LBL-24199 Action at a distance at a speed greater than the speed of light was not an acceptable idea for Einstein, Podolsky, and Rosen (EPR) [1], but it was for Heisenberg [2]. Today, because of experimental results [3,4] and theoretical analysis [5,6], such action looks, in all likelihood, like a real effect. The argument leading to this conclusion can be explained in simple terms, as long as the word "real" is given a conventional meaning. However, the need for such action can also be shown with more general definitions of this word [7]. Several pictures of reality can still be drawn without cOIltradicting the results of any experiment performed to date. The choice between the different possibilities depends partly on one's guess about the outcome of possible future experiments and partly on one's philosophical view of the world. tThis work was supported by the u.s. Department of Energy under Contract No. DE-AC03-76SF00098.

S. Abachi h , M. Abolins q, B.S . Acharya ab , I . Adam g, S . Alm h , H. Aihara n, G. Alvarez 1 , G.A. Alves f , N. Amos P, W. Anderson m, Yu. Antipov W, S.H . Aronson °, R. Astur Z, R.E. Avery `, A . Baden °, J . Balderston k, B. Baldin W, J . Bantly d , E. Barasch Z, J.F . Bartlett h , K . Bazizi e, T. Behnke Z, V. Bezzubov W, P.C . Bhat h, G. Blazey X, S. Blessing t , A . Boehnlein ad , F . Borcherding h , J . Borders X, N. Bozko W, A. Brandt h, R. Brock q, A. Bross h , D. Buchholz `, V. Burtovoy W, J.M. Butler h , O . Callot Z, D. Chakraborty Z, S. Chekulaev W, J . Chen b, L.-P . Chen n, W. Chen Z, B.C . Choudhary e, J.H . Christenson h , D. Claes Z, A.R. Clark n, W.G. Cobau °, J . Cochran Z, W.E. Cooper h , C . Cretsinger X, D. Cullen-Vidal d , M. Cummings k , D. Cutts d , 0.1 . Dahl n, B. Daniels °, K. De ac, M. Demarteau h , K. Denisenko h , N . Denisenko h, D. Denisov W, S. Denisov W, W. Dharmaratna i, H.T . Diehl h , M . Diesburg h , R. Dixon h, P . Draper ac, Y. Ducros Y, S. Durston-Johnson X, D. Eartly h , P.H. Eberhard n, D. Edmunds q, A. Efimov W, J . Ellison e, V.D. Elvira h , R . Engelmann Z, O. Eroshin W, V. Evdokimov W, S . Fahey q, G. Fanourakis ', M. Fatyga c, J . Featherly c, S. Feher Z, D. Fein b , T . Ferbel X, D. Finley h , G. Finocchiaro Z, H.E. Fisk h , E. Flattum q, G.E. Forden b , M. Fortner s, P. Franzini g, S . Fuess h , E . Gallas ad , C.S . Gao h, T.L . Geld P, K. Genser h , C.E. Gerber h , B . Gibbard e, V. Glebov aa, J.F. Glicenstein Y, B. Gobbi t, M. Goforth ', M.L . Good Z, F. Goozen n, H. Gordon ', N. Graf c, P.D. Grannis Z, D.R. Green h , J . Green s, H. Greenlee h , N . Grossman q, P . Grudberg n, J.A. Guida Z, J.M. Guida `, W. Guryn c, N.J . Hadley °, H. Haggerty h , S . Hagopian ', V . Hagopian ', R.E. Hall e, S . Hansen h, J . Hauptman m, D. Hedin s, A.P . Heinson e, U. Heintz g, T. Heuring Z, R. Hirosky X, K. Hodel X, J.S . Hoftun d , J.R . Hubbard Y, T. Huehn e, R. Huson ad , S . Igarashi h , A.S . Ito h , E . James b , J . Jiang Z, K. Johns b , C.R . Johnson ae, M. Johnson h, A. Jonckheere h , M. Jones k , H. Jdstlein h, C.K. Jung Z, S. Kahn e, S . Kanekal g, A. Kernan e, L. Kerth n, A. Kirunin ', A. Klatchko ', B . Klima h , B . Klochkov W, C. Klopfenstein Z, V. Klyukhin W, V. Kochetkov W, J .M . Kohli °, W. Kononenko v, J . Kotcher aa, I . Kotov `", J . Kourlas r, A. Kozelov `", E. Kozlovsky W, G. Krafczyk h , K . Krempetz h , M.R . Krishnaswamy ab , P. Kroon c, S . Krzywdzinski h , S . Kunori °, S . Lami Z, G. Landsberg Z, R.E. Lanou d , P . Laurens q, J . Lee-Franzini Z, J . Li ac, R . Li h , Q .Z. Li-Demarteau h , J.G.R. Lima f , S.L . Linn ', J . Linnemann q, R. Lipton h , Y .-C. Liu t , D. Lloyd-Owen Z, F. Lobkowicz ', S .C . Loken n, S . Lokos Z, L. Lueking h, A.K.A . Maciel f , R.J . Madaras n, R. Madden ', E . Malamud h, Ph. Mangeot Y, I . Manning h , B. Mansoulié Y, V. Manzella Z, H.-S . Mao h , M. Marcin P, L. Markosky b, T . Marshall 1 , H.J . Martin 1 , M.I . Martin h , P.S . Martin h , M . Marx Z, B. May b , A . Mayorov W, R. McCarthy Z, J . McKinley q, D. Mendoza a, X.-C . Meng h, K.W. Merritt h , A. Milder b , A. Mincer r, N.K. Mondal ab , M. Montag c, P. Mooney q, M. Mudan r, G.T . Mulholland h, C. Murphy 1 , C.T . Murphy h , F . Nang d , M. Narain h V.S . Narasimham ab , H.A. Neal P, P. Nemethy r, D . Nesié d , K.K . Ng Z, D. Norman', L. Oesch P, V. Oguri f , E . Oltman n, N. Oshima h, D. Owen q, M. Pang m, A. Para h ,

