196 research outputs found

    Heavy Quarkonia sector in PYTHIA 6.324: tuning, validation and perspectives at LHC(b)

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    In this note we investigate the impact of the recent insertion of Color Octet Model processes in PYTHIA version 6.324, through a tuning of different PYTHIA parameters, including the low-pT_T behaviour. The Non-relativistic QCD parameters have been chosen according to the most recent theoretical calculations and fits to CDF data. This analysis has been mainly focused on J/ψ\psi and ΄\Upsilon prompt production, with a comparison of the Monte Carlo predictions with available data from CDF at Run I and Run II energies. A prediction at the LHC energy, within different acceptance regions (CMS-Atlas and LHCb ones), is also given

    Guidelines for public administrations on location privacy

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    Public administrations increasingly use location data to deliver public services, including location-enabled tools, apps for tourists, toll collection services and cadastral web applications. Location data, such as addresses, GPS coordinates or camera images, is key to many public services and can also be linked to all sorts of other data, generating new information that was not available before. Despite the increased consumption of location data, its potential to reveal personal information is often underestimated, especially in comparison to other sensitive data, for instance in the financial and health domains. Location data not only say where an individual is, but it also says who he/she is and what his/her interests and preferences are. Therefore, location data privacy is of paramount importance for public administrations dealing with location data. While location data privacy has many aspects in common with general data protection principles, it also has unique characteristics that require specific consideration. The goal of this guidance document is therefore twofold: to outline the key obligations that public administrations should comply with when handling personal location data and raising awareness about the importance of location data privacy, highlighting key implications and risks associated with the processing of location data. It does so by guiding the reader through concrete scenarios that public administrations might face when processing personal location data and provides a set of effective and practical recommendations that can help ensure the adequate protection of personal location data. The guidance has been updated following the introduction of GDPR, taking into account market research in the location industry of the impact of GDPR. The updated document includes new models and concepts as well as using examples throughout to illustrate changes and potential approaches. It is a guide to practitioners and while touching on the key relevant parts of GDPR, it is not a legal document or legal advice.JRC.B.6-Digital Econom

    Phenomenological Constraints on Extended Quark Sectors

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    We study the flavor physics in two extensions of the quark sector of the Standard Model (SM): a four generation model and a model with a single vector--like down--type quark (VDQ). In our analysis we take into account the experimental constraints from tree--level charged current processes, rare Kaon decay processes, rare B decay processes, the Z→bbˉZ\to b \bar{b} decay, KK, BB and DD mass differences, and the CP violating parameters \frac \epsilon^\prime}{\epsilon}, Ï”K\epsilon_K and aψKa_{\psi K}. All the constraints are taken at two sigma. We find bounds on parameters which can be used to represent the New Physics contributions in these models (λtâ€Čbd\lambda_{t^ \prime}^{bd}, λtâ€Čbs\lambda_{t^ \prime}^{bs} and λtâ€Čsd\lambda_{t^ \prime}^{sd} in the four--generation model, and UbdU_{bd}, UbsU_{bs} and UsdU_{sd} in the VDQ model) due to all the above constraints. In both models the predicted ranges for aSLa_{SL} (the CP asymmetry in semi-leptonic decays), ΔMD\Delta M_D, B(K+→π+ΜΜˉ)B(K^+\to\pi^+ \nu \bar{\nu}), B(KL→π0ΜΜˉ)B(K_L\to\pi^0 \nu \bar{\nu}) and B(KL→ΌΌˉ)SDB(K_L\to \mu \bar{\mu})_{SD} can be significantly higher than the predictions of the SM, while the allowed ranges for aψKa_{\psi K} and for ΔmBS\Delta m_{B_S} are consistent with the SM prediction.Comment: 22 pages, 5 figures (v3: added a reference, updated a reference, added missing units

    Complex flavour couplings in supersymmetry and unexpected CP-violation in the decay B -> phi K

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    Complex flavour couplings (off-diagonal mass terms) in the squark sector of supersymmetric theories may drastically alter both the rate and the CP-violating asymmetry of certain B-meson decays. We consider the effects of couplings that induce b -> s transitions and lead to final state with strangeness one. We investigate the bounds that must be satisfied by the new terms and explore the possible implications on direct and mixing induced asymmetries in the charged and neutral B -> J/Psi K and B -> phi K decays.Comment: 14 pages, 3 figure

