New Higgs signals induced by mirror fermion mixing effects

We study the conditions under which flavor violation arises in scalar-fermion interactions, as a result of the mixing phenomena between the standard model and exotic fermions. Phenomenological consequences are discussed within the specific context of a left-right model where these additional fermions have mirror properties under the new SU(2)_R gauge group. Bounds on the parameters of the model are obtained from LFV processes; these results are then used to study the LFV Higgs decays (H --> tau l_j, l_j = e, mu), which reach branching ratios that could be detected at future colliders.Comment: 12 pages, 2 figures, ReVTex4, graphicx, to be published in Phys. Rev.

Bounds for Lepton Flavor Violation and the Pseudoscalar Higgs in the General Two Higgs Doublet Model using g−2g-2 muon factor

Current experimental data from the $g-2$ muon factor, seems to show the necessity of physics beyond the Standard Model (SM), since the difference between SM and experimental predictions is 2.6$\sigma$. In the framework of the General Two Higgs Doublet Model (2HDM), we calculate the muon anomalous magnetic moment to get lower and upper bounds for the Flavour Changing (FC) Yukawa couplings in the leptonic sector. We also obtain lower bounds for the mass of the pseudoscalar Higgs ($m_{A^0}$) as a function of the parameters of the model.Comment: 12 pages, RevTex4, 5 figures. Improved presentation, updated experimental data, amplified analysis, new figures added. Subbmited to Phys. Rev.

Flavor changing t -> c l_1^- l_2^+ decay in the general two Higgs doublet model

We study the flavor changing t-> c l_1^- l_2^+ decay in the framework of the general two Higgs doublet model, the so called model III. We predict the branching ratio for l_1=\tau, l_2=\mu at the order of magnitude of BR \sim 10^{-8}.Comment: 12 Pages, 5 Figure

Flavor Violating Higgs Decays

We study a class of nonstandard interactions of the newly discovered 125 GeV Higgs-like resonance that are especially interesting probes of new physics: flavor violating Higgs couplings to leptons and quarks. These interaction can arise in many frameworks of new physics at the electroweak scale such as two Higgs doublet models, extra dimensions, or models of compositeness. We rederive constraints on flavor violating Higgs couplings using data on rare decays, electric and magnetic dipole moments, and meson oscillations. We confirm that flavor violating Higgs boson decays to leptons can be sizeable with, e.g., h -> tau mu and h -> tau e branching ratios of order 10% perfectly allowed by low energy constraints. We estimate the current LHC limits on h -> tau mu and h -> tau e decays by recasting existing searches for the SM Higgs in the tau-tau channel and find that these bounds are already stronger than those from rare tau decays. We also show that these limits can be improved significantly with dedicated searches and we outline a possible search strategy. Flavor violating Higgs decays therefore present an opportunity for discovery of new physics which in some cases may be easier to access experimentally than flavor conserving deviations from the Standard Model Higgs framework.Comment: 39 pages, 12 figures, 3 tables; v2: Improved referencing, updated mu -> 3e bounds to include large loop contributions, corrected single top constraints; conclusions unchanged; matches version to be published in JHEP; v3: included 2-loop contributions in mu -> e conversion, improved discussion of tau -> 3 mu and of EDM constraints on FV top-Higgs couplings; conclusions unchange

Lepton Flavor Violation in the Two Higgs Doublet Model type III

We consider the Two Higgs Doublet Model (2HDM) of type III which leads to Flavour Changing Neutral Currents (FCNC) at tree level in the leptonic sector. In the framework of this model we can have, in principle, two situations: the case (a) when both doublets acquire a vacuum expectation value different from zero and the case (b) when only one of them is not zero. In addition, we show that we can make two types of rotations for the flavor mixing matrices which generates four types of lagrangians, with the rotation of type I we recover the case (b) from the case (a) in the limit $\tan \beta \to \infty$, and with the rotation of type II we obtain the case (b) from (a) in the limit $\tan \beta \to 0.$Moreover, two of the four possible lagrangians correspond to the models of types I and II plus Flavor Changing (FC) interactions. The analitical expressions of the partial lepton number violating widths $\Gamma (\mu \to eee)$ and $\Gamma (\mu \to e\gamma)$are derived for the cases (a) and (b) and both types of rotations.$$In all cases these widths go asymptotically to zero in the decoupling limit for all Higgses. We present from our analysis upper bounds for the flavour changing transition $\mu \to e,$ and we show that such bounds are sensitive to the VEV structure and the type of rotation utilized.Comment: 7 pages RevTeX4, 4 figures postscript, new section added and some new reference

Evaluación de la contaminación con agentes citotóxicos en hospitales en Colombia.