The D0 detector is a large general purpose detector for the study of short-distance phenomena in high energy antiproton-proton collisions, now in operation at the Fermilab Tevatron collider. The detector focusses upon the detection of electrons, muons, jets and missing transverse momentum. We describe the design and performance of the major elements of the detector, including the tracking chambers, transition radiation detector, liquid argon calorimetry and muon detection. The associated electronics, triggering systems and data acquisition systems are presented. The global mechanical, high voltage, and experiment monitoring and control systems which support the detector are described. We also discuss the design and implementation of software and software support systems that are specific to D0.

We present branching fraction measurements of three-prong decays of the tau- lepton based on data from the TPC/Two-Gamma detector at SLAC PEP. The decays are classified according to the identities of the charged tracks to give simultaneous measurements of B[tau- --> nu(tau)K-pi+pi-]=0.58(-0.13)+0.15% and B[tau- --> nu(tau)K-K+pi-]=0.15+0.15(-0.07)+0.09)%, and upper limits of B[tau- --> nu(tau)pi-K+pi-]<0.25% B[tau- --> nu(tau)K-pi+K-]<0.09%, and B[tau- --> nu(tau)K-K+K-]<0.21%, where additional neutrals may be present in each case. The branching fractions are normalized to the world average three-prong topological branching fraction and there is an estimated 20% systematic error in addition to the listed statistical errors. We find the mass distributions in the K-pi+pi- decay are consistent with K1 dominance, and obtain branching fractions of B[tau- --> nu(tau)K1-(1270)]=0.41(-0.35)+0.41% and B[tau- --> nu(tau)K1-(1400)]=0.76(-0.33)+0.40%

The two End Calorimeter Electromagnetic (ECEM) modules of the D0 liquid argon calorimeter system have been constructed as monolithic units of 1 m radius to provide full azimuthal coverage in the forward and backward regions (1.4 < \eta\ < 4.0) for the study of ppBAR collisions at the Fermilab Tevatron Collider. An ECEM module consists of 18 layers of absorber disks (mostly 4 mm thick uranium) with interleaved signal disks that have readout pads in semi-projective towers. The mechanical design and construction of the ECEM modules is described in detail. The performance of one ECEM module has been studied in beam tests with electrons. Results are given for the linearity and uniformity of response, the energy and position resolutions, and pion rejection.

used in the SSC test beam fines. It follows a 20-m drift section of beam tube downstream of the last silicon strip detector. A bending dipole just in of the last silicon strip detector produces the synchrotron radiation that is detected in a 50-mm-square cross section NaI crystal. A secondary scintillator made of Bicron BC-400 plastic is used to discriminate whether it is synchrotron radiation or a stray particle that causes the triggering of the NaI crystal`s photo multiplier tube (PMT).

