The chiral SUð3Þ Lagrangian with charmed baryons of spin J P ¼ 1=2 þ and J P ¼ 3=2 þ is analyzed. We consider all counterterms that are relevant at next-to-next-to-next-to-leading order (N 3 LO) in a chiral extrapolation of the charmed baryon masses. At N 2 LO we find 16 low-energy parameters. There are three mass parameters for the antitriplet and the two sextet baryons, six parameters describing the mesonbaryon vertices and seven symmetry breaking parameters. The heavy-quark spin symmetry predicts four sum rules for the meson-baryon vertices and degenerate masses for the two baryon sextet fields. Here a large-N c operator analysis at next-to-leading order (NLO) suggests the relevance of one further spin-symmetry breaking parameter. Going from N 2 LO to N 3 LO adds 53 ¼ 17 þ 36 parameters. For the leading symmetry conserving two-body counterterms involving two baryon fields and two Goldstone boson fields we find 36 terms. While the heavy-quark spin symmetry leads to 36 − 16 ¼ 20 sum rules, an expansion in 1=N c at NLO generates 36 − 7 ¼ 29 parameter relations. A combined expansion leaves six unknown parameters only. For the symmetry breaking counterterms we find 17 terms, for which there are 17 − 9 ¼ 8 sum rules from the heavy-quark spin symmetry and 17 − 5 ¼ 12 sum rules from a 1=N c expansion at NLO.

We consider a dynamical system of phantom scalar field under exponential potential in background of loop quantum cosmology. In our analysis, there is neither stable node nor repeller unstable node but only two saddle points, hence no Big Rip singularity. Physical solutions always possess potential energy greater than magnitude of the negative kinetic energy. We found that the universe bounces after accelerating even in the domination of the phantom field. After bouncing, the universe finally enters oscillatory regime.Comment: 8 pages, 6 figures, Revtex 4, Figures and References added. Version accepted by Physical Review D1

Several experimental investigations have observed parity violation in nuclear systems-a consequence of the weak force between quarks. We apply the 1/Nc expansion of QCD to the P-violating T-conserving component of the nucleon-nucleon (NN) potential. We show there are two leadingorder operators, both of which affect pp scattering at order Nc. We find an additional four operators at order N 0 c sin 2 θW and six at O(1/Nc). Pion exchange in the PV NN force is suppressed by 1/Nc and sin 2 θW , providing a quantitative explanation for its non-observation up to this time. The large-Nc hierarchy of other PV NN force mechanisms is consistent with estimates of the couplings in phenomenological models. The PV observed in pp scattering data is compatible with natural values for the strong and weak coupling constants: there is no evidence of fine tuning. The strong-nuclear and electromagnetic forces play the most prominent role in proton-proton (pp) scattering. There are also parity-violating (PV) pp interactions, which manifest the presence of weak interactions between the quarks inside each proton. Measurements of longitudinal beam asymmetries ∼ 10 and TRIUMF [3] demonstrate that PV nucleon-nucleon (NN) forces exist. PV in NN systems is also probed via an asymmetry in the reaction np → dγ [4,5]. And ab initio calculations of few-nucleon systems allow us to take models of the PV NN force and predict, e.g., the longitudinal asymmetry in 3 He( n, p) 3 H [6], which is soon to be measured [7]. Nuclear parity violation is also observed in, e.g., the radiative decay of the first excited state of 19 F, but there theoretical uncertainties in the relationship between the observable and the model of the PV NN force are harder to quantify. Much work has gone into constraining the PV NN force from a variety of nuclear experiments, see Refs. [8,9] for recent reviews.The prevailing paradigm in such analyses is based on single-meson exchange between nucleons, most commonly in the framework developed by Desplanques, Donoghue, and Holstein (DDH) [10]. The quantum numbers of the exchanged mesons determine the operator structures that contribute, while operator coefficients involve products of strong and weak meson-nucleonnucleon coupling constants. In this paper we show that Standard Model (SM) couplings and the 1/N c expansion of QCD predict the operators, and the sizes of the associated coefficients, which appear in the PV NN potential.An alternative framework-suitable for studying PV at very low energies-that systematizes pioneering studies [11,12] has recently emerged [13][14][15], but has, as yet, been applied to far fewer experiments. The extension of chiral perturbation theory to few-nucleon systems, χEFT [16] has also been invoked [17][18][19][20][21]. In χEFT the one-pion-exchange piece of the PV NN force dominates, with all other effects suppressed by two orders in the chiral expansion.One-pion exchange gives the long-distance parityconserving potential, and drives many of the properties of light nuclei. But, thus far, experiment...

