Being a flavor changing neutral current process, inclusive semileptonic B- meson decays provide reliable testing grounds for the Standard Model at the loop level. They are also importanat in the CKM phenomology and investing the CP violation due to the existence of sizable interference terms in the decay amplitude. In this work , the rare inclusive semileptonic B- meson decays for (lepton is electron ,muon , tau) are investigated in the context of the Standard Model.The differential branching ratio, forward-backward asymmetry ,CP &ndash / violating asymmetry and CP &ndash / violating asymmetry in the forward-backward asymmetry in these processes are examined.The dependencies of these physical parameters on the Standard Model parametres are analyzed by paying a special attention to the long distance effects. Although the branching ratios predicted for the inclusive semileptonic B- meson decays are relatively small because of CKM suppression , it has been found that there is a significant ACP and ACP(AFB) for these processes.

Using the general, model indepenent form of the effective Hamiltonian, the general expressions of the longitudinal, normal and transversal polarization asymmetries for l+ and l- for the effective B -&gt / K(K*)l+l- decays has been calculated. Existence of regions of Wilson coefficients for which the branching ratio coincides with the Standard Model result, while the lepton polarizations differ from the standard model prediction is expected. Hence, studying lepton polarizations in these regions of Wilson coefficients may be helpful in establishing new physics beyond standard model.

We use a global fit to determine the form factor slopes and branching fractions of the decays B --> Dlnu and B --> D*lnu. We reconstruct Dl pairs and construct a 3-dimensional distribution binned in lepton momentum, D momentum and cosTheta(B-Dl). These kinematic variables provide good separation between the signal and background. We fit electron and muon samples separately and combine them after calculating systematic uncertainties. The form factor slopes, rhoD^2 for B --> Dlnu and rho^2 for B --> D*lnu decays, are measured to be rhoD^2 = 1.22 +- 0.04 +- 0.07 and rho^2 = 1.21 +- 0.02 +- 0.07, where the errors are statistical and systematic, respectively. Branching fractions are fitted to be B(B+ --> D0lnu) = (2.36 +- 0.03 +- 0.12) % and B(B^+ --> D*0lnu) = (5.37 +- 0.02 +- 0.21) %. We use these results to determine the products, G(1)|Vcb| = (43.8 +- 0.8 +- 2.3)*10^{-3} and F(1)|Vcb| = (35.7 +- 0.2 +- 1.2)*10^{-3} of the form factors at zero recoil and the CKM matrix element |Vcb|, from which |Vcb| can be extracted using theoretical input.

No description available.

La masse du quark top est un paramètre fondamental du Modèle Standard de la physique des particules. L'un des défis du programme de physique du LHC, où le quark top est produit en abondance, est la détermination précise de ce paramètre. Actuellement, il est mesuré via la reconstruction directe de tous les produits de désintégration du quark top. L'incertitude systématique sur la calibration en énergie des jets et sur l'étiquetage de quarks b limite grandement la précision de cette mesure et il est donc indispensable de développer des mesures alternatives. Une possibilité très prometteuse – jusque-là jamais exploitée – est l'étude de désintégrations de paires de quarks top, où l'un des deux quarks se désintègre dans le canal leptonique avec un J/psi créé lors de la fragmentation du quark b. La masse du quark top est extraite à travers sa corrélation à la masse invariante de la combinaison du J/psi et du lepton chargé. Cette méthode présente l'avantage de n'utiliser que des leptons chargés, dont l'énergie-impulsion est mesurée avec une grande précision dans le détecteur CMS / The top quark mass is a fundamental parameter of the Standard Model of Particle Physics. One of the challenges in the LHC physics case, where the top quark is produced in abundance, is the precise determination of this parameter. Currently, it is measured through the direct reconstruction of all the top quark decay products. The systematic uncertainty on the jet energy calibration and b tagging sensibly limits the precision on this measurement and it is thus vital to develop alternative measurements. A very promising possibility – never exploited until now – is the study of top pair decays, where one of the two quarks decays in the leptonic channel with a J/psi created in the b quark fragmentation. The top quark mass is extracted through its correlation to the invariant mass of the J/psi-charged lepton combination. This method presents the advantages of using charged leptons only, whose energy momentum is measured with great accuracy in the CMS detector

