Pich, A., & Rodriguez-Sanchez, A. (2016). Updated determination of alpha(s)(m(tau)(2)) from tau decays. Mod. Phys. Lett. A, 31(30), 1630032–15pp.
Abstract: Using the most recent release of the ALEPH tau decay data, we present a very detailed phenomenological update of the alpha(s)(m(tau)(2)) determination. We have exploited the sensitivity to the strong coupling in many different ways, exploring several complementary methodologies. All determinations turn out to be in excellent agreement, allowing us to extract a very reliable value of the strong coupling. We find alpha((nf =3))(s)(m(tau)(2)) = 0.328 +/- 0.012 which implies alpha((nf=5))(s)(M-Z(2)) = 0.1197 +/- 0.0014. We critically revise previous work, and point out the problems flawing some recent analyses which claim slightly smaller values.
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Olmo, G. J., Rubiera-Garcia, D., & Sanchez-Puente, A. (2016). Impact of curvature divergences on physical observers in a wormhole space-time with horizons. Class. Quantum Gravity, 33(11), 115007–12pp.
Abstract: The impact of curvature divergences on physical observers in a black hole space-time, which, nonetheless, is geodesically complete is investigated. This space-time is an exact solution of certain extensions of general relativity coupled to Maxwell's electrodynamics and, roughly speaking, consists of two Reissner-Nordstrom (or Schwarzschild or Minkowski) geometries connected by a spherical wormhole near the center. We find that, despite the existence of infinite tidal forces, causal contact is never lost among the elements making up the observer. This suggests that curvature divergences may not be as pathological as traditionally thought.
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Albiol, F., Corbi, A., & Albiol, A. (2016). Geometrical Calibration of X-Ray Imaging With RGB Cameras for 3D Reconstruction. IEEE Trans. Med. Imaging, 35(8), 1952–1961.
Abstract: We present a methodology to recover the geometrical calibration of conventional X-ray settings with the help of an ordinary video camera and visible fiducials that are present in the scene. After calibration, equivalent points of interest can be easily identifiable with the help of the epipolar geometry. The same procedure also allows the measurement of real anatomic lengths and angles and obtains accurate 3D locations from image points. Our approach completely eliminates the need for X-ray-opaque reference marks (and necessary supporting frames) which can sometimes be invasive for the patient, occlude the radiographic picture, and end up projected outside the imaging sensor area in oblique protocols. Two possible frameworks are envisioned: a spatially shifting X-ray anode around the patient/object and a moving patient that moves/rotates while the imaging system remains fixed. As a proof of concept, experiences with a device under test (DUT), an anthropomorphic phantom and a real brachytherapy session have been carried out. The results show that it is possible to identify common points with a proper level of accuracy and retrieve three-dimensional locations, lengths and shapes with a millimetric level of precision. The presented approach is simple and compatible with both current and legacy widespread diagnostic X-ray imaging deployments and it can represent a good and inexpensive alternative to other radiological modalities like CT.
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Gimenez-Alventosa, V., Vijande, J., Ballester, F., & Perez-Calatayud, J. (2016). Transit dose comparisons for Co-60 and Ir-192 HDR sources. J. Radiol. Prot., 36(4), 858–864.
Abstract: The goal of this study is to evaluate the ambient dose due to the transit of high dose rate (HDR) Co-60 sources along a transfer tube as compared to Ir-192 ones in a realistic clinical scenario. This goal is accomplished by evaluating air-kerma differences with Monte Carlo calculations using PENELOPE2011. Scatter from both the afterloader and the patient was not taken into account. Two sources, mHDR-v2 and Flexisource Co-60, (Elekta Brachytherapy, Veenendaal, the Netherlands) have been considered. These sources were simulated within a standard transfer tube located in an infinite air phantom. The movement of the source was included by displacing their positions along the connecting tube from z = – 75 cm to z = + 75 cm and combining them. Since modern afterloaders like Flexitron (Elekta) or Saginova (BEBIG GmbH) are able to use equally 192Ir and 60Co sources, it was assumed that both sources are displaced with equal speed. Typical HDR source activity content values were provided by the manufacturer. 2D distributions were obtained with type-A uncertainties (k = 2) less than 0.01%. From those, the air-kerma ratio Co-60/Ir-192 was evaluated weighted by their corresponding typical activities. It was found that it varies slowly with distance (less than 10% variation at 75 cm) but strongly in time due to the shorter half-life of the 192Ir (73.83 d). The maximum ratio is located close to the tube. It reaches a value of 0.57 when the typical activity of the sources at the time when they were installed by the vendor was used. Such ratio increases up to 1.28 at the end of the recommended working life (90 d) of the Ir-192 source. Co-60/Ir-192 air-kerma ratios are almost constant (0.51-0.57) in the vicinity of the source-tube with recent installed sources. Nevertheless, air-kerma ratios increase rapidly (1.15-1.29) whenever the Ir-192 is approaching the end of its life. In case of a medical event requiring the medical staff to access the treatment room, these ratios indicate that the dosimetric impact on the medical team will be lower, with a few exceptions, in the case of Co-60-based HDR brachytherapy as compared to Ir-192-based one when typical air-kerma strength values are considered.
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LHCb Collaboration(Aaij, R. et al), Martinez-Vidal, F., Oyanguren, A., Ruiz Valls, P., & Sanchez Mayordomo, C. (2016). Study of the production of A(b)(0) and (B)over-bar(0) hadrons in pp collisions and first measurement of the A(b)(0)-> J/psi pK(-) branching fraction. Chin. Phys. C, 40(1), 011001–16pp.
Abstract: The product of the A(b)(0) ((B) over bar (0)) differential production cross-section and the branching fraction of the decay A(b)(0)-> J/psi pK(-) ((B) over bar (0)-> J/psi p (K) over bar*(892)(0)) is measured as a function of the beauty hadron transverse momentum, p(T), and rapidity, y. The kinematic region of the measurements is p(T) <20 GeV/c and 2.0 < y < 4.5. The measurements use a data sample corresponding to an integrated luminosity of 3fb(-1) collected by the LHCb detector in pp collisions at centre-of-mass energies root s=7 TeV in 2011 and root s=8 TeV in 2012. Based on previous LHCb results of the fragmentation fraction ratio, f(Ab0)/f(d), the branching fraction of the decay A(b)(0)-> J/psi pK(-) is measured to be B(A(b)(0)-> J/psi pK(-))=(3.17 +/- 0.04 +/- 0.07 +/- 0.34(-0.28)(+0.45))x10(-4) where the first uncertainty is statistical, the second is systematic, the third is due to the uncertainty on the branching fraction of the decay (B) over bar (0)-> J/psi p (K) over bar*(892)(0), and the fourth is due to the knowledge of f(Ab0)/f(d). The sum of the asymmetries in the production and decay between A(b)(0) and (A) over bar (0)(b) is also measured as a function of p(T) and y. The previously published branching fraction of A(b)(0)-> J/psi p pi(-), relative to that of A(b)(0)-> J/psi pK(-), is updated. The branching fractions of A(b)(0)-> P-c(+)(-> J/psi p)K- are determined.
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