The ATLAS collaboration will determine the absolute luminosity of the CERN LHC at Interaction Point 1 by measuring the trajectory of protons elastically scattered at very small angles (?rad). A scintillating fibre tracker system called ALFA (Absolute Luminosity For ATLAS) is proposed for this ...
NASA Astrophysics Data System (ADS)
The ATLAS collaboration plans to determine the absolute luminosity of the CERN LHC at Interaction Point 1 by measuring the trajectory of protons elastically scattered at very small angles (?rad). A scintillating fibre tracker system called ALFA (Absolute Luminosity For ATLAS) is proposed for ...
... Accession Number : AD0288016. Title : ABSOLUTE LUMINOSITY, SIZE, AND VELOCITY OF INDIVIDUAL LABORATORY MICROMETEORS. ...
DTIC Science & Technology
Measurements of luminosity obtained using the ATLAS detector during early running of the Large Hadron Collider (LHC) at sqrt{s} = 7 TeV are presented. The luminosity is independently determined using several detectors and multiple algorithms, each having different acceptances, systematic uncertainties and sensitivity to background. The ...
We are reporting about a scintillating fibre tracking detector which is proposed for the precise determination of the absolute luminosity of the CERN LHC at interaction point 1 where the ATLAS experiment is located. The detector needs to track protons elastically scattered under $\\mu$rad angles in direct vicinity to the ...
E-print Network
We are reporting about a scintillating fiber tracking detector which is proposed for a precise determination of the absolute luminosity of the CERN LHC at interaction point 1 where the ATLAS experiment is located. The detector needs to track protons elastically scattered under micro-radian angles in direct vicinity to the ...
After a number of years of operation at nominal parameters, the LHC will be upgraded to a higher luminosity. This paper discusses the possibility of using a limited number of Nb3Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgra...
National Technical Information Service (NTIS)
In this paper we discuss luminosity measurements at Tevatron and HERA as well as plans for luminosity measurements at LHC. We discuss luminosity measurements using the luminosity detectors of the experiments as well as measurements by the machine. We address uncertainties of the measurements, ...
DOE Information Bridge
The start of the Large Hadron Collider (LHC) is scheduled for the Summer 2008. The accelerator is going to provide unprecedented amount of proton-proton colli- sions with a record center-of-mass energy. The total number of collisions produced in an interaction point is directly connected to a collider characteristic called `absolute ...
The projected lifetime of the LHC low-beta quadrupoles and evolution of the statistical error halving time call for an LHC luminosity upgrade by the middle of the coming decade. In the framework of the EU CARE-HHH network, two scenarios have been developed for increasing the LHC peak luminosity ...
Luminosity in the LHC will depend critically on the alignment of the triplet quadrupoles. These quadrupoles are closest to the interaction points (IPs), have large gradients and the functions have their largest values within these quadrupoles. Within a tr...
Luminosity in the LHC will depend critically on the alignment of the triplet quadrupoles. These quadrupoles are closest to the interaction points (IPs), have large gradients and the {beta} functions have their largest values within these quadrupoles. Within a triplet, the cold masses of the Q1 and Q3 quadrupoles will be housed in separate cryostats while ...
Energy Citations Database
A novel segmented, multi-gap, pressurized gas ionization chamber is being developed for optimization of the luminosity of the LHC. The ionization chambers are to be installed in the front quadrupole and zero degree neutral particle absorbers in the high l...
The expected sensitivity of the LHC experiments to the discovery of the Higgs boson and the measurement of its properties is presented in the context of both the standard model and the its minimal supersymmetric extension. Prospects for a luminosity-upgra...
LUCID is the luminosity monitor of the LHC accelerator for the ATLAS experiment. Thanks to an intrinsically fast response and to its custom readout electronics, LUCID estimates the number of interactions per LHC bunch crossing and provides an interaction trigger to the experiment. The performance of LUCID is evaluated in the full ...
Richard Brenner � Uppsala University IKP Seminar � 4 April 2007 Impact of the LHC luminosity #12;Richard Brenner � Uppsala University IKP Seminar � 4 April 2007 Time to half errors Luminosity Luminosity upgrade based on new low- IR magnets around ~2014-2015 #12;Richard Brenner � Uppsala University IKP ...
Luminosity measurements at the high luminosity points of the LHC are very challenging due to the extremely high radiation levels in the order of 180 MGy/yr. They have designed an ionization chamber that uses a flowing inorganic gas mixture and a combination of metals and ceramics. With such a choice, an additional challenge is ...
The LHC detectors are well into their construction phase. The LHC schedule shows first beam to ATLAS and CMS in 2007. Because the LHC accelerator has begun to plan for a ten fold increase in LHC design luminosity (the SLHC or super LHC) it is none too soon to begin to think ...
The statistical limits on detectability of an anomalous chromomagnetic moment of a quark coupling to a gluon are projected to higher luminosities at the Tevatron at Fermilab, and to the LHC. They roughly scale as the energy, and are not strongly improved with increasing luminosity.
Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton luminosi...
After the LHC operates for several years at nominal parameters, it will be necessary to upgrade it for higher luminosity. Replacing the low-{beta} insertions with a higher performance design based on advanced superconducting magnets is one of the most straightforward steps in this direction. Preliminary studies show that, with magnet technology that is ...
The Luminosity Monitor for the LHC has been built at LBNL and will be operational in the LHC during the upcoming run. The device, a gas ionization chamber, is installed in the high luminosity regions (those dedicated to the ATLAS and CMS experiments) and capable to resolve bunch-by-bunch ...
In this paper we consider possible scenarios to upgrade the LHC luminosity beyond 1034 cm-2s-1. By pushing the accelerator parameters to the ultimate performance we can increase to 1.7 1011 the bunch population and eventually reach a peak luminosity of 2.3x1034 cm-2s-1. To go beyond, a considerable improvement of the ...
The LHC beam luminosity monitor is based on the following principle. The neutrals that originate in LHC at every PP interaction develop showers of minimum ionizing particles in the absorbers placed in front of the separation dipoles. The shower energy, me...
At design luminosity and inelastic cross section (sigma)(sub pp) = 80mb there are 8 (times) 10(sup 8) inelastic collisions per second at the high luminosity interaction points IP1 and IP5 of the LHC. These interactions give rise to (approximately) 0.9 kW ...
This paper provides an overview of the Tevatron Run II luminosity progress and plans, including SC magnet measurements and modeling of field errors in view of the LHC operation. It also discusses antiproton production, stacking and cooling.
The large cross-sections and luminosity expected at the LHC promise very large samples of W, Z and jet events. The resulting potential for improvement in the determination of the proton structure functions, in particular the gluon distributions, is presented. The implications for precision measurements and on discovery physics are discussed.
An upgrade of the LHC interaction regions could potentially increase the luminosity by a factor of two or more. Several IR layouts are presented. The challenges and open questions related to the optics design, energy deposition and magnet design are discussed.
