Conflict and cooperation in the water-security nexus: A global comparative analysis of river basins under climate change

Adequate fresh water availability is an important factor for human security in many parts of the world. In transboundary river basins, decreased water supply due to local environmental change and global climate change and increased water demand due to growing populations and continued economic development can aggravate water scarcity. Contrary to the claim that water scarcity may result in an increased risk of armed conflict, there is no simple relationship between freshwater availability and violent conflict. Other crucial factors need to be taken into consideration that also directly influence resource availability and personal human well‐being. In this review, we assess the scientific literature on conflict and cooperation in transboundary river systems. Most international river basins are already jointly managed by the riparians, but successful management in times of climate change necessitates the inclusion of more factors besides mere allocation schemes. On the basis of a substantial body of literature on the management of transboundary watersheds, an analytical framework of the water‐security nexus is developed that integrates the physical and socioeconomic pathways connecting water availability with conflict or cooperation. This framework is subsequently applied to two transboundary river basins—the Nile River and the Syr Darya/Amu Darya—as they represent two world regions that could become future water hot spots. An improved understanding of the developments leading to water conflicts and their interaction can help to successfully reduce the risk of water conflicts in these regions and to move toward increased cooperation among the riparians of transboundary river systems

Search for T Violation in Charm Meson Decays

Using data from the FOCUS (E831) experiment, we have searched for T violation in charm meson decays using the four-body decay channels $D^0 \to K^-K^+\pi^-\pi^+$, $D^+ \to K^0_SK^+\pi^-\pi^+$, and $D^+_s \to K^0_SK^+\pi^-\pi^+$. The T violation asymmetry is obtained using triple-product correlations and assuming the validity of the CPT theorem. We find the asymmetry values to be $A_Tviol (D^0) = 0.010 \pm 0.057(stat.) \pm 0.037(syst.)$, $A_Tviol (D^+) = 0.023 \pm 0.062(stat.) \pm 0.022(syst.)$, and $A_Tviol (D^+_s) = -0.036 \pm 0.067(stat.) \pm 0.023(syst.)$. Each measurement is consistent with no T violation. New measurements of the CP asymmetries for some of these decay modes are also presented.Comment: 17 pages,6 figures,submitted to Phys.Lett.

Recent glitches detected in the Crab pulsar

From 2000 to 2010, monitoring of radio emission from the Crab pulsar at Xinjiang Observatory detected a total of nine glitches. The occurrence of glitches appears to be a random process as described by previous researches. A persistent change in pulse frequency and pulse frequency derivative after each glitch was found. There is no obvious correlation between glitch sizes and the time since last glitch. For these glitches $\Delta\nu_{p}$ and $\Delta\dot{\nu}_{p}$ span two orders of magnitude. The pulsar suffered the largest frequency jump ever seen on MJD 53067.1. The size of the glitch is $\sim$ 6.8 $\times 10^{-6}$ Hz, $\sim$ 3.5 times that of the glitch occured in 1989 glitch, with a very large permanent changes in frequency and pulse frequency derivative and followed by a decay with time constant $\sim$ 21 days. The braking index presents significant changes. We attribute this variation to a varying particle wind strength which may be caused by glitch activities. We discuss the properties of detected glitches in Crab pulsar and compare them with glitches in the Vela pulsar.Comment: Accepted for publication in Astrophysics & Space Scienc

Study of Cabibbo Suppressed Decays of the Ds Charmed-Strange Meson involving a KS

We study the decay of Ds meson into final states involving a Ks and report the discovery of Cabibbo suppressed decay modes Ds -> Kspi-pi+pi+ (179 +/- 36 events) and Ds -> Kspi+ (113 +/-26 events). The branching ratios for the new modes are Gamma(Ds -> Kspi-pi+pi+)/Gamma(Ds -> KsK-pi+pi+) = 0.18 +/- 0.04 +/- 0.05 and Gamma(Ds -> Kspi+)/Gamma(Ds -> KsK+) = 0.104 +/- 0.024 +/- 0.013.Comment: 11 pages, 6 figure

