15927966
Exotic and higher spin mesons in charmonium
Exotic and higher spin (> 1) mesons are still not thoroughly investigated in lattice QCD. Using a set of derivative based operators we report our exploratory study of these mesons in charmonium region. We use a 12{sup 3} x 48 anisotropic (xi = 3) clover lattice with inverse temporal lattice spacing a{sup -1} = 6.05 GeV. Techniques developed in this exploratory study will be utilized in our future comprehensive study of light hybrid mesons that are to be explored in the 12 GeV GlueX experiment at Jefferson Laboratory.
14262604
Hybrid meson production by electromagnetic and weak interactions in a flux tube simulation of lattice QCD
We calculate rates for hybrid meson production by electromagnetic and weak interactions in the flux-tube model. Applications include photo and electroproduction at Jefferson Laboratory and HERA, and the production of light strange and charmed hybrids in the weak decays of heavy flavours. Photoproduction of some light hybrids is predicted to be prominent in charge exchange reactions, $\gamma p \to n \cal{H}$ and accessible in $\gamma p \to p \cal{H}$. Production of light or charmed hybrids in $B$ and $D$ decays may be feasible with high statistics. Photoproduction of the axial hybrid meson is predicted to be large courtesy of $\pi$ exchange, and its strange counterpart is predicted in $B \to \psi K_H(1^+)$ with $b.r. \sim 10^{-4}$. Production rates for exotic hybrid candidates $1^{-+};(0,2)^{+-}$ are given special attention. Selection rules that can help to distinguish between hybrid and conventional states with the same $J^{PC}$ are noted.
125997156
Charmonium Radiative Physics
15493314
Pentaquark implications for exotic mesons
If the exotic baryon {theta}{sup +}(1540) is a correlated ududs with J{sup P}=(1{sup +}/2), then there should exist an exotic meson {theta}{sup +} with strangeness +2, J{sup P}=1{sup -}, mass {approx}1.6 GeV, decaying to K{sup +}K{sup 0} with width O(10-100) MeV. The {pi}{sub 1}(1400;1600) may be broad members of 10{+-}10 in such a picture, and it is possible that vector mesons in the 1.4-1.7 GeV mass range are related to this multiplet. We suggest that dynamical correlations may limit the spectrum of J{sup P(C)} such that the 1{sup -({+-}}{sup )} states are isolated.
120601853
Radiative Physics in Charmonium from Lattice QCD
Charmonium is an attractive system for the application of lattice QCD methods owing to the possibility of computing with the physical quark mass in a reasonable time. While the sub-threshold spectrum has been considered in some detail in previous works, it is only very recently that further properties such as radiative transitions and two-photon decays have come to be calculated; herein we discuss this recent progress.
16434102
Pentaquark symmetries, selection rules and another potentially narrow state
Abstract We identify essential differences between the pentaquark and chiral soliton models of 10 5 and 8 5 pentaquarks and conventional 8 3 states, which are experimentally measurable. We show how the decays of Ξ5 states in particular can test models of the pentaquarks, recommend study of the relative branching ratios of, e.g., Ξ − 5 →Ξ − π 0 :Ξ 0 π − , and predict that the decay amplitude Ξ 5 →Ξ ∗ π is zero at leading order in pentaquark models for any mixture of 10 and the associated 8 5 . We also include a pedagogic discussion of wavefunctions in the pentaquark picture and show that pentaquark models have this 8 5 with F/D=1/3, in leading order forbidding Ξ5→ΛK. The role of Fermi–Dirac symmetry in the qqqq wavefunction and its implications for the width of pentaquarks are briefly discussed. The relative couplings g 2 (Θ Q NK Q ∗ )/g 2 (Θ Q NK Q )=3 for Q≡s,c,b. A further potentially narrow state Λ in 8 5 with JP=3/2+ is predicted around 1650 MeV.
42987743
Nuclear tetrahedral symmetry: possibly present throughout the periodic table.
More than half a century after the fundamental, spherical shell structure in nuclei had been established, theoretical predictions indicated that the shell gaps comparable or even stronger than those at spherical shapes may exist. Group-theoretical analysis supported by realistic mean-field calculations indicate that the corresponding nuclei are characterized by the TD(d) ("double-tetrahedral") symmetry group. Strong shell-gap structure is enhanced by the existence of the four-dimensional irreducible representations of TD(d); it can be seen as a geometrical effect that does not depend on a particular realization of the mean field. Possibilities of discovering the TD(d) symmetry in experiment are discussed.
18843760
Atomic Nuclei with Tetrahedral and Octahedral Symmetries
We present possible manifestations of octahedral and tetrahedral symmetries in nuclei. These symmetries are associated with the OhD and TdD double point groups. Both of them have very characteristic finger-prints in terms of the nucleonic level properties - unique in the Fermionic universe. The tetrahedral symmetry leads to the four-fold degeneracies in the nucleonic spectra; it does not preserve the parity. The octahedral symmetry leads to the four-fold degeneracies in the nucleonic spectra as well but it does preserve the parity. 
Microscopic predictions have been obtained using mean-field theory based on the relativistic equations and confirmed by using 'traditional' Schroedinger equation formalism. Calculations are performed in multidimensional deformation spaces using newly designed algorithms. 
We discuss some experimental fingerprints of the hypothetical new symmetries and possibilities of their verification through experiments.
119434628
Superdeformed bands in S-32 and neighboring nuclei predicted within the Hartree-Fock method
Superdeformed configurations in 32S, and in neighboring nuclei 33S, 31S, 33Cl, and 31P, are determined within the Hartree-Fock approach with the Skyrme interaction. Energies, angular momenta, quadrupole moments, particle-emission Q-values, and relative alignments and quadrupole moments are calculated for a number of superdeformed rotational bands in these nuclei. A new mechanism implying an existence of signature-separated rotational bands, distinct from the well-known signature-split bands, is discussed and associated with the time-odd channels of effective interactions.
121709694
Extended investigation of superdeformed bands in Tb-151,Tb-152 nuclei
A detailed study of known and new SD bands in Tb isotopes has been performed with the use of the EUROBALL IV gamma-ray array. The high-statistics data set has allowed for the extension of known SD bands at low and high spins by new gamma-ray transitions. These transitions, as it turns out, correspond to the rotational frequencies where the principal superdeformed gaps (Z=66,N=86) close giving rise to up- or down-bending mechanisms. This enables to attribute the underlying theoretical configurations with much higher confidence as compared to the previous identifications. Five new SD bands have been discovered, three of them assigned to the Tb-152 and the two others to the Tb-151 nuclei. Nuclear mean-field calculations have been used to interpret the structure of known SD bands as well as of the new ones in terms of nucleonic configurations.
119453196
Search for the Jacobi shape transition in light nuclei
Abstract.The $\gamma$-rays following the reaction 105 MeV 18O + 28Si have been measured using the EUROBALL IV, HECTOR and EUCLIDES arrays in order to investigate the predicted Jacobi shape transition. The high-energy $\gamma$-ray spectrum from the GDR decay indicates the presence of large deformations in the hot 46Ti nucleus, in agreement with new theoretical calculations based on the rotating liquid-drop model.