Energy deposition in the superconducting magnets by particles from p- p collisions is a significant challenge for the design of the LHC high luminosity insertions. We have studies the dependence of the energy deposition on the apertures and strengths of i...
The 14 TeV center of mass proton-proton collisions in the LHC produce not only debris interesting for physics but also showers of particles ending up in the accelerator equipment, in particular in the superconducting magnet coils. Evaluations of this cont...
A number of issues for computing and data handling in the online in environment at future high-luminosity, high-energy colliders, such as the Superconducting Super Collider (SSC) and Large Hadron Collider (LHC), are outlined. Requirements for trigger proc...
The luminosity at the four interaction points of the Large Hadron Collider (LHC) must be continuously monitored in order to provide an adequate tool for the control and optimisation of beam parameters. Polycrystalline cadmium telluride (CdTe) detectors have previously been tested, showing their high potential to fulfil the requirements of ...
On December 14, 2009, the unprecedented reign of the Fermilab Tevatron as the world's highest energy collider ended after almost a quarter century, when the LHC successfully collided two beams of 1.18 TeV each. It soon reached its current energy of 3.5 TeV per beam, and over the next few years should reach the design energy of 7 TeV per beam and a ...
This document reviews some recent work on physics simulations for SSC/LHC. Included are reviews of some of the recent developments in physics simulations for the SSC/LHC and comments upon the requirements that are placed upon detectors by the need to extract specific physics signatures. The material in the various EOI/LOI documents submitted to the SCC ...
The expected sensitivity of the LHC experiments to the discovery of the Higgs boson and the measurement of its properties is presented in the context of both the standard model and the its minimal supersymmetric extension. Prospects for a luminosity-upgraded ''Super-LHC'' are also presented. If it ...
Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton luminosity for gg, u{bar d}, and qq interactions over the energy ...
ALFA is a high-precision scintillating fibre tracking detector under construction for the absolute determination of the LHC luminosity at the ATLAS interaction point. This detector, mounted in so-called Roman Pots, will track protons elastically scattered under ?rad angles at IP1.In total there are four pairs of vertically arranged ...
Results from irradiated detector modules assembled with sensors made out of standard p-in-n FZ silicon will be presented. The modules were read out using LHC speed front-end electronics and characterised with different techniques. Two complementary methods to generate the charge inside the sensor were used: An IR laser set-up with a wavelength of ?=982nm and a ? set-up ...
The development of silicon microstrip detectors for high luminosity application at the Large Hadron Collider (LHC) is described. The technical choices are most severely restricted by the anticipated radiation damage. A radiation-tolerant choice for the silicon tracker of the LHC detector ATLAS are sandwiches of single-sided detectors ...
The Large Hadron Collider (LHC) at CERN near Geneva is the world's newest and most powerful tool for Particle Physics research. It is designed to collide proton beams with a centre-of-mass energy of 14 TeV and an unprecedented luminosity of 1034 cm-2 s-1. It can also collide heavy (Pb) ions with an energy of 2.8 TeV per nucleon and a peak ...
Since previous BEAM'06 workshop a year ago, significant progress has been made in the field of beam-beam compensation (BBC)--it has been experimentally demonstrated that both Tevatron Electron Lenses (TEL) significantly improve proton and luminosity lifetimes in high-luminosity stores. This article summarizes these results and discusses prospects ...
This paper analyses possible D2 magnet designs for the 'dipole-first' option of the LHC luminosity upgrade based on Nb3Sn superconductor and compares them in terms of the maximum field, field quality, and Lorentz forces in the coils.
The relation between absolute optical luminosity and optical variability is examined for quasars. Broad categories of quasar theories lead to different expectations for this relation. The available data do not support any of the simple theories. Additional observations are suggested that would permit more restrictive theoretical inferences. ...
Methods to perform the absolute energy calibration of DELPHI's Small Angle Tagger luminosity calorimeters at LEP are presented and compared. The input was small angle Bhabha scattering events. A significant non-linearity in the response of the calorimeter...
, until now the Tevatron, in the near future the Large Hadron Collider (LHC) and beyond that its upgrades, the Super�LHC (SLHC) and the hypothetical Very Large Hadron Collider (VLHC). After LHC, both a luminosity to 28 TeV are being discussed (SLHC). An example of a design study for a Very Large Hadron Collider
The CERN Large Hadron Collider (LHC) started operation a few months ago. The machine will deliver proton-proton and nucleus-nucleus collisions at energies as high as = 14 TeV and luminosities up to ~ 1034 cm?2s?1 never reached before. The main open scientific questions that the seven LHC experiments - ATLAS, CMS, ALICE, LHCb, TOTEM, ...
We examine the potential of the pp?p?p?pWqX reaction to probe anomalous WW? couplings at the LHC. We find 95% confidence level bounds on the anomalous coupling parameters with various values of the integrated luminosity. We show that the reaction pp?p?p?pWqX at the LHC highly improves the current limits.
After the successful start of the Large Hadron Collider (LHC) in November 2009 plans for a luminosity upgrade, called super-LHC (sLHC), are already advancing well. With a planned luminosity of 5�1034cm?2s?1 the ATLAS detector has to cope with both a high instantaneous and integrated ...
The LHC will begin colliding lead nuclei at a nucleon-nucleon center of mass energy of 2.76 TeV in November, 2010. The luminosity during this first LHC heavy ion run is expected to be roughly one hundredth of the Pb+Pb �design� luminosity. The ATLAS experiment is prepared to carry out measurements during this ...
Modern colliders bring into collision a large number of bunches per pulse or per turn to achieve a high luminosity. The long-range beam-beam effects arising from parasitic encounters at such colliders are mitigated by introducing a crossing angle. Under these conditions, crab cavities (CC) can be used to restore effective head-on collisions and thereby to increase the ...
After a number of years of operation at nominal parameters, the LHC will be upgraded to a higher luminosity. This paper discusses the possibility of using a limited number of Nb{sub 3}Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgrades with both NbTi and Nb{sub 3}Sn quadrupoles. Magnet ...
After a number of years of operation at nominal parameters, the LHC will be upgraded for higher luminosity. This paper discusses the possibility of using a limited number of Nb{sub 3}Sn quadrupoles for hybrid optics layouts for the LHC Phase I luminosity upgrades with both NbTi and Nb{sub 3}Sn quadrupoles. Magnet ...
One of the straightforward ways towards the higher luminosity in the LHC is a replacement of the present 70-mm NbTi quadrupoles with Nb{sub 3}Sn quadrupoles which would provide the same field gradient but in a larger aperture. Conceptual designs of such quadrupoles with 90 mm aperture have been developed and studied. This paper discusses the possibilities ...
A novel, segmented, multi-gap, pressurized gas ionization chamber is being developed for optimization of the luminosity of the LHC. The ionization chambers are to be installed in the front quadrupole and zero degree neutral particle absorbers in the high luminosity IRs and sample the energy deposited near the maxima of the ...
