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Sample records for twin higgs mechanism

  1. The Twin Higgs mechanism and Composite Higgs

    CERN Document Server

    Low, Matthew; Wang, Lian-Tao

    2015-01-01

    We combine the Twin Higgs mechanism with the paradigm of Composite Higgs models. In this class of models the Higgs is a pseudo-Nambu-Goldstone boson from a strongly coupled sector near the TeV scale, and it is additionally protected by a discrete symmetry due to the twin mechanism. We discuss the model building issues associated with this setup and quantify the tuning needed to achieve the correct electroweak vacuum and the Higgs mass. In contrast to standard Composite Higgs models, the lightest resonance associated with the top sector is the uncolored mirror top, while the colored top partners can be made parameterically heavier without extra tuning. In some cases, the vector resonances are predicted to lie in the multi-TeV range. We present models where the resonances - both fermions and vectors - being heavier alleviates the pressure on naturalness coming from direct searches demonstrating that theories with low tuning may survive constraints from the Large Hadron Collider.

  2. Minimal Mirror Twin Higgs

    CERN Document Server

    Barbieri, Riccardo; Harigaya, Keisuke

    2016-01-01

    In a Mirror Twin World with a maximally symmetric Higgs sector the little hierarchy of the Standard Model can be significantly mitigated, perhaps displacing the cutoff scale above the LHC reach. We show that consistency with observations requires that the Z2 parity exchanging the Standard Model with its mirror be broken in the Yukawa couplings. A minimal such effective field theory, with this sole Z2 breaking, can generate the Z2 breaking in the Higgs sector necessary for the Twin Higgs mechanism, and has constrained and correlated signals in invisible Higgs decays, direct Dark Matter Detection and Dark Radiation, all within reach of foreseen experiments. For dark matter, both mirror neutrons and a variety of self-interacting mirror atoms are considered. Neutrino mass signals and the effects of a possible additional Z2 breaking from the vacuum expectation values of B-L breaking fields are also discussed.

  3. The vector-like twin Higgs

    Science.gov (United States)

    Craig, Nathaniel; Knapen, Simon; Longhi, Pietro; Strassler, Matthew

    2016-07-01

    We present a version of the twin Higgs mechanism with vector-like top partners. In this setup all gauge anomalies automatically cancel, even without twin leptons. The matter content of the most minimal twin sector is therefore just two twin tops and one twin bottom. The LHC phenomenology, illustrated with two example models, is dominated by twin glueball decays, possibly in association with Higgs bosons. We further construct an explicit four-dimensional UV completion and discuss a variety of UV completions relevant for both vector-like and fraternal twin Higgs models.

  4. The Vector-like Twin Higgs

    CERN Document Server

    Craig, Nathaniel; Longhi, Pietro; Strassler, Matthew

    2016-01-01

    We present a version of the twin Higgs mechanism with vector-like top partners. In this setup all gauge anomalies automatically cancel, even without twin leptons. The matter content of the most minimal twin sector is therefore just two twin tops and one twin bottom. The LHC phenomenology, illustrated with two example models, is dominated by twin glueball decays, possibly in association with Higgs bosons. We further construct an explicit four-dimensional UV completion and discuss a variety of UV completions relevant for both vector-like and fraternal twin Higgs models.

  5. Holographic twin Higgs model.

    Science.gov (United States)

    Geller, Michael; Telem, Ofri

    2015-05-15

    We present the first realization of a "twin Higgs" model as a holographic composite Higgs model. Uniquely among composite Higgs models, the Higgs potential is protected by a new standard model (SM) singlet elementary "mirror" sector at the sigma model scale f and not by the composite states at m_{KK}, naturally allowing for m_{KK} beyond the LHC reach. As a result, naturalness in our model cannot be constrained by the LHC, but may be probed by precision Higgs measurements at future lepton colliders, and by direct searches for Kaluza-Klein excitations at a 100 TeV collider.

  6. Twin Higgs WIMP Dark Matter

    CERN Document Server

    García, Isabel García; March-Russell, John

    2015-01-01

    Dark matter (DM) without a matter asymmetry is studied in the context of Twin Higgs (TH) theories in which the LHC naturalness problem is addressed. These possess a twin sector related to the Standard Model (SM) by a (broken) $\\mathbb{Z}_2$ symmetry, and interacting with the SM via a specific Higgs portal. We focus on the minimal realisation of the TH mechanism, the Fraternal Twin Higgs, with only a single generation of twin quarks and leptons, and $SU(3)'\\times SU(2)'$ gauge group. We show that a variety of natural twin-WIMP DM candidates are present (directly linked to the weak scale by naturalness), the simplest and most attractive being the $\\tau^\\prime$ lepton with a mass $m_{\\tau^\\prime} > m_{\\rm Higgs}/2$, although spin-1 $W^{\\prime\\pm}$ DM and multicomponent DM are also possible (twin baryons are strongly disfavoured by tuning). We consider in detail the dynamics of the possibly (meta)stable glueballs in the twin sector, the nature of the twin QCD phase transition, and possible new contributions to th...

  7. The Radiative Z2 Breaking Twin Higgs

    CERN Document Server

    Yu, Jiang-Hao

    2016-01-01

    In twin Higgs model, the Higgs boson mass is protected by a $Z_2$ symmetry. The $Z_2$ symmetry needs to be broken either explicitly or spontaneously to obtain misalignment between electroweak and new physics vacua. We propose a novel $Z_2$ breaking mechanism, in which the $Z_2$ is spontaneously broken by radiative corrections to the Higgs potential. Two twin Higgses with different vacua are needed, and vacuum misalignment is realized by opposite but comparable contributions from gauge and Yukawa interactions to the potential. Due to fully radiative symmetry breaking, the Higgs sector is completely determined by twin Higgs vacuum, Yukawa and gauge couplings. There are eight pseudo-Goldstone bosons: the Higgs boson, inert doublet Higgs, and three twin scalars. We show the 125 GeV Higgs mass and constraints from Higgs coupling measurements could be satisfied.

  8. Twin Higgs Asymmetric Dark Matter.

    Science.gov (United States)

    García García, Isabel; Lasenby, Robert; March-Russell, John

    2015-09-18

    We study asymmetric dark matter (ADM) in the context of the minimal (fraternal) twin Higgs solution to the little hierarchy problem, with a twin sector with gauged SU(3)^{'}×SU(2)^{'}, a twin Higgs doublet, and only third-generation twin fermions. Naturalness requires the QCD^{'} scale Λ_{QCD}^{'}≃0.5-20  GeV, and that t^{'} is heavy. We focus on the light b^{'} quark regime, m_{b^{'}}≲Λ_{QCD}^{'}, where QCD^{'} is characterized by a single scale Λ_{QCD}^{'} with no light pions. A twin baryon number asymmetry leads to a successful dark matter (DM) candidate: the spin-3/2 twin baryon, Δ^{'}∼b^{'}b^{'}b^{'}, with a dynamically determined mass (∼5Λ_{QCD}^{'}) in the preferred range for the DM-to-baryon ratio Ω_{DM}/Ω_{baryon}≃5. Gauging the U(1)^{'} group leads to twin atoms (Δ^{'}-τ^{'}[over ¯] bound states) that are successful ADM candidates in significant regions of parameter space, sometimes with observable changes to DM halo properties. Direct detection signatures satisfy current bounds, at times modified by dark form factors.

  9. Cosmological Signals of a Mirror Twin Higgs

    CERN Document Server

    Craig, Nathaniel; Trott, Timothy

    2016-01-01

    We investigate the cosmology of the minimal model of neutral naturalness, the mirror Twin Higgs. The softly-broken mirror symmetry relating the Standard Model to its twin counterpart leads to significant dark radiation in tension with BBN and CMB observations. We quantify this tension and illustrate how it can be mitigated in several simple scenarios that alter the relative energy densities of the two sectors while respecting the softly-broken mirror symmetry. In particular, we consider both the out-of-equilibrium decay of a new scalar as well as reheating in a toy model of twinned inflation, Twinflation. In both cases the dilution of energy density in the twin sector does not merely reconcile the existence of a mirror Twin Higgs with cosmological constraints, but predicts contributions to cosmological observables that may be probed in current and future CMB experiments. This raises the prospect of discovering evidence of neutral naturalness through cosmology rather than colliders.

  10. Cosmology in Mirror Twin Higgs and Neutrino Masses

    CERN Document Server

    Chacko, Zackaria; Fox, Patrick J; Harnik, Roni

    2016-01-01

    We explore a simple solution to the cosmological challenges of the original Mirror Twin Higgs (MTH) model that leads to interesting implications for experiment. We consider theories in which both the standard model and mirror neutrinos acquire masses through the familiar seesaw mechanism, but with a low right-handed neutrino mass scale of order a few GeV. In these $\

  11. The flavor of the Composite Twin Higgs

    Science.gov (United States)

    Csáki, Csaba; Geller, Michael; Telem, Ofri; Weiler, Andreas

    2016-09-01

    The assumption of anarchic quark flavor puts serious stress on composite Higgs models: flavor bounds imply a tuning of a few per-mille (at best) in the Higgs potential. Composite twin Higgs (CTH) models significantly reduce this tension by opening up a new region of parameter space, obtained by raising the coupling among the composites close to the strong coupling limit g ∗ ˜ 4π, thereby raising the scale of composites to around 10 TeV. This does not lead to large tuning in the Higgs potential since the leading quantum corrections are canceled by the twin partners (rather than the composites). We survey the leading flavor bounds on the CTH, which correspond to tree-level Δ F = 2 four-Fermi operators from Kaluza-Klein (KK) Z exchange in the kaon system and 1-loop corrections from KK fermions to the electric dipole moment of the neutron. We provide a parametric estimate for these bounds and also perform a numeric scan of the parameter space using the complete calculation for both quantities. The results confirm our expectation that CTH models accommodate anarchic flavor significantly better than regular composite Higgs (CH) models. Our conclusions apply both to the identical and fraternal twin cases.

  12. Exotic Quarks in Twin Higgs Models

    CERN Document Server

    Cheng, Hsin-Chia; Salvioni, Ennio; Tsai, Yuhsin

    2015-01-01

    The Twin Higgs model provides a natural theory for the electroweak symmetry breaking without the need of new particles carrying the standard model gauge charges below a few TeV. In the low energy theory, the only probe comes from the mixing of the Higgs fields in the standard model and twin sectors. However, an ultraviolet completion is required below ~ 10 TeV to remove residual logarithmic divergences. In non-supersymmetric completions, new exotic fermions charged under both the standard model and twin gauge symmetries have to be present to accompany the top quark, thus providing a high energy probe of the model. Some of them carry standard model color, and may therefore be copiously produced at current or future hadron colliders. Once produced, these exotic quarks can decay into a top together with twin sector particles. If the twin sector particles escape the detection, we have the irreducible stop-like signals. On the other hand, some twin sector particles may decay back into the standard model particles ...

  13. The Flavor of the Composite Twin Higgs

    CERN Document Server

    Csaki, Csaba; Telem, Ofri; Weiler, Andreas

    2015-01-01

    The assumption of anarchic quark flavor puts serious stress on composite Higgs models: flavor bounds imply a tuning of a few per-mille (at best) in the Higgs potential. Composite twin Higgs (CTH) models significantly reduce this tension by opening up a new region of parameter space, obtained by raising the coupling among the composites close to the strong coupling limit $g_* \\sim 4\\pi$, thereby raising the scale of composites to around 10 TeV. This does not lead to large tuning in the Higgs potential since the leading quantum corrections are canceled by the twin partners (rather than the composites). We survey the leading flavor bounds on the CTH, which correspond to tree-level $\\Delta F=2$ four-Fermi operators from Kaluza-Klein (KK) Z exchange in the kaon system and 1-loop corrections from KK fermions to the electric dipole moment of the neutron. We provide a parametric estimate for these bounds and also perform a numeric scan of the parameter space using the complete calculation for both quantities. The res...

  14. Single Higgs boson production at the ILC in the left-right twin Higgs model

    CERN Document Server

    Liu, Yao-Bei

    2014-01-01

    In this work, we analyse three dominant single SM-like Higgs boson production processes in the left-right twin Higgs model (LRTHM): the Higgs-strahlung (HS) process $e^{+}e^{-}\\rightarrow Zh$, the vector boson fusion (VBF) process $e^{+}e^{-}\\rightarrow \

  15. The graviton Higgs mechanism

    Science.gov (United States)

    Arraut, Ivan

    2015-09-01

    The Higgs mechanism at the graviton level formulated as a Vainshtein mechanism in time domains implies that the extra-degrees of freedom become relevant depending on the direction of time (frame of reference) with respect to the preferred time direction (preferred frame) defined by the Stückelberg function T_0(r,t) which contains the information of the extra-degrees of freedom of the theory. In this manuscript, I make the general definition of the Higgs mechanism by analyzing the gauge symmetries of the action and the general form of the vacuum solutions for the graviton field. In general, the symmetry generators depending explicitly on the Stückelberg fields are broken at the vacuum level. These broken generators, define the number of Nambu-Goldstone bosons which will be eating up by the dynamical metric in order to become massive.

  16. The graviton Higgs mechanism

    CERN Document Server

    Arraut, Ivan

    2015-01-01

    The Higgs mechanism at the graviton level formulated as a Vainshtein mechanism in time domains implies that the extra-degrees of freedom become relevant depending on the direction of time (frame of reference) with respect to the preferred time direction (preferred frame) defined by the St\\"uckelberg function $T_0(r,t)$ which contains the information of the extra-degrees of freedom of the theory. In this manuscript, I make the general definition of the Higgs mechanism by analyzing the gauge symmetries of the action and the general form of the vacuum solutions for the graviton field. In general, the symmetry generators depending explicitly on the St\\"uckelberg fields are broken at the vacuum level. These broken generators, define the number of Nambu-Goldstone bosons which will be eating up by the dynamical metric in order to become massive.

  17. The RG-improved Twin Higgs effective potential at NNLL

    CERN Document Server

    Greco, Davide

    2016-01-01

    We present the Renormalization Group improvement of the Twin Higgs effective potential at cubic order in logarithmic accuracy. We first introduce a model-independent low-energy effective Lagrangian that captures both the pseudo-Nambu-Goldstone boson nature of the Higgs field and the twin light degrees of freedom charged under a copy of the Standard Model. We then apply the background field method to systematically re-sum all the one loop diagrams contributing to the potential. We show how this technique can be efficient to implicitly renormalize the higher-dimensional operators in the twin sector without classifying all of them. A prediction for the Higgs mass in the Twin Higgs model is derived and found to be of the order of $M_H \\sim 120 ~\\text{GeV}$ with an ultraviolet cut-off $m_*\\sim 10-20 ~\\text{TeV}$. Irrespective of any possible ultraviolet completion of the low-energy Lagrangian, the infrared degrees of freedom alone are therefore enough to account for the observed value of the Higgs mass through run...

  18. The RG-improved Twin Higgs effective potential at NNLL

    Science.gov (United States)

    Greco, Davide; Mimouni, Kin

    2016-11-01

    We present the Renormalization Group improvement of the Twin Higgs effective potential at cubic order in logarithmic accuracy. We first introduce a model-independent low-energy effective Lagrangian that captures both the pseudo-Nambu-Goldstone boson nature of the Higgs field and the twin light degrees of freedom charged under a copy of the Standard Model. We then apply the background field method to systematically re-sum all the one loop diagrams contributing to the potential. We show how this technique can be efficient to implicitly renormalize the higher-dimensional operators in the twin sector without classifying all of them. A prediction for the Higgs mass in the Twin Higgs model is derived and found to be of the order of M H ˜ 120 GeV with an ultraviolet cut-off m * ˜ 10-20 TeV. Irrespective of any possible ultraviolet completion of the low-energy Lagrangian, the infrared degrees of freedom alone are therefore enough to account for the observed value of the Higgs mass through running effects.

  19. Reconciling large- and small-scale structure in Twin Higgs models

    Science.gov (United States)

    Prilepina, Valentina; Tsai, Yuhsin

    2017-09-01

    We study possible extensions of the Twin Higgs model that solve the Hierarchy problem and simultaneously address problems of the large- and small-scale structures of the Universe. Besides naturally providing dark matter (DM) candidates as the lightest charged twin fermions, the twin sector contains a light photon and neutrinos, which can modify structure formation relative to the prediction from the ΛCDM paradigm. We focus on two viable scenarios. First, we study a Fraternal Twin Higgs model in which the spin-3/2 baryon \\widehat{Ω}˜ (\\widehat{b}\\widehat{b}\\widehat{b}) and the lepton twin tau \\widehat{τ} contribute to the dominant and subcomponent dark matter densities. A non-decoupled scattering between the twin tau and twin neutrino arising from a gauged twin lepton number symmetry provides a drag force that damps the density inhomogeneity of a dark matter subcomponent. Next, we consider the possibility of introducing a twin hydrogen atom Ĥ as the dominant DM component. After recombination, a small fraction of the twin protons and leptons remains ionized during structure formation, and their scattering to twin neutrinos through a gauged U(1) B-L force provides the mechanism that damps the density inhomogeneity. Both scenarios realize the Partially Acoustic dark matter (PAcDM) scenario and explain the σ 8 discrepancy between the CMB and weak lensing results. Moreover, the self-scattering neutrino behaves as a dark fluid that enhances the size of the Hubble rate H 0 to accommodate the local measurement result while satisfying the CMB constraint. For the small-scale structure, the scattering of \\widehat{Ω} 's and Ĥ's through the twin photon exchange generates a self-interacting dark matter (SIDM) model that solves the mass deficit problem from dwarf galaxy to galaxy cluster scales. Furthermore, when varying general choices of the twin photon coupling, bounds from the dwarf galaxy and the cluster merger observations can set an upper limit on the twin

  20. Pair production of neutral Higgs bosons from the left-right twin Higgs model via γγ collisions

    Institute of Scientific and Technical Information of China (English)

    马威; 岳崇兴; 张婷婷

    2011-01-01

    The left-right twin Higgs (LRTH) model predicts the existence of the neutral Higgs bosons (h, φ0), which can be produced in pairs (φ0φ0, hh, φ0h) via γγ collisions at the next generation e+eInternational Linear Collider (ILC). Our numerical results show t

  1. The left-right twin Higgs model confronted with the latest LHC Higgs data

    CERN Document Server

    Liu, Yao-Bei; Xiao, Zhen-Jun

    2013-01-01

    Motivated by the latest LHC Higgs data, we calculate the new physics contributions to the Higgs decay channels of $h\\to \\gamma\\gamma, Z\\gamma, \\tau\\tau, WW^*$ and $ ZZ^*$ in the left-right twin Higgs (LRTH) model, induced by the loops involving the heavy T-quark, the $W_H$ and $\\phi^\\pm$ bosons appeared in the LRTH model. We find that (a) for a SM-like Higgs boson around 125.5 GeV, the signal rates normalized to the corresponding standard model (SM) predictions are always suppressed when new physics contributions are taken into account and approach the SM predictions for a large scalar parameter $f$; and (b) the LRTH prediction for $R_{\\gamma\\gamma}$ agree well with the CMS measurement $R_{\\gamma\\gamma}=0.77\\pm 0.27$ at $1\\sigma$ level, but differ with the ATLAS result. The forthcoming precision measurement of the diphoton signal at the LHC can be a sensitive probe for the LRTH model.

  2. Triple Higgs Coupling as a Probe of the Twin-Peak Scenario

    CERN Document Server

    Ahriche, Amine; Nasri, Salah

    2015-01-01

    In this letter, we investigate the case of a twin peak around the observed 125 GeV scalar resonance, using di-Higgs production processes at both LHC and $e^{+}e^{-}$ Linear Colliders. We show that the triple Higgs couplings play an important role to identify this scenario; and also that this scenario is surely distinguishable from any Standard Model extension by extra massive particles which might modify the triple Higgs coupling.

  3. Pair production of neutral Higgs bosons from the left-right twin Higgs model via γγ collisions

    Institute of Scientific and Technical Information of China (English)

    MA Wei; YUE Chong-Xing; ZHANG Ting-Ting

    2011-01-01

    The left-right twin Higgs (LRTH) model predicts the existence of the neutral Higgs bosons (h, φ), which can be produced in pairs (φφ, hh, φh) via γγ collisions at the next generation ee International Linear Collider (ILC). Our numerical results show that the production cross section of the neutral Higgs boson pair φφ can reach 8.8 fb. The subprocess γγ→φφ might be used to test the LRTH model in future ILC experiments.

  4. Light Higgs decay modes of Z-boson in the left-right twin Higgs model

    Energy Technology Data Exchange (ETDEWEB)

    Wang Lei [Department of Physics, Yantai University, Yantai 264005 (China); Han Xiaofang, E-mail: xfhan@itp.ac.cn [Department of Physics, Yantai University, Yantai 264005 (China)

    2011-09-11

    The left-right twin Higgs model predicts a light pseudoscalar boson {phi}{sup 0} and opens up some new decay modes for Z-boson, such as Z{yields}f-barf{phi}{sup 0} and Z{yields}{phi}{sup 0{gamma}}. We examine these decay modes in the parameter space allowed by current experiments, and find that the branching ratios can reach 10{sup -8} for Z{yields}b-barb{phi}{sup 0}, which should be accessible at the GigaZ option of the ILC. However, the branching ratios can reach 10{sup -9} for Z{yields}{tau}-bar{tau}{phi}{sup 0} and Z{yields}{phi}{sup 0{gamma}}, which are hardly accessible at the GigaZ option.

  5. Single Production of Charged Gauge Boson W-H from Left-Right Twin Higgs Model in Association with Top Quark at LHC

    Institute of Scientific and Technical Information of China (English)

    HU Li-Yun; LIU Yao-Bei; FAN Hong-Yi; WANG Xue-Lei; HAN Hong-Mei; CAO Yong-Hua

    2008-01-01

    The twin Higgs mechanism has recently been proposed to solve the little hierarchy problem. In the context of the left-right twin Higgs (LRTH) model, we discuss single production of the new charged gauge boson W-H, which is predicted by the left-right twin Higgs model, in association with top quark at the CERN Large Hadron Collider (LHC). It is found that, for a typical nonzero value of mass mixing parameter M = 150 GeV in the LRTH model, the production cross section is in the range of 3 × 10-2 ~ 6.07 × 103fb at the LHC. As long as the W-H is not too heavy, the possible signatures of the heavy charged gauge boson might be detected at the LHC experiments.

  6. Associated ZH and WH Production in Left-Right Twin Higgs Model at LHC

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan-Ju; LU Gong-Ru

    2011-01-01

    At the CERN large hadron collider (LHC), production of the Higgs boson in association with Z or W bosons provides a dramatic experimental signal for detecting the standard model (SM) Higgs boson. In this paper, we consider the contributions of the left-right twin Higgs (LRTH) model to the processes q(q′) → Z(W)H. Our numerical results show that, in the favorable parameter spaces, the cross sections deviate distinctly from the predictions of the SM.The possible signals of the LRTH model can be detected via these processes at the LHC experiments.

  7. Reconciling Large And Small-Scale Structure In Twin Higgs Models

    CERN Document Server

    Prilepina, Valentina

    2016-01-01

    We study an extension of the Twin Higgs model that solves the Hierarchy problem and simultaneously addresses problems of the large- and small-scale structures of the Universe. Besides naturally providing dark matter (DM) candidates as the lightest charged twin fermions, the twin sector contains a light photon and neutrinos, which can modify structure formation relative to the prediction from the $\\Lambda$CDM paradigm. We focus on a Fraternal Twin Higgs scenario in which the spin-3/2 baryon $\\hat{\\Omega}\\sim(\\hat{b}\\hat{b}\\hat{b})$ and the lepton twin tau $\\hat{\\tau}$ contribute to the dominant and subcomponent dark matter densities. A non-decoupled scattering between the twin tau and twin neutrino arising from a gauged twin lepton number symmetry provides a drag force that damps the density inhomogeneity of a dark matter subcomponent. This realizes the Partially Acoustic dark matter (PAcDM) scenario and explains the $\\sigma_8$ discrepancy between the CMB and weak lensing results. Moreover, the self-scattering...

  8. Gamma-rays from dark showers with twin Higgs models

    Science.gov (United States)

    Freytsis, Marat; Knapen, Simon; Robinson, Dean J.; Tsai, Yuhsin

    2016-05-01

    We consider a twin WIMP scenario whose twin sector contains a full dark copy of the SM hadrons, where the lightest twin particles are twin pions. By analogy to the standard WIMP paradigm, the dark matter (DM) freezes out through twin electroweak interactions, and annihilates into a dark shower of light twin hadrons. These are either stable or decay predominantly to standard model (SM) photons. We show that this `hadrosymmetric' scenario can be consistent with all applicable astrophysical, cosmological and collider constraints. In order to decay the twin hadrons before the big-bang nucleosynthesis epoch, an additional portal between the SM and twin sector is required. In most cases we find this additional mediator is within reach of either the LHC or future intensity frontier experiments. Furthermore, we conduct simulations of the dark shower and consequent photon spectra. We find that fits of these spectra to the claimed galactic center gamma-ray excess seen by Fermi -LAT non-trivially coincide with regions of parameter space that both successfully generate the observed DM abundance and exhibit minimal fine-tuning.

  9. Gamma-rays from dark showers with twin Higgs models

    Energy Technology Data Exchange (ETDEWEB)

    Freytsis, Marat [Institute of Theoretical Science, University of Oregon,Eugene, OR 97403 (United States); Knapen, Simon; Robinson, Dean J. [Department of Physics, University of California,Berkeley, CA 94720 (United States); Ernest Orlando Lawrence Berkeley National Laboratory,University of California, Berkeley, CA 94720 (United States); Tsai, Yuhsin [Maryland Center for Fundamental Physics, Department of Physics,University of Maryland, College Park, MD 20742 (United States)

    2016-05-03

    We consider a twin WIMP scenario whose twin sector contains a full dark copy of the SM hadrons, where the lightest twin particles are twin pions. By analogy to the standard WIMP paradigm, the dark matter (DM) freezes out through twin electroweak interactions, and annihilates into a dark shower of light twin hadrons. These are either stable or decay predominantly to standard model (SM) photons. We show that this ‘hadrosymmetric’ scenario can be consistent with all applicable astrophysical, cosmological and collider constraints. In order to decay the twin hadrons before the big-bang nucleosynthesis epoch, an additional portal between the SM and twin sector is required. In most cases we find this additional mediator is within reach of either the LHC or future intensity frontier experiments. Furthermore, we conduct simulations of the dark shower and consequent photon spectra. We find that fits of these spectra to the claimed galactic center gamma-ray excess seen by Fermi-LAT non-trivially coincide with regions of parameter space that both successfully generate the observed DM abundance and exhibit minimal fine-tuning.

