[en] The dispersion of ion-acoustic fluctuations has been measured using a novel technique that employed multiple color Thomson scattering to measure the frequency spectrum for two separate thermal ion-acoustic fluctuations with significantly different wave vectors. The plasma fluctuations are shown to become dispersive with increasing electron temperature. They demonstrate that this technique allows a time resolved local measurement of electron density and temperature in inertial confinement fusion plasmas

[en] The first measurements of the d(gamma,p)n differential cross section at forward angles and photon energies above 4 GeV were performed at the Thomas Jefferson National Accelerator Facility (JLab). The results indicate evidence of an angular dependent scaling threshold. Results at theta_cm = 37^o are consistent with the constituent counting rules for E_gamma∼> 4 GeV, while those at 70^o are consistent with the constituent counting rules for E_gamma ∼> 1.5 GeV

[en] We present an observation of the decay B⁰->π⁰π⁰ based on a sample of 124 million Bbar B pairs recorded by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We observe 46+-13+-3 events, where the first error is statistical and the second is systematic, corresponding to a significance of 4.2 standard deviations including systematic uncertainties. We measure the branching fractionΒ(B⁰->π⁰π⁰) = (2.1+-0.6+-0.3) x 10^-6, averaged over B⁰ and bar B⁰ decays

No abstract available

[en] The differential cross section, dsigma/dt, for omega meson exclusive photoproduction on the proton above the resonance region (2.6< W<2.9 GeV) was measured up to a momentum transfer -t = 5 GeV2 using the CLAS detector at Jefferson Laboratory. The omega channel was identified by detecting a proton and pi+ in the final state and using the missing mass technique. While the low momentum transfer region shows the typical diffractive pattern expected from Pomeron and Reggeon exchange, at large -t the differential cross section has a flat behavior. This feature can be explained by introducing quark interchange processes in addition to the QCD-inspired two-gluon exchange

[en] The reaction γp → π⁺ K^- K⁺n was studied at Jefferson Lab using a tagged photon beam with an energy range of 3-5.47 GeV. A narrow baryon state with strangeness S = +1 and mass M = 1555 ± 10 MeV/c² was observed in the nK⁺ invariant mass spectrum. The peak's width is consistent with the CLAS resolution (FWHM = 26 MeV/c²), and its statistical significance is 7.8 ± 1.0 σ. A baryon with positive strangeness has exotic structure and cannot be described in the framework of the naive constituent quark model. The mass of the observed state is consistent with the mass predicted by a chiral soliton model for the Θ⁺ baryon. In addition, the pK⁺ invariant mass distribution was analyzed in the reaction γ p → K^- K⁺p with high statistics in search of doubly-charged exotic baryon states. No resonance structures were found in this spectrum

[en] In many quantum architectures the solid-state qubits, such as quantum dots or color centers, are interfaced via emitted photons. However, the frequency of photons emitted by solid-state systems exhibits slow uncontrollable fluctuations over time (spectral diffusion), creating a serious problem for implementation of the photon-mediated protocols. Here we show that a sequence of optical pulses applied to the solid-state emitter can stabilize the emission line at the desired frequency. We demonstrate efficiency, robustness, and feasibility of the method analytically and numerically. Taking nitrogen-vacancy center in diamond as an example, we show that only several pulses, with the width of 1 ns, separated by few ns (which is not difficult to achieve) can suppress spectral diffusion. As a result, our method provides a simple and robust way to greatly improve the efficiency of photon-mediated entanglement and/or coupling to photonic cavities for solid-state qubits

[en] High resolution angle-resolved photoemission measurements have been carried out on (La 1.4-x Nd 0.6 Sr x)CuO4, a model system with static stripes, and (La 1.85 Sr 0.15)CuO4, a high temperature superconductor (Tc=40K) with possible dynamic stripes. We have identified the existence of nodal spectral weight and its associated Fermi surface in the electronic structure of both the static and dynamic stripe systems. The ARPES spectra in the nodal regions show well-defined Fermi cut-off, indicating a metallic character of this charge-ordered state

[en] Separated longitudinal and transverse structure functions for the reaction 1H(e,eprime pi+)n were measured in the momentum transfer region Q2=0.6-1.6 (GeV/c)**2 at a value of the invariant mass W=1.95 GeV. New values for the pion charge form factor were extracted from the longitudinal cross section by using a recently developed Regge model. The results indicate that the pion form factor in this region is larger than previously assumed and is consistent with a monopole parameterization fitted to very low Q2 elastic data

[en] High-convergence ignition-like double-shell implosion experiments have been performed on the Omega laser facility [T.R. Boehly et al., Opt. Commun. 133, 495 (1997)] using cylindrical gold hohlraums with 40 drive beams. For the first time, repeatable, dominant primary (2.45 MeV) neutron production from the mix-susceptible compressional phase of a double-shell implosion, using fall-line design optimization and exacting fabrication standards, is demonstrated. Effective control of fuel-pusher mix during final compression is essential for achieving noncryogenic ignition with double-shell targets on the National Ignition Facility [Paisner et al., Laser Focus World 30, 75 (1994)]