search
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
3,816 Research products, page 1 of 382

  • Canada
  • Publications
  • Research data
  • Research software
  • Natural Sciences and Engineering Research Council of Canada
  • IT

10
arrow_drop_down
Relevance
arrow_drop_down
  • Open Access English
    Authors: 
    Sean N Hatton; Khoa H Huynh; Leonardo Bonilha; Eugenio Abela; Saud Alhusaini; Andre Altmann; Marina KM Alvim; Akshara R Balachandra; Emanuele Bartolini; Benjamin Bender; +64 more
    Publisher: Cold Spring Harbor Laboratory
    Project: NIH | Multimodal imaging of cog... (2R01NS065838-06A1), UKRI | Brain architecture and co... (MR/S00355X/1), NIH | ENIGMA-SD: Understanding ... (1R01MH116147-01), CIHR , NIH | ENIGMA Center for Worldwi... (3U54EB020403-04S1), UKRI | Translation of novel imag... (G0802012), NIH | ENIGMA World Aging Center (1R56AG058854-01), UKRI | Imaging prognostic marker... (MR/K023152/1), NSERC , NHMRC | Human Epilepsy: Understan... (1091593),...

    AbstractThe epilepsies are commonly accompanied by widespread abnormalities in cerebral white matter. ENIGMA-Epilepsy is a large quantitative brain imaging consortium, aggregating data to investigate patterns of neuroimaging abnormalities in common epilepsy syndromes, including temporal lobe epilepsy, extratemporal epilepsy, and genetic generalized epilepsy. Our goal was to rank the most robust white matter microstructural differences across and within syndromes in a multicentre sample of adult epilepsy patients. Diffusion-weighted MRI data were analyzed from 1,069 non-epileptic controls and 1,249 patients: temporal lobe epilepsy with hippocampal sclerosis (N=599), temporal lobe epilepsy with normal MRI (N=275), genetic generalized epilepsy (N=182) and nonlesional extratemporal epilepsy (N=193). A harmonized protocol using tract-based spatial statistics was used to derive skeletonized maps of fractional anisotropy and mean diffusivity for each participant, and fiber tracts were segmented using a diffusion MRI atlas. Data were harmonized to correct for scanner-specific variations in diffusion measures using a batch-effect correction tool (ComBat). Analyses of covariance, adjusting for age and sex, examined differences between each epilepsy syndrome and controls for each white matter tract (Bonferroni corrected at p<0.001). Across “all epilepsies” lower fractional anisotropy was observed in most fiber tracts with small to medium effect sizes, especially in the corpus callosum, cingulum and external capsule. Less robust effects were seen with mean diffusivity. Syndrome-specific fractional anisotropy and mean diffusivity differences were most pronounced in patients with hippocampal sclerosis in the ipsilateral parahippocampal cingulum and external capsule, with smaller effects across most other tracts. Those with temporal lobe epilepsy and normal MRI showed a similar pattern of greater ipsilateral than contralateral abnormalities, but less marked than those in patients with hippocampal sclerosis. Patients with generalized and extratemporal epilepsies had pronounced differences in fractional anisotropy in the corpus callosum, corona radiata and external capsule, and in mean diffusivity of the anterior corona radiata. Earlier age of seizure onset and longer disease duration were associated with a greater extent of microstructural abnormalities in patients with hippocampal sclerosis. We demonstrate microstructural abnormalities across major association, commissural, and projection fibers in a large multicentre study of epilepsy. Overall, epilepsy patients showed white matter abnormalities in the corpus callosum, cingulum and external capsule, with differing severity across epilepsy syndromes. These data further define the spectrum of white matter abnormalities in common epilepsy syndromes, yielding new insights into pathological substrates that may be used to guide future therapeutic and genetic studies.

  • Open Access
    Authors: 
    Morad Aaboud; Alexander Kupco; Stefan Schmitt; Ahmed Bassalat; Matej Melo; Marjorie Shapiro; Grigore Tarna; Till Eifert; Maximiliano Sioli; Nello Bruscino; +816 more
    Publisher: American Physical Society (APS)
    Project: NSERC

    A measurement of the associated production of a top-quark pair (tt) with a vector boson (W, Z) in proton-proton collisions at a center-of-mass energy of 13 TeV is presented, using 36.1 fb-1 of integrated luminosity collected by the ATLAS detector at the Large Hadron Collider. Events are selected in channels with two same- or opposite-sign leptons (electrons or muons), three leptons or four leptons, and each channel is further divided into multiple regions to maximize the sensitivity of the measurement. The ttZ and ttW production cross sections are simultaneously measured using a combined fit to all regions. The best-fit values of the production cross sections are σttZ=0.95±0.08stat±0.10syst pb and σttW=0.87±0.13stat±0.14syst pb in agreement with the Standard Model predictions. The measurement of the ttZ cross section is used to set constraints on effective field theory operators which modify the ttZ vertex.

