalitat de Catalunya grant SGR-661/2017.

Background: Isobaric quintets provide the best test of the isobaric multiplet mass equation (IMME) and can uniquely identify higher order corrections suggestive of isospin symmetry breaking effects in the nuclear Hamiltonian. The generalized IMME (GIMME) is a novel microscopic interaction theory that predicts an extension to the quadratic form of the IMME. Only the $A=20,32$ $T=2$ quintets have the exotic ${T}_{z}=\ensuremath{-}2$ member ground state mass determined to high precision by Penning trap mass spectrometry.Purpose: We aim to establish $A=36$ as the third $T=2$ isobaric quintet with the ${T}_{z}=\ensuremath{-}2$ member ground state mass measured by Penning trap mass spectrometry and provide the first test of the predictive power of the GIMME.Method: A radioactive beam of neutron-deficient $^{36}\mathrm{Ca}$ was produced by projectile fragmentation at the National Superconducting Cyclotron Laboratory. The beam was thermalized and the masses of $^{36}\mathrm{Ca}^{+}$ and $^{36}\mathrm{Ca}^{2+}$ were measured by the time-of-flight ion cyclotron resonance method in the LEBIT 9.4 T Penning trap.Results: We measure the mass excess of $^{36}\mathrm{Ca}$ to be $\mathrm{ME}=\ensuremath{-}6483.6(56)$ keV, an improvement in precision by a factor of 6 over the literature value. The new datum is considered together with evaluated nuclear data on the $A=36$, $T=2$ quintet. We find agreement with the quadratic form of the IMME given by isospin symmetry, but only coarse qualitative agreement with predictions of the GIMME.Conclusion: A total of three isobaric quintets have their most exotic members measured by Penning trap mass spectrometry. The GIMME predictions in the $T=2$ quintet appear to break down for $A=32$ and greater.

The Bouguer gravity anomaly map of Turkey shows relatively high values around the Cumra region, Konya. This area has a flat topography and a thick cover of sediments despite being seated on a suture zone formed between Anatolide and Tauride Platforms after the Neo-Tethys Ocean closed. High Bouguer gravity anomalies indicate an anomalous mass excess buried under the flat topography. In the present study, the gravity anomaly is studied using several analysis and processing methods in order to understand and infer its possible sources. Spectral analysis of the anomaly showed that the mass should be buried at a depth of about 4.8 km. The geometry of the mass is forward modelled using the vertical prisms method, which assumes that the mass is a homogeneous layer, represented by separate identical prisms. The observed anomaly and the calculated anomaly retrieved from the modelled geometry are compared mathematically and the mass geometry is updated depending on the differences between them. After a total of 10 iterations, the RMS error decreases below 1% and thus the calculated model is considered accurate. Then the achieved model is used for mass estimations, which showed that if the density difference between the medium and the target mass is set as 0.25 g/cm 3 , about 67 Gt of extra mass is needed to produce such a gravity anomaly. Correlation with geological maps and aeromagnetic anomalies of the region points out that this excess mass may be due to a remnant ophiolitic rock from the Neo-Tethys Ocean.

The concept of heavy particle radioactivity is studied using modified generalised liquid drop model (MGLDM) in the superheavy element Z = 126. The eight different proximity functions and different mass excess values were used to evaluate cluster/HPR. The logarithmic half-lives using different proximity functions and mass excess values are compared with that of experiments. The HPR of 60Ni to 102Ru have been studied in the superheavy region 126 306 to 126 326 . The HPR half-lives has been compared with the different decay modes such as α-decay, β-decay and spontaneous fission. 9 HPR emitters, 4 α emitters, 1 β + emitter and 7 spontaneous fission nuclei were identified in the superheavy nuclei 126 306 − 314 , 126 315 − 318 , 126 319 and 126 320 − 326 respectively.

Half-life for two-proton radioactivity of emitter nuclides of mass number A 70 has been calculated by using a phenomenological, effective liquid drop model ( eldm ) which has been applied successfully to one-proton radioactivity, alpha decay, cluster radioactivity and cold fission processes. Following this approach, we estimate half-life values for several 2 p -emitted nuclides and compare our results with predictions from other models, as well as the existing data in the literature, specifically the cases for 16 Ne, 19 Mg, 45 Fe, 48 Ni, 54 Zn and 67 Kr parent nuclei. It is seen that the eldm version adapted to deal with 2 p -decay process reproduces the available experimental data quite satisfactorily, asserting that shell corrections and pairing effects for the ground state nucleus have been well incorporated into the model via the experimental mass excess values. The present estimates for half-lives show a number of nuclei with detectable 2 p -emission mode, which predictions may serve as indicators for further experimental investigations.

