K. Hatakeyama

A precise determination of the energy scale of jets at the Collider Detector at Fermilab at the Tevatron pp¯ collider is described. Jets are used in many analyses to estimate the energies of partons resulting from the underlying physics process. Several correction factors are developed to estimate the original parton energy from the observed jet energy in the calorimeter. The jet energy response is compared between data and Monte Carlo simulation for various physics processes, and systematic uncertainties on the jet energy scale are determined. For jets with transverse momenta above 50 GeV the jet energy scale is determined with a 3% systematic uncertainty.

In this article, we review some of the complexities of jet algorithms and of the resultant comparisons of data to theory. We review the extensive experience with jet measurements at the Tevatron, the extrapolation of this acquired wisdom to the LHC and the differences between the Tevatron and LHC environments. We also describe a framework (SpartyJet) for the convenient comparison of results using different jet algorithms.

The CDF Plug Upgrade calorimeter, which fully exploits the tile–fiber technique, was tested at the Fermilab meson beamline. The calorimeter was exposed to positron, positively charged pion and positive muon beams with energies in the range of 5–230GeV. The energy resolution of the electromagnetic calorimeter to the positron beam is consistent with the design value of 16%/E⊕1%, where E is the energy in units of GeV and ⊕ represents sum in quadrature. The non-linearity for positrons is studied in an energy range of 11–181GeV. It is important to incorporate the response of the preshower detector, the first layer of the electromagnetic calorimeter which is readout separately, into that of the calorimeter to reduce the non-linearity to 1% or less. The energy scale is about 1.46pC/GeV with HAMAMATSU R4125 operated typically at a gain of 2.5×104. The response non-uniformity over the surface of a tower of the electromagnetic calorimeter is found to be about 2% with 57GeV positrons. Studies of several detailed detector characteristics are also presented.

A feasibility study is presented for the search of the lightest bottom squark (sbottom) in a compressed scenario, where its mass difference from the lightest neutralino is 5 GeV. Two separate studies are performed: $(1)$ final state containing two VBF-like tagging jets, missing transverse energy, and zero or one $b$-tagged jet; and $(2)$ final state consisting of initial state radiation (ISR) jet, missing transverse energy, and at least one $b$-tagged jet. An analysis of the shape of the missing transverse energy distribution for signal and background is performed in each case, leading to significant improvement over a cut and count analysis, especially after incorporating the consideration of systematics and pileup. The shape analysis in the VBF-like tagging jet study leads to a $3\sigma$ exclusion potential of sbottoms with mass up to $530 \, (462)$ GeV for an integrated luminosity of $300$ fb$^{-1}$ at 14 TeV, with $5\%$ systematics and PU $= 0 \, (50)$.

The experiments at Run 2 of the Tevatron have each accumulated over 1 inverse femtobarn of high-transverse momentum data. Such a dataset allows for the first precision (i.e. comparisons between theory and experiment at the few percent level) tests of QCD at a hadron collider. While the Large Hadron Collider has been designed as a discovery machine, basic QCD analyses will still need to be performed to understand the working environment. The Tevatron-for-LHC workshop was conceived as a communication link to pass on the expertise of the Tevatron and to test new analysis ideas coming from the LHC community. The TeV4LHC QCD Working Group focussed on important aspects of QCD at hadron colliders: jet definitions, extraction and use of Parton Distribution Functions, the underlying event, Monte Carlo tunes, and diffractive physics. This report summarizes some of the results achieved during this workshop.

The energy measurement of jets produced by b-quarks at hadron colliders suffers from biases due to the peculiarities of the hadronization and decay of the originating B hadron. The impact of these effects can be estimated by reconstructing the mass of Z boson decays into pairs of b-quark jets. From a sample of 584 pb-1 of data collected by the CDF experiment in 1.96 TeV proton-antiproton collisions at the Tevatron collider, we show how the Z signal can be identified and measured. Using the reconstructed mass of Z candidates we determine a jet energy scale factor for b-quark jets with a precision better than 2%. This measurement allows a reduction of one of the dominant source of uncertainty in analyses based on high transverse momentum b-quark jets. We also determine, as a cross-check of our analysis, the Z boson cross section in hadronic collisions using the b-bbar final state as sigma x B(Z->b-bbar) = 1578 +636 -410 pb.