  10. Unveiling the Higgs mechanism to students

    Science.gov (United States)

    Organtini, Giovanni

    2012-09-01

    In this paper we outline a lecture given to undergraduate students to explain why physicists are so interested in the Higgs boson. The lecture was conceived for students not yet familiar with advanced physics and is suitable for those studying several other disciplines. The Higgs mechanism is introduced through semi-classical arguments mimicking basic field-theory concepts, assuming the validity of a symmetry principle in the expression of the energy of particles in a classical field. The lecture is divided into two parts. The first, suitable even for high-school students, shows how the mass of a particle results from a dynamical effect caused by interaction between a massless particle and a field (as in the Higgs mechanism). The audience for the second, much more technical part consists mainly of teachers and university students from disciplines other than physics.

  11. Unveiling the Higgs mechanism to students

    CERN Document Server

    Organtini, Giovanni

    2012-01-01

    In this paper we give the outline of a lecture given to undergraduate students aiming at understanding why physicists are so much interested in the Higgs boson. The lecture has been conceived for students not yet familiar with advanced physics and is suitable for several disciplines, other than physics. The Higgs mechanism is introduced by semi-classical arguments mimicking the basic field theory concepts, assuming the validity of a symmetry principle in the expression of the energy of particles in a classical field. The lecture is divided in two parts: the first, suitable even to high--school students, shows how the mass of a particle results as a dynamical effect due to the interaction between a massless particle and a field (as in the Higgs mechanism). The audience of the second part, much more technical, consists mainly of teachers and university students of disciplines other than physics.

  12. Quantum gauge models without (classical) Higgs mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Duetsch, Michael [Univ. Goettingen, Courant Research Center ' ' Higher order Structures in Mathematics' ' , Mathematisches Institut, Goettingen (Germany); Gracia-Bondia, Jose M. [Universidad de Zaragoza, Departamento de Fisica Teorica, Zaragoza (Spain); Scheck, Florian [Johannes Gutenberg-Universitaet, Institut fuer Physik, Theoretische Elementarteilchenphysik, Mainz (Germany); Varilly, Joseph C. [Universidad de Costa Rica, Escuela de Matematica, San Jose (Costa Rica)

    2010-10-15

    We examine the status of massive gauge theories, such as those usually obtained by spontaneous symmetry breakdown, from the viewpoint of causal (Epstein-Glaser) renormalization. The BRST formulation of gauge invariance in this framework, starting from canonical quantization of massive (as well as massless) vector bosons as fundamental entities, and proceeding perturbatively, allows one to rederive the reductive group symmetry of interactions, the need for scalar fields in gauge theory, and the covariant derivative. Thus the presence of higgs particles is understood without recourse to a Higgs(-Englert-Brout-Guralnik-Hagen-Kibble) mechanism. Along the way, we dispel doubts about the compatibility of causal gauge invariance with grand unified theories. (orig.)

  13. Turning on gravity with the Higgs mechanism

    CERN Document Server

    Alexander, Stephon; Magueijo, Joao

    2016-01-01

    We investigate how a Higgs mechanism could be responsible for the emergence of gravity in extensions of Einstein theory. In this scenario, at high energies, symmetry restoration could "turn off" gravity, with dramatic implications for cosmology and quantum gravity. The sense in which gravity is muted depends on the details of the implementation. In the most extreme case gravity's dynamical degrees of freedom would only be unleashed after the Higgs field acquires a non-trivial vacuum expectation value, with gravity reduced to a topological field theory in the symmetric phase. We might also identify the Higgs and the Brans-Dicke fields in such a way that in the unbroken phase Newton's constant vanishes, decoupling matter and gravity. We discuss the broad implications of these scenarios.

  14. Atomistic deformation mechanisms in twinned copper nanospheres.

    Science.gov (United States)

    Bian, Jianjun; Niu, Xinrui; Zhang, Hao; Wang, Gangfeng

    2014-01-01

    In the present study, we perform molecular dynamic simulations to investigate the compression response and atomistic deformation mechanisms of twinned nanospheres. The relationship between load and compression depth is calculated for various twin spacing and loading directions. Then, the overall elastic properties and the underlying plastic deformation mechanisms are illuminated. Twin boundaries (TBs) act as obstacles to dislocation motion and lead to strengthening. As the loading direction varies, the plastic deformation transfers from dislocations intersecting with TBs, slipping parallel to TBs, and then to being restrained by TBs. The strengthening of TBs depends strongly on the twin spacing.

  15. Single Production of a Heavy T-Quark in the Left-Right Twin Higgs Model at LHeC

    Institute of Scientific and Technical Information of China (English)

    SHEN Jie-Fen; CUI Xiao-Min; LI Yu-Qi; GAO Yin-Hao

    2011-01-01

    In the context of the left-right twin Higgs model, we study single production of a T-quark at the Large Hadron electron Collider based ep and γp colliders, which proceed via the processes e+b→ (v)eT and 76→W~T. For the main decay mode T→φ+ b→ tbb, these two processes mainly transfer to the final states of 3b+l (e or μ) + missing Et and 3b + 2l + missing Et, respectively. With the electron energy Ee = 500 GeV and photon energy Ep=7 TeV, we find that the production rates can reach tensfb when the heavy T-quark mass mT < 600 GeV. A simple phenomenological analysis is also given for the decay mode T→W+b. Our numerical results show that the SM background can be reduced by applying a cut on the transverse momentum of the final b-quark and the invariant mass of Wb. However, such a channel is only useful for a tiny parameter space.%In the context of the left-right twin Higgs model,we study single production of a T-quark at the Large Hadron electron Collider based ep and γp colliders,which proceed via the processes e+ b → (V)T and γb → W-T.For the main decay mode T → φ+ b → t(b)b,these two processes mainly transfer to the final states of 3b+ l (e or μ) + missing ET and 3b + 2l + missing ET,respectively.With the electron energy Ee =500 GeV and photon energy Ep =7 TeV,we find that the production rates can reach tensfb when the heavy T-quark mass mrT < 600GeV.A simple phenomenological analysis is also given for the decay mode T → W+b.Our numerical results show that the SM background can be reduced by applying a cut on the transverse momentum of the final b-quark and the invariant mass of Wb.However,such a channel is only useful for a tiny parameter space.The twin Higgs mechanism[1,2] was proposed recently as an intresting solution to the little hierarchy problem,which can be implemented in left-right models with left-right symmetry.[2] A new heavy T-quark is one of the most crucial ingredients of the left-right twin Higgs (LRTH) model.The collider

  16. Dislocation Mechanism of Twinning in Ni-Mn-Ga

    Science.gov (United States)

    Zárubová, N.; Ge, Y.; Gemperlová, J.; Gemperle, A.; Hannula, S.-P.

    2012-03-01

    Tensile tests were performed in situ in a transmission electron microscope to investigate the twinning mechanism in non-modulated Ni-Mn-Ga martensite. The reorientation of the twin variants occurs via twinning dislocations. Their generation and movement were followed; the glide plane and Burgers vector were verified. Individual twinning dislocations were visualized.

  17. The Higgs Mechanism from an extra dimension

    CERN Document Server

    A., Yu

    2016-01-01

    The standard $SU(2) \\times U(1)$ fields are considered in 4D plus one extra compact dimension. As a result two basic effects are obtained. First, four Goldstone-like scalars are produced, three of them are used to create longitudinal modes of the $W,Z$ fields, while the fourth becomes the Higgs-like scalar. Second, $W$ and $Z$ get their masses from the extra compact dimension with the standard pattern of symmetry violation. The resulting theory has the same fields as in the standard model, but without the Higgs vacuum average. The properties of the new Higgs scalar and its interaction with fermions are briefly discussed.

  18. Higgs boson production and decay at e+e− colliders as a probe of the Left–Right twin Higgs model

    Directory of Open Access Journals (Sweden)

    Jinzhong Han

    2015-07-01

    Full Text Available In the framework of the Left–Right twin Higgs (LRTH model, we consider the constrains from the latest search for high-mass dilepton resonances at the LHC and find that the heavy neutral boson ZH is excluded with mass below 2.76 TeV. Under these constrains, we study the Higgs–Gauge coupling production processes e+e−→ZH, e+e−→νeνe¯H and e+e−→e+e−H, top quark Yukawa coupling production process e+e−→tt¯H, Higgs self-couplings production processes e+e−→ZHH and e+e−→νeνe¯HH at e+e− colliders. Besides, we study the major decay modes of the Higgs boson, namely h→ff¯(f=b,c,τ, VV⁎(V=W,Z, gg, γγ. We find that the LRTH effects are sizable so that the Higgs boson processes at e+e− collider can be a sensitive probe for the LRTH model.

  19. Alternatives to an Elementary Higgs

    CERN Document Server

    Csaki, Csaba; Terning, John

    2015-01-01

    We review strongly coupled and extra dimensional models of electroweak symmetry breaking. Models examined include warped extra dimensions, bulk Higgs, "little" Higgs, dilaton Higgs, composite Higgs, twin Higgs, quantum critical Higgs, and "fat" SUSY Higgs. We also discuss current bounds and future LHC searches for this class of models.

  20. Higgs Mechanism and the Added-Mass Effect

    CERN Document Server

    Krishnaswami, Govind S

    2014-01-01

    In the Higgs mechanism, mediators of the weak force acquire masses by interacting with the Higgs condensate, leading to a vector boson mass matrix. On the other hand, a rigid body accelerated through an inviscid, incompressible and irrotational fluid feels an opposing force linearly related to its acceleration, via an added-mass tensor. We uncover a striking physical analogy between the two effects and propose a dictionary relating them. The correspondence turns the gauge Lie algebra into the flow domain, and encodes the pattern of gauge symmetry breaking in the shape of an associated body. The new viewpoint is illustrated with numerous examples, and raises interesting questions, notably on the fluid analogs of the broken symmetry and Higgs particle.

  1. Philosophical perspectives on ad hoc hypotheses and the Higgs mechanism

    NARCIS (Netherlands)

    Friederich, Simon; Harlander, Robert; Karaca, Koray

    2014-01-01

    We examine physicists' charge of ad hocness against the Higgs mechanism in the standard model of elementary particle physics. We argue that even though this charge never rested on a clear-cut and well-entrenched definition of "ad hoc", it is based on conceptual and methodological assumptions and pri

  2. Cosmological tracking solution and the Super-Higgs mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Landim, Ricardo C.G. [Universidade de Sao Paulo, Instituto de Fisica, Caixa Postal 66318, Sao Paulo, Sao Paulo (Brazil)

    2016-08-15

    In this paper we argue that minimal supergravity with a flat Kaehler metric and a power-law superpotential can relate the Super-Higgs mechanism for the local spontaneous supersymmetry breaking and the cosmological tracking solution, leading in turn to a late-time accelerated expansion of the universe and alleviating the coincidence problem. (orig.)

  3. Twin Baryogenesis

    CERN Document Server

    Farina, Marco; Shin, Chang Sub

    2016-01-01

    In the context of Twin Higgs models, we study a simple mechanism that simultaneously generates asymmetries in the dark and visible sector through the out-of-equilibrium decay of a TeV scale particle charged under a combination of baryon and twin baryon number. We predict the dark matter to be a 5 GeV twin baryon, which is easy to achieve because of the similarity between the two confinement scales. Dark matter is metastable and can decay to three quarks, yielding indirect detection signatures. The mechanism requires the introduction of a new colored particle, typically within the reach of the LHC, of which we study the rich collider phenomenology, including prompt and displaced dijets, multi-jets, monojets and monotops.

  4. Mechanical twinning in small quartz crystals

    Science.gov (United States)

    Laughner, J. W.; Newnham, R. E.; Cross, L. E.

    1982-02-01

    Quartz is known to be ferrobielastic; that is, quartz crystals have domain states (Dauphiné twins) which differ in their elastic compliance values and which can be switched by an appropriately oriented stress. Polycrystalline quartz has also been reported (Tullis 1970) to show preferential orientation of these domains following application of large uniaxial stresses. These experiments were designed to study twinning of synthetic quartz “grains” (minimum size 0.07×0.07×0.02 cm) in specially-constructed composites and of grains in three natural quartz aggregates — a quartzite, a novaculite, and a jasper. Backreflection X-ray techniques were used to verify twinning in the composite grains, while special electroding and electrical detection allowed the twinning processes to be examined in “real time.” Small synthetic quartz crystals were found to behave identically to the massive samples previously studied. Electrical pulses due to the reversal of piezoelectric coefficient d 11 in twinned quartz were detected from quartzite and from the man-made composites. Novaculite also gave electrical pulses which were probably from twinning (evidenced by the correlation of expected and observed pulse sizes and shapes), while no pulses from the jaspers indicative of twinning were detected. Grain size distribution differences are considered the main structural reason for the different behaviors.

  5. Single vector-like top partner production in the Left-Right Twin Higgs model at TeV energy $e\\gamma$ colliders

    CERN Document Server

    Zhan-Ying, Guo; Bing-Fang, Yang

    2013-01-01

    The left-right twin Higgs model contains a new vector-like heavy top quark, which mixes with the SM-like top quark. In this work, we studied the single vector-like top partner production via process $e^{-}\\gamma \\rightarrow \

  6. Probing lepton flavor violation signal via γ γ →l¯ilj in the left-right twin Higgs model at the ILC

    Science.gov (United States)

    Liu, Guo-Li; Wang, Fei; Xie, Kuan; Guo, Xiao-Fei

    2017-08-01

    To explain the small neutrino masses, heavy Majorana neutrinos are introduced in the left-right twin Higgs model. The heavy neutrinos—together with the charged scalars and the heavy gauge bosons—may contribute large mixings between the neutrinos and the charged leptons, which may induce some distinct lepton-flavor-violating processes. We check ℓ¯iℓj (i ,j =e ,μ ,τ ,i ≠j ) production in γ γ collisions in the left-right twin Higgs model, and find that the production rates may be large in some specific parameter space. In optimal cases, it is even possible to detect them with reasonable kinematical cuts. We also show that these collisions can effectively constrain the model parameters—such as the Higgs vacuum expectation value, the right-handed neutrino mass, etc.—and may serve as a sensitive probe of this new physics model.

  7. The Brother Higgs arXiv

    CERN Document Server

    Serra, Javi

    We present a version of the twin Higgs mechanism with minimal symmetry structure and particle content. The model is built upon a composite Higgs theory with global $SO(6)/SO(5)$ symmetry breaking. The leading contribution to the Higgs potential, from the top sector, is solely cancelled via the introduction of a Standard Model neutral top partner. We show that the inherent $Z_2$ breaking of this construction is under control and of the right size to achieve electroweak symmetry breaking, with a fine-tuning at the level of $5-10\\%$, and compatibly with the observed Higgs mass. We briefly discuss the particular phenomenological features of this scenario.

  8. Single Production of Top Quark via eγ-Collision in Left-Right Twin Higgs Model

    Institute of Scientific and Technical Information of China (English)

    LIU Yao-Bei; WANG Xue-Lei; CAO Jun; HAN Hong-Mei

    2008-01-01

    In the context of the left-right twin Higgs (LRTH) model, we fist study single production of the standard model (SM) top quark via e-γ collisions. We find that the corrections of the LRTH model to the cross section of the process e-γ→ vebt might be observed only for f ≤ 750 GeV and the heavy top quark mass scale M ≥ 500 GeV in future integrated luminosity of £=100 fb-1. We also consider single production of the heavy top quark T via e-γ collisions. Our numerical results show that the possible signals of the heavy top quark T might be observed via the decay channel T→φ+b→tbb in future LC experiment with ∫8=3 TeV and £=500fb-1.

  9. TWINNING MECHANISMS IN LASER PROCESSED CERAMIC COATINGS

    NARCIS (Netherlands)

    de Hosson, J.T.M.

    Twinning behaviour and martensitic transformations are observed in laser treated (Fe, Cr) spinel with chemical formula FexCr3-xO4 (0

  10. Scale-Setting Without the Higgs Mechanism:. Non-Abelian Symmetry

    Science.gov (United States)

    Anderson, J. T.

    For the non-Abelian Higgs model it is shown that the coupled equations of motion for Aμ, ϕ and ϕ* have nonanalytic singularities which must be removed if the equations are integrable. Current conservation is found to remove the singularities in the vector-field equation and give a mass scale independent of V and the Higgs mechanism. The self-consistent field solutions for Aμ and the ϕ fields give either (1) the Higgs mechanism, zero current and the pure-gauge solution, or (2) nonzero current, a gauge-covariant solution and the mass scale independent of V and the Higgs mechanism.

  11. Mechanical twinning as stress indicator in fault rocks

    Science.gov (United States)

    Wenk, H.

    2011-12-01

    At low stresses and elevated temperatures rocks deform by dislocation movements and diffusion. At very high stresses they undergo brittle failure. For many minerals there is an intermediate regime where mechanical twinning occurs. This has been studied extensively in calcite (Turner, Griggs and Heard, GSA Mem. 1954) and also documented for quartz (Tullis, Science, 1972). In this study we use twinning microstructures to characterize rocks that were subjected to seismic stresses, specifically pseudotachylites and samples from the San Andreas Fault Observatory at Depth. For calcite in SAFOD samples, dislocation densities derived from TEM images as well as twin densities measured by optical microscopy, indicate stresses between 50 and 200 MPa. Similar residual stress magnitudes were obtained from preserved lattice distortion determined by synchrotron X-ray microdiffraction. Also quartz shows characteristic twin microstructures. Orientation maps with SEM-EBSD reveal that quartz associated with pseudotachylite veins is profusely twinned, similar to structures observed in quartz subjected to meteorite impacts. It suggests that local dynamic seismic stresses during earthquakes are responsible for Dauphiné twinning. Thus microstructures in minerals add information to constrain macroscopic conditions during faulting.

  12. Probing the mechanism of EWSB with a rho parameter defined in terms of Higgs couplings

    CERN Document Server

    Díaz-Cruz, J L

    2003-01-01

    A definition of the rho parameter based on the Higgs couplings with the gauge bosons, rho_h= g_{hWW}}/c^2_W g_{hZZ}, is proposed as a new probe into the origin of the mechanism of electroweak symmetry breaking. While $\\rho_h=1$ holds in the SM, deviations from one are predicted in models with extended Higgs sector. We derive a general expresion of rho_h for a model with arbitrary Higgs multiplets, and discuss its size within the context of specific models with Higgs triplets, including the ``Little Higgs'' models recently proposed. We find the even for Higgs models that incorporate the custodial symmetry to make rho=1, one could have rho_h\

  13. Orientation-dependent mechanical behaviour of electrodeposited copper with nanoscale twins.

    Science.gov (United States)

    Mieszala, Maxime; Guillonneau, Gaylord; Hasegawa, Madoka; Raghavan, Rejin; Wheeler, Jeffrey M; Mischler, Stefano; Michler, Johann; Philippe, Laetitia

    2016-09-21

    The mechanical properties of electrodeposited copper with highly-oriented nanoscale twins were investigated by micropillar compression. Uniform nanotwinned copper films with preferred twin orientations, either vertical or horizontal, were obtained by controlling the plating conditions. In addition, an ultrafine grained copper film was synthesized to be used as a reference sample. The mechanical properties were assessed by in situ SEM microcompression of micropillars fabricated with a focused ion beam. Results show that the mechanical properties are highly sensitive to the twin orientation. When compared to the ultrafine grained sample, an increase of 44% and 130% in stress at 5% offset strain was observed in quasi-static tests for vertically and horizontally aligned twins, respectively. Inversely strain rate jump microcompression testing reveals higher strain sensitivity for vertical twins. These observations are attributed to a change in deformation mechanism from dislocation pile-ups at the twin boundary for horizontal twins to dislocations threading inside the twin lamella for vertical twins.

  14. Searches for new neutral gauge boson at the Tevatron and LHC in the left-right twin Higgs model

    Institute of Scientific and Technical Information of China (English)

    LIU YaoBei; ZHANG WenQing; YAN LeiBing

    2012-01-01

    In the framework of the left-right twin Higgs (LRTH) model,we study the possibilities to detect the new Z' boson at the Tevatron and LHC.First,using p(p) collision data collected by the DO and CDF Ⅱ detectors,we find that the LRTH Z' boson is excluded with masses below 940 GeV.Then we search for signatures of the Z' boson at the LHC from the analysis of some distributions for p(p) →/μ+μ- + X,such as the number of events,the differential cross section of the dimuon invariant mass,the distributions of the transverse momentum and the forward-backward charge asymmetry.We do our calculation for two typical values of the LHC center of mass energy (7 and 14 TeV).The numerical results show that,by applying convenient cuts on some of the observables,the dimuon invariant mass and final particle PΤ distributions can reveal the presence of the heavy neutral gauge boson Z' contribution in the LRTH model.

  15. A New Mechanism of Higgs Bosons in Producing Charge Particles

    DEFF Research Database (Denmark)

    Javadi, Hossein; Forouzbakhsh, Farshid

    2006-01-01

    A new production method of elementary particles by Higgs Bosons will be shown. But before that the structure of photon will be considered deeply, while a new definition of Higgs Boson about color-charges and color-magnet will be given for the first time.......A new production method of elementary particles by Higgs Bosons will be shown. But before that the structure of photon will be considered deeply, while a new definition of Higgs Boson about color-charges and color-magnet will be given for the first time....

  16. The Englert-Brout-Higgs mechanism — An unfinished project

    Science.gov (United States)

    Cao, Tian Yu

    2016-12-01

    The conceptual foundation of the Englert-Brout-Higgs (EBH) mechanism (understood as a set of a scalar field’s couplings to a gauge system and a fermion system) is clarified (as being provided by broken symmetry solution of the scalar field and broken symmetry solutions of the gauge and fermion systems induced by the scalar field’s couplings to these systems, which are manifested in massive scalar and vector bosons as a result of reorganizing the physical degrees of freedom in the scalar and gauge sectors, whose original organization renders possible the broken symmetry solution to the scalar sector and symmetrical solutions to the gauge sector); its ontological status, as a physically real mechanism or merely an instrumental device, is examined, and a new ontologically primary entity, the symbiont of scalar-vector moments is suggested to replace the old ontology of scalar field and vector (gauge) field as the physical underpinning for a realistic understanding of the EBH mechanism; with a conclusion that two puzzles, the transmutation of the Goldstone modes’ dynamic identity and the fixity in reorganizing the physical degrees of freedom within the symbiont, have to be properly addressed before a consistent realist understanding of the mechanism can be developed.

  17. Higgs as a Probe of Supersymmetric Grand Unification with the Hosotani Mechanism

    CERN Document Server

    Kakizaki, Mitsuru; Taniguchi, Hiroyuki; Yamashita, Toshifumi

    2013-01-01

    The supersymmetric grand unified theory where the SU(5) gauge symmetry is broken by the Hosotani mechanism predicts the existence of adjoint chiral superfields whose masses are at the supersymmetry breaking scale. The Higgs sector is extended with the SU(2)_L triplet with hypercharge zero and neutral singlet chiral multiplets from that in the minimal supersymmetric standard model. Since the triplet and singlet chiral multiplets originate from a higher-dimensional vector multiplet, this model is highly predictive. Properties of the particles in the Higgs sector are characteristic and can be different from those in the Standard Model and other models. We evaluate deviations in coupling constants of the standard model-like Higgs boson and the mass spectrum of the additional Higgs bosons. We find that our model is discriminative from the others by precision measurements of these coupling constants and masses of the additional Higgs bosons. This model can be a good example of grand unification that is testable at ...

  18. Double Higgs mechanisms, supermassive stable particles and the vacuum energy

    Science.gov (United States)

    Santillán, Osvaldo P.; Gabbanelli, Luciano

    2016-07-01

    In the present work, a hidden scenario which cast a long-lived superheavy particle A0 and simultaneously an extremely light particle a with mass ma ˜ 10-32-10-33 eV is presented. The potential energy V (a) of the particle a models the vacuum energy density of the universe ρc ≃ 10-47GeV4. On the other hand, the A0 particle may act as superheavy dark matter at present times and the products of its decay may be observed in high energy cosmic ray events. The hidden sector proposed here include light fermions with masses near the neutrino mass mν ˜ 10-2 eV and superheavy ones with masses of the order of the GUT scale, interacting through a hidden SU(2)L interaction which also affects the ordinary sector. The construction of such combined scenario is nontrivial since the presence of light particles may spoil the stability of the heavy particle A0. However, double Higgs mechanisms may be helpful for overcoming this problem. In this context, the stability of the superheavy particle A0 is ensured due to chiral symmetry arguments elaborated in the text.

  19. Crystallographic mechanism of inverse twinning in ordered β′-CuZn alloy

    Institute of Scientific and Technical Information of China (English)

    毛卫民

    2000-01-01

    The basic process of mechanical twinning in β’-CuZn phase, as an example of B2 structured metals, has been analyzed under the rolling stresses. The behavior of inverse twinning in B2 structured metals is discussed in terms of mechanics and crystallographic stability. It is shown that the inverse twinning could remain the B2 structure, and the resulting strains will have the lowest resistance during the rolling deformation of the polycrystalline.

  20. Crystallographic mechanism of inverse twinning in ordered β'-CuZn alloy

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The basic process of mechanical twinning in β'-CuZn phase, as an example of B2 structured metals, has been analyzed under the rolling stresses. The behavior of inverse twinning in B2 structured metals is discussed in terms of mechanics and crystallographic stability. It is shown that the inverse twinning could remain the B2 structure, and the resulting strains will have the lowest resistance during the rolling deformation of the polycrystalline.

  1. High resolution transmission electron microscope observation of zero-strain deformation twinning mechanisms in Ag.

    Science.gov (United States)

    Liu, L; Wang, J; Gong, S K; Mao, S X

    2011-04-29

    We have observed a new deformation-twinning mechanism using the high resolution transmission electron microscope in polycrystalline Ag films, zero-strain twinning via nucleation, and the migration of a Σ3{112} incoherent twin boundary (ITB). This twinning mechanism produces a near zero macroscopic strain because the net Burgers vectors either equal zero or are equivalent to a Shockley partial dislocation. This observation provides new insight into the understanding of deformation twinning and confirms a previous hypothesis: detwinning could be accomplished via the nucleation and migration of Σ3{112} ITBs. The zero-strain twinning mechanism may be unique to low staking fault energy metals with implications for their deformation behavior.

