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Author |
Nguyen, C.V.; Gillam, J.E.; Brown, J.M.C.; Martin, D.V.; Nikulin, D.A.; Dimmock, M.R. |
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Title |
Towards Optimal Collimator Design for the PEDRO Hybrid Imaging System |
Type |
Journal Article |
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Year |
2011 |
Publication |
IEEE Transactions on Nuclear Science |
Abbreviated Journal |
IEEE Trans. Nucl. Sci. |
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Volume |
58 |
Issue |
3 |
Pages |
639-650 |
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Keywords |
Compton scattering enhancement; multiple pinhole; PEDRO |
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Abstract |
The Pixelated Emission Detector for RadiOisotopes (PEDRO) is a hybrid imaging system designed for the measurement of single photon emission from small animal models. The proof-of-principle device consists of a Compton-camera situated behind a mechanical collimator and is intended to provide optimal detection characteristics over a broad spectral range, from 30 to 511 keV. An automated routine has been developed for the optimization of large-area slits in the outer regions of a collimator which has a central region allocated for pinholes. The optimization was tested with a GEANT4 model of the experimental prototype. The data were blurred with the expected position and energy resolution parameters and a Bayesian interaction ordering algorithm was applied. Images were reconstructed using cone back-projection. The results show that the optimization technique allows the large-area slits to both sample fully and extend the primary field of view (FoV) determined by the pinholes. The slits were found to provide truncation of the back-projected cones of response and also an increase in the success rate of the interaction ordering algorithm. These factors resulted in an increase in the contrast and signal-to-noise ratio of the reconstructed image estimates. Of the two configurations tested, the cylindrical geometry outperformed the square geometry, primarily because of a decrease in artifacts. This was due to isotropic modulation of the cone surfaces, that can be achieved with a circular shape. Also, the cylindrical geometry provided increased sampling of the FoV due to more optimal positioning of the slits. The use of the cylindrical collimator and application of the transmission function in the reconstruction was found to improve the resolution of the system by a factor of 20, as compared to the uncollimated Compton camera. Although this system is designed for small animal imaging, the technique can be applied to any application of single photon imaging. |
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Address |
[Nguyen, Chuong V.; Dimmock, Matthew R.] Monash Univ, Sch Phys, Melbourne, Vic 3800, Australia, Email: chuong.nguyen@monash.edu |
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Ieee-Inst Electrical Electronics Engineers Inc |
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English |
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0018-9499 |
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Notes |
ISI:000291655900008 |
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no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
650 |
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Author |
ATLAS Collaboration (Aad, G. et al); Amoros, G.; Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Escobar, C.; Ferrer, A.; Fuster, J.; Garcia, C.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Kaci, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Miñano, M.; Mitsou, V.A.; Moles-Valls, R.; Moreno Llacer, M.; Oliver Garcia, E.; Perez Garcia-Estañ, M.T.; Ros, E.; Salt, J.; Solans, C.A.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Villaplana Perez, M.; Vos, M.; Wildauer, A. |
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Title |
Measurements of underlying-event properties using neutral and charged particles in pp collisions at sqrt(s) = 900 GeV and sqrt(s) = 7 TeV with the ATLAS detector at the LHC |
Type |
Journal Article |
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Year |
2011 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume |
71 |
Issue |
5 |
Pages |
1636 - 24pp |
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Abstract |
We present first measurements of charged and neutral particle-flow correlations in pp collisions using the ATLAS calorimeters. Data were collected in 2009 and 2010 at centre-of-mass energies of 900 GeV and 7 TeV. Events were selected using a minimum-bias trigger which required a charged particle in scintillation counters on either side of the interaction point. Particle flows, sensitive to the underlying event, are measured using clusters of energy in the ATLAS calorimeters, taking advantage of their fine granularity. No Monte Carlo generator used in this analysis can accurately describe the measurements. The results are independent of those based on charged particles measured by the ATLAS tracking systems and can be used to constrain the parameters of Monte Carlo generators. |
