arXiv subjects

Xiao-Hua Li

Publications and source records attributed to Xiao-Hua Li.

At least 37 records · Page 2Linked to original sources

arXiv2023

Potential and string breaking of doubly heavy baryon at finite temperature and chemical potential

Using gauge/gravity duality, we first study the string breaking and melting of doubly heavy baryon at a finite chemical potential and temperature in this paper. The decay mode $\rm{Q Q q \rightarrow Q q q+Q \bar{q}}$ is investigated with the presence of temperature and chemical potential in this paper. With the increase of temperature and chemical potential, string breaking takes place at a smaller potential energy and the string-breaking distance will increase slightly. It is also found that the $\rm{QQq}$ melts at small separate distance with the increase of temperature and chemical potential. Then, we compare the screening distance of $\rm{QQq}$ with $\rm{Q \bar{Q}}$ under the same conditions. Finally, we draw the melting diagram of $\rm{QQq}$ and $\rm{Q \bar{Q}}$ in the $T-μ$ plane.

hep-ph↗

arXiv2022

Systematic study of proton radioactivity half-lives based on the relationship between the Skyrme-Hartree-Fock and the macroscopic quantities of nuclear matter

In the present work, we systematically study the proton radioactivity half-lives of 33 spherical nuclei based on the relationship between the Skyrme parameters and the macroscopic quantities of nuclear matter. Using the two-potential approach with the spherical Skyrme-Hartree-Fock model, the correlation between proton radioactivity half-life and macroscopic quantities was analyzed. Moreover, we obtained a new Skyrme parameter set by fitting the two most weighted macroscopic quantities. Compared with Skyrme parameters MSL0 and the theoretical model of proton radioactivity UDLP, the theoretical proton radioactivity half-life calculated by the new Skyrme parameter set can better reproduce the experimental data.

nucl-th↗

arXiv2022

Two-proton radioactivity within Coulomb and proximity potential model

Considering the preformation probability of the two emitted protons in the parent nucleus, we extend the Coulomb and proximity potential model (CPPM) to systematically study two-proton (2p) radioactivity half-lives of the nuclei close to proton drip line. The proximity potential chosen is Prox. 81 proposed by Blocki et al. in 1981. Furthermore, we apply this model to predict the half-lives of possible 2p radioactive candidates whose 2p radioactivity is energetically allowed or observed but not yet quantified in the evaluated nuclear properties table NUBASE2016. The predicted results are in good agreement with those from other theoretical models and empirical formulas, namely the effective liquid drop model (ELDM), generalized liquid drop model (GLDM), Gamow-like model, Sreeja formula and Liu formula.

nucl-th↗

arXiv2021

Systematic study of two-proton radioactivity half-lives based on a modified Gamow-like model

In the present work, we systematically study the two-proton (2p) radioactivity half-lives of nuclei close to the proton drip line within a modified Gamow-like model. Using this model, the calculated 2p radioactivity half-lives can well reproduce the experimental data. Moreover, we use this model to predict the 2p radioactivity half-lives of 22 candidates whose 2p radioactivity is energetically allowed or observed but not yet quantied in evaluated nuclear properties table NUBASE2016. The predicted results are in good agreement with the ones obtained by using Gamow-like model, effective liquid drop model (ELDM), generalized liquid drop model (GLDM) as well as a four-parameter formula.

nucl-th↗

arXiv2021

Systematic study on proton radioactivity of spherical proton emitters within two--potential approach

In the present work we systematically study the half--lives of proton radioactivity for spherical proton emitters with ${Z\ge 69}$ based on two--potential approach. While the nuclear potential of the emitted proton--daughter nucleus is adopted by a parameterized cosh type, the parameters of the depth and diffuseness for nuclear potential are determined by fitting experimental data of 32 spherical proton emitters. In order to reduce the deviations between experimental half-lives and calculated ones, we propose a simple analytic expression for formation probability of proton radioactivity with the same orbital angular momentum $l$. The results indicate that the formation probability can be simply described by a formula of $A_d^{1/3}$. Moreover, the linear relationship between the formation probability and the fragmentation potential also exists. The calculated half-lives can well reproduce the experimental data.

nucl-th↗

arXiv2020

New Geiger-Nuttall law for two-proton radioactivity

In the present work, combining with the Geiger-Nuttall law, a two-parameter empirical formula is proposed to study the two-proton (2p) radioactivity. Using this formula, the calculated 2p radioactivity half-lives are in good agreement with the experimental data as well as the calculated ones obtained by Goncalves et al: ([Phys. Lett. B 774, 14 (2017)]) using the effective liquid drop model (ELDM), Sreeja et al: ([Eur. Phys. J. A 55, 33 (2019)]) using a four-parameter empirical formula and Cui et al: ([Phys. Rev. C 101: 014301 (2020)]) using a generalized liquid drop model (GLDM). In addition, this two-parameter empirical formula is extended to predict the half-lives of 22 possible 2p radioactivity candidates, whose the 2p radioactivity released energy Q2p>0, obtained from the latest evaluated atomic mass table AME2016. The predicted results have good consistency with ones using other theoretical models such as the ELDM, GLDM and four-parameter empirical formula.

