16089695
Spin--unitary-spin splitting of SU(8) supermultiplets
The suprising narrowness of the J or psi (3.1) is interpreted as indication of a pure cc state, and hence as evidence for the SU(8) ..-->.. SU(6) x SU(2)/subS//subc/ x U(1)/subY//subc/ symmetry-breaking chain (S/subc/ = charmed-quark--spin generators, Y/subc/ = hypercharm generator) instead of an approximate SU(8) ..-->.. SU(4) x SU(2)/subS/ chain (S = quark spin generators) which would imply strong mixings. Decompositions under both chains of the s-wave qq meson states of the 64 = 1 + 63 of SU(8) and of the 3q baryon states of the three-particle symmetric 120 representation are given. The most general mass-splitting operators with breaking in the Y and Y/subc/ directions for these two multiplets are derived, which commute with the Casimir operators of the SU(6) x SU(2)/subS//subc/ x U(1)/subY//subc/ chain, which contain only one- and two-body operators, and which are invariant under rotations. Two independent mass relations follow for mesons containing charmed quarks; six, for baryons containing charmed quarks. In an appendix, for reference relative to previous SU(6) -symmetric quark-model mass analyses, the reduced numerical coefficients as determined by the meson 36 of SU(6) are listed. (AIP)
119987004
Rishon model of quarks and leptons with double SU(2) symmetry and Dirac magnetic moments
Abstract Two-doublet rishon models are proposed to avoid some of the kinematic and dynamic difficulties of the single-doublet rishon model. One has point-like magnetic moments only for leptons. The other, based on an anti-pairing hypothesis, has point-like leptons and quarks.
119847840
Linear Regge trajectories for the psion family and O(4) dynamics
The newly discovered psion family can be described by mass-squared linear Regge trajectories. The new J/subP//subC/ assignments are for 2.8 GeV/ c$sup 2$, 0$sup ++$, and for the 3.4 region, 2$sup ++$, 1$sup -+$, 0$sup ++$. All radiative decays are related through a single S/sub mu//sub nu/F/sub mu//sub nu/ coupling. A good fit is obtained. (AIP)
14270584
Tau decays beyond the standard model
In a recent paper, 8 semileptonic parameters were defined to specify the most general Lorentz-invariant spin correlation functions for 2-body τ decays. These parameters can be used to search for anomalous Γ L , Γ T polarized-partial widths, for non-CKM-type leptonic CP violation, and for leptonic T FS violation. They can also be used to bound the effective-mass scales A for “new physics” arising from additional Lorentz structures, e.g. from lepton compositeness, tau weak magnetism, weak electricity, or second-class currents. It is emphasized that (i) for these tests “different modes have different merits” and that (ii) the parameters can be measured either by using spin-correlation techniques without polarized beams, or with longitudinally polarized beams.
115882781
Cheng-wu picture applied to gamma p ---> rho0 p and phi p
11827113
DETERMINATIONS OF P, AND CP, FOR HEAVY MESONS AND TESTS FOR THEIR VIOLATIONS WITHOUT POLARIZATION EXPERIMENTS
Powerful results are tabulated which can be used at modern colliders to make fundamental symmetry tests by analysis of sequential decays of X + V1V2. By generalization of the ty$ parity test which has recently been used to determine the parity of the r|c, the P (or CP) quantum number can always be determined for X of any spin J which decays P (or respectively CP) invariantly into VV or VV where each vector meson decays into two spin-0 bosons, or is (0. P can also always be determined from a mode like K + K °. A neutral spin-0 technipion and an elementary Higgs particle, for instance, can be distinguished by such CP invariant decay modes and by <j>p , <j)J, JT, or i£ sufficiently massive by <f>Z° or JZ° where J/\JJ and Z° go into a lepton-antilepton pair. Generalization to the gZ° and gg decay channels, g = gluon jet, which would be relevant to new resonance physics, for example, at the CERN collider is discussed. There are also very simple tests for possible violations of P, of the combination of C plus isospin, of both P and CP, and of both C and CP. The practicality and state-of-the-art property of the c)><|> parity test /1/ has been recently demonstrated by its use /2/ by the Mark III collaboration at SLAC-SPEAR