  • Open Access English
    Authors: 
    Juris Meija; Zoltán Mester; Alessandro D'Ulivo;
    Countries: Italy, Canada
    Project: NSERC

    Mass spectra of fully and partially deuterated As, Sb, Bi, Ge, and Sn hydrides have been obtained using several mathematical approaches aimed at signal extraction and reconstruction. Study of such hydride mixtures is important for the elucidation of hydride generation mechanisms. In this approach, mass spectra of partially deuterated isotopomers, i.e., AsH2D and AsHD2, are extracted using the weighted two-band target entropy minimization method. Alternatively, these mass spectra were constructed from the mass spectra of fully deuterated and hydrogenated hydrides using the statistical approach in fragmentation pathways. Concentration profiles of all deuterated hydrides were obtained from their overlapping mixture mass spectra using least-squares deconvolution.

  • Publication . Article . Preprint . 2013 . Embargo End Date: 01 Jan 2013
    Open Access
    Authors: 
    Georg P. Engel; Christian B. Lang; Daniel Mohler; Andreas Schäfer;
    Publisher: arXiv
    Project: NSERC

    We present a study of baryon ground states and low lying excitations of non-strange and strange baryons. The results are based on seven gauge field ensembles with two dynamical light Chirally Improved (CI) quarks corresponding to pion masses between 255 and 596 MeV and a strange valence quark with mass fixed by the Omega baryon. The lattice spacing varies between 0.1324 and 0.1398 fm. Given in lattice units, the bulk of our results are for size 16^3\times 32, for two ensembles with light pion masses (255 and 330 MeV) we also use 24^3\times 48 lattices and perform an infinite volume extrapolation. We derive energy levels for the spin 1/2 and 3/2 channels for both parities. In general, our results in the infinite volume limit compare well with experiment. We analyze the flavor symmetry content by identifying the singlet/octet/decuplet contributions of the resulting eigenstates. The ground states compositions agree with quark model expectations. In some cases the excited states, however, disagree and we discuss possible reasons. Comment: 22 pages, 27 figures

  • Open Access
    Authors: 
    T. Aaltonen; Ronen Alon; A. Anastassov; Giorgio Apollinari; Tetsuo Arisawa; A. Artikov; J. Asaadi; A. Barbaro-Galtieri; Virgil E Barnes; B. A. Barnett; +210 more
    Publisher: American Physical Society
    Countries: Spain, Spain, Italy
    Project: EC | TAUKITFORNEWPHYSICS (302103), NSERC , SNSF | Measurements of Higgs bos... (153664)

    This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation; the A. P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the Korean World Class University Program, the National Research Foundation of Korea; the Science and Technology Facilities Council and the Royal Society, United Kingdom; the Russian Foundation for Basic Research; the Ministerio de Ciencia e Innovación, and Programa Consolider-Ingenio 2010, Spain; the Slovak R&D Agency; the Academy of Finland; the Australian Research Council (ARC); and the EU community Marie Curie Fellowship Contract No. 302103. This work was also supported by the Shrum Foundation, the Weizman Institute of Science and the Israel Science Foundation. Results of a study of the substructure of the highest transverse momentum (pT) jets observed by the CDF Collaboration are presented. Events containing at least one jet with pT>400 GeV/c in a sample corresponding to an integrated luminosity of 5.95 fb−1, collected in 1.96 TeV proton-antiproton collisions at the Fermilab Tevatron collider, are selected. A study of the jet mass, angularity, and planar-flow distributions is presented, and the measurements are compared with predictions of perturbative quantum chromodynamics. A search for boosted top-quark production is also described, leading to a 95% confidence level upper limit of 38 fb on the production cross section of top quarks with pT>400 GeV/c. Peer Reviewed et al.

