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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.
Title Lifetime of (26)S and a limit for its 2p decay energy Type Journal Article
Year 2011 Publication International Journal of Modern Physics E Abbreviated Journal Int. J. Mod. Phys. E
Volume 20 Issue 6 Pages 1491-1508
Keywords Properties of nuclei; nuclear energy
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
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
Corporate Author Thesis
Publisher World Scientific Publ Co Pte Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0218-3013 ISBN Medium
Area Expedition Conference
Notes WOS:000292644900010 Approved no
Is ISI yes International Collaboration yes
Call Number (up) IFIC @ pastor @ Serial 693
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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.
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
Year 2011 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 71 Issue 2 Pages 1557 - 29pp
Keywords
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%.
Address [Lamsa, J.] Iowa State Univ, Dept Phys & Astron, Ames, IA 50011 USA, Email: timmerma@mail.cern.ch
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes ISI:000291694100016 Approved no
Is ISI yes International Collaboration yes
Call Number (up) IFIC @ pastor @ Serial 655
Permanent link to this record
 

 
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.
Title Luminosity determination in pp collisions at sqrt(s)=7 TeV using the ATLAS detector at the LHC Type Journal Article
Year 2011 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 71 Issue 4 Pages 1630 - 37pp
Keywords
Abstract Measurements of luminosity obtained using the ATLAS detector during early running of the Large Hadron Collider (LHC) at root s = 7 TeV are presented. The luminosity is independently determined using several detectors and multiple algorithms, each having different acceptances, systematic uncertainties and sensitivity to background. The ratios of the luminosities obtained from these methods are monitored as a function of time and of mu, the average number of inelastic interactions per bunch crossing. Residual time- and mu-dependence between the methods is less than 2% for 0 < μ< 2.5. Absolute luminosity calibrations, performed using beam separation scans, have a common systematic uncertainty of +/- 11%, dominated by the measurement of the LHC beam currents. After calibration, the luminosities obtained from the different methods differ by at most +/- 2%. The visible cross sections measured using the beam scans are compared to predictions obtained with the PYTHIA and PHOJET event generators and the ATLAS detector simulation.
Address [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.; Hartert, J.; Heldmann, M.; Herten, G.; Horner, S.; Jakobs, K.; Ketterer, C.; Koenig, S.; Kollefrath, M.; Kononov, A. I.; Kuehn, S.; Lai, S.; Landgraf, U.; Lohwasser, K.; Ludwig, I.; Ludwig, J.; Lumb, D.; Maassen, M.; 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, D-79104 Freiburg, Germany, Email: atlas.secretariat@cern.ch
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes ISI:000291698800013 Approved no
Is ISI yes International Collaboration yes
Call Number (up) IFIC @ pastor @ Serial 656
Permanent link to this record
 

 
Author Courtoy, A.; Scopetta, S.; Vento, V.
Title Non-perturbative momentum dependence of the coupling constant and hadronic models Type Journal Article
Year 2011 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 47 Issue 4 Pages 49 - 7pp
Keywords
Abstract Models of hadron structure are associated with a hadronic scale which allows by perturbative evolution to calculate observables in the deep inelastic region. The resolution of Dyson-Schwinger equations leads to the freezing of the QCD running coupling (effective charge) in the infrared, which is best understood as a dynamical generation of a gluon mass function, giving rise to a momentum dependence which is free from infrared divergences. We use this new development to understand why perturbative treatments are working reasonably well despite the smallness of the hadronic scale.
Address [Courtoy, A.] Ist Nazl Fis Nucl, Sez Pavia, I-27100 Pavia, Italy, Email: Aurore.Courtoy@pv.infn.it
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes ISI:000291659500003 Approved no
Is ISI yes International Collaboration yes
Call Number (up) IFIC @ pastor @ Serial 657
Permanent link to this record
 

 
Author HADES Collaboration (Agakishiev, G. et al); Diaz, J.; Gil, A.
Title pp and pi pi intensity interferometry in collisions of Ar+KCl at 1.76A GeV Type Journal Article
Year 2011 Publication European Physical Journal A Abbreviated Journal Eur. Phys. J. A
Volume 47 Issue 5 Pages 63 - 8pp
Keywords
Abstract Results on pp, pi(+) pi(+), and pi-pi-intensity interferometry are reported for collisions of Ar+KCl at 1.76A GeV beam energy, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18/GSI. The experimental correlation functions as a function of the relative momentum are compared to model calculations allowing the determination of the space-time extent of the corresponding emission sources. The pp source radii are found significantly larger than the pp emission radius. The present radii do well complement the beam-energy dependences of Gaussian source radii of the collision system of size A + A similar or equal to 40 + 40. The pp source radius at fixed beam energy is found to increase linearly with the cube root of the number of participants. From this trend, a lower limit of the pp correlation radius is deduced.
Address [Finocchiaro, P.] Ist Nazl Fis Nucl, Lab Nazl Sud, I-95125 Catania, Italy, Email: kotte@fzd.de
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6001 ISBN Medium
Area Expedition Conference
Notes ISI:000291659900005 Approved no
Is ISI yes International Collaboration yes
Call Number (up) IFIC @ pastor @ Serial 658
Permanent link to this record