CERN-Fermilab Hadron Collider Physics Summer School

CERN Multimedia

2007-01-01

Applications are now open for the 2nd CERN-Fermilab Hadron Collider Physics Summer School, which will take place at CERN from 6 to 15 June 2007. The school web site is http://cern.ch/hcpss with links to the academic program and application procedure. The application deadline is 9 March 2007. The results of the selection process will be announced shortly thereafter. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The first school in the series, held last summer at Fermilab, covered extensively the physics at the Tevatron collider experiments. The second school to be held at CERN, will focus on the technology and physics of the LHC experiments. Emphasis will be given on the first years of data-taking at the LHC and on the discovery potential of the programme. The series of lectures will be  supported by in-depth discussion sess...

PROSPECTS FOR COLLIDERS AND COLLIDER PHYSICS TO THE 1 PEV ENERGY SCALE

International Nuclear Information System (INIS)

KING, B.J.

2000-01-01

A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing the authors progress in elementary particle physics by extending the energy reach of hadron and lepton colliders as quickly and economically as might be technically and financially feasible. The scenario comprises 5 colliders beyond the LHC--one each of e + e - and hadron colliders and three μ + μ - colliders--and is able to hold to the historical rate of progress in the log-energy reach of hadron and lepton colliders, reaching the 1 PeV constituent mass scale by the early 2040's. The technical and fiscal requirements for the feasibility of the scenario are assessed and relevant long-term R and D projects are identified. Considerations of both cost and logistics seem to strongly favor housing most or all of the colliders in the scenario in a new world high energy physics laboratory

PROSPECTS FOR COLLIDERS AND COLLIDER PHYSICS TO THE 1 PEV ENERGY SCALE

Energy Technology Data Exchange (ETDEWEB)

KING,B.J.

2000-05-05

A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing the authors progress in elementary particle physics by extending the energy reach of hadron and lepton colliders as quickly and economically as might be technically and financially feasible. The scenario comprises 5 colliders beyond the LHC--one each of e{sup +}e{sup {minus}} and hadron colliders and three {mu}{sup +}{mu}{sup {minus}} colliders--and is able to hold to the historical rate of progress in the log-energy reach of hadron and lepton colliders, reaching the 1 PeV constituent mass scale by the early 2040's. The technical and fiscal requirements for the feasibility of the scenario are assessed and relevant long-term R and D projects are identified. Considerations of both cost and logistics seem to strongly favor housing most or all of the colliders in the scenario in a new world high energy physics laboratory.

Summary of the very large hadron collider physics and detector workshop

International Nuclear Information System (INIS)

Anderson, G.; Berger, M.; Brandt, A.; Eno, S.

1997-01-01

One of the options for an accelerator beyond the LHC is a hadron collider with higher energy. Work is going on to explore accelerator technologies that would make such a machine feasible. This workshop concentrated on the physics and detector issues associated with a hadron collider with an energy in the center of mass of the order of 100 to 200 TeV

Hadronic cross-sections in two photon processes at a future linear collider

International Nuclear Information System (INIS)

Godbole, Rohini M.; Roeck, Albert de; Grau, Agnes; Pancheri, Giulia

2003-01-01

In this note we address the issue of measurability of the hadronic cross-sections at a future photon collider as well as for the two-photon processes at a future high energy linear e + e - collider. We extend, to higher energy, our previous estimates of the accuracy with which the γ γ cross-section needs to be measured, in order to distinguish between different theoretical models of energy dependence of the total cross-sections. We show that the necessary precision to discriminate among these models is indeed possible at future linear colliders in the Photon Collider option. Further we note that even in the e + e - option a measurement of the hadron production cross-section via γ γ processes, with an accuracy necessary to allow discrimination between different theoretical models, should be possible. We also comment briefly on the implications of these predictions for hadronic backgrounds at the future TeV energy e + e - collider CLIC. (author)

Flat beams in a 50 TeV hadron collider

International Nuclear Information System (INIS)

Peggs, S.; Harrison, M.; Pilat, F.; Syphers, M.

1997-01-01

The basic beam dynamics of a next generation 50 x 50 TeV hadron collider based on a high field magnet approach have been outlined over the past several years. Radiation damping not only produces small emittances, but also flat beams, just as in electron machines. Based on open-quotes Snowmass 96close quotes parameters, we investigate the issues associated with flat beams in very high energy hadron colliders

Charged Hadron Multiplicity Distribution at Relativistic Heavy-Ion Colliders

Directory of Open Access Journals (Sweden)

Ashwini Kumar

2013-01-01

Full Text Available The present paper reviews facts and problems concerning charge hadron production in high energy collisions. Main emphasis is laid on the qualitative and quantitative description of general characteristics and properties observed for charged hadrons produced in such high energy collisions. Various features of available experimental data, for example, the variations of charged hadron multiplicity and pseudorapidity density with the mass number of colliding nuclei, center-of-mass energies, and the collision centrality obtained from heavy-ion collider experiments, are interpreted in the context of various theoretical concepts and their implications. Finally, several important scaling features observed in the measurements mainly at RHIC and LHC experiments are highlighted in the view of these models to draw some insight regarding the particle production mechanism in heavy-ion collisions.

Physics at hadron colliders: Experimental view

International Nuclear Information System (INIS)

Siegrist, J.L.

1987-08-01

The physics of the hadron-hadron collider experiment is considered from an experimental point of view. The problems encountered in determination of how well the standard model describes collider results are discussed. 53 refs., 58 figs

High luminosity electron-hadron collider eRHIC

Energy Technology Data Exchange (ETDEWEB)

Ptitsyn, V.; Aschenauer, E.; Bai, M.; Beebe-Wang, J.; Belomestnykh, S.; Ben-Zvi, I.; Blaskiewicz, M..; Calaga, R.; Chang, X.; Fedotov, A.; Gassner, D.; Hammons, L.; Hahn, H.; Hammons, L.; He, P.; Hao, Y.; Jackson, W.; Jain, A.; Johnson, E.C.; Kayran, D.; Kewisch, J.; Litvinenko, V.N.; Luo, Y.; Mahler, G.; McIntyre, G.; Meng, W.; Minty, M.; Parker, B.; Pikin, A.; Rao, T.; Roser, T.; Skaritka, J.; Sheehy, B.; Skaritka, J.; Tepikian, S.; Than, Y.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Webb, S.; Wu, Q.; Xu, W.; Pozdeyev, E.; Tsentalovich, E.

2011-03-28

We present the design of a future high-energy high-luminosity electron-hadron collider at RHIC called eRHIC. We plan on adding 20 (potentially 30) GeV energy recovery linacs to accelerate and to collide polarized and unpolarized electrons with hadrons in RHIC. The center-of-mass energy of eRHIC will range from 30 to 200 GeV. The luminosity exceeding 10{sup 34} cm{sup -2} s{sup -1} can be achieved in eRHIC using the low-beta interaction region with a 10 mrad crab crossing. We report on the progress of important eRHIC R&D such as the high-current polarized electron source, the coherent electron cooling, ERL test facility and the compact magnets for recirculation passes. A natural staging scenario of step-by-step increases of the electron beam energy by building-up of eRHIC's SRF linacs is presented.

Prospects for colliders and collider physics to the 1 PeV energy scale

Science.gov (United States)

King, Bruce J.

2000-08-01

A review is given of the prospects for future colliders and collider physics at the energy frontier. A proof-of-plausibility scenario is presented for maximizing our progress in elementary particle physics by extending the energy reach of hadron and lepton colliders as quickly and economically as might be technically and financially feasible. The scenario comprises 5 colliders beyond the LHC—one each of e+e- and hadron colliders and three μ+μ- colliders — and is able to hold to the historical rate of progress in the log-energy reach of hadron and lepton colliders, reaching the 1 PeV constituent mass scale by the early 2040's. The technical and fiscal requirements for the feasibility of the scenario are assessed and relevant long-term R&D projects are identified. Considerations of both cost and logistics seem to strongly favor housing most or all of the colliders in the scenario in a new world high energy physics laboratory.

12th CERN-Fermilab Hadron Collider Physics Summer School

CERN Document Server

2017-01-01

CERN and Fermilab are jointly offering a series of "Hadron Collider Physics Summer Schools", to prepare young researchers for these exciting times. The school has alternated between CERN and Fermilab, and will return to CERN for the twelfth edition, from 28th August to 6th September 2017. The CERN-Fermilab Hadron Collider Physics Summer School is an advanced school targeted particularly at young postdocs and senior PhD students working towards the completion of their thesis project, in both Experimental High Energy Physics (HEP) and phenomenology. Other schools, such as the CERN European School of High Energy Physics, may provide more appropriate training for students in experimental HEP who are still working towards their PhDs. Mark your calendar for 28 August - 6 September 2017, when CERN will welcome students to the twelfth CERN-Fermilab Hadron Collider Physics Summer School. The School will include nine days of lectures and discussions, and one free day in the middle of the period. Limited scholarship ...

Design Study for a Staged Very Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Chao, Alex W.

2002-02-27

Particle physics makes its greatest advances with experiments at the highest energy. The only sure way to advance to a higher-energy regime is through hadron colliders--the Tevatron, the LHC, and then, beyond that, a Very Large Hadron Collider. At Snowmass-1996 [1], investigators explored the best way to build a VLHC, which they defined as a 100 TeV collider. The goals in this study are different. The current study seeks to identify the best and cheapest way to arrive at frontier-energy physics, while simultaneously starting down a path that will eventually lead to the highest-energy collisions technologically possible in any accelerator using presently conceivable technology. This study takes the first steps toward understanding the accelerator physics issues, the technological possibilities and the approximate cost of a particular model of the VLHC. It describes a staged approach that offers exciting physics at each stage for the least cost, and finally reaches an energy one-hundred times the highest energy currently achievable.

Hadron Collider Physics with Real Time Trajectory Reconstruction

Energy Technology Data Exchange (ETDEWEB)

Annovi, Alberto [Univ. of Pisa (Italy)

2005-01-01

During last century experiments with accelerators have been extensively used to improve our understanding of matter. They are now the most common tool used to search for new phenomena in high energy physics. In the process of probing smaller distances and searching for new particles the center of mass energy has been steadily increased. The need for higher center of mass energy made hadron colliders the natural tool for discovery physics. Hadron colliders have a major drawback with respect to electron-positron colliders. As shown in fig. 1 the total cross section is several orders of magnitude larger than the cross section of interesting processes such as top or Higgs production. This means that, in order to observe interesting processes, it’s necessary to have collisions at very high rates and it becomes necessary to reject on-line most of the “non-interesting” events. In this thesis I have described the wide range of SVT applications within CDF.

The 20th Hadron Collider Physics Symposium in Evian

CERN Multimedia

Ludwik Dobrzynski and Emmanuel Tsesmelis

The 20th Hadron Collider Physics Symposium took place in Evian from 16 to 20 November 2009. The Hadron Collider Physics Symposium series has been a major forum for presentations of physics at the Tevatron over the past two decades. The merger of the former Topical Conference on Hadron Collider Physics with the LHC Symposium in 2005 brought together the Tevatron and LHC communities in a single forum. The 20th Hadron Collider Physics Symposium took place in Evian, on the shores of Lake Geneva, from 16-20 November 2009, some 17 years after the historic ECFA-CERN Evian meeting in March 1992 when Expressions of Interest for LHC detectors were presented for the first time. The 2009 event was organized jointly by CERN and the French high-energy physics community (CNRS-IN2P3 and CEA-IRFU). More than 170 people registered for this symposium. This year’s symposium was held at an important time for both the Tevatron and the LHC. It stimulated the completion of analyses for a significant Tevatron data sam...

Accelerator physics and technology limitations to ultimate energy and luminosity in very large hadron colliders

Energy Technology Data Exchange (ETDEWEB)

P. Bauer et al.

2002-12-05

The following presents a study of the accelerator physics and technology limitations to ultimate energy and luminosity in very large hadron colliders (VLHCs). The main accelerator physics limitations to ultimate energy and luminosity in future energy frontier hadron colliders are synchrotron radiation (SR) power, proton-collision debris power in the interaction regions (IR), number of events-per-crossing, stored energy per beam and beam-stability [1]. Quantitative estimates of these limits were made and translated into scaling laws that could be inscribed into the particle energy versus machine size plane to delimit the boundaries for possible VLHCs. Eventually, accelerator simulations were performed to obtain the maximum achievable luminosities within these boundaries. Although this study aimed at investigating a general VLHC, it was unavoidable to refer in some instances to the recently studied, [2], 200 TeV center-of-mass energy VLHC stage-2 design (VLHC-2). A more thorough rendering of this work can be found in [3].

Beyond the Large Hadron Collider: A First Look at Cryogenics for CERN Future Circular Colliders

Science.gov (United States)

Lebrun, Philippe; Tavian, Laurent

Following the first experimental discoveries at the Large Hadron Collider (LHC) and the recent update of the European strategy in particle physics, CERN has undertaken an international study of possible future circular colliders beyond the LHC. The study, conducted with the collaborative participation of interested institutes world-wide, considers several options for very high energy hadron-hadron, electron-positron and hadron-electron colliders to be installed in a quasi-circular underground tunnel in the Geneva basin, with a circumference of 80 km to 100 km. All these machines would make intensive use of advanced superconducting devices, i.e. high-field bending and focusing magnets and/or accelerating RF cavities, thus requiring large helium cryogenic systems operating at 4.5 K or below. Based on preliminary sets of parameters and layouts for the particle colliders under study, we discuss the main challenges of their cryogenic systems and present first estimates of the cryogenic refrigeration capacities required, with emphasis on the qualitative and quantitative steps to be accomplished with respect to the present state-of-the-art.

Possibilities of polarized protons in Sp anti p S and other high energy hadron colliders

International Nuclear Information System (INIS)

Courant, E.D.

1984-01-01

The requirements for collisions with polarized protons in hadron colliders above 200 GeV are listed and briefly discussed. Particular attention is given to the use of the ''Siberan snake'' to eliminate depolarizing resonances, which occur when the spin precession frequency equals a frequency contained in the spectrum of the field seen by the beam. The Siberian snake is a device which makes the spin precession frequency essentially constant by using spin rotators, which precess the spin by 180 0 about either the longitudinal or transverse horizontal axis. It is concluded that operation with polarized protons should be possible at all the high energy hadron colliders

TOP AND HIGGS PHYSICS AT THE HADRON COLLIDERS

Energy Technology Data Exchange (ETDEWEB)

Jabeen, Shabnam

2013-10-20

This review summarizes the recent results for top quark and Higgs boson measurements from experiments at Tevatron, a proton–antiproton collider at a center-of-mass energy of √ s =1 . 96 TeV, and the Large Hadron Collider, a proton–proton collider at a center- of-mass energy of √ s = 7 TeV. These results include the discovery of a Higgs-like boson and measurement of its various properties, and measurements in the top quark sector, e.g. top quark mass, spin, charge asymmetry and production of single top quark.

The future of the Large Hadron Collider and CERN.

Science.gov (United States)

Heuer, Rolf-Dieter

2012-02-28

This paper presents the Large Hadron Collider (LHC) and its current scientific programme and outlines options for high-energy colliders at the energy frontier for the years to come. The immediate plans include the exploitation of the LHC at its design luminosity and energy, as well as upgrades to the LHC and its injectors. This may be followed by a linear electron-positron collider, based on the technology being developed by the Compact Linear Collider and the International Linear Collider collaborations, or by a high-energy electron-proton machine. This contribution describes the past, present and future directions, all of which have a unique value to add to experimental particle physics, and concludes by outlining key messages for the way forward.

1st Large Hadron Collider Physics Conference

CERN Document Server

Juste, A; Martínez, M; Riu, I; Sorin, V

2013-01-01

The conference is the result of merging two series of international conferences, "Physics at Large Hadron Collider" (PLHC2012) and "Hadron Collider Physics Symposium" (HCP2012). With a program devoted to topics such as the Standard Model and Beyond, the Higgs Boson, Supersymmetry, Beauty and Heavy Ion Physics, the conference aims at providing a lively forum for discussion between experimenters and theorists of the latest results and of new ideas. LHCP 2013 will be hosted by IFAE (Institut de Fisica d'Altes Energies) in Barcelona (Spain), and will take place from May 13 to 18, 2013. The venue will be the Hotel Catalonia Plaza, Plaza España (Barcelona). More information will be posted soon. For questions, please contact lhcp2013@ifae.es.

Computing and data handling requirements for SSC [Superconducting Super Collider] and LHC [Large Hadron Collider] experiments

International Nuclear Information System (INIS)

Lankford, A.J.

1990-05-01

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 sketched. 6 refs., 3 figs

B factory with hadron colliders

International Nuclear Information System (INIS)

Lockyer, N.S.

1990-01-01

The opportunities to study B physics in a hadron collider are discussed. Emphasis is placed on the technological developments necessary for these experiments. The R and D program of the Bottom Collider Detector group is reviewed. (author)

3rd CERN-Fermilab Hadron Collider Physics Summer School

CERN Multimedia

2008-01-01

August 12-22, 2008, Fermilab The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 29 FEBRUARY 2008. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high-energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The third session of the summer school will focus on exposing young post-docs and advanced graduate students to broader theories and real data beyond what they’ve learned at their home institutions. Experts from across the globe will lecture on the theoretical and experimental foundations of hadron collider physics, host parallel discussion sessions and answer students’ questions. This year’s school will also have a greater focus on physics beyond the Standard Model, as well as more time for questions at the end of each lecture. The 2008 School will be held at ...

3rd CERN-Fermilab HadronCollider Physics Summer School

CERN Multimedia

EP Department

2008-01-01

August 12-22, 2008, Fermilab The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 29 FEBRUARY 2008. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high-energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The third session of the summer school will focus on exposing young post-docs and advanced graduate students to broader theories and real data beyond what they’ve learned at their home institutions. Experts from across the globe will lecture on the theoretical and experimental foundations of hadron collider physics, host parallel discussion sessions and answer students’ questions. This year’s school will also have a greater focus on physics beyond the Standard Model, as well as more time for questions at the end of each lecture. The 2008 School will be held at Fermilab. Further enquiries should ...

Academic Training Lecture: Higgs Boson Searches at Hadron Colliders

CERN Multimedia

HR Department

2010-01-01

Regular Programme 21, 22, 23 & 24 June 2010 from 11:00 to 12:00 - Main Auditorium, Bldg. 500-1-001 Higgs Boson Searches at Hadron Colliders by Dr. Karl Jakobs (University of Freiburg) In these Academic Training lectures, the phenomenology of Higgs bosons and search strategies at hadron colliders are discussed. After a brief introduction on Higgs bosons in the Standard Model and a discussion of present direct and indirect constraints on its mass the status of the theoretical cross section calculations for Higgs boson production at hadron colliders is reviewed. In the following lectures important experimental issues relevant for Higgs boson searches (trigger, measurements of leptons, jets and missing transverse energy) are presented. This is followed by a detailed discussion of the discovery potential for the Standard Model Higgs boson for both the Tevatron and the LHC experiments. In addition, various scenarios beyond the Standard Model, primarily the MSSM, are considered. Finally, the potential and ...

2nd CERN-Fermilab Hadron Collider Physics Summer School

CERN Document Server

2007-01-01

June 6-15, 2007, CERN The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 9 MARCH 2007 The results of the selection process will be announced shortly thereafter. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The first school in the series, held last summer at Fermilab, extensively covered the physics at the Tevatron collider experiments. The second school, to be held at CERN, will focus on the technology and physics of the LHC experiments. Emphasis will be placed on the first years of data-taking at the LHC and on the discovery potential of the programme. The series of lectures will be supported by in-depth discussion sessions and will include the theory and phenomenology of hadron collisions, discovery physics topics, detector and analysis t...

Updates on the optics of the future hadron-hadron collider FCC-hh

CERN Document Server

AUTHOR|(CDS)2093721; Boutin, David Jean Henri; Dalena, Barbara; Holzer, Bernhard; Langner, Andy Sven; Schulte, Daniel

2017-01-01

The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the three options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. The layout of FCC-hh has been optimized to a more compact design following recommendations from civil engineering aspects. The updates on the first order and second order optics of the ring will be shown for collisions at the required centre-of-mass energy of 100 TeV. Special emphasis is put on the dispersion suppressors and general beam cleaning sections as well as first considerations of injection and extraction sections.

Performance Limitations in High-Energy Ion Colliders

CERN Document Server

Fischer, Wolfram

2005-01-01

High-energy ion colliders (hadron colliders operating with species other than protons) are premier research tools for nuclear physics. The collision energy and high luminosity are important design and operations considerations. However, the experiments also expect flexibility with frequent changes in the collision energy, lattice configuration, and ion species, including asymmetric collisions. For the creation, acceleration, and storage of bright intense ion beams, attention must be paid to space charge, charge exchange, and intra-beam scattering effects. The latter leads to luminosity lifetimes of only a few hours for heavy ions. Ultimately cooling at full energy is needed to overcome this effect. Currently, the Relativistic Heavy Ion Collider at BNL is the only operating high-energy ion collider. The Large Hadron Collider, under construction at CERN, will also run with heavy ions.

Ntuples for NLO Events at Hadron Colliders

CERN Document Server

Bern, Z.; Febres Cordero, F.; Höche, S.; Ita, H.; Kosower, D.A.; Maitre, D.

2014-01-01

We present an event-file format for the dissemination of next-to-leading-order (NLO) predictions for QCD processes at hadron colliders. The files contain all information required to compute generic jet-based infrared-safe observables at fixed order (without showering or hadronization), and to recompute observables with different factorization and renormalization scales. The files also make it possible to evaluate cross sections and distributions with different parton distribution functions. This in turn makes it possible to estimate uncertainties in NLO predictions of a wide variety of observables without recomputing the short-distance matrix elements. The event files allow a user to choose among a wide range of commonly-used jet algorithms and jet-size parameters. We provide event files for a $W$ or $Z$ boson accompanied by up to four jets, and for pure-jet events with up to four jets. The files are for the Large Hadron Collider with a center of mass energy of 7 or 8 TeV. A C++ library along with a Python in...

Theoretical studies of hadronic calorimetry for high luminosity, high energy colliders

Energy Technology Data Exchange (ETDEWEB)

Brau, J.E.; Gabriel, T.A.

1989-01-01

Experiments at the high luminosity, high energy colliders of the future are going to demand optimization of the state of the art of calorimetry design and construction. During the past few years, the understanding of the basic phenomenology of hadron calorimeters has advanced through paralleled theoretical and experimental investigations. The important underlying processes are reviewed to set the framework for the presentation of recent calculations of the expected performance of silicon detector based hadron calorimeters. Such devices employing uranium are expected to achieve the compensation condition (that is, e/h approx. 1.0) based on the understanding that has been derived from the uranium-liquid argon and uranium-plastic scintillator systems. In fact, even lead-silicon calorimeters are found to achieve the attractive value for the e/h ratio of 1.16 at 10 GeV. 62 refs., 22 figs., 3 tabs.

Theoretical studies of hadronic calorimetry for high luminosity, high energy colliders

International Nuclear Information System (INIS)

Brau, J.E.; Gabriel, T.A.

1989-01-01

Experiments at the high luminosity, high energy colliders of the future are going to demand optimization of the state of the art of calorimetry design and construction. During the past few years, the understanding of the basic phenomenology of hadron calorimeters has advanced through paralleled theoretical and experimental investigations. The important underlying processes are reviewed to set the framework for the presentation of recent calculations of the expected performance of silicon detector based hadron calorimeters. Such devices employing uranium are expected to achieve the compensation condition (that is, e/h ∼ 1.0) based on the understanding that has been derived from the uranium-liquid argon and uranium-plastic scintillator systems. In fact, even lead-silicon calorimeters are found to achieve the attractive value for the e/h ratio of 1.16 at 10 GeV. 62 refs., 22 figs., 3 tabs

Top Quark Production at Hadron Colliders

Energy Technology Data Exchange (ETDEWEB)

Phaf, Lukas Kaj [Univ. of Amsterdam (Netherlands)

2004-03-01

This thesis describes both theoretical and experimental research into top quark production. The theoretical part contains a calculation of the single-top quark production cross section at hadron colliders, at Next to Leading Order (NLO) accuracy. The experimental part describes a measurement of the top quark pair production cross section in proton-antiproton collisions, at a center of mass energy of 1.96 TeV.

Prospects for heavy flavor physics at hadron colliders

International Nuclear Information System (INIS)

Butler, J.N.

1997-09-01

The role of hadron colliders in the observation and study of CP violation in B decays is discussed. We show that hadron collider experiments can play a significant role in the early studies of these phenomena and will play an increasingly dominant role as the effort turns towards difficult to measure decays, especially those of the B s meson, and sensitive searches for rare decays and subtle deviations from Standard Model predictions. We conclude with a discussion of the relative merits of hadron collider detectors with 'forward' vs 'central' rapidity coverage

Large Hadron Collider

CERN Multimedia

2007-01-01

"In the spring 2008, the Large Hadron Collider (LHC) machine at CERN (the European Particle Physics laboratory) will be switched on for the first time. The huge machine is housed in a circular tunnel, 27 km long, excavated deep under the French-Swiss border near Geneva." (1,5 page)

A Large Hadron Electron Collider at CERN, Physics, Machine, Detector

CERN Document Server

Adolphson, C

2011-01-01

The physics programme and the design are described of a new electron-hadron collider, the LHeC, in which electrons of $60$ to possibly $140$\\,GeV collide with LHC protons of $7000$\\,GeV. With an $ep$ design luminosity of about $10^{33}$\\,cm$^{-2}$s$^{-1}$, the Large Hadron Electron Collider exceeds the integrated luminosity collected at HERA by two orders of magnitude and the kinematic range by a factor of twenty in the four-momentum squared, $Q^2$, and in the inverse Bjorken $x$. The physics programme is devoted to an exploration of the energy frontier, complementing the LHC and its discovery potential for physics beyond the Standard Model with high precision deep inelastic scattering (DIS) measurements. These are projected to solve a variety of fundamental questions in strong and electroweak interactions. The LHeC thus becomes the world's cleanest high resolution microscope, designed to continue the path of deep inelastic lepton-hadron scattering into unknown areas of physics and kinematics. The physics ...

Department of Energy assessment of the Large Hadron Collider

International Nuclear Information System (INIS)

1996-06-01

This report summarizes the conclusions of the committee that assessed the cost estimate for the Large Hadron Collider (LHC). This proton-proton collider will be built at CERN, the European Laboratory for Particle Physics near Geneva, Switzerland. The committee found the accelerator-project cost estimate of 2.3 billion in 1995 Swiss francs, or about $2 billion US, to be adequate and reasonable. The planned project completion date of 2005 also appears achievable, assuming the resources are available when needed. The cost estimate was made using established European accounting procedures. In particular, the cost estimate does not include R and D, prototyping and testing, spare parts, and most of the engineering labor. Also excluded are costs for decommissioning the Large Electron-Positron collider (LEP) that now occupies the tunnel, modifications to the injector system, the experimental areas, preoperations costs, and CERN manpower. All these items are assumed by CERN to be included in the normal annual operations budget rather than the construction budget. Finally, contingency is built into the base estimate, in contrast to Department of Energy (DOE) estimates that explicitly identify contingency. The committee's charge, given by Dr. James F. Decker, Deputy Directory of the DOE Office of Energy Research, was to understand the basis for the LHC cost estimate, identify uncertainties, and judge the overall validity of the estimate, proposed schedule, and related issues. The committee met at CERN April 22--26, 1996. The assessment was based on the October 1995 LHC Conceptual Design Report or ''Yellow Book,'' cost estimates and formal presentations made by the CERN staff, site inspection, detailed discussions with LHC technical experts, and the committee members' considerable experience

Production and decay channels of charged Higgs boson at high energy hadron colliders

Science.gov (United States)

Demirci, Alev Ezgi; ćakır, Orhan

2018-02-01

We have studied charged Higgs boson interactions and production cross sections within the framework of two Higgs doublet model, which is an extension of standard model and the decay processes of charged Higgs boson have been calculated. There are different scenarios which have been studied in this work and these parameters have been transferred to the event generator, and the cross sections calculations for different center of mass energies of hadron colliders have been performed.

Higgs-photon associated production at hadron colliders

International Nuclear Information System (INIS)

Abbasabadi, A.; Repko, W.W.

1997-01-01

The authors present cross sections for the reactions p anti p → Hγ and pp → Hγ arising from the subprocess q anti q → Hγ. The calculation includes the complete one-loop contribution from all light quarks and is the main source of Higgs-photon associated production in hadron colliders. At Tevatron energies, the cross section is typically 0.1 fb or less, while at LHC energies it can exceed 1.0fb

High energy colliders

International Nuclear Information System (INIS)

Palmer, R.B.; Gallardo, J.C.

1997-02-01

The authors consider the high energy physics advantages, disadvantages and luminosity requirements of hadron (pp, p anti p), lepton (e + e - , μ + μ - ) and photon-photon colliders. Technical problems in obtaining increased energy in each type of machine are presented. The machines relative size are also discussed

Nucleon Decay and Neutrino Experiments, Experiments at High Energy Hadron Colliders, and String Theor

Energy Technology Data Exchange (ETDEWEB)

Jung, Chang Kee [State University of New York at Stony Brook; Douglas, Michaek [State University of New York at Stony Brook; Hobbs, John [State University of New York at Stony Brook; McGrew, Clark [State University of New York at Stony Brook; Rijssenbeek, Michael [State University of New York at Stony Brook

2013-07-29

This is the final report of the DOE grant DEFG0292ER40697 that supported the research activities of the Stony Brook High Energy Physics Group from November 15, 1991 to April 30, 2013. During the grant period, the grant supported the research of three Stony Brook particle physics research groups: The Nucleon Decay and Neutrino group, the Hadron Collider Group, and the Theory Group.

FCC-hh Hadron Collider - Parameter Scenarios and Staging Options

CERN Document Server

Benedikt, Michael; Schulte, Daniel; Zimmermann, F; Syphers, M J

2015-01-01

FCC-hh is a proposed future energy-frontier hadron collider, based on dipole magnets with a field around 16 T installed in a new tunnel with a circumference of about 100 km, which would provide proton collisions at a centre-of-mass energy of 100 TeV, as well as heavy-ion collisions at the equivalent energy. The FCC-hh should deliver a high integrated proton-proton luminosity at the level of several 100 fb−1 per year, or more. The challenges for operating FCC-hh with high beam current and at high luminosity include the heat load from synchrotron radiation in a cold environment, the radiation from collision debris around the interaction region, and machine protection. In this paper, starting from the FCC-hh design baseline parameters we explore different approaches for increasing the integrated luminosity, and discuss the impact of key individual pa- rameters, such as the turnaround time. We also present some injector considerations and options for early hadron-collider operation.

Large hadron collider in the LEP tunnel. Proceedings. Vol. 2

International Nuclear Information System (INIS)

1984-01-01

A Workshop, jointly organized by ECFA and CERN, took place at Lausanne and at CERN in March 1984 to study various options for a pp (or panti p) collider which might be installed at a later data alongside LEP in the LEP tunnel. Following the exploration of e + e - physics up to the highest energy now foreseeable, this would open up the opportunity to investigate hadron collisions in the new energy range of 10 to 20 TeV in the centre of mass. These proceedings put together the documents prepared in connection with this Workshop. They cover possible options for a Large Hadron Collider (LHC) in the LEP tunnel, the physics case as it stands at present, and studies of experimental possibilities in this energy range with luminosities as now considered. See hints under the relevant topics. (orig./HSI)

Large hadron collider in the LEP tunnel. Proceedings. Vol. 1

International Nuclear Information System (INIS)

1984-01-01

A Workshop, jointly organized by ECFA and CERN, took place at Lausanne and at CERN in March 1984 to study various options for a pp (or panti p) collider which might be installed at a later date alongside LEP in the LEP tunnel. Following the exploration of e + e - physics up to the highest energy now foreseeable, this would open up the opportunity to investigate hadron collisions in the new energy range of 10 to 20 TeV in the centre of mass. These proceedings put together the documents prepared in connection with this Workshop. They cover possible options for a Large Hadron Collider (LHC= in the LEP tunnel, the physics case at it stands at present, and studies of experimental possibilities in this energy range with luminosities as now considered. See hints under the relevant topics. (orig.)

K factor for Higgs boson production via gluon fusion process at hadron colliders

International Nuclear Information System (INIS)

Tanaka, H.

1992-01-01

In this paper soft gluon corrections for Higgs boson production at hadron colliders are calculated. It is found that the soft contributions for the Higgs boson production via gluon fusion process is large and it cannot be neglected even at SSC energy. Some qualitative discussions for the QCD corrections to the Higgs boson production at hadron colliders and their background processes are presented for various Higgs boson mass cases

Large Hadron Collider manual

CERN Document Server

Lavender, Gemma

2018-01-01

What is the universe made of? How did it start? This Manual tells the story of how physicists are seeking answers to these questions using the world’s largest particle smasher – the Large Hadron Collider – at the CERN laboratory on the Franco-Swiss border. Beginning with the first tentative steps taken to build the machine, the digestible text, supported by color photographs of the hardware involved, along with annotated schematic diagrams of the physics experiments, covers the particle accelerator’s greatest discoveries – from both the perspective of the writer and the scientists who work there. The Large Hadron Collider Manual is a full, comprehensive guide to the most famous, record-breaking physics experiment in the world, which continues to capture the public imagination as it provides new insight into the fundamental laws of nature.

The Large Hadron Collider in the LEP tunnel

International Nuclear Information System (INIS)

Brianti, G.; Huebner, K.

1987-01-01

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 33 cm -2 s -1 per interaction point. It can be installed in the tunnel of the Large Electron-Positron Storage Ring (LEP) above the LEP elements. It will use superconducting magnets of a novel, compact design, having two horizontally separated channels for the two counter-rotating bunched proton beams, which can collide in a maximum of seven interaction points. Collisions between protons of the LHC and electrons of LEP are also possible with a centre-of-mass energy of up to 1.8 TeV and a luminosity of up to 2 x 10 32 cm -2 s -1 . (orig.)

Top quark studies at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Sinervo, P.K. [Univ. of Toronto, Ontario (Canada)

1997-01-01

The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and DO Collaborations are reviewed, including the top quark cross section, mass, branching fractions, and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented.

Top quark studies at hadron colliders

International Nuclear Information System (INIS)

Sinervo, P.K.

1997-01-01

The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and DO Collaborations are reviewed, including the top quark cross section, mass, branching fractions, and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented

Top quark studies at hadron colliders

International Nuclear Information System (INIS)

Sinervo, P.K.

1996-08-01

The techniques used to study top quarks at hadron colliders are presented. The analyses that discovered the top quark are described, with emphasis on the techniques used to tag b quark jets in candidate events. The most recent measurements of top quark properties by the CDF and D null collaborations are reviewed, including the top quark cross section, mass, branching fractions and production properties. Future top quark studies at hadron colliders are discussed, and predictions for event yields and uncertainties in the measurements of top quark properties are presented

Dijet physics with CMS detector at the Large Hadron Collider

Indian Academy of Sciences (India)

2012-10-06

Oct 6, 2012 ... Hadron Collider, at a proton–proton collision energy of. √ ... generator predicts less azimuthal decorrelation than observed in data [8]. ... The dijet mass spectrum predicted by quantum chromodynamics (QCD) falls smoothly.

Hadron collider physics

Energy Technology Data Exchange (ETDEWEB)

Pondrom, L.

1991-10-03

An introduction to the techniques of analysis of hadron collider events is presented in the context of the quark-parton model. Production and decay of W and Z intermediate vector bosons are used as examples. The structure of the Electroweak theory is outlined. Three simple FORTRAN programs are introduced, to illustrate Monte Carlo calculation techniques. 25 refs.

Hadron collider physics

International Nuclear Information System (INIS)

Pondrom, L.

1991-01-01

An introduction to the techniques of analysis of hadron collider events is presented in the context of the quark-parton model. Production and decay of W and Z intermediate vector bosons are used as examples. The structure of the Electroweak theory is outlined. Three simple FORTRAN programs are introduced, to illustrate Monte Carlo calculation techniques. 25 refs

Higgs Boson Searches at Hadron Colliders (1/4)

CERN Multimedia

CERN. Geneva

2010-01-01

In these Academic Training lectures, the phenomenology of Higgs bosons and search strategies at hadron colliders are discussed. After a brief introduction on Higgs bosons in the Standard Model and a discussion of present direct and indirect constraints on its mass the status of the theoretical cross section calculations for Higgs boson production at hadron colliders is reviewed. In the following lectures important experimental issues relevant for Higgs boson searches (trigger, measurements of leptons, jets and missing transverse energy) are presented. This is followed by a detailed discussion of the discovery potential for the Standard Model Higgs boson for both the Tevatron and the LHC experiments. In addition, various scenarios beyond the Standard Model, primarily the MSSM, are considered. Finally, the potential and strategies to measured Higgs boson parameters and the investigation of alternative symmetry breaking scenarios are addressed.

Diffraction at collider energies

International Nuclear Information System (INIS)

Frankfurt, L.L.

1992-01-01

Lessons with ''soft'' hadron physics to explain (a) feasibility to observe and to investigate color transparency, color opacity effects at colliders; (b) significant probability and specific features of hard diffractive processes; (c) feasibility to investigate components of parton wave functions of hadrons with minimal number of constituents. This new physics would be more important with increase of collision energy

10th joint CERN-Fermilab Hadron Collider Physics Summer School

CERN Document Server

2015-01-01

The CERN-Fermilab Hadron Collider Physics Summer Schools are targeted particularly at young postdocs and senior PhD students working towards the completion of ther thesis project, in both experimental High Energy Physics (HEP) and phenomenology.

A conceptual solution for a beam halo collimation system for the Future Circular hadron-hadron Collider (FCC-hh)

Science.gov (United States)

Fiascaris, M.; Bruce, R.; Redaelli, S.

2018-06-01

We present the first conceptual solution for a collimation system for the hadron-hadron option of the Future Circular Collider (FCC-hh). The collimation layout is based on the scaling of the present Large Hadron Collider collimation system to the FCC-hh energy and it includes betatron and momentum cleaning, as well as dump protection collimators and collimators in the experimental insertions for protection of the final focus triplet magnets. An aperture model for the FCC-hh is defined and the geometrical acceptance is calculated at injection and collision energy taking into account mechanical and optics imperfections. The performance of the system is then assessed through the analysis of normalized halo distributions and complete loss maps for an ideal lattice. The performance limitations are discussed and a solution to improve the system performance with the addition of dispersion suppression collimators around the betatron cleaning insertion is presented.

Status of the Large Hadron Collider (LHC)

International Nuclear Information System (INIS)

Evans, Lyndon R.

2004-01-01

The Large Hadron Collider (LHC), due to be commissioned in 2007, will provide particle physics with the first laboratory tool to access the energy frontier above 1 TeV. In order to achieve this, protons must be accelerated and stored at 7 TeV, colliding with an unprecedented luminosity of 10 34 cm -2 s -1 The 8.3 Tesla guide field is obtained using conventional NbTi technology cooled to below the lambda point of helium. The machine is now well into its installation phase, with first beam injection foreseen for spring 2007. A brief status report is given and future prospects are discussed. (orig.)

The Quest for High Luminosity in Hadron Colliders (413th Brookhaven Lecture)

International Nuclear Information System (INIS)

Fischer, Wolfram

2006-01-01

In 1909, by bombarding a gold foil with alpha particles from a radioactive source, Ernest Rutherford and coworkers learned that the atom is made of a nucleus surrounded by an electron cloud. Ever since, scientists have been probing deeper and deeper into the structure of matter using the same technique. With increasingly powerful machines, they accelerate beams of particles to higher and higher energies, to penetrate more forcefully into the matter being investigated and reveal more about the contents and behavior of the unknown particle world. To achieve the highest collision energies, projectile particles must be as heavy as possible, and collide not with a fixed target but another beam traveling in the opposite direction. These experiments are done in machines called hadron colliders, which are some of the largest and most complex research tools in science. Five such machines have been built and operated, with Brookhaven's Relativistic Heavy Ion Collider (RHIC) currently the record holder for the total collision energy. One more such machine is under construction. Colliders have two vital performance parameters on which their success depends: one is their collision energy, and the other, the number of particle collisions they can produce, which is proportional to a quantity known as the luminosity. One of the tremendous achievements in the world's latest collider, RHIC, is the amazing luminosity that it produces in addition to its high energy. To learn about the performance evolution of these colliders and the way almost insurmountable difficulties can be overcome, especially in RHIC, join Wolfram Fischer, a physicist in the Collider-Accelerator (C-A) Department, who will give the next Brookhaven Lecture, on 'The Quest for High Luminosity in Hadron Colliders.'

Dijet asymmetry at the energies available at the CERN Large Hadron Collider

International Nuclear Information System (INIS)

Young, Clint; Jeon, Sangyong; Gale, Charles; Schenke, Bjoern

2011-01-01

The martini numerical simulation allows for direct comparison of theoretical model calculations and the latest results for dijet asymmetry from the ATLAS and CMS collaborations. In this paper, partons are simulated as undergoing radiative and collisional processes throughout the evolution of central lead-lead collisions at the Large Hadron Collider. Using hydrodynamical background evolution determined by a simulation which fits well with the data on charged particle multiplicities from ALICE and a value of α s ≅0.25-0.3, the dijet asymmetry is found to be consistent with partonic energy loss in a hot, strongly interacting medium.

Parton Distributions at a 100 TeV Hadron Collider

NARCIS (Netherlands)

Rojo, Juan

2016-01-01

The determination of the parton distribution functions (PDFs) of the proton will be an essential input for the physics program of a future 100 TeV hadron collider. The unprecedented center-of-mass energy will require knowledge of PDFs in currently unexplored kinematical regions such as the ultra

The Tevatron Hadron Collider: A short history

International Nuclear Information System (INIS)

Tollestrup, A.V.

1994-11-01

The subject of this presentation was intended to cover the history of hadron colliders. However this broad topic is probably better left to historians. I will cover a much smaller portion of this subject and specialize my subject to the history of the Tevatron. As we will see, the Tevatron project is tightly entwined with the progress in collider technology. It occupies a unique place among accelerators in that it was the first to make use of superconducting magnets and indeed the basic design now forms a template for all machines using this technology. It was spawned in an incredibly productive era when new ideas were being generated almost monthly and it has matured into our highest energy collider complete with two large detectors that provide the major facility in the US for probing high Pt physics for the coming decade

Hadron production of Majorana neutrinos at VLHC energies

International Nuclear Information System (INIS)

Almeida Junior, F.M.L. de; Coutinho, Y.A.; Martins Simoes, J.A.; Vale, M.A.B. do

2003-01-01

The Very Large Hadron Collider (VLHC) is being proposed as a 50+50 TeV hadron collider to extend the energy frontier beyond the LHC. Since 1998-1999 the option of a ep collider operating with the 3 TeV proton booster has been considered. This design uses a 80 GeV electron beam to produce ep collisions with a luminosity of 2600 Pb-1/yr with a center of mass energy of 1 TeV. We study the discovery potential of this proposed ep collider for detecting new neutral heavy Majorana leptons suggested by different extensions of the Standard Model, using the channel e - p →e + = jets. (author)

Crystal Ball: On the Future High Energy Colliders

Energy Technology Data Exchange (ETDEWEB)

Shiltsev, Vladimir [Fermilab

2015-09-20

High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of next generation collider facilities have been proposed and are currently under consideration for the medium- and far-future of the accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance reach and cost range. We briefly review such post-LHC options as linear e+e- colliders in Japan (ILC) or at CERN (CLIC), muon collider, and circular lepton or hadron colliders in China (CepC/SppC) and Europe (FCC). We conclude with a look into ultimate energy reach accelerators based on plasmas and crystals, and some perspectives for the far future of accelerator-based particle physics.

Precision Muon Tracking Detectors for High-Energy Hadron Colliders

CERN Document Server

Gadow, Philipp; Kroha, Hubert; Richter, Robert

2016-01-01

Small-diameter muon drift tube (sMDT) chambers with 15 mm tube diameter are a cost-effective technology for high-precision muon tracking over large areas at high background rates as expected at future high-energy hadron colliders including HL-LHC. The chamber design and construction procedures have been optimized for mass production and provide sense wire positioning accuracy of better than 10 ?m. The rate capability of the sMDT chambers has been extensively tested at the CERN Gamma Irradiation Facility. It exceeds the one of the ATLAS muon drift tube (MDT) chambers, which are operated at unprecedentedly high background rates of neutrons and gamma-rays, by an order of magnitude, which is sufficient for almost the whole muon detector acceptance at FCC-hh at maximum luminosity. sMDT operational and construction experience exists from ATLAS muon spectrometer upgrades which are in progress or under preparation for LHC Phase 1 and 2.

Large Hadron Collider nears completion

CERN Multimedia

2008-01-01

Installation of the final component of the Large Hadron Collider particle accelerator is under way along the Franco-Swiss border near Geneva, Switzerland. When completed this summer, the LHC will be the world's largest and most complex scientific instrument.

Extra dimension searches at hadron colliders to next-to-leading ...

Indian Academy of Sciences (India)

The quantitative impact of NLO-QCD corrections for searches of large and warped extra dimensions at hadron colliders are investigated for the Drell-Yan process. The K-factor for various observables at hadron colliders are presented. Factorisation, renormalisation scale dependence and uncertainties due to various parton ...

Large Hadron Collider at CERN: Beams Generating High-Energy-Density Matter

CERN Document Server

Tahir, N A; Shutov, A; Lomonosov, IV; Piriz, A R; Hoffmann, D H H; Deutsch, C; Fortov, V E

2009-01-01

This paper presents numerical simulations that have been carried out to study the thermodynamic and hydrodynamic response of a solid copper cylindrical target that is facially irradiated along the axis by one of the two Large Hadron Collider (LHC) 7 TeV/c proton beams. The energy deposition by protons in solid copper has been calculated using an established particle interaction and Monte Carlo code, FLUKA, which is capable of simulating all components of the particle cascades in matter, up to multi-TeV energies. This data has been used as input to a sophisticated two--dimensional hydrodynamic computer code, BIG2 that has been employed to study this problem. The prime purpose of these investigations was to assess the damage caused to the equipment if the entire LHC beam is lost at a single place. The FLUKA calculations show that the energy of protons will be deposited in solid copper within about 1~m assuming constant material parameters. Nevertheless, our hydrodynamic simulations have shown that the energy de...

Physics and Analysis at a Hadron Collider - An Introduction (1/3)

CERN Multimedia

CERN. Geneva

2010-01-01

This is the first lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This first lecture provides a brief introduction to hadron collider physics and collider detector experiments as well as offers some analysis guidelines. The lectures are aimed at graduate students.

Excited quark production at hadron colliders

International Nuclear Information System (INIS)

Baur, U.; Hinchliffe, I.; Zeppenfeld, D.

1987-06-01

Composite models generally predict the existence of excited quark and lepton states. We consider the production and experimental signatures of excited quarks Q* of spin and isospin 1/2 at hadron colliders and estimate the background for those channels which are most promising for Q* identification. Multi-TeV pp-colliders will give access to such particles with masses up to several TeV

Secondary particle background levels and effects on detectors at future hadron colliders

International Nuclear Information System (INIS)

Pal, T.

1993-01-01

The next generation of hadron colliders, the Superconducting Super Collider (SSC) and the Large Hadron Collider (LHC), will operate at high center-of-mass energies and luminosities. Namely, for the SSC(LHC) √s=40TeV (√s=16TeV) and L=10 33 cm -2 s -1 (L=3x10 34 cm -2 s -1 ). These conditions will result in the production of large backgrounds as well as radiation environments. Ascertaining the backgrounds, in terms of the production of secondary charged and neutral particles, and the radiation environments are important considerations for the detectors proposed for these colliders. An initial investigation of the radiation levels in the SSC detectors was undertaken by D. Groom and colleagues, in the context of the open-quotes task force on radiation levels in the SSC interaction regions.close quotes The method consisted essentially of an analytic approach, using standard descriptions of average events in conjunction with simulations of secondary processes

Flavorful leptoquarks at hadron colliders

Science.gov (United States)

Hiller, Gudrun; Loose, Dennis; Nišandžić, Ivan

2018-04-01

B -physics data and flavor symmetries suggest that leptoquarks can have masses as low as a few O (TeV ) , predominantly decay to third generation quarks, and highlight p p →b μ μ signatures from single production and p p →b b μ μ from pair production. Abandoning flavor symmetries could allow for inverted quark hierarchies and cause sizable p p →j μ μ and j j μ μ cross sections, induced by second generation couplings. Final states with leptons other than muons including lepton flavor violation (LFV) ones can also arise. The corresponding couplings can also be probed by precision studies of the B →(Xs,K*,ϕ )e e distribution and LFV searches in B -decays. We demonstrate sensitivity in single leptoquark production for the large hadron collider (LHC) and extrapolate to the high luminosity LHC. Exploration of the bulk of the parameter space requires a hadron collider beyond the reach of the LHC, with b -identification capabilities.

The higgsino-singlino world at the large hadron collider

Energy Technology Data Exchange (ETDEWEB)

Kim, Jong Soo [Universidad Autonoma de Madrid, Instituto de Fisica Teorica UAM/CSIC, Madrid (Spain); Ray, Tirtha Sankar [University of Melbourne, ARC Centre of Excellence for Particle Physics at the Terascale, School of Physics, Melbourne, VIC (Australia)

2015-02-01

We consider light higgsinos and singlinos in the next-to-minimal supersymmetric standard model at the large hadron collider. We assume that the singlino is the lightest supersymmetric particle and that the higgsino is the next-to-lightest supersymmetric particle with the remaining supersymmetric particles in the multi-TeV range. This scenario, which is motivated by the flavor and CP issues, provides a phenomenologically viable dark matter candidate and improved electroweak fit consistent with the measured Higgs mass. Here, the higgsinos decay into on (off)-shell gauge boson and the singlino. We consider the leptonic decay modes and the resulting signature is three isolated leptons and missing transverse energy which is known as the trilepton signal. We simulate the signal and the Standard Model backgrounds and present the exclusion region in the higgsino-singlino mass plane at the large hadron collider at √(s) = 14 TeV for an integrated luminosity of 300 fb{sup -1}. (orig.)

