4,127 research outputs found

    The H→bsˉH\rightarrow b\bar{s} decay and its implication for the vector-like singlet fermion model

    Full text link
    The decay width H→bsˉH\rightarrow b\bar{s} is firstly evaluated at leading order perturbation theory in the standard model. The result suggests that it is difficult to observe this mode because of the small width compared with other decays of the Higgs boson. Then based on the vector-like singlet model, assuming that the top partner only mixes with the third generation quark, we consider the contribution from coupling of top quark to its vector-like singlet partner. Further results show that the width of H→bsˉH\rightarrow b\bar{s} may rise to an extent to which the LHC experiments can accesses.Comment: 21 pages, 6 figure

    Quotients with respect to strongly LL-subgyrogroups

    Full text link
    A topological gyrogroup is a gyrogroup endowed with a compatible topology such that the multiplication is jointly continuous and the inverse is continuous. In this paper, we study the quotient gyrogroups in topological gyrogroups with respect to strongly LL-subgyrogroups, and prove that let (G,τ,⊕)(G, \tau,\oplus) be a topological gyrogroup and HH a closed strongly LL-subgyrogroup of GG, then the natural homomorphism π\pi from a topological gyrogroup GG to its quotient topology on G/HG/H is an open and continuous mapping, and G/HG/H is a homogeneous T1T_1-space. We also establish that for a locally compact strongly LL-subgyrogroup HH of a topological gyrogroup GG, the natural quotient mapping π\pi of GG onto the quotient space G/HG/H is a locally perfect mapping. This leads us to some interesting results on how properties of GG depend on the properties of G/HG/H. Some classical results in topological groups are generalized.Comment: 10. arXiv admin note: substantial text overlap with arXiv:2003.08843 by other authors; text overlap with arXiv:2204.02079 by other author

    On the continuity of the inverse in (strongly) paratopological gyrogroups

    Full text link
    In this paper, we consider the continuity of the inverse in (strongly) paratopological gyrogroups. The conclusions are established as follows: (1)\, Every pseudocompact Tychonoff strongly paratopological gyrogroup is a topological gyrogroup; (2) Suppose that (G,τ,⊕)(G, \tau,\oplus) is a locally compact strongly paratopological gyrogroup with a symmetric neighborhood base B\mathscr{B} at 0. Then GG is a strongly topological gyrogroup

    New predictions on the mass of the 1−+1^{-+} light hybrid meson from QCD sum rules

    Full text link
    We calculate the coefficients of the dimension-8 quark and gluon condensates in the current-current correlator of 1−+1^{-+} light hybrid current gqˉ(x)γνiGμν(x)q(x)g\bar{q}(x)\gamma_{\nu}iG_{\mu\nu}(x)q{(x)}. With inclusion of these higher-power corrections and updating the input parameters, we re-analyze the mass of the 1−+1^{-+} light hybrid meson from Monte-Carlo based QCD sum rules. Considering the possible violation of factorization of higher dimensional condensates and variation of ⟨g3G3⟩\langle g^3G^3\rangle, we obtain a conservative mass range 1.72--2.60\,GeV, which favors π1(2015)\pi_{1}(2015) as a better hybrid candidate compared with π1(1600)\pi_{1}(1600) and π1(1400)\pi_{1}(1400).Comment: 12pages, 2 figures, the version appearing in JHE

    Electromagnetic radiation of baryons containing two heavy quarks

    Get PDF
    The two heavy quarks in a baryon which contains two heavy quarks and a light one, can constitute a scalar or axial vector diquark. We study electromagnetic radiations of such baryons, (i) \Xi_{(bc)_1} -> \Xi_{(bc)_0}+\gamma, (ii) \Xi_{(bc)_1}^* -> \Xi_{(bc)_0}+\gamma, (iii) \Xi_{(bc)_0}^{**}(1/2, l=1) -> \Xi_{(bc)_0}+\gamma, (iv) \Xi_{(bc)_0}^{**}(3/2, l=1) -> \Xi_{(bc)_0}+\gamma and (v) \Xi_{(bc)_0}^{**}(3/2, l=2) -> \Xi_{(bc)_0}+\gamma, where \Xi_{(bc)_{0(1)}}, \Xi^*_{(bc)_1} are S-wave bound states of a heavy scalar or axial vector diquark and a light quark, and \Xi_{(bc)_0}^{**}(l is bigger than 1) are P- or D-wave bound states of a heavy scalar diquark and a light quark. Analysis indicates that these processes can be attributed into two categories and the physical mechanisms which are responsible for them are completely distinct. Measurements can provide a good judgment for the diquark structure and better understanding of the physical picture.Comment: 15 pages, Late

    Instanton Effects in QCD Sum Rules for the 0++0^{++} Hybrid

    Full text link
    In this paper, we study instanton contributions to the correlator of the hybrid current gqˉσμνGνμaTaqg\bar q \sigma_{\mu\nu}G^a_{\nu\mu}T^a q. These contributions are then included in a QCD sum-rule analysis of the isoscalar 0++0^{++} hybrid mass. We find a mass at 1.83 GeV for the (uˉug+dˉdg)/2(\bar uug+\bar ddg)/\sqrt{2} hybrid. However, for the sˉsg\bar ssg hybrid, we find the sum rules are unstable. We also study non-zero width effects, which affect the mass prediction. The mixing effects between these two states are studied and we find QCD sum rules support the existence of a flavor singlet hybrid with mass at around 1.9 GeV. Finally, we study the mixing effects between hybrid and glueball currents. The mixing between the (uˉug+dˉdg)/2(\bar uug+\bar ddg)/\sqrt{2}(sˉsg\bar ssg) and the glueball causes two states, one in the region 1.4-1.8 GeV(1.4-2.2 GeV), and the other in the range 1.8-2.2 GeV(2.2-2.6 GeV).Comment: 12 pages, revised versio
    • …
    corecore