  • Open Access
    Authors: 
    Jouhyun Jeon; Satra Nim; Joan Teyra; Alessandro Datti; Jeffrey L. Wrana; Sachdev S. Sidhu; Jason Moffat; Philip M. Kim;
    Publisher: Springer Science and Business Media LLC
    Project: CIHR , NSERC

    We present an integrated approach that predicts and validates novel anti-cancer drug targets. We first built a classifier that integrates a variety of genomic and systematic datasets to prioritize drug targets specific for breast, pancreatic and ovarian cancer. We then devised strategies to inhibit these anti-cancer drug targets and selected a set of targets that are amenable to inhibition by small molecules, antibodies and synthetic peptides. We validated the predicted drug targets by showing strong anti-proliferative effects of both synthetic peptide and small molecule inhibitors against our predicted targets. Electronic supplementary material The online version of this article (doi:10.1186/s13073-014-0057-7) contains supplementary material, which is available to authorized users.

  • Open Access English
    Authors: 
    Abbiendi, G.; Ainsley, C.; Åkesson, P.F.; Alexander, G.; Allison, J.; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; +190 more
    Country: Italy
    Project: NSERC

    AbstractA search for the Higgsstrahlung process e+e−→hZ is described, where the neutral Higgs boson h is assumed to decay into hadronic final states. In order to be sensitive to a broad range of models, the search is performed independent of the flavour content of the Higgs boson decay. The analysis is based on e+e− collision data collected by the OPAL detector at energies between 192 and 209 GeV. The search does not reveal any significant excess over the Standard Model background prediction. Results are combined with previous searches at energies around 91 and at 189 GeV. A limit is set on the product of the cross-section and the hadronic branching ratio of the Higgs boson, as a function of the Higgs boson mass. Assuming the hZ coupling predicted by the Standard Model, and a Higgs boson decaying only into hadronic final states, a lower bound of 104 GeV/c2 is set on the mass at the 95% confidence level.

  • Publication . Preprint . Article . 2020 . Embargo End Date: 01 Jan 2020
    Open Access
    Authors: 
    Kate Pattle; Shih-Ping Lai; James Di Francesco; Sarah Sadavoy; Derek Ward-Thompson; Doug Johnstone; Thiem Hoang; Doris Arzoumanian; Pierre Bastien; Tyler L. Bourke; +19 more
    Publisher: arXiv
    Project: FCT | UIDB/04434/2020 (UIDB/04434/2020), NSERC , FCT | UID/FIS/04434/2019 (UID/FIS/04434/2019)

    We present 850$\mu$m polarization observations of the L1689 molecular cloud, part of the nearby Ophiuchus molecular cloud complex, taken with the POL-2 polarimeter on the James Clerk Maxwell Telescope (JCMT). We observe three regions of L1689: the clump L1689N which houses the IRAS 16293-2422 protostellar system, the starless clump SMM-16, and the starless core L1689B. We use the Davis-Chandrasekhar-Fermi method to estimate plane-of-sky field strengths of $366\pm 55$ $\mu$G in L1689N, $284\pm 34$ $\mu$G in SMM-16, and $72\pm 33$ $\mu$G in L1689B, for our fiducial value of dust opacity. These values indicate that all three regions are likely to be magnetically trans-critical with sub-Alfv\'{e}nic turbulence. In all three regions, the inferred mean magnetic field direction is approximately perpendicular to the local filament direction identified in $Herschel$ Space Telescope observations. The core-scale field morphologies for L1689N and L1689B are consistent with the cloud-scale field morphology measured by the $Planck$ Space Observatory, suggesting that material can flow freely from large to small scales for these sources. Based on these magnetic field measurements, we posit that accretion from the cloud onto L1689N and L1689B may be magnetically regulated. However, in SMM-16, the clump-scale field is nearly perpendicular to the field seen on cloud scales by $Planck$, suggesting that it may be unable to efficiently accrete further material from its surroundings. Comment: 29 pages, 9 figures, 4 tables. Accepted for publication in the Astrophysical Journal

  • Publication . Article . Preprint . 2019 . Embargo End Date: 01 Jan 2019
    Open Access
    Authors: 
    Ramit Dey; Stefano Liberati; Zahra Mirzaiyan; Daniele Pranzetti;
    Publisher: arXiv
    Country: Italy
    Project: NSERC