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Address |
[Aleksa, M.; Amaral, P.; Anghinolfi, F.; Arfaoui, S.; Asai, S.; Baak, M. A.; Bachas, K.; Bachy, G.; Pedrosa, F. Baltasar Dos Santos; Banfi, D.; Battistin, M.; Bellina, F.; Beltramello, O.; Berge, D.; Bertinelli, F.; Bianchi, R. M.; Blanchot, G.; Bogaerts, J. A.; Boyd, J.; Braem, A.; Bremer, J.; Burckhart, H.; Butin, F.; Campana, S.; Garrido, M. D. M. Capeans; Carli, T.; Cataneo, F.; Catinaccio, A.; Cattai, A.; Cerri, A.; Chromek-Burckhart, D.; Cook, J.; Cote, D.; Danielsson, H. O.; Dauvergne, J. P.; Branco, M. De Oliveira; Dell'Acqua, A.; Delmastro, M.; Delruelle, N.; Di Girolamo, A.; Di Girolamo, B.; Dittus, F.; Dobinson, R.; Dobson, E.; Drevermann, H.; Dudarev, A.; Duehrssen, M.; Dunford, M.; Dydak, F.; Eifert, T.; Ellis, N.; Elsing, M.; Fabre, C.; Farthouat, P.; Fassnacht, P.; Fedorko, I.; Flammer, J.; Foussat, A.; Francis, D.; Franz, S.; Froeschl, R.; Froidevaux, D.; Torregrosa, E. Fullana; Gabaldon, C.; Gallas, M. V.; Garelli, N.; Garonne, V.; Gayde, J. -C.; Gianotti, F.; Gibson, S. M.; Godlewski, J.; Gonidec, A.; Goossens, L.; Gorini, B.; Grafstroem, P.; Grognuz, J.; Gruwe, M.; Haas, S.; Hahn, F.; Haider, S.; Hatch, M.; Hauschild, M.; Hawkings, R. J.; Correia, A. M. Henriques; Hervas, L.; Hoecker, A.; Huhtinen, M.; Inigo-Golfin, J.; Jaekel, M. R.; Jenni, P.; Jonsson, O.; Joram, C.; Kaplon, J.; Kerschen, N.; Klioutchnikova, T.; Knobloch, J.; Koblitz, B.; Koeneke, K.; Koffas, T.; Kollar, D.; Kotamaeki, M. J.; La Rosa, A.; Lamanna, M.; Lantzsch, K.; Lasseur, C.; Lassnig, M.; Leahu, M.; Miotto, G. Lehmann; Lichard, P.; Magnoni, L.; Mapelli, A.; Mapelli, L.; Marchand, J. F.; Marchesotti, M.; Martin, B.; Maugain, J. M.; McLaren, R. A.; Menot, C.; Messina, A.; Meyer, T. C.; Michal, S.; Miele, P.; Molina-Perez, J.; Morley, A. K.; Mornacchi, G.; Nairz, A. M.; Negri, G.; Nessi, M.; Nicquevert, B.; Niinikoski, T.; Nordberg, M.; Nyman, T.; Palestini, S.; Pastore, Fr; Pauly, T.; Pengo, R.; Pernegger, H.; Petersen, B. A.; Petersen, J.; Piacquadio, G.; Pirotte, O.; Pommes, K.; Poppleton, A.; Poulard, G.; Pribyl, L.; Price, M. J.; Raymond, M.; Rembser, C.; Dos Santos, D. Roda; Roe, S.; Salzburger, A.; Savu, D. O.; Schlenker, S.; Schott, M.; Schuh, S.; Schuler, G.; Sfyrla, A.; Shimizu, S.; Sloper, J.; Spigo, G.; Spiwoks, R.; Stanecka, E.; Stockton, M. C.; Sumida, T.; Szeless, B.; Tackmann, K.; Tappern, G. P.; Ten Kate, H.; Viegas, F. J. Tique Aires; Torchiani, I.; Tremblet, L.; Tricoli, A.; Tsarouchas, C.; Tyrvainen, H.; Unal, G.; van der Ster, D.; Vandelli, W.; Vandoni, G.; Rodriguez, F. Varela; Veness, R.; Vinek, E.; Voss, R.; Vuillermet, R.; Wells, P. S.; Wengler, T.; Wenig, S.; Werner, P.; Wilkens, H. G.; Winklmeier, F.; Wotschack, J.; Zajacova, Z.; Zema, P. F.; Zsenei, A.; Zwalinski, L.; ATLAS Collaboration] CERN, CH-1211 Geneva 23, Switzerland, Email: atlas.publications@cern.ch |
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Springer |
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English |
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Abbreviated Series Title |
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Series Issue |
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Edition |
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ISSN |
1434-6044 |
ISBN |
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Expedition |
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Conference |
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Notes |
ISI:000291249300022 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
647 |
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| Permanent link to this record |
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Author |
Miñano, M. |
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Title |
Radiation Hard Silicon Strips Detectors for the SLHC |
Type |
Journal Article |
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Year |
2011 |
Publication |
IEEE Transactions on Nuclear Science |
Abbreviated Journal |
IEEE Trans. Nucl. Sci. |
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Volume |
58 |
Issue |
3 |
Pages |
1135-1140 |
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Keywords |
High energy physics; microstrip; radiation detectors; silicon; SLHC |
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Abstract |