In this paper we investigate the LHC potential for discovering doubly charged vector bileptons considering the measurable process p, p?e?e??�?�X. We perform the study using four different bilepton masses and three different exotics quark masses. Minimal LHC integrated luminosities needed for discovering and for setting limits on ...
LUCID (LUminosity measurement using Cherenkov Integrating Detector) is a Cherenkov counter designed to monitor the luminosity in the ATLAS experiment. Since the final accuracy of the measurement of some crucial physical quantities in the LHC program will depend on the precision of the luminosity measurement, it is ...
The luminosity upgrade of the Large Hadron Collider (LHC) at CERN to the Super LHC (sLHC) will increase the radiation dose at the experiments by roughly an order of magnitude. The elevated radiation levels require the LHC experiments to upgrade their tracking systems with extremely radiation ...
A Workshop on Low Energy Ring (LER) in the LHC tunnel as main injector was convened at CERN on October 11-12, 2006. We present the outline of the LER based on the presentations, and respond to the raised questions and discussions including the post-workshop studies. We also outline the possibility of using the LER accelerator technologies for the fast cycling injector ...
An upgrade of the large hadron collider (LHC), the Super-LHC (SLHC), towards higher luminosities is currently being discussed as an extension of the LHC physics program. The goal of the SLHC is to operate at a luminosity of 1035 cm?2 s?1 (10 times larger than that of the ...
We review the LHC luminosity progress in 2010, discuss the luminosity evolution of the Tevatron collider at different stages of the Collider Runs, emphasize general dynamics of the process, compare with the performance of the other colliders analyze planned and delivered luminosity integrals, and discuss the ...
Discoveries at the LHC will soon set the physics agenda for future colliders. This report of a CERN Theory Institute includes the summaries of Working Groups that reviewed the physics goals and prospects of LHC running with 10 to 300 fb{sup -1} of integrated luminosity, of the proposed sLHC ...
The Q0 scheme of the LHC insertion region is based on the introduction of a doublet of quadrupoles at 13 m from the IP. We present here the doublet optics and the magnets layout such as gradients, lengths, positions and apertures. In this scheme we show the gain in luminosity and chromaticity, with respect to a nominal layout with ...
Interaction region inner triplets are among the systems which may limit the LHC performance. An option for a new higher luminosity IR is a double-bore inner triplet with separation dipoles placed in front of the first quadrupole. The radiation load on the first dipole, resulting from pp-interactions, is a key parameter to determine the feasibility of this ...
One serious challenge for hadron calorimeters is setting the absolute calibration. Electromagnetic calorimeters in a magnetic spectrometer have the momentum of electrons to calibrate against. In addition, at hadron colliders, Z supplies a narrow resonance to determine calibrations. No such well-measured processes have been available in the past for hadron calorimeters. In high ...
We construct LHC signature footprints for four semirealistic string/M theory vacua with a minimal supersymmetric standard model visible sector. We find that they all give rise to limited regions in LHC signature space and are qualitatively different from each other for understandable reasons. We also propose a technique in which correlations of ...
The BEPCII Luminosity Monitor (BLM) monitors relative luminosity per bunch. The counting rates of gamma photons, which are proportional to the luminosities from the BLM at the center of mass system energy of the ? (3770) resonance, are obtained with a statistical error of 0.01% and a systematic error of 4.1%. ...
We study the collider phenomenology of sbottom�bino co-annihilation scenario at both the 7 TeV and 14 TeV LHC. This co-annihilation scenario requires that the NLSP sbottom and LSP bino masses are apart by no more than about 20% or so, and for M>M+M, the sbottom decays exclusively into b+?�10. We propose a search for sbottom pairs through bb� plus missing energy. By ...
Increasing the collider luminosity by replacing bunches having Gaussian line-charge distribution with flat bunches, but with same beam-beam tune shift at collision, has been studied widely in recent years. But, creation of 'stable' flat bunches (and their acceleration) using a multiple harmonic RF system has not been fully explored. Here, we review our ...
This LBNL report is a compilation of the 24 papers presented by Indoor Environment Department researchers and our collaborators at other institutions at the 8th International Conference on Indoor Air Quality & Climate (Indoor Air 99), held in Edinburgh, S...
The aim of the LHC workshop at Aachen was to discuss the 'discovery potential' of a high-luminosity hadron collider (the Large Hadron Collider) and to define the requirements of the detectors. Of central interest was whether a Higgs particle with mass bel...
The CDF and D0 experiments were able to set the tools for Higgs searches at the Teva- tron Collider already in Run I. While the luminosity foreseen for Run IIa is probably not enough to discover the Higgs, the Run IIb, which will allow each detector to co...
We present recent work performed in ATLAS on the SUSY mass measurement techniques by selecting exclusive decay chains as well as on the determination of SUSY model parameters with an integrated luminosity of 1 fb-1 at 14 TeV center of mass energy.
A overview of the ATLAS and CMS detectors and first physics results from the 2010 data taking campaign at the LHC collider is presented. Measurements with pp collisions at s=7TeV and for integrated luminosities reaching up to about 40 pb?1 are summarized for weak bosons and top quark production, as well as for the search of the Higgs Boson(s), ...
Challenging beam-induced energy deposition issues are addressed for the next generation of the LHC high-luminosity interaction regions based on Nb{sub 3}Sn quadrupoles. Detailed MARS15 Monte Carlo energy deposition calculations are performed for various coil diameters, thicknesses and materials of the inner absorber at a field gradient of 200 T/m. It is ...
When the LHC started running at the end of March 2010�after a 14-month shutdown for major repairs�one of the main objectives was reaching a luminosity of 1032 cm ? 2 s ? 1 by the end of 2010. On 13 October 2010 that goal was achieved. One important parameter to take into account to reach this luminosity is the number of protons ...
Measurements of distributions associated with the pair production of top quarks at the LHC can be used to constrain (or observe) the anomalous chromomagnetic dipole moment(k) of the top. For example, using either the tt(bar) invariant mass or the Pt distribution of top we find that sensitivities to ; k; of order 0.05 are obtainable with 100 /fb of integrated ...
We study the W/Z pair production via two-photon exchange at the LHC and give the sensitivities on trilinear and quartic gauge anomalous couplings between photons and W/Z bosons for an integrated luminosity of 30 and 200 fb{sup -1}. For simplicity and to obtain lower backgrounds, only the leptonic decays of the electroweak bosons are considered.
Algorithms are presented for the optimisation of the luminosity in pp and /SUP p/ p colliders. Their average luminosity is lower than the peak luminosity because the transverse dimensions of the beams increase due to intra-beam scattering, and the beam currents decay due to the collisions with the rest gas and the opposite beam. ...
The proposed High-Energy LHC project presents an unusual combination of strong synchrotron radiation damping and intrabeam scattering, which is not seen in present-day hadron colliders. The subject of investigation reported in this paper was the simulation of beam-beam effect for the HE-LHC parameters. Parameters of SR and IBS are calculated, and the ...