Introducción: Las revisiones del 2007 a la farmacopea americana vigente en todo el hemisferio occidental (USP capítulo 797) incluyen una sección sobre el manejo de fármacos peligrosos como preparaciones magistrales estériles, donde se recomienda el muestreo ambiental para detectar trazas de fármacos peligrosos no contenidos, afirmando que esta medida de calidad debe llevarse a cabo de forma rutinaria. Objetivo: Determinar la tasa de contaminación con agentes citotóxicos en las áreas de trabajo de tres instituciones hospitalarias de Colombia. Material y métodos: Estudio descriptivo, prospectivo, transversal. Se recolectaron muestras de 18 áreas evaluando simultáneamente la presencia de tres fármacos que han sido históricamente usados como trazadores de contaminación química: Ciclofosfamida, 5-Fluorouracilo y Carboplatino. Se evalúan superficies de áreas de preparación (cabina de seguridad biológica-CSB o aislador de barrera-AB), alistamiento y administración de medicamentos oncológicos incluyendo áreas comunes a la central de mezclas y la sala de administración de medicamentos oncológicos. Resultados: En el departamento de enfermería y farmacia existe contaminación química debido a los medicamentos citostáticos. En enfermería la contaminación se dio más debido a Carboplatino mientras que en el área de central de mezclas, el fármaco que más detectado fue 5-fluoruracilo. La comparación entre ambos departamentos permite evidenciar que la mayor tasa de contaminación se ha encontrado en farmacia. El principio activo más detectado fue 5-fluoruracilo. Conclusión: Se recomienda que las instituciones revisen los estándares para la preparación y administración de fármacos peligrosos a la luz de la normatividad mundial (USP, ASHP, ISOPP) en aspectos como la política y el procedimiento actual, controles de ingeniería, procedimientos de limpieza, manipulación de los viales del fabricante, evaluación de la CSB o AB, capacitación y educación del personal tanto en las áreas de preparación y administración, uso de EPP adecuados, la incidencia de derrames recientes en el área de la farmacia o de preparación que podrían elevar los niveles de detección y la implementación de CSTD

Evaluación de la contaminación con agentes citotóxicos en hospitales en Colombia.

Introducción: Las revisiones del 2007 a la farmacopea americana vigente en todo el hemisferio occidental (USP capítulo 797) incluyen una sección sobre el manejo de fármacos peligrosos como preparaciones magistrales estériles, donde se recomienda el muestreo ambiental para detectar trazas de fármacos peligrosos no contenidos, afirmando que esta medida de calidad debe llevarse a cabo de forma rutinaria. Objetivo: Determinar la tasa de contaminación con agentes citotóxicos en las áreas de trabajo de tres instituciones hospitalarias de Colombia. Material y métodos: Estudio descriptivo, prospectivo, transversal. Se recolectaron muestras de 18 áreas evaluando simultáneamente la presencia de tres fármacos que han sido históricamente usados como trazadores de contaminación química: Ciclofosfamida, 5-Fluorouracilo y Carboplatino. Se evalúan superficies de áreas de preparación (cabina de seguridad biológica-CSB o aislador de barrera-AB), alistamiento y administración de medicamentos oncológicos incluyendo áreas comunes a la central de mezclas y la sala de administración de medicamentos oncológicos. Resultados: En el departamento de enfermería y farmacia existe contaminación química debido a los medicamentos citostáticos. En enfermería la contaminación se dio más debido a Carboplatino mientras que en el área de central de mezclas, el fármaco que más detectado fue 5-fluoruracilo. La comparación entre ambos departamentos permite evidenciar que la mayor tasa de contaminación se ha encontrado en farmacia. El principio activo más detectado fue 5-fluoruracilo. Conclusión: Se recomienda que las instituciones revisen los estándares para la preparación y administración de fármacos peligrosos a la luz de la normatividad mundial (USP, ASHP, ISOPP) en aspectos como la política y el procedimiento actual, controles de ingeniería, procedimientos de limpieza, manipulación de los viales del fabricante, evaluación de la CSB o AB, capacitación y educación del personal tanto en las áreas de preparación y administración, uso de EPP adecuados, la incidencia de derrames recientes en el área de la farmacia o de preparación que podrían elevar los niveles de detección y la implementación de CSTD

