Neutron-proton momentum correlation functions are constructed from three-body photodisintegration channel, i.e.
Enthused by the availability of the recent experimental as well as theoretical data on the energy levels of odd-mass 151-161Pm and odd-odd 154,156Pm, we applied the theoretical framework of the Projected Shell Model with the aim to further understand the nuclear structure of these nuclei. The calculations have reproduced well the experimental data reported on the yrast bands of these isotopes by assuming an axial (prolate) deformation of ~0.3. Other properties along the yrast line, such as transition energies, transition probabilities, etc., have also been discussed. Band diagrams are plotted to understand their intrinsic multi-quasiparticle structure which turn out to be dominated by 1-quasiparticle bands for the odd-mass Pm isotopes and 2-quasiparticle bands for doubly-odd Pm isotopes under study. The present study has not only confirmed the recently reported experimental/ theoretical data but also extended the already available information on the energy levels and added new information on the reduced transition probabilities.
We reduce all the most complicated Feynman integrals in two-loop five-light-parton scattering amplitudes to basic master integrals, while other integrals can be reduced even more easily. Our results are expressed as systems of linear relations in block-triangular form, which are very efficient for numerical calculation. Our results are crucial for complete next-to-next-to-leading order QCD calculation for three jets, photons, or hadrons production at hadron colliders. In order to find out the block-triangular relations, we develop a new method which is efficient and general. The method may provide a practical solution for the bottleneck problem of reducing multiloop multiscale integrals.
High transverse momentum (
By studying the
The survival probability of excited compound nucleus was studied by using two different approaches of shell effect washing out with excitation energy based on superasymmetric reaction system. The estimated evaporation residue cross sections based on the two different methods are compared with the available experimental data, and both methods agree with experimental data to some extent for some specific reactions and
We develop a covariant kinetic theory for massive fermions in curved spacetime and external electromagnetic field based on quantum field theory. We derive four coupled semi-classical kinetic equations accurate at
The scenario of two components warm tachyon inflation is considered where the tachyon field plays the role of inflaton and drives inflation. During inflation, the tachyon scalar field interacts with the other component of the Universe which is considered as photon gas, i.e. radiation. The interacting term contains a dissipation coefficient, and the study is modeled based on two different and familiar choices of the coefficient that have been studied in the literature. By applying the latest observational data, the acceptable ranges for the free parameters of the model are obtained. For any choice inside the estimated ranges, there is an acceptable concordance between the theoretical predictions and observations. Whereas the model is established based on some assumptions, it is vital to check their validity for the obtained values of the free parameters of the model. It is realized that the model is not self-consistent for all values of the ranges and sometimes the assumptions are violated. Therefore, to have both self-consistency and agreement with data the parameters of the model need to be constrained again. After that, we are going to consider the recently proposed swampland conjecture, which imposes two conditions on the inflationary models. These criteria could rule out some of the inflationary models, however, warm inflation is known as one of those models that could successfully satisfy the swampland criteria. A precise investigation determines that the proposed warm tachyon inflation could not satisfy the swampland criteria for some cases. In fact, for the first case of the dissipation coefficient, where there is dependency only on the scalar field, the model could agree with observational data, however, it is in direct tension with the swampland criteria. But, for the second case where the dissipation coefficient has a dependency on both scalar field and temperature, the model shows an acceptable agreement with observational data and it could properly satisfy the swampland criteria.
Quasinormal modes (QNMs) for massless and massive Dirac perturbations of Born-Infeld black holes (BHs) in higher dimensions are investigated. Solving the corresponding master equation in accordance hypergeometric functions and the QNMs are evaluated. We pay more attention to discuss the relationships between QNM frequencies and spacetime dimension. Meanwhile, we discuss the stability of the Born-Infeld BH by calculating the temporal evolution of the perturbation field. Both the perturbation frequencies and the decay rate increase with the enhance of the dimension of spacetime n. This shows that the Born-Infeld BHs become more and more unstable in higher dimensions. Furthermore, the traditional finite difference method is improved, so that it can be used to calculate massive Dirac field. And we elucidate the dynamical evolution of Born-Infeld BHs in massive Dirac field. Because the number of extra dimensions is related to the string scale, there is a relationship between spacetime dimension n and the properties of Born-Infeld BHs which might be advantageous to the development of extra-dimensional brane worlds and string theory.
