A. Zanetti | Università degli studi di Pavia (original) (raw)

Papers by A. Zanetti

Research paper thumbnail of Search for New Dielectron Resonances and Randall-Sundrum Gravitons at the Collider Detector at Fermilab

Physical Review Letters, 2011

A search for new dielectron mass resonances using data recorded by the CDF II detector and corres... more A search for new dielectron mass resonances using data recorded by the CDF II detector and corresponding to an integrated luminosity of 5.7 fb −1 is presented. No significant excess over the expected standard model prediction is observed. In this dataset, an event with the highest dielectron mass ever observed (960 GeV/c 2 ) was recorded. The results are interpreted in the Randall-Sundrum (RS) model. Combined with the 5.4 fb −1 diphoton analysis, the RS-graviton lower mass limit for the coupling k/M P l = 0.1 is 1058 GeV/c 2 , making it the strongest limit to date.

Research paper thumbnail of Search for First Generation Scalar Leptoquark Pairs in pp¯ Collisions at s=1.8 TeV

Physical Review Letters, 1998

Search for first generation scalar leptoquarks in pp collisions at √ s = 7 TeV with the ATLAS det... more Search for first generation scalar leptoquarks in pp collisions at √ s = 7 TeV with the ATLAS detector ✩ .ATLAS Collaboration a r t i c l e i n f o a b s t r a c t

Research paper thumbnail of Measurement of the top-quark mass in the lepton+jets channel using a matrix element technique with the CDF II detector

Physical Review D, 2011

This letter reports a measurement of the top quark mass, Mtop, in data from pp collisions at √ s ... more This letter reports a measurement of the top quark mass, Mtop, in data from pp collisions at √ s = 1.96 TeV corresponding to 2.7 fb −1 of integrated luminosity at the Fermilab Tevatron using the CDF II detector. Events with the lepton+jets topology are selected. An unbinned likelihood is constructed based on the dependence of the lepton transverse momentum, PT, on Mtop. A maximum likelihood fit to the data yields a measured mass Mtop = 176.9 ± 8.0stat ± 2.7syst GeV/c 2 . In this measurement, the contribution by the jet energy scale uncertainty to the systematic error is negligible. The result provides an important consistency test for other Mtop measurements where explicit use of the jet energy is made for deriving the top quark mass. * Deceased † With visitors from

Research paper thumbnail of Origin of LREE-depleted amphiboles in the subcontinental mantle

Geochimica et Cosmochimica Acta, 1995

Research paper thumbnail of Nb and Ta incorporation and fractionation in titanian pargasite and kaersutite: crystal–chemical constraints and implications for natural systems

Earth and Planetary Science Letters, 2000

New partition coefficients between liquid and pargasitic/kaersutitic amphiboles ( AmphaL D Nb , T... more New partition coefficients between liquid and pargasitic/kaersutitic amphiboles ( AmphaL D Nb , Ta ) experimentally determined for Nb and Ta at upper-mantle conditions, combined with single-crystal structure refinement of the synthesised amphiboles, show that AmphaL D NbYTa are strongly dependent on the structure and composition of both amphibole and melt. The correlation of the AmphaL D NbYTa with the amphibole oxy-component is explained by the ordering of Nb and Ta at the M1 site, contributing with the fraction of Ti at M1 to locally balance the O3 O 23 H O3 (OH) 3 substitution. In our set of dehydrogenated amphiboles, variations in the SiO 2 content of the melt from 41.5 to 54.6 correspond to a six-fold increase of the AmphaL D NbYTa , in which AmphaL D Nb varies from 0.14 to 0.71 and AmphaL D Ta from 0.11 to 0.54. Partition coefficients for Nb and Ta abruptly increase in Ti-depleted compositions ( AmphaL D Nb up to 1.63 and AmphaL D Ta to 1.00). The ratio of D Nb to D Ta ( AmphaL D NbaTa ) varies from 0.71 to 1.63, and is a function of the M1 site dimension, which in turn depends on its Fe, Mg and Ti contents. The observed variations can be explained by assuming that the ionic radius of Nb is (V0.01^0.02 A î ) larger than that of Ta, contrary to the common assumption that they are both equal to 0.64 A î . We calibrated a simplified model for the prediction of AmphaL D NbaTa values shown to be negatively related mainly to mg# [Mg/(Mg+Fe)] and to Ti content. High-mg# amphiboles have AmphaL D NbaTa close to unity, so the low Nb/Ta found in convergent margin volcanics and in the continental crust cannot be explained by the involvement of amphibole in the mantle wedge. Amphibole in the subducting slab may have lower mg# and consequently high Nb/Ta values, and thus may give rise to subchondritic Nb/Ta values in coexisting melts. Nb/La is also negatively correlated with mg#, and strongly increases in Ti-depleted compositions. ß

