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Search for lepton flavour violating decays tau -> lKs with the BABAR detector
A search for the lepton flavour violating decays tau->lKs has been performed using a data sample corresponding to an integrated luminosity of 469 fb-1, collected with the BABAR
detector at the SLAC PEP-II e+eâ asymmetric energy collider, a selection optimized to obtain the best sensitivity, and the "Modified Frequentist analysis". No statistically significant signal has been observed in either channel and the estimated upper limits on branching fractions are B(tau->e Ks) muKs) < 4.0e-8 at 90% confidence level
Real-time reconstruction of long-lived particles at LHCb using FPGAs
Finding tracks downstream of the magnet at the earliest LHCb trigger level is
not part of the baseline plan of the upgrade trigger, on account of the
significant CPU time required to execute the search. Many long-lived particles,
such as and strange baryons, decay after the vertex track detector, so
that their reconstruction efficiency is limited. We present a study of the
performance of a future innovative real-time tracking system based on FPGAs,
developed within a R\&D effort in the context of the LHCb Upgrade Ib (LHC
Run~4), dedicated to the reconstruction of the particles downstream of the
magnet in the forward tracking detector (Scintillating Fibre Tracker), that is
capable of processing events at the full LHC collision rate of 30 MHz.Comment: ACAT 2019 proceedings. 7 pages, 2 figure
Gamma-spectrometric measurement of radioactivity in agricultural soils of the Lombardia region, northern Italy
Abstract This work is part of a wider monitoring project of the agricultural soils in Lombardia, which aims to build a database of topsoil properties and the potentially toxic elements, organic pollutants and gamma emitting radionuclides that the topsoils contain. A total of 156 agricultural soils were sampled according to the LUCAS (Land Use/Cover Area frame statistical Survey) standard procedure. The aim was to provide a baseline to document the conditions present at the time of sampling. The results of the project concerning soil radioactivity are presented here. The aim was to assess the content of 238U, 232Th, 137Cs and 40K by measuring soil samples by gamma spectrometry. 238U, 232Th and 40K activities range 24â231, 20â70, and 242â1434 Bq kgâ1 respectively. The geographic distribution of 238U reflects the geophysical framework of the Lombardia region: the soils with high content of uranium are distributed for the most part in the South Alpine belt, where the presence of magmatic rocks is widespread. These soils show an higher activity of 238U than of 232Th. The 238U activities become lower than 232Th when soils are located in the plain, originating from basic sedimentary rocks. 137Cs activity ranges 0.4â86.8 kBq mâ2. The lowest activity of 137Cs is in the plain, whereas the highest is in the North on soils kept as lawn or pasture. The 137Cs activity of some samples suggests the presence of accumulation processes that lead to 137Cs enriched soils. This is the first survey of gamma emitting radionuclides in Lombardia that is based on the LUCAS standard sampling. The results from this monitoring campaign are important for the human radiation exposure and provide the zero point, which will be useful for assessing future effects due to external factors such as human activities
Plexiform architecture in gastrointestinal stromal tumors is not restricted to succinate dehydrogenase-deficient cases
Accumulating evidence reveals the heterogeneous features of gastrointestinal stromal tumors (GISTs), primarily distinguished by their various molecular triggers defining well characterized subgroups. The identification of the pathogenetic group a given GIST belongs to, in combination with the currently adopted GIST prognosticators, is pivotal for the correct management of GIST patients. Epidemiological, anatomical and morphological features are more or less strictly associated with the various possible GIST molecular pathogenesis; therefore, they can concur to addressing molecular analysis or even influence the identification of GIST subsets by themselves. This is particularly true in a cost/benefit perspective aimed at cutting the expenses of pathology labs. Under these circumstances, a correct classical