We present a detailed examination of the heavy flavor properties of jets produced at the Fermilab Tevatron collider. The data set, collected with the Collider Detector at Fermilab, consists of events with two or more jets with transverse energy ET>~15GeV and pseudorapidity |η|<~1.5. The heavy flavor content of the data set is enriched by requiring that at least one of the jets (lepton-jet) contains a lepton with a transverse momentum larger than 8GeV/c. Jets containing hadrons with heavy flavor are selected via the identification of secondary vertices. The parton-level cross sections predicted by the HERWIG Monte Carlo generator program are tuned within theoretical and experimental uncertainties to reproduce the secondary-vertex rates in the data. The tuned simulation provides new information on the origin of the discrepancy between the bb¯ cross section measurements at the Tevatron and the next-to-leading order QCD prediction. We also compare the rate of away-jets (jets recoiling against the lepton-jet) containing a soft lepton (pT>~2GeV/c) in the data to that in the tuned simulation. We find that this rate is larger than what is expected for the conventional production and semileptonic decay of pairs of hadrons with heavy flavor.Received 2 December 2003DOI:https://doi.org/10.1103/PhysRevD.69.072004©2004 American Physical Society

Proceedings of ISMD08

This is the summary report of the energy frontier QCD working group prepared for Snowmass 2013. We review the status of tools, both theoretical and experimental, for understanding the strong interactions at colliders. We attempt to prioritize important directions that future developments should take. Most of the efforts of the QCD working group concentrate on proton-proton colliders, at 14 TeV as planned for the next run of the LHC, and for 33 and 100 TeV, possible energies of the colliders that will be necessary to carry on the physics program started at 14 TeV. We also examine QCD predictions and measurements at lepton-lepton and lepton-hadron colliders, and in particular their ability to improve our knowledge of strong coupling constant and parton distribution functions.

The experiments at Run 2 of the Tevatron have each accumulated over 1 fb{sup -1} of high-transverse momentum data. Such a dataset allows for the first precision (i.e. comparisons between theory and experiment at the few percent level) tests of QCD at a hadron collider. While the Large Hadron Collider has been designed as a discovery machine, basic QCD analyses will still need to be performed to understand the working environment. The Tevatron-for-LHC workshop was conceived as a communication link to pass on the expertise of the Tevatron and to test new analysis ideas coming from the LHC community. The TeV4LHC QCD Working Group focused on important aspects of QCD at hadron colliders: jet definitions, extraction and use of Parton Distribution Functions, the underlying event, Monte Carlo tunes, and diffractive physics. This report summarizes some of the results achieved during this workshop.

Three different methods of setting the hadronic energy scale of a longitudinally segmented calorimeter system are compared with each other. The merits of these methods have been studied with testbeam data from the CDF Plug Upgrade Calorimeter. It turns out that one of the (commonly used) calibration methods introduces a number of undesirable side effects, such as an increased hadronic signal nonlinearity and trigger biases resulting from the fact that the reconstructed energy of hadrons depends on the starting point of their showers. These problems can be avoided when a different calibration method is used. The results of this study are applied to determine the e/h values of the calorimeter and its segments.

A preshower detector consisting of plastic scintillating plates with optical-fiber readout was tested at the Fermilab meson beamline. The detector was placed at a depth of about 1.5X0, followed by an electromagnetic and hadronic calorimeter, and exposed to positron, positively charged pion and positive muon beams with energies in the range of 5–227 GeV. Multianode phototubes, HAMAMATSU R5900-M16, were used for the photon readout. The efficiency for detecting two minimum ionizing particles with noise occupancy of <1% was 90–100% for gains of (1–4)×105. It was also found that by requiring an appropriately large signal in the preshower detector, the rate of charged pions depositing a large fraction of energy in the electromagnetic calorimeter could be reduced by a factor of 1.4–2.0 (1.4–2.8) while keeping 95% (90%) efficiency for positrons.