    We analyze Hawking radiation as perceived by a freely-falling observer and try to draw an inference about the region of origin of the Hawking quanta. To do so, first we calculate the energy density from the stress energy tensor, as perceived by a freely-falling observer. Then we compare this with the energy density computed from an effective temperature functional which depends on the state of the observer. The two ways of computing these quantities show a mismatch at the light ring outside the black hole horizon. To better understand this ambiguity, we show that even taking into account the (minor) breakdown of the adiabatic evolution of the temperature functional which has a peak in the same region of the mismatch, is not enough to remove it. We argue that the appearance of this discrepancy can be traced back to the process of particle creation by showing how the Wentzel–Kramers–Brillouin approximation for the field modes breaks down between the light ring at 3M and 4M, with a peak at r=3.3M exactly where the energy density mismatch is maximized. We hence conclude that these facts strongly support a scenario where the Hawking flux does originate from a “quantum atmosphere” located well outside the black hole horizon.

  • Closed Access
    Authors: 
    Atriya Biswas; Pier Giuseppe Anselma; Aashit Rathore; Ali Emadi;
    Publisher: Elsevier BV
    Project: NSERC

    Abstract An online simulation framework is developed in this article to evaluate the performance of a multi-mode electrified powertrain equipped with more than one power source. An electrically variable transmission with two planetary gear-set has been chosen as the centerpiece of the powertrain considering the versatility and prospects of such transmissions. A novel architecture topology of the aforementioned class of transmission is selected through rigorous screening process whose workflow is presented here with brevity. The article systematically delineates the steps for deriving dynamics associated with all the feasible operating modes facilitated by the selected topology. The dynamics associated with all the feasible mode-shift events are also heeded judiciously. One of the legitimate concern of multi-mode transmission is its proclivity to contribute discontinuity of power-flow downstream of the powertrain. Mode-shift events can be predominantly held responsible for engendering such discontinuity. Many scholars in literature have substantiated the advent of dynamic coordinated control as a technique for ameliorating such discontinuity. Hence, a system-level coordinated control is employed within the energy management system (equivalent consumption minimization strategy), which governs the mode schedule of the multi-mode powertrain in real-time simulation. Simulation results corroborate the effect of coordinated control on the equivalent consumption minimization strategy in generating optimal mode schedule.

search
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
3,816 Research products, page 1 of 382
  • Open Access English
    Authors: 
    Sean N Hatton; Khoa H Huynh; Leonardo Bonilha; Eugenio Abela; Saud Alhusaini; Andre Altmann; Marina KM Alvim; Akshara R Balachandra; Emanuele Bartolini; Benjamin Bender; +64 more
    Publisher: Cold Spring Harbor Laboratory
    Project: NIH | Multimodal imaging of cog... (2R01NS065838-06A1), UKRI | Brain architecture and co... (MR/S00355X/1), NIH | ENIGMA-SD: Understanding ... (1R01MH116147-01), CIHR , NIH | ENIGMA Center for Worldwi... (3U54EB020403-04S1), UKRI | Translation of novel imag... (G0802012), NIH | ENIGMA World Aging Center (1R56AG058854-01), UKRI | Imaging prognostic marker... (MR/K023152/1), NSERC , NHMRC | Human Epilepsy: Understan... (1091593),...

