[en] Rare lepton decays of the B0 (s) mesons are sensitive probes of New Physics. The search for the decays B⁰_(s)⟶μ⁺μ^- may provide information on the presence of new (pseudo-) scalar particles. Also the study of the electroweak penguin processes are powerful probes for new physics, as physics beyond the Standard Model (SM) can enter via virtual particles at the same level as SM physics. The Tevatron collider opened the way to high precision Heavy Flavor physics at hadron collider experiments, while the LHCb experiment definitively proved the physics performances are competitive with the B-factories. This is a short review of the searches of rare decays performed at the hadron colliders.

[en] 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. (paper)

[en] The Kloe experiment has collected 2.5 fg^-1 of e^- e^- collision at the φ peak and about 300 pb^-1 in the center-of-mass energy region 1000-1030 MeV. Data taken on peak are used to study the properties of light scalar and pseudoscalar mesons, produced through φ radioactive decays, and to precisely measure the pion form factor using Initial State Radiation events. Energy scan data are used to measure the cross section of the process e^- e^- → ωπ⁰ as a function of the center-of-mass energy and to perform a preliminary study of the reaction e^- e^- → e^- e^- ππ⁰.

[en] 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 0.35μm 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.

[en] The KLOE experiment has collected an integrated luminosity of about 2.5 fb^-1 at the φ factory DAφNE. φ radiative decays have been used to investigate the properties of the light scalar mesons f₀(980)/a₀(980), whose structure is still controversial.A direct search of σ(600)→π⁰π⁰ decay has been performed with data taken at 1 GeV, where φ decays are suppressed.The whole KLOE data set includes also 100 million η's produced through the radiative decay φ→ηγ and tagged by means of the monochromatic recoil photon. From this sample we have investigated η decays relevant to test ChPT predictions. We present published and preliminary results achieved from full statistics.

[en] Using a sample of over 600 million φ → K⁺K^- decays collected at the DAΦNE e⁺e^- collider, we have measured with the KLOE detector the absolute branching ratios for the charged kaon semileptonic decays, K^± → π⁰e^±ν(γ) and K^± → π⁰μ^±ν(γ). The results, BR(K_e3) = 0.04965±0.00038_stat±0.00037_syst and BR(K_μ3) = 0.03233±0.00029_stat±0.00026_syst, are inclusive of radiation. Accounting for correlations, we derive the ratio Γ(K_μ3)/Γ(K_e3) = 0.6511±0.0064. Using the semileptonic form factors measured in the same experiment, we obtain |V_us f₊(0)| = 0.2141 ±0.0013$

[en] We have measured the charged kaon lifetime using a sample of 15 x 10⁶ tagged kaon decays. Charged kaons were produced in pairs at the DAΦNE φ-factory, e⁺e^- → φ → K⁺K^-. The decay of a K⁺ was tagged by the production of a K^- and viceversa. The lifetime was obtained, for both charges, from independent measurements of the decay time and decay length distributions. From fits to the four distributions we find τ = (12.347±0.030) ns

[en] A method is described which allows to deduce the dead-time of the front-end electronics of the LHCb muon detector from a series of measurements performed at different luminosities at a bunch-crossing rate of 20 MHz. The measured values of the dead-time range from ∼ 70 ns to ∼ 100 ns. These results allow to estimate the performance of the muon detector at the future bunch-crossing rate of 40 MHz and at higher luminosity

[en] The LHCb Outer Tracker is a gaseous detector covering an area of 5 × 6 m² with 12 double layers of straw tubes. The performance of the detector is presented based on data of the LHC Run 2 running period from 2015 and 2016. Occupancies and operational experience for data collected in pp, pPb and PbPb collisions are described. An updated study of the ageing effects is presented showing no signs of gain deterioration or other radiation damage effects. In addition several improvements with respect to LHC Run 1 data taking are introduced. A novel real-time calibration of the time-alignment of the detector and the alignment of the single monolayers composing detector modules are presented, improving the drift-time and position resolution of the detector by 20%. Finally, a potential use of the improved resolution for the timing of charged tracks is described, showing the possibility to identify low-momentum hadrons with their time-of-flight.

[en] Muon identification is of paramount importance for the physics programme of LHCb. In the upgrade phase, starting from Run 3 of the LHC, the trigger of the experiment will be solely based on software. The luminosity increase to $2\times <!--\; ??\; -->{10}^{33}$ cm${}^{-<!--\; ???\; -->2}$s${}^{-<!--\; ???\; -->1}$ will require an improvement of the muon identification criteria, aiming at performances equal or better than those of Run 2, but in a much more challenging environment. In this paper, two new muon identification algorithms developed in view of the /lhcb upgrade are presented, and their performance in terms of signal efficiency versus background reduction is shown.