9,871 research outputs found

    New Physics Signatures in Kaon Decays

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    Kaon physics provides a unique opportunity to identify new flavour and CP violating interactions beyond the Standard Model (SM). In the SM, implied by the hierarchical structure of the CKM matrix and the GIM mechanism, flavour changing neutral current processes are most strongly suppressed in the kaon sector while the suppression is much less effective in the B meson systems. Thus their theoretical cleanness makes rare K decays, in particular the K -> pi nu anti-nu system, extremely well suited to look for deviations from their tiny SM values. Despite the increasingly stringent constraints on new physics from direct search experiments as well as indirect searches in B meson decays, large enhancements of both K^+ -> pi^+ nu anti-nu and K_L -> pi^0 nu anti-nu are still possible, and deviations from the SM could be observed even for a multi-TeV new physics scale. In addition the correlation betweeen the charged and neutral K -> pi nu anti-nu modes provides insight on the new physics operator structure in K^0 - anti-K^0 mixing and its interplay with rare K decays. Useful model-discriminating correlations exist also in the K_L -> pi^0 l^+ l^- system. Finally the K -> l nu decays provide a clean test of lepton universality and place constraints on new physics complementary to the ones obtained from the searches for charged lepton flavour violating decays.Comment: 10 pages, 7 figures. Proceedings for KAON13 - 2013 Kaon Physics International Conference at the University of Michigan, Ann Arbor, April 29-May 1 201

    Phenomenological aspects of flavoured dark matter

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    Flavour symmetries in the dark sector are a theoretically motivated and phenomenologically appealing concept. The dark matter particle can be stabilised with the help of flavour symmetries, without the need to introduce an additional discrete symmetry by hand. Apart from the usual searches in direct and indirect detection experiments and high energy colliders, flavoured dark matter generally also gives rise to new flavour violating interactions leading to interesting signatures in rare meson decays. This proceedings article reviews a simplified model of flavoured dark matter in which the dark matter coupling to quarks constitutes a new source of flavour violation, so that the model goes beyond Minimal Flavour Violation. Particular emphasis is put on the discussion of its phenomenological implications in flavour, collider and direct detection experiments.Comment: 7 pages, proceedings of The European Physical Society Conference on High Energy Physics, 22-29 July 2015, Vienna, Austri

    Quo vadis flavour physics? - FPCP2017 theory summary and outlook

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    We review the recent highlights of theoretical flavour physics, based on the theory summary talk given at FPCP2017. Over the past years, a number of intriguing anomalies have emerged in flavour violating KK and BB meson decays, constituting some of the most promising hints for the presence of physics beyond the Standard Model. We discuss the theory status of these anomalies and outline possible future directions to test the underlying New Physics.Comment: 15 pages, 4 figures. Proceedings for FPCP2017, 5-9 June 2017, Prague. v2: references added, final version to appear in Po

    Wearable Artwork & The Design Process

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    Undergraduate Creative and Artisti

    Introduction to Flavour Physics and CP Violation

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    These lecture notes provide an introduction to the theoretical concepts of flavour physics and CP violation, based on a series of lectures given at the ESHEP 2016 summer school. In the first lecture we review the basics of flavour and CP violation in the Standard Model. The second lecture is dedicated to the phenomenology of K and B meson decays, where we focus on a few representative observables. In the third lecture we give an introduction to flavour physics beyond the Standard Model, both within the framework of Minimal Flavour Violation and beyond.Comment: 30 pages, 10 figures. v2: Few references added. Lectures given at the ESHEP 2016 summer school in Skeikampen, Norway, 15-28 June 2016. To be published as CERN Yellow Repor

    CP Violation in D0 - anti-D0 Oscillations: General Considerations and Applications to the Littlest Higgs Model with T-Parity

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    The observed D0 - anti-D0 oscillations provide a new stage in our search for New Physics in heavy flavour dynamics. The theoretical verdict on the observed values of x_D and y_D remains ambiguous: while they could be totally generated by Standard Model dynamics, they could also contain a sizable or even leading contribution from New Physics. Those oscillations are likely to enhance the observability of CP violation as clear manifestations of New Physics. We present general formulae for D0 - anti-D0 oscillations, concentrating on the case of negligible direct CP violation. In particular we derive a general formula for the time-dependent mixing-induced CP asymmetry in decays to a CP eigenstate and its correlation with the semileptonic CP asymmetry a_SL(D0) in D0(t) -> l nu K. We apply our formalism to the Littlest Higgs model with T-parity, using the time-dependent CP asymmetry in D -> K_S phi as an example. We find observable effects at a level well beyond anything possible with CKM dynamics. Comparisons with CP violation in the K and B systems offer an excellent test of this scenario and reveal the specific pattern of flavour and CP violation in the D0 - anti-D0 system predicted by this model. We discuss a number of charm decays that could potentially offer an insight in the dynamics of CP violation in D decays. We also apply our formalism to B_s - anti-B_s mixing.Comment: 26 pages, 9 png figures, 1 table. v2: eq. (A.1) corrected, minor clarifying comments and few references added. v3: typos corrected, matches published versio

    Effect of calcified seaweed application on grazing preference by dairy cows

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    This report was presented at the UK Organic Research 2002 Conference. An experiment was carried out to determine whether the application of calcified seaweed improved the preference of organic dairy cows for pasture. Two treatments were applied in May 2001; calcified seaweed applied at 625kg/ha (C+) or no application (C-). The number of cows grazing within individual plots was recorded in July and August 2001. A significantly higher number of cows were recorded in C+ plots than in C- plots. This effect could not be explained by changes in soil or herbage analysis. There may have been additional unknown effects of the C+ treatment on herbage palatability but the results may also have been influenced by external factors such as the location of water troughs

    Global smoothness estimation of a Gaussian process from regular sequence designs

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    We consider a real Gaussian process XX having a global unknown smoothness (r0,β0)(r_{\scriptscriptstyle 0},\beta_{\scriptscriptstyle 0}), r_{\scriptscriptstyle 0}\in \mathds{N}_0 and β0]0,1[\beta_{\scriptscriptstyle 0} \in]0,1[, with X(r0)X^{(r_{\scriptscriptstyle 0})} (the mean-square derivative of XX if r01r_{\scriptscriptstyle 0}\ge 1) supposed to be locally stationary with index β0\beta_{\scriptscriptstyle 0}. From the behavior of quadratic variations built on divided differences of XX, we derive an estimator of (r0,β0)(r_{\scriptscriptstyle 0},\beta_{\scriptscriptstyle 0}) based on - not necessarily equally spaced - observations of XX. Various numerical studies of these estimators exhibit their properties for finite sample size and different types of processes, and are also completed by two examples of application to real data.Comment: 28 page
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