Angular analysis of polarized top quark decay into B mesons in two different helicity systems

作者：Nejad S Mohammad Moosavi^*; Balali Mahboobe

来源：Physical Review D - Particles, Fields, Gravitation and Cosmology, 2014, 90(11): 114017.

DOI：10.1103/PhysRevD.90.114017

We calculate the O(alpha(s)) radiative corrections to the spin-dependent differential decay rates of the process t -> b + W+. These are needed to study the angular distribution of the energy of hadrons produced in polarized top quark decays at next-to-leading order. In our previous work, we studied the angular distribution of the scaled energy of bottom-flavored hadrons (B) from polarized top quark decays, using a specific helicity coordinate system where the top quark spin was measured relative to the bottom momentum (system 1). Here, we study the angular distribution of the energy spectrum of B hadrons in a different helicity system, where the top spin is specified relative to the W momentum (system 2). These energy distributions are governed by the polarized and unpolarized rate functions which are related to the density matrix elements of the decay t -> W+ + b. Through this paper, we present our predictions of the B-hadron spectrum in the polarized and unpolarized top decay and shall compare the polarized results in two different helicity systems. These predictions can be used to determine the polarization states of top quarks and also provide direct access to the B-hadron fragmentation functions, and allow us to deepen our knowledge of the hadronization process.

• 出版日期2014-12-12