Ωcγ→Ωc∗\Omega_c \gamma \rightarrow\Omega_c^\ast transition in lattice QCD

We study the electromagnetic $\Omega_c \gamma \rightarrow\Omega_c^\ast$ transition in 2+1 flavor lattice QCD, which gives access to the dominant decay mode of $\Omega_c^\ast$ baryon. The magnetic dipole and the electric quadrupole transition form factors are computed. The magnetic dipole form factor is found to be mainly determined by the strange quark and the electric quadrupole form factor to be negligibly small, in consistency with the quark model. We also evaluate the helicity amplitudes and the decay rate.Comment: 8 pages, 1 figure. Added references and discussio

A look inside charmed-strange baryons from lattice QCD

The electromagnetic form factors of the spin-3/2 $\Omega$ baryons, namely $\Omega$, $\Omega_c^\ast$, $\Omega_{cc}^\ast$ and $\Omega_{ccc}$, are calculated in full QCD on $32^3\times 64$ PACS-CS lattices with a pion mass of 156(9) MeV. The electric charge radii and magnetic moments from the $E0$ and $M1$ multipole form factors are extracted. Results for the electric quadrupole form factors, $E2$, are also given. Quark sector contributions are computed individually for each observable and then combined to obtain the baryon properties. We find that the charm quark contributions are systematically smaller than the strange-quark contributions in the case of the charge radii and magnetic moments. $E2$ moments of the $\Omega_{cc}^\ast$ and $\Omega_{ccc}$ provide a statistically significant data to conclude that their electric charge distributions are deformed to an oblate shape. Properties of the spin-1/2 $\Omega_c$ and $\Omega_{cc}$ baryons are also computed and a thorough comparison is given. This complete study gives valuable hints about the heavy-quark dynamics in charmed hadrons.Comment: 14 pages, 14 figures. Includes a subsection on the systematic effect

Electromagnetic structure of charmed baryons in Lattice QCD

As a continuation of our recent work on the electromagnetic properties of the doubly charmed $\Xi_{cc}$ baryon, we compute the charge radii and the magnetic moments of the singly charmed $\Sigma_c$, $\Omega_c$ and the doubly charmed $\Omega_{cc}$ baryons in 2+1 flavor Lattice QCD. In general, the charmed baryons are found to be compact as compared to the proton. The charm quark acts to decrease the size of the baryons to smaller values. We discuss the mechanism behind the dependence of the charge radii on the light valence- and sea-quark masses. The magnetic moments are found to be almost stable with respect to changing quark mass. We investigate the individual quark sector contributions to the charge radii and the magnetic moments. The magnetic moments of the singly charmed baryons are found to be dominantly determined by the light quark and the role of the charm quark is significantly enhanced for the doubly charmed baryons.Comment: Updated results, improved analysis. Version to appear in JHE

Electromagnetic properties of doubly charmed baryons in Lattice QCD

We compute the electromagnetic properties of \Xi_cc baryons in 2+1 flavor Lattice QCD. By measuring the electric charge and magnetic form factors of \Xi_cc baryons, we extract the magnetic moments, charge and magnetic radii as well as the \Xi_cc \Xi_cc \rho coupling constant, which provide important information to understand the size, shape and couplings of the doubly charmed baryons. We find that the two heavy charm quarks drive the charge radii and the magnetic moment of \Xi_cc to smaller values as compared to those of, e.g., the proton.Comment: 15 pages, 5 figures; added discussions and references, version accepted by PL

Vector and axial-vector couplings of D and D* mesons in 2+1 flavor Lattice QCD

Using the axial-vector coupling and the electromagnetic form factors of the D and D* mesons in 2+1 flavor Lattice QCD, we compute the D*D\pi, DD\rho and D*D*\rho coupling constants, which play an important role in describing the charm hadron interactions in terms of meson-exchange models. We also extract the charge radii of D and D* mesons and determine the contributions of the light and charm quarks separately.Comment: 19 pages, 3 figures; added references and comments, published versio