All-IP networks, including next generation networks (NGNs), in which IP technology is used to integrate all services, are being studied or introduced in earnest worldwide. To support any services in all-IP networks, it is necessary to allocate both the computing resource (processing ability) and the network resource (bandwidth) simultaneously. This paper discusses congestion control schemes for all-IP based networks, based on the joint allocation of multiple types of resources. This paper first analyzes congestion control schemes used in existing services and networks, and proposes basic principles on congestion control for all-IP networks, assuming the joint allocation of multiple types of resources. Next, two schemes are proposed to materialized a part of basic principles. First scheme is a flexible resource reallocation scheme in which a part of network resources not fully used in one center are reallocated to other center. Second scheme is a smart request restriction scheme to ease the congestion, which does not restrict all requests uniformly but restricts only those requests that require a large amount of resource of the congested resource type. Finally, we demonstrate the effectiveness of the proposed schemes by numerical computation and simulation evaluations.

Two MiniPlug calorimeters, designed to measure the energy and lateral position of particles in the (forward) pseudorapidity region of 3.6<|η|<5.1 of the CDF detector, have been recently installed as part of the Run II CDF upgrade at the Tevatron p̄p collider. In this paper we describe the final design of the MiniPlugs and present results from a cosmic ray test, in which a light yield of approximately 100pe/MIP was obtained, exceeding our design requirements.

These reports present the results of the 2013 Community Summer Study of the APS Division of Particles and Fields ("Snowmass 2013") on the future program of particle physics in the U.S. Chapter 3, on the Energy Frontier, discusses the program of research with high-energy colliders. This area includes experiments on the Higgs boson, the electroweak and strong interactions, and the top quark. It also encompasses direct searches for new particles and interactions at high energy.

The use of RFID tag which identifies a thing and an object will be expanded with progress of ubiquitous society, and it is supposed that the various RFID-based services will be provided in the near future. Therefore, it is necessary to study how to construct RFID network system as a social infrastructure like the Internet. This paper proposes the virtualization method of RFID tag network system to enable the same physical RFID network system to be used by multiple different service systems. The system virtualization not only reduces the system cost but also can dramatically reduce the installation space of physical readers and the operation cost. It is proposed that all equipments in the RFID network system except radio tag could be shared with the conventional virtual technologies for servers or networks. It is also proposed to add two new identifiers, in order to improve user convenience in the infra-structured RFID network system. One is ‘system ID’ to keep the association between a virtual reader element and a physical RFID tag, and the other is ‘policy number’ that specifies the conditional tag ID processing.

2022年3月の福島県沖地震において，東北新幹線の2層式RCラーメン高架橋の中層梁損傷が広範囲で確認された．一般的に，2層式高架橋における中層梁損傷は，柱部の損傷低減に繋がるとされているが，当該地震で確認された中層梁の損傷モードはせん断破壊型であり，理想とするエネルギー吸収性能が発揮されていないといえる．また，中層梁損傷が高架橋の耐震性能に与える影響についての検討は過去に実施されているが，中層梁損傷が地震後の列車走行性に与える影響についての検討事例は見当たらない．そこで本研究では，構造物の耐震性能と社会へ提供されるサービス水準の定量的関係に関する検討の一例として，中層梁の損傷モードの違いに着目した数値解析を実施し，構造物の耐震性能と地震後の列車走行性に与える影響の定量化に向けた検証プロセスを示した．

EM-wave pyramidal-shaped absorbers produced by the traditional smoked roof-tile production process are introduced. In the smoking process, the carbon-coated layer having good electrical conductivity was formed on a dry-shaping pyramid surface made of roof tile clay. It has a superior long-term stability and thermal stability against high power incidence. In this paper, the absorption properties of the absorbers were measured. It is possible to improve the absorption property by controlling the surface resistance of the pyramids. The relationship between EM-wave absorption and surface conductivity are discussed. In addition, pyramidal-shaped absorbers in the millimeter region are developed.

Two MiniPlug calorimeters, designed to measure the energy and lateral position of particles in the pseudorapidity region of 3.6<|eta|<5.1 of the CDF detector, have been installed as part of the Run II CDF upgrade at the Tevatron collider. Detector performance and first results from $\bar pp$ collision data are presented.

Streaming media distribution services has been spreading rapidly, in which users view movies and music programs delivered over IP-based networks. In IP-based networks where resources are shared but cannot be reserved, it is difficult to prevent temporary congestion from occurring. Therefore, when temporary network congestion occurs, some packets will be discarded, resulting in the deterioration in the user's perceptual video quality. This paper first evaluates the relationship between packet discarding patterns and perceptual video quality is evaluated, assuming the delivery of UDP-based MPEG2 streaming videos. Based on the evaluation, this paper proposes the optimal packet discarding patterns which do not lead to any deterioration in the perceptual video quality and indicates that the perceptual video quality deterioration can be avoided by selecting an appropriate packet discarding pattern, if the total number of discarding packets is less than several percent of all packets being generated. The practical applicability of the proposed method is also examined.