Heavy-Ion Collimation at the Large Hadron Collider: Simulations and Measurements

OpenAIRE

Hermes, Pascal Dominik; Wessels, Johannes Peter; Bruce, Roderik; Wessels, Johannes Peter; Bruce, Roderik

2017-01-01

The CERN Large Hadron Collider (LHC) stores and collides proton and $^{208}$Pb$^{82+}$ beams of unprecedented energy and intensity. Thousands of superconducting magnets, operated at 1.9 K, guide the very intense and energetic particle beams, which have a large potential for destruction. This implies the demand for a multi-stage collimation system to provide protection from beam-induced quenches or even hardware damage. In heavy-ion operation, ion fragments with significant rigidity offsets ca...

On the Future High Energy Colliders

Energy Technology Data Exchange (ETDEWEB)

Shiltsev, Vladimir [Fermilab

2015-09-28

High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of the next generation collider facilities have been proposed and are currently under consideration for the medium and far-future of accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance potential and cost range.

CERN-Fermilab Hadron Collider Physics Summer School 2013 open for applications

CERN Multimedia

2013-01-01

Mark your calendar for 28 August - 6 September 2013, when CERN will welcome students to the eighth CERN-Fermilab Hadron Collider Physics Summer School.   Experiments at hadron colliders will continue to provide our best tools for exploring physics at the TeV scale for some time. With the completion of the 7-8 TeV runs of the LHC, and the final results from the full Tevatron data sample becoming available, a new era in particle physics is beginning, heralded by the Higgs-like particle recently discovered at 125 GeV. To realize the full potential of these developments, CERN and Fermilab are jointly offering a series of "Hadron Collider Physics Summer Schools", to prepare young researchers for these exciting times. The school has alternated between CERN and Fermilab, and will return to CERN for the eighth edition, from 28 August to 6 September 2013. The CERN-Fermilab Hadron Collider Physics Summer School is an advanced school which particularly targets young postdocs in exper...

The Large Hadron Collider

CERN Document Server

Juettner Fernandes, Bonnie

2014-01-01

What really happened during the Big Bang? Why did matter form? Why do particles have mass? To answer these questions, scientists and engineers have worked together to build the largest and most powerful particle accelerator in the world: the Large Hadron Collider. Includes glossary, websites, and bibliography for further reading. Perfect for STEM connections. Aligns to the Common Core State Standards for Language Arts. Teachers' Notes available online.

CERN's Large Hadron Collider project

Science.gov (United States)

Fearnley, Tom A.

1997-03-01

The paper gives a brief overview of CERN's Large Hadron Collider (LHC) project. After an outline of the physics motivation, we describe the LHC machine, interaction rates, experimental challenges, and some important physics channels to be studied. Finally we discuss the four experiments planned at the LHC: ATLAS, CMS, ALICE and LHC-B.

CERN's Large Hadron Collider project

International Nuclear Information System (INIS)

Fearnley, Tom A.

1997-01-01

The paper gives a brief overview of CERN's Large Hadron Collider (LHC) project. After an outline of the physics motivation, we describe the LHC machine, interaction rates, experimental challenges, and some important physics channels to be studied. Finally we discuss the four experiments planned at the LHC: ATLAS, CMS, ALICE and LHC-B

Z-Z' mixing effects in W±-boson pair production processes at hadron and lepton high-energy colliders

International Nuclear Information System (INIS)

Bobovnikov, I.D.; Pankov, A.A.

2016-01-01

The potential to search for Z−Z' mixing in the W ± -boson pair production processes in proton-proton and electron-positron collisions at the Large Hadron Collider (LHC) and International Linear Collider (ILC), respectively, was studied. We found that the W ± -boson pair production processes are very sensitive to Z−Z' mixing angle, and their measurements at current and future collider experiments allow one to improve the present limits on Z−Z' mixing for the investigated models with extended gauge sector. The LHC at nominal energy and integrated luminosity, 14 TeV and 100 fb -1 , can provide a much more precise information on Z-Z' mixing and Z 2 mass, M 2 , with respect to those which can be obtained at the lepton collider ILC (0.5 TeV)

2nd CERN-Fermilab Hadron Collider Physics Summer School, June 6-15, 2007, CERN

CERN Multimedia

2007-01-01

The school web site is http://cern.ch/hcpss with links to the academic programme and the application procedure. The APPLICATION DEADLINE IS 9 MARCH 2007. The results of the selection process will be announced shortly thereafter. The goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers in high energy physics a concentrated syllabus on the theory and experimental challenges of hadron collider physics. The first school in the series, held last summer at Fermilab, covered extensively the physics at the Tevatron collider experiments. The second school, to be held at CERN, will focus on the technology and physics of the LHC experiments. Emphasis will be placed on the first years of data-taking at the LHC and on the discovery potential of the programme. The series of lectures will be supported by in-depth discussion sessions and will include the theory and phenomenology of hadron collisions, discovery physics topics, detector and analysis techniques and tools...

The Large Hadron Collider: Present Status and Prospects

CERN Document Server

Evans, Lyndon R

2000-01-01

The Large Hadron Collider (LHC), due to be commissioned in 2005, will provide particle physics with the first laboratory tool to access the energy frontier above 1 TeV. In order to achieve this , protons must be accelerated and stored at 7 TeV, colliding with an unprecedented luminosity of 1034 cm-2 s-1. The 8.3 Tesla guide field is obtained using conventional NbTi technology cooled to below the lambda point of helium. Considerable modification of the infrastructure around the existing LEP tunnel is needed to house the LHC machine and detectors. The project is advancing according to schedule with most of the major hardware systems including cryogenics and magnets under construction. A brief status report is given and future prospects are discussed.

The Large Hadron Collider Present Status and Prospects

CERN Document Server

Evans, Lyndon R

2001-01-01

The Large Hadron Collider (LHC), due to be commissioned in 2005, will provide particle physics with the first laboratory tool to access the energy frontier above 1 TeV. In order to achieve this , protons must be accelerated and stored at 7 TeV, colliding with an unprecedented luminosity of 1034 cm-2 s-1. The 8.3 Tesla guide field is obtained using conventional NbTi technology cooled to below the lambda point of helium. Considerable modification of the infrastructure around the existing LEP tunnel is needed to house the LHC machine and detectors. The project is advancing according to schedule with most of the major hardware systems including cryogenics and magnets under construction. A brief status report is given and future prospects are discussed.

Hadron collider searches for diboson resonances

Science.gov (United States)

Dorigo, Tommaso

2018-05-01

This review covers results of searches for new elementary particles that decay into boson pairs (dibosons), performed at the CERN Large Hadron Collider in proton-proton collision data collected by the ATLAS and CMS experiments at 7-, 8-, and 13-TeV center-of-mass energy until the year 2017. The available experimental results of the analysis of final states including most of the possible two-object combinations of W and Z bosons, photons, Higgs bosons, and gluons place stringent constraints on a variety of theoretical ideas that extend the standard model, pushing into the multi-TeV region the scale of allowed new physics phenomena.

GPU-Powered Modelling of Nonlinear Effects due to Head-On Beam-Beam Interactions in High-Energy Hadron Colliders.

CERN Document Server

Furuseth, Sondre

2017-01-01

The performance of high-energy circular hadron colliders, as the Large Hadron Collider, is limited by beam-beam interactions. The strongly nonlinear force between the two opposing beams causes diverging Hamiltonians and resonances, which can lead to a reduction of the lifetime of the beams. The nonlinearity makes the effect of the force difficult to study analytically, even at first order. Numerical models are therefore needed to evaluate the overall effect of different configurations of the machines. This report discusses results from an implementation of the weak-strong model, studying the effects of head-on beam-beam interactions. The assumptions has been shown to be valid for configurations where the growth and losses of the beam are small. The tracking has been done using an original code which applies graphic cards to reduce the computation time. The bunches in the beams have been modelled cylindrically symmetrical, based on a Gaussian distribution in three dimensions. This choice fits well with bunches...

Top production at hadron colliders

Indian Academy of Sciences (India)

New results on top quark production are presented from four hadron collider experiments: CDF and D0 at the Tevatron, and ATLAS and CMS at the LHC. Cross-sections for single top and top pair production are discussed, as well as results on the top–antitop production asymmetry and searches for new physics including ...

For Information: CERN-Fermilab2006 Hadron Collider Physics Summer School

CERN Multimedia

2006-01-01

Applications are Now Open for the CERN-Fermilab2006 Hadron Collider Physics Summer School August 9-18, 2006 Please go to the school web site http://hcpss.fnal.gov/ and follow the links to the Application process. The APPLICATION DEADLINE IS APRIL 8, 2006. Successful applicants and support awards will be announced shortly thereafter. Also available on the web is the tentative academic program of the school. The main goal of the CERN-Fermilab Hadron Collider Physics Summer Schools is to offer students and young researchers a broad picture of both the theoretical and experimental aspects of hadron collider physics. The emphasis of the first school will be on the physics potential of the first years of data taking at the LHC, and on the experimental and theoretical tools needed to exploit that potential. A series of lectures and informal discussions will include an introduction to the theoretical and phenomenological framework of hadron collisions, and current theoretical models of frontier physics, as...

First Considerations on Beam Optics and Lattice Design for the Future Hadron-Hadron Collider FCC

CERN Document Server

Alemany Fernandez, R

2014-01-01

The present document explains the steps carried out in order to make the first design of the Future Hadron-Hadron Collider (FCC-hh) following the base line parameters that can be found in [1]. Two lattice layouts are presented, a ring collider with 12 arcs and 12 straight sections, four of them designed as interaction points, and a racetrack like collider with two arcs and two straight sections, each of them equipped with two interaction points. The lattice design presented in the paper is modular allowing the same modules be used for both layouts. The present document addresses as well the beta star reach at the interaction points.

Physics possibilities of lepton and hadron colliders

International Nuclear Information System (INIS)

Peccei, R.D.

1985-05-01

After a brief introduction to lepton and hadron colliders presently being planned, I give some examples of the nice standard physics which is expected to be seen in them. The bulk of the discussion, however, is centered on signals for new physics. Higgs searches at the new colliders are discussed, as well as signatures and prospects for detecting effects of supersymmetry, compositeness and dynamical symmetry breakdown. (orig.)

Electroweak results from hadron colliders

International Nuclear Information System (INIS)

Demarteau, Marcel

1997-01-01

A review of recent electroweak results from hadron colliders is given. Properties of the W ± and Z 0 gauge bosons using final states containing electrons and muons based on large integrated luminosities are presented. The emphasis is placed on the measurement of the mass of the W boson and the measurement of trilinear gauge boson couplings

Hard QCD at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Moch, S

2008-02-15

We review the status of QCD at hadron colliders with emphasis on precision predictions and the latest theoretical developments for cross sections calculations to higher orders. We include an overview of our current information on parton distributions and discuss various Standard Model reactions such as W{sup {+-}}/Z-boson, Higgs boson or top quark production. (orig.)

Hard QCD at hadron colliders

International Nuclear Information System (INIS)

Moch, S.

2008-02-01

We review the status of QCD at hadron colliders with emphasis on precision predictions and the latest theoretical developments for cross sections calculations to higher orders. We include an overview of our current information on parton distributions and discuss various Standard Model reactions such as W ± /Z-boson, Higgs boson or top quark production. (orig.)

An investigation of triply heavy baryon production at hadron colliders

CERN Document Server

Gomshi Nobary, M A

2006-01-01

The triply heavy baryons have a rather diverse mass range. While some of them possess considerable production rates at existing facilities, others need to be produced at future high energy colliders. Here we study the direct fragmentation production of the Ωccc and Ωbbb baryons as the prototypes of triply heavy baryons at the hadron colliders with different . We present and compare the transverse momentum distributions of the differential cross sections, distributions of total cross sections and the integrated total cross sections of these states at the RHIC, the Tevatron Run II and the CERN LHC.

arXiv Energy-Frontier Lepton-Hadron Collisions at CERN: the LHeC and the FCC-eh

CERN Document Server

Kuze, Masahiro

2018-05-03

Lepton-hadron colliders that use a proton or nucleus beam of current and future hadron colliders and let it collide with an electron beam from a newly built electron accelerator bring attractive physics programs which are strong and complementary to the hadron collider physics. Machine development for Energy Recovery LINAC and physics performance studies of such electron-hadron colliders, specifically the LHeC that uses the existing LHC beam and FCC-eh that is an option of Future Circular Collider program, are ongoing and reviewed in this article.

Super High Energy Colliding Beam Accelerators

International Nuclear Information System (INIS)

Abdelaziz, M.E.

2009-01-01

This lecture presents a review of cyclic accelerators and their energy limitations. A description is given of the phase stability principle and evolution of the synchrotron, an accelerator without energy limitation. Then the concept of colliding beams emerged to yield doubling of the beam energy as in the Tevatron 2 trillion electron volts (TeV) proton collider at Fermilab and the Large Hadron Collider (LHC) which is now planned as a 14-TeV machine in the 27 kilometer tunnel of the Large Electron Positron (LEP) collider at CERN. Then presentation is given of the Superconducting Supercollider (SSC), a giant accelerator complex with energy 40-TeV in a tunnel 87 kilometers in circumference under the country surrounding Waxahachie in Texas, U.S.A. These superhigh energy accelerators are intended to smash protons against protons at energy sufficient to reveal the nature of matter and to consolidate the prevailing general theory of elementary particle.

Energy-range relations for hadrons in nuclear matter

Science.gov (United States)

Strugalski, Z.

1985-01-01

Range-energy relations for hadrons in nuclear matter exist similarly to the range-energy relations for charged particles in materials. When hadrons of GeV kinetic energies collide with atomic nuclei massive enough, events occur in which incident hadron is stopped completely inside the target nucleus without causing particle production - without pion production in particular. The stoppings are always accompanied by intensive emission of nucleons with kinetic energy from about 20 up to about 400 MeV. It was shown experimentally that the mean number of the emitted nucleons is a measure of the mean path in nuclear matter in nucleons on which the incident hadrons are stopped.

Preliminary design of the beam screen cooling for the Future Circular Collider of hadron beams

CERN Document Server

Kotnig, C

2015-01-01

Following recommendations of the recent update of the European strategy in particle physics, CERN has undertaken an international study of possible future circular colliders beyond the LHC. This study considers an option for a very high energy (100 TeV) hadron-hadron collider located in a quasi-circular underground tunnel having a circumference of 80 to 100 km. The synchrotron radiation emitted by the high-energy hadron beam increases by more than two orders of magnitude compared to the LHC. To reduce the entropic load on the superconducting magnets' refrigeration system, beam screens are indispensable to extract the heat load at a higher temperature level. After illustrating the decisive constraints of the beam screen's refrigeration design, this paper presents a preliminary design of the length of a continuous cooling loop comparing helium and neon, for different cooling channel geometries with emphasis on the cooling length limitations and the exergetic efficiency.

Preliminary design of the beam screen cooling for the Future Circular Collider of hadron beams

Science.gov (United States)

Kotnig, C.; Tavian, L.

2015-12-01

Following recommendations of the recent update of the European strategy in particle physics, CERN has undertaken an international study of possible future circular colliders beyond the LHC. This study considers an option for a very high energy (100 TeV) hadron-hadron collider located in a quasi-circular underground tunnel having a circumference of 80 to 100 km. The synchrotron radiation emitted by the high-energy hadron beam increases by more than two orders of magnitude compared to the LHC. To reduce the entropic load on the superconducting magnets’ refrigeration system, beam screens are indispensable to extract the heat load at a higher temperature level. After illustrating the decisive constraints of the beam screen's refrigeration design, this paper presents a preliminary design of the length of a continuous cooling loop comparing helium and neon, for different cooling channel geometries with emphasis on the cooling length limitations and the exergetic efficiency.

Searching for color sextet quarks at high energy hardon colliders

International Nuclear Information System (INIS)

Kantar, M.

2005-01-01

We analyze the resonance and pair production of color sextet quarks and their decay modes at very high energy hadron colliders such as VHLC (Very Large Hadron Collider) with the energy of 28 TeV and SSC (Superconducting Super Collider) for two options with energies of 40 TeV and 100 TeV, respectively. The total cross sections of color sextet quark for three different machines are calculated and plotted versus its mass. The distributions of transverse momentum T p and invariant mass jj m of two final state jets are plotted for signals and backgrounds and analyzed the discovery limits of this resonance particle. The observation condition of color sextet quarks are performed by the number of signal events to the number of background events

Hadronic energy reconstruction in the CALICE combined calorimeter system

Energy Technology Data Exchange (ETDEWEB)

Israeli, Yasmine [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Muenchen (Germany); Collaboration: CALICE-D-Collaboration

2016-07-01

Future linear electron-positron colliders, ILC and CLIC, aim for precision measurements and discoveries beyond and complementary to the program of the LHC. For this purpose, detectors with the capability for sophisticated reconstruction of final states with energy resolutions substantially beyond the current state of the art are being designed. The CALICE collaboration develops highly granular calorimeters for future colliders, among them silicon-tungsten electromagnetic calorimeters and hadronic calorimeters with scintillators read out by SiPMs. Such a combined system was tested with hadrons at CERN as well as at Fermilab. In this contribution, we report on the energy reconstruction in the combined setup, which requires different intercalibration factors to account for the varying longitudinal sampling of sub-detectors. Software compensation methods are applied to improve the energy resolution and to compensate for the different energy deposit of hadronic and electromagnetic showers.

Spin rotation and depolarization of high-energy particles in crystals at Hadron Collider (LHC) and Future Circular Collider (FCC) energies and the possibility to measure the anomalous magnetic moments of short-lived particles

CERN Document Server

Baryshevsky, V.G.

2015-01-01

We study the phenomena of spin rotation and depolarization of high-energy particles in crystals in the range of high energies that will be available at Hadron Collider (LHC) and Future Circular Collider (FCC). It is shown that these phenomena can be used to measure the anomalous magnetic moments of short-lived particles in this range of energies. We also demonstrate that the phenomenon of particle spin depolarization in crystals provides a unique possibility of measuring the anomalous magnetic moment of negatively-charged particles (e.g., beauty baryons), for which the channeling effect is hampered due to far more rapid dechanneling as compared to that for positively-charged particles. Channeling of particles in either straight or bent crystals with polarized nuclei could be used for polarization and the analysis thereof of high-energy particles.

Production of electroweak bosons at hadron colliders: theoretical aspects

CERN Document Server

Mangano, Michelangelo L.

2016-01-01

Since the W and Z discovery, hadron colliders have provided a fertile ground, in which continuously improving measurements and theoretical predictions allow to precisely determine the gauge boson properties, and to probe the dynamics of electroweak and strong interactions. This article will review, from a theoretical perspective, the role played by the study, at hadron colliders, of electroweak boson production properties, from the better understanding of the proton structure, to the discovery and studies of the top quark and of the Higgs, to the searches for new phenomena beyond the Standard Model.

An investigation of triply heavy baryon production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Gomshi Nobary, M.A. [Department of Physics, Faculty of Science, Razi University, Kermanshah (Iran, Islamic Republic of) and Center for Theoretical Physics and Mathematics, AEOI, Roosbeh Building, PO Box 11365-8486, Tehran (Iran, Islamic Republic of)]. E-mail: mnobary@razi.ac.ir; Sepahvand, R. [Department of Physics, Faculty of Science, Razi University, Kermanshah (Iran, Islamic Republic of)

2006-05-01

The triply heavy baryons have a rather diverse mass range. While some of them possess considerable production rates at existing facilities, others need to be produced at future high energy colliders. Here we study the direct fragmentation production of the {omega}{sub ccc} and {omega}{sub bbb} baryons as the prototypes of triply heavy baryons at the hadron colliders with different s. We present and compare the transverse momentum distributions of the differential cross sections, p{sub T}{sup min} distributions of total cross sections and the integrated total cross sections of these states at the RHIC, the Tevatron Run II and the CERN LHC.

Hadroproduction of heavy flavors at collider energies

International Nuclear Information System (INIS)

Scott, D.M.

1979-11-01

The possibility of detecting the top quark in hadron interactions at collider energies is investigated. The production of bound and naked t-quarks for m/sub t/ = 15 - 100 GeV, and the experimental signatures from their leptonic and semileptonic decay modes are studied. The background to any leptonic signature is expected to be severe, suggesting the requirement of simultaneous detection of hadrons

The large hadron collider beauty experiment calorimeters

International Nuclear Information System (INIS)

Martens, A.; LHCb Collaboration; Martens, A.

2010-01-01

The Large Hadron Collider beauty experiment (LHCb), one of the four largest experiments at the LHC at CERN, is dedicated to precision studies of CP violation and other rare effects, in particular in the b and c quark sectors. It aims at precisely measuring the Standard Model parameters and searching for effects inconsistent with this picture. The LHCb calorimeter system comprises a scintillating pad detector, a pre-shower (PS), electromagnetic (ECAL) and hadronic calorimeters, all of these employing the principle of transporting the light from scintillating layers with wavelength shifting fibers to photomultipliers. The fast response of the calorimeters ensures their key role in the LHCb trigger, which has to cope with the LHC collision rate of 40MHz. After discussing the design and expected performance of the LHCb calorimeter system, one addresses the time and energy calibration issues. The results obtained with the calorimeter system from the first LHC data will be shown.

Tolerable systematic errors in Really Large Hadron Collider dipoles

International Nuclear Information System (INIS)

Peggs, S.; Dell, F.

1996-01-01

Maximum allowable systematic harmonics for arc dipoles in a Really Large Hadron Collider are derived. The possibility of half cell lengths much greater than 100 meters is justified. A convenient analytical model evaluating horizontal tune shifts is developed, and tested against a sample high field collider

Large Hadron Collider (LHC) phenomenology, operational challenges and theoretical predictions

CERN Document Server

Gilles, Abelin R

2013-01-01

The Large Hadron Collider (LHC) is the highest-energy particle collider ever constructed and is considered "one of the great engineering milestones of mankind." It was built by the European Organization for Nuclear Research (CERN) from 1998 to 2008, with the aim of allowing physicists to test the predictions of different theories of particle physics and high-energy physics, and particularly prove or disprove the existence of the theorized Higgs boson and of the large family of new particles predicted by supersymmetric theories. In this book, the authors study the phenomenology, operational challenges and theoretical predictions of LHC. Topics discussed include neutral and charged black hole remnants at the LHC; the modified statistics approach for the thermodynamical model of multiparticle production; and astroparticle physics and cosmology in the LHC era.

Taking Energy to the Physics Classroom from the Large Hadron Collider at CERN

Science.gov (United States)

Cid, Xabier; Cid, Ramon

2009-01-01

In 2008, the greatest experiment in history began. When in full operation, the Large Hadron Collider (LHC) at CERN will generate the greatest amount of information that has ever been produced in an experiment before. It will also reveal some of the most fundamental secrets of nature. Despite the enormous amount of information available on this…

Improved squark and gluino mass limits from searches for supersymmetry at hadron colliders

NARCIS (Netherlands)

Beenakker, W.; Brensing, S.; D'Onofrio, M.; Krämer, M.; Kulesza, A.; Laenen, E.; Martinzez, M.; Niessen, I.

2012-01-01

Squarks and gluinos have been searched for at hadron colliders in events with multiple jets and missing transverse energy. No excess has been observed to date, and from a comparison of experimental cross section limits and theoretical cross section predictions one can deduce lower bounds on the

The large Hadron Collider (LHC) and the search for the divine particle

International Nuclear Information System (INIS)

Sanchez, G.

2008-01-01

The large Hadron Collider (LHC) is a particle circular accelerator of 27 km of circumference. I t will be used to study the smallest known particles. Two beams of subatomic particles called hadrons either protons or lead ion- will travel in opposite directions inside the circular accelerator gaining energy with every lap. Physicists will use the LHC to recreate the conditions just after the Big Bang, by colliding the two beams had-on at very high energy. There are many theories as to what will result from these collisions, but what's for sure is that a brave new world of physics will emerge from the new accelerator, as knowledge in particle physics goes on to describe the working of the Universe. for decades, the Standard Model of particle physics has served physicists well as a means of understanding the fundamental laws of Nature, but it does not tell the whole story. Only experimental data using the higher energies reached by the LHC can push knowledge forward, challenging those who seek confirmation of established knowledge, and those who dare to dream beyond the paradigm. The Higgs boson, that complete the standard model, is waited to be found. (Author)

The Large Hadron Collider of CERN and the roadmap toward higher performance

CERN Document Server

Rossi, L

2012-01-01

The Large Hadron Collider is exploring the new frontier of particle physics. It is the largest and most ambitious scientific instrument ever built and 100 years after the Rutherford experiment it continues that tradition of “smashing atoms” to unveil the secret of the infinitely small. LHC makes use of all what we learnt in 40 years of hadron colliders, in particular of ISR and Sp-pbarS at CERN and Tevatron at Fermilab, and it is based on Superconductivity, discovered also 100 years ago. Designing, developing the technology, building and finally commissioning the LHC took more than twenty years. While LHC is now successfully running, we are already preparing the future for the next step. First, by increasing of a factor five the LHC luminosity in ten years from now, and then by increasing its energy by a factor two or more, on the horizon of the next twenty years. These LHC upgrades, in luminosity and energy, will be the super-exploitation of the CERN infrastructure and is the best investment that the HEP...

Vector-like quarks coupling discrimination at the LHC and future hadron colliders

Science.gov (United States)

Barducci, D.; Panizzi, L.

2017-12-01

The existence of new coloured states with spin one-half, i.e. extra-quarks, is a striking prediction of various classes of new physics models. Should one of these states be discovered during the 13 TeV runs of the LHC or at future high energy hadron colliders, understanding its properties will be crucial in order to shed light on the underlying model structure. Depending on the extra-quarks quantum number under SU(2) L , their coupling to Standard Model quarks and bosons have either a dominant left- or right-handed chiral component. By exploiting the polarisation properties of the top quarks arising from the decay of pair-produced extra quarks, we show how it is possible to discriminate among the two hypothesis in the whole discovery range currently accessible at the LHC, thus effectively narrowing down the possible interpretations of a discovered state in terms of new physics scenarios. Moreover, we estimate the discovery and discrimination power of future prototype hadron colliders with centre of mass energies of 33 and 100 TeV.

Working group report: Physics at the Large Hadron Collider

Indian Academy of Sciences (India)

cally viable physics issues at two hadron colliders currently under operation, the p¯p collider ... corrections to different SM processes are very important. ... Keeping all these in mind and the available skills and interests of the ... relation involving the masses of the Standard Model particles as well as the masses of any.

Effects of bulk viscosity and hadronic rescattering in heavy ion collisions at energies available at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

Science.gov (United States)

Ryu, Sangwook; Paquet, Jean-François; Shen, Chun; Denicol, Gabriel; Schenke, Björn; Jeon, Sangyong; Gale, Charles

2018-03-01

We describe ultrarelativistic heavy ion collisions at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider with a hybrid model using the IP-Glasma model for the earliest stage and viscous hydrodynamics and microscopic transport for the later stages of the collision. We demonstrate that within this framework the bulk viscosity of the plasma plays an important role in describing the experimentally observed radial flow and azimuthal anisotropy simultaneously. We further investigate the dependence of observables on the temperature below which we employ the microscopic transport description.

Workshop on Hadron-Hadron & Cosmic-Ray Interactions at multi-TeV Energies

CERN Document Server

Alessandro, B; Bergman, D; Bongi, M; Bunyatyan, A; Cazon, L; d'Enterria, D; de Mitri, I; Doll, P; Engel, R; Eggert, K; Garzelli, M; Gerhardt, L; Gieseke, S; Godbole, R; Grosse-Oetringhaus, J F; Gustafson, G; Hebbeker, T; Kheyn, L; Kiryluk, J; Lipari, P; Ostapchenko, S; Pierog, T; Piskounova, O; Ranft, J; Rezaeian, A; Rostovtsev, A; Sakurai, N; Sapeta, S; Schleich, S; Schulz, H; Sjostrand, T; Sonnenschein, L; Sutton, M; Ulrich, R; Werner, K; Zapp, K; CRLHC10; CRLHC 10

2011-01-01

The workshop on "Hadron-Hadron and Cosmic-Ray Interactions at multi-TeV Energies" held at the ECT* centre (Trento) in Nov.-Dec. 2010 gathered together both theorists and experimentalists to discuss issues of the physics of high-energy hadronic interactions of common interest for the particle, nuclear and cosmic-ray communities. QCD results from collider experiments -- mostly from the LHC but also from the Tevatron, RHIC and HERA -- were discussed and compared to various hadronic Monte Carlo generators, aiming at an improvement of our theoretical understanding of soft, semi-hard and hard parton dynamics. The latest cosmic-ray results from various ground-based observatories were also presented with an emphasis on the phenomenological modeling of the first hadronic interactions of the extended air-showers generated in the Earth atmosphere. These mini-proceedings consist of an introduction and short summaries of the talks presented at the meeting.

Towards future circular colliders

Science.gov (United States)

Benedikt, Michael; Zimmermann, Frank

2016-09-01

The Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN) presently provides proton-proton collisions at a center-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics program will extend through the second half of the 2030's. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ˜100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCCee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb3 S n superconductor, for the FCC-hh hadron collider, and a highly-efficient superconducting radiofrequency system for the FCC-ee lepton collider. Following the FCC concept, the Institute of High Energy Physics (IHEP) in Beijing has initiated a parallel design study for an e + e - Higgs factory in China (CEPC), which is to be succeeded by a high-energy hadron collider (SPPC). At present a tunnel circumference of 54 km and a hadron collider c.m. energy of about 70 TeV are being considered. After a brief look at the LHC, this article reports the motivation and the present status of the FCC study, some of the primary design challenges and R&D subjects, as well as the emerging global collaboration.

CERN Library | Mario Campanelli presents "Inside CERN's Large Hadron Collider" | 16 March

CERN Multimedia

CERN Library

2016-01-01

"Inside CERN's Large Hadron Collider" by Mario Campanelli. Presentation on Wednesday, 16 March at 4 p.m. in the Library (bldg 52-1-052) The book aims to explain the historical development of particle physics, with special emphasis on CERN and collider physics. It describes in detail the LHC accelerator and its detectors, describing the science involved as well as the sociology of big collaborations, culminating with the discovery of the Higgs boson.  Inside CERN's Large Hadron Collider  Mario Campanelli World Scientific Publishing, 2015  ISBN 9789814656641​

Measurement of very forward neutron energy spectra for 7 TeV proton--proton collisions at the Large Hadron Collider

CERN Document Server

Adriani, O.; Bonechi, L.; Bongi, M.; Castellini, G.; D'Alessandro, R.; Del Prete, M.; Haguenauer, M.; Itow, Y.; Kasahara, K.; Kawade, K.; Makino, Y.; Masuda, K.; Matsubayashi, E.; Menjo, H.; Mitsuka, G.; Muraki, Y.; Okuno, Y.; Papini, P.; Perrot, A-L.; Ricciarini, S.; Sako, T.; Sakurai, N.; Sugiura, Y.; Suzuki, T.; Tamura, T.; Tiberio, A.; Torii, S.; Tricomi, A.; Turner, W.C.; Zhou, Q.D.

2015-01-01

The Large Hadron Collider forward (LHCf) experiment is designed to use the LHC to verify the hadronic-interaction models used in cosmic-ray physics. Forward baryon production is one of the crucial points to understand the development of cosmic-ray showers. We report the neutron-energy spectra for LHC $\\sqrt{s}$ = 7 TeV proton--proton collisions with the pseudo-rapidity $\\eta$ ranging from 8.81 to 8.99, from 8.99 to 9.22, and from 10.76 to infinity. The measured energy spectra obtained from the two independent calorimeters of Arm1 and Arm2 show the same characteristic feature before unfolding the difference in the detector responses. We unfolded the measured spectra by using the multidimensional unfolding method based on Bayesian theory, and the unfolded spectra were compared with current hadronic-interaction models. The QGSJET II-03 model predicts a high neutron production rate at the highest pseudo-rapidity range similar to our results and the DPMJET 3.04 model describes our results well at the lower pseudo-...

Unveiling the top secrets with the Large Hadron Collider

Science.gov (United States)

Chierici, R.

2013-12-01

Top quark physics is one of the pillars of fundamental research in the field of high energy physics. It not only gives access to precision measurements for constraining the Standard Model of particles and interactions but also it represents a privileged domain for new physics searches. This contribution summarizes the main results in top quark physics obtained with the two general-purpose detectors ATLAS and CMS during the first two years of operations of the Large Hadron Collider (LHC) at CERN. It covers the 2010 and 2011 data taking periods, where the LHC ran at a centre-of-mass energy of 7 TeV.

Unveiling the top secrets with the Large Hadron Collider

International Nuclear Information System (INIS)

Chierici, R

2013-01-01

Top quark physics is one of the pillars of fundamental research in the field of high energy physics. It not only gives access to precision measurements for constraining the Standard Model of particles and interactions but also it represents a privileged domain for new physics searches. This contribution summarizes the main results in top quark physics obtained with the two general-purpose detectors ATLAS and CMS during the first two years of operations of the Large Hadron Collider (LHC) at CERN. It covers the 2010 and 2011 data taking periods, where the LHC ran at a centre-of-mass energy of 7 TeV. (paper)

Hadron collider tests of neutrino mass-generating mechanisms

Science.gov (United States)

Ruiz, Richard Efrain

The Standard Model of particle physics (SM) is presently the best description of nature at small distances and high energies. However, with tiny but nonzero neutrino masses, a Higgs boson mass unstable under radiative corrections, and little guidance on understanding the hierarchy of fermion masses, the SM remains an unsatisfactory description of nature. Well-motivated scenarios that resolve these issues exist but also predict extended gauge (e.g., Left-Right Symmetric Models), scalar (e.g., Supersymmetry), and/or fermion sectors (e.g., Seesaw Models). Hence, discovering such new states would have far-reaching implications. After reviewing basic tenets of the SM and collider physics, several beyond the SM (BSM) scenarios that alleviate these shortcomings are investigated. Emphasis is placed on the production of a heavy Majorana neutrinos at hadron colliders in the context of low-energy, effective theories that simultaneously explain the origin of neutrino masses and their smallness compared to other elementary fermions, the so-called Seesaw Mechanisms. As probes of new physics, rare top quark decays to Higgs bosons in the context of the SM, the Types I and II Two Higgs Doublet Model (2HDM), and the semi-model independent framework of Effective Field Theory (EFT) have also been investigated. Observation prospects and discovery potentials of these models at current and future collider experiments are quantified.

Measurement of Hadronic Event Shapes and Jet Substructure in Proton-Proton Collisions at 7.0 TeV Center-of-Mass Energy with the ATLAS Detector at the Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Miller, David Wilkins

2012-03-20

This thesis presents the first measurement of 6 hadronic event shapes in proton-proton collisions at a center-of-mass energy of {radical}s = 7 TeV using the ATLAS detector at the Large Hadron Collider. Results are presented at the particle-level, permitting comparisons to multiple Monte Carlo event generator tools. Numerous tools and techniques that enable detailed analysis of the hadronic final state at high luminosity are described. The approaches presented utilize the dual strengths of the ATLAS calorimeter and tracking systems to provide high resolution and robust measurements of the hadronic jets that constitute both a background and a signal throughout ATLAS physics analyses. The study of the hadronic final state is then extended to jet substructure, where the energy flow and topology within individual jets is studied at the detector level and techniques for estimating systematic uncertainties for such measurements are commissioned in the first data. These first substructure measurements in ATLAS include the jet mass and sub-jet multiplicity as well as those concerned with multi-body hadronic decays and color flow within jets. Finally, the first boosted hadronic object observed at the LHC - the decay of the top quark to a single jet - is presented.

Extra dimension searches at hadron colliders to next-to-leading order-QCD

Science.gov (United States)

Kumar, M. C.; Mathews, Prakash; Ravindran, V.

2007-11-01

The quantitative impact of NLO-QCD corrections for searches of large and warped extra dimensions at hadron colliders are investigated for the Drell-Yan process. The K-factor for various observables at hadron colliders are presented. Factorisation, renormalisation scale dependence and uncertainties due to various parton distribution functions are studied. Uncertainties arising from the error on experimental data are estimated using the MRST parton distribution functions.

Particle production at energies available at the CERN Large Hadron Collider within an evolutionary model

Science.gov (United States)

Sinyukov, Yu. M.; Shapoval, V. M.

2018-06-01

The particle yields and particle number ratios in Pb+Pb collisions at the CERN Large Hadron Collider (LHC) energy √{sN N}=2.76 TeV are described within the integrated hydrokinetic model (iHKM) at two different equations of state (EoS) for quark-gluon matter and the two corresponding hadronization temperatures T =165 MeV and T =156 MeV. The role of particle interactions at the final afterburner stage of the collision in the particle production is investigated by means of comparison of the results of full iHKM simulations with those where the annihilation and other inelastic processes (except for resonance decays) are switched off after hadronization/particlization, similarly as in the thermal models. An analysis supports the picture of continuous chemical freeze-out in the sense that the corrections to the sudden chemical freeze-out results, which arise because of the inelastic reactions at the subsequent evolution times, are noticeable and improve the description of particle number ratios. An important observation is that, although the particle number ratios with switched-off inelastic reactions are quite different at different particlization temperatures which are adopted for different equations of state to reproduce experimental data, the complete iHKM calculations bring very close results in both cases.

Very large hadron collider (VLHC)

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-09-01

A VLHC informal study group started to come together at Fermilab in the fall of 1995 and at the 1996 Snowmass Study the parameters of this machine took form. The VLHC as now conceived would be a 100 TeV hadron collider. It would use the Fermilab Main Injector (now nearing completion) to inject protons at 150 GeV into a new 3 TeV Booster and then into a superconducting pp collider ring producing 100 TeV c.m. interactions. A luminosity of {approximately}10{sup 34} cm{sup -2}s{sup -1} is planned. Our plans were presented to the Subpanel on the Planning for the Future of US High- Energy Physics (the successor to the Drell committee) and in February 1998 their report stated ``The Subpanel recommends an expanded program of R&D on cost reduction strategies, enabling technologies, and accelerator physics issues for a VLHC. These efforts should be coordinated across laboratory and university groups with the aim of identifying design concepts for an economically and technically viable facility`` The coordination has been started with the inclusion of physicists from Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL), and Cornell University. Clearly, this collaboration must expanded internationally as well as nationally. The phrase ``economically and technically viable facility`` presents the real challenge.

The Large Hadron Collider, a personal recollection

CERN Document Server

Evans, L

2014-01-01

The construction of the Large Hadron Collider (LHC) has been a massive endeavor spanning almost 30 years from conception to commissioning. Building the machine with the highest possible energy (7 TeV) in the existing LEP tunnel of 27 km circumference and with a tunnel diameter of only 3.8m has required considerable innovation. The first was the development of an idea first proposed by Bob Palmer at Brookhaven National Laboratory in 1978, where the two rings are integrated into a single magnetic structure. This compact 2-in-1 structure was essential for the LHC due to both the limited space available in the existing Large Electron-Positron collider tunnel and the cost. The second innovation was the bold move to use superfluid helium cooling on a massive scale, which was imposed by the need to achieve a high (8.3 T) magnetic field using an affordable Nb-Ti superconductor. In this article, no attempt is made to give a comprehensive review of the machine design. This can be found in the LHC Design Report {[}1], w...

Status of the 16 T dipole development program for a future hadron collider

NARCIS (Netherlands)

Tommasini, Davide; Arbelaez, Diego; Auchmann, Bernhard; Bajas, Hugues; Bajko, Marta; Ballarino, Amalia; Barzi, Emanuela; Bellomo, Giovanni; Benedikt, Michael; Izquierdo Bermudez, Susana; Bordini, Bernardo; Bottura, Luca; Brouwer, Lucas; Buzio, Marco; Caiffi, Barbara; Caspi, Shlomo; Dhalle, Marc; Durante, Maria; De Rijk, Gijs; Fabbricatore, Pasquale; Farinon, Stefania; Ferracin, Paolo; Gao, Peng; Gourlay, Steve; Juchno, Mariusz; Kashikhin, Vadim; Lackner, Friedrich; Lorin, Clement; Marchevsky, Maxim; Marinozzi, Vittorio; Martinez, Teresa; Munilla, Javier; Novitski, Igor; Ogitsu, Toru; Ortwein, Rafal; Perez, Juan Carlos; Petrone, Carlo; Prestemon, Soren; Prioli, Marco; Rifflet, Jean Michel; Rochepault, Etienne; Russenschuck, Stephan; Salmi, Tiina; Savary, Frederic; Schoerling, Daniel; Segreti, Michel; Senatore, Carmine; Sorbi, Massimo; Stenvall, Antti; Todesco, Ezio; Toral, Fernando; Verweij, Arjan P.; Wessel, W.A.J.; Wolf, Felix; Zlobin, Alexander

A next step of energy increase of hadron colliders beyond the LHC requires high-field superconducting magnets capable of providing a dipolar field in the range of 16 T in a 50 mm aperture with accelerator quality. These characteristics could meet the re-quirements for an upgrade of the LHC to twice

Probing nuclei with high-energy hadronic reactions

International Nuclear Information System (INIS)

Moss, J.M.

1995-01-01

I review the subject of hadron-nucleus collisions at energies where peturbative theory is applicable. Reactions studied experimentally at the Fermilab Tevatron and CERN's Super Proton Synchrotron include the Drell-Yan Process, direct photon production, quarkonium production, and open charm production. I conclude with an observation about a new era of proton-nucleus and nucleus-nucleus experiments which will be carried out at the hadron colliders, RHIC and LHC

Design of the large hadron electron collider interaction region

Science.gov (United States)

Cruz-Alaniz, E.; Newton, D.; Tomás, R.; Korostelev, M.

2015-11-01

The large hadron electron collider (LHeC) is a proposed upgrade of the Large Hadron Collider (LHC) within the high luminosity LHC (HL-LHC) project, to provide electron-nucleon collisions and explore a new regime of energy and luminosity for deep inelastic scattering. The design of an interaction region for any collider is always a challenging task given that the beams are brought into crossing with the smallest beam sizes in a region where there are tight detector constraints. In this case integrating the LHeC into the existing HL-LHC lattice, to allow simultaneous proton-proton and electron-proton collisions, increases the difficulty of the task. A nominal design was presented in the the LHeC conceptual design report in 2012 featuring an optical configuration that focuses one of the proton beams of the LHC to β*=10 cm in the LHeC interaction point to reach the desired luminosity of L =1033 cm-2 s-1 . This value is achieved with the aid of a new inner triplet of quadrupoles at a distance L*=10 m from the interaction point. However the chromatic beta beating was found intolerable regarding machine protection issues. An advanced chromatic correction scheme was required. This paper explores the feasibility of the extension of a novel optical technique called the achromatic telescopic squeezing scheme and the flexibility of the interaction region design, in order to find the optimal solution that would produce the highest luminosity while controlling the chromaticity, minimizing the synchrotron radiation power and maintaining the dynamic aperture required for stability.

Radiation protection at the LHC, CERN's large hadron collider

International Nuclear Information System (INIS)

Potter, K.M.; Hoefert, M.; Stevenson, G.R.

1996-01-01

After a brief description of the Large Hadron Collider (LHC), which will produce 7 TeV on 7 TeV proton collisions, some of the radiological questions it raises will be discussed. The machine will be built in the 27 km circumference ring-tunnel of an existing collider at CERN. It aims to achieve collision rates of 10 9 per second in two of its high-energy particle detectors. This requires two high-intensity beams of more than 10 14 protons each. Shielding, access control and activation in addition to the high power in the proton-proton collisions must be taken into account. The detectors and local electronics of the particle physics experiments, which will surround these collisions, will have to be radiation resistant. Some of the environmental issues raised by the project will be discussed. (author)

Signals of doubly-charged Higgsinos at the CERN Large Hadron Collider

International Nuclear Information System (INIS)

Demir, Durmus A.; Frank, Mariana; Turan, Ismail; Huitu, Katri; Rai, Santosh Kumar

2008-01-01

Several supersymmetric models with extended gauge structures, motivated by either grand unification or by neutrino mass generation, predict light doubly-charged Higgsinos. In this work we study productions and decays of doubly-charged Higgsinos present in left-right supersymmetric models, and show that they invariably lead to novel collider signals not found in the minimal supersymmetric model or in any of its extensions motivated by the μ problem or even in extra dimensional theories. We investigate their distinctive signatures at the Large Hadron Collider in both pair- and single-production modes, and show that they are powerful tools in determining the underlying model via the measurements at the Large Hadron Collider experiments.

Muon-muon and other high energy colliders

International Nuclear Information System (INIS)

Palmer, R.B.; Gallardo, J.C.

1997-02-01

The first section looks at the high energy physics advantages, disadvantages and luminosity requirements of hadron, of lepton and photon-photon colliders for comparison. The second section discusses the physics considerations for the muon collider. The third section covers muon collider components. The fourth section is about the intersection region and detectors. In the fifth section, the authors discuss modifications to enhance the muon polarization's operating parameters with very small momentum spreads, operations at energies other than the maximum for which the machine is designed, and designs of machines for different maximum energies. The final section discusses a Research and Development plan aimed at the operation of a 0.5 TeV demonstration machine by the year 2010, and of the 4 TeV machine by the year 2020

Top quark pair production and calorimeter energy resolution studies at a future collider experiment

Energy Technology Data Exchange (ETDEWEB)

Seidel, Katja

2012-03-27

This thesis is focused on detector concepts and analyses investigated at a future linear electron positron collider. For precision measurements at such a collider, the CALICE collaboration develops imaging calorimeters, which are characterized by a fine granularity. CALICE has constructed prototypes of several design options for electromagnetic and hadronic calorimeters and has successfully operated these detectors during combined test beam programs at DESY, CERN and Fermilab. To improve the hadronic energy reconstruction and energy resolution of a hadron calorimeter prototype with analog readout three software compensation techniques are presented in this thesis, of which one is a local and two are global software compensation approaches. One method is based on a neural network to optimize the energy reconstruction, while two are energy weighting techniques, depending on the energy density. Weight factors are extracted from and applied to simulated and test beam data and result in an average energy resolution improvement of 15 - 25% compared to a reconstruction without software compensation. Whether such software compensation techniques are also applicable to a detector concept for a future linear electron positron collider is studied in the second part of this thesis. Simulated data, two different hadronic detector models and a local software compensation technique are used for this study. The energy resolutions for single hadrons and for jets are presented with and without software compensation. In the third part of this thesis, a study on top quark pair production at a center-of-mass energy of 500 GeV at the proposed electron positron collider CLIC is presented. The analysis is based on full detector simulations, including realistic background contributions dominated by two photon processes. The mass and width of the top quark are studied in fully-hadronic and semi-leptonic decays of top quark pairs using event samples of signal and Standard Model background

Top quark pair production and calorimeter energy resolution studies at a future collider experiment

International Nuclear Information System (INIS)

Seidel, Katja

2012-01-01

This thesis is focused on detector concepts and analyses investigated at a future linear electron positron collider. For precision measurements at such a collider, the CALICE collaboration develops imaging calorimeters, which are characterized by a fine granularity. CALICE has constructed prototypes of several design options for electromagnetic and hadronic calorimeters and has successfully operated these detectors during combined test beam programs at DESY, CERN and Fermilab. To improve the hadronic energy reconstruction and energy resolution of a hadron calorimeter prototype with analog readout three software compensation techniques are presented in this thesis, of which one is a local and two are global software compensation approaches. One method is based on a neural network to optimize the energy reconstruction, while two are energy weighting techniques, depending on the energy density. Weight factors are extracted from and applied to simulated and test beam data and result in an average energy resolution improvement of 15 - 25% compared to a reconstruction without software compensation. Whether such software compensation techniques are also applicable to a detector concept for a future linear electron positron collider is studied in the second part of this thesis. Simulated data, two different hadronic detector models and a local software compensation technique are used for this study. The energy resolutions for single hadrons and for jets are presented with and without software compensation. In the third part of this thesis, a study on top quark pair production at a center-of-mass energy of 500 GeV at the proposed electron positron collider CLIC is presented. The analysis is based on full detector simulations, including realistic background contributions dominated by two photon processes. The mass and width of the top quark are studied in fully-hadronic and semi-leptonic decays of top quark pairs using event samples of signal and Standard Model background

Higgs physics at the Large Hadron Collider

Indian Academy of Sciences (India)

Higgs boson; Large Hadron Collider; electroweak symmetry; spin and CP of the Higgs boson ... I shall then give a short description of the pre-LHC constraints on the Higgs mass and the theoretical predictions for the LHC along with a discussion of the current experimental results, ending with prospects in the near future at ...

The CERN Large Hadron Collider as a tool to study high-energy density matter.

Science.gov (United States)

Tahir, N A; Kain, V; Schmidt, R; Shutov, A; Lomonosov, I V; Gryaznov, V; Piriz, A R; Temporal, M; Hoffmann, D H H; Fortov, V E

2005-04-08

The Large Hadron Collider (LHC) at CERN will generate two extremely powerful 7 TeV proton beams. Each beam will consist of 2808 bunches with an intensity per bunch of 1.15x10(11) protons so that the total number of protons in one beam will be about 3x10(14) and the total energy will be 362 MJ. Each bunch will have a duration of 0.5 ns and two successive bunches will be separated by 25 ns, while the power distribution in the radial direction will be Gaussian with a standard deviation, sigma=0.2 mm. The total duration of the beam will be about 89 mus. Using a 2D hydrodynamic code, we have carried out numerical simulations of the thermodynamic and hydrodynamic response of a solid copper target that is irradiated with one of the LHC beams. These calculations show that only the first few hundred proton bunches will deposit a high specific energy of 400 kJ/g that will induce exotic states of high energy density in matter.

