Search for quark compositeness at LHC: Dijet angular distributions

Effects of dijet angular distributions coming from a model of quark compositeness are presented. The influence of the parton distribution, calorimeter nonlinearity, and energy resolution is investigated. The sensitivity of data to the quark-compositeness scale for a low and a high LHC luminosity is studied.     

Search for Majoron at the COMET experiment

A new Goldstone particle named Majoron is introduced in order to explain the origin of neutrino mass via some new physics models assuming that neutrinos are Majorana particles. By expanding the signal region and using likelihood analysis, it becomes possible to search for Majoron using experiments originally designed to search for begin{document}$ mu-e $end{document} conversion. For the COMET experiment, the sensitivity of process begin{document}$ mu rightarrow eJ $end{document} is able to reach begin{document}$ {cal{B}}(mu rightarrow eJ)=2.3times 10^{-5} $end{document} in Phase-I and begin{document}$ O(10^{-8}) $end{document} in Phase-II. Meanwhile, the sensitivities to search for Majoron in future experiments are also discussed in this article.     

Search for magnetic monopoles with the nuclear track detector of the MACRO experiment at gran SASSO

In this paper the limits are presented which were obtained by the search for magnetic monopoles using the MACRO track-etch subdetector as a stand alone detector. We compare the flux upper limit for g = g_D monopoles to other limits obtained by different subdetectors of MACRO, till August 1, 1995, when the construction of the apparatus was completed. The global MACRO monopole limit is compared with other limits from different experiments.     

A high-performance silicon tracker for the Compressed Baryonic Matter experiment at FAIR

The Compressed Baryonic Matter (CBM) experiment is a fixed-target heavy-ion experiment planned at GSI's future international Facility for Antiproton and Ion Research (FAIR). CBM will study strongly interacting matter at high baryon densities where the QCD phase diagram is poorly known. The experiment applies a detector concept new to heavy-ion physics: All charged particles as well as secondary vertices from heavy-flavor decays are exclusively reconstructed in a high-performance silicon tracking system. It will be installed in a magnetic dipole field between the target and further detection systems for particle identification and calorimetry. High track densities and high collision rates require the application of most advanced silicon detectors. The technological challenges include high position resolution in thinnest possible pixel and microstrip sensors, combined with extreme radiation hardness, fast self-triggered readout and ultra low-mass mechanical supports. The article outlines the physics and detector concept of CBM and discusses the performance requirements of the silicon tracker and the beginning R&D. for the CBM collaboration Presented in the Poster Session “Future Experiments and Facilities” at the 18th International Conference “Quark Matter 2005”, Budapest, Hungary, 4–9 August 2005.     

The MTV experiment: searching for T-violation in polarized Li-8 at TRIUMF

The MTV experiment (Mott Polarimetry for T-Violation Experiment) is running at TRIUMF, to search for a large T-violating transverse electron-polarization in polarized ⁸Li β-decay. We aim at reaching precision of 10^?4 for the R-correlation, which is defined as a T-violating triple vector correlation in the β-decay rate function. A Mott polarimeter system using a CDC (Cylindrical Drift Chamber) is used to measure the left-right scattering asymmetry in the Mott scattering from a thin metal foil. In the present study, we aim to discuss systematic effects in Mott polarimetry using the CDC.     

Search for weakly interacting sub-eV particles with the OSQAR laser-based experiment: results and perspectives

Recent Planck measurements show some CMB anomalies on large angular scales, which confirms the early observations by WMAP. We show that an inflationary model, in which before the slow-roll inflation the Universe is in a superinflationary phase, can generate a large-scale cutoff in the primordial power spectrum, which may account for not only the power suppression on large angular scales, but also a large dipole power asymmetry in the CMB. We discuss an implementation of our model in string theory.     

The LPCTrap experiment: measurement of the β–ν angular correlation in 6He using a transparent Paul trap

We report on the status of the LPCTrap experiment, devoted to measure the β–ν angular correlation in the pure Gamow–Teller decay of ⁶He. This measurement is motivated by the search for the presence of tensor type contributions to the weak interaction. The ⁶He ions are confined in a novel transparent Paul trap. The β particles and the recoil ions are detected in coincidence to deduce the angular correlation parameter. The commissioning run performed in 2005 has given the proof of principle of this experiment. Up to 10⁵ coincidences were recorded during a second run in 2006.     

The inversion procedure for nuclear scattering problems from phase shifts at fixed angular momentum

The inverse scattering problem is solved for fixed angular momentum by using energy-dependent phases and a Povzner-Levitan representation of the wave function. In order to test the proposed method we show the inversion of phase shifts corresponding to repulsive square-well potentials and an optical Woods-Saxon potential. The parameters of the scattering problem are taken the same as in nuclear heavy-ion scattering.     

Search for anomalous and exotic cosmic rays phenomena in the CMS experiment on the CASTOR calorimeter at the large hadron collider

The creation of the CASTOR forward calorimeter in the compact muon spectrometer (CMS) experiment at the Large Hadron Collider (LHC), CERN enabled us to perform experiments at energies corresponding to those of cosmic rays but at much greater intensities, the most important factor in studying rare and anomalous phenomena.     

