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The XL-Calibur balloon-borne hard X-ray polarimetry mission comprises a Compton-scattering polarimeter placed at the focal point of an X-ray mirror. The polarimeter is housed within a BGO anticoincidence shield, which is needed to mitigate the considerable background radiation present at the observation altitude of ~40 km. This paper details the design, construction and testing of the anticoincidence shield, as well as the performance measured during the week-long maiden flight from Esrange Space Centre to the Canadian Northwest Territories in July 2022. The in-flight performance of the shield followed design expectations, with a veto threshold <100 keV and a measured background rate of ~0.5 Hz (20-40 keV). This is compatible with the scientific goals of the mission, where %-level minimum detectable polarisation is sought for a Hz-level source rate., Comment: Submitted to Nuclear Instruments and Methods A

The MuSEUM collaboration is planning measurements of the ground-state hyperfine structure (HFS) of muonium at the Japan Proton Accelerator Research Complex (J-PARC), Materials and Life Science Experimental Facility. The high-intensity beam that will soon be available at H-line allows for more precise measurements by one order of magnitude. We plan to conduct two staged measurements. First, we will measure the Mu-HFS in a near-zero magnetic field, and thereafter we will measure it in a strong magnetic field. We have developed two microwave cavities for this purpose. Furthermore, we evaluated systematic uncertainties from such a fluctuation of microwave fields and confirm the requirement of the microwave system, we use a microwave field distribution calculated from the finite element method.

We observed the atomic $1s$ and $2p$ states of $\pi^-$ bound to ${}^{121}{\rm Sn}$ nuclei as distinct peak structures in the missing mass spectra of the ${}^{122}{\rm Sn}(d,{}^3{\rm He})$ nuclear reaction. A very intense deuteron beam and a spectrometer with a large angular acceptance let us achieve potential of discovery, which includes capability of determining the angle-dependent cross sections with high statistics. The $2p$ state in a Sn nucleus was observed for the first time. The binding energies and widths of the pionic states are determined and found to be consistent with previous experimental results of other Sn isotopes. The spectrum is measured at finite reaction angles for the first time. The formation cross sections at the reaction angles between 0 and $2^\circ$ are determined. The observed reaction-angle dependence of each state is reproduced by theoretical calculations. However, the quantitative comparison with our high-precision data reveals a significant discrepancy between the measured and calculated formation cross sections of the pionic $1s$ state.

A complete set of analyzing powers for the dd->3Hp reaction at the kinetic beam energy of 200 MeV has been measured in the full angular range in the c.m. frame. The observed signs of the tensor analyzing powers Ayy, Axx, and Axz at forward and backward directions have clearly demonstrated the sensitivity to the ratio of the D- and S-wave components of the triton and deuteron, respectively. The new high-precision data are compared with the prediction of the relativistic multiple-scattering model by using standard wave functions of the three-nucleon bound state and of the deuteron.

A complete high precision set of deuteron analyzing powers for elastic deuteron-proton ($dp$) scattering at 250 MeV/nucleon (MeV/N) has been measured. The new data are presented together with data from previous measurements at 70, 100, 135 and 200 MeV/N. They are compared with the results of three-nucleon (3N) Faddeev calculations based on modern nucleon-nucleon (NN) potentials alone or combined with two models of three nucleon forces (3NFs): the Tucson-Melbourne 99 (TM99) and Urbana IX. At 250 MeV/N large discrepancies between pure NN models and data, which are not resolved by including 3NFs, were found at c.m.\ backward angles of $\theta_{\rm c.m.}\gtrsim 120^\circ$ for almost all the deuteron analyzing powers. These discrepancies are quite similar to those found for the cross section at the same energy. We found small relativistic effects that cannot resolve the discrepancies with the data indicating that other, short-ranged 3NFs are required to obtain a proper description of the data., Comment: submitted to Phys. Rev. C

