55497708
Dilepton and Dihadron Production in Proton-Nucleus Collisions at 800 GeV *
A high statistics measurement of the atomic mass dependence of Drell-Yan, J/{psi}, {psi}{prime} and {Upsilon} production induced by 800 GeV protons on deuterium, carbon, calcium, iron and tungsten targets has been performed at FermiLab (E772). The data consist of about 700,000 muon pairs covering the mass region 3 GeV {le}M{mu}{mu} < 14 GeV. No nuclear modification is seen in the production of massive muon pairs in the Drell-Yan region for 0.1 < x{sub 2} < 0.3. The relative dimuon yield for fractional antiquark momentum x{sub 2} < 0.1 is slightly less than unity for heavy nuclei. J/{psi} and {psi}{prime} production are strongly suppressed in heavy nuclei. An upgraded version on the spectrometer designed to measure two-body decays of neutral c and b-quark hadrons (E789) will be discussed. 17 refs., 8 figs.
122682011
Magnetic field measurements of the initial Fermilab Main Injector production quadrupoles
A large sample of the 2.54-meter quadrupoles for lattice matching in the Fermilab Main Injector have been fabricated and measured. The resulting properties are reported and compared to the accelerator requirements.
42818936
Summary of the TeV 33 Working Group
This summary of the TeV33 working group at Snowmass reports on work in the areas of Tevatron store parameters, the beam-beam interaction, Main Injector intensity (slip stacking), antiproton production, and electron cooling. I. OVERVIEW OF TEV33 The goal of the TeV33 project is to develop a plan for the Fermilab Tevatron Collider beyond the year 2000 when the Main Injector project will be finished and collider Run II is expected to be well underway. The TeV2000 committee report [1] suggests a goal of 30 fb of proton-antiproton collisions at 2 TeV in the center of mass system by the year 2006. The physics potential of such a data sample is summarized in the committee’s report and is described in more detail in the report of the TeV2000 Study Group [2]. The goal of obtaining a sample of 30 fb of protonantiproton collisions is widely believed to be technically feasible, but it is uncertain whether it can be achieved within the likely fiscal and schedule constraints. An upgrade to a higher energy or a higher luminosity proton-proton collider is also technically possible but, based on performance, cost, and schedule considerations, is judged to be an unrealistic competitor for the Large Hadron Collider (LHC). The purpose of the TeV33 group and, in particular, the Snowmass study group, is to develop a realistic plan for TeV33 that can form the basis for future decisions. The TeV33 project assumes the successful completion of the Main Injector project and other upgrade projects that are associated with Run II. Some of the important elements of the Run II upgrade are: 1. Main Injector with both physical and dynamic apertures greatly exceeding those available with the existing Main Ring. 2. Antiproton recovery, including the construction of a “Recycler” ring in the Main Injector tunnel. 3. Antiproton source improvements in targeting and beam cooling. While the details of the TeV33 plan are not well defined, many of the major considerations are already clear. These are: 1. The antiproton production rate must be improved by about a factor of 5. 2. The antiproton cooling must be improved to accommodate the increased flux. The current plan is to use a. 4-8 GHz stochastic cooling in the existing Debuncher and Accumulator Rings, and b. electron cooling in the Recycler Ring. 3. The existing detector technology (with modest upgrades) must be capable of analyzing the collisions for rare processes. The important considerations for the accelerator are: a. Limiting the number of interactions per crossing to a sufficiently small value by using roughly 100 bunches in the Tevatron, b. Reducing the peak luminosity (luminosity leveling) to further reduce the number of interactions per crossing, and c. Maintaining low backgrounds. 4. The proton and antiproton beams must be kept well separated in the Tevatron except at the desired collision points to avoid the adverse effects of the beam-beam interaction. Obtaining adequate separation becomes increasingly difficult as the number of bunches is increased to 100 or more bunches. At Snowmass we developed some of the aspects of the TeV33 plan, but not all the important issues were covered. This paper is intended to report the work completed in conjunction with Snowmass study, and is not a balanced presentation of the current thinking on all the important elements of the TeV33 project. II. ELEMENTS OF TEV33 A. Tevatron Store Parameters The performance of a TeV33 scenario is determined by the average production rate of events that can be analyzed to study interesting physics processes. The study described below considered various initial store parameters and calculated the dependence of the integrated luminosity on several possible choices of parameters. The more delicate question of whether the events produced could be analyzed by a given detector was not considered. 1. The Luminosity Calculation It is straight-forward to calculate the luminosity (L) by integrating the beam phase-space distributions. A relatively compact expression can be obtained when the distributions are assumed to be gaussian in transverse and longitudinal positions. In this case the luminosity per interaction region is given by L = + ( ) − ( )   
45590013
Indication of pionic-atom anomalies in pion-nucleus elastic scattering.
Elastic cross sections for the scattering of positive and negative pions from /sup 58/Ni were measured at 30 MeV incident pion energy. Statistical errors of +- 3% and normalization errors of +- 6% were achieved. These data appear to confirm the theoretical construct that the physics which explains anomalously small shifts and widths in pionic atoms would be manifested in low energy pion-nucleus elastic scattering. The data show good agreement with the cross sections calculated assuming s and p partial waves are anomalous. Here anomalous refers to partial waves that are calculated from an optical potential which reproduces anomalously small level shifts and widths in pionic atoms. Conventional optical potentials do not agree as well with both the ..pi../sup +/ and ..pi../sup -/ data. Various conventional possibilities such as a larger neutron radius than proton radius in the nuclear density were tried, but these did not result in good agreement with the data.
54946396
Study of stability of beam in the Fermilab main injector
The Fermilab Main Injector is a new 150‐GeV proton synchrotron, designed to replace the Main Ring and improve the high energy physics potential of Fermilab. The status of the Fermilab accelerator complex upgrade will be discussed. Study of the stability of the beam in the Main injector will be discussed. Detuning and corrector schemes to improve the dynamic aperture of the Main Injector will be presented. Tune modulation caused by octupolar detuning will be discussed.
54609000
Strength and shape of the magnetic field of the Fermilab Main Injector dipoles
Measurements of 230 6-meter and 136 4-meter dipoles constructed for the Fermilab Main Injector were carried out as part of the magnet production effort. An automated measurement system provided data on magnetic field strength and shape using several partially redundant systems. Results of these measurements are available for each individual magnet for use in accelerator modelling. In this report we will summarise the results on all of the magnets to characterise the properties which will govern accelerator operation.
118292450
Radial infall of two compact objects: 2.5PN linear momentum flux and associated recoil
The loss rate of linear momentum from a binary system composed of compact objects (radially falling towards each other under mutual gravitational influence) has been investigated using the multipolar post-Minkowskian approach. The 2.5PN accurate analytical formula for the linear momentum flux is provided, in terms of the separation of the two objects, in harmonic coordinates, both for a finite and infinite initial separation. The 2.5PN formulas for the linear momentum flux are finally used to estimate the recoil velocity accumulated during a premerger phase of the binary evolution.