While the Large Hadron Collider (LHC) began taking data in 2009, scenarios for a machine upgrade to achieve a much higher luminosity are being developed. In the current planning, it is foreseen to increase the luminosity of the LHC at CERN around 2018. As radiation damage scales with integrated luminosity, the particle physics experiments will need to be equipped with a new generation of radiation hard detectors. This article reports on the status of the R&D projects on radiation hard silicon strips detectors for particle physics, linked to the Large Hadron Collider Upgrade, super-LHC (sLHC) of the ATLAS microstrip detector. The primary focus of this report is on measuring the radiation hardness of the silicon materials and the detectors under study. This involves designing silicon detectors, irradiating them to the sLHC radiation levels and studying their performance as particle detectors. The most promising silicon detector for the different radiation levels in the different regions of the ATLAS microstrip detector will be presented. Important challenges related to engineering layout, powering, cooling and reading out a very large strip detector are presented. Ideas on possible schemes for the layout and support mechanics will be shown. |
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Address |
IFIC UV CSIC, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: mercedes.minano@ific.uv.es |
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Ieee-Inst Electrical Electronics Engineers Inc |
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English |
Summary Language |
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0018-9499 |
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Conference |
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Notes |
ISI:000291659300001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
no |
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Call Number |
IFIC @ pastor @ |
Serial |
651 |
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Author |
Brambilla, N. et al; Sanchis-Lozano, M.A. |
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Title |
Heavy quarkonium: progress, puzzles, and opportunities |
Type |
Journal Article |
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Year |
2011 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume |
71 |
Issue |
2 |
Pages |
1534 - 178pp |
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Keywords |
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Abstract |
A golden age for heavy-quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the B-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations at BESIII, the LHC, RHIC, FAIR, the Super Flavor and/or Tau-Charm factories, JLab, the ILC, and beyond. The list of newly found conventional states expanded to include h(c)(1P), chi(c2)(2P), B-c(+), and eta(b)(1S). In addition, the unexpected and still-fascinating X(3872) has been joined by more than a dozen other charmonium- and bottomonium-like “XYZ” states that appear to lie outside the quark model. Many of these still need experimental confirmation. The plethora of new states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c (c) over bar, b (b) over bar, and b (c) over bar bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. Lattice QCD has grown from a tool with computational possibilities to an industrial-strength effort now dependent more on insight and innovation than pure computational power. New effective field theories for the description of quarkonium in different regimes have been developed and brought to a high degree of sophistication, thus enabling precise and solid theoretical predictions. Many expected decays and transitions have either been measured with precision or for the first time, but the confusing patterns of decays, both above and below open-flavor thresholds, endure and have deepened. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts. |
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Address |
[Brambilla, N.; Vairo, A.] Tech Univ Munich, Dept Phys, D-85748 Garching, Germany, Email: bkh2@cornell.edu |
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Springer |
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English |
Summary Language |
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Abbreviated Series Title |
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ISSN |
1434-6044 |
ISBN |
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Conference |
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Notes |
ISI:000291694100001 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
652 |
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Author |
Dmitrasinovic, V.; Chen, H.X. |
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Title |
Bi-local baryon interpolating fields with two flavors |
Type |
Journal Article |
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Year |
2011 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume |
71 |
Issue |
2 |
Pages |
1543 - 12pp |
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Keywords |
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Abstract |
