133 research outputs found
Various Models for Pion Probability Distributions from Heavy-Ion Collisions
Various models for pion multiplicity distributions produced in relativistic
heavy ion collisions are discussed. The models include a relativistic
hydrodynamic model, a thermodynamic description, an emitting source pion laser
model, and a description which generates a negative binomial description. The
approach developed can be used to discuss other cases which will be mentioned.
The pion probability distributions for these various cases are compared.
Comparison of the pion laser model and Bose-Einstein condensation in a laser
trap and with the thermal model are made. The thermal model and hydrodynamic
model are also used to illustrate why the number of pions never diverges and
why the Bose-Einstein correction effects are relatively small. The pion
emission strength of a Poisson emitter and a critical density
are connected in a thermal model by , and this fact
reduces any Bose-Einstein correction effects in the number and number
fluctuation of pions. Fluctuations can be much larger than Poisson in the pion
laser model and for a negative binomial description. The clan representation of
the negative binomial distribution due to Van Hove and Giovannini is discussed
using the present description. Applications to CERN/NA44 and CERN/NA49 data are
discussed in terms of the relativistic hydrodynamic model.Comment: 12 pages, incl. 3 figures and 4 tables. You can also download a
PostScript file of the manuscript from
http://p2hp2.lanl.gov/people/schlei/eprint.htm
First observations of separated atmospheric nu_mu and bar{nu-mu} events in the MINOS detector
The complete 5.4 kton MINOS far detector has been taking data since the beginning of August 2003 at a depth of 2070 meters water-equivalent in the Soudan mine, Minnesota. This paper presents the first MINOS observations of nu” and [overline nu ]” charged-current atmospheric neutrino interactions based on an exposure of 418 days. The ratio of upward- to downward-going events in the data is compared to the Monte Carlo expectation in the absence of neutrino oscillations, giving Rup/downdata/Rup/downMC=0.62-0.14+0.19(stat.)±0.02(sys.). An extended maximum likelihood analysis of the observed L/E distributions excludes the null hypothesis of no neutrino oscillations at the 98% confidence level. Using the curvature of the observed muons in the 1.3 T MINOS magnetic field nu” and [overline nu ]” interactions are separated. The ratio of [overline nu ]” to nu” events in the data is compared to the Monte Carlo expectation assuming neutrinos and antineutrinos oscillate in the same manner, giving R[overline nu ][sub mu]/nu[sub mu]data/R[overline nu ][sub mu]/nu[sub mu]MC=0.96-0.27+0.38(stat.)±0.15(sys.), where the errors are the statistical and systematic uncertainties. Although the statistics are limited, this is the first direct observation of atmospheric neutrino interactions separately for nu” and [overline nu ]”
Digital girl:Cyberfeminism and the emancipation potential of digital entrepreneurship in emerging economies
Digital entrepreneurship has been described as a âgreat levelerâ in terms of equalizing the
entrepreneurial playing field for women. However, little is known of the emancipatory
possibilities offered by digital entrepreneurship for women constrained by social and cultural
practices such as male guardianship of female relatives and legally enforced gender
segregation. In order to address this research gap, this paper examines womenâs engagement
in digital entrepreneurship in emerging economies with restrictive social and cultural practices.