The environment inside the atomic nucleus is one of the most fascinating arenas for the study of quantum chromodynamics (QCD). The strongly-interacting nature of the nuclear medium affects the nature of both QCD processes and the quark-gluon structure of hadrons, allowing several unique aspects of the strong nuclear force to be investigated in reactions involving nuclear targets. The research presented in this dissertation explores two aspects of nuclear QCD: firstly, the partonic structure of the nucleus itself; and secondly, the use of the nucleus as a micro-laboratory in which QCD processes can be studied. The partonic structure of the nucleus is calculated in this work by deriving and utilizing a convolution formula. The hadronic structure of the nucleus and the quark-gluon structure of its constituent nucleons are taken together to determine the nuclear partonic structure. Light cone descriptions of short range correlations, in terms of both hadronic and partonic structure, are derived and taken into account. Medium modifications of the bound nucleons are accounted for using the color screening model, and QCD evolution is used to connect nuclear partonic structure at vastly different energy scales. The formalism developed for calculating nuclear partonic structure is applied to inclusive dijet production from proton-nucleus collisions at LHC kinematics, and novel predictions are calculated and presented for the dijet cross section. The nucleus is investigated as a micro-laboratory in vector meson photoproduction reactions. In particular, the deuteron is studied in the break-up reaction γd → Vpn, for both the ϕ(1020) and J/ψ vector mesons. The generalized eikonal approximation is utilized, allowing unambiguous separation of the impulse approximation and final state interactions (FSIs). Two peaks or valleys are seen in the angular distribution of the reaction cross section, each of which is due to an FSI between either the proton and neutron, or the produced vector meson and the spectator nucleon. The presence and size of the latter FSI valley/peak contains information about the meson-nucleon interaction, and it is shown that several models of this interaction can be distinguished by measuring the angular distribution for the deuteron breakup reaction.

In this work we present the basic theoretical concepts of the description of the nucleon spin structure. The theoretical background of two processes of interest - Semi-inclusive DIS and Drell-Yan - in the terms of Transverse Momentum De- pendent Parton distribution Functions is presented. The COMPASS experiment and particularly its unique polarised target are described in detail. Several target related measurements are presented. The express analysis and detector efficien- cies analysis are presented as examples of important hardware related analysis. Finally two measurements of Transverse Spin Asymmetries are presented. The first measurement is the measurement of the Transverse Spin Asymmetries in J/ψ production in the Semi-inclusive DIS on polarised protons. The second mea- surement is the measurement of Transverse Spin Asymmetries in J/ψ in the π− p polarised Drell-Yan data. 1

No description available.

This thesis presents an analysis of inclusive semileptonic $B \to X_u e \nu$ decays using approximately 454 million $\Upsilon(4S) \to B \bar{B}$ decays collected during the years 1999 to 2008 with the BABAR detector. The electron energy, $E_e$, and the invariant mass squared of the electron-neutrino pair,$ q^2$, are reconstructed, where the neutrino kinematics is deduced from the decay products of both B mesons. The final hadronic state,$ X_u$, consists of a sum of many hadronic channels, each of which contains at least one $u$ quark. The variables $q^2$ and $E_e$ are then combined to compute the maximum kinematically allowed invariant mass squared of the hadronic system, $s_h^{max}$. Using these kinematic quantities, the partial branching fraction, $\Delta BR(B \to X_u e \nu)$, unfolded for detector effects, is measured to be $\Delta BR(E_e>2.0 GeV, s_h^{max}<3.52 GeV^2) = (3.33 \pm 0.18 \pm 0.21) \times 10^{-4} in the $\Upsilon(4S)$ and \Delta \tilde{\BR}(\tilde E_e>1.9 GeV, \tilde {s}^{max}_{h} < 3.5 GeV^2) = (4.57 \pm 0.24 \pm 0.32) \times 10^{-4} in the $B$ meson rest frames. The quoted errors are statistical and systematic, respectively. The CKM matrix element $|V_{ub}|$ is determined from the measured $\Delta \tilde{\BR}$ using theoretical calculation based on Heavy Quark Expansion. The result is $|V_{ub}| = (4.19 \pm 0.18{}^{+0.26}_{-0.20} {}^{+0.26}_{-0.25}) \times 10^{-3}, where the errors represent experimental uncertainties, uncertainties from HQE parameters and theoretical uncertainties, respectively.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第20914号 / 理博第4366号 / 新制||理||1626(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 國廣 悌二, 教授 川合 光, 教授 永江 知文 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM