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111.
DASP Collaboration R. Brandelik W. Braunschweig H. -U. Martyn H. G. Sander D. Schmitz W. Sturm W. Wallraff 《Physics letters. [Part B]》1979,80(4-5):412-418
Inclusive cross sections of η production by e+e- annihilation for c.m. energies between 4.0 and 5.0 GeV are presented. The η production is shown to be correlated with the production of a weakly decaying particle, indicating that its main source is F production. At the 4.42 GeV resonance it is correlated with a low energy photon, suggesting
or
production. A mass determination of the F is made at 4.42 GeV using the F → ηπ decay channel. 相似文献
112.
J. Blachot J. Crançon B. de Goncourt A. Gizon A. Llères 《Zeitschrift für Physik A Hadrons and Nuclei》1985,321(4):645-651
Cross sections, recoil energy distributions for residues produced by14N,20Ne,40Ar on124Sn targets have been measured in the 10–70 MeV/u intermediate energy range. As the projectile energy increases, processes as complete fusion-evaporation, incomplete fusion-evaporation and intranuclear cascade-evaporation participate progressively in the nuclear collisions. Peculiar residues corresponding to a gain of 4, 5 or even 6 protons for the124Sn target have been observed in the 30–50 MeV energy range. 相似文献
113.
114.
J. Badier J. Boucrot J. Bourotte G. Burgun O. Callot Ph. Charpentier M. Crozon D. Decamp P. Delpierre B. Gandois R. Hagelberg M. Hansroul Y. Karyotakis W. Kienzle P. Le D? J. Lefran?ois Th. Leray J. Maillard A. Michelini Ph. Miné G. Rahal O. Runolfsson P. Siegrist A. Tilquin R. Vanderhaghen S. Weisz NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1985,26(4):489-494
115.
Multijet production rates in neutral current deep inelastic scattering have been measured in the range of exchanged boson
virtualities
. The data were taken at the ep collider HERA with centre-of-mass energy
using the ZEUS detector and correspond to an integrated luminosity of
. Jets were identified in the Breit frame using the kT cluster algorithm in the longitudinally invariant inclusive mode. Measurements of differential dijet and trijet cross sections
are presented as functions of jet transverse energy (
), pseudorapidity (
) and Q2 with
and
. Next-to-leading-order QCD calculations describe the data well. The value of the strong coupling constant
, determined from the ratio of the trijet to dijet cross sections, is
.
Received: 1 April 2005, Revised: 28 June 2005, Published online: 30 August 2005 相似文献
116.
The H Collaboration 《The European Physical Journal C - Particles and Fields》2005,38(4):437-445
Results are presented on the photoproduction of isolated prompt photons, inclusively and associated with jets, in the
center of mass energy range 142 < W < 266 GeV. The cross sections are measured for the transverse momentum range of the photons
GeV and for associated jets with E
T
jet > 4.5 GeV. They are measured differentially as a function of
, the pseudorapidities
and
and estimators of the momentum fractions
and x
p
of the incident photon and proton carried by the constituents participating in the hard process. In order to further investigate the underlying dynamics, the angular correlation between the prompt photon and the jet in the transverse plane is studied. Predictions by perturbative QCD calculations in next to leading order are about
below the inclusive prompt photon data after corrections for hadronisation and multiple interactions, but are in reasonable agreement with the results for prompt photons associated with jets. Comparisons with the predictions of the event generators PYTHIA and HERWIG are also presented.Received: 13 July 2004, Revised: 15 November 2004, Published online: 17 December 2004 相似文献
117.
Background
High concentrations of glutamate can accumulate in the brain and may be involved in the pathogenesis of neurodegenerative disorders such as Alzheimer's disease. This form of neurotoxicity involves changes in the regulation of cellular calcium (Ca2+) and generation of free radicals such as peroxynitrite (ONOO-). Estrogen may protect against glutamate-induced cell death by reducing the excitotoxic Ca2+ influx associated with glutamate excitotoxicity. In this study, the inhibition of N-methyl-D-aspartate (NMDA) receptor and nitric oxide synthase (NOS) along with the effect of 17β-estradiol (17β-E2) and a more potent antioxidant Δ8, 17β-estradiol (Δ8, 17β-E2) on cell viability and intracellular Ca2+ ([Ca2+]i), following treatment of rat cortical cells with glutamate, was investigated. 相似文献118.