The CERN Large Hadron Collider as a tool to study high-energy density matter

CERN Document Server

Tahir, N A; Gryaznov, V; Hoffmann, Dieter H H; Kain, V; Lomonosov, I V; Piriz, A R; Schmidt, R; Shutov, A; Temporal, M

2005-01-01

The Large Hadron Collider (LHC) at CERN will generate two extremely powerful 7 TeV proton beams. Each beam will consist of 2808 bunches with an intensity per bunch of 1.15*10/sup 11/ protons so that the total number of protons in one beam will be about 3*10/sup 14/ and the total energy will be 362 MJ. Each bunch will have a duration of 0.5 ns and two successive bunches will be separated by 25 ns, while the power distribution in the radial direction will be Gaussian with a standard deviation, sigma =0.2 mm. The total duration of the beam will be about 89 mu s. Using a 2D hydrodynamic code, we have carried out numerical simulations of the thermodynamic and hydrodynamic response of a solid copper target that is irradiated with one of the LHC beams. These calculations show that only the first few hundred proton bunches will deposit a high specific energy of 400 kJ/g that will induce exotic states of high energy density in matter.

Protection of the CERN Large Hadron Collider

Science.gov (United States)

Schmidt, R.; Assmann, R.; Carlier, E.; Dehning, B.; Denz, R.; Goddard, B.; Holzer, E. B.; Kain, V.; Puccio, B.; Todd, B.; Uythoven, J.; Wenninger, J.; Zerlauth, M.

2006-11-01

The Large Hadron Collider (LHC) at CERN will collide two counter-rotating proton beams, each with an energy of 7 TeV. The energy stored in the superconducting magnet system will exceed 10 GJ, and each beam has a stored energy of 362 MJ which could cause major damage to accelerator equipment in the case of uncontrolled beam loss. Safe operation of the LHC will therefore rely on a complex system for equipment protection. The systems for protection of the superconducting magnets in case of quench must be fully operational before powering the magnets. For safe injection of the 450 GeV beam into the LHC, beam absorbers must be in their correct positions and specific procedures must be applied. Requirements for safe operation throughout the cycle necessitate early detection of failures within the equipment, and active monitoring of the beam with fast and reliable beam instrumentation, mainly beam loss monitors (BLM). When operating with circulating beams, the time constant for beam loss after a failure extends from apms to a few minutes—failures must be detected sufficiently early and transmitted to the beam interlock system that triggers a beam dump. It is essential that the beams are properly extracted on to the dump blocks at the end of a fill and in case of emergency, since the beam dump blocks are the only elements of the LHC that can withstand the impact of the full beam.

VUV photoemission studies of candidate Large Hadron Collider vacuum chamber materials

CERN Document Server

Cimino, R; Baglin, V

1999-01-01

In the context of future accelerators and, in particular, the beam vacuum of the Large Hadron Collider (LHC), a 27 km circumference proton collider to be built at CERN, VUV synchrotron radiation (SR) has been used to study both qualitatively and quantitatively candidate vacuum chamber materials. Emphasis is given to show that angle and energy resolved photoemission is an extremely powerful tool to address important issues relevant to the LHC, such as the emission of electrons that contributes to the creation of an electron cloud which may cause serious beam instabilities and unmanageable heat loads on the cryogenic system. Here we present not only the measured photoelectron yields from the proposed materials, prepared on an industrial scale, but also the energy and in some cases the angular dependence of the emitted electrons when excited with either a white light (WL) spectrum, simulating that in the arcs of the LHC, or monochromatic light in the photon energy range of interest. The effects on the materials ...

Jet and Leading Hadron Production in High-energy Heavy-ion Collisions

International Nuclear Information System (INIS)

Wang, Xin-Nian

2005-01-01

Jet tomography has become a powerful tool for the study of properties of dense matter in high-energy heavy-ion collisions. I will discuss recent progresses in the phenomenological study of jet quenching, including momentum, colliding energy and nuclear size dependence of single hadron suppression, modification of dihadron correlations and the soft hadron distribution associated with a quenched jet

Considerations on Energy Frontier Colliders after LHC

Energy Technology Data Exchange (ETDEWEB)

Shiltsev, Vladimir [Fermilab

2016-11-15

Since 1960’s, particle colliders have been in the forefront of particle physics, 29 total have been built and operated, 7 are in operation now. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). The future of the world-wide HEP community critically depends on the feasibility of possible post-LHC colliders. The concept of the feasibility is complex and includes at least three factors: feasibility of energy, feasibility of luminosity and feasibility of cost. Here we overview all current options for post-LHC colliders from such perspective (ILC, CLIC, Muon Collider, plasma colliders, CEPC, FCC, HE-LHC) and discuss major challenges and accelerator R&D required to demonstrate feasibility of an energy frontier accelerator facility following the LHC. We conclude by taking a look into ultimate energy reach accelerators based on plasmas and crystals, and discussion on the perspectives for the far future of the accelerator-based particle physics. This paper largely follows previous study [1] and the presenta ion given at the ICHEP’2016 conference in Chicago [2].

Higgs boson production at hadron colliders at N3LO in QCD

Science.gov (United States)

Mistlberger, Bernhard

2018-05-01

We present the Higgs boson production cross section at Hadron colliders in the gluon fusion production mode through N3LO in perturbative QCD. Specifically, we work in an effective theory where the top quark is assumed to be infinitely heavy and all other quarks are considered to be massless. Our result is the first exact formula for a partonic hadron collider cross section at N3LO in perturbative QCD. Furthermore, our result is an analytic computation of a hadron collider cross section involving elliptic integrals. We derive numerical predictions for the Higgs boson cross section at the LHC. Previously this result was approximated by an expansion of the cross section around the production threshold of the Higgs boson and we compare our findings. Finally, we study the impact of our new result on the state of the art prediction for the Higgs boson cross section at the LHC.

SEARCHING FOR HIGGS BOSONS AND NEW PHYSICS AT HADRON COLLIDERS

International Nuclear Information System (INIS)

Chung Kao

2007-01-01

The objectives of research activities in particle theory are predicting the production cross section and decay branching fractions of Higgs bosons and new particles at hadron colliders, developing techniques and computer software to discover these particles and to measure their properties, and searching for new phenomena and new interactions at the Fermilab Tevatron and the CERN Large Hadron Collider. The results of our project could lead to the discovery of Higgs bosons, new particles, and signatures for new physics, or we will be able to set meaningful limits on important parameters in particle physics. We investigated the prospects for the discovery at the CERN Large Hadron Collider of Higgs bosons and supersymmetric particles. Promising results are found for the CP-odd pseudoscalar (A 0 ) and the heavier CP-even scalar (H 0 ) Higgs bosons with masses up to 800 GeV. Furthermore, we study properties of the lightest neutralino (χ 0 ) and calculate its cosmological relic density in a supersymmetric U(1)(prime) model as well as the muon anomalous magnetic moment a μ = (g μ -2)/2 in a supersymmetric U(1)(prime) model. We found that there are regions of the parameter space that can explain the experimental deviation of a μ from the Standard Model calculation and yield an acceptable cold dark matter relic density without conflict with collider experimental constraints. Recently, we presented a complete next-to-leading order (NLO) calculation for the total cross section of inclusive Higgs pair production via bottom-quark fusion (b(bar b) to hh) at the CERN Large Hadron Collider (LHC) in the Standard Model and the minimal supersymmetric model. We plan to predict the Higgs pair production rate and to study the trilinear coupling among the Higgs bosons. In addition, we have made significant contributions in B physics, single top production, charged Higgs search at the Fermilab as well as in grid computing for both D0 and ATLAS

Black Holes and the Large Hadron Collider

Science.gov (United States)

Roy, Arunava

2011-01-01

The European Center for Nuclear Research or CERN's Large Hadron Collider (LHC) has caught our attention partly due to the film "Angels and Demons." In the movie, an antimatter bomb attack on the Vatican is foiled by the protagonist. Perhaps just as controversial is the formation of mini black holes (BHs). Recently, the American Physical Society…

Mean charged hadron multiplicities in high-energy collisions

Energy Technology Data Exchange (ETDEWEB)

Albini, E [Istituto di Matematica dell' Universita Cattolica di Brescia (Italy); Capiluppi, P; Giacomelli, G; Rossi, A M [Bologna Univ. (Italy). Istituto di Fisica

1976-03-01

A collection of mean charged hadron multiplicities per inelastic collision in various high-energy processes is presented. An extensive list of fits of as a function of energy is presented and discussed. As the energy increases the multiplicities for different collisions tend to a unique curve, independent of the type of colliding particles.

Design of the large hadron electron collider interaction region

Directory of Open Access Journals (Sweden)

E. Cruz-Alaniz

2015-11-01

Full Text Available The large hadron electron collider (LHeC is a proposed upgrade of the Large Hadron Collider (LHC within the high luminosity LHC (HL-LHC project, to provide electron-nucleon collisions and explore a new regime of energy and luminosity for deep inelastic scattering. The design of an interaction region for any collider is always a challenging task given that the beams are brought into crossing with the smallest beam sizes in a region where there are tight detector constraints. In this case integrating the LHeC into the existing HL-LHC lattice, to allow simultaneous proton-proton and electron-proton collisions, increases the difficulty of the task. A nominal design was presented in the the LHeC conceptual design report in 2012 featuring an optical configuration that focuses one of the proton beams of the LHC to β^{*}=10  cm in the LHeC interaction point to reach the desired luminosity of L=10^{33}  cm^{-2} s^{-1}. This value is achieved with the aid of a new inner triplet of quadrupoles at a distance L^{*}=10  m from the interaction point. However the chromatic beta beating was found intolerable regarding machine protection issues. An advanced chromatic correction scheme was required. This paper explores the feasibility of the extension of a novel optical technique called the achromatic telescopic squeezing scheme and the flexibility of the interaction region design, in order to find the optimal solution that would produce the highest luminosity while controlling the chromaticity, minimizing the synchrotron radiation power and maintaining the dynamic aperture required for stability.

Higgs Bosons, Electroweak Symmetry Breaking, and the Physics of the Large Hadron Collider

CERN Document Server

Quigg, Chris

2007-01-01

The Large Hadron Collider, a 7 + 7 TeV proton-proton collider under construction at CERN (the European Laboratory for Particle Physics in Geneva), will take experiments squarely into a new energy domain where mysteries of the electroweak interaction will be unveiled. What marks the 1-TeV scale as an important target? Why is understanding how the electroweak symmetry is hidden important to our conception of the world around us? What expectations do we have for the agent that hides the electroweak symmetry? Why do particle physicists anticipate a great harvest of discoveries within reach of the LHC?

Impact of high energy high intensity proton beams on targets: Case studies for Super Proton Synchrotron and Large Hadron Collider

CERN Document Server

Tahir, N A; Shutov, A; Schmidt, R; Piriz, A R

2012-01-01

The Large Hadron Collider (LHC) is designed to collide two proton beams with unprecedented particle energy of 7 TeV. Each beam comprises 2808 bunches and the separation between two neighboring bunches is 25 ns. The energy stored in each beam is 362 MJ, sufficient to melt 500 kg copper. Safety of operation is very important when working with such powerful beams. An accidental release of even a very small fraction of the beam energy can result in severe damage to the equipment. The machine protection system is essential to handle all types of possible accidental hazards; however, it is important to know about possible consequences of failures. One of the critical failure scenarios is when the entire beam is lost at a single point. In this paper we present detailed numerical simulations of the full impact of one LHC beam on a cylindrical solid carbon target. First, the energy deposition by the protons is calculated with the FLUKA code and this energy deposition is used in the BIG2 code to study the corresponding...

QCD-resummation and non-minimal flavour-violation for supersymmetric particle production at hadron colliders

International Nuclear Information System (INIS)

Fuks, B.

2007-06-01

Cross sections for supersymmetric particles production at hadron colliders have been extensively studied in the past at leading order and also at next-to-leading order of perturbative QCD. The radiative corrections include large logarithms which have to be re-summed to all orders in the strong coupling constant in order to get reliable perturbative results. In this work, we perform a first and extensive study of the resummation effects for supersymmetric particle pair production at hadron colliders. We focus on Drell-Yan like slepton-pair and slepton-sneutrino associated production in minimal supergravity and gauge-mediated supersymmetry-breaking scenarios, and present accurate transverse-momentum and invariant-mass distributions, as well as total cross sections. In non-minimal supersymmetric models, novel effects of flavour violation may occur. In this case, the flavour structure in the squark sector cannot be directly deduced from the trilinear Yukawa couplings of the fermion and Higgs supermultiplets. We perform a precise numerical analysis of the experimentally allowed parameter space in the case of minimal supergravity scenarios with non-minimal flavour violation, looking for regions allowed by low-energy, electroweak precision, and cosmological data. Leading order cross sections for the production of squarks and gauginos at hadron colliders are implemented in a flexible computer program, allowing us to study in detail the dependence of these cross sections on flavour violation. (author)

Really large hadron collider working group summary

International Nuclear Information System (INIS)

Dugan, G.; Limon, P.; Syphers, M.

1996-01-01

A summary is presented of preliminary studies of three 100 TeV center-of-mass hadron colliders made with magnets of different field strengths, 1.8T, 9.5T and 12.6T. Descriptions of the machines, and some of the major and most challenging subsystems, are presented, along with parameter lists and the major issues for future study

Beam-related machine protection for the CERN Large Hadron Collider experiments

Directory of Open Access Journals (Sweden)

R. B. Appleby

2010-06-01

Full Text Available The Large Hadron Collider at CERN, Geneva stores 360 MJ per beam of protons at the top machine energy. This amount of energy storage presents a considerable challenge to the machine protection systems designed to protect both the machine and the six LHC experiments. This paper provides an overview of the machine protection systems relevant to the protection of the experiments, and demonstrates their operation and level of protection through a series of injection and stored beam failure scenarios. We conclude that the systems provide sufficient coverage for the protection of the experiments as far as reasonably possible.

Large hadron collider workshop. Proceedings. Vol. 3

International Nuclear Information System (INIS)

Jarlskog, G.; Rein, D.

1990-01-01

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 below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentaiton and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

Large hadron collider workshop. Proceedings. Vol. 2

International Nuclear Information System (INIS)

Jarlskog, G.; Rein, D.

1990-01-01

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 below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol.1 of these proceedings contains the papers presented at the plenary sessions, Vol.2 the individual contributions to the physics sessions, and Vol.3 those to the instrumentation sessions. (orig.)

Large hadron collider workshop. Proceedings. Vol. 1

International Nuclear Information System (INIS)

Jarlskog, G.; Rein, D.

1990-01-01

The aim of the LCH 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 below 1 TeV could be seen using detectors potentially available within a few years from now. Other topics included supersymmetry, heavy quarks, excited gauge bosons, and exotica in proton-proton collisions, as well as physics to be observed in electron-proton and heavy-ion collisions. A large part of the workshop was devoted to the discussion of instrumental and detector concepts, including simulation, signal processing, data acquisition, tracking, calorimetry, lepton identification and radiation hardness. The workshop began with parallel sessions of working groups on physics and instrumentation and continued, in the second half, with plenary talks giving overviews of the LHC project and the SSC, RHIC, and HERA programmes, summaries of the working groups, presentations from industry, and conclusions. Vol. 1 of these proceedings contains the papers presented at the plenary sessions, Vol. 2 the individual contributions to the physics sessions, and Vol. 3 those to the instrumentation sessions. (orig.)

The ATLAS experiment at the CERN Large Hadron Collider

NARCIS (Netherlands)

Aad, G.; et al., [Unknown; Bentvelsen, S.; Bobbink, G.J.; Bos, K.; Boterenbrood, H.; Brouwer, G.; Buis, E.J.; Buskop, J.J.F.; Colijn, A.P.; Dankers, R.; Daum, C.; de Boer, R.; de Jong, P.; Ennes, P.; Gosselink, M.; Groenstege, H.; Hart, R.G.G.; Hartjes, F.; Hendriks, P.J.; Hessey, N.P.; Jansweijer, P.P.M.; Kieft, G.; Klok, P.F.; Klous, S.; Kluit, P.; Koffeman, E.; Koutsman, A.; Liebig, W.; Limper, M.; Linde, F.; Luijckx, G.; Massaro, G.; Muijs, A.; Peeters, S.J.M.; Reichold, A.; Rewiersma, P.; Rijpstra, M.; Scholte, R.C.; Schuijlenburg, H.W.; Snuverink, J.; van der Graaf, H.; van der Kraaij, E.; van Eijk, B.; van Kesteren, Z.; van Vulpen, I.; Verkerke, W.; Vermeulen, J.C.; Vreeswijk, M.; Werneke, P.

2008-01-01

The ATLAS detector as installed in its experimental cavern at point 1 at CERN is described in this paper. A brief overview of the expected performance of the detector when the Large Hadron Collider begins operation is also presented.

For information - Université de Genève : Accelerator Physics Challenges for the Large Hadron Collider at CERN

CERN Multimedia

Université de Genève

2005-01-01

UNIVERSITE DE GENEVE Faculte des sciences Section de physique - Département de physique nucléaire et corspusculaire 24, Quai Ernest-Ansermet - 1211 GENEVE 4 Tél : (022) 379 62 73 Fax: (022) 379 69 92 Mercredi 16 March SEMINAIRE DE PHYSIQUE CORPUSCULAIRE à 17h00 - Auditoire Stückelberg Accelerator Physics Challenges for the Large Hadron Collider at CERN Prof. Olivier Bruning / CERN The Large Hadron Collider project at CERN will bring the energy frontier of high energy particle physics back to Europe and with it push the accelerator technology into uncharted teritory. The talk presents the LHC project in the context of the past CERN accelerator developments and addresses the main challenges in terms of technology and accelerator physics. Information: http://dpnc.unige.ch/seminaire/annonce.html Organizer: A. Cervera Villanueva

Estimates of Hadronic Backgrounds in a 5 TeV e+e- Linear Collider

International Nuclear Information System (INIS)

Murayama, H.; Ohgaki, Tomomi; Xie, M.

1998-01-01

We have estimated hadronic backgrounds by γγ collisions in an e + e - linear collider at a center-of-mass energy of 5 TeV. We introduce a simple ansatz, that is, a total γγ cross section of σ γγ = (σγ p ) 2 /σ pp shall be saturated by minijet productions, whose rate is controlled by p t,min (√s). We present that the background yields are small and the energy deposits are tinier than the collision energy of the initial electron and positron beams by a simulation

arXiv Proceedings of the Sixth International Workshop on Multiple Partonic Interactions at the Large Hadron Collider

CERN Document Server

Astalos, R.; Bartalini, P.; Belyaev, I.; Bierlich, Ch.; Blok, B.; Buckley, A.; Ceccopieri, F.A.; Cherednikov, I.; Christiansen, J.R.; Ciangottini, D.; Deak, M.; Ducloue, B.; Field, R.; Gaunt, J.R.; Golec-Biernat, K.; Goerlich, L.; Grebenyuk, A.; Gueta, O.; Gunnellini, P.; Helenius, I.; Jung, H.; Kar, D.; Kepka, O.; Klusek-Gawenda, M.; Knutsson, A.; Kotko, P.; Krasny, M.W.; Kutak, K.; Lewandowska, E.; Lykasov, G.; Maciula, R.; Moraes, A.M.; Martin, T.; Mitsuka, G.; Motyka, L.; Myska, M.; Otwinowski, J.; Pierog, T.; Pleskot, V.; Rinaldi, M.; Schafer, W.; Siodmok, A.; Sjostrand, T.; Snigirev, A.; Stasto, A.; Staszewski, R.; Stebel, T.; Strikman, M.; Szczurek, A.; Treleani, D.; Trzebinski, M.; van Haevermaet, H.; van Hameren, A.; van Mechelen, P.; Waalewijn, W.; Wang, W.Y.; MPI@LHC 2014

2014-01-01

Multiple Partonic Interactions are often crucial for interpreting results obtained at the Large Hadron Collider (LHC). The quest for a sound understanding of the dynamics behind MPI - particularly at this time when the LHC is due to start its "Run II" operations - has focused the aim of this workshop. MPI@LHC2014 concentrated mainly on the phenomenology of LHC measurements whilst keeping in perspective those results obtained at previous hadron colliders. The workshop has also debated some of the state-of-the-art theoretical considerations and the modeling of MPI in Monte Carlo event generators. The topics debated in the workshop included: Phenomenology of MPI processes and multiparton distributions; Considerations for the description of MPI in Quantum Chromodynamics (QCD); Measuring multiple partonic interactions; Experimental results on inelastic hadronic collisions: underlying event, minimum bias, forward energy flow; Monte Carlo generator development and tuning; Connections with low-x phenomena, diffractio...

Heavy-Ion Collimation at the Large Hadron Collider Simulations and Measurements

CERN Document Server

AUTHOR|(CDS)2083002; Wessels, Johannes Peter; Bruce, Roderik; Wessels, Johannes Peter; Bruce, Roderik

The CERN Large Hadron Collider (LHC) stores and collides proton and $^{208}$Pb$^{82+}$ beams of unprecedented energy and intensity. Thousands of superconducting magnets, operated at 1.9 K, guide the very intense and energetic particle beams, which have a large potential for destruction. This implies the demand for a multi-stage collimation system to provide protection from beam-induced quenches or even hardware damage. In heavy-ion operation, ion fragments with significant rigidity offsets can still scatter out of the collimation system. When they irradiate the superconducting LHC magnets, the latter risk to quench (lose their superconducting property). These secondary collimation losses can potentially impose a limitation for the stored heavy-ion beam energy. Therefore, their distribution in the LHC needs to be understood by sophisticated simulations. Such simulation tools must accurately simulate the particle motion of many different nuclides in the magnetic LHC lattice and simulate their interaction with t...

Probing two-photon decay widths of mesons at energies available at the CERN Large Hadron Collider (LHC)

International Nuclear Information System (INIS)

Bertulani, C. A.

2009-01-01

Meson production cross sections in ultraperipheral relativistic heavy ion collisions at the CERN Large Hadron Collider are revisited. The relevance of meson models and of exotic QCD states is discussed. This study includes states that have not been considered before in the literature.

Top quark pair production and calorimeter energy resolution studies at a future collider experiment

CERN Document Server

Seidel, Katja

This thesis is focused on detector concepts and analyses investigated at a future linear electron positron collider. For precision measurements at such a collider, the CALICE collaboration develops imaging calorimeters, which are characterized by a fine granularity. CALICE has constructed prototypes of several design options for electromagnetic and hadronic calorimeters and has successfully operated these detectors during combined test beam programs at DESY, CERN and Fermilab. To improve the hadronic energy reconstruction and energy resolution of a hadron calorimeter prototype with analog readout three software compensation techniques are presented in this thesis, of which one is a local and two are global software compensation approaches. One method is based on a neural network to optimize the energy reconstruction, while two are energy weighting techniques, depending on the energy density. Weight factors are extracted from and applied to simulated and test beam data and result in an average energy resolutio...

Advanced Superconducting Technology for Global Science The Large Hadron Collider at CERN

CERN Document Server

Lebrun, P

2002-01-01

The Large Hadron Collider (LHC), presently in construction at CERN, the European Organisation for Nuclear Research near Geneva (Switzerland), will be, upon its completion in 2005 and for the next twenty years, the most advanced research instrument of the world's high-energy physics community, providing access to the energy frontier above 1 TeV per elementary constituent. Re-using the 26.7-km circumference tunnel and infrastructure of the past LEP electron-positon collider, operated until 2000, the LHC will make use of advanced superconducting technology - high-field Nb-Ti superconducting magnets operated in superfluid helium and a cryogenic ultra-high vacuum system - to bring into collision intense beams of protons and ions at unprecedented values of center-of-mass energy and luminosity (14 TeV and 1034 cm-2.s-1, respectively with protons). After some ten years of focussed R&D, the LHC components are presently series-built in industry and procured through world-wide collaboration. After briefly recalling ...

High energy colliders as black hole factories: The end of short distance physics

International Nuclear Information System (INIS)

Giddings, Steven B.; Thomas, Scott

2002-01-01

If the fundamental Planck scale is of order of a TeV, as is the case in some extra-dimension scenarios, future hadron colliders such as the CERN Large Hadron Collider will be black hole factories. The nonperturbative process of black hole formation and decay by Hawking evaporation gives rise to spectacular events with up to many dozens of relatively hard jets and leptons with a characteristic ratio of hadronic to leptonic activity of roughly 5:1. The total transverse energy of such events is typically a sizable fraction of the beam energy. Perturbative hard scattering processes at energies well above the Planck scale are cloaked behind a horizon, thus limiting the ability to probe short distances. The high energy black hole cross section grows with energy at a rate determined by the dimensionality and geometry of the extra dimensions. This dependence therefore probes the extra dimensions at distances larger than the Planck scale

Viewpoint: the End of the World at the Large Hadron Collider?

International Nuclear Information System (INIS)

Peskin, Michael E.

2008-01-01

New arguments based on astrophysical phenomena constrain the possibility that dangerous black holes will be produced at the CERN Large Hadron Collider. On 8 August, the Large Hadron Collider (LHC) at CERN injected its first beams, beginning an experimental program that will produce proton-proton collisions at an energy of 14 TeV. Particle physicists are waiting expectantly. The reason is that the Standard Model of strong, weak, and electromagnetic interactions, despite its many successes, is clearly incomplete. Theory says that the holes in the model should be filled by new physics in the energy region that will be studied by the LHC. Some candidate theories are simple quick fixes, but the most interesting ones involve new concepts of spacetime waiting to be discovered. Look up the LHC on Wikipedia, however, and you will find considerable space devoted to safety concerns. At the LHC, we will probe energies beyond those explored at any previous accelerator, and we hope to create particles that have never been observed. Couldn't we, then, create particles that would actually be dangerous, for example, ones that would eat normal matter and eventually turn the earth into a blob of unpleasantness? It is morbid fun to speculate about such things, and candidates for such dangerous particles have been suggested. These suggestions have been analyzed in an article in Reviews of Modern Physics by Jaffe, Busza, Wilczek, and Sandweiss and excluded on the basis of constraints from observation and from the known laws of physics. These conclusions have been upheld by subsequent studies conducted at CERN.

CERN to start Large Hadron Collider november 2007

CERN Multimedia

2006-01-01

"The Large Hadron Collider (LHC) is expected to provide its first collisions in November 2007, CERN has announced. A two-month run at 0.9 TeV is planned for 2007 to test the accelerating and detecting equipment, and a full power run at 14 TeV is expected in the spring of 2008."

Secondary particle in background levels and effects on detectors at future hadron colliders

International Nuclear Information System (INIS)

Pal, T.

1993-06-01

The next generation of hadron colliders, the Superconducting Super Collider (SSC) and the Large Hadron Collider (LHC), will operate at high center-of-mass energies and luminosities. Namely, for the SSC (LHC) √s = 40 TeV (√s = 16 TeV) and L = 10 33 cm -2 s -1 (L = 3 x 10 34 cm -2 s -1 ). These conditions will result in the production of large backgrounds as well as radiation environments. Ascertaining the backgrounds, in terms of the production of secondary charged and neutral particles, and the radiation environments are important considerations for the detectors proposed for these colliders. An initial investigation of the radiation levels in the SSC detectors was undertaken by D. Groom and colleagues, in the context of the ''task force on radiation levels in the SSC interaction regions.'' The method consisted essentially of an analytic approach, using standard descriptions of average events in conjunction with simulations of secondary processes. Following Groom's work, extensive Monte Carlo simulations were performed to address the issues of backgrounds and radiation environments for the GEM and SD C3 experiments proposed at the SSC, and for the ATLAS and CMS experiments planned for the LHC. The purpose of the present article is to give a brief summary of some aspects of the methods, assumptions, and calculations performed to date (principally for the SSC detectors), and to stress the relevance of such calculations to the detectors proposed for the study of B-physics in particular

A Large Hadron Electron Collider at CERN: Report on the Physics and Design Concepts for Machine and Detector

CERN Document Server

Abelleira Fernandez, J.L.; Akay, A.N.; Aksakal, H.; Albacete, J.L.; Alekhin, S.; Allport, P.; Andreev, V.; Appleby, R.B.; Arikan, E.; Armesto, N.; Azuelos, G.; Bai, M.; Barber, D.; Bartels, J.; Behnke, O.; Behr, J.; Belyaev, A.S.; Ben-Zvi, I.; Bernard, N.; Bertolucci, S.; Bettoni, S.; Biswal, S.; Blumlein, J.; Bottcher, H.; Bogacz, A.; Bracco, C.; Brandt, G.; Braun, H.; Brodsky, S.; Buning, O.; Bulyak, E.; Buniatyan, A.; Burkhardt, H.; Cakir, I.T.; Cakir, O.; Calaga, R.; Cetinkaya, V.; Ciapala, E.; Ciftci, R.; Ciftci, A.K.; Cole, B.A.; Collins, J.C.; Dadoun, O.; Dainton, J.; De Roeck, A.; d'Enterria, D.; Dudarev, A.; Eide, A.; Enberg, R.; Eroglu, E.; Eskola, K.J.; Favart, L.; Fitterer, M.; Forte, S.; Gaddi, A.; Gambino, P.; Garcia Morales, H.; Gehrmann, T.; Gladkikh, P.; Glasman, C.; Godbole, R.; Goddard, B.; Greenshaw, T.; Guffanti, A.; Guzey, V.; Gwenlan, C.; Han, T.; Hao, Y.; Haug, F.; Herr, W.; Herve, A.; Holzer, B.J.; Ishitsuka, M.; Jacquet, M.; Jeanneret, B.; Jimenez, J.M.; Jowett, J.M.; Jung, H.; Karadeniz, H.; Kayran, D.; Kilic, A.; Kimura, K.; Klein, M.; Klein, U.; Kluge, T.; Kocak, F.; Korostelev, M.; Kosmicki, A.; Kostka, P.; Kowalski, H.; Kramer, G.; Kuchler, D.; Kuze, M.; Lappi, T.; Laycock, P.; Levichev, E.; Levonian, S.; Litvinenko, V.N.; Lombardi, A.; Maeda, J.; Marquet, C.; Mellado, B.; Mess, K.H.; Milanese, A.; Moch, S.; Morozov, I.I.; Muttoni, Y.; Myers, S.; Nandi, S.; Nergiz, Z.; Newman, P.R.; Omori, T.; Osborne, J.; Paoloni, E.; Papaphilippou, Y.; Pascaud, C.; Paukkunen, H.; Perez, E.; Pieloni, T.; Pilicer, E.; Pire, B.; Placakyte, R.; Polini, A.; Ptitsyn, V.; Pupkov, Y.; Radescu, V.; Raychaudhuri, S.; Rinol, L.; Rohini, R.; Rojo, J.; Russenschuck, S.; Sahin, M.; Salgado, C.A.; Sampei, K.; Sassot, R.; Sauvan, E.; Schneekloth, U.; Schorner-Sadenius, T.; Schulte, D.; Senol, A.; Seryi, A.; Sievers, P.; Skrinsky, A.N.; Smith, W.; Spiesberger, H.; Stasto, A.M.; Strikman, M.; Sullivan, M.; Sultansoy, S.; Sun, Y.P.; Surrow, B.; Szymanowski, L.; Taels, P.; Tapan, I.; Tasci, T.; Tassi, E.; Ten Kate, H.; Terron, J.; Thiesen, H.; Thompson, L.; Tokushuku, K.; Tomas Garcia, R.; Tommasini, D.; Trbojevic, D.; Tsoupas, N.; Tuckmantel, J.; Turkoz, S.; Trinh, T.N.; Tywoniuk, K.; Unel, G.; Urakawa, J.; VanMechelen, P.; Variola, A.; Veness, R.; Vivoli, A.; Vobly, P.; Wagner, J.; Wallny, R.; Wallon, S.; Watt, G.; Weiss, C.; Wiedemann, U.A.; Wienands, U.; Willeke, F.; Xiao, B.W.; Yakimenko, V.; Zarnecki, A.F.; Zhang, Z.; Zimmermann, F.; Zlebcik, R.; Zomer, F.

2012-01-01

The physics programme and the design are described of a new collider for particle and nuclear physics, the Large Hadron Electron Collider (LHeC), in which a newly built electron beam of 60 GeV, up to possibly 140 GeV, energy collides with the intense hadron beams of the LHC. Compared to HERA, the kinematic range covered is extended by a factor of twenty in the negative four-momentum squared, $Q^2$, and in the inverse Bjorken $x$, while with the design luminosity of $10^{33}$ cm$^{-2}$s$^{-1}$ the LHeC is projected to exceed the integrated HERA luminosity by two orders of magnitude. The physics programme is devoted to an exploration of the energy frontier, complementing the LHC and its discovery potential for physics beyond the Standard Model with high precision deep inelastic scattering measurements. These are designed to investigate a variety of fundamental questions in strong and electroweak interactions. The physics programme also includes electron-deuteron and electron-ion scattering in a $(Q^2, 1/x)$ ran...

Radioactivation of silicon tracker modules in high-luminosity hadron collider radiation environments

CERN Document Server

Dawson, I; Buttar, C; Cindro, V; Mandic, I

2003-01-01

One of the consequences of operating detector systems in harsh radiation environments will be radioactivation of the components. This will certainly be true in experiments such as ATLAS and CMS, which are currently being built to exploit the physics potential at CERN's Large Hadron Collider. If the levels of radioactivity and corresponding dose rates are significant, then there will be implications for any access or maintenance operations. This paper presents predictions for the radioactivation of ATLAS's Semi- Conductor Tracker (SCT) barrel system, based on both calculations and measurements. It is shown that both neutron capture and high-energy hadron reactions must be taken into account. The predictions also show that the SCT barrel-module should not pose any serious radiological problems after operation in high radiation environments.

Stop decay into right-handed sneutrino LSP at hadron colliders

International Nuclear Information System (INIS)

Gouvea, Andre de; Gopalakrishna, Shrihari; Porod, Werner

2006-01-01

Right-handed neutrinos offer us the possibility of accommodating neutrino masses. In a supersymmetric model, this implies the existence of right-handed sneutrinos. Right-handed sneutrinos are expected to be as light as other supersymmetric particles if the neutrinos are Dirac fermions or if the lepton-number breaking scale is at (or below) the supersymmetry (SUSY) breaking scale, assumed to be around the electroweak scale. Depending on the mechanism of SUSY breaking, the lightest right-handed sneutrino may be the lightest supersymmetric particle (LSP). We consider the unique hadron collider signatures of a weak scale right-handed sneutrino LSP, assuming R-parity conservation. For concreteness, we concentrate on stop pair-production and decay at the Tevatron and the Large Hadron Collider, and briefly comment on the production and decay of other supersymmetric particles

Detectors and luminosity for hadron colliders

International Nuclear Information System (INIS)

Diebold, R.

1983-01-01

Three types of very high energy hadron-hadron coliders are discussed in terms of the trade-off between energy and luminosity. The usable luminosity depends both on the physics under study and the rate capabilities of the detector

Radial scaling in inclusive jet production at hadron colliders

Science.gov (United States)

Taylor, Frank E.

2018-03-01

Inclusive jet production in p-p and p ¯ -p collisions shows many of the same kinematic systematics as observed in single-particle inclusive production at much lower energies. In an earlier study (1974) a phenomenology, called radial scaling, was developed for the single-particle inclusive cross sections that attempted to capture the essential underlying physics of pointlike parton scattering and the fragmentation of partons into hadrons suppressed by the kinematic boundary. The phenomenology was successful in emphasizing the underlying systematics of the inclusive particle productions. Here we demonstrate that inclusive jet production at the Large Hadron Collider (LHC) in high-energy p-p collisions and at the Tevatron in p ¯ -p inelastic scattering shows similar behavior. The ATLAS inclusive jet production plotted as a function of this scaling variable is studied for √s of 2.76, 7 and 13 TeV and is compared to p ¯ -p inclusive jet production at 1.96 TeV measured at the CDF and D0 at the Tevatron and p-Pb inclusive jet production at the LHC ATLAS at √sNN=5.02 TeV . Inclusive single-particle production at Fermi National Accelerator Laboratory fixed target and Intersecting Storage Rings energies are compared to inclusive J /ψ production at the LHC measured in ATLAS, CMS and LHCb. Striking common features of the data are discussed.

Forward-central jet correlations at the Large Hadron Collider

International Nuclear Information System (INIS)

Deak, M.; Hautmann, F.; Jung, H.; Antwerpen Univ.; Kutak, K.

2010-12-01

For high-p T forward processes at the Large Hadron Collider (LHC), QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. The theoretical framework to resum consistently both kinds of logarithmic corrections to higher orders in perturbation theory is based on QCD high-energy factorization. We present numerical Monte Carlo applications of this method to final-state observables associated with production of one forward and one central jet. By computing jet correlations in rapidity and azimuth, we analyze the role of corrections to the parton-showering chain from large-angle gluon radiation, and discuss this in relationship with Monte Carlo results modeling interactions due to multiple parton chains. (orig.)

Cooldown and Warmup Studies for the Large Hadron Collider

CERN Document Server

Lebrun, P; Tavian, L; Wagner, U

1998-01-01

The Large Hadron Collider (LHC), currently under construction at CERN, will make use of superconducting magnets operating in superfluid helium below 2 K. The LHC ring is divided in 8 sectors, each of them cooled by a refrigerator of 18 kW at 4.5 K equivalent cooling power. For the cooldown and warmup of a 3.3 km long LHC sector, the flow available above 80 K per refrigerator is 770 g/s and the cor responding capacity is 600 kW. This paper presents the results of cooldown and warmup simulations, as concerns time delays, temperature difference across magnets, available power and flow-rates, and estimates of energy and liquid nitrogen consumption.

Literature in focus - The Large Hadron Collider: A Marvel of Technology

CERN Document Server

Cecile Noels

Inside an insulating vacuum chamber in a tunnel about 100 metres below the surface of the Franco-Swiss plain near Geneva, packets of protons whirl around the 27-km circumference of the Large Hadron Collider (LHC) at a speed close to that of light, colliding every 25 nanoseconds at four beam crossing points. The products of these collisions, of which hundreds of billions will be produced each second, are observed and measured with the most advanced particle-detection technology, capable of tracking individual particles as they generate a signature track during their passage through the detectors. All this information is captured, filtered and piped to huge networks of microprocessors for analysis and study by an international team of physicists. When the Large Hadron Collider (LHC) comes on line in 2009, it will be the largest scientific experiment ever constructed, and the data it produces will lead to a new understanding of our Universe. Many thousands of scientists and engineers were behind the planning...

Literature in focus - The Large Hadron Collider: A Marvel of Technology

CERN Document Server

Cecile Noels

2009-01-01

Inside an insulating vacuum chamber in a tunnel about 100 metres below the surface of the Franco-Swiss plain near Geneva, packets of protons whirl around the 27-km circumference of the Large Hadron Collider (LHC) at a speed close to that of light, colliding every 25 nanoseconds at four beam crossing points. The products of these collisions, of which hundreds of billions will be produced each second, are observed and measured with the most advanced particle-detection technology, capable of tracking individual particles as they generate a signature track during their passage through the detectors. All this information is captured, filtered and piped to huge networks of microprocessors for analysis and study by an international team of physicists. When the Large Hadron Collider (LHC) comes on line in 2009, it will be the largest scientific experiment ever constructed, and the data it produces will lead to a new understanding of our Universe. Many thousands of scientists and engineers were behind the planning...

Supersymmetric Higgs pair discovery prospects at hadron colliders

CERN Document Server

Belyaev, A; Éboli, Oscar J P; Mizukoshi, J K; Novaes, S F

2000-01-01

We study the potential of hadron colliders in the search for the pair production of neutral Higgs bosons in the framework of the Minimal Supersymmetric Standard Model. Using analytical expressions for the relevant amplitudes, we perform a detailed signal and background analysis, working out efficient kinematical cuts for the extraction of the signal. The important role of squark loop contributions to the signal is emphasised. If the signal is sufficiently enhanced by these contributions, it could even be observable at the next run of the upgraded Tevatron collider in the near future. At the LHC the pair production of light and heavy Higgs bosons might be detectable simultaneously.

High-Luminosity Large Hadron Collider (HL-LHC) Preliminary Design Report

CERN Document Server

Apollinari, G; Béjar Alonso, I; Brüning, O; Lamont, M; Rossi, L

2015-01-01

The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community of about 7,000 scientists working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will need a major upgrade in the 2020s. This will increase its luminosity (rate of collisions) by a factor of five beyond the original design value and the integrated luminosity (total collisions created) by a factor ten. The LHC is already a highly complex and exquisitely optimised machine so this upgrade must be carefully conceived and will require about ten years to implement. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11-12 tesla superconducting magnets, compact superconducting cav...

Searches for supersymmetry at high-energy colliders

International Nuclear Information System (INIS)

Feng, Jonathan L.; Grivaz, Jean-Francois; Nachtman, Jane

2010-01-01

This review summarizes the state of the art in searches for supersymmetry at colliders on the eve of the Large Hadron Collider era. Supersymmetry is unique among extensions of the standard model in being motivated by naturalness, dark matter, and force unification, both with and without gravity. At the same time, weak-scale supersymmetry encompasses a wide range of experimental signals that are also found in many other frameworks. Motivations for supersymmetry are recalled and the various models and their distinctive features are reviewed. Searches for neutral and charged Higgs bosons and standard-model superpartners at the high energy frontier are summarized comprehensively, considering both canonical and noncanonical supersymmetric models, and including results from the LEP collider at CERN, HERA at DESY, and the Fermilab Tevatron.

Large Hadron Collider commissioning and first operation.

Science.gov (United States)

Myers, S

2012-02-28

A history of the commissioning and the very successful early operation of the Large Hadron Collider (LHC) is described. The accident that interrupted the first commissioning, its repair and the enhanced protection system put in place are fully described. The LHC beam commissioning and operational performance are reviewed for the period from 2010 to mid-2011. Preliminary plans for operation and future upgrades for the LHC are given for the short and medium term.

The large hadron collider project

International Nuclear Information System (INIS)

Maiani, L.

1999-01-01

Knowledge of the fundamental constituents of matter has greatly advanced, over the last decades. The standard theory of fundamental interactions presents us with a theoretically sound picture, which describes with great accuracy known physical phenomena on most diverse energy and distance scales. These range from 10 -16 cm, inside the nucleons, up to large-scale astrophysical bodies, including the early Universe at some nanosecond after the Big-Bang and temperatures of the order of 10 2 GeV. The picture is not yet completed, however, as we lack the observation of the Higgs boson, predicted in the 100-500 GeV range - a particle associated with the generation of particle masses and with the quantum fluctuations in the primordial Universe. In addition, the standard theory is expected to undergo a change of regime in the 10 3 GeV region, with the appearance of new families of particles, most likely associated with the onset of a new symmetry (supersymmetry). In 1994, the CERN Council approved the construction of the large hadron collider (LHC), a proton-proton collider of a new design to be installed in the existing LEP tunnel, with an energy of 7 TeV per beam and extremely large luminosity, of ∝10 34 cm -2 s -1 . Construction was started in 1996, with the additional support of the US, Japan, Russia, Canada and other European countries, making the LHC a really global project, the first one in particle physics. After a short review of the physics scenario, I report on the present status of the LHC construction. Special attention is given to technological problems such as the realization of the super-conducting dipoles, following an extensive R and D program with European industries. The construction of the large LHC detectors has required a vast R and D program by a large international community, to overcome the problems posed by the complexity of the collisions and by the large luminosity of the machine. (orig.)

The Large Hadron Collider: lessons learned and summary

CERN Document Server

Llewellyn Smith, Chris

2012-01-01

The Large Hadron Collider (LHC) machine and detectors are now working superbly. There are good reasons to hope and expect that the new domain that the LHC is already exploring, operating at 7 TeV with a luminosity of 1033 cm−2 s−1, or the much bigger domain that will be opened up as the luminosity increases to over 1034 and the energy to 14 TeV, will provide clues that will usher in a new era in particle physics. The arguments that new phenomena will be found in the energy range that will be explored by the LHC have become stronger since they were first seriously analysed in 1984, although their essence has changed little. I will review the evolution of these arguments in a historical context, the development of the LHC project since 1984, and the outlook in the light of reports on the performance of the machine and detectors presented at this meeting.

Longitudinal emittance blowup in the large hadron collider

CERN Document Server

Baudrenghien, P

2013-01-01

The Large Hadron Collider (LHC) relies on Landau damping for longitudinal stability. To avoid decreasing the stability margin at high energy, the longitudinal emittance must be continuously increased during the acceleration ramp. Longitudinal blowup provides the required emittance growth. The method was implemented through the summer of 2010. Band-limited RF phase-noise is injected in the main accelerating cavities during the whole ramp of about 11min. Synchrotron frequencies change along the energy ramp, but the digitally created noise tracks the frequency change. The position of the noise-band, relative to the nominal synchrotron frequency, and the bandwidth of the spectrum are set by pre-defined constants, making the diffusion stop at the edges of the demanded distribution. The noise amplitude is controlled by feedback using the measurement of the average bunch length. This algorithm reproducibly achieves the programmed bunch length of about 1.2ns, at flat top with low bunch-to-bunch scatter and provides a...

Towards Future Circular Colliders

CERN Document Server

AUTHOR|(CDS)2108454; Zimmermann, Frank

2016-01-01

The Large Hadron Collider (LHC) at CERN presently provides proton-proton collisions at a centre-of-mass (c.m.) energy of 13 TeV. The LHC design was started more than 30 years ago, and its physics programme will extend through the second half of the 2030’s. The global Future Circular Collider (FCC) study is now preparing for a post-LHC project. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh) in a new ∼100 km tunnel. It also includes the design of a high-luminosity electron-positron collider (FCC-ee) as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on $Nb_3Sn$ superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton c...

Hadronic vs. electromagnetic pulse shape discrimination in CsI(Tl) for high energy physics experiments

Science.gov (United States)

Longo, S.; Roney, J. M.

2018-03-01

Pulse shape discrimination using CsI(Tl) scintillators to perform neutral hadron particle identification is explored with emphasis towards application at high energy electron-positron collider experiments. Through the analysis of the pulse shape differences between scintillation pulses from photon and hadronic energy deposits using neutron and proton data collected at TRIUMF, it is shown that the pulse shape variations observed for hadrons can be modelled using a third scintillation component for CsI(Tl), in addition to the standard fast and slow components. Techniques for computing the hadronic pulse amplitudes and shape variations are developed and it is shown that the intensity of the additional scintillation component can be computed from the ionization energy loss of the interacting particles. These pulse modelling and simulation methods are integrated with GEANT4 simulation libraries and the predicted pulse shape for CsI(Tl) crystals in a 5 × 5 array of 5 × 5 × 30 cm3 crystals is studied for hadronic showers from 0.5 and 1 GeV/c KL0 and neutron particles. Using a crystal level and cluster level approach for photon vs. hadron cluster separation we demonstrate proof-of-concept for neutral hadron detection using CsI(Tl) pulse shape discrimination in high energy electron-positron collider experiments.

Luminosity Tuning at the Large Hadron Collider

CERN Document Server

Wittmer, W

2006-01-01

By measuring and adjusting the beta-functions at the interaction point (IP the luminosity is being optimized. In LEP (Large Electron Positron Collider) this was done with the two closest doublet magnets. This approach is not applicable for the LHC (Large Hadron Collider) and RHIC (Relativistic Heavy Ion Collider) due to the asymmetric lattice. In addition in the LHC both beams share a common beam pipe through the inner triplet magnets (in these region changes of the magnetic field act on both beams). To control and adjust the beta-functions without perturbation of other optics functions, quadrupole groups situated on both sides further away from the IP have to be used where the two beams are already separated. The quadrupoles are excited in specific linear combinations, forming the so-called "tuning knobs" for the IP beta-functions. For a specific correction one of these knobs is scaled by a common multiplier. The different methods which were used to compute such knobs are discussed: (1) matching in MAD, (2)i...

submitter Projects for ultra-high-energy circular colliders at CERN

CERN Document Server

Bogomyagkov, A V; Levichev, E B; Piminov, P A; Sinyatkin, S V; Shatilov, D N; Benedict, M; Oide, K; Zimmermann, F

2016-01-01

Within the Future Circular Collider (FCC) design study launched at CERN in 2014, it is envisaged to construct hadron (FCC-hh) and lepton (FCC-ee) ultra-high-energy machines aimed to replace the LHC upon the conclusion of its research program. The Budker Institute of Nuclear Physics is actively involved in the development of the FCC-ee electron–positron collider. The Crab Waist (CR) scheme of the collision region that has been proposed by INP and will be implemented at FCC-ee is expected to provide high luminosity over a broad energy range. The status and development of the FCC project are described, and its parameters and limitations are discussed for the lepton collider in particular.

QCD threshold corrections for gluino pair production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Langenfeld, Ulrich [Wuerzburg Univ. (Germany); Moch, Sven-Olaf; Pfoh, Torsten [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2012-11-15

We present the complete threshold enhanced predictions in QCD for the total cross section of gluino pair production at hadron colliders at next-to-next-to-leading order. Thanks to the computation of the required one-loop hard matching coefficients our results are accurate to the next-to-next-to-leading logarithm. In a brief phenomenological study we provide predictions for the total hadronic cross sections at the LHC and we discuss the uncertainties arising from scale variations and the parton distribution functions.

