<p>Next-to-minimal super-symmetric extensions of the Standard Model (SM) predict the existence of several non-SM like Higgs bosons. The process pp→a₁h^±→4b+W involves the production and the decay of a spin-0 charged Higgs boson and a CP-odd Higgs boson a₁ which can have a sizable cross section in the NMSSM. The invariant masses of these intermediate bosons can be reconstructed from the four momenta of the final state particles using mass minimization algorithms. This thesis presents a cut-based analysis of two mass scenarios and specialized algorithms that are capable of recovering the signal in a large background arising from Standard Model processes such as ttbar. The analysis is tested with a realistic ATLAS detector simulation investigating trigger efficiencies and probing several jet reconstruction algorithms.</p>

Next-to-minimal super-symmetric extensions of the Standard Model (SM) predict the existence of several non-SM like Higgs bosons. The process pp→a1h±→4b+W involves the production and the decay of a spin-0 charged Higgs boson and a CP-odd Higgs boson a1 which can have a sizable cross section in the NMSSM. The invariant masses of these intermediate bosons can be reconstructed from the four momenta of the final state particles using mass minimization algorithms. This thesis presents a cut-based analysis of two mass scenarios and specialized algorithms that are capable of recovering the signal in a large background arising from Standard Model processes such as ttbar. The analysis is tested with a realistic ATLAS detector simulation investigating trigger efficiencies and probing several jet reconstruction algorithms.

Die Arbeit beschäftigt sich mit Faltungsoperatoren auf Kegeln, die in Lebesgueräumen L^p(R^2) (1<p<\infty) von Funktionen auf der Ebene wirken. Es werden asymptotische Spektraleigenschaften der zugehörigen Finite Sections studiert. Im Falle p=2 (Hilbertraum) wird das Invertierbarkeitsproblem von Operatoren vom Faltungstyp auf Kegeln mit Hilfe der Methode der Standard-Modell-Algebren untersucht.

High-precision half-life and branching-ratio measurements for the superallowed beta+ emitter 26Alm were performed at the TRIUMF-ISAC radioactive ion beam facility located in Vancouver, Canada. The branching ratio measurement was performed with the 8pi Spectrometer, an array of 20 high-purity germanium detectors, in conjunction with SCEPTAR, a plastic scintillator array used to detect the emitted beta particles. An upper limit of <= 12 ppm at 90% confidence level was found for the second forbidden beta + decay of 26Alm to the first 2+ state at 1809 keV in 26Mg. An inclusive upper limit of <= 15 ppm at 90% confidence level was found when considering all possible non-analogue beta +/EC decay branches of 26Alm, resulting in a superallowed branching ratio of 100.0000+0−0.0015%. The half-life measurement was performed using a 4pi continuous-flow gas proportional counter and fast tape transport system. The resulting value for the 26Alm half-life, T1/2 = 6.34654(76) s, is consistent with, but 2.5 times more precise than, the previous world average, and represents the single most precisely measured half-life of any superallowed emitting nucleus to date. Combining these results with world-average Q-value measurements yields a superallowed beta -decay ft value of 3037.58(60) s, the most precisely determined ft value for any superallowed emitting nucleus to date. Combined with the small, and precisely quoted, theoretical isospin-symmetry-breaking corrections for this nucleus, the corrected Ft value for 26Alm of 3073.1(12) s is also the most precisely determined for any superallowed emitter by nearly a factor of two and now rivals the precision of all the other 12 precisely measured superallowed beta decays combined. The high-precision experimental ft value for 26Alm superallowed decay reported here provides a new benchmark to refine theoretical models of isospin-symmetry-breaking effects in superallowed Fermi beta decays.

No description available.

In this thesis, using a general model independent form of the effective Hamiltonian, the CP-violating asymmetries in the b -&gt / d l l transition, when one of the leptons is polarized, is investigated. The sensitivity of the CP-violating asymmetries on the new Wilson coefficients are analyzed. Next, in the frame work of the same formalism, the polarized lepton pair forward&amp / #8211 / backward asymmetries in B-&gt / K l l decay are studied. We present the general expression for the nine double&amp / #8211 / polarization forward&amp / #8211 / backward asymmetries. It is obtained that, the zero point position of the forward&amp / #8211 / backward asymmetries of the doubly&amp / #8211 / polarized lepton pair does not depend on long distance effects but depends on short distance dynamics. Furthermore, it is shown that the zero position of AFB is very sensitive to the sign of the new Wilson coefficients. When sign of the Wilson coefficients is positive (negative) the zero position of the forward&amp / #8211 / backward asymmetries shifts to the left(right) compared to the SM. Moreover, the dependencies of the nine double&amp / #8211 / polarization forward&amp / #8211 / backward asymmetries on new Wilson coefficients, and the correlation of the averaged nine double&amp / #8211 / polarization forward&amp / #8211 / backward asymmetries with branching ratio, have been studied. It is observed that, the study of the nine double&amp / #8211 / polarization forward&amp / #8211 / backward asymmetries can serve as a good test in establishing new physics beyond the Standard Model. Finally, we observed that there are exist such regions of new Wilson coefficients for which the nine double&amp / #8211 / polarization forward&amp / #8211 / backward asymmetries considerably depart from the SM result, while the branching ratio coincides with that of the SM prediction. In other words, new physics effects can be established by analyzing polarized forwardbackward asymmetry in this region of the new Wilson coefficients.

Thesis (Ph.D.)--Michigan State University. Dept. of Physics, 2008. / Title from PDF t.p. (viewed on Mar. 27, 2009) Includes bibliographical references (p. 216-218). Also issued in print.

Thesis (M.A.) - Carleton University, 2003. / Includes bibliographical references (p. 219-224). Also available in electronic format on the Internet.

Thesis (M.Sc.) - Carleton University, 2008. / Includes bibliographical references (p. 75-79). Also available in electronic format on the Internet.

Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: Qaisar Shafi, Dept. of Physics & Astronomy. Includes bibliographical references.