Light-Cone Distribution Amplitudes for the Light 11P11^1P_1 Mesons

We present a study of light-cone distribution amplitudes of the light $1^1P_1$ mesons. The first few Gegenbauer moments of leading twist light-cone distribution amplitudes are calculated by using the QCD sum rule technique.Comment: 18 pages, 9 figures, v3: a sentence revised in the introduction, to appear in JHE

Exploring the Unitarity Triangle through CP violation observables in Bs→K+K−B_s \to K^+ K^-

We discuss the determination of the CKM parameters from the forthcoming $CP$ violation observables in $B_s \to K^+ K^-$ decays. Combining the information on mixing induced CP violation in $B_s \to K^+ K^-$, with the $B_d \to J/\psi K_s$ precision observable $\sin 2\beta$ and the $B^0_s$--$\bar{B^0_s}$ mixing phase $\phi_s$, we propose a determination of the unitarity triangle $(\bar\rho, \bar\eta)$. Computing the penguin parameters $(r, \theta)$ within QCD factorization yield precise determination of $(\bar\rho, \bar\eta)$, reflected by a weak dependence on the $\theta$ which is shown as a second order effect. The impact of the direct CP violation observable $C_{KK}$ on the penguin parameters are investigated and a lower bound on $C_{KK}$ is extracted. We also discuss the effect of the $B^0_s$--$\bar{B^0_s}$ new physics mixing phase on the penguin parameters $(r, \theta)$ and $S_{KK}$. 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 analyze systematically the SU(3)-symmetry breaking factor within QCD factorization.Comment: 22 pages, 6 figures, typos corrected, reference and some remarks adde

The decay of the observed JPC=1−+J^{PC}=1^{-+} (1400) and JPC=1−+J^{PC}=1^{-+}(1600) hybrid candidates

We study the possible interpretation of the two exotic resonances $J^{PC}= 1^{-+}$ at 1400 and 1600 MeV, claimed to be observed by BNL, decaying respectively into $\eta\pi$, $\eta'\pi$, $f_{1}\pi$ and $\rho\pi$. These objects are interpreted as hybrid mesons, in the quark-gluon constituent model using a chromoharmonic confining potentiel. The quantum numbers $J^{PC}I^{G} = 1^{-+} 1^{-}$ can be considered in a constituent model as an hybrid meson ($q \bar q g$). The lowest $J^{PC}= 1^{-+}$states may be built in two ways : $l_{g}$=1 (gluon-excited) corresponding to an angular momentum between the gluon and ($q \bar q$) system, while $l_{q \bar q}=1$ (quarks-excited) corresponds to an angular momentum between $q$ and $\bar q$. For the gluon-excited mode $1^{-+}$ hybrids, we find the decay dominated by the $b_{1}\pi$ channel, and by the $\rho \pi$ channel for the quark-excited mode. In our model, neither the quark-excited nor the gluon-excited $1^{-+}$ (1400 MeV) hybrids can decay into $\eta\pi$ and $\eta'\pi$, in contradiction with experiment. Hence, the 1400 MeV resonance seems unlikely to be an hybrid state. The $1^{-+}$ (1600 MeV) gluon-excited hybrid is predicted with too large a total decay width, to be considered as an hybrid candidate. On the contrary the quark-excited mode has a total decay width around 165 MeV, with a $\rho \pi$ preferred decay channel, in agreement with BNL. Our conclusion is that {\it{this resonance may be considered as a hybrid meson in the quark-excited mode}}Comment: 13 pages, 1 figur

Radiative B decays to the axial KK mesons at next-to-leading order

We calculate the branching ratios of $B\to K_1\gamma$ at next-to-leading order (NLO) of $\alpha_s$ where $K_1$ is the orbitally excited axial vector meson. The NLO decay amplitude is divided into the vertex correction and the hard spectator interaction part. The one is proportional to the weak form factor of $B\to K_1$ transition while the other is a convolution between light-cone distribution amplitudes and hard scattering kernel. Using the light-cone sum rule results for the form factor, we have \calB(B^0\to K_1^0(1270)\gamma)=(0.828\pm0.335)\times 10^{-5} and \calB(B^0\to K_1^0(1400)\gamma)=(0.393\pm0.151)\times 10^{-5}.Comment: 17pages, 4 figures. Minor changes, typos corrected. PRD accepted versio

Forward-backward and isospin asymmetry for B -> K* l+ l- decay in the standard model and in supersymmetry