nucl-th↗

arXiv2020

Systematic study of proton radioactivity of spherical proton emitters with Skyrme interactions

Proton radioactivity is an important and common process of the natural radioactivity of proton-rich nuclei. In our previous work [J. H. Cheng et al., Nucl. Rhys. A 997, 121717 (2020)], we systematically studied the proton radioactivity half-lives of 53< Z <83 nuclei within the two-potential approach with Skyrme-Hartree-Fock. The calculations can well reproduce the experimental data of spherical nuclei. The present work is an extension of the previous work. We systematically study 32 proton radioactivity half-lives of spherical nuclei with the two-potential approach with Skyrme-Hartree-Fock (TPA-SHF) within 115 different versions of the Skyrme interactions. The calculated results indicate that the SLy7 Skyrme interaction gives the lowest r.m.s. deviation in the description of the experimental data of the spherical proton emitters among all the different versions of the Skyrme interactions. In addition, we use this model with the SLy7 Skyrme interaction to predict the proton radioactivity half-lives of 7 spherical nuclei in the same region, whose proton radioactivity is energetically allowed or has been observed but is not yet quantified.

nucl-th↗

arXiv2020

Systematic study of the $α$ decay preformation factor of nuclei around the $\boldsymbol{Z=82}$, $\boldsymbol{N=126}$ shell closures within a generalized liquid drop model

In this work, we systematically study the $α$ decay preformation factors $P_α$ and $α$ decay half-lives of 152 nuclei around $Z$ = 82, $N$ = 126 closed shells based on a generalized liquid drop model while $P_α$ is extracted from the ratio of the calculated $α$ decay half-life to the experimental one. The results show that there is an obvious linear relationship between $P_α$ and the product of valance protons (holes) $N_p$ and valance neutrons (holes) $N_n$. At the same time, we extract the $$P_α$ values of even-even nuclei around $\emph{Z}$ = 82, $\emph{N}$ = 126 closed shells from the work of Sun \textit{et al.} [\href {https://doi.org/10.1088/1361-6471/aac981} {J. Phys. G: Nucl. Part. Phys. $\bm{45}$, 075106 (2018)}], in which the $P_α$ can be calculated by two different microscopic formulas. We find that the $P_α$ are also related to $N_pN_n$. Combining with our previous works [Sun \textit{et al.}, \href {https://doi.org/10.1103/PhysRevC.94.024338} {Phys. Rev. C $\bm{94}$, 024338 (2016)}; Deng \textit{et al.}, \href {https://doi.org/10.1103/ PhysRevC 96.024318} {ibid. $\bm{96}$, 024318 (2017)}; Deng \textit{et al.}, \href {https://doi.org/10.1103/PhysRevC.97.044322} {ibid. $\bm{97}$, 044322 (2018)}] and the work of Seif \textit{et al.} [\href {http://dx.doi.org/10.1103/PhysRevC.84.064608}{Phys. Rev. C $\bm{84}$, 064608 (2011)}], we suspect that this phenomenon of linear relationship for the nuclei around those closed shells is model independent. It may be caused by the effect of the valence protons (holes) and valence neutrons (holes) around the shell closures. Finally, using the formula obtained by fitting the $P_α$ calculated by the generalized liquid drop model (GLDM), we calculate the $α$ decay half-lives of these nuclei. The calculated results are agree with the experimental data well.

nucl-th↗

arXiv2019

New Geiger-Nuttall law for proton radioactivity

In the present work considering the contributions of the daughter nuclear charge and the orbital angular momentum taken away by the emitted proton, we propose a two-parameter formula of new Geiger-Nuttall law for proton radioactivity. A set of universal parameters of this law is obtained by fitting 44 experimental data of proton emitters in the ground state and isomeric state. The calculated results can reproduce the experimental data well. For a comparison, the calculations performed using other theoretical methods, such as UDLP proposed by Qi, et al. [https://journals.aps.org/prc/abstract/10.1103/PhysRevC.85.011303], the CPPM-Guo2013 analyzed by our previous work [Deng, et al., https://link.springer.com/article/10.1140/epja/i2019-12728-0] and the modified Gamow-like model proposed by us [Chen, et al., https://iopscience.iop.org/article/10.1088/1361-6471/ab1a56] are also included. Meanwhile, we extend this new Geiger-Nuttall law to predict the proton radioactivity half-lives for $51 \leq Z \leq 91$ nuclei, whose proton radioactivity is energetically allowed or observed but not yet quantified in NUBASE2016.