Comprehending particle production in proton+proton and heavy-ion collisions at the Large Hadron Collider

International Nuclear Information System (INIS)

Sahoo, Raghunath

2017-01-01

In the extreme conditions of temperature and energy density, nuclear matter undergoes a transition to a new phase, which is governed by partonic degrees of freedom. This phase is called Quark-Gluon Plasma (QGP). The transition to QGP phase was conjectured to take place in central nucleus-nucleus collisions. With the advent of unprecedented collision energy at the Large Hadron Collider (LHC), at CERN, it has been possible to create energy densities higher than that was predicted by lattice QCD for a deconfinement transition

The Initial Stages of Colliding Nuclei and Hadrons

International Nuclear Information System (INIS)

Tribedy, Prithwish

2017-01-01

The final day of the Hot Quarks 2016 conference was focused on the discussions of the initial stages of colliding nuclei and hadrons. In this conference proceedings we give a brief overview of a few selective topics discussed at the conference that include latest developments in the theoretical description of the initial state towards understanding a number of recent experimental results from RHIC and LHC. (paper)

Forward-central jet correlations at the Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Deak, M. [Univ. Autonoma de Madrid, Cantoblanco (Spain). Inst. de Fisica Teorica UAM/CSIC; Hautmann, F. [Oxford Univ. (United Kingdom). Theoretical Physics Dept.; Jung, H. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Antwerpen Univ. (Belgium). Elementaire Deeltjes Fysics; Kutak, K. [Antwerpen Univ. (Belgium). Elementaire Deeltjes Fysics

2010-12-15

For high-p{sub T} forward processes at the Large Hadron Collider (LHC), QCD logarithmic corrections in the hard transverse momentum and in the large rapidity interval may both be quantitatively significant. The theoretical framework to resum consistently both kinds of logarithmic corrections to higher orders in perturbation theory is based on QCD high-energy factorization. We present numerical Monte Carlo applications of this method to final-state observables associated with production of one forward and one central jet. By computing jet correlations in rapidity and azimuth, we analyze the role of corrections to the parton-showering chain from large-angle gluon radiation, and discuss this in relationship with Monte Carlo results modeling interactions due to multiple parton chains. (orig.)

A Large Hadron Electron Collider at CERN

CERN Document Server

Abelleira Fernandez, J L; Adzic, P; Akay, A N; Aksakal, H; Albacete, J L; Allanach, B; Alekhin, S; Allport, P; Andreev, V; Appleby, R B; Arikan, E; Armesto, N; Azuelos, G; Bai, M; Barber, D; Bartels, J; Behnke, O; Behr, J; Belyaev, A S; Ben-Zvi, I; Bernard, N; Bertolucci, S; Bettoni, S; Biswal, S; Blumlein, J; Bottcher, H; Bogacz, A; Bracco, C; Bracinik, J; Brandt, G; Braun, H; Brodsky, S; Bruning, O; Bulyak, E; Buniatyan, A; Burkhardt, H; Cakir, I T; Cakir, O; Calaga, R; Caldwell, A; Cetinkaya, V; Chekelian, V; Ciapala, E; Ciftci, R; Ciftci, A K; Cole, B A; Collins, J C; Dadoun, O; Dainton, J; Roeck, A.De; d'Enterria, D; DiNezza, P; Dudarev, A; Eide, A; Enberg, R; Eroglu, E; Eskola, K J; Favart, L; Fitterer, M; Forte, S; Gaddi, A; Gambino, P; Garcia Morales, H; Gehrmann, T; Gladkikh, P; Glasman, C; Glazov, A; Godbole, R; Goddard, B; Greenshaw, T; Guffanti, A; Guzey, V; Gwenlan, C; Han, T; Hao, Y; Haug, F; Herr, W; Herve, A; Holzer, B J; Ishitsuka, M; Jacquet, M; Jeanneret, B; Jensen, E; Jimenez, J M; Jowett, J M; Jung, H; Karadeniz, H; Kayran, D; Kilic, A; Kimura, K; Klees, R; Klein, M; Klein, U; Kluge, T; Kocak, F; Korostelev, M; Kosmicki, A; Kostka, P; Kowalski, H; Kraemer, M; Kramer, G; Kuchler, D; Kuze, M; Lappi, T; Laycock, P; Levichev, E; Levonian, S; Litvinenko, V N; Lombardi, A; Maeda, J; Marquet, C; Mellado, B; Mess, K H; Milanese, A; Milhano, J G; Moch, S; Morozov, I I; Muttoni, Y; Myers, S; Nandi, S; Nergiz, Z; Newman, P R; Omori, T; Osborne, J; Paoloni, E; Papaphilippou, Y; Pascaud, C; Paukkunen, H; Perez, E; Pieloni, T; Pilicer, E; Pire, B; Placakyte, R; Polini, A; Ptitsyn, V; Pupkov, Y; Radescu, V; Raychaudhuri, S; Rinolfi, L; Rizvi, E; Rohini, R; Rojo, J; Russenschuck, S; Sahin, M; Salgado, C A; Sampei, K; Sassot, R; Sauvan, E; Schaefer, M; Schneekloth, U; Schorner-Sadenius, T; Schulte, D; Senol, A; Seryi, A; Sievers, P; Skrinsky, A N; Smith, W; South, D; Spiesberger, H; Stasto, A M; Strikman, M; Sullivan, M; Sultansoy, S; Sun, Y P; Surrow, B; Szymanowski, L; Taels, P; Tapan, I; Tasci, T; Tassi, E; Kate, H.Ten; Terron, J; Thiesen, H; Thompson, L; Thompson, P; Tokushuku, K; Tomas Garcia, R; Tommasini, D; Trbojevic, D; Tsoupas, N; Tuckmantel, J; Turkoz, S; Trinh, T N; Tywoniuk, K; Unel, G; Ullrich, T; Urakawa, J; VanMechelen, P; Variola, A; Veness, R; Vivoli, A; Vobly, P; Wagner, J; Wallny, R; Wallon, S; Watt, G; Weiss, C; Wiedemann, U A; Wienands, U; Willeke, F; Xiao, B W; Yakimenko, V; Zarnecki, A F; Zhang, Z; Zimmermann, F; Zlebcik, R; Zomer, F; CERN. Geneva. LHeC Department

2012-01-01

This document provides a brief overview of the recently published report on the design of the Large Hadron Electron Collider (LHeC), which comprises its physics programme, accelerator physics, technology and main detector concepts. The LHeC exploits and develops challenging, though principally existing, accelerator and detector technologies. This summary is complemented by brief illustrations of some of the highlights of the physics programme, which relies on a vastly extended kinematic range, luminosity and unprecedented precision in deep inelastic scattering. Illustrations are provided regarding high precision QCD, new physics (Higgs, SUSY) and electron-ion physics. The LHeC is designed to run synchronously with the LHC in the twenties and to achieve an integrated luminosity of O(100) fb$^{-1}$. It will become the cleanest high resolution microscope of mankind and will substantially extend as well as complement the investigation of the physics of the TeV energy scale, which has been enabled by the LHC.

Recent results from the Large Hadron Collider

CERN Document Server

Alcaraz Maestre, J

2013-01-01

We present an overview of the physics results obtained by experiments at the Large Hadron Collider (LHC) in 2009–2010, for an integrated luminosity of L ≈ 40 pb$^{−1}$ , collected mostly at a centre-of-mass energy of √ s = 7 TeV. After an introduction to the physics environment at the LHC and the current performance of the accelerator and detectors, we will discuss quantum chro- modynamics and B-physics analyses, W and Z production, the first results in the top sector, and searches for new physics, with particular emphasis on su- persymmetry and Higgs studies. While most of the presented results are in remarkable agreement with Standard Model predictions, the excellent perfor- mance of the LHC machine and experiments, the prompt analysis of all data within just a few months after the end of data taking, and the high quality of the results obtained constitute an encouraging step towards unique measurements and exciting discoveries in the 2011–2012 period and beyond.

Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider

CERN Document Server

Bruce, R.; Boccone, V.; Bracco, C.; Brugger, M.; Cauchi, M.; Cerutti, F.; Deboy, D.; Ferrari, A.; Lari, L.; Marsili, A.; Mereghetti, A.; Mirarchi, D.; Quaranta, E.; Redaelli, S.; Robert-Demolaize, G.; Rossi, A.; Salvachua, B.; Skordis, E.; Tambasco, C.; Valentino, G.; Weiler, T.; Vlachoudis, V.; Wollmann, D.

2014-08-21

The CERN Large Hadron Collider (LHC) is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010--2013, the LHC was routinely storing protons at 3.5--4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An un-controlled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multi-stage collimation system has been installed in order to safely intercept high-amplitude beam protons before they are lost elsewhere. To guarantee adequate protection from the collimators, a detailed theoretical understanding is needed. This article presents results of numerical simulations of the distribution of beam losses around the LHC that have leaked out of the co...

Detector development for the High Luminosity Large Hadron Collider

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00367854; Gößling, Claus

To maximise the discovery potential of the Large Hadron Collider, it will be upgraded to the High Luminosity Large Hadron Collider in 2024. New detector challenges arise from the higher instantaneous luminosity and the higher particle flux. The new ATLAS Inner Tracker will replace the current tracking detector to be able to cope with these challenges. Many pixel detector technologies exist for particle tracking, but their suitability for the ATLAS Inner Tracker needs to be studied. Active high-voltage CMOS sensors, which are produced in industrialised processes, offer a fast readout and radiation tolerance. In this thesis the HV2FEI4v2 sensor, which is capacitively coupled to the ATLAS Pixel FE-I4 readout chip, is characterised for the usage in the outer layers of the ATLAS Inner Tracker. Key quantities of this prototype module are studied, such as the hit efficiency and the subpixel encoding. The early HV2FEI4v2 prototype shows promising results as a starting point for further module developments. Active CMO...

Energy Extraction in the CERN Large Hadron Collider a Project Overview

CERN Document Server

Dahlerup-Petersen, K; Kazmine, B; Medvedko, A S; Sytchev, V V; Vasilev, L B

2001-01-01

In case of a resistive transition (quench), fast and reliable extraction of the magnetic energy, stored in the superconducting coils of the electromagnets of a particle collider, represents an important part of its magnet protection system. In general, the quench detectors, the quench heaters and the cold by-pass diodes across each magnet, together with the energy extraction facilities provide the required protection of the quenching superconductors against damage due to local energy dissipation. In CERN's LHC machine the energy stored in each of its eight superconducting dipole chains exceeds 1300 MJ. Following an opening of the extraction switches this energy will be absorbed in large extraction resistors located in the underground collider tunnel or adjacent galleries, during the exponential current decay. Also the sixteen, 13 kA quadrupole chains (QF, QD) and more than one hundred and fifty, 600 A circuits of the corrector magnets will be equipped with extraction systems. The extraction switch-gear is bas...

Hunting electroweakinos at future hadron colliders and direct detection experiments

Energy Technology Data Exchange (ETDEWEB)

Cortona, Giovanni Grilli di [SISSA - International School for Advanced Studies,Via Bonomea 265, I-34136 Trieste (Italy); INFN - Sezione di Trieste,via Valerio 2, I-34127 Trieste (Italy)

2015-05-07

We analyse the mass reach for electroweakinos at future hadron colliders and their interplay with direct detection experiments. Motivated by the LHC data, we focus on split supersymmetry models with different electroweakino spectra. We find for example that a 100 TeV collider may explore Winos up to ∼7 TeV in low scale gauge mediation models or thermal Wino dark matter around 3 TeV in models of anomaly mediation with long-lived Winos. We show moreover how collider searches and direct detection experiments have the potential to cover large part of the parameter space even in scenarios where the lightest neutralino does not contribute to the whole dark matter relic density.

Theory Overview of Electroweak Physics at Hadron Colliders

Energy Technology Data Exchange (ETDEWEB)

Campbell, John M. [Fermilab

2016-09-03

This contribution summarizes some of the important theoretical progress that has been made in the arena of electroweak physics at hadron colliders. The focus is on developments that have sharpened theoretical predictions for final states produced through electroweak processes. Special attention is paid to new results that have been presented in the last year, since LHCP2015, as well as on key issues for future measurements at the LHC.

Fast symplectic map tracking for the CERN Large Hadron Collider

Directory of Open Access Journals (Sweden)

Dan T. Abell

2003-06-01

Full Text Available Tracking simulations remain the essential tool for evaluating how multipolar imperfections in ring magnets restrict the domain of stable phase-space motion. In the Large Hadron Collider (LHC at CERN, particles circulate at the injection energy, when multipole errors are most significant, for more than 10^{7} turns, but systematic tracking studies are limited to a small fraction of this total time—even on modern computers. A considerable speedup is expected by replacing element-by-element tracking with the use of a symplectified one-turn map. We have applied this method to the realistic LHC lattice, version 6, and report here our results for various map orders, with special emphasis on precision and speed.

The Large Hadron Collider unraveling the mysteries of the universe

CERN Document Server

Beech, Martin

2010-01-01

The Large Hadron Collider (LHC) is the largest engineering project ever undertaken, and one of the most expensive. Why are physicists around the world so excited about it? What secrets of the universe does this gargantuan piece of machinery hope to reveal? What risks are there in operating it? Could the exotic particles that are produced in the collisions—including tiny black holes that should wink into and out of existence— between subatomic particles be a threat not only to humankind but to the planet itself? In this thorough and engaging review of cutting-edge physics and cosmology, you will learn why the collider was built and how it works. You will find out what scientists are hoping to find out and what current aspects of the Standard Model might need to be revised. You will even learn about the quest to identify so-called dark matter and dark energy, which many now feel make up most of what's out there. This is a wild ride into some very unfamiliar and strange territory, but it is well worth your t...

Industrial Technology for Unprecented Energy and Luminosity The Large Hadron Collider

CERN Document Server

Lebrun, P

2004-01-01

With over 3 billion Swiss francs procurement contracts under execution in industry and the installation of major technical systems in its first 3.3 km sector, the Large Hadron Collider (LHC) construction is now in full swing at CERN, the European Organization for Nuclear Research. The LHC is not only the most challenging particle accelerator, it is also the largest global project ever for a scientific instrument based on advanced technology. Starting from accelerator performance requirements, we recall how these can be met by an appropriate combination of technologies, such as high-field superconducting magnets, superfluid helium cryogenics, power electronics, with particular emphasis on developments required to meet demanding specifications, and industrialization issues which had to be solved for achieving series production of precision components under tight quality assurance and within limited resources. This provides the opportunity for reviewing the production status of the main systems and the progress ...

Advanced superconducting technology for global science: The Large Hadron Collider at CERN

Science.gov (United States)

Lebrun, Ph.

2002-05-01

The Large Hadron Collider (LHC), presently in construction at CERN, the European Organization for Nuclear Research near Geneva (Switzerland), will be, upon its completion in 2005 and for the next twenty years, the most advanced research instrument of the world's high-energy physics community, providing access to the energy frontier above 1 TeV per elementary constituent. Re-using the 26.7-km circumference tunnel and infrastructure of the past LEP electron-positon collider, operated until 2000, the LHC will make use of advanced superconducting technology-high-field Nb-Ti superconducting magnets operated in superfluid helium and a cryogenic ultra-high vacuum system-to bring into collision intense beams of protons and ions at unprecedented values of center-of-mass energy and luminosity (14 TeV and 1034 cm-2ṡs-1, respectively with protons). After some ten years of focussed R&D, the LHC components are presently series-built in industry and procured through world-wide collaboration. After briefly recalling the physics goals, performance challenges and design choices of the machine, we describe its major technical systems, with particular emphasis on relevant advances in the key technologies of superconductivity and cryogenics, and report on its construction progress.

Probing gluon number fluctuation effects in future electron–hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Amaral, J.T.; Gonçalves, V.P. [Instituto de Física e Matemática, Universidade Federal de Pelotas, Caixa Postal 354, CEP 96010-900, Pelotas, RS (Brazil); Kugeratski, M.S. [Universidade Federal de Santa Catarina, Campus Joinville, Rua Presidente Prudente de Moraes, 406, CEP 89218-000, Joinville, SC (Brazil)

2014-10-15

The description of the QCD dynamics in the kinematical range which will be probed in the future electron–hadron colliders is still an open question. Although phenomenological studies indicate that the gluon number fluctuations, which are related to discreteness in the QCD evolution, are negligible at HERA, the magnitude of these effects for the next generation of colliders still should be estimated. In this paper we investigate inclusive and diffractive ep observables considering a model for the physical scattering amplitude which describes the HERA data. Moreover, we estimate, for the first time, the contribution of the fluctuation effects for the nuclear structure functions. Our results indicate that the study of these observables in the future colliders can be useful to constrain the presence of gluon number fluctuations.

Large Hadron Collider at CERN: Beams generating high-energy-density matter.

Science.gov (United States)

Tahir, N A; Schmidt, R; Shutov, A; Lomonosov, I V; Piriz, A R; Hoffmann, D H H; Deutsch, C; Fortov, V E

2009-04-01

This paper presents numerical simulations that have been carried out to study the thermodynamic and hydrodynamic responses of a solid copper cylindrical target that is facially irradiated along the axis by one of the two Large Hadron Collider (LHC) 7 TeV/ c proton beams. The energy deposition by protons in solid copper has been calculated using an established particle interaction and Monte Carlo code, FLUKA, which is capable of simulating all components of the particle cascades in matter, up to multi-TeV energies. These data have been used as input to a sophisticated two-dimensional hydrodynamic computer code BIG2 that has been employed to study this problem. The prime purpose of these investigations was to assess the damage caused to the equipment if the entire LHC beam is lost at a single place. The FLUKA calculations show that the energy of protons will be deposited in solid copper within about 1 m assuming constant material parameters. Nevertheless, our hydrodynamic simulations have shown that the energy deposition region will extend to a length of about 35 m over the beam duration. This is due to the fact that first few tens of bunches deposit sufficient energy that leads to high pressure that generates an outgoing radial shock wave. Shock propagation leads to continuous reduction in the density at the target center that allows the protons delivered in subsequent bunches to penetrate deeper and deeper into the target. This phenomenon has also been seen in case of heavy-ion heated targets [N. A. Tahir, A. Kozyreva, P. Spiller, D. H. H. Hoffmann, and A. Shutov, Phys. Rev. E 63, 036407 (2001)]. This effect needs to be considered in the design of a sacrificial beam stopper. These simulations have also shown that the target is severely damaged and is converted into a huge sample of high-energy density (HED) matter. In fact, the inner part of the target is transformed into a strongly coupled plasma with fairly uniform physical conditions. This work, therefore, has

Vector-like fermion and standard Higgs production at hadron colliders

International Nuclear Information System (INIS)

Aguila, F. del; Ametller, L.; Kane, G.L.; Vidal, J.; Centro Mixto Valencia Univ./CSIC, Valencia

1990-01-01

Vector-like fermions are characterized by large neutral current decay rates, in particular into Higgs bosons. If they exist, their clear signals at hadron colliders open a window to Higgs detection, especially to the intermediate Higgs mass region. We discuss in some detail rates and signatures for simple cases. (orig.)

Search for invisibly decaying Higgs boson at Large Hadron Collider

Indian Academy of Sciences (India)

In several scenarios of Beyond Standard Model physics, the invisible decay mode of the Higgs boson is an interesting possibility. The search strategy for an invisible Higgs boson at the Large Hadron Collider (LHC), using weak boson fusion process, has been studied in detail, by taking into account all possible ...

Destination Universe: The Incredible Journey of a Proton in the Large Hadron Collider

CERN Multimedia

Lefevre, C

2008-01-01

This brochure illustrates the incredible journey of a proton as he winds his way through the CERN accelerator chain and ends up inside the Large Hadron Collider (LHC). The LHC is CERN's flagship particle accelerator which can collide protons together at close to the speed of light, creating circumstances like those just seconds after the Big Bang.

High energy hadron-hadron collisions

International Nuclear Information System (INIS)

Chou, T.T.

1990-01-01

Results of a study on high energy collision with the geometrical model are summarized in three parts: (i) the elastic hadron-hadron collision, (ii) the inelastic hadron-hadron collision, and (iii) the e + e - annihilation. The geometrical description of high-energy elastic scattering developed earlier is still in general agreement with experiments at the CERN-S bar ppS energies. A simple one-parameter expression for the blackness of bar pp system has been proposed recently which describes very well all existing data from ISR to S bar ppS energies. The geometrical description has also been extended to include processes of fragmentation and diffraction dissociation and other phenomena. In the past five years, a unified physical picture for multiparticle emission in hadron-hadron and e + e - collisions was developed. It focuses on the idea of the wide range of values for the total angular momentum in hadron-hadron collisions. An extension of this consideration yields a theory for the momentum distribution of the outgoing particles which agrees with bar pp and e + e - collision experiments. The results and conclusions of this theory have been extrapolated to higher energies and yielded many predictions which can be experimentally tested. 37 refs

The gluon condensation at high energy hadron collisions

Energy Technology Data Exchange (ETDEWEB)

Zhu, Wei, E-mail: weizhu@mail.ecnu.edu.cn [Department of Physics, East China Normal University, Shanghai 200241 (China); Lan, Jiangshan [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

2017-03-15

We report that the saturation/CGC model of gluon distribution is unstable under action of the chaotic solution in a nonlinear QCD evolution equation, and it evolves to the distribution with a sharp peak at the critical momentum. We find that this gluon condensation is caused by a new kind of shadowing–antishadowing effects, and it leads to a series of unexpected effects in high energy hadron collisions including astrophysical events. For example, the extremely intense fluctuations in the transverse-momentum and rapidity distributions of the gluon jets present the gluon-jet bursts; a sudden increase of the proton–proton cross sections may fill the GZK suppression; the blocking QCD evolution will restrict the maximum available energy of the hadron–hadron colliders.

High-energy high-luminosity electron-ion collider eRHIC

International Nuclear Information System (INIS)

Litvinenko, V.N.; Ben-Zvi, I.; Hammons, L.; Hao, Y.; Webb, S.

2011-01-01

In this paper, we describe a future electron-ion collider (EIC), based on the existing Relativistic Heavy Ion Collider (RHIC) hadron facility, with two intersecting superconducting rings, each 3.8 km in circumference. The replacement cost of the RHIC facility is about two billion US dollars, and the eRHIC will fully take advantage and utilize this investment. We plan adding a polarized 5-30 GeV electron beam to collide with variety of species in the existing RHIC accelerator complex, from polarized protons with a top energy of 325 GeV, to heavy fully-striped ions with energies up to 130 GeV/u. Brookhaven's innovative design, is based on one of the RHIC's hadron rings and a multi-pass energy-recovery linac (ERL). Using the ERL as the electron accelerator assures high luminosity in the 10 33 -10 34 cm -2 sec -1 range, and for the natural staging of eRHIC, with the ERL located inside the RHIC tunnel. The eRHIC will provide electron-hadron collisions in up to three interaction regions. We detail the eRHIC's performance in Section 2. Since first paper on eRHIC paper in 2000, its design underwent several iterations. Initially, the main eRHIC option (the so-called ring-ring, RR, design) was based on an electron ring, with the linac-ring (LR) option as a backup. In 2004, we published the detailed 'eRHIC 0th Order Design Report' including a cost-estimate for the RR design. After detailed studies, we found that an LR eRHIC has about a 10-fold higher luminosity than the RR. Since 2007, the LR, with its natural staging strategy and full transparency for polarized electrons, became the main choice for eRHIC. In 2009, we completed technical studies of the design and dynamics for MeRHIC with 3-pass 4 GeV ERL. We learned much from this evaluation, completed a bottom-up cost estimate for this $350M machine, but then shelved the design. In the same year, we turned again to considering the cost-effective, all-in-tunnel six-pass ERL for our design of the high-luminosity eRHIC. In it

Drell-Yan production at collider energies

International Nuclear Information System (INIS)

Neerven, W.L. Van

1995-01-01

We present some results of the Drell-Yan cross sections dσ/dm and σ tot which includes the O (α s 2 ) contribution to the coefficient function. In particular we study the total cross section σ tot for vector boson production and dσ/dm for low invariant masses m of the lepton pairs at large hadron collider energies. This study includes a detailed discussion of the dependence of the cross sections on the chosen scheme (bar MS versus DIS) and the factorization scale

Measuring CP nature of top-Higgs couplings at the future Large Hadron electron Collider

Directory of Open Access Journals (Sweden)

Baradhwaj Coleppa

2017-07-01

Full Text Available We investigate the sensitivity of top-Higgs coupling by considering the associated vertex as CP phase (ζt dependent through the process pe−→t¯hνe in the future Large Hadron electron Collider. In particular the decay modes are taken to be h→bb¯ and t¯ → leptonic mode. Several distinct ζt dependent features are demonstrated by considering observables like cross sections, top-quark polarisation, rapidity difference between h and t¯ and different angular asymmetries. Luminosity (L dependent exclusion limits are obtained for ζt by considering significance based on fiducial cross sections at different σ-levels. For electron and proton beam-energies of 60 GeV and 7 TeV respectively, at L=100 fb−1, the regions above π/5<ζt≤π are excluded at 2σ confidence level, which reflects better sensitivity expected at the Large Hadron Collider. With appropriate error fitting methodology we find that the accuracy of SM top-Higgs coupling could be measured to be κ=1.00±0.17(0.08 at s=1.3(1.8 TeV for an ultimate L=1ab−1.

Large Hadron particle collider may not have its run this November

CERN Multimedia

2007-01-01

"The Large Hadron Collider (LHC), based at CERN in Geneva, Switzerland, will not run in November this year as scheduled. The LHC was supposed to have a test run this yera, before switching on the scientific search for the Higgs boson in 2008."(1 page)

Revealing Partons in Hadrons: From the ISR to the SPS Collider

CERN Document Server

Darriulat, Pierre

2015-01-01

Our understanding of the structure of hadrons has developed during the seventies and early eighties from a few vague ideas to a precise theory, Quantum Chromodynamics, that describes hadrons as made of elementary partons (quarks and gluons). Deep inelastic scattering of electrons and neutrinos on nucleons and electron–positron collisions have played a major role in this development. Less well known is the role played by hadron collisions in revealing the parton structure, studying the dynamic of interactions between partons and offering an exclusive laboratory for the direct study of gluon interactions. The present article recalls the decisive contributions made by the CERN Intersecting Storage Rings and, later, the proton–antiproton SPS Collider to this chapter of physics.

QCD test in three-jet Z0 decays at SLD and detector development for H0 → γγ searches in high energy hadron colliders

International Nuclear Information System (INIS)

Hwang, Hyun.

1994-08-01

Polarized Z degrees decays into three jets have been detected and measured in the SLAC Large Detector (SLD) experiment operating it the SLAC Linear Collider (SLC). The hadrons from the jets were detected in the SLD liquid argon calorimeter, providing a sensitivity over 98% of the solid angle. The spin of the gluon was tested by studying the scaled jet energies (x 1 , x 2 , x 3 ), the Ellis-Karliner angle (cosθ EK ) and the parameters of event plane orientation (α, α N , β). These measured variables are compared with quantum chromodynamics (QCD) and a scalar gluon model. Good agreement is found between data, and the vector QCD model for the distributions of (x 1 , x 2 , x 3 ) and (cosθ EK ). Two detector prototypes for the GEM detector of the Superconducting Super Collider have been studied: a prototype silicon-tungsten preradiator and a liquid argon hadron calorimeter. The silicon-tungsten preradiator was designed for the GEM detector to distinguish between single photons from Higgs decay and background photon pairs from π degrees decay. This preradiator was tested in a beam at Brookhaven National Laboratory in July, 1992. A lead glass array placed behind the silicon was used to determine energy resolution effects. The results from the test on spatial distributions and energy resolution, including correction for the energy deposited in the preradiator are presented, along with comparisons to EGS simulations. Data from a beam test of the liquid argon prototype was analyzed and compared to CALOR89 simulations. The studies concentrated on energy resolution optimization and electronic noise suppression

A high granularity plastic scintillator tile hadronic calorimeter with APD readout for a linear collider detector

Czech Academy of Sciences Publication Activity Database

Andreev, V.; Cvach, Jaroslav; Danilov, M.; Devitsin, E.; Dodonov, V.; Eigen, G.; Garutti, E.; Gilitzky, Yu.; Groll, M.; Heuer, R.D.; Janata, Milan; Kacl, Ivan; Korbel, V.; Kozlov, V. Yu; Meyer, H.; Morgunov, V.; Němeček, Stanislav; Pöschl, R.; Polák, Ivo; Raspereza, A.; Reiche, S.; Rusinov, V.; Sefkow, F.; Smirnov, P.; Terkulov, A.; Valkár, Š.; Weichert, Jan; Zálešák, Jaroslav

2006-01-01

Roč. 564, - (2006), s. 144-154 ISSN 0168-9002 R&D Projects: GA MŠk(CZ) LC527; GA MŠk(CZ) 1P05LA259; GA ČR(CZ) GA202/05/0653 Institutional research plan: CEZ:AV0Z10100502 Keywords : hadronic calorimeter * plastic scintillator tile * APD readout * linear collider detector Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.185, year: 2006

Low-energy neutron measurements in an iron calorimeter structure irradiated by 200 GeV/c hadrons

Energy Technology Data Exchange (ETDEWEB)

Russ, J S [Carnegie-Mellon University, Pittsburgh, PA (United States); Stevenson, G R; Fasso, A; Nielsen, M C [CERN, Geneva (Switzerland); Furetta, C; Rancoita, P G; Vismara, I [INFN, Milan (Italy)

1989-04-21

Of serious concern in the design of detectors for the new high-luminosity hadron-hadron colliders are the radiation damage effects on silicon and other detectors of low-energy neutrons produced by spallation evaporation or fission processes. Because of the lack of experimental information on the number of neutrons with energies between 0.1 and 10 MeV in the cascades originating from high-energy hadrons, an experiment was carried out using activation detector techniques to measure the neutron fluence in a cascade initiated by 200 GeV hadrons in acalorimeter-like iron structure. It was found that at the maximum of the cascade one produces approximately 3 neutrons per GeV of incident energy: some 70% of these are of energies between 0.1 and 5 MeV, the remainder are fairly uniformly distributed in energy between 5 and several hundred MeV. The number of albedo neutrons leaving the front face of the calorimeter structure was about 0.3 neutrons per GeV of incident energy with in energy distribution similar to those at cascade maximum These data confirm that neutron-induced damage will he of concern in the design of detectors for the new colliders and that further measurements and calculations are necessary for a correct assessment of this damage. (author)

High-Luminosity Large Hadron Collider (HL-LHC) : Preliminary Design Report

Energy Technology Data Exchange (ETDEWEB)

Apollinari, G. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Béjar Alonso, I. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Brüning, O. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Lamont, M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Rossi, L. [European Organization for Nuclear Research (CERN), Geneva (Switzerland)

2015-12-17

The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community of about 7,000 scientists working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will need a major upgrade in the 2020s. This will increase its luminosity (rate of collisions) by a factor of five beyond the original design value and the integrated luminosity (total collisions created) by a factor ten. The LHC is already a highly complex and exquisitely optimised machine so this upgrade must be carefully conceived and will require about ten years to implement. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11-12 tesla superconducting magnets, compact superconducting cavities for beam rotation with ultra-precise phase control, new technology and physical processes for beam collimation and 300 metre-long high-power superconducting links with negligible energy dissipation. The present document describes the technologies and components that will be used to realise the project and is intended to serve as the basis for the detailed engineering design of HL-LHC.

High-Luminosity Large Hadron Collider (HL-LHC) : Preliminary Design Report

International Nuclear Information System (INIS)

Apollinari, G.; Béjar Alonso, I.; Brüning, O.; Lamont, M.; Rossi, L.

2015-01-01

The Large Hadron Collider (LHC) is one of the largest scientific instruments ever built. Since opening up a new energy frontier for exploration in 2010, it has gathered a global user community of about 7,000 scientists working in fundamental particle physics and the physics of hadronic matter at extreme temperature and density. To sustain and extend its discovery potential, the LHC will need a major upgrade in the 2020s. This will increase its luminosity (rate of collisions) by a factor of five beyond the original design value and the integrated luminosity (total collisions created) by a factor ten. The LHC is already a highly complex and exquisitely optimised machine so this upgrade must be carefully conceived and will require about ten years to implement. The new configuration, known as High Luminosity LHC (HL-LHC), will rely on a number of key innovations that push accelerator technology beyond its present limits. Among these are cutting-edge 11-12 tesla superconducting magnets, compact superconducting cavities for beam rotation with ultra-precise phase control, new technology and physical processes for beam collimation and 300 metre-long high-power superconducting links with negligible energy dissipation. The present document describes the technologies and components that will be used to realise the project and is intended to serve as the basis for the detailed engineering design of HL-LHC.

Hadrons in a highly granular silicon-tungsten electromagnetic calorimeter - Top quark production at the International Linear Collider

International Nuclear Information System (INIS)

Doublet, P.

2011-10-01

The International Linear Collider (ILC) is a proposed e + e - collider with a center-of-mass energy of 500 GeV or more, aimed at precision measurements, e.g. of a light Higgs boson that could be discovered soon at the Large Hadron Collider. Its detectors foresee the use of fine grained calorimeters to achieve the desired accuracy. This thesis presents the study of the response to hadrons of a highly granular silicon-tungsten electromagnetic calorimeter (SiW ECAL), and the study of top quark pair production at the ILC. The SiW ECAL prototype developed by the CALICE collaboration was tested with beams of charged particles at FNAL in May and July 2008. After selecting single negatively charged pions entering the ECAL, its fine granularity is used to introduce a classification among four types of events, used to describe hadronic interactions. Motivated by extra-dimensional models which may explain the A FB b LEP anomaly by modifying the couplings of third generation quarks to the Z boson, the semileptonic decay of the top quark is studied with a full simulation of the proposed ILD detector for the ILC at center-of-mass energy of √(s)=500 GeV and integrated luminosity L=500 fb -1 . Detector performances permit to reach efficiencies larger than 70% in finding those events with a purity larger than 95%. This translates into a relative accuracy of about 1% on both the left-right asymmetry of top production A LR 0,t and the top forward-backward asymmetry A FB t with electrons polarized at 80% and no polarization of the positrons. The relative uncertainties in the left and right couplings of the top quark to the Z boson could be as good as 0.9% and 1.5%. (author)

Soviet Hadron Collider

Science.gov (United States)

Kotchetkov, Dmitri

2017-01-01

Rapid growth of the high energy physics program in the USSR during 1960s-1970s culminated with a decision to build the Accelerating and Storage Complex (UNK) to carry out fixed target and colliding beam experiments. The UNK was to have three rings. One ring was to be built with conventional magnets to accelerate protons up to the energy of 600 GeV. The other two rings were to be made from superconducting magnets, each ring was supposed to accelerate protons up to the energy of 3 TeV. The accelerating rings were to be placed in an underground tunnel with a circumference of 21 km. As a 3 x 3 TeV collider, the UNK would make proton-proton collisions with a luminosity of 4 x 1034 cm-1s-1. Institute for High Energy Physics in Protvino was a project leading institution and a site of the UNK. Accelerator and detector research and development studies were commenced in the second half of 1970s. State Committee for Utilization of Atomic Energy of the USSR approved the project in 1980, and the construction of the UNK started in 1983. Political turmoil in the Soviet Union during late 1980s and early 1990s resulted in disintegration of the USSR and subsequent collapse of the Russian economy. As a result of drastic reduction of funding for the UNK, in 1993 the project was restructured to be a 600 GeV fixed target accelerator only. While the ring tunnel and proton injection line were completed by 1995, and 70% of all magnets and associated accelerator equipment were fabricated, lack of Russian federal funding for high energy physics halted the project at the end of 1990s.

Three-hadron angular correlations in high-energy proton-proton and nucleus-nucleus collisions from perturbative QCD

International Nuclear Information System (INIS)

Ayala, Alejandro; Ortiz, Antonio; Paic, Guy; Jalilian-Marian, Jamal; Magnin, J.; Tejeda-Yeomans, Maria Elena

2011-01-01

We study three-hadron azimuthal angular correlations in high-energy proton-proton and central nucleus-nucleus collisions at the BNL Relativistic Heavy Ion Collider (RHIC) and the CERN Large Hadron Collider at midrapidity. We use the leading-order parton matrix elements for 2→3 processes and include the effect of parton energy loss in the quark-gluon plasma using the modified fragmentation function approach. For the case when the produced hadrons have either the same or not too different momenta, we observe two away-side peaks at 2π/3 and 4π/3. We consider the dependence of the angular correlations on energy loss parameters that have been used in studies of single inclusive hadron production at RHIC. Our results on the angular dependence of the cross section agree well with preliminary data by the PHENIX Collaboration. We comment on the possible contribution of 2→3 processes to dihadron angular correlations and how a comparison of the two processes may help characterize the plasma further.

Collider constraints on interactions of dark energy with the standard model

Energy Technology Data Exchange (ETDEWEB)

Brax, P. [CEA, IPhT, CNRS, Gif-sur-Yvette (France). Inst. de Physique Theorique; Burrage, C. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Davis, A.C.; Seery, D. [Cambridge Univ. (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics; Weltman, A. (eds.) [Cambridge Univ. (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics; Cape Town Univ. (South Africa). Dept. of Mathematics and Applied Mathematics

2009-04-15

We study models in which a light scalar dark energy particle couples to the gauge fields of the electroweak force, the photon, Z, and W{sup {+-}} bosons. Our analysis applies to a large class of interacting dark energy models, including those in which the dark energy mass can be adjusted to evade fifth-force bounds by the so-called ''chameleon'' mechanism. We conclude that - with the usual choice of Higgs sector - electroweak precision observables are screened from the indirect effects of dark energy, making such corrections effectively unobservable at present-day colliders, and limiting the dark energy discovery potential of any future International Linear Collider. We show that a similar screening effect applies to processes mediated by flavour-changing neutral currents, which can be traced to the Glashow-Iliopoulos-Maiani mechanism. However, Higgs boson production at the Large Hadron Collider via weak boson fusion may receive observable corrections. (orig.)

Large Area Silicon Tracking Detectors with Fast Signal Readout for the Large Hadron Collider (LHC) at CERN

CERN Document Server

Köstner, S

2005-01-01

The Standard Model of elementary particles, which is summarized briefly in the second chapter, incorporates a number of successful theories to explain the nature and consistency of matter. However not all building blocks of this model could yet be tested by experiment. To confirm existing theories and to improve nowadays understanding of matter a new machine is currently being built at CERN, the Large Hadron Collider (LHC), described in the third chapter. LHC is a proton-proton collider which will reach unprecedented luminosities and center of mass energies. Five experiments are attached to it to give answers to questions like the existence of the Higgs meson, which allows to explain the mass content of matter, and the origin of CP-violation, which plays an important role in the baryogenesis of the universe. Supersymmetric theories, proposing a bosonic superpartner for each fermion and vice versa, will be tested. By colliding heavy ions, high energy and particle densities can be achieved and probed. This stat...

Heavy-ion physics with the ALICE experiment at the CERN Large Hadron Collider.

Science.gov (United States)

Schukraft, J

2012-02-28

After close to 20 years of preparation, the dedicated heavy-ion experiment A Large Ion Collider Experiment (ALICE) took first data at the CERN Large Hadron Collider (LHC) accelerator with proton collisions at the end of 2009 and with lead nuclei at the end of 2010. After a short introduction into the physics of ultra-relativistic heavy-ion collisions, this article recalls the main design choices made for the detector and summarizes the initial operation and performance of ALICE. Physics results from this first year of operation concentrate on characterizing the global properties of typical, average collisions, both in proton-proton (pp) and nucleus-nucleus reactions, in the new energy regime of the LHC. The pp results differ, to a varying degree, from most quantum chromodynamics-inspired phenomenological models and provide the input needed to fine tune their parameters. First results from Pb-Pb are broadly consistent with expectations based on lower energy data, indicating that high-density matter created at the LHC, while much hotter and larger, still behaves like a very strongly interacting, almost perfect liquid.

Advanced superconducting technology for global science: The Large Hadron Collider at CERN

International Nuclear Information System (INIS)

Lebrun, Ph.

2002-01-01

The Large Hadron Collider (LHC), presently in construction at CERN, the European Organization for Nuclear Research near Geneva (Switzerland), will be, upon its completion in 2005 and for the next twenty years, the most advanced research instrument of the world's high-energy physics community, providing access to the energy frontier above 1 TeV per elementary constituent. Re-using the 26.7-km circumference tunnel and infrastructure of the past LEP electron-positon collider, operated until 2000, the LHC will make use of advanced superconducting technology-high-field Nb-Ti superconducting magnets operated in superfluid helium and a cryogenic ultra-high vacuum system-to bring into collision intense beams of protons and ions at unprecedented values of center-of-mass energy and luminosity (14 TeV and 10 34 cm -2 ·s -1 , respectively with protons). After some ten years of focussed R and D, the LHC components are presently series-built in industry and procured through world-wide collaboration. After briefly recalling the physics goals, performance challenges and design choices of the machine, we describe its major technical systems, with particular emphasis on relevant advances in the key technologies of superconductivity and cryogenics, and report on its construction progress

Supersymmetric dark matter in the harsh light of the Large Hadron Collider

Science.gov (United States)

Peskin, Michael E.

2015-01-01

I review the status of the model of dark matter as the neutralino of supersymmetry in the light of constraints on supersymmetry given by the 7- to 8-TeV data from the Large Hadron Collider (LHC). PMID:25331902

Summary of the Very Large Hadron Collider Physics and Detector subgroup

International Nuclear Information System (INIS)

Denisov, D.; Keller, S.

1996-01-01

We summarize the activity of the Very Large Hadron Collider Physics and Detector subgroup during Snowmass 96. Members of the group: M. Albrow, R. Diebold, S. Feher, L. Jones, R. Harris, D. Hedin, W. Kilgore, J. Lykken, F. Olness, T. Rizzo, V. Sirotenko, and J. Womersley. 9 refs

Advances in elementary particle physics with applied superconductivity. Contribution of superconducting technology to CERN large hadron collider accelerator

International Nuclear Information System (INIS)

Yamamoto, Akira

2011-01-01

The construction of the Large Hadron Collider (LHC) was started in 1994 and completed in 2008. The LHC consists of more than seven thousand superconducting magnets and cavities, which play an essential role in elementary particle physics and its energy frontier. Since 2010, physics experiments at the new energy frontier have been carried out to investigate the history and elementary particle phenomena in the early universe. The superconducting technology applied in the energy frontier physics experiments is briefly introduced. (author)

Naming Conventions for the Large Hadron Collider Project

CERN Document Server

Faugeras, Paul E

1997-01-01

This report gives the procedures for defining standard abbreviations for the various machine components of the Large Hadron Collider (LHC) Project, as well as for the surface buildings and the underground Civil Engineering works of the LHC. The contents of this report has been approved by the LHC Project Leader and is published in the form of a Project Report in order to allow its immediate implementation. It will be incorporated later in the Quality Assurance Plan of the LHC Project which is under preparation.

One-loop helicity amplitudes for t anti t production at hadron colliders

International Nuclear Information System (INIS)

Badger, Simon; Yundin, Valery

2011-01-01

We present compact analytic expressions for all one-loop helicity amplitudes contributing to t anti t production at hadron colliders. Using recently developed generalised unitarity methods and a traditional Feynman based approach we produce a fast and flexible implementation. (ORIG.)

One-loop helicity amplitudes for t anti t production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Badger, Simon [The Niels Bohr International Academy and Discovery Center, Copenhagen (Denmark). Niels Bohr Inst.; Sattler, Ralf [Humboldt Univ. Berlin (Germany). Inst. fuer Physik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Yundin, Valery [Silesia Univ., Katowice (Poland). Inst. of Physics; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

2011-01-15

We present compact analytic expressions for all one-loop helicity amplitudes contributing to t anti t production at hadron colliders. Using recently developed generalised unitarity methods and a traditional Feynman based approach we produce a fast and flexible implementation. (ORIG.)

Photoproduction at collider energies: from RHIC and HERA to the LHC

CERN Document Server

Baltz, A; Brodsky, S J; D'Enterria, D G; Dreyer, U; Engel, R; Frankfurt, L; Gorbunov, Y; Guzey, V; Hamilton, A; Klasen, M; Klein, S R; Kowalski, H; Levonian, S; Lourenço, C; Machado, M V T; Nachtmann, O; Nagy, Z; Nystrand, J; Piotrzkowski, K; Ramalhete, P; Savin, A; Scapparone, E; Schicker, R; Silvermyr, D; Strikman, M I; Valkárová, A; Vogt, R; Yilmaz, M; Enterria, David d'

2007-01-01

We present the mini-proceedings of the workshop on "Photoproduction at collider energies: from RHIC and HERA to the LHC" held at the European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*, Trento) from January 15 to 19, 2007. The workshop gathered both theorists and experimentalists to discuss the current status of investigations of high-energy photon-induced processes at different colliders (HERA, RHIC, and Tevatron) as well as preparations for extension of these studies at the LHC. The main physics topics covered were: (i) small-$x$ QCD in photoproduction studies with protons and in electromagnetic (aka. ultraperipheral) nucleus-nucleus collisions, (ii) hard diffraction physics at hadron colliders, and (iii) photon-photon collisions at very high energies: electroweak and beyond the Standard Model processes. These mini-proceedings consist of an introduction and short summaries of the talks presented at the meeting.

Weak boson emission in hadron collider processes

International Nuclear Information System (INIS)

Baur, U.

2007-01-01

The O(α) virtual weak radiative corrections to many hadron collider processes are known to become large and negative at high energies, due to the appearance of Sudakov-like logarithms. At the same order in perturbation theory, weak boson emission diagrams contribute. Since the W and Z bosons are massive, the O(α) virtual weak radiative corrections and the contributions from weak boson emission are separately finite. Thus, unlike in QED or QCD calculations, there is no technical reason for including gauge boson emission diagrams in calculations of electroweak radiative corrections. In most calculations of the O(α) electroweak radiative corrections, weak boson emission diagrams are therefore not taken into account. Another reason for not including these diagrams is that they lead to final states which differ from that of the original process. However, in experiment, one usually considers partially inclusive final states. Weak boson emission diagrams thus should be included in calculations of electroweak radiative corrections. In this paper, I examine the role of weak boson emission in those processes at the Fermilab Tevatron and the CERN LHC for which the one-loop electroweak radiative corrections are known to become large at high energies (inclusive jet, isolated photon, Z+1 jet, Drell-Yan, di-boson, tt, and single top production). In general, I find that the cross section for weak boson emission is substantial at high energies and that weak boson emission and the O(α) virtual weak radiative corrections partially cancel

Discovering a Light Scalar or Pseudoscalar at The Large Hadron Collider

DEFF Research Database (Denmark)

Frandsen, Mads Toudal; Sannino, Francesco

2012-01-01

The allowed standard model Higgs mass range has been reduced to a region between 114 and 130 GeV or above 500 GeV, at the 99% confidence level, since the Large Hadron Collider (LHC) program started. Furthermore some of the experiments at Tevatron and LHC observe excesses that could arise from...

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

NARCIS (Netherlands)

Aad, G.; et al., [Unknown; Bentvelsen, S.; Berglund, E.; Bobbink, G.J.; Bos, K.; Boterenbrood, H.; Colijn, A.P.; de Jong, P.; de Nooij, L.; Deviveiros, P.O.; Doxiadis, A.D.; Ferrari, P.; Garitaonandia, H.; Geerts, D.A.A.; Gosselink, M.; Hartjes, F.; Hessey, N.P.; Igonkina, O.; Kayl, M.S.; Klous, S.; Kluit, P.; Koffeman, E.; Lee, H.; Lenz, T.; Linde, F.; Luijckx, G.; Massaro, G.; Mechnich, J.; Mussche, I.; Ottersbach, J.P.; Reichold, A.; Rijpstra, M.; Ruckstuhl, N.; Snuverink, J.; Ta, D.; Tsiakiris, M.; Turlay, E.; van der Graaf, H.; van der Kraaij, E.; van der Leeuw, R.; van der Poel, E.; van Kesteren, Z.; van Vulpen, I.; Verkerke, W.; Vermeulen, J.C.; Vranjes Milosavljevic, M.; Vreeswijk, M.

2013-01-01

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at

Mighty Murines: Neutrino Physics at very high Energy Muon Colliders

International Nuclear Information System (INIS)

King, B.J.

2000-01-01

An overview is given of the potential for neutrino physics studies through parasitic use of the intense high energy neutrino beams that would be produced at future many-TeV muon colliders. Neutrino experiments clearly cannot compete with the collider physics. Except at the very highest energy muon colliders, the main thrust of the neutrino physics program would be to improve on the measurements from preceding neutrino experiments at lower energy muon colliders, particularly in the fields of B physics, quark mixing and CP violation. Muon colliders at the 10 TeV energy scale might already produce of order 10 8 B hadrons per year in a favorable and unique enough experimental environment to have some analytical capabilities beyond any of the currently operating or proposed B factories. The most important of the quark mixing measurements at these energies might well be the improved measurements of the important CKM matrix elements |V ub | and |V cb | and, possibly, the first measurements of |V td | in the process of flavor changing neutral current interactions involving a top quark loop. Muon colliders at the highest center-of-mass energies that have been conjectured, 100--1,000 TeV, would produce neutrino beams for neutrino-nucleon interaction experiments with maximum center-of-mass energies from 300--1,000 GeV. Such energies are close to, or beyond, the discovery reach of all colliders before the turn-on of the LHC. In particular, they are comparable to the 314 GeV center-of-mass energy for electron-proton scattering at the currently operating HERA collider and so HERA provides a convenient benchmark for the physics potential. It is shown that these ultimate terrestrial neutrino experiments, should they eventually come to pass, would have several orders of magnitude more luminosity than HERA. This would potentially open up the possibility for high statistics studies of any exotic particles, such as leptoquarks, that might have been previously discovered at these

Computer simulation of the emittance growth due to noise in large hadron colliders

International Nuclear Information System (INIS)

Lebedev, V.