SS433, located at the center of the supernova remnant W50, is a close proximity binary system consisting of a compact star and a normal star. Jets of material are directed outwards from the vicinity of the compact star symmetrically to the east and west. Non-thermal hard X-ray emission is detected from lobes lying on both sides. Shock accelerated electrons are expected to generate sub-TeV gamma rays through the inverse-Compton process in the lobes. Observations of the western X-ray lobe region of SS433/W50 system have been performed to detect sub-TeV gamma-rays using the 10m CANGAROO-II telescope in August and September, 2001, and July and September, 2002. The total observation times are 85.2 hours for ON source, and 80.8 hours for OFF source data. No significant excess of sub-TeV gamma rays has been found at 3 regions of the western X-ray lobe of SS433/W50 system. We have derived 99% confidence level upper limits to the fluxes of gamma rays and have set constraints on the strengths of the magnetic fields assuming the synchrotron/inverse-Compton model for the wide energy range of photon spectrum from radio to TeV. The derived lower limits are 4.3 microgauss for the center of the brightest X-ray emission region and 6.3 microgauss for the far end from SS433 in the western X-ray lobe. In addition, we suggest that the spot-like X-ray emission may provide a major contribution to the hardest X-ray spectrum in the lobe., Comment: 7 pages, 8 figures, to be published in Astroparticle Physics

A time projection chamber (TPC) is a strong candidate for the central tracker of the international linear collider (ILC) experiment and we have been conducting a series of cosmic ray experiments under a magnetic field up to 4 T, using a small prototype TPC with a replaceable readout device: multi-wire proportional chamber (MWPC) or gas electron multiplier (GEM). We first confirmed that the MWPC readout could not be a fall-back option of the ILC-TPC under a strong axial magnetic field of 4 T since its spatial resolution suffered severely from the so called E x B effect in the vicinity of the wire planes. The GEM readout, on the other hand, was found to be virtually free from the E x B effect as had been expected and gave the resolution determined by the transverse diffusion of the drift electrons (diffusion limited). Furthermore, GEMs allow a wider choice of gas mixtures than MWPCs. Among the gases we tried so far a mixture of Ar-CF4-isobutane, in which MWPCs could be prone to discharges, seems promising as the operating gas of the ILC-TPC because of its small diffusion constant especially under a strong magnetic field. We report the measured drift properties of this mixture including the diffusion constant as a function of the electric field and compare them with the predictions of Magboltz. Also presented is the spatial resolution of a GEM-based ILC-TPC estimated from the measurement with the prototype., Comment: 4 pages, 8 figures. Preprint submitted to TIPP09 Proceedings

The data on the tensor Ayy, Axx, Axz and vector Ay analyzing powers in the dd->3Hen obtained at Td= 270 MeV in the angular range 0 - 110 degrees in the c.m. are presented. The observed negative sign of the tensor analyzing powers Ayy, Axx and Axz at small angles clearly demonstrate the sensitivity to the ratio of the D and S wave component of the 3He wave function. However, the one-nucleon exchange calculations by using the standard 3He wave functions have failed to reproduce the strong variation of the tensor analyzing powers as a function of the angle in the c.m., Comment: 8 pages, 7 figures, 4 tables. Submitted to EPJA

High precision vector and tensor analyzing powers of elastic deuteron-proton d+p scattering have been measured at intermediate energies to investigate effects of three-nucleon forces (3NF). Angular distribution in the range of 70-120 degree in the center-of mass frame for incident-deuteron energies of 130 and 180 MeV were obtained using the RIKEN facility. The beam polarization was unambiguously determined by measuring the 12C(d,alpha)10B(2+) reaction at 0 degree. Results of the measurements are compared with state-of-the-art three-nucleon calculations. The present modeling of nucleon-nucleon forces and its extension to the three-nucleon system is not sufficient to describe the high precision data consistently and requires, therefore, further investigation.

