75,788 research outputs found
Magnetic and quadrupole moments of the Z(c)(3900)
No full textAzizi, Kazem (Doğuş Author)The electromagnetic properties of the tetraquark state Z(c)(3900) are investigated in the diquark-antidiquark picture and its magnetic and quadrupole moments are extracted. To this end, the light-cone QCD sum rule in electromagnetic background field is used. The magnetic and quadrupole moments encode the spatial distributions of the charge and magnetization in the particle. The result obtained for the magnetic moment is quite large and can be measured in future experiments. We obtain a nonzero but small value for the quadrupole moment of Z(c)(3900) indicating a nonspherical charge distribution
Magnetic dipole moment of Z(b)(10610) in light-cone QCD
No full textAzizi, Kazem (Dogus Author) -- Özdem, Ulaş (Dogus Author)The magnetic dipole moment of the exotic Z(b)(10610) state is calculated within the light cone QCD sum rule method using the diquark-antidiquark and molecule interpolating currents. The magnetic dipole moment is obtained as mu(Zb) = 1.73 +/- 0.63 mu(N) in diquark-antidiquark picture and mu(Zb) = 1.59 +/- 0.58 mu(N) in the molecular case. The obtained results in both pictures together with the results of other theoretical studies on the spectroscopic parameters of the Zb(10610) state may be useful in determination of the nature and quark organization of this state
The electromagnetic multipole moments of the charged open-flavor Z((c)over-barq) states
No full textAzizi, Kazem (Dogus Author)The electromagnetic multipole moments of the open-flavor Z (c) over barq states are investigated by assuming a diquark-antidiquark picture for their internal structure and quantum numbers J(PC) = 1(+-) for their spin-parity. In particular, their magnetic and quadrupole moments are extracted in the framework of light-cone QCD sum rule by the help of the photon distribution amplitudes. The electromagnetic multipole moments of the open-flavor Z (c) over barq states are important dynamical observables, which encode valuable information on their underlying structure. The results obtained for the magnetic moments of different structures are considerably large and can be measured in future experiments. We obtain very small values for the quadrupole moments of Z (c) over barq states indicating a nonspherical charge distribution
Strong Z(c)(+)(3900) -> J/psi pi(+); eta c rho(+)decays in QCD
No full textAzizi, Kazem (Dogus Author)The widths of the strong decaysZ(c)(+)(3900) -> J/psi pi(+); and Z(c)(+) (3900) -> are calculated. To this end, the mass and decay constant of the exotic Z(c)(+) (3900) state are computed by means of a two -point sum rule. The obtained results are then used to calculate the strong couplings gz(c)J/psi pi and gz(c)eta(c)p employing QCD sum rules on the light cone supplied by a technique of the soft -meson approximation. We compare our predictions on the mass and decay widths \vith available experimental data and other theoretical results
Probing an axial-vector tetraquark Z(s) via its semileptonic decay Z(s) -> X(4274)(I)over-bar nu(I)
No full textAzizi, Kazem (Dogus Author)The semileptonic decays of the open charm-bottom axial-vector tetraquark Z(s) = [cs][(b) over bar(s) over bar] to X(4274) (l) over bar nu(l) = e, mu, tau are explored by means of the QCD three-point sum rule method. Both Z(s) and X(4274) = [cs][(cs) over bar] are treated as color sextet diquark-antidiquark states. The full width of the decays Z(s) -> X(4274) (l) over bar nu(l) is found. Obtained predictions for Gamma(Z(s) -> X(4274)(l) over bar nu(l)) demonstrate that, as in the case of the conventional hadrons, the semileptonic transitions form a very small part of its full width
Treating Z(c)(3900) and Z(4430) as the ground state and first radially excited tetraquarks
No full textAzizi, Kazem (Doğuş Author)Exploration of the resonances Z(c)(3900) and Z(4430) are performed by assuming that they are the ground state and first radial excitation of the same tetraquark with J(P) = 1(+). The mass and current coupling of the Zc(3900) and Z(4430) states are calculated using the QCD two-point sum rule method by taking into account vacuum condensates up to eight dimensions. We investigate the vertices Z(c)M(h)M(l) and ZM(h)M(l), with M-h and M-l being the heavy and light mesons and evaluate the strong couplings g(ZcMhMl) and g(ZMhMl) using the QCD sum rule on the light cone. The extracted couplings allow us to find the partial width of the decays Z(c)(3900)-> J/psi pi, psi'pi, eta(c)rho and Z(4430)-> psi'pi, J/psi pi, eta'(c)rho, eta(c)rho which may help in comprehensive investigation of these resonances. We compare the width of the decays of Z(c)(3900) and Z(4430) resonances with available experimental data as well as existing theoretical predictions