  2. The production and decay of the top partner $T$ in the left-right twin higgs model at the ILC and CLIC

    CERN Document Server

    Liu, Yao-Bei

    2014-01-01

    The left-right twin Higgs model (LRTHM) predicts the existence of the top partner $T$. In this work, we make a systematic investigation for the single and pair production of this top partner $T$ through the processes: $e^{+}e^{-}\\to t\\ov{T} + T\\bar{t}$ and $ T\\ov{T}$, the neutral scalar (the SM-like Higgs boson $h$ or neutral pseudoscalar boson $\\phi^{0}$) associate productions $e^{+}e^{-}\\to t\\ov{T}h +T\\bar{t}h$, $T\\ov{T}h$, $t\\ov{T}\\phi^{0}+T\\bar{t}\\phi^{0}$ and $ T\\ov{T}\\phi^{0}$. From the numerical evaluations for the production cross sections and relevant phenomenological analysis we find that (a) the production rates of these processes, in the reasonable parameter space, can reach the level of several or tens of fb; (b) for some cases, the peak value of the resonance production cross section can be enhanced significantly and reaches to the level of pb; (c) the subsequent decay of $T\\to \\phi^{+}b \\to t\\bar{b}b$ may generate typical phenomenological features rather different from the signals from other ne...

  3. The standard model as a low-energy effective theory. What is triggering the Higgs mechanism?

    Energy Technology Data Exchange (ETDEWEB)

    Jegerlehner, Fred [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Humboldt Univ., Berlin (Germany). Inst. fuer Physik

    2013-04-15

    The discovery of the Higgs by ATLAS and CMS at the LHC not only provided the last missing building block of the electroweak Standard Model, the mass of the Higgs has been found to have a very peculiar value about 125 GeV, which is such that vacuum stability is extending up to the Planck scale. This may have much deeper drawback than anticipated so far. The impact on the running of the SM gauge, Yukawa and Higgs couplings up to the Planck scale has been discussed in several articles recently. Here we consider the impact on the running masses and we discuss the role of quadratic divergences within the Standard Model. The change of sign of the coefficient of the quadratically divergent terms showing up at about {mu}{sub 0}{proportional_to}7 x 10{sup 16} GeV may be understood as a first order phase transition restoring the symmetric phase, while its large negative values at lower scales triggers the Higgs mechanism, running parameters evolve in such a way that the symmetry is restored two orders of magnitude before the Planck scale. Thus, the electroweak phase transition takes place at the scale {mu}{sub 0} and not at the electroweak scale {upsilon}{proportional_to}250 GeV. The SM Higgs system and its phase transition could play a key role for the inflation of the early universe. Also baryogenesis has to be reconsidered under the aspect that perturbative arguments surprisingly work up to the Planck scale.

  4. The Born-Infeld vortices induced from a generalized Higgs mechanism.

    Science.gov (United States)

    Han, Xiaosen

    2016-04-01

    We construct self-dual Born-Infeld vortices induced from a generalized Higgs mechanism. Two specific models of the theory are of focused interest where the Higgs potential is either of a |ϕ|(4)- or |ϕ|(6)-type. For the |ϕ|(4)-model, we obtain a sharp existence and uniqueness theorem for doubly periodic and planar vortices. For doubly periodic solutions, a necessary and sufficient condition for the existence is explicitly derived in terms of the vortex number, the Born-Infeld parameter, and the size of the periodic lattice domain. For the |ϕ|(6)-model, we show that both topological and non-topological vortices are present. This new phenomenon distinguishes the model from the classical Born-Infeld-Higgs theory studied earlier in the literature. A series of results regarding doubly periodic, topological, and non-topological vortices in the |ϕ|(6)-model are also established.

  5. Tadpole-Induced Electroweak Symmetry Breaking and pNGB Higgs Models

    Energy Technology Data Exchange (ETDEWEB)

    Harnik, Roni [Fermilab; Howe, Kiel [Fermilab; Kearney, John [Fermilab

    2016-03-11

    We investigate induced electroweak symmetry breaking (EWSB) in models in which the Higgs is a pseudo-Nambu-Goldstone boson (pNGB). In pNGB Higgs models, Higgs properties and precision electroweak measurements imply a hierarchy between the EWSB and global symmetry-breaking scales, $v_H \\ll f_H$. When the pNGB potential is generated radiatively, this hierarchy requires fine-tuning to a degree of at least $\\sim v_H^2/f_H^2$. We show that if Higgs EWSB is induced by a tadpole arising from an auxiliary sector at scale $f_\\Sigma \\ll v_H$, this tuning is significantly ameliorated or can even be removed. We present explicit examples both in Twin Higgs models and in Composite Higgs models based on $SO(5)/SO(4)$. For the Twin case, the result is a fully natural model with $f_H \\sim 1$ TeV and the lightest colored top partners at 2 TeV. These models also have an appealing mechanism to generate the scales of the auxiliary sector and Higgs EWSB directly from the scale $f_H$, with a natural hierarchy $f_\\Sigma \\ll v_H \\ll f_H \\sim{\\rm TeV}$. The framework predicts modified Higgs coupling as well as new Higgs and vector states at LHC13.

  6. Formation mechanism of fivefold deformation twins in a face-centered cubic alloy

    Science.gov (United States)

    Zhang, Zhenyu; Huang, Siling; Chen, Leilei; Zhu, Zhanwei; Guo, Dongming

    2017-01-01

    The formation mechanism considers fivefold deformation twins originating from the grain boundaries in a nanocrystalline material, resulting in that fivefold deformation twins derived from a single crystal have not been reported by molecular dynamics simulations. In this study, fivefold deformation twins are observed in a single crystal of face-centered cubic (fcc) alloy. A new formation mechanism is proposed for fivefold deformation twins in a single crystal. A partial dislocation is emitted from the incoherent twin boundaries (ITBs) with high energy, generating a stacking fault along {111} plane, and resulting in the nucleating and growing of a twin by the successive emission of partials. A node is fixed at the intersecting center of the four different slip {111} planes. With increasing stress under the indentation, ITBs come into being close to the node, leading to the emission of a partial from the node. This generates a stacking fault along a {111} plane, nucleating and growing a twin by the continuous emission of the partials. This process repeats until the formation of fivefold deformation twins. PMID:28349995

  7. Formation mechanism of fivefold deformation twins in a face-centered cubic alloy.

    Science.gov (United States)

    Zhang, Zhenyu; Huang, Siling; Chen, Leilei; Zhu, Zhanwei; Guo, Dongming

    2017-03-28

    The formation mechanism considers fivefold deformation twins originating from the grain boundaries in a nanocrystalline material, resulting in that fivefold deformation twins derived from a single crystal have not been reported by molecular dynamics simulations. In this study, fivefold deformation twins are observed in a single crystal of face-centered cubic (fcc) alloy. A new formation mechanism is proposed for fivefold deformation twins in a single crystal. A partial dislocation is emitted from the incoherent twin boundaries (ITBs) with high energy, generating a stacking fault along {111} plane, and resulting in the nucleating and growing of a twin by the successive emission of partials. A node is fixed at the intersecting center of the four different slip {111} planes. With increasing stress under the indentation, ITBs come into being close to the node, leading to the emission of a partial from the node. This generates a stacking fault along a {111} plane, nucleating and growing a twin by the continuous emission of the partials. This process repeats until the formation of fivefold deformation twins.

  8. The London-Anderson-Englert-Brout-Higgs-Guralnik-Hagen-Kibble-Weinberg mechanism and Higgs boson reveal the unity and future excitement of physics

    CERN Document Server

    Allen, Roland E

    2013-01-01

    The particle recently discovered by the CMS and ATLAS collaborations at CERN is almost certainly a Higgs boson, fulfilling a quest that can be traced back to three seminal high energy papers of 1964, but which is intimately connected to ideas in other areas of physics that go back much further. One might oversimplify the history of the features which (i) give mass to the W and Z particles that mediate the weak nuclear interaction, (ii) effectively break gauge invariance, (iii) eliminate physically unacceptable Nambu-Goldstone bosons, and (iv) give mass to fermions (like the electron) by collectively calling them the London-Anderson-Englert-Brout-Higgs-Guralnik-Hagen-Kibble-Weinberg mechanism. More important are the implications for the future: a Higgs boson appears to point toward supersymmetry, since new physics is required to protect its mass from enormous quantum corrections, while the discovery of neutrino masses seems to point toward grand unification of the nongravitational forces.

  9. The Higgs boson

    CERN Document Server

    Pimenta, Jean Jûnio Mendes; Natti, Érica Regina Takano; Natti, Paulo Laerte

    2013-01-01

    The Higgs boson was predicted in 1964 by British physicist Peter Higgs. The Higgs is the key to explain the origin of the mass of other elementary particles of Nature. However, only with the coming into operation of the LHC, in 2008, there were technological conditions to search for the Higgs boson. Recently, a major international effort conducted at CERN, by means of ATLAS and CMS experiments, has enabled the observation of a new bosonic particle in the region of 125 GeVs. In this paper, by means of known mechanisms of symmetry breaking that occur in the BCS theory of superconductivity and in the theory of nuclear pairing, we discuss the Higgs mechanism in the Standard Model. Finally, we present the current state of research looking for the Higgs boson and the alternative theories and extensions of the Standard Model for the elementary particle physics. Keywords: Higgs boson, BCS theory, nuclear pairing, Higgs mechanism, Standard Model.

  10. SIMULATIONS OF MECHANICAL BEHAVIOR OF POLYCRYSTALLINE COPPER WITH NANO-TWINS

    Institute of Scientific and Technical Information of China (English)

    Bo Wu; Yueguang Wei

    2008-01-01

    Mechanical behavior and microstructure evolution of polycrystalline copper with nano-twins were investigated in the present work by finite element simulations.The fracture of grain boundaries axe described by a cohesive interface constitutive model based on the strain gradient plasticity theory.A systematic study of the strength and ductility for different grain sizes and twin lamellae distributions is performed.The results show that the material strength and ductility strongly depend on the grain size and the distribution of twin lamellae microstructures in the polycrystalline copper.

  11. Mechanical properties of gold twinned nanocubes under different triaxial tensile rates

    Science.gov (United States)

    Yang, Zailin; Zhang, Guowei; Luo, Gang; Sun, Xiaoqing; Zhao, Jianwei

    2016-08-01

    The gold twinned nanocubes under different triaxial tensile rates are explored by molecular dynamics simulation. Hydrostatic stress and Mises stress are defined in order to understand triaxial stresses. Twin boundaries prevent dislocations between twin boundaries from developing and dislocation angles are inconspicuous, which causes little difference between triaxial stresses. The mechanical properties of the nanocubes under low and high tensile rates are different. The curves of nanocubes under high tensile rates are more abrupt than those under low tensile rates. When the tensile rate is extremely big, the loadings are out of the nanocubes and there are not deformation and fracture in the internal nanocubes.

  12. Probing New Gauge Boson Z‧ from the Left-Right Twin Higgs Model at High-Energy e+e- Colliders

    Science.gov (United States)

    Liu, Yao-Bei; Du, Lin-Lin; Chang, Qin

    The left-right twin Higgs (LRTH) model predicts the existence of the new neutral gauge boson Z‧. In this paper, we calculate the contributions of this new particle to the processes e+e-→l+l-, bbar b and cbar c and study the possibility of detecting this new particle via these processes in the future high-energy linear e+e- collider (LC) experiments with √ {s}=500 GeV and £int = 340 fb-1, both for unpolarized and polarized beams. We find that the new gauge boson Z‧ is most sensitive to the process e+e--> cbar {c} with suitably polarized beams. As long as MZ‧ ≤ 1.9 TeV, the absolute value of the relative correction parameter is larger than 5%. We calculate the forward-backward asymmetries for the process e+e--> fbar {f}, the results show that the possible signals of Z‧ might be detected via measuring the deviations of AFB from its SM prediction for √ {s}˜= MZ'. Bounds on Z‧ masses are also estimated within 95% confidence level. From our analysis, we conclude that the new gauge boson is most sensitive to the process F>e+e^--> cbar c and its virtual effects are most easy to be observed via this process in the future LC experiments.

  13. Current Progress of Mechanical Properties of Metals with Nano-scale Twins

    Institute of Scientific and Technical Information of China (English)

    Lei LU

    2008-01-01

    Focus on face-centered cubic (fcc) metals with nano-scale twins lamellar structure, this paper presents a brief overview of the recent progress made in improving mechanical properties, including strength, ductility, work hardening, strain rate sensitivities, and in mechanistically understanding the underling deformation mechanisms. Significant developments have been achieved in nano-twinned fcc metals with a combination of high strength and considerable ductility at the same time, enhanced work hardening ability and enhanced rate sensitivity. The findings elucidate the role of interactions between dislocations and twin boundaries (TBs) and their contribution to the origin of outstanding properties. The computer simulation analysis accounts for high plastic anisotropy and rate sensitivity anisotropy by treating TBs as internal interfaces and allowing special slip geometry arrangements that involve soft and hard modes of deformation. Parallel to the novel mechanical behaviors of the nano-twinned materials, the investigation and developments of nanocrystalline materials are also discussed in this overview for comparing the contribution of grain boundaries/TBs and grain size/twin lamellar spacing to the properties. The recent advances in the experimental and computational studies of plastic deformation of the fcc metals with nano-scale twin lamellar structures provide insights into the possible means of optimizing comprehensive mechanical properties through interfacial engineering.

  14. Phenomenological constraints on the Higgs as pseudo-Goldstone boson mechanism in supersymmetric GUT theories

    CERN Document Server

    Csáki, C; Csaki, Csaba; Randall, Lisa

    1995-01-01

    There are few robust solutions to the doublet-triplet splitting problem in supersymmetric GUT theories. One of the more promising solutions is the Higgs as pseudo-Goldstone boson mechanism. In its minimal implementation, such a solution places an additional restriction on the parameter space of the minimal supersymmetric standard model. A testable consequence of this constraint is an equation for \\tan \\beta. We present this restriction and study its solutions in order to constrain the allowed parameter space. Thus the assumptions on the GUT scale Higgs sector should yield testable predictions for weak scale physics. If the SUSY parameters are measured then it should be possible to check the predictions, yielding insight into GUT scale physics.

  15. Role of five-fold twin boundary on the enhanced mechanical properties of fcc Fe nanowires.

    Science.gov (United States)

    Wu, J Y; Nagao, S; He, J Y; Zhang, Z L

    2011-12-14

    The role of 5-fold twin boundary on the structural and mechanical properties of fcc Fe nanowire under tension is explored by classical molecular dynamics. Twin-stabilized fcc nanowire with various diameters (6-24 nm) are examined by tension tests at several temperatures ranging from 0.01 to 1100 K. Significant increase in the Young's modulus of the smaller nanowires is revealed to originate from the central area of quinquefoliolate-like stress-distribution over the 5-fold twin, rather than from the surface tension that is often considered as the main source of such size-effects found in nanostructures. Because of the excess compressive stress caused by crossing twin-boundaries, the atoms in the center behave stiffer than those in bulk and even expand laterally under axial tension, providing locally negative Poisson's ratio. The yield strength of nanowire is also enhanced by the twin boundary that suppresses dislocation nucleation within a fcc twin-domain; therefore, the plasticity of nanowire is initiated by strain-induced fcc→bcc phase transformation that destroys the twin structure. After the yield, the nucleated bcc phase immediately spreads to the entire area, and forms a multigrain structure to realize ductile deformation followed by necking. As temperature elevated close to the critical temperature between bcc and fcc phases, the increased stability of fcc phase competes with the phase transformation under tension, and hence dislocation nucleations in fcc phase are observed exclusively at the highest temperature in our study.

  16. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2016-01-01

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  17. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2017-01-01

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  18. SUSY Meets Her Twin

    CERN Document Server

    Katz, Andrey; Pokorski, Stefan; Redigolo, Diego; Ziegler, Robert

    2017-01-31

    We investigate the general structure of mirror symmetry breaking in the Twin Higgs scenario. We show, using the IR effective theory, that a significant gain in fine tuning can be achieved if the symmetry is broken hardly. We emphasize that weakly coupled UV completions can naturally accommodate this scenario. We analyze SUSY UV completions and present a simple Twin SUSY model with a tuning of around 10% and colored superpartners as heavy as 2 TeV. The collider signatures of general Twin SUSY models are discussed with a focus on the extended Higgs sectors.

  19. Toward understanding twin–twin interactions in hcp metals: Utilizing multiscale techniques to characterize deformation mechanisms in magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Morrow, B.M., E-mail: morrow@lanl.gov; Cerreta, E.K.; McCabe, R.J.; Tomé, C.N.

    2014-09-08

    The mechanical properties of hexagonal close-packed (hcp) metals depend heavily on both slip and twinning, and interactions between twins have important implications on hardening behavior. Electron backscatter diffraction (EBSD), as well as conventional, in situ straining, and high resolution (HR) transmission electron microscopy (TEM) are used to study these interactions. HRTEM is used to observe the twin boundary structure. Twin boundaries that deviate from the characteristic {101"¯2} twin planes at the macroscale are revealed to be a combination of perfect {101"¯2} boundaries and characteristic facets at the nanoscale. Faceting for tensile {101"¯2} twins adopts basal-prismatic (B-P) character, where basal planes in the matrix very nearly align with prism planes in the twin, or similarly, prism planes in the matrix align with basal planes in the twin. Such features play a significant role in twin boundaries, where faceting accommodates the large changes to boundary shape observed. in situ straining is used to study twin–twin interactions as they occur, and also detwinning behavior upon load reversal. During the initial interaction, considerable changes to the shape of the twin boundaries are observed, consistent with post-mortem analyses. On load reversal, detwinning is observed, and the interacting twins disengage from one another, however a change in boundary structure due to the interaction is retained.

  20. Coupled thermal-fluid-mechanics analysis of twin roll casting of A7075 aluminum alloy

    Science.gov (United States)

    Lee, Yun-Soo; Kim, Hyoung-Wook; Cho, Jae-Hyung; Chun, Se-Hwan

    2017-09-01

    Better understanding of temperature distribution and roll separation force during twin roll casting of aluminum alloys is critical to successfully fabricate good quality of aluminum strips. Therefore, the simulation techniques are widely applied to understand the twin roll casting process in a comprehensive way and to reduce the experimental time and cost of trial and error. However, most of the conventional approaches are considered thermally coupled flow, or thermally coupled mechanical behaviors. In this study, a fully coupled thermal-fluid-mechanical analysis of twin roll casting of A7075 aluminum strips was carried out using the finite element method. Temperature profile, liquid fraction and metal flow of aluminum strips with different thickness were predicted. Roll separation force and roll temperatures were experimentally obtained from a pilot-scale twin roll caster, and those results were compared with model predictions. Coupling the fluid of the liquid melt to the thermal and mechanical modeling reasonably predicted roll temperature distribution and roll separation force during twin roll casting.

  1. Beyond Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Bardeen, William A.; /Fermilab

    2008-05-01

    I discuss the Standard Model of Elementary Particle Physics and potential for discoveries of the physics responsible for electroweak symmetry breaking. I review the ideas leading to development of the Brout-Englert-Higgs mechanism that now forms the basis for the conventional Standard Model. I discuss various issues that challenge application of the Standard Model to the known physics of elementary particles. I examine alternatives to the Standard Model that address these issues and may lead to new discoveries at the LHC that go Beyond Higgs.

  2. Tadpole-Induced Electroweak Symmetry Breaking and pNGB Higgs Models

    CERN Document Server

    Harnik, Roni; Kearney, John

    2016-01-01

    We investigate induced electroweak symmetry breaking (EWSB) in models in which the Higgs is a pseudo-Nambu-Goldstone boson (pNGB). In pNGB Higgs models, Higgs properties and precision electroweak measurements imply a hierarchy between the EWSB and global symmetry-breaking scales, $v_H \\ll f_H$. When the pNGB potential is generated radiatively, this hierarchy requires fine-tuning to a degree of at least $\\sim v_H^2/f_H^2$. We show that if Higgs EWSB is induced by a tadpole arising from an auxiliary sector at scale $f_\\Sigma \\ll v_H$, this tuning is significantly ameliorated or can even be removed. We present explicit examples both in Twin Higgs models and in Composite Higgs models based on $SO(5)/SO(4)$. For the Twin case, the result is a fully natural model with $f_H \\sim 1$ TeV and the lightest colored top partners at 2 TeV. These models also have an appealing mechanism to generate the scales of the auxiliary sector and Higgs EWSB directly from the scale $f_H$, with a natural hierarchy $f_\\Sigma \\ll v_H \\ll ...

  3. Development of pulsating twin jets mechanism for mixing flow heat transfer analysis.

    Science.gov (United States)

    Gitan, Ali Ahmed; Zulkifli, Rozli; Abdullah, Shahrir; Sopian, Kamaruzzaman

    2014-01-01

    Pulsating twin jets mechanism (PTJM) was developed in the present work to study the effect of pulsating twin jets mixing region on the enhancement of heat transfer. Controllable characteristics twin pulsed jets were the main objective of our design. The variable nozzle-nozzle distance was considered to study the effect of two jets interaction at the mixing region. Also, the phase change between the frequencies of twin jets was taken into account to develop PTJM. All of these factors in addition to the ability of producing high velocity pulsed jet led to more appropriate design for a comprehensive study of multijet impingement heat transfer problems. The performance of PTJM was verified by measuring the pulse profile at frequency of 20 Hz, where equal velocity peak of around 64 m/s for both jets was obtained. Moreover, the jet velocity profile at different pulsation frequencies was tested to verify system performance, so the results revealed reasonable velocity profile configuration. Furthermore, the effect of pulsation frequency on surface temperature of flat hot plate in the midpoint between twin jets was studied experimentally. Noticeable enhancement in heat transfer was obtained with the increasing of pulsation frequency.

  4. p-adic description of Higgs mechanism; 3, calculation of elementary particle masses

    CERN Document Server

    Pitkänen, M

    1994-01-01

    This paper belongs to the series devoted to the calculation of particle masses in the framework of p-adic conformal field theory limit of Topological GeometroDynamics. In paper II the general formulation of p-adic Higgs mechanism was given. In this paper the calculation of the fermionic and bosonic masses is carried out. The calculation of the masses necessitates the evaluation of dege- neracies for states as a function of conformal weight in certain tensor product of Super Virasoro algebras. The masses are very sen- sitive to the degeneracy ratios: Planck mass results unless the ratio for the degeneracies for first excited states and massless states is an integer multiple of 2/3. For leptons, quarks and gauge bosons this miracle occurs. The main deviation from standard model is the prediction of light color excited leptons and quarks as well as colored boson exotics. Higgs particle is absent from spectrum as is also graviton: the latter is due to the basic approximation of p-adic TGD. Reason for replacement:...

  5. Higgs as a probe of supersymmetric grand unification with the Hosotani mechanism

    CERN Document Server

    Yamashita, T

    2015-01-01

    The supersymmetric grand unified theory where the $SU(5)$ gauge symmetry is broken by the Hosotani mechanism provides a natural solution to the so-called doublet-triplet splitting problem. At the same time, this model derives a general and distinctive prediction that is testable at TeV scale collider experiments. To be more concrete, adjoint chiral supermultiplets with masses around TeV scale appear. Since these additional fields originate from a higher-dimensional gauge supermultiplet, our model is highly predictive. We study especially the Higgs sector and show that our model is discriminative from the others by precision measurements of the couplings and masses. Namely, we may get a hint of the breaking mechanism of the grand unification at future collider experiments.

  6. Investigations on the mechanical behavior of nanowires with twin boundaries by atomistic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Xia, E-mail: tianxia@lsec.cc.ac.cn [College of Mechanics and Materials, HoHai University, Nanjing 210098 (China)

    2015-03-10

    Atomistic simulations are used to study the deformation behavior of twinned Cu nanowires with a <111> growth orientation under tension. Due to the existence of the twin boundaries, the strength of the twinned nanowires is higher than that of the twin-free nanowire and the yielding stress of twinned nanowires is inversely proportional to the spacings of the twin boundaries. Moreover, The ductility of the twin-free nanowire is the highest of all and it grows with the increasing spacings of the twin boundaries for twinned nanowires. Besides, we find that the twin boundaries can be served as dislocation sources as well as the free surfaces and grain boundaries.

  7. Does the Higgs mechanism favour electron-electron bound states in Maxwell-Chern-Simons $QED_{3}$?

    CERN Document Server

    Belich, H; Helayël-Neto, José A

    2000-01-01

    The low-energy electron-electron scattering potential is derived and discussed for the Maxwell-Chern-Simons model coupled to QED_3 with spontaneous symmetry breaking. One shows that the Higgs mechanism might favour electron-electron bound states.

  8. Anatomizing Exotic Production of the Higgs Boson

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Felix [Fermilab

    2014-07-10

    We discuss exotic production modes of the Higgs boson and how their phenomenology can be probed in current Higgs analyses. We highlight the importance of differential distributions in disentangling standard production mechanisms from exotic modes. We present two model benchmarks for exotic Higgs production arising from chargino-neutralino production and study their impact on the current Higgs dataset. As a corollary, we emphasize that current Higgs coupling fits do not fully explore the space of new physics deviations possible in Higgs data.

  9. Testing neutrino mass generation mechanisms from the lepton flavor violating decay of the Higgs boson

    Science.gov (United States)

    Aoki, Mayumi; Kanemura, Shinya; Sakurai, Kodai; Sugiyama, Hiroaki

    2016-12-01

    We investigate how observations of the lepton flavor violating decay of the Higgs boson (h → ℓℓ‧) can narrow down models of neutrino mass generation mechanisms, which were systematically studied in Refs. [1,2] by focusing on the combination of new Yukawa coupling matrices with leptons. We find that a wide class of models for neutrino masses can be excluded if evidence for h → ℓℓ‧ is really obtained in the current or future collider experiments. In particular, simple models of Majorana neutrino masses cannot be compatible with the observation of h → ℓℓ‧. It is also found that some of the simple models to generate masses of Dirac neutrinos radiatively can be compatible with a significant rate of the h → ℓℓ‧ process.