Mass defect is associated with the binding energy of the nucleus. It is a fundamental property of the nucleus and the principle behind nuclear energy. Mass defect has also entered into the mass spectrometry terminology with the availability of high resolution mass spectrometry and has found application in mass spectral analysis. In this application, isobaric masses are differentiated and identified by their mass defect. What is the relationship between nuclear mass defect and mass defect used in mass spectral analysis, and are they the same? Graphical Abstract ᅟ.

In this paper, a measurement of the atomic mass and mass excess of Re 75 190 are presented. This isotope and Ir 77 192 were produced at the Maier-Leibnitz Laboratory (MLL) in Munich in the 192Os(d, α)190Re and 194Pt(d, α)192Ir reactions. The Q3D magnetic spectrograph was used to measure the momenta of the α-particle ejectiles in order to reconstruct states in both 190Re and 192Ir. A mass calibration was performed using known energy levels in 192Ir. These measurements were used to obtain a new value of the mass excess of 190Re, −35583 ± 5 keV. The previously known literature value is −35640 ± 70 keV.

The $ \alpha$-decay half-lives of synthesized superheavy nuclei (SHN) from seaborgium to oganesson are calculated by employing the generalized liquid-drop model (GLDM), the Royer formula and the universal decay law (UDL) with experimental $ \alpha$-decay energies $Q_{\alpha}$. For the GLDM, we consider the shell correction. The agreement between the experimental data and the calculations indicates that all the methods we used are successful to reproduce $\alpha$-decay half-lives of known SHN. The decay-modes of known nuclei on the 294Og decay-chain are also consistent with the experiments. For the unknown nuclei, the $ \alpha$-decay half-lives have been predicted by inputting $ Q_{\alpha}$ values extracted from the newest Weizsacker-Skyrme-4 (WS4) model. In the GLDM with shell correction, we adopt the constant $ \alpha$-preformation factor $ P_{\alpha}$ as well as $ P_{\alpha}$ extracted by Cluster Formation Model (CFM). To calculate CFM $ P_{\alpha}$ values, we use FRDM binding energies and WS4 mass excess values. The relationship of $ P_{\alpha}$ and $ Q_{\alpha}$ shows that 294, 296, 314, 316, 320Og isotopes are relatively stable. The competition between $ \alpha$-decay and spontaneous fission is discussed in detail for 283-339Og isotopes. The decay-chains of 290-300Og have also been presented. Since the $ \alpha$-decay half-lives of 283-303Og isotopes are obviously lower than their spontaneous fission half-lives by more than 6 orders, these isotopes would mainly have $ \alpha$-decay. The 306-334Og isotopes may undergo spontaneous fission. The nuclei 304, 305Og would have both $ \alpha$-decay and spontaneous fission. By the shell-effect included GLDM with CFM $ P_{\alpha}$, we predict 295Og undergoes $ \alpha$-decay and $ T_{\alpha}^{1/2} = 0.37$ ms. The 296Og is also $ \alpha$-decay and has $ T_{\alpha}^{1/2} = 0.40$ ms.

Isochronous mass spectrometry has been applied in the storage ring CSRe to measure the masses of the neutron-rich Sc52–54 and Ti54,56 nuclei. The new mass excess values ME(Sc52)=−40525(65) keV, ME(Sc53)=−38910(80) keV, and ME(Sc54)=−34485(360) keV, deviate from the Atomic Mass Evaluation 2012 by 2.3σ, 2.8σ, and 1.7σ, respectively. These large deviations significantly change the systematics of the two-neutron separation energies of scandium isotopes. The empirical shell gap extracted from our new experimental results shows a significant subshell closure at N=32 in scandium, with a similar magnitude as in calcium. Moreover, we present ab initio calculations using the valence-space in-medium similarity renormalization group based on two- and three-nucleon interactions from chiral effective field theory. The theoretical results confirm the existence of a substantial N=32 shell gap in Sc and Ca with a decreasing trend towards lighter isotones, thus providing a consistent picture of the evolution of the N=32 magic number from the pf into the sd shell.

