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M Barone

Publications and source records attributed to M Barone.

At least 37 records · Page 2Linked to original sources
PubMed2004

Measurement of the tt production cross section in pp collisions at sqrt[s]=1.96 TeV using dilepton events.

We report a measurement of the tt production cross section using dilepton events with jets and missing transverse energy in pp collisions at a center-of-mass energy of 1.96 TeV. Using a 197+/-12 pb(-1) data sample recorded by the upgraded Collider Detector at Fermilab, we use two complementary techniques to select candidate events. We compare the number of observed events and selected kinematical distributions with the predictions of the standard model and find good agreement. The combined result of the two techniques yields a tt production cross section of 7.0(+2.4)(-2.1)(stat)+1.6-1.1(syst)+/-0.4(lum) pb.

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PubMed2004

Observation of the narrow state X(3872)-->J/psipi+pi- in pp collisions at sqaure root of s=1.96 TeV.

We report the observation of a narrow state decaying into J/psipi+pi- and produced in 220 pb(-1) of p p-bar collisions at =1.96 Tesqaure root of sV in the CDF II experiment. We observe 730+/-90 decays. The mass is measured to be 3871.3+/-0.7(stat)+/-0.4(syst) MeV/c2, with an observed width consistent with the detector resolution. This is in agreement with the recent observation by the Belle Collaboration of the X(3872) meson.

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PubMed2004

Inclusive search for anomalous production of high-pT like-sign lepton pairs in pp collisions at square root s = 1.8 TeV.

We report on a search for anomalous production of events with at least two charged, isolated, like-sign leptons, each with pT > 11 GeV/c using a 107 pb(-1) sample of 1.8 TeV pp collisions collected by the CDF detector. We define a signal region containing low background from standard model processes. To avoid bias, we fix the final cuts before examining the event yield in the signal region using control regions to test the Monte Carlo predictions. We observe no events in the signal region, consistent with an expectation of 0.63(+0.84)(-0.07) events. We present 95% confidence level limits on new physics processes in both a signature-based context as well as within a representative minimal supergravity (tanbeta = 3) model.

Journal Article↗
PubMed2004

Search for B0s-->micro+micro- and B0d-->micro+micro- decays in pp collisions at square root s = 1.96 TeV.

We report on a search for B(0)(s)-->micro(+)micro(-) and B(0)(d)-->micro(+)micro(-) decays in pp collisions at square root of s=1.96 TeV using 171 pb(-1) of data collected by the CDF II experiment at the Fermilab Tevatron Collider. The decay rates of these rare processes are sensitive to contributions from physics beyond the standard model. One event survives all our selection requirements, consistent with the background expectation. We derive branching ratio limits of B(B(0)(s)-->micro(+)micro(-))<5.8x10(-7) and B(B(0)(d)-->micro(+)micro(-))<1.5x10(-7) at 90% confidence level.

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PubMed2004

Search for Kaluza-Klein graviton emission in pp collisions at square root[s] = 1.8 TeV using the missing energy signature.

We report on a search for direct Kaluza-Klein graviton production in a data sample of 84 pb(-1) of ppmacr; collisions at sqrt[s]=1.8 TeV, recorded by the Collider Detector at Fermilab. We investigate the final state of large missing transverse energy and one or two high energy jets. We compare the data with the predictions from a (3+1+n)-dimensional Kaluza-Klein scenario in which gravity becomes strong at the TeV scale. At 95% confidence level (C.L.) for n=2, 4, and 6 we exclude an effective Planck scale below 1.0, 0.77, and 0.71 TeV, respectively.

Journal Article↗
PubMed2004

Sequential treatment for Helicobacter pylori does not share the risk factors of triple therapy failure.

BACKGROUND: Predicting factors for the outcome of conventional Helicobacter pylori triple therapy have been identified. Of these, the presence of the CagA gene is a strong predictor of successful treatment. Our preliminary data show that this factor becomes irrelevant when sequential therapy is used. AIM: To identify predicting factors for the outcome of H. pylori eradication using two therapeutic schemes (triple and sequential) of equal duration (10 days). METHODS: Ninety-six patients with H. pylori infection were randomly assigned to receive one of the following therapeutic schemes: group A: rabeprazole (20 mg b.d.) plus amoxicillin (1 g b.d.) for 5 days, followed by rabeprazole (20 mg b.d.) plus tinidazole (500 mg b.d.) and clarithromycin (500 mg b.d.) for a further 5 days; group B: rabeprazole (20 mg b.d.) plus amoxicillin (1 g b.d.) and clarithromycin (500 mg b.d.) for 10 days. Age, sex, smoking, endoscopic and histological findings, and CagA and VacA status were considered as candidates for a model of multivariate analysis which used therapeutic outcome as the dependent variable. CagA and VacA status were assessed by polymerase chain reaction on DNA isolated from gastric antral specimens. RESULTS: The sequential scheme was significantly more effective than prolonged triple therapy (P < 0.05). Smoking (P < 0.001) and the absence of the CagA gene (P < 0.05) were significantly associated with the failure of triple therapy, but the effectiveness of sequential treatment was not predicted by these factors. CONCLUSION: Our data suggest that sequential therapy is not affected by bacterial and host factors which have, until now, predicted the outcome of conventional eradication treatments.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2004

Search for pair production of scalar top quarks in R-parity violating decay modes in pp collisions at square root of s=1.8 TeV.