As a first step toward the development of a large-aperture Nb{sub 3}Sn superconducting quadrupole for the Large Hadron Collider (LHC) luminosity upgrade, two-layer technological quadrupole models (TQS01 at LBNL and TQC01 at Fermilab) are being constructed within the framework of the US LHC Accelerator Research Program (LARP). Both ...
jet spectroscopy. The dijet mass distribution for Z(120) events at HI luminosity is shown in Fig.5hep�ex/0402031 ################ 1 Fermilab�FN�0743 February 17, 2004 Mass Resolution Corrections at the LHC Dan Green Fermilab dgreen@fnal.gov Introduction The utility of jet spectroscopy at the LHC
The CMS experiment at LHC is planning a major upgrade to adapt to increases in luminosity. It will be achieved in two stages, with a long shutdown about ten years after start-up. The new tracker should cope with several hundred interactions per bunch crossing and fluxes of thousands of charged particles emerging from 40 MHz collisions. CMS has identified a ...
Double-aperture Nb{sub 3}Sn quadrupoles with asymmetric coils and with cold and warm iron yokes were studied for the dipole-first upgrade scenario of the LHC Interaction Regions (IR). This paper describes the magnet design concepts and discusses their performance parameters, including field gradient and field quality limitations.
Models with a nonuniversal Z' exhibit in general flavor changing neutral currents at tree-level. When the Z' couplings favor the third generation, flavor changing transitions of the form Z'tc and Z'tu could be large enough to be observable at the LHC. In this paper we explore this possibility using the associated production of a single top-quark with the Z' and find that ...
project, aiming for a peak luminosity L 1 (nbs) 1. The next machine is the Large Hadron Collider LHC at CERN, planned to come into operation in 2005. The last set of machines are Very Large Hadron Colliders of events in a collision to nc 13. 3 Large Hadron Collider LHC In this chapter on the Large Hadron Collider
For use at the future Super-LHC a new type of muon detector has been developed. It is based on the proven MDT drift tube design, but with tubes of half the diameter, leading to higher rate capabilities by an order of magnitude. We present test results on efficiency and position resolution at high background rates and describe the practical implementation in a real-size ...
This paper analyses possible D2 magnet designs for the dipole-first option of the LHC luminosity upgrade based on Nb3Sn superconductor and compares them in terms of the maximum field, field quality, and Lorentz forces in the coils.
A number of issues for computing and data handling in the online in environment at future high-luminosity, high-energy colliders, such as the Superconducting Super Collider (SSC) and Large Hadron Collider (LHC), are outlined. Requirements for trigger processing, data acquisition, and online processing are discussed. Some aspects of possible solutions are ...
Using the properties of RR Lyrae stars we have calibrated the Galactic Globular Cluster Luminosity Function (GCLF) and tested the constancy of itspeak absolute magnitude M_V(TO).
It is foreseen to increase the luminosity of the Large Hadron Collider (LHC) at CERN around 20I8 by about an order of magnitude, with the upgraded machine dubbed Super-LHC or sLHC. The ATLAS experiment will require a new tracker for sLHC operation. In order to cope with the order of magnitude ...
Recently DuPuy suggested that RV Tauri variables show evidence for approx.1.5 mag of nearly neutral extinction in the visual region. The suggestion is based upon an apparent discrepancy between photometric absolute magnitudes and spectroscopic luminosity classes. We have reexamined the evidence and conclude that no discrepancy exists if the ...
... Individual absolute magnitudes are available for only 2 Mira variables (X Oph and X Mon) in the northern sky, but the agreement of their values with ...
INTRODUCTION The CERN Large Hadron Collider will provide protonproton collisions with a centre of mass energy up to 14 TeV with a nominal luminosity of 10 34 cm -2 s -1 and heavy ion (Pb-Pb) collisions with a luminosity of up to 10 27 cm -2 s -1 . The reference design of the LHC has been presented at several conferences ...
We are developing n+-in-p, p-bulk and n-readout, microstrip sensors, fabricated by Hamamatsu Photonics, as a non-inverting radiation hard silicon detector for the ATLAS tracker upgrade at the super-LHC (sLHC) proposed facility. The bulk radiation damage after neutron and proton irradiations is characterized with the leakage current, charge collection and ...
The ATLAS experiment has completed its first data taking run in 2010 with proton-proton collisions at 7 TeV center of mass energy after accumulating about 45pb-1 of integrated luminosity, as well as about 10?b-1 of Pb-Pb collisions. After a winter shutdown, the LHC will resume running in about March of 2011, perhaps at slightly higher center of mass ...
Detailed MARS15 Monte Carlo energy deposition calculations are performed for two main designs of the LHC interaction regions (IR) capable to achieve a luminosity of 10{sup 35} cm{sup -2} s{sup -1}: a traditional quadrupole-first scheme and the one with a dual-bore inner triplet with separation dipoles placed in front of the quadrupoles. It is shown that ...
The US LHC Accelerator Research Program (LARP) is developing Nb{sub 3}Sn accelerator magnet technology for the LHC luminosity upgrade. Two 90 mm 'Technology Quadrupole' models (TQS01, TQC01) are being developed in close collaboration between LBNL and FNAL, using identical coil design, but two different support ...
Two proposals have been presented for the construction of super high luminosity B factories, the SuperB in Italy and SuperKEKB in Japan. We review the physics case for the construction of such facilities in the LHC era and highlight several topics of hadronic physics that can benefit from the high luminosity they will integrate. The ...
Electron-cloud instabilities are expected to be important in most high-luminosity double-ring colliders. In this report, the author describes a few parameter regimes and some critical parameter dependences of this type of instability, and illustrate these with simulation results for the PEP-II and KEK B factories, the LHC, the VLHC, and DAPHNE. In ...
Two linear accelerator projects CLIC (Compact Linear Collider) and ILC (International Linear Collider) with LHC (Large Hadron Collider) project offer a big opportunity to build ?p collider. In the ?p collider, high energy ? photons are produced by the Compton backscattering of the laser photons off high energy electrons at the conversion region. Backscattered ? photons are ...
A small angle (< 1 mrad) crab scheme is an attractive option for the LHC luminosity upgrade to recover the geometric luminosity loss from the finite crossing angle [I]. The luminosity loss increases steeply to unacceptable levels as the IP beta function is reduced below its nominal value (see Fig. 1 in Ref. ...
The LHC experiments will perform sensitive tests of physics phenomena beyond the Standard Model (BSM). Investigation of decays of beauty hadrons represents an alternative approach in addition to direct BSM searches. The ATLAS efforts concentrate on those B decays that can be selected already at the first and second trigger levels. The most favorable trigger signature will be ...
The front IR quadrupole absorbers (TAS) and the IR neutral particle absorbers (TAN) in the high luminosity insertions of the LHC each absorb approximately 1.8TeV of forward collision products on average per pp interaction ({approximately}235W at design luminosity 1034cm-2s-1). This secondary particle flux can be exploited to provide a ...
