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Bevan, A. J. et al, Martinez-Vidal, F., Pich, A., Azzolini, V., Bernabeu, J., Lopez-March, N., et al. (2014). The Physics of the B Factories. Eur. Phys. J. C, 74(11), 3026–916pp.
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NEXT Collaboration(Ghosh, S. et al), Martin-Albo, J., Carcel, S., Carrion, J. V., Diaz, J., Felkai, R., et al. (2020). Dependence of polytetrafluoroethylene reflectance on thickness at visible and ultraviolet wavelengths in air. J. Instrum., 15(11), P11031–16pp.
Abstract: Polytetrafluoroethylene (PTFE) is an excellent diffuse reflector widely used in light collection systems for particle physics experiments. However, the reflectance of PTFE is a function of its thickness. In this work, we investigate this dependence in air for light of wavelengths 260 nm and 450 nm using two complementary methods. We find that PTFE reflectance for thicknesses from 5 mm to 10 mm ranges from 92.5% to 94.5% at 450 nm, and from 90.0% to 92.0% at 260 nm We also see that the reflectance of PIFE of a given thickness can vary by as much as 2.7% within the same piece of material. Finally, we show that placing a specular reflector behind the PTFE can recover the loss of reflectance in the visible without introducing a specular component in the reflectance.
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BABAR Collaboration(del Amo Sanchez, P. et al), Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Evidence for Direct CP Violation in the Measurement of the Cabbibo-Kobayashi-Maskawa Angle gamma with B-/+ -> D-(*K-)(()*()-/+) Decays. Phys. Rev. Lett., 105(12), 121801–7pp.
Abstract: We report the measurement of the Cabibbo-Kobayashi-Maskawa CP-violating angle gamma through a Dalitz plot analysis of neutral D-meson decays to K-S(0)pi(+) pi(-) and K-S(0) K+ K- produced in the processes B--/+ -> DK -/+, B--/+ -> D* K--/+ with D* -> D pi(0), D gamma and B -/+ DK*-/+ with K*(-/+) -> K-S(0)pi(-/+), using 468 million B (B) over bar pairs collected by the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at SLAC. We measure gamma = (68 +/- 14 +/- 4 +/- 3)degrees (modulo 180 degrees), where the first error is statistical, the second is the experimental systematic uncertainty, and the third reflects the uncertainty in the description of the neutral D decay amplitudes. This result is inconsistent with gamma = 0 ( no direct CP violation) with a significance of 3.5 standard deviations.
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NEXT Collaboration(McDonald, A. D. et al), Alvarez, V., Benlloch-Rodriguez, J. M., Botas, A., Carcel, S., Carrion, J. V., et al. (2018). Demonstration of Single-Barium-Ion Sensitivity for Neutrinoless Double-Beta Decay Using Single-Molecule Fluorescence Imaging. Phys. Rev. Lett., 120(13), 132504–6pp.
Abstract: A new method to tag the barium daughter in the double-beta decay of Xe-136 is reported. Using the technique of single molecule fluorescent imaging (SMFI), individual barium dication (Ba++) resolution at a transparent scanning surface is demonstrated. A single-step photobleach confirms the single ion interpretation. Individual ions are localized with superresolution (similar to 2 nm), and detected with a statistical significance of 12.9 sigma over backgrounds. This lays the foundation for a new and potentially background-free neutrinoless double-beta decay technology, based on SMFI coupled to high pressure xenon gas time projection chambers.
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BABAR Collaboration(Lees, J. P. et al), Azzolini, V., Lopez-March, N., Martinez-Vidal, F., Milanes, D. A., & Oyanguren, A. (2010). Search for Charged Lepton Flavor Violation in Narrow Gamma Decays. Phys. Rev. Lett., 104(15), 151802–7pp.
Abstract: Charged-lepton flavor-violating processes are unobservable in the standard model, but they are predicted to be enhanced in several extensions to the standard model, including supersymmetry and models with leptoquarks or compositeness. We present a search for such processes in a sample of 99 x 10(6)Gamma(2S) decays and 117 x 10(6)Gamma(3S) decays collected with the BABAR detector. We place upper limits on the branching fractions B(Gamma(nS) --> e(+/-)tau(-/+)) and B(Gamma(n(S) --> mu(+/-)tau(-/+)) (n = 2, 3) at the 10(-6) level and use these results to place lower limits of order 1 TeV on the mass scale of charged-lepton flavor-violating effective operators.
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