Prospects for B physics with the ATLAS and CMS detectors

The possibility of observing the radion using the ATLAS detector at the LHC is investigated. Studies on searches for the Standard Model Higgs with the ATLAS detector are re-interpreted to obtain limits on radion decay to γγ and ZZ^(*). The observability of radion decays into Higgs pairs, which subsequently decay into or is then estimated.     

Heavy ion physics with CMS

The European Physical Journal C - The study of ultra-relativistic nuclear collisions with CMS is reviewed. The ability of the detector to function in the resulting high multiplicity environment is...     

Heavy ion physics with the ATLAS detector

The European Physical Journal C - Recent results from RHIC experiments suggest that a hot and dense QCD matter, which maybe the quark gluon plasma (QGP), is formed in Gold+Gold collisions at a...     

Visions: The coming revolutions in particle physics

We study the branching ratio, CP-violating asymmetry, forward-backward asymmetry and the CP-violating asymmetry in the forward-backward asymmetry for the exclusive decay B → Kτ⁺τ⁻ in the two Higgs doublet model with tree level flavor changing neutral currents (model III). We analyse the dependencies of these quantities on the neutral Higgs boson contributions and the CP parameter sinθ in the model III. We observe that to determine the neutral Higgs boson effects, the measurements of the forward-backward asymmetry and the CP-violating asymmetry in the forward-backward asymmetry for the decay B → Kτ⁺τ⁻ are promising.     

Electroweak and CP violation physics at a Linear Collider Z-factory

A future linear collider such as TESLA may be able to run on the Z⁰ resonance with very high luminosity and polarised electron and positron beams. The possibilities of measuring electroweak quantities with high precision are investigated. Huge improvements with respect to the present precision can be expected, especially for the asymmetries A_LR and where beam polarisation can be exploited. The very large sample of events also allows studies of various CP-violating b decays. The precision achievable on the CKM unitarity triangle angles is comparable to experiments at b factories and future hadron colliders.     

Heavy ion physics withthe ATLAS detector

Soon after the LHC is commissioned with proton beams the ATLAS experiment will begin studies of Pb-Pb collisions with a center of mass energy of $\sqrt {s_{NN} } = 5.5$ TeV. The ATLAS program is a natural extension of measurements at RHIC in a direction that exploits the higher LHC energies and the superb ATLAS calorimeter and tracking coverage. At LHC energies, collisions will be produced with even higher energy density than observed at RHIC. The properties of the resulting hot medium can be studied with higher energy probes, which are more directly interpreted through modification of jet properties emerging from these collisions, for example. Other topics which are enabled by the 30-fold increase in center of mass energy include probing the partonic structure of nuclei with deep inelastic photoproduction (in UltraPeripheral Collisions) and in p-Pb collisions. Here we report on evaluation of ATLAS capabilities for Heavy Ion Physics.     

CMS: Jet/b,Jet/<Emphasis Type="Italic">τ</Emphasis>, Missing E<Subscript>T</Subscript>

It is often claimed [1] that the (Hodge type) duality operation is defined only in even dimensional spacetimes and that self-duality is further restricted to twice-odd dimensional spacetime theories. The purpose of this paper is to extend the notion of both duality symmetry as well as self-duality.By considering tensorial doublets, we introduce a novel well-defined notion of self-duality based on a duality Hodge-type operation in arbitrary dimension and for any rank of these tensors. Thus, a generalized Self-Dual Action is defined such that equations of motion are the claimed generalized self-duality relations. We observe in addition, that taking the proper limit on the parameters of this action, it always provides us with a master-action, which interpolates models well-studied in physics; by considering a particular limit, we find an action which describes an interesting type of relation, referred to as semi-self-duality, which results to be the parent action between Maxwell-type actions.Finally, we apply these ideas to construct manifest Hodge-type self-dual solutions in a (2+1)-dimensional version of the Maxwell’s theory.     

Dijet physics with CMS detector at the Large Hadron Collider

The results from various dijet distributions in proton?Cproton collisions at a centre-of-mass energy of 7 TeV, with 2010 and 2011 data from the CMS experiment, are presented. The measurements of the dijet mass spectra, centrality ratio, azimuthal decorrelation and angular distribution are shown. Sensitivity of the phenomenological parameters used to model different event generators is also investigated. Prospects for observing evidence for new physics in these distributions are presented.     

Frequentist and Bayesian confidence intervals

Frequentist (classical) and Bayesian approaches to the construction of confidence limits are compared. Various examples which illustrate specific problems are presented. The Likelihood Principle and the Stopping Rule Paradox are discussed. The performance of the different methods is investigated relative to the properties coherence, precision, bias, universality, simplicity. A proposal on how to define error limits in various cases are derived from the comparison. They are based on the likelihood function only and follow in most cases the general practice in high energy physics. Classical methods are not recommended because they violate the Likelihood Principle, they can produce inconsistent results, suffer from lack of precision and generality. Also the extreme Bayesian approach with arbitrary choice of the prior probability density or priors deduced from scaling laws is rejected.     

