Final State Rescattering and Color-suppressed \bar B^0-> D^{(*)0} h^0 Decays

The color-suppressed \bar B^0-> D^{(*)0}\pi^0, D^{(*)0}\eta, D^0\omega decay modes have just been observed for the first time. The rates are all larger than expected, hinting at the presence of final state interactions. Considering \bar B^0-> D^{(*)0}\pi^0 mode alone, an elastic D^{(*)}\pi -> D^{(*)}\pi rescattering phase difference \delta \equiv \delta_{1/2} - \delta_{3/2} \sim 30^\circ would suffice, but the \bar B^0-> D^{(*)0}\eta, D^0\omega modes compel one to extend the elastic formalism to SU(3) symmetry. We find that a universal a_2/a_1=0.25 and two strong phase differences 20^\circ \sim \theta < \delta < \delta^\prime \sim 50^\circ can describe both DP and D^*P modes rather well; the large phase of order 50^\circ is needed to account for the strength of {\it both} the D^{(*)0}\pi^0 and D^{(*)0}\eta modes. For DV modes, the nonet symmetry reduces the number of physical phases to just one, giving better predictive power. Two solutions are found. We predict the rates of the \bar B^0-> D^{+}_s K^-, D^{*+}_s K^-, D^0\rho^0, D^+_s K^{*-} and D^0\phi modes, as well as \bar B^0-> D^{0}\bar K^0, D^{*0}\bar K^0, D^{0}\bar K^{*0} modes. The formalism may have implications for rates and CP asymmetries of charmless modes.Comment: REVTeX4, 18 pages, 5 figures, to appear in Phys. Rev.

Safety and feasibility of NeuroFlo use in eight- to 24-hour ischemic stroke patients.

BACKGROUND: Acute treatment of ischemic stroke patients presenting more than eight-hours after symptom onset remains limited and largely unproven. Partial aortic occlusion using the NeuroFlo catheter can augment cerebral perfusion in animals. We investigated the safety and feasibility of employing this novel catheter to treat ischemic stroke patients eight-hours to 24 h following symptom onset. METHODS: A multicenter, single-arm trial enrolled ischemic stroke patients at nine international academic medical centers. Eligibility included age 18-85 years old, National Institutes of Health stroke scale (NIHSS) score between four and 20, within eight-hours to 24 h after symptom onset, and perfusion-diffusion mismatch confirmed by magnetic resonance imaging. The primary outcome was all adverse events occurring from baseline to 30 days posttreatment. Secondary outcomes included stroke severity on neurological indices through 90 days. This study is registered with ClinicalTrials.gov, number NCT00436592. RESULTS: A total of 26 patients were enrolled. Of these, 25 received treatment (one excluded due to aortic morphology); five (20%) died. Favorable neurological outcome at 90 days (modified Rankin score 0-2 vs. 3-6) was associated with lower baseline NIHSS (P &lt; 0·001) and with longer duration from symptom discovery to treatment. There were no symptomatic intracranial hemorrhages or parenchymal hematomas. Asymptomatic intracranial hemorrhage was visible on computed tomography in 32% and only on microbleed in another 20%. CONCLUSIONS: Partial aortic occlusion using the NeuroFlo catheter, a novel collateral therapeutic strategy, appears safe and feasible in stroke patients eight-hours to 24 h after symptom onset

When Will Adolescents Tell Someone About Dating Violence Victimization?

This study examined factors that influence help-seeking among a diverse sample of adolescents who experienced dating violence. A sample of 57 high school students in an urban community reported on the prevalence and characteristics of dating violence in their relationships. Someone observing a dating violence incident and a survivor’s attaching an emotional meaning to the event significantly influenced adolescents to talk to someone. When dating violence occurred in isolation, survivors were more likely to receive no support from others in the aftermath of the incident. Differences between boys’ and girls’ help-seeking and implications for dating violence intervention and prevention programming are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90887/1/Black-Tolman-Callahan-Saunders- Weisz- 2008-When will adolescents tell someone about dating violence VAW.pd

Elastic and inelastic SU(3)-breaking final-state interactions in B decays to pseudoscalar mesons

We discuss all contributions from Zweig-rule-satisfying SU(3)-breaking final state interactions (FSIs)in the B -> PP decays (neglecting charmed intermediate states), where PP=pi pi, pi K, KK, pi eta (eta'), and K eta (eta'). First, effects of SU(3) breaking in rescattering through Pomeron exchange are studied. Then, after making a plausible assumption concerning the pattern of SU(3) breaking in non-Pomeron FSIs, we give general formulas for how the latter modify short-distance (SD) amplitudes. In the SU(3) limit, these formulas depend on three effective parameters characterizing the strength of all non-Pomeron rescattering effects. We point out that the experimental bounds on the B -> K^+K^- branching ratio may limit the value of only one of these FSI parameters. Thus, the smallness of the B -> K^+K^- decay rate does not imply negligible rescattering effects in other decays. Assuming a vanishing value of this parameter, we perform various fits to the available B -> PP branching ratios. The fits determine the quark-diagram SD amplitudes, the two remaining FSI parameters and the weak angle gamma. While the set of all B -> PP branching ratios is well described with gamma around its expected SM value, the fits permit other values of gamma as well. For a couple of such good fits, we predict asymmetries for the B -> K pi, pi^+ eta (eta'), K^+ eta (eta') decays as well as the values of the CP-violating parameters S_{pi pi} and C_{pi pi} for the time-dependent rate of B^0(t) -> pi^+ pi^-. Apart from a problem with the recent B^+ -> pi^+ eta asymmetry measurement, comparison with the data seems to favour the values of gamma in accordance with SM expectations.Comment: 27 pages, 5 figure

Kaon Production and Kaon to Pion Ratio in Au+Au Collisions at \snn=130 GeV

Mid-rapidity transverse mass spectra and multiplicity densities of charged and neutral kaons are reported for Au+Au collisions at \snn=130 GeV at RHIC. The spectra are exponential in transverse mass, with an inverse slope of about 280 MeV in central collisions. The multiplicity densities for these particles scale with the negative hadron pseudo-rapidity density. The charged kaon to pion ratios are $K^+/\pi^- = 0.161 \pm 0.002 {\rm (stat)} \pm 0.024 {\rm (syst)}$ and $K^-/\pi^- = 0.146 \pm 0.002 {\rm (stat)} \pm 0.022 {\rm (syst)}$ for the most central collisions. The $K^+/\pi^-$ ratio is lower than the same ratio observed at the SPS while the $K^-/\pi^-$ is higher than the SPS result. Both ratios are enhanced by about 50% relative to p+p and $\bar{\rm p}$+p collision data at similar energies.Comment: 6 pages, 3 figures, 1 tabl

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results