14121745
Lifetime differences in heavy mesons with time independent measurements
Heavy meson pairs produced in the decays of heavy quarkonium resonances at ${e}^{+}{e}^{\ensuremath{-}}$ machines (beauty and tau-charm factories) have the useful property that the two mesons are in the $CP$-correlated states. We show that this leads to time-independent correlations allowing the extraction of the lifetime difference $\ensuremath{\Delta}{\ensuremath{\Gamma}}_{D}$ and other mixing parameters. In particular, for the decay $\ensuremath{\psi}(3770)\ensuremath{\rightarrow}{D}^{0}{\overline{D}}^{0}$ the correlation of a flavor specific decay of one $D$ with a $CP$-specific decay of the other $D$ is linearly sensitive to the ${D}^{0}$ lifetime difference. The utility of this method is considered at CLEO-c as well as future threshold charm factories. We include the impact of possible $CP$-violating effects and present the complete results for time-integrated $CP$-entangled decay rates with $CP$ violation taken into account. We comment on the utility of using this method to extract the lifetime difference of neutral $B$ mesons at future high luminosity $B$ factories.
35942201
Is B-->Xs gamma equal to b-->s gamma ? Spectator contributions to rare inclusive B decays.
In $B \to X_s \gamma $ there are perturbative $QCD$ corrections at order $\alpha_s$ not only to the single quark line process $ b \to s \gamma$ but also coming from a set of diagrams where the weak interaction vertex involves a gluon which interacts with the spectator quark in the B hadron. We discuss the impact of the full set of these diagrams. These can influence the decay rate and also the line shape of the photon spectrum as they favor a softer photon energy than does the pure spectator decay $b \to s \gamma$. A subset of these diagrams generate differences in the decay rates for charged and neutral B's , $B^+ \to X_s \gamma$ vs. $B^0 \to X_s \gamma$ which can be searched for experimentally, although our calculation indicates that the effect will be hard to observe. Bound state effects turn out to be required to give rise to spectator corrections to the decay rate at order $\alpha_s$. The resulting contribution to the total rate is rather small (of about $5 \% $ ), although the effect is somewhat larger on portions of the photon spectrum.
118687281
Hadronic D and D(s) Meson Decays
We provide a comprehensive review of hadronic decays of D and D_s mesons. We discuss current theoretical and experimental challenges and successes in understanding of hadronic transitions of those mesons. A brief overview of the theoretical and experimental tools are given before discussing the absolute branching fractions for D and D_s mesons. Cabibbo suppressed and rare hadronic decays are discussed and compared with theory before discussing our understanding of hadronic multibody decays.
117901603
X(3872) in effective field theory
We consider the implications from the possibility that the recently observed state X(3872) is a meson‐antimeson molecule. We write an effective Lagrangian consistent with the heavy‐quark and chiral symmetries needed to describe X(3872) and study its properties.
14759150
Heavy meson molecules in effective field theory
We consider the implications from the possibility that the recently observed state X(3872) is a meson-antimeson molecule. We write an effective Lagrangian consistent with the heavy-quark and chiral symmetries needed to describe X(3872). We explore the consequences of the assumption that X(3872) is a molecular bound state of D�0 and D0 mesons for the existence of bound states in the D0D0 and D�0D �0
17946700
CP-violation in charm
I review recent results in theoretical and experimental analyses of CP-violation in charmed transitions, paying particular attention to constraints on parameters of beyond the Standard Model interactions.
119117693
Three-dimensional Lorentz-violating action
We demonstrate the generation of the three-dimensional Chern-Simons-like Lorentz-breaking ``mixed" quadratic action via an appropriate Lorentz-breaking coupling of vector and scalar fields to the spinor field and study some features of the scalar QED with such a term. We show that the same term emerges through a nonpertubative method, namely the Julia-Toulouse approach of condensation of charges and defects.
118542970
Ambiguities of the C P T -even aether-like Lorentz-breaking term at finite temperature
In this paper, we consider the finite-temperature behavior of the $CPT$-even aether-like Lorentz-breaking term in the extended Lorentz-breaking QED and demonstrate that its ambiguities, whose presence has been shown earlier in the zero-temperature case, stay also at a finite temperature.
119224824
On the effective potential for Horava-Lifshitz-like theories
The Horava-Lifshitz (HL) approach [1] has recently acquired a great scientific attention. This approach is characterized by an essential asymmetry between space and time coordinates (space-time anisotropy): the equations of motion of the theory are invariant under the rescaling x → bx, t → bt, where z, the critical exponent, is a number characterizing its ultraviolet behaviour. The main reason for it is that for the HL-like reformulation of the known field theory models with a nontrivial critical exponent z > 1 leads to an improvement of the renormalization of these models. In particular, the four-dimensional gravity becomes renormalizable at z = 3. Different issues related to the HL gravity, including its cosmological aspects [2], exact solutions [3], black holes [4] were considered in a number of papers. At the same time, the study of the impacts of the HL extension to other field theories is a very interesting problem. Some aspects of the HL generalizations for the gauge field theories were presented in [5]. Renormalizability of the scalar field theory models with space-time anisotropy has been discussed in details in [6]. The four-fermion HL-like theory has been studied in [7]. The Casimir effect for the HL-like scalar field theory has been considered in [8]. In [9], the HL modifications of the CP were studied. The possibility of restoration of the Lorentz symmetry in the theories with the space-time anisotropy is discussed in [5, 10]. It is well known that the effective potential is a key object in the quantum field theory useful for studying many of its aspects. Some interesting results for the HL-like theories have been obtained in the papers [11, 12] where the effective potential for the φ and the Liouville-
118356440
On the effective potential in higher-derivatives superfield theories
Abstract We study the one-loop quantum corrections for higher-derivative superfield theories, generalizing the approach for calculating the superfield effective potential. In particular, we calculate the effective potential for two versions of higher-derivative chiral superfield models. We point out that the equivalence of the higher-derivative theory for the chiral superfield and the one without higher derivatives but with an extended number of chiral superfields occurs only when the mass term is contained in the general Lagrangian. The presence of divergences can be taken as an indication of that equivalence.
119202862
Note on the Gauss-Bonnet braneworld scenario
In this work we deal with the presence of braneworld solutions in a ve-dimensional space-time with a single extra spatial dimension of innite extent. The braneworld scenario is built under the presence of a single real scalar eld, and we modify the gravity sector to include generic function of the Gauss-Bonnet term. We study several specic models, and we construct exact braneworld solutions, in particular for including the Gauss-Bonnet term at rst and second order power. As an interesting result, we show that the brane tends to split for a specic modication in the gravity sector, in the presence of non constant Gauss-Bonnet term.