排序方式: 共有11条查询结果,搜索用时 390 毫秒
1.
E. Eisenhandler W.R. Gibson C. Hojvat P.I.P. Kalmus L.C.Y.Lee Chi Kwong T.W. Pritchard E.C. Usher D.T. Williams M. Harrison W.H. Range M.A.R. Kemp A.D. Rush J.N. Woulds G.T.J. Arnison A. Astbury D.P. Jones A.S.L. Parsons 《Physics letters. [Part B]》1973,47(6):531-535
We present measurements from a spark chamber experiment of the differential cross-sections for p → π?π+, K?K+ at 20 momenta in the range 0.8–2.4 GeV/c (c.m. energy 2.02 to 2.57 GeV). The c.m. angular range was . There are about 2000π?π+ events and about 300 K?K+ events at each momentum. 相似文献
2.
E. Eisenhandler W.R. Gibson C. Hojvat P.I.P. Kalmus L.C.Y.Lee Chi Kwong T.W. Pritchard E.C. Usher D.T. Williams M. Harrison W.H. Range M.A.R. Kemp A.D. Rush J.N. Woulds G.T.J. Arnison A. Astbury D.P. Jones A.S.L. Parsons 《Physics letters. [Part B]》1973,47(6):536-540
The differential cross-sections for p → π?π+ in the momentum range 0.8 to 2.4 GeV/c (centre-of-mass energy 2.02 to 2.57 GeV) are analysed in terms of the possible existence of s-channel resonances. The systematics of the dip structures and the s-dependence of dσ/dt are presented. 相似文献
3.
M. Z. Akrawy G. Alexander J. Allison P. P. Allport K. J. Anderson J. C. Armitage G. T. J. Arnison P. Ashton G. Azuelos J. T. M. Baines et al. 《Zeitschrift fur Physik C Particles and Fields》1991,50(3):373-384
The OPAL detector at LEP is used to measure the branching ratio of theZ
0 into invisible particles by measuring the cross section of single photon events ine
+
e
– collisions at centre-of-mass energies near theZ
0 resonance. In a data sample of 5.3 pb–1, we observe 73 events with single photons depositing more than 1.5 GeV in the electromagnetic calorimeter, with an expected background of 8±2 events not associated with invisibleZ
0 decay. With this data we determine theZ
0 invisible width to be 0.50±0.07±0.03 GeV, where the first error is statistical and the second systematic. This corresponds to 3.0±0.4±0.2 light neutrino generations in the Standard Model. 相似文献
4.
G. Arnison A. Astbury B. Aubert C. Bacci G. Bauer A. Bézaguet R.K. Bock T.J.V. Bowcock M. Calvetti T. Carroll P. Catz P. Cennini S. Centro F. Ceradini S. Cittolin D. Cline C. Cochet E. Zurfluh 《Physics letters. [Part B]》1984,136(4):294-300
The two-jet cross section measured in the UA1 apparatus at the CERN Collider has been analysed in terms of the centre-of-mass scattering angle θ and the scaled longitudinal parton momenta x1 and x2. The angular distribution dσ/d cos σ rises rapidly as cos → 1, independent of x2 and x2, as expected in vector gluon theories (QCD). The differential cross section in x1 and x2 is consistent with factorization and provides a measurement of the proton structure function at values of the four-momentum transfer squared, -t? ≈ 2000 GeV2. Over the range x = 0.10?0.80 the structure function shows an exponential x dependence and may be parametrized by the form F(x) = 6.2 exp (?9.5x). 相似文献
5.
G. Arnison A. Astbury B. Aubert C. Bacci G. Bauer A. Bézaguet R.K. Bock T.J.V. Bowcock M. Calvetti P. Catz P. Cennini S. Centro F. Ceradini S. Cittolin D. Cline C. Cochet J. Colas E. Zurfluh 《Physics letters. [Part B]》1984,134(6):469-476
Muons of high transverse momentum pμT have been observed in the large drift chambers surrounding the UA1 detector at the CERN 540 GeV pp? collider. For an integrated luminosity of 108 nb?1, 14 isolated muons have been found with pT > 15 GeV/c. They are correlated with a large imbalance in total transverse energy, and show a kinematic behaviour consistent with the muonic decay of the Intermediate Vector Boson W± of weak interactions. The partial cross section is in agreement with previous measurements for electronic decays and with muon-electron universality. The W mass is determined to be mW = 81+6?7 GeV/c2. 相似文献
6.
M. Z. Akrawy G. Alexander J. Allison P. P. Allport K. J. Anderson J. C. Armitage G. T. J. Arnison P. Ashton G. Azuelos J. T. M. Baines et al. 《Zeitschrift fur Physik C Particles and Fields》1991,49(1):1-15
A search for minimal standard model (MSM) and minimal supersymmetric model (MSSM), Higgs bosons with masses larger than 3 GeV/c2 has been performed by the OPAL collaboration one
+
e
– data from LEP corresponding to an integrated luminosity of 1.24 pb–1. The limits for MSM Higgs bosons have been obtained using the channelsZ
0Z
0*
H
0,Z
0*(v
ore
+
e
– or µ+, µ–. The search for MSSM Higgs bosons has been performed using the channelsZ
0Z
0*
H
0,v
ore
+
e
– or µ+µ–),h
0 q
andZ
0h
0
A
0,h
0
A
0(4 jet or
+
– or 4), whereh
0 andA
0 are the two lightest neutral MSSM Higgs bosons. No Higgs boson signal has been observed. The MSM Higgs boson is excluded in the mass range 3 GeV
<25.3>25.3>2 at the 95% confidence level; limits on the masses of the two lightest neutral MSSM Higgs bosons are obtained forh
0 mases up to 40.5 GeV/c2.Now at Applied Silicon Inc. 相似文献
7.
G. Arnison O.C. Allkofer A. Astbury B. Aubert C. Bacci R. Batley G. Bauer A. Bézaguet R.K. Bock T.J.V. Bowcock E.J. Buckley M. Calvetti P. Catz P. Cennini S. Centro F. Ceradini G. Ciapetti L. Zanello 《Physics letters. [Part B]》1985,158(6):494-504
Results are presented on two-jet and three-jet cross sections, measured in the UA1 experiment at the CERN Super Proton Synchrotron (SPS) pp? Collider, at the highest available subprocess cms energies (). Precise measurements of the two-jet angular distribution are consistent with previous results but show significant scale-breaking effects. The three-jet Dalitz plot and the three-jet angular distributions show evidence for final- and initial-state bremsstrahlung processes, in agreement with the leading-order QCD predictions. A comparison of the yield of wide-angle three-jet events with the yield of two-jet events at smaller scattering angles gives for the strong interaction coupling constant: at Q2≈4000 GeV2, where the factor may plausibly be assumed to be close to unity. 相似文献
8.
T. J. Sumner J. J. Quenby A. Bewick N. J. T. Smith W. G. Jones T. Ali B. Ahmed D. Davidge G. J. Davies A. Howard M. K. Joshi P. F. Smith G. J. Homer G. T. J. Arnison J. D. Lewin G. J. Alner N. J. Spooner L. Thompson P. Sellin S. Walker J. Roberts C. Peak J. C. Barton 《Nuclear Physics B - Proceedings Supplements》1999,70(1-3)
The UK Dark Matter Collaboration has run a 5–6 kg NaI detector in a well-shielded underground environment for about a year. Signatures of Cold Dark Matter (CDM) interactions are sought using pulse shape discrimination techniques by searching for the relatively short scintillation pulses arising from nuclear recoils among the residual, longer, background events from residual radioactivity in the detector and its environment. Here we report on an improvement to the limits on the CDM cross section for spin dependent interactions using our latest data from a crystal with improved detection efficiency and taking into account recent improved estimates of the spin factor correction between the nucleus and nucleon-supersymmetric particle cross sections. 相似文献
9.
H.C. Bryant A.A. Carter M. Coupland E. Eisenhandler W.R. Gibson P.I.P. Kalmus T.W. Pritchard H. Sandhu S.J. Watts G.T.J. Arnison A. Astbury J.K. Davies G.H. Grayer D. Hill A.W. Robertson T.P. Shah C. Sutton 《Nuclear Physics B》1980,168(2):207-221
The polarization parameter has been measured for K?p elastic scattering at nine incident beam momenta between 0.955 and 1.272 GeV/c covering the c.m. angular range . Experimental results and coefficients of Legendre polynomial fits to the data are presented and compared with other measurements and a partial-wave analysis. 相似文献
10.
E. Eisenhandler W.R. Gibson C. Hojvat P.I.P. Kalmus L.C.Y. Lee Chi Kwong T.W. Pritchard E.C. Usher D.T. Williams M. Harrison W.H. Range M.A.R. Kemp A.D. Rush J.N. Woulds G.T.J. Arnison A. Astbury D.P. Jones A.S.L. Parsons 《Physics letters. [Part B]》1974,49(2):201-204
We present Legendre coefficients from fits to the differential cross-sections for in the momentum range 0.8 to 2.4 GeV/c. The s-dependence of the cross-sections at small angles is examined for evidence of Reggeized baryon exchange, and a fit made to this channel and backward K+p elastic scattering. Comparisons are made with . 相似文献