1993-03-01

The problem of emittance growth due to random fluctuations of the magnetic field in a hadron collider is considered. The results of computer simulations are compared with the analytical theory developed earlier. A good agreement was found between the analytical theory predictions and the computer simulations for the collider tunes located far enough from high order betatron resonances. The dependencies of the emittance growth rate on noise spectral density, beam separation at the Interaction Point (IP) and value of beam separation at long range collisions are studied. The results are applicable to the Superconducting Super Collider (SSC)

Inside CERN's Large Hadron Collider from the proton to the Higgs boson

CERN Document Server

AUTHOR|(CDS)2051256

2016-01-01

The book aims to explain the historical development of particle physics, with special emphasis on CERN and collider physics. It describes in detail the LHC accelerator and its detectors, describing the science involved as well as the sociology of big collaborations, culminating with the discovery of the Higgs boson. Readers are led step-by-step to understanding why we do particle physics, as well as the tools and problems involved in the field. It provides an insider's view on the experiments at the Large Hadron Collider.

A high-granularity scintillator hadronic-calorimeter with SiPM readout for a linear collider detector

International Nuclear Information System (INIS)

Andreev, V.; Balagura, V; Bobchenko, B.

2004-01-01

We report upon the design, construction and operation of a prototype for a high-granularity tile hadronic calorimeter for a future international linear collider(ILC) detector. Scintillating tiles are read out via wavelength-shifting fibers which guides the scintillation light to a novel photodetector, the Silicon Photomultiplier. The prototype has been tested at DESY using a positron test beam. The results are compared with a reference prototype equipped with multichannel vacuum photomultipliers. Detector calibration, noise, linearity and stability are discussed, and the energy response in a 1-6 GeV positron beam is compared with simulation. The work presented serves to establish the application of SiPM for calorimetry, and leads to the choice of this device for the construction of a 1m 3 calorimeter prototype for tests in hadron beams. (orig.)

Science and the Large Hadron Collider: a probe into instrumentation, periodization and classification

CERN Document Server

Roy, Arpita

2012-01-01

On September 19, 2008, the Large Hadron Collider (LHC) at CERN, Switzerland, began the world’s highest energy experiments as a probe into the structure of matter and forces of nature. Just nine days after the gala start-up, an explosion occurred in the LHC tunnel that brought the epic collider to a complete standstill. In light of the catastrophic incident that disrupted the operation of the LHC, the paper investigates the relation of temporality to the cycle of work in science, and raises the question: What kind of methodological value should we ascribe to events such as crises or breakdowns? Drawing upon and integrating classical anthropological themes with two and a half years of fieldwork at the LHC particle accelerator complex, the paper explores how the incident in September, which affected the instrument, acquaints us with the distribution of work in the laboratory. The incident discloses that the organization of science is not a homogenous ensemble, but marked by an enormous diversity of tasks and p...

Next steps in the Energy Frontier - Hadron colliders workshop at LPC@FNAL

CERN Document Server

2014-01-01

With the observation of the Standard Model Higgs boson, the high energy physics community is investigating possible next steps for entering into a new era in particle physics. The aim of this workshop is to bring together physics, instrumentation/detector and accelerator experts to present, outline and discuss all aspects needed for the next steps in the energy frontier. The workshop will focus on the lessons learned with 7 and 8 TeV LHC, physics requirements and subsequent detector technologies for HL-LHC, as well as development needs for future 100 TeV proton collider. The goal is to identify synergies and common approaches where further collaboration between various initiatives could be fruitful. The discovery potential for a future 100 TeV proton collider will depend on the detector / instrumentation capabilities in order to explore the highest energy and phenomena. Many of these detection capabilities will need further studies such as muon detection at several 10s of TeV range, calorimeters capable of me...

Future colliders

International Nuclear Information System (INIS)

Palmer, R.B.; Gallardo, J.C.

1996-10-01

The high energy physics advantages, disadvantages and luminosity requirements of hadron (pp, pp), of lepton (e + e - , μ + μ - ) and photon-photon colliders are considered. Technical arguments for increased energy in each type of machine are presented. Their relative size, and the implications of size on cost are discussed

Probing the $WW \\gamma$ vertex at hadron colliders

CERN Document Server

Papavassiliou, J

1999-01-01

We present a new, model independent method for extracting bounds for the anomalous $\\gamma WW$ couplings from hadron collider experiments. At the partonic level we introduce a set of three observables which are constructed from the unpolarized differential cross-section for the process $d\\bar{u}\\to W^{-}\\gamma$ by appropriate convolution with a set of simple polynomials depending only on the center-of-mass angle. One of these observables allows for the direct determination of the anomalous coupling usually denoted by presence of a radiation zero. The other two observables impose two sum rules on the remaining three anomalous couplings. The inclusion of the structure functions is discussed in detail for both $p\\bar{p}$ and $pp$ colliders. We show that, whilst for $p\\bar{p}$ experiments this can be accomplished straightforwardly, in the $pp$ case one has to resort to somewhat more elaborate techniques, such as the binning of events according to their longitudinal momenta.

Experiments and detectors for high energy heavy ion colliders

Energy Technology Data Exchange (ETDEWEB)

Ludlam, T.

1984-01-01

Problems and possibilities are discussed for experiments at the highest collision energies achievable in man-made accelerators; i.e., colliding beams of heavy nuclei at cm energies greater than or equal to 100 GeV/amu, well beyond the threshold of nuclear transparency. Here the final state consists of two hot, dense, baryon-rich fireballs flying away from each other at large rapidity (the fragmentation regions), and thermally-produced particles with near-zero net baryon number populating the central rapidity range. The matter produced at central rapidity (the lab frame for a collider) may reach extremely high temperatures and energy densities, and it is here that one expects to produce thermodynamic conditions similar to those which existed when the early universe condensed from a plasma of quarks and gluons to a gas of hadrons. The problem of tracking, lepton measurements, and calorimeters are discussed. (WHK)

Helicity antenna showers for hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Fischer, Nadine; Skands, Peter [Monash University, School of Physics and Astronomy, Clayton, VIC (Australia); Lifson, Andrew [Monash University, School of Physics and Astronomy, Clayton, VIC (Australia); ETH Zuerich, Zurich (Switzerland)

2017-10-15

We present a complete set of helicity-dependent 2 → 3 antenna functions for QCD initial- and final-state radiation. The functions are implemented in the Vincia shower Monte Carlo framework and are used to generate showers for hadron-collider processes in which helicities are explicitly sampled (and conserved) at each step of the evolution. Although not capturing the full effects of spin correlations, the explicit helicity sampling does permit a significantly faster evaluation of fixed-order matrix-element corrections. A further speed increase is achieved via the implementation of a new fast library of analytical MHV amplitudes, while matrix elements from Madgraph are used for non-MHV configurations. A few examples of applications to QCD 2 → 2 processes are given, comparing the newly released Vincia 2.200 to Pythia 8.226. (orig.)

Helicity antenna showers for hadron colliders

Science.gov (United States)

Fischer, Nadine; Lifson, Andrew; Skands, Peter

2017-10-01

We present a complete set of helicity-dependent 2→ 3 antenna functions for QCD initial- and final-state radiation. The functions are implemented in the Vincia shower Monte Carlo framework and are used to generate showers for hadron-collider processes in which helicities are explicitly sampled (and conserved) at each step of the evolution. Although not capturing the full effects of spin correlations, the explicit helicity sampling does permit a significantly faster evaluation of fixed-order matrix-element corrections. A further speed increase is achieved via the implementation of a new fast library of analytical MHV amplitudes, while matrix elements from Madgraph are used for non-MHV configurations. A few examples of applications to QCD 2→ 2 processes are given, comparing the newly released Vincia 2.200 to Pythia 8.226.

QCD studies at the hadron colliders

International Nuclear Information System (INIS)

Flaugher, B.L.

1990-01-01

Two hadron collider experiments are actively pursuing QCD jet analyses. They are CDF, with a √s = 1800 GeV, and UA2, with a √s = 630 GeV. Recent results from these collaborations are discussed. The inclusive jet spectrum, dijet mass and angular distribution are compared to QCD predictions and used to set limits on quark substructure. Data from both experiments are compared to the O(α s 3 ) calculations for the inclusive jet cross section. Studies of 3-jet, 4-jet and 5-jet events are described. A limit is set on the cross section for double parton scattering from the UA2 4-jet analysis. The inclusive photon cross section has been measured by both CDF and UA2 and is compared to theoretical predictions. 13 refs., 17 figs., 1 tab

submitter Training Behavior of the Main Dipoles in the Large Hadron Collider

CERN Document Server

Todesco, Ezio; Bajko, Marta; Bottura, Luca; Bruning, Oliver; De Rijk, Gijs; Fessia, Paolo; Hagen, Per; Naour, Sandrine Le; Modena, Michele; Perez, Juan Carlos; Rossi, Lucio; Schmidt, Rudiger; Siemko, Andrzej; Tock, Jean-Philippe; Tommasini, Davide; Verweij, Arjan; Willering, Gerard

2017-01-01

In 2015, the 1232 Nb-Ti dipole magnets in the Large Hadron Collider (LHC) have been commissioned to 7.8 T operational field, with 172 quenches. More than 80% of these quenches occurred in the magnets of one of the three cold mass assemblers (3000 series), confirming what was already observed in 2008. In this paper, the recent analysis carried out on the quench performance of the Large Hadron Collider dipole magnets is reported, including the individual reception tests and the 2008 and 2015 commissioning campaigns, to better understand the above-mentioned anomaly and give an outlook for future operation and possible increase of the operational field. The lower part of the quench probability spectrum is compatible with Gaussian distributions; therefore, the training curve can be fit through error functions. An essential ingredient in this analysis is the estimate of the error to be associated with the training data due to sampling of rare events, allowing to test different hypothesis. Using this approach, an es...

The case for future hadron colliders from B → K (*) μ + μ - decays

Science.gov (United States)

Allanach, B. C.; Gripaios, Ben; You, Tevong

2018-03-01

Recent measurements in B → K (*) μ + μ - decays are somewhat discrepant with Standard Model predictions. They may be harbingers of new physics at an energy scale potentially accessible to direct discovery. We estimate the sensitivity of future hadron colliders to the possible new particles that may be responsible for the anomalies at tree-level: leptoquarks or Z's. We consider luminosity upgrades for a 14 TeV LHC, a 33 TeV LHC, and a 100 TeV pp collider such as the FCC-hh. In the most conservative and pessimistic models, for narrow particles with perturbative couplings, Z' masses up to 20 TeV and leptoquark masses up to 41 TeV may in principle explain the anomalies. Coverage of Z' models is excellent: a 33 TeV 1 ab-1 LHC is expected to cover most of the parameter space up to 8 TeV in mass, whereas the 100 TeV FCC-hh with 10 ab-1 will cover all of it. A smaller portion of the leptoquark parameter space is covered by future colliders: for example, in a μ + μ - jj di-leptoquark search, a 100 TeV 10 ab-1 collider has a projected sensitivity up to leptoquark masses of 12 TeV (extendable to 21 TeV with a strong coupling for single leptoquark production).

Destination Universe: The Incredible Journey of a Proton in the Large Hadron Collider (English version)

CERN Multimedia

Lefevre, C

2008-01-01

This brochure illustrates the incredible journey of a proton as he winds his way through the CERN accelerator chain and ends up inside the Large Hadron Collider (LHC). The LHC is CERN's flagship particle accelerator which can collide protons together at close to the speed of light, creating circumstances like those just seconds after the Big Bang.

The Large Hadron Collider

CERN Multimedia

't Hooft, Gerardus; Llewellyn Smith, Christopher Hubert; Brüning, Oliver Sim; Collier, Paul; Stapnes, Steinar; Ellis, Jonathan Richard; Braun-Munzinger, Peter; Stachel, Johanna; Lederman, Leon Max

2007-01-01

Several articles about the LHC: The Making of the standard model; high-energy colliders and the rise of the standard model; How the LHC came to be; Building a behemoth; Detector challenges at the LHC; Beyond the standard model with the LHC; The quest for the quark-gluon plasma; The God particle et al. (42 pages

Cryogenic Studies for the Proposed CERN Large Hadron Electron Collider (LHeC)

CERN Document Server

Haug, F

2011-01-01

The LHeC (Large Hadron electron Collider) is a proposed future colliding beam facility for lepton-nucleon scattering particle physics at CERN. A new 60 GeV electron accelerator will be added to the existing 27 km circumference 7 TeV LHC for collisions of electrons with protons and heavy ions. Two basic design options are being pursued. The first is a circular accelerator housed in the existing LHC tunnel which is referred to as the "Ring-Ring" version. Low field normal conducting magnets guide the particle beam while superconducting (SC) RF cavities cooled to 2 K are installed at two opposite locations at the LHC tunnel to accelerate the beams. For this version in addition a 10 GeV re-circulating SC injector will be installed. In total four refrigerators with cooling capacities between 1.2 kW and 3 kW @ 4.5 K are needed. The second option, referred to as the "Linac-Ring" version consists of a race-track re-circulating energy-recovery type machine with two 1 km long straight acceleration sections. The 944 hi...

Ion Colliders

CERN Document Server

Fischer, W

2014-01-01

High-energy ion colliders are large research tools in nuclear physics to study the Quark-Gluon-Plasma (QGP). The range of collision energy and high luminosity are important design and operational considerations. The experiments also expect flexibility with frequent changes in the collision energy, detector fields, and ion species. Ion species range from protons, including polarized protons in RHIC, to heavy nuclei like gold, lead and uranium. Asymmetric collision combinations (e.g. protons against heavy ions) are also essential. For the creation, acceleration, and storage of bright intense ion beams, limits are set by space charge, charge change, and intrabeam scattering effects, as well as beam losses due to a variety of other phenomena. Currently, there are two operating ion colliders, the Relativistic Heavy Ion Collider (RHIC) at BNL, and the Large Hadron Collider (LHC) at CERN.

Minimum Bias Measurements with the ATLAS Detector at the CERN Large Hadron Collider

CERN Document Server

Leyton, M

2009-01-01

The Large Hadron Collider (LHC) at CERN will collide bunches of protons (p) at a center-of-mass energy of sqrt(s) = 14 TeV and a rate of 40 MHz. The unprecedented collision energy and interaction rate at the LHC will allow us to explore the TeV mass scale and take a major step forward in our understanding of the fundamental nature of matter. The initial physics run of the LHC is expected to start in November 2009 and continue until the end of 2010, with collisions at sqrt(s) = 900 GeV, 7 TeV and 10 TeV. ATLAS (A Toroidal LHC ApparatuS) is a 4pi general-purpose detector designed for studying LHC collisions at the particle level. The design and layout of ATLAS are intended to cover the wide spectrum of physics signatures that are possible at the TeV mass scale. Construction and installation of the ATLAS detector at CERN are now complete. This dissertation focuses on measuring the properties of inelastic pp interactions at the LHC with the ATLAS detector. A method for measuring the central pseudorapidity den...

Messung der Produktion von aus leichten Quarks zusammengesetzten Hadronen und Anti-Kernen am Large Hadron Collider

CERN Document Server

Kalweit, Alexander; Wambach, Jochen

With the recording of the first collisions of the Large Hadron Collider (LHC) in November 2009, a new era in the domain of high energy and relativistic heavy-ion physics has started. As one of the early observables which can be addressed, the measurement of light quark flavor production is presented in this thesis. Hadrons that consist only of u, d, and s quarks constitute the majority of the produced particles in pp and Pb–Pb collisions. Their measurement forms the basis for a detailed understanding of the collision and for the answer of the question if hadronic matter undergoes a phase transition to the deconfined quark-gluon plasma at high temperatures. The basics of ultra-relativistic heavyion physics are briefly introduced in the first chapter followed by a short description of the ALICE experiment. A particular focus is put on the unique particle identification (PID) capabilities as they provide the basis of the measurements which are presented in the following chapters. The particle identification vi...

Signatures of massive sgoldstinos at hadron colliders

International Nuclear Information System (INIS)

Perazzi, Elena; Ridolfi, Giovanni; Zwirner, Fabio

2000-01-01

In supersymmetric extensions of the Standard Model with a very light gravitino, the effective theory at the weak scale should contain not only the goldstino G-tilde, but also its supersymmetric partners, the sgoldstinos. In the simplest case, the goldstino is a gauge-singlet and its superpartners are two neutral spin-0 particles, S and P. We study possible signals of massive sgoldstinos at hadron colliders, focusing on those that are most relevant for the Tevatron. We show that inclusive production of sgoldstinos, followed by their decay into two photons, can lead to observable signals or to stringent combined bounds on the gravitino and sgoldstino masses. Sgoldstino decays into two gluon jets may provide a useful complementary signature

How to Find a Hidden World at the Large Hadron Collider

CERN Document Server

Wells, James D.

2008-01-01

I discuss how the Large Hadron Collider era should broaden our view of particle physics research, and apply this thinking to the case of Hidden Worlds. I focus on one of the simplest representative cases of a Hidden World, and detail the rich implications it has for LHC physics, including universal suppression of Higgs boson production, trans-TeV heavy Higgs boson signatures, heavy-to-light Higgs boson decays, weakly coupled exotic gauge bosons, and Higgs boson decays to four fermions via light exotic gauge bosons. Some signatures may be accessible in the very early stages of collider operation, whereas others motivate a later high-lumonosity upgrade.

Near-Threshold Production of W±, Z0, and H0 at a Fixed-Target Experiment at the Future Ultrahigh-Energy Proton Colliders

Directory of Open Access Journals (Sweden)

J. P. Lansberg

2015-01-01

Full Text Available We outline the opportunities to study the production of the Standard Model bosons, W±, Z0, and H0, at “low” energies at fixed-target experiments based on possible future ultrahigh-energy proton colliders, that is, the High-Energy LHC, the Super proton-proton Collider, and the Future Circular Collider hadron-hadron. These can be indeed made in conjunction with the proposed future colliders designed to reach up to s=100 TeV by using bent crystals to extract part of the halo of the beam which would then impinge on a fixed target. Without disturbing the collider operation, this technique allows for the extraction of a substantial amount of particles in addition to serving for a beam-cleaning purpose. With this method, high-luminosity fixed-target studies at centre-of-mass energies above the W±, Z0, and H0 masses, s≃170–300 GeV, are possible. We also discuss the possibility offered by an internal gas target, which can also be used as luminosity monitor by studying the beam transverse shape.

Precision Muon Tracking at Future Hadron Colliders with sMDT Chambers

CERN Document Server

Kortner, Oliver; Müller, Felix; Nowak, Sebastian; Richter, Robert

2016-01-01

Small-diameter muon drift tube (sMDT) chambers are a cost-effective technology for high-precision muon tracking. The rate capability of the sMDT chambers has been extensively tested at the Gamma Irradiation Facility at CERN in view of expected rates at future high-energy hadron colliders. Results show that it fulfills the requirements over most of the acceptance of muon detectors. The optimization of the read-out electronics to further increase the rate capability of the detectors is discussed. Chambers of this type are under construction for upgrades of the muon spectrometer of the ATLAS detector at high LHC luminosities. Design and construction procedures have been optimized for mass production while providing a precision of better than 10 micrometers in the sense wire positions and the mechanical stability required to cover large areas.

Investigation of collimator materials for the High Luminosity Large Hadron Collider

CERN Document Server

AUTHOR|(CDS)2085459; Bertarelli, Alessandro; Redaelli, Stefano

This PhD thesis work has been carried out at the European Organisation for Nuclear Research (CERN), Geneva, Switzerland), in the framework of the High Luminosity (HL) upgrade of the Large Hadron Collider (LHC). The HL-LHC upgrade will bring the accelerator beyond the nominal performance: it is planning to reach higher stored beam energy up to 700 MJ, through more intense proton beams. The present multi-stage LHC collimation system was designed to handle 360 MJ stored beam energy and withstand realistic losses only for this nominal beam. Therefore, the challenging HL-LHC beam parameters pose strong concerns for beam collimation, which call for important upgrades of the present system. The objective of this thesis is to provide solid basis for optimum choices of materials for the different collimators that will be upgraded for the baseline layout of the HL-LHC collimation system. To achieve this goal, material-related limitations of the present system are identified and novel advanced composite materials are se...

An energy recovery electron linac-on-ring collider

International Nuclear Information System (INIS)

Merminga, L.; Krafft, G.A.; Lebedev, V.A.; Ben-Zvi, I.

2000-01-01

We present the design of high-luminosity electron-proton/ion colliders in which the electrons are produced by an Energy Recovering Linac (ERL). Electron-proton/ion colliders with center of mass energies between 14 GeV and 100 GeV (protons) or 63 GeV/A (ions) and luminosities at the 10 33 (per nucleon) level have been proposed recently as a means for studying hadronic structure. The linac-on-ring option presents significant advantages with respect to: (1) spin manipulations (2) reduction of the synchrotron radiation load in the detectors (3) a wide range of continuous energy variability. Rf power and beam dump considerations require that the electron linac recover the beam energy. Based on extrapolations from actual measurements and calculations, energy recovery is expected to be feasible at currents of a few hundred mA and multi-GeV energies. Luminosity projections for the linac-ring scenario based on fundamental limitations are presented. The feasibility of an energy recovery electron linac-on-proton ring collider is investigated and four conceptual point designs are shown corresponding to electron to proton energies of: 3 GeV on 15 GeV, 5 GeV on 50 GeV and 10 GeV on 250 GeV, and for gold ions with 100 GeV/A. The last two designs assume that the protons or ions are stored in the existing RHIC accelerator. Accelerator physics issues relevant to proton rings and energy recovery linacs are discussed and a list of required R and D for the realization of such a design is presented

Extracting the top-quark running mass using t anti t + 1-jet events produced at the Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Fuster, J.; Vos, M. [IFIC, Universitat de Valencia y CSIC, Paterna (Spain); Irles, A. [Universite de Paris-Sud XI, CNRS/IN2P3, Laboratoire de l' Accelerateur Lineaire, Orsay (France); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Melini, D. [IFIC, Universitat de Valencia y CSIC, Paterna (Spain); Universidad de Granada, Departamento de Fisica Teorica y del Cosmos, Granada (Spain); Uwer, P. [Humboldt-Universitaet Berlin (Germany)

2017-11-15

We present the calculation of the next-to-leading order QCD corrections for top-quark pair production in association with an additional jet at hadron colliders, using the modified minimal subtraction scheme to renormalize the top-quark mass. The results are compared to measurements at the Large Hadron Collider run I. In particular, we determine the top-quark running mass from a fit of the theoretical results presented here to the LHC data. (orig.)

Extracting the top-quark running mass using t anti t+1-jet events produced at the Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Fuster, J.; Vos, M. [Valencia Univ. and CSIC, Paterna (Spain). IFIC; Irles, A. [Paris-Sud XI Univ., CNRS/IN2P3, Orsay (France). Lab. de l' Accelerateur Lineaire; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Melini, D. [Valencia Univ. and CSIC, Paterna (Spain). IFIC; Granada Univ. (Spain). Dept. de Fisica Teorica y del Cosmos; Uwer, P. [Humboldt-Univ., Berlin (Germany)

2017-04-04

We present the calculation of the next-to-leading order QCD corrections for top quark pair production in association with an additional jet at hadron colliders, using the modified minimal subtraction scheme to renormalize the top-quark mass. The results are compared to measurements at the Large Hadron Collider run I. In particular, we determine the top-quark running mass from a fit of the theoretical results presented here to the LHC data.

Study of high muon multiplicity cosmic ray events with ALICE at the CERN Large Hadron Collider

CERN Document Server

Rodriguez Cahuantzi, Mario

2015-01-01

ALICE is one of four large experiments at the CERN Large Hadron Collider. Located 52 meters undergroundwith 28meters of overburden rock, it has also been used to detect atmosphericmuons produced by cosmic-ray interactions in the upper atmosphere. We present the muon multiplicity distribution of these cosmic-ray events and their comparison with Monte Carlo simulation. This analysis exploits the large size and excellent tracking capability of the ALICE Time Projection Chamber. A special emphasis is given to the study of high multiplicity events containing more than 100 reconstructed muons and corresponding to a muon areal density larger than 5.9 m$^{−2}$. The measured rate of these events shows that they stem from primary cosmic-rays with energies above 10$^{16}$ eV. The frequency of these events can be successfully described by assuming a heavy mass composition of primary cosmic-rays in this energy range and using the most recent hadronic interaction models to simulate the development of the resulting air sh...

Diffractive dissociation of top hadrons at collider energies

International Nuclear Information System (INIS)

Di Bitonto, D.

1983-01-01

In an optical model in which heavy-flavour production is described as coherent scattering within the nucleon, the total heavy-flavour cross-section is expected to obey a m q -2 dependence, while the partial differential cross-section dσ/dp T for top hadrons is expected to show a broad plateau above approx. 20 GeV/c in transverse momentum. The expected top hadron signal dσ/dp T is 60 nb for m t = 20 GeV/c 2 appearing in the approx. angular range of expected value of θ 10 deg - 20 deg. (author)

Development of large-capacity refrigeration at 1.8 K for the Large Hadron Collider at CERN

CERN Document Server

Lebrun, P; Claudet, G

1996-01-01

CERN, the European Laboratory for Particle Physics, is working towards the construction of the Large Hadron Collider (LHC), a high-energy, high-luminosity particle accelerator and collider [1] of 26.7 km circumference, due to start producing frontier physics, by bringing into collision intense proton and ion beams with centre-of-mass energies in the TeV-per-constituent range, at the beginning of the next century. The key technology for achieving this ambitious scientific goal at economically acceptable cost is the use of high-field superconducting magnets using Nb-Ti conductor operating in superfluid helium [2]. To maintain the some 25 km of bending and focusing magnets at their operating temperature of 1.9 K, the LHC cryogenic system will have to produce an unprecedented total refrigeration capacity of about 20 kW at 1.8 K, in eight cryogenic plants distributed around the machine circumference [3]. This has requested the undertaking of an industrial development programme, in the form of a collaboration betwe...

Scattering, diffraction and multiparticle production on hadron and nuclei at high energy

International Nuclear Information System (INIS)

Ter-Martirosyan, K.A.; Zoller, V.R.

1988-01-01

The cross sections for different types of interactions of hadronic with hadrons and nuclei at high energy are obtained in the simple form in the supercritical pomeron theory. Diffraction desintegration (DD) of hadrons both in the intermediate states, between rescatterings on pomerons, and in the final states is taken into account. With the same accuracy the cross sections δ n for production of n pomeron jets on hadrons and nuclei are also obtained. They determine the whole dynamics of the multiple particle productions, i.e. the spectra and multiplicities of produced particles, the cross sections for DD of colliding hadrons and nucleons inside the target nuclei. The numerical results for δ tot , δ el and for dδ el /dp tr 2 with the set of the pomeron and f, ω-reggeons pole parameters obtained early are presented. 19 refs.; 6 figs

Smash! exploring the mysteries of the Universe with the Large Hadron Collider

CERN Document Server

Latta, Sara

2017-01-01

What is the universe made of? At CERN, the European Organization for Nuclear Research, scientists have searched for answers to this question using the largest machine in the world: the Large Hadron Collider. It speeds up tiny particles, then smashes them togetherand the collision gives researchers a look at the building blocks of the universe.

Challenges for MSSM Higgs searches at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Carena, Marcela S.; /Fermilab; Menon, A.; /Argonne /Chicago U., EFI; Wagner, C.E.M.; /Argonne /Chicago U., EFI /KICP, Chicago /Chicago U.

2007-04-01

In this article we analyze the impact of B-physics and Higgs physics at LEP on standard and non-standard Higgs bosons searches at the Tevatron and the LHC, within the framework of minimal flavor violating supersymmetric models. The B-physics constraints we consider come from the experimental measurements of the rare B-decays b {yields} s{gamma} and B{sub u} {yields} {tau}{nu} and the experimental limit on the B{sub s} {yields} {mu}{sup +}{mu}{sup -} branching ratio. We show that these constraints are severe for large values of the trilinear soft breaking parameter A{sub t}, rendering the non-standard Higgs searches at hadron colliders less promising. On the contrary these bounds are relaxed for small values of A{sub t} and large values of the Higgsino mass parameter {mu}, enhancing the prospects for the direct detection of non-standard Higgs bosons at both colliders. We also consider the available ATLAS and CMS projected sensitivities in the standard model Higgs search channels, and we discuss the LHC's ability in probing the whole MSSM parameter space. In addition we also consider the expected Tevatron collider sensitivities in the standard model Higgs h {yields} b{bar b} channel to show that it may be able to find 3 {sigma} evidence in the B-physics allowed regions for small or moderate values of the stop mixing parameter.

Beam dynamics aspects of crab cavities in the CERN Large Hadron Collider

CERN Document Server

Sun, Y P; Barranco, J; Tomás, R; Weiler, T; Zimmermann, F; Calaga, R; Morita, A

2009-01-01

Modern colliders bring into collision a large number of bunches 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 geometric luminosity. Such crab cavities have been proposed for both linear and circular colliders. The crab cavities are rf cavities operated in a transverse dipole mode, which imparts on the beam particles a transverse kick that varies with the longitudinal position along the bunch. The use of crab cavities in the Large Hadron Collider (LHC) may not only raise the luminosity, but it could also complicate the beam dynamics, e.g., crab cavities might not only cancel synchrobetatron resonances excited by the crossing angle but they could also excite new ones, they could reduce the dynamic aperture for off-momentum particles, they could influence the aperture and orbit...

A Silicon Strip Detector for the Phase II High Luminosity Upgrade of the ATLAS Detector at the Large Hadron Collider

CERN Document Server

INSPIRE-00425747; McMahon, Stephen J

2015-01-01

ATLAS is a particle physics experiment at the Large Hadron Collider (LHC) that detects proton-proton collisions at a centre of mass energy of 14 TeV. The Semiconductor Tracker is part of the Inner Detector, implemented using silicon microstrip detectors with binary read-out, providing momentum measurement of charged particles with excellent resolution. The operation of the LHC and the ATLAS experiment started in 2010, with ten years of operation expected until major upgrades are needed in the accelerator and the experiments. The ATLAS tracker will need to be completely replaced due to the radiation damage and occupancy of some detector elements and the data links at high luminosities. These upgrades after the first ten years of operation are named the Phase-II Upgrade and involve a re-design of the LHC, resulting in the High Luminosity Large Hadron Collider (HL-LHC). This thesis presents the work carried out in the testing of the ATLAS Phase-II Upgrade electronic systems in the future strips tracker a...

Reconstruction, Energy Calibration, and Identification of Hadronically Decaying Tau Leptons in the ATLAS Experiment for Run-2 of the LHC

CERN Document Server

The ATLAS collaboration

2015-01-01

The reconstruction algorithm, energy calibration, and identification methods for hadronically decaying tau leptons in ATLAS used at the start of Run-2 of the Large Hadron Collider are described in this note. All algorithms have been optimised for Run-2 conditions. The energy calibration relies on Monte Carlo samples with hadronic tau lepton decays, and applies multiplicative factors based on the pT of the reconstructed tau lepton to the energy measurements in the calorimeters. The identification employs boosted decision trees. Systematic uncertainties on the energy scale, reconstruction efficiency and identification efficiency of hadronically decaying tau leptons are determined using Monte Carlo samples that simulate varying conditions.

Next to leading order three jet production at hadron colliders

International Nuclear Information System (INIS)

Kilgore, W.

1997-01-01

Results from a next-to-leading order event generator of purely gluonic jet production are presented. This calculation is the first step in the construction of a full next-to-leading order calculation of three jet production at hadron colliders. Several jet algorithms commonly used in experiments are implemented and their numerical stability is investigated. A numerical instability is found in the iterative cone algorithm which makes it inappropriate for use in fixed order calculations beyond leading order. (author)

Study of Drell-Yan process in CMS experiment at Large Hadron Collider

CERN Document Server

Jindal, Monika

The proton-proton collisions at the Large Hadron Collider (LHC) is the begining of a new era in the high energy physics. It enables the possibility of the discoveries at high-energy frontier and also allows the study of Standard Model physics with high precision. The new physics discoveries and the precision measurements can be achieved with highly efficient and accurate detectors like Compact Muon Solenoid. In this thesis, we report the measurement of the differential production cross-section of the Drell-Yan process, $q ar{q} ightarrow Z/gamma^{*} ightarrowmu^{+}mu^{-}$ in proton-proton collisions at the center-of-mass energy $sqrt{s}=$ 7 TeV using CMS experiment at the LHC. This measurement is based on the analysis of data which corresponds to an integrated luminosity of $intmath{L}dt$ = 36.0 $pm$ 1.4 pb$^{-1}$. The measurement of the production cross-section of the Drell-Yan process provides a first test of the Standard Model in a new energy domain and may reveal exotic physics processes. The Drell...

Processes with weak gauge boson pairs at hadron colliders. Precise predictions and future prospects

Energy Technology Data Exchange (ETDEWEB)

Salfelder, Lukas

2017-02-08

In the last years, scattering processes comprising pairs of the massive weak gauge bosons gain more and more attention. Those reactions provide particularly promising means to investigate the very mechanism responsible for electroweak symmetry breaking in the Standard Model of particle physics and to search for new physics entering via the weak sector of the theory. Precisely predicting the differential distributions of the final-state particles in realistic conditions is an essential prerequisite to potentially reveal tiny deviations induced by physics beyond the Standard Model. In this thesis we present a calculation of the next-to-leading order (NLO) electroweak corrections to W-boson pair production at CERNs Large Hadron Collider (LHC), as well as a detailed analysis of vector-boson scattering (VBS) processes at a future high-energy proton.proton collider. In particular, our calculation of the NLO electroweak corrections to the hadronic process pp→W{sup +}W{sup -}→4 leptons takes the leptonic W-boson decays as well as all off-shell effects fully into account and, thus, is the first prediction providing NLO accuracy everywhere in phase space. Employing realistic event selection criteria, we study the influence of the corrections in situations that are typical for the experimental analyses in the high-energy region and for Higgs-boson precision studies in the channel H→WW{sup *}, to which direct W-boson pair production represents an important irreducible background. We observe non-trivial distortions of the differential distributions that, if not properly included in upcoming analyses, could easily be misidentified as first signs of new physics. Furthermore, we compare our predictions to previous results obtained by employing the so-called double-pole approximation. At small and intermediate scales the two approaches show the expected agreement at the level of fractions of a percent, while in the TeV range the differences may easily reach several tens of

QCD and Jets at Hadron Colliders

CERN Document Server

Sapeta, Sebastian

2016-01-01

We review various aspects of jet physics in the context of hadron colliders. We start by discussing the definitions and properties of jets and recent development in this area. We then consider the question of factorization for processes with jets, in particular for cases in which jets are produced in special configurations, like for example in the region of forward rapidities. We review numerous perturbative methods for calculating predictions for jet processes, including the fixed-order calculations as well as various matching and merging techniques. We also discuss the questions related to non-perturbative effects and the role they play in precision jet studies. We describe the status of calculations for processes with jet vetoes and we also elaborate on production of jets in forward direction. Throughout the article, we present selected comparisons between state-of-the-art theoretical predictions and the data from the LHC.

Fault Tracking of the Superconducting Magnet System at the CERN Large Hadron Collider

CERN Document Server

Griesemer, Tobias

2016-03-25

The Large Hadron Collider (LHC) at CERN is one of the most complex machines ever built. It is used to explore the mysteries of the universe by reproducing conditions of the big bang. High energy particles are collide in particle detectors and as a result of the collision process secondary particles are created. New particles could be discovered during this process. The operation of such a machine is not straightforward and is subject to many different types of failures. A model of LHC operation needs to be defined in order to understand the impact of the various failures on availability. As an example a typical operational cycle is described: the beams are first injected, then accelerated, and finally brought into collisions. Under nominal conditions, beams should be in collision (so-called ‘stable beams’ period) for about 10 hours and then extracted onto a beam dump block. In case of a failure, the Machine Protection Systems ensure safe extraction of the beams. From the experience in LHC Run 1 (2009 - 20...

CERN celebrating the Lowering of the final detector element for large Hadron Collider

CERN Multimedia

2008-01-01

In the early hours of the morning the final element of the Compact Muon Solenoid (CMS) detector began the descent into its underground experimental cavern in preparation for the start-up of CERNs Large Hadron Collider (LHC) this summer. This is a pivotal moment for the CMS collaboration.

Superconductive technologies for the Large Hadron collider at CERN

CERN Document Server

Rossi, L

2000-01-01

The Large Hadron Collider (LHC) project is the largest plant based on superconductivity and cryogenics: 27 km of tunnel filled with superconducting magnets and other equipment that will be kept at 1.9 K. The dipole magnets have to generate a minimum magnetic field of 8.3 T to allow collisions of proton beams at an energy of 14 TeV in the centre of mass. The construction of LHC started in 1997 at CERN in Geneva and required 10 years of research and development on fine- filament NbTi superconducting wires and cables, on magnet technology and on He-II refrigerators. In particular the project needs the production of about 1000 tons of high-homogeneity NbTi with current densities of more than 2000 A mm/sup -2/ at 9 T and 1.9 K, with tight control also of all other cable properties such as magnetization, interstrand resistance and copper resistivity. The paper describes the main dipole magnets and reviews the most significant steps in the research and development, focusing on the issues related to the conductor, to...

Physics and Analysis at a Hadron Collider - Making Measurements (3/3)

CERN Multimedia

CERN. Geneva

2010-01-01

This is the third lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This third lecture discusses techniques important for analyses making a measurement (e.g. determining a cross section or a particle property such as its mass or lifetime) using some CDF top-quark analyses as specific examples. The lectures are aimed at graduate students.

A Measurement of Jet Shapes in Proton-Proton Collisions at 7.0 TeV Center-of-Mass Energy with the ATLAS Detector at the Large Hadron Collider

CERN Document Server

Marshall, Zachary L

2010-01-01

A study of jet shapes is presented using 300 nb−1 of proton-proton collision data collected at a center of mass energy of 7 TeV using the ATLAS detector at the Large Hadron Collider. The analysis includes jets with rapidity |y| < 2.8 and with calibrated transverse momentum 40< pT <600 GeV. Results are compared with several tuned Monte Carlo programs. Jets are found to be wider than predicted, although the evolution of the jet shape with transverse momentum is well described.

Large Hadron Collider Physics (LHCP2017) conference | 15-20 May 2017 | Shanghai

CERN Multimedia

2016-01-01

The fifth Annual Large Hadron Collider Physics will be held in Shanghai and hosted by Shanghai Jiao Tong University in the period of May 15-20, 2017. The main goal of the conference is to provide intense and lively discussions between experimenters and theorists in such research areas as the Standard Model Physics and Beyond, the Higgs Boson, Supersymmetry, Heavy Quark Physics and Heavy Ion Physics as well as to share a recent progress in the high luminosity upgrades and future colliders developments.     The LHCP2017 website: http://lhcp2017.physics.sjtu.edu.cn/ Event date: 15 - 20 May 2017 Location: Shanghai, China

SUSY-QCD corrections to Higgs boson production at hadron colliders

International Nuclear Information System (INIS)

Djouadi, A.; Spira, M.

1999-12-01

We analyze the next-to-leading order SUSY-QCD corrections to the production of Higgs particles at hadron colliders in supersymmetric extensions of the standard model. Besides the standard QCD corrections due to gluon exchange and emission, genuine supersymmetric corrections due to the virtual exchange of squarks and gluinos are present. At both the Tevatron and the LHC, these corrections are found to be small in the Higgs-strahlung, Drell-Yan-like Higgs pair production and vector boson fusion processes. (orig.)

Reconstruction of semileptonically decaying beauty hadrons produced in high energy pp collisions

Energy Technology Data Exchange (ETDEWEB)

Ciezarek, G. [Nikhef,Science Park 105, 1098 XG Amsterdam (Netherlands); Lupato, A. [INFN Padova,Viale dell’Università, 2, 35020 Legnaro PD (Italy); Rotondo, M. [Laboratori Nazionali di Frascati,Via Enrico Fermi, 40, 00044 Frascati RM (Italy); Vesterinen, M. [Physicalisches Institute Heidelberg,Klaus-Tschira-Gebäude, Im Neuenheimer Feld 226, 69120 Heidelberg (Germany)

2017-02-06

It is well known that in b-hadron decays with a single unreconstructible final state particle, the decay kinematics can be solved up to a quadratic ambiguity, without any knowledge of the b-hadron momentum. We present a method to infer the momenta of b-hadrons produced in hadron collider experiments using information from their reconstructed flight vectors. Our method is strictly agnostic to the decay itself, which implies that it can be validated with control samples of topologically similar decays to fully reconstructible final states. A multivariate regression algorithm based on the flight information provides a b-hadron momentum estimate with a resolution of around 60% which is sufficient to select the correct solution to the quadratic equation in around 70% of cases. This will improve the ability of hadron collider experiments to make differential decay rate measurements with semileptonic b-hadron decays.

High energy hadron-hadron collisions. Annual progress report

International Nuclear Information System (INIS)

Chou, T.T.

1979-03-01

Work on high energy hadron-hadron collisions in the geometrical model, performed under the DOE Contract No. EY-76-S-09-0946, is summarized. Specific items studied include the behavior of elastic hadron scatterings at super high energies and the existence of many dips, the computation of meson radii in the geometrical model, and the hadronic matter current effects in inelastic two-body collisions

Very high energy colliders

International Nuclear Information System (INIS)

Richter, B.

1986-03-01

The luminosity and energy requirements are considered for both proton colliders and electron-positron colliders. Some of the basic design equations for high energy linear electron colliders are summarized, as well as design constraints. A few examples are given of parameters for very high energy machines. 4 refs., 6 figs

The application of the Monte Carlo code FLUKA in radiation protection studies for the large hadron collider

International Nuclear Information System (INIS)

Battistoni, Giuseppe; Broggi, Francesco; Brugger, Markus

2010-01-01

The multi-purpose particle interaction and transport code FLUKA is integral part of all radiation protection studies for the design and operation of the Large Hadron Collider (LHC) at CERN. It is one of the very few codes available for this type of calculations which is capable to calculate in one and the same simulation proton-proton and heavy ion collisions at LHC energies as well as the entire hadronic and electromagnetic particle cascade initiated by secondary particles in detectors and beam-line components from TeV energies down to energies of thermal neutrons. The present paper reviews these capabilities of FLUKA in giving details of relevant physics models along with examples of radiation protection studies for the LHC such as shielding studies for underground areas occupied by personnel during LHC operation and the simulation of induced radioactivity around beam loss points. Integral part of the FLUKA development is a careful benchmarking of specific models as well as the code performance in complex, real life applications which is demonstrated with examples of studies relevant to radiation protection at the LHC. (author)

Weak mixing angle measurements at hadron colliders

CERN Document Server

Di Simone, Andrea; The ATLAS collaboration

2015-01-01

The Talk will cover weak mixing angle measurements at hadron colliders ATLAS and CMS in particular. ATLAS has measured the forward-backward asymmetry for the neutral current Drell Yan process in a wide mass range around the Z resonance region using dielectron and dimuon final states with $\\sqrt{s}$ =7 TeV data. For the dielectron channel, the measurement includes electrons detected in the forward calorimeter which extends the covered phase space. The result is then used to extract a measurement of the effective weak mixing angle. Uncertainties from the limited knowledge on the parton distribution functions in the proton constitute a significant part of the uncertainty and a dedicated study is performed to obtain a PDF set describing W and Z data measured previously by ATLAS. Similar studies from CMS will be reported.

Cost-Benefit Analysis of the Large Hadron Collider to 2025 and beyond

CERN Document Server

Florio, Massimo; Sirtori, Emanuela

2015-01-01

Social cost-benefit analysis (CBA) of projects has been successfully applied in different fields such as transport, energy, health, education, and environment, including climate change. It is often argued that it is impossible to extend the CBA approach to the evaluation of the social impact of research infrastructures, because the final benefit to society of scientific discovery is generally unpredictable. Here, we propose a quantitative approach to this problem, we use it to design an empirically testable CBA model, and we apply it to the the Large Hadron Collider (LHC), the highest-energy accelerator in the world, currently operating at CERN. We show that the evaluation of benefits can be made quantitative by determining their value to users (scientists, early-stage researchers, firms, visitors) and non-users (the general public). Four classes of contributions to users are identified: knowledge output, human capital development, technological spillovers, and cultural effects. Benefits for non-users can be ...

CERN 's large hadron collider : Radiation protection aspects of design and commissioning

International Nuclear Information System (INIS)

Forkel-Wirth, Doris; Brugger, Markus; Menzel, Hans; Roesler, Stefan; Vincke, Heinz; Vincke, Helmut

2008-01-01

Full text: CERN, the world's largest particle physics laboratory provides high energy hadron beams for experiments exploring matter. For this purpose various accelerators are operated and in 2008 the last link will be added to the accelerator chain: beam will be injected into CERN 's new 'flagship', the Large Hadron Collider (LHC). From then on high energy physics experiments will exploit the LHC 's colliding beams of protons and lead ions with a center of mass energy of 14 TeV and 1150 TeV, respectively. Radiation Protection aspects were taken into account during the whole duration of the design phase. Conservative design constraints were defined in 1996; some years later some of them, in particular with respect to the dose to occupational exposed workers, had to be readjusted to account for the latest development in CERN 's radiation protection rules and regulations. Numerous radiation protection studies had been performed to ensure a lay-out of the machine and its experiments in compliance with these constraints. These studies assessed all radiation risks related to the various beam-operation modes of the accelerator. In all cases external exposure was identified as the major risk: due to high energetic, mixed radiation fields during beam-on and due to beta and gamma radiation fields caused by induced radioactivity during beam-off. Counter measures were implemented like an optimized beam operation to limit beam losses, installation of thick shielding, prohibition of access to the major part of the LHC underground areas during beam-operation and optimization of the equipment and its handling during maintenance and repair. Detailed Monte Carlo simulations were performed to derive from the various beam loss scenarios the dose rates the workers will be exposed to. Individual and collective doses were projected based on the calculations and the maintenance scenarios provided by the teams concerned. In an iterative way the lay-out of the various regions were optimized

Progress with High-Field Superconducting Magnets for High-Energy Colliders

Science.gov (United States)

Apollinari, Giorgio; Prestemon, Soren; Zlobin, Alexander V.

2015-10-01

One of the possible next steps for high-energy physics research relies on a high-energy hadron or muon collider. The energy of a circular collider is limited by the strength of bending dipoles, and its maximum luminosity is determined by the strength of final focus quadrupoles. For this reason, the high-energy physics and accelerator communities have shown much interest in higher-field and higher-gradient superconducting accelerator magnets. The maximum field of NbTi magnets used in all present high-energy machines, including the LHC, is limited to ˜10 T at 1.9 K. Fields above 10 T became possible with the use of Nb3Sn superconductors. Nb3Sn accelerator magnets can provide operating fields up to ˜15 T and can significantly increase the coil temperature margin. Accelerator magnets with operating fields above 15 T require high-temperature superconductors. This review discusses the status and main results of Nb3Sn accelerator magnet research and development and work toward 20-T magnets.

Cryogenics for the Large Hadron Collider

CERN Document Server

Lebrun, P

2000-01-01

The Large Hadron Collider (LHC), a 26.7 km circumference superconducting accelerator equipped with high-field magnets operating in superfluid helium below 1.9 K, has now fully entered construction at CERN, the European Laboratory for Particle Physics. The heart of the LHC cryogenic system is the quasi-isothermal magnet cooling scheme, in which flowing two-phase saturated superfluid helium removes the heat load from the 36000 ton cold mass, immersed in some 400 m/sup 3/ static pressurised superfluid helium. The LHC also makes use of supercritical helium for nonisothermal cooling of the beam screens which intercept most of the dynamic heat loads at higher temperature. Although not used in normal operation, liquid nitrogen will provide the source of refrigeration for precooling the machine. Refrigeration for the LHC is produced in eight large refrigerators, each with an equivalent capacity of about 18 kW at 4.5 K, completed by 1.8 K refrigeration units making use of several stages of hydrodynamic cold compressor...

A feedback microprocessor for hadron colliders

International Nuclear Information System (INIS)

Herrup, D.A.; Chapman, L.; Franck, A.; Groves, T.; Lublinsky, B.

1992-12-01

A feedback microprocessor has been built for the TEVATRON. It has been constructed to be applicable to hadron colliders in general. Its inputs are realtime accelerator measurements, data describing the state of the TEVATRON, and ramp tables. The microprocessor software includes a finite state machine. Each state corresponds to a specific TEVATRON operation and has a state-specific TEVATRON model. Transitions between states are initiated by the global TEVATRON clock. Each state includes a cyclic routine which is called periodically and where all calculations are performed. The output corrections are inserted onto a fast TEVATRON-wide link from which the power supplies will read the realtime corrections. We also store all of the input data and output corrections in a set of buffers which can easily be retrieved for diagnostic analysis. In this paper we will describe this device and its use to control the TEVATRON tunes as well as other possible applications

High luminosity particle colliders

International Nuclear Information System (INIS)

Palmer, R.B.; Gallardo, J.C.

1997-03-01

The authors consider the high energy physics advantages, disadvantages and luminosity requirements of hadron (pp, p anti p), lepton (e + e - , μ + μ - ) and photon-photon colliders. Technical problems in obtaining increased energy in each type of machine are presented. The machines relative size are also discussed

The Large Hadron Collider project: organizational and financial matters (of physics at the terascale)

NARCIS (Netherlands)

Engelen, J.

