共查询到20条相似文献,搜索用时 15 毫秒
1.
P K Chatley 《Pramana》1983,20(2):143-156
We investigate how a new bag phenomenology with a variable bag pressure as its main ingredient is successful in reproducing
various properties of heavy hadrons. Our results for masses, magnetic moments and M1 radiative decay widths indicate that
these properties arise in a natural and consistent manner from the theory and that no additionalad hoc assumption is required to explain them. 相似文献
2.
An investigation of the newly discovered charmed mesonsD 0 andD +, particularly their non-leptonic decay modes, is carried out in the framework of the MIT bag model. The amplitude for a
number of two-body final state decays are explicitly evaluated and compared with other available estimates. 相似文献
3.
The consequences of the variable pressure bag model for the nonleptonic decays of hyperons and Ω− are investigated. Though the order of magnitude and the relative sign for the various decay amplitudes are correctly reproduced,
the overall results are small by a factor of 2 to 4, indicating that the theoretical predictions are strongly dependent on
the model parameters. 相似文献
4.
LIU LiangGang 《理论物理通讯》2000,34(4):655-662
The MIT bag model, chiral bag model and cloudy bag model are revisited. A typical work on the hadron mass calculation by chiral bag model and cloudy bag model is shown in more details with the quark-quark-pi vertex correction and quark self-energy being emphasized. More details are given to review the quark-meson coupling model and its application in nuclear matter. We put forth the Lagrangian of the quark-meson coupling model and studied the possibility of using the model to calculate the hadron mass. 相似文献
5.
The suggestion made by Lipkin regarding the quark masses and magnetic moments of baryons is examined in the context of the
variable pressure bag model. We find that the exact agreement obtained by Lipkin between theory and experiment in the case
ofμ(Λ) cannot be considered accidental, contrary to the scepticism expressed by Minami. 相似文献
6.
Transition magnetic moments of J~P=3/2~+ decuplet to J~P=1/2~+ octet baryons in the chiral constituent quark model 下载免费PDF全文
Harleen Dahiya 《中国物理C(英文版)》2018,42(9):093102-093102
In light of the developments of the chiral constituent quark model(χ~(CQM)) in studying low energy hadronic matrix elements of the ground-state baryons, we extend this model to investigate their transition properties.The magnetic moments of transitions from the J~P=3/2~+ decuplet to J~P=1/2~+ octet baryons are calculated with explicit valence quark spin, sea quark spin and sea quark orbital angular momentum contributions. Since the experimental data is available for only a few transitions, we compare our results with the results of other available models. The implications of other complicated effects such as chiral symmetry breaking and SU(3) symmetry breaking arising due to confinement of quarks are also discussed. 相似文献
7.
Recoil corrections to magnetic moments of charmed baryons are studied in themit bag model. It is noticed that such corrections which improve the octet baryon magnetic moments have considerably significant
contributions to charmed baryon’s moments also. 相似文献
8.
We study the stability properties of magnetized strange quark matter and strangelets under a strong magnetic field in the MIT bag model. The free energy per baryon of strange quark matter feels a great influence from the magnetic field. At the field strength about 1017G, the magnetized strange quark matter becomes more stable. Considering the finite size effect, the magnetic influence on strangelets becomes complicated. For a given magnetic field, there exists a critical baryon number, below which the magnetized strangelets have lower energy than the non-magnetized strangelets. For the field strength of 5× 1017G, the critical baryon number is Ac ~ 100. Generally, the critical baryon number increases with the decreasing external magnetic field. When the field strength is smaller than 1017G, the critical baryon number goes up to Ac~ 105. The stable radius, electric charge, and quark flavor fractions of magnetized strangelets are shown. 相似文献
9.
A model forN-N interaction proposed earlier by two of us (VSB and VKG), has been extended to incorporate the tensor component of the nuclear
force. Based on the quark compound bag model (QCB), the nucleon-nucleon potential has a short range repulsive core which is
non-local and has a characteristic energy dependence and is expressed in terms of the parameters relating to the six-quark
compound bag. To account for the low energy properties, this repulsive core interaction is supplemented by a phenomenological
non-local potential containing both central (S-wave) and tensor components and operates only outside the QCB. Using this model, we analyse and compare the results with
the experimental data for the electromagnetic form factors of the deuteron, theD-state observables, such as the quadrupole moment, theD-state probability, and theD/S ratio along with then-p scattering phase shifts up to about 400 MeV. 相似文献
10.
The magnetic moments of charmed baryons are studied in the covariant oscillator quark model including isospin symmetry breaking
effect. In the uncharmed sector, the results differ from those obtained using conventional non-relativistic quark model (nrqm). But in the charmed sector the present values are much nearer to thenrqm results than those calculated using models with hadron mass dependence. 相似文献
11.
