107314581
Switchyard in the Main Injector era conceptual design report
This report presents elements of a design of the Switchyard and of the present fixed target beamlines in the era of the Main Injector (MI). It presumes that 800 GeV Tevatron beam will be transported to this area in the MI era, and permits it to share cycles with 120 GeV Main Injector beam if this option is desired. Geographically, the region discussed extends from the vicinity of AO to downstream points beyond which beam properties will be determined by the requirements of specific experiments. New neutrino lines not utilizing the present Switchyard (NuMI, BooNE) are not addressed. Similarly Main Injector beams upstream of AO are described fully in MI documentation and are unaffected by what is presented here. The timing both of the preparation of this report and of its recommendations for proceeding with construction relate to a desire to do required work in Transfer Hall and Enclosure B during the Main Injector construction shutdown (September 1997 - September 1998). As these areas are off-limits during any Tevatron operation, it is necessary for the fixed target program that work be completed here during this extended down period. The design presented here enables the operation of all beamlines in the manner specified in the current Laboratory plans for future fixed- target physics.
120121929
Characteristics of the radiation damage seen in the silicon microstrip detector of Fermilab experiment E771
The central region of the silicon microstrip detector used in Fermilab experiment E771 was subjected to a peak fluence of 9.5 × 1013 p/cm2 induced by 800 GeV protons over a two-month period. Fourteen 300 μm thick planes manufactured by Micron Semiconductor were operated at bias voltages ranging from 84 to 109 V. Analysis of data from low intensity beam triggers taken near the end of the run shows that the mean pulse height from our amplifiers began to decline at a fluence of approximately 2 × 1013 p/cm2 and fell to near zero by 6 × 1013 p/cm2. We show that the use of fast amplifiers contributed to this early loss of signal.
122051077
Results from experiments of crystal extraction of 900 GeV proton beams from the Tevatron Collider
The extraction of a small flux of primary protons from a collider in a parasitic manner is very attractive for a number of fixed target applications. The key requirements of the extracted beam are small average currents with relatively small temporal variations. At this time a bent crystal is installed in the Tevatron Collider which is designed to channel protons down an instrumented beam abort transfer line. In this paper the results of experiments with this crystal are presented. The impact on the high energy physics collider detectors of the crystal as a collimator and the transverse mechanism necessary to deposit the protons into the crystal for alignment purposes are described.
124276644
Cross sections for the reactions anti-p + p ---> pi-plus + pi-minus and k-plus + k-minus near 2 gev/c
38493149
Position Determination of High Energy Photons in Lead Glass
Two 25 element SF5 lead glass Cerenkov counter arrays have been used in the study of photon and ¿° production in pN collisions at Fermilab. The method used to identify shower patterns, and the determination of the position of the photon in the lead glass arrays in the energy range 2-32 GeV is presented. The method enables the spatial position of photons in this energy range width to be measured with a resolution of ¿ = 0.25 inches.
95691104
Preparing crystals for channeling experiments at high energies
Abstract On the basis of the experience of silicon crystal preparation for two Fermilab experiments on particle channeling (E761 and E853) the requirements for the crystal perfection for high energy physics experiments are discussed. Techniques which provide the cutting, orientation with high accuracy and test the quality of the initial and completed crystals are presented.
122070076
Muon trigger electronics for hadron collider experiments
Abstract Trigger electronics designed and constructed for the SDC muon system are described briefly and results of beam tests carried out at KEK are presented. The implementation is based on custom VLSI designs in 1.2 μm CMOS. The performance characteristics of the circuits were measured and confirmed to meet specifications. Designs based on this approach are applicable to future collider experiments.
110445102
Operating a production pilot factory serving several scientific domains
Pilot infrastructures are becoming prominent players in the Grid environment. One of the major advantages is represented by the reduced effort required by the user communities (also known as Virtual Organizations or VOs) due to the outsourcing of the Grid interfacing services, i.e. the pilot factory, to Grid experts. One such pilot factory, based on the glideinWMS pilot infrastructure, is being operated by the Open Science Grid at University of California San Diego (UCSD). This pilot factory is serving multiple VOs from several scientific domains. Currently the three major clients are the analysis operations of the HEP experiment CMS, the community VO HCC, which serves mostly math, biology and computer science users, and the structural biology VO NEBioGrid. The UCSD glidein factory allows the served VOs to use Grid resources distributed over 150 sites in North and South America, in Europe, and in Asia. This paper presents the steps taken to create a production quality pilot factory, together with the challenges encountered along the road.
172822549
Inclusive J / $\psi$ Production at D0
86860651
Theoretical constraints on additional Higgs bosons in light of the 126 GeV Higgs
A bstractWe present a sum rule for Higgs fields in general representations under SU(2)L × U(1)Y that follows from the connection between the Higgs couplings and the mechanism that gives the electroweak bosons their masses, and at the same time restricts these couplings. Sum rules that follow from perturbative unitarity will require us to include singly and doubly charged Higgses in our analysis. We examine the consequences of these sum rules for Higgs phenomenology in both model independent and model specific ways. The relation between our sum rules and other works, based on dispersion relations, is also clarified.
89614484
Searching for new physics in the three-body decays of the Higgs-like particle
A bstractWe show that the three-body decays of the resonance recently discovered at the LHC are potentially sensitive to effects of new physics. Even if the fully integrated partial decay widths are consistent with the minimal Standard Model there is information that is lost upon integration, which can be uncovered in the differential decay widths. Concentrating on the decay h → Zℓ$ \overline{\ell} $, we identify the regions in the three-body phase space in which these effects become especially pronounced and could be detected in future experiments.