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
120421012
The psion family: Relativistic charmonium
The authors have reported earlier that the spectrum of the psion family suggests a treatment based on an O(4) harmonic-oscillator family with O(4) quantum number M = 0 (equally spaced, mass-squared linear Regge trajectories). This results in the new J/subP//subC/ quantum numbers: 0$sup ++$ for 2.8 GeV/ c$sup 2$; 2$sup ++$, 1$sup -+$, 0$sup ++$ for the 3.4-GeV/c$sup 2$ mass region. All radiative decays are related through a single O(4) coupling S/sub mu//sub nu/ F/sub mu//sub nu/, where S/sub mu//sub nu/ is the internal-space angular-momentum operator. The details of the calculations of radiative transition widths and of the $gamma$$gamma$ angular correlation functions are given. Experimental signatures are discussed and compared with the nonrelativistic charmonium scheme; among others J $Yields$ O (2.8) + $gamma$ and psi ' $Yields$ O (2.8) + $gamma$ are small, being forbidden in the strict O(4) limit. O (2.8) is expected to be narrow like all other psions below the 4.0-GeV/c$sup 2$ region. chi$sub 0$(3.41) and chi$sub 1$(3.49) total widths are expected to be around 630 keV and 185 keV respectively. The missing decays of psi ' could be due to psi ' $Yields$ O + $omega$ ( approx. 32%). (AIP)
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)
115882781
Cheng-wu picture applied to gamma p ---> rho0 p and phi p
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.
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.
21292465
The MINOS near detector front end electronics
The Near Detector for the MINOS Experiment at Fermilab is composed of alternating planes of scintillator strips and steel plates, and is read out with 64-channel, multi-anode photomultiplier tubes. The instrumentation uses a custom integrated circuit designed at Fermilab for the front end analog processing, called the QIE. The system can measure single photoelectrons to high precision with a dynamic range of 16 bits. The electronics operates in two modes. It records all events that occur during the 10 /spl mu/s "fast spill" of the beam from the Fermilab Main Injector at a rate of 53 MHz, using a gate from the beamline controls to force data acquisition. The system can also acquire data from cosmic rays that pass through the detector for calibration. In this case, dynode signals from the photomultipliers are used as the trigger, causing digitization and readout of the associated channels. Zero suppression and normalization are done in the front end electronics. The system is "triggerless" in that there is no global hardware trigger. Instead, each event is tagged with a "timestamp", which is used in postprocessing to reconstruct events and discard noise hits. The system of 10,000 channels is now built and installed, and operational at Fermilab. The components of the system are described and preliminary system performance is reported.
122601142
SVX', the new CDF silicon vertex detector
Abstract The Collider Detector at Fermilab (CDF) radiation hardened silicon vertex detector (SVX') is described. The new detector has several improvements over its predecessor such as better signal to noise and higher efficiency. It is expected to have a radiation tolerance in excess of 1 Mrad. It has been taking data for several months and some preliminary results are shown.
21840141
Commissioning of the control and data acquisition electronics for the CDF silicon vertex detector
The SVX (silicon vertex detector) data acquisition system includes three components: a Fastbus sequencer, an SVX rabbit crate controller, and a digitizer. These modules are integrated into the Collider Detector Facility (CDF) data acquisition system and operate the readout chips. The results of the extensive functional tests of the SVX modules are reported. The authors discuss the sequencer's stability, systematic differences between them, and methods of synchronization with the Tevatron beam crossing. The digitizer ADC (analog-to-digital converter) calibration procedure run on the microsequencer is described. The microsequencer code used for data taking and SVX chip calibration modes is described. Measurements of the SVX data scan time under different conditions are discussed.<<ETX>>
44977344
The upgraded CDF front end electronics for calorimetry
The front-end electronics used in the calorimetry of the Collision Detector Facility (CDF) detector has been upgraded to meet system requirements for higher expected luminosity. A fast digitizer utilizing a 2- mu s, 16-b analog-to-digital converter (ADC) has been designed and built. Improvements to the front-end trigger circuitry have been implemented, including the production of 900 new front-end modules. Operational experience with the previous system is presented, with discussion of the problems and performance goals.<<ETX>>
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)