Probing Topcolor-Assisted Technicolor from Top-Charm Associated Production at LHC

We propose to probe the topcolor-assisted technicolor (TC2) model from the top-charm associated productions at the LHC, which are highly suppressed in the Standard Model. Due to the flavor-changing couplings of the top quark with the scalars (top-pions and top-Higgs) in TC2 model, the top-charm associated productions can occur via both the s-channel and t-channel parton processes by exchanging a scalar field at the LHC. We examined these processes through Monte Carlo simulation and found that they can reach the observable level at the LHC in quite a large part of the parameter space of the TC2 model.Comment: Version to appear in PRD (Rapid Communication

Phases in the gaugino sector: direct reconstruction of the basic parameters and impact on the neutralino pair production

We consider recovering analytically the (generally complex) parameters $\mu$, $M_1$ and $M_2$ of the gaugino and Higgsino Lagrangian, from appropriate physical input in the chargino and neutralino sectors. For given $\tan\beta$, we obtain very simple analytic solutions for $M_2$, $| \mu|$, $Arg[\mu]$ in the chargino sector and a twofold $| M_1 |$, $Arg[M_1]$ analytic solution in the neutralino sector, assuming two chargino, two neutralino masses, and one of the chargino mixing angles as physical input. The twofold ambiguity in the neutralino parameters reconstruction may be essentially resolved by measuring the $e^+e^- \to \chi^0_1 \chi^0_2$ production cross-section at future linear collider energies, which we study explicitly with the phase dependences. Some salient features and specific properties of this complex case gaugino "spectrum inversion" are illustrated and compared with the similar inversion in the real case. In particular, our algorithms exhibit in a direct and transparent way the non-trivial theoretical correlation among the chargino and neutralino parameters, and the resulting allowed domains when only a subset of the required physical input masses and production cross-sections is known.Comment: Latex, 28 pages, 10 figure

Flavor changing single top quark production channels at e^+e^- colliders in the effective Lagrangian description

We perform a global analysis of the sensitivity of LEP2 and e^+e^- colliders with a c.m. energy in the range 500 - 2000 GeV to new flavor-changing single top quark production in the effective Lagrangian approach. The processes considered are sensitive to new flavor-changing effective vertices such as Ztc, htc, four-Fermi tcee contact terms as well as a right-handed Wtb coupling. We show that e^+ e^- colliders are most sensitive to the physics responsible for the contact tcee vertices. For example, it is found that the recent data from the 189 GeV LEP2 run can be used to rule out any new flavor physics that can generate these four-Fermi operators up to energy scales of \Lambda > 0.7 - 1.4 TeV, depending on the type of the four-Fermi interaction. We also show that a corresponding limit of \Lambda > 1.3 - 2.5 and \Lambda > 17 - 27 TeV can be reached at the future 200 GeV LEP2 run and a 1000 GeV e^+e^- collider, respectively. We note that these limits are much stronger than the typical limits which can be placed on flavor diagonal four-Fermi couplings. Similar results hold for \mu^+\mu^- colliders and for tu(bar) associated production. Finally we briefly comment on the necessity of measuring all flavor-changing effective vertices as they can be produced by different types of heavy physics.Comment: 34 pages, plain latex, 7 figures embadded in the text using epsfig. Added new references and discussions regarding their relevance to the paper. Added more comments on the comparison between flavor-changing and flavor-diagonal contact terms and on the importance of measuring the Ztc verte