In this work, we have performed Skyrme density functional theory (DFT) calculations of nuclei around 132Sn to study whether the abnormal odd-even staggering (OES) behavior of binding energies around N = 82 can be reproduced. With the Skyrme force SLy4 and SkM*, we test the volume- and surface-type of pairing forces, and also the intermediate between these two pairing forces, in the Hartree-Fock-Bogoliubov (HFB) approximation with or without the Lipkin-Nogami (LN) approximation or particle number projection after the convergence of HFBLN (PLN). The UNEDF parameter sets are also used. The trend of the neutron OES against the neutron number or proton number does not change much, by tuning the density dependence of the pairing force. And, for the pairing force which is more favoured at the nuclear surface, the larger mass OES is obtained, and vice versa. It seems that the mix between the volume and surface pairing can give better agreement with data. In the studies of the OES, larger ratio of the surface to volume pairing might be favoured. And, in most cases, the OES given by the HFBLN approximation agrees better with the experimental data. We found that both the Skyrme and pairing forces can influence the OES behavior. The mass OES calculated by the UNEDF DFT is explictly smaller than the experimental one. UNEDF1 and UNEDF2 force can reproduce the experimental trend of the abnormal OES around 132Sn. The neutron OES of the tin isotopes given by SkM* force agrees better with the experimental one than that by SLy4 force, in most cases. Both SLy4 and SkM* DFT have difficulties to reproduce the abnormal OES around 132Sn. By the PLN method, the systematics of OES is improved for several combinations of the Skyrme and pairing forces.
We show that the scotogenic dark symmetry can be obtained as a residual subgroup of the global
We investigate the invariant-mass distribution of top-quark pairs near the 2mt threshold, which has strong impact on the determination of the top-quark mass mt. We show that higher-order nonrelativistic corrections lead to large contributions which are not included in the state-of-the-art theoretical predictions. We derive a factorization formula to resum such corrections to all orders in the strong-coupling, and calculate necessary ingredients to perform the resummation at next-to-leading power. We combine the resummation with fixed-order results and present phenomenologically relevant numeric results. We find that the resummation effect significantly enhances the differential cross section in the threshold region, and makes the theoretical prediction more compatible with experimental data. We estimate that using our prediction in the determination of mt will lead to a value closer to the result of direct measurement.
Banerjee-Ghosh's work shows that the singularity problem can be naturally avoided by the fact that the black hole evaporation stops at the remnant mass greater than the critical mass when including the GUP effects with the first- and second-order corrections. In this paper, we first follow their steps to reexamine the Banerjee-Ghosh's work, but find an interesting result that the remnant mass is always equal to the critical mass at the final stage of the black hole evaporation with the inclusion of the GUP effects. Then, we use the Hossenfelder's GUP, i.e. another GUP model with higher-order corrections, to restudy the final evolution behavior of the black hole evaporation, and confirm the intrinsic self-consistency between the black hole remnant and critical mass once more. In both cases, we also find that the thermodynamic quantities are not singular at the final stage of the black hole evaporation.
We investigate the strongly coupled minimal walking technicolor model (MWT) in the framework of a bottom-up holographic model, where the global
We study chiral magnetic effect in collisions of AuAu, RuRu and ZrZr at
Based on the idea of the black hole molecule proposed in [Phys. Rev. Lett. 115 (2015) 111302], in this paper, by choosing the appropriate extensive variables, we have solved the puzzle whether the molecules of the Reissner-Nordström black hole is an interaction or not through the Ruppeiner thermodynamic geometry. Our results show that the Reissner-Nordström black hole is indeed an interaction system that may be dominated by repulsive interaction. More importantly, with the help of a new quantity, thermal-charge density, we describe the fine micro-thermal structures of the Reissner-Nordström black hole in detail. It presents three different phases, the free, interactive and balanced phases. The thermal-charge density plays a role similar to the order parameter, and the back hole undergoes a new phase transition between the free phase and interactive phase. The competition between the free phase and interactive phase exists, which leads to the extreme behavior of the temperature of the Reissner-Nordström black hole. For extreme Reissner-Nordström black hole, the whole system is completely in the interactive phase. What is more significant is that we provide the thermodynamic micro-mechanism for the formation of the naked singularity of the Reissner-Nordström black hole.