Inelastic $\alpha$ scattering on 16O is studied at 400 MeV by using an ice target. Near the 4-alpha breakup threshold of 14.4 MeV, a broad peak is observed at an excitation energy of 13.6+/-0.2 MeV with a width of 0.6+/-0.2 MeV. The spin-parity is estimated to be 0+ from the momentum-transfer dependence. The observed width is significantly larger than those of the neighboring 0+ states indicating a state with a well-developed alpha cluster structure. The magnitude of the cross section is sensitive to the density distribution of the constituent alpha clusters. The observed cross section is consistent with the theoretical prediction for the alpha cluster condensed state characterized by its dilute density distribution with a large root-mean-square radius of about 4.3 fm., Comment: 12 pages, 5 fugures, submitted to Phys. Lett. B

Three precise measurements for elastic pd scattering at 135 MeV/A have been performed with the three different experimental setups. The cross sections are described well by the theoretical predictions based on modern nucleon-nucleon forces combined with three nucleon forces. Relativistic Faddeev calculations show that relativistic effects are restricted to backward angles. This result supports the two measurements recently reported by RIKEN and contradicts the KVI data., Comment: accepted by Physical Review Letter

The cross section of the ${}^{16}{\rm O}(p,p'){}^{16}{\rm O}(0^-,T=1)$ scattering was measured at a bombarding energy of 295 MeV in the momentum transfer range of $1.0 \mathrm{fm^{-1}}$ $\le$ $q_{\rm c.m.}$ $\le$ $2.1 \mathrm{fm^{-1}}$. The isovector $0^-$ state at $E_x$ = 12.8 MeV is clearly separated from its neighboring states owing to the high energy resolution of about 30 keV. The cross section data were compared with distorted wave impulse approximation (DWIA) calculations employing shell-model wave functions. The observed cross sections around $q_{\rm c.m.}$ $\simeq$ $1.7 {\rm fm^{-1}}$ are significantly larger than predicted by these calculations, suggesting pionic enhancement as a precursor of pion condensation in nuclei. The data are successfully reproduced by DWIA calculations using random phase approximation response functions including the $\Delta$ isobar that predict pionic enhancement., Comment: 13 pages, 4 figures, submitted to Phys. Rev. Lett

The data on the tensor analyzing power T20 in the dd->^3Hen and dd-> ^3Hp reactions at 140, 200 and 270 MeV of the deuteron kinetic energy and at zero degree obtained at RIKEN Accelerator Research Facility are presented. The observed positive sign of T20 clearly demonstrates the sensitivity to the D/S wave ratios in the ^3He and ^3H in the energy domain of the measurements. The T20 data for the ^3He-n and ^3H-p channels are in agreement within experimental accuracy., Comment: 9 pages, 3 figures, submitted in Phys.Lett.B

The deuteron to proton polarization transfer coefficients for the $d$--$p$ elastic scattering were precisely measured with an incoming deuteron energy of 135 MeV/u at the RIKEN Accelerator Research Facility. The data are compared to theoretical predictions based on exact solutions of three-nucleon Faddeev equations with high--precision nucleon--nucleon forces combined with different three-nucleon forces (3NFs), representing the current, most popular models: the $2\pi$-exchange Tucson-Melbourne model, a modification thereof closer to chiral symmetry TM'(99), and the Urbana IX 3NF. Theory predicts large 3NF effects, especially in the angular range around the cross section minimum, but the present data only partially concurs, predominantly for $K_{xx}^{y'}-K_{yy}^{y'}$ ($K_{xx}^{y'}$, $K_{yy}^{y'}$). For the induced polarization, $P^{y'}$, the TM$'$(99) and Urbana IX 3NFs reproduce the data, but the Tucson-Melbourne 3NF fails to describe the data. For the polarization transfer coefficients, $K_{y}^{y'}$ and $K_{xz}^{y'}$, the predicted 3NF ffects are in drastic conflict to the data. These facts clearly reveal the defects of the 3NF models currently used., Comment: 32 pages, 12 figures, Submitted to Physical Review C