nucl-th↗

arXiv2019

Systematic study of $\mathcalα$ decay half-lives based on Gamow--like model with a screened electrostatic barrier

In the present work we systematically study $\mathcalα$ decay half-lives of $Z>51$ nuclei using the modified Gamow-like model which includes the effects of the centrifugal potential and electrostatic shielding. For the case of even-even nuclei, this model contains two adjustable parameters: the parameter $a$ related to the screened electrostatic barrier and the radius constant $r_0$, while for the case of odd-odd and odd-A nuclei, it is added a new parameter i.e. hindrance factor $h$ which is used to describe the effect of an odd-proton and/or an odd-neutron. Our calculations can well reproduce the experimental data. In addition, we use this modified Gamow-like model to predict the $\mathcalα$-decay half-lives of seven even-even nuclei with $Z=120$ and some un-synthesized nuclei on their $\mathcalα$ decay chains.

nucl-th↗

arXiv2019

Systematic study of proton radioactivity based on Gamow--like model with a screened electrostatic barrier

In the present work we systematically study the half--lives of proton radioactivity for $51 \leq Z \leq 83$ nuclei based on the Gamow--like model with a screened electrostatic barrier. In this model there are two parameters while considering the screened electrostatic effect of Coulomb potential with the Hulthen potential i.e. the effective nuclear radius parameter r_0 and the screening parameter a. The calculated results can well reproduce the experimental data. In addition, we extend this model to predict the proton radioactivity half--lives of 16 nuclei in the same region within a factor of 2.94, whose proton radioactivity are energetically allowed or observed but not yet quantified. Meanwhile, studying on the proton radioactivity half-life by a type of universal decay law has been done. The results indicate that the calculated half--lives are linearly dependent on Coulomb parameter with the same orbital angular momentum.

nucl-th↗

arXiv2019

Systematic study of proton radioactivity of spherical proton emitters within various versions of proximity potential formalisms

In this work we present a systematic study of the proton radioactivity half-lives of spherical proton emitters within the Coulomb and proximity potential model. We investigate 28 different versions of the proximity potential formalisms developed for the description of proton radioactivity, $\mathcalα$ decay and heavy particle radioactivity. It is found that 21 of them are not suitable to deal with the proton radioactivity, because the classical turning points $r_{\text{in}}$ cannot be obtained due to the fact that the depth of the total interaction potential between the emitted proton and the daughter nucleus is above the proton radioactivity energy. Among the other 7 versions of the proximity potential formalisms, it is Guo2013 which gives the lowest rms deviation in the description of the experimental half-lives of the known spherical proton emitters. We use this proximity potential formalism to predict the proton radioactivity half-lives of 13 spherical proton emitters, whose proton radioactivity is energetically allowed or observed but not yet quantified, within a factor of 3.71.

nucl-th↗

arXiv2019

Systematic study of $α$ decay for odd-$A$ nuclei within a two-potential approach

$α$ decay is usually associated with both ground and low-lying isomeric states of heavy and superheavy nuclei, and the unpaired nucleon plays a key role on $α$ decay. In this work, we systematically studied the $α$ decay half-lives of odd-$A$ nuclei, including both favored and unfavored $α$ decay within the two-potential approach based on the isospin dependent nuclear potential. The $α$ preformation probabilities are estimated by using an analytic formula taking into account the shell structure and proton-neutron correlation, and the parameters are obtained through the $α$ decay half-lives data. The results indicate that in general the $α$ preformation probabilities of even-$Z$, odd-$N$ nuclei are slightly smaller than the odd-$Z$, even-$N$ ones. We found that the odd-even staggering effect may play a more important role on spontaneous fission than $α$ decay. The calculated half-lives can well reproduce the experimental data.

nucl-th↗

arXiv2019

Systematic study of unfavored $\mathcalα$ decay half-lives of closed shell nuclei related to ground and isomeric states

In present work, the unfavored $\mathcalα$ decay half-lives and $\mathcalα$ preformation probabilities of closed shell nuclei related to ground and isomeric states around $Z=82$, $N=82$ and 126 shell closures are investigated by adopting two-potential approach from the perspective of valence nucleon (hole) and isospin asymmetry of the parent nucleus. The results indicate that $\mathcalα$ preformation probability is linear dependence on $N_p N_n$ or $N_p N_n I$, the same as the case of favored $\mathcalα$ decay in our previous work [X.-D. Sun \textit{et al.}, Phys. Rev. C 94, 024338 (2016)]. $N_p$, $N_n$, and $I$ represent the number of valence protons (holes), the number of valence neutrons (holes), and the isospin of the parent nucleus, respectively. Fitting the $\mathrmα$ preformation probabilities data extracted from the differences between experimental data and calculated half-lives without a shell correction, we give two linear formulas of the $\mathcalα$ preformation probabilities and the values of corresponding parameters. Based on the formulas and corresponding parameters, we calculate the $\mathrmα$ decay half-lives for those nuclei. The calculated results can well reproduce the experimental data.