The ambition of the present work is to highlight the phenomena of strong gravitational lensing and deflection angle for the photons coupling with Weyl tensor in a Kiselev black hole. Here, we have extended the prior work of Chen and Jing [
In this work, we systematically study the
We study the rare decays
In this exploratory study, two photon decay widths of pseudo-scalar (
Inspired by [
A DGP brane-world model with a perfect fluid brane matter including a Brans-Dicke (BD) scalar field on brane has been utilized to investigate the problem of the quark-hadron phase (QHP) transition in early times of the Universe evolution. The presence of the BD scalar field comes up with some modification terms in the Friedmann equation. Since the behavior of phase transition strongly depends on the basic evolution equations, even a small change in these relations might come to interesting results about the time of transition. The phase transition is investigated using two scenarios of the first-order phase transition and smooth crossover phase transition. For first-order scenario, which is used for intermediate temperature regime, the evolution of the physical quantities, such as temperature and scale factor, are investigated before, during and after the phase transition. The results show that the transition occurs in about micro-second. In the next part, the phenomenon is studied by assuming a smooth crossover transition where the lattice QCD data is utilized to obtain a realistic equation of state for the matter. The investigation for this part is performed in two regimes of high and low-temperature. Using trace anomaly in the high-temperature regime specifies a simple equation of state which states that the quark-gluon behaves like radiation. However, in the low-temperature regime, the trace anomaly is affected by discretization effects, and the hadron resonance gas model is utilized instead. Using this model, a more realistic equation of state could be found in the low-temperature regime. The crossover phase transition in both regimes is considered. The results determine that the transition occurs at the time around a few micro-second. Also, it is realized that the transition in the low-temperature regime occurs after the transition in the high-temperature regime.
With partially restored isospin symmetry, we calculate the nuclear matrix element for a special decay mode of 2νββ (two neutrino double beta decay) – the decay to the first 2+ excited states. With the realistic CD-Bonn nuclear force, we analyze the dependence of the nuclear matrix elements on the iso-vector and iso-scalar parts of proton-neutron particle-particle interaction. The dependence on the different nuclear matrix element is observed and the results are explained. We also give the phase space factors with numerical electron wave functions and properly chosen excitation energies. Finally we give our results for the half-lives of this decay mode for different nuclei.
The relativistic mean field theory with the Green's function method is taken to study the single-particle resonant states. Different from our previous work [Phys.Rev.C 90,054321(2014)], the resonant states are identified by searching for the poles of Green's function or the extremes of the density of states. This new approach is very effective for all kinds of resonant states, no matter it is broad or narrow. The dependence on the space size for the resonant energies, widths, and the density distributions in the coordinate space has been checked and it is found very stable. Taking
The preference of the normal neutrino mass ordering from the recent cosmological constraint and the global fit of neutrino oscillation experiments does not seem like a wise choice at first glance since it obscures the neutrinoless double beta decay and hence the Majorana nature of neutrinos. Contrary to this naive expectation, we point out that the actual situation is the opposite. The normal ordering opens the possibility of excluding the higher solar octant and simultaneously measuring the two Majorana CP phases in future
In this paper, we investigate the tensor form factors of
We construct an alternative uniformly accelerated reference frame based on 3+1 formalism in adapted coordinate. It is distinguished with Rindler coordinate that there is time-dependent redshift drift between co-moving observers. The experimentally falsifiable distinguishment might promote our understanding of non-inertial frame in laboratory.
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