3,838 research outputs found

    Heavy Quark Parameters and Vcb from Spectral Moments in Semileptonic B Decays

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    We extract the heavy quark masses and non-perturbative parameters from the Delphi preliminary measurements of the first three moments of the charged lepton energy and hadronic mass distributions in semileptonic B decays, using a multi-parameter fit. We adopt two formalisms, one of which does not rely on a 1/mc expansion and makes use of running quark masses. The data are consistent and the level of accuracy of the experimental inputs largely determines the present sensitivity. The results allow to improve on the uncertainty in the extraction of Vcb.Comment: 13 pages, 2 figure

    Measurement of ΄ production in pp collisions at √s=2.76TeV

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    Aaij, R. et al.The production of ΄(1S) , ΄(2S) and ΄(3S) mesons decaying into the dimuon final state is studied with the LHCb detector using a data sample corresponding to an integrated luminosity of 3.3pb−1 collected in proton–proton collisions at a centre-of-mass energy of s√=2.76 TeV. The differential production cross-sections times dimuon branching fractions are measured as functions of the ΄ transverse momentum and rapidity, over the ranges pT<15 GeV/ c and 2.0<y<4.5 . The total cross-sections in this kinematic region, assuming unpolarised production, are measured to be σ(pp→΄(1S)X)×B(΄(1S)→Ό+Ό−) =1.111±0.043±0.044nb, σ(pp→΄(2S)X)×B(΄(2S)→Ό+Ό−) where the first uncertainty is statistical and the second =0.264±0.023±0.011nb, σ(pp→΄(3S)X)×B(΄(3S)→Ό+Ό−) =0.159±0.020±0.007nb, systematic.We acknowledge support from CERN and from the national agencies: CAPES, CNPq, FAPERJ and FINEP (Brazil); NSFC (China); CNRS/IN2P3 and Region Auvergne (France);BMBF, DFG,HGFandMPG(Germany); SFI (Ireland); INFN (Italy); FOM and NWO (The Netherlands); SCSR (Poland); MEN/IFA (Romania); MinES, Rosatom, RFBR and NRC “Kurchatov Institute” (Russia); MinECo, XuntaGal and GENCAT (Spain); SNSF and SER (Switzerland); NAS Ukraine (Ukraine); STFC (United Kingdom); NSF (USA).We also acknowledge the support received from the ERC under FP7. The Tier1 computing centres are supported by IN2P3 (France), KIT and BMBF (Germany), INFN (Italy), NWO and SURF (The Netherlands), PIC (Spain), GridPP (United Kingdom)Peer reviewe

    Memorino on the `1/2 vs. 3/2 Puzzle' in Bˉ→lΜˉXc\bar B \to l \bar \nu X_c

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    After the successes the OPE description has scored in describing Bˉ→lΜˉXc\bar B \to l \bar \nu X_c decays, we need to study what can be said about the composition of the hadronic final state XcX_c. The same OPE treatment yields sum rules implying the dominance of jq=3/2j_q = 3/2 charm states in XcX_c over their jq=1/2j_q=1/2 counterparts. This prediction is supported by other general arguments as well as quark model calculations. At present it is unclear to which degree data conform to these predictions. More experimental information is essential. We want to ask our experimental colleagues for a redoubled effort to establish, which hadronic configurations -- D/D∗+π,D/D∗+2π,...D/D^* + \pi, D/D^* + 2 \pi, ... -- make up Γ(Bˉ→lΜˉXc)\Gamma (\bar B \to l \bar \nu X_c) beyond Bˉ→lΜˉD/D∗\bar B \to l \bar \nu D/D^*, what their quantum numbers are and their mass distributions. The latter is most relevant for the determination of hadronic mass moments in Bˉ→lΜˉXc\bar B \to l \bar \nu X_c. Since all this will require considerable effort on their part, we want to explain the theoretical issues involved, why they carry `gravitas' -- i.e. are weighty -- and why a better understanding of them will be of significant value. In this brief memo we sketch the underlying arguments based on heavy quark theory, the OPE, a special class of quark models and lattice QCD in a nutshell. After summarizing the experimental situation we conclude with two lists, namely one with measurements that need to be done and one with items of theoretical homework. Some of the latter can be done by employing existing theoretical tools, whereas others need new ideas.Comment: 13 pages, no figure