The thermodynamics of strange quark matter with density dependent bag constant are studied self-consistently in the framework of the general ensemble theory and the MIT bag model.In our treatment,an additional term is found in the expression of pressure.With the additional term,the zero pressure locates exactly at the lowest energy state,indicating that our treatment is a self-consistently thermodynamic treatment.The self-consistent equations of state of strange quark matter in both the normal and color-fla... 相似文献
12.
13.
二次电子发射模型的精度对二次电子倍增击穿阈值的模拟计算影响很大, 针对现有两种经典二次电子发射唯象模型的不足, 以修正Vaughan模型作为Furman模型中的真二次电子发射系数计算模型, 建立起一种二次电子发射的复合唯象模型. 该模型不仅适用于倍增击穿过程的数值模拟, 还很大程度上提高了与实验数据拟合的准确性. 通过对银和铝合金两种材料二次电子发射系数实验结果和模型拟合结果的对比发现, 在不同入射角情况下, 复合唯象模型的平均误差较原有两种模型降低了10%以上.
关键词:
二次电子发射
唯象模型
击穿阈值 相似文献
14.
Mass difference oft-flavored hadrons is calculated using bag model modified for considering heavy quarks inside the bag. Both electric and magnetic
contributions to mass differences are evaluated without the assumption of degenerate intermediate state. Mass differences
between up and down quarks inside the bag is taken to be a constant in the absence of a dynamical calculations for the same. 相似文献
15.
A rumor spreading model with the consideration of forgetting rate changing over time is examined in small-world networks. The mean-field equations are derived to describe the dynamics of rumor spreading in small-world networks. Further, numerical solutions are conducted on LiveJournal, an online social blogging platform, to better understand the performance of the model. Results show that the forgetting rate has a significant impact on the final size of rumor spreading: the larger the initial forgetting rate or the faster the forgetting speed, the smaller the final size of the rumor spreading. Numerical solutions also show that the final size of rumor spreading is much larger under a variable forgetting rate compared to that under a constant forgetting rate. 相似文献
16.
A relativistic quark model based on Dirac equation with the independent-quark confining potential of the form (1 +γ
0)[a ln(r/b)] is used to compute the weak electric and magnetic form factors for semileptonic baryonic decays in the electronic decay
modes. The values obtained for (g
2/g
1) agree with the non relativistic results and those for (f
2/f
1) agree with the MIT bag model values of Donoghue and Holstein. The SU(3) symmetry breaking does not generate appreciable
departures in (f
2/f
1) values from corresponding Cabibbo values. 相似文献
17.
Probing the QCD phase structure with higher order baryon numbersusceptibilities within the NJL model
Conserved charge fluctuations can be used to probe the phase structure of strongly interacting nuclear matter in relativistic heavy-ion collisions. To obtain the characteristic signatures of the conserved charge fluctuations for the quantum chromodynamics(QCD) phase transition, we study the susceptibilities of dense quark matter up to eighth order in detail, using an effective QCD-based model. We studied two cases, one with the QCD critical end point(CEP) and one without owing to an additional vector interaction term. The higher order susceptibilities display rich structures near the CEP and show sign changes as well as large fluctuations. These can provide us information about the presence and location of the CEP. Furthermore, we find that the case without the CEP also shows a similar sign change pattern, but with a relatively smaller magnitude compared with the case with the CEP. Finally, we conclude that higher order susceptibilities of conserved charge can be used to probe the QCD phase structures in heavyion collisions. 相似文献
18.
19.
R. Zouari 《Phase Transitions》2017,90(2):167-174
The present work is devoted to a review of the phenomenological model proposed by Mahmoud Aly Hamad (M. Aly Hamad, Phase Transitions 85 (2012) 106–112) to predict the magnetocaloric effect in ferromagnetic material from the only measure of its magnetization as a function of temperature under an applied magnetic field. We questioned the reliability of that model. Based on some experimental data available in the literature, we have shown that, contrary to what is expected, the prediction of the magnetocaloric effect by this model is poor. 相似文献
20.
A kinematical model is necessary for understanding the gross structure of the coronal magnetic field and its slow evolution
in consistency with the small scale structure of the photospheric fields. Here we have developed a preliminary phenomenological
model in terms of flux tubes of flux amounts ≈ 1017 − 1018.5 Mx rising across the inner corona in the form of arches and opening out in the outer corona. In contrast to Parker’s estimate,
this model is consistent with the observed spans of the chromospheric fibrils and x-ray arches. It is also consistent with
the number of flux tubes present above the photosphere as estimated from the observed abundance of spicules. 相似文献