  10. Emerging of massive gauge particles in inhomogeneous local gauge transformations: replacement of Higgs mechanism

    CERN Document Server

    Struckmeier, Jürgen

    2013-01-01

    A generalized theory of gauge transformations is presented on the basis of the covariant Hamiltonian formalism of field theory, for which the covariant canonical field equations are equivalent to the Euler-Lagrange field equations. Similar to the canonical transformation theory of point dynamics, the canonical transformation rules for fields are derived from generating functions. Thus---in contrast to the usual Lagrangian description---the covariant canonical transformation formalism automatically ensures the mappings to preserve the action principle, and hence to be {\\em physical}. On that basis, we work out the theory of inhomogeneous local gauge transformations that generalizes the conventional local SU(N) gauge transformation theory. It is shown that massive gauge bosons naturally emerge in this description, which thus could supersede the Higgs mechanism.

  11. Higgs mechanism in three-dimensional topological superconductors and anomalous Hall effect in zero magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Flavio; Eremin, Ilya [Theoretische Physik III, Ruhr-Universitaet Bochum (Germany)

    2015-07-01

    We discuss the peculiar nature of Higgs mechanism in an effective field theory for three-dimensional topological superconductors. The effective theory features two order parameters associated to the two chiral fermion species in the system. The resulting electrodynamics of such a topological superconductor exhibits a topological magnetoelectric effect with an axion field given by the phase difference of the order parameters. As consequence, the London regime is highly non-linear and anomalous Hall effect in the absence of an external magnetic field occurs. In this anomalous Hall effect the generated current transverse to an applied electric field changes sign with the temperature. We also discuss the scaling behavior of the penetration depth near the transition temperature, which is also shown to exhibit a scaling exponent that is crucially influenced by the axion term, varying continuously as function of the average phase difference.

  12. Testing neutrino mass generation mechanisms from the lepton flavor violating decay of the Higgs boson

    CERN Document Server

    Aoki, Mayumi; Sakurai, Kodai; Sugiyama, Hiroaki

    2016-01-01

    We investigate how observations of the lepton flavor violating decay of the Higgs boson ($h \\to \\ell\\ell^\\prime$) can narrow down models of neutrino mass generation mechanisms, which were systematically studied in Refs. [1,2] by focusing on the combination of new Yukawa coupling matrices with leptons. We find that a wide class of models for neutrino masses can be excluded if evidence for $h \\to \\ell\\ell^\\prime$ is really obtained in the current or future collider experiments. In particular, simple models of Majorana neutrino masses cannot be compatible with the observation of $h \\to \\ell\\ell^\\prime$. It is also found that some of the simple models to generate masses of Dirac neutrinos radiatively can be compatible with a significant rate of the $h \\to \\ell\\ell^\\prime$ process.

  13. Hierarchical ZnO with twinned structure: Morphology evolution, formation mechanism and properties

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Ruixia; Song, Xueling; Li, Jia; Yang, Ping, E-mail: mse_yangp@ujn.edu.cn

    2015-04-15

    Various hierarchical ZnO architectures constructed by twinned structures have been synthesized via a trisodium citrate assisted hydrothermal method on a large scale. The probable formation mechanisms of hierarchical ZnO structures with twinned structure were proposed and discussed. The hierarchical ZnO with twinned structures are composed of two hemispheres with a center concave junction to join them together at their waists. The ZnO microspheres with rough surfaces were obtained when the concentration of trisodium citrate is 0.1 M. However, the football-like microspheres consisted of hexagonal nanosheets were formed when adding glycerol into the water, which should be attributed to the slower nucleation and growth rate of nanocrystals. The hamburger-like ZnO with different aspect ratio and nonuniform ZnO microspheres were generated due to the different quantity of initial nuclei and growth units when simply modulating the concentration of trisodium citrate. The surface area of football-like ZnO is about 3.51 times of microspheres composed of irregular particles. However their photocatalytic performances are similar under UV light irradiation, which indicates that pore sizes of the sample have more important influences on the photocatalytic activity. - Highlights: • Hierarchical ZnO constructed by twinned structures have been synthesized. • The formation mechanisms of ZnO with twinned structure were discussed. • Football-like microspheres were obtained due to the slower nucleation and growth. • Hamburger-like ZnO was formed due to the amount of initial nuclei and growth units. • Pore sizes have important effects on the photocatalytic activity of sample.

  14. Higgs Starobinsky inflation

    Science.gov (United States)

    Calmet, Xavier; Kuntz, Iberê

    2016-05-01

    In this paper we point out that Starobinsky inflation could be induced by quantum effects due to a large non-minimal coupling of the Higgs boson to the Ricci scalar. The Higgs Starobinsky mechanism provides a solution to issues attached to large Higgs field values in the early universe which in a metastable universe would not be a viable option. We verify explicitly that these large quantum corrections do not destabilize Starobinsky's potential.

  15. Higgs Starobinsky Inflation

    CERN Document Server

    Calmet, Xavier

    2016-01-01

    In this paper we point out that Starobinky inflation could be induced by quantum effects due to a large non-minimal coupling of the Higgs boson to the Ricci scalar. The Higgs Starobinsky mechanism provides a solution to issues attached to large Higgs field values in the early universe which in a metastable universe would not be a viable option. We verify explicitly that these large quantum corrections do not destabilize Starobinsky's potential.

  16. Higgs Starobinsky inflation

    Energy Technology Data Exchange (ETDEWEB)

    Calmet, Xavier; Kuntz, Ibere [University of Sussex, Physics and Astronomy, Brighton (United Kingdom)

    2016-05-15

    In this paper we point out that Starobinsky inflation could be induced by quantum effects due to a large non-minimal coupling of the Higgs boson to the Ricci scalar. The Higgs Starobinsky mechanism provides a solution to issues attached to large Higgs field values in the early universe which in a metastable universe would not be a viable option. We verify explicitly that these large quantum corrections do not destabilize Starobinsky's potential. (orig.)

  17. A discrete twin-boundary approach for simulating the magneto-mechanical response of Ni-Mn-Ga

    Science.gov (United States)

    Faran, Eilon; Shilo, Doron

    2016-09-01

    The design and optimization of ferromagnetic shape memory alloys (FSMA)-based devices require quantitative understanding of the dynamics of twin boundaries within these materials. Here, we present a discrete twin boundary modeling approach for simulating the behavior of an FSMA Ni-Mn-Ga crystal under combined magneto-mechanical loading conditions. The model is based on experimentally measured kinetic relations that describe the motion of individual twin boundaries over a wide range of velocities. The resulting calculations capture the dynamic response of Ni-Mn-Ga and reveal the relations between fundamental material parameters and actuation performance at different frequencies of the magnetic field. In particular, we show that at high field rates, the magnitude of the lattice barrier that resists twin boundary motion is the important property that determines the level of actuation strain, while the contribution of twinning stress property is minor. Consequently, type II twin boundaries, whose lattice barrier is smaller compared to type I, are expected to show better actuation performance at high rates, irrespective of the differences in the twinning stress property between the two boundary types. In addition, the simulation enables optimization of the actuation strain of a Ni-Mn-Ga crystal by adjusting the magnitude of the bias mechanical stress, thus providing direct guidelines for the design of actuating devices. Finally, we show that the use of a linear kinetic law for simulating the twinning-based response is inadequate and results in incorrect predictions.

  18. Micro-mechanical properties of 2219 welded joints with twin wire welding

    Institute of Scientific and Technical Information of China (English)

    Xu Wenli; Li Qingfen; Meng Qingguo; Fang Hongyuan; Gao Na

    2006-01-01

    Nanoindentation method was adopted to investigate the distribution regularities of micro-mechanical properties of 2219 twin wire welded joints, thus providing the necessary theoretical basis and guidance for joint strengthening and improvement of welding procedure.Experimental results show that in weld zone, micro-mechanical properties are seriously uneven.Both hardness and elastic modulus distribute as uneven sandwich layers, while micro-mechanical properties in bond area are much more uniform than weld zone;In heat-affected zone of 2219 twin wire welded joint, distribution regularity of hardness is similar to elastic modulus.The average hardness in quenching zone is higher than softening zone, and the average elastic modulus in solid solution zone is slightly higher than softening zone.As far as the whole welded joint is concerned,metal in weld possesses the lowest hardness.For welded specimens without reinforcement, fracture position is the weld when tensioning.While for welded specimens with reinforcement, bond area is the poorest position with joint strength coefficient of 61%.So, it is necessary to strengthen the poor positions-weld and bond area of 2219 twin wire welded joint in order to solve joint weakening of welding this kind of alloy.

  19. Nanoindentation of BaTiO{sub 3}: dislocation nucleation and mechanical twinning

    Energy Technology Data Exchange (ETDEWEB)

    Gaillard, Y; Anglada, M [Department of Materials Science and Metallurgy (CMEM), Universitat Politecnica de Catalunya, Avda. Diagonal 647 (ETSEIB), 08028 Barcelona (Spain); MacIas, A Hurtado [Centro de Investigacion en Materiales Avanzados, SC, Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua, 31109 (Mexico); Munoz-Saldana, J; Trapaga, G, E-mail: jmunoz@qro.cinvestav.m [Centro de Investigacion y Estudios Avanzados del IPN, Unidad Queretaro Apdo, Postal 1-798, 76001 Queretaro, Qro. (Mexico)

    2009-04-21

    This paper presents a study of the deformation mechanisms of barium titanate under nanoindentation. The (0 0 1) and (1 1 0) crystallographic orientations of BaTiO{sub 3} giant grains were indented and critical mean contact pressures for dislocation nucleation were extracted from the indentation curves. The orientation of the dislocation slip lines was identified by atomic force microscopy, showing that the (1 1 0){l_brace}1 1 0{r_brace} glide systems were activated. Twin bands, observed on both orientations, also occur on the {l_brace}1 1 0{r_brace} habit planes and actively participate in the accommodation of the plastic deformation. Furthermore, dislocation pile-ups introduced by spherical indentations have shown a close relation between dislocations and twinning formation.

  20. Mechanical properties of homogenized twin-roll cast and conventionally cast AZ31 magnesium alloys

    Directory of Open Access Journals (Sweden)

    Mariia Zimina

    2015-02-01

    Full Text Available The improvement of mechanical properties of magnesium alloys nowadays is very important, because of the variety of industrial applications. For this goal, the number of casting techniques and further treatments were developed. Among the continuous casting techniques, which allow producing long strips of the alloys, is twin-roll casting. Using this process one can get the magnesium alloy with finest microstructure and higher specific strength. In this paper the comparison of tensile properties of conventionally cast and twin-roll cast AZ31 magnesium alloys was made. Tensile tests were carried out with constant strain rate 10-3 s-1 at temperatures ranging from 100 to 300 °C. Both materials were tested in as-cast state and after homogenization treatment at 450 °C for 10 hours. The investigation showed that there are no significant changes in ductility of AZ31 conventionally cast alloy even after heat treatment, while the ductility of twin-roll cast alloy increases.

  1. Spin-Gauge Theory of Gravity with Higgs-field Mechanism

    CERN Document Server

    Dehnen, H

    2013-01-01

    We propose a Lorentz-covariant Yang-Mills spin-gauge theory, where the function valued Dirac matrices play the role of a non-scalar Higgs-field. As symmetry group we choose $SU(2) \\times U(1)$. After symmetry breaking a non-scalar Lorentz-covariant Higgs-field gravity appears, which can be interpreted within a classical limit as Einstein's metrical theory of gravity, where we restrict ourselves in a first step to its linearized version.

  2. Simulation study of mechanical properties of bulk metallic glass systems: martensitic inclusions and twinned precipitates

    Science.gov (United States)

    Zaheri, A.; Abdeljawad, F.; Haataja, M.

    2014-12-01

    Monolithic bulk metallic glasses (BMGs) exhibit a unique combination of mechanical properties, such as high strength and large elasticity limits, but the lack of ductility is considered the main Achilles' heel of BMG systems. To increase the competitiveness of BMGs vis-à-vis conventional structural materials, the problem of catastrophic failure via intense plastic strain localization (‘shear banding’) has to be addressed. Recent experimental observations suggest that the addition of structural heterogeneities, in the form of crystalline particles, to BMG systems hinders the catastrophic propagation of shear bands and leads to enhanced ductility. These structural heterogeneities can be introduced by either forming BMG composites, where second-phase crystalline particles accommodate applied loads via martensitic transformation mechanisms, or developing glassy alloys that precipitate crystalline particles under deformation, a process by which further deformation can be sustained by twinning mechanisms in the crystalline phase. In this work, we present a non-linear continuum model capable of capturing the structural heterogeneity in the glassy phase and accounting for intrinsic work hardening via martensitic transformations in second-phase reinforcements in BMG composites and deformation twinning in precipitated crystalline particles. Simulation results reveal that in addition to intrinsic work hardening in the crystalline phase, particle size greatly affects the overall mechanical behavior of these BMG systems. The precipitation of crystalline particles in monolithic BMGs yields two-phase microstructures that promote more homogeneous deformation, delay the propagation of incipient shear bands, and ultimately result in improved ductility characteristics.

  3. The Higgs mechanism and superconductivity: A case study of formal analogies

    Science.gov (United States)

    Fraser, Doreen; Koberinski, Adam

    2016-08-01

    Following the experimental discovery of the Higgs boson, physicists explained the discovery to the public by appealing to analogies with condensed matter physics. The historical root of these analogies is the analogies to models of superconductivity that inspired the introduction of spontaneous symmetry breaking (SSB) into particle physics in the early 1960s. We offer a historical and philosophical analysis of the analogies between the Higgs model of the electroweak (EW) interaction and the Ginsburg-Landau (GL) and Bardeen-Cooper-Schrieffer (BCS) models of superconductivity, respectively. The conclusion of our analysis is that both sets of analogies are purely formal in virtue of the fact that they are accompanied by substantial physical disanalogies. In particular, the formal analogies do not map the temporal, causal, or modal structures of SSB in superconductivity to temporal, causal, or modal structures in the Higgs model. These substantial physical disanalogies mean that analogies to models of superconductivity cannot supply the basis for the physical interpretation of EW SSB; however, an appreciation of the contrast between the physical interpretations of SSB in superconductivity and the Higgs model does help to clarify some foundational issues. Unlike SSB in superconductivity, SSB in the Higgs sector of the Standard Model (without the addition of new physics) is neither a temporal nor a causal process. We discuss the implications for the 'eating' metaphor for mass gain in the Higgs model. Furthermore, the distinction between the phenomenological GL model and the dynamical BCS model does not carry over to EW models, which clarifies the desiderata for the so-called 'dynamical' models of EW SSB (e.g., minimal technicolor). Finally, the development of the Higgs model is an illuminating case study for philosophers of science because it illustrates how purely formal analogies can play a fruitful heuristic role in physics.

  4. What monozygotic twins discordant for phenotype illustrate about mechanisms influencing genetic forms of neurodegeneration

    NARCIS (Netherlands)

    Ketelaar, M. E.; Hofstra, R. M. W.; Hayden, M. R.

    2012-01-01

    As monozygotic (MZ) twins are believed to be genetically identical, discordance for disease phenotype between MZ twins has been used in genetic research to understand the contribution of genetic vs environmental factors in disease development. However, recent studies show that MZ twins can differ bo

  5. Does amniotic fluid volume affect fetofetal transfusion in monochorionic twin pregnancies? Modelling two possible mechanisms

    Science.gov (United States)

    Umur, Asli; van Gemert, Martin J. C.; Ross, Michael G.

    2002-06-01

    Clinical evidence suggests that increased amniotic fluid volume due to polyhydramnios increases placental vascular resistance. We have sought to model the possible effects of an increased amniotic fluid volume on the net fetofetal transfusion in monochorionic twin pregnancies. We wanted to compare these effects with the results of previous simulations, which aimed to explain why the twin-twin transfusion syndrome (TTTS) placentas more often include bidirectional arteriovenous (AV) rather than AV plus arterioarterial (AA) anastomoses. We extended our mathematical model of TTTS by simulating two different mechanisms that increase the placental vascular resistance as a consequence of polyhydramnios. First, there is an increase in the placental capillary resistance and hence in deep AV and opposite AV (denoted as VA) resistances due to polyhydramnios. Second, there is an increase in the resistance of chorionic veins due to polyhydramnios, assuming that these veins act as Starling resistors. We then simulated the effects of polyhydramnios on different placental anastomotic patterns. The results were as follows. In the first mechanism (polyhydramnios affects AV-VA resistances), an increased amniotic fluid volume hardly affected bidirectional AV, but slightly decreased fetofetal transfusion in AV plus AA anastomoses. However, for these effects to change the natural development of the pregnancy, polyhydramnios needed to persist for approximately 4 weeks, and by comparing the effects of polyhydramnios with the effects of amnioreduction, amnioreduction was more beneficial for normalizing the donor amniotic fluid volume. Therefore, these beneficial effects due to polyhydramnios have no practical clinical significance. In the second mechanism (Starling resistor for chorionic veins), polyhydramnios slightly increased fetofetal transfusion and hence slightly increased TTTS severity in bidirectional AV and AV plus VV, but did not affect AV plus AA anastomoses. In conclusion, we

  6. Deformation mechanism of kink-step distorted coherent twin boundaries in copper nanowire

    Directory of Open Access Journals (Sweden)

    Bobin Xing

    2017-01-01

    Full Text Available In the construction of nanotwinned (NT copper, inherent kink-like steps are formed on growth twin boundaries (TBs. Such imperfections in TBs play a crucial role in the yielding mechanism and plastic deformation of NT copper. Here, we used the molecular dynamic (MD method to examine the influence of kink-step characteristics in depth, including kink density and kink-step height, on mechanical behavior of copper nanowire (NW in uniaxial tension. The results showed that the kink-step, a stress-concentrated region, is preferential in nucleating and emitting stress-induced partial dislocations. Mixed dislocation of hard mode I and II and hard mode II dislocation were nucleated from kink-step and surface atoms, respectively. Kink-step height and kink density substantially affected the yielding mechanism and plastic behavior, with the yielding stress functional-related to kink-step height. However, intense kink density (1 kink per 4.4 nm encourages dislocation nucleation at kink-steps without any significant decline in tensile stress. Defective nanowires with low kink-step height or high kink density offered minimal resistance to kink migration, which has been identified as one of the primary mechanisms of plastic deformation. Defective NWs with refined TB spacing were also studied. A strain-hardening effect due to the refined TB spacing and dislocation pinning was observed for defective NWs. This study has implications for designing NT copper to obtain optimum mechanical performance.

  7. Higgs physics: Theory

    Indian Academy of Sciences (India)

    Abdelhak Djouadi

    2012-10-01

    The theoretical aspects of the physics of Higgs bosons are reviewed focussing on the elements that are relevant for the production and detection at present hadron colliders. After briefly summarizing the basics of electroweak symmetry breaking in the Standard Model, the Higgs production at the LHC and at the Tevatron is discussed, with some focus on the main production mechanism, the gluon–gluon fusion process, and the main Higgs decay modes and the experimental detection channels are discussed. Then the case of the minimal supersymmetric extension of the Standard Model is briefly surveyed. In the last section, the prospects for determining the fundamental properties of the Higgs particles are reviewed, once they have been experimentally observed.

  8. Higgs physics at LHC

    Indian Academy of Sciences (India)

    S Dasu

    2004-02-01

    The large hadron collider (LHC) and its detectors, ATLAS and CMS, are being built to study TeV scale physics, and to fully understand the electroweak symmetry breaking mechanism. The Monte-Carlo simulation results for the standard model and minimal super symmetric standard model Higgs boson searches and parameter measurements are discussed. Emphasis is placed on recent investigations of Higgs produced in association with top quarks and in vector boson fusion channels. These results indicate that Higgs sector can be explored in many channels within a couple of years of LHC operation i.e., $\\mathcal{L}=30$ fb-1. Complete coverage including measurements of Higgs parameters can be carried out with full LHC program.

  9. Microstructure and formation mechanism of twins of laths of austenite with high nitrogen

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The microstructure of composite diffusion layer of the nitrided and chromized 0.2% carbon steel is investigated using TEM and EDS. It is found that laths of austenite with high nitrogen (λN) precipitate from α-ferrite matrix in the deeper zone of the diffusion layer. These λN laths are all twins, with their {111} twinning planes parallel to the lath axis, thus forming a characteristic "back-to-back" morphology. There are two types of λN lath. The first is a genuinely {111} twin, and λN and α keep the accurate K-S relationship, and each λN and α form a sharp and smooth λN/α interface of {335}λN//{341}a, namely habit plane {335}fcc. The second is a pseudo-twin, with micro-twins {111} or faults formed within the two twin components. Localized lattice deformation (relaxation) seems to have occurred at the interfaces of the second type of λN due to the formation of micro-twins or faults within the twin components. These micro-twins or faults make the orientation relationship (OR) between each of the λN and the (-matrix deviate from the accurate K-S OR, and the OR between two λN twin components deviate from the genuine {111} twin relationship. In addition, the λN/α interface of the second type of λN is not as sharp or smooth as that of the first one.

  10. Higgs CAT

    Energy Technology Data Exchange (ETDEWEB)

    Passarino, Giampiero [Universita di Torino, Dipartimento di Fisica Teorica, Turin (Italy); INFN, Sezione di Torino, Turin (Italy)

    2014-05-15

    Higgs Computed Axial Tomography, an excerpt. The Higgs boson lineshape (..and the devil hath power to assume a pleasing shape, Hamlet, Act II, scene 2) is analyzed for the gg → ZZ process, with special emphasis on the off-shell tail which shows up for large values of the Higgs virtuality. The effect of including background and interference is also discussed. The main focus of this work is on residual theoretical uncertainties, discussing how much-improved constraint on the Higgs intrinsic width can be revealed by an improved approach to analysis. (orig.)

  11. The role of deformation twinning in the fracture behavior and mechanism of basal textured magnesium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ando, D., E-mail: dando@material.tohoku.ac.jp; Koike, J.; Sutou, Y.

    2014-04-01

    AZ31 magnesium alloys were deformed to 10% and to failure strain by tensile loading at room temperature. Scribed grids were drawn by a focused ion beam system (FIB) to visualize the local deformation in each grain. This showed that the magnitude of the strain was distributed non-uniformly in each grain. It was found that the low-strain grains accompanied {10–12} twins, while the severely strained grains accompanied {10–11}–{10–12} double twins. Cracks nucleated at the double twins and tended to propagate along {10–12} twin interfaces as well as within grains. Furthermore, fractography revealed three types of microstructural features: dimples, elliptic facets and sheared dimples. Most abundant were the dimples formed by ductile failure. The elliptic facets appeared to be due to crack propagation along the {10–12} twin interfaces. The sheared dimples were frequently observed in connection with localized shear deformation within the double twins. These results led us to conclude that premature and catastrophic failure of Mg alloys is mainly associated with double twins. Prevention of double twinning is essential to improve the ductility of Mg alloys.

  12. Design and Development of Electro-Mechanical Twins Tipping Buckets Runoff-Meter

    Directory of Open Access Journals (Sweden)

    Olotu Yahaya

    2014-07-01

    Full Text Available Electro-mechanical tipping bucket runoff-meter was designed and developed to measure surface runoff water using locally-sourced components. The instrument consists of metallic-fabricated runoff plot area of 2 m 2 , depth 0.25 m and metal gauge of 3mm. The tipping operation was initiated by arranging the sensitive electro-mechanical components such digital micro-switch (SW1,SW2, SW3 and SW4, pair of open/close circuit breakers (No,Nc, electronic speed gear and circular rotating disc to a pair of twins buckets of runoff volume 0.141 liter capacity per bucket which corresponds to 0.25 mm runoff depth. The whole arrangement was powered by a 12V by 75 AH battery and the tipping processes was being recorded by the electro-mechanical data logger. The instrument has a measuring accuracy of ±0.001 liter per tip. It was calibrated to measure minimum and maximum runoff volume from 0.14l to 200 liters, these values correspond to 0.25 mm and 800 mm runoff depths respectively. Therefore, precise results obtained using the instrument could be used to establish strong database for measuring and storing accurate surface runoff data which in turn could be applied for hydrological modeling for sustainable water resources management and design of hydraulic structures

  13. Higgs mechanism from fluxes and two mass hierarchies in the "fat" throat solution of Type IIA supegravity

    CERN Document Server

    Altshuler, Boris L

    2008-01-01

    Spectra of Kaluza-Klein gauge fields are calculated at the background of the magnetic fluxbrane throat-like solution of the Type IIA supergravity equations. Magnetic flux plays the role of Higgs scalar generating the electroweak scale mass of non-abelian KK gauge field. The same "flux-Higgs" mechanism gives the scale of the "second mass hierarchy", 0.001 eV, in the spectrum of KK excitations at the background of the throat deformed in a Reissner-Nordstrom way. Gauge coupling constants in 4 dimensions are calculated; they prove to be of the physically sensible values for the EW scale massive modes of the gauge fields and are extremely small for the long range gauge fields. 5D effective Action with the flux-generated mass terms of the KK gauge fields associated with isometries of compactified subspaces is put down, correspondence of the "classical" KK approach and dual holography approach to the low-dimensional gauge theories is discussed, and idea of Bootstrap Holography is set forth.

  14. Higgs mechanism and cosmological constant in N = 1 supergravity with inflaton in a vector multiplet

    Energy Technology Data Exchange (ETDEWEB)

    Aldabergenov, Yermek [Tokyo Metropolitan University, Department of Physics, Tokyo (Japan); Ketov, Sergei V. [Tokyo Metropolitan University, Department of Physics, Tokyo (Japan); The University of Tokyo, Kavli Institute for the Physics and Mathematics of the Universe (IPMU), Chiba (Japan); Tomsk Polytechnic University, Institute of Physics and Technology, Tomsk (Russian Federation)

    2017-04-15

    The N = 1 supergravity models of cosmological inflation with an inflaton belonging to a massive vector multiplet and spontaneous SUSY breaking after inflation are reformulated as the supersymmetric U(1) gauge theories of a massless vector superfield interacting with the Higgs and Polonyi chiral superfields, all coupled to supergravity. The U(1) gauge sector is identified with the U(1) gauge fields of the super-GUT coupled to supergravity, whose gauge group has a U(1) factor. A positive cosmological constant (dark energy) is included. The scalar potential is calculated, and its de Sitter vacuum solution is found to be stable. (orig.)

