Evidence for SU(3) symmetry breaking from hyperon production

We examine the SU(3) symmetry breaking in hyperon semileptonic decays (HSD) by considering two typical sets of quark contributions to the spin content of the octet baryons: Set-1 with SU(3) flavor symmetry and Set-2 with SU(3) flavor symmetry breaking in HSD. The quark distributions of the octet baryons are calculated with a successful statistical model. Using an approximate relation between the quark fragmentation functions and the quark distributions, we predict polarizations of the octet baryons produced in $e^+e^-$ annihilation and semi-inclusive deeply lepton-nucleon scattering in order to reveal the SU(3) symmetry breaking effect on the spin structure of the octet baryons. We find that the SU(3) symmetry breaking significantly affects the hyperon polarization. The available experimental data on the $\Lambda$ polarization seem to favor the theoretical predictions with SU(3) symmetry breaking. We conclude that there is a possibility to get a collateral evidence for SU(3) symmetry breaking from hyperon production. The theoretical errors for our predictions are discussed.Comment: 3 tables, 14 figure

Search for the Rare Decay KL --> pi0 ee

The KTeV/E799 experiment at Fermilab has searched for the rare kaon decay KL--> pi0ee. This mode is expected to have a significant CP violating component. The measurement of its branching ratio could support the Standard Model or could indicate the existence of new physics. This letter reports new results from the 1999-2000 data set. One event is observed with an expected background at 0.99 +/- 0.35 events. We set a limit on the branching ratio of 3.5 x 10^(-10) at the 90% confidence level. Combining the results with the dataset taken in 1997 yields the final KTeV result: BR(KL --> pi0 ee) < 2.8 x 10^(-10) at 90% CL.Comment: 4 pages, three figure

Fabrication of CuO nanoparticle interlinked microsphere cages by solution method

Here we report a very simple method to convert conventional CuO powders to nanoparticle interlinked microsphere cages by solution method. CuO is dissolved into aqueous ammonia, and the solution is diluted by alcohol and dip coating onto a glass substrate. Drying at 80 °C, the nanostructures with bunchy nanoparticles of Cu(OH)2can be formed. After the substrate immerges into the solution and we vaporize the solution, hollow microspheres can be formed onto the substrate. There are three phases in the as-prepared samples, monoclinic tenorite CuO, orthorhombic Cu(OH)2, and monoclinic carbonatodiamminecopper(II) (Cu(NH3)2CO3). After annealing at 150 °C, the products convert to CuO completely. At annealing temperature above 350 °C, the hollow microspheres became nanoparticle interlinked cages

Measurements Of The Decay Kl → E+e-μ+μ-

Several 132 KL → e+e- μ+ μ- events were observed from the 1997 and 1999 runs of the KTeV experiments, with an estimated background of 0.8 events. In the first measurement of the parameter α using this decay mode, it was found that α=-1.59±0.37. No evidence was found for CP-violating contributions to the KLγ*γ* interaction.9014141801/1141801/5Wolfenstein, L., (1983) Phys. Rev. Lett., 51, p. 1945Belanger, G., Geng, C.Q., (1991) Phys. Rev. D, 43, p. 140Buras, A.J., Fleischer, R., (1998) Advanced Ser. Direct. High Energy Phys., 15, p. 65Uy, Z.E.S., (1991) Phys. Rev. D, 43, p. 802D'Ambrosio, G., Isidori, G., Portolès, J., (1998) Phys. Lett. B, 423, p. 385Alavi-Harati, A., (2001) Phys. Rev. Lett., 87, p. 71801. , KTeV CollaborationAlavi-Harati, A., (2001) Phys. Rev. Lett., 86, p. 5425. , KTeV CollaborationUy, Z.E.S., (2002) Eur. Phys. J. C, 23, p. 113Alavi-Harati, A., (2001) Phys. Rev. Lett., 87, p. 111802. , KTeV CollaborationHamm, J.C., (2002), Ph.D. thesis, The University of Arizona(Fermilab Report No. fERMILAB-THESIS-2002-09)Alavi-Harati, A., (1999) Phys. Rev. Lett., 83, p. 922. , KTeV CollaborationAlavi-Harati, A., (2000) Phys. Rev. D, 61, p. 072006. , KTeV CollaborationBrown, C., (1996) Nucl. Instrum. Methods Phys. Res., Sect. A, 369, p. 248Quinn, G.B., (2000), Ph.D. thesis, The University of ChicagoBarker, A.R., Huang, H., Toale, P.A., Engle, J., hep-ph/0210174Bergström, L., Massó, E., Singer, P., (1983) Phys. Lett., 131 B, p. 229Fanti, V., (1999) Phys. Lett. B, 458, p. 553. , NA48 Collaboratio