    Oral vaccination stimulates neutrophil functionality and exerts protection in a Mycobacterium avium subsp. paratuberculosis infection model

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    Abstract Mycobacterium avium subsp. paratuberculosis (Map) causes paratuberculosis (PTB), a granulomatous enteritis in ruminants that exerts high economic impact on the dairy industry worldwide. Current vaccines have shown to be cost-effective against Map and in some cases confer beneficial non-specific effects against other pathogens suggesting the existence of trained immunity. Although Map infection is mainly transmitted by the fecal-oral route, oral vaccination has not been deeply studied. Therefore, the aim of this study was to compare the oral route with a set of mycobacterial and non-mycobacterial vaccines with a subcutaneously administered commercially available vaccine. Training effects on polymorphonuclear neutrophils (PMNs) and homologous and heterologous in vivo protection against Map were investigated in the rabbit infection model. Oral vaccination with inactivated or live vaccines was able to activate mucosal immunity as seen by elevation of serum IgA and the expression of IL4 in peripheral blood mononuclear cells (PBMCs). In addition, peripheral PMN phagocytosis against Map was enhanced by vaccination and extracellular trap release against Map and non-related pathogens was modified by both, vaccination and Map-challenge, indicating trained immunity. Finally, PBMCs from vaccinated animals stimulated in vitro with Map antigens showed a rapid innate activation cytokine profile. In conclusion, our data show that oral vaccination against PTB can stimulate neutrophil activity and both innate and adaptive immune responses that correlate with protection.The research was funded by the Department of Economy, Sustainability and Environment of the Basque Government and by grant RTA 2017-00089-00-00 of the National Institute for Agronomic Research (INIA) to N.E. I.L.-A. and M.O. both held predoctoral fellowships from the DEI of the Basque Government. This research was also partly supported by the Agriculture Funding Consortium members Alberta Agriculture and Forestry and Alberta Milk (2018F019R) to J.D.B. CIC bioGUNE thanks the Ministry of Science and Innovation for the Severo Ochoa excellence award (SEV-2016-0644

    SuperB: A High-Luminosity Heavy Flavour Factory. Conceptual Design Report.

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    479 pĂĄginas.-- INFN/AE - 07/2, SLAC-R-856, LAL 07-15.-- et al.Work supported in part by US department of Energy contract DE-AC02-7 6SF00515. SuperB project.Peer reviewe

    Averages of bb-hadron, cc-hadron, and τ\tau-lepton properties as of summer 2014

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    This article reports world averages of measurements of bb-hadron, cc-hadron, and τ\tau-lepton properties obtained by the Heavy Flavor Averaging Group (HFAG) using results available through summer 2014. For the averaging, common input parameters used in the various analyses are adjusted (rescaled) to common values, and known correlations are taken into account. The averages include branching fractions, lifetimes, neutral meson mixing parameters, CPCP violation parameters, parameters of semileptonic decays and CKM matrix elements.Comment: 436 pages, many figures and tables. Online updates available at http://www.slac.stanford.edu/xorg/hfag

    Differential branching fraction and angular analysis of the decay B0→K∗0ÎŒ+Ό−

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    The angular distribution and differential branching fraction of the decay B 0→ K ∗0 ÎŒ + ÎŒ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions

    Observation of an Excited Bc+ State

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    Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+π+π- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bc∗(2S31)+ state reconstructed without the low-energy photon from the Bc∗(1S31)+→Bc+Îł decay following Bc∗(2S31)+→Bc∗(1S31)+π+π-. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date
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