The Radiative rare decays B→K∗∗γB\to K^{**}\gamma in the light-cone QCD sum rule approach

We predict contributions of higher $K$-resonances to the radiative rare decays $b\to s\gamma$, in the framework of the QCD sum rules on the light cone, which combines the traditional QCD sum rule method with the description of final state mesons in terms of the light-cone wave functions of increasing twist. Our calculations are restricted to the leading twist-two operators for $K^*(892)$ and to the asymptotic wave function for the other $K^{**}$-mesons. Using experimental data on the semileptonic $\tau\to K^{**}\nu_{\tau}$ decays, we extract the corresponding decay constants for vector and axial-vector $K^{**}$-mesons. Based on our estimate of the transition form factor $F_1^{K^*(892)}(0)=0.32 \pm 0.06$ and the $K_2^*(1430)$ decay constant $f_{K_2^*(1430)}=(160\pm 20) MeV$, we find good agreement with experimental results. The two largest fractions of the inclusive $b\to s\gamma$ branching ratio are found to be $(10.0\pm 4.0)$ for $B\to K^*(892) \gamma$ and $(5.0\pm 2.0)$ for $B\to K_2^*(1430)\gamma$ decays. We also compare our results with the existing theoretical predictions.Comment: 29 pages, 20 figures, to be submitted to European Physical Journal

CP Violation in B Decays within QCD Factorization

We analyze the extraction of weak phases from CP violation in $B\to\pi^+\pi^-$ decays. By combining the information on mixing induced CP violation in $B\to\pi^+\pi^-$, namely $S_{\pi\pi}$, with the precision observable $\sin 2\beta$ obtained from the ``gold-plated''mode $B\to\psi K_S$, we propose the determination of the unitarity triangle. We also discuss alternative ways to analyze $S_{\pi\pi}$ which can be useful if new physics affects $B_d$--$\bar B_d$ mixing. Predictions and uncertainties for $r$ and $\phi$ in QCD factorization are examined in detail. It is pointed out that a simultaneous expansion in $1/m_b$ and $1/N_C$ leads to interesting simplifications. At first order infrared divergences are absent, while the most important effects are retained. Independent experimental tests of the factorization framework are briefly discussed.Comment: 3 pages; 2 figures; To appear in the proceedings of International Europhysics Conference on High-Energy Physics (HEP 2003), Aachen, Germany, 17-23 Jul 200

CKM matrix from non-leptonic B-decays

We analyze the impact of the forthcoming CP-violating observables in the $B_s\to K^+ K^-$ system, combined with the precise measurement of $\sin2\beta$ , in the extraction of the CKM matrix. Computing the penguin parameters $(r, \theta)$ within QCD factorization yields a precise determination of $(\bar\rho, \bar\eta)$, reflected by a weak dependence on $\theta$, which is shown to be a second order effect. Using the SU(3)-flavour symmetry argument and the current $B$-factories data provided by the $B_d \to \pi^+ \pi^-$ modes, we complement the $B_s \to K^+ K^-$ CP-violating observables in a variety of ways, in particular we find that $S_{KK}>0$. Finally, we investigate systematically the SU(3)-symmetry breaking factor within QCD factorization.Comment: 4 pages; 4 figures (requires epsfig, psfrag); To appear in the proceedings of 32nd International Conference on High-Energy Physics (ICHEP 04), Beijing, China, 16-22 Aug 200

Who leaves, who moves in? The impact of positive and negative income shocks on migration in Senegal