Final Results From The Ktev Experiment On The Decay Kl→π0γ γ

We report on a new measurement of the branching ratio B(KL→π 0γγ) using the KTeV detector. We reconstruct 1982 events with an estimated background of 608, that results in B(KL→π0γγ)=(1. 29±0.03stat±0.05syst)×10-6. We also measure the parameter, aV, which characterizes the strength of vector meson exchange terms in this decay. We find aV=-0.31±0.05stat±0.07syst. These results utilize the full KTeV data set collected from 1997 to 2000 and supersede earlier KTeV measurements of the branching ratio and aV. © 2008 The American Physical Society.7711Barr, G.D., (1990) Phys. Lett. B, 242, p. 523. , PYLBAJ 0370-2693 10.1016/0370-2693(90)91806-MPapadimitriou, V., (1991) Phys. Rev. D, 44, p. 573. , PRVDAQ 0556-2821 10.1103/PhysRevD.44.R573Barr, G.D., (1992) Phys. Lett. B, 284, p. 440. , PYLBAJ 0370-2693 10.1016/0370-2693(92)90458-GEcker, G., Pich, A., De Rafael, E., (1987) Phys. Lett. B, 189, p. 363. , PYLBAJ 0370-2693 10.1016/0370-2693(87)91448-1D'Ambrosio, G., Portoles, J., (1997) Nucl. Phys., 492, p. 417. , NUPBBO 0550-3213 10.1016/S0550-3213(97)00116-8Gabbiani, F., Valencia, G., (2002) Phys. Rev. D, 66, p. 074006. , PRVDAQ 0556-2821 10.1103/PhysRevD.66.074006Truong, T.N., (1993) Phys. Lett. B, 313, p. 221. , PYLBAJ 0370-2693 10.1016/0370-2693(93)91216-AAlavi-Harati, A., (2004) Phys. Rev. Lett., 93, p. 021805. , PRLTAO 0031-9007 10.1103/PhysRevLett.93.021805Alavi-Harati, A., (2000) Phys. Rev. Lett., 84, p. 5279. , PRLTAO 0031-9007 10.1103/PhysRevLett.84.5279Buchalla, G., D'Ambrosio, G., Isidori, G., (2003) Nucl. Phys., 672, p. 387. , NUPBBO 0550-3213 10.1016/j.nuclphysb.2003.09.010Mescia, F., Smith, C., Trine, S., J. High Energy Phys., 2006 (8), p. 88. , JHEPFG 1029-8479 10.1088/1126-6708/2006/08/088Batley, J.R., (2003) Phys. Lett. B, 576, p. 43. , PYLBAJ 0370-2693 10.1016/j.physletb.2003.10.001Alavi-Harati, A., (1999) Phys. Rev. Lett., 83, p. 917. , PRLTAO 0031-9007 10.1103/PhysRevLett.83.917Lai, A., (2002) Phys. Lett. B, 536, p. 229. , PYLBAJ 0370-2693 10.1016/S0370-2693(02)01863-4Alavi-Harati, A., (2003) Phys. Rev. D, 67, p. 012005. , PRVDAQ 0556-2821 10.1103/PhysRevD.67.012005Alavi-Harati, A., (2003) Phys. Rev. D, 67, p. 012005. , PRVDAQ 0556-2821 10.1103/PhysRevD.67.012005Bown, C., (1996) Nucl. Instrum. Methods Phys. Res., Sect. a, 369, p. 248. , NIMAER 0168-9002 10.1016/0168-9002(95)00799-7Brun, R., Carminati, F., W5013 (unpublished)Alexopoulos, T., (2004) Phys. Rev. D, 70, p. 092006. , PRVDAQ 0556-2821 10.1103/PhysRevD.70.092006Yao, W.-M., (2006) J. Phys. G, 33, p. 1. , JPGPED 0954-3899 10.1088/0954-3899/33/1/001http://www.aip.org/pubservs/epaps.html, See EPAPS Document No. E-PRVDAQ-77-071811 for tables of data and acceptance used in extracting aV. For more information on EPAPS, se