  15. Discovering Uncolored Naturalness in Exotic Higgs Decays

    CERN Document Server

    Curtin, David

    2015-01-01

    Solutions to the hierarchy problem usually require top partners. In standard SUSY or composite Higgs theories, the partners carry SM color and are becoming increasingly constrained by LHC searches. However, theories like Folded SUSY (FS), Twin Higgs (TH) and Quirky Little Higgs (QLH) introduce uncolored top partners, which can be SM singlets or carry electroweak charge. Their small production cross section left doubt as to whether the LHC can effectively probe such scenarios. Typically, these partners are charged under their own mirror color gauge group. In FS and QLH, the absence of light mirror matter allows glueballs to form at the bottom of the mirror spectrum, this is also the case in some TH realizations. The Higgs can decay to these mirror glueballs, with the glueballs decaying into SM particles with potentially observable lifetimes. We undertake the first detailed study of this glueball signature and quantitatively demonstrate the discovery potential of uncolored naturalness via exotic Higgs decays at...

  16. Current loops, phase transitions, and the Higgs mechanism in Josephson-coupled multicomponent superconductors

    Science.gov (United States)

    Galteland, Peder Notto; Sudbø, Asle

    2016-08-01

    The N -component London U (1 ) superconductor is expressed in terms of integer-valued supercurrents. We show that the inclusion of interband Josephson couplings introduces monopoles in the current fields, which convert the phase transitions of the charge-neutral sector to crossovers. The monopoles only couple to the neutral sector, and leave the phase transition of the charged sector intact. The remnant noncritical fluctuations in the neutral sector influence the one remaining phase transition in the charged sector, and may alter this phase transition from a 3 D X Y inverted phase transition into a first-order phase transition depending on what the values of the gauge charge and the intercomponent Josephson coupling are. This preemptive effect becomes more pronounced with increasing number of components N , since the number of charge-neutral fluctuating modes that can influence the charged sector increases with N . We also calculate the gauge-field correlator, and by extension the Higgs mass, in terms of current-current correlators. We show that the onset of the Higgs mass of the photon (Meissner effect) is given in terms of a current loop blowout associated with going into the superconducting state as the temperature of the system is lowered.

  17. 左右双Higgs模型中新的重顶夸克在LHeC上的产生%Production of New Heavy T Quark in the Left-right Twin Higgs Model at LHeC

    Institute of Scientific and Technical Information of China (English)

    曹军; 秦鑫

    2013-01-01

    在左右双Higgs模型(LRTH)中,研究了单个顶夸克在大型强子-电子对撞机上通过e+b→ve-T和γb→W-T过程的产生.对于顶夸克主要的衰变模式T→φ-b→ tbb,这两个过程会分别产生3b+1+ET和3b+21+ET的末态信号.当电子能量Ee=500 GeV,质子能量取Ep=7 TeV时,发现产生截面在顶夸克质量小于600 GeV时会达到几十fb.也对T→W+b的衰变模式进行了唯像分析.%In the context of the left-right twin Higgs model, we study single production of the Tquark at the Large Had-ron electron Collider (LHeC), which proceed via the processes W-T. For the main decay mode tbb, these two processes mainly transfers to the final states of 3b+l+Er and Zb+2l+ET, respectively. With the electron energy Et= 500 GeV and photon energy Ep = 7 TeV, we find that the production rates can reach tens fb when the heavy Tquark mass smaller than 600 GeV. A simply phenomenological analysis is also given for the decay mode T→W+ b.

  18. Higgs production through sterile neutrinos

    Science.gov (United States)

    Antusch, Stefan; Cazzato, Eros; Fischer, Oliver

    2016-10-01

    In scenarios with sterile (right-handed) neutrinos with an approximate “lepton-number-like” symmetry, the heavy neutrinos (the mass eigenstates) can have masses around the electroweak scale and couple to the Higgs boson with, in principle, unsuppressed Yukawa couplings, while the smallness of the light neutrinos’ masses is guaranteed by the approximate symmetry. The on-shell production of the heavy neutrinos at lepton colliders, together with their subsequent decays into a light neutrino and a Higgs boson, constitutes a resonant contribution to the Higgs production mechanism. This resonant mono-Higgs production mechanism can contribute significantly to the mono-Higgs observables at future lepton colliders. A dedicated search for the heavy neutrinos in this channel exhibits sensitivities for the electron neutrino Yukawa coupling as small as ˜ 5 × 10-3. Furthermore, the sensitivity is enhanced for higher center-of-mass energies, when identical integrated luminosities are considered.

  19. Conjoined Twins

    Science.gov (United States)

    ... sites of conjoined twins. Abdomen. Omphalopagus (om-fuh-LOP-uh-gus) twins are joined near the bellybutton. ... brain tissue. Head and chest. Cephalopagus (sef-uh-LOP-uh-gus) twins are joined at the face ...

  20. Dependence of stress-induced omega transition and mechanical twinning on phase stability in metastable β Ti–V alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.L.; Li, L.; Mei, W.; Wang, W.L.; Sun, J., E-mail: jsun@sjtu.edu.cn

    2015-09-15

    Tensile properties and deformation microstructures of a series of binary β Ti–16–22V alloys have been investigated. The results show that the plastic deformation mode changes from the plate-like stress-induced ω phase transformation with a special habit plane of (− 5052){sub ω}//(3 − 3 − 2){sub β} to (332)<113> type deformation twinning with increasing the content of vanadium in the β Ti–16–22 wt.% V alloys. The plate-like stress-induced ω phase has a special orientation relationship with the β phase matrix, i.e., [110]{sub β}//[− 12 − 10]{sub ω}, (3 − 3 − 2){sub β}//(− 5052){sub ω} and (− 55 − 4){sub β}//(30 − 31){sub ω}. The alloys plastically deformed by stress-induced ω phase transformation exhibit relatively higher yield strength than those deformed via (332)<113> type deformation twinning. It can be concluded that the stability of β phase plays a significant role in plastic deformation mode, i.e., stress-induced ω phase transformation or (332)<113> type deformation twinning, which governs the mechanical property of the β Ti–16–22 wt.% V alloys. - Highlights: • Tensile properties and deformed microstructures of β Ti–16–22V alloys were studied. • Stress-induced ω phase transformation and (332)<113> twinning occur in the alloys. • Stability of β phase plays a significant role in plastic deformation mode. • Plastic deformation mode governs the mechanical property of the alloys.

  1. The Higgs boson

    CERN Multimedia

    Brunet, S

    2014-01-01

    ATLAS Higgs poster targeted to general public, explaining the Brout-Englert-Higgs mechanism and why it is important. It also explains the role of the Higgs Boson, how we look for it, the journey of the discovery and what comes after the discovery. Also available in French (http://cds.cern.ch/record/1697501). Don’t hesitate to use it in your institute’s corridors and in your outreach events! The poster is in A0 format. You can click on the image to download the high-quality .pdf version and print it at your favorite printshop. For any questions or comments you can contact atlas-outreach-coordination@cern.ch.

  2. ACARDIAC TWIN

    OpenAIRE

    Vinayachandran; Jyothi,; Bindu; Umadevi

    2014-01-01

    Acardiac twin is a very rare complication occurring in monozygotic twins in which one fetus develops normally (pump twin) and the other (recipient twin) demonstrate cardiac non development and othe r anomalies. This may represent an extreme form of TTTS, also referred to as TRAP sequence. 1,2,

  3. On the possible importance of mechanical twinning for the development of the brass-type rolling texture and final comment on the above remarks by T. Leffers

    DEFF Research Database (Denmark)

    Leffers, Torben

    1970-01-01

    The author presents his final comments on the discussion between himself and Heye and Wasserman (see abstrs. A11834 and A11835 of 1970) which arose from the latter authors' paper on mechanical twinning (see abstr. A19815 of 1969). The validity of the twinning theory for the brass-type rolling...... texture is questioned for two reasons: There is no convincing crystallographic model explaining how the formation of the brass-type texture by combined twinning and slip should work in theory, and there are experimental results indicating that it should not work in practice...

  4. Tribute to dr louis keith: twin and physician extraordinaire/twin research reports: influences on asthma severity; chimerism revisited; DNA strand break repair/media reports: twins born apart; elevated twin frequencies; celebrity father of twins; conjoined twinning.

    Science.gov (United States)

    Segal, Nancy L

    2014-10-01

    The International Society for Twin Studies has lost a valued friend and colleague. Dr Louis Keith, Emeritus Professor of Obstetrics and Gynecology at Northwestern University, in Chicago, passed away on Sunday, July 6, 2014. His life and work with twins will be acknowledged at the November 2014 International Twin Congress in Budapest, Hungary. Next, twin research reports on the severity of asthma symptoms, a case of chimerism, and factors affecting DNA breakage and repair mechanisms are reviewed. Media reports cover twins born apart, elevated twin frequencies, a celebrity father of twins, and a family's decision to keep conjoined twins together.

  5. Dislocation mechanisms and 3D twin architectures generate exceptional strength-ductility-toughness combination in CrCoNi medium-entropy alloy

    Science.gov (United States)

    Zhang, Zijiao; Sheng, Hongwei; Wang, Zhangjie; Gludovatz, Bernd; Zhang, Ze; George, Easo P.; Yu, Qian; Mao, Scott X.; Ritchie, Robert O.

    2017-02-01

    Combinations of high strength and ductility are hard to attain in metals. Exceptions include materials exhibiting twinning-induced plasticity. To understand how the strength-ductility trade-off can be defeated, we apply in situ, and aberration-corrected scanning, transmission electron microscopy to examine deformation mechanisms in the medium-entropy alloy CrCoNi that exhibits one of the highest combinations of strength, ductility and toughness on record. Ab initio modelling suggests that it has negative stacking-fault energy at 0K and high propensity for twinning. With deformation we find that a three-dimensional (3D) hierarchical twin network forms from the activation of three twinning systems. This serves a dual function: conventional twin-boundary (TB) strengthening from blockage of dislocations impinging on TBs, coupled with the 3D twin network which offers pathways for dislocation glide along, and cross-slip between, intersecting TB-matrix interfaces. The stable twin architecture is not disrupted by interfacial dislocation glide, serving as a continuous source of strength, ductility and toughness.

  6. The Twin Interdisciplinary Neuroticism Study

    NARCIS (Netherlands)

    Riese, Harriette; Rijsdijk, Fruehling V.; Snieder, Harold; Ormel, Johan

    The Twin Interdisciplinary Neuroticism Study (TWINS) is a three-wave study including >800 twin pairs from the northern part of the Netherlands. The aim of the study is to unravel why neuroticism reflects vulnerability to mental disorders. In this study, we focus on possible mechanisms underlying

  7. The Higgs Portal and Cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Assamagan, Ketevi [Brookhaven National Lab. (BNL), Upton, NY (United States); Chen, Chien-Yi [Perimeter Inst. for Theoretical Physics, Waterloo, ON (Canada); Univ. of Victoria, BC (Canada); Chou, John Paul [Rutgers Univ., Piscataway, NJ (United States); Curtin, David [Univ. of Maryland, College Park, MD (United States); Fedderke, Michael A. [Univ. of Chicago, IL (United States); Gershtein, Yuri [Rutgers Univ., Piscataway, NJ (United States); He, Xiao-Gang [Shanghai Jiao Tong Univ. (China); Klute, Markus [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Kozaczuk, Jonathon [TRIUMF, Vancouver, BC (Canada); Kotwal, Ashutosh [Duke Univ., Durham, NC (United States); Lowette, Steven [Vrije Univ., Brussels (Belgium); No, Jose Miguel [Univ. of Sussex, Brighton (United Kingdom); Plehn, Tilman [Heidelberg Univ. (Germany); Qian, Jianming [Univ. of Michigan, Ann Arbor, MI (United States); Ramsey-Musolf, Michael [Univ. of Massachusetts, Amherst, MA (United States); Safonov, Alexei [Texas A & M Univ., College Station, TX (United States); Shelton, Jessie [Univ. of Illinois, Urbana-Champaign, IL (United States); Spannowsky, Michael [Durham Univ. (United Kingdom); Su, Shufang [Univ. of Arizona, Tucson, AZ (United States); Walker, Devin G. E. [Univ. of Washington, Seattle, WA (United States); Willocq, Stephane [Univ. of Massachusetts, Amherst, MA (United States); Winslow, Peter [Univ. of Massachusetts, Amherst, MA (United States)

    2016-04-18

    Higgs portal interactions provide a simple mechanism for addressing two open problems in cosmology: dark matter and the baryon asymmetry. In the latter instance, Higgs portal interactions may contain the ingredients for a strong first-order electroweak phase transition as well as new CP-violating interactions as needed for electroweak baryogenesis. These interactions may also allow for a viable dark matter candidate. We survey the opportunities for probing the Higgs portal as it relates to these questions in cosmology at the LHC and possible future colliders.

  8. The Higgs Portal and Cosmology

    Energy Technology Data Exchange (ETDEWEB)

    Assamagan, Ketevi [Brookhaven National Lab. (BNL), Upton, NY (United States); Chen, Chien-Yi [Perimeter Inst. for Theoretical Physics, Waterloo, ON (Canada); Univ. of Victoria, BC (Canada); Chou, John Paul [Rutgers Univ., Piscataway, NJ (United States); Curtin, David [Univ. of Maryland, College Park, MD (United States); Fedderke, Michael A. [Univ. of Chicago, IL (United States); Gershtein, Yuri [Rutgers Univ., Piscataway, NJ (United States); He, Xiao-Gang [Shanghai Jiao Tong Univ. (China); Klute, Markus [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Kozaczuk, Jonathon [TRIUMF, Vancouver, BC (Canada); Kotwal, Ashutosh [Duke Univ., Durham, NC (United States); Lowette, Steven [Vrije Univ., Brussels (Belgium); No, Jose Miguel [Univ. of Sussex, Brighton (United Kingdom); Plehn, Tilman [Heidelberg Univ. (Germany); Qian, Jianming [Univ. of Michigan, Ann Arbor, MI (United States); Ramsey-Musolf, Michael [Univ. of Massachusetts, Amherst, MA (United States); Safonov, Alexei [Texas A & M Univ., College Station, TX (United States); Shelton, Jessie [Univ. of Illinois, Urbana-Champaign, IL (United States); Spannowsky, Michael [Durham Univ. (United Kingdom); Su, Shufang [Univ. of Arizona, Tucson, AZ (United States); Walker, Devin G. E. [Univ. of Washington, Seattle, WA (United States); Willocq, Stephane [Univ. of Massachusetts, Amherst, MA (United States); Winslow, Peter [Univ. of Massachusetts, Amherst, MA (United States)

    2016-04-18

    Higgs portal interactions provide a simple mechanism for addressing two open problems in cosmology: dark matter and the baryon asymmetry. In the latter instance, Higgs portal interactions may contain the ingredients for a strong first order electroweak phase transition as well as new CP-violating interactions as needed for electroweak baryogenesis. These interactions may also allow for a viable dark matter candidate. We survey the opportunities for probing the Higgs portal as it relates to these questions in cosmology at the LHC and possible future colliders.

  9. The Higgs Portal and Cosmology

    CERN Document Server

    Assamagan, Ketevi; Chou, John Paul; Curtin, David; Fedderke, Michael A; Gershtein, Yuri; He, Xiao-Gang; Klute, Markus; Kozaczuk, Jonathan; Kotwal, Ashutosh; Lowette, Steven; No, Jose Miguel; Plehn, Tilman; Qian, Jianming; Ramsey-Musolf, Michael; Safonov, Alexei; Shelton, Jessie; Spannowsky, Michael; Su, Shufang; Walker, Devin G E; Willocq, Stephane; Winslow, Peter

    2016-01-01

    Higgs portal interactions provide a simple mechanism for addressing two open problems in cosmology: dark matter and the baryon asymmetry. In the latter instance, Higgs portal interactions may contain the ingredients for a strong first order electroweak phase transition as well as new CP-violating interactions as needed for electroweak baryogenesis. These interactions may also allow for a viable dark matter candidate. We survey the opportunities for probing the Higgs portal as it relates to these questions in cosmology at the LHC and possible future colliders.

  10. Higgs Physics

    CERN Document Server

    Grojean, C

    2016-01-01

    The cause of the screening of the weak interactions at long distances puzzled the high-energy community for more nearly half a century. With the discovery of the Higgs boson a new era started with direct experimental information on the physics behind the breaking of the electroweak symmetry. This breaking plays a fundamental role in our understanding of particle physics and sits at the high-energy frontier beyond which we expect new physics that supersedes the Standard Model. The Higgs boson (inclusive and differential) production and decay rates offer a new way to probe this frontier.

  11. A Tale of Two Twin Higgses: Addressing Little Hierarchy in Natural 2HDM Framework

    CERN Document Server

    Yu, Jiang-Hao

    2016-01-01

    In original twin Higgs model, vacuum misalignment between electroweak and new physics scales is realized by adding explicit $\\mathbb{Z}_2$ breaking term. Introducing additional twin Higgs could accommodate spontaneous $\\mathbb{Z}_2$ breaking, which explains the origin of this misalignment. We introduce a class of two twin Higgs doublet models with most general scalar potential, and discuss general conditions which trigger electroweak and $\\mathbb{Z}_2$ symmetry breaking. Various scenarios on realising the vacuum misalignment are systematically discussed in a natural two Higgs double model framework: explicit $\\mathbb{Z}_2$ breaking, radiative $\\mathbb{Z}_2$ breaking, tadpole-induced $\\mathbb{Z}_2$ breaking, and quartic-induced $\\mathbb{Z}_2$ breaking. We investigate the Higgs mass spectra and the Higgs phenomenology in these scenarios.

  12. Little Higgs models and parity

    Indian Academy of Sciences (India)

    Maxim Perelstein

    2006-11-01

    Little Higgs models are an interesting extension of the Standard Model at the TeV scale. They provide a simple and attractive mechanism of electroweak symmetry breaking. We review one of the simplest models of this class, the Littlest Higgs model, and its extension with parity. The model with parity satisfies precision electroweak constraints without fine-tuning, contains an attractive dark matter candidate, and leads to interesting phenomenology at the Large Hadron Collider (LHC).

  13. Higgs Discovery

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2013-01-01

    a Weyl-consistent computation. I will carefully examine the fundamental reasons why what has been discovered might not be the standard model Higgs. Dynamical electroweak breaking naturally addresses a number of the fundamental issues unsolved by the standard model interpretation. However this paradigm...

  14. Twin births

    DEFF Research Database (Denmark)

    Hoffmann, Elise; Oldenburg, Anna; Rode, Line;

    2012-01-01

    To assess morbidity and mortality in twin pregnancy deliveries, according to chorionicity and mode of delivery.......To assess morbidity and mortality in twin pregnancy deliveries, according to chorionicity and mode of delivery....

  15. Effect of melt conditioning on heat treatment and mechanical properties of AZ31 alloy strips produced by twin roll casting

    Energy Technology Data Exchange (ETDEWEB)

    Das, Sanjeev, E-mail: sanjeevdas80@gmail.com [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom); Barekar, N.S. [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom); El Fakir, Omer; Wang, Liliang [Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Prasada Rao, A.K.; Patel, J.B.; Kotadia, H.R.; Bhagurkar, A. [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom); Dear, John P. [Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ (United Kingdom); Fan, Z. [The EPSRC Centre ‐ LiME, BCAST, Brunel University, Uxbridge UB8 3PH (United Kingdom)

    2015-01-03

    In the present investigation, magnesium strips were produced by twin roll casting (TRC) and melt conditioned twin roll casting (MC-TRC) processes. Detailed optical microscopy studies were carried out on as-cast and homogenized TRC and MC-TRC strips. The results showed uniform, fine and equiaxed grain structure was observed for MC-TRC samples in as-cast condition. Whereas, coarse columnar grains with centreline segregation were observed in the case of as-cast TRC samples. The solidification mechanisms for TRC and MC-TRC have been found completely divergent. The homogenized TRC and MC-TRC samples were subjected to tensile test at elevated temperature (250–400 °C). At 250 °C, MC-TRC sample showed significant improvement in strength and ductility. However, at higher temperatures the tensile properties were almost comparable, despite of TRC samples having larger grains compared to MC-TRC samples. The mechanism of deformation has been explained by detailed fractures surface and sub-surface analysis carried out by scanning electron and optical microscopy. Homogenized MC-TRC samples were formed (hot stamping) into engineering component without any trace of crack on its surface. Whereas, TRC samples cracked in several places during hot stamping process.

  16. The Higgs Boson.

    Science.gov (United States)

    Veltman, Martinus J. G.

    1986-01-01

    Reports recent findings related to the particle Higgs boson and examines its possible contribution to the standard mode of elementary processes. Critically explores the strengths and uncertainties of the Higgs boson and proposed Higgs field. (ML)

  17. Higgs couplings and new signals from Flavon-Higgs mixing effects within multi-scalar models

    Science.gov (United States)

    Diaz-Cruz, J. Lorenzo; Saldaña-Salazar, Ulises J.

    2016-12-01

    Testing the properties of the Higgs particle discovered at the LHC and searching for new physics signals, are some of the most important tasks of Particle Physics today. Current measurements of the Higgs couplings to fermions and gauge bosons, seem consistent with the Standard Model, and when taken as a function of the particle mass, should lay on a single line. However, in models with an extended Higgs sector the diagonal Higgs couplings to up-quarks, down-quarks and charged leptons, could lay on different lines, while non-diagonal flavor-violating Higgs couplings could appear too. We describe these possibilities within the context of multi-Higgs doublet models that employ the Froggatt-Nielsen (FN) mechanism to generate the Yukawa hierarchies. Furthermore, one of the doublets can be chosen to be of the inert type, which provides a viable dark matter candidate. The mixing of the Higgs doublets with the flavon field, can provide plenty of interesting signals, including: i) small corrections to the couplings of the SM-like Higgs, ii) exotic signals from the flavon fields, iii) new signatures from the heavy Higgs bosons. These aspects are studied within a specific model with 3 + 1 Higgs doublets and a singlet FN field. Constraints on the model are derived from the study of K and D mixing and the Higgs search at the LHC. For last, the implications from the latter aforementioned constraints to the FCNC top decay t → ch are presented too.

  18. The $\\mu$-Problem and Seesaw-type Mechanism in the Higgs Sector

    CERN Document Server

    Ito, M

    2001-01-01

    We explore a new solution to the $\\mu$-problem. In the scenario of SUSY breaking mediation via anti-generation fields, we point out that the $B\\mu$ term has its origin in seesaw-type mechanism as well as in loop diagram through gauge interactions. It is shown that the dominant contributions to the $B\\mu$ term are controlled by the flavor symmetry in the model.

  19. Higgs factories

    CERN Document Server

    Telnov, V I

    2013-01-01

    Over the past two decades, the high energy physics community has been actively discussing and developing a number of post-LHC collider projects; however, none of them have been approved due to high costs and the uncertainty in post-LHC physics scenarios. There have been great expectations of rich new physics in the 0.1-1 TeV mass region: the Higgs boson (one or several), supersymmetry, or perhaps new particles from the dark-matter family. It has been the general consensus that the best machine for the detailed study of new physics to be discovered at the LHC would be an energy-frontier linear e+e- collider. Physicists held their breath waiting for the results from the LHC. In summer 2012, two LHC detectors, ATLAS and CMS, announced the discovery of a Higgs boson with the mass of 126 GeV and (still) nothing else. The absence of new physics in the region below 1 TeV has changed the post-LHC collider R&D priorities and triggered a zoo of project proposals for the precision study of the 126 GeV Higgs boson, p...

  20. τ-lepton as a Composition of Massless Preons: an Alternative to Higgs Mechanism

    Science.gov (United States)

    Goncharov, Yuri P.

    2015-09-01

    Within the framework of the confinement mechanism proposed earlier by the author in QCD the problem of masses for fundamental fermions in particle physics is discussed by the example of τ-lepton τ -. It is shown that the observed parameters of τ-lepton such as its mass and magnetic moment can be obtained in a preon model dynamically due to a preon gauge interaction. The radius of τ-lepton is also estimated. Under the circumstances preons might be massless in virtue of existence of the nonzero chiral limit for the preon interaction energy.

  1. Interview to prof. Peter Higgs about the latest results on the searches for the Higgs boson at the LHC

    CERN Multimedia

    CERN Video Productions

    2012-01-01

    Peter Higgs answers questions about his feelings following the announcement of the discovery of a new particle by ATLAS and CMS that looks like the Higgs boson, at a seminar at CERN on July 4, 2012. He also explains his role in the proposal of a Higgs mechanism.

  2. Higgs Branching Ratio Study in CEPC

    Institute of Scientific and Technical Information of China (English)

    HU; Shou-yang; LIANG; Hao; ZHOU; Jing; LI; Xiao-mei; LI; Xing-long; ZHOU; Shu-hua

    2015-01-01

    Higgs branching ratio(BR)measurement is one of the important issue of the Circular Electron Positron Collider(CEPC)project,which is strongly related to the coupling strength with particles and reveal their mass generation mechanism.The Large Hadron Collider(LHC)has discovered the Higgs boson in 2012,CEPC can confirm whether that is the standard model(SM)

  3. Baryogenesis via Elementary Goldstone Higgs Relaxation

    CERN Document Server

    Gertov, Helene; Pearce, Lauren; Yang, Louis

    2016-01-01

    We extend the relaxation mechanism to the Elementary Goldstone Higgs frame- work. Besides studying the allowed parameter space of the theory we add the minimal ingredients needed for the framework to be phenomenologically viable. The very nature of the extended Higgs sector allows to consider very flat scalar potential directions along which the relaxation mechanism can be implemented. This fact translates into wider regions of applicability of the relaxation mechanism when compared to the Standard Model Higgs case. Our results show that, if the electroweak scale is not fundamental but radiatively generated, it is possible to generate the observed matter-antimatter asymmetry via the relaxation mechanism.

  4. Investigation of Deformation Mechanisms in Deep-Drawn and Tensile-Strained Austenitic Mn-Based Twinning Induced Plasticity (TWIP) Steel

    NARCIS (Netherlands)

    Van Tol, R.T.; Zhao, L.; Schut, H.; Sietsma, J.

