118458838
Search for charmonium and charmonium-like states in $\Upsilon(1S)$ radiative decays
Using a sample of 102 million Υ(1S) events collected with the Belle detector, we report on the first search for charge-parity-even charmonium and charmonium-like states in Υ(1S) radiative decays. No significant χcJ or ηc signal is observed and 90% C.L. limits on B(Υ(1S) → γχc0) < 6.5 × 10, B(Υ(1S) → γχc1) < 2.3 × 10, B(Υ(1S) → γχc2) < 7.6 × 10, and B(Υ(1S) → γηc) < 5.7 × 10 are obtained. The product branching fraction limits B(Υ(1S) → γX(3872))B(X(3872) → ππJ/ψ) < 1.6 × 10, B(Υ(1S) → γX(3872))B(X(3872) → πππJ/ψ) < 2.8 × 10, B(Υ(1S) → γX(3915))B(X(3915) → ωJ/ψ) < 3.0 × 10, and B(Υ(1S) → γY (4140))B(Y (4140) → φJ/ψ) < 2.2 × 10 are obtained at the 90% C.L. Furthermore, no evidence is found for excited charmonium states below 4.8 GeV/c. PACS numbers: 14.40.Nd, 14.20.Lq, 13.25.Gv
119194057
Search for charmonium and charmonium-like states in $\Upsilon(1S)$ and $\Upsilon(2S)$ radiative decays
Using samples of 102 million Υ(1S) and 158 million Υ(2S) event samples collected with the Belle detector, we report on the first search for charge-parity-even charmonium and charmonium-like states in Υ(1S) and Υ(2S) radiative decays. No significant χcJ or ηc signal is observed and 90% C.L. limits on BR(Υ(nS) → γχcJ) (n = 1, 2 and J = 1, 2, 3) are obtained. No significant signal of any charmonium-like state is observed. The product branching fraction limits BR(Υ(nS) → γX(3872)) BR(X(3872) → ππJ/ψ), BR(Υ(nS) → γX(3872)) BR(X(3872) → πππJ/ψ), BR(Υ(nS) → γX(3915)) BR(X(3915) → ωJ/ψ), and BR (Υ(1S) → γY (4140))BR(Y (4140) → φJ/ψ) (n = 1, 2) are obtained at the 90% C.L. At the same time, BR(Υ(2S) → γX(4350))BR(X(4350) → φJ/ψ)) is also determined at the 90% C.L. Furthermore, no evidence is found for excited charmonium states below 4.8 GeV/c.
119330852
Extraction of K-->pipi Matrix Elements with Wilson Fermions
We present the status of a lattice calculation for the K-->pipi matrix elements of the (delta S=1) effective weak Hamiltonian, directly with two pion in the final state. We study the energy shift of two pion in a finite volume both in the I=0 and I=2 channels. We explain a method to avoid the Goldstone pole contamination in the computation of renormalization constants for (delta I=3/2) operators. Finally we show some preliminary results for the matrix elements of (delta I=1/2) operators. Our quenched simulation is done at beta=6.0, with Wilson fermions, on a (24^3 X 64) lattice.
119159980
System size and energy dependence of the near-side of high-$p_T$ triggered di-hadron correlations in STAR
Previous studies have indicated that the near-side peak of h igh-pT triggered di-hadron correlations can be decomposed into two parts, a jet-like correlati on and theRidge. We present data from Cu+Cu and Au+Au collisions at √ sNN = 62 GeV and 200 GeV, which should allow more robust tests of models. The jet-like correlation is narrow i n both azimuth and pseudorapidity and has properties similar to those expected from vacuum fragme ntation. The yield of particles in the jet-like correlation are presented for both systems and at both energies and compared to the yields expected from di-hadron correlations in PYTHIA 8.1. The Ridge is narrow in azimuth but broad in pseudorapidity and roughly independent of pseu dorapidity within STAR’s acceptance. Attempts have been made to explain the production of t he Ridge component as coming from recombination, momentum kicks, Glasma flux tubes, and a plasma instability. However, few models have attempted to quantitatively calculate the c haracteristics of theRidge. The yield in theRidge is compared for all systems and energies. The implications f r measurements at the LHC are discussed in context of the data and models.