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Section on Supernova Remnants and Cosmic Rays of the White Paper on the Status and Future of Ground-Based Gamma-Ray Astronomy

Description: This is a report on the findings of the SNR/cosmic-ray working group for the white paper on the status and future of ground-based gamma-ray astronomy. The white paper is an APS commissioned document, and the overall version has also been released and can be found on astro-ph. This detailed section of the white paper discusses the status of past and current attempts to observe shell-type supernova remnants and diffuse emission from cosmic rays at GeV-TeV energies. We concentrate on the potential of future ground-based gamma-ray experiments to study the acceleration of relativistic charged particles which is one of the main unsolved, yet fundamental, problems in modern astrophysics. The acceleration of particles relies on interactions between energetic particles and magnetic turbulence. In the case of SNRs we can perform spatially resolved studies in systems with known geometry, and the plasma physics deduced from these observations will help us to understand other systems where rapid particle acceleration is believed to occur and where observations as detailed as those of SNRs are not possible.
Date: November 9, 2011
Creator: Pohl, M.; U., /Iowa State; Abdo, Aous A.; U., /Michigan State; Atoyan, A.; U., /McGill et al.
Partner: UNT Libraries Government Documents Department

Solid State Technology Meets Collider Challenge

Description: Probing the frontiers of particle physics and delving into the mysteries of the universe and its beginnings require machines that can accelerate beams of fundamental particles to very high energies and then collide those beams together, producing a multitude of exotic subatomic particles. The proposed Next Linear Collider (NLC), being developed by Stanford Linear Accelerator Center (SLAC), Lawrence Livermore and Lawrence Berkeley national laboratories, and Fermi National Accelerator Laboratory (Fermilab), is such a machine. The NLC is expected to produce a variety of subatomic particles by smashing together electrons and their antimatter counterparts (positrons) at nearly the speed of light with energies in the teraelectronvolt (TeV) range. Plans are that the NLC will initially operate at 0.5 TeV and ultimately be scaled up to 1.5 TeV. (See S&TR, April 2000, pp. 12-16.) Work at the facility will complement the research to be conducted at another high-energy particle accelerator, the 14-TeV Large Hadron Collider at the European Laboratory for Particle Physics (commonly known by the acronym CERN from its former name) in Geneva, which is scheduled for completion in 2007. Achieving beam energy levels in the TeV range requires modulator systems that can convert ac line power--the same type of power one gets from the wall plug--into dc pulses. Ultimately, these pulses are transformed into radiofrequency (rf) pulses that ''kick'' the particles up to the required energy levels. Livermore scientists and engineers have designed a solid-state modulator to replace oldstyle modulators based on vacuum-tube technology. These new modulators promise to be far more efficient, reliable, and serviceable than the previous components. Livermore's Laboratory Directed Research and Development Program supported the basic research and development on the solid-state modulator technology, and SLAC supported the systems integration.
Date: September 20, 2005
Creator: Hazi, A
Partner: UNT Libraries Government Documents Department

Excitation Curves of small quadrupoles for tev I Beam Line Use

Description: Excitation curves for at least one magnet of each length of TeV I Small Quadrupole have been measured utilizing the MIF-TeV I VAX standard measurement system. Since the standard measurement sequence does not include this sort of excitation curve, the standard reports issued on the magnet does not contain this data. Measurements were taken with the gradient probe SQ25 (probe ID No.40) centered in the aperture and extending through the field length to integrate the strength of the magnet. The parameter BETA2 reported below is the probe calibration factor for this probe in meters**2. The gradient strength of the magnet in Tesla-meters/meter is obtained from the measured flux by dividing by BETA2. The data were collected from MEAS BASE runs in which the measurement probe flux is recorded in a baseline measurement sequence. The hysteresis of the magnet is set by ramping to the specified maximum current then back to zero. The integrator is zeroed at zero current and the integrator voltage recorded one or more times. The current is then ramped successively to the measurement current where the integrator voltage is recorded, to full field and back to zero where the integrator voltage is again recorded for each current at which data is desired. After correction for drift, amplifier gain and integrator Re, the data is recorded in the Reduced data files. This report collects this data for measurements on several magnets. The data at non-zero currents are converted to Tesla and reported also in Tesla/Amp. In order to prepare the report entirely with the DATATRIEVE query language, the usual averaging of Probe Up and Probe Down measurements was not carried out. The reader is invited instead to look at both sets of data to observe that the error to be canceled is small. In addition, this report may ...
Date: February 1, 1985
Creator: Brown, B.
Partner: UNT Libraries Government Documents Department

