820 research outputs found
Searches for LFV and LNV Decays at LHCb
The paper presents the latest progress on the searches for Lepton Number
Violating (LNV) B Meson decays, the Lepton Flavour Violating (LFV) decay
\Ptau^- \to \Pmu^-\Pmu^-\Pmu^+, and the Lepton and Baryon Number Violating
(LNV and BNV) decays \Ptau^- \to \mu^+ \mu^- \APproton and \Ptau^- \to \mu^-
\mu^- \Pproton at the LHCb. These searches have been performed at a hadron
collider for the first time. In the absence of signal we put upper limits,
which are as follows: , \mathcal{B}(\Ptau^- \to \mu^- \mu^+ \APproton) < 3.4 \times
10^{-7}, \mathcal{B}(\Ptau^- \to \mu^- \mu^- \Pproton) < 4.4 \times 10^{-7}
at 90% CL.Comment: 9 pages, 5 figures, Proceedings of CKM 2012, the 7th International
Workshop on the CKM Unitarity Triangl
Long-distance effects in from Analyticity
We discuss a novel approach to systematically determine the long-distance
contribution to decays in the kinematic region where the
dilepton invariant mass is below the open charm threshold. This approach
provides the most consistent and reliable determination to date and can be used
to compute Standard Model predictions for all observables of interest,
including the kinematic region where the dilepton invariant mass lies between
the and the resonances. We illustrate the power of our
results by performing a New Physics fit to the Wilson coefficient . This
approach is systematically improvable from theoretical and experimental sides,
and applies to other decay modes of the type ,
and .Comment: 10 pages, 5 figure
Increasing Quality of the Corpus of Frequency Dictionary of Contemporary Polish for Morphosyntactic Tagging of the Polish Language
The paper is devoted to the issue of correction of the erroneous and ambiguous corpus of Frequency Dictionary of Contemporary Polish (FDCP) and its application to morphosyntactic tagging of the Polish language. Several stages of corpus transformation are presented and baseline part-of-speech tagging algorithms are evaluated, too
A Case Study of Algorithms for Morphosyntactic Tagging of Polish Language
The paper presents an evaluation of several part-of-speech taggers, representing main tagging algorithms, applied to corpus of frequency dictionary of the contemporary Polish language. We report our results considering two tagging schemes: IPI PAN positional tagset and its simplified version. Tagging accuracy is calculated for different training sets and takes into account many subcategories (accuracy on known and unknown tokens, word segments, sentences etc.) The comparison of results with other inflecting and analytic languages is done. Performance aspects (time demands) of used tagging tools are also discussed
A model-independent analysis of transitions with GAMBIT ’s FlavBit
The search for flavour-changing neutral current effects in B-meson decays is a powerful probe of physics beyond the Standard Model. Deviations from SM behaviour are often quantified by extracting the preferred values of the Wilson coefficients of an operator product expansion. We use the FlavBit module of the GAMBIT package to perform a simultaneous global fit of the Wilson coefficients C7, C9, and C10 using a combination of all current data on b→sμ+μ− transitions. We further extend previous analyses by accounting for the correlated theoretical uncertainties at each point in the Wilson coefficient parameter space, rather than deriving the uncertainties from a Standard Model calculation. We find that the best fit deviates from the SM value with a significance of 6.6σ. The largest deviation is associated with a vector coupling of muons to b and s quarks
Reinterpretation of LHC Results for New Physics: Status and recommendations after Run 2
We report on the status of efforts to improve the reinterpretation of searches and measurements at the LHC in terms of models for new physics, in the context of the LHC Reinterpretation Forum. We detail current experimental offerings in direct searches for new particles, measurements, technical implementations and Open Data, and provide a set of recommendations for further improving the presentation of LHC results in order to better enable reinterpretation in the future. We also provide a brief description of existing software reinterpretation frameworks and recent global analyses of new physics that make use of the current data
Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires
The production of tt‾ , W+bb‾ and W+cc‾ is studied in the forward region of proton–proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fb−1 . The W bosons are reconstructed in the decays W→ℓν , where ℓ denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of , and is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 0.02 \mbox{fb}^{-1}. The bosons are reconstructed in the decays , where denotes muon or electron, while the and quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions
Multidifferential study of identified charged hadron distributions in -tagged jets in proton-proton collisions at 13 TeV
Jet fragmentation functions are measured for the first time in proton-proton
collisions for charged pions, kaons, and protons within jets recoiling against
a boson. The charged-hadron distributions are studied longitudinally and
transversely to the jet direction for jets with transverse momentum 20 GeV and in the pseudorapidity range . The
data sample was collected with the LHCb experiment at a center-of-mass energy
of 13 TeV, corresponding to an integrated luminosity of 1.64 fb. Triple
differential distributions as a function of the hadron longitudinal momentum
fraction, hadron transverse momentum, and jet transverse momentum are also
measured for the first time. This helps constrain transverse-momentum-dependent
fragmentation functions. Differences in the shapes and magnitudes of the
measured distributions for the different hadron species provide insights into
the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any
supplementary material and additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb
public pages
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