Measurements of Ξc+\Xi_c^{+} Branching Ratios

Using data collected by the fixed target Fermilab experiment FOCUS, we measure the branching ratios of the Cabibbo favored decays $\Xi_c^+ \to \Sigma^+K^-\pi^+$, $\Xi_c^+ \to \Sigma^+ \bar{K}^{*}(892)^0$, and $\Xi_c^+ \to \Lambda^0K^-\pi^+\pi^+$ relative to $\Xi_c^+ \to \Xi^-\pi^+\pi^+$ to be $0.91\pm0.11\pm0.04$, $0.78\pm0.16\pm0.06$, and $0.28\pm0.06\pm0.06$, respectively. We report the first observation of the Cabibbo suppressed decay $\Xi_c^+ \to \Sigma^+K^+K^-$ and we measure the branching ratio relative to $\Xi_c^+ \to \Sigma^+K^-\pi^+$ to be $0.16\pm0.06\pm0.01$. We also set 90% confidence level upper limits for $\Xi_c^+ \to \Sigma^+ \phi$ and $\Xi_c^+ \to \Xi^*(1690)^0(\Sigma^+ K^-) K^+$ relative to $\Xi_c^+ \to \Sigma^+K^-\pi^+$ to be 0.12 and 0.05, respectively. We find an indication of the decays $\Xi_c^+ \to \Omega^-K^{+}\pi^+$ and $\Xi_c^+ \to \Sigma^{*}(1385)^+ \bar{K}^0$ and set 90% confidence level upper limits for the branching ratios with respect to $\Xi_c^+ \to \Xi^-\pi^+\pi^+$ to be 0.12 and 1.72, respectively. Finally, we determine the 90% C.L. upper limit for the resonant contribution $\Xi_c^+ \to \Xi^{*}(1530)^0 \pi^+$ relative to $\Xi_c^+ \to \Xi^-\pi^+\pi^+$ to be 0.10.Comment: 14 pages, 8 figure

Measurement of the Ratio of the Vector to Pseudoscalar Charm Semileptonic Decay Rate \Gamma(D+ > ANTI-K*0 mu+ nu)/\Gamma(D+ > ANTI-K0 mu+ nu)

Using a high statistics sample of photo-produced charm particles from the FOCUS experiment at Fermilab, we report on the measurement of the ratio of semileptonic rates \Gamma(D+ > ANTI-K pi mu+ nu)/\Gamma(D+ > ANTI-K0 mu+ nu)= 0.625 +/- 0.045 +/- 0.034. Allowing for the K pi S-wave interference measured previously by FOCUS, we extract the vector to pseudoscalar ratio \Gamma(D+ > ANTI-K*0 mu+ nu)/\Gamma(D+ > ANTI-K0 mu+ nu)= 0.594 +/- 0.043 +/- 0.033 and the ratio \Gamma(D+ > ANTI-K0 mu+ nu)/\Gamma(D+ > K- pi+ pi+)= 1.019 +/- 0.076 +/- 0.065. Our results show a lower ratio for \Gamma(D > K* \ell nu})/\Gamma(D > K \ell nu) than has been reported recently and indicate the current world average branching fractions for the decays D+ >ANTI-K0(mu+, e+) nu are low. Using the PDG world average for B(D+ > K- pi+ pi+) we extract B(D+ > ANIT-K0 mu+ nu)=(9.27 +/- 0.69 +/- 0.59 +/- 0.61)%.Comment: 15 pages, 1 figur

