119211852
Lorentz violation and the proper-time method
Abstract In this Letter, we apply the proper-time method to generate the Lorentz-violating Chern–Simons terms in the four-dimensional Yang–Mills and non-linearized gravity theories. It is shown that the coefficient of the induced Chern–Simons term is finite but regularization dependent.
118338237
Supersymmetric extensions of k-field models
Abstract We investigate the supersymmetric extension of k-field models, in which the scalar field is described by generalized dynamics. We illustrate some results with models that support static solutions with the standard kink or the compact profile.
2496873
Complete low-energy effective action in N=4 SYM: A Direct N=2 supergraph calculation
Using the covariant N=2 harmonic supergraph techniques we calculate the one-loop low-energy effective action of N=4 super-Yang–Mills theory in Coulomb branch with gauge group SU(2) spontaneously broken down to U(1). The full dependence of the low-energy effective action on both the hypermultiplet and gauge fields is determined. The direct quantum calculation confirms the correctness of the exact N=4 SYM low-energy effective action derived in hep-th/0111062 on the purely algebraic ground by invoking a hidden N=2 supersymmetry which completes the manifest N=2 one to N=4. Our results provide an exhaustive solution to the problem of finding out the exact completely N=4 supersymmetric low-energy effective action for the theory under consideration.
119277679
Four-dimensional aether-like Lorentz-breaking QED revisited and problem of ambiguities
In this paper, we consider the perturbative generation of the CPT-even aether-like Lorentz-breaking term in the extended Lorentz-breaking QED within different approaches and discuss its ambiguities.
123177090
Two-dimensional Lorentz-violating Chern-Simons-like action
Abstract We demonstrate generation of the two-dimensional Chern–Simons-like Lorentz-breaking action via an appropriate Lorentz-breaking coupling of scalar and spinor fields at zero as well as at the finite temperature and via the noncommutative fields method and study the dispersion relations corresponding to this action.
118435943
Equivalence between supersymmetric self-dual and Maxwell–Chern–Simons models coupled to a matter spinor superfield
Abstract We study the duality of the supersymmetric self-dual and Maxwell–Chern–Simons theories coupled to a fermionic matter superfield, using a master action. This approach evades the difficulties inherent to the quartic couplings that appear when matter is represented by a scalar superfield. The price is that the spinorial matter superfield represents a unusual supersymmetric multiplet, whose main physical properties we also discuss.
117694102
B0 anti-B0 mixing beyond factorization
We present a calculation of the B°-B° mixing matrix element in the framework of QCD sum rules for three-point functions. We compute α s corrections to a three-point function at the three-loop level in QCD perturbation theory, which allows one to extract the matrix element with next-to-leading order (NLO) accuracy. This calculation is imperative for a consistent evaluation of experimentally measured mixing parameters since the coefficient functions of the effective Hamiltonian for B 0 -B 0 mixing are known at NLO. We find that radiative corrections violate factorization at NLO; this violation is under full control and amounts to 10%. The resulting value of the B parameter is found to be B B (m b ) = 1 + 0.1 P T - 0.05 n o n - P T .
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.
2033960
Intrinsic charm of light mesons and CP violation in heavy quark decay
We investigate the impact of the intrinsic heavy quark states on the predicted values of CP asymmetries in the decays of heavy mesons. It is shown that the intrinsic charm contribution, although dynamically suppressed in QCD, is favored by the weak interaction, and therefore it can significantly dilute the predicted values of CP-violating asymmetries. This introduces additional non-perturbative uncertainty into the estimate of direct CP violating effects.
19200788
Final state rescattering as a contribution to B->rho gamma
We provide a new estimate of the long-distance component to the radiative transition B{r_arrow}{rho}{gamma}. Our mechanism involves the soft scattering of on-shell hadronic products of nonleptonic B decay, as in the chain B{r_arrow}{rho}{rho}{r_arrow}{rho}{gamma}. We employ a phenomenological fit to scattering data to estimate the effect. The specific intermediate states considered here modify the B{r_arrow}{rho}{gamma} decay rate at roughly the 5{minus}8{percent} level, although the underlying effect has the potential to be larger. Contrary to other mechanisms of long distance physics which have been discussed in the literature, this yields a non-negligible modification of the B{sup 0}{r_arrow}{rho}{sup 0}{gamma} channel and hence will provide an uncertainty in the extraction of V{sub td}. This mechanism also affects the isospin relation between the rates for B{sup {minus}}{r_arrow}{rho}{sup {minus}}{gamma} and B{sup 0}{r_arrow}{rho}{sup 0}{gamma} and may generate CP asymmetries at experimentally observable levels. {copyright} {ital 1997} {ital The American Physical Society}
118578287
Charm Meson Decays
We review some recent developments in charm meson physics. In particular, we discuss the theoretical predictions and experimental measurements of charmed meson decays to leptonic, semileptonic, and hadronic final states and the implications of such measurements to searches for new physics. We discuss mixing and CP violation in charm, as well as future experimental prospects and theoretical challenges in this area.