Hunting the CKM weak phase with time-integrated Dalitz analyses of Bs -> K pi pi decays

We present a new technique to extract information on the Unitarity Triangle from the study of Bs -> K pi pi Dalitz plot. Using isospin symmetry and the possibility to access the decay amplitudes from Dalitz analyses, we propose a new strategy to extract the weak phase gamma from Bs to K pi pi.Comment: 2 pages. v2: Discussion of interference on Dalitz plot clarified. Bs -> K K pi channels removed. v3: Improved discussion of experimental aspects. Final version to appear in Phys. Lett.

B_s to K^(*)0 \bar K^(*)0 decays: the golden channels for new physics searches

We point out that time-dependent CP asymmetries in B_s to K^{*0} \bar K^{*0} decays probe the presence of new physics in b to s transitions with an unprecedented theoretical accuracy. We show that, contrary to the case of B_d to phi K_S, it is possible to obtain a model-independent prediction for the coefficient S(B_s to K^{*0} \bar K^{*0}) in the Standard Model. We give an estimate of the experimental precision achievable with the next generation of B physics experiments. We also discuss how this approach can be extended to the case of B_s to \bar K^{*0} K^0, B_s to K^{*0} \bar K^0 and B_s to K^0 \bar K^0 decays and the different experimental challenges for these channels.Comment: 4 pages, 1 figure. v2: Corrected dependence on CKM angles, expanded discussion of multiple polarizations, conclusions strengthened. Final version to appear in PR

Improved Determination of the CKM Angle alpha from B to pi pi decays

Motivated by a recent paper that compares the results of the analysis of the CKM angle alpha in the frequentist and in the Bayesian approaches, we have reconsidered the information on the hadronic amplitudes, which helps constraining the value of alpha in the Standard Model. We find that the Bayesian method gives consistent results irrespective of the parametrisation of the hadronic amplitudes and that the results of the frequentist and Bayesian approaches are equivalent when comparing meaningful probability ranges or confidence levels. We also find that from B to pi pi decays alone the 95% probability region for alpha is the interval [80^o,170^o], well consistent with recent analyses of the unitarity triangle where, by using all the available experimental and theoretical information, one gets alpha = (93 +- 4)^o. Last but not least, by using simple arguments on the hadronic matrix elements, we show that the unphysical region alpha ~ 0, present in several experimental analyses, can be eliminated.Comment: 16 pages, 7 figure

CP Asymmetries in B to f_0 K_S Decays

We consider the branching ratio and the CP asymmetries in B to f_0(980)K_S decay to the end of determining the deviation of the time-dependent CP asymmetry from sin(2 beta) arising from Standard Model physics. We obtain Delta S_{f_0 K_S} within the context of the QCD factorization framework for the B to f_0(980)K_S decay amplitudes assuming the f_0(980) is a q\bar{q} state and employing a random scan over the theoretical parameter space to assess the possible range in Delta S_{f_0 K_S}. Imposing the value of the experimental branching ratio within 1 sigma and 3 sigma, respectively, of its central value as a constraint, we find the range of Delta S_{f_0 K_S} to be [0.018, 0.033] for a scan in which the parameters are allowed to vary within 1 sigma of their central values and the range [-0.019, 0.064] for a scan in which the parameters vary within 3 sigma of their central values.Comment: 27 pages, 10 figures, references adde

On the Estimation of Euler Equations in the Presence of a Potential Regime Shift

The concept of a peso problem is formalized in terms of a linear Euler equation and a nonlinear marginal model describing the dynamics of the exogenous driving process. It is shown that, using a threshold autoregressive model as a marginal model, it is possible to produce time-varying peso premia. A Monte Carlo method and a method based on the numerical solution of integral equations are considered as tools for computing conditional future expectations in the marginal model. A Monte Carlo study illustrates the poor performance of the generalized method of moment (GMM) estimator in small and even relatively large samples. The poor performance is particularly acute in the presence of a peso problem but is also serious in the simple linear case.peso problem; Euler equations; GMM; threshold autoregressive models

Challenges for MSSM Higgs searches at Hadron Colliders

In this article we analyze the impact of B-physics and Higgs physics at LEP on standard and non-standard Higgs bosons searches at the Tevatron and the LHC, within the framework of minimal flavor violating supersymmetric models. The B-physics constraints we consider come from the experimental measurements of the rare B-decays b -> s gamma and B_u -> tau nu and the experimental limit on the B_s -> mu+ mu- branching ratio. We show that these constraints are severe for large values of the trilinear soft breaking parameter A_t, rendering the non-standard Higgs searches at hadron colliders less promising. On the contrary these bounds are relaxed for small values of A_t and large values of the Higgsino mass parameter mu, enhancing the prospects for the direct detection of non-standard Higgs bosons at both colliders. We also consider the available ATLAS and CMS projected sensitivities in the standard model Higgs search channels, and we discuss the LHC's ability in probing the whole MSSM parameter space. In addition we also consider the expected Tevatron collider sensitivities in the standard model Higgs h -> b bbar channel to show that it may be able to find 3 sigma evidence in the B-physics allowed regions for small or moderate values of the stop mixing parameter.Comment: 22 pages, 5 figures. Added references and acknowledgements. Submitted to PR

Modification of the Unitarity Relation for sin2beta-Vub in Supersymmetric Models

Recently, a more than 2sigma discrepancy has been observed between the well measured inclusive value of Vub and the predicted value of Vub from the unitarity triangle fit using the world average value of sin2beta. We attempt to resolve this tension in the context of grand unified SO(10) and SU(5) models where the neutrino mixing matrix is responsible for flavor changing neutral current at the weak scale and the models with non-proportional A-terms (can be realized simply in the context of intersecting D-brane models) and investigate the interplay between the constraints arising from B_{s,d}-\bar B_{s,d} mixings, epsilon_K, Br(tau -> mu gamma), Br(mu -> e gamma) and a fit of this new discrepancy. We also show that the ongoing measurement of the phase of Bs mixing will be able to identify the grand unified model. The measurement of Br(tau -> e gamma) will also be able to test these scenarios, especially the models with non-proportional A-terms.Comment: 20 pages, 4 figures. Minor corrections, references adde