    2012-01-01

    The effect of strain on the deformation mechanisms in an austenitic Mn-based twinning induced plasticity (TWIP) steel is investigated using magnetic measurements, XRD, positron beam Doppler spectroscopy, and finite element method simulations. The experimental observations reveal the formation of a0-

  5. Gauge-invariant description of Higgs phenomenon and quark confinement

    Science.gov (United States)

    Kondo, Kei-Ichi

    2016-11-01

    We propose a novel description for the Higgs mechanism by which a gauge boson acquires the mass. We do not assume spontaneous breakdown of gauge symmetry signaled by a non-vanishing vacuum expectation value of the scalar field. In fact, we give a manifestly gauge-invariant description of the Higgs mechanism in the operator level, which does not rely on spontaneous symmetry breaking. This enables us to discuss the confinement-Higgs complementarity from a new perspective. The "Abelian" dominance in quark confinement of the Yang-Mills theory is understood as a consequence of the gauge-invariant Higgs phenomenon for the relevant Yang-Mills-Higgs model.

  6. 反式twin-block治疗安氏Ⅲ类错牙合作用机理的研究%Mechanisms of Reverse Twin-block Appliance Therapy on Angle class Ⅲ Malocclusion

    Institute of Scientific and Technical Information of China (English)

    朱丽亚; 黄岩; 杨睿

    2014-01-01

    目的:通过治疗前后X线头颅定位侧位片的头影测量分析,得到反式Twin-block对生长发育期安氏Ⅲ类错(牙合)的治疗原理。方法选择替牙期、恒牙早期安氏Ⅲ类错牙合患者20例(男10例,女10例),平均年龄10岁8个月,全天戴用反式Twin-block矫治器治疗4.5-11个月。分别对治疗前后头颅定位侧位片进行头影测量。结果①上牙弓位置前移,上颌向前发育;②下颌向下后方向旋转;③上下颌牙齿发生代偿性移动。结论反式Twin-block可以有效矫治生长发育期安氏Ⅲ类错牙合,在患者侧面Ⅲ类骨面形得到明显改善的同时,牙齿发生代偿性移动。%Objective To assess the effect and mechanism of ClassⅢ malocclusions treatment with reverse Twin -block appliance.Methods Twenty subjects of ClassⅢ malocclusions were included in this study(10male,10 female).All patients were treated for all the day and for total of 4.5-11 months.The cephalometric re-cords of these subjects were examined before and after the treatments.The acquired data were processed with SPSS 10.0.Results①the reverse Twin-block could accel-erate the development of the maxillary bone .② the Mandibular showed a rotation of after the downward direction .③mandible teeth occurring compensatory move on . Conclusion Reverse Twin-block appliance could treat effectively angle classⅢ malocclusions.Patients had a significant improve in side of the form ,while the occur-rence of compensatory tooths movement .

  7. Higgs results from ATLAS

    Directory of Open Access Journals (Sweden)

    Chen Xin

    2016-01-01

    Full Text Available The updated Higgs measurements in various search channels with ATLAS Run 1 data are reviewed. Both the Standard Model (SM Higgs results, such as H → γγ, ZZ, WW, ττ, μμ, bb̄, and Beyond Standard Model (BSM results, such as the charged Higgs, Higgs invisible decay and tensor couplings, are summarized. Prospects for future Higgs searches are briefly discussed.

  8. Higgs properties

    CERN Document Server

    Brandstetter, Johannes

    2016-01-01

    ATLAS and CMS analyses of the most important decay channels are outlined and measurements of Higgs boson properties are summarized and compared with standard model expectations. This report presents ATLAS and CMS analyses with LHC run 1 data taken at centre-of-mass energies of $\\sqrt{s}=7~$TeV and $\\sqrt{s}=8~$TeV as well as the latest analyses with 2015 LHC run 2 data taken at a centre-of-mass energy of $\\sqrt{s}=13~$TeV.

  9. Higgs Pain? Take a Preon!

    CERN Document Server

    Dugne, J J; Hansson, J; Predazzi, Enrico

    1997-01-01

    The Higgs mechanism is the favourite cure for the main problem with electroweak unification, namely how to reconcile a gauge theory with the need for massive gauge bosons. This problem does not exist in preon models for quark and lepton substructure with composite $Z^0$ and $W$s, which, consequently, also avoid all other theoretical complications and paradoxes with the Higgs mechanism. We present a new, minimal preon model, which explains the family structure, and predicts several new, heavy quarks, leptons and vector bosons. Our preons obey a phenomenological supersymmetry, but without so-called squarks and sleptons, since this SUSY is effective only on the composite scale.

  10. Quantum dissipative Higgs model

    Energy Technology Data Exchange (ETDEWEB)

    Amooghorban, Ehsan, E-mail: Ehsan.amooghorban@sci.sku.ac.ir; Mahdifar, Ali, E-mail: mahdifar_a@sci.sku.ac.ir

    2015-09-15

    By using a continuum of oscillators as a reservoir, we present a classical and a quantum-mechanical treatment for the Higgs model in the presence of dissipation. In this base, a fully canonical approach is used to quantize the damped particle on a spherical surface under the action of a conservative central force, the conjugate momentum is defined and the Hamiltonian is derived. The equations of motion for the canonical variables and in turn the Langevin equation are obtained. It is shown that the dynamics of the dissipative Higgs model is not only determined by a projected susceptibility tensor that obeys the Kramers–Kronig relations and a noise operator but also the curvature of the spherical space. Due to the gnomonic projection from the spherical space to the tangent plane, the projected susceptibility displays anisotropic character in the tangent plane. To illuminate the effect of dissipation on the Higgs model, the transition rate between energy levels of the particle on the sphere is calculated. It is seen that appreciable probabilities for transition are possible only if the transition and reservoir’s oscillators frequencies to be nearly on resonance.

  11. Development of TRIP-Aided Lean Duplex Stainless Steel by Twin-Roll Strip Casting and Its Deformation Mechanism

    Science.gov (United States)

    Zhao, Yan; Zhang, Weina; Liu, Xin; Liu, Zhenyu; Wang, Guodong

    2016-12-01

    In the present work, twin-roll strip casting was carried out to fabricate thin strip of a Mn-N alloyed lean duplex stainless steel with the composition of Fe-19Cr-6Mn-0.4N, in which internal pore defects had been effectively avoided as compared to conventional cast ingots. The solidification structure observed by optical microscope indicated that fine Widmannstatten structure and coarse-equiaxed crystals had been formed in the surface and center, respectively, with no columnar crystal structures through the surface to center of the cast strip. By applying hot rolling and cold rolling, thin sheets with the thickness of 0.5 mm were fabricated from the cast strips, and no edge cracks were formed during the rolling processes. With an annealing treatment at 1323 K (1050 °C) for 5 minutes after cold rolling, the volume fractions of ferrite and austenite were measured to be approximately equal, and the distribution of alloying elements in the strip was further homogenized. The cold-rolled and annealed sheet exhibited an excellent combination of strength and ductility, with the ultimate tensile strength and elongation having been measured to be 1000 MPa and 65 pct, respectively. The microstructural evolution during deformation was investigated by XRD, EBSD, and TEM, indicating that ferrite and austenite had different deformation mechanisms. The deformation of ferrite phase was dominated by dislocation slipping, and the deformation of austenite phase was mainly controlled by martensitic transformation in the sequence of γ→ ɛ-martensite→ α'-martensite, leading to the improvement of strength and plasticity by the so-called transformation-induced plasticity (TRIP) effect. By contrast, lean duplex stainless steels of Fe-21Cr-6Mn-0.5N and Fe-23Cr-7Mn-0.6N fabricated by twin-roll strip casting did not show TRIP effects and exhibited lower strength and elongation as compared to Fe-19Cr-6Mn-0.4N.

  12. Twin pregnancy

    DEFF Research Database (Denmark)

    Sperling, Lene; Tabor, A

    2001-01-01

    Determination of chorionicity is one of the most important issues in the management of twin pregnancy. Modern ultrasound equipment has made it possible to accurately assess placentation already in the first trimester with the lambda sign. With regard to prenatal diagnosis, it is important to know...... for clinicians caring for twin pregnancies....

  13. Effect of reduction of area on microstructure and mechanical properties of twinning-induced plasticity steel during wire drawing

    Science.gov (United States)

    Hwang, Joong-Ki; Son, Il-Heon; Yoo, Jang-Yong; Zargaran, A.; Kim, Nack J.

    2015-09-01

    The effect of reduction of area (RA), 10%, 20%, and 30%, during wire drawing on the inhomogeneities in microstructure and mechanical properties along the radial direction of Fe-Mn-Al-C twinning-induced plasticity steel has been investigated. After wire drawing, the deformation texture developed into the major and minor duplex fiber texture. However, the texture became more pronounced in both center and surface areas as the RA per pass increased. It also shows that a larger RA per pass resulted in a higher yield strength and smaller elongation than a smaller RA per pass at all strain levels. Although inhomogeneities in microstructure and mechanical properties along the radial direction decreased with increasing RA per pass, there existed an optimum RA per pass for maximum drawing limit. Insufficient penetration of strain from surface to center at small RA per pass (e.g., 10%) and high friction and unsound metal flow at large RA per pass (e.g., 30%) all resulted in heterogeneous microstructure and mechanical properties along the radial direction of drawn wire. On the other hand, 20% RA per pass improved the drawing limit by about 30% as compared to the 10% and 30% RAs per pass.

  14. ILC Higgs White Paper

    CERN Document Server

    Asner, D.M.; Calancha, C.; Fujii, K.; Graf, N.; Haber, H.E.; Ishikawa, A.; Kanemura, S.; Kawada, S.; Kurata, M.; Miyamoto, A.; Neal, H.; Ono, H.; Potter, C.; Strube, J.; Suehara, T.; Tanabe, T.; Tian, J.; Tsumura, J.; Watanuki, S.; Weiglein, G.; Yagyu, K.; Yokoya, H.

    2013-01-01

    The ILC Higgs White Paper is a review of Higgs Boson theory and experiment at the International Linear Collider (ILC). Theory topics include the Standard Model Higgs, the two-Higgs doublet model, alternative approaches to electroweak symmetry breaking, and precision goals for Higgs boson experiments. Experimental topics include the measurement of the Higgs cross section times branching ratio for various Higgs decay modes at ILC center of mass energies of 250, 500, and 1000 GeV, and the extraction of Higgs couplings and the total Higgs width from these measurements. Luminosity scenarios based on the ILC TDR machine design are used throughout. The gamma-gamma collider option at the ILC is also discussed.

  15. ILC Higgs White Paper

    CERN Document Server

    Asner, D M; Calancha, C; Fujii, K; Graf, N; Haber, H E; Ishikawa, A; Kanemura, S; Kawada, S; Kurata, M; Miyamoto, A; Neal, H; Ono, H; Potter, C; Strube, J; Suehara, T; Tanabe, T; Tian, J; Tsumura, J; Watanuki, S; Weiglein, G; Yagyu, K; Yokoya, H

    2013-01-01

    The ILC Higgs White Paper is a review of Higgs Boson theory and experiment at the International Linear Collider (ILC). Theory topics include the Standard Model Higgs, the two-Higgs doublet model, alternative approaches to electroweak symmetry breaking, and precision goals for Higgs boson experiments. Experimental topics include the measurement of the Higgs cross section times branching ratio for various Higgs decay modes at ILC center of mass energies of 250, 500, and 1000 GeV, and the extraction of Higgs couplings and the total Higgs width from these measurements. Luminosity scenarios based on the ILC TDR machine design are used throughout. The gamma-gamma collider option at the ILC is also discussed.

  16. Higgs inflation and the cosmological constant

    Energy Technology Data Exchange (ETDEWEB)

    Jegerlehner, Fred [Humboldt-Universitaet, Berlin (Germany). Inst. fuer Physik; Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2014-02-15

    The Higgs not only induces the masses of all SM particles, the Higgs, given its special mass value, is the natural candidate for the inflaton and in fact is ruling the evolution of the early universe, by providing the necessary dark energy which remains the dominant energy density. SM running couplings not only allow us to extrapolate SM physics up to the Planck scale, but equally important they are triggering the Higgs mechanism. This is possible by the fact that the bare mass term in the Higgs potential changes sign at about μ{sub 0}≅1.40 x 10{sup 16} GeV and in the symmetric phase is enhanced by quadratic terms in the Planck mass. Such a huge Higgs mass term is able to play a key role in triggering inflation in the early universe. In this article we extend our previous investigation by working out the details of a Higgs inflation scenario. We show how different terms contributing to the Higgs Lagrangian are affecting inflation. Given the SM and its extrapolation to scales μ>μ{sub 0} we find a calculable cosmological constant V(0) which is weakly scale dependent and actually remains large during inflation. This is different to the Higgs fluctuation field dependent ΔV(φ), which decays exponentially during inflation, and actually would not provide a sufficient amount of inflation. The fluctuation field has a different effective mass which shifts the bare Higgs transition point to a lower value μ'{sub 0} ≅7.7 x 10{sup 14} GeV. The vacuum energy V(0) being proportional to M{sub Pl}{sup 4} has a coefficient which vanishes near the Higgs transition point, such that the bare and the renormalized cosmological constant match at this point. The role of the Higgs in reheating and baryogenesis is emphasized.

  17. Partially composite two-Higgs doublet model

    Indian Academy of Sciences (India)

    Dong-Won Jung

    2007-11-01

    In the extra dimensional scenarios with gauge fields in the bulk, the Kaluza-Klein (KK) gauge bosons can induce Nambu-Jona-Lasinio (NJL) type attractive four-fermion interactions, which can break electroweak symmetry dynamically with accompanying composite Higgs fields. We consider a possibility that electroweak symmetry breaking (EWSB) is triggered by both a fundamental Higgs and a composite Higgs arising in a dynamical symmetry breaking mechanism induced by a new strong dynamics. The resulting Higgs sector is a partially composite two-Higgs doublet model with specific boundary conditions on the coupling and mass parameters originating at a compositeness scale . The phenomenology of this model is discussed including the collider phenomenology at LHC and ILC.

  18. Collider Signatures of Flavorful Higgs Bosons

    CERN Document Server

    Altmannshofer, Wolfgang; Gori, Stefania; Lotito, Matteo; Martone, Mario; Tuckler, Douglas

    2016-01-01

    Motivated by our limited knowledge of the Higgs couplings to first two generation fermions, we analyze the collider phenomenology of a class of two Higgs doublet models (2HDMs) with a non-standard Yukawa sector. One Higgs doublet is mainly responsible for the masses of the weak gauge bosons and the third generation fermions, while the second Higgs doublet provides mass for the lighter fermion generations. The characteristic collider signatures of this setup differ significantly from well-studied 2HDMs with natural flavor conservation, flavor alignment, or minimal flavor violation. New production mechanisms for the heavy scalar, pseudoscalar, and charged Higgs involving second generation quarks can become dominant. The most interesting decay modes include H/A -> cc, tc, {\\mu}{\\mu}, {\\tau}{\\mu} and H+ -> cb, cs, {\\mu}{\

  19. Higgs Physics and Cosmology

    Science.gov (United States)

    Roberts, Alex

    2016-08-01

    Recently, a new framework for describing the multiverse has been proposed which is based on the principles of quantum mechanics. The framework allows for well-defined predictions, both regarding global properties of the universe and outcomes of particular experiments, according to a single probability formula. This provides complete unification of the eternally inflating multiverse and many worlds in quantum mechanics. We elucidate how cosmological parameters can be calculated in this framework, and study the probability distribution for the value of the cosmological constant. We consider both positive and negative values, and find that the observed value is consistent with the calculated distribution at an order of magnitude level. In particular, in contrast to the case of earlier measure proposals, our framework prefers a positive cosmological constant over a negative one. These results depend only moderately on how we model galaxy formation and life evolution therein. We explore supersymmetric theories in which the Higgs mass is boosted by the non-decoupling D-terms of an extended U(1) X gauge symmetry, defined here to be a general linear combination of hypercharge, baryon number, and lepton number. Crucially, the gauge coupling, gX, is bounded from below to accommodate the Higgs mass, while the quarks and leptons are required by gauge invariance to carry non-zero charge under U(1)X. This induces an irreducible rate, sigmaBR, for pp → X → ll relevant to existing and future resonance searches, and gives rise to higher dimension operators that are stringently constrained by precision electroweak measurements. Combined, these bounds define a maximally allowed region in the space of observables, (sigmaBR, mX), outside of which is excluded by naturalness and experimental limits. If natural supersymmetry utilizes non-decoupling D-terms, then the associated X boson can only be observed within this window, providing a model independent 'litmus test' for this broad

  20. On the Higgs potential in a model with spontaneous parity violation and neutrino masses in the inverse see-saw mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Malta, P.C.; Candido, M.M; Simoes, J.A.M.; Ramalho, A.J. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Inst. de Fisica. Dept. de Fisica Teorica

    2011-07-01

    Full text: There is an increasing experimental evidence for neutrino oscillations coming from atmospheric, solar and reactor neutrino experiments. These results imply that neutrinos have small masses. A known mechanism to generate neutrino masses is the so called 'canonical see-saw', which provides tiny masses to observed neutrinos. Despite of this achievement, this model also predicts extremely heavy neutrinos, currently unattainable to experiment. An alternative to this undesirable feature is the 'inverse see-saw' , which does not involve symmetry breaking energy scales far beyond a few TeV. In this work we use this mechanism in a model with spontaneous parity violation and gauge structure SU(2){sub R} x SU(2){sub L} x U(1){sub B-L}. We shall study both the Higgs potential and sector in order to find experimental consequences that could be sought for at the LHC. (author)

  1. El boson de Higgs

    CERN Document Server

    Gelmini, Graciela B

    2014-01-01

    The last particle that completes the Standard Model of Elementary Particles, the most sophisticated theory of nature in human history, was discovered in 2012. Although the present formulation of the theory comes from the 1960s and 70s, it incorporates all discoveries that thousands of scientists made about elementary particles and their interactions (except for gravity) since the 1700s. Even if briefly, here we review the development of the major concepts included in the theory and explain the relevance of the new particle and the mechanism for which F. Englert and P. Higgs received the Nobel Prize in Physics 2013

  2. Higgs at LHC

    CERN Document Server

    Bolognesi, Sara; Di Simone, Andrea

    2008-01-01

    An overview of recent theoretical results on the Higgs boson and its discovery strategy at ATLAS and CMS will be presented, focusing on the main Higgs analysis effective with low integrated luminosity (less than 30 fb^-1).

  3. Epigenetic Epidemiology of Complex Diseases Using Twins

    DEFF Research Database (Denmark)

    Tan, Qihua

    2013-01-01

    through multiple epigenetic mechanisms. This paper reviews the new developments in using twins to study disease-related epigenetic alterations, links them to lifetime environmental exposure with a focus on the discordant twin design and proposes novel data-analytical approaches with the aim of promoting...... a more efficient use of twins in epigenetic studies of complex human diseases....

  4. Higgs physics at CMS

    Science.gov (United States)

    Holzner, André G.

    2016-12-01

    This article reviews recent measurements of the properties of the standard model (SM) Higgs boson using data recorded with the CMS detector at the LHC: its mass, width and couplings to other SM particles. We also summarise highlights from searches for new physical phenomena in the Higgs sector as they are proposed in many extensions of the SM: flavour violating and invisible decay modes, resonances decaying into Higgs bosons and searches for additional Higgs bosons.

  5. Future ATLAS Higgs Studies

    CERN Document Server

    Smart, Ben; The ATLAS collaboration

    2017-01-01

    The High-Luminosity LHC will prove a challenging environment to work in, with for example $=200$ expected. It will however also provide great opportunities for advancing studies of the Higgs boson. The ATLAS detector will be upgraded, and Higgs prospects analyses have been performed to assess the reach of ATLAS Higgs studies in the HL-LHC era. These analyses are presented, as are Run-2 ATLAS di-Higgs analyses for comparison.

  6. Higgs Measurement from ATLAS

    CERN Document Server

    Liu, Bo; The ATLAS collaboration

    2015-01-01

    Using run-I data record by ATLAS detector, many searches on the higgs decay modes have been done. Also some properties measurement of the Higgs Boson has been done. This talk will summarise the recent result of Higgs search and measurement from ATLAS.

  7. The universal Higgs fit

    DEFF Research Database (Denmark)

    Giardino, P. P.; Kannike, K.; Masina, I.

    2014-01-01

    Higgs models, models with extra Higgs doublets, supersymmetry, extra particles in the loops, anomalous top couplings, and invisible Higgs decays into Dark Matter. Best fit regions lie around the Standard Model predictions and are well approximated by our 'universal' fit. Latest data exclude the dilaton...

  8. The Higgs hunter's guide

    CERN Document Server

    Gunion, John F; Haber, Howard E; Kane, Gordon L

    1989-01-01

    The Higgs Hunter's Guide is a definitive and comprehensive guide to the physics of Higgs bosons. In particular, it discusses the extended Higgs sectors required by those recent theoretical approaches that go beyond the Standard Model, including supersymmetry and superstring-inspired models.

  9. Higgs searches at ATLAS

    CERN Document Server

    Lafaye, R

    2002-01-01

    This proceeding is an overview of ATLAS capabilities on Higgs studies. After a short introduction on LEP and Tevatron searches on this subject, the ATLAS potential on a standard model and a supersymmetric Higgs discovery are summarized. Last, a section presents the Higgs parameters measurement that will be possible at LHC. (6 refs).

  10. MSSM Higgs at LHC

    CERN Document Server

    Vivarelli, I; Gennai, S; Primo workshop italiano sulla fisica di ATLAS e CMS

    2003-01-01

    The ATLAS and CMS discovery potential for the MSSM Higgs bosons is reviewed in this paper. The attention is focused on the direct Higgs production and on the Standard Model decay channels. After a short introduction, the most promising final states are discussed, showing that, if supersymmetry exists, its Higgs sector can be explored at LHC with an integrated luminosity of 10 fb$^{-1}$.

  11. Effect of twin-screw extrusion parameters on mechanical hardness of direct-expanded extrudates

    Indian Academy of Sciences (India)

    M Brnčić; B Tripalo; D Ježek; D Semenski; N Drvar; M Ukrainczyk

    2006-10-01

    Mechanical properties of cereal (starch-based) extrudates are perceived by the final consumer as criteria of quality. We investigate one of the important characteristics of extrudates, mechanical hardness, which is one of the main texture parameters. Texture quality has an influence on taste sensory evaluation, and thus on the acceptability of the product. Characteristics that have great influence on acceptability are crispness, elasticity, hardness and softness. These attributes are narrowly related to, and affected by, the process parameters. A 2-level–4-factor factorial experimental design was used to investigate the influence of temperature of expansion, screw speed, feed moisture content and feed rate, and their interactions, on the mechanical hardness of extrudates. Feed moisture content, screw speed and temperature are found to influence, while feed rate does not have significant effect on extrudate hardness. Mechanical properties of specimens were measured by means of compression testing, based on the concept of nominal stress, using a universal testing machine and special grips that were constructed for this purpose.

  12. The Effect of Twins on the Mechanical Behavior of Boron Carbide

    Science.gov (United States)

    2012-05-01

    and six hot-pressed U.S. GOVERNMENT WORK NOT PROTECTED BY U.S. COPYRIGHT TOMOKO SANO, Materials Engineer , and CHARLES L. RANDOW, Mechanical Engineer ...Ex = Ey = 482 GPa, Ez = 450 GPa, Gxy = 98 GPa, Gyz = Gzx = 90.5 GPa, mxy = 0.213, myz = mzx = 0.187. These nonunique val- ues were chosen to give a

  13. Colloquium on the 2013 Nobel Prize in Physics Awarded to Francois Englert and Peter Higgs

    CERN Document Server

    Mannheim, Philip D

    2015-01-01

    In 2013 the Nobel Prize in Physics was awarded to Francois Englert and Peter Higgs for their development in 1964 of the mass generation mechanism (the Higgs mechanism) in local gauge theories. This mechanism requires the existence of a massive scalar particle, the Higgs boson, and in 2012 the Higgs boson was finally observed at the Large Hadron Collider after an almost half a century search. In this talk we review the work of these Nobel recipients and discuss its implications.

  14. Cross section and couplings measurements with the ATLAS detector for the 125 GeV Higgs Boson

    CERN Document Server

    Herde, Hannah; The ATLAS collaboration

    2017-01-01

    Detailed measurements of the properties of the 125 GeV Higgs boson are fundamental for the understanding of the electroweak symmetry breaking mechanism. Measurements of the Higgs boson allow to study the gauge, loop induced and Yukawa couplings of the Higgs boson both in production and decay modes. This talk summarizes recent ATLAS measurements of the 125 GeV Higgs boson.

  15. Tests of Higgs and Top Effective Interactions

    CERN Document Server

    Díaz-Cruz, J L; Toscano, J J

    1997-01-01

    We study the possibility to detect heavy physics effects in the interactions of Higgs bosons and the top quark at future colliders using the effective Lagrangian approach. The modification of the interactions may enhance the production of Higgs bosons at hadron colliders through the mechanisms of gluon fusion and associated production with a W boson or $t\\bar{t}$ pairs. The most promising signature is through the decay of the Higgs boson into two photons, whose branching ratio is also enhanced in this approach. As a consequence of our analysis we get a bound on the chromomagnetic dipole moment of the top quark.

  16. 7th Higgs Hunting 2016

    CERN Document Server

    2016-01-01

    A subject of major importance in fundamental physics is the investigation of the origin of Electroweak Symmetry Breaking. The mechanism of mass generation through the spontaneous breaking of a gauge symmetry is called the Brout-Englert-Higgs mechanism and is associated with the appearance of a physical scalar boson. The discovery announced at CERN on 4th July 2012 by the ATLAS and CMS Collaborations of a boson at a mass close to 125 GeV/c2, compatible with this scalar boson of the Standard Model, the so-called Higgs boson, mainly in γγ, ZZ and WW decay modes, with compatible evidence also found at Fermilab in the bb mode, changed the landscape. This important discovery was acknowledged as decisive for the attribution of the 2013 Nobel Prize in Physics awarded jointly to François Englert and Peter Higgs . This 7th workshop of the "Higgs Hunting" series organized in Paris on August 31 - September 2, 2016 will discuss the developments of LHC run 2 analyses, detailed studies of the new boson and possible de...

  17. Photon collider Higgs factories

    CERN Document Server

    Telnov, V I

    2014-01-01

    The discovery of the Higgs boson (and still nothing else) have triggered appearance of many proposals of Higgs factories for precision measurement of the Higgs properties. Among them there are several projects of photon colliders (PC) without e+e- in addition to PLC based on e+e- linear colliders ILC and CLIC. In this paper, following a brief discussion of Higgs factories physics program I give an overview of photon colliders based on linear colliders ILC and CLIC, and of the recently proposed photon-collider Higgs factories with no e+e- collision option based on recirculation linacs in ring tunnels.