Research paper thumbnail of The effect of oxo-component on the high-pressure behavior of amphiboles

American Mineralogist, 2010

Research paper thumbnail of EVIDENCE FOR PERVASIVE MELT MIGRATION OF EXTREMELY DEPLETED MELTS IN MANTLE PERIDOTITES FROM SUPRA-SUBDUCTION ZONE: AN EXAMPLE FROM THE IZU-BONIN-MARIANA FOREARC

Abstract The petrographic, mineralogical and geochemical features of the serpentinites recovered ... more Abstract The petrographic, mineralogical and geochemical features of the serpentinites recovered at the top of three seamounts located in the Izu-Bonin-Mariana forearc (South Chamorro, Site 1200, ODP Leg 195; Conical, Site 779A, Leg 125; Torishima, Site 784A, ...

Research paper thumbnail of A crystal chemical re-evaluation of amphibole/melt and amphibole/clinopyroxene DTi values in petrogenetic studies

American …, 2000

Constraints on the calculation and use of mineral/melt and two-mineral partition coefficients for... more Constraints on the calculation and use of mineral/melt and two-mineral partition coefficients for Ti (D Ti ) have been derived from current knowledge of the distinct crystal-chemical mechanisms for the incorporation of Ti 4+ in the amphibole structure as follows: (1) mineral/melt ...

Research paper thumbnail of Search for New Dielectron Resonances and Randall-Sundrum Gravitons at the Collider Detector at Fermilab

Physical Review Letters, 2011

A search for new dielectron mass resonances using data recorded by the CDF II detector and corres... more A search for new dielectron mass resonances using data recorded by the CDF II detector and corresponding to an integrated luminosity of 5.7 fb −1 is presented. No significant excess over the expected standard model prediction is observed. In this dataset, an event with the highest dielectron mass ever observed (960 GeV/c 2 ) was recorded. The results are interpreted in the Randall-Sundrum (RS) model. Combined with the 5.4 fb −1 diphoton analysis, the RS-graviton lower mass limit for the coupling k/M P l = 0.1 is 1058 GeV/c 2 , making it the strongest limit to date.

Research paper thumbnail of Search for First Generation Scalar Leptoquark Pairs in pp¯ Collisions at s=1.8 TeV

Physical Review Letters, 1998

Search for first generation scalar leptoquarks in pp collisions at √ s = 7 TeV with the ATLAS det... more Search for first generation scalar leptoquarks in pp collisions at √ s = 7 TeV with the ATLAS detector ✩ .ATLAS Collaboration a r t i c l e i n f o a b s t r a c t

Research paper thumbnail of Measurement of the top-quark mass in the lepton+jets channel using a matrix element technique with the CDF II detector

Physical Review D, 2011

This letter reports a measurement of the top quark mass, Mtop, in data from pp collisions at √ s ... more This letter reports a measurement of the top quark mass, Mtop, in data from pp collisions at √ s = 1.96 TeV corresponding to 2.7 fb −1 of integrated luminosity at the Fermilab Tevatron using the CDF II detector. Events with the lepton+jets topology are selected. An unbinned likelihood is constructed based on the dependence of the lepton transverse momentum, PT, on Mtop. A maximum likelihood fit to the data yields a measured mass Mtop = 176.9 ± 8.0stat ± 2.7syst GeV/c 2 . In this measurement, the contribution by the jet energy scale uncertainty to the systematic error is negligible. The result provides an important consistency test for other Mtop measurements where explicit use of the jet energy is made for deriving the top quark mass. * Deceased † With visitors from