Study of Hadronic Five-Body Decays of Charmed Mesons Involving KS0K_S^0

We study the decay of $D^0$ and $D^+_s$ mesons into five-body final states including a $K_S^0$ and report the discovery of the decay mode $D_s^+\to K_S^0 K_S^0\pi^+\pi^+\pi^-$. The branching ratio for the new mode is {${\Gamma(D_s^+\to K_S^0K_S^0\pi^+\pi^-\pi^+)} \over {\Gamma(D_s^+\to K_S^0K^-\pi^+\pi^+)}$} = 0.102$\pm0.029\pm$0.029. We also determine the branching ratio of {${\Gamma(D^0\to K_S^0\pi^+\pi^+\pi^-\pi^-)} \over {\Gamma(D^0 \to K_S^0\pi^+\pi^-)}$} = 0.095$\pm0.005\pm$0.007 as well as an upper limit for {${\Gamma(D^0\to K_S^0K^-\pi^+\pi^+\pi^-)} \over {\Gamma(D^0\to K_S^0\pi^+\pi^+\pi^-\pi^-)}$} $<$ 0.054 (90% CL). An analysis of the resonant substructure for $D^0 \to K_S^0\pi^+\pi^+\pi^-\pi^-$ is also performed

Measurement of the branching ratio of the decay D^0 -> \pi^-\mu^+\nu relative to D^0 -> K^-\mu^+\nu

We present a new measurement of the branching ratio of the Cabibbo suppressed decay D^0\to \pi^-\mu^+\nu relative to the Cabibbo favored decay D^0\to K^-\mu^+\nu and an improved measurement of the ratio |\frac{f_+^{\pi}(0)}{f_+^{K}(0)}|. Our results are 0.074 \pm 0.008 \pm 0.007 for the branching ratio and 0.85 \pm 0.04 \pm 0.04 \pm 0.01 for the form factor ratio, respectively.Comment: 13pages, 3 figure

A Non-parametric Approach to Measuring the \kpi{} Amplitudes in \dpkkpi{} Decay

Using a large sample of \dpkkpi{} decays collected by the FOCUS photoproduction experiment at Fermilab, we present the first non-parametric analysis of the \kpi{} amplitudes in \dpkkpi{} decay. The technique is similar to the technique used for our non-parametric measurements of the \krzmndk{} form factors. Although these results are in rough agreement with those of E687, we observe a wider S-wave contribution for the \ksw{} contribution than the standard, PDG \cite{pdg} Breit-Wigner parameterization. We have some weaker evidence for the existence of a new, D-wave component at low values of the $K^- \pi^+$ mass.Comment: 13 pages 3 figure

Measurements of Six-Body Hadronic Decays of the D^0 Charmed Meson

Using data collected by the FOCUS experiment at Fermilab, we report the discovery of the decay modes D^0 --> K- pi+ pi+ pi+ pi- pi- and D^0 --> pi+ pi+ pi+ pi- pi- pi-. With a sample of 48 +/- 10 reconstructed D^0 --> K- pi+ pi+ pi+ pi- pi- decays and 149 +/- 17 reconstructed D^0 --> pi+ pi+ pi+ pi- pi- pi- decays, we measure the following relative branching ratios: ${\Gamma (D^0 \to K^- \pi^+ \pi^+ \pi^+ \pi^- \pi^-) / \Gamma (D^0 \to K^- \pi^+ \pi^+ \pi^-)} = (2.70 \pm 0.58 \pm 0.38) \times 10^{-3}$ ${\Gamma (D^0 \to \pi^+ \pi^+ \pi^+ \pi^- \pi^- \pi^-) / \Gamma (D^0 \to K^- \pi^+ \pi^+ \pi^-)} = (5.23 \pm 0.59 \pm 1.35) \times 10^{-3}$ ${\Gamma (D^0 \to \pi^+ \pi^+ \pi^+ \pi^- \pi^- \pi^-) / \Gamma (D^0 \to K^- \pi^+ \pi^+ \pi^+ \pi^- \pi^-)} = 1.93 \pm 0.47 \pm 0.48$ The first errors are statistical and the second are systematic. The branching fraction of the Cabibbo suppressed six-body decay mode is measured to be a factor of two higher than the branching fraction of the Cabibbo favored six-body decay mode.Comment: To be submitted to Phys. Lett.