Top quarks dominantly decay into b-quark jets and W bosons, and the W bosons often decay into jets, thus the precise determination of the jet energy scale is crucial in measurements of many top quark properties.I present the strategies used by the CDF and DØ collaborations to determine the jet energy scale.The various cross checks performed to verify the determined jet energy scale and evaluate its systematic uncertainty are also discussed.

The data processing model for the CDF experiment is described. Data processing reconstructs events from parallel data streams taken with different combinations of physics event triggers and further splits the events into datasets of specialised physics interests. The design of the processing control system makes strict requirements on bookkeeping records, which trace the status of data files and event contents during processing and storage. The computing architecture was updated to meet the mass data flow of the Run II data collection, recently upgraded to a maximum rate of 40 MByte/sec. The data processing facility consists of a large cluster of Linux computers with data movement managed by the CDF data handling system to a multi-petaByte Enstore tape library. The latest processing cycle has achieved a stable speed of 35 MByte/sec (3 TByte/day). It can be readily scaled by increasing CPU and data-handling capacity as required

collision data collected during the LHC Run 1 at the center-of-mass energy of p s = 7‐ 8 TeV. In this paper, a review of recent results from these searches are presented. Future prospects for these searches from the LHC experiments are also discussed.

Future experiments in high energy and nuclear physics may require large, inexpensive calorimeters that can continue to operate after receiving doses of 50 Mrad or more. The light output of liquid scintillators suffers little degradation under irradiation. However, many challenges exist before liquids can be used in sampling calorimetry, especially regarding developing a packaging that has sufficient efficiency and uniformity of light collection, as well as suitable mechanical properties. We present the results of a study of a scintillator tile based on the EJ-309 liquid scintillator using cosmic rays and test beam on the light collection efficiency and uniformity, and some preliminary results on radiation hardness.

A review is presented on studies of high $E_T$ jet production and production of photon, $W$ and $Z$ associated with jets from the HERA and Tevatron experiments. Such studies have been used to examine the Standard Model (SM) in the area of the strong interaction, Quantum Chromodynamics, at highest energies currently attainable in collider experiments, to extract values of the coupling of the strong interaction, to determine the parton distribution functions in the proton, and to provide constraints on SM processes that constitute background to the Higgs boson and new physics searches. Some of them are also directly sensitive to the presence of physics beyond the SM. Future prospects for results from the LHC experiments are discussed.

Recent measurements on the vector boson plus heavy-flavor jets production by the CDF and D0 experiments are presented in comparisons with recent theoretical predictions. Good understanding of such processes is important to improve our understanding of QCD and also to enhance the potential to search for yet-to-be-discovered new physics phenomena which lead to similar final states.

Recent searches for dijet, dielectron, and dimuon resonances by the CDF Collaboration are presented. No evidence for a signal is found in any channel, so 95% confidence level upper limits are set on the new particle production.

Recent results on diffractive dijet and vector boson production and exclusive dijet production from the Collider Detector at Fermilab (CDF) experiment are presented.

Recent results on diffractive dijet and vector boson production and exclusive dijet production from the Collider Detector at Fermilab (CDF) experiment are presented.

A review is presented on studies of high $E_T$ jet production and production of photon, $W$ and $Z$ associated with jets from the HERA and Tevatron experiments. Such studies have been used to examine the Standard Model (SM) in the area of the strong interaction, Quantum Chromodynamics, at highest energies currently attainable in collider experiments, to extract values of the coupling of the strong interaction, to determine the parton distribution functions in the proton, and to provide constraints on SM processes that constitute background to the Higgs boson and new physics searches. Some of them are also directly sensitive to the presence of physics beyond the SM. Future prospects for results from the LHC experiments are discussed.

Recent results on jet physics at the Fermilab Tevatron $p\bar p$ collider from the CDF Collaboration are presented. The main focus is put on results for the inclusive jet and dijet, $b\bar b$ dijet, $W/Z+$jets and $W/Z+b$-jets production.