In so doing, we draw upon the analytical frameworks provided by entrepreneurship as
emancipation and cyberfeminism. Using empirical data from an exploratory investigation of
entrepreneurship in Saudi Arabia, we examine how women use digital technologies in the
pursuit of entrepreneurial opportunities. Our findings reveal that women in Saudi Arabia use
digital entrepreneurship to transform their embodied selves and lived realities rather than to
escape gender embodiment as offered by the online environment
Empirical Legal Studies Before 1940: A Bibliographic Essay
The modern empirical legal studies movement has well-known antecedents in the law and society and law and economics traditions of the latter half of the 20th century. Less well known is the body of empirical research on legal phenomena from the period prior to World War II. This paper is an extensive bibliographic essay that surveys the English language empirical legal research from approximately 1940 and earlier. The essay is arranged around the themes in the research: criminal justice, civil justice (general studies of civil litigation, auto accident litigation and compensation, divorce, small claims, jurisdiction and procedure, civil juries), debt and bankruptcy, banking, appellate courts, legal needs, legal profession (including legal education), and judicial staffing and selection. Accompanying the essay is an extensive bibliography of research articles, books, and reports
âWorking the SystemââBritish American Tobacco's Influence on the European Union Treaty and Its Implications for Policy: An Analysis of Internal Tobacco Industry Documents
Katherine Smith and colleagues investigate the ways in which British American Tobacco influenced the European Union Treaty so that new EU policies advance the interests of major corporations, including those that produce products damaging to health
Search for standard model production of four top quarks in the lepton + jets channel in pp collisions at âs = 8 TeV
Open Access, Copyright CERN, for the benefit of the CMS Collaboration. Article funded by SCOAP3.Abstract: A search is presented for standard model (SM) production of four top quarks (Formula presented.) in pp collisions in the lepton + jets channel. The data correspond to an integrated luminosity of 19.6 fbâ1 recorded at a centre-of-mass energy of 8 TeV with the CMS detector at the CERN LHC. The expected cross section for SM (Formula presented.) production is (Formula presented.). A combination of kinematic reconstruction and multivariate techniques is used to distinguish between the small signal and large background. The data are consistent with expectations of the SM, and an upper limit of 32 fb is set at a 95% confidence level on the cross section for producing four top quarks in the SM, where a limit of 32 ± 17 fb is expected
Charged particle spectra in central S+S collisions at 200 GeV/c per nucleon
The transverse momentum and rapidity distributions of negative hadrons and participant protons have been measured for central 32S+ 32S collisions at plab=200 GeV/c per nucleon. The proton mean rapidity shift ~1.6 and mean transverse momentum ~0.6 GeV/c are much higher than in pp or peripheral AA collisions and indicate an increase in the nuclear stopping power. All pT spectra exhibit similar source temperatures. Including previous results for K0s Lambda , and Lambda -bar, we account for all important contributions to particle production.Authors: BĂ€chler, J.; Bartke, J.; Bialkowska, H.; Bock, R.; Brockmann, R.; Buncic, P.; Chase, S. I.; Derado, I.; Eckardt, V.; Eschke, J.; Ferenc, D.; Fleischmann, B.; Foka, P.; Fuchs, M.; Gazdzicki, M.; Gladysz, E.; Harris, J. W.; Heck, W.; Hoffmann, M.; Jacobs, P. M.; Kabana, S.; Kadija, K.; Keidel, R.; Kosiec, J.; Kowalski, M.; KĂŒhmichel, A.; Lahanas, M.; Lee, J. Y.; Ljubicic, A.; Margetis, S.; Morse, R.; Nappi, E.; Odyniec, G.; Paic, G.; Panagiotu, A. D.; Petridis, A.; Piper, A.; Posa, F.; Poskanzer, A. M.; Pugh, H. G.; PĂŒhlhofer, F.; Rai, G.; Rauch, W.; Renfordt, R.; Röhrich, D.; Roland, G.; Rothard, H.; Runge, K.; Sandoval, A.; Schambach, J. J.; Schmitz, N.; Schmoetten, E.; Schneider, I.; Seyboth, P.; Seyerlein, J.; Skrzypczak, E.; Stefanski, P.; Stock, R.; Ströbele, H.; Teitelbaum, L.; Tincknell, M. L.; Tonse, S.; Vasileiadis, G.; Vesztergombi, G.; Vranic, D.; Wenig, S
Foxp3 and Treg cells in HIV-1 infection and immuno-pathogenesis
FoxP3+CD4+CD25+ regulatory T (Treg) cells are implicated in a number of pathologic processes including elevated levels in cancers and infectious diseases, and reduced levels in autoimmune diseases. Treg cells are activated to modulate immune responses to avoid over-reactive immunity. However, conflicting findings are reported regarding relative levels of Treg cells during HIV-1 infection and disease progression. The role of Treg cells in HIV-1 diseases (aberrant immune activation) is poorly understood due to lack of a robust model. We summarize here the regulation and function of Foxp3 in Treg cells and in modulating HIV-1 replication. Based on recent findings from SIV/monkey and HIV/humanized mouse models, a model of the dual role of Treg cells in HIV-1 infection and immuno-pathogenesis is discussed
Observation of Muon Neutrino Disappearance with the MINOS Detectors in the NuMI Neutrino Beam
This Letter reports results from the MINOS experiment based on its initial exposure to neutrinos from the Fermilab NuMI beam. The rates and energy spectra of charged current ΜΌ interactions are compared in two detectors located along the beam axis at distances of 1 and 735 km. With 1.27Ă1020 120 GeV protons incident on the NuMI target, 215 events with energies below 30 GeV are observed at the Far Detector, compared to an expectation of 336±14 events. The data are consistent with ΜΌ disappearance via oscillations with |Îm322|=2.74-0.26+0.44Ă10-3ââeV2 and sinâĄ2(2Ξ23)>0.87 (68% C.L.)
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