We present results from a measurement of double diffraction dissociation in pp collisions at the Fermilab Tevatron collider. The production cross section for events with a central pseudorapidity gap of width Deltaeta(0)>3 (overlapping eta = 0) is found to be 4.43+/-0.
View Article and Find Full Text PDFWe report on a measurement of the mass dependence of the forward-backward charge asymmetry, A(FB), and production cross section d sigma/dM for e(+)e(-) pairs with mass M(ee)>40 GeV/c(2). The data sample consists of 108 pb(-1) of pp macro collisions at square root of s = 1.8 TeV taken by the Collider Detector at Fermilab during 1992-1995.
View Article and Find Full Text PDFWe have measured the p(T) distribution of top quarks that are pair produced in pp collisions at sqrt[s] = 1.8 TeV using a sample of tt decays in which we observe a single high- p(T) charged lepton, a neutrino, and four or more jets. We use a likelihood technique that corrects for the experimental bias introduced due to event reconstruction and detector resolution effects.
View Article and Find Full Text PDFWe present the results of a search for neutral Higgs bosons produced in association with b quarks in pp-->bb(phi)-->bbb final states with 91+/-7 pb(-1) of pp collisions at sqrt[s] = 1.8 TeV recorded by the Collider Detector at Fermilab. We find no evidence of such a signal and the data are interpreted in the context of the neutral Higgs sector of the minimal supersymmetric extension of the standard model.
View Article and Find Full Text PDFWe have measured the ratio of prompt production rates of the charmonium states chi(c1) and chi(c2) in 110 pb(-1) of pp collisions at sqrt[s] = 1.8 TeV. The photon from their decay into J/psi(gamma) is reconstructed through conversion into e+e- pairs.
View Article and Find Full Text PDFWe present the first measurement of the ratio of branching fractions R identical withB(t-->Wb)/B(t-->Wq) from p_p collisions at sqrt[s] = 1.8 TeV. The data set corresponds to 109 pb(-1) of data recorded by the Collider Detector at Fermilab during the 1992-95 Tevatron run.
View Article and Find Full Text PDFWe have measured the polarization of J/psi and psi(2S) mesons produced in pp collisions at sqrt[s] = 1.8 TeV, using data collected at the Collider Detector at Fermilab during 1992-1995. The polarization of promptly produced J/psi [psi(2S)] mesons is isolated from those produced in B-hadron decay, and measured over the kinematic range 4 [5.
View Article and Find Full Text PDFWe 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 107 pb-1 data sample recorded by the Collider Detector at Fermilab. We consider the decay channel W'-->&munumu and search for anomalous production of high transverse mass munumu lepton pairs.
View Article and Find Full Text PDFWe have searched for direct pair production of scalar top and scalar bottom quarks in 88 pb-1 of pp collisions at sqrt[s]=1.8 TeV with the CDF detector. We looked for events with a pair of heavy flavor jets and missing energy, consistent with scalar top (bottom) quark decays to a charm (bottom) quark and a neutralino.
View Article and Find Full Text PDFWe have studied the production of B hadrons in 1.8-TeV pp[over ¯] collisions. We present measurements of the fragmentation fractions, f_{u}, f_{d}, f_{s}, and f_{baryon}, of produced b quarks that yield B^{+}, B^{0}, B_{s}^{0}, and Λ[over ¯]_{b}^{0} hadrons.
View Article and Find Full Text PDFWe present in this paper a simulation of cometary spectra between 3 and 4 micrometers performed by using the optical properties of various carbon-based materials measured at different temperatures in the range 300-520 K. In our computations we have used new laboratory data obtained for hydrogenated amorphous carbon (HAC) grains and three kinds of polycyclic aromatic hydrocarbons (PAHs). All these materials show significant features in the near IR region; however, only the synthetic spectra obtained from HAC grains show a satisfactory agreement with the profile of the cometary bands.
View Article and Find Full Text PDFActa Otolaryngol Suppl
October 1984
Sixteen children with benign paroxysmal vertigo (BPV) are presented. The great majority had a family history of migraine, neurological and autonomic signs associated with vertiginous attacks, and headache or other sign of the periodic syndrome (motion sickness, cyclic vomiting, abdominal pain) unrelated to the attacks. Vestibular examination, including bithermal caloric and rotational testing with ENG recording, showed normal or transiently decreased vestibular function.
View Article and Find Full Text PDFORL J Otorhinolaryngol Relat Spec
April 1984
The two main problems in defining and classifying the syndrome of benign paroxysmal vertigo (BPV) in childhood are the vestibular function pattern and the relationship between BPV and migraine. 13 children suffering from this syndrome were submitted to complete otoneurological examination, including caloric and rotational labyrinthine stimulation with ENG recording, and to headache provocation tests with nitroglycerin, histamine and fenfluramine. Vestibular responses were normal in all except 2 cases which presented signs of central vestibular impairment at the level of the vestibulocerebellar pathways.
View Article and Find Full Text PDFG Ital Med Lav
September 1983
The Authors report the results of an investigation carried out in a factory producing tartaric acid in order to evaluate the effects of occupational exposure to this substance. A group of 44 subjects exposed to the acid and a group of 30 subjects not exposed, as a means of control, were submitted to anamnestic questionnaire, othorinolaringoyatric examination, spirometry, bronchodilatation test with salbutamol. Our data show a higher prevalence of oropharyngeal and cutaneous lesions in the exposed subjects, while no difference between the two groups was found for dental, bronchial and gastric lesions.
View Article and Find Full Text PDFActa Otorhinolaryngol Ital
September 1983