123193403
The rate of the sphaleron transition in the (1 + 1)-dimensional Abelian Higgs model on a circle
Abstract The rate of fermion number non-conservation at finite temperatures is discussed in the (1 + 1)-dimensional Abelian Higgs model on a circle. An effective potential is used to estimate the one-loop correction to the effective action remaining after the treatment of zero modes. With this method it is not necessary to know all the normal modes of the sphaleron. The expression of the rate is given for the case of M W ⪡ M H .
119209195
Generalized Froggatt–Nielsen mechanism
We propose a Generalized Froggatt–Nielsen mechanism in which the GUT gauge symmetry breaking and the generation of hierarchical flavor structure have the same origin. Assuming universality conditions for coefficients corresponding to different contractions, we can get the realistic standard model mass hierarchy and mixings in SU(5) GUT model as well as in SO(10) GUT model in several ways. With very free parameters, the Generalized Froggatt–Nielsen mechanism is very predictive and it can be very useful in GUT model building as well as in solving the flavor puzzle in standard model.
119408784
Meson spectrum in Regge phenomenology
Abstract.Under the assumption that both light and heavy quarkonia populate approximately linear Regge trajectories with the requirements of additivity of intercepts and inverse slopes, the masses of different meson multiplets are estimated. The predictions derived from the quasi-linear Regge trajectories are in reasonable agreement with those given by many other references.
119187687
CP-violating Phases in Active-Sterile Solar Neutrino Oscillations
The effects of CP-violating phases in active-sterile solar neutrino oscillations are discussed in a general scheme of 3 + N-s mixing, without any constraint on the mixing between the three active and the Ns sterile neutrinos, assuming only a realistic hierarchy of neutrino mass-squared differences. A generalized Parke formula describing the neutrino oscillation probabilities inside the Sun is calculated. The validity of the analytical calculation and the probability variation due to the unknown CP-violating phases are illustrated with a numerical calculation of the evolution equation in the case of 3 + 1 neutrino mixing.
119512566
Drell-Hearn-Gerasimov sum-rule for the deuteron in nuclear effective field theory
Abstract The Drell–Hearn–Gerasimov sum rule for the deuteron is studied in nuclear effective field theory. The low-energy theorem for the spin-dependent Compton amplitude f 1 ( ω ) is derived to the next-to-leading order in low-energy expansion. The spin-dependent photo-disintegration cross-section σ P − σ A is calculated to the same order, and its contribution to the dispersive integral is evaluated.
118460727
N 3 LO Higgs boson and Drell-Yan production at threshold: The one-loop two-emission contribution
In this paper, we study phenomenologically interesting soft radiation distributions in massless QCD. Specifically, we consider the emission of two soft partons off of a pair of lightlike Wilson lines, in either the fundamental or the adjoint representation, at next-to-leading order. Our results are an essential component of the next-to-next-to-next-to-leading order threshold corrections to both Higgs boson production in the gluon fusion channel and Drell-Yan lepton production. Our calculations are consistent with the recently published results for Higgs boson production. As a nontrivial cross-check on our analysis, we rederive a recent prediction for the Drell-Yan threshold cross section using a completely different strategy. Our results are compact, valid to all orders in the dimensional regularization parameter, and expressed in terms of pure functions.
18559665
Topological sigma-models with H-flux and twisted generalized complex manifolds
We study the topological sector of N = 2 sigma-models with HH-flux. It has been known for a long time that the target-space geometry of these theories is not Kahler and can be described in terms of a pair of complex structures, which do not commute, in general, and are parallel with respect to two different connections with torsion. Recently an alternative description of this geometry was found, which involves a pair of commuting twisted generalized complex structures on the target space. In this paper, we define and study the analogs of A and B-models for N = 2 sigma-models with HH-flux and show that the results are naturally expressed in the language of twisted generalized complex geometry. For example, the space of topological observables is given by the cohomology of a Lie algebroid associated to one of the two twisted generalized complex structures. We determine the topological scalar product, which endows the algebra of observables with the structure of a Frobenius algebra. We also discuss mirror symmetry for twisted generalized Calabi-Yau manifolds.
58938119
Exclusive soft function for Drell-Yan at next-to-next-to-leading order
We present next-to-next-to-leading-order (NNLO) results for an exclusive soft function that appears in a recently developed factorization theorem for transverse momentum distributions. The factorization theorem, derived using the Soft Collinear Effective Theory, involves both a soft function and unintegrated nucleon distribution functions fully differential in momentum coordinates. The soft function is given by the vacuum matrix element of soft Wilson lines and is also fully differential in all components. We give results and relevant technical details for the NNLO calculation of the soft function, including finite parts, and derive the corresponding anomalous dimension. These results are necessary for achieving low transverse momentum resummation at next-to-next-to-leading-logarithmic accuracy in this effective field theory approach with unintegrated distribution functions.