1st Sharjah International Conference on Particle Physics, Astrophysics and Cosmology, FISICPAC 2018 -- 11 November 2018 through 13 November 2018 -- -- 153573, We investigate the abundance of 19 F in the Sun through the nucleosynthesis scenario. In addition, we calculate the rate equations and reaction rates of the nucleosynthesis of 19 F at different temperature scale. Other important functions of this nucleosynthesis (nuclear partition function and statistical equilibrium conditions) are also obtained. The resulting stability of 19 F occurs at nucleus with A = 19 and Mass Excess = -1.4874 MeV. As a result, this will tend to a series of neutron captures and beta-decay until 19 F is produced. The reaction rate of 15 N (?, ?) 19 F was dominated by the contribution of three low-energy resonances, which enhanced the final 19 F abundance in the envelope. © 2019 IOP Publishing Ltd. All rights reserved., University of Chinese Academy of Sciences, UCAS Ege Üniversitesi United Arab Emirates University, UAEU American University of Sharjah, AUS University of Jordan, UJ, 1Key Lab of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, A20 Datun Road, Chaoyang, Beijing 100102, People’s Republic of China 2School of Astronomy and Space Science, University of Chinese Academy of Sciences, No.19(A) Yuquan Road, Shijingshan District, Beijing, 100049, People’s Republic of China 3Department of Physics, University of Jordan, Amman, 11942 Jordan 4Department of Physics and Institute of Astronomy and Space Sciences, Al Al-Bayt University, Mafraq, 25113 Jordan 5Physics Department, Faculty of Science, Al-Balqa Applied University, 19117 Salt, Jordan 6Astronomy and Space Sciences Department, Ege University, Izmir, Turkey 6Department of Applied Physics and Astronomy, Sharjah University, Sharjah, United Arab Emirates 7Royal Jordanian Geographic Center, Amman, 11941 Jordan

Background: The $^{51}\mathrm{Fe}(p,\ensuremath{\gamma})^{52}\mathrm{Co}$ reaction lies along the main rp-process path leading up to the $^{56}\mathrm{Ni}$ waiting point. The uncertainty in the reaction $Q$ value, which determines the equilibrium between the forward proton-capture and reverse photodisintegration $^{52}\mathrm{Co}(\ensuremath{\gamma},p)^{51}\mathrm{Fe}$ reaction, contributes to considerable uncertainty in the reaction rate in the temperature range of interest for Type I x-ray bursts and thus to an $\ensuremath{\approx}10%$ uncertainty in burst ashes lighter than $A=56$.Purpose: With a recent Penning trap mass measurement of $^{52}\mathrm{Co}$ reducing the uncertainty on its mass to 6.6 keV [Nesterenko et al., J. Phys. G 44, 065103 (2017)], the dominant source of uncertainty in the reaction $Q$ value is now the mass of $^{51}\mathrm{Fe}$, reported in the 2016 atomic mass evaluation to a precision of 9 keV [Wang et al., Chin. Phys. C 41, 030003 (2017)]. A new, high-precision Penning trap mass measurement of $^{51}\mathrm{Fe}$ was performed to allow the determination of an improved precision $Q$ value and thus new reaction rates.Method: $^{51}\mathrm{Fe}$ was produced using projectile fragmentation at the Coupled Cyclotron Facility at the National Superconducting Cyclotron Laboratory, and separated using the A1900 fragment separator. The resulting secondary beam was then thermalized in the beam stopping area before a mass measurement was performed using the LEBIT 9.4T Penning trap mass spectrometer.Results: The new mass excess, $\mathrm{ME}=\ensuremath{-}40189.2(1.6)$ keV, is sixfold more precise than the current AME value, and $1.6\ensuremath{\sigma}$ less negative. This value was used to calculate a new proton separation energy for $^{52}\mathrm{Co}$ of 1431(7) keV. New excitation levels were then calculated for $^{52}\mathrm{Co}$ using the nushellx code with the GXPF1A interaction, and a new reaction rate and burst ash composition was calculated.Conclusions: With a new measured $Q$ value, the uncertainty on the $^{51}\mathrm{Fe}(p,\ensuremath{\gamma})$ reaction rate is dominated by the poorly measured $^{52}\mathrm{Co}$ level structure. Reducing this uncertainty would allow a more precise rate calculation and a better determination of the mass abundances in the burst ashes.