Non-inclusive Searches for Squarks and Gluinos at the Tevatron

Non-inclusive Searches for Squarks and Gluinos at the Tevatron PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 3

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Book Description
Recent results from the CDF and D0 Collaborations on searches for squarks and gluinos at the Run II of the Fermilab Tevatron collider are presented. This review covers searches for final states involving specific mass hierarchies. The analyzed datasets correspond to an integrated luminosity of 300-1000 pb−1 collected from proton anti-proton collisions at a center-of-mass energy of 1.96 TeV. No significant deviations from the Standard Model expectations are observed and limits on parameters of supersymmetry are set in generic MSSM and in specific mSUGRA scenarios.

Non-inclusive Searches for Squarks and Gluinos at the Tevatron

Non-inclusive Searches for Squarks and Gluinos at the Tevatron PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 3

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Book Description
Recent results from the CDF and D0 Collaborations on searches for squarks and gluinos at the Run II of the Fermilab Tevatron collider are presented. This review covers searches for final states involving specific mass hierarchies. The analyzed datasets correspond to an integrated luminosity of 300-1000 pb−1 collected from proton anti-proton collisions at a center-of-mass energy of 1.96 TeV. No significant deviations from the Standard Model expectations are observed and limits on parameters of supersymmetry are set in generic MSSM and in specific mSUGRA scenarios.

Inclusive Search for Squarks and Gluinos Production at CDF.

Inclusive Search for Squarks and Gluinos Production at CDF. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 4

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Book Description
Abstract: We present preliminary results on a search for squarks and gluinos in proton-antiproton collisions with a center-of-mass energy of 1.96 TeV and based on 1.1 fb-1 of data collected by the CDF detector in the Tevatron Run II. Events with multiple jets of hadrons and large missing transverse energy in the final state are studied within the framework of minimal supergravity and assuming R-parity conservation. No excess with respect to Standard Model predictions is observed and new limits on the gluino and squark masses are extracted.

Fundamental Interactions - Proceedings Of The 23rd Lake Louise Winter Institute 2008

Fundamental Interactions - Proceedings Of The 23rd Lake Louise Winter Institute 2008 PDF Author: Alan Astbury
Publisher: World Scientific
ISBN: 981446709X
Category : Science
Languages : en
Pages : 429

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Book Description
This book contains pedagogical lectures on both theoretical and experimental particle physics, cosmology, and atomic trap physics. Numerous additional contributions provide up-to-date information on new experimental results from accelerators, underground laboratories, and nuclear astrophysics. This combination of pedagogical talks and topical short discussions presents a comprehensive amount of information and latest developments to researchers.

Searches for New Physics at Colliders

Searches for New Physics at Colliders PDF Author: My Phuong Thi Le
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 277

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Book Description
The turning-on of the Large Hadron Collider is the momentous milestone in our quest for new physics beyond the Standard Model. Soon, we will be presented with the task of detecting, identifying, and studying the possibly large parameter space of the underlying model. In this thesis, we will look at some possible extensions to the SM, their signatures at colliders, and possible search strategies to explore the new physics in a model-independent way. In chapter 2, we study the extended neutral gauge sector of the Littlest Higgs model at the 500 GeV e+e- collider using the fermion pair production and Higgs associate production channel. We find that these channels can provide an accurate determination of the fundamental parameters and thus allows the verification of the little Higgs mechanism designed to cancel the Higgs mass quadratic divergence. In chapter 3, we study the ATLAS supersymmetry searches proposed for the 14 TeV pp collider using the $\sim$ 70k models of the phenomenological Minimal Supersymmetric Model (pMSSM) moldel set, that have survived many theoretical and experimental constraints. Since pMSSM does not make any simplifying assumptions about its SUSY-breaking mechanism at high scale, this encompasses a broad class of Supersymmetric models. We find that even though these searches were optimized mostly for mSUGRA signals, they are relatively robust in observing the more general pMSSM models. For the case of models in which squarks and gluinos have mass below 1 TeV, essentially all of these models ($> 99\%$) were observable in at least one of these searches, with 1 $fb^{-1}$ of integrated luminosity allowing for an uncertainty of 50\% in the SM background. We found that 0-lepton searches are the most powerful searches, while searches with 1-2 leptons do not have coverage as good as has been shown for mSUGRA. We then study possible reasons why a model could not be observed. These difficult models mostly include those with long-lived charginos which lead to small Missing Tranverse Energy (MET) and models with squeezed spectra which lead to soft jets that fail the jet cuts. In chapter 4, we study similar searches that have been carried out by ATLAS at the 7 TeV LHC. We found that systematic uncertainty again plays an important role in determining the coverage of the searches. This is especially true for searches with a large SM background, such as $n$-jet 0 lepton searches. We study the implication of a null result from the 7 TeV LHC. We find that the degree of fine-tuning in the pMSSM depends on the prior in which we scan our 19-dimensional space, but overall it is not as large as in mSUGRA. We find that a null result at the 7 TeV with $10 fb^{-1}$ and 20\% systematic errors would imply a need for a higher energy e+e- machine than the 500 GeV ILC to study Supersymmetry. Continuing on along the line of Supersymmetry, in chapter 5 we explore the possibility of adding one more generation to the MSSM (4GMSSM). We find that the CP-odd A boson can be very light due to the contribution of the heavy 4th generation fermion loops while all other Higgs particles (including the CP-even {\it h}) are all quite heavy. The parameter $tan(\beta)$ is strongly constrained to be between 0.5 and 2 due to perturbativity requirements on Yukawa couplings. We study the electroweak constraints as well as collider signatures on the possibility of a light A of mass $\sim$115 GeV. As for an LHC discovery, we find that this light A can be seen in the standard 2-photon Higgs search channel with cross-section more than an order of magnitude greater than that of the SM Higgs. In the last two chapters, we study possible search strategies to explore the new physics in a model-independent way. In chapter 6, we attempt to show how one could be largely agnostic about the underlying model in exploring the complete kinematically-allowed parameter space of pair-produced color octet particles (with mass $m_{\tilde{g}}$) that each directly decay into two jets plus a neutral stable particle (with mass $m_{\tilde{B}}$) that would escape the detectors and appear as MET. The kinematics of this process can be completely described by two parameters $m_{\tilde {g}}$ and $m_{\tilde {B}}$ , and in particular their splitting determines the softness or hardness of jets from the decay products. In order to cover the whole parameter space, one would need separate searches for different regions. We show that optimizing the final cuts for every ($m_{\tilde {g}}$, $m_{\tilde {B}}$) point, and combining all searches, can extend the coverage significantly. Since this is just based on the kinematics of the decay, this result can be easily interpreted for any model with this decay topology. In chapter 7, we carry this model-independent approach further in jets plus missing energy searches, by proposing that one should bin the measured data (or simulated SM background) differentially in MET and $H_T$ (scalar sum of invisible energy) for each search, and use them to set limits on any model of interest. We demonstrate this technique by carrying out a search similar to that studied in chapter 6, with one added decay step for the color octet particle, mainly it decays to 2 jets and another particle (with mass $m_{\tilde {W}}$) and it in turn decays to the neutral stable particle and 2 jets. We study different kinematic regions and set bounds in this 3-dimensional parameter space ($m_{\tilde {g}}$, $m_{\tilde {W}}$, $m_{\tilde {B}}$).

