A comprehensive study of analyzing powers in the proton–deuteron break-up channel at 135 MeV

A measurement of the analyzing powers for the $$^2\hbox {H}(\vec {p},pp)n$$ 2 H ( p → , p p ) n break-up reaction was carried out at KVI exploiting a polarized-proton beam at an energy of $$135\,\hbox {MeV}$$ 135 MeV . The scattering angles and energies of the final-state protons were measured using the Big Instrument for Nuclear-polarization Analysis (BINA) with a nearly $$4\pi $$ 4 π geometrical acceptance. In this work, we analyzed a large number of kinematical geometries including forward–forward configurations in which both the final-state particles scatter to small polar angles and backward–forward configurations in which one of the final-state particles scatters to large polar angles. The results are compared with Faddeev calculations based on modern nucleon–nucleon (NN) and three-nucleon (3N) potentials. Discrepancies between polarization data and theoretical predictions are observed for configurations corresponding to small relative azimuthal angles between the two final-state protons. These configurations show a large sensitivity to 3N force effects.

Muographic data analysis method for medium-sized rock overburden inspections

Muographic measurements of rock overburdens are of particular interest because they can be applied to natural resources and undiscovered cave explorations, and even to searching for hidden chambers in historic architectural structures. In order to derive the absolute density distribution of the overburden, we conventionally needed to know accurate information about the measurement conditions, e.g., the detector's geometrical acceptance, detection efficiency, and measurement time, in order to derive the absolute value of the transmitted muon flux. However, in many cases, it is not a simple task to accurately gauge such conditions. Open-sky muon data taken with the same detector are useful as reference data to cancel these factors; however, if the detector is not transportable, this data taking method is not feasible. In this work, we found that the transmitted muon flux will follow a simple function of the areal density along the muon path as long as the incident muon energies are below a few hundred GeV. Based on this finding, we proposed a simple analysis method that does not require detailed knowledge of the detector's conditions by combining the independently measured density information for the partial volume of the target. We anticipate that this simple method is applicable to future muographic measurements of rock overburdens.

Muographic data analysis method for medium-sized rock overburden inspections

Muographic measurements of rock overburdens are of particular interests because they can be applied to natural resources and undiscovered cave explorations, and even to searching for hidden chambers in historic architectural structures. In order to derive the absolute density distribution of the overburden, we conventionally needed to know the accurate information about the measurement conditions, e.g., the detector's geometrical acceptance, detection efficiency, measurement time, etc. in order to derive the absolute value of the transmitted muon flux. However, in many cases, it is not a simple task to accurately gauge such conditions. Open-sky muon data taken with the same detector are useful as reference data to cancel these factors, however, if the detector is not transportable, this data taking method is not feasible. In this work, we found that the transmitted muon flux will follow a linear function of the areal density along the muon path as long as the incident muon energies are below a few hundred GeV. Based on this finding, we proposed a simple analysis method that does not require detailed knowledge of the detector's conditions by combining the independently measured density information for the partial volume of the target. We anticipate that this simple method is applicable to future muographic measurements of rock overburdens.

Searches for discrete symmetries violation in ortho-positronium decay using the J-PET detector

In this paper, we present prospects for using the Jagiellonian positron emission tomograph (J-PET) detector to search for discrete symmetries violations in a purely leptonic system of the positronium atom. We discuss tests of CP and CPT symmetries by means of ortho-positronium decays into three photons. No zero expectation values for chosen correlations between ortho-positronium spin and momentum vectors of photons would imply the existence of physics phenomena beyond the standard model. Previous measurements resulted in violation amplitude parameters for CP and CPT symmetries consistent with zero, with an uncertainty of about 10−3. The J-PET detector allows to determine those values with better precision, thanks to the unique time and angular resolution combined with a high geometrical acceptance. Achieving the aforementioned is possible because of the application of polymer scintillators instead of crystals as detectors of annihilation quanta.

A SPECTROMETER TO STUDY ELASTIC AND DIFFRACTIVE PHYSICS AT LHC

The possibility to study elastic and diffractive physics in pp collisions at LHC is discussed. For this purpose we have considered detectors close to the beam in conjunction with the magnetic elements of the accelerator to provide a high precision spectrometer for very forward final state protons. The geometrical acceptance is given and the momentum resolution is calculated for different spatial resolution detectors.