The LHC experiments rely on a proper and stable timing for the sampling of the detector signals and for the synchronization of the readout system. The LHC timing is distributed and received at the experiments by a system which is common to all experiments. The control and monitoring of the reception, and the integration into the overall experiment control ...
We investigate the implications for supersymmetry from an assumed absence of any signal in the first period of LHC data taking at 7 TeV center-of-mass energy and with 1 to 7fb-1 of integrated luminosity. We consider the zero-lepton plus four jets and missing transverse energy signature, and perform a combined fit of low-energy measurements, the dark matter ...
We present a detailed study of the anomalous top quark production with subsequent decay at the LHC induced by model-independent flavor-changing neutral-current couplings, incorporating the complete next-to-leading order QCD effects. Our results show that, taking into account the current limits from the Tevatron, the LHC with sqrt[s]=7??TeV may discover the ...
PubMed
We present a detailed study of the anomalous top quark production with subsequent decay at the LHC induced by model-independent flavor-changing neutral-current couplings, incorporating the complete next-to-leading order QCD effects. Our results show that, taking into account the current limits from the Tevatron, the LHC with s=7TeV may discover the ...
The LHC experiments will perform sensitive tests of physics beyond the standard model (BSM). The investigation of decays of beauty hadrons represents an alternative approach in addition to direct BSM searches. The ATLAS and CMS efforts concentrate on those B-decays that can be efficiently selected already at the first and second level trigger. The most favorable trigger ...
We present an analysis of cosmic muon data (taken with and without magnetic field) and LHC early beam data taken in late 2009. Cosmic ray results provide invaluable validation of initial calibration and offer the possibility of verification of the absolute energy scale of the calorimeter, while LHC beam data allows measurement of the ...
In this paper we will present an LHCb custom-made acquisition board which was developed for a continuous beam and background monitoring during LHC operations at CERN. The paper describes both the conceptual design and its performance, and concludes with results from the first period of beam operations at the LHC. The main purpose of the acquisition board ...
Associated production of a baryonic Z' boson with the W boson can account for the excess in Wjj production observed by the CDF Collaboration at the Tevatron. We analyze other possible channels of this Z' at the Tevatron and at the LHC, including ?Z' and ZZ' with Z'?jj. We show that the chances of confirming this baryonic Z' are better at the Tevatron than at the ...
The LHC-B Collaboration proposes to build a forward collider detector dedicated to the study of CP violation and other rare phenomena in the decays of Beauty particles. The forward geometry results in an average 80 GeV momentum of reconstructed B-mesons and, with multiple, efficient and redundant triggers, yields large event samples. B-hadron decay products are efficiently ...
The work described in this thesis was developed, implemented and completely put in operations during the first year of physics data taking at the LHC. It is shown here that it is aimed at studying beam and background characteristics, monitor the global timing of the experiment, monitor online the luminosity at LHCb and monitor most the experimental ...
The LHC beam luminosity monitor is based on the following principle. The neutrals that originate in LHC at every PP interaction create showers in the absorbers placed in front of the cryogenic separation dipoles. The shower energy, as it can be measured by suitable detectors in the absorbers is proportional to the number of neutral ...
We discuss an extended standard model electroweak sector which contains a stable scalar dark matter particle, the D boson. To search for the D boson at the LHC we exploit the flavor-changing neutral current top quark decay, t?cDD, mediated by the lightest standard model-like Higgs h0 in a two Higgs doublet model framework. The branching ratio for t?cDD in this case can be as ...
We present the results of a study of Higgs triplet boson production arising in the littlest Higgs, left-right symmetric, and Georgi-Machacek models in the W�W�, W�Z, W+W-, and ZZ channels at the LHC. We focus on the �gold-plated� purely leptonic decay modes and consider the irreducible electroweak, QCD, and t-quark backgrounds, applying a combination of forward-jet ...
Experience at high luminosity hadron collider experiments shows that tracking information enhances the trigger rejection capabilities while retaining high efficiency for interesting physics events [1]. The design of a tracking based trigger for Super LHC (S-LHC), the high luminosity upgrade of the ...
Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I quantify the advantage of increasing the beam energy from 3.5 TeV to 4 TeV. I present parton luminosities, ratios of parton luminosities, and contours of fixed parton ...
Extending the frontiers of experimental high energy physics in a manner that maximizes discovery potential requires the building accelerators of ever higher particle energies and luminosities. Both hadron and e{sup +}e{sup {minus}} colliders have been proposed for this role. Based on a self-consistent computational model, this paper explores the features of hadron ...
Extending the frontiers of experimental high energy physics in a manner that maximizes discovery potential requires the building of accelerators of ever higher particle energies and luminosities. Both hadron and e(+)e(-) colliders have been proposed for this role. Based on a self-consistent computational model, this paper explores the features of hadron supercolliders beyond ...
The muon detectors of the experiments at the Large Hadron Collider (LHC) have to cope with unprecedentedly high neutron and gamma ray background rates. In the forward regions of the muon spectrometer of the ATLAS detector, for instance, counting rates of 1.7kHz/cm2 are reached at the LHC design luminosity. For ...
Two developments over the past decade have made it possible to design a high-luminosity 100 TeV hadron collider in the SSC tunnel in Texas. First, superconducting magnet technology has matured so that it is now feasible to build 16 Tesla Nb3Sn dipoles and 450 T/m quadrupoles for a collider lattice. Second, Fermilab has advanced the state of art of antiproton sources so that it ...
We demonstrate that there are regions of parameter space in the next-to-minimal (i.e. two-Higgs-doublet, one-Higgs-singlet superfield) supersymmetric extension of the SM for which none of the Higgs bosons are observable either at LEP2 with $\\sqrt{s}=192 GeV$ and an integrated luminosity of $L=1000inverse pb$ or at the LHC with $L=600 inverse fb$.
The two-photon exclusive production of charged supersymmetric pairs at the LHC has a clean and unique signature-two very forward scattered protons and two opposite charged leptons produced centraly. For low-mass SUSY scenarios, significant cross-sections are expected and background processes are well controlled. Measurement of the forward proton energies would allow for mass ...
The Large Hadron Collider (LHC) offers unprecedented opportunities to study in detail interactions in the unexplored energy range around 1 TeV, where new physical phenomena undoubtedly exist. The luminosity expected in the first year of LHC operation will make it possible to thoroughly tune and calibrate physical facilities, clear up ...
In November and December 2009, the LHC delivered the first proton�proton collisions with beams of 450 GeV and then of 1.18 TeV, an unprecedented energy. On the 30th of March 2010, LHC operation moved forward to the physics era with collisions at a 7 TeV center of mass energy and, by the time of the IPRD10 conference, an integrated ...
At the startup of the LHC, the CMS data acquisition is expected to be able to sustain an event readout rate of up to 100 kHz from the Level-1 trigger. These events will be read into a large processor farm which will run the 'High-Level Trigger'(HLT) selection algorithms and will output a rate of about 150 Hz for permanent data storage. In this report HLT ...
