Using a large sample of pure, slow, short lived
K
0
mesons collected with KLOE detector at DAΦNE, we have measured the
K
S
lifetime. From a fit to the proper time distribution we find
τ
(
K
S
...)=(89.562±0.029
stat
±0.043
syst
) ps. This is the most precise measurement to date of the short lived
K
0
meson lifetime, in good agreement with the world average derived from previous measurements. We observe no dependence of the lifetime on the direction of the
K
S
in galactic coordinates.
We present a measurement of the KL lifetime using the KLOE detector. From a sample of ∼4×108KSKL pairs following the reaction e+e−→ϕ→KSKL we select ∼15×106KL→π0π0π0 decays tagged by KS→π+π− events. ...From a fit of the proper time distribution we find τL=(50.92±0.17stat±0.25syst) ns. This is the most precise measurement of the KL lifetime performed to date.
Solitary plasmacytoma is plasma cell neoplasm. It is a localized bone disease and for this reason it is different from multiple myeloma (systemic plasma cell neoplasm). Sometimes, solitary ...plasmacytoma precedes a following multiple myeloma. Clinical findings of solitary plasmacytoma are related to the univocal localization on damaged bone, while laboratory findings could be similar to multiple myeloma (i.e. M component, kidney dysfunction, blood calcium alterations, increased beta-2-microglobulin). However, during a solitary plasmacytoma, laboratory findings could not be present contemporaneously such clinical complications (i.e. kidney failure, immunological disorders with a trend toward infectious disease and/or autoimmunity, neurological disorders, haematological disorders, amyloidosis, POEMS syndrome). These raise the reason because solitary plasmacytoma has better prognosis compared to multiple myeloma.
Measurement of with the KLOE detector Babusci, D; Badoni, D; Balwierz-Pytko, I ...
Physics letters. B,
01/2013, Volume:
718, Issue:
3
Journal Article
Peer reviewed
The ratio R IDT = Phi (IDT a pi + pi - gamma ) / Phi (IDT a pi + pi - pi 0) has been measured by analysing 22 million I a IDT gamma decays collected by the KLOE experiment at DAIBBNE, corresponding ...to an integrated luminosity of 558 pb-1. The IDT a pi + pi - gamma proceeds both via the I resonant contribution, and possibly a non-resonant direct term, connected to the box anomaly. Our result, R IDT = 0.1856 +/- 0.0005 stat +/- 0.0028 syst , points out a sizable contribution of the direct term to the total width. The di-pion invariant mass for the IDT a pi + pi - gamma decay could be described in a model-independent approach in terms of a single free parameter, alpha . The determined value of the parameter alpha is alpha = (1.32 +/- 0.08 stat - 0.09 syst + 0.10 +/- 0.02 theo) GeV - 2 .
An analysis is presented of events containing jets including at least one b-tagged jet, sizeable missing transverse momentum, and at least two leptons including a pair of the same electric charge, ...with the scalar sum of the jet and lepton transverse momenta being large. A data sample with an integrated luminosity of 20.3 fb(-1) of pp collisions at root s = 8 TeV recorded by the ATLAS detector at the Large Hadron Collider is used. Standard Model processes rarely produce these final states, but there are several models of physics beyond the Standard Model that predict an enhanced rate of production of such events; the ones considered here are production of vector-like quarks, enhanced fourtop-quark production, pair production of chiral b '-quarks, and production of two positively charged top quarks. Eleven signal regions are defined; subsets of these regions are combined when searching for each class of models. In the three signal regions primarily sensitive to positively charged top quark pair production, the data yield is consistent with the background expectation. There are more data events than expected from background in the set of eight signal regions defined for searching for vector-like quarks and chiral b ' quarks, but the significance of the discrepancy is less than two standard deviations. The discrepancy reaches 2.5 standard deviations in the set of five signal regions defined for searching for four-top-quark production. The results are used to set 95% CL limits on various models.
The production of a W boson in association with a single charm quark is studied using 4.6 fb-1 of pp collision data at $ \sqrt{s} $ = 7 TeV collected with the ATLAS detector at the Large Hadron ...Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96$ ^{+0.26}_{-0.30} $ at Q2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally the cross-section ratio σ(W+ + $ \bar{c} $)/σ(W- +c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s–$ \bar{s} $ quark asymmetry.
A search for strongly produced supersymmetric particles is conducted using signatures involving multiple energetic jets and either two isolated leptons (e or μ) with the same electric charge, or at ...least three isolated leptons. The search also utilises jets originating from b-quarks, missing transverse momentum and other observables to extend its sensitivity. The analysis uses a data sample corresponding to a total integrated luminosity of 20.3 fb-1 of $ \sqrt{s} $ = 8 TeV proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider in 2012. No deviation from the Standard Model expectation is observed. New or significantly improved exclusion limits are set on a wide variety of supersymmetric models in which the lightest squark can be of the first, second or third generations, and in which R-parity can be conserved or violated.
We present the result of a direct search for the decay KS→e+e−, obtained with a sample of e+e−→ϕ→KSKL events produced at DAΦNE, the Frascati ϕ-factory, for an integrated luminosity of 1.9 fb−1. The ...search has been performed using a pure KS beam tagged by the simultaneous detection of a KL interaction in the calorimeter. Background rejection has been optimized by using both kinematic and particle identification cuts. We find BR(KS→e+e−)<9×10−9 at 90% CL, which improves by an order of magnitude on the previous best limit.
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