Search results for "UNITARITY"
showing 10 items of 245 documents
Study ofCPviolation inB∓→Dh∓(h=K,π) with the modesD→K∓π±π0,D→π+π−π0andD→K+K−π0
2015
An analysis of the decays of B--/+ -> DK -/+ and B--/+ -> D pi(-/+) is presented in which the D meson is reconstructed in the three-body final states K--/+pi(+/-)pi(0), pi(+)pi(-)pi(0) and K+K-pi(0). Using data from LHCb corresponding to an integrated luminosity of 3.0 fb(-1) of pp collisions, measurements of several CP observables are performed. First observations are obtained of the suppressed Atwood-Dunietz-Soni decay B--/+ -> [pi K-+(+/-)pi(0)](D)pi(-/+) and the quasi-Gronau-London-Wyler decay B--/+ -> [K+K-pi(0)](D)pi(-/+). The results are interpreted in the context of the unitarity triangle angle gamma and related parameters.
Measurement of Time-DependentCPAsymmetries inB0→D(*)±D∓Decays
2005
We present updated results on time-dependent CP asymmetries in fully reconstructed B-0 -> D-(*)+/-pi(-/+) and B-0 -> D-+/-rho(-/+) decays in approximately 232x10(6) Upsilon(4S)-> B (B) over bar events collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. From a time-dependent maximum-likelihood fit we obtain for the parameters related to the CP violation angle 2 beta+gamma: a(D pi)=-0.010 +/- 0.023 +/- 0.007, c(lep)(D pi)=-0.033 +/- 0.042 +/- 0.012, a(D*)pi=-0.040 +/- 0.023 +/- 0.010, c(lep)(D*)pi=0.049 +/- 0.042 +/- 0.015,a(D rho)=-0.024 +/- 0.031 +/- 0.009, c(lep)(D rho)=-0.098 +/- 0.055 +/- 0.018, where the first error is statistical and the second is syste…
Global fits in the coloured scalar model
2020
Abstract In this work we study the phenomenological constraints on the parameter space of scalars carrying colour quantum numbers. In particular we constrain the Manohar-Wise model based on the addition of a SU(2) doublet and SU(3) octet to the minimal Higgs model. The fits are performed using the open-source package HEPfit . We include both theoretical constraints, such as unitarity and perturbativity, and experimental constraints, like the ones coming from flavour and electroweak observables. For the first time we combine all these results and we are able to constrain the parameters of the potential, the Yukawa couplings and the masses of the scalars.
Amplitude analysis ofB0→K+π−π0and evidence of directCPviolation inB→K*πdecays
2011
We analyze the decay B0-->K+ pi- pi0 with a sample of 454 million B Bbar events collected by the BaBar detector at the PEP-II asymmetric-energy B factory at SLAC, and extract the complex amplitudes of seven interfering resonances over the Dalitz plot. These results are combined with amplitudes measured in B0-->K_S pi+ pi- decays to construct isospin amplitudes from B0-->K* pi and B0-->rho K decays. We measure the phase of the isospin amplitude Phi_3/2, useful in constraining the CKM unitarity triangle angle gamma and evaluate a CP rate asymmetry sum rule sensitive to the presence of new physics operators. We measure direct CP violation in B0-->K*+ pi- decays at the level of 3 sigma when mea…
Beyond the dark matter effective field theory and a simplified model approach at colliders
2016
Direct detection of and LHC search for the singlet fermion dark matter (SFDM) model with Higgs portal interaction are considered in a renormalizable model where the full Standard Model (SM) gauge symmetry is imposed by introducing a singlet scalar messenger. In this model, direct detection is described by an effective operator m_q \bar{q} q \bar{\chi} \chi as usual, but the full amplitude for monojet + \not E_T involves two intermediate scalar propagators, which cannot be seen within the effective field theory (EFT) or in the simplified model without the full SM gauge symmetry. We derive the collider bounds from the ATLAS monojet + \not E_T as well as the CMS t\bar{t} + \not E_T data, findi…
Building the full Pontecorvo-Maki-Nakagawa-Sakata matrix from six independent Majorana-type phases
2009
In the framework of three light Majorana neutrinos, we show how to reconstruct, through the use of 3 x 3 unitarity, the full PMNS matrix from six independent Majorana-type phases. In particular, we express the strength of Dirac-type CP violation in terms of these Majorana-type phases by writing the area of the unitarity triangles in terms of these phases. We also study how these six Majorana phases appear in CP-odd weak-basis invariants as well as in leptonic asymmetries relevant for flavored leptogenesis.
Fermion masses and unitarity without a Higgs boson
2004
We discuss the consistency of fermion mass generation by boundary conditions and brane localized terms in higher dimensional models of gauge symmetry breaking without a Higgs boson. The sum rules imposed by tree-level unitarity and Ward identities are applied to check the consistency of mass generation by orbifold projections and more general boundary conditions consistent with the variational principle. We find that the sum rules are satisfied for boundary conditions corresponding to brane localized mass and kinetic terms consistent with the reduced gauge symmetry on the brane.
Strategy to find the two $\Lambda(1405)$ states from lattice QCD simulations
2012
Theoretical studies within the chiral unitary approach, and recent experiments, have provided evidence of the existence of two isoscalar states in the region of the $\Lambda(1405)$. In this paper we use the same chiral approach to generate energy levels in a finite box. In a second step, assuming that these energies correspond to lattice QCD results, we devise the best strategy of analysis to obtain the two states in the infinite volume case, with sufficient precision to distinguish them. We find out that using energy levels obtained with asymmetric boxes and/or with a moving frame, with reasonable errors in the energies, one has a successful scheme to get the two $\Lambda(1405)$ poles.
Measurement ofCPobservables inB±→DCPK±decays and constraints on the CKM angleγ
2010
Using the entire sample of 467×10^6 Υ(4S)→BB[overbar] decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the SLAC National Accelerator Laboratory, we perform an analysis of B^± → DK^± decays, using decay modes in which the neutral D meson decays to either CP-eigenstates or non-CP-eigenstates. We measure the partial decay rate charge asymmetries for CP-even and CP-odd D final states to be A_(CP+) = 0.25±0.06±0.02 and A_(CP-) = -0.09±0.07±0.02, respectively, where the first error is the statistical and the second is the systematic uncertainty. The parameter A_(CP+) is different from zero with a significance of 3.6 standard deviations, constituting evidence f…
B0andBs0decays intoJ/ψf0(980)andJ/ψf0(500)and the nature of the scalar resonances
2014
Abstract We describe the B 0 and B s 0 decays into J / ψ f 0 ( 500 ) and J / ψ f 0 ( 980 ) by taking into account the dominant process for the weak decay of B 0 and B s 0 into J / ψ and a q q ¯ component. After hadronization of this q q ¯ component into pairs of pseudoscalar mesons we obtain certain weights for the meson–meson components and allow them to interact among themselves. The final state interaction of the meson–meson components, described in terms of chiral unitary theory, gives rise to the f 0 ( 980 ) and f 0 ( 500 ) resonances and we can obtain the π + π − invariant mass distributions after the decay of the resonances, which allows us to compare directly to the experiments. We …