  18. Higgs boson and inflation

    Directory of Open Access Journals (Sweden)

    FENG Chaojun

    2014-08-01

    Full Text Available Higgs is the only scalar particle that already observed up to now.In the standard model of particle physics,Higgs plays a very important role.On the other hand,inflation is also driven by scalar field called inflaton.Higgs boson can not be the inflaton since the large hierarchy energy scale of the mass between inflaton and itself.However,by using some indirectly method,inflaton could be another aspect of the Higgs boson.In this paper,the authors review some Higgs inflation models and discuss the role of the cosmological constant during inflation.

  19. Kinematic and mechanical profile of the self-actuation of thermosalient crystal twins of 1,2,4,5-tetrabromobenzene: a molecular crystalline analogue of a bimetallic strip.

    Science.gov (United States)

    Sahoo, Subash Chandra; Sinha, Shashi Bhushan; Kiran, M S R N; Ramamurty, Upadrasta; Dericioglu, Arcan F; Reddy, C Malla; Naumov, Panče

    2013-09-18

    A paradigm shift from hard to flexible, organic-based optoelectronics requires fast and reversible mechanical response from actuating materials that are used for conversion of heat or light into mechanical motion. As the limits in the response times of polymer-based actuating materials are reached, which are inherent to the less-than-optimal coupling between the light/heat and mechanical energy in them, a conceptually new approach to mechanical actuation is required to leapfrog the performance of organic actuators. Herein, we explore single crystals of 1,2,4,5-tetrabromobenzene (TBB) as actuating elements and establish relations between their kinematic profile and mechanical properties. Centimeter-size acicular crystals of TBB are the only naturally twinned crystals out of about a dozen known materials that exhibit the thermosalient effect-an extremely rare and visually impressive crystal locomotion. When taken over a phase transition, crystals of this material store mechanical strain and are rapidly self-actuated to sudden jumps to release the internal strain, leaping up to several centimeters. To establish the structural basis for this colossal crystal motility, we investigated the mechanical profile of the crystals from macroscale, in response to externally induced deformation under microscope, to nanoscale, by using nanoindentation. Kinematic analysis based on high-speed recordings of over 200 twinned TBB crystals exposed to directional or nondirectional heating unraveled that the crystal locomotion is a kinematically complex phenomenon that includes at least six kinematic effects. The nanoscale tests confirm the highly elastic nature, with an elastic deformation recovery (60%) that is far superior to those of molecular crystals reported earlier. This property appears to be critical for accumulation of stress required for crystal jumping. Twinned crystals of TBB exposed to moderate directional heating behave as all-organic analogue of a bimetallic strip, where

  20. On a Singular Solution in Higgs Field (3) - Relativistical Energy Flow towards Higgs boson

    Science.gov (United States)

    Kitazawa, Kazuyoshi

    2012-03-01

    The mass of SM Higgs boson (H^0) is re-examined under fluid mechanical consideration of micro (femt-scale) Reynolds number in Higgs boson sea for the process of Higgs mechanism. In this analysis, two gauge particles (W and Z bosons) are adopted as representatives to describe the process through their each mass acquisition. The mass value of fluid mechanical H^0 (f.m.-H^0) is calculated relativistically at 128.6 GeV/c^2, which is a little (6.6 per-cent) larger than our mass value of the asymptotic solution (theoretical mass: 120.611 GeV/c^2) of Higgs field.footnotetextK. Kitazawa, DPF MEETING 2011: 166. This difference of mass value shows that there would be some extent of excess in sectional area's evaluation for f.m.-H^0. Because, in this numerical calculation we assumed that f.m.-H^0 in Higgs boson sea is sphere. While theoretical mass of H^0 had a shape of truncated-Octahedron which inscribes to the sectional circle of f.m.-H^0. So we may reduce this excess of mass since the drag force against the flow, which is proportional to sectional area of f.m.-H^0, corresponds to acquired mass by Higgs mechanism. It is noteworthy that theoretical mass above is almost at center of the most like range of latest LHC's result for SM Higgs boson mass.

  1. Radiative corrections to the Triple Higgs Coupling in the Inert Higgs Doublet Model

    CERN Document Server

    Arhrib, Abdesslam; Falaki, Jaouad El; Jueid, Adil

    2015-01-01

    We investigate the implication of the recent discovery of a Higgs-like particle in the first phase of the LHC Run 1 on the Inert Higgs Doublet Model (IHDM). The determination of the Higgs couplings to SM particles and its intrinsic properties will get improved during the new LHC Run 2 starting this year. The new LHC Run 2 would also shade some light on the triple Higgs coupling. Such measurement is very important in order to establish the details of the electroweak symmetry breaking mechanism. Given the importance of the Higgs couplings both at the LHC and $e^+e^-$ Linear Collider machines, accurate theoretical predictions are required. We study the radiative corrections to the triple Higgs coupling $hhh$ and to $hZZ$, $hWW$ couplings in the context of the IHDM. By combining several theoretical and experimental constraints on parameter space, we show that extra particles might modify the triple Higgs coupling near threshold regions. Finally, we discuss the effect of these corrections on the double Higgs produ...

  2. Radiative corrections to the triple Higgs coupling in the inert Higgs doublet model

    Science.gov (United States)

    Arhrib, Abdesslam; Benbrik, Rachid; El Falaki, Jaouad; Jueid, Adil

    2015-12-01

    We investigate the implication of the recent discovery of a Higgs-like particle in the first phase of the LHC Run 1 on the Inert Higgs Doublet Model (IHDM). The determination of the Higgs couplings to SM particles and its intrinsic properties will get improved during the new LHC Run 2 starting this year. The new LHC Run 2 would also shade some light on the triple Higgs coupling. Such measurement is very important in order to establish the details of the electroweak symmetry breaking mechanism. Given the importance of the Higgs couplings both at the LHC and e + e - Linear Collider machines, accurate theoretical predictions are required. We study the radiative corrections to the triple Higgs coupling hhh and to hZZ, hW W couplings in the context of the IHDM. By combining several theoretical and experimental constraints on parameter space, we show that extra particles might modify the triple Higgs coupling near threshold regions. Finally, we discuss the effect of these corrections on the double Higgs production signal at the e + e - LC and show that they can be rather important.

  3. Probing the Higgs vacuum with general relativity

    Science.gov (United States)

    Mannheim, Philip D.; Kazanas, Demosthenes

    1991-01-01

    It is shown that the structure of the Higgs vacuum can be revealed in gravitational experiments which probe the Schwarzschild geometry to only one order in MG/r beyond that needed for the classical tests of general relativity. The possibility that deviations from the conventional geometry are at least theoretically conceivable is explored. The deviations obtained provide a diagnostic test for searching for the existence of macroscopic scalar fields and open up the possiblity for further exploring the Higgs mechanism.

  4. Frequently Asked Questions: The Higgs!

    CERN Multimedia

    CERN Bulletin

    2012-01-01

    Why have we tried so hard to find the Higgs particle? How does the Higgs mechanism work? What is the difference in physics between strong evidence and a discovery? Why do physicists speak in terms of "sigmas"? Find out here!   Why have we tried so hard to find the Higgs particle? Because it could be the answer to the question: how does Nature decide whether or not to assign mass to particles? All the fundamental particles making up matter – the electron, the quarks, etc. – have masses. Moreover, quantum physics requires that forces are also carried by particles. The W and Z particles that carry the weak force responsible for radioactivity must also have masses, whereas the photon, the carrier of the electromagnetic force, has no mass at all. This is the root of the “Higgs problem”: how to give masses to the fundamental particles and break the symmetry between the massive W and Z and the massless photon? Just assigning masses by hand...

  5. Volume Renormalization and the Higgs

    CERN Document Server

    Dai, De-Chang

    2014-01-01

    Traditionally, Quantum Field Theory (QFT) treats particle excitations as point-like objects, which is the source of ubiquitous divergences. We demonstrate that a minimal modification of QFT with finite volume particles may cure QFT of divergences and illuminate the physics behind the mathematical construct of our theories. The method allows for a non-perturbative treatment of the free field and self-interacting theories (though extensions to all interacting field theories might be possible). In particular, non-perturbatively defined mass is finite. When applied to the standard model Higgs mechanism, the method implies that a finite range of parameters allows for creation of a well defined Higgs particle, whose Compton wavelength is larger than its physical size, in the broken symmetry phase (as small oscillations around the vacuum). This has profound consequences for Higgs production at the LHC. The parameter range in which the Higgs excitation with the mass of 125 GeV behaves as a proper particle is very res...

  6. Epigenetic Epidemiology of Complex Diseases Using Twins

    DEFF Research Database (Denmark)

    Tan, Qihua

    2013-01-01

    In the past decades, studies on twins have had a great impact on dissecting the genetic and environmental contributions to human diseases and complex traits. In the era of functional genomics, the valuable samples of twins help to bridge the gap between gene activity and environmental conditions...... through multiple epigenetic mechanisms. This paper reviews the new developments in using twins to study disease-related epigenetic alterations, links them to lifetime environmental exposure with a focus on the discordant twin design and proposes novel data-analytical approaches with the aim of promoting...... a more efficient use of twins in epigenetic studies of complex human diseases....

  7. Can a Higgs boson be produced at the LHC?

    Institute of Scientific and Technical Information of China (English)

    TAN Zhi-Guang; ZHENG Hua; HUANG Li-Yuan

    2012-01-01

    A simple model is designed to simulate,by using the mean free path method,the probability of Higgs boson production at the Large Hadron Collider (LHC).The probability that the colliding particles could get close to a given distance with different colliding energies is discussed in this model.Calculated results imply that the probability of producing a Higgs boson is near zero according to the existing theoretical mechanism for Higgs boson production.

  8. Higgs-radion mixing in stabilized brane world models

    CERN Document Server

    Boos, Edward E; Perfilov, Maxim A; Smolyakov, Mikhail N; Volobuev, Igor P

    2015-01-01

    We consider a quartic interaction of the Higgs and Goldberger-Wise fields, which connects the mechanism of the extra dimension size stabilization with spontaneous symmetry breaking on our brane and gives rise to a coupling of the Higgs field to the radion and its KK tower. We estimate a possible influence of this coupling on the Higgs-radion mixing and study its experimental consequences.

  9. Higgs-radion mixing in stabilized brane world models

    Science.gov (United States)

    Boos, Edward E.; Bunichev, Viacheslav E.; Perfilov, Maxim A.; Smolyakov, Mikhail N.; Volobuev, Igor P.

    2015-11-01

    We consider a quartic interaction of the Higgs and Goldberger-Wise fields, which connects the mechanism of the extra dimension size stabilization with spontaneous symmetry breaking on our brane and gives rise to a coupling of the Higgs field to the radion and its KK tower. We estimate a possible influence of this coupling on the Higgs-radion mixing and study restrictions on model parameters from the LHC data.

  10. Partially Natural Two Higgs Doublet Models

    CERN Document Server

    Draper, Patrick; Ruderman, Joshua T

    2016-01-01

    It is possible that the electroweak scale is low due to the fine-tuning of microscopic parameters, which can result from selection effects. The experimental discovery of new light fundamental scalars other than the Standard Model Higgs boson would seem to disfavor this possibility, since generically such states imply parametrically worse fine-tuning with no compelling connection to selection effects. We discuss counterexamples where the Higgs boson is light because of fine-tuning, and a second scalar doublet is light because a discrete symmetry relates its mass to the mass of the Standard Model Higgs boson. Our examples require new vectorlike fermions at the electroweak scale, and the models possess a rich electroweak vacuum structure. The mechanism that we discuss does not protect a small CP-odd Higgs mass in split or high-scale supersymmetry-breaking scenarios of the MSSM due to an incompatibility between the discrete symmetries and holomorphy.

  11. Flavor issues in the Higgs sector

    CERN Document Server

    Díaz-Cruz, J L

    2002-01-01

    We discuss the conditions under which the flavor structure of SUSY model induces, either radiatively or through mixing, new flavor-violating interactions in the Higgs sector. The radiative flavor mediation mechanism is illustrated using the minimal SUSY extension of the SM (MSSM) with generic trilinear A-terms, and applied to evaluate the corrections to Lepton Flavor-Violating (LFV) and Flavor-Conserving (LFC) Higgs vertices. Flavor mediation through mixing is discussed within the context of an $E_6$-inspired multi-Higgs model, suplemented with an abelian flavor symmetry. Tevatron and LHC can probe the flavor structure of these models through the detection of the LFV Higgs mode h->tau mu, while NLC can perform high-precision tests of the LFC mode h ->tau+ tau-.

  12. Higgs At Last

    CERN Document Server

    Falkowski, Adam; Urbano, Alfredo

    2013-01-01

    We update the experimental constraints on the parameters of the Higgs effective Lagrangian. We combine the most recent LHC Higgs data in all available search channels with electroweak precision observables from SLC, LEP-1, LEP-2, and the Tevatron. Overall, the data are well consistent with the 126 GeV particle being the Standard Model Higgs boson, apart from the slight excess in the diphoton channel. The Higgs coupling to the W and Z mass relative to the Standard Model one is constrained in the range [0.97,1.07] at 95% confidence level. Higher-order Higgs couplings to electroweak gauge bosons are also well constrained by a combination of LHC Higgs data and electroweak precision tests.

  13. Higgs Physics at CMS

    CERN Document Server

    Donato, Silvio

    2017-01-01

    The discovery of the Standard Model Higgs boson performed by the CMS and ATLAS collaborations during the LHC Run 1 has been an important success. This document is a short review of the search for the Higgs boson performed by the CMS collaboration during the LHC Run 1 and Run 2. In the first part, after a brief description of the Higgs boson production and decay channels, the Run-1 results are presented emphasizing the possible hints of New Physics. The main part of this document is devoted to the search for the Higgs boson with the 13 TeV data collected by the CMS experiment in 2015 and 2016, including the Standard Model searches as well as the Beyond Standard Model searches, such as the search for additional Higgs bosons and for resonant and non-resonant double Higgs boson production.

  14. Hilbert-Twin – A Novel Hilbert Transform-Based Method To Compute Envelope Of Free Decaying Oscillations Embedded In Noise, And The Logarithmic Decrement In High-Resolution Mechanical Spectroscopy HRMS

    Directory of Open Access Journals (Sweden)

    Magalas L.B.

    2015-06-01

    Full Text Available In this work, we present a novel Hilbert-twin method to compute an envelope and the logarithmic decrement, δ, from exponentially damped time-invariant harmonic strain signals embedded in noise. The results obtained from five computing methods: (1 the parametric OMI (Optimization in Multiple Intervals method, two interpolated discrete Fourier transform-based (IpDFT methods: (2 the Yoshida-Magalas (YM method and (3 the classic Yoshida (Y method, (4 the novel Hilbert-twin (H-twin method based on the Hilbert transform, and (5 the conventional Hilbert transform (HT method are analyzed and compared. The fundamental feature of the Hilbert-twin method is the efficient elimination of intrinsic asymmetrical oscillations of the envelope, aHT (t, obtained from the discrete Hilbert transform of analyzed signals. Excellent performance in estimation of the logarithmic decrement from the Hilbert-twin method is comparable to that of the OMI and YM for the low- and high-damping levels. The Hilbert-twin method proved to be robust and effective in computing the logarithmic decrement and the resonant frequency of exponentially damped free decaying signals embedded in experimental noise. The Hilbert-twin method is also appropriate to detect nonlinearities in mechanical loss measurements of metals and alloys.

  15. Fivefold twinned boron carbide nanowires.

    Science.gov (United States)

    Fu, Xin; Jiang, Jun; Liu, Chao; Yuan, Jun

    2009-09-01

    Chemical composition and crystal structure of fivefold twinned boron carbide nanowires have been determined by electron energy-loss spectroscopy and electron diffraction. The fivefold cyclic twinning relationship is confirmed by systematic axial rotation electron diffraction. Detailed chemical analysis reveals a carbon-rich boron carbide phase. Such boron carbide nanowires are potentially interesting because of their intrinsic hardness and high temperature thermoelectric property. Together with other boron-rich compounds, they may form a set of multiply twinned nanowire systems where the misfit strain could be continuously tuned to influence their mechanical properties.

  16. Darkening the little Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Travis A.W., E-mail: tmartin@triumf.ca; Puente, Alejandro de la, E-mail: adelapue@triumf.ca

    2013-12-18

    We present a novel new method for incorporating dark matter into little Higgs models in a way that can be applied to many existing models without introducing T-parity, while simultaneously alleviating precision constraints arising from heavy gauge bosons. The low energy scalar potential of these dark little Higgs models is similar to, and can draw upon existing phenomenological studies of, inert doublet models. Furthermore, we apply this method to modify the littlest Higgs model to create the next to littlest Higgs model, and describe details of the dark matter candidate and its contribution to the relic density.

  17. The universal Higgs fit

    DEFF Research Database (Denmark)

    Giardino, P. P.; Kannike, K.; Masina, I.;

    2014-01-01

    We perform a state-of-the-art global fit to all Higgs data. We synthesise them into a 'universal' form, which allows to easily test any desired model. We apply the proposed methodology to extract from data the Higgs branching ratios, production cross sections, couplings and to analyse composite H...... as an alternative to the Higgs, and disfavour fits with negative Yukawa couplings. We derive for the first time the SM Higgs boson mass from the measured rates, rather than from the peak positions, obtaining M-h = 124.4 +/- 1.6 GeV....

  18. Galileon Higgs vortices

    Energy Technology Data Exchange (ETDEWEB)

    Chagoya, Javier [Departmento de Física, Universidad de Guanajuato, DCI,Campus León, C.P. 37150, León, Guanajuato (Mexico); Tasinato, Gianmassimo [Department of Physics, Swansea University,Swansea, SA2 8PP (United Kingdom)

    2016-02-09

    Vortex solutions are topologically stable field configurations that can play an important role in condensed matter, field theory, and cosmology. We investigate vortex configuration in a 2+1 dimensional Abelian Higgs theory supplemented by higher order derivative self-interactions, related with Galileons. Our vortex solutions have features that make them qualitatively different from well-known Abrikosov-Nielsen-Olesen configurations, since the derivative interactions turn on gauge invariant field profiles that break axial symmetry. By promoting the system to a 3+1 dimensional string configuration, we study its gravitational backreaction. Our results are all derived within a specific, analytically manageable system, and might offer indications for understanding Galileonic interactions and screening mechanisms around configurations that are not spherically symmetric, but only at most cylindrically symmetric.

  19. Galileon Higgs Vortices

    CERN Document Server

    Chagoya, Javier

    2015-01-01

    Vortex solutions are topologically stable field configurations that can play an important role in condensed matter, field theory, and cosmology. We investigate vortex configuration in a 2+1 dimensional Abelian Higgs theory supplemented by higher order derivative self-interactions, related with Galileons. Our vortex solutions have features that make them qualitatively different from well-known Abrikosov-Nielsen-Olesen configurations, since the derivative interactions turn on gauge invariant field profiles that break axial symmetry. By promoting the system to a 3+1 dimensional string configuration, we study its gravitational backreaction. Our results are all derived within a specific, analytically manageable system, and might offer indications for understanding Galileonic interactions and screening mechanisms around configurations that are not spherically symmetric, but only at most cylindrically symmetric.

  20. Galileon Higgs vortices

    Science.gov (United States)

    Chagoya, Javier; Tasinato, Gianmassimo

    2016-02-01

    Vortex solutions are topologically stable field configurations that can play an important role in condensed matter, field theory, and cosmology. We investigate vortex configuration in a 2+1 dimensional Abelian Higgs theory supplemented by higher order derivative self-interactions, related with Galileons. Our vortex solutions have features that make them qualitatively different from well-known Abrikosov-Nielsen-Olesen configurations, since the derivative interactions turn on gauge invariant field profiles that break axial symmetry. By promoting the system to a 3+1 dimensional string configuration, we study its gravitational backreaction. Our results are all derived within a specific, analytically manageable system, and might offer indications for understanding Galileonic interactions and screening mechanisms around configurations that are not spherically symmetric, but only at most cylindrically symmetric.

  1. The lightest Higgs boson mass in pure gravity mediation model

    Energy Technology Data Exchange (ETDEWEB)

    Ibe, Masahiro, E-mail: ibe@icrr.u-tokyo.ac.jp [ICRR, University of Tokyo, Kashiwa 277-8582 (Japan); IPMU, TODIAS, University of Tokyo, Kashiwa 277-8583 (Japan); Yanagida, Tsutomu T. [ICRR, University of Tokyo, Kashiwa 277-8582 (Japan)

    2012-03-23

    We discuss the lightest Higgs boson mass in the minimal supersymmetric Standard Model with 'pure gravity mediation'. By requiring that the model provides the observed dark matter density, we find that the lightest Higgs boson is predicted to be below 132 GeV. We also find that the upper limit on the lightest Higgs boson mass becomes 128 GeV, if we further assume thermal leptogenesis mechanism as the origin of baryon asymmetry of universe. The interrelations between the Higgs boson mass and the gaugino masses are also discussed.

  2. Twins eye study in Tasmania (TEST): rationale and methodology to recruit and examine twins.

    Science.gov (United States)

    Mackey, David A; Mackinnon, Jane R; Brown, Shayne A; Kearns, Lisa S; Ruddle, Jonathan B; Sanfilippo, Paul G; Sun, Cong; Hammond, Christopher J; Young, Terri L; Martin, Nicholas G; Hewitt, Alex W

    2009-10-01

    Visual impairment is a leading cause of morbidity and poor quality of life in our community. Unravelling the mechanisms underpinning important blinding diseases could allow preventative or curative steps to be implemented. Twin siblings provide a unique opportunity in biology to discover genes associated with numerous eye diseases and ocular biometry. Twins are particularly useful for quantitative trait analysis through genome-wide association and linkage studies. Although many studies involving twins rely on twin registries, we present our approach to the Twins Eye Study in Tasmania to provide insight into possible recruitment strategies, expected participation rates and potential examination strategies that can be considered by other researchers for similar studies. Five separate avenues for cohort recruitment were adopted: (1) piggy-backing existing studies where twins had been recruited, (2) utilizing the national twin registry, (3) word-of-mouth and local media publicity, (4) directly approaching schools, and finally (5) collaborating with other research groups studying twins.

  3. Fetal growth disorders in twin gestations.

    LENUS (Irish Health Repository)

    Breathnach, Fionnuala M

    2012-06-01

    Twin growth is frequently mismatched. This review serves to explore the pathophysiologic mechanisms that underlie growth aberrations in twin gestations, the prenatal recognition of abnormal twin growth, and the critical importance of stratifying management of abnormal twin growth by chorionicity. Although poor in utero growth of both twins may reflect maternal factors resulting in global uteroplacental dysfunction, discordant twin growth may be attributed to differences in genetic potential between co-twins, placental dysfunction confined to one placenta only, or one placental territory within a shared placenta. In addition, twin-twin transfusion syndrome represents a distinct entity of which discordant growth is a common feature. Discordant growth is recognized as an independent risk factor for adverse perinatal outcome. Intertwin birth weight disparity of 18% or more should be considered to represent a discordance threshold, which serves as an independent risk factor for adverse perinatal outcome. At this cutoff, perinatal morbidity is found to increase both for the larger and the smaller twin within a discordant pair. There remains uncertainty surrounding the sonographic parameters that are most predictive of discordance. Although heightening of fetal surveillance in the face of discordant twin growth follows the principles applied to singleton gestations complicated by fetal growth restriction, the timing of intervention is largely influenced by chorionicity.

  4. Enhanced Higgs mass in Compact Supersymmetry

    Science.gov (United States)

    Tobioka, Kohsaku; Kitano, Ryuichiro; Murayama, Hitoshi

    2016-04-01

    The current LHC results make weak scale supersymmetry difficult due to relatively heavy mass of the discovered Higgs boson and the null results of new particle searches. Geometrical supersymmetry breaking from extra dimensions, Scherk-Schwarz mechanism, is possible to accommodate such situations. A concrete example, the Compact Supersymmetry model, has a compressed spectrum ameliorating the LHC bounds and large mixing in the top and scalar top quark sector with |{A}_t|˜ 2{m}_{tilde{t}} which radiatively raises the Higgs mass. While the zero mode contribution of the model has been considered, in this paper we calculate the Kaluza-Klein tower effect to the Higgs mass. Although such contributions are naively expected to be as small as a percent level for 10 TeV Kaluza-Klein modes, we find the effect significantly enhances the radiative correction to the Higgs quartic coupling by from 10 to 50%. This is mainly because the top quark wave function is pushed out from the brane, which makes the top mass depend on higher powers in the Higgs field. As a result the Higgs mass is enhanced up to 15 GeV from the previous calculation. We also show the whole parameter space is testable at the LHC run II.

  5. Colorless Top Partners, a 125 GeV Higgs, and the Limits on Naturalness

    CERN Document Server

    Burdman, Gustavo; Harnik, Roni; de Lima, Leonardo; Verhaaren, Christopher B

    2014-01-01

    Theories of physics beyond the Standard Model that address the hierarchy problem generally involve top partners, new particles that cancel the quadratic divergences associated with the Yukawa coupling of the Higgs to the top quark. With extensions of the Standard Model that involve new colored particles coming under strain from collider searches, scenarios in which the top partners carry no charge under the strong interactions have become increasingly compelling. Although elusive for direct searches, these theories predict modified couplings of the Higgs boson to the Standard Model particles. This results in corrections to the Higgs production and decay rates that can be detected at the Large Hadron Collider (LHC) provided the top partners are sufficiently light, and the theory correspondingly natural. In this paper we consider three theories that address the little hierarchy problem and involve colorless top partners, specifically the Mirror Twin Higgs, Folded Supersymmetry, and the Quirky Little Higgs. For ...

  6. Searches for Standard Model Higgs at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Cortavitarte, Rocio Vilar; /Cantabria Inst. of Phys.

    2007-11-01

    A summary of the latest results of Standard Model Higgs boson searches from CDF and D0 presented at the DIS 2007 conference is reported in this paper. All analyses presented use 1 fb{sup -1} of Tevatron data. The strategy of the different analyses is determined by the Higgs production mechanism and decay channel.