J/{psi} and {psi}{prime} production at CDF

Description: This paper presents measurements of the J/{psi} and {psi}{prime} production cross sections in p{ovr p} collisions at {radical}s = 1.8 TeV. The cross sections are measured in the kinematic region P{sub T} {gt} 5 GeV/c, {vert_bar}{eta}{vert_bar} {lt} 0.6 using the dimuon decay channel. The fraction of events from B decays is measured and used to calculate the J/{psi} and {psi}{prime} cross sections from B decay. The fraction of J/{psi} events from {chi}{sub c} decays is also measured and used to calculate the J/{psi} cross section from direct production. 11 refs., 5 figs., 1 tab.
Date: July 1, 1996
Creator: Abe, F.
Partner: UNT Libraries Government Documents Department

Comparison of the total cross sections measurements of CDF and E811

Description: The total cross section at {radical}s = 1.8 TeV has been measured by three groups (CDF, E710, and E811). We think that CDF should quote results based only on our own measurement. We also indicate how to compare cross sections measured by both CDF and D0.
Date: March 3, 1999
Creator: Albrow, M.; Beretvas, A.; Nodulman, L. & Giromini, P.
Partner: UNT Libraries Government Documents Department

{Lambda}{sub b} results from CDF

Description: The CDF experiment has recorded 110 pb{sup {minus}1} of p{ovr p} collisions at {radical}s = 1.8 TeV during the 1992-1995 data taking period. Using this dataset, searches for inclusive and semileptonic {Lambda}{sub b} decays were performed. The {Lambda}{sub b} mass was measured to be M{sub {Lambda}{sub b}} {equals} 5623 {plus_minus} 5(stat.) {plus_minus} 4(syst.) MeV/c{sup 2}, using a sample of exclusively reconstructed {Lambda}{sub b} candidate events in the {Lambda}{sub b} {r_arrow} {Lambda}J/{psi} channel. The {Lambda}{sub b} lifetime was measured to be {tau}{sub {Lambda}{sub b}} {equals} 1. 32 {plus_minus} 0.08(stat.) {plus_minus} 0.05(syst.) ps, using a sample of 197 {plus_minus} 25 partially reconstructed semileptonic {Lambda}{sub b} {r_arrow} l{sup {minus}}{Lambda}{sub c}{sup {plus}}X decays, with {Lambda}{sub c}{sup {plus}} reconstructed from its decay to the pK{sup {minus}}{pi}{sup {plus}} final state. Using the same decay channels, the product branching ratios were measured to be f(b {r_arrow} {Lambda}{sub b})B({Lambda}{sub b} {r_arrow} {Lambda}J/{psi}) = 4.2{plus_minus}1.8(stat.){plus_minus}0.7(syst. ){times}10{sup {minus}5} and f(b {r_arrow} {Lambda}{sub b})B({Lambda}{sub b} {r_arrow} l{sup {minus}}{Lambda}{sub c}{sup {plus}}{ovr {nu}})B({Lambda}{sub c}{sup {plus}} {r_arrow} pK{sup {minus}}{pi}{sup {plus}}) {equals} 9.3{plus_minus}2.5(stat. ){plus_minus}{sup {plus}4.6}{sub {minus}4.0}(syst.){times}10{sup {minus}4}, where f(b {r_arrow} {Lambda}{sub b}) is the fraction of b quarks forming b baryons, and l is either an electron or a muon. 15 refs., 4 figs., 1 tab.
Date: September 1, 1996
Creator: Tkaczyk, S.
Partner: UNT Libraries Government Documents Department

Search for new exotic particles at CDF

Description: We present recent results of searches for new particles beyond the Standard Model at the Collider Detector at Fermilab (CDF). These include searches for heavy gauge bosons (Z{prime}, W{prime}), leptoquarks and stable massive charged particles. For most of these particles we set the currently most stringent limits. 15 refs., 7 figs.
Date: July 1, 1996
Creator: Wensel, H.
Partner: UNT Libraries Government Documents Department

Preliminary measurement of the inclusive jet and dijet cross section in {bar p}p collisions at {radical} s = 1.8 TeV

Description: We report on preliminary measurements of the central, |{eta}| {le} 0.5, inclusive jet and dijet cross sections at {radical}s = 1.8 TeV. Two data sets with integrated luminosities of 91 pb{sup {minus}1} and 14 pb{sup {minus}1} were collected at the Fermilab Tevatron p{ovr p} Collider with the D0 detector. The inclusive jet cross section measured with both data sets and reported as a function of transverse jet energy (35 GeV {le} E{sub T} {le} 470 GeV) and the dijet cross section measured with the 91 pb{sup {minus}1} data set and reported as a function of dijet mass (200 GeV {le} M{sub JJ} {le} 1 TeV) are in excellent agreement with next-to-leading order QCD. 11 refs., 5 figs.
Date: June 1, 1996
Creator: Blazey, G.C.
Partner: UNT Libraries Government Documents Department