We construct bi-local interpolating field operators for baryons consisting of three quarks with two flavors, assuming good isospin symmetry. We use the restrictions following from the Pauli principle to derive relations/identities among the baryon operators with identical quantum numbers. Such relations that follow from the combined spatial, Dirac, color, and isospin Fierz transformations may be called the (total/complete) Fierz identities. These relations reduce the number of independent baryon operators with any given spin and isospin. We also study the Abelian and non-Abelian chiral transformation properties of these fields and place them into baryon chiral multiplets. Thus we derive the independent baryon interpolating fields with given values of spin (Lorentz group representation), chiral symmetry (U-L(2) x U-R(2) group representation) and isospin appropriate for the first angular excited states of the nucleon. |
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Address |
[Dmitrasinovic, V.] Univ Belgrade, Inst Phys, Belgrade 11080, Serbia, Email: hxchen@rcnp.osaka-u.ac.jp |
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Publisher |
Springer |
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English |
Summary Language |
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Series Editor |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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ISSN |
1434-6044 |
ISBN |
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Conference |
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Notes |
ISI:000291694100005 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
653 |
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| Permanent link to this record |
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Author |
DELPHI Collaboration (Abdallah, J. et al); Costa, M.J.; Ferrer, A.; Fuster, J.; Garcia, C.; Oyanguren, A.; Perepelitsa, V.; Salt, J.; Tortosa, P. |
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Title |
Search for single top quark production via contact interactions at LEP2 |
Type |
Journal Article |
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Year |
2011 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume |
71 |
Issue |
2 |
Pages |
1555 - 13pp |
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Keywords |
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Abstract |
Single top quark production via four-fermion contact interactions associated to flavour-changing neutral currents was searched for in data taken by the DELPHI detector at LEP2. The data were accumulated at centre-of-mass energies ranging from 189 to 209 GeV, with an integrated luminosity of 598.1 pb(-1). No evidence for a signal was found. Limits on the energy scale Lambda, were set for scalar-, vector- and tensor-like coupling scenarios. |
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Address |
[Lamsa, J.] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA, Email: timmerma@mail.cern.ch |
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Publisher |
Springer |
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English |
Summary Language |
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Original Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1434-6044 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000291694100014 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
654 |
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| Permanent link to this record |
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Author |
Fomichev, A.S.; Mukha, I.; Stepantsov, S.V.; Grigorenko, L.V.; Litvinova, E.V.; Chudoba, V.; Egorova, I.A.; Golovkov, M.S.; Gorshkov, A.V.; Gorshkov, V.A.; Kaminski, G.; Krupko, S.A.; Parfenova, Y.L.; Sidorchuk, S.I.; Slepnev, R.S.; Ter-Akopian, G.M.; Wolski, R.; Zhukov, M.V. |
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Title |
Lifetime of (26)S and a limit for its 2p decay energy |
Type |
Journal Article |
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Year |
2011 |
Publication |
International Journal of Modern Physics E |
Abbreviated Journal |
Int. J. Mod. Phys. E |
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Volume |
20 |
Issue |
6 |
Pages |
1491-1508 |
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Keywords |
Properties of nuclei; nuclear energy |
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Abstract |
The unknown isotope (26)S, expected to decay by two-proton (2p) emission, was studied theoretically and searched experimentally. The structure of this nucleus was examined within the relativistic mean field (RMF) approach. A method for taking into account the many-body structure in the three-body decay calculations was developed. The results of the RMF calculations were used as an input for the three-cluster decay model optimized for the study of a possible 2p decay branch of this nucleus. The experimental search for (26)S was performed by fragmentation of a 50.3 A MeV (32)S beam. No events of a particles table (26)S or (25)P (a presumably proton-unstable subsystem of (26)S) were observed. Based on the obtained production systematics, an upper half-life limit of T(1/2) < 79 ns was established from the time-of-flight through the fragment separator. Together with the theoretical lifetime estimates for two-proton decay, this gives a decay energy limit of Q(2p) > 640 keV for (26)S. Analogous limits for (25)P are found as T(1/2) < 38 ns and Q(p) > 110 keV. In the case that the one-proton emission is the main branch of the (26)S decay, a limit Q(2p) > 230 keV would follow for this nucleus. According to these limits, it is likely that (26)S resides in the picosecond life time range |
