[en] We construct two flavor models based on S₄ family symmetry and generalised CP symmetry. In both models, the S₄ family symmetry is broken down to the Z₂^SU subgroup in the neutrino sector, as a consequence, the trimaximal TM₁ lepton mixing is produced. Depending on the free parameters in the flavon potential, the Dirac CP is predicted to be either conserved or maximally broken, and the Majorana CP phases are trivial. The two models differ in the neutrino sector. The flavon fields are involved in the Dirac mass terms at leading order in the first model, and the neutrino mass matrix contains three real parameters such that the absolute neutrino masses are fixed. Nevertheless, the flavon fields enter into the Majorana mass terms at leading order in the second model. The leading order lepton mixing is of the tri-bimaximal form which is broken down to TM₁ by the next to leading order contributions

[en] The interpretation of Y(4140) as a D^*_s anti D^*_s molecule is studied dynamically in the one boson exchange approach, where σ, η and φ exchange are included. Ten allowed D^*_s anti D^*_s states with low spin parity are considered, and we find that the J^PC=0⁺⁺, 1^+-, 0^-+, 2⁺⁺ and 1^-D^*_s anti D^*_s configurations are most tightly bound. We suggest that the most favorable quantum numbers are J^PC=0⁺⁺ for Y(4140) as a D^*_s anti D^*_s molecule; however, J^PC=0^-+ and 2⁺⁺ cannot be excluded. We propose to search for the 1^+- and 1^- partners in the J/ψη and J/ψη' final states, which is an important test of the molecular hypothesis of Y(4140) and the reasonability of our model. The 0⁺⁺B^*_s anti B^*_s molecule should be deeply bound; experimental search in the Υ(1S)φ channel at Tevatron and LHC is suggested. (orig.)

[en] The lepton flavor mixing matrix having one row or one column in common with the bimaximal mixing up to permutations is still compatible with the present neutrino oscillation data. We provide a thorough exploration of generating such a mixing matrix from S_4 family symmetry and generalized CP symmetry H_C_P. Supposing that S_4⋊H_C_P is broken down to Z_2"S"T""2"S"U×H_C_P"ν in the neutrino sector and Z_4"T"S"T""2"U⋊H_C_P"l in the charged lepton sector, one column of the PMNS matrix would be of the form (1/2,1/√2,1/2)"T up to permutations, both Dirac CP phase and Majorana CP phases are trivial to accommodate the observed lepton mixing angles. The phenomenological implications of the remnant symmetry K_4"("T"S"T""2","T""2"U")×H_C_P"ν in the neutrino sector and Z_2"S"U×H_C_P"l in the charged lepton sector are studied. One row of PMNS matrix is determined to be (1/2,1/2,−i/√2), and all the three leptonic CP phases can only be trivial to fit the measured values of the mixing angles. Two models based on S_4 family symmetry and generalized CP are constructed to implement these model independent predictions enforced by remnant symmetry. The correct mass hierarchy among the charged leptons is achieved. The vacuum alignment and higher order corrections are discussed.

[en] We study lepton mixing patterns which can be derived from the A_5 family symmetry and generalized CP. We find five phenomenologically interesting mixing patterns for which one column of the PMNS matrix is (√(((5+√5)/10)),(1/(√(5+√5))),(1/(√(5+√5))))"T (the first column of the golden ratio mixing), (√(((5−√5)/10)),(1/(√(5−√5))),(1/(√(5−√5))))"T (the second column of the golden ratio mixing), (1,1,1)"T/√3 or (√5+1,−2,√5−1)"T/4. The three lepton mixing angles are determined in terms of a single real parameter θ, and agreement with experimental data can be achieved for certain values of θ. The Dirac CP violating phase is predicted to be trivial or maximal while Majorana phases are trivial. We construct a supersymmetric model based on A_5 family symmetry and generalized CP. The lepton mixing is exactly the golden ratio pattern at leading order, and the mixing patterns of case III and case IV are reproduced after higher order corrections are considered.

[en] We have performed a comprehensive analysis of the type D group D_9_n_,_3_n"("1") as flavor symmetry and the generalized CP symmetry. All possible residual symmetries and their consequences for the prediction of the mixing parameters are studied. We find that only one type of mixing pattern is able to accommodate the measured values of the mixing angles in both “direct” and “variant of semidirect” approaches, and four types of mixing patterns are phenomenologically viable in the “semidirect” approach. The admissible values of the mixing angles as well as CP violating phases are studied in detail for each case. It is remarkable that the first two smallest D_9_n_,_3_n"("1") groups with n=1,2 can fit the experimental data very well. The phenomenological predictions for neutrinoless double beta decay are discussed.