Nonuniform character of the population of spin projections K for a fissile nucleus at the scission point and anisotropies in the angular distributions of fragments originating from the induced fission of nuclei

It is shown that the emergence of anisotropies in the angular distributions of fragments originating from the spontaneous and induced fission of oriented actinide nuclei is possible only if nonuniformities in the population of the projectionsM (K) of the fissile-nucleus spin onto the z axis of the laboratory frame (fissile-nucleus symmetry axis) appear simultaneously in the vicinity of the scission point but not in the vicinity of the outer saddle point of the deformation potential. The possibilities for creating the orientation of fissile nuclei for spontaneous and induced fission and the effect of these orientations on the anisotropies under analysis are considered. The role of Coriolis interaction as a unique source of the mixing of different-K fissile-nucleus states at all stages of the fission process is studied with allowance for the dynamical enhancement of this interaction for excited thermalized states of the nucleus involved that is characterized by a high energy density. It is shown that the absence of thermalization of excited states of the fissile nucleus that appear because of the effect of nonadiabaticity of its collective deformation motion in the vicinity of the scission point is a condition of conservation of the influence that transition fission states formed at the inner and outer fission barriers exerts on the distribution of the spin projections K for lowenergy spontaneous nuclear fission. It is confirmed that anisotropies observed in the angular distributions of fragments originating from the fission of nuclei that is induced by fast light particles (multiply charged ions) are due to the appearance of strongly excited equilibrium(nonequilibrium) states of the fissile nucleus in the vicinity of its scission point that have a Gibbs (non-Gibbs) distribution of projections K.     

Search for quark compositeness at the LHC: Transverse-energy distributions of jets

Quark substructure effects that should manifest themselves at LHC energies are examined. The inclusive jet transverse-energy spectrum as would be observed by the ATLAS detector is predicted. The effect of the choice of parton distribution function and calorimeter nonlinearity on the compositeness effect is studied. The sensitivity of data to the quark-compositeness scale for low and high LHC luminosity is discussed.     

58Ni: an unpaired band crossing at new heights of angular momentum for rotating nuclei

High-spin states in 58Ni have been investigated by means of the fusion-evaporation reaction 28Si(32S, 2p)58Ni at 130 MeV beam energy. Discrete-energy levels are observed in 58Ni at record-breaking 42 MeV excitation energy and angular momenta in excess of 30h. The states form regular rotational bands with unprecedented high rotational frequencies. A comparison with configuration dependent cranked Nilsson-Strutinsky calculations reveals an exceptional two-band crossing scenario, the interaction strength of which is strongly shape dependent.     

Double Chooz project: Status of a reactor experiment aimed at searches for neutrino oscillations

Double Chooz is an experiment that is devoted to searches for reactor-antineutrino oscillations at the CHOOZ nuclear power plant. This project is aimed at measuring the unknown mixing angle θ ₁₃. It is assumed that the value of θ ₁₃ will be extracted from an analysis of the distortion of the antineutrino spectra obtained in relative measurements at two distances from the nuclear reactors by means of two identical detectors. The method makes it possible to minimize systematic errors of the experiment and to improve the sensitivity to the sought parameter. To date, the most stringent constraint on the parameter θ ₁₃ was obtained from the CHOOZ experiment in 1995–1997 [sin²(2θ ₁₃) < 0.19, with the difference of the squares of the neutrino masses being Δm ₁₃ ² = 2.5 × 10^?3 eV²].     

Using clathrate hydrates for gas storage and gas-mixture separations: experimental and computational studies at multiple length scales

ABSTRACT

Clathrate hydrates have characteristic properties that render them attractive for a number of industrial applications. Of particular interest are the following two cases: (i) the incorporation of large amounts of gas molecules into the solid structure has resulted in considering hydrates as possible material for the storage/transportation of energy or environmental gases, and (ii) the selective incorporation of guest molecules into the solid structure has resulted in considering hydrates for gas-mixture separations. For the proper design of such industrial applications, it is essential to know accurately a number of thermodynamic, structural and transport properties. Such properties can either be measured experimentally or calculated at different scales that span the molecular scale-up to the continuum scale. By using clathrate hydrates as a particular case study, we demonstrate that performing studies at multiple length scales can be utilised in order to obtain properties that are essential to process design.     

3D H2BC: A novel experiment for small-molecule and biomolecular NMR at natural isotopic abundance

3D H2BC is introduced for heteronuclear assignment on natural abundance samples even for biomolecules up to at least 10 kDa in low millimolar concentrations as an overnight experiment using the latest generation of cryogenically cooled probes. The short pulse sequence duration of H2BC is maintained in the 3D version due to multiple use of the constant-time delay. Applications ranging from a small lipid to a non-recombinant protein demonstrate the merits of 3D H2BC and the ease of obtaining assignments in chains of protonated carbons.     

Search for new physics in dijet mass and angular distributions in pp collisions at {\boldsymbol{\sqrt{\boldsymbol{s}}} \boldsymbol{=} {\bf 7}} TeV measured with the ATLAS detector

We present a search for physics beyond the Standard Model in proton?Cproton collisions at a centre-of-mass energy of $\sqrt{s} = {7}\;{\rm{TeV}}$ , performed with the ATLAS detector at the Large Hadron Collider (LHC). No evidence for new physics is found in dijet mass and angular distributions and stringent limits are set on a variety of models of new physics, including excited quarks, quark contact interactions, axigluons, and quantum black holes.