1473086
CKM phenomenology and B meson physics: Present status and current issues
We review the status of the Cabibbo-Kobayashi-Maskawa (CKM) matrix elements and the CP-violating phases in the CKM-unitarity triangle. The emphasis in these lecture notes is on $B$-meson physics, though we also review the current status and issues in the light quark sector of this matrix. Selected applications of theoretical methods in QCD used in the interpretation of data are given and some of the issues restricting theoretical precision on the CKM matrix elements discussed. The overall consistency of the CKM theory with the available data in flavour physics is impressive and we quantify this consistency. Current data also show some anomalies which, however, are not yet statistically significant. They are discussed briefly. Some benchmark measurements that remain to be done in experiments at the $B$-factories and hadron colliders are listed. Together with the already achieved results, they will provide unprecedented tests of the CKM theory and by the same token may lead to the discovery of new physics.
117634637
The LHC signatures of the extended gauge structures in supersymmetry
13281897
Majorana neutrinos and same-sign dilepton production at LHC and in rare meson decays
Abstract. We discuss same-sign dilepton production mediated by Majorana neutrinos in high-energy proton–proton collisions $pp\rightarrow \ell^+ \ell^{\prime +}X$ for $\ell, \ell^\prime = e, \mu, \tau$ at the LHC energy $ s^{1/2} =14$ TeV, and in the rare decays of the $K, D, D_s$, and B mesons of the type $M^+\rightarrow M^{\prime -}\ell ^+\ell ^{\prime+}$. For the pp reaction, assuming one heavy Majorana neutrino of mass $m_N$, we present discovery limits in the $\left(m_N,\left|U_{\ell N}U_{\ell^\prime N}\right|\right)$ plane where $U_{\ell N}$ are the mixing parameters. Taking into account the present limits from low-energy experiments, we show that at LHC one has sensitivity to heavy Majorana neutrinos up to a mass $m_N\leq 2--5$ TeV in the dilepton channels $\mu\mu, \tau\tau$, and $\mu\tau$, but the dilepton states $e\ell$ will not be detectable due to the already existing constraints from neutrinoless double beta decay. We work out a large number of rare meson decays, both for the light and heavy Majorana neutrino scenarios, and argue that the present experimental bounds on the branching ratios are too weak to set reasonable limits on the effective Majorana masses.
117235251
B Decays in the Standard Model - Status and Perspectives
These lectures review some of the progress made in the quantitative understanding of B decays. The emphasis here is on applications of QCD using perturbative and non-perturbative techniques. In some cases, however, phenomenological models must at present be invoked to make meaningful comparison with data. The resulting picture is consistent with the standard model (SM) and this agreement is quantified in terms of the branching ratios, mixing probabilities, and lifetimes which measure the charge current and effective flavour changing neutral current transitions involving B hadrons. This, in turn, enables a determination of five of the nine elements of the quark mixing matrix. We discuss several proposals on improving the precision on the parameters of this matrix in forthcoming experiments. Issues intimately related to the quark mixing matrix such as the profile of the unitarity triangle and CP-violating asymmetries in B decays are discussed. In particular, we emphasize the role of rare B decays and B^0 - $\overline{B^0}$ mixings in testing the SM quantitatively and in searching for physics beyond the SM.
121188586
Heavy quark physics at HERA
Abstract A brief overview of the anticipated heavy quark physics at HERA is given. The topics discussed include heavy quark photo- and leptoproduction cross sections at HERA calculated in the context of perturbative QCD, various mechanisms of J / ϕ -leptoproduction and their rates, determination of the gluon density of the proton using open and bound charmed hadrons, and rare D 0 -meson decays. Some selected aspects of B -Physics at HERA are also discussed.
10853970
Rare B decays in the standard model
Abstract We discuss the electromagnetic-penguin-dominated radiative B decays B → X s + γ , B ±(0) → K ∗±(0) + γ , and B s → φ + γ in the context of the Standard Model (SM) and their Cabibbo-Kobayashi-Maskawa (CKM)-suppressed counterparts, B → X d + γ , B ± → ϱ ± + γ , B 0 → ( ϱ 0 , ω ) + γ , and B s → K ∗0 + γ , using QCD sum rules for the exclusive decays. The importance of these decays in determining the parameters of the CKM matrix [1] is emphasized. The semileptonic decays B → X s l + l − are also discussed in the context of the SM and their role in determining the Wilson coefficients of the effective theory is stressed. Comparison with the existing measurements are made and SM-based predictions for a large number of rare B decays are presented.
119191368
Minimal length in quantum gravity, equivalence principle and holographic entropy bound
A possible discrepancy has been found between the results of a neutron interferometry experiment and quantum mechanics. This experiment suggests that the weak equivalence principle is violated at small length scales, which quantum mechanics cannot explain. In this paper, we investigated whether the generalized uncertainty principle (GUP), proposed by some approaches to quantum gravity such as string theory and doubly special relativity theories, can explain the violation of the weak equivalence principle at small length scales. We also investigated the consequences of the GUP on the Liouville theorem in statistical mechanics. We have found a new form of invariant phase space in the presence of GUP. This result should modify the density states and affect the calculation of the entropy bound of local quantum field theory, the cosmological constant, black body radiation, etc. Furthermore, such modification may have observable consequences at length scales much larger than the Planck scale. This modification leads to a -type correction to the bound of the maximal entropy of a bosonic field which would definitely shed some light on the holographic theory.
118350400
The Generalized Uncertainty Principle and Quantum Gravity Phenomenology
In this article we examine a Generalized Uncertainty Principle which differs from the Heisenberg Uncertainty Principle by terms linear and quadratic in particle momenta, as proposed by the authors in an earlier paper. We show that this affects all Hamiltonians, and in particular those which describe low energy experiments. We discuss possible observational consequences. Further, we also show that this indicates that space may be discrete at the fundamental level.
56052541
Effect of the Generalized Uncertainty Principle on post-inflation preheating
We examine effects of the Generalized Uncertainty Principle, predicted by various theories of quantum gravity to replace the Heisenberg's uncertainty principle near the Planck scale, on post inflation preheating in cosmology, and show that it can predict either an increase or a decrease in parametric resonance and a corresponding change in particle production. Possible implications are considered.