The TPC/Two-Gamma Collaboration has measured the inclusive cross section for production of charmed D∗± mesons in photon-photon collisions. The reaction utilized was e+e-→e+e-D∗±X, with D∗±→DOπ+-, DO→K-+π ±, and either zero or one outgoing e± detected. The result, σ(e+e- → e+e-D∗±X) = 74±26±19 pb, is in agreement with the quark parton mo del prediction for e+e- → e+e-cc, combined with a Lund model for the hadronization of the charmed quarks.

The TPC/Two-Gamma facility at the SLAC e+e− storage ring PEP was used to study the reactions γγ*→η and γγ*→η'. The ηγ*γ and η'γ*γ transition form factors were measured as functions of Q2, the negative of the invariant mass squared of the tagged photon, in the range 0.1

We report a measurement of the e+e−→e+e−p¯pπ+π− process with the TPC/Two-Gamma facility at the PEP e+e− storage ring at SLAC. Forty-five p¯pπ+π− events were identified in data corresponding to an integrated e+e− luminosity of 142 pb−1. The cross section for γγ→p¯pπ+π− is given both as a function of the γγ center-of-mass energy Wγγ, with Wγγ between 2.5 and 5.5 GeV, and as a function of the in variant mass squared q2 of one of the photons, with −q2<7 GeV2. This cross section falls much less rapidly with Wγγ than does the cross section for a similar process, γγ→p¯p. No Δ0¯Δ0 production is observed, and only a small fraction of the events at low Wγγ is consistent with γγ→Δ++¯Δ−−, Δ++¯pπ−, or ¯Δ−−pπ+. In an expanded search through the same data, four events compatible with either Λ¯Λ(Λ→pπ−) or Σ0¯Λ(Σ0→Λγ) production were found.Received 7 April 1989DOI:https://doi.org/10.1103/PhysRevD.40.2772©1989 American Physical Society

In the study of rapidity distributions of charged pions produced ine+e− annihilation at 29 GeV, we observe a significant dip in the rapidity distributions aty≈0 for events with low sphericity. A comparison of data with several QCD-based phenomenological models strongly suggests that this structure is related to the emission of multiple soft and/or collinear gluons.

Disclaimer/Complaints regulations If you believe that digital publication of certain material infringes any of your rights or (privacy) interests, please let the Library know, stating your reasons. In case of a legitimate complaint, the Library will make the material inaccessible and/or remove it from the website. Please Ask the Library: http://uba.uva.nl/en/contact, or a letter to: Library of the University of Amsterdam, Secretariat, Singel 425, 1012 WP Amsterdam, The Netherlands. You will be contacted as soon as possible.