Spectroscopic parameters and decays of the resonance Z(b)(10610)
No full textAzizi, Kazem (Dogus Author)The resonance Zb(10610) is investigated as the diquark-antidiquark Zb = [bu][(b) over bar(d) over bar] state with spin-parity J(P) = 1(+). The mass and current coupling of the resonance Z(b)(10610) are evaluated using QCD two-point sum rule and taking into account the vacuum condensates up to ten dimensions. We study the vertices Z(b)r(nS)pi (n = 1, 2, 3) by applying the QCD light-cone sum rule to compute the corresponding strong couplings gZb.(nS) p and widths of the decays Z(b)-> r(nS)pi. We explore also the vertices Z(b)h(b)(mP)pi (m = 1, 2) and calculate the couplings gZ(b)h(b)(mP) p and the widths of the decay channels Z(b) -> hb(mP)pi To this end, we calculate the mass and decay constants of the h(b)(1P) and h(b)(2P) mesons. The results obtained are compared with experimental data of the Belle Collaboration
New charged resonance Z−c(4100) : the spectroscopic parameters and width
No full textAzizi, Kazem (Dogus Author)The mass, coupling and width of the newly observed charged resonance Z−c(4100) are calculated by treating it as a scalar four-quark system with a diquark–antidiquark structure. The mass and coupling of the state Z−c(4100) are calculated using the QCD two-point sum rules. In these calculations we take into account contributions of the quark, gluon and mixed condensates up to dimension ten. The spectroscopic parameters of Z−c(4100) obtained by this way are employed to study its S-wave decays to ηc(1S)π− , ηc(2S)π− , D0D− , and J/ψρ− final states. To this end, we evaluate the strong coupling constants corresponding to the vertices Zcηc(1S)π− , Zcηc(2S)π− , ZcD0D− , and ZcJ/ψρ− respectively. The couplings gZcηc1π , gZcηc2π , and gZcDD are computed by means of the QCD three-point sum rule method, whereas gZcJ/ψρ is obtained from the QCD light-cone sum rule approach and soft-meson approximation. Our results for the mass m=(4080±150) MeV and total width Γ=(147±19) MeV of the resonance Z−c(4100) are in excellent agreement with the existing LHCb data
Open charm-bottom axial-vector tetraquarks and their properties
No full textAzizi, Kazem (Doğuş Author)The charged axial-vector J (P) = 1(+) tetraquarks Z(q) = [cq][ (b) over bar(q) over bar] and Z(s) = [cs][ (b) over ar(s) over bar] with the open charm-bottom contents are studied in the diquark-antidiquark model. The masses and meson-current couplings of these states are calculated by employing aQCDtwo-point sum rule approach, where the quark, gluon and mixed condensates up to eight dimensions are taken into account. These rameters of the tetraquark states Z(q) and Z(s) are used to analyze the vertices Z(q) B-c rho and Z(s) B-c phi to etermine the strong gZ(q) B-c rho and gZ(s) B-c phi couplings. For these purposes, the QCD light-cone sum rule method and its soft-meson approximation are utilized. The couplings gZ(q) B-c rho and gZ(s) B-c phi, extracted from this alysis, are applied for evaluating the strong Z(q) -> B-c rho and Z(s) -> B-c phi decays' widths, which are essential results of the present investigation. Our predictions for the masses of the Z(q) and Z(s) states are confronted with similar results available in the literature
The Benefits of Being Economics Professor A (and not Z)
No full textAlphabetic name ordering on multi-authored academic papers, which is the convention in the economics discipline and various other disciplines, is to the advantage of people whose last name initials are placed early in the alphabet. As it turns out, Professor A, who has been a first author more often than Professor Z, will have published more articles and experienced afaster growth rate over the course of her career as a result of reputation and visibility. Moreover, authors know that name ordering matters and indeed take ordering seriously: Several characteristics of an author group composition determine the decision to deviate from the default alphabetic name order to a significant extent.performance measurement, incentives, economists, name ordering
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