|
|
Baker, M. J., Bordes, J., Hong-Mo, C., & Tsun, T. S. (2013). On the corner elements of the CKM and PMNS matrices. EPL, 102(4), 41001–6pp.
Abstract: Recent experiments show that the top-right corner element (U-e3) of the PMNS matrix is small but nonzero, and suggest further via unitarity that it is smaller than the bottom-left corner element (U-tau 1). Here, it is shown that if to the assumption of a universal rank-one mass matrix, long favoured by phenomenologists, one adds that this matrix rotates with scale, then it follows that A) by inputting the mass ratios m(c)/m(t), m(s)/m(b), m(mu)/m(tau), and m(2)/m(3), i) the corner elements are small but nonzero, ii) V-ub < V-td, U-e3 < U-tau 1, iii) estimates result for the ratios V-ub/V-td and U-e3/U-tau 1, and B) by inputting further the experimental values of V-us, V-tb and U-e2, U-mu 3, iv) estimates result for the values of the corner elements themselves. All the inequalities and estimates obtained are consistent with present data within expectation for the approximations made.
|
|
|
|
Goel, N., Domingo-Pardo, C., Habermann, T., Ameil, F., Engert, T., Gerl, J., et al. (2013). Characterisation of a symmetric AGATA detector using the gamma-ray imaging scanning technique. Nucl. Instrum. Methods Phys. Res. A, 700, 10–21.
Abstract: The imaging scanning technique for the characterisation of large volume, highly segmented, HPGe detectors is demonstrated by comparing the measured spatial response of a symmetric AGATA crystal versus the theoretical calculations obtained with the Multi-Geometry Simulation (MGS) code. The signal rise-times measured as a function of the gamma-ray interaction positions, in both coaxial and planar regions of the detection volume, are presented and confronted with the expected behaviour obtained via MGS. The transition in charge carrier transport behaviour as a function of the depth is studied for the region of the complex electric field. In general, a fairly good agreement between theory and experiment is obtained. Only systematic deviations between simulation and measurement are observed in the critical front part of the AGATA detector. They may be ascribed to a non-linear impurity concentration profile of the germanium crystal.
|
|
|
|
Clinthorne, N., Brzezinski, K., Chesi, E., Cochran, E., Grkovski, M., Grosicar, B., et al. (2013). Silicon as an unconventional detector in positron emission tomography. Nucl. Instrum. Methods Phys. Res. A, 699, 216–220.
Abstract: Positron emission tomography (PET) is a widely used technique in medical imaging and in studying small animal models of human disease. In the conventional approach, the 511 keV annihilation photons emitted from a patient or small animal are detected by a ring of scintillators such as LYSO read out by arrays of photodetectors. Although this has been successful in achieving similar to 5 mm FWHM spatial resolution in human studies and similar to 1 mm resolution in dedicated small animal instruments, there is interest in significantly improving these figures. Silicon, although its stopping power is modest for 511 keV photons, offers a number of potential advantages over more conventional approaches including the potential for high intrinsic spatial resolution in 3D. To evaluate silicon in a variety of PET “magnifying glass” configurations, an instrument was constructed that consists of an outer partial-ring of PET scintillation detectors into which various arrangements of silicon detectors are inserted to emulate dual-ring or imaging probe geometries. Measurements using the test instrument demonstrated the capability of clearly resolving point sources of Na-22 having a 1.5 mm center-to-center spacing as well as the 1.2 mm rods of a F-18-filled resolution phantom. Although many challenges remain, silicon has potential to become the PET detector of choice when spatial resolution is the primary consideration. (C) 2012 Elsevier B.V. All rights reserved.
|
|
|
|
Bernabeu, J., Di Domenico, A., & Villanueva-Perez, P. (2013). Direct test of time reversal symmetry in the entangled neutral kaon system at a phi-factory. Nucl. Phys. B, 868(1), 102–119.
Abstract: We present a novel method to perform a direct T (time reversal) symmetry test in the neutral kaon system, independent of any CP and/or CPT symmetry tests. This is based on the comparison of suitable transition probabilities, where the required interchange of in <-> out states for a given process is obtained exploiting the Einstein-Podolski-Rosen correlations of neutral kaon pairs produced at a phi-factory. In the time distribution between the two decays, we compare a reference transition like the one defined by the time-ordered decays (l(-), pi pi) with the T-conjugated one defined by (3 pi(0), l(+)). With the use of this and other T-conjugated comparisons, the KLOE-2 experiment at DA Phi NE could make a statistically significant test.
|
|
|
|
de Azcarraga, J. A., Izquierdo, J. M., Lukierski, J., & Woronowicz, M. (2013). Generalizations of Maxwell (super)algebras by the expansion method. Nucl. Phys. B, 869(2), 303–314.
Abstract: The Lie algebras expansion method is used to show that the four-dimensional spacetime Maxwell (super)algebras and some of their generalizations can be derived in a simple way as particular expansions of o(3,2) and osp(N vertical bar 4).
|
|