We have measured the cross sections and analyzing powers Ay and Ayy for the elastic and inelastic scattering of deuterons from the 0+(g.s.), 2+(4.44 MeV), 3-(9.64 MeV), 1+(12.71 MeV), and 2-(18.3 MeV) states in 12C at an incident energy of 270 MeV. The data are compared with microscopic distorted-wave impulse approximation calculations where the projectile-nucleon effective interactionis taken from the three-nucleon t-matrix given by rigorous Faddeev calculations presently available at intermediate energies. The agreement between theory and data compares well with that for the (p,p') reactions at comparable incident energies/nucleon., Comment: 17 pages, 3 Postscript figures

The deuteron single and double spin-flip probabilities, S1 and S2, have been measured for the 12C(pol{d},pol{d}') reaction at Ed = 270 MeV for an excitation energy range between 4 and 24 MeV and a scattering angular range between Theta_lab = 2.5 and 7.5 deg. The extracted S1 exhibits characteristic values depending on the structure of the excited state. The S2 is close to zero over the measured excitation energy range. The SFP angular distribution data for the 2+ (4.44 MeV) and 1+ (12.71 MeV) states are well described by the microscopic DWIA calculations.

For backward elastic scattering of deuterons by ^3He, cross sections \sigma and tensor analyzing power T_{20} are measured at E_d=140-270 MeV. The data are analyzed by the PWIA and by the general formula which includes virtual excitations of other channels, with the assumption of the proton transfer from ^3He to the deuteron. Using ^3He wave functions calculated by the Faddeev equation, the PWIA describes global features of the experimental data, while the virtual excitation effects are important for quantitative fits to the T_{20} data. Theoretical predictions on T_{20}, K_y^y (polarization transfer coefficient) and C_{yy} (spin correlation coefficient) are provided up to GeV energies., Comment: REVTEX+epsfig, 17 pages including 6 eps figs, to be published in Phys. Rev. C

The Hayabusa spacecraft made two touchdowns on the surface of Asteroid 25143 Itokawa on November 20th and 26th, 2005. The Asteroid 25143 Itokawa is classified as an S-type asteroid and inferred to consist of materials similar to ordinary chondrites or primitive achondrites [1]. Near-infrared spectroscopy by the Hayabusa spacecraft proposed that the surface of this body has an olivine-rich mineral assemblage potentially similar to that of LL5 or LL6 chondrites with different degrees of space weathering [2]. The spacecraft made the reentry into the Earth s atmosphere on June 12th, 2010 and the sample capsule was successfully recovered in Australia on June 13th, 2010. Although the sample collection processes on the Itokawa surface had not been made by the designed operations, more than 1,500 grains were identified as rocky particles in the sample curation facility of JAXA, and most of them were judged to be of extraterrestrial origin, and definitely from Asteroid Itokawa on November 17th, 2010 [3]. Although their sizes are mostly less than 10 microns, some larger grains of about 100 microns or larger were also included. The mineral assembly is olivine, pyroxene, plagioclase, iron sulfide and iron metal. The mean mineral compositions are consistent with the results of near-infrared spectroscopy from Hayabusa spacecraft [2], but the variations suggest that the petrologic type may be smaller than the spectroscopic results. Several tens of grains of relatively large sizes among the 1,500 grains will be selected by the Hayabusa sample curation team for preliminary examination [4]. Each grain will be subjected to one set of preliminary examinations, i.e., micro-tomography, XRD, XRF, TEM, SEM, EPMA and SIMS in this sequence. The preliminary examination will start from the last week of January 2011. Therefore, samples for isotope analyses in this study will start from the last week of February 2011. By the time of the LPSC meeting we will have measured the oxygen and magnesium isotopic composition of several grains. We will present the first results from the isotope analyses that will have been performed.