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Address |
[Fomichev, AS; Stepantsov, SV; Grigorenko, LV; Chudoba, V; Golovkov, MS; Gorshkov, AV; Gorshkov, VA; Kaminski, G; Krupko, SA; Parfenova, YL; Sidorchuk, SI; Slepnev, RS; Ter-Akopian, GM; Wolski, R] JINR, Flerov Lab Nucl React, RU-141980 Dubna, Russia, Email: fomichev@jinr.ru |
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Publisher |
World Scientific Publ Co Pte Ltd |
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English |
Summary Language |
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Edition |
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ISSN |
0218-3013 |
ISBN |
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Area |
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Conference |
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Notes |
WOS:000292644900010 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ pastor @ |
Serial |
693 |
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| Permanent link to this record |
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Author |
DELPHI Collaboration (Abdallah, J. et al); Costa, M.J.; Ferrer, A.; Fuster, J.; Garcia, C.; Oyanguren, A.; Perepelitsa, V.; Salt, J.; Tortosa, P. |
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Title |
A study of the b-quark fragmentation function with the DELPHI detector at LEP I and an averaged distribution obtained at the Z Pole |
Type |
Journal Article |
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Year |
2011 |
Publication |
European Physical Journal C |
Abbreviated Journal |
Eur. Phys. J. C |
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Volume |
71 |
Issue |
2 |
Pages |
1557 - 29pp |
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Keywords |
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Abstract |
The nature of b-quark jet hadronisation has been investigated using data taken at the Z peak by the DELPHI detector at LEP. Two complementary methods are used to reconstruct the energy of weakly decaying b-hadrons, E-B(weak). The average value of x(B)(weak) = E-B(weak)/E-beam is measured to be 0.699 +/- 0.011. The resulting x(B)(weak) distribution is then analysed in the framework of two choices for the perturbative contribution (parton shower and Next to Leading Log QCD calculation) in order to extract measurements of the non-perturbative contribution to be used in studies of b-hadron production in other experimental environments than LEP. In the parton shower framework, data favour the Lund model ansatz and corresponding values of its parameters have been determined within PYTHIA 6.156 from DELPHI data: a = 1.84(-0.21)(+0.23) and b = 0.642(-0.063)(+0.073) GeV-2, with a correlation factor rho = 92.2%. Combining the data on the b-quark fragmentation distributions with those obtained at the Z peak by ALEPH, OPAL and SLD, the average value of x(B)(weak) is found to be 0.7092 +/- 0.0025 and the non-perturbative fragmentation component is extracted. Using the combined distribution, a better determination of the Lund parameters is also obtained: a = 1.48(-0.10)(+0.11) and b = 0.509(-0.023)(+0.024) GeV-2, with a correlation factor rho = 92.6%. |
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Address |
[Lamsa, J.] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA, Email: timmerma@mail.cern.ch |
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Springer |
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English |
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1434-6044 |
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ISI:000291694100016 |
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no |
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Is ISI |
yes |
International Collaboration |
yes |
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IFIC @ pastor @ |
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655 |
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Author |
ATLAS Collaboration (Aad, G. et al); Amoros, G.; Cabrera Urban, S.; Castillo Gimenez, V.; Costa, M.J.; Escobar, C.; Ferrer, A.; Fuster, J.; Garcia, C.; Gonzalez de la Hoz, S.; Hernandez Jimenez, Y.; Higon-Rodriguez, E.; Irles Quiles, A.; Kaci, M.; Lacasta, C.; Lacuesta, V.R.; Marti-Garcia, S.; Miñano, M.; Mitsou, V.A.; Moles-Valls, R.; Moreno Llacer, M.; Oliver Garcia, E.; Perez Garcia-Estañ, M.T.; Ros, E.; Salt, J.; Solans, C.A.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valladolid Gallego, E.; Valls Ferrer, J.A.; Villaplana Perez, M.; Vos, M.; Wildauer, A. |
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Title |
Search for a Heavy Particle Decaying into an Electron and a Muon with the ATLAS Detector in sqrt(s)=7 TeV pp collisions at the LHC |