pathological analysis still appears a fundamental step to achieve an optimal GIST characterization.We herein report a gastric epithelioid PDGFRA-mutant GIST displaying the multinodular/plexiform architecture distinctive of succinate dehydrogenase (SDH)-deficient GISTs. Immunohistochemistry and molecular analysis led to the correct tumor characterization. The reported case constitutes a valuable contribution to GIST pathology in that it demonstrates that multinodular/plexiform architecture is not restricted to SDH-deficient GISTs, but can be found also in PDGFRA-mutant ones; this is an event to be aware of, given the predilection for gastric location and epithelioid morphology shared by these two GIST subgroups, only the latter of which includes imatinib-sensitive cases. Keywords: Gastrointestinal stromal tumor, Platelet-derived growth factor receptor alpha, Multinodular architecture, Plexiform architecture, Succinate dehydrogenas
Polyamine Oxidase, a Hydrogen Peroxide-Producing Enzyme, Is Up-Regulated by Light and Down-Regulated by Auxin in the Outer Tissues of the Maize Mesocotyl
Measurement of ISR-FSR interference in the processes e+ e- --> mu+ mu- gamma and e+ e- --> pi+ pi- gamma
Charge asymmetry in processes e+ e- --> mu+ mu- gamma and e+ e- --> pi+ pi-
gamma is measured using 232 fb-1 of data collected with the BABAR detector at
center-of-mass energies near 10.58 GeV. An observable is introduced and shown
to be very robust against detector asymmetries while keeping a large
sensitivity to the physical charge asymmetry that results from the interference
between initial and final state radiation. The asymmetry is determined as
afunction of the invariant mass of the final-state tracks from production
threshold to a few GeV/c2. It is compared to the expectation from QED for e+ e-
--> mu+ mu- gamma and from theoretical models for e+ e- --> pi+ pi- gamma. A
clear interference pattern is observed in e+ e- --> pi+ pi- gamma, particularly
in the vicinity of the f_2(1270) resonance. The inferred rate of lowest order
FSR production is consistent with the QED expectation for e+ e- --> mu+ mu-
gamma, and is negligibly small for e+ e- --> pi+ pi- gamma.Comment: 32 pages,29 figures, to be submitted to Phys. Rev.
Search for heavy neutral lepton production in K+ decays
A search for heavy neutral lepton production in K + decays using a data sample collected with a minimum
bias trigger by the NA62 experiment at CERN in 2015 is reported. Upper limits at the 10â7 to 10â6 level
are established on the elements of the extended neutrino mixing matrix |Ue4|
2 and |UΌ4|
2 for heavy
neutral lepton mass in the ranges 170â448 MeV/c2 and 250â373 MeV/c2, respectively. This improves on
the previous limits from HNL production searches over the whole mass range considered for |Ue4|2 and
above 300 MeV/c2 for |UΌ4|2
Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires
The production of tt⟠, W+bb⟠and W+cc⟠is studied in the forward region of protonâproton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fbâ1 . The W bosons are reconstructed in the decays WââÎœ , where â denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of , and is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 0.02 \mbox{fb}^{-1}. The bosons are reconstructed in the decays , where denotes muon or electron, while the and quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions
Measurement of the very rare decay
The decay K+âÏ+ÎœÎœÂŻ
, with a very precisely predicted branching ratio of less than 10â10
,
is among the best processes to reveal indirect effects of new physics.
The NA62 experiment at CERN SPS is designed to study the K+âÏ+ÎœÎœÂŻ
decay and to measure its branching ratio using a decay-in-flight technique.
NA62 took data in 2016, 2017 and 2018, reaching the sensitivity of the Standard Model
for the K+âÏ+ÎœÎœÂŻ
decay by the analysis of the 2016 and 2017 data,
and providing the most precise measurement of the branching ratio to date
by the analysis of the 2018 data.
This measurement is also used to set limits on BR(K+âÏ+X
), where X
is a scalar
or pseudo-scalar particle.
The final result of the BR(K+âÏ+ÎœÎœÂŻ
) measurement and its interpretation in terms
of the K+âÏ+X
decay from the analysis of the full 2016-2018 data set is presented, and future plans and prospects are reviewed
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