    AbstractThe epilepsies are commonly accompanied by widespread abnormalities in cerebral white matter. ENIGMA-Epilepsy is a large quantitative brain imaging consortium, aggregating data to investigate patterns of neuroimaging abnormalities in common epilepsy syndromes, including temporal lobe epilepsy, extratemporal epilepsy, and genetic generalized epilepsy. Our goal was to rank the most robust white matter microstructural differences across and within syndromes in a multicentre sample of adult epilepsy patients. Diffusion-weighted MRI data were analyzed from 1,069 non-epileptic controls and 1,249 patients: temporal lobe epilepsy with hippocampal sclerosis (N=599), temporal lobe epilepsy with normal MRI (N=275), genetic generalized epilepsy (N=182) and nonlesional extratemporal epilepsy (N=193). A harmonized protocol using tract-based spatial statistics was used to derive skeletonized maps of fractional anisotropy and mean diffusivity for each participant, and fiber tracts were segmented using a diffusion MRI atlas. Data were harmonized to correct for scanner-specific variations in diffusion measures using a batch-effect correction tool (ComBat). Analyses of covariance, adjusting for age and sex, examined differences between each epilepsy syndrome and controls for each white matter tract (Bonferroni corrected at p<0.001). Across “all epilepsies” lower fractional anisotropy was observed in most fiber tracts with small to medium effect sizes, especially in the corpus callosum, cingulum and external capsule. Less robust effects were seen with mean diffusivity. Syndrome-specific fractional anisotropy and mean diffusivity differences were most pronounced in patients with hippocampal sclerosis in the ipsilateral parahippocampal cingulum and external capsule, with smaller effects across most other tracts. Those with temporal lobe epilepsy and normal MRI showed a similar pattern of greater ipsilateral than contralateral abnormalities, but less marked than those in patients with hippocampal sclerosis. Patients with generalized and extratemporal epilepsies had pronounced differences in fractional anisotropy in the corpus callosum, corona radiata and external capsule, and in mean diffusivity of the anterior corona radiata. Earlier age of seizure onset and longer disease duration were associated with a greater extent of microstructural abnormalities in patients with hippocampal sclerosis. We demonstrate microstructural abnormalities across major association, commissural, and projection fibers in a large multicentre study of epilepsy. Overall, epilepsy patients showed white matter abnormalities in the corpus callosum, cingulum and external capsule, with differing severity across epilepsy syndromes. These data further define the spectrum of white matter abnormalities in common epilepsy syndromes, yielding new insights into pathological substrates that may be used to guide future therapeutic and genetic studies.

  • Open Access
    Authors: 
    Morad Aaboud; Alexander Kupco; Stefan Schmitt; Ahmed Bassalat; Matej Melo; Marjorie Shapiro; Grigore Tarna; Till Eifert; Maximiliano Sioli; Nello Bruscino; +816 more
    Publisher: American Physical Society (APS)
    Project: NSERC

    A measurement of the associated production of a top-quark pair (tt) with a vector boson (W, Z) in proton-proton collisions at a center-of-mass energy of 13 TeV is presented, using 36.1 fb-1 of integrated luminosity collected by the ATLAS detector at the Large Hadron Collider. Events are selected in channels with two same- or opposite-sign leptons (electrons or muons), three leptons or four leptons, and each channel is further divided into multiple regions to maximize the sensitivity of the measurement. The ttZ and ttW production cross sections are simultaneously measured using a combined fit to all regions. The best-fit values of the production cross sections are σttZ=0.95±0.08stat±0.10syst pb and σttW=0.87±0.13stat±0.14syst pb in agreement with the Standard Model predictions. The measurement of the ttZ cross section is used to set constraints on effective field theory operators which modify the ttZ vertex.

  • Open Access English
    Authors: 
    Juris Meija; Zoltán Mester; Alessandro D'Ulivo;
    Countries: Italy, Canada
    Project: NSERC

    Mass spectra of fully and partially deuterated As, Sb, Bi, Ge, and Sn hydrides have been obtained using several mathematical approaches aimed at signal extraction and reconstruction. Study of such hydride mixtures is important for the elucidation of hydride generation mechanisms. In this approach, mass spectra of partially deuterated isotopomers, i.e., AsH2D and AsHD2, are extracted using the weighted two-band target entropy minimization method. Alternatively, these mass spectra were constructed from the mass spectra of fully deuterated and hydrogenated hydrides using the statistical approach in fragmentation pathways. Concentration profiles of all deuterated hydrides were obtained from their overlapping mixture mass spectra using least-squares deconvolution.

  • Publication . Article . Preprint . 2013 . Embargo End Date: 01 Jan 2013
    Open Access
    Authors: 
    Georg P. Engel; Christian B. Lang; Daniel Mohler; Andreas Schäfer;
    Publisher: arXiv
    Project: NSERC

    We present a study of baryon ground states and low lying excitations of non-strange and strange baryons. The results are based on seven gauge field ensembles with two dynamical light Chirally Improved (CI) quarks corresponding to pion masses between 255 and 596 MeV and a strange valence quark with mass fixed by the Omega baryon. The lattice spacing varies between 0.1324 and 0.1398 fm. Given in lattice units, the bulk of our results are for size 16^3\times 32, for two ensembles with light pion masses (255 and 330 MeV) we also use 24^3\times 48 lattices and perform an infinite volume extrapolation. We derive energy levels for the spin 1/2 and 3/2 channels for both parities. In general, our results in the infinite volume limit compare well with experiment. We analyze the flavor symmetry content by identifying the singlet/octet/decuplet contributions of the resulting eigenstates. The ground states compositions agree with quark model expectations. In some cases the excited states, however, disagree and we discuss possible reasons. Comment: 22 pages, 27 figures