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Journal Article |
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Year |
2011 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
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Volume |
106 |
Issue |
25 |
Pages |
251801 - 18pp |
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Abstract |
This Letter presents the first search for a heavy particle decaying into an e(+/-)mu(-/+) final state in root s = 7 TeV pp collisions at the LHC. The data were recorded by the ATLAS detector during 2010 and correspond to a total integrated luminosity of 35 pb(-1). No excess above the standard model background expectation is observed. Exclusions at 95% confidence level are placed on two representative models. In an R-parity violating supersymmetric model, tau sneutrinos with a mass below 0.75 TeV are excluded, assuming all R-parity violating couplings are zero except lambda(311)' = 0.11 and lambda(312) = 0.07. In a lepton flavor violating model, a Z'-like vector boson with masses of 0.70-1.00 TeV and corresponding cross sections times branching ratios of 0.175-0.183 pb is excluded. These results extend to higher mass R-parity violating sneutrinos and lepton flavor violating Z's than previous constraints from the Tevatron. |
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[Aad, G.; Ahles, F.; Beckingham, M.; Bernhard, R.; Bitenc, U.; Bruneliere, R.; Caron, S.; Carpentieri, C.; Christov, A.; Dahlhoff, A.; Dietrich, J.; Eckert, S.; Fehling-Kaschek, M.; Flechl, M.; Glatzer, J.; Guler, H.; Hartert, J.; Heldmann, M.; Herten, G.; Horner, S.; Jakobs, K.; Ketterer, C.; Kollefrath, M.; Kononov, A. I.; Kuehn, S.; Lai, S.; Landgraf, U.; Lohwasser, K.; Ludwig, I.; Ludwig, J.; Lumb, D.; Mahboubi, K.; Meinhardt, J.; Mohr, W.; Nilsen, H.; Parzefall, U.; Bueso, X. Portell; Rammensee, M.; Runge, K.; Rurikova, Z.; Schmidt, E.; Schumacher, M.; Siegert, F.; Stoerig, K.; Sundermann, J. E.; Temming, K. K.; Thoma, S.; Tobias, J.; Tsiskaridze, V.; Venturi, M.; Vivarelli, I.; von Radziewski, H.; Warsinsky, M.; Weiser, C.; Werner, M.; Wiik, L. A. M.; Winkelmann, S.; Xie, S.; Zimmermann, S.] Univ Freiburg, Fak Math & Phys, Freiburg, Germany |
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Amer Physical Soc |
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English |
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ISSN |
0031-9007 |
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ISI:000291942400003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
659 |
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Author |
Giusarma, E.; Corsi, M.; Archidiacono, M.; de Putter, R.; Melchiorri, A.; Mena, O.; Pandolfi, S. |
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Title |
Constraints on massive sterile neutrino species from current and future cosmological data |
Type |
Journal Article |
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Year |
2011 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
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Volume |
83 |
Issue |
11 |
Pages |
115023 - 10pp |
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Abstract |
Sterile massive neutrinos are a natural extension of the standard model of elementary particles. The energy density of the extra sterile massive states affects cosmological measurements in an analogous way to that of active neutrino species. We perform here an analysis of current cosmological data and derive bounds on the masses of the active and the sterile neutrino states, as well as on the number of sterile states. The so-called (3 + 2) models, with three sub-eV active massive neutrinos plus two sub-eV massive sterile species, is well within the 95% CL allowed regions when considering cosmological data only. If the two extra sterile states have thermal abundances at decoupling, big bang nucleosynthesis bounds compromise the viability of (3 + 2) models. Forecasts from future cosmological data on the active and sterile neutrino parameters are also presented. Independent measurements of the neutrino mass from tritium beta-decay experiments and of the Hubble constant could shed light on sub-eV massive sterile neutrino scenarios. |
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[Giusarma, Elena; de Putter, Roland; Mena, Olga] Univ Valencia, CSIC, IFIC, Valencia 46071, Spain |
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Amer Physical Soc |
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English |
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1550-7998 |
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Notes |
ISI:000292039800003 |
Approved |
no |
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Is ISI |
yes |
International Collaboration |
yes |
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Call Number |
IFIC @ elepoucu @ |
Serial |
660 |
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| Permanent link to this record |
