Search for CP Violation in the decays D+ -> K_S pi+ and D+ -> K_S K+

A high statistics sample of photo-produced charm from the FOCUS(E831) experiment at Fermilab has been used to search for direct CP violation in the decays D+->K_S pi+ and D+ -> K_S K+. We have measured the following asymmetry parameters relative to D+->K-pi+pi+: A_CP(K_S pi+) = (-1.6 +/- 1.5 +/- 0.9)%, A_CP(K_S K+) = (+6.9 +/- 6.0 +/- 1.5)% and A_CP(K_S K+) = (+7.1 +/- 6.1 +/- 1.2)% relative to D+->K_S pi+. The first errors quoted are statistical and the second are systematic. We also measure the relative branching ratios: \Gamma(D+->\bar{K0}pi+)/\Gamma(D+->K-pi+pi+) = (30.60 +/- 0.46 +/- 0.32)%, \Gamma(D+->\bar{K0}K+)/\Gamma(D+->K-pi+pi+) = (6.04 +/- 0.35 +/- 0.30)% and \Gamma(D+->\bar{K0}K+)/\Gamma(D+->\bar{K0}pi+) = (19.96 +/- 1.19 +/- 0.96)%.Comment: 4 pages, 3 figure

Anatomic mapping of the collateral branches of the external carotid artery with regard to daily clinical practice

Background: To identify the anatomical variations of the main branches of the external carotid artery (lingual, facial, occipital, ascending pharyngeal and sternocleidomastoid), giving information about the calibers and origins with the aim of creating a new classification useful in clinical practice. Material and methods: 193 human embalmed body-donors were dissected. The data collected were analyzed using the Chi² test. The results of previous studies were reviewed. Results: The majority of the anterior arterial branches (superior thyroid, facial and lingual artery) were observed with an independent origin, respectively, classified as pattern I (80.83%, 156/193). In 17.62% (34/193) a linguofacial trunk, pattern II, has been observed, only in 1,04% (2/193) a thyrolingual trunk, pattern III, has been found and in one case (1/193, 0.52%) one thyrolinguofacial trunk, pattern IV, was found. Depending on the posterior branches (occipital and ascending pharyngeal), four different types could be determined: type a, the posterior arteries originated independently, type b, the posterior arteries originated in a common trunk, type c, the ascending pharyngeal artery was absent, type d, the occipital artery was absent. Conclusion: Anatomical variations in these arteries are relevant in daily clinical practice due to growing applications, e.g., in Interventional Radiology techniques. Knowledge of these anatomical references could help clinicians in the interpretation of the carotid system

End-diastolic wall thickness as a predictor of recovery of function in myocardial hibernation Relation to rest-redistribution Tl-201 tomography and dobutamine stress echocardiography

AbstractOBJECTIVESThe study assessed whether end-diastolic wall thickness (EDWT), measured with echocardiography, is an important marker of myocardial viability in patients with suspected myocardial hibernation, and it compared this index to currently established diagnostic modalities of dobutamine stress echocardiography (DSE) and rest-redistribution thallium-201 (Tl-201) scintigraphy.BACKGROUNDBecause myocardial necrosis is associated with myocardial thinning, preserved EDWT may provide a simple index of myocardial viability that is readily available from the resting echocardiogram.METHODSAccordingly, 45 patients with stable coronary artery disease and ventricular dysfunction underwent rest 2D echocardiograms, DSE and rest-redistribution Tl-201 tomography before revascularization and a repeat resting echocardiogram ≥2 months later.RESULTSGlobal wall motion score index decreased from 2.38 ± 0.73 to 1.94 ± 0.82 after revascularization (p < 0.001). Thirty-eight percent of severely dysfunctional segments recovered resting function. Compared to segments without recovery of resting function, those with recovery had greater EDWT (0.94 ± 0.18 cm vs. 0.67 ± 0.22 cm, p ≤ 0.0001) and a higher Tl-201 uptake (78 ± 13% vs. 59 ± 21%; p < 0.0001). An EDWT >0.6 cm had a sensitivity of 94% and specificity of 48% for recovery of function. Similarly, a Tl-201 maximal uptake of ≥60% had a sensitivity of 91% and specificity of 50%. Receiver operating characteristic curves for prediction of recovery of regional and global function were similar for EDWT and maximum Tl-201 uptake. Combination of EDWT and any contractile reserve during DSE for recovery of regional function improved the specificity to 77% without a significant loss in sensitivity (88%).CONCLUSIONSEnd-diastolic wall thickness is an important marker of myocardial viability in patients with suspected hibernation, and it can predict recovery of function similar to Tl-201 scintigraphy. Importantly, a simple measurement of EDWT ≤0.6 cm virtually excludes the potential for recovery of function and is a valuable adjunct to DSE in the assessment of myocardial viability

A measurement of branching ratios of D+D^+ and Ds+D^+_s hadronic decays to four-body final states containing a KSK_S

We have studied hadronic four-body decays of $D^+$ and $D^+_s$ mesons with a $K_S$ in the final state using data recorded during the 1996-1997 fixed-target run at Fermilab high energy photoproduction experiment FOCUS. We report a new branching ratio measurement of $\Gamma(D^+\to K_S K^-\pi^+\pi^+)/\Gamma(D^+\to K_S \pi^+\pi^+\pi^-)=0.0768\pm0.0041\pm0.0032$. We make the first observation of three new decay modes with branching ratios $\Gamma(D^+\to K_S K^+\pi^+\pi^-)/\Gamma(D^+\to K_S \pi^+\pi^+\pi^-)=0.0562\pm0.0039\pm0.0040$, \Gamma(D^+\to\K_S K^+ K^-\pi^+)/\Gamma(D^+\to K_S \pi^+\pi^+\pi^-)=0.0077\pm0.0015\pm0.0009, and $\Gamma(D^+_s\to K_S K^+\pi^+\pi^-)/\Gamma(D^+_s\to K_S K^-\pi^+\pi^+)=0.586\pm0.052\pm0.043$, where in each case the first error is statistical and the second error is systematic.Comment: 4 pages, 1 table, 2 figures, submitted to Physical Review Letter

A High Statistics Measurement of the Lambdac+ Lifetime

A high statistics measurement of the Lambdac+ lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis technique with particular attention to the determination of the systematic uncertainty. The measured value of 204.6 +/- 3.4 (stat.) +/- 2.5 (syst.) fs from 8034 +/- 122 Lambdac -> pKpi decays represents a significant improvement over the present world average.Comment: Submitted to Physical Review Letter

A Measurement of the Ds+ Lifetime

A high statistics measurement of the Ds+ lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis of the two decay modes, Ds+ -> phi(1020)pi+ and Ds+ -> \bar{K}*(892)0K+, used for the measurement. The measured lifetime is 507.4 +/- 5.5 (stat.) +/- 5.1 (syst.) fs using 8961 +/- 105 Ds+ -> phi(1020)pi+ and 4680 +/- 90 Ds+ -> \bar{K}*(892)0K+ decays. This is a significant improvement over the present world average.Comment: 5 pages, 3 figures, 2 tables, submitted to PR

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