No Arabic abstract
ORKA is a proposed experiment to measure the K+ -> pi+nunubar branching ratio with 5% precision using the Fermilab Main Injector high-intensity proton source. The detector design is based on the BNL E787/E949 experiments, which detected seven K+ -> pi+nunubar candidate events. ORKA is expected to acheive two orders of magnitude improvement in sensitivity relative to the BNL experiments as a result of enhancements to the beam line and the detector acceptance. Precise measurement of the K+ -> pi+nunubar branching ratio with the same level of uncertainty as the well-understood Standard Model prediction allows for sensitivity to new physics at and beyond the LHC mass scale. Detector R&D, simulation-based optimization of the experiment design, and preparation of the experiment location are underway.
ORKA is a proposed experiment to measure the K+ -> pi+ nu nubar branching ratio with 5% precision using the Fermilab Main Injector high intensity proton source. The detector design is based on the BNL E787/E949 experiments, which detected seven candidate events. Two orders of magnitude improvement in sensitivity relative to the BNL experiments comes from enhancements to the beam line and the detector acceptance. Precise measurement of the K+ -> pi+ nu nubar branching ratio with the same level of uncertainty as the well-understood Standard Model prediction allows for sensitivity to new physics at and beyond the LHC mass scale.
More than 400 $K^{+}topi^{+}mu^+mu^-$ events were observed in a rare $K^+$ decay experiment at the AGS. Normalized to the $K^{+}topi^{+}pi^+pi^-$ decay, the branching ratio is determined to be $(9.22 pm 0.60 (stat) pm 0.49 (syst))times 10^{-8}$. This branching ratio and the $mumu$ mass spectrum is in very good agreement with the measurement of the $K^{+}topi^{+}e^+e^-$ decay, but deviates significantly from the previous measurement.
The energy dependence of the energy and position resolutions of the electromagnetic calorimeter prototype made of lead tungstate crystals produced in Bogoroditsk (Russia) and Shanghai (China) is presented. These measurementswere carried out at the Protvino accelerator using a 1 to 45 GeV electron beam. The crystals were coupled to photomultiplier tubes. The dependence of energy and position resolutions on different factors as well as the measured electromagnetic shower lateral profile are presented.
The last decade was remarkable for neutrino physics. In particular, the phenomenon of neutrino flavor oscillations has been firmly established by a series of independent measurements. All parameters of the neutrino mixing are now known and we have elements to plan a judicious exploration of new scenarios that are opened by these recent advances. With precise measurements, we can test the 3-neutrino paradigm, neutrino mass hierarchy and CP asymmetry in the lepton sector. The future long-baseline experiments are considered to be a fundamental tool to deepen our knowledge of electroweak interactions. The Deep Underground Neutrino Experiment -- DUNE will detect a broad-band neutrino beam from Fermilab in an underground massive Liquid Argon Time-Projection Chamber at an L/E of about $10^3$ km / GeV to reach good sensitivity for CP-phase measurements and the determination of the mass hierarchy. The dimensions and the depth of the Far Detector also create an excellent opportunity to look for rare signals like proton decay to study violation of baryonic number, as well as supernova neutrino bursts, broadening the scope of the experiment to astrophysics and associated impacts in cosmology. In this presentation, we will discuss the physics motivations and the main experimental features of the DUNE project required to reach its scientific goals.
TeO2 bolometers have been used for many years to search for neutrinoless double beta decay in 130-Te. CUORE, a tonne-scale TeO2 detector array, recently published the most sensitive limit on the half-life, $T_{1/2}^{0 u} > 1.5 times 10^{25},$yr, which corresponds to an upper bound of $140-400$~meV on the effective Majorana mass of the neutrino. While it makes CUORE a world-leading experiment looking for neutrinoless double beta decay, it is not the only study that CUORE will contribute to in the field of nuclear and particle physics. As already done over the years with many small-scale experiments, CUORE will investigate both rare decays (such as the two-neutrino double beta decay of 130-Te and the hypothesized electron capture in 123-Te), and rare processes (e.g., dark matter and axion interactions). This paper describes some of the achievements of past experiments that used TeO2 bolometers, and perspectives for CUORE.