nucl-th↗

arXiv2018

Systematic study of $\boldsymbol{\mathcalα}$ decay of nuclei around $\boldsymbol{Z=82}$, $\boldsymbol{N=126}$ shell closure within the cluster-formation model and proximity potential 1977 formalism

In the present work, we systematically study the $\mathcalα$ decay preformation factors $P_α$ within the cluster-formation model and $\mathcalα$ decay half-lives by the proximity potential 1977 formalism for nuclei around $Z=82$, $N=126$ closed shells. The calculations show that the realistic $P_α$ is linearly dependent on the product of valance protons (holes) and valance neutrons (holes) $N_pN_n$. It is consistent with our previous works [X.-D. Sun \textit{et al.}, \href{https://journals.aps.org/prc/abstract/10.1103/PhysRevC.94.024338}{ Phys. Rev. C 94, 024338 (2016)}, J.-G. Deng \textit{et al.}, \href{https://journals.aps.org/prc/abstract/10.1103/PhysRevC.96.024318}{Phys. Rev. C 96, 024318 (2017)}], which $P_α$ are model-dependent and extracted from the ratios of calculated $\mathcalα$ half-lives to experimental data. Combining with our previous works, we confirm that the valance proton-neutron interaction plays a key role in the $\mathcalα$ preformation for nuclei around $Z=82$, $N=126$ shell closures whether the $P_α$ is model-dependent or microcosmic. In addition, our calculated $\mathcalα$ decay half-lives by using the proximity potential 1977 formalism taking $P_α$ evaluated by the cluster-formation model can well reproduce the experimental data and significantly reduce the errors.

nucl-th↗

arXiv2018

$\boldsymbol{\mathcalα}$ decay properties of $\boldsymbol{^{296}}$Og within the two-potential approach

The present work is a continuations of our previous paper [J.-G. Deng, et al., Chin. Phys. C, {\bf41}: 124109 (2017)]. In present work, the $\mathcalα$ decay half-life of unknown nucleus $^{296}$Og is predicted within the two-potential approach and the hindrance factors of all 20 even-even nuclei in the same region with $^{296}$Og, i.e. proton number $82<Z<126$ and neutron number $152<N<184$, from $^{250}$Cm to $^{294}$Og are extracted. The prediction is 1.09 ms within a factor of 5.12. In addition, based on the latest experimental data, a new set of parameters of $\mathcalα$ decay hindrance factors for the even-even nuclei in this region considering the shell effect and proton-neutron interaction are obtained.

nucl-th↗

arXiv2017

$\mathcalα$ decay properties of nucleus $^{297}$Og within two-potential approach

The $\mathcalα$ decay half-life of unknown nucleus $^{297}$Og is predicted within two-potential approach, and $\mathcalα$ preformation probabilities of 64 odd-$A$ nuclei in the region of proton numbers $82<Z<126$ and neutron numbers $152<N<184$ from $^{251}$Cf to $^{295}$Og are extracted. In addition, based on the latest experimental data, a new set of parameters for $\mathcalα$ preformation probabilities considering the shell effect and proton-neutron interaction are obtained. The predicted $\mathcalα$ decay half-life of $^{297}$Og is 0.16 ms within a factor of 4.97 as well as the spin and parity of ground states for nuclei $^{269}$Sg, $^{285}$Fl and $^{293}$Lv are $3/2^+$, $3/2^+$ and $5/2^+$, respectively.

nucl-th↗

arXiv2016

Isospin dependence of nucleon effective masses in neutron-rich matter

In this talk, we first briefly review the isospin dependence of the total nucleon effective mass $M^{\ast}_{J}$ inferred from analyzing nucleon-nucleus scattering data within an isospin dependent non-relativistic optical potential model, and the isospin dependence of the nucleon E-mass $M^{\ast,\rm{E}}_{J}$ obtained from applying the Migdal-Luttinger theorem to a phenomenological single-nucleon momentum distribution in nuclei constrained by recent electron-nucleus scattering experiments. Combining information about the isospin dependence of both the nucleon total effective mass and E-mass, we then infer the isospin dependence of nucleon k-mass using the well-known relation $M^{\ast}_{J}=M^{\ast,\rm{E}}_{J}\cdot M^{\ast,\rm{k}}_{J}$. Implications of the results on the nucleon mean free path (MFP) in neutron-rich matter are discussed.

nucl-th↗