    Developments in Rare Kaon Decay Physics

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    We review the current status of the field of rare kaon decays. The study of rare kaon decays has played a key role in the development of the standard model, and the field continues to have significant impact. The two areas of greatest import are the search for physics beyond the standard model and the determination of fundamental standard-model parameters. Due to the exquisite sensitivity of rare kaon decay experiments, searches for new physics can probe very high mass scales. Studies of the k->pnn modes in particular, where the first event has recently been seen, will permit tests of the standard-model picture of quark mixing and CP violation.Comment: One major revision to the text is the branching ratio of KL->ppg, based on a new result from KTeV. Several references were updated, with minor modifications to the text. A total of 48 pages, with 28 figures, in LaTeX; to be published in the Annual Review of Nuclear and Particle Science, Vol. 50, December 200

    Extraction of the KK-bar isovector scattering length from pp -> d K^+ K-bar^0 data near threshold

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    The results of a recent experiment measuring the reaction pp -> dK^+ \bar K^0 near threshold are interpreted in terms of a spectator model that encapsulates the main features of the observed K^+ \bar K^0 invariant mass distribution. A chi^2 fit to this data leads to an imaginary part of the isovector scattering length in the K \bar K channel of Im(a_1) = -(0.63 \pm 0.24) fm. We then use the Flatte representation of the scattering amplitude to infer a value Re(a_1) = -(0.02 \pm 0.02) fm for the real part under the assumption that scaling is approximately satisfied. We show further that it is not possible to exclude the effects of \pi^+\eta to K^+ \bar K^0 channel coupling within the context of our model.Comment: 10 pages, 2 figures, 1 tabl

    The CKM Matrix and The Unitarity Triangle: Another Look

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    The unitarity triangle can be determined by means of two measurements of its sides or angles. Assuming the same relative errors on the angles (α,ÎČ,Îł)(\alpha,\beta,\gamma) and the sides (Rb,Rt)(R_b,R_t), we find that the pairs (Îł,ÎČ)(\gamma,\beta) and (Îł,Rb)(\gamma,R_b) are most efficient in determining (ϱˉ,ηˉ)(\bar\varrho,\bar\eta) that describe the apex of the unitarity triangle. They are followed by (α,ÎČ)(\alpha,\beta), (α,Rb)(\alpha,R_b), (Rt,ÎČ)(R_t,\beta), (Rt,Rb)(R_t,R_b) and (Rb,ÎČ)(R_b,\beta). As the set \vus, \vcb, RtR_t and ÎČ\beta appears to be the best candidate for the fundamental set of flavour violating parameters in the coming years, we show various constraints on the CKM matrix in the (Rt,ÎČ)(R_t,\beta) plane. Using the best available input we determine the universal unitarity triangle for models with minimal flavour violation (MFV) and compare it with the one in the Standard Model. We present allowed ranges for sin⁥2ÎČ\sin 2\beta, sin⁥2α\sin 2\alpha, Îł\gamma, RbR_b, RtR_t and ΔMs\Delta M_s within the Standard Model and MFV models. We also update the allowed range for the function FttF_{tt} that parametrizes various MFV-models.Comment: "published version. few typos corrected, results unchanged

    Positive Parity Scalar Mesons in the 1-2 GeV Mass Range

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    Based on the observation that K_0(1430) is lighter than its SU_3 counterpart, a_0(1450), we examine the possibility that these particles, together with f_0(1370), f_0(1500) and f_0(1710), fill a tetraquark recurrence of the sub-GeV 0^{++} nonet mixed with a glueball state. We find the picture to be consistent with the known data about the three f_0 resonances, more than the q-qbar hypothesis. Conventional spin-orbit coupling suggests the q-qbar, P-wave, nonet to lie around 1200 MeV. We review possible experimental indications of a scalar isovector resonance at 1.29 GeV, first observed by OBELIX in p-pbar annihilation.Comment: 12 pages, 9 figures. Extended version. References added. Results and conclusions unchange

    The antinucleon-nucleon interaction at low energy : annihilation dynamics

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    The general properties of antiproton-proton annihilation at rest are presented, with special focus on the two-meson final states. The data exhibit remarkable dynamical selection rules : some allowed annihilation modes are suppressed by one order of magnitude with respect to modes of comparable phase-space. Various phenomenological analyses are reviewed, based on microscopic quark dynamics or symmetry considerations. The role of initial- and final-state interaction is also examined.Comment: 128 pages, 49 tables, 27 figure
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