Overview: APEC Future Education Consortium

Institute of APEC Collaborative Education APEC국제교육협력원 2007 Asia-Pacific Cybereducation Journal Vol.3 No.1

어니스트비 오피스

Wynk 콜라보레티브(Wynk Collaborative),조비앙 림(사진) 현대건축사 2017 (월간)Maru Vol.- No.179

어니스트비 오피스

Wynk 콜라보레티브(Wynk Collaborative),조비앙 림(사진) 현대건축사 2017 마루 Vol.- No.179

Search for pair-produced resonances decaying to jet pairs in proton-proton collisions at s=8 TeV

North-Holland Pub. Co 2015 Physics letters. Section B Vol.747 No.-

<P>Results are reported of a general search for pair production of heavy resonances decaying to pairs of hadronic jets in events with at least four jets. The study is based on up to 19.4 fb(-1) of integrated luminosity from proton-proton collisions at a center-of-mass energy of 8 TeV, recorded with the CMS detector at the LHC. Limits are determined on the production of scalar top quarks (top squarks) in the framework of R-parity violating supersymmetry and on the production of color-octet vector bosons (colorons). First limits at the LHC are placed on top squark production for two scenarios. The first assumes decay to a bottom quark and a light-flavor quark and is excluded for masses between 200 and 385 GeV, and the second assumes decay to a pair of light-flavor quarks and is excluded for masses between 200 and 350 GeV at 95% confidence level. Previous limits on colorons decaying to light-flavor quarks are extended to exclude masses from 200 to 835 GeV. (C) 2015 CERN for the benefit of the CMS Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license.</P>

HΛ3 and H@?Λ@?3 production in Pb-Pb collisions at s_NN=2.76 TeV

North-Holland Pub. Co 2016 Physics letters. Section B Vol.754 No.-

<P>The production of the hypertriton nuclei H-3(Lambda) and (3)((Lambda) over bar)(H) over bar has been measured for the first time in Pb-Pb collisions at root s(NN) = 2.76 TeVwith the ALICE experiment at LHC. The p(T)-integrated H-3(Lambda) yield in one unity of rapidity, dN/dy x B.R.((3 Lambda H -> 3He,pi-)) = (3.86 +/- 0.77(stat.) +/- 0.68(syst.)) x 10(-5) in the 0-10% most central collisions, is consistent with the predictions from a statistical thermal model using the same temperature as for the light hadrons. The coalescence parameter B-3 shows a dependence on the transverse momentum, similar to the B-2 of deuterons and the B-3 of He-3 nuclei. The ratio of yields S-3 = H-3(Lambda)/(He-3 x Lambda/p) was measured to be S-3 = 0.60 +/- 0.13(stat.) +/- 0.21(syst.) in 0-10% centrality events; this value is compared to different theoretical models. The measured S-3 is compatible with thermal model predictions. The measured H-3(Lambda) lifetime, tau = 181(-39)(+54)(stat.) +/- 33(syst.) psis in agreement within 1s with the world average value. (C) 2016 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.</P>

Inclusive and differential measurements of the tt@? charge asymmetry in pp collisions at s=8 TeV

North-Holland Pub. Co 2016 Physics letters: B Vol.757 No.-

<P>The t (t) over bar charge asymmetry is measured in proton-proton collisions at a centre-of-mass energy of 8 TeV. The data, collected with the CMS experiment at the LHC, correspond to an integrated luminosity of 19.7 fb(-1). Selected events contain an electron or a muon and four or more jets, where at least one jet is identified as originating from b-quark hadronization. The inclusive charge asymmetry is found to be 0.0010 +/- 0.0068 (stat)+/- 0.0037 (syst). In addition, differential charge asymmetries as a function of rapidity, transverse momentum, and invariant mass of the If system are studied. For the first time at the LHC, the measurements are also performed in a reduced fiducial phase space of top quark pair production, with an integrated result of -0.0035 +/- 0.0072 (stat) +/- 0.0031 (syst). All measurements are consistent within two standard deviations with zero asymmetry as well as with the predictions of the standard model. (C) 2016 CERN for the benefit of the CMS Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).</P>

Centrality evolution of the charged-particle pseudorapidity density over a broad pseudorapidity range in Pb-Pb collisions at s_NN=2.76 TeV