2012-01-01

n this paper, I present a view of organizational and financial matters relevant for the successful construction and operation of the experimental set-ups at the Large Hadron Collider of CERN, the European Laboratory for Particle Physics in Geneva. Construction of these experiments was particularly

Linear colliders for photon collisions

International Nuclear Information System (INIS)

Anon.

1994-01-01

The enthusiasm of the first international workshop on photonphoton colliders and associated physics, held at the Lawrence Berkeley Laboratory from 28 March - 1 April, could have set a ball rolling. According to proponents of this physics, the particle physics one can study with a high energy linear collider is special and complements that of a hadron supercollider

Forward-backward asymmetries of lepton pairs in events with a large-transverse-momentum jet at hadron colliders

International Nuclear Information System (INIS)

Aguila, F. del; Ametller, Ll.; Talavera, P.

2002-01-01

We discuss forward-backward charge asymmetries for lepton-pair production in association with a large-transverse-momentum jet at hadron colliders. The lepton charge asymmetry relative to the jet direction A FB j gives a new determination of the effective weak mixing angle sin 2 θ eff lept (M Z 2 ) with a statistical precision after cuts of ∼10 -3 (8x10 -3 ) at LHC (Tevatron). This is to be compared with the current uncertainty at LEP and SLD from the asymmetries alone, 2x10 -4 . The identification of b jets also allows for the measurement of the bottom-quark-Z asymmetry A FB b at hadron colliders, the resulting statistical precision for sin 2 θ eff lept (M Z 2 ) being ∼9x10 -4 (2x10 -2 at Tevatron), also lower than the reported precision at e + e - colliders, 3x10 -4

The promise of the large collider

CERN Multimedia

2007-01-01

"In 2007, the most powerful particle accelerator ever built, CERN's new Large hadron Collider, will probe the secrets of matter in the energy states prevailing in the moments after the Big Bang. By colliding particles together when they are moving at close to the speed of ight, physicists hope to find out about matter in its earliest forms, using the energy produced by the collisions." (2 pages)

A search for technicolor at the large hadron collider

Science.gov (United States)

Love, Jeremy R.

The Standard Model of particle physics provides an accurate description of all experimental data to date. The only unobserved piece of the Standard Model is the Higgs boson, a consequence of the spontaneous breaking of electroweak symmetry by the Higgs mechanism. An alternative to the Higgs mechanism is proposed by Technicolor theories which break electroweak symmetry dynamically through a new force. Technicolor predicts many new particles, called Technihadrons, that could be observed by experiments at hadron colliders. This thesis presents a search for two of the lightest Technihadrons, the rhoT and oT. The Low-Scale Technicolor model predicts the phenomenology of these new states. The rhoT and oT are produced through qq annihilation and couple to Standard Model fermions through the Drell-Yan process, which can result in the dimuon final state. The rhoT and oT preferentially decay to the piT and a Standard Model gauge boson if kinematically allowed. Changing the mass of the piT relative to that of the rhoT and o T affects the cross section times branching fraction to dimuons. The rhoT and oT are expected to have masses below about 1 TeV. The Large Hadron Collider (LHC) at CERN outside of Geneva, Switzerland, produces proton-proton collisions with a center of mass energy of 7 TeV. A general purpose high energy physics detector ATLAS has been used in this analysis to search for Technihadrons decaying to two muons. We use the ATLAS detector to reconstruct the tracks of muons with high transverse momentum coming from these proton-proton collisions. The dimuon invariant mass spectrum is analyzed above 130 GeV to test the consistency of the observed data with the Standard Model prediction. We observe excellent agreement between our data and the background only hypothesis, and proceed to set limits on the cross section times branching ratio of the rhoT and oT as a function of their mass using the Low-Scale Technicolor model. We combine the dielectron and dimuon channels

Search for excited electrons using the CMS detector at the Large Hadron Collider

International Nuclear Information System (INIS)

Jain, Shilpi

2013-01-01

The start of the Large Hadron Collider (LHC) opened a new window to the energy scale far beyond 1 TeV. There are different theories that predict new physics, and hence it is not clear what signature to expect in the data and which of the theory will describe it properly. However new physics could as well manifest itself in ways no one has yet thought of. Thus we have implemented a Model Unspecific Search in CMS (MUSiC). This approach has been applied to the CMS data and we have obtained the preliminary results. I will talk about this details of the analysis techniques, its implementation in analysing CMS data, results obtained and the discussion on the discrepancy observed

Grid computing in pakistan and: opening to large hadron collider experiments

International Nuclear Information System (INIS)

Batool, N.; Osman, A.; Mahmood, A.; Rana, M.A.

2009-01-01

A grid computing facility was developed at sister institutes Pakistan Institute of Nuclear Science and Technology (PINSTECH) and Pakistan Institute of Engineering and Applied Sciences (PIEAS) in collaboration with Large Hadron Collider (LHC) Computing Grid during early years of the present decade. The Grid facility PAKGRID-LCG2 as one of the grid node in Pakistan was developed employing mainly local means and is capable of supporting local and international research and computational tasks in the domain of LHC Computing Grid. Functional status of the facility is presented in terms of number of jobs performed. The facility developed provides a forum to local researchers in the field of high energy physics to participate in the LHC experiments and related activities at European particle physics research laboratory (CERN), which is one of the best physics laboratories in the world. It also provides a platform of an emerging computing technology (CT). (author)

Introduction to beauty-hadron physics

International Nuclear Information System (INIS)

Fridman, A.

1995-03-01

These lectures discuss methods for analyzing the decay of beauty hadrons (B mesons and beauty baryons) produced in pp interactions. At the c.m. energies around 14 TeV planned for the Large Hadron Collider (LHC) at CERN, the B meson production rate is expected to be ca 105 larger than in an e+e- B factory. The pp collider could then offer, in principle, important advantages. However, the detection of beauty hadrons produced in a pp collider will be a task of great complexity. In particular, the triggering difficulties of events in a large background will be one of the major problems. Therefore, it would be useful to discuss the various aspects that can be investigated in beauty physics arising from pp interactions. It is first described the general features of the formalisms of B mixing and search for CP violation in the meson decays. Then the specific problems appearing for beauty hadrons produced in pN interactions are considered. Some comparison between investigations which could be carried out with B factories and pp colliders are also mentioned, although this is not the main concern of these lectures. Finally it is also presented some elements of beauty baryon decays which can only be studied efficiently by means of pN interaction

Introduction to beauty-hadron physics

Energy Technology Data Exchange (ETDEWEB)

Fridman, A. [Istituto Nazionale di Fisica Nucleare, Trieste (Italy)

1995-03-01

These lectures discuss methods for analyzing the decay of beauty hadrons (B mesons and beauty baryons) produced in pp interactions. At the c.m. energies around 14 TeV planned for the Large Hadron Collider (LHC) at CERN, the B meson production rate is expected to be ca 105 larger than in an e+e- B factory. The pp collider could then offer, in principle, important advantages. However, the detection of beauty hadrons produced in a pp collider will be a task of great complexity. In particular, the triggering difficulties of events in a large background will be one of the major problems. Therefore, it would be useful to discuss the various aspects that can be investigated in beauty physics arising from pp interactions. It is first described the general features of the formalisms of B mixing and search for CP violation in the meson decays. Then the specific problems appearing for beauty hadrons produced in pN interactions are considered. Some comparison between investigations which could be carried out with B factories and pp colliders are also mentioned, although this is not the main concern of these lectures. Finally it is also presented some elements of beauty baryon decays which can only be studied efficiently by means of pN interaction.

Accelerating and storing polarized hadron beams

International Nuclear Information System (INIS)

Teng, L.C.

1990-10-01

Polarization hadron experiments at high energies continue to generate surprises. Many questions remain unanswered or unanswerable within the frame work of QCD. These include such basic questions as to why at high energies the polarization analyzing power in pp elastic scattering remains high, why hyperons are produced with high polarizations etc. It is, therefore, interesting to investigate the possibilities of accelerating and storing polarized beams in high energy colliders. On the technical side the recent understanding and confirmation of the actions of partial and multiple Siberian snakes made it possible to contemplate accelerating and storing polarized hadron beams to multi-TeV energies. In this paper, we will examine the equipment, the operation and the procedure required to obtain colliding beams of polarized protons at TeV energies

Measurement of Electroweak Gauge Boson Scattering in the Channel $pp \\rightarrow W^{\\pm}W^{\\pm}jj$ with the ATLAS Detector at the Large Hadron Collider

CERN Document Server

AUTHOR|(CDS)2080413; Kobel, Michael; Heinemann, Beate; Klein, Uta

Particle physics deals with the elementary constituents of our universe and their interactions. The electroweak symmetry breaking mechanism in the Standard Model of Particle Physics is of paramount importance and it plays a central role in the physics programmes of current high-energy physics experiments at the Large Hadron Collider. The study of scattering processes of massive electroweak gauge bosons provides an approach complementary to the precise measurement of the properties of the recently discovered Higgs boson. Owing to the unprecedented energies achieved in proton-proton collisions at the Large Hadron Collider and the large amount of data collected, experimental studies of these processes become feasible for the first time. Especially the scattering of two $W^{\\pm}$ bosons of identical electric charge is considered a promising process for an initial study due to its distinct experimental signature. In the course of this work, $20.3 \\, \\mathrm{fb}^{−1}$ of proton-proton collision data recorded by t...

Heavy-ion collisions at the dawn of the large hadron collider era

International Nuclear Information System (INIS)

Takahashi, J.

2011-01-01

In this paper I present a review of the main topics associated with the study of heavy-ion collisions, intended for students starting or interested in the field. It is impossible to summarize in a few pages the large amount of information that is available today, after a decade of operations of the Relativistic Heavy Ion Collider and the beginning of operations at the Large Hadron Collider. Thus, I had to choose some of the results and theories in order to present the main ideas and goals. All results presented here are from publicly available references, but some of the discussions and opinions are my personal view, where I have made that clear in the text (author)

Last magnet in place for colossal collider

CERN Document Server

Cho, Adrian

2007-01-01

"Workers have installed the last magnet for the world's mew highest-energy particle smasher, the Large Hadron Collider (LHC). The installation marks an important milestone; however, researchers still may not get the collider completed in time to start it up in November as planned." (1 page)

Electroweak corrections to top quark pair production in association with a hard photon at hadron colliders

International Nuclear Information System (INIS)

Duan, Peng-Fei; Zhang, Yu; Wang, Yong; Song, Mao; Li, Gang

2017-01-01

We present the next-to-leading order (NLO) electroweak (EW) corrections to the top quark pair production associated with a hard photon at the current and future hadron colliders. The dependence of the leading order (LO) and NLO EW corrected cross sections on the photon transverse momentum cut are investigated. We also provide the LO and NLO EW corrected distributions of the transverse momentum of final top quark and photon and the invariant mass of top quark pair and top–antitop-photon system. The results show that the NLO EW corrections are significant in high energy regions due to the EW Sudakov effect.

Il Collisore LHC (Large Hadron Collider)

CERN Multimedia

Brianti, Giorgio

2004-01-01

In 2007, in a new Collider in the tunnel of 27km, collisions will be made between very powerful beams of protons and ions. The energies will be very high to try to catch the most tiny particle (1 page)

Physics and Analysis at a Hadron Collider - Searching for New Physics (2/3)

CERN Multimedia

CERN. Geneva

2010-01-01

This is the second lecture of three which together discuss the physics of hadron colliders with an emphasis on experimental techniques used for data analysis. This second lecture discusses techniques important for analyses searching for new physics using the CDF B_s --> mu+ mu- search as a specific example. The lectures are aimed at graduate students.

Status of the Future Circular Collider Study

Science.gov (United States)

Benedikt, Michael

2016-03-01

Following the 2013 update of the European Strategy for Particle Physics, the international Future Circular Collider (FCC) Study has been launched by CERN as host institute, to design an energy frontier hadron collider (FCC-hh) in a new 80-100 km tunnel with a centre-of-mass energy of about 100 TeV, an order of magnitude beyond the LHC's, as a long-term goal. The FCC study also includes the design of a 90-350 GeV high-luminosity lepton collider (FCC-ee) installed in the same tunnel, serving as Higgs, top and Z factory, as a potential intermediate step, as well as an electron-proton collider option (FCC-he). The physics cases for such machines will be assessed and concepts for experiments will be developed in time for the next update of the European Strategy for Particle Physics by the end of 2018. The presentation will summarize the status of machine designs and parameters and discuss the essential technical components to be developed in the frame of the FCC study. Key elements are superconducting accelerator-dipole magnets with a field of 16 T for the hadron collider and high-power, high-efficiency RF systems for the lepton collider. In addition the unprecedented beam power presents special challenges for the hadron collider for all aspects of beam handling and machine protection. First conclusions of geological investigations and implementation studies will be presented. The status of the FCC collaboration and the further planning for the study will be outlined.

Production of H H H and H H V (V =γ ,Z ) at the hadron colliders

Science.gov (United States)

Agrawal, Pankaj; Saha, Debashis; Shivaji, Ambresh

2018-02-01

We consider the production of two Higgs bosons in association with a gauge boson or another Higgs boson at the hadron colliders. We compute the cross sections and distributions for the processes p p →H H H and H H Z within the standard model. In particular, we compute the gluon-gluon fusion one-loop contributions mediated via heavy quarks in the loop. It is the leading order contribution to p p →H H H process. To the process p p →H H Z , it is next-to-next-to-leading-order (NNLO) contribution in QCD coupling. We also compare this contribution to the next-to-leading-order (NLO) QCD contribution to this process. The NNLO contribution can be similar to NLO contribution at the Large Hadron Collider (LHC), and significantly more at higher center-of-mass energy machines. We also study new physics effects in these processes by considering t t H , H H H , H H H H , H Z Z , and H H Z Z interactions as anomalous. The anomalous couplings can enhance the cross sections significantly. The g g →H H H process is specially sensitive to anomalous trilinear Higgs boson self-coupling. For the g g →H H Z process, there is some modest dependence on anomalous H Z Z couplings.

High Energy Accelerator and Colliding Beam User Group

International Nuclear Information System (INIS)

Snow, G.A.; Skuja, A.

1992-05-01

This report discusses research in the following areas: the study of e + e - interactions; Hadron collider physics at Fermilab; fixed target physics and particle physics of general interest; and, the solenoidal detector collaboration at SSCL

The fast tracker processor for hadronic collider triggers

CERN Document Server

Annovi, A; Bardi, A; Carosi, R; Dell'Orso, Mauro; D'Onofrio, M; Giannetti, P; Iannaccone, G; Morsani, F; Pietri, M; Varotto, G

2000-01-01

Perspective for precise and fast track reconstruction in future hadronic collider experiments are addressed. We discuss the feasibility of a pipelined highly parallelized processor dedicated to the implementation of a very fast algorithm. The algorithm is based on the use of a large bank of pre-stored combinations of trajectory points (patterns) for extremely complex tracking systems. The CMS experiment at LHC is used as a benchmark. Tracking data from the events selected by the level-1 trigger are sorted and filtered by the Fast Tracker processor at a rate of 100 kHz. This data organization allows the level-2 trigger logic to reconstruct full resolution traces with transverse momentum above few GeV and search secondary vertexes within typical level-2 times. 15 Refs.

Heavy-Quark Associated Production with One Hard Photon at Hadron Colliders

Energy Technology Data Exchange (ETDEWEB)

Hartanto, Heribertus Bayu [Florida State Univ., Tallahassee, FL (United States)

2013-01-01

We present the calculation of heavy-quark associated production with a hard photon at hadron colliders, namely $pp(p\\bar p) → Q\\bar Q +X$γ (for $Q=t,b$), at Next-to-Leading Order (NLO) in Quantum Chromodynamics (QCD). We study the impact of NLO QCD corrections on the total cross section and several differential distributions at both the Tevatron and the Large Hadron Collider (LHC). For $t\\bar t$γ production we observe a sizeable reduction of the renormalization and factorization scale dependence when the NLO QCD corrections are included, while for $b\\bar b$γ production a considerable scale dependence still persists at NLO in QCD. This is consistent with what emerges in similar processes involving $b$ quarks and vector bosons and we explain its origin in detail. For $b\\bar b$γ production we study both the case in which at least one $b$ jet and the case in which at least two $b$ jets are observed. We perform the $b\\bar b$γ calculation using the Four Flavor Number Scheme (4FNS) and compare the case where at least one $b$ jet is observed with the corresponding results from the Five Flavor Number Scheme (5FNS) calculation. Finally we compare our results for $p\\bar p →+b+X$γ with the Tevatron data.

Machine Protection and High Energy Density States in Matter for High Energy Hadron Accelerators

CERN Document Server

Blanco Sancho, Juan; Schmidt, R

The Large Hadron Collider (LHC) is the largest accelerator in the world. It is designed to collide two proton beams with unprecedented particle energy of 7TeV. The energy stored in each beam is 362MJ, sufficient to melt 500kg of copper. An accidental release of even a small fraction of the beam energy can result in severe damage to the equipment. Machine protection systems are essential to safely operate the accelerator and handle all possible accidents. This thesis deals with the study of different failure scenarios and its possible consequences. It addresses failure scenarios ranging from low intensity losses on high-Z materials and superconductors to high intensity losses on carbon and copper collimators. Low beam losses are sufficient to quench the superconducting magnets and the stabilized superconducting cables (bus-bars) that connects the main magnets. If this occurs and the energy from the bus-bar is not extracted fast enough it can lead to a situation similar to the accident in 2008 at LHC during pow...

Future Circular Colliders

CERN Document Server

AUTHOR|(CDS)2108454; Zimmermann, Frank

2016-01-01

In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detector, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb$_{3}$Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The int...

Future Circular Colliders

CERN Document Server

AUTHOR|(CDS)2108454; Zimmermann, Frank

2016-01-01

In response to a request from the 2013 Update of the European Strategy for Particle Physics, the global Future Circular Collider (FCC) study is preparing the foundation for a next-generation large-scale accelerator infrastructure in the heart of Europe. The FCC study focuses on the design of a 100-TeV hadron collider (FCC-hh), to be accommodated in a new ∼100 km tunnel near Geneva. It also includes the design of a high-luminosity electron-positron collider (FCC-ee), which could be installed in the same tunnel as a potential intermediate step, and a lepton-hadron collider option (FCC-he). The scope of the FCC study comprises accelerators, technology, infrastructure, detectors, physics, concepts for worldwide data services, international governance models, and implementation scenarios. Among the FCC core technologies figure 16-T dipole magnets, based on Nb$_{3}$Sn superconductor, for the FCC-hh hadron collider, and a highly efficient superconducting radiofrequency system for the FCC-ee lepton collider. The in...

Discussion on muon collider parameters at center of mass energies from 0.1 TeV to 100 TeV

International Nuclear Information System (INIS)

King, B.J.

1998-06-01

The main motivation for research and development efforts on muon collider technology is the assertion that affordably priced muon colliders might provide lepton-lepton collisions at much higher center of mass (CoM) energies than is feasible for electron colliders, and perhaps eventually explore the spectrum of elementary particles at mass scales inaccessible even to hadron colliders. This paper attempts to present some justification for these assertions through discussion and evaluation of the self-consistent muon collider parameter sets given in table 1 at CoM energies ranging from 0.1 to 100 TeV. The parameter set at 0.1 TeV CoM energy was included as a lower energy reference point and was constrained to essentially reproduce one of the sets of parameters currently under study by the Muon Collider Collaboration (MCC). In contrast, the other parameter sets represent speculation by the author on how the parameters might evolve with CoM energy and they have not been studied or discussed in detail within the MCC

A Search for Technicolor at The Large Hadron Collider

CERN Document Server

Love, Jeremy R

The ATLAS detector has been used in this analysis to search for Technihadrons, predicted by Technicolor theories, decaying to two muons. These new states can be produced by the Large Hadron Collider in proton-proton collisions with a center of mass energy of 7 TeV. The Low-Scale Technicolor model predicts the phenomenology of the new $\\rho_T$ and $\\omega_T$. The dimuon invariant mass spectrum is analyzed above 130 GeV to test the consistency of the observed data with the Standard Model prediction. We observe excellent agreement between our data and the background only hypothesis, and proceed to set limits on the cross section times branching ratio of the $\\rho_T$ and $\\omega_T$ as a function of their mass. We combine the dielectron and dimuon channels to exclude masses of the $\\rho_T$ and $\\omega_T$ between 130 GeV - 480 GeV at 95 % Confidence Level for masses of the $\\pi_T$ between 50 GeV - 480 GeV. In addition for the parameter choice of m($\\pi_T$) = m($\\rho_T$/$\\omega_T$) - 100 GeV, 95 % Confidence Level l...

Top quark threshold scan and study of detectors for highly granular hadron calorimeters at future linear colliders

International Nuclear Information System (INIS)

Tesar, Michal

2014-01-01

Two major projects for future linear electron-positron colliders, the International Linear Collider (ILC) and the Compact Linear Collider (CLIC), are currently under development. These projects can be seen as complementary machines to the Large Hadron Collider (LHC) which permit a further progress in high energy physics research. They overlap considerably and share the same technological approaches. To meet the ambitious goals of precise measurements, new detector concepts like very finely segmented calorimeters are required. We study the precision of the top quark mass measurement achievable at CLIC and the ILC. The employed method was a t anti t pair production threshold scan. In this technique, simulated measurement points of the t anti t production cross section around the threshold are fitted with theoretical curves calculated at next-to-next-to-leading order. Detector effects, the influence of the beam energy spectrum and initial state radiation of the colliding particles are taken into account. Assuming total integrated luminosity of 100 fb -1 , our results show that the top quark mass in a theoretically well-defined 1S mass scheme can be extracted with a combined statistical and systematic uncertainty of less than 50 MeV. The other part of this work regards experimental studies of highly granular hadron calorimeter (HCAL) elements. To meet the required high jet energy resolution at the future linear colliders, a large and finely segmented detector is needed. One option is to assemble a sandwich calorimeter out of many low-cost scintillators read out by silicon photomultipliers (SiPM). We characterize the areal homogeneity of SiPM response with the help of a highly collimated beam of pulsed visible light. The spatial resolution of the experiment reach the order of 1 μm and allows to study the active area structures within single SiPM microcells. Several SiPM models are characterized in terms of relative photon detection efficiency and probability crosstalk

QCD and low-x physics at a Large Hadron electron Collider

CERN Document Server

Laycock, Paul

2012-01-01

The Large Hadron electron Collider (LHeC) is a proposed facility which will exploit the new world of energy and intensity offered by the LHC for electron-proton scattering, through the addition of a new electron accelerator. This contribution, which is derived from the draft CERN-ECFA-NuPECC Conceptual Design report (due for release in 2012), addresses the expected impact of the LHeC precision and extended kinematic range for low Bjorken-x and diffractive physics, and detailed simulation studies and prospects for high precision QCD and electroweak fits. Numerous observables which are sensitive to the expected low-x saturation of the parton densities are explored. These include the inclusive electron-proton scattering cross section and the related structure functions $F_2$ and $F_L$, as well as exclusive processes such as deeply-virtual Compton scattering and quasi-elastic heavy vector meson production and diffractive virtual photon dissociation. With a hundred times the luminosity that was achieved at HERA, s...

Experiments at future hadron colliders

International Nuclear Information System (INIS)

Paige, F.E.

1991-01-01

This report summarizes signatures and backgrounds for processes in high-energy hadronic collisions, particularly at the SSC. It includes both signatures for new particles -- t quarks, Higgs bosons, new Ζ' bosons, supersymmetric particles, and technicolor particles -- and other experiments which might be done. It is based on the 1990 Snowmass Workshop and on work contained in the Expressions of Interest submitted to the SSC. 46 refs., 19 figs., 1 tab

Slip-Stick Mechanism in Training the Superconducting Magnets in the Large Hadron Collider

CERN Document Server

Granieri, P P; Todesco, E

2011-01-01

Superconducting magnets can exhibit training quenches during successive powering to reaching nominal performance. The slip–stick motion of the conductors is considered to be one of the mechanisms of training. In this paper, we present a simple quantitative model where the training is described as a discrete dynamical system matching the equilibrium between the energy margin of the superconducting cable and the frictional energy released during the conductor motion. The model can be explicitly solved in the linearized case, showing that the short sample limit is reached via a power law. Training phenomena have a large random component. A large set of data of the large hadron collider magnet tests is postprocessed according to previously defined methods to extract an average training curve for dipoles and quadrupoles. These curves show the asymptotic power law predicted by the model. The curves are then fit through the model, which has two free parameters. The model shows good agreement over a large range, bu...

Slip-Stick Mechanism in Training the Superconducting Magnets in the Large Hadron Collider

CERN Document Server

Granieri, P P; Lorin, C

2011-01-01

Superconducting magnets can exhibit training quenches during successive powering to reaching nominal performance. The slip-stick motion of the conductors is considered to be one of the mechanisms of training. In this paper, we present a simple quantitative model where the training is described as a discrete dynamical system matching the equilibrium between the energy margin of the superconducting cable and the frictional energy released during the conductor motion. The model can be explicitly solved in the linearized case, showing that the short sample limit is reached via a power law. Training phenomena have a large random component. A large set of data of the large hadron collider magnet tests is postprocessed according to previously defined methods to extract an average training curve for dipoles and quadrupoles. These curves show the asymptotic power law predicted by the model. The curves are then fit through the model, which has two free parameters. The model shows good agreement over a large range, but ...

Collider workshop

International Nuclear Information System (INIS)

Anon.

1982-01-01

The promise of initial results after the start of operations at CERN's SPS proton-antiproton collider and the prospects for high energy hadron collisions at Fermilab (Tevatron) and Brookhaven (ISABELLE) provided a timely impetus for the recent Topical Workshop on Forward Collider Physics', held at Madison, Wisconsin, from 10-12 December. It became the second such workshop to be held, the first having been in 1979 at the College de France, Paris. The 100 or so participants had the chance to hear preliminary results from the UA1, UA4 and UA5 experiments at the CERN SPS collider, together with other new data, including that from proton-antiproton runs at the CERN Intersecting Storage Rings

University of Tennessee deploys force10 C-series to analyze data from CERN's Large Hadron Collider

CERN Multimedia

2007-01-01

"Force20 networks, the pioneer in building and securing reliable networks, today announced that the University of Tennessee physics department has deployed the C300 resilient switch to analyze data form CERN's Large Hadron Collider." (1 page)

High Energy Accelerator and Colliding Beam User Group

Energy Technology Data Exchange (ETDEWEB)

Snow, G.A.; Skuja, A.

1992-05-01

This report discusses research in the following areas: the study of e{sup +}e{sup {minus}} interactions; Hadron collider physics at Fermilab; fixed target physics and particle physics of general interest; and, the solenoidal detector collaboration at SSCL.

Physics at the Large Hadron Collider

CERN Document Server

Mukhopadhyaya, Biswarup; Raychaudhari, Amitava

2009-01-01

In an epoch when particle physics is awaiting a major step forward, the Large Hydron Collider (LHC) at CERN, Geneva will soon be operational. It will collide a beam of high energy protons with another similar beam circulation in the same 27 km tunnel but in the opposite direction, resulting in the production of many elementary particles some never created in the laboratory before. It is widely expected that the LHC will discover the Higgs boson, the particle which supposedly lends masses to all other fundamental particles. In addition, the question as to whether there is some new law of physics at such high energy is likely to be answered through this experiment. The present volume contains a collection of articles written by international experts, both theoreticians and experimentalists, from India and abroad, which aims to acquaint a non-specialist with some basic issues related to the LHC. At the same time, it is expected to be a useful, rudimentary companion of introductory exposition and technical expert...

Resummation for supersymmetric particle production at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Brensing, Silja Christine

2011-05-10

The search for supersymmetry is among the most important tasks at current and future colliders. Especially the production of coloured supersymmetric particles would occur copiously in hadronic collisions. Since these production processes are of high relevance for experimental searches accurate theoretical predictions are needed. Higher-order corrections in quantum chromodynamics (QCD) to these processes are dominated by large logarithmic terms due to the emission of soft gluons from initial-state and final-state particles. A systematic treatment of these logarithms to all orders in perturbation theory is provided by resummation methods. We perform the resummation of soft gluons at next-to-leading-logarithmic (NLL) accuracy for all possible production processes in the framework of the Minimal Supersymmetric Standard Model. In particular we consider pair production processes of mass-degenerate light-flavour squarks and gluinos as well as the pair production of top squarks and non-mass-degenerate bottom squarks. We present analytical results for all considered processes including the soft anomalous dimensions. Moreover numerical predictions for total cross sections and transverse-momentum distributions for both the Large Hadron Collider (LHC) and the Tevatron are presented. We provide an estimate of the theoretical uncertainty due to scale variation and the parton distribution functions. The inclusion of NLL corrections leads to a considerable reduction of the theoretical uncertainty due to scale variation and to an enhancement of the next-to-leading order (NLO) cross section predictions. The size of the soft-gluon corrections and the reduction in the scale uncertainty are most significant for processes involving gluino production. At the LHC, where the sensitivity to squark and gluino masses ranges up to 3 TeV, the corrections due to NLL resummation over and above the NLO predictions can be as high as 35 % in the case of gluino-pair production, whereas at the

Electromagnetic Design and Optimization of Directivity of Stripline Beam Position Monitors for the High Luminosity Large Hadron Collider

CERN Document Server

Draskovic, Drasko; Jones, Owain Rhodri; Lefèvre, Thibaut; Wendt, Manfred

2015-01-01

This paper presents the preliminary electromagnetic design of a stripline Beam Position Monitor (BPM) for the High Luminosity program of the Large Hadron Collider (HL-LHC) at CERN. The design is fitted into a new octagonal shielded Beam Screen for the low-beta triplets and is optimized for high directivity. It also includes internal Tungsten absorbers, required to reduce the energy deposition in the superconducting magnets. The achieved broadband directivity in wakefield solver simulations presents significant improvement over the directivity of the current stripline BPMs installed in the LHC.

CrossRef Energy Reconstruction in a High Granularity Semi-Digital Hadronic Calorimeter for ILC Experiments

CERN Document Server

Mannai, S; Cortina, E; Laktineh, I

2016-01-01

Abstract: The Semi-Digital Hadronic CALorimeter (SDHCAL) is one of the two hadronic calorimeter options proposed by the International Large Detector (ILD) project for the future International Linear Collider (ILC) experiments. It is a sampling calorimeter with 48 active layers made of Glass Resistive Plate Chambers (GRPCs) and their embedded electronics. A fine lateral segmentation is obtained thanks to pickup pads of 1 cm2. This ensures the high granularity required for the application of the Particle Flow Algorithm (PFA) in order to improve the jet energy resolution in the ILC experiments. The performance of the SDHCAL technological prototype was tested successfully in several beam tests at CERN. The main point to be discussed here concerns the energy reconstruction in SDHCAL. Based on Monte Carlo simulation of the SDHCAL prototype using the GEANT4 package, we present different energy reconstruction methods to study the energy linearity and resolution of the detector response to single hadrons. In particula...

The standard model and colliders

International Nuclear Information System (INIS)

Hinchliffe, I.

1987-03-01

Some topics in the standard model of strong and electroweak interactions are discussed, as well as how these topics are relevant for the high energy colliders which will become operational in the next few years. The radiative corrections in the Glashow-Weinberg-Salam model are discussed, stressing how these corrections may be measured at LEP and the SLC. CP violation is discussed briefly, followed by a discussion of the Higgs boson and the searches which are relevant to hadron colliders are then discussed. Some of the problems which the standard model does not solve are discussed, and the energy ranges accessible to the new colliders are indicated

Conceptual design of hollow electron lenses for beam halo control in the Large Hadron Collider

CERN Document Server

Stancari, Giulio; Valishev, Alexander; Bruce, Roderik; Redaelli, Stefano; Rossi, Adriana; Salvachua Ferrando, Belen

2014-01-01

Collimation with hollow electron beams is a technique for halo control in high-power hadron beams. It is based on an electron beam (possibly pulsed or modulated in intensity) guided by strong axial magnetic fields which overlaps with the circulating beam in a short section of the ring. The concept was tested experimentally at the Fermilab Tevatron collider using a hollow electron gun installed in one of the Tevatron electron lenses. Within the US LHC Accelerator Research Program (LARP) and the European FP7 HiLumi LHC Design Study, we are proposing a conceptual design for applying this technique to the Large Hadron Collider at CERN. A prototype hollow electron gun for the LHC was built and tested. The expected performance of the hollow electron beam collimator was based on Tevatron experiments and on numerical tracking simulations. Halo removal rates and enhancements of halo diffusivity were estimated as a function of beam and lattice parameters. Proton beam core lifetimes and emittance growth rates were check...

A real-time tracker for hadronic collider experiments

International Nuclear Information System (INIS)

Bardi, A.; Belforte, S.; Galeotti, S.; Giannetti, P.; Morsani, F.; Spinella, F.; Dell'Orso, M.; Meschi, E.

1999-01-01

In this paper the authors propose highly parallel dedicated processors, able to provide precise on-line track reconstruction for future hadronic collider experiments. The processors, organized in a 2-level pipelined architecture, execute very fast algorithms based on the use of a large bank of pre-stored patterns of trajectory points. An associative memory implements the first stage by recognized track candidates at low resolution to match the demanding task of tracking at the detector readout rate. Alternative technological implementations for the associative memory are compared. The second stage receives track candidates and high resolution hits to refine pattern recognition at the associative memory output rate. A parallel and pipelines hardware implements a binary search strategy inside a hierarchically structured pattern bank, stored in the high density commercial RAMs

The fast tracker processor for hadron collider triggers

CERN Document Server

Annovi, A; Bardi, A; Carosi, R; Dell'Orso, Mauro; D'Onofrio, M; Giannetti, P; Iannaccone, G; Morsani, E; Pietri, M; Varotto, G

2001-01-01

Perspectives for precise and fast track reconstruction in future hadron collider experiments are addressed. We discuss the feasibility of a pipelined highly parallel processor dedicated to the implementation of a very fast tracking algorithm. The algorithm is based on the use of a large bank of pre-stored combinations of trajectory points, called patterns, for extremely complex tracking systems. The CMS experiment at LHC is used as a benchmark. Tracking data from the events selected by the level-1 trigger are sorted and filtered by the Fast Tracker processor at an input rate of 100 kHz. This data organization allows the level-2 trigger logic to reconstruct full resolution tracks with transverse momentum above a few GeV and search for secondary vertices within typical level-2 times. (15 refs).

A new micro-strip tracker for the new generation of experiments at hadron colliders

International Nuclear Information System (INIS)

Dinardo, Mauro E.; Milan U.

2005-01-01

This thesis concerns the development and characterization of a prototype Silicon micro-strip detector that can be used in the forward (high rapidity) region of a hadron collider. These detectors must operate in a high radiation environment without any important degradation of their performance. The innovative feature of these detectors is the readout electronics, which, being completely data-driven, allows for the direct use of the detector information at the lowest level of the trigger. All the particle hits on the detector can be readout in real-time without any external trigger and any particular limitation due to dead-time. In this way, all the detector information is available to elaborate a very selective trigger decision based on a fast reconstruction of tracks and vertex topology. These detectors, together with the new approach to the trigger, have been developed in the context of the BTeV RandD program; our aim was to define the features and the design parameters of an optimal experiment for heavy flavour physics at hadron colliders

On measuring the masses of pair-produced semi-invisibly decaying particles at hadron colliders

International Nuclear Information System (INIS)

Tovey, Daniel R.

2008-01-01

A straightforward new technique is introduced which enables measurement at hadron colliders of an analytical combination of the masses of pair-produced semi-invisibly decaying particles and their invisible decay products. The new technique makes use of the invariance under contra-linear Lorentz boosts of a simple combination of the transverse momentum components of the aggregate visible products of each decay chain. In the general case where the invariant masses of the visible decay products are non-zero it is shown that in principle the masses of both the initial particles from the hard scattering and the invisible particles produced in the decay chains can be determined independently. This application is likely to be difficult to realise in practice however due to the contamination of the final state with ISR jets. The technique may be of most use for measurements of SUSY particle masses at the LHC, however the technique should be applicable to any class of hadron collider events in which heavy particles of unknown mass are pair-produced and decay to semi-invisible final states

Optimising charged Higgs boson searches at the Large Hadron Collider across bb¯W± final states

Directory of Open Access Journals (Sweden)

Stefano Moretti

2016-09-01

Full Text Available In the light of the most recent data from Higgs boson searches and analyses, we re-assess the scope of the Large Hadron Collider in accessing heavy charged Higgs boson signals in bb¯W± final states, wherein the contributing channels can be H+→tb¯, hW±, HW± and AW±. We consider a 2-Higgs Doublet Model Type-II and we assume as production mode bg→tH−+c.c., the dominant one over the range MH±≥480 GeV, as dictated by b→sγ constraints. Prospects of detection are found to be significant for various Run 2 energy and luminosity options.

