55 research outputs found
Experimental Study on the Demolding Force in Micro Metal Injection Molding
In this paper experimental study on the demolding force needed to eject micro structures in Micro Metal Injection
Molding (ÎŒMIM) is conducted. Injection molding is done on a variotherm mold mounted on a Battenfeld injection molding machine and demolding force measurement is done on an Instron tensile testing machine. Green part is a round disc of Ï16 mm and thickness 1.5 mm with an array of Ï100 ÎŒm Ă height 200 ÎŒm micro structures at the center. The experimental results are in good accordance with the previous analysis results.Singapore-MIT Alliance (SMA
Micro Injection-Molding of Cyclic Olefin Copolymer Using Metallic Glass Insert
There is shift in trend towards the use of high quality polymers as the base material in manufacturing microfluidic chips. In this paper, an amorphous metallic alloy mold insert was used in a micro injection-molding process to fabricate microfluidic features onto cyclic-olefin-copolymer (COC) material. The insert and fabricated samples were compared in terms of the geometry and surface roughness attained. Findings indicate that replication, in general, was possible but the microfeatures formed had significant flashing and tearing at the edges.Singapore-MIT Alliance (SMA
Study of the production of and hadrons in collisions and first measurement of the branching fraction
The product of the () differential production
cross-section and the branching fraction of the decay () is
measured as a function of the beauty hadron transverse momentum, ,
and rapidity, . The kinematic region of the measurements is and . The measurements use a data sample
corresponding to an integrated luminosity of collected by the
LHCb detector in collisions at centre-of-mass energies in 2011 and in 2012. Based on previous LHCb
results of the fragmentation fraction ratio, , the
branching fraction of the decay is
measured to be \begin{equation*} \mathcal{B}(\Lambda_b^0\rightarrow J/\psi
pK^-)= (3.17\pm0.04\pm0.07\pm0.34^{+0.45}_{-0.28})\times10^{-4},
\end{equation*} where the first uncertainty is statistical, the second is
systematic, the third is due to the uncertainty on the branching fraction of
the decay , and the
fourth is due to the knowledge of . The sum of the
asymmetries in the production and decay between and
is also measured as a function of and .
The previously published branching fraction of , relative to that of , is updated.
The branching fractions of are determined.Comment: 29 pages, 19figures. All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-032.htm
Measurements of long-range near-side angular correlations in TeV proton-lead collisions in the forward region
Two-particle angular correlations are studied in proton-lead collisions at a
nucleon-nucleon centre-of-mass energy of TeV, collected
with the LHCb detector at the LHC. The analysis is based on data recorded in
two beam configurations, in which either the direction of the proton or that of
the lead ion is analysed. The correlations are measured in the laboratory
system as a function of relative pseudorapidity, , and relative
azimuthal angle, , for events in different classes of event
activity and for different bins of particle transverse momentum. In
high-activity events a long-range correlation on the near side, , is observed in the pseudorapidity range . This
measurement of long-range correlations on the near side in proton-lead
collisions extends previous observations into the forward region up to
. The correlation increases with growing event activity and is found
to be more pronounced in the direction of the lead beam. However, the
correlation in the direction of the lead and proton beams are found to be
compatible when comparing events with similar absolute activity in the
direction analysed.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-040.htm
Evidence for the strangeness-changing weak decay
Using a collision data sample corresponding to an integrated luminosity
of 3.0~fb, collected by the LHCb detector, we present the first search
for the strangeness-changing weak decay . No
hadron decay of this type has been seen before. A signal for this decay,
corresponding to a significance of 3.2 standard deviations, is reported. The
relative rate is measured to be
, where and
are the and fragmentation
fractions, and is the branching
fraction. Assuming is bounded between 0.1 and
0.3, the branching fraction would lie
in the range from to .Comment: 7 pages, 2 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm
Erratum: first observation of the rare BĂŸ â DĂŸKĂŸÏâ decay [Phys. Rev. D 93, 051101(R) (2016)]
No abstract available
Scholarly publishing depends on peer reviewers
The peer-review crisis is posing a risk to the scholarly peer-reviewed journal system. Journals have to ask many potential peer reviewers to obtain a minimum acceptable number of peers accepting reviewing a manuscript. Several solutions have been suggested to overcome this shortage. From reimbursing for the job, to eliminating pre-publication reviews, one cannot predict which is more dangerous for the future of scholarly publishing. And, why not acknowledging their contribution to the final version of the article published? PubMed created two categories of contributors: authors [AU] and collaborators [IR]. Why not a third category for the peer-reviewer?Scopu
Model-independent measurement of mixing parameters in Dââ K ÏÏ decays
The first model-independent measurement of the charm mixing parameters in the
decay is reported, using a sample of collision
data recorded by the LHCb experiment, corresponding to an integrated luminosity
of 1.0 fb at a centre-of-mass energy of 7 TeV. The measured values are
\begin{eqnarray*} x &=& (-0.86 \pm 0.53 \pm 0.17) \times 10^{-2}, \\ y &=&
(+0.03 \pm 0.46 \pm 0.13) \times 10^{-2}, \end{eqnarray*} where the first
uncertainties are statistical and include small contributions due to the
external input for the strong phase measured by the CLEO collaboration, and the
second uncertainties are systematic.Comment: 25 pages, 3 figures. Sign error in x fixed as of v2. All figures and
tables, along with any supplementary material and additional information, are
available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-042.htm
Search for the lepton-flavour violating decay
A search for the lepton-flavour violating decay is made with a dataset corresponding to an integrated luminosity of fb of proton-proton collisions at centre-of-mass energies of TeV and TeV, collected by the LHCb experiment. Candidate mesons are selected using the decay and the branching fraction is measured using the decay mode as a normalisation channel. No significant excess of candidates over the expected background is seen, and a limit is set on the branching fraction, , at 90 % confidence level. This is an order of magnitude lower than the previous limit and it further constrains the parameter space in some leptoquark models and in supersymmetric models with R-parity violation.A search for the lepton-flavour violating decay D0âe±Όâ is made with a dataset corresponding to an integrated luminosity of 3.0fbâ1 of protonâproton collisions at centre-of-mass energies of 7 TeV and 8 TeV , collected by the LHCb experiment. Candidate D0 mesons are selected using the decay Dâ+âD0Ï+ and the D0âe±Όâ branching fraction is measured using the decay mode D0âKâÏ+ as a normalization channel. No significant excess of D0âe±Όâ candidates over the expected background is seen, and a limit is set on the branching fraction, B(D0âe±Όâ)<1.3Ă10â8 , at 90% confidence level. This is an order of magnitude lower than the previous limit and it further constrains the parameter space in some leptoquark models and in supersymmetric models with R-parity violation.A search for the lepton-flavour violating decay is made with a dataset corresponding to an integrated luminosity of 3.0 fb of proton-proton collisions at centre-of-mass energies of TeV and TeV, collected by the LHCb experiment. Candidate mesons are selected using the decay and the branching fraction is measured using the decay mode as a normalisation channel. No significant excess of candidates over the expected background is seen, and a limit is set on the branching fraction, , at 90 % confidence level. This is an order of magnitude lower than the previous limit and it further constrains the parameter space in some leptoquark models and in supersymmetric models with R-parity violation
- âŠ