53591668
Liquid-gas phase transition in nuclear matter including strangeness
We apply the chiral SU(3) quark mean field model to study the properties of strange hadronic matter at finite temperature. The liquid-gas phase transition is studied as a function of the strangeness fraction. The pressure of the system cannot remain constant during the phase transition, since there are two independent conserved charges (baryon and strangeness number). In a range of temperatures around 15 MeV (precise values depending on the model used) the equation of state exhibits multiple bifurcates. The difference in the strangeness fraction f{sub s} between the liquid and gas phases is small when they coexist. The critical temperature of strange matter turns out to be a nontrivial function of the strangeness fraction.
123370023
Chiral symmetry restoration of nuclear matter
The phase transition of chiral symmetry restoration of nuclear matter is studied in the chiral SU(3) quark mean field model. For some kinds of confining potentials, there exists a critical density ρc. When the baryon density is larger than ρc, nuclear matter will be in the phase of chiral symmetry restoration. At critical density, the physical quantities change discontinuously. The critical density will become larger when the vector part of the confining potential increases.
117796835
Static three-body potential in baryons
The first principle of quantum chromodynamics is used to calculate the static perturbative three-body potential between three valence quarks in baryons, which is gauge invariant and flavor-dependent, and of magnitude of the same order as the next non-leading static q-q potential. Its effect on an S-state baryon composed of three valence quarks of equal mass may be viewed as a slight increase of the constituent quark masses with respect to those in mesons.
121124456
An Extended Chiral SU(3) Quark Model
The chiral SU(3) quark model is extended by including the vector meson exchanges to describe the short range interactions. The phase shifts of NN scattering are studied in this model. Compared with the results of the chiral SU(3) quark model in which only the pseudo-scalar and scalar chiral fields are considered, the phase shifts of 1S0 wave are obviously improved.
118632293
Nucleon magnetic form factors with non-local chiral effective Lagrangian
Chiral perturbation theory is a useful method to investigate the hadron properties. We apply the non-local chiral effective Lagrangian to study the nucleon magnetic form factors. The octet and decuplet intermediate states are included in the one-loop calculation. With the modified propagators and non-local interaction, the loop integral is convergent. The obtained proton and neutron magnetic form factors are both reasonable up to relatively large Q2.
121034531
Strange hadronic matter in a chiral model
The strange hadronic matter with nucleon, Λ-hyperon and Ξ-hyperon is studied by using a chiral symmetry model in a mean-field approximation. The saturation properties and stabilities of the strange hadronic matter are discussed. The result indicates a quite large strangeness fraction (fS) region where the strange hadronic matter is stable against particle emission. In the large fS region, the Ξ component dominates, resulting in a deep minimum in the curve of the binding energy per baryon EB versus the strangeness fraction fS with (EB, fS) (-26.0 MeV, 1.23).
15056774
NN interactions in the extended chiral SU(3) quark model
Abstract The chiral SU (3) quark model is extended to include coupling between vector chiral field and quarks. By using this model, the phase shifts of NN scattering for different partial waves are studied. The results are very similar to those of the chiral SU (3) quark model calculation, in which one gluon exchange (OGE) plays dominate role in the short range part of the quark–quark interactions. Only in the 1 S 0 case, the one channel phase shifts of the extended chiral SU (3) quark model are obviously improved.
118915362
The Interference between continuum and resonance in e+ e- ---> c anti-c experiment
e+e- experiments at charmonium production threshold are reviewed, it is found that the contribution of the continuum process via virtual photon has been neglected in almost all the experiments and most channels analyzed. It is pointed out that the contribution of the continuum part may affect the final results significantly in psi(2S) and psi(3770) decays, while the interference between the continuum amplitude and the resonance amplitude may even affect the J/psi decays as well as the psi(2S) and psi(3770). This leads to the revise of the analysis of strong and electromagnetic amplitude in psi(2S) decays, including psi(2S) ->VP which is the long lasting puzzle between J/psi and psi(2S) decays. For psi(3770) physics, a large constructive interference for light hadron modes and destructive interference for DDbar could be responsible for the discrepancy between the larger cross section of inclusive hadrons by direct measurement of e+e- -> psi(3770)-> hadrons than the DDbar cross section measured using D single-tag and double-tag method.
25602732
Measurement of the differential branching fraction and forward-backward asymmetry for B --> K(*)l+l-.
We study B --> K(*)l+l- decays (l = e, mu) based on a data sample of 657 x 10(6) BB pairs collected with the Belle detector at the KEKB e+e- collider. We report the differential branching fraction, isospin asymmetry, K* polarization, and the forward-backward asymmetry (A(FB)) as functions of q2 = M(ll)(2)c2. The fitted A(FB) spectrum exceeds the standard model expectation by 2.7 standard deviations. The measured branching fractions are B(B --> K*l+l-) = (10.7(-1.0)(+1.1) +/- 0.9) x 10(-7) and B(B --> Kl+l-) = (4.8(-0.4)(+0.5) +/- 0.3) x 10(-7), where the first errors are statistical and the second are systematic, with the muon to electron ratios R(K*) = 0.83 +/- 0.17 +/- 0.08 and R(K) = 1.03 +/- 0.19 +/- 0.06.
625243
CosmoMC Installation and Running Guidelines
CosmoMC is a Fortran 95 Markov-Chain Monte-Carlo (MCMC) engine to explore the cosmological parameter space, plus a Python suite for plotting and presenting results (see this http URL). This document describes the installation of the CosmoMC on a Linux system (Ubuntu 14.04.1 LTS 64-bit version). It is written for those who want to use it in their scientific research but without much training on Linux and the program. Besides a step-by-step installation guide, we also give a brief introduction of how to run the program on both a desktop and a cluster. We share our way to generate the plots that are commonly used in the references of cosmology. For more information, one can refer to the CosmoCoffee forum (this http URL) or contact the authors of this document. Questions and comments would be much appreciated.
53723212
Search for doubly charmed baryons and study of charmed strange baryons at Belle
We report results of a study of doubly charmed baryons and charmed strange baryons. The analysis is performed using a 980 fb(-1) data sample collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. We search for doubly charmed baryons Xi(+(+))(cc) with the Lambda(+)(c) K- pi(+)(pi(+) ) and. Xi(0)(c) pi(+)(pi(+)) final states. No significant signal is observed. We also search for two excited charmed strange baryons, Xi(c)(3055)(+) and Xi(c)(3123)(+) with the Sigma(++)(c)(2455)K- and Sigma(++)(c)(2520)K- final states. The Xi(c)(3055)(+) signal is observed with a significance of 6.6 standard deviations including systematic uncertainty, while no signature of the Xi(c)(3123)(+) is seen. We also study properties of the Xi(c)(2645)(+) and measure a width of 2.6 +/- 0.2(stat) +/- 0.4(syst) MeV/c(2), which is the first significant determination.