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

CERN Document Server

Aad, Georges; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat; Abi, Babak; Abolins, Maris; AbouZeid, Ossama; Abramowicz, Halina; Abreu, Henso; Acerbi, Emilio; Acharya, Bobby Samir; Adamczyk, Leszek; Adams, David; Addy, Tetteh; Adelman, Jahred; Aderholz, Michael; Adomeit, Stefanie; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov, Andrei; Akiyama, Kunihiro; Alam, Mohammad; Alam, Muhammad Aftab; Albert, Justin; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alessandria, Franco; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Aliyev, Magsud; Allbrooke, Benedict; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alvarez Gonzalez, Barbara; Alviggi, Mariagrazia; Amako, Katsuya; Amaral, Pedro; Amelung, Christoph; Ammosov, Vladimir; Amorim, Antonio; Amorós, Gabriel; Amram, Nir; Anastopoulos, Christos; Ancu, Lucian Stefan; Andari, Nansi; Andeen, Timothy; Anders, Christoph Falk; Anders, Gabriel; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Andrieux, Marie-Laure; Anduaga, Xabier; Angerami, Aaron; Anghinolfi, Francis; Anisenkov, Alexey; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonov, Alexey; Antos, Jaroslav; Anulli, Fabio; Aoun, Sahar; Aperio Bella, Ludovica; Apolle, Rudi; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Arfaoui, Samir; Arguin, Jean-Francois; Arik, Engin; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnault, Christian; Artamonov, Andrei; Artoni, Giacomo; Arutinov, David; Asai, Shoji; Asfandiyarov, Ruslan; Ask, Stefan; Åsman, Barbro; Asquith, Lily; Assamagan, Ketevi; Astbury, Alan; Astvatsatourov, Anatoli; Aubert, Bernard; Auge, Etienne; Augsten, Kamil; Aurousseau, Mathieu; Avolio, Giuseppe; Avramidou, Rachel Maria; Axen, David; Ay, Cano; Azuelos, Georges; Azuma, Yuya; Baak, Max; Baccaglioni, Giuseppe; Bacci, Cesare; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Backhaus, Malte; Badescu, Elisabeta; Bagnaia, Paolo; Bahinipati, Seema; Bai, Yu; Bailey, David; Bain, Travis; Baines, John; Baker, Oliver Keith; Baker, Mark; Baker, Sarah; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Bansil, Hardeep Singh; Barak, Liron; Baranov, Sergei; Barashkou, Andrei; Barbaro Galtieri, Angela; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barone, Gaetano; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Barrillon, Pierre; Bartoldus, Rainer; Barton, Adam Edward; Bartsch, Valeria; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Beale, Steven; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Hans Peter; Becker, Sebastian; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Andrew; Beddall, Ayda; Bedikian, Sourpouhi; Bednyakov, Vadim; Bee, Christopher; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellina, Francesco; Bellomo, Massimiliano; Belloni, Alberto; Beloborodova, Olga; Belotskiy, Konstantin; Beltramello, Olga; Ben Ami, Sagi; Benary, Odette; Benchekroun, Driss; Benchouk, Chafik; Bendel, Markus; Benekos, Nektarios; Benhammou, Yan; Benhar Noccioli, Eleonora; Benitez Garcia, Jorge-Armando; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertella, Claudia; Bertin, Antonio; Bertinelli, Francesco; Bertolucci, Federico; Besana, Maria Ilaria; Besson, Nathalie; Bethke, Siegfried; Bhimji, Wahid; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Bieniek, Stephen Paul; Bierwagen, Katharina; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Binet, Sebastien; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bitenc, Urban; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste; Blanchot, Georges; Blazek, Tomas; Blocker, Craig; Blocki, Jacek; Blondel, Alain; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bobrovnikov, Victor; Bocchetta, Simona Serena; Bocci, Andrea; Boddy, Christopher Richard; Boehler, Michael; Boek, Jennifer; Boelaert, Nele; Bogaerts, Joannes Andreas; Bogdanchikov, Alexander; Bogouch, Andrei; Bohm, Christian; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Bolnet, Nayanka Myriam; Bona, Marcella; Bondarenko, Valery; Bondioli, Mario; Boonekamp, Maarten; Booth, Chris; Bordoni, Stefania; Borer, Claudia; Borisov, Anatoly; Borissov, Guennadi; Borjanovic, Iris; Borri, Marcello; Borroni, Sara; Bortolotto, Valerio; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Botterill, David; Bouchami, Jihene; Boudreau, Joseph; Bouhova-Thacker, Evelina Vassileva; Boumediene, Djamel Eddine; Bourdarios, Claire; Bousson, Nicolas; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozhko, Nikolay; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Braem, André; Branchini, Paolo; Brandenburg, George; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brelier, Bertrand; Bremer, Johan; Brenner, Richard; Bressler, Shikma; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Brodbeck, Timothy; Brodet, Eyal; Broggi, Francesco; Bromberg, Carl; Bronner, Johanna; Brooijmans, Gustaaf; Brooks, William; Brown, Gareth; Brown, Heather; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Buanes, Trygve; Buat, Quentin; Bucci, Francesca; Buchanan, James; Buchanan, Norman; Buchholz, Peter; Buckingham, Ryan; Buckley, Andrew; Buda, Stelian Ioan; Budagov, Ioulian; Budick, Burton; Büscher, Volker; Bugge, Lars; Bulekov, Oleg; Bunse, Moritz; Buran, Torleiv; Burckhart, Helfried; Burdin, Sergey; Burgard, Carsten Daniel; Burgess, Thomas; Burke, Stephen; Busato, Emmanuel; Bussey, Peter; Buszello, Claus-Peter; Butin, François; Butler, Bart; Butler, John; Buttar, Craig; Butterworth, Jonathan; Buttinger, William; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Caloi, Rita; Calvet, David; Calvet, Samuel; Camacho Toro, Reina; Camarri, Paolo; Cambiaghi, Mario; Cameron, David; Caminada, Lea Michaela; Campana, Simone; Campanelli, Mario; Canale, Vincenzo; Canelli, Florencia; Canepa, Anadi; Cantero, Josu; Capasso, Luciano; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capriotti, Daniele; Capua, Marcella; Caputo, Regina; Caramarcu, Costin; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Bryan; Caron, Sascha; Carrillo Montoya, German D; Carter, Antony; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Cascella, Michele; Caso, Carlo; Castaneda Hernandez, Alfredo Martin; Castaneda-Miranda, Elizabeth; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Cataldi, Gabriella; Cataneo, Fernando; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cauz, Diego; Cavalleri, Pietro; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Santiago Cerqueira, Augusto; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cetin, Serkant Ali; Cevenini, Francesco; Chafaq, Aziz; Chakraborty, Dhiman; Chan, Kevin; Chapleau, Bertrand; Chapman, John Derek; Chapman, John Wehrley; Chareyre, Eve; Charlton, Dave; Chavda, Vikash; Chavez Barajas, Carlos Alberto; Cheatham, Susan; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chelstowska, Magda Anna; Chen, Chunhui; Chen, Hucheng; Chen, Shenjian; Chen, Tingyang; Chen, Xin; Cheng, Shaochen; Cheplakov, Alexander; Chepurnov, Vladimir; Cherkaoui El Moursli, Rajaa; Chernyatin, Valeriy; Cheu, Elliott; Cheung, Sing-Leung; Chevalier, Laurent; Chiefari, Giovanni; Chikovani, Leila; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chisholm, Andrew; Chizhov, Mihail; Choudalakis, Georgios; Chouridou, Sofia; Christidi, Illectra-Athanasia; Christov, Asen; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Ciapetti, Guido; Ciba, Krzysztof; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciobotaru, Matei Dan; Ciocca, Claudia; Ciocio, Alessandra; Cirilli, Manuela; Citterio, Mauro; Ciubancan, Mihai; Clark, Allan G; Clark, Philip James; Cleland, Bill; Clemens, Jean-Claude; Clement, Benoit; Clement, Christophe; Clifft, Roger; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H; Coe, Paul; Cogan, Joshua Godfrey; Coggeshall, James; Cogneras, Eric; Colas, Jacques; Colijn, Auke-Pieter; Collard, Caroline; Collins, Neil; Collins-Tooth, Christopher; Collot, Johann; Colon, German; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Consonni, Michele; Consorti, Valerio; Constantinescu, Serban; Conta, Claudio; Conventi, Francesco; Cook, James; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Costin, Tudor; Côté, David; Coura Torres, Rodrigo; Courneyea, Lorraine; Cowan, Glen; Cowden, Christopher; Cox, Brian; Cranmer, Kyle; Crescioli, Francesco; Cristinziani, Markus; Crosetti, Giovanni; Crupi, Roberto; Crépé-Renaudin, Sabine; Cuciuc, Constantin-Mihai; Cuenca Almenar, Cristóbal; Cuhadar Donszelmann, Tulay; Curatolo, Maria; Curtis, Chris; Cuthbert, Cameron; Cwetanski, Peter; Czirr, Hendrik; Czodrowski, Patrick; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; D'Orazio, Alessia; Da Silva, Paulo Vitor; Da Via, Cinzia; Dabrowski, Wladyslaw; Dai, Tiesheng; Dallapiccola, Carlo; Dam, Mogens; Dameri, Mauro; Damiani, Daniel; Danielsson, Hans Olof; Dannheim, Dominik; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Davey, Will; Davidek, Tomas; Davidson, Nadia; Davidson, Ruth; Davies, Eleanor; Davies, Merlin; Davison, Adam; Davygora, Yuriy; Dawe, Edmund; Dawson, Ian; Dawson, John; Daya, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Castro Faria Salgado, Pedro; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; De La Taille, Christophe; De la Torre, Hector; De Lotto, Barbara; de Mora, Lee; De Nooij, Lucie; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; Dean, Simon; Dearnaley, William James; Debbe, Ramiro; Debenedetti, Chiara; Dedovich, Dmitri; Degenhardt, James; Dehchar, Mohamed; Del Papa, Carlo; Del Peso, Jose; Del Prete, Tarcisio; Delemontex, Thomas; Deliyergiyev, Maksym; Dell'Acqua, Andrea; Dell'Asta, Lidia; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delruelle, Nicolas; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demirkoz, Bilge; Deng, Jianrong; Denisov, Sergey; Derendarz, Dominik; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Devetak, Erik; Deviveiros, Pier-Olivier; Dewhurst, Alastair; DeWilde, Burton; Dhaliwal, Saminder; Dhullipudi, Ramasudhakar; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Luise, Silvestro; Di Mattia, Alessandro; Di Micco, Biagio; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Diaz, Marco Aurelio; Diblen, Faruk; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dindar Yagci, Kamile; Dingfelder, Jochen; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djobava, Tamar; Barros do Vale, Maria Aline; Do Valle Wemans, André; Doan, Thi Kieu Oanh; Dobbs, Matt; Dobinson, Robert; Dobos, Daniel; Dobson, Ellie; Dobson, Marc; Dodd, Jeremy; Doglioni, Caterina; Doherty, Tom; Doi, Yoshikuni; Dolejsi, Jiri; Dolenc, Irena; Dolezal, Zdenek; Dolgoshein, Boris; Dohmae, Takeshi; Donadelli, Marisilvia; Donega, Mauro; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dos Anjos, Andre; Dosil, Mireia; Dotti, Andrea; Dova, Maria-Teresa; Dowell, John; Doxiadis, Alexander; Doyle, Tony; Drasal, Zbynek; Drees, Jürgen; Dressnandt, Nandor; Drevermann, Hans; Driouichi, Chafik; Dris, Manolis; Dubbert, Jörg; Dube, Sourabh; Duchovni, Ehud; Duckeck, Guenter; Dudarev, Alexey; Dudziak, Fanny; Dührssen, Michael; Duerdoth, Ian; Duflot, Laurent; Dufour, Marc-Andre; Dunford, Monica; Duran Yildiz, Hatice; Duxfield, Robert; Dwuznik, Michal; Dydak, Friedrich; Düren, Michael; Ebenstein, William; Ebke, Johannes; Eckweiler, Sebastian; Edmonds, Keith; Edwards, Clive; Edwards, Nicholas Charles; Ehrenfeld, Wolfgang; Ehrich, Thies; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Eisenhandler, Eric; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Katherine; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Engelmann, Roderich; Engl, Albert; Epp, Brigitte; Eppig, Andrew; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Escobar, Carlos; Espinal Curull, Xavier; Esposito, Bellisario; Etienne, Francois; Etienvre, Anne-Isabelle; Etzion, Erez; Evangelakou, Despoina; Evans, Hal; Fabbri, Laura; Fabre, Caroline; Fakhrutdinov, Rinat; Falciano, Speranza; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farley, Jason; Farooque, Trisha; Farrington, Sinead; Farthouat, Philippe; Fassnacht, Patrick; Fassouliotis, Dimitrios; Fatholahzadeh, Baharak; Favareto, Andrea; Fayard, Louis; Fazio, Salvatore; Febbraro, Renato; Federic, Pavol; Fedin, Oleg; Fedorko, Woiciech; Fehling-Kaschek, Mirjam; Feligioni, Lorenzo; Fellmann, Denis; Feng, Cunfeng; Feng, Eric; Fenyuk, Alexander; Ferencei, Jozef; Ferland, Jonathan; Fernando, Waruna; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferreira de Lima, Danilo Enoque; Ferrer, Antonio; Ferrer, Maria Lorenza; Ferrere, Didier; Ferretti, Claudio; Ferretto Parodi, Andrea; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filippas, Anastasios; Filthaut, Frank; Fincke-Keeler, Margret; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Gordon; Fischer, Peter; Fisher, Matthew; Flechl, Martin; Fleck, Ivor; Fleckner, Johanna; Fleischmann, Philipp; Fleischmann, Sebastian; Flick, Tobias; Floderus, Anders; Flores Castillo, Luis; Flowerdew, Michael; Fokitis, Manolis; Fonseca Martin, Teresa; Forbush, David Alan; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Foster, Joe; Fournier, Daniel; Foussat, Arnaud; Fowler, Andrew; Fowler, Ken; Fox, Harald; Francavilla, Paolo; Franchino, Silvia; Francis, David; Frank, Tal; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; Fratina, Sasa; French, Sky; Friedrich, Felix; Froeschl, Robert; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gadfort, Thomas; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Gan, KK; Gao, Yongsheng; Gapienko, Vladimir; Gaponenko, Andrei; Garberson, Ford; Garcia-Sciveres, Maurice; García, Carmen; García Navarro, José Enrique; Gardner, Robert; Garelli, Nicoletta; Garitaonandia, Hegoi; Garonne, Vincent; Garvey, John; Gatti, Claudio; Gaudio, Gabriella; Gaur, Bakul; Gauthier, Lea; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gayde, Jean-Christophe; Gazis, Evangelos; Ge, Peng; Gee, Norman; Geerts, Daniël Alphonsus Adrianus; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Gemmell, Alistair; Genest, Marie-Hélène; Gentile, Simonetta; George, Matthias; George, Simon; Gerlach, Peter; Gershon, Avi; Geweniger, Christoph; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giakoumopoulou, Victoria; Giangiobbe, Vincent; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Adam; Gibson, Stephen; Gilbert, Laura; Gilewsky, Valentin; Gillberg, Dag; Gillman, Tony; Gingrich, Douglas; Ginzburg, Jonatan; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giovannini, Paola; Giraud, Pierre-Francois; Giugni, Danilo; Giunta, Michele; Giusti, Paolo; Gjelsten, Børge Kile; Gladilin, Leonid; Glasman, Claudia; Glatzer, Julian; Glazov, Alexandre; Glitza, Karl-Walter; Glonti, George; Goddard, Jack Robert; Godfrey, Jennifer; Godlewski, Jan; Goebel, Martin; Göpfert, Thomas; Goeringer, Christian; Gössling, Claus; Göttfert, Tobias; Goldfarb, Steven; Golling, Tobias; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçalo, Ricardo; Goncalves Pinto Firmino Da Costa, Joao; Gonella, Laura; Gonidec, Allain; Gonzalez, Saul; González de la Hoz, Santiago; Gonzalez Parra, Garoe; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodson, Jeremiah Jet; Goossens, Luc; Gorbounov, Petr Andreevich; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Gorokhov, Serguei; Goryachev, Vladimir; Gosdzik, Bjoern; Gosselink, Martijn; Gostkin, Mikhail Ivanovitch; Gough Eschrich, Ivo; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Gozpinar, Serdar; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Grancagnolo, Francesco; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Grebenyuk, Oleg; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregersen, Kristian; Gregor, Ingrid-Maria; Grenier, Philippe; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grinstein, Sebastian; Grishkevich, Yaroslav; Grivaz, Jean-Francois; Groh, Manfred; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Grybel, Kai; Guarino, Victor; Guest, Daniel; Guicheney, Christophe; Guida, Angelo; Guindon, Stefan; Guler, Hulya; Gunther, Jaroslav; Guo, Bin; Guo, Jun; Gupta, Ambreesh; Gusakov, Yury; Gushchin, Vladimir; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hackenburg, Robert; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hahn, Ferdinand; Haider, Stefan; Hajduk, Zbigniew; Hakobyan, Hrachya; Hall, David; Haller, Johannes; Hamacher, Klaus; Hamal, Petr; Hamer, Matthias; Hamilton, Andrew; Hamilton, Samuel; Han, Hongguang; Han, Liang; Hanagaki, Kazunori; Hanawa, Keita; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, John Renner; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, Peter Henrik; Hansson, Per; Hara, Kazuhiko; Hare, Gabriel; Harenberg, Torsten; Harkusha, Siarhei; Harper, Devin; Harrington, Robert; Harris, Orin; Harrison, Karl; Hartert, Jochen; Hartjes, Fred; Haruyama, Tomiyoshi; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Hatch, Mark; Hauff, Dieter; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawes, Brian; Hawkes, Christopher; Hawkings, Richard John; Hawkins, Anthony David; Hawkins, Donovan; Hayakawa, Takashi; Hayashi, Takayasu; Hayden, Daniel; Hayward, Helen; Haywood, Stephen; Hazen, Eric; He, Mao; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heller, Claudio; Heller, Matthieu; Hellman, Sten; Hellmich, Dennis; Helsens, Clement; Henderson, Robert; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Henry-Couannier, Frédéric; Hensel, Carsten; Henß, Tobias; Medina Hernandez, Carlos; Hernández Jiménez, Yesenia; Herrberg, Ruth; Hershenhorn, Alon David; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hesketh, Gavin Grant; Hessey, Nigel; Higón-Rodriguez, Emilio; Hill, Daniel; Hill, John; Hill, Norman; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirsch, Florian; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holder, Martin; Holmgren, Sven-Olof; Holy, Tomas; Holzbauer, Jenny; Homma, Yasuhiro; Hong, Tae Min; Hooft van Huysduynen, Loek; Horazdovsky, Tomas; Horn, Claus; Horner, Stephan; Hostachy, Jean-Yves; Hou, Suen; Houlden, Michael; Hoummada, Abdeslam; Howarth, James; Howell, David; Hristova, Ivana; Hrivnac, Julius; Hruska, Ivan; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Huang, Guang Shun; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huettmann, Antje; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Hughes-Jones, Richard; Huhtinen, Mika; Hurst, Peter; Hurwitz, Martina; Husemann, Ulrich; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibbotson, Michael; Ibragimov, Iskander; Ichimiya, Ryo; Iconomidou-Fayard, Lydia; Idarraga, John; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Yuri; Iliadis, Dimitrios; Ilic, Nikolina; Imori, Masatoshi; Ince, Tayfun; Inigo-Golfin, Joaquin; Ioannou, Pavlos; Iodice, Mauro; Ippolito, Valerio; Irles Quiles, Adrian; Isaksson, Charlie; Ishikawa, Akimasa; Ishino, Masaya; Ishmukhametov, Renat; Issever, Cigdem; Istin, Serhat; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakubek, Jan; Jana, Dilip; Jankowski, Ernest; Jansen, Eric; Jansen, Hendrik; Jantsch, Andreas; Janus, Michel; Jarlskog, Göran; Jeanty, Laura; Jelen, Kazimierz; Jen-La Plante, Imai; Jenni, Peter; Jeremie, Andrea; Jež, Pavel; Jézéquel, Stéphane; Jha, Manoj Kumar; Ji, Haoshuang; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Ge; Jin, Shan; Jinnouchi, Osamu; Joergensen, Morten Dam; Joffe, David; Johansen, Lars; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tegid; Jones, Tim; Jonsson, Ove; Joram, Christian; Jorge, Pedro; Joseph, John; Jovicevic, Jelena; Jovin, Tatjana; Ju, Xiangyang; Jung, Christian; Jungst, Ralph Markus; Juranek, Vojtech; Jussel, Patrick; Juste Rozas, Aurelio; Kabachenko, Vasily; Kabana, Sonja; Kaci, Mohammed; Kaczmarska, Anna; Kadlecik, Peter; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kaiser, Steffen; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kaneti, Steven; Kanno, Takayuki; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagoz, Muge; Karnevskiy, Mikhail; Karr, Kristo; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasieczka, Gregor; Kasmi, Azzedine; Kass, Richard; Kastanas, Alex; Kataoka, Mayuko; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kazanin, Vassili; Kazarinov, Makhail; Keeler, Richard; Kehoe, Robert; Keil, Markus; Kekelidze, George; Kennedy, John; Kenney, Christopher John; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Keung, Justin; Khakzad, Mohsen; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Kholodenko, Anatoli; Khomich, Andrei; Khoo, Teng Jian; Khoriauli, Gia; Khoroshilov, Andrey; Khovanskiy, Nikolai; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hyeon Jin; Kim, Min Suk; Kim, Shinhong; Kimura, Naoki; Kind, Oliver; King, Barry; King, Matthew; King, Robert Steven Beaufoy; Kirk, Julie; Kirsch, Lawrence; Kiryunin, Andrey; Kishimoto, Tomoe; Kisielewska, Danuta; Kittelmann, Thomas; Kiver, Andrey; Kladiva, Eduard; Klaiber-Lodewigs, Jonas; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimek, Pawel; Klimentov, Alexei; Klingenberg, Reiner; Klinger, Joel Alexander; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Kluth, Stefan; Knecht, Neil; Kneringer, Emmerich; Knobloch, Juergen; Knoops, Edith; Knue, Andrea; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Kocian, Martin; Kodys, Peter; Köneke, Karsten; König, Adriaan; Koenig, Sebastian; Köpke, Lutz; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kogan, Lucy Anne; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Koi, Tatsumi; Kokott, Thomas; Kolachev, Guennady; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Kollefrath, Michael; Kolya, Scott; Komar, Aston; Komori, Yuto; Kondo, Takahiko; Kono, Takanori; Kononov, Anatoly; Konoplich, Rostislav; Konstantinidis, Nikolaos; Kootz, Andreas; Koperny, Stefan; Korcyl, Krzysztof; Kordas, Kostantinos; Koreshev, Victor; Korn, Andreas; Korol, Aleksandr; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostyukhin, Vadim; Kotamäki, Miikka Juhani; Kotov, Sergey; Kotov, Vladislav; Kotwal, Ashutosh; Kourkoumelis, Christine; Kouskoura, Vasiliki; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, James; Kraus, Jana; Kreisel, Arik; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Kruker, Tobias; Krumnack, Nils; Krumshteyn, Zinovii; Kruth, Andre; Kubota, Takashi; Kuday, Sinan; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kundu, Nikhil; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kuwertz, Emma Sian; Kuze, Masahiro; Kvita, Jiri; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labarga, Luis; Labbe, Julien; Lablak, Said; Lacasta, Carlos; Lacava, Francesco; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Remi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Laisne, Emmanuel; Lamanna, Massimo; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Lane, Jenna; Lange, Clemens; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larionov, Anatoly; Larner, Aimee; Lasseur, Christian; Lassnig, Mario; Laurelli, Paolo; Lavorini, Vincenzo; Lavrijsen, Wim; Laycock, Paul; Lazarev, Alexandre; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Maner, Christophe; Le Menedeu, Eve; Lebel, Céline; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lee, Lawrence; Lefebvre, Michel; Legendre, Marie; Leger, Annie; LeGeyt, Benjamin; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leite, Marco Aurelio Lisboa; Leitner, Rupert; Lellouch, Daniel; Leltchouk, Mikhail; Lemmer, Boris; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leontsinis, Stefanos; Leroy, Claude; Lessard, Jean-Raphael; Lesser, Jonas; Lester, Christopher; Leung Fook Cheong, Annabelle; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Levitski, Mikhail; Lewis, Adrian; Lewis, George; Leyko, Agnieszka; Leyton, Michael; Li, Bo; Li, Haifeng; Li, Shu; Li, Xuefei; Liang, Zhijun; Liao, Hongbo; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Lifshitz, Ronen; Lilley, Joseph; Limbach, Christian; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linde, Frank; Linnemann, James; Lipeles, Elliot; Lipinsky, Lukas; Lipniacka, Anna; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Minghui; Liu, Yanwen; Livan, Michele; Livermore, Sarah; Lleres, Annick; Llorente Merino, Javier; Lloyd, Stephen; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Loddenkoetter, Thomas; Loebinger, Fred; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Loken, James; Lombardo, Vincenzo Paolo; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Lorenz, Jeanette; Lorenzo Martinez, Narei; Losada, Marta; Loscutoff, Peter; Lo Sterzo, Francesco; Losty, Michael; Lou, Xinchou; Lounis, Abdenour; Loureiro, Karina; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Ludwig, Andreas; Ludwig, Dörthe; Ludwig, Inga; Ludwig, Jens; Luehring, Frederick; Luijckx, Guy; Lumb, Debra; Luminari, Lamberto; Lund, Esben; Lund-Jensen, Bengt; Lundberg, Björn; Lundberg, Johan; Lundquist, Johan; Lungwitz, Matthias; Lutz, Gerhard; Lynn, David; Lys, Jeremy; Lytken, Else; Ma, Hong; Ma, Lian Liang; Macana Goia, Jorge Andres; Maccarrone, Giovanni; Macchiolo, Anna; Maček, Boštjan; Machado Miguens, Joana; Mackeprang, Rasmus; Madaras, Ronald; Mader, Wolfgang; Maenner, Reinhard; Maeno, Tadashi; Mättig, Peter; Mättig, Stefan; Magnoni, Luca; Magradze, Erekle; Mahalalel, Yair; Mahboubi, Kambiz; Mahout, Gilles; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makovec, Nikola; Mal, Prolay; Malaescu, Bogdan; Malecki, Pawel; Malecki, Piotr; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Malone, Caitlin; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mameghani, Raphael; Mamuzic, Judita; Manabe, Atsushi; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Mangeard, Pierre-Simon; Manhaes de Andrade Filho, Luciano; Manjavidze, Ioseb; Mann, Alexander; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Manz, Andreas; Mapelli, Alessandro; Mapelli, Livio; March, Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchiori, Giovanni; Marcisovsky, Michal; Marin, Alexandru; Marino, Christopher; Marroquim, Fernando; Marshall, Robin; Marshall, Zach; Martens, Kalen; Marti-Garcia, Salvador; Martin, Andrew; Martin, Brian; Martin, Brian Thomas; Martin, Franck Francois; Martin, Jean-Pierre; Martin, Philippe; Martin, Tim; Martin, Victoria Jane; Martin dit Latour, Bertrand; Martin-Haugh, Stewart; Martinez, Mario; Martinez Outschoorn, Verena; Martyniuk, Alex; Marx, Marilyn; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massaro, Graziano; Massol, Nicolas; Mastrandrea, Paolo; Mastroberardino, Anna; Masubuchi, Tatsuya; Mathes, Markus; Matricon, Pierre; Matsumoto, Hiroshi; Matsunaga, Hiroyuki; Matsushita, Takashi; Mattravers, Carly; Maugain, Jean-Marie; Maurer, Julien; Maxfield, Stephen; Maximov, Dmitriy; May, Edward; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mazzanti, Marcello; Mazzoni, Enrico; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCarthy, Tom; McCubbin, Norman; McFarlane, Kenneth; Mcfayden, Josh; McGlone, Helen; Mchedlidze, Gvantsa; McLaren, Robert Andrew; Mclaughlan, Tom; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehdiyev, Rashid; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Mendoza Navas, Luis; Meng, Zhaoxia; Mengarelli, Alberto; Menke, Sven; Menot, Claude; Meoni, Evelin; Mercurio, Kevin Michael; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Merritt, Hayes; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Carsten; Meyer, Christopher; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Meyer, Thomas Christian; Meyer, W Thomas; Miao, Jiayuan; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Miller, Robert; Mills, Bill; Mills, Corrinne; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano Moya, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Miralles Verge, Lluis; Misiejuk, Andrzej; Mitrevski, Jovan; Mitrofanov, Gennady; Mitsou, Vasiliki A; Mitsui, Shingo; Miyagawa, Paul; Miyazaki, Kazuki; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Mockett, Paul; Moed, Shulamit; Moeller, Victoria; Mönig, Klaus; Möser, Nicolas; Mohapatra, Soumya; Mohr, Wolfgang; Mohrdieck-Möck, Susanne; Moisseev, Artemy; Moles-Valls, Regina; Molina-Perez, Jorge; Monk, James; Monnier, Emmanuel; Montesano, Simone; Monticelli, Fernando; Monzani, Simone; Moore, Roger; Moorhead, Gareth; Mora Herrera, Clemencia; Moraes, Arthur; Morange, Nicolas; Morel, Julien; Morello, Gianfranco; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morgenstern, Marcus; Morii, Masahiro; Morin, Jerome; Morley, Anthony Keith; Mornacchi, Giuseppe; Morozov, Sergey; Morris, John; Morvaj, Ljiljana; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Mudrinic, Mihajlo; Mueller, Felix; Mueller, James; Mueller, Klemens; Müller, Thomas; Mueller, Timo; Muenstermann, Daniel; Muir, Alex; Munwes, Yonathan; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Nadal, Jordi; Nagai, Koichi; Nagano, Kunihiro; Nagarkar, Advait; Nagasaka, Yasushi; Nagel, Martin; Nairz, Armin Michael; Nakahama, Yu; Nakamura, Koji; Nakamura, Tomoaki; Nakano, Itsuo; Nanava, Gizo; Napier, Austin; Narayan, Rohin; Nash, Michael; Nation, Nigel; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Neal, Homer; Nebot, Eduardo; Nechaeva, Polina; Neep, Thomas James; Negri, Andrea; Negri, Guido; Nektarijevic, Snezana; Nelson, Andrew; Nelson, Silke; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newman, Paul; Nguyen Thi Hong, Van; Nickerson, Richard; Nicolaidou, Rosy; Nicolas, Ludovic; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Niinikoski, Tapio; Nikiforou, Nikiforos; Nikiforov, Andriy; Nikolaenko, Vladimir; Nikolaev, Kirill; Nikolic-Audit, Irena; Nikolics, Katalin; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Ninomiya, Yoichi; Nisati, Aleandro; Nishiyama, Tomonori; Nisius, Richard; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Nordberg, Markus; Nordkvist, Bjoern; Norton, Peter; Novakova, Jana; Nozaki, Mitsuaki; Nozka, Libor; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; O'Brien, Brendan Joseph; O'Neale, Steve; O'Neil, Dugan; O'Shea, Val; Oakes, Louise Beth; Oakham, Gerald; Oberlack, Horst; Ocariz, Jose; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Ohshita, Hidetoshi; Ohsugi, Takashi; Okada, Shogo; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olariu, Albert; Olcese, Marco; Olchevski, Alexander; Olivares Pino, Sebastian Andres; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Omachi, Chihiro; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Otero y Garzon, Gustavo; Ottersbach, John; Ouchrif, Mohamed; Ouellette, Eric; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Ovcharova, Ana; Owen, Mark; Owen, Simon; Ozcan, Veysi Erkcan; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Pagan Griso, Simone; Paganis, Efstathios; Paige, Frank; Pais, Preema; Pajchel, Katarina; Palacino, Gabriel; Paleari, Chiara; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panes, Boris; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Panuskova, Monika; Paolone, Vittorio; Papadelis, Aras; Papadopoulou, Theodora; Paramonov, Alexander; Park, Woochun; Parker, Andy; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passaggio, Stefano; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor, Gabriella; Pataraia, Sophio; Patel, Nikhul; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Pecsy, Martin; Pedraza Morales, Maria Isabel; Peleganchuk, Sergey; Peng, Haiping; Pengo, Ruggero; Penning, Bjoern; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Perez Cavalcanti, Tiago; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Perrodo, Pascal; Persembe, Seda; Perus, Antoine; Peshekhonov, Vladimir; Peters, Krisztian; Petersen, Brian; Petersen, Jorgen; Petersen, Troels; Petit, Elisabeth; Petridis, Andreas; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petschull, Dennis; Petteni, Michele; Pezoa, Raquel; Phan, Anna; Phillips, Peter William; Piacquadio, Giacinto; Piccaro, Elisa; Piccinini, Maurizio; Piec, Sebastian Marcin; Piegaia, Ricardo; Pignotti, David; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinder, Alex; Pinfold, James; Ping, Jialun; Pinto, Belmiro; Pirotte, Olivier; Pizio, Caterina; Placakyte, Ringaile; Plamondon, Mathieu; Pleier, Marc-Andre; Pleskach, Anatoly; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Poghosyan, Tatevik; Pohl, Martin; Polci, Francesco; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomarede, Daniel Marc; Pomeroy, Daniel; Pommès, Kathy; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Portell Bueso, Xavier; Posch, Christoph; Pospelov, Guennady; Pospisil, Stanislav; Potrap, Igor; Potter, Christina; Potter, Christopher; Poulard, Gilbert; Poveda, Joaquin; Pozdnyakov, Valery; Prabhu, Robindra; Pralavorio, Pascal; Pranko, Aliaksandr; Prasad, Srivas; Pravahan, Rishiraj; Prell, Soeren; Pretzl, Klaus Peter; Pribyl, Lukas; Price, Darren; Price, Joe; Price, Lawrence; Price, Michael John; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przybycien, Mariusz; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Pueschel, Elisa; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qian, Jianming; Qian, Zuxuan; Qin, Zhonghua; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radescu, Voica; Radics, Balint; Radloff, Peter; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rahm, David; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Randle-Conde, Aidan Sean; Randrianarivony, Koloina; Ratoff, Peter; Rauscher, Felix; Rave, Tobias Christian; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reichold, Armin; Reinherz-Aronis, Erez; Reinsch, Andreas; Reisinger, Ingo; Rembser, Christoph; Ren, Zhongliang; Renaud, Adrien; Renkel, Peter; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richards, Alexander; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rijpstra, Manouk; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Rios, Ryan Randy; Riu, Imma; Rivoltella, Giancesare; Rizatdinova, Flera; Rizvi, Eram; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robinson, Mary; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; Rodriguez, Diego; Roe, Adam; Roe, Shaun; Røhne, Ole; Rojo, Victoria; Rolli, Simona; Romaniouk, Anatoli; Romano, Marino; Romanov, Victor; Romeo, Gaston; 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2013-03-02

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of $\\sqrt{s}$ = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.

High luminosity μ+ μ- collider: Report of a feasibility study

International Nuclear Information System (INIS)

Palmer, R.B.; Gallardo, J.C.; Tollestrup, A.; Sessler, A.

1996-12-01

Parameters are given of 4 TeV and 0.5 TeV (c-of-m) high luminosity μ + μ - colliders, and of a 0.5 TeV lower luminosity demonstration machine. We discuss the various systems in such muon colliders, starting from the proton accelerator needed to generate the muons and proceeding through muon cooling, acceleration and storage in a collider ring. Detector background, polarization, and nonstandard operating conditions are analyzed. Muon Colliders have unique technical and physics advantages and disadvantages when compared with both hadron and electron machines. They should thus be regarded as complementary. We briefly mention the luminosity requirements of hadrons and lepton machines and their high-energy-physics advantages and disadvantages in reference to their effective center of mass energy. Finally, we present an R ampersand D plan to determine whether such machines are practical

Klystron switching power supplies for the Internation Linear Collider

Energy Technology Data Exchange (ETDEWEB)

Fraioli, Andrea; /Cassino U. /INFN, Pisa

2009-12-01

The International Linear Collider is a majestic High Energy Physics particle accelerator that will give physicists a new cosmic doorway to explore energy regimes beyond the reach of today's accelerators. ILC will complement the Large Hadron Collider (LHC), a proton-proton collider at the European Center for Nuclear Research (CERN) in Geneva, Switzerland, by producing electron-positron collisions at center of mass energy of about 500 GeV. In particular, the subject of this dissertation is the R&D for a solid state Marx Modulator and relative switching power supply for the International Linear Collider Main LINAC Radio Frequency stations.

Aperture meter for the Large Hadron Collider

International Nuclear Information System (INIS)

Mueller, G.J.; Fuchsberger, K.; Redaelli, S.

2012-01-01

The control of the high intensity beams of the CERN Large Hadron Collider (LHC) is particular challenging and requires a good modeling of the machine and monitoring of various machine parameters. During operation it is crucial to ensure a minimal distance between the beam edge and the aperture of sensitive equipment, e.g. the superconducting magnets, which in all cases must be in the shadow of the collimator's that protect the machine. Possible dangerous situations must be detected as soon as possible. In order to provide the operator with information about the current machine bottlenecks an aperture meter application was developed based on the LHC online modeling tool-chain. The calculation of available free aperture takes into account the best available optics and aperture model as well as the relevant beam measurements. This paper describes the design and integration of this application into the control environment and presents results of the usage in daily operation and from validation measurements. (authors)

Stop Lepton Associated Production at Hadron Colliders

CERN Document Server

Alves, A; Plehn, Tilman

2003-01-01

At hadron colliders, the search for R-parity violating supersymmetry can probe scalar masses beyond what is covered by pair production processes. We evaluate the next-to-leading order SUSY-QCD corrections to the associated stop or sbottom production with a lepton through R-parity violating interactions. We show that higher order corrections render the theoretical predictions more stable with respect to variations of the renormalization and factorization scales and that the total cross section is enhanced by a factor up to 70% at the Tevatron and 50% at the LHC. We investigate in detail how the heavy supersymmetric states decouple from the next-to-leading order process, which gives rise to a theory with an additional scalar leptoquark. In this scenario the inclusion of higher order QCD corrections increases the Tevatron reach on leptoquark masses by up to 40 GeV and the LHC reach by up to 200 GeV.

Beam-energy dependence of charge balance functions from Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider

Science.gov (United States)

Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, H. F.; Cheng, J.; Cherney, M.; Christie, W.; Codrington, M. J. M.; Contin, G.; Crawford, H. J.; Cui, X.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, X.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Klein, S. R.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, Z. M.; Li, X.; Li, W.; Li, Y.; Li, X.; Li, C.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, R. M.; Ma, Y. G.; Magdy, N.; Mahapatra, D. P.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solanki, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X. M.; Sun, Z.; Sun, Y.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Takahashi, J.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A. N.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, H.; Wang, F.; Wang, G.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, N.; Xu, Z.; Xu, H.; Xu, Y.; Xu, Q. H.; Yan, W.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, Z. P.; Zhang, J. B.; Zhang, J. L.; Zhang, Y.; Zhang, S.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, Y. H.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

2016-08-01

Balance functions have been measured in terms of relative pseudorapidity (Δ η ) for charged particle pairs at the BNL Relativistic Heavy Ion Collider from Au + Au collisions at √{sNN}=7.7 GeV to 200 GeV using the STAR detector. These results are compared with balance functions measured at the CERN Large Hadron Collider from Pb + Pb collisions at √{sNN}=2.76 TeV by the ALICE Collaboration. The width of the balance function decreases as the collisions become more central and as the beam energy is increased. In contrast, the widths of the balance functions calculated using shuffled events show little dependence on centrality or beam energy and are larger than the observed widths. Balance function widths calculated using events generated by UrQMD are wider than the measured widths in central collisions and show little centrality dependence. The measured widths of the balance functions in central collisions are consistent with the delayed hadronization of a deconfined quark gluon plasma (QGP). The narrowing of the balance function in central collisions at √{sNN}=7.7 GeV implies that a QGP is still being created at this relatively low energy.

Silicon detectors operating beyond the LHC collider conditions: scenarios for radiation fields and detector degradation

International Nuclear Information System (INIS)

Lazanu, I.; Lazanu, S.

2004-01-01

Particle physics makes its greatest advances with experiments at the highest energies. The way to advance to a higher energy regime is through hadron colliders, or through non-accelerator experiments, as for example the space astroparticle missions. In the near future, the Large Hadron Collider (LHC) will be operational, and beyond that, its upgrades: the Super-LHC (SLHC) and the hypothetical Very Large Hadron Collider (VLHC). At the present time, there are no detailed studies for future accelerators, except those referring to LHC. For the new hadron collider LHC and some of its updates in luminosity and energy, the silicon detectors could represent an important option, especially for the tracking system and calorimetry. The main goal of this paper is to analyse the expected long-time degradation of the silicon as material and for silicon detectors, during continuous radiation, in these hostile conditions. The behaviour of silicon in relation to various scenarios for upgrade in energy and luminosity is discussed in the frame of a phenomenological model developed previously by the authors and now extended to include new mechanisms, able to explain and give solutions to discrepancies between model predictions and detector behaviour after hadron irradiation. Different silicon material parameters resulting from different technologies are considered to evaluate what materials are harder to radiation and consequently could minimise the degradation of device parameters in conditions of continuous long time operation. (authors)

25th anniversary of the Large Hadron Collider (LHC) experimental programme

CERN Multimedia

AUTHOR|(CDS)2094367

2017-01-01

On Friday 15 December 2017, CERN celebrated the 25th anniversary of the Large Hadron Collider (LHC) experimental programme. The occasion was marked with a special scientific symposium looking at the LHC’s history, the physics landscape into which the LHC experiments were born, and the challenging path that led to the very successful LHC programme we know today. The anniversary was linked to a meeting that took place in 1992, in Evian, entitled "Towards the LHC Experimental Programme", marking a crucial milestone in the design and development of the LHC experiments.

Polar Coding for the Large Hadron Collider: Challenges in Code Concatenation

CERN Document Server

AUTHOR|(CDS)2238544; Podzorny, Tomasz; Uythoven, Jan

2018-01-01

In this work, we present a concatenated repetition-polar coding scheme that is aimed at applications requiring highly unbalanced unequal bit-error protection, such as the Beam Interlock System of the Large Hadron Collider at CERN. Even though this concatenation scheme is simple, it reveals significant challenges that may be encountered when designing a concatenated scheme that uses a polar code as an inner code, such as error correlation and unusual decision log-likelihood ratio distributions. We explain and analyze these challenges and we propose two ways to overcome them.

Muon collider progress

Energy Technology Data Exchange (ETDEWEB)

Noble, Robert J. FNAL

1998-08-01

Recent progress in the study of muon colliders is presented. An international collaboration consisting of over 100 individuals is involved in calculations and experiments to demonstrate the feasibility of this new type of lepton collider. Theoretical efforts are now concentrated on low-energy colliders in the 100 to 500 GeV center-of-mass energy range. Credible machine designs are emerging for much of a hypothetical complex from proton source to the final collider. Ionization cooling has been the most difficult part of the concept, and more powerful simulation tools are now in place to develop workable schemes. A collaboration proposal for a muon cooling experiment has been presented to the Fermilab Physics Advisory Committee, and a proposal for a targetry and pion collection channel experiment at Brookhaven National Laboratory is in preparation. Initial proton bunching and space-charge compensation experiments at existing hadron facilities have occurred to demonstrate proton driver feasibility.

Emittance growth due to noise and its suppression with the Feedback system in large hadron colliders

International Nuclear Information System (INIS)

Lebedev, V.; Parkhomchuk, V.; Shiltsev, V.; Stupakov, G.

1993-03-01

The problem of emittance growth due to random fluctuation of the magnetic field in hadron colliders is considered. Based on a simple one-dimensional linear model, a formula for an emittance growth rate as a function of the noise spectrum is derived. Different sources of the noise are analyzed and their role is estimated for the Superconducting Super Collider (SSC). A theory of feedback suppression of the emittance growth is developed which predicts the residual growth of the emittance in the accelerator with a feedback system

Quest for precision in hadronic cross sections at low energy: Monte Carlo tools vs. experimental data

Energy Technology Data Exchange (ETDEWEB)

Actis, S [Paul-Scherrer-Institute Wuerenlingen and Villigen, Villigen (Switzerland); Arbuzov, A [Joint Institute for Nuclear Research, Dubna (Russian Federation). Bogoliubov Lab. of Theoretical Physics; Balossini, G [Pavia Univ. (Italy). Dipt. di Fisica Nucleare e Teorica; INFN, Pavia [IT; and others

2009-12-15

We present the achievements of the last years of the experimental and theoretical groups working on hadronic cross section measurements at the low energy e{sup +}e{sup -} colliders in Beijing, Frascati, Ithaca, Novosibirsk, Stanford and Tsukuba and on {tau} decays. We sketch the prospects in these fields for the years to come. We emphasise the status and the precision of the Monte Carlo generators used to analyse the hadronic cross section measurements obtained as well with energy scans as with radiative return, to determine luminosities and {tau} decays. The radiative corrections fully or approximately implemented in the various codes and the contribution of the vacuum polarisation are discussed. (orig.)

Quest for precision in hadronic cross sections at low energy: Monte Carlo tools vs. experimental data

International Nuclear Information System (INIS)

Actis, S.; Arbuzov, A.

2009-12-01

We present the achievements of the last years of the experimental and theoretical groups working on hadronic cross section measurements at the low energy e + e - colliders in Beijing, Frascati, Ithaca, Novosibirsk, Stanford and Tsukuba and on τ decays. We sketch the prospects in these fields for the years to come. We emphasise the status and the precision of the Monte Carlo generators used to analyse the hadronic cross section measurements obtained as well with energy scans as with radiative return, to determine luminosities and τ decays. The radiative corrections fully or approximately implemented in the various codes and the contribution of the vacuum polarisation are discussed. (orig.)

High Energy Colliders and Hidden Sectors

Science.gov (United States)

Dror, Asaf Jeff

This thesis explores two dominant frontiers of theoretical physics, high energy colliders and hidden sectors. The Large Hadron Collider (LHC) is just starting to reach its maximum operational capabilities. However, already with the current data, large classes of models are being put under significant pressure. It is crucial to understand whether the (thus far) null results are a consequence of a lack of solution to the hierarchy problem around the weak scale or requires expanding the search strategy employed at the LHC. It is the duty of the current generation of physicists to design new searches to ensure that no stone is left unturned. To this end, we study the sensitivity of the LHC to the couplings in the Standard Model top sector. We find it can significantly improve the measurements on ZtRtR coupling by a novel search strategy, making use of an implied unitarity violation in such models. Analogously, we show that other couplings in the top sector can also be measured with the same technique. Furthermore, we critically analyze a set of anomalies in the LHC data and how they may appear from consistent UV completions. We also propose a technique to measure lifetimes of new colored particles with non-trivial spin. While the high energy frontier will continue to take data, it is likely the only collider of its kind for the next couple decades. On the other hand, low-energy experiments have a promising future with many new proposed experiments to probe the existence of particles well below the weak scale but with small couplings to the Standard Model. In this work we survey the different possibilities, focusingon the constraints as well as possible new hidden sector dynamics. In particular, we show that vector portals which couple to an anomalous current, e.g., baryon number, are significantly constrained from flavor changing meson decays and rare Z decays. Furthermore, we present a new mechanism for dark matter freezeout which depletes the dark sector through an

Search for Supersymmetry in final states with three leptons and missing transverse energy with the ATLAS detector at the Large Hadron Collider

CERN Document Server

Santoyo Castillo, Itzebelt

The ATLAS experiment at the Large Hadron Collider has collected an unprecedented amount of data in the 3 years of data taking since its start. In this document I will dis- cuss the results of the analysis I performed during my PhD at the university of Sussex for the search of Supersymmetry in events with three leptons (electron/muon/tau) and missing transverse energy in the final state. The search is performed on the full dataset collected by the experiment in 2012, at a centre-of-mass energy of 8 TeV. These results are interpreted in SUSY models with chargino-neutralino pair production via decays involving sleptons, staus, gauge bosons and the newly discovered Higgs boson. These results presen- ted improve on previous searches performed at ATLAS in three lepton final states with only electrons and muons. Special focus will be given to the optimisation process of Su- persymmetry signal with respect to the SM background, and the statistical interpretation of the results obtained with this search.

How hadron collider experiments contributed to the development of QCD: from hard-scattering to the perfect liquid

Science.gov (United States)

Tannenbaum, M. J.

2018-05-01

A revolution in elementary particle physics occurred during the period from the ICHEP1968 to the ICHEP1982 with the advent of the parton model from discoveries in Deeply Inelastic electron-proton Scattering at SLAC, neutrino experiments, hard-scattering observed in p+p collisions at the CERN ISR, the development of QCD, the discovery of the J/ Ψ at BNL and SLAC and the clear observation of high transverse momentum jets at the CERN SPS p¯ + p collider. These and other discoveries in this period led to the acceptance of QCD as the theory of the strong interactions. The desire to understand nuclear physics at high density such as in neutron stars led to the application of QCD to this problem and to the prediction of a Quark-Gluon Plasma (QGP) in nuclei at high energy density and temperatures. This eventually led to the construction of the Relativistic Heavy Ion Collider (RHIC) at BNL to observe superdense nuclear matter in the laboratory. This article discusses how experimental methods and results which confirmed QCD at the first hadron collider, the CERN ISR, played an important role in experiments at the first heavy ion collider, RHIC, leading to the discovery of the QGP as a perfect liquid as well as discoveries at RHIC and the LHC which continue to the present day.

Geometric branching model of high-energy hadron-hadron collisions

International Nuclear Information System (INIS)

Chen, W.

1988-01-01

A phenomenological model is proposed to describe collisions between hadrons at high energies. In the context of the eikonal formalism, the model consists of two components: soft and hard. The former only involves the production of particles with small transverse momenta; the latter is characterized by jet production. Geometrical scaling is taken as an essential input to describe the geometrical properties of hadrons as extended objects on the one hand, and on the other to define the soft component in both regions below and above the jet threshold. A stochastical Furry branching process is adopted as the mechanism of soft particle production, while the jet fragmentation and gluon initial-state bremsstrahlung are for the production of hadrons in hard collisions. Impact parameter and virtuality are smeared to describe the statistical averaging effects of hadron-hadron collisions. Many otherwise separated issues, ranging from elastic scattering to parton decay function, are connected together in the framework of this model. The descriptions of many prominent features of hadronic collisions are in good agreement with the observed experimental data at all available energies. Multiplicity distributions at all energies are discussed as a major issue in this paper. KNO scaling is achieved for energies within ISR range. The emergence of jets is found to be responsible not only for the violation of both geometrical scaling and KNO scaling, but also for the continuous broadening of the multiplicity distribution with ever increasing energy. It is also shown that the geometrical size of a hadron reaches an asymptote in the energy region of CERN-SppS. A Monte Carlo version of the model for soft production is constructed

Test of Relativistic Gravity for Propulsion at the Large Hadron Collider

Science.gov (United States)

Felber, Franklin

2010-01-01

A design is presented of a laboratory experiment that could test the suitability of relativistic gravity for propulsion of spacecraft to relativistic speeds. An exact time-dependent solution of Einstein's gravitational field equation confirms that even the weak field of a mass moving at relativistic speeds could serve as a driver to accelerate a much lighter payload from rest to a good fraction of the speed of light. The time-dependent field of ultrarelativistic particles in a collider ring is calculated. An experiment is proposed as the first test of the predictions of general relativity in the ultrarelativistic limit by measuring the repulsive gravitational field of bunches of protons in the Large Hadron Collider (LHC). The estimated `antigravity beam' signal strength at a resonant detector of each proton bunch is 3 nm/s2 for 2 ns during each revolution of the LHC. This experiment can be performed off-line, without interfering with the normal operations of the LHC.

The feasibility of experiments at high luminosity at the large hadron collider

International Nuclear Information System (INIS)

Mulvey, J.H.

1988-01-01

The studies reported in this volume extend some of those made during Workshop on Physics at Future Accelerators held at La Thuile and CERN in January 1987 (CERN 87-07, Vol. 1 and 2). They consider the feasibility of performing experiments with a 16 TeV proton-proton collider, the Large Hadron Collider (LHC), at luminosities as high as 5.10 34 cm -2 s -1 . To illustrate the difficulties and the extent to which the potential for discovery at the LHC might be improved by such a step, three specific topics were chosen: searches for a) a massive Higgs boson, b) SUSY gluinos and squarks, and c) a new Z'. Following the Summary Report of the High Luminosity Study Group are papers discussing a possible detector system, radiation levels, and the analyses leading to estimated mass-limits for the searches. (orig.)

Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider

Science.gov (United States)

Bruce, R.; Assmann, R. W.; Boccone, V.; Bracco, C.; Brugger, M.; Cauchi, M.; Cerutti, F.; Deboy, D.; Ferrari, A.; Lari, L.; Marsili, A.; Mereghetti, A.; Mirarchi, D.; Quaranta, E.; Redaelli, S.; Robert-Demolaize, G.; Rossi, A.; Salvachua, B.; Skordis, E.; Tambasco, C.; Valentino, G.; Weiler, T.; Vlachoudis, V.; Wollmann, D.

2014-08-01

The CERN Large Hadron Collider (LHC) is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010-2013, the LHC was routinely storing protons at 3.5-4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An uncontrolled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multistage collimation system has been installed in order to safely intercept high-amplitude beam protons before they are lost elsewhere. To guarantee adequate protection from the collimators, a detailed theoretical understanding is needed. This article presents results of numerical simulations of the distribution of beam losses around the LHC that have leaked out of the collimation system. The studies include tracking of protons through the fields of more than 5000 magnets in the 27 km LHC ring over hundreds of revolutions, and Monte Carlo simulations of particle-matter interactions both in collimators and machine elements being hit by escaping particles. The simulation results agree typically within a factor 2 with measurements of beam loss distributions from the previous LHC run. Considering the complex simulation, which must account for a very large number of unknown imperfections, and in view of the total losses around the ring spanning over 7 orders of magnitude, we consider this an excellent agreement. Our results give confidence in the simulation tools, which are used also for the design of future accelerators.

Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider

Directory of Open Access Journals (Sweden)

R. Bruce

2014-08-01

Full Text Available The CERN Large Hadron Collider (LHC is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010–2013, the LHC was routinely storing protons at 3.5–4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An uncontrolled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multistage collimation system has been installed in order to safely intercept high-amplitude beam protons before they are lost elsewhere. To guarantee adequate protection from the collimators, a detailed theoretical understanding is needed. This article presents results of numerical simulations of the distribution of beam losses around the LHC that have leaked out of the collimation system. The studies include tracking of protons through the fields of more than 5000 magnets in the 27 km LHC ring over hundreds of revolutions, and Monte Carlo simulations of particle-matter interactions both in collimators and machine elements being hit by escaping particles. The simulation results agree typically within a factor 2 with measurements of beam loss distributions from the previous LHC run. Considering the complex simulation, which must account for a very large number of unknown imperfections, and in view of the total losses around the ring spanning over 7 orders of magnitude, we consider this an excellent agreement. Our results give confidence in the simulation tools, which are used also for the design of future accelerators.

Using Data from the Large Hadron Collider in the Classroom

Science.gov (United States)

Smith, Jeremy

2017-01-01

Now is an exciting time for physics students, because they have access to technology and experiments all over the world that were unthinkable a generation ago. Therefore, now is also the ideal time to bring these experiments into the classroom, so students can see what cutting edge science looks like, both in terms of the underlying physics and in terms of the technology used to gather data. With the continued running of the Large Hadron Collider at CERN, and the lab's continued dedication to providing open, worldwide access to their data, there is a unique opportunity for students to use these data in a manner very similar to how it's done in the particle physics community. In this session, we will explore ways for students to analyze real data from the CMS experiment at the LHC, plot these data to discover patterns and signals, and use these plots to determine quantities such as the invariant masses of the W, Z and Higgs bosons. Furthermore, we will show how such activities already fit well into standard introductory physics classes, and can in fact enhance already-existing lessons in the topics of momentum, kinematics, energy and electromagnetism.

Search for Microscopic Black Hole Signatures at the Large Hadron Collider

Energy Technology Data Exchange (ETDEWEB)

Tsang, Ka Vang [Brown Univ., Providence, RI (United States)

2011-05-01

A search for microscopic black hole production and decay in proton-proton collisions at a center-of-mass energy of 7 TeV has been conducted using Compact Muon Solenoid (CMS) detector at the CERN Large Hadron Collider. A total integrated luminosity of 35 pb^-1 data sample, taken by CMS Collaboration in year 2010, has been analyzed. A novel background estimation for multi-jet events beyond TeV scale has been developed. A good agreement with standard model backgrounds, dominated by multi-jet production, is observed for various final-state multiplicities. Using semi-classical approximation, upper limits on minimum black hole mass at 95% confidence level are set in the range of 3.5 - 4.5 TeV for values of the Planck scale up to 3 TeV. Model-independent limits are provided to further constrain microscopic black hole models with additional regions of parameter space, as well as new physics models with multiple energetic final states. These are the first limits on microscopic black hole production at a particle accelerator.

Hadron collider physics. Final report, February 1, 1991--January 31, 1994

International Nuclear Information System (INIS)

1994-01-01

This report contains summaries of work accomplished for Task A1 and A2 (Hadron Collider physics) and Task B. During the first half of the contract period work for Task A1 was focused on the design and implementation of both the D0 detector high voltage system and Level 1 muon trigger. During the second half the emphasis shifted to data analysis. For the major project of Task A2, OPAL, they have recorded and analyzed over one million decays of the Z 0 boson. They began participating in the RD5 experiment at the CERN SPS to study muon tracking in high energy collisions. The LSND experiment at LAMPF recorded physics data in the fall of 1993 and expects to report analysis results at upcoming conferences. In this three year period, the theory task, Task B, completed a number of projects, resulting in over 40 publications. The main emphasis of the research is on a better understanding of the fundamental interactions of quarks and leptons, and the possibility of physics beyond the standard model

Calibration of the hadronic calorimeter prototype for a future lepton collider

Energy Technology Data Exchange (ETDEWEB)

Schroeder, Sarah; Garutti, Erika [Institute for Experimental Physics, Hamburg University, Luruper Chaussee 149, D-22761 Hamburg (Germany); Collaboration: CALICE-D-Collaboration

2016-07-01

The CALICE AHCAL technological prototype is a hadronic calorimeter prototype for a future e{sup +}e{sup -} - collider. It is designed as a sampling calorimeter alternating steel absorber plates and active readout layers, segmented in single plastic scintillator tiles of 3 x 3 x 0.3 cm{sup 3} volume. Each tile is individually coupled to a silicon photomultiplier, read out by a dedicated ASIC with energy measurement and time stamping capability. The high granularity is meant to enable imaging and separation of single showers, for a Particle Flow approach to the jet energy measurement. The prototype aims to establish a scalable solution for an ILC detector. A total of 3456 calorimeter cells need to be inter-calibrated, for this the response to muons is used. The calibration procedure is presented, and the statistic and systematic uncertainties are discussed, which have a direct impact on the constant term of the calorimeter energy resolution. Additionally, the MIP yield in number of fired SiPM pixels can be compared betw een the muon calibration and a test bench calibrations obtained using a Sr sourc e on the single tiles before the assembly of the calorimeter. A good correlation would enable pre-calibation of the single channels on the test bench to be port able to the assemble detector. This hypothesis is checked with the present work.

Prompt D*+ production in proton-proton and lead-lead collisions, measured with the ALICE experiment at the CERN Large Hadron Collider

NARCIS (Netherlands)

de Rooij, R. S.

2013-01-01

In this thesis the results are presented of the first measurements of the D*+ meson nuclear modification factor RAA in heavy ion collisions at the Large Hadron Collider (LHC) using the ALICE (A Large Ion Collider Experiment) detector at CERN. These open charmed mesons are a useful tool to

First evidence for WW and WZ diboson production with semi-leptonic decays at a Hadron Collider

International Nuclear Information System (INIS)

Haley, Joseph Glenn Biddle

2009-01-01

Presented is a measurement of the simultaneous production of a W ± boson in association with a second weak boson (W ± or Z 0 ) in p(bar p) collisions at √s = 1.96 TeV. Events are consider with one electron or one muon, missing transverse energy, and at least two hadronic jets. The data were collected by the D0 detector in Run IIa of the Tevatron accelerator and correspond to 1.07 fb -1 of integrated luminosity for each of the two channels (WW/WZ → eνq(bar q) and WW/WZ → μνq(bar q)). The cross section for WW + WZ production is measured to be 20.2 ± 2.5(stat) ± 3.6(sys) ± 1.2(lum) pb with a Gaussian significance of 4.4 standard deviations above the background-only scenario. This measurement is consistent with the Standard Model prediction and represents the first direct evidence for WW and WZ production with semi-leptonic decays at a hadron collider

Azimuthal coil size and field quality in the main CERN Large Hadron Collider dipoles

Directory of Open Access Journals (Sweden)

P. Ferracin

2002-06-01

Full Text Available Field quality in superconducting magnets strongly depends on the geometry of the coil. Fiberglass spacers (shims placed between the coil and the collars have been used to optimize magnetic and mechanical performances of superconducting magnets in large accelerators. A change in the shim thickness affects both the geometry of the coil and its state of compression (prestress under operational conditions. In this paper we develop a coupled magnetomechanical model of the main Large Hadron Collider dipole. This model allows us to evaluate the prestress dependence on the shim thickness and the map of deformations of the coil and the collars. Results of the model are compared to experimental measurements carried out in a dedicated experiment, where a magnet model has been reassembled 5 times with different shims. A good agreement is found between simulations and experimental data both on the mechanical behavior and on the field quality. We show that this approach allows us to improve this agreement with respect to models previously used in the literature. We finally evaluate the range of tunability that will be provided by shims during the production of the Large Hadron Collider main dipoles.

Collider and Detector Protection at Beam Accidents

Science.gov (United States)

Rakhno, I. L.; Mokhov, N. V.; Drozhdin, A. I.

2003-12-01

Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occured at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section.

Collider and Detector Protection at Beam Accidents

International Nuclear Information System (INIS)

Rakhno, I.L.; Mokhov, N.V.; Drozhdin, A.I.

2003-01-01

Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occurred at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section

Collider and detector protection at beam accidents

International Nuclear Information System (INIS)

Rakhno, I.L.; Mokhov, N.V.; Drozhdin, A.I.