We discuss two dedicated observables in exclusive B -> K* l+ l- decay that can be used to study effects of physics beyond the standard model, namely the forward-backward asymmetry in the lepton spectrum and the isospin-asymmetry between decays of charged and neutral B mesons. We consider the region of large recoil-energy (i.e. small invariant mass of the lepton pair), and employ the QCD factorization approach to exclusive B meson decays. Sub-leading effects in the heavy quark mass expansion have been taken into account for the calculation of the isospin-asymmetry. We give predictions for decay asymmetries in the standard model, and its supersymmetric extension with minimal flavor violation, using parameter values allowed by current experimental constraints on B->X_s gamma decay.Comment: 21 pages, LaTeX with 6 figures, added reference

Photon polarization in radiative B decays

We study decay distributions in B -> K pi pi gamma, combining contributions from several overlapping resonances in a K pi pi mass range near 1400 MeV, (1^+) K_1(1400), (2^+) K^*_2(1430) and (1^-) K^*(1410). A method is proposed for using these distributions to determine a photon polarization parameter in the effective radiative weak Hamiltonian. This parameter is measured through an up-down asymmetry of the photon direction relative to the K pi pi decay plane. We calculate a dominant up-down asymmetry of 0.33 +- 0.05 from the K1(1400) resonance, which can be measured with about 10^8 B B-bar pairs, thus providing a new test for the Standard Model and a probe for some of its extensions.Comment: 22 pages, 3 figures, version to appear in Phys. Rev.

Ward Identities, B-> \rho Form Factors and |V_ub|

The exclusive FCNC beauty semileptonic decay B-> \rho is studied using Ward identities in a general vector meson dominance framework, predicting vector meson couplings involved. The long distance contributions are discussed which results to obtain form factors and |V_ub|. A detailed comparison is given with other approaches.Comment: 30 pages+four postscript figures, an Appendix adde

The radiative rare decays B#->#K"*"*#gamma# in the light-cone QCD sum rule approach

We predict contributions of higher K-resonances to the radiative rare decays b#->#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# #-># 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""*"("8"9"2")(0)=0.32#+-#0.06 and the K_2"*(1430) decay constant f_K__2_"*_(_1_4_3_0_)=(160 #+-# 20) MeV, we find good agreement with experimental results. The two largest fractions of the inclusive b#->#s#gamma# branching ratio are found to be (10.0#+-#4.0)% for B#->#K"*(892)#gamma# and (5.0#+-#2.0)% for B#-># K_2"*(1430)#gamma# decays. We also compare our results with the existing theoretical predictions. (orig.)Available from TIB Hannover: RA 2999(01-138) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Exclusive B#->#K"*"*#gamma# decays in the QCD LCSR approach

We predict contributions of higher K-resonances to the radiative rare decays b #-># s#gamma#, in the framework of the QCD sum rules on the light cone (LCSR). 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# #-># K"*"*#nu#_#tau# decays, we extract the corresponding decay constants for vector and axial-vector K"*"*-mesons. We present results for the corresponding branching ratios and compare them with the existing theoretical predictions. (orig.)Available from TIB Hannover: RA 2999(02-047) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

B#->#K"*l"+l"-(pl#nu#_l) helicity analysis in the LEET

We calculate the independent helicity amplitudes in the decays B #-># K"*l"+l"- and B #-># #rho#l#nu#_l in the so-called large-energy-effective-theory (LEET). Taking into account the dominant O(#alpha#_s) and SU(3) symmetry-breaking effects, we calculate various single (and total) distributions in these decays making use of the presently available data and decay form factors calculated in the QCD sum rule approach. Differential decay rates in the dilepton invariant mass and the Forward-Backward asymmetry in B #-># K"*l"+l"-are worked out. Measurements of the ratios R_i(s) triple bond d#GAMMA#_H__i(s)(B #-># K"*l"+l"-)/d#GAMMA#_H__i(s)(B #-># #rho#l#nu#_l), involving the helicity amplitudes H_i(s), i = 0, +1, -1, as precision tests of the standard model in semileptonic rare B-decays are emphasized. We argue that R_0(s) and R_-(s) can be used to determine the CKM ratio vertical stroke V_u_b vertical stroke / vertical stroke V_t_s vertical stroke and search for new physics, where the later is illustrated by supersymmetry. (orig.)Available from TIB Hannover: RA 2999(02-143) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman