182 research outputs found
Concentration of apricot juice using complex membrane technology
In this study, pressed apricot (Prunus armeniaca L.) juice was concentrated using complex membrane technology with different module combinations: UF-RO-OD, UF-RO-MD, UF-NF-OD and UF-NF-MD. In case of the best combination a cross-flow polyethylene ultrafiltration membrane (UF) was applied for clarification, after which preconcentration was done using reverse osmosis (RO) with a polyamide membrane, and the final concentration was completed by osmotic distillation (OD) using a polypropylene module. The UF-RO-OD procedure resulted in a final concentrate with a 65-70 °Brix dry solid content and an excellent quality juice with high polyphenol content and high antioxidant capacity.Nanofiltration (NF) and membrane distillation (MD) were not proper economic solutions.The influence of certain operation parameters was examined experimentally. Temperatures of UF and RO were: 25, 30, and 35 °C, and of OD 25 °C. Recycle flow rates were: UF: 1, 1.5, and 2 m3 hâ1; RO: 200, 400, and 600 l hâ1; OD: 20, 30 and 40 l hâ1. The flow rates in the module were expressed by the Reynolds number, as well. Based on preliminary experiments, the transmembrane pressures of UF and RO filtration were 4 bar and 50 bar, respectively. Each experimental run was performed three times. The following optimal operation parameters provided the lowest total cost: UF: 35 °C, 2 m3 hâ1, 4 bar; RO: 35 °C, 600 l hâ1, 50 bar; OD: 20, 30 and 40 l hâ1; temperature 25 °C.In addition, experiments were performed for apricot juice concentration by evaporation, which technique is widely applied in the industry using vacuum and low temperature.For description the UF filtration, a dynamic model and regression by SPSS 14.0 statistics software were applied
flavour tagging using charm decays at the LHCb experiment
An algorithm is described for tagging the flavour content at production of
neutral mesons in the LHCb experiment. The algorithm exploits the
correlation of the flavour of a meson with the charge of a reconstructed
secondary charm hadron from the decay of the other hadron produced in the
proton-proton collision. Charm hadron candidates are identified in a number of
fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is
calibrated on the self-tagged decay modes and using of data collected by the LHCb
experiment at centre-of-mass energies of and
. Its tagging power on these samples of
decays is .Comment: All figures and tables, along with any supplementary material and
additional information, are available at
http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm
Identification of beauty and charm quark jets at LHCb
Identification of jets originating from beauty and charm quarks is important
for measuring Standard Model processes and for searching for new physics. The
performance of algorithms developed to select - and -quark jets is
measured using data recorded by LHCb from proton-proton collisions at
TeV in 2011 and at TeV in 2012. The efficiency for
identifying a jet is about 65%(25%) with a probability for
misidentifying a light-parton jet of 0.3% for jets with transverse momentum
GeV and pseudorapidity . The dependence of
the performance on the and of the jet is also measured
Search for Bâşc decays to the ppâžĎâş final state
A search for the decays of the B + c meson to pp-Ď + is performed for the first time using a data sample corresponding to an integrated luminosity of 3.0 fb -1 collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV. No signal is found and an upper limit, at 95% confidence level, is set, fcfuĂB(B + c âppĎ + ) < 3.6Ă10-8 in the kinematic region m(pp) < 2.85 GeV/c2, p T (B) < 20 GeV/c and 2.0 < y(B) < 4.5, where B is the branching fraction and f c (f u ) is the fragmentation fraction of the b quark into a B c + (B + ) meson
Observation of the decay B0s â Ď(2S)K +Ďâ
The decay B0
s â Ď(2S)K +Ďâ is observed using a data set corresponding to an integrated luminosity of
3.0 fbâ1 collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV.
The branching fraction relative to the B0 â Ď(2S)K +Ďâ decay mode is measured to be
B(B0
s â Ď(2S)K +Ďâ)
B(B0 â Ď(2S)K +Ďâ) = 5.38 Âą 0.36 (stat) Âą 0.22 (syst) Âą 0.31 (f s/ fd)%,
where f s/ fd indicates the uncertainty due to the ratio of probabilities for a b quark to hadronise into
a B0
s or B0 meson. Using an amplitude analysis, the fraction of decays proceeding via an intermediate
Kâ(892)0 meson is measured to be 0.645 Âą 0.049 (stat) Âą 0.049 (syst) and its longitudinal polarisation
fraction is 0.524 Âą 0.056 (stat) Âą 0.029 (syst). The relative branching fraction for this component is
determined to be
B(B0
s â Ď(2S)Kâ(892)0)
B(B0 â Ď(2S)Kâ(892)0) = 5.58 Âą 0.57 (stat) Âą 0.40 (syst) Âą 0.32 (f s/ fd)%.