We have observed the formation of two spin-one mesons in \ensuremath{\gamma}\ensuremath{\gamma} fusion reactions in which one photon was highly virtual. The first, consistent with being the ${J}^{\mathrm{PC}}$${=1}^{++}$ ${f}_{1}$(1285), was seen in the final state \ensuremath{\eta}${\ensuremath{\pi}}^{+}$${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$ (\ensuremath{\eta}\ensuremath{\rightarrow}\ensuremath{\gamma}\ensuremath{\gamma}), as was the \ensuremath{\eta}'(958). We have previously reported the observation of the second spin-one state, the X(1420), in the final state ${K}^{\ifmmode\pm\else\textpm\fi{}}$${K}_{S}^{0}$${\ensuremath{\pi}}^{\ensuremath{\mp}}$ (${K}_{S}^{0}$\ensuremath{\rightarrow}${\ensuremath{\pi}}^{+}$${\ensuremath{\pi}}^{\mathrm{\ensuremath{-}}}$). The formation of this state, which may be the ${f}_{1}$(1420) observed in hadronic interactions, is reanalyzed using a new model and more data. We consider whether the X(1420) could be the partner of the ${f}_{1}$(1285) in the ${J}^{\mathrm{PC}}$${=1}^{++}$ meson nonet. The \ensuremath{\gamma}${\ensuremath{\gamma}}^{\mathrm{*}}$ width of each resonance was determined in several ${Q}^{2}$ bins. Using a model due to Cahn with a \ensuremath{\rho} form factor, we obtained for the coupling parameter \ensuremath{\Gamma}${\ifmmode \tilde{}\else \~{}\fi{}}_{\ensuremath{\gamma}\ensuremath{\gamma}}$(${f}_{1}$(1285)) the value 2.4\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}0.5 keV.We also found B(X(1420)\ensuremath{\rightarrow}KK\ifmmode\bar\else\textasciimacron\fi{}\ensuremath{\pi})\ensuremath{\Gamma}${\mathrm{\ifmmode \tilde{}\else \~{}\fi{}}}_{\ensuremath{\gamma}\ensuremath{\gamma}}$(X(1420))=1.3\ifmmode\pm\else\textpm\fi{}0.5\ifmmode\pm\else\textpm\fi{}0.3 keV using a \ensuremath{\rho} form factor, or 0.63\ifmmode\pm\else\textpm\fi{}0.24\ifmmode\pm\else\textpm\fi{}0.15 keV using a \ensuremath{\varphi} form factor. The decay distributions of the observed X(1420) events are consistent with a decay proceeding via ${K}^{\mathrm{*}}$(892)K, and favor positive, but do not exclude negative, parity. Assuming that the X(1420) and the ${f}_{1}$(1285) are members of the same qq\ifmmode\bar\else\textasciimacron\fi{} meson nonet and that B(X(1420)\ensuremath{\rightarrow}KK\ifmmode\bar\else\textasciimacron\fi{}\ensuremath{\pi})\ensuremath{\approxeq}1, and using a \ensuremath{\varphi} form factor in the model for X(1420) formation, we determined the singlet-octet mixing angle of that nonet. The result, (45.4\ifmmode\pm\else\textpm\fi{}6.2)\ifmmode^\circ\else\textdegree\fi{}, agrees well with the 42.2\ifmmode^\circ\else\textdegree\fi{} implied by the Gell-Mann--Okubo quadratic mass formula; it is farther from the 35.3\ifmmode^\circ\else\textdegree\fi{} ideal mixing angle. Our results are thus consistent with the X(1420) being the mostly ss\ifmmode\bar\else\textasciimacron\fi{} isoscalar member of the axial-vector qq\ifmmode\bar\else\textasciimacron\fi{} meson nonet; however, we have no evidence contrary to hypotheses that the X(1420) is an exotic ${q}^{2}$q\ifmmode\bar\else\textasciimacron\fi{} $^{2}$ or qq\ifmmode\bar\else\textasciimacron\fi{}g state.

We have observed formation of the f1 (1285) in the reaction e+e-→e+e-π+π-η(η→γγ). Its γγ∗ width is determined in several Q2 bins. The γγ coupling parameter for the f1 (1285) is found to be 2.4±0.5±0.5 keV. This value is compared to that for the X (1420), another J=1 state formed in γγ fusion reactions, which may belong to the same meson nonet.

The multiplicities per event of π± and K± are measured separately for e+e- annihilation into cc, bb, and light quark pairs at Ecm=29 GeV. The K± multiplicity is higher for heavy quark events than for light quark events. The π± multiplicity and the π± scaled differential cross section at low x=Ebeam/Ebeam are found to be higher for bb events than for other events.

We present a measurement of the photon structure functionF 2 γ in the reactionee→eeX forQ2 in the range 0.2<Q2<7 GeV2, using 9,200 multihadron events obtained with the TPC/Two-Gamma detector at PEP. The data have been corrected for detector effects using a regularized unfolding procedure and are presented as a function ofx andQ2. The structure function shows scaling in the region 0.3<Q2<1.6 GeV2,x<0.3 and rises for higherQ2. AtQ2=5.1 GeV2 the results are compared with QCD and, within the scheme of Antoniadis and Grunberg, rather conservative bounds for the QCD scale parameter of 133±50<\(\Lambda _{\overline {{\rm M}S} } \)<268±98 MeV are obtained. A study of the final state structure shows that the rise ofF 2 γ is consistent with being entirely due to the pointlike component of the photon.