Research paper thumbnail of Origin of LREE-depleted amphiboles in the subcontinental mantle

Geochimica et Cosmochimica Acta, 1995

Research paper thumbnail of Nb and Ta incorporation and fractionation in titanian pargasite and kaersutite: crystal–chemical constraints and implications for natural systems

Earth and Planetary Science Letters, 2000

New partition coefficients between liquid and pargasitic/kaersutitic amphiboles ( AmphaL D Nb , T... more New partition coefficients between liquid and pargasitic/kaersutitic amphiboles ( AmphaL D Nb , Ta ) experimentally determined for Nb and Ta at upper-mantle conditions, combined with single-crystal structure refinement of the synthesised amphiboles, show that AmphaL D NbYTa are strongly dependent on the structure and composition of both amphibole and melt. The correlation of the AmphaL D NbYTa with the amphibole oxy-component is explained by the ordering of Nb and Ta at the M1 site, contributing with the fraction of Ti at M1 to locally balance the O3 O 23 H O3 (OH) 3 substitution. In our set of dehydrogenated amphiboles, variations in the SiO 2 content of the melt from 41.5 to 54.6 correspond to a six-fold increase of the AmphaL D NbYTa , in which AmphaL D Nb varies from 0.14 to 0.71 and AmphaL D Ta from 0.11 to 0.54. Partition coefficients for Nb and Ta abruptly increase in Ti-depleted compositions ( AmphaL D Nb up to 1.63 and AmphaL D Ta to 1.00). The ratio of D Nb to D Ta ( AmphaL D NbaTa ) varies from 0.71 to 1.63, and is a function of the M1 site dimension, which in turn depends on its Fe, Mg and Ti contents. The observed variations can be explained by assuming that the ionic radius of Nb is (V0.01^0.02 A î ) larger than that of Ta, contrary to the common assumption that they are both equal to 0.64 A î . We calibrated a simplified model for the prediction of AmphaL D NbaTa values shown to be negatively related mainly to mg# [Mg/(Mg+Fe)] and to Ti content. High-mg# amphiboles have AmphaL D NbaTa close to unity, so the low Nb/Ta found in convergent margin volcanics and in the continental crust cannot be explained by the involvement of amphibole in the mantle wedge. Amphibole in the subducting slab may have lower mg# and consequently high Nb/Ta values, and thus may give rise to subchondritic Nb/Ta values in coexisting melts. Nb/La is also negatively correlated with mg#, and strongly increases in Ti-depleted compositions. ß

Research paper thumbnail of The effect of oxo-component on the high-pressure behavior of amphiboles

American Mineralogist, 2010

Research paper thumbnail of EVIDENCE FOR PERVASIVE MELT MIGRATION OF EXTREMELY DEPLETED MELTS IN MANTLE PERIDOTITES FROM SUPRA-SUBDUCTION ZONE: AN EXAMPLE FROM THE IZU-BONIN-MARIANA FOREARC

Abstract The petrographic, mineralogical and geochemical features of the serpentinites recovered ... more Abstract The petrographic, mineralogical and geochemical features of the serpentinites recovered at the top of three seamounts located in the Izu-Bonin-Mariana forearc (South Chamorro, Site 1200, ODP Leg 195; Conical, Site 779A, Leg 125; Torishima, Site 784A, ...

Research paper thumbnail of A crystal chemical re-evaluation of amphibole/melt and amphibole/clinopyroxene DTi values in petrogenetic studies

American …, 2000

Constraints on the calculation and use of mineral/melt and two-mineral partition coefficients for... more Constraints on the calculation and use of mineral/melt and two-mineral partition coefficients for Ti (D Ti ) have been derived from current knowledge of the distinct crystal-chemical mechanisms for the incorporation of Ti 4+ in the amphibole structure as follows: (1) mineral/melt ...