At the startup of the LHC, the CMS data acquisition is expected to be able to sustain an event readout rate of up to 100 kHz from the Level-1 trigger. These events will be read into a large processor farm which will run the ``High-Level Trigger'' (HLT) selection algorithms and will output a rate of about 150 Hz for permanent data storage. In this report HLT performances are ...
Detectors based on the bulk-Micromegas technology exhibit position resolution better than 100 ?m at counting rates of up to several tens of kHz/cm2, along with trigger capabilities. These characteristics, combined with the detector's mechanical robustness and the possibility for cost-effective industrial production, makes them a promising candidate for the ATLAS Muon Spectrometer upgrade in a ...
This paper discusses the status of the two colliders at CERN near Geneva, Switzerland. The electron-positron collider LEP2 now operates above the threshold for W{sup {plus_minus}} pair production. The Large Hadron Collider Project LHC, a proton-proton collider with a planned luminosity of 10nb{sup {minus}1}s{sup {minus}1} at a centre-of-mass energy of 14 ...
Solid state detectors play a fundamental role in particle physics providing precision vertex detection, identification of heavy quarks and leptons, and momentum measurement. The status of the LHC experiments will be reviewed including their performance and the lesson that we have learned from their construction. The development of extremely radiation hard sensors, for the ...
Results of studies on the capabilities of the ATLAS detector to measure Bs0 oscillations in pp interactions at the Large Hadron Collider (LHC) are presented. For these studies, Bs0 candidates in the Ds-?+ and Ds- a1+ decay modes from semileptonic events were fully simulated and reconstructed, using a detailed detector description. The sensitivity and the expected accuracy for ...
We define a CP-asymmetric observable that is sensitive to CP-violating interactions in the gauge-boson sector. We illustrate the utility of this observable by studying how well the LHC can measure the coefficient of a particular dimension-six WWZ operator. We find that sensitivity at the 10{sup -3} level is possible at the LHC with 100 fb{sup -1} of ...
In this paper, we present the results of our analysis of the growth and decay of black holes possibly produced at the Large Hadron Collider, based on our previous study of black holes in the context of the warped brane-world scenario. The black hole mass accretion and decay is obtained as a function of time, and the maximum black hole mass are obtained as a function of a critical mass parameter. ...
In preparation for the LHC luminosity upgrades, high field and large aperture Nb{sub 3}Sn quadrupoles are being studied. This development has to incorporate all the relevant features for an accelerator magnet like alignment and cooling channels. The LARP HQ model is a high field and large bore quadrupole that will meet these requirements. The 2-layer coils ...
For the unprecedentedly high radiation level at the sLHC, the luminosity upgrade of the LHC, new tracking detectors are investigated. Among different approaches, silicon detectors in 3D technology constitute a promising option. Columnar electrodes are etched into the substrate, therefore the distance for charge collection and depletion ...
We study the sensitivity of the Tevatron and the 7 TeV LHC to a leptoquark S coupling to a top quark and a charged lepton L (=e, ?, or ?). For the Tevatron, we focus on the case mSmt, we show ...
A solution to the PAMELA positron excess with Higgsino dark matter within extended supergravity grand unified (SUGRA) models is proposed. The models are compliant with the photon constraints recently set by Fermi-LAT and produce positron as well as antiproton fluxes consistent with the PAMELA experiment. The SUGRA models considered have an extended hidden sector with extra degrees of freedom which ...
Models with a nonuniversal Z{sup '} exhibit in general flavor changing neutral currents at tree-level. When the Z{sup '} couplings favor the third generation, flavor changing transitions of the form Z{sup '}tc and Z{sup '}tu could be large enough to be observable at the LHC. In this paper we explore this possibility using the associated ...
We investigate the prospects of supersymmetry searches at the LHC with 7 TeV energy. A new set of selection cuts is proposed based on event shapes to control backgrounds. Our preliminary studies show that it is possible to minimize backgrounds to a significantly low level and a conservative estimate suggests that the mass reach can be extended to �1.1TeV for ...
We explore the potential for discovery of an exotic color sextet scalar in same-sign top quark pair production in early running at the LHC. We present the first phenomenological analysis at colliders of color sextet scalars with full top quark spin correlations included. We demonstrate that one can measure the scalar mass, the top quark polarization, and confirm the scalar ...
Cooling intense high-energy hadron beams poses a major challenge for modern accelerator physics. The synchrotron radiation emitted from such beams is feeble; even in the Large Hadron Collider (LHC) operating with 7 TeV protons, the longitudinal damping time is about 13 hours. None of the traditional cooling methods seem able to cool LHC-class protons ...
The anomalous top quark interactions with gluon (tug, tcg) allow the production of single top quarks at the Large Hadron Collider (LHC). Using the angular distribution of the charged lepton from the W boson in the top decay, we show that with the data of 10 fb?1 of integrated luminosity and in the collisions with the center of mass energy of 14 TeV, the ...
This work reports a Monte Carlo study of ?++ resonance production and decay in p-p collisions at sqrt{{s}} = 10 TeV. For this study case, the ALICE detector at the LHC collider has been chosen. The ?++ ? ? p decay is studied using a simulation of the full ALICE detector response. Special care is taken to extract the signal using the event-mixing technique for background ...
The Pixel Luminosity Telescope (PLT) is a dedicated luminosity monitor, presently under construction, for the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC). It measures the particle flux in several three layered pixel diamond detectors that are aligned precisely with respect to each other and the beam ...
This paper investigates the use of switching converters for the power supply distribution to calorimeters in the ATLAS experiment when the Large Hadron Collider (LHC) will be upgraded beyond the nominal luminosity. Due to the highly hostile environment the converters must operate in, all the main aspects are considered in the investigation, from the ...
We summarize the physics case of a high-luminosity e{sup +}e{sup -} flavor factory collecting an integrated luminosity of 50 - 75 ab{sup -1}. Many New Physics sensitive measurements involving B and D mesons and {tau} leptons, unique to a Super Flavor Factory, can be performed with excellent sensitivity to new particles with masses up to {approx} 100 (or ...
Beam-induced energy deposition in the LHC high luminosity interaction region components is one of the serious limits for the machine performance. The results of further optimization and comprehensive MARS14 calculations in the IP1 and IP5 inner and outer triplets are summarized for the updated lattice, calculation model, baseline pp-collision source term, ...
The limitation of the luminosity lifetime in high energy heavy ion colliders like RHIC or LHC operating in ion mode is set by the very large cross section of beam - beam interactions. One of the dominant processes at relativistic energies is electron capture from pair production in the strong electromagnetic field provided by the high Z of the ions. The ...
In support of the Large Hadron Collider luminosity upgrade, a large bore (120 mm) Nb{sub 3}Sn quadrupole with 15 T peak coil field is being developed within the framework of the US LHC Accelerator Research Program (LARP). The 2-layer design with a 15 mm wide cable is aimed at pre-stress control, alignment and field quality while exploring the magnet ...