We present the results of a search for pair production of scalar top quarks (t(1)) in an R-parity violating supersymmetry scenario in 106 pb(-1) of pp collisions at square root of s=1.8 TeV collected by the Collider Detector at Fermilab. In this mode each t(1) decays into a tau lepton and a b quark. We search for events with two tau's, one decaying leptonically (e or mu) and one decaying hadronically, and two jets. No candidate events pass our final selection criteria. We set a 95% confidence level lower limit on the t(1) mass at 122 GeV/c(2) for Br(t(1)-->tau b)=1.

Journal Article↗
PubMed2004

Repaglinide is more efficient than glimepiride on insulin secretion and post-prandial glucose excursions in patients with type 2 diabetes. A short term study.

OBJECTIVES: To compare the effect of Repaglinide vs Glimepiride on glucose- and meal-induced insulin secretion and on meal-test induced postprandial glucose excursions. METHODS: After 2 weeks washout period, a 3-Month randomised, cross-over parallel group trial of R (1 mg x 2/die) vs G (2 mg/die) in 14 patients with type 2 diabetes "naive" in diet treatment was made. RESULTS: Both R and G significantly but similarly lowered fasting glucose levels and improved fasting plasma insulin levels vs baseline. Hyperglycemic clamp showed that both 1st (129.15 +/- 23.6 vs 106.90 +/- 18.6 pmol/L; p=0.01) and 2nd phase (189.42 +/- 34.4 vs 144.21 +/- 37.3 pmol/L; p=0.003) B-cell response to glucose as well as area under the curve (52.07 +/- 10.86 vs 39.54 +/- 10.27 micromol/L x 120'; p=0.005) were greater in R than G groups. Insulin action (4.0 +/- 1.1 vs 3.2 +/- 0.9 mg x Kg x 60'/microU/mL; p=0.046) was also improved by R than G administration. In the meal test, R therapy produced a more rapId induction of insulin secretion during the first part. In fact, the mean rise in insulin secretion peaked at 45 min in R (p=0.001 vs G) and at 60 min in G (p=0.001 vs R). Consequently, glucose spike at 60 min was higher in G group compared to glucose spike at 45 min in R group (p=0.002). CONCLUSIONS: Our study demonstrates that R is more efficient that G on improving glucose- and meal- induced insulin secretion as well as on controlling for postprandial glucose excursion.

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PubMed2003

Measurement of prompt charm meson production cross sections in pp collisions at square root s = 1.96 TeV.

We report on measurements of differential cross sections dsigma/dp(T) for prompt charm meson production in ppmacr; collisions at sqrt[s]=1.96 TeV using 5.8+/-0.3 pb(-1) of data from the CDF II detector at the Fermilab Tevatron. The data are collected with a new trigger that is sensitive to the long lifetime of hadrons containing heavy flavor. The charm meson cross sections are measured in the central rapidity region |y|</=1 in four fully reconstructed decay modes: D0-->K-pi(+), D(*+)-->D0pi(+), D+-->K-pi(+)pi(+), D(+)(s)-->phipi(+), and their charge conjugates. The measured cross sections are compared to theoretical calculations.

Journal Article↗
PubMed2003

Search for lepton flavor violating decays of a heavy neutral particle in p(-)p collisions at sqrt[s]=1.8 TeV.

We report on a search for a high mass, narrow width particle that decays directly to emu, etau, or microtau. We use approximately 110 pb(-1) of data collected with the Collider Detector at Fermilab from 1992 to 1995. No evidence of lepton flavor violating decays is found. Limits are set on the production and decay of sneutrinos with R-parity violating interactions.

Journal Article↗
PubMed2003

Central pseudorapidity gaps in events with a leading antiproton at the fermilab tevatron pp collider.

We report a measurement of the fraction of events with a large pseudorapidity gap deltaeta within the pseudorapidity region available to the proton dissociation products X in p+p-->p+X. For a final state p of fractional momentum loss xi(p) and 4-momentum transfer squared t(p) within 0.06 3 is found to be 0.246+/-0.001 (stat)+/-0.042 (syst) [0.184+/-0.001 (stat)+/-0.043 (syst)]. Our results are compared with gap fractions measured in minimum bias pp collisions and with theoretical expectations.