[en] We discussed the scenario that a discrete flavor group combined with CP symmetry is broken to $Z_2\times <!--\; ??\; -->CP$ in both neutrino and charged lepton sectors. All lepton mixing angles and CP violation phases are predicted to depend on two free parameters ${\mathrm{\theta <!--\; ??\; -->}}_l$ and ${\mathrm{\theta <!--\; ??\; -->}}_{\mathrm{\nu <!--\; ??\; -->}}$ varying in the range of $[0,\mathrm{\pi <!--\; ??\; -->})$. As an example, we comprehensively study the lepton mixing patterns which can be derived from the flavor group $\mathrm{\Delta <!--\; ??\; -->}(6n^2)$ and CP symmetry. Three kinds of phenomenologically viable lepton mixing matrices are obtained up to row and column permutations. We further extend this approach to the quark sector. The precisely measured quark mixing angles and CP invariant can be accommodated for certain values of the free parameters ${\mathrm{\theta <!--\; ??\; -->}}_u$ and ${\mathrm{\theta <!--\; ??\; -->}}_d$. A simultaneous description of quark and lepton flavor mixing structures can be achieved from a common flavor group $\mathrm{\Delta <!--\; ??\; -->}(6n^2)$ and CP, and accordingly the smallest value of the group index $n$ is $n=7$.

[en] The unparticle stuff scenario related to the nontrivial IR fixed point in 4D-conformal field theory was recently suggested by Georgi. We illustrate its physical effects in the deep inelastic scattering (DIS) process. The possible signals of the unparticle related to parity violation asymmetry in DIS is investigated. It is found out that the behavior of this parity violation signal is sensitive to the value of the scale dimension d_U of the unparticle

[en] We have studied the lepton and quark mixing patterns which can be derived from the dihedral group D_n in combination with CP symmetry. The left-handed lepton and quark doublets are assigned to the direct sum of a singlet and a doublet of D_n. A unified description of the observed structure of the quark and lepton mixing can be achieved if the flavor group D_n and CP are broken to Z₂ × CP in neutrino, charged lepton, up quark and down quark sectors, and the minimal group is D₁₄. We also consider another scenario in which the residual symmetry of the charged lepton and up quark sector is Z₂ while Z₂ × CP remains preserved by the neutrino and down quark mass matrices. Then D₇ can give the experimentally favored values of CKM and PMNS mixing matrices.

[en] We extend the even weight modular forms of modular invariant approach to general integral weight modular forms. We find that the modular forms of integral weights and level N can be arranged into irreducible representations of the homogeneous finite modular group ${\mathrm{\Gamma <!--\; ??\; -->}}_N^{\mathrm{\prime <!--\; ???\; -->}}$ which is the double covering of Γ_N. The lowest weight 1 modular forms of level 3 are constructed in terms of Dedekind eta-function, and they transform as a doublet of ${\mathrm{\Gamma <!--\; ??\; -->}}_3^{\mathrm{\prime <!--\; ???\; -->}}$ ≅ T′. The modular forms of weights 2, 3, 4, 5 and 6 are presented. We build a model of lepton masses and mixing based on T′ modular symmetry.

[en] X(1835) has been treated as a baryonium with sizable gluon content, and to be almost flavor singlet. This picture allows us to rationally understand X(1835) production in J/ψ radiative decays, and its large couplings with p anti p,η'ππ. The processes Υ(1S)→ γX(1835) and J/ψ → ωX(1835) have been examined. It has been found that Br(Υ(1S)→ γX(1835))Br(X(1835)→p)<6.45 x 10^-7, which is compatible with CLEO's recent experimental result (Phys. Rev. D 73, 032001 (2006) hep-ex/0510015). The branching fractions Br(J/ψ→ωX(1835)), Br(J/ψ→ρX(1835)) with X(1835)→p anti p and X(1835)→η'π⁺π^- have been estimated by the quark-pair creation model. We show that they are heavily suppressed, so the signal of X(1835) is very difficult, if not impossible, to be observed in these processes. The experimental checks for these estimations are expected. The existence of the baryonium nonet is conjectured, and a model-independent derivation of their production branching fractions is presented. (orig.)