2003-01-01

Dealing with beam loss due to abort kicker prefire is considered for hadron colliders. The prefires occurred at Tevatron (Fermilab) during Run I and Run II are analyzed and a protection system implemented is described. The effect of accidental beam loss in the Large Hadron Collider (LHC) at CERN on machine and detector components is studied via realistic Monte Carlo calculations. The simulations show that beam loss at an unsynchronized beam abort would result in severe heating of conventional and superconducting magnets and possible damage to the collider detector elements. A proposed set of collimators would reduce energy deposition effects to acceptable levels. Special attention is paid to reducing peak temperature rise within the septum magnet and minimizing quench region length downstream of the LHC beam abort straight section

Design optimization of 600 A-13 kA current leads for the Large Hadron Collider project at CERN

CERN Document Server

Spiller, D M; Al-Mosawl, M K; Friend, C M; Thacker, P; Ballarino, A

2001-01-01

The requirements of the Large Hadron Collider project at CERN for high-temperature superconducting (HTS) current leads have been widely publicized. CERN require hybrid current leads of resistive and HTS materials with current ratings of 600 A, 6 kA and 13 kA. BICC General Superconductors, in collaboration with the University of Southampton, have developed and manufactured prototype current leads for the Large Hadron Collider project. The resistive section consists of a phosphorus de-oxidized copper conductor and heat exchanger and the HTS section is constructed from BICC General's (Pb, Bi)2223 tapes with a reduced thermal conductivity Ag alloy sheath. We present the results of the materials optimization studies for the resistive and the HTS sections. Some results of the acceptance tests at CERN are discussed. (9 refs).

Magnet R and D for future colliders

International Nuclear Information System (INIS)

Sabbi, Gian Luca

2001-01-01

High-energy colliders complementing and expanding the physics reach of LHC are presently under study in the United States, Europe and Japan. The magnet system is a major cost driver for hadron colliders at the energy frontier, and critical to the successful operation of muon colliders. Under most scenarios, magnet design as well as vacuum and cryogenic systems are complicated by high radiation loads. Magnet R and D programs are underway worldwide to take advantage of new developments in superconducting materials, achieve higher efficiency and simplify fabrication while preserving accelerator-class field quality. A review of recent progress in magnet technology for future colliders is presented, with emphasis on the most innovative design concepts and fabrication techniques

RHIC spin: The first polarized proton collider

International Nuclear Information System (INIS)

Roser, T.

1994-01-01

The very successful program of QCD and electroweak tests at the high energy hadron colliders have shown that the perturbative QCD has progressed towards becoming a ''precision'' theory. At the same time, it has been shown that with the help of Siberian Snakes it is feasible to accelerate polarized protons to high enough energies where the proven methods of collider physics can be used to probe the spin content of the proton but also where fundamental tests of the spin effects in the standard model are possible. With Siberian Snakes the Relativistic Heavy Ion Collider (RHIC) will be the first collider to allow for 250 GeV on 250 GeV polarized proton collisions

Jet shapes in hadron and electron colliders

International Nuclear Information System (INIS)

Wainer, N.

1993-05-01

High energy jets are observed both in hadronic machines like the Tevatron and electron machines like LEP. These jets have an extended structure in phase space which can be measured. This distribution is usually called the jet shape. There is an intrinsic relation between jet variables, like energy and direction, the jet algorithm used, and the jet shape. Jet shape differences can be used to separate quark and gluon jets

Effective models of new physics at the Large Hadron Collider

International Nuclear Information System (INIS)

Llodra-Perez, J.

2011-07-01

With the start of the Large Hadron Collider runs, in 2010, particle physicists will be soon able to have a better understanding of the electroweak symmetry breaking. They might also answer to many experimental and theoretical open questions raised by the Standard Model. Surfing on this really favorable situation, we will first present in this thesis a highly model-independent parametrization in order to characterize the new physics effects on mechanisms of production and decay of the Higgs boson. This original tool will be easily and directly usable in data analysis of CMS and ATLAS, the huge generalist experiments of LHC. It will help indeed to exclude or validate significantly some new theories beyond the Standard Model. In another approach, based on model-building, we considered a scenario of new physics, where the Standard Model fields can propagate in a flat six-dimensional space. The new spatial extra-dimensions will be compactified on a Real Projective Plane. This orbifold is the unique six-dimensional geometry which possesses chiral fermions and a natural Dark Matter candidate. The scalar photon, which is the lightest particle of the first Kaluza-Klein tier, is stabilized by a symmetry relic of the six dimension Lorentz invariance. Using the current constraints from cosmological observations and our first analytical calculation, we derived a characteristic mass range around few hundred GeV for the Kaluza-Klein scalar photon. Therefore the new states of our Universal Extra-Dimension model are light enough to be produced through clear signatures at the Large Hadron Collider. So we used a more sophisticated analysis of particle mass spectrum and couplings, including radiative corrections at one-loop, in order to establish our first predictions and constraints on the expected LHC phenomenology. (author)

Large Hadron Collider The Discovery Machine

CERN Multimedia

2008-01-01

The mammoth machine, after a nine-year construction period, is scheduled (touch wood) to begin producing its beams of particles later this year. The commissioning process is planned to proceed from one beam to two beams to colliding beams; from lower energies to the terascale; from weaker test intensities to stronger ones suitable for producing data at useful rates but more difficult to control.

Design study of the large hadron electron collider and a rapid cycling synchrotron as alternative to the PS booster upgrade at CERN

International Nuclear Information System (INIS)

Fitterer, Miriam

2013-01-01

With the Large Hadron Collider (LHC) the exploration of particle physics at center of mass energies at the TeV scale has begun. To extend the discovery potential of the LHC, a major upgrade is foreseen around 2020 of the LHC itself and the LHC injectors - the chain of accelerators preparing the beam for the LHC. One of the injectors - the second one in the chain - is the Proton Synchrotron (PS) Booster. Its performance is currently limited by the space-charge effect, which is the effect of the electromagnetic field of the particle beam on itself. This effect becomes weaker with higher energy, and therefore an energy upgrade of the PS Booster to 2 GeV maximum beam energy is foreseen. As the PS Booster is with its 40 years already an old machine, the construction of a new accelerator, a Rapid Cycling Synchrotron (RCS), to replace the PS Booster has been proposed. In this thesis different options for the beam guidance in the RCS - referred to as lattice and optics - are studied, followed by a more general comparison of different lattices and optics and their performance under consideration of the space-charge effect. To further complement the LHC physics program, also the possibility of deep inelastic lepton-nucleon scattering at the LHC has been suggested, referred to as Large Hadron Electron Collider (LHeC). In this case the proton beam of the LHC collides with the electron beam, which is accelerated in a separate newly built machine. Two options are considered as electron accelerator: a new energy recovery linac - the Linac-Ring option - and the installation of an electron ring in the existing LHC tunnel - the Ring-Ring option. One of the main challenges of the Ring-Ring option is the integration of the electron ring in the current LHC tunnel. A layout, lattice and optics of the electron accelerator is developed in this thesis, which meets the requirements with regard to integration and reaches the beam parameters demanded by the particle physics experiments.

Design study of the large hadron electron collider and a rapid cycling synchrotron as alternative to the PS booster upgrade at CERN

Energy Technology Data Exchange (ETDEWEB)

Fitterer, Miriam

2013-02-22

With the Large Hadron Collider (LHC) the exploration of particle physics at center of mass energies at the TeV scale has begun. To extend the discovery potential of the LHC, a major upgrade is foreseen around 2020 of the LHC itself and the LHC injectors - the chain of accelerators preparing the beam for the LHC. One of the injectors - the second one in the chain - is the Proton Synchrotron (PS) Booster. Its performance is currently limited by the space-charge effect, which is the effect of the electromagnetic field of the particle beam on itself. This effect becomes weaker with higher energy, and therefore an energy upgrade of the PS Booster to 2 GeV maximum beam energy is foreseen. As the PS Booster is with its 40 years already an old machine, the construction of a new accelerator, a Rapid Cycling Synchrotron (RCS), to replace the PS Booster has been proposed. In this thesis different options for the beam guidance in the RCS - referred to as lattice and optics - are studied, followed by a more general comparison of different lattices and optics and their performance under consideration of the space-charge effect. To further complement the LHC physics program, also the possibility of deep inelastic lepton-nucleon scattering at the LHC has been suggested, referred to as Large Hadron Electron Collider (LHeC). In this case the proton beam of the LHC collides with the electron beam, which is accelerated in a separate newly built machine. Two options are considered as electron accelerator: a new energy recovery linac - the Linac-Ring option - and the installation of an electron ring in the existing LHC tunnel - the Ring-Ring option. One of the main challenges of the Ring-Ring option is the integration of the electron ring in the current LHC tunnel. A layout, lattice and optics of the electron accelerator is developed in this thesis, which meets the requirements with regard to integration and reaches the beam parameters demanded by the particle physics experiments.

Threshold resummation for slepton-pair production at hadron colliders

International Nuclear Information System (INIS)

Bozzi, Giuseppe; Fuks, Benjamin; Klasen, Michael

2007-01-01

We present a first and extensive study of threshold resummation effects for supersymmetric (SUSY) particle production at hadron colliders, focusing on Drell-Yan like slepton-pair and slepton-sneutrino associated production. After confirming the known next-to-leading order (NLO) QCD corrections and generalizing the NLO SUSY-QCD corrections to the case of mixing squarks in the virtual loop contributions, we employ the usual Mellin N-space resummation formalism with the minimal prescription for the inverse Mellin-transform and improve it by resumming 1/N-suppressed and a class of N-independent universal contributions. Numerically, our results increase the theoretical cross sections by 5 to 15% with respect to the NLO predictions and stabilize them by reducing the scale dependence from up to 20% at NLO to less than 10% with threshold resummation

Threshold resummation for slepton-pair production at hadron colliders

International Nuclear Information System (INIS)

Bozzi, Giuseppe; Fuks, Benjamin; Klasen, Michael

2007-01-01

We present a first and extensive study of threshold resummation effects for supersymmetric (SUSY) particle production at hadron colliders, focusing on Drell-Yan like slepton-pair and slepton-sneutrino associated production. After confirming the known next-to-leading order (NLO) QCD corrections and generalizing the NLO SUSY-QCD corrections to the case of mixing squarks in the virtual loop contributions, we employ the usual Mellin N-space resummation formalism with the minimal prescription for the inverse Mellin-transform and improve it by re-summing 1/N-suppressed and a class of N-independent universal contributions. Numerically, our results increase the theoretical cross sections by 5 to 15% with respect to the NLO predictions and stabilize them by reducing the scale dependence from up to 20% at NLO to less than 10% with threshold resummation. (authors)

Study for a failsafe trigger generation system for the Large Hadron Collider beam dump kicker magnets

CERN Document Server

Rampl, M

1999-01-01

The 27 km-particle accelerator Large Hadron Collider (LHC), which will be completed at the European Laboratory for Particle Physics (CERN) in 2005, will work with extremely high beam energies (~334 MJ per beam). Since the equipment and in particular the superconducting magnets must be protected from damage caused by these high energy beams the beam dump must be able to absorb this energy very reliable at every stage of operation. The kicker magnets that extract the particles from the accelerator are synchronised with the beam by the trigger generation system. This thesis is a first study for this electronic module and its functions. A special synchronisation circuit and a very reliable electronic switch were developed. Most functions were implemented in a Gate-Array to improve the reliability and to facilitate modifications during the test stage. This study also comprises the complete concept for the prototype of the trigger generation system. During all project stages reliability was always the main determin...

NLO production of W' bosons at hadron colliders using the MCatNLO and POWHEG methods

International Nuclear Information System (INIS)

Papaefstathiou, A.; Latunde-Dada, O.

2009-01-01

We present a next-to-leading order (NLO) treatment of the production of a new charged heavy vector boson, generically called W', at hadron colliders via the Drell-Yan process. We fully consider the interference effects with the Standard Model W boson and allow for arbitrary chiral couplings to quarks and leptons. We present results at both leading order (LO) and NLO in QCD using the MCatNLO/Herwig++ and POWHEG methods. We derive theoretical observation curves on the mass-width plane for both the LO and NLO cases at different collider luminosities. The event generator used, Wpnlo, is fully customisable and publicly available.

Phenomenology of the Higgs at the hadron colliders: from the standard model to supersymmetry

International Nuclear Information System (INIS)

Baglio, J.

2011-10-01

This thesis has been conducted in the context of one of the utmost important searches at current hadron colliders, that is the search for the Higgs boson, the remnant of the electroweak symmetry breaking. We wish to study the phenomenology of the Higgs boson in both the Standard Model (SM) framework and its minimal Supersymmetric extension (MSSM). After a review of the Standard Model in a first part and of the key reasons and ingredients for the supersymmetry in general and the MSSM in particular in a third part, we will present the calculation of the inclusive production cross sections of the Higgs boson in the main channels at the two current hadron colliders that are the Fermilab Tevatron collider and the CERN Large Hadron Collider (LHC), starting by the SM case in the second part and presenting the MSSM results, where we have 5 Higgs bosons and focusing on the two main production channels that are the gluon gluon fusion and the bottom quarks fusion, in the fourth part. The main output of this calculation is the extensive study of the various theoretical uncertainties that affect the predictions: the scale uncertainties which probe our ignorance of the higher-order terms in a fixed order perturbative calculation, the parton distribution functions (PDF) uncertainties and its related uncertainties from the value of the strong coupling constant, and the uncertainties coming from the use of an effective field theory to simplify the hard calculation. We then move on to the study of the Higgs decay branching ratios which are also affected by diverse uncertainties. We will present the combination of the production cross sections and decay branching fractions in some specific cases which will show interesting consequences on the total theoretical uncertainties. We move on to present the results confronted to experiments and show that the theoretical uncertainties have a significant impact on the inferred limits either in the SM search for the Higgs boson or on the MSSM

Physics and planning for future colliders

International Nuclear Information System (INIS)

Kane, G.L.

1985-01-01

Physics opportunities at future (not presently under construction) colliders are examined, particularly with reference to the motivations for building them. First a number of considerations involved in planning and choosing beams, energies, and luminosities are discussed. Higgs physics, which currently seems to be the central problem of particle physics, is emphasized, with detailed study of how to do WW scattering and how to detect effects of heavy Higgs bosons. Some new results are included. High energy hadron colliders dominate the discussion, but alternatives are examined for comparison and when they have unique capabilities

\\psi (2S) enhancement in p-Pb collision as an indication of quark-gluon plasma formation at the Large Hadron Collider

Science.gov (United States)

Ganesh, S.; Singh, R., Captain; Mishra, M.

2018-03-01

Proton-nucleus collisions serve as an important baseline for the understanding and interpretation of the nucleus-nucleus collisions. These collisions have been employed to characterize the cold nuclear matter effects at SPS and Relativistic Heavy-Ion Collider energies for the past several years, as it was thought that quark-gluon plasma (QGP) is not formed in such collisions. However, at the Large Hadron Collider (LHC), there seems a possibility that QGP is formed during proton-lead (p-Pb) collisions. In this work, we have derived an expression for gluon induced excitation of J/\\psi to \\psi (2S), using pNRQCD, and show that the relative enhancement of \\psi (2S) vis-à-vis J/\\psi , especially at high p T , gives further indication that the QGP is indeed formed in p-Pb collisions at the most central collisions at LHC energy. J/\\psi and \\psi (2S) suppression effects seen at ALICE are also qualitatively explained.

Impact of high energy high intensity proton beams on targets: Case studies for Super Proton Synchrotron and Large Hadron Collider

Directory of Open Access Journals (Sweden)

N. A. Tahir

2012-05-01

Full Text Available The Large Hadron Collider (LHC is designed to collide two proton beams with unprecedented particle energy of 7 TeV. Each beam comprises 2808 bunches and the separation between two neighboring bunches is 25 ns. The energy stored in each beam is 362 MJ, sufficient to melt 500 kg copper. Safety of operation is very important when working with such powerful beams. An accidental release of even a very small fraction of the beam energy can result in severe damage to the equipment. The machine protection system is essential to handle all types of possible accidental hazards; however, it is important to know about possible consequences of failures. One of the critical failure scenarios is when the entire beam is lost at a single point. In this paper we present detailed numerical simulations of the full impact of one LHC beam on a cylindrical solid carbon target. First, the energy deposition by the protons is calculated with the FLUKA code and this energy deposition is used in the BIG2 code to study the corresponding thermodynamic and the hydrodynamic response of the target that leads to a reduction in the density. The modified density distribution is used in FLUKA to calculate new energy loss distribution and the two codes are thus run iteratively. A suitable iteration step is considered to be the time interval during which the target density along the axis decreases by 15%–20%. Our simulations suggest that the full LHC proton beam penetrates up to 25 m in solid carbon whereas the range of the shower from a single proton in solid carbon is just about 3 m (hydrodynamic tunneling effect. It is planned to perform experiments at the experimental facility HiRadMat (High Radiation Materials at CERN using the proton beam from the Super Proton Synchrotron (SPS, to compare experimental results with the theoretical predictions. Therefore simulations of the response of a solid copper cylindrical target hit by the SPS beam were performed. The particle

Impact of high energy high intensity proton beams on targets: Case studies for Super Proton Synchrotron and Large Hadron Collider

Science.gov (United States)

Tahir, N. A.; Sancho, J. Blanco; Shutov, A.; Schmidt, R.; Piriz, A. R.

2012-05-01

The Large Hadron Collider (LHC) is designed to collide two proton beams with unprecedented particle energy of 7 TeV. Each beam comprises 2808 bunches and the separation between two neighboring bunches is 25 ns. The energy stored in each beam is 362 MJ, sufficient to melt 500 kg copper. Safety of operation is very important when working with such powerful beams. An accidental release of even a very small fraction of the beam energy can result in severe damage to the equipment. The machine protection system is essential to handle all types of possible accidental hazards; however, it is important to know about possible consequences of failures. One of the critical failure scenarios is when the entire beam is lost at a single point. In this paper we present detailed numerical simulations of the full impact of one LHC beam on a cylindrical solid carbon target. First, the energy deposition by the protons is calculated with the FLUKA code and this energy deposition is used in the BIG2 code to study the corresponding thermodynamic and the hydrodynamic response of the target that leads to a reduction in the density. The modified density distribution is used in FLUKA to calculate new energy loss distribution and the two codes are thus run iteratively. A suitable iteration step is considered to be the time interval during which the target density along the axis decreases by 15%-20%. Our simulations suggest that the full LHC proton beam penetrates up to 25 m in solid carbon whereas the range of the shower from a single proton in solid carbon is just about 3 m (hydrodynamic tunneling effect). It is planned to perform experiments at the experimental facility HiRadMat (High Radiation Materials) at CERN using the proton beam from the Super Proton Synchrotron (SPS), to compare experimental results with the theoretical predictions. Therefore simulations of the response of a solid copper cylindrical target hit by the SPS beam were performed. The particle energy in the SPS beam is 440

Undergraduate Laboratory Experiment: Measuring Matter Antimatter Asymmetries at the Large Hadron Collider

CERN Document Server

Parkes, Chris; Gutierrez, J

2015-01-01

This document is the student manual for a third year undergraduate laboratory experiment at the University of Manchester. This project aims to measure a fundamental difference between the behaviour of matter and antimatter through the analysis of data collected by the LHCb experiment at the Large Hadron Collider. The three-body dmecays $B^\\pm \\rightarrow h^\\pm h^+ h^-$, where $h^\\pm$ is a $\\pi^\\pm$ or $K^\\pm$ are studied. The inclusive matter antimatter asymmetry is calculated, and larger asymmetries are searched for in localized regions of the phase-space.

NNLO QCD corrections to jet production at hadron colliders from gluon scattering

International Nuclear Information System (INIS)

Currie, James; Ridder, Aude Gehrmann-De; Glover, E.W.N.; Pires, João

2014-01-01

We present the next-to-next-to-leading order (NNLO) QCD corrections to dijet production in the purely gluonic channel retaining the full dependence on the number of colours. The sub-leading colour contribution in this channel first appears at NNLO and increases the NNLO correction by around 10% and exhibits a p T dependence, rising from 8% at low p T to 15% at high p T . The present calculation demonstrates the utility of the antenna subtraction method for computing the full colour NNLO corrections to dijet production at the Large Hadron Collider

Simulation of backgrounds in detectors and energy deposition in superconducting magnets at μ+μ- colliders

International Nuclear Information System (INIS)

Mokhov, N.V.; Striganov, S.I.

1996-01-01

A calculational approach is described to study beam induced radiation effects in detector and storage ring components at high-energy high-luminosity μ + μ - colliders. The details of the corresponding physics process simulations used in the MARS code are given. Contributions of electromagnetic showers, synchrotron radiation, hadrons and daughter muons to the background rates in a generic detector for a 2 x 2 TeV μ + μ - collider are investigated. Four configurations of the inner triplet and a detector are examined for two sources: muon decays and beam halo interactions in the lattice elements. The beam induced power density in superconducting magnets is calculated and ways to reduce it are proposed

Hadron energy resolution at ICAL

International Nuclear Information System (INIS)

Devi, Moon Moon; Ghosh, Anushree; Kaur, Daljeet; Mohan, Lakshmi S.

2013-01-01

We have performed a simulation study for determining the hadron energy resolution of INO-ICAL detector within a GEANT4 based simulation framework. We do this by propagating single pions from a fixed or a randomised vertex, as also with the NUANCE (neutrino event generator) generated events in which hadrons are produced in the energy range (0.5 ≤ E ≤ 15 GeV). Hadron interactions produce a shower of hits inside the detector. The energy of hadrons can therefore be reconstructed only by taking these hits into account. Hit distribution for each energy and angle bin has been obtained and analyzed. In order to find the suitable fit for such hit distributions a comparative study has been performed by applying different fit functions and results will be shown

Simulations of fast crab cavity failures in the high luminosity Large Hadron Collider

Science.gov (United States)

Yee-Rendon, Bruce; Lopez-Fernandez, Ricardo; Barranco, Javier; Calaga, Rama; Marsili, Aurelien; Tomás, Rogelio; Zimmermann, Frank; Bouly, Frédéric

2014-05-01

Crab cavities (CCs) are a key ingredient of the high luminosity Large Hadron Collider (HL-LHC) project for increasing the luminosity of the LHC. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of the order of a few LHC turns and considering the significant stored energy in the HL-LHC beam, CC failures represent a serious threat in regard to LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, the one needed to dump the beam. The simulations assume a quasistationary-state distribution to assess the particles losses for the HL-LHC. These distributions produce beam losses below the safe operation threshold for Gaussian tails, while, for non-Gaussian tails are on the same order of the limit. Additionally, some mitigation strategies are studied for reducing the damage caused by the CC failures.

High Luminosity Large Hadron Collider A description for the European Strategy Preparatory Group

CERN Document Server

Rossi, L

2012-01-01

The Large Hadron Collider (LHC) is the largest scientific instrument ever built. It has been exploring the new energy frontier since 2009, gathering a global user community of 7,000 scientists. It will remain the most powerful accelerator in the world for at least two decades, and its full exploitation is the highest priority in the European Strategy for Particle Physics, adopted by the CERN Council and integrated into the ESFRI Roadmap. To extend its discovery potential, the LHC will need a major upgrade around 2020 to increase its luminosity (rate of collisions) by a factor of 10 beyond its design value. As a highly complex and optimized machine, such an upgrade of the LHC must be carefully studied and requires about 10 years to implement. The novel machine configuration, called High Luminosity LHC (HL-LHC), will rely on a number of key innovative technologies, representing exceptional technological challenges, such as cutting-edge 13 tesla superconducting magnets, very compact and ultra-precise superconduc...

Simulations of fast crab cavity failures in the high luminosity Large Hadron Collider

Directory of Open Access Journals (Sweden)

Bruce Yee-Rendon

2014-05-01

Full Text Available Crab cavities (CCs are a key ingredient of the high luminosity Large Hadron Collider (HL-LHC project for increasing the luminosity of the LHC. At KEKB, CCs have exhibited abrupt changes of phase and voltage during a time period of the order of a few LHC turns and considering the significant stored energy in the HL-LHC beam, CC failures represent a serious threat in regard to LHC machine protection. In this paper, we discuss the effect of CC voltage or phase changes on a time interval similar to, or longer than, the one needed to dump the beam. The simulations assume a quasistationary-state distribution to assess the particles losses for the HL-LHC. These distributions produce beam losses below the safe operation threshold for Gaussian tails, while, for non-Gaussian tails are on the same order of the limit. Additionally, some mitigation strategies are studied for reducing the damage caused by the CC failures.

Large hadron collider (LHC) project quality assurance plan

Energy Technology Data Exchange (ETDEWEB)

Gullo, Lisa; Karpenko, Victor; Robinson, Kem; Turner, William; Wong, Otis

2002-09-30

The LHC Quality Assurance Plan is a set of operating principles, requirements, and practices used to support Berkeley Lab's participation in the Large Hadron Collider Project. The LHC/QAP is intended to achieve reliable, safe, and quality performance in the LHC project activities. The LHC/QAP is also designed to fulfill the following objectives: (1) The LHC/QAP is Berkeley Lab's QA program document that describes the elements necessary to integrate quality assurance, safety management, and conduct of operations into the Berkeley Lab's portion of the LHC operations. (2) The LHC/QAP provides the framework for Berkeley Lab LHC Project administrators, managers, supervisors, and staff to plan, manage, perform, and assess their Laboratory work. (3) The LHC/QAP is the compliance document that conforms to the requirements of the Laboratory's Work Smart Standards for quality assurance (DOE O 414.1, 10 CFR 830.120), facility operations (DOE O 5480.19), and safety management (DOE P 450.4).

Large hadron collider (LHC) project quality assurance plan

International Nuclear Information System (INIS)

Gullo, Lisa; Karpenko, Victor; Robinson, Kem; Turner, William; Wong, Otis

2002-01-01

The LHC Quality Assurance Plan is a set of operating principles, requirements, and practices used to support Berkeley Lab's participation in the Large Hadron Collider Project. The LHC/QAP is intended to achieve reliable, safe, and quality performance in the LHC project activities. The LHC/QAP is also designed to fulfill the following objectives: (1) The LHC/QAP is Berkeley Lab's QA program document that describes the elements necessary to integrate quality assurance, safety management, and conduct of operations into the Berkeley Lab's portion of the LHC operations. (2) The LHC/QAP provides the framework for Berkeley Lab LHC Project administrators, managers, supervisors, and staff to plan, manage, perform, and assess their Laboratory work. (3) The LHC/QAP is the compliance document that conforms to the requirements of the Laboratory's Work Smart Standards for quality assurance (DOE O 414.1, 10 CFR 830.120), facility operations (DOE O 5480.19), and safety management (DOE P 450.4)

Sextupole correction magnets for the Large Hadron Collider

CERN Document Server

Meinke, R B; Senti, M; Op de Beeck, W J; De Ryck, C; MacKay, W W

1999-01-01

About 2500 superconducting sextupole corrector magnets (MCS) are needed for the Large Hadron Collider (LHC) at CERN to compensate persistent current sextupole fields of the main dipoles. The MCS is a cold bore magnet with iron yoke. The coils are made from a NbTi conductor, which is cooled to 1.9 K. In the original CERN design 6 individual sub-coils, made from a monolithic composite conductor, are assembled and spliced together to form the sextupole. The coils are individually wound around precision-machined central islands and stabilized with matching saddle pieces at both ends. The Advanced Magnet Lab, Inc. (AML) has produced an alternative design, which gives improved performance and reliability at reduced manufacturing cost. In the AML design, the magnet consists of three splice-free sub-coils, which are placed with an automated winding process into pockets of prefabricated G-11 support cylinders. Any assembly process of sub-coils with potential misalignment is eliminated. The AML magnet uses a Kapton-wra...

High energy hadron spin-flip amplitude

International Nuclear Information System (INIS)

Selyugin, O.V.

2016-01-01

The high-energy part of the hadron spin-flip amplitude is examined in the framework of the new high-energy general structure (HEGS) model of the elastic hadron scattering at high energies. The different forms of the hadron spin-flip amplitude are compared in the impact parameter representation. It is shown that the existing experimental data of the proton-proton and proton-antiproton elastic scattering at high energy in the region of the diffraction minimum and at large momentum transfer give support in the presence of the energy-independent part of the hadron spin-flip amplitude with the momentum dependence proposed in the works by Galynskii-Kuraev. [ru

Tracking study of hadron collider boosters

Energy Technology Data Exchange (ETDEWEB)

Machida, S.; Bourianoff, G.; Huang, Y.; Mahale, N.

1992-07-01

A simulation code SIMPSONS (previously called 6D-TEASE T) of single- and multi-particle tracking has been developed for proton synchrotrons. The 6D phase space coordinates are calculated each time step including acceleration with an arbitrary ramping curve by integration of the rf phase. Space-charge effects are modelled by means of the Particle In Cell (PIC) method. We observed the transverse emittance growth around the injection energy of the Low Energy Booster (LEB) of the Superconducting Super Collider (SSC) with and without second harmonic rf cavities which reduce peak line density. We also employed the code to see the possible transverse emittance deterioration around the transition energy in the Medium Energy Booster (MEB) and to estimate the emittance dilution due to an injection error of the MEB.

Future Circular Collider Study (FCC) kick-off meeting | 12-15 February

CERN Multimedia

2014-01-01

The kick-off meeting of the international "Future Circular Collider Study" (FCC) will take place in Geneva from 12 to 15 February 2014 at the University of Geneva, Unimail site. The programme and registration details can be found on the meeting's website. This meeting is the starting point of the five-year international "Future Circular Collider Study" (FCC). The main emphasis of the conceptual design study will be on a hadron collider with a centre-of-mass energy of the order of 100 TeV in a new tunnel with a 80-100 km circumference for the purposes of studying physics at the highest energies. The study will also include a lepton collider, as a potential intermediate step towards realisation of the hadron facility. Options for e-p scenarios will also be considered. The main purpose of this meeting is to discuss the study topics and to prepare international collaborations. The meeting is a public meeting with a registration deadline closing on Friday 31 Janua...

Busca por dimensões extras no detector CMS do large hadron collider

CERN Document Server

Fernandez Perez Tomei, T R

We present the results of a search for experimental evidence of extra space dimensions in proton-proton collisions at a center-of-mass energy of 7 TeV, furnished by the Large Hadron Collider accelerator. We analyzed the data taken by the Compact Muon Solenoid experiment during 2011, which total an integrated luminosity of 4.7 fb−1. The Randall-Sundrum warped extra dimensions model was used as a standard benchmark for the experimental signatures which could be observed in the data, in the presence of extra dimensions. The studied reaction is pp → G∗→ ZZ→ qqνν, where G∗ is the first Randall-Sundrum graviton resonance. The observations agree witht he Standard Model predictions. In the absence of experimental signals of extra dimensions, we put limits on the parameters of the Randall-Sundrum model. Upper limits, with 95% confidence, for the cross-section of processes which would raise the event yield in the channel considered are in the [0.047 – 0.021] pb range, for resonance masses in the [1000...

Geant4 Hadronic Cascade Models and CMS Data Analysis : Computational Challenges in the LHC era

CERN Document Server

Heikkinen, Aatos

This work belongs to the field of computational high-energy physics (HEP). The key methods used in this thesis work to meet the challenges raised by the Large Hadron Collider (LHC) era experiments are object-orientation with software engineering, Monte Carlo simulation, the computer technology of clusters, and artificial neural networks. The first aspect discussed is the development of hadronic cascade models, used for the accurate simulation of medium-energy hadron-nucleus reactions, up to 10 GeV. These models are typically needed in hadronic calorimeter studies and in the estimation of radiation backgrounds. Various applications outside HEP include the medical field (such as hadron treatment simulations), space science (satellite shielding), and nuclear physics (spallation studies). Validation results are presented for several significant improvements released in Geant4 simulation tool, and the significance of the new models for computing in the Large Hadron Collider era is estimated. In particular, we es...

The optics of the low energy FFAG cell of the eRHIC collider, using realistic field maps

Energy Technology Data Exchange (ETDEWEB)

Tsoupas, N. [Brookhaven National Lab. (BNL), Upton, NY (United States); Brooks, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Jain, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Meot, F. [Brookhaven National Lab. (BNL), Upton, NY (United States); Mahler, G. [Brookhaven National Lab. (BNL), Upton, NY (United States); Ptitsyn, V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Trbojevic, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Severance, M. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2015-07-02

The proposed electron accelerator of the eRHIC complex [1] will use a 1.32 GeV Energy Recovery Linac (ERL) to accelerate the e-bunches to a top energy of 21.2 GeV before they collide with the hadron bunches. The e-bunches attain the 21.2 GeV energy after passing through the ERL 16 times as they recirculate in two rings which are placed alongside the RHIC hadron accelerator. The two rings [1] are made of periodic cells and each cell is made of one focusing and one defocusing permanent magnet qudrupole. In this paper we present the electromagnetic calculations of the 2D and 3D models of a cell which is comprised of two modified Halbach quadrupoles [4], and the optical properties of the cell.

Proton-Proton and Proton-Antiproton Colliders

CERN Document Server

Scandale, Walter

2014-01-01

In the last five decades, proton–proton and proton–antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion–ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

Future Circular Collider Study FCC-he Baseline Parameters

CERN Document Server

Bruning, Oliver; Klein, Max; Pellegrini, Dario; Schulte, Daniel; Zimmermann, Frank

2017-01-01

Initial considerations are presented on the FCC-he, the electron-hadron collider con guration within the Future Circular Collider study. This note considers arguments for the choice of the electron beam energy based on physics, ep scattering kinematics and cost. The default con guration for the electron accelerator, as for the LHeC, is chosen to be a multi-turn energy recovery linac external to the proton beam tunnel. The main accelerator parameters of the FCC-he are discussed, assuming the concurrent operation of ep with the 100TeV cms energy pp collider. These are compared with the LHeC design concept, for increased performance as for a Higgs facility using the HL-LHC, and also the high energy HE-LHC ep collider configuration. Initial estimates are also provided for the luminosity performance of electron-ion colliders for the 60 GeV electron ERL when combined with the LHC, the HE-LHC and the FCC ion beams.

Hadron jets in perspective

International Nuclear Information System (INIS)

Quigg, C.

1982-11-01

The subject of hadron jet studies, to judge by the work presented at this workshop, is a maturing field which is still gathering steam. The very detailed work being done in lepton-lepton and lepton-hadron collisions, the second-generation measurements being carried out at Fermilab, the CERN SPS, and the ISR, and the very high energy hard scatterings being observed at the CERN Collider all show enormous promise for increased understanding. Perhaps we shall yet reach that long-sought nirvana in which high-p/sub perpendicular/ collisions become truly simple

High energy hadron-nucleus scattering

International Nuclear Information System (INIS)

Koplik, J.; Mueller, A.H.

1975-01-01

Theoretical expectations for hadron-nucleus scattering at high energy if the basic hadron-hadron interaction is due to Regge poles and cuts arising in multiperipheral or soft field theory models are described. Experiments at Fermilab may provide a critical test of such models

Multibunch operation in the Tevatron Collider

International Nuclear Information System (INIS)

Holt, J.A.; Finley, D.A.; Bharadwaj, V.

1993-05-01

The Tevatron Collider at Fermilab is the world's highest energy hadron collider, colliding protons with antiprotons at a center of mass energy of 1800 GeV. At present six proton bunches collide with six antiproton bunches to generate luminosities of up to 9 x 10 30 cm -2 s -1 . It is estimated that to reach luminosities significantly greater than 10 31 cm -2 s -1 while minimizing the number of interactions per crossing, the number of bunches will have to be increased. Thirty-six bunch operation looks like the most promising plan. This paper looks at the strategies for increasing the number of particle bunches, the new hardware that needs to be designed and changes to the operating mode in filling the Tevatron. An interactive program which simulates the filling of the Tevatron collider is also presented. The time scale for multibunch operation and progress towards running greater than six bunches is given in this paper

The Fermi motion contribution to J/{psi} production at the hadron colliders

Energy Technology Data Exchange (ETDEWEB)

Gomshi Nobary, M.A. [Department of Physics, Faculty of Science, Razi University, Kermanshah (Iran, Islamic Republic of) and Center for Theoretical Physics and Mathematics, AEOI, Roosbeh Building, P.O. Box 11365-8486 Tehran (Iran, Islamic Republic of)]. E-mail: mnobary@razi.ac.ir; Nikoobakht, B. [Department of Physics, Faculty of Science, Razi University, Kermanshah (Iran, Islamic Republic of)

2006-08-17

We investigate the relativistic Fermi motion effect in the case of J/{psi} production in various hadron colliders. A light-cone wave function is adopted to represent the J/{psi} final state. The change in the confint parameter which sets a scale for the size of the final state, allows one to see the effect in an explicit manner. While the effect has considerable influence on the fragmentation probabilities and the differential cross sections, the total cross sections essentially are left unchanged. Such a feature is in agreement with the momentum sum rule which the fragmentation functions should satisfy.

VUV photoemission studies of candidate Large Hadron Collider vacuum chamber materials

Directory of Open Access Journals (Sweden)

R. Cimino

1999-06-01

Full Text Available In the context of future accelerators and, in particular, the beam vacuum of the Large Hadron Collider (LHC, a 27 km circumference proton collider to be built at CERN, VUV synchrotron radiation (SR has been used to study both qualitatively and quantitatively candidate vacuum chamber materials. Emphasis is given to show that angle and energy resolved photoemission is an extremely powerful tool to address important issues relevant to the LHC, such as the emission of electrons that contributes to the creation of an electron cloud which may cause serious beam instabilities and unmanageable heat loads on the cryogenic system. Here we present not only the measured photoelectron yields from the proposed materials, prepared on an industrial scale, but also the energy and in some cases the angular dependence of the emitted electrons when excited with either a white light (WL spectrum, simulating that in the arcs of the LHC, or monochromatic light in the photon energy range of interest. The effects on the materials examined of WL irradiation and /or ion sputtering, simulating the SR and ion bombardment expected in the LHC, were investigated. The studied samples exhibited significant modifications, in terms of electron emission, when exposed to the WL spectrum from the BESSY Toroidal Grating Monochromator beam line. Moreover, annealing and ion bombardment also induce substantial changes to the surface thereby indicating that such surfaces would not have a constant electron emission during machine operation. Such characteristics may be an important issue to define the surface properties of the LHC vacuum chamber material and are presented in detail for the various samples analyzed. It should be noted that all the measurements presented here were recorded at room temperature, whereas the majority of the LHC vacuum system will be maintained at temperatures below 20 K. The results cannot therefore be directly applied to these sections of the machine until

Radiation protection considerations in the design of the LHC, CERN's large hadron collider

International Nuclear Information System (INIS)

Hoefert, M.; Huhtinen, M.; Moritz, L.E.; Nakashima, H.; Potter, K.M.; Rollet, S.; Stevenson, G.R.; Zazula, J.M.

1996-01-01

This paper describes the radiological concerns which are being taken into account in the design of the LHC (CERN's future Large Hadron Collider). The machine will be built in the 27 km circumference ring tunnel of the existing LEP collider at CERN. The high intensity of the circulating beams (each containing more than 10 14 protons at 7 TeV) determines the thickness specification of the shielding of the main-ring tunnel, the precautions to be taken in the design of the beam dumps and their associated caverns and the radioactivity induced by the loss of protons in the main ring by inelastic beam-gas interactions. The high luminosity of the collider is designed to provide inelastic collision rates of 10 9 per second in each of the two principal detector installations, ATLAS and CMS. These collisions determine the shielding of the experimental areas, the radioactivity induced in both the detectors and in the machine components on either side of the experimental installations and, to some extent, the radioactivity induced in the beam-cleaning (scraper) systems. Some of the environmental issues raised by the project will be discussed. (author)

Search for Supersymmetry using Heavy Flavour Jets with the ATLAS Detector at the Large Hadron Collider

CERN Document Server

Tua, Alan

The Standard Model of particle physics, despite being extremely successful, is not the ultimate description of physics. The nature of dark matter is not well described, unification of the forces is not achieved and the theory is plagued by a hierarchy problem. One of the proposed solutions to these issues is supersymmetry. This thesis describes numerous searches for supersymmetry carried out using the ATLAS detector at the Large Hadron Collider. In scenarios where R-parity is conserved, supersymmetric final states contain large amounts of missing transverse energy. Furthermore, should supersymmetry correctly describe Nature, the scalar partners of the third generation quarks might be the lightest scalar quarks. The searches reported here exploit these possibilities and make use of signatures which are rich in missing transverse energy and jets coming from heavy flavour quarks. Searches are carried out for direct pair production of third generation scalar quarks as well as gluino-mediated production of these p...

Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab

Energy Technology Data Exchange (ETDEWEB)

Abeyratne, S; Ahmed, S; Barber, D; Bisognano, J; Bogacz, A; Castilla, A; Chevtsov, P; Corneliussen, S; Deconinck, W; Degtiarenko, P; Delayen, J; Derbenev, Ya; DeSilva, S; Douglas, D; Dudnikov, V; Ent, R; Erdelyi, B; Evtushenko, P; Fujii, Yu; Filatov, Yury; Gaskell, D; Geng, R; Guzey, V; Horn, T; Hutton, A; Hyde, C; Johnson, R; Kim, Y; Klein, F; Kondratenko, A; Kondratenko, M; Krafft, G; Li, R; Lin, F; Manikonda, S; Marhauser, F; McKeown, R; Morozov, V; Dadel-Turonski, P; Nissen, E; Ostroumov, P; Pivi, M; Pilat, F; Poelker, M; Prokudin, A; Rimmer, R; Satogata, T; Sayed, H; Spata, M; Sullivan, M; Tennant, C; Terzic, B; Tiefenback, M; Wang, M; Wang, S; Weiss, C; Yunn, B

2012-08-01

Researchers have envisioned an electron-ion collider with ion species up to heavy ions, high polarization of electrons and light ions, and a well-matched center-of-mass energy range as an ideal gluon microscope to explore new frontiers of nuclear science. In its most recent Long Range Plan, the Nuclear Science Advisory Committee (NSAC) of the US Department of Energy and the National Science Foundation endorsed such a collider in the form of a 'half-recommendation.' As a response to this science need, Jefferson Lab and its user community have been engaged in feasibility studies of a medium energy polarized electron-ion collider (MEIC), cost-effectively utilizing Jefferson Lab's already existing Continuous Electron Beam Accelerator Facility (CEBAF). In close collaboration, this community of nuclear physicists and accelerator scientists has rigorously explored the science case and design concept for this envisioned grand instrument of science. An electron-ion collider embodies the vision of reaching the next frontier in Quantum Chromodynamics - understanding the behavior of hadrons as complex bound states of quarks and gluons. Whereas the 12 GeV Upgrade of CEBAF will map the valence-quark components of the nucleon and nuclear wave functions in detail, an electron-ion collider will determine the largely unknown role sea quarks play and for the first time study the glue that binds all atomic nuclei. The MEIC will allow nuclear scientists to map the spin and spatial structure of quarks and gluons in nucleons, to discover the collective effects of gluons in nuclei, and to understand the emergence of hadrons from quarks and gluons. The proposed electron-ion collider at Jefferson Lab will collide a highly polarized electron beam originating from the CEBAF recirculating superconducting radiofrequency (SRF) linear accelerator (linac) with highly polarized light-ion beams or unpolarized light- to heavy-ion beams from a new ion accelerator and storage complex. Since the very

Science Requirements and Conceptual Design for a Polarized Medium Energy Electron-Ion Collider at Jlab

International Nuclear Information System (INIS)

Abeyratne, S.; Accardi, A.; Ahmed, S.; Barber, D.; Bisognano, J.; Bogacz, A.; Castilla, A.; Chevtsov, P.; Corneliussen, S.; Deconinck, W.; Degtiarenko, P.; Delayen, J.; Derbenev, Ya.; DeSilva, S.; Douglas, D.; Dudnikov, V.; Ent, R.; Erdelyi, B.; Evtushenko, P.; Fujii, Yu; Filatov, Yury; Gaskell, D.; Geng, R.; Guzey, V.; Horn, T.; Hutton, A.; Hyde, C.; Johnson, R.; Kim, Y.; Klein, F.; Kondratenko, A.; Kondratenko, M.; Krafft, G.; Li, R.; Lin, F.; Manikonda, S.; Marhauser, F.; McKeown, R.; Morozov, V.; Dadel-Turonski, P.; Nissen, E.; Ostroumov, P.; Pivi, M.; Pilat, F.; Poelker, M.; Prokudin, A.; Rimmer, R.; Satogata, T.; Sayed, H.; Spata, M.; Sullivan, M.; Tennant, C.; Terzic, B.; Tiefenback, M.; Wang, H.; Wang, S.; Weiss, C.; Yunn, B.; Zhang, Y.

2012-01-01

Researchers have envisioned an electron-ion collider with ion species up to heavy ions, high polarization of electrons and light ions, and a well-matched center-of-mass energy range as an ideal gluon microscope to explore new frontiers of nuclear science. In its most recent Long Range Plan, the Nuclear Science Advisory Committee (NSAC) of the US Department of Energy and the National Science Foundation endorsed such a collider in the form of a 'half-recommendation.' As a response to this science need, Jefferson Lab and its user community have been engaged in feasibility studies of a medium energy polarized electron-ion collider (MEIC), cost-effectively utilizing Jefferson Lab's already existing Continuous Electron Beam Accelerator Facility (CEBAF). In close collaboration, this community of nuclear physicists and accelerator scientists has rigorously explored the science case and design concept for this envisioned grand instrument of science. An electron-ion collider embodies the vision of reaching the next frontier in Quantum Chromodynamics - understanding the behavior of hadrons as complex bound states of quarks and gluons. Whereas the 12 GeV Upgrade of CEBAF will map the valence-quark components of the nucleon and nuclear wave functions in detail, an electron-ion collider will determine the largely unknown role sea quarks play and for the first time study the glue that binds all atomic nuclei. The MEIC will allow nuclear scientists to map the spin and spatial structure of quarks and gluons in nucleons, to discover the collective effects of gluons in nuclei, and to understand the emergence of hadrons from quarks and gluons. The proposed electron-ion collider at Jefferson Lab will collide a highly polarized electron beam originating from the CEBAF recirculating superconducting radiofrequency (SRF) linear accelerator (linac) with highly polarized light-ion beams or unpolarized light- to heavy-ion beams from a new ion accelerator and storage complex. Since the very

NLO corrections to production of heavy particles at hadron colliders

International Nuclear Information System (INIS)

Pagani, Davide

2013-01-01

In this thesis we study specific aspects of the production of heavy particles at hadron colliders, with emphasis on precision predictions including next-to-leading order (NLO) corrections from the strong and electroweak interactions. In the first part of the thesis we consider the top quark charge asymmetry. In particular, we discuss in detail the calculation of the electroweak contributions from the asymmetric part of the top quark pair production cross section at O(α 2 s α) and O(α 2 ) and their numerical impact on predictions for the asymmetry measurements at the Tevatron. These electroweak contributions provide a non-negligible addition to the QCD-induced asymmetry with the same overall sign and, in general, enlarge the Standard Model predictions by a factor around 1.2, diminishing the deviations from experimental measurements. In the second part of the thesis we consider the production of squarks, the supersymmetric partners of quarks, at the Large Hadron Collider (LHC). We discuss the calculation of the contribution of factorizable NLO QCD corrections to the production of squark-squark pairs combined at fully differential level with squark decays. Combining the production process with two different configurations for the squark decays, our calculation is used to provide precise phenomenological predictions for two different experimental signatures that are important for the search of supersymmetry at the LHC. We focus, for one signature, on the impact of our results on important physical differential distributions and on cut-and-count searches performed by the ATLAS and CMS collaborations. Considering the other signature, we analyze the effects from NLO QCD corrections and from the combination of production and decays on distributions relevant for parameter determination. In general, factorizable NLO QCD corrections have to be taken into account to obtain precise phenomenological predictions for the analyzed distributions and inclusive quantities. Moreover

Mass measurement of right-handed scalar quarks and time measurement of hadronic showers for the compact linear collider

CERN Document Server

Weuste, Lars

The Compact Linear Collider (CLIC) is a concept for a 48.3km long e+ e- accelerator with a center-of-mass energy of 3TeV. Its purpose is the precise measurement of particles discovered by the LHC as well as the discovery of yet unknown particles. The International Large Detector (ILD) is one of its detector concepts which was specifically designed for the usage of the Particle Flow Algorithm. This thesis is divided into two parts, both within the context of CLIC. In the first part of this thesis the unprecedented measurement on time structure of hadronic showers in calorimeters with tungsten absorber material, which is used in the ILD concept for CLIC, will be presented. It shows the development and the construction of a small testbeam experiment called Tungsten Timing Testbeam (T3B) which consists of only 15 scintillator tiles of 30mm x 30mm x 5mm, read out with Silicon Photomultipliers which in turn were connected to USB oscilloscopes. T3B was placed downstream of the CALICE tungsten analog hadron calorimet...

Physics at a future collider beyond the LHC and a TeV class linear collider

CERN Multimedia

CERN. Geneva

2003-01-01

After the LHC will have probed the physics at the TeV frontier, new generations of colliders capable of reaching into the multi-TeV energy domain will need to be considered. Concepts for both high energy e+e- linear colliders and muon storage rings have been proposed as well as hadron colliders. Highly challenging R&D programs are presently pursued to demonstrate their principles. The definition of a physics programme in the multi-TeV range still requires essential data that is likely to become available only after the first years of LHC operation and, possibly, also the results from a TeV-class linear collider. At present we have to envisage several possible scenarios for the fundamental questions to be addressed by collider experiments in the next decade, to guide the choices in the accelerator designs and parameters. After a brief review of the main accelerator projects and the present status of their R&D, I shall discuss the main signatures of the physics of possible relevance in relation to the e...