Results on the inclusive b-jet production, Z + b-jet production, and b-jet production from W + b{bar b} process at the Tevatron are presented.

Recent results on jet physics at the Fermilab Tevatron $p\bar p$ collider from the CDF Collaboration are presented. The main focus is put on results for the inclusive jet and dijet, $b\bar b$ dijet, $W/Z+$jets and $W/Z+b$-jets production.

The data production for the CDF experiment is conducted on a large Linux PC farm designed to meet the needs of data collection at a maximum rate of 40 MByte/sec. We present two data production models that exploits advances in computing and communication technology. The first production farm is a centralized system that has achieved a stable data processing rate of approximately 2 TByte per day. The recently upgraded farm is migrated to the SAM (Sequential Access to data via Metadata) data handling system. The software and hardware of the CDF production farms has been successful in providing large computing and data throughput capacity to the experiment.

The data production for the CDF experiment is conducted on a large Linux PC farm designed to meet the needs of data collection at a maximum rate of 40 MByte/sec. We present two data production models that exploits advances in computing and communication technology. The first production farm is a centralized system that has achieved a stable data processing rate of approximately 2 TByte per day. The recently upgraded farm is migrated to the SAM (Sequential Access to data via Metadata) data handling system. The software and hardware of the CDF production farms has been successful in providing large computing and data throughput capacity to the experiment.

Results on rapidity gaps in pp collisions obtained by the CDF collaboration, in ep collisions by the ZEUS and H1 collaborations, and in e+e− collisions by the L3 collaboration are presented.

Experimental results of hard single diffraction and double pomeron exchange studies at the Fermilab Tevatron pp̄ collider are presented. Single diffraction results are compared with predictions from phenomenological models and expectations from results obtained in diffractive deep inelastic scattering experiments at the DESY ep collider HERA. Double pomeron exchange results are compared with corresponding single diffraction results to test factorization.

Let us consider the situation in which an electromagnetic wave is leaking through an aperture on a metallic box so that an electromagnetic field distribution is formed outside the box. By measuring the magnetic field distribution on the surface S1 near the box surface, the current distribution on the metallic box surface can be estimated (inverse analysis). Next, the electromagnetic field distribution on an arbitrary surface S2 outside the box can be predicted from the product of the above current distribution and a coefficient matrix (forward analysis). In this paper, the greatest likelihood estimation method is used for the inverse analysis. When the electromagnetic field distributions on surface S2 are predicted from the nearby magnetic field distribution by the inverse–forward analysis, there appear prediction error distributions that depend on the setting of the lattice meshes on surface S1, the box surface, and surface S2 in addition to the measurement errors. In this paper, the prediction error distributions dependent on the setting are obtained. In order to discuss the effectiveness of the above inverse–forward analysis, the magnetic field distribution on surface S1 where the measurement was carried out is derived by forward analysis from the current distribution on the box as a special case. The results are compared with the measured values. The comparison reveals good agreement. In order to consider the maximum electromagnetic interference level to obtain the maximum possible measurement error distribution, the distributions where all measurement points have the same value are assumed and the prediction error distributions are computed. Based on this assumption, the measurement error distribution is expressed in terms of the product of the unit matrix with the constant σ0, indicating the standard deviation of the measured error distribution (measurement error matrix). Then, the predicted error distribution of the electric field obtained by inverse–forward analysis is determined by the constant σ0 and the setting of the lattice meshes on surface S1, the box surface, and surface S2. Hence, if the maximum possible measurement error is assumed, the electromagnetic field distributions on an arbitrary surface can be computed with the associated prediction error. When some measure to reduce the leakage from a metal box is applied and its effect is studied, the prediction error distributions appear equally if the same lattice meshes as above are used in the measurement and calculations before and after such a provision is applied, and hence the effect of the error-reduction measure can be evaluated only from the electromagnetic distributions on the prediction surface S2. A model wave source simulating a metal box for electronic equipment with leakage was fabricated in an experiment. The magnetic field distribution near the model source was measured and the electromagnetic field distribution and its error distribution were predicted on a circular cylinder with a radius of 3.0 m. © 2000 Scripta Technica, Electron Comm Jpn Pt 2, 83(3): 39–52, 2000