3,838 research outputs found
Heavy Quark Parameters and Vcb from Spectral Moments in Semileptonic B Decays
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 âs=2.76TeV
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 3.3pbâ1 collected in protonâproton collisions at a centre-of-mass energy of sâ=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
Ï(ppâ΄(1S)X)ĂB(΄(1S)âÎŒ+ÎŒâ)
=1.111±0.043±0.044nb,
Ï(ppâ΄(2S)X)ĂB(΄(2S)âÎŒ+ÎŒâ) where the first uncertainty is statistical and the second
=0.264±0.023±0.011nb,
Ï(ppâ΄(3S)X)ĂB(΄(3S)âÎŒ+ÎŒâ)
=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 âKurchatov Instituteâ
(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
After the successes the OPE description has scored in describing decays, we need to study what can be said about the composition
of the hadronic final state . The same OPE treatment yields sum rules
implying the dominance of charm states in over their
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 -- -- make up
beyond , what
their quantum numbers are and their mass distributions. The latter is most
relevant for the determination of hadronic mass moments in . 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
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.
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 -hadron, -hadron, and -lepton properties as of summer 2014
This article reports world averages of measurements of -hadron,
-hadron, and -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,
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
Recommended from our members
Measurement of B(B-->X_s {\gamma}), the B-->X_s {\gamma} photon energy spectrum, and the direct CP asymmetry in B-->X_{s+d} {\gamma} decays
The photon spectrum in B --> X_s {\gamma} decay, where X_s is any strange
hadronic state, is studied using a data sample of (382.8\pm 4.2) \times 10^6
e^+ e^- --> \Upsilon(4S) --> BBbar events collected by the BABAR experiment at
the PEP-II collider. The spectrum is used to measure the branching fraction B(B
--> X_s \gamma) = (3.21 \pm 0.15 \pm 0.29 \pm 0.08)\times 10^{-4} and the
first, second, and third moments = 2.267 \pm 0.019 \pm 0.032 \pm
0.003 GeV,, )^2> = 0.0484 \pm 0.0053 \pm 0.0077 \pm
0.0005 GeV^2, and )^3> = -0.0048 \pm 0.0011 \pm 0.0011
\pm 0.0004 GeV^3, for the range E_\gamma > 1.8 GeV, where E_{\gamma} is the
photon energy in the B-meson rest frame. Results are also presented for
narrower E_{\gamma} ranges. In addition, the direct CP asymmetry A_{CP}(B -->
X_{s+d} \gamma) is measured to be 0.057 \pm 0.063. The spectrum itself is also
unfolded to the B-meson rest frame; that is the frame in which theoretical
predictions for its shape are made.Comment: 37 pages, 19 postscript figures, submitted to Phys. Rev. D. No
analysis or results have changed from previous version. Some changes to
improve clarity based on interactions with Phys. Rev. D referees, including
one new Figure (Fig. 13), and some minor wording/punctuation/spelling
mistakes fixe
Differential branching fraction and angular analysis of the decay B0âKâ0ÎŒ+ÎŒâ
The angular distribution and differential branching fraction of the decay B 0â K â0 ÎŒ + ÎŒ â are studied using a data sample, collected by the LHCb experiment in pp collisions at sâ=7 TeV, corresponding to an integrated luminosity of 1.0 fbâ1. 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
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+Ï+Ï- 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 Bcâ(2S31)+ state reconstructed without the low-energy photon from the Bcâ(1S31)+âBc+Îł decay following Bcâ(2S31)+âBcâ(1S31)+Ï+Ï-. A second state is seen with a global (local) statistical significance of 2.2Ï (3.2Ï) 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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