432 research outputs found

    Light charged Higgs boson production at the Large Hadron electron Collider

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    We study the production of a light charged Higgs boson at the future Large Hadron electron Collider (LHeC), through the process epνeHqe^- p \to \nu_e H^- q considering both decay channels HbcˉH^- \to b \bar c and HτνˉτH^- \to \tau \bar \nu_\tau in the final state. We analyse these processes in the context of the 2-Higgs Doublet Model Type III (2HDM-III) and assess the LHeC sensitivity to such HH^- signals against a variety of both reducible and irreducible backgrounds. We confirm that prospects for HH^- detection in the 2HDM-III are excellent assuming standard collider energy and luminosity conditions.Comment: 12 pages, 12 figures. Accepted in Physical Review

    Confirmation of symmetrical distributions of clinical attachment loss and tooth loss in a homogeneous Mexican adult male population

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    Background/purpose To ascertain whether or not clinical attachment loss and tooth loss are present with similar severity and prevalence across the two sides of the mouth in a homogeneous sample of urban male adults. Materials and methods A cross-sectional study was carried out on 161 policemen (a largely homogeneous group in terms of ethnic background, socioeconomic status, sex, occupation, and medical/dental insurance) in Campeche, Mexico. Periodontal examinations were undertaken using the Florida Probe System in a dental chair by one trained and standardized examiner (kappa ≥ 0.60) to determine clinical attachment loss and tooth loss. We examined six sites in all teeth present in the mouth (a maximum of 168 sites, no third molars). Because of correlated data between observations, McNemar (for tooth loss) and Wilcoxon (for attachment loss) signed-rank tests were used to compare right and left sites within the same patient. Results The mean age was 38.4 ± 11.0 years. The mean number of teeth present was 24.4 ± 4.6; the mean number of periodontal sites/person was 146.7 ± 27.8. All P values were ≥ 0.05 (except for attachment loss in the upper first premolars), suggesting that there were no statistically significant differences between the right and left sides for the frequency of presentation of these two conditions. Conclusion Tooth loss and attachment loss measurements largely resemble each other on both sides of the mouth

    Analysis of the quark sector in the 2HDM-III with a four-zero Yukawa texture using the most recent data on the CKM matrix

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    In this letter we analyse, in the context of the general 2-Higgs Doublet Model, the structure of the Yukawa matrices, Y~1,2q\widetilde{ \bf Y}_{ _{1,2} }^{q}, by assuming a four-zero texture ansatz for their definition. In this framework, we obtain compact expressions for Y~1,2q\widetilde{ \bf Y}_{ _{1,2} }^{q}, which are reduced to the Cheng and Sher ansatz with the difference that they are obtained naturally as a direct consequence of the invariants of the fermion mass matrices. Furthermore, in order to avoid large flavour violating effects coming from charged Higgs exchange, we consider the main flavour constraints on the off-diagonal terms of Yukawa texture {{(χ~jq)kl\left( \widetilde{\chi}_{j}^q \right)_{kl}}} (klk\neq l). We perform a χ2\chi^2-fit based on current experimental data on the quark masses and the Cabibbo-Kobayashi-Maskawa mixing matrix VCKM{ \bf V}_{\rm CKM }. Hence, we obtain the allowed ranges for the parameters Y~1,2q\widetilde{ \bf Y}_{ _{1,2} }^{q} at 1σ\sigma for several values of tanβ\tan \beta. The results are in complete agreement with the bounds obtained taking into account constraints on Flavour Changing Neutral Currents reported in the literature.Comment: 12 pages, 1 figure. Version accepted in Phys. Lett.

    Effects of physics beyond the standard model on the neutrino charge radius: an effective Lagrangian approach