In addition, the mass splitting between the B0
s and B0 mesons is measured as
M(B0
s ) â M(B0) = 87.45 Âą 0.44 (stat) Âą 0.09 (syst) MeV/c2
Observation of the B0 â Ď0Ď0 decay from an amplitude analysis of B0 â (Ď+Ďâ)(Ď+Ďâ) decays
Protonâproton collision data recorded in 2011 and 2012 by the LHCb experiment, corresponding to
an integrated luminosity of 3.0 fbâ1, are analysed to search for the charmless B0 â Ď0Ď0 decay.
More than 600 B0 â (Ď+Ďâ)(Ď+Ďâ) signal decays are selected and used to perform an amplitude
analysis, under the assumption of no CP violation in the decay, from which the B0 â Ď0Ď0 decay is
observed for the first time with 7.1 standard deviations significance. The fraction of B0 â Ď0Ď0 decays
yielding a longitudinally polarised final state is measured to be fL = 0.745+0.048
â0.058(stat) Âą 0.034(syst).
The B0 â Ď0Ď0 branching fraction, using the B0 â ĎKâ(892)0 decay as reference, is also reported as
B(B0 â Ď0Ď0) = (0.94 Âą 0.17(stat) Âą 0.09(syst) Âą 0.06(BF)) Ă 10â6
Measurement of the CP-violating phase β in B0 â J/ĎĎ+Ďâ decays and limits on penguin effects
Time-dependent CP violation is measured in the (â)
B 0 â J/ĎĎ+Ďâ channel for each Ď+Ďâ resonant
final state using data collected with an integrated luminosity of 3.0 fbâ1 in pp collisions using the LHCb
detector. The final state with the largest rate, J/ĎĎ0(770), is used to measure the CP-violating angle
2βeff to be (41.7 ¹ 9.6+2.8
â6.3)âŚ. This result can be used to limit the size of penguin amplitude contributions
to CP violation measurements in, for example, (â)
B 0
s â J/ĎĎ decays. Assuming approximate SU(3) flavour
symmetry and neglecting higher order diagrams, the shift in the CP-violating phase Ďs is limited to be
within the interval [â1.05âŚ,+1.18âŚ] at 95% confidence level. Changes to the limit due to SU(3) symmetry
breaking effects are also discussed
LHCb detector performance
The LHCb detector is a forward spectrometer at the Large Hadron Collider (LHC) at CERN. The experiment is designed for precision measurements of CP violation and rare decays of beauty and charm hadrons. In this paper the performance of the various LHCb sub-detectors and the trigger system are described, using data taken from 2010 to 2012. It is shown that the design criteria of the experiment have been met. The excellent performance of the detector has allowed the LHCb collaboration to publish a wide range of physics results, demonstrating LHCb's unique role, both as a heavy flavour experiment and as a general purpose detector in the forward region
Erratum: first observation of the rare BĂž â DĂžKĂžĎâ decay [Phys. Rev. D 93, 051101(R) (2016)]
No abstract available
Measurement of the charge ratio of atmospheric muons with the CMS detector
This is the pre-print version of this Article. The official published version can be accessed from the link below - Copyright @ 2010 ElsevierWe present a measurement of the ratio of positive to negative muon fluxes from cosmic ray interactions in the atmosphere, using data collected by the CMS detector both at ground level and in the underground experimental cavern at the CERN LHC. Muons were detected in the momentum range from 5 GeV/c to 1 TeV/c. The surface flux ratio is measured to be 1.2766 \pm 0.0032(stat.) \pm 0.0032 (syst.), independent of the muon momentum, below 100 GeV/c. This is the most precise measurement to date. At higher momenta the data are consistent with an increase of the charge ratio, in agreement with cosmic ray shower models and compatible with previous measurements by deep-underground experiments
- âŚ