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Campanario, F., & Kubocz, M. (2013). Higgs-boson production in association with three jets via gluon fusion at the LHC: Gluonic contributions. Phys. Rev. D, 88(5), 054021–5pp.
Abstract: Higgs production in association with three jets via gluon fusion is an important channel for the measurement of the CP properties of the Higgs particle at the LHC. In this paper, we go beyond the heavy top effective theory approximation and include at LO the full mass dependence of the top- and bottom-quark contributions. We consider the dominant subchannel gg -> Hggg which involves the manipulation of massive rank-5 hexagon integrals. Furthermore, we present results for several differential distributions and show deviations from the effective theory as large as 100% at high p(T) for light Higgs masses.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Search for a low-mass scalar Higgs boson decaying to a tau pair in single-photon decays of Y(1S). Phys. Rev. D, 88(7), 071102–8pp.
Abstract: We search for a low-mass scalar CP-odd Higgs boson, A(0), produced in the radiative decay of the upsilon resonance and decaying into a tau(+)tau(-) pair: Y(1S) -> gamma A(0). The production of Y(1S) mesons is tagged by Y(2S) -> pi(+)pi(-) Y(1S) transitions, using a sample of (98.3 +/- 0.9) x 10(6) Y(2S) mesons collected by the BABAR detector. We find no evidence for a Higgs boson in the mass range 3: 5 <= m(A)0 <= 9: 2 GeV, and combine these results with our previous search for the tau decays of the light Higgs in radiative Y(3S) decays, setting limits on the coupling of A(0) to the b (b) over bar quarks in the range 0.09-1.9. Our measurements improve the constraints on the parameters of the next-to-minimal-supersymmetric Standard Model and similar theories with low-mass scalar degrees of freedom.
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Helo, J. C., Kovalenko, S. G., Hirsch, M., & Pas, H. (2013). Short-range mechanisms of neutrinoless double beta decay at the LHC. Phys. Rev. D, 88(7), 073011–19pp.
Abstract: Lepton number violation (LNV) mediated by short- range operators can manifest itself in both neutrinoless double beta decay (0 nu beta beta) and in processes with same- sign dilepton final states at the LHC. We derive limits from existing LHC data at root s = 8 TeV and compare the discovery potential of the forthcoming root s = 14 TeV phase of the LHC with the sensitivity of current and future 0 nu beta beta decay experiments, assuming the short-range part of the 0 nu beta beta decay amplitude dominates. We focus on the first of two possible topologies triggered by one fermion and two bosons in the intermediate state. In all cases, except for the pure leptoquark mechanism, the LHC will be more sensitive than 0 nu beta beta decay in the future. In addition, we propose to search for a charge asymmetry in the final state leptons and to use different invariant mass peaks as a possible tool to discriminate the various possible mechanisms for LNV signals at the LHC.
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Liang, W. H., Albaladejo, M., & Oset, E. (2013). Searching for a hidden charm h(1) state in the X(4660) -> eta h(1) and X(4660) -> eta D*(D)over-bar* decays. Phys. Rev. D, 88(7), 074027–7pp.
Abstract: We explore the possibility of experimentally detecting a predicted h(1) inverted right perpendicular I-G(J(PC)) = 0(-)(1(+-))inverted left perpendicular state of hidden charm made out from the D*(D) over bar* interaction. The method consists in measuring the decay of X(4660) into eta D*(D) over bar* and determining the binding energy with respect to the D*(D) over bar* threshold from the shape of the D*(D) over bar* invariant mass distribution. A complementary method consists in looking at the inclusive X(4660) -> eta X decay and searching for a peak in the X invariant mass distribution. We make calculations to determine the partial decay width of X(4660) -> eta h(1) from the measured X(4660) -> eta D*(D) over bar* distribution. This estimation should serve in an experiment to foresee the possibility of detecting the h(1) state on top of the background of inclusive events.
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Olmo, G. J., & Rubiera-Garcia, D. (2013). Importance of torsion and invariant volumes in Palatini theories of gravity. Phys. Rev. D, 88(8), 084030–11pp.
Abstract: We study the field equations of extensions of general relativity formulated within a metric-affine formalism setting torsion to zero (Palatini approach). We find that different (second-order) dynamical equations arise depending on whether torsion is set to zero (i) a priori or (ii) a posteriori, i.e., before or after considering variations of the action. Considering a generic family of Ricci-squared theories, we show that in both cases the connection can be decomposed as the sum of a Levi-Civita connection and terms depending on a vector field. However, while in case (i) this vector field is related to the symmetric part of the connection, in (ii) it comes from the torsion part and, therefore, it vanishes once torsion is completely removed. Moreover, the vanishing of this torsion-related vector field immediately implies the vanishing of the antisymmetric part of the Ricci tensor, which therefore plays no role in the dynamics. Related to this, we find that the Levi-Civita part of the connection is due to the existence of an invariant volume associated with an auxiliary metric h(mu v), which is algebraically related with the physical metric g(mu v).
