The standard model of particle physics is our best description yet of fundamental particles and their interactions, but it is known to be incomplete. As yet undiscovered particles and interactions ...might exist. One of the most powerful ways to search for new particles is by studying processes known as flavour-changing neutral current decays, whereby a quark changes its flavour without altering its electric charge. One example of such a transition is the decay of a beauty quark into a strange quark. Here we review some intriguing anomalies in these decays, which have revealed potential cracks in the standard model-hinting at the existence of new phenomena.
LHCb data quality monitoring Adinolfi, M; Archilli, F; Baldini, W ...
Journal of physics. Conference series,
10/2017, Letnik:
898, Številka:
9
Journal Article
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Data quality monitoring, DQM, is crucial in a high-energy physics experiment to ensure the correct functioning of the experimental apparatus during the data taking. DQM at LHCb is carried out in two ...phases. The first one is performed on-site, in real time, using unprocessed data directly from the LHCb detector, while the second, also performed on-site, requires the reconstruction of the data selected by the LHCb trigger system and occurs later. For the LHC Run II data taking the LHCb collaboration has re-engineered the DQM protocols and the DQM graphical interface, moving the latter to a web-based monitoring system, called Monet, thus allowing researchers to perform the second phase off-site. In order to support the operator's task, Monet is also equipped with an automated, fully configurable alarm system, thus allowing its use not only for DQM purposes, but also to track and assess the quality of LHCb software and simulation over time.
We present a precise measurement of the ratio RK=Γ(K→eν(γ))/Γ(K→μν(γ)) and a study of the radiative process K→eνγ, performed with the KLOE detector. The results are based on data collected at the ...Frascati e+e− collider DAΦNE for an integrated luminosity of 2.2 fb−1. We find RK=(2.493±0.025stat±0.019syst)×10−5, in agreement with the Standard Model expectation. This result is used to improve constraints on parameters of the Minimal Supersymmetric Standard Model with lepton flavor violation. We also measured the differential decay rate dΓ(K→eνγ)/dEγ for photon energies 10<Eγ< 250 MeV. Results are compared with predictions from theory.
Using a large sample of pure, slow, short lived K0 mesons collected with KLOE detector at DAΦNE, we have measured the KS lifetime. From a fit to the proper time distribution we find ...τ(KS)=(89.562±0.029stat±0.043syst) ps. This is the most precise measurement to date of the short lived K0 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 KS in galactic coordinates.
In recent works we presented the results of the characterization and the study of performance of several Silicon Photomultipliers delivered from MEPHI (Moscow Engineering and Physics Institute) and ...we proposed an electrical model of the SiPM to be used in analog simulations for the VLSI design of the pilot chip with
0.35
μ
m
technology produced. The results of the simulations was also presented. In this work we present the results of several test performed on the SiPM connected to the pilot chip. We also describe the prototype board with a micro-controller designed to adjust the parameters of the chip and to provide an adjustable and temperature controlled power supply to the SiPM. The results of the tests obtained allow us to refine the circuits design for the next chip. This chip has been developed inside the ALTCRISS and KLOE collaboration.
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