Search with the ATLAS detector for new physics with significant missing transverse energy and two isolated leptons

Results of searches for supersymmetry in events with significant missing transverse energy and two isolated leptons with the ATLAS experiment at the LHC are presented. Three analyses are presented here, the first two are analyses with leptons of opposite charge and same charge, respectively. The third one is an analysis that searches for an excess of same-flavour opposite-charge lepton pairs over those of different-flavour. Data corresponding to an integrated luminosity of 1 fb^?1 are analysed.     

B→0+(1+)+ missing energy in unparticle physics

We examine the effects of an unparticle U as a possible source of missing energy in the p-wave decays of a B meson. The dependence of the differential branching ratio on the K0* (K1) - meson's energy is discussed in the presence of scalar and vector unparticle operators and significant deviation from the standard model value is found after addition of these operators. Finally, we have shown the dependence of the branching ratio for the above-mentioned decays on the parameters of unparticle stuff like effective couplings, cutoff scale Au and the scale dimensions du.     

Optimal observable analysis for the decay $$b \rightarrow s$$ plus missing energy

The decay \(b\rightarrow s\nu {\bar{\nu }}\) has received comparatively less attention than the semileptonic decay \(b\rightarrow s\ell ^+\ell ^-\), because neutrinos pass undetected and hence the process offers lesser number of observables. We show how the decay \(b\rightarrow s~+\) invisible(s) can shed light, even with a limited number of observables, on possible new physics beyond the Standard Model and also show, quantitatively, the reach of future B factories like SuperBelle to uncover such new physics. Depending on the operator structure of new physics, different channels may act as the best possible probe. We show, using the optimal observable technique, how almost the entire parameter space allowed till now can successfully be probed at a high-luminosity B factory.     

New possibilities for testing local realism in high energy physics

The three photons from the dominant ortho-positronium decay and two vector mesons from the η_c exclusive decays are found to be in tripartite and high-dimensional entangled states, respectively. These two classes of entangled states possess the Hardy type nonlocality and allow a priori for quantum mechanics vs local realism test via Bell inequalities. The experimental realizations are shown to be feasible, and a concrete scheme to fulfill the test in experiment via two-vector-meson entangled state is proposed.     

Event-shape of dileptons plus missing energy at a linear collider as a supersymmetry/Arkani-Hamed-Dimopoulos-Dvali discriminant

An event-shape analysis of the dileptons in the process e ⁺ e ⁻ → ℓ⁺ℓ⁻ , studied in ILC or CLIC, can clearly discriminate between a supersymmetric or a large extra dimensional (ADD) production mechanism.      

Particle accelerator physics and technology for high energy density physics research

Interaction phenomena of intense ion- and laser radiation with matter have a large range of application in different fields of science, extending from basic research of plasma properties to applications in energy science, especially in inertial fusion. The heavy ion synchrotron at GSI now routinely delivers intense uranium beams that deposit about 1 kJ/g of specific energy in solid matter, e.g. solid lead. Our simulations show that the new accelerator complex FAIR (Facility for Antiproton and Ion Research) at GSI as well as beams from the CERN large hadron collider (LHC) will vastly extend the accessible parameter range for high energy density states. A natural example of hot dense plasma is provided by our neighbouring star the sun, and allows a deep insight into the physics of fusion, the properties of matter at high energy density, and is moreover an excellent laboratory for astroparticle physics. As such the sun's interior plasma can even be used to probe the existence of novel particles and dark matter candidates. We present an overview on recent results and developments of dense plasma physics addressed with heavy ion and laser beams combined with accelerator- and nuclear physics technology.     

Rotation curves of galaxies: Missing mass or missing physics

The rotation curves of galaxies are modelled using very special properties of an hydrodynamically turbulent fluid possessing helicity fluctuations. The development of correlations among these fluctuations leads to the formation of organized structures characterized by a new flat branch of the spatial energy spectrum in addition to the well known Kolmogorov spectrum. It is proposed that the flat nature of the rotation curves of galaxies may be a result of the energy cascading processes occuring in turbulent galactic atmospheres. Thus, in this model, there is no need of invoking dark matter to account for the flat rotation curves of galaxies.     

Search for large extra dimensions via single photon plus missing energy final states at sqrt s = 1.96 TeV

We report on a search for large extra dimensions in a data sample of approximately 1 fb(-1) of pp[over] collisions at sqrt s=1.96 TeV. We investigate Kaluza-Klein graviton production with a photon and missing transverse energy in the final state. At the 95% C.L. we set limits on the fundamental mass scale M(D) from 884 to 778 GeV for two to eight extra dimensions.     

Number theory meets high energy physics

Feynman amplitudes in perturbative quantum field theory are being expressed in terms of an algebra of functions, extending the familiar logarithms, and associated numbers—periods. The study of these functions (including hyperlogarithms) and numbers (like the multiple zeta values), that dates back to Leibniz and Euler, has attracted anew the interest of algebraic geometers and number theorists during the last decades. The two originally independent developments are recently coming together in an unlikely collaboration between particle physics and what were regarded as the most abstruse branches of mathematics.     

Wigner functions in high energy physics

Recent developments are (meta)reviewed in the applications of Wigner functions to describe the observed single-particle spectra and two-particle Bose-Einstein (or Hanbury Brown-Twiss) correlations in high energy particle and nuclear physics, with examples from hadron-proton and Pb+Pb collisions at CERN SPS.     

Recent developments in high energy physics

Recent results from experiments with solar, atmospheric and accelerator neutrinos are presented. Some of the important results from the LEP and TEVATRON colliders are summarised.     

Intermetallics: New physics

Intermetallic compounds, or 'intermetallics' for short, have received extensive attention in recent years because of their technological promise as high-temperature structural materials. This technical research has been accompanied by a programme of curiosity-driven research which has uncovered a number of novel physical features, beginning with a major burst of research on vacant lattice sites in certain intermetallics, and continuing with such phenomena as dislocation injection across phase boundaries, structural aspects of Laves phases and the use of an intermetallic to separate hydrogen isotopes. Some of these recent developments are surveyed here.     

New physics with beauty

We review the effects of new physics on CP asymmetries and decays of B mesons. Possible sources and corresponding signals for new physics are studied briefly. We discuss how the decay mode b → s ℓℓ (and B → K*ℓℓ) will enable us to understand the nature of new physics. We also examine the possibility of truly clean signature of new physics — a signature based on observables alone and without hadronic uncertainties.     

Silicon detector systems in high energy physics

Silicon sensors have been used in High Energy Physics for about 25 years. They have been continuously improved to meet new requirements and challenges. Based on a simple detection principle many different types of silicon sensors have been developed. This article gives an introduction to the basic properties of silicon sensors and the related readout electronics. Then several silicon sensor types are described, which are the building blocks of detectors for tracking and scintillator readout. Besides reviewing state of the art sensor types some new developments will be discussed. This includes extremely radiation hard sensors, novel sensors for photon counting and especially trends to integrate sensor and readout electronics into monolithic devices. Finally some selected examples of large detector systems in existing or planned experiments will be reviewed.     

Experimental aspects of high energy neutrino physics

Neutrino physics from the viewpoint of the high energy results from Fermilab are discussed. The high energy experiments are described and their results are discussed. The status of both the charged current reactions are reviewed in detail. Also, the important observations of topologies indicating new particle production by neutrinos are covered. Comparisons between results of different experiments are made where relevant.