119230860
On the aether-like Lorentz-breaking actions
We demonstrate the generation of the CPT-even, aether-like Lorentz-breaking actions for the scalar and electromagnetic fields via their appropriate Lorentz-breaking coupling to spinor fields in three, four and five space-time dimensions. Besides, we show that the aether-like terms for the spinor field also can be generated as a consequence of the same couplings. Also we discuss the dispersion relations in the theories with aether-like Lorentz-breaking terms and find the tree-level effective (Breit) potential for fermion scattering and the one-loop effective potential corresponding to the action of the scalar field.
96444982
Horava-Lifshitz-like extensions of supersymmetric theories
Within the superfield approach, we formulate two different extensions of the Wess-Zumino model and super-QED with Horava-Lifshitz-like additive terms, discuss their quantum properties and calculate lower contributions to the effective action. In the case of the gauge theory, the one-loop effective potential turns out to be gauge independent.
118533824
Free energy of Lorentz-violating QED at high temperature
In this paper we study the one- and two-loop contribution to the free energy in QED with Lorentz symmetry breaking introduced via constant CPT-even Lorentz-breaking parameters at the high temperature limit. We find the impact of the Lorentz-violating term for the free energy and carry out a numerical estimation for the Lorentz-breaking parameter.
118455730
Effective potential for a SUSY Lee–Wick model: The Wess–Zumino case
Using a superfield generalization of the tadpole method, we study the one-loop effective potential for a Wess–Zumino model modified by a higher derivative term, inspired by the Lee–Wick model. The one-loop Kahlerian potential is also obtained by other methods and compared with the effective potential.
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.
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.
119494597
X(3872): Hadronic molecules in effective field theory
Abstract 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 D ¯ 0 mesons for the existence of bound states in the D 0 D ¯ 0 and D ∗ 0 D ¯ ∗ 0 channels.
118893294
CP-VIOLATION AND MIXING IN CHARMED MESONS
The Standard Model contribution to D0 D 0 mixing is dominated by the contributions of light s and d quarks. Neglecting the tiny effects due to b quark, both mass and lifetime differences vanish in the limit of SU(3)F symmetry. Thus, the main challenge in the Standard Model calculation of the mass and width difference in the D0 D 0 system is to estimate the size of SU(3) breaking effects. We prove that D meson mixing occurs in the Standard Model only at second order in SU(3) violation. We consider the possibility that phase space effects may be the dominant source of SU(3) breaking. We find that y = (�) /(2) of the order of one percent is natural in the Standard Model, potentially reducing the sensitivity to new physics of measurements of D meson mixing. We also discuss the possibility of observing lifetime differences and CP violation in charmed mesons both at the currently operating and proposed facilities.
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.
16727874
Spectator effects and lifetimes of heavy hadrons
We present a calculation of subleading 1/m{sub b} corrections to spectator effects in the ratios of beauty hadron lifetimes in heavy-quark expansion. We find that these effects are sizable and should be taken into account in systematic analyses of heavy hadron lifetimes. In particular, the inclusion of 1/m{sub b} corrections brings into agreement the theoretical predictions and experimental observations of the ratio of lifetimes of {lambda}{sub b} baryon and B{sub d} meson. We obtain {tau}(B{sub u})/{tau}(B{sub d})=1.06{+-}0.02, {tau}(B{sub s})/{tau}(B{sub d})=1.00{+-}0.01, {tau}({lambda}{sub b})/{tau}(B{sub d})=0.86{+-}0.05.
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 .