Possible Effects of D0−Dˉ0D^0-\bar{D}^0 Mixing in Weak BB Decays

$D^0-\bar{D}^0$ mixing at a detectable level requires the presence of new physics and may lead to some observable effects in weak decays of $B$ mesons. We show that $CP$ violation induced by $D^0-\bar{D}^0$ mixing can manifest itself in the decay-rate asymmetry of $B^+_u\rightarrow D_{L(H)}l^+\nu^{~}_l$ vs $B^-_u\rightarrow D_{L(H)}l^-\bar{\nu}^{~}_l$. A rephasing-invariant generalization of the Gronau-Wyler approach is made to determine the weak phase shift in $B^{\pm}_u\rightarrow D_{L(H)}K^{\pm}$, which is only sensitive to the underlying new physics in $D^0-\bar{D}^0$ mixing. We also demonstrate the possible effect of $D^0-\bar{D}^0$ mixing on $CP$ violation in decay modes of the type $B_d\rightarrow D_{L(H)}+(\pi^0, \rho^0, {\rm etc})$. Finally the model of four quark families is taken as an example to illustrate how the new physics affects $D^0-\bar{D}^0$ mixing, $B^0_d-\bar{B}^0_d$ mixing and $CP$ asymmetries in the relevant $B$ decays.Comment: Postscript 10 page

On equal values of power sums of arithmetic progressions

In this paper we consider the Diophantine equation \begin{align*}b^k +\left(a+b\right)^k &+ \cdots + \left(a\left(x-1\right) + b\right)^k=\\ &=d^l + \left(c+d\right)^l + \cdots + \left(c\left(y-1\right) + d\right)^l, \end{align*} where $a,b,c,d,k,l$ are given integers. We prove that, under some reasonable assumptions, this equation has only finitely many integer solutions.Comment: This version differs slightly from the published version in its expositio

B -> D* l nu and B -> D l nu form factors in staggered chiral perturbation theory

We calculate the B -> D and B -> D* form factors at zero recoil in Staggered Chiral Perturbation Theory. We consider heavy-light mesons in which only the light (u, d, or s) quark is staggered; current lattice simulations generally use a highly improved action such as the Fermilab or NRQCD action for the heavy (b or c) quark. We work to lowest nontrivial order in the heavy quark expansion and to one-loop in the chiral expansion. We present results for a partially quenched theory with three sea quarks in which there are no mass degeneracies (the "1+1+1" theory) and for a partially quenched theory in which the u and d sea quark masses are equal (the "2+1" theory). We also present results for full (2+1) QCD, along with a numerical estimate of the size of staggered discretization errors. Finally, we calculate the finite volume corrections to the form factors and estimate their numerical size in current lattice simulations.Comment: 19 pages, 6 figures, references added, expanded discussion in Section I