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Measurement of the B+ -> omega l(+) nu branching fraction with semileptonically tagged B mesons. Phys. Rev. D, 88(7), 072006–8pp.
Abstract: We report a measurement of the branching fraction of the exclusive charmless semileptonic decay B+ -> omega l(+) nu, where l is either an electron or amuon. We use samples of B+ mesons tagged by a reconstructed charmed semileptonic decay of the other B meson in the event. The measurement is based on a data set of 426.1 fb(-1) of e(+)e(-) collisions at a center-of-mass energy of 10.58 GeV recorded with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) storage rings. We measure a branching fraction of B(B+ -> omega l(+) nu) = (1.35 +/- 0.21 +/- 0.11) x 10(-4), where the uncertainties are statistical and systematic, respectively. We also present measurements of the partial branching fractions in three bins of q(2), the invariant-mass squared of the lepton-neutrino system, and we compare them to theoretical predictions of the form factors.
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Aguilar, A. C., Binosi, D., & Papavassiliou, J. (2013). Gluon mass generation in the presence of dynamical quarks. Phys. Rev. D, 88(7), 074010–12pp.
Abstract: We study in detail the impact of dynamical quarks on the gluon mass generation mechanism, in the Landau gauge, for the case of a small number of quark families. As in earlier considerations, we assume that the main bulk of the unquenching corrections to the gluon propagator originates from the fully dressed quark-loop diagram. The nonperturbative evaluation of this diagram provides the key relation that expresses the unquenched gluon propagator as a deviation from its quenched counterpart. This relation is subsequently coupled to the integral equation that controls the momentum evolution of the effective gluon mass, which contains a single adjustable parameter; this constitutes a major improvement compared to the analysis presented in Aguilar et al. [Phys. Rev. D 86, 014032 (2012)], where the behavior of the gluon propagator in the deep infrared was estimated through numerical extrapolation. The resulting nonlinear system is then treated numerically, yielding unique solutions for the modified gluon mass and the quenched gluon propagator, which fully confirms the picture put forth recently in several continuum and lattice studies. In particular, an infrared finite gluon propagator emerges, whose saturation point is considerably suppressed, due to a corresponding increase in the value of the gluon mass. This characteristic feature becomes more pronounced as the number of active quark families increases, and can be deduced from the infrared structure of the kernel entering in the gluon mass equation.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Measurement of an excess of (B)over-bar -> D-(*) tau(-)(v)over-bar(tau) decays and implications for charged Higgs bosons. Phys. Rev. D, 88(7), 072012–30pp.
Abstract: Based on the full BABAR data sample, we report improved measurements of the ratios R(D) = B((B) over bar -> D tau(-)(v) over bar (tau))/B((B) over bar -> Dl(-)(v) over bar (l)) and R(D*) = B((B) over bar -> D*tau(-)(v) over bar (tau))/B((B) over bar -> D*l(-)(v) over bar (l)), where l refers to either an electron or muon. These ratios are sensitive to new physics contributions in the form of a charged Higgs boson. We measure R(D) = 0.440 +/- 0.058 +/- 0.042 and R(D*) = 0.332 +/- 0.024 +/- 0.018, which exceed the standard model expectations by 2.0 sigma and 2.7 sigma, respectively. Taken together, the results disagree with these expectations at the 3.4 sigma level. This excess cannot be explained by a charged Higgs boson in the type II two-Higgs-doublet model. Kinematic distributions presented here exclude large portions of the more general type III two-Higgs-doublet model, but there are solutions within this model compatible with the results.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Measurement of the mass of the D-0 meson. Phys. Rev. D, 88(7), 071104–7pp.
Abstract: We report a measurement of the D-0 meson mass using the decay chain D* (2010) + -> D-0 pi(+) with D-0 -> K-K-K+pi(+). The data were recorded with the BABAR detector at center-of-mass energies at and near the Upsilon(4S) resonance, and correspond to an integrated luminosity of approximately 477 fb(-1). We obtain m(D-0) (1864: 841 +/- 0: 048 +/- 0: 063) MeV, where the quoted errors are statistical and systematic, respectively. The uncertainty of this measurement is half that of the best previous measurement.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., Oyanguren, A., & Villanueva-Perez, P. (2013). Measurement of the e(+)e(-) -> p(p)over-bar cross section in the energy range from 3.0 to 6.5 GeV. Phys. Rev. D, 88(7), 072009–12pp.
Abstract: The e(+)e(-) -> p (p) over bar cross section and the proton magnetic form factor have been measured in the center-of-mass energy range from 3.0 to 6.5 GeV using the initial-state radiation technique with an undetected photon. This is the first measurement of the form factor at energies higher than 4.5 GeV. The analysis is based on 469 fb-1 of integrated luminosity collected with the BABAR detector at the PEP-II collider at e(+)e(-) center-of-mass energies near 10.6 GeV. The branching fractions for the decays J/psi -> p (p) over bar and psi(2S) -> p (p) over bar have also been measured.
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