North-Holland Pub. Co 2016 Physics letters. Section B Vol.754 No.-

<P>The centrality dependence of the charged-particle pseudorapidity density measured with ALICE in Pb-Pb collisions at root s(NN) = 2.76 TeV over a broad pseudorapidity range is presented. This Letter extends the previous results reported by ALICE to more peripheral collisions. No strong change of the overall shape of charged-particle pseudorapidity density distributions with centrality is observed, and when normalised to the number of participating nucleons in the collisions, the evolution over pseudorapidity with centrality is likewise small. The broad pseudorapidity range (-3.5 < eta < 5) allows precise estimates of the total number of produced charged particles which we find to range from 162 +/- 22(syst.) to 17170 +/- 770(syst.) in 80-90% and 0-5% central collisions, respectively. The total charged-particle multiplicity is seen to approximately scale with the number of participating nucleons in the collision. This suggests that hard contributions to the charged-particle multiplicity are limited. The results are compared to models which describe dN(ch)/d(eta) at mid-rapidity in the most central Pb-Pb collisions and it is found that these models do not capture all features of the distributions. (C) 2016 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.</P>

Search for neutral MSSM Higgs bosons decaying to μ⁺μ^- in pp collisions at s=7 and 8 TeV

North-Holland Pub. Co 2016 Physics letters: B Vol.752 No.-

<P>search for neutral Higgs bosons predicted in the minimal supersymmetric standard model (MSSM) for mu(+) mu(-) decay channels is presented. The analysis uses data collected by the CMS experiment at the LHC in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV, corresponding to integrated luminosities of 5.1 and 19.3 fb(-1), respectively. The search is sensitive to Higgs bosons produced either through the gluon fusion process or in association with a b (b) over bar quark pair. No statistically significant excess is observed in the mu(+) mu(-) mass spectrum. Results are interpreted in the framework of several benchmark scenarios, and the data are used to set an upper limit on the MSSM parameter tan beta as a function of the mass of the pseudoscalar A boson in the range from 115 to 300 GeV. Model independent upper limits are given for the product of the cross section and branching fraction for gluon fusion and b quark associated production at root s = 8 TeV. They are the most stringent limits obtained to date in this channel. (C) 2015 CERN for the benefit of the CMS Collaboration. Published by Elsevier B.V.</P>

Measurement of electrons from heavy-flavour hadron decays in p-Pb collisions at s_NN=5.02TeV

North-Holland Pub. Co 2016 Physics letters. Section B Vol.754 No.-

<P>The production of electrons from heavy-flavour hadron decays was measured as a function of transverse momentum (p(T)) in minimum-bias p-Pb collisions at root s(NN) = 5.02 TeV using the ALICE detector at the LHC. The measurement covers the p(T) interval 0.5 < p(T) < 12 GeV/c and the rapidity range -1.065 < y(cms) < 0.135 in the centre-of-mass reference frame. The contribution of electrons from background sources was subtracted using an invariant mass approach. The nuclear modification factor R-pPb was calculated by comparing the p(T)-differential invariant cross section in p-Pb collisions to a pp reference at the same centre-of-mass energy, which was obtained by interpolating measurements at root s = 2.76 TeV and root s= 7 TeV. The R-pPb is consistent with unity within uncertainties of about 25%, which become larger for p(T) below 1 GeV/c. The measurement shows that heavy-flavour production is consistent with binary scaling, so that a suppression in the high-p(T) yield in Pb-Pb collisions has to be attributed to effects induced by the hot medium produced in the final state. The data in p-Pb collisions are described by recent model calculations that include cold nuclear matter effects. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V.</P>

Transverse momentum spectra of inclusive b jets in pPb collisions at s_NN=5.02 TeV

North-Holland Pub. Co 2016 Physics letters: B Vol.754 No.-

<P>We present a measurement of b jet transverse momentum (p(T)) spectra in proton-lead (pPb) collisions using a dataset corresponding to about 35nb(-1) collected with the CMS detector at the LHC. Jets from b quark fragmentation are found by exploiting the long lifetime of hadrons containing a b quark through tagging methods using distributions of the secondary vertex mass and displacement. Extracted cross sections for b jets are scaled by the effective number of nucleon-nucleon collisions and are compared to a reference obtained from PYTHIA simulations of pp collisions. The PYTHIA-based estimate of the nuclear modification factor is found to be 1.22 +/- 0.15 (stat + syst pPb) +/- 0.27 (syst PYTHIA) averaged over all jets with p(T) between 55 and 400 GeV/c and with |eta(lab)| < 2. We also compare this result to predictions from models using perturbative calculations in quantum chromodynamics. (C) 2016 CERN for the benefit of the CMS Collaboration. Published by Elsevier B.V.</P>