Numerical observation of non-axisymmetric vesicles in fluid membranes

By means of Surface Evolver (Exp. Math,1,141 1992), a software package of brute-force energy minimization over a triangulated surface developed by the geometry center of University of Minnesota, we have numerically searched the non-axisymmetric shapes under the Helfrich spontaneous curvature (SC) energy model. We show for the first time there are abundant mechanically stable non-axisymmetric vesicles in SC model, including regular ones with intrinsic geometric symmetry and complex irregular ones. We report in this paper several interesting shapes including a corniculate shape with six corns, a quadri-concave shape, a shape resembling sickle cells, and a shape resembling acanthocytes. As far as we know, these shapes have not been theoretically obtained by any curvature model before. In addition, the role of the spontaneous curvature in the formation of irregular crenated vesicles has been studied. The results shows a positive spontaneous curvature may be a necessary condition to keep an irregular crenated shape being mechanically stable.Comment: RevTex, 14 pages. A hard copy of 8 figures is available on reques

Non-spherical shapes of capsules within a fourth-order curvature model

We minimize a discrete version of the fourth-order curvature based Landau free energy by extending Brakke's Surface Evolver. This model predicts spherical as well as non-spherical shapes with dimples, bumps and ridges to be the energy minimizers. Our results suggest that the buckling and faceting transitions, usually associated with crystalline matter, can also be an intrinsic property of non-crystalline membranes.Comment: 6 pages, 4 figures (LaTeX macros EPJ), accepted for publication in EPJ

Radiative transitions of doubly charmed baryons in lattice QCD

We evaluate the spin-3/2→spin-1/2 electromagnetic transitions of the doubly charmed baryons on 2+1 flavor, 323×64 PACS-CS lattices with a pion mass of 156(9) MeV/c2. A relativistic heavy quark action is employed to minimize the associated systematic errors on charm-quark observables. We extract the magnetic dipole, M1, and the electric quadrupole, E2, transition form factors. In order to make a reliable estimate of the M1 form factor, we carry out an analysis by including the effect of excited-state contributions. We find that the M1 transition is dominant and light degrees of freedom (u/d- or s-quark) play the leading role. E2 form factors, on the other hand, are found to be negligibly small, which in turn, have a minimal effect on the helicity and transition amplitudes. We predict the decay widths and lifetimes of Ξcc∗+,++ and Ωcc∗+ based on our results. Finite size effects on these ensembles are expected to be around 1%. Differences in kinematical and dynamical factors with respect to the Nγ→Δ transition are discussed and compared to nonlattice determinations while keeping possible systematic artifacts in mind. A comparison to Ωcγ→Ωc∗ transition and a discussion on systematic errors related to the choice of heavy quark action are also given. Results we present here are particularly suggestive for experimental facilities such as LHCb, PANDA, Belle II, and BESIII to search for further states.TÜBİTAK ; KAKENHIPublisher versio

Inoculation response of mycorrhizas on morphology and physiological behaviour of trifoliate orange (Poncirus trifoliata) roots under salt stress

Citrus is highly sensitive to salt stress, and little efforts have been successful microbiologically to mitigate such abiotic stress. In this background, trifoliate orange [Poncirus trifoliata (L.) Raf.] seedlings were inoculated with Diversispora versiformis and exposed to 100 mM NaCl treatment for 85 days under controlled conditions. The NaCl application, though, strongly inhibited root mycorrhizal colonization in seedlings, but mycorrhizal inoculation considerably increased the root projected area and number of second- and third-order lateral roots under 100 mM NaCl treatment. Mycorrhizal-inoculated seedlings showed significantly higher soluble protein concentration, ornithine decarboxylase, arginine decarboxylase, and superoxide dismutase activity in leaves and roots, irrespective of NaCl concentration. While mycorrhizal seedlings displayed significantly lower polyamine oxidase activity and diamine oxidase activity in leaves and roots, irrespective of NaCl concentration. These results, thus, suggested that mycorrhizal plants were physiologically activated through mycorrhizal inoculation to downplay the adverse effect of salt stress