We study the detectability of the lightest CP-odd Higgs boson of the next-to-minimal supersymmetric standard model (NMSSM), a1, at the LHC through its production in association with a bottom-quark pair followed by the a1?b&bmacr; decay. It is shown that, for large tan?? and very high luminosity of the LHC, there exist regions of ...
The coupling of unparticles to the Standard Model (SM) Higgs boson leads to a breaking of conformal symmetry which produces an effective mass term in the unparticle propagator. Simultaneously, the unparticle couplings to other SM fields produces an effective unparticle decay width via one-loop self-energy graphs. The resulting unparticle propagator then leads to a rather unique appearance for the ...
We carry out an analysis of the potential of the Large Hadron Collider (LHC) to discover supersymmetry in runs at s=7TeV with an accumulated luminosity of (0.1-2)fb-1 of data. The analysis is done with both minimal supergravity and supergravity models with nonuniversal soft breaking. Benchmarks for early discovery with (0.1-2)fb-1 of data are given. We ...
Using as basic observable an angular-integrated asymmetry to be measured in Drell-Yan lepton-pair production at the LHC, we discuss the identification reach on the spin-2 of the lowest-lying Randall-Sundrum resonance predicted by gravity in one warped extra dimension, against the spin-1 and spin-0 hypotheses. Numerical results indicate that, depending on the graviton coupling ...
The single and central diffractive production of the Standard Model Higgs boson is computed using the diffractive factorization formalism, taking into account a parametrization for the Pomeron structure function provided by the H1 Collaboration. We compute the cross sections at NLO accuracy for the gluon fusion process, since it is the leading mechanism for the Higgs boson production. The gap ...
We examine resonant slepton production at the LHC with gravitinos in the final state. The slepton undergoes gauge decay into a neutralino and a lepton, the neutralino decays into a photon and a gravitino. By measuring the transverse masses of the ?G~ and the l?G~ subsystems it is possible to accurately reconstruct both the slepton and the neutralino masses. In some regions of ...
The upgrade of the ATLAS experiment for the High Luminosity LHC (HL-LHC) will include a new pixel detector. A completely new detector control system (DCS) for this pixel detector will be required in order to cope with the substantial increase in radiation at the HL-LHC. The DCS has to have a very high reliability ...
Triply heavy baryons are very interesting hadrons to be explored for they provide particular information about strong interactions, hadron structures, and weak decays of heavy baryons. We calculate the hadronic production cross sections of the ? ccc and the ? ccb , which are dominated by the gg fusion subprocesses containing 4362 and 1454 Feynman diagrams, respectively. A method for generating ...
We investigate the possibility of probing high reheating temperature scenarios at the LHC, in supersymmetric models where the gravitino is the lightest supersymmetric particle, and the stau is the next-to-lightest supersymmetric particle. In such scenarios, the big-bang nucleosynthesis and the gravitino abundance give a severe upper bound on the gluino mass. We find that, if ...
One of the luminosity limitations of the LHC is the rather low injection energy (0.45 TeV) with respect to the collision energy (7 TeV). The magnetic multipoles in the main dipoles at low field and their dynamic behavior are considered to limit the achievable bunch intensity and emittance. We report on a preliminary study to increase the injection energy ...
The planned luminosity upgrade to LHC is likely to necessitate a large crossing angle and a local crab crossing scheme. For this scheme crab cavities align bunches prior to collision. The scheme requires at least four such cavities, a pair on each beam line either side of the interaction point (IP). Upstream cavities initiate rotation and downstream ...
Amongst all the modifications of the PS Complex to produce the LHC ion beams, the conversion of the old Low-Energy Antiproton Ring into the Low-Energy Ion Ring (LEIR) is a major issue. The accumulation in LEIR of 9�108 lead ions in normalized transverse emittances of 0.7?m allows the production of 4 of the 592 bunches needed in one LHC ring, in one LEIR ...
We compute the rapidity distributions of W and Z bosons produced at the Tevatron and the LHC through next-to-next-to leading order in QCD. Our results demonstrate remarkable stability with respect to variations of the factorization and renormalization scales for all values of rapidity accessible in current and future experiments. These processes are therefore ...
We perform a detailed parton level study on the feasibility of the detection of a Higgs boson in the gluon fusion process pp( gg + gq) ? h + jet ? ?+?- + jet at the Large Hadron Collider (LHC) for ? s = 14 TeV. The obtained results are applied to a few chosen Beyond the Standard Model (BSM) scenarios where the branching ratio of a Higgs boson decaying into a ?+?? pair is ...
A luminosity upgrade of the CERN Large Hadron Collider (LHC) is planned to coincide with the expected end of life of the existing inner triplet quadrupole magnets. The upgraded inner triplet will have much larger heat loads to be removed from the magnets by the cryogenics system. A number of cryogenics design studies have been completed under the ...
The 14 TeV center of mass proton-proton collisions in the LHC produce not only debris interesting for physics but also showers of particles ending up in the accelerator equipment, in particular in the superconducting magnet coils. Evaluations of this contribution to the heat, that has to be transported by the cryogenic system, have been made to guarantee that the energy ...
Electromagnetic interactions of high-energy nuclei in ultraperipheral collisions are considered. Such collisions, which take place without any overlap of nuclear densities, can be considered as irradiation of nuclei by intense photon beams with a broad energy spectrum. This leads to several unusual phenomena, such as mutual electromagnetic excitation of nuclei, including exotic double and triple ...
Silicon strip detectors are widely used as part of the inner tracking layers in particle physics experiments. For applications at the luminosity upgrade of the Large Hadron Collider (LHC), the sLHC, silicon detectors with extreme radiation hardness are required. The 3D detector design, where electrodes are processed from underneath the ...
We investigate the LHC discovery potential of R-parity violating supersymmetric models with a right-handed selectron or smuon as the lightest supersymmetric particle. These particles arise naturally in R-parity violating minimal supergravity models. We classify the hadron collider signatures and perform for the first time within these models a detailed signal over background ...
Even though CERN's Large Hadron Collider (LHC) is mainly conceived to accelerate protons, a heavy ion physics program is also foreseen. In order to reach the luminosity required for LHC, the ion accelerator chain needed to be upgraded, and a central part is the new Low Energy Ion Ring (LEIR). Its role is to transform a series of long, ...
We investigate a neutrino mass model in which the neutrino data is accounted for by bilinear R-parity violating supersymmetry with anomaly mediated supersymmetry breaking. We focus on the CERN Large Hadron Collider (LHC) phenomenology, studying the reach of generic supersymmetry search channels with leptons, missing energy and jets. A special feature of this model is the ...
At the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), for example, virtual photons produce many particles. At small impact parameters where the colliding nuclei make peripheral collisions, photon fluxes are very large and these are responsible for the multiple photonuclear interactions. Free pair productions, bound free pair productions, and ...