  • Open Access
    Authors: 
    T. Aaltonen; Ronen Alon; A. Anastassov; Giorgio Apollinari; Tetsuo Arisawa; A. Artikov; J. Asaadi; A. Barbaro-Galtieri; Virgil E Barnes; B. A. Barnett; +210 more
    Publisher: American Physical Society
    Countries: Spain, Spain, Italy
    Project: EC | TAUKITFORNEWPHYSICS (302103), NSERC , SNSF | Measurements of Higgs bos... (153664)

    This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Culture, Sports, Science and Technology of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; the Swiss National Science Foundation; the A. P. Sloan Foundation; the Bundesministerium für Bildung und Forschung, Germany; the Korean World Class University Program, the National Research Foundation of Korea; the Science and Technology Facilities Council and the Royal Society, United Kingdom; the Russian Foundation for Basic Research; the Ministerio de Ciencia e Innovación, and Programa Consolider-Ingenio 2010, Spain; the Slovak R&D Agency; the Academy of Finland; the Australian Research Council (ARC); and the EU community Marie Curie Fellowship Contract No. 302103. This work was also supported by the Shrum Foundation, the Weizman Institute of Science and the Israel Science Foundation. Results of a study of the substructure of the highest transverse momentum (pT) jets observed by the CDF Collaboration are presented. Events containing at least one jet with pT>400 GeV/c in a sample corresponding to an integrated luminosity of 5.95 fb−1, collected in 1.96 TeV proton-antiproton collisions at the Fermilab Tevatron collider, are selected. A study of the jet mass, angularity, and planar-flow distributions is presented, and the measurements are compared with predictions of perturbative quantum chromodynamics. A search for boosted top-quark production is also described, leading to a 95% confidence level upper limit of 38 fb on the production cross section of top quarks with pT>400 GeV/c. Peer Reviewed et al.

  • Open Access
    Authors: 
    Jouhyun Jeon; Satra Nim; Joan Teyra; Alessandro Datti; Jeffrey L. Wrana; Sachdev S. Sidhu; Jason Moffat; Philip M. Kim;
    Publisher: Springer Science and Business Media LLC
    Project: CIHR , NSERC

    We present an integrated approach that predicts and validates novel anti-cancer drug targets. We first built a classifier that integrates a variety of genomic and systematic datasets to prioritize drug targets specific for breast, pancreatic and ovarian cancer. We then devised strategies to inhibit these anti-cancer drug targets and selected a set of targets that are amenable to inhibition by small molecules, antibodies and synthetic peptides. We validated the predicted drug targets by showing strong anti-proliferative effects of both synthetic peptide and small molecule inhibitors against our predicted targets. Electronic supplementary material The online version of this article (doi:10.1186/s13073-014-0057-7) contains supplementary material, which is available to authorized users.

  • Open Access English
    Authors: 
    Abbiendi, G.; Ainsley, C.; Åkesson, P.F.; Alexander, G.; Allison, J.; Amaral, P.; Anagnostou, G.; Anderson, K.J.; Arcelli, S.; Asai, S.; +190 more
    Country: Italy
    Project: NSERC

    AbstractA search for the Higgsstrahlung process e+e−→hZ is described, where the neutral Higgs boson h is assumed to decay into hadronic final states. In order to be sensitive to a broad range of models, the search is performed independent of the flavour content of the Higgs boson decay. The analysis is based on e+e− collision data collected by the OPAL detector at energies between 192 and 209 GeV. The search does not reveal any significant excess over the Standard Model background prediction. Results are combined with previous searches at energies around 91 and at 189 GeV. A limit is set on the product of the cross-section and the hadronic branching ratio of the Higgs boson, as a function of the Higgs boson mass. Assuming the hZ coupling predicted by the Standard Model, and a Higgs boson decaying only into hadronic final states, a lower bound of 104 GeV/c2 is set on the mass at the 95% confidence level.