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    In this work, we look for possible new physics effects on the electromagnetic charge and anapole form factors, fQ(q2)f_Q(q^2) and fA(q2)f_A(q^2), for a massless Dirac neutrino, when these quantities are calculated in the context of an effective electroweak Yang-Mills theory, which induces the most general SUL(2)SU_L(2)--invariant Lorentz tensor structure of nonrenormalizable type for the WWγWW\gamma vertex. It is found that in this context, besides the standard model contribution, the additional contribution to fQ(q2)f_{Q}(q^2) and fA(q2)f_{A}(q^2) (fQOW(q2)f_{Q}^{O_W}(q^2) and fAOW(q2)f_{A}^{O_W}(q^2), respectively) are gauge independent and finite functions of q2q^2 after adopting a renormalization scheme. These form factors, fQOW(q2)f_{Q}^{O_W}(q^2) and fAOW(q2)f_{A}^{O_W}(q^2), get contribution at the one loop level only from the proper neutrino electromagnetic vertex. Besides, the relation fQeff(q2)=q2fAeff(q2)f_{Q}^{eff}(q^2)=q^2f_{A}^{eff}(q^2) (fQeff(q2)=fQSM(q2)+fQOW(q2)f_{Q}^{eff}(q^2)=f_{Q}^{SM}(q^2)+f_{Q}^{O_W}(q^2), fAeff(q2)=fASM(q2)+fAOW(q2)f_{A}^{eff}(q^2)=f_{A}^{SM}(q^2)+f_{A}^{O_W}(q^2)) is still fulfilled and hence the relation aνeff=eff/6a_{\nu}^{eff} = ^{eff} /6 (aνeff=aνSM+aνOWa_{\nu}^{eff} = a_{\nu}^{SM}+ a_{\nu}^{O_W}, eff=SM+<rν2>OW ^{eff} = ^{SM}+< r^2_{\nu} > ^{O_W})is gotten, just as in the SM. Using the experimental constraint on the anomalous WWγWW\gamma vertex, a value for the additional contribution to the charge radius of |^{O_W}| \lsim 10^{-34} cm^2 is obtained, which is one order of magnitude lower than the SM value.Comment: 9 pages, 3 figure

    Tratamiento con nicergolina de dos casos de disfunción cognitiva en perros geriátricos

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    Dos perros con signos de disfunción cognitiva fueron tratados con nicergolina. El objetivo era poder mejorar el aporte sanguíneo al cerebro y retrasar los efectos propios del síndrome. En ambos casos se observó una mejora ostensible de su conducta. La nicergolina puede se útil en el tratamiento sintomático del síndrome.

    Orai2 Modulates Store-Operated Ca2+ Entry and Cell Cycle Progression in Breast Cancer Cells

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    Breast cancer is a heterogeneous disease from the histological and molecular expression point of view, and this heterogeneity determines cancer aggressiveness. Store-operated Ca2+ entry (SOCE), a major mechanism for Ca2+ entry in non-excitable cells, is significantly remodeled in cancer cells and plays an important role in the development and support of different cancer hallmarks. The store-operated CRAC (Ca2+ release-activated Ca2+) channels are predominantly comprised of Orai1 but the participation of Orai2 and Orai3 subunits has been reported to modulate the magnitude of Ca2+ responses. Here we provide evidence for a heterogeneous expression of Orai2 among different breast cancer cell lines. In the HER2 and triple negative breast cancer cell lines SKBR3 and BT20, respectively, where the expression of Orai2 was greater, Orai2 modulates the magnitude of SOCE and sustain Ca2+ oscillations in response to carbachol. Interestingly, in these cells Orai2 modulates the activation of NFAT1 and NFAT4 in response to high and low agonist concentrations. Finally, we have found that, in cells with high Orai2 expression, Orai2 knockdown leads to cell cycle arrest at the G0-G1 phase and decreases apoptosis resistance upon cisplatin treatment. Altogether, these findings indicate that, in breast cancer cells with a high Orai2 expression, Orai2 plays a relevant functional role in agonist-evoked Ca2+ signals, cell proliferation and apoptosis resistance.Ministerio de Ciencia e Innovación: PID2019-104084GB-C21Ministerio de Ciencia e Innovación: PID2019-104084GB-C22Consejería de Educación y Empleo, Junta de Extremadura: IB20007Consejería de Educación y Empleo, Junta de Extremadura: GR18061Consejería de Educación y Empleo, Junta de Extremadura: PD16072Consejería de Educación y Empleo, Junta de Extremadura: GR2100

    Yukawa txtures and charged Higgs boson phenomenology in the type-III two-Higgs-doublet model

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    We discuss the implications of assuming a four-zero Yukawa texture for the properties of the charged Higgs boson within the context of the general 2-Higgs Doublet Model of Type III. We begin by presenting a detailed analysis of the charged Higgs boson couplings with heavy quarks and the resulting pattern for its decays. The production of charged Higgs bosons is also sensitive to the modifications of its couplings, so that we also evaluate the resulting effects on the top decay tbH+t \to b H^{+} as well as on `direct' cbˉH++c.c.c\bar{b}\to H^++c. c. and `indirect' qqˉ,ggtˉbH++c.c.q\bar q,gg\to \bar t b H^++c. c. production. Significant scope exists at the Large Hadron Collider for several H±H^\pm production and decay channels combined to enable one to distinguish between such a model and alternative 2-Higgs doublet scenarios.Comment: 30 pages, 18 figure
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