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The hadroproduction experiments HARP and NA61 (SHINE) as well as their implications for neutrino physics are discussed. Recent HARP measurements have already been used for precise predictions of neutrino beams in K2K and MiniBooNE/SciBooNE experiments and are also being used to improve the atmospheric neutrino flux predictions and to help in the optimization of neutrino factory and super-beam designs. First preliminary data from NA61 are of significant importance for a precise prediction of a new neutrino beam at J-PARC to be used for the first stage of the T2K experiment. Both HARP and NA61 provide a large amount of input for validation and tuning of hadroproduction models in Monte-Carlo generators. THE HARP EXPERIMENTThe HARP experiment [1, 2] at the CERN PS was designed to make measurements of hadron yields from a large range of nuclear targets and for incident particle momenta from 1.5 GeV/c to 15 GeV/c. The main motivations are the measurement of pion yields for a quantitative design of the proton driver of a future neutrino factory [3], a substantial improvement in the calculation of the atmospheric neutrino flux [4] and the measurement of particle yields as input for the flux calculation of accelerator neutrino experiments, such as K2K [5,6], MiniBooNE [7] and SciBooNE [8]. In addition to these specific aims, the data provided by HARP are valuable for validating hadron production models used in simulation programs.To provide a large angular and momentum coverage of the produced charged particles the HARP experiment makes use of a large-acceptance spectrometer consisting of a forward and large-angle detection system. A detailed description of the experimental apparatus can be found in Ref [2]. The forward spectrometer -based on large area drift chambers [9] and a dipole magnet complemented by a set of detectors for particle identification (PID): a time-offlight wall [10] (TOFW), a large Cherenkov detector (CHE) and an electromagnetic calorimeter -covers polar angles up to 250 mrad which is well matched to the angular range of interest for the measurement of hadron production to calculate the properties of conventional neutrino beams. The large-angle spectrometer -based on a Time Projection Chamber (TPC) located inside a solenoidal magnet -has a large acceptance in the momentum and angular range for the pions relevant to the production of the muons in a neutrino factory. It covers the large majority of the pions accepted in the focusing system of a typical design. The neutrino beam of a neutrino factory originates from the decay of muons which are in turn the decay products of pions.A large amount of data collected by the HARP experiment with thin (5% of nuclear interaction length, Aj) and

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The NA48/2 and NA62 experiments at CERN have collected large samples of charged kaons decays in 2003-2004 and in 2007-2008, respectively. In this paper some recent results will be reported. A preliminary measurement by NA48/2 and by NA62 of the K ± → π ± γγ branching ratio is quoted, an analysis by NA62 of K + → e + νγ(SD + ) is shown, a first evidence of the K ± → π ± π 0 e + e − decay by NA48/2 is reported. New measurements of K l3 form factors are presented and finally the branching ratio of K e4 decays is shown. All the results are preliminary.Kaon decays are a privileged system to study low energy QCD interactions, especially in the chiral perturbation theory framework. The model can be tested at the O(p 4 ) and in some cases even at the O(p 6 ) order. The NA48/2 and NA62 experiments at CERN have collected the largest sample of charged kaon decays in the world. In this paper some recent preliminary results will be presented.The CERN kaon facility is located in the North Area extraction line of the SPS accelerator. The NA48/2 experiment took data in 2003/2004 with two simultaneous K ± beams produced by 400 GeV/c protons impinging on a beryllium target; the beamline selected kaons with a (60 ± 3) GeV/c momentum range. The NA62 experiment took data in 2007 and 2008 (R K phase) with a modified beam line which provided K + or K − with momenta of (74.0 ± 1.4) GeV/c. For both the experiments the main detectors, following the beam line, are a magnetic spectrometer (made by four drift chambers with a dipole magnet between the second and the third one) providing a momentum resolution σ p /p = 1.00% ⊕ 0.044% × p [NA48/2] and σ p /p = 0.48% ⊕ 0.009% × p [NA62], with p in GeV/c, a scintillator hodoscope with 150 ps time resolution and a Liquid Krypton Electromagnetic Calorimeter (127 cm thick and made by 13248 readout cells) with energy resolution σ E /E = 3.2%/ √ E ⊕ 9%/E ⊕ 0.42% with E in GeV. A detailed description of the detectors can be found in [1]. For a charged particle the ratio between the energy E in GeV measured by the electromagnetic calorimeter and the momentum p in GeV/c measured by the magnetic spectrometer is used for particle identification: electrons/positrons are selected requiring 0.95 < E/p < 1.05, muons are identified by E/p < 0.1 and the rest are charged pions; tighter cuts are used in some analysis. 1 on behalf of the NA48 and NA62 collaborations