  • Publication . Preprint . Article . 2020 . Embargo End Date: 01 Jan 2020
    Open Access
    Authors: 
    Kate Pattle; Shih-Ping Lai; James Di Francesco; Sarah Sadavoy; Derek Ward-Thompson; Doug Johnstone; Thiem Hoang; Doris Arzoumanian; Pierre Bastien; Tyler L. Bourke; +19 more
    Publisher: arXiv
    Project: FCT | UIDB/04434/2020 (UIDB/04434/2020), NSERC , FCT | UID/FIS/04434/2019 (UID/FIS/04434/2019)

    We present 850$\mu$m polarization observations of the L1689 molecular cloud, part of the nearby Ophiuchus molecular cloud complex, taken with the POL-2 polarimeter on the James Clerk Maxwell Telescope (JCMT). We observe three regions of L1689: the clump L1689N which houses the IRAS 16293-2422 protostellar system, the starless clump SMM-16, and the starless core L1689B. We use the Davis-Chandrasekhar-Fermi method to estimate plane-of-sky field strengths of $366\pm 55$ $\mu$G in L1689N, $284\pm 34$ $\mu$G in SMM-16, and $72\pm 33$ $\mu$G in L1689B, for our fiducial value of dust opacity. These values indicate that all three regions are likely to be magnetically trans-critical with sub-Alfv\'{e}nic turbulence. In all three regions, the inferred mean magnetic field direction is approximately perpendicular to the local filament direction identified in $Herschel$ Space Telescope observations. The core-scale field morphologies for L1689N and L1689B are consistent with the cloud-scale field morphology measured by the $Planck$ Space Observatory, suggesting that material can flow freely from large to small scales for these sources. Based on these magnetic field measurements, we posit that accretion from the cloud onto L1689N and L1689B may be magnetically regulated. However, in SMM-16, the clump-scale field is nearly perpendicular to the field seen on cloud scales by $Planck$, suggesting that it may be unable to efficiently accrete further material from its surroundings. Comment: 29 pages, 9 figures, 4 tables. Accepted for publication in the Astrophysical Journal

  • Publication . Article . Preprint . 2019 . Embargo End Date: 01 Jan 2019
    Open Access
    Authors: 
    Ramit Dey; Stefano Liberati; Zahra Mirzaiyan; Daniele Pranzetti;
    Publisher: arXiv
    Country: Italy
    Project: NSERC

    We analyze Hawking radiation as perceived by a freely-falling observer and try to draw an inference about the region of origin of the Hawking quanta. To do so, first we calculate the energy density from the stress energy tensor, as perceived by a freely-falling observer. Then we compare this with the energy density computed from an effective temperature functional which depends on the state of the observer. The two ways of computing these quantities show a mismatch at the light ring outside the black hole horizon. To better understand this ambiguity, we show that even taking into account the (minor) breakdown of the adiabatic evolution of the temperature functional which has a peak in the same region of the mismatch, is not enough to remove it. We argue that the appearance of this discrepancy can be traced back to the process of particle creation by showing how the Wentzel–Kramers–Brillouin approximation for the field modes breaks down between the light ring at 3M and 4M, with a peak at r=3.3M exactly where the energy density mismatch is maximized. We hence conclude that these facts strongly support a scenario where the Hawking flux does originate from a “quantum atmosphere” located well outside the black hole horizon.

  • Closed Access
    Authors: 
    Atriya Biswas; Pier Giuseppe Anselma; Aashit Rathore; Ali Emadi;
    Publisher: Elsevier BV
    Project: NSERC

    Abstract An online simulation framework is developed in this article to evaluate the performance of a multi-mode electrified powertrain equipped with more than one power source. An electrically variable transmission with two planetary gear-set has been chosen as the centerpiece of the powertrain considering the versatility and prospects of such transmissions. A novel architecture topology of the aforementioned class of transmission is selected through rigorous screening process whose workflow is presented here with brevity. The article systematically delineates the steps for deriving dynamics associated with all the feasible operating modes facilitated by the selected topology. The dynamics associated with all the feasible mode-shift events are also heeded judiciously. One of the legitimate concern of multi-mode transmission is its proclivity to contribute discontinuity of power-flow downstream of the powertrain. Mode-shift events can be predominantly held responsible for engendering such discontinuity. Many scholars in literature have substantiated the advent of dynamic coordinated control as a technique for ameliorating such discontinuity. Hence, a system-level coordinated control is employed within the energy management system (equivalent consumption minimization strategy), which governs the mode schedule of the multi-mode powertrain in real-time simulation. Simulation results corroborate the effect of coordinated control on the equivalent consumption minimization strategy in generating optimal mode schedule.