Journal Article↗
PubMed2003

Search for the supersymmetric partner of the top quark in dilepton events from pp collisions at square root of s=1.8 TeV.

We have searched for pair production of the supersymmetric partner of the top quark (stop) in 107 pb(-1) of pp collisions at square root of s=1.8 TeV collected by the Collider Detector at Fermilab (CDF). Each stop is assumed to decay into a lepton, bottom quark, and supersymmetric neutrino. Such a scenario would give rise to events with two leptons, two hadronic jets, and a substantial imbalance of transverse energy. No evidence of such a stop signal has been found. We exclude stop masses in the region (80</=m(t)</=135 GeV/c(2)) in the mass plane of stop versus sneutrino.

Journal Article↗
PubMed2003

Search for long-lived charged massive particles in pp collisions at square root s = 1.8 TeV.

We report a search for the production of long-lived charged massive particles in a data sample of 90 pb(-1) of square root[s]=1.8 TeV pp collisions recorded by the Collider Detector at Fermilab. The search uses the muonlike penetration and anomalously high ionization energy loss signature expected for such a particle to discriminate it from backgrounds. The data are found to agree with background expectations, and cross section limits of O(1) pb are derived using two reference models, a stable quark and a stable scalar lepton.

Journal Article↗
PubMed2003

Search for a W' boson decaying to a top and bottom quark pair in 1.8 TeV pp collisions.

We report the results of a search for a W' boson produced in pp; collisions at a center-of-mass energy of 1.8 TeV using a 106 pb(-1) data sample recorded by the Collider Detector at Fermilab. We observe no significant excess of events above background for a W' boson decaying to a top and bottom quark pair. In a model where this boson would mediate interactions involving a massive right-handed neutrino (nu(R)) and have standard model strength couplings, we use these data to exclude a W' boson with mass between 225 and 536 GeV/c(2) at 95% confidence level for M(W')>>M(nu(R)) and between 225 and 566 GeV/c(2) at 95% confidence level for M(W')<M(nu(R)).

Journal Article↗
PubMed2003

Second harmonic imaging improves trans-abdominal ultrasound detection of biliary sludge in 'idiopathic' pancreatitis.

BACKGROUND: Recently, biliary sludge has been strongly correlated with 'idiopathic pancreatitis'. It is often diagnosed by trans-abdominal ultrasonography, despite the low sensitivity of this investigation. New scanners, using second harmonic imaging, may improve the quality of the echographic picture. AIM: To verify the impact of this methodology on the detection of biliary sludge in patients with 'idiopathic' pancreatitis. METHODS: Fifty patients with 'idiopathic' pancreatitis observed over a 18-month period entered the study. Exclusion criteria were gall-bladder stones, polyps, clinical conditions related to biliary sludge development and haemolytic disorders. Patients were assessed blind by two operators using either conventional ultrasonography or second harmonic imaging. The parameters of diagnostic quality of both examinations were evaluated using, as the gold standard, microscopic examination of the gall-bladder content collected at endoscopy after cholecystokinin infusion. RESULTS: An improvement in sensitivity, specificity, efficiency and negative predictive value was obtained by second harmonic imaging compared with conventional ultrasonography. CONCLUSIONS: Second harmonic imaging, in our experience, is a reliable non-invasive tool for the diagnosis and follow-up of biliary sludge in the course of 'idiopathic' pancreatitis.

Acute Disease↗
PubMed2003

Mycophenolate mofetil in the treatment of autoimmune HCV-associated haematological disorders showing steroid resistance or dependence.

We report two cases of hepatitis C virus (HCV) associated autoimmune haematological disorders successfully treated with an unusual protocol (mycophenolate mofetil: MMF). The first case was a male patient with chronic HCV infection who developed, during interferon (IFN)/ribavirin therapy, severe autoimmune thrombocytopenia unresponsive to steroids. MMF was then administered and, simultaneously, the steroid dose was gradually reduced until withdrawal. Following this strategy, a progressive increase in platelet count and complete negativity of anti-PLT antibodies were achieved without changes in HCV-RNA quantitative determination. The second case was a woman with HCV liver cirrhosis with severe anaemia and Coombs test positivity partially responsive to continuous administration of steroid high doses. However, this treatment unmasked a severely painful vertebral osteoporosis. For this reason we introduced MMF and simultaneously steroid therapy was progressively reduced until withdrawal. Haemoglobin reached a normal value and the Coombs test became negative within 60 days. These case reports suggest that MMF may represent an interesting therapeutic approach for autoimmune HCV associated haematological disorders.

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