Using a recent household survey conducted in Senegal, I examine the impact of negative and positive income shocks on departures from and entries in the household. I focus on differences in responses to shocks across the urban and rural sectors as well as age and gender groups. Striking differences emerge. Positive shocks increase entries of young girls and adult females in rural areas while they attract adult males in urban areas. Negative shocks decrease the arrivals of boys in urban areas while, in rural areas, they only impact the entries of adult males. Migration only increases after negative shocks, for prime-age adults wherever they reside and for adult children of urban household heads. In addition to migration, I examine private transfers. They show much less contrast between urban and rural areas but a sharp contrast between males and females. Adult males increase the amount of transfers they send after positive shocks and receive more transfers after negative shocks, wherever they reside, pointing towards the use of transfers as insurance. Females send and receive on average more transfers than males. However, negative shocks do not increase the amount of transfers they receive. Negative shocks only reduce transfers given by older rural females. Overall, both in terms of movements and transfers, individuals benefit very differently from their external relations, depending on their place of residence, gender and age. Given the heterogenous responses of migration and private transfers to income shocks, identical public policies may have very different effects for urban and rural areas and across age and gender.geographic mobility ; transfers ; risk ; rural-urban differences ; Senegal

Phenomenological study of the double radiative decay B−>KγγB ->K\gamma\gamma

Using the operator product expansion (OPE) technique, we study the rare double radiative decay $B\to K \gamma\gamma$ in the Standard Model (SM) and beyond. We estimate the short-distance (SD) contribution to the decay amplitude in a region of the phase space which is around the point where all decay products have energy $\sim m_b/3$ in the rest frame of the $B$-meson. At lowest order in $1/m_b$, the $B\to K \gamma\gamma$ matrix element is then expressed in terms of the usual $B\to K$ form factors known from semileptonic rare decays. The integrated SD branching ratio in the SM in the OPE region turns out to be $\Delta {\cal{B}}(B \to K \gamma \gamma)_{SM}^{OPE} \simeq 1 \times 10^{-9}$. We work out the di-photon invariant mass distribution with and without the resonant background through $B\to K \{\eta_c,\chi_{c0}\}\to K\gamma \gamma$. In the SM, the resonance contribution is dominant in the region of phase space where the OPE is valid. On the other hand, the present experimental upper limit on $B_s \to \tau^+ \tau^-$ decays, leaves considerable room for New Physics (NP) in the one-particle-irreducible contribution to $B\to K \gamma \gamma$ decays. In this case, we find that the SD $B\to K \gamma \gamma$ branching ratio can be enhanced by one order of magnitude with respect to its SM value and the SD contribution can lie outside of the resonance peaks.Comment: 4 pages, 2 figures (requires epsfig, psfrag), To appear in the proceedings of the International Europhysics Conference on High Energy Physics, 21-27 July 2005, Lisboa, Portuga

Model Independent Bound on the Unitarity Triangle from CP Violation in B-> pi+ pi- and B-> psi K_S

We derive model independent lower bounds on the CKM parameters (1-rhobar) and etabar as functions of the mixing-induced CP asymmetry S in B-> pi+ pi- and sin(2 beta) from B->psi K_S. The bounds do not depend on specific results of theoretical calculations for the penguin contribution to B-> pi+ pi-. They require only the very conservative condition that a hadronic phase, which vanishes in the heavy-quark limit, does not exceed 90 degrees in magnitude. The bounds are effective if -sin(2 beta) < S < 1. Dynamical calculations indicate that the limits on rhobar and etabar are close to their actual values.Comment: 5 pages, 2 figure

Viable Syntax: Rethinking Minimalist Architecture

Hauser et al. (2002) suggest that the human language faculty emerged as a genetic innovation in the form of what is called here a ‘keystone factor’—a single, simple, formal mental capability that, interacting with the pre-existing faculties of hominid ancestors, caused a cascade of effects resulting in the language faculty in modern humans. They take Merge to be the keystone factor, but instead it is posited here that Merge is the pre-existing mechanism of thought made viable by a principle that permits relations interpretable at the interfaces to be mapped onto c-command. The simplified minimalist architecture proposed here respects the keystone factor as closely as possible, but is justified on the basis of linguistic analyses it makes available, including a relativized intervention theory applicable across Case, scope, agreement, selection and linearization, a derivation of the A/A’-distinction from Case theory, and predictions such as why in situ wh-interpretation is island-insensitive, but susceptible to intervention effects