  7. Searches for standard model Higgs at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Vilar Cortabitarte, Rocio; /Cantabria U., Santander

    2007-04-01

    A summary of the latest results of Standard Model Higgs boson searches from CDF and D0 presented at the DIS 2007 conference is reported in this paper. All analyses presented use 1 fb{sup -1} of Tevatron data. The strategy of the different analyses is determined by the Higgs production mechanism and decay channel.

  8. Theory News Higgs

    CERN Document Server

    Brod, Joachim

    2016-01-01

    I review new developments in Higgs physics, with a focus on Yukawa couplings in and beyond the standard model. In particular, I discuss different methods of measuring the light Yukawas, new sources of CP violation in the Higgs sector, and lepton flavor violation.

  9. Higgs Boson Pizza Day

    CERN Multimedia

    Stefania Pandolfi

    2016-01-01

    CERN celebrated the fourth anniversary of the historical Higgs boson announcement with special pizzas.    400 pizzas were served on Higgs pizza day in Restaurant 1 at CERN to celebrate the fourth anniversary of the announcement of the discovery of the Higgs Boson (Image: Maximilien Brice/ CERN) What do the Higgs boson and a pizza have in common? Pierluigi Paolucci, INFN and CMS collaboration member, together with INFN president Fernando Ferroni found out the answer one day in Naples: the pizza in front of them looked exactly like a Higgs boson event display. A special recipe was then created in collaboration with the chef of the historic “Ettore” pizzeria in the St. Lucia area of Naples, and two pizzas were designed to resemble two Higgs boson decay channel event displays. The “Higgs Boson Pizza Day” was held on Monday, 4 July 2016, on the fourth anniversary of the announcement of the discovery of the Higgs boso...

  10. Higgs searches with ATLAS

    CERN Document Server

    Price, J D; The ATLAS collaboration

    2013-01-01

    Summary of the ATLAS analyses for the rarer SM Higgs decay channels, and the limits of the SM Higgs invisible decay width. Analyses included are the VH->Vbb, H->tautau, VH->VWW, H->Zy, H->mumu, ttH->ttyy and ZH->ll+inv.

  11. Where Is Higgs Boson?

    CERN Multimedia

    2008-01-01

    Quantum physicists think they know the answer. Probabilistic calculations reveal than the data provided by previous experiments has been miscalculated and that the Higgs boson has in fact been discovered. Weird! The Higgs boson is the only particle predicted by the Standard Model that hasn't been discovered yet.

  12. Pseudo-Goldstone Higgs Doublets from Non-Vectorlike Grand Unified Higgs Sector

    CERN Document Server

    Hernández, A E Cárcamo

    2016-01-01

    We present a novel way of realizing the pseudo-Nambu-Goldstone boson mechanism for the doublet-triplet splitting in supersymmetric grand unified theories. The global symmetries of the Higgs sector are attributed to a non-vectorlike Higgs content, which is consistent with unbroken supersymmetry in a scenario with flat extra dimensions and branes. We also show how in such a model one can naturally obtain a realistic pattern for the Standard Model fermion masses and mixings.

  13. Little Higgs Review

    CERN Document Server

    Schmaltz, M; Schmaltz, Martin; Tucker-Smith, David

    2005-01-01

    Recently there has been renewed interest in the possibility that the Higgs particle of the Standard Model is a pseudo-Nambu-Goldstone boson. This development was spurred by the observation that if certain global symmetries are broken only by the interplay between two or more coupling constants, then the Higgs mass-squared is free from quadratic divergences at one loop. This "collective symmetry" breaking is the essential ingredient in little Higgs theories, which are weakly coupled extensions of the Standard Model with little or no fine tuning, describing physics up to an energy scale ~10 TeV. Here we give a pedagogical introduction to little Higgs theories. We review their structure and phenomenology, focusing mainly on the SU(3) theory, the Minimal Moose, and the Littlest Higgs as concrete examples.

  14. Boosted Higgs Shapes

    CERN Document Server

    Schlaffer, Matthias; Takeuchi, Michihisa; Weiler, Andreas; Wymant, Chris

    2014-01-01

    The inclusive Higgs production rate through gluon fusion has been measured to be in agreement with the Standard Model (SM). We show that even if the inclusive Higgs production rate is very SM-like, a precise determination of the boosted Higgs transverse momentum shape offers the opportunity to see effects of natural new physics. These measurements are generically motivated by effective field theory arguments and specifically in extensions of the SM with a natural weak scale, like composite Higgs models and natural supersymmetry. We show in detail how a measurement at high transverse momentum of $H\\to 2\\ell+\\mathbf{p}\\!\\!/_T$ via $H\\to \\tau\\tau$ and $H\\to WW^*$ could be performed and demonstrate that it offers a compelling alternative to the $t\\bar t H$ channel. We discuss the sensitivity to new physics in the most challenging scenario of an exactly SM-like inclusive Higgs cross-section.

  15. Generalized Higgs inflation

    Energy Technology Data Exchange (ETDEWEB)

    Kamada, Kohei [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kobayashi, Tsutomu [Kyoto Univ. (Japan). Hakubi Center; Kyoto Univ. (Japan). Dept. of Physics; Takahashi, Tomo [Saga Univ. (Japan). Dept. of Physics; Yamaguchi, Masahide [Tokyo Institute of Technology (Japan). Dept. of Physics; Yokoyama, Jun' ichi [Tokyo Univ. (JP). Research Center for the Early Universe (RESCEU); Tokyo Univ., Chiba (JP). Inst. for the Physics and Mathematics of the Universe (IPMU)

    2012-03-15

    We study Higgs inflation in the context of generalized G-inflation, i.e., the most general single-field inflation model with second-order field equations. The four variants of Higgs inflation proposed so far in the literature can be accommodated at one time in our framework. We also propose yet another class of Higgs inflation, the running Einstein inflation model, that can naturally arise from the generalized G-inflation framework. As a result, five Higgs inflation models in all should be discussed on an equal footing. Concise formulas for primordial fluctuations in these generalized Higgs inflation models are provided, which will be helpful to determine which model is favored from the future experiments and observations such as the Large Hadron Collider and the Planck satellite.

  16. Boosted Higgs shapes

    Energy Technology Data Exchange (ETDEWEB)

    Schlaffer, Matthias [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Spannowsky, Michael [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Takeuchi, Michihisa [King' s College London (United Kingdom). Theoretical Physics and Cosmology Group; Weiler, Andreas [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Wymant, Chris [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology; Laboratoire d' Annecy-le-Vieux de Physique Theorique, Annecy-le-Vieux (France)

    2014-05-15

    The inclusive Higgs production rate through gluon fusion has been measured to be in agreement with the Standard Model (SM). We show that even if the inclusive Higgs production rate is very SM-like, a precise determination of the boosted Higgs transverse momentum shape offers the opportunity to see effects of natural new physics. These measurements are generically motivated by effective field theory arguments and specifically in extensions of the SM with a natural weak scale, like composite Higgs models and natural supersymmetry. We show in detail how a measurement at high transverse momentum of H→2l+p{sub T} via H→ττ and H→WW{sup *} could be performed and demonstrate that it offers a compelling alternative to the t anti tH channel. We discuss the sensitivity to new physics in the most challenging scenario of an exactly SM-like inclusive Higgs cross-section.

  17. Boosted Higgs shapes

    Energy Technology Data Exchange (ETDEWEB)

    Schlaffer, Matthias [DESY, Hamburg (Germany); Spannowsky, Michael [Durham University, Department of Physics, Institute for Particle Physics Phenomenology, Durham (United Kingdom); Takeuchi, Michihisa [King' s College London, Theoretical Physics and Cosmology Group, Department of Physics, London (United Kingdom); Weiler, Andreas [DESY, Hamburg (Germany); CERN, Theory Division, Physics Department, Geneva 23 (Switzerland); Wymant, Chris [Durham University, Department of Physics, Institute for Particle Physics Phenomenology, Durham (United Kingdom); Laboratoire d' Annecy-le-Vieux de Physique Theorique, 9 Chemin de Bellevue, 74940, Annecy-le-Vieux (France); Imperial College London, Department of Infectious Disease Epidemiology, London (United Kingdom)

    2014-10-15

    The inclusive Higgs production rate through gluon fusion has been measured to be in agreement with the Standard Model (SM). We show that even if the inclusive Higgs production rate is very SM-like, a precise determination of the boosted Higgs transverse momentum shape offers the opportunity to see effects of natural new physics. These measurements are generically motivated by effective field theory arguments and specifically in extensions of the SM with a natural weak scale, like composite Higgs models and natural supersymmetry. We show in detail how a measurement at high transverse momentum of H → 2l + p{sub T} via H → ττ and H → WW* could be performed and demonstrate that it offers a compelling alternative to the t anti tH channel. We discuss the sensitivity to newphysics in the most challenging scenario of an exactly SM-like inclusive Higgs cross section. (orig.)

  18. Statistical analysis and comparison of a continuous high shear granulator with a twin screw granulator: Effect of process parameters on critical granule attributes and granulation mechanisms.

    Science.gov (United States)

    Meng, Wei; Kotamarthy, Lalith; Panikar, Savitha; Sen, Maitraye; Pradhan, Shankali; Marc, Michaelis; Litster, James D; Muzzio, Fernando J; Ramachandran, Rohit

    2016-11-20

    This study is concerned with identifying the design space of two different continuous granulators and their respective granulation mechanisms. Performance of a continuous high shear granulator and a twin screw granulator with paracetamol formulations were examined by face-centered cubic design, which focused on investigating key performance metrics, namely, granule size, porosity, flowability and particle morphology of granules as a function of essential input process parameters (liquid content, throughput and rotation speed). Liquid and residence time distribution tests were also performed to gain insights into the liquid-powder mixing and flow behavior. The results indicated that continuous high shear granulation was more sensitive to process variation and produced spherical granules with monomodal size distribution and distinct internal structure and strength variation. Twin screw granulation with such a particular screw configuration showed narrower design space and granules were featured with multimodal size distribution, irregular shape, less detectible porosity difference and tighter range of strength. Granulation mechanisms explored on the basis of nucleation and growth regime maps revealed that for most cases liquid binder was uniformly distributed with fast droplet penetration into the powder bed and that granule consolidation and coalescence mainly took place in the nucleation, steady growth and rapid growth regimes.

  19. Annual Workshop: Higgs Couplings 2016

    CERN Document Server

    2016-01-01

    Higgs Couplings 2016 is this year's installment of an annual workshop devoted to new experimental and theoretical results on the Higgs boson. The 2016 workshop will present the latest results from the LHC run 2 on the Higgs boson mass, spin/parity, and couplings and will present new theoretical work devoted to the measurement of Higgs parameters and possibilities for exotic Higgs decays. The workshop will provide an opportunity for critical discussion of the current strategies for studying the Higgs boson at the LHC and the next steps in the LHC program. The workshop will also include discussion of the longer-term Higgs boson program at future facilities.

  20. METHOD FOR CALCULATION OF DISPLACEMENT FIELDS AND STRESSES IN SYSTEM OF PARALLEL LENTICULAR MECHANICAL TWINS OCCURRING IN MARTENSITIC PHASE OF Ni2MnGa-MAGNETIC ALLOY HAVING PROPERTY OF SHAPE MEMORY

    Directory of Open Access Journals (Sweden)

    E. V. Shmatok

    2015-01-01

    Full Text Available Nowadays mathematical modeling of peculiar features of a stress-strain state is considered as a perspective direction of research. In this regard the aim of this paper has been to make calculations of the stress-strain state initiated by a system of parallel lenticular residual mechanical twins that occur due to local surface deformation of  Ni2MnGa single crystal martensitic phase.The method is applied while using a superposition principle of fields and approximation of a continuous distribution of twinning dislocations on twin boundaries in a continuous elastic medium.The calculations have made it possible to obtain distribution graphs of displacement fields and stresses and point out the fact that a configuration of displacement component distribution uy is significantly different from the displacement of components ux and uz having a displacement distribution similar to each other. The highest value of displacement occurs in the component uy in twins peaks.The paper also presents results of calculations for six components of a stress field the tensor. The obtained results have revealed similarity in stress distribution character of the components  sxz and szz, but they differ numerically from each other about in two times. The largest value of the stresses occurring in the lenticular twins has been observed in components sxx, sxz, syy, syz and it has been focused mainly at the borders and peaks  of twins.A common feature of the obtained components of displacement and stresses in a lenticular twins system is symmetry with regard to OY. In addition, the stress distribution of all obtained tensor components has been mainly localized at the borders and at the tops of twins where the highest values of stresses capable of exerting a significant impact on dislocation and diffusion processes are generally concentrated.

  1. The search for the Higgs boson

    CERN Multimedia

    Riordan, M; Wu Sau Lan

    2001-01-01

    A critical requirement of the Standard Model is a mechanism to endow elementary particles with mass. This mechanism should manifest itself as the Higgs boson and a number of accelerator laboratories are designing machines and experiments to find it (1 1/2 pages).

  2. The study of microstructure and mechanical properties of twin-roll cast AZ31 magnesium alloy after constrained groove pressing

    Science.gov (United States)

    Zimina, M.; Bohlen, J.; Letzig, D.; Kurz, G.; Cieslar, M.; Zník, J.

    2014-08-01

    Microstructure investigation and microhardness mapping were done on the material with ultra-fine grained structure prepared by constrained groove pressing of twin-roll cast AZ31 magnesium strips. The microstructure observations showed significant drop of the grain size from 200 gm to 20 gm after constrained groove pressing. Moreover, the heterogeneities in the microhardness along the cross-section observed in the as-cast strip were replaced by the bands of different microhardness in the constrained groove pressed material. It is shown that the constrained groove pressing technique is a good tool for the grain refinement of magnesium alloys.

  3. General Composite Higgs Models

    CERN Document Server

    Marzocca, David; Shu, Jing

    2012-01-01

    We construct a general class of pseudo-Goldstone composite Higgs models, within the minimal $SO(5)/SO(4)$ coset structure, that are not necessarily of moose-type. We characterize the main properties these models should have in order to give rise to a Higgs mass at around 125 GeV. We assume the existence of relatively light and weakly coupled spin 1 and 1/2 resonances. In absence of a symmetry principle, we introduce the Minimal Higgs Potential (MHP) hypothesis: the Higgs potential is assumed to be one-loop dominated by the SM fields and the above resonances, with a contribution that is made calculable by imposing suitable generalizations of the first and second Weinberg sum rules. We show that a 125 GeV Higgs requires light, often sub-TeV, fermion resonances. Their presence can also be important for the model to successfully pass the electroweak precision tests. Interestingly enough, the latter can be passed also by models with a heavy Higgs around 320 GeV. The composite Higgs models of the moose-type conside...

  4. Natural NMSSM Higgs bosons

    Energy Technology Data Exchange (ETDEWEB)

    King, Stephen F. [School of Physics and Astronomy, University of Southampton (United Kingdom); Muehlleitner, Margarete; Walz, Kathrin [Institute for Theoretical Physics, Karlsruhe Institute of Technology (Germany); Nevzorov, Roman [Institute for Theoretical and Experimental Physics, Moscow (Russian Federation)

    2013-07-01

    The Higgs sector of the Next-to Minimal Supersymmetric Extension of the Standard Model (NMSSM) features five neutral Higgs bosons. Compared to the MSSM it is extended by one additional complex singlet field. The discovery of a Higgs-like boson at the LHC last summer opens up the exciting possibility to consider the idea that this might actually be one of the NMSSM Higgs bosons. We study the phenomenology of the NMSSM Higgs sector requiring the presence of a CP-even Higgs boson with a mass close to 126 GeV. To this end we perform a parameter scan and investigate the observable Higgs cross sections into the final states γγ, WW, ZZ, bb and ττ. Our focus is on an enhanced rate into γγ. We discuss where such an enhancement can originate from and study the correlations between the different channels. Our scenarios feature light stop masses, which leads to low fine-tuning, and comply nicely with the LHC results.

  5. Di-Higgs phenomenology: The forgotten channel

    CERN Document Server

    Englert, Christoph; Spannowsky, Michael; Thompson, Jennifer

    2014-01-01

    Searches for multi-Higgs final states allow to constrain parameters of the SM (or extensions thereof) that directly relate to the mechanism of electroweak symmetry breaking. Multi-Higgs production cross sections, however, are small and the phenomenologically accessible final states are challenging to isolate in the busy multi-jet hadron collider environment of the LHC run 2. This makes the necessity to extend the list of potentially observable production mechanisms obvious. Most of the phenomenological analyses in the past have focused on $gg\\to hh+jets$; in this paper we study $pp\\to t\\bar t hh$ at LHC run 2 and find that this channel for $h\\to b\\bar b$ and semi-leptonic and hadronic top decays has the potential to provide an additional handle to constrain the Higgs trilinear coupling in a global fit at the end of run 2.

  6. A More Flavored Higgs boson in Supersymmetric models

    CERN Document Server

    Díaz-Cruz, J L

    2003-01-01

    A More flavored Higgs boson arises when the flavor structure encoded in SUSY extensions of the SM is transmited to the Higgs sector. The flavor-Higgs transmition mechanism can have a radiative or mixing origin, as it is illustrated with several examples, and can produce interesting Higgs signatures that can be probed at future high-energy colliders. Within the MSSM, the flavor mediation mechanism can be of radiative type, as it is realized though gaugino-slepton loops, which transmit the flavorstructture of the soft-breaking sector to the Higgs bosons. In particular we focus on evaluating the contributions from the general trilinear terms to the lepton flavor violating Higgs (LFV) vertices. On the other hand, as an example of flavor mediation through mixing, we discuss an E_6 inspired multi-Higgs model, with an abelian flavor symmetry, where LFV as well as lepton flavor conserving Higgs effects are found to arise, though in this case at tree-level. We find that Tevatron and LHC can provide information on the ...

  7. The influence of specific mechanical energy on cornmeal viscosity measured by an on-line system during twin-screw extrusion

    Directory of Open Access Journals (Sweden)

    CHANG Y. K.

    1999-01-01

    Full Text Available The influence of specific mechanical energy (SME on cornmeal viscosity during the twin-screw extrusion at feed moisture contents of 25 and 30% and screw speeds in the range from 100 to 500 rpm was measured. Cornmeal was extruded in a co-rotating, intermeshing twin-screw coupled to a slit die rheometer. One approach to the on-line rheological measurement is to use a slit die with the extruder. In the present work it was show that shear viscosity decreased as a function of SME. The viscosity of cornmeal at the exit die was influenced by screw speed, rate of total mass flow, mass temperature inside the extruder and SME. An increase in screw speed resulted in an increase in SME and a decrease in viscosity. A reduction in slit die height and an increase in screw speed and mass temperature led to a remarkable macromolecular degradation of the starch, as evidenced by the decrease in viscosity.

  8. (120) and (122-bar) monazite deformation twins

    Energy Technology Data Exchange (ETDEWEB)

    Hay, R.S

    2003-10-20

    Unusual features of (120) and (122-bar) deformation twins in monazite (monoclinic LaPO{sub 4}) are described and analyzed. These features are kinks and other irregularities in (120) twins, and V-shaped indentations on (120) and (122-bar) twin planes. Twinning shear analysis suggests that the kinks are a type II deformation twin mode with shear direction ({eta}{sub 1}) of [21-bar0]. This complements previous analysis based on atom shuffling considerations. Shear strain compatibility requires extensive plastic deformation in the kink. The V-shaped indentations may be analogous to similar structures in b.c.c metal deformation twins. Deformation mechanisms that may be associated with these structures are discussed.

  9. Higgs production and decay in the little Higgs model

    OpenAIRE

    Dib, C; Rosenfeld, R.; Zerwekh, A.

    2003-01-01

    We analyse the consequences of the little Higgs model for double Higgs boson production at the LHC and for the partial decay width of the Higgs into two photons. In particular, we study the sensitivity of these processes in terms of the parameters of the model. We find that the little Higgs model contributions are proportional to (v/f)^4 and hence do not change significantly either single or double Higgs production at hadron colliders or the partial decay width of the Higgs into two photons a...

  10. Multi-Higgs Mass Spectrum in Gauge-Higgs Unification

    CERN Document Server

    Kojima, Kentaro; Yamashita, Toshifumi

    2008-01-01

    We study an SU(2) supersymmetric gauge model in a framework of gauge-Higgs unification. Multi-Higgs spectrum appears in the model at low energy. We develop a useful perturbative approximation scheme for evaluating effective potential to study the multi-Higgs mass spectrum. We find that both tree-massless and massive Higgs scalars obtain mass corrections of similar size from finite parts of the loop effects. The corrections modify multi-Higgs mass spectrum, and hence, the loop effects are significant in view of future verifications of the gauge-Higgs unification scenario in high-energy experiments.

  11. The Qingdao Twin Registry

    DEFF Research Database (Denmark)

    Duan, Haiping; Ning, Feng; Zhang, Dongfeng;

    2013-01-01

    In 1998, the Qingdao Twin Registry was initiated as the main part of the Chinese National Twin Registry. By 2005, a total of 10,655 twin pairs had been recruited. Since then new twin cohorts have been sampled, with one longitudinal cohort of adolescent twins selected to explore determinants...... of metabolic disorders and health behaviors during puberty and young adulthood. Adult twins have been sampled for studying heritability of multiple phenotypes associated with metabolic disorders. In addition, an elderly twin cohort has been recruited with a focus on genetic studies of aging-related phenotypes...

  12. Effect of intermediate annealing on the microstructure and mechanical property of ZK60 magnesium alloy produced by twin roll casting and hot rolling

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hongmei, E-mail: hmchen@just.edu.cn [Provincial Key Lab of Advanced Welding Technology, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Zang, Qianhao [Provincial Key Lab of Advanced Welding Technology, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Yu, Hui [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300132 (China); Zhang, Jing [School of Metallurgical and Materials Engineering, Jiangsu University of Science and Technology, Zhang Jiagang 215600 (China); Jin, Yunxue [Provincial Key Lab of Advanced Welding Technology, Jiangsu University of Science and Technology, Zhenjiang 212003 (China)

    2015-08-15

    Twin roll cast (designated as TRC in short) ZK60 magnesium alloy strip with 3.5 mm thickness was used in this paper. The TRC ZK60 strip was multi-pass rolled at different temperatures, intermediate annealing heat treatment was performed when the thickness of the strip changed from 3.5 mm to 1 mm, and then continued to be rolled until the thickness reached to 0.5 mm. The effect of intermediate annealing during rolling process on microstructure, texture and room temperature mechanical properties of TRC ZK60 strip was studied by using OM, TEM, XRD and electronic universal testing machine. The introduction of intermediate annealing can contribute to recrystallization in the ZK60 sheet which was greatly deformed, and help to reduce the stress concentration generated in the rolling process. Microstructure uniformity and mechanical properties of the ZK60 alloy sheet were also improved; in particular, the room temperature elongation was greatly improved. When the TRC ZK60 strip was rolled at 300 °C and 350 °C, the room temperature elongation of the rolled sheet with 0.5 mm thickness which was intermediate annealed during the rolling process was increased by 95% and 72% than that of no intermediate annealing, respectively. - Highlights: • Intermediate annealing was introduced during hot rolling process of twin roll cast ZK60 alloy. • Intermediate annealing can contribute to recrystallization and reduce the stress concentration in the deformed ZK60 sheet. • Microstructure uniformity and mechanical properties of the ZK60 sheet were improved, in particular, the room temperature elongation. • The elongation of the rolled ZK60 sheet after intermediate annealed was increased by 95% and 72% than that of no intermediate annealing.

  13. Cross section and coupling measurements with the ATLAS detector for the 125 GeV Higgs Boson in the fermion decay channels

    CERN Document Server

    Gregersen, Kristian; The ATLAS collaboration

    2017-01-01

    Detailed measurements of the properties of the 125 GeV Higgs boson are fundamental for the understanding of the electroweak symmetry breaking mechanism. Measurements of the Higgs boson in fermion final states allow to study the Yukawa couplings of the Higgs boson through the decay mode and the gauge couplings of the Higgs boson through the production mode. This talk summarizes ATLAS measurements of the 125 GeV Higgs boson in decays involving b, tau and mu.

  14. Higgs portal inflation

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, Oleg [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Lee, Hyun Min [European Organization for Nuclear Research (CERN), Geneva (Switzerland)

    2011-05-15

    The Higgs sector of the Standard Model offers a unique opportunity to probe the hidden sector. The Higgs squared operator is the only dimension two operator which is Lorentz and gauge invariant. It can therefore couple both to scalar curvature and the hidden sector at the dim-4 level. We consider the possibility that a combination of the Higgs and a singlet from the hidden sector plays the role of inflaton, due to their large couplings to gravity. This implies that the quartic couplings satisfy certain constraints which leads to distinct low energy phenomenology, including Higgs signals at the LHC. We also address the unitarity issues and show that our analysis survives the unitarization procedure. (orig.)

  15. Remarks on Higgs Inflation

    CERN Document Server

    Atkins, Michael

    2010-01-01

    We discuss models where the Higgs boson of the electroweak standard model plays the role of the inflaton. We focus on the question of the violation of perturbative unitarity due to the coupling of the Higgs boson either to the Ricci scalar or to the Einstein tensor and discuss the background dependence of the unitarity bounds. Our conclusion is that the simplest model which restricts itself to the standard model Higgs boson without introducing further degrees of freedom has a serious problem. However, in the asymptotically safe gravity scenario, the Higgs boson of the standard model could be the inflaton and no physics beyond the standard model is required to explain both inflation and the spontaneous breaking of the electroweak symmetry of the standard model.

  16. Higgs hunt gets heavy

    CERN Multimedia

    Reich, Eugenie Samuel

    2004-01-01

    "The search for the elusive Higgs particle has maddened physicists since the particle's existence was proposed in the 1960s. And now they know why. A new analysis indicates the particle is heavier than anyone expected" (1/2 page)

  17. Higgs measurements with ATLAS

    CERN Document Server

    Queitsch-Maitland, Michaela; The ATLAS collaboration

    2017-01-01

    The final Run 1 and first Run 2 results with the ATLAS detector on the measurement of the cross sections, couplings and properties of the Higgs boson in individual final states and their combination are presented.

  18. Higgs Portal Inflation

    CERN Document Server

    Lebedev, Oleg

    2011-01-01

    The Higgs sector of the Standard Model offers a unique opportunity to probe the hidden sector. The Higgs squared operator is the only dimension two operator which is Lorentz and gauge invariant. It can therefore couple both to scalar curvature and the hidden sector at the dim--4 level. We consider the possibility that a combination of the Higgs and a