79 research outputs found
Search for supersymmetric particles assuming R-parity non-conservation in collisions at =192 to 208 GeV
Search for pair production of supersymmetric particles with R-parity violating LLE couplings at = 192-202 GeV$
The influence of the global atmospheric properties on the detection of UHECR by EUSO on board of the ISS
The influence of the global atmospheric properties on the detection of UHECR by EUSO on board of the ISS
Cross sections for the excitation of isovector charge-exchange resonances in 208Tl
The Glauber approximation for the treatment of heavy-ion scattering, has
already been shown to give reliable predictions for the reaction cross section
in the particular case of intermediate energy charge-exchange processes. In the
present work, we couple a Glauber-type model to microscopic Random Phase
Approximation calculations of the charge-exchange excitations of Pb.
The aim is to solve the longstanding question whether the very elusive
charge-exchange isovector monopole has been really identified in the past
experiments, or other multipoles were prevalent in the observed spectra.Comment: text + 4 figures; accepted for publication in Phys. Rev.
The EUSO simulation and analysis framework
ESAF is the simulation and analysis software framework developed for the EUSO experiment. ESAF's scope is the whole process of data simulations and data-analysis, from the primary particle interaction in atmosphere to the reconstruction of the event. Based on the ROOT package and designed using Object Oriented technology, ESAF is organized in two main programs: the full montecarlo simulation and the reconstruction framework. The former includes all the relevant physical contributions, shower development in atmosphere, light transport to the detector pupil and detector response, while the latter comprises basic data cleaning, track direction, shower profile and energy reconstruction algorithms. Here we describe the software architecture and its main features
Annexin-A5 assembled into two-dimensional arrays promotes cell membrane repair
Eukaryotic cells possess a universal repair machinery that ensures rapid resealing of plasma membrane disruptions. Before resealing, the torn membrane is submitted to considerable tension, which functions to expand the disruption. Here we show that annexin-A5 (AnxA5), a protein that self-assembles into two-dimensional (2D) arrays on membranes upon Ca2+ activation, promotes membrane repair. Compared with wild-type mouse perivascular cells, AnxA5-null cells exhibit a severe membrane repair defect. Membrane repair in AnxA5-null cells is rescued by addition of AnxA5, which binds exclusively to disrupted membrane areas. In contrast, an AnxA5 mutant that lacks the ability of forming 2D arrays is unable to promote membrane repair. We propose that AnxA5 participates in a previously unrecognized step of the membrane repair process: triggered by the local influx of Ca2+, AnxA5 proteins bind to torn membrane edges and form a 2D array, which prevents wound expansion and promotes membrane resealing
Search for the exotic Resonance in 340GeV/c -Nucleus Interactions
We report on a high statistics search for the resonance in
-nucleus collisions at 340GeV/c. No evidence for this resonance is
found in our data sample which contains 676000 candidates above
background. For the decay channel and the
kinematic range 0.150.9 we find a 3 upper limit for the
production cross section of 3.1 and 3.5 b per nucleon for reactions with
carbon and copper, respectively.Comment: 5 pages, 4 figures, modification of ref. 43 and 4
Measurement of the Omega_c Lifetime
We present the measurement of the lifetime of the Omega_c we have performed
using three independent data samples from two different decay modes. Using a
Sigma- beam of 340 GeV/c we have obtained clean signals for the Omega_c
decaying into Xi- K- pi+ pi+ and Omega- pi+ pi- pi+, avoiding topological cuts
normally used in charm analysis. The short but measurable lifetime of the
Omega_c is demonstrated by a clear enhancement of the signals at short but
finite decay lengths. Using a continuous maximum likelihood method we
determined the lifetime to be tau(Omega_c) = 55 +13-11(stat) +18-23(syst) fs.
This makes the Omega_c the shortest living weakly decaying particle observed so
far. The short value of the lifetime confirms the predicted pattern of the
charmed baryon lifetimes and demonstrates that the strong interaction plays a
vital role in the lifetimes of charmed hadrons.Comment: 15 pages, including 7 figures; gzipped, uuencoded postscrip
Search for the pentaquark candidate (1540) in the hyperon beam experiment WA89
We report on a high-statistics search for the \t1540 resonance in
-nucleus collisions at 340 \gevc1 . No evidence for this resonance
was found in our data sample which contains 13 millions
decays above background. For the decay channel and the
kinematic range 0.05 we find the production cross section to be
1.8 b per nucleon at 99% CL.Comment: 5 pages, 4 figure
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