High Energy Physics

High Energy Physics PDF Author:
Publisher: World Scientific
ISBN: 981447651X
Category :
Languages : en
Pages : 81

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Book Description


Fundamental Interactions

Fundamental Interactions PDF Author: A. Astbury
Publisher: World Scientific
ISBN: 9814280941
Category : Science
Languages : en
Pages : 429

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Book Description
This book contains pedagogical lectures on both theoretical and experimental particle physics, cosmology, and atomic trap physics. Numerous additional contributions provide up-to-date information on new experimental results from accelerators, underground laboratories, and nuclear astrophysics. This combination of pedagogical talks and topical short discussions presents a comprehensive amount of information and latest developments to researchers. Sample Chapter(s). Chapter 1: New Physics and the LHC (9,214 KB). Contents: New Physics and the LHC (G Altarelli); Very High Energy Cosmic Rays: Results from the Pierre Auger Observatory (C E Covault); Neutrinos at Lake Louise (S Davidson); Physics Impact of the Tevatron (D C O''Neil); Cosmology and the LHC (V Rubakov); CMK Angle Measurements from BABAR (J M Anderson); An Overview of Top Quark Analyses from the CMS Collaboration (J Andrea); Heavy Quark Production at HERA and Heavy Quark Contributions to the Proton Structure Function (D Bartsch); ATLAS Commissioning and Physics with Early Data (P J Bell); Search for Heavy Stable Charged Particles at CMS (J Chen); A High-Sensitivity Search for Charged Lepton Flavor Violation at Fermilab (E C Dukes); Prospects for CP Violation Studies at LHCb (V V Gligorov); Measurements of a 3 () at Belle (Y Horii); High P T Jets and Photons at Dy (Z Hubacek); SUSY Search at ATLAS (Y Kataoka); Neutrino Physics with the IceCube Detector (J Kirkyluk); Determination of the Strong Phase in D 0 OaAE K + C - Using Quantum-Correlated Measurements (A Lincoln); Results on Top Quark Physics at Dy (Y Peters); Quarkonium Production and Polarisation with Early Data at ATLAS (D D Price); and other papers. Readership: Graduate students, researchers and academics in high energy physics (HEP), astrophysics and atomic physics."

From The Tevatron To The Lhc: Physics At Large Accelerators - Proceedings Of The Xxiv International Meeting On Fundamen

From The Tevatron To The Lhc: Physics At Large Accelerators - Proceedings Of The Xxiv International Meeting On Fundamen PDF Author: Antonio Ferrer
Publisher: World Scientific
ISBN: 9814546380
Category :
Languages : en
Pages : 234

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Book Description
This book collects a series of papers presented at the XXIV International Meeting on Fundamental Physics. This annual conference is devoted to reviewing current topics in the field of high energy physics. From the Tevatron to the LHC reviews the present status of experiments at large accelerators (Tevatron, LEP, LHC) and deals with selected subjects like CP violation, B physics, glueballs, neutrinos and supersymmetry.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704

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Book Description


The Search for Squarks, Gluinos and Stop Squarks in

The Search for Squarks, Gluinos and Stop Squarks in PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description


Search for Squarks and Gluinos in

Search for Squarks and Gluinos in PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description