Electroweak measurements from CDF and D0

Description: This paper highlights results from electroweak measurements recently obtained by the CDF and D0 collaborations in 1.8 TeV p{ovr p} collisions. The W decay width was extracted from the measurement of W/Z cross section times leptonic branching ratios, and in a direct measurement from a fit of the high-mass tail of the transverse mass spectrum of the W system. Various limits on anomalous gauge boson couplings were obtained in studies of W/Z + {gamma} processes, single leptonic WW, WZ production and double leptonic WW production. Values for {sigma}B(W{gamma}{r_arrow}l{nu}{gamma}), {sigma}B(Z{gamma}{r_arrow}l{sup +}l{sup -}{gamma}), and {sigma}(p{ovr p}{r_arrow}WW + X) were measured. CDF also reports on the observation of an asymmetry in photon rapidity distributions as predicted by the Standard Model. 17 refs., 2 figs., 1 tab.
Date: July 1, 1996
Creator: Neuberger, D. & Collaborations, CDF and D0
Partner: UNT Libraries Government Documents Department

Search for a fourth generation charge {minus}1/3 quark via flavor changing neutral currents

Description: There is some likelihood that a light (< m{sub t}) fourth generation charge -1/3 quark (b{prime}) would decay predominantly via loop induced flavor changing neutral currents. The charged current decay of b{prime} to charm would be highly Cabibbo suppressed due to the fact that it changes the generation number by two. The D0 experiment has searched for b{prime} pair production where one or both b{prime} quarks decays via b{prime} {r_arrow} b+{gamma}, giving signatures photon + three jets and two photons + two jets. WE don not see a significant excess of such events over background. In both modes, we set an upper limit on the cross section times branching ratio that is sufficient to rule out a standard sequential b{prime} decaying predominantly via FCNC in the mass range m{sub Z}/2 < m{sub b{prime}} < m{sub Z} + m{sub b}. For b{prime} masses larger than this, the dominant FCNC decay mode is expected to be b{prime} {r_arrow} b + Z. 14 refs., 13 figs., 5 tabs.
Date: July 1, 1996
Creator: D0 Collaboration
Partner: UNT Libraries Government Documents Department

Measurement of the t {anti t} cross section at D0

Description: We have measured the t{anti t} cross-section in p{anti p} collisions at {radical}s = 1.8 TeV using dilepton and single lepton final states. This analysis uses approximately 106 pb{sup -1} of data collected with the D0 detector at Fermilab during the 1992-1996 run. We observe 37 events with an expected background of 13.4 {+-} 3.4 events, giving {sigma}{sub t{anti t}} of 5.3 {+-} 1.8 pb for m{sub t} = 169 GeV. 4 refs., 1 fig., 1 tab.
Date: August 1, 1996
Creator: Kehoe, R.L.
Partner: UNT Libraries Government Documents Department

Polarized and unpolarized double prommpt photon production in next-to-leading order QCD

Description: We calculate O({alpha}{sub s}) corrections to inclusive and isolated double prompt photon production, both for the unpolarized case, and for longitudinal polarization of the incoming hadrons. The calculation is performed using purely analytical techniques for the inclusive case, and a combination of analytical and Monte Carlo techniques to perform the phase space integration in the isolated case. A brief phenomenological study is made of the process pp {r_arrow} {gamma}{gamma}X at CMS energies appropriate for the RHIC heavy ion collider. 21 refs., 8 figs.
Date: March 1, 1996
Creator: Coriano, C. & Gordon, L.E.
Partner: UNT Libraries Government Documents Department

Heavy quark results at D0

Description: Recent results in heavy quark physics from the D0 experiment at the Fermilab Tevatron Collider are reported. Topics included are top quark production and mass determination, bottom production and correlations, and charmonium production. 20 refs., 10 figs., 2 tabs.
Date: January 1, 1997
Creator: Fein, D.K.
Partner: UNT Libraries Government Documents Department

W and Z boson production with jets and inclusive jet production in p pbar collisions at square root s = 1.8TeV

Description: The production properties of jets produced in p{ovr p} collisions at {radical}s = 1.8 TeV have been measured using the CDF detector. The data are compared to predictions of leading order and next to leading order QCD predictions. Both inclusive jets and those produced in association with W and Z bosons are used for this analysis. In general, good agreement with QCD predictions is found except for very high E{sub t} inclusive jets. 10 refs., 7 figs., 2 tabs.
Date: August 1, 1996
Creator: Goshaw, A.T.
Partner: UNT Libraries Government Documents Department

The dijet mass spectrum with the D0 detector

Description: The authors present preliminary results from an analysis of dijet data collected during the 1994--1995 Tevatron Collider run with an integrated luminosity of 91 pb{sup {minus}1}. Measurements of dijet mass spectrum distributions in {anti p}p collisions at {radical}s = 1.8 TeV are compared with next-to-leading order QCD theory.
Date: September 1, 1996
Creator: Choi, S.
Partner: UNT Libraries Government Documents Department