منابع مشابه
From Superstring Derived Models
It was recently suggested that the reported anomalies in Rb and Rc can be interpreted as the effect of a heavy vector boson that couples to quarks and is universally decoupled from leptons. We examine how an extra gauge boson with this property can arise from superstring derived models. In a specific three generation model we show that the U(1)B−L symmetry combines with the horizontal flavor sy...
متن کاملHigher-derivative Gravitation in Bosonic and Superstring Theories
Abstract. A discussion of the number of degrees of freedom, and their dynamical properties, in higher-derivative gravitational theories is presented. The complete non-linear sigma model for these degrees of freedom is exhibited using the method of auxiliary fields. As a by-product we present a consistent non-linear coupling of a spin-2 tensor to gravitation. It is shown that non-vanishing (Cμνα...
متن کاملLocal Discrete Symmetries From Superstring Derived Models
Discrete and global symmetries play an essential role in many extensions of the Standard Model, for example, to preserve the proton lifetime, to prevent flavor changing neutral currents, etc. An important question is how can such symmetries survive in a theory of quantum gravity, like superstring theory. In a specific string model I illustrate how local discrete symmetries may arise in string m...
متن کاملLeptophobic 2’ from superstring derived models
It was recently suggested that the reported anomalies in Rb and R, can be interpreted as the effect of a heavy vector boson that couples to quarks and is universally decoupled from leptons. We examine how an extra gauge boson with this property can arise from supersting derived models. In a specific three generation model we show that the U( ~)B__L symmetry combines with the horizontal flavor s...
متن کاملExotic Leptoquarks from Superstring Derived Models
The H1 and ZEUS collaborations have recently reported a significant excess of e+p → e+ jet events at high Q2. While there exists insufficient data to conclusively determine the origin of this excess, one possibility is that it is due to a new leptoquark at mass scale around 200 GeV. We examine the type of leptoquark states that exist in superstring derived standard–like models, and show that, w...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Physics Letters B
سال: 1987
ISSN: 0370-2693
DOI: 10.1016/0370-2693(87)91694-7