The chiral SUð3Þ Lagrangian with pseudoscalar and vector D mesons and with the octet and decuplet baryons is considered. The leading two-body counter terms involving two baryon fields and two D meson fields are constructed in the open-charm sector. There are 26 terms. A combined expansion in the inverse of the charm quark mass and in the inverse of the number of colors provides sum rules that reduce the number of free parameters down to 5 only. Our result shows the feasibility of a systematic computation of the open-charm baryon spectrum based on coupled-channel dynamics.

The detection of gravitational waves (GWs) from a binary neutron star (BNS) has opened a new window on gravitational wave astronomy. With current sensitivities, detectable signals coming from compact objects like neutron stars turn out to be a crucial ingredient for probing their structure, composition, and evolution. Moreover, astronomical observations on pulsars and their mass–radius relations place important constraints on the dense matter equation of state. In this paper, we consider a homogeneous and unpaired charge-neutral three-flavor interacting quark matter with corrections that account for the moderately heavy strange quark instead of the naive MIT bag model. We perform a detailed analysis of strange quark stars in the context of the recently proposed 4D Einstein–Gauss–Bonnet (EGB) theory of gravity. However, this theory does not have standard 4D equations. Thus, we show that the equivalence of the actions in the regularized 4D EGB theory and in the original one is satisfied for a spherically symmetric spacetime. We pay particular attention to the possible existence of neutron stars of mass compatible with . Our findings suggest that the fourth-order correction parameter (a 4) of the quantum chromodynamic perturbation and coupling constant α of the GB term play an important role in the mass–radius relation as well as the stability of the quark star. Finally, we compare the results with the well-measured limits of pulsars and their mass and radius extracted from the spectra of several X-ray compact sources.

In this work, we analyze the epidemic data of cumulative infected cases collected from many countries as reported by WHO starting from January 21 st 2020 and up till March 21 st 2020. Our inspection is motivated by the renormalization group (RG) framework. Here we propose the RGinspired logistic function of the form αE(t) = a 1 + e −c(t−t 0 ) −n as an epidemic strength function with n being asymmetry in the modified logistic function. We perform the non-linear least-squares analysis with data from various countries. The uncertainty for model parameters is computed using the squared root of the corresponding diagonal components of the covariance matrix. We carefully divide countries under consideration into 2 categories based on the estimation of the inflection point: the maturing phase and the growth-dominated phase. We observe that long-term estimations of cumulative infected cases of countries in the maturing phase for both n = 1 and n = 1 are close to each other. We find from the value of root mean squared error (RMSE) that the RG-inspired logistic model with n = 1 is slightly preferable in this category. We also argue that n determines the characteristic of the epidemic at an early stage. However, in the second category, the estimated asymptotic number of cumulative infected cases contain rather large uncertainty. Therefore, in the growth-dominated phase, we focus on using n = 1 for countries in this phase. Some of them are in an early stage of an epidemic with an insufficient amount of data leading to a large uncertainty on parameter fits. In terms of the accuracy of the size estimation, the results do strongly depend on limitations on data collection and the epidemic phase for each country.

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In this work, we analyze the epidemic data of cumulative infected cases collected from many countries as reported by WHO starting from January 21st,2020 and up till March 21st,2020. Our inspection is motivated by the renormalization group (RG) framework. Here we propose the RG-inspired logistic function of the form αE(t) = a(1 + ec(t-t0))-n as an epidemic strength function with n being asymmetry in the modified logistic function. We perform the non-linear least-squares analysis with data from various countries. The uncertainty for model parameters is computed using the squared root of the corresponding diagonal components of the covariance matrix. We carefully divide countries under consideration into 2 categories based on the estimation of the inflection point: the maturing phase and the growth-dominated phase. We observe that long-term estimations of cumulative infected cases of countries in the maturing phase for both n=1 and n≠ 1 are close to each other. We find from the value of root mean squared error (RMSE) that the RG-inspired logistic model with n≠ 1 is slightly preferable in this category. We also argue that n determines the characteristic of the epidemic at an early stage. However, in the second category, the estimated asymptotic number of cumulative infected cases contain rather large uncertainty. Therefore, in the growth-dominated phase, we focus on using n≠ 1 for countries in this phase. Some of them are in an early stage of an epidemic with an insufficient amount of data leading to a large uncertainty on parameter fits. In terms of the accuracy of the size estimation, the results do strongly depend on limitations on data collection and the epidemic phase for each country.