to determine the parity of the t) . Less than twenty events were needed to measure the dependence of the decay correlation function I((ji) = 1 + 6 cos2<f) on the azimuthal angle <j> between the two <f> -* K+KT decay planes and to show agreement with B = -1 (pseudoscalar), instead of 0 <_ 6 <_ 1 (scalar). This (j)(j) parity test /1/ for a spin-zero particle was proposed by Ngee-Pong Chang and myself in 1978 as an analogue of Yang's parity test /3/ for the ir°. By means of the h'elicity formalism /4/, it was soon elegantly generalized /5/ by Trueman for a decaying X particle of any spin J. In the last few months the test has been extended /6,7/ to other V1V2 decay modes, for X of any spin J, including those of neutral X particles with odd chargeconjugation and those of charged X states. It has also been found that a spin-0 technipion and an elementary Higgs particle can be distinguished by a decay mode like (jxj) or JJ (identical vector mesons), K*°K ° (particle-antiparticle pair), <j)p°, <J)J, JT, or if sufficiently massive by cfiZ or JZO where j/t|i and Z° go into a leptonantilepton pair. In this talk we will summarize these new results, explain what has to be measured, and tabulate what can be learned from analysis of specific V1V2 decay modes. Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1985229 c2-262 JOURNAL DE PHYSIQUE The advantages of t h i s type of t e s t a r e t h a t it i s r igorous, t h a t t he s ignatures a r e s t r i k i n g , t h a t t he P/CP determination i s independent of t he po la r i za t ion s t a t e of t he decaying X system (and so the t e s t is independent of t he production mechanism), t h a t t he P/CP determination never f a i l s f o r J=0 o r when the re i s a Vlt*.V2 exchange property, and t h a t the t e s t i s normally applicable i n semi-inclusive p roduc t i on experiments s ince many X decay modes y i e ld observed s t a t e s with only charged pa r t i c l e s . We w i l l f i r s t consider t he following sequent ia l decay of an X system of any spin J X + v1 v2 Spin 0 mesons A1, B1, ... In t he X r e s t frame the nine h e l i c i t y amplitudes a r e speci f ied by where X = XI-X2 and @ , @ a r e the polar and azimuthal angles of V l . By Lorentzinvariance t h e general decay co r r e l a t i on funct ion is 161 + Bd(01,02) cos 2$ + Bx(01,02) s i n 2+ where the polar angles el and 82 f o r A 1 and A2 momenta a r e defined /5,6/ a s i n Fig. 1. In pa r t i cu l a r , although the azimuthal angle 4 i s invar iant under Lorentz boosts
120517617
Elastic Photoproduction of omega Mesons from Hydrogen, Deuterium, and Complex Nuclei
We have studied ..omega.. photoproduction using 7.5- to 10.5-GeV tagged photons. Cross sections from hydrogen lie 22% below the bubble chamber results of Ballam et al., but have a similar slope. Density matrices indicate approximate s-channel helicity conservation. The proton--neutron cross-section difference is midway between zero and the value suggested by the ..gamma..p--..gamma..n total-cross-section difference. Fits to the cross sections for D, Be, and Cu and those for Be, C, Al, Cu, and Pb from a previous experiment yield sigma/sub ..omega..N/ = 25.4 +- 2.7 mb and ..gamma../sub ..omega..//sup 2//4..pi.. = 7.6 +- 1.2. (AIP)
110910531
FRONT-END ELECTRONICS UPGRADE FOR THE CDF CALORIMETERS
116135045
Eta gamma Decays of rho0, omega, and phi Mesons
eta..gamma.. decays of rho/sup 0/, ..omega.., and phi are studied. We find GAMMA (phi..-->..eta..gamma..) =55 +- 12 keV. Our data admit two solutions for (rho/sup 0/, ..omega..) ..-->..eta..gamma..: Either GAMMA (rho/sup 0/..-->..eta..gamma..) =50 +- 13 keV, GAMMA (..omega -->..eta..gamma..) =3.0/sup +2//sup .//sup 5//sub -//sub 1//sub .//sub 8/ keV, and the (..omega..,rho) ..-->..eta..gamma.. relative decay phase is near zero; or GAMMA (rho/sup 0/..-->..eta..gamma..) =76 +- 15 keV, GAMMA (..omega -->..eta..gamma..) =29 +- 7 keV, and the decay phase is near 180degree. (AIP)
59496828
Enhanced 200-GeV/c K+ Beam Using Beryllium Filter
Abstract Using beryllium as a selective hadron filter, the kaon fraction of a positively charged 200 GeV/ c secondary beam has been increased from 3% to ∼15% without an appreciable effect on tagging efficiency.
183079972
Operating Characteristics of Lecroy-2280/2285 ADC System