5D action for longitudinal five branes on a pp-wave

String modes in a pp-wave background are generically massive, and the worldvolume description of the branes is to be given by `massive' gauge theories. In this paper, we present a five dimensional super Yang-Mills action with the Kahler-Chern-Simons term plus the Myers term as a low energy worldvolume description of the longitudinal five branes in a maximally supersymmetric pp-wave background. We derive the action from the M-theory matrix model on the pp-wave. We utilize the previously found 4/32 BPS solution of rotating five branes with stacks of membranes, but, to obtain the static configuration, we reformulate the matrix model in a rotating coordinate system which provides the inertial frame for the branes. Expanding the matrix model around the solution, we first obtain a non-commutative field theory action naturally equipped with the full sixteen dynamical supersymmetries. In the commutative limit, we show only four supersymmetries survive, resulting in a novel five dimensional "N=1/2" theory.Comment: 1+19 pages, No figure, JHEP style; a reference added, to appear in JHE

Study of the radiative decay ϕ→ηγ\phi \to \eta \gamma with CMD-2 detector

Using the $1.9 pb^{-1}$ of data collected with the CMD-2 detector at VEPP-2M the decay mode $\phi \to \eta \gamma$, $\eta \to \pi^+\pi^-\pi^0$ has been studied. The obtained branching ratio is B($\phi \to \eta \gamma) = (1.18 \pm 0.03 \pm 0.06)$.Comment: 13 pages, 5 figures, LaTex2e, to be published in Phys. Lett.

Observation of KS0K_S^0 semileptonic decays with CMD-2 detector

The decay $K_S^0 \to \pi e \nu$ has been observed by the CMD-2 detector at the e^+e^- collider VEPP-2M at Novosibirsk. Of 6 million produced $K_L^0K_S^0$ pairs, $75 \pm 13$ events of the $K_S^0 \to \pi e \nu$ decay were selected. The corresponding branching ratio is $B(K_S^0 \to \pi e \nu)=(7.2 \pm 1.4)\times10^{-4}$. This result is consistent with the evaluation of $B(K_S^0 \to \pi e \nu)$ from the $K_L^0$ semileptonic rate and $K_S^0$ lifetime assuming $\Delta S=\Delta Q$ .Comment: 7 pages, 6 figures, LaTex2e. Submitted to Phys.Lett.

Study of the process e+e- to pi+pi-pi+pi-pi0 with CMD-2 detector

The process e+e- to pi+ pi- pi+ pi- pi0 has been studied in the center of mass energy range 1280 -- 1380 MeV using 3.0 1/pb of data collected with the CMD-2 detector in Novosibirsk. Analysis shows that the cross section of the five pion production is dominated by the contributions of the eta pi+pi- and omega pi+pi- intermediate states.Comment: 8 pages, 3 figure. Submitted to Phys. Lett.

The spectrum features of UHECRs below and surrounding GZK

The energy spectrum of UHECRs is discussed on the basis of the Yakutsk array database analysis. In the region E=0.1 to 30 EeV the showers are detected under trigger-500, while at energies above 30 EeV the whole acceptance area for trigger-1000 is used in order to utilize all the data available in the region of GZK cutoff.Comment: Invited talk at CRIS2004: GZK and surroundings, Catania, Italy, 31.05.04. To appear in Nucl. Phys. B Proc. Supp

High-statistics measurement of the pion form factor in the rho-meson energy range with the CMD-2 detector

We present a measurement of the pion form factor based on e+e- annihilation data from the CMD-2 detector in the energy range 0.6<sqrt(s)<1.0 GeV with a systematic uncertainty of 0.8%. A data sample is five times larger than that used in our previous measurement.Comment: 18 pages, 10 figures. Added comparison with KLOE measurement, minor updates. Accepted by PL

Observation of the conversion decay ϕ→π0e+e−\phi\to\pi^0e^+e^- at CMD-2

Using 15.1^{-1} of data collected by CMD-2 in the $\phi$-meson energy range, the branching ratio of the conversion decay $\phi\to\pi^0e^+e^-$ has been measured for the first time: B(\phi\to\pi^0e^+e^-) = (1.22 \pm 0.34 \pm 0.21) \cdot 10 ^{-5}.Comment: 13 pages, 6 PostScript figures, uses refmerge.sty. To be published in Phys. Lett.

Cross section of the reaction e+e−→π+π−π+π−e^+ e^- \to \pi^+\pi^-\pi^+\pi^- below 1 GeV at CMD-2

Using 3.07 ${pb}^{-1}$ of data collected in the energy range 0.60-0.97 GeV by CMD-2, about 150 events of the process \epm \to \pch have been selected. The energy dependence of the cross section agrees with the assumption of the $a_1(1260) \pi$ intermediate state which is dominant above 1 GeV. For the first time \fourpi events are observed at the $\rho$ meson energy. Under the assumption that all these events come from the $\rho$ meson decay, the value of the cross section at the $\rho$ meson peak corresponds to the following decay width: \Gamma(\rho^0 \to \fourpi) = (2.8 \pm 1.4 \pm 0.5) {keV} or to the branching ratio B(\rho^0 \to \fourpi) = (1.8 \pm 0.9 \pm 0.3) \cdot 10 ^{-5}.Comment: 15 pages, 5 figure

Spin asymmetry A_1^d and the spin-dependent structure function g_1^d of the deuteron at low values of x and Q^2

We present a precise measurement of the deuteron longitudinal spin asymmetry A_1^d and of the deuteron spin-dependent structure function g_1^d at Q^2 < 1 GeV^2 and 4*10^-5 < x < 2.5*10^-2 based on the data collected by the COMPASS experiment at CERN during the years 2002 and 2003. The statistical precision is tenfold better than that of the previous measurement in this region. The measured A_1^d and g_1^d are found to be consistent with zero in the whole range of x.Comment: 17 pages, 10 figure

Gluon polarization in the nucleon from quasi-real photoproduction of high-pT hadron pairs

We present a determination of the gluon polarization Delta G/G in the nucleon, based on the helicity asymmetry of quasi-real photoproduction events, Q^2<1(GeV/c)^2, with a pair of large transverse-momentum hadrons in the final state. The data were obtained by the COMPASS experiment at CERN using a 160 GeV polarized muon beam scattered on a polarized 6-LiD target. The helicity asymmetry for the selected events is = 0.002 +- 0.019(stat.) +- 0.003(syst.). From this value, we obtain in a leading-order QCD analysis Delta G/G=0.024 +- 0.089(stat.) +- 0.057(syst.) at x_g = 0.095 and mu^2 =~ 3 (GeV}/c)^2.Comment: 10 pages, 3 figure