In support of the Large Hadron Collider (LHC) luminosity upgrade, the US LHC Accelerator Research Program (LARP) has been developing a 1-meter long, 120 mm bore Nb{sub 3}Sn IR quadrupole magnet (HQ). With a design short sample gradient of 219 T/m at 1.9 K and a peak field approaching 15 T, one of the main challenges of this magnet is ...
With an expected 10-fold increase in luminosity in S-LHC, the radiation environment in the tracker volumes will be considerably harsher for silicon-based detectors than the already harsh LHC environment. Since 2006, a group of CMS institutes, using a modified CMS DAQ system, has been exploring the use of Magnetic Czochralski silicon as ...
ATLAS is a general purpose experiment at the Large Hadron Collider (LHC) at CERN which began operation in September, 2009. ATLAS has a large muon spectrometer which is designed to measure muon momentum with a resolution ranging from 3% at 100 GeV/c to 10% at 1 TeV for a pseudorapidity range of 0-2.7. In this paper, we describe the derivation and validation of calibration ...
The possibility of distinguishing between two Higgs boson production mechanisms, {ital W} fusion and gluon fusion, due to rapidity gap existence is investigated using the Monte Carlo event generator PYTHIA. It is shown that, considering the designed c.m. energy and luminosity for the CERN LHC, it is not possible to distinguish between the two Higgs boson ...
The Large Hadron Collider (LHC) is expected to undergo upgrades in two phases in next decade. Luminosity at the completion of the second phase is expected to increase by an order of magnitude to 1035/cm2 s. The upgrade of the CMS Hadron Calorimeter (HCAL) is being planned to sustain an increased dose of radiation and challenges arising from occupancy rate ...
The Tevatron in Collider Run II (2001-present) is operating with six times more bunches, many times higher beam intensities and luminosities than in Run I (1992-1995). Beam diagnostics were crucial for the machine start-up and the never-ending luminosity upgrade campaign. We present the overall picture of the Tevatron diagnostics development for Run II, ...
One of the possible practical applications of the Nb{sub 3}Sn accelerator magnets is the LHC luminosity upgrade that involves replacing the present NbTi focusing quadrupoles in two high-luminosity interaction regions (IR). The IR magnets are exposed to strong radiation from the interaction point that requires a detailed investigation ...
We discuss the physics opportunities and detector challenges at future hadron colliders. As guidelines for energies and luminosities we use the proposed luminosity and/or energy upgrade of the LHC (SLHC), and the Fermilab design of a Very Large Hadron Collider (VLHC). We illustrate the physics capabilities of future hadron colliders ...
Over the past 2 years the Tevatron peak luminosity steadily progressed and reached the level of 3.15 {center_dot} 10{sup 32} cm{sup -2} s{sup -1} which exceeds the Run II Upgrade goal. We discuss the collider performance, illustrate limitations and understanding of beam-beam effects and present experimental results of compensation of the beam-beam effects by electron lenses--a ...
Crab cavities may be used improve the luminosity in colliding beam colliders with crab crossing. In a global crab crossing correction, only one crab cavity is installed in each ring and the crab cavities generate a horizontally titled bunch oscillating around the ring. The electron cloud in positively charged rings may distort the crabbed bunch and cause the ...
The Run II era at Fermilab began in March 2001. Many changes to the accelerator complex were made to support the Tevatron proton-antiproton collider operation with peak luminosities of 2-4 x 10{sup 32} cm{sup -2} s{sup -1} while delivering greater than 5 fb{sup -1} of integrated luminosity before the LHC begins its physics program. ...
The front IR quadrupole absorbers (TAS) and the IR neutral particle absorbers (TAN) in the high luminosity insertions of the Large Hadron Collider (LHC) each absorb approximately 1.8 TeV of forward collision products on average per pp interaction (~;;235W at design luminosity 1034cm-2s-1). This secondary particle flux can be exploited ...
We study the relation between the mass accretion rate, the jet power, and the black hole mass of blazars. To this aim, we make use of the Sloan Digital Sky Survey (SDSS) and the 11 months catalog of blazars detected at energies larger than 100 MeV by the Large Area Telescope (LAT) onboard the Fermi satellite. This allows to construct a relatively large sample of blazars with information about the ...
We consider direct experimental verification of warped models, based on the Randall-Sundrum (RS) scenario, that explain gauge and flavor hierarchies, assuming that the gauge fields and fermions of the Standard Model (SM) propagate in the 5D bulk. Most studies have focused on the bosonic Kaluza Klein (KK) signatures and indicate that discovering gauge KK modes is likely possible, yet challenging, ...
Bosons Models with two general purpose detectors of the Large Hadron Collider (LHC) at the European #12;Beyond Standard Model Physics at the Large Hadron Collider at CERN 357 the 5-dim Planck scale). The 5 at the Large Hadron Collider at CERN 359 The results show that with an integrated luminosity of 100 fb-1, ATLAS
Supersymmetry is regarded as the most promising candidate for physics beyond the Standard Model. Various search strategies for SUSY are conducted at the Atlas and CMS experiments. In the early data inclusive searches, with different lepton multiplicities, are most sensitive and will be discussed here. The reach of both experiments is interpreted within the mSUGRA model.The LHC ...
This paper describes the results of design and analyses performed on 120-mm Nb3Sn and NbTi quadrupole magnets with parameters relevant for the LHC IR upgrade. A realistic radiation heat load is evaluated in a wide luminosity range and translated into the magnet quench performance. The simulation results are supported by thermal measurements on a 90-mm ...
INTERVIEW Tevatron prepares to be very intense Roger Dixon is head of the accelerator division at Fermilab in Batavia, Illinois. Fermilab's Tevatron, a proton-antiproton collider second only in size and speed to the Large Hadron Collider, has been used to discover two major components of the Standard Model: the bottom quark (May-June 1977) and the top quark (February 1995). David Smith spoke to ...
We reopen the discussion on the two-photon production of the intermediate mass Higgs boson in peripheral ultrarelativistic heavy-ion collisions at LHC. Due to larger expected luminosity, larger collision energy and higher photon energies the Higgs product...
The status of the studies for the CERN Large Hadron Collider (LHC) is described. This collider will provide proton-proton collisions with 16 TeV centre-of-mass energy and a luminosity exceeding 10/sup 33/ cm/sup -2/ s/sup -1/ per interaction point. It can...
Parton luminosities are convenient for estimating how the physics potential of Large Hadron Collider experiments depends on the energy of the proton beams. I quantify the advantage of increasing the beam energy from 3.5 TeV to 4 TeV. I present parton lumi...
Extra dimensions provide a very useful tool in addressing a number of the fundamental problems faced by the Standard Model. The following provides a very basic introduction to this very broad subject area as given at the VIII School of the Gravitational and Mathematical Physics Division of the Mexican Physical Society in December 2009. Some prospects for extra dimensional searches at the 7 TeV ...
The discovery of some particles (Higgs, top,..) foreseen by theoretical models should be achieved at future colliders allowing to reach an energy scale of about 1 TeV. Efficient detectors must be designed to handle the very high luminosity of the LHC coll...