Abazov VM Abbott B Abolins M Acharya BS Adams M Adams T Agelou M Agram JL Ahn SH Ahsan M Alexeev GD Alkhazov G Alton A Alverson G Alves GA Anastasoaie M Andeen T Anderson S Andrieu B Arnoud Y Askew A Asman B Jesus AC Atramentov O Autermann C Avila C Badaud F Baden A Baldin B Balm PW Banerjee S Barberis E Bargassa P Baringer P Barnes C Barreto J Bartlett JF Bassler U Bauer D Bean A Beauceron S Begel M Bellavance A Beri SB Bernardi G Bernhard R Bertram I Besançon M Beuselinck R Bezzubov VA 《Physical review letters》2005,95(5):051802
We present a measurement of the Zgamma production cross section and limits on anomalous ZZgamma and Zgammagamma couplings for form-factor scales of lambda = 750 and 1000 GeV. The measurement is based on 138 (152) candidates in the eegamma (mumugamma) final state using 320(290) pb(-1) of pp(-1) collisions at square root of s = 1.96 TeV. The 95% C.L. limits on real and imaginary parts of individual anomalous couplings are /h(10,30)Z/ < 0.23, /h(20,40)Z/ < 0.020, /h(10,30)gamma/ < 0.23, and /h(20,40)gamma/ < 0.019 for lambda = 1000 GeV. 相似文献
119.
Jørgensen LV Amoretti M Bonomi G Bowe PD Canali C Carraro C Cesar CL Charlton M Doser M Fontana A Fujiwara MC Funakoshi R Genova P Hangst JS Hayano RS Kellerbauer A Lagomarsino V Landua R Lodi Rizzini E Macrì M Madsen N Mitchard D Montagna P Rotondi A Testera G Variola A Venturelli L van der Werf DP Yamazaki Y;ATHENA Collaboration 《Physical review letters》2005,95(2):025002
We have developed a new method, based on the ballistic transfer of preaccumulated plasmas, to obtain large and dense positron plasmas in a cryogenic environment. The method involves transferring plasmas emanating from a region with a low magnetic field (0.14 T) and relatively high pressure (10(-9) mbar) into a 15 K Penning-Malmberg trap immersed in a 3 T magnetic field with a base pressure better than 10(-13) mbar. The achieved positron accumulation rate in the high field cryogenic trap is more than one and a half orders of magnitude higher than the previous most efficient UHV compatible scheme. Subsequent stacking resulted in a plasma containing more than 1.2 x 10(9) positrons, which is a factor 4 higher than previously reported. Using a rotating wall electric field, plasmas containing about 20 x 10(6) positrons were compressed to a density of 2.6 x 10(10) cm(-3). This is a factor of 6 improvement over earlier measurements. 相似文献
120.
Agnello M Beer G Benussi L Bertani M Bianco S Botta E Bressani T Busso L Calvo D Camerini P Cerello P Dalena B De Mori F D'Erasmo G Di Santo D Fabbri FL Faso D Feliciello A Filippi A Filippini V Fiore EM Fujioka H Gianotti P Grion N Lucherini V Marcello S Maruta T Mirfakhrai N Morra O Nagae T Olin A Outa H Pace E Palomba M Pantaleo A Panzarasa A Paticchio V Piano S Pompili F Rui R Simonetti G So H Tomassini S Toyoda A Wheadon R Zenoni A;FINUDA Collaboration 《Physical review letters》2005,94(21):212303
We have searched for a deeply bound kaonic state by using the FINUDA spectrometer installed at the e(+)e(-) collider DAPhiNE. Almost monochromatic K(-)'s produced through the decay of phi(1020) mesons are used to observe K(-) absorption reactions stopped on very thin nuclear targets. Taking this unique advantage, we have succeeded to detect a kaon-bound state K(-)pp through its two-body decay into a Lambda hyperon and a proton. The binding energy and the decay width are determined from the invariant-mass distribution as 115(+6)(-5)(stat)(+3)(-4)(syst) MeV and 67(+14)(-11)(stat)(+2)(-3)(syst) MeV, respectively. 相似文献