Possibility of the odderon discovery via observation of charge asymmetry in the diffractive π+π− production at HERA

It is shown that the energy deposition pattern in deep calorimeters could be the spectacular and unconventional signature of different kinds of stable and unstable strangelets. As an example the detection method of strongly penetrating objects, such as strangelets possibly produced in the baryon-rich environment formed in central Pb-Pb collisions at LHC energies, is described.     

Top-Antitop Pair Production Close to Threshold Synopsis of Recent NNLO Results

Using non-relativistic effective theories, new next-to-next-to-leading order (NNLO) QCD corrections to the total production cross section at the Linear Collider have been calculated recently. In this article the NNLO calculations of several groups are compared and the remaining uncertainties are discussed. The theoretical prospects for an accurate determination of top quark mass parameters are discussed in detail. An outlook on possible future improvements is given.     

Phenomenology of Stops, Sbottoms, τ-Sneutrinos, and Staus at an e + e − Linear Collider

We discuss production and decays of stops, sbottoms, -sneutrinos, and staus in e⁺e^– annihilation in the energy range s = 0.5-1TeV. We present numerical predictions within the Minimal Supersymmetric Standard Model for cross sections and decay rates, including one-loop radiative corrections as well as initial state radiation. We also study the importance of beam polarization for the determination of the underlying SUSY parameters. Moreover, we make a comparison of the potential to study squarks and sleptons of the 3rd generation between Tevatron, LHC, and Linear Collider.     

xF_3^{\gamma Z} in charged lepton scattering

Measurements of the structure function are now becoming available in charged lepton deep inelastic scattering at HERA. The correction factors which are necessary to compare these with measurements of in neutrino-nucleon scattering are deduced and a comparison is made between the H1 and the CCFR data. A sum rule is derived for the structure function measured in charged lepton scattering which is the analogue of the Gross Llewellyn-Smith sum rule for neutrino-nucleon scattering.     

Hadronic vacuum polarization contribution to the Lamb shift in muonic hydrogen

We report on the accuracy of the measurement of the total cross section of the process e⁺e^– ZH and of the Higgs boson mass that would be achieved in a linear collider operating at a centre-of-mass energy of 350 GeV, assuming an integrated luminosity of 500 fb^–1. For that we have exploited the recoil mass off the Z using its leptonic decays into electron and muon pairs. The Higgs mass is determined with 150 MeV accuracy, the recoil mass resolution is about 1.5 GeV and the cross section is obtained with a statistical error of 3%.     

Branching Fraction Measurements of the SM Higgs with a Mass of 160 GeV at Future Linear e + e − Colliders

Assuming an integrated luminosity of 500 fb^–1 and a center-of-mass energy of 350 GeV, we examine the prospects for measuring branching fractions of a Standard Model-like Higgs boson with a mass of 160 GeV at the future linear e⁺e^–collider TESLA when the Higgs boson is produced via the Higgsstrahlung mechanism, e⁺e^– HZ. The Higgs boson mass chosen close to the W pair threshold covers a mass regime with complicated background structures. We study in detail including some detector responds the precisions achievable for the branching fractions of the Higgs boson into WW^(*), ZZ^* and , whereas the measurement of BF(H ) remains a great challenge. Expectations for the total Higgs width are discussed using either the BF(Z ZZ^*) measurement of this study and the expected error for the inclusive Higgsstrahlung cross section or in addition the precise cross section expected for the weak boson fusion process, e⁺e^– v H, or W,Z-universality.     

Comparison of Higgs boson mass and width determination of the LHC and a linear collider

The method originally developed for the exact calculations in QED theory is applied for the calculation of NLO effects in QCD Compton processes. QCD corrections to the structure functions and sum rules are obtained. Different interpretations of the NLO effects due to finite quark mass are discussed.     

A preliminary search for Q-balls by delayed coincidences in NaI(Tl)

A preliminary search for Q-balls, stable non-topological solitons allowed by supersymmetric models, with highly radiopure NaI(Tl) detectors is discussed.     

Search for Z’ → WW at LHC with the ATLAS detector

The potential for measuring the Z‘WW coupling with the ATLAS detector at the LHC is investigated under conditions of low and high luminosity. It is estimated that detection of the decay channel Z’ → WW → lν _l jj is possible with 300 fb ⁻¹, for a Z’ boson with sequential model couplings and with a mass up to 2.2 TeV.     

A visualization of the SU(2) vacuum on the lattice

Configurations of pure SU(2) gauge field theory on lattice are transformed to Landau gauge. After Fourier transformation, large momentum amplitudes are suppressed (filtered) by a variable amount, and the configurations are transformed back to x-space. Spectacular peaks in electric and magnetic field strengths are found, which share many properties with either almost pointlike instantons or with extended anti-instantons. The environment around those peaks are visualized with respect to the action, to the topological charge density, to the gauge fields and to electric and magnetic field strengths. The density of the peaks is of order 1 fm^–4, and it scales according to the string tension under a variation of the coupling constant. The evolution of the peaks under the amount of Fourier filtering is visualy compared to the evolution under cooling, and the gauge dependence of the peaks is discussed. Advantages and shortcomings of this method are discussed, with emphasis on possible strong distortions of the action and topological charge density, which become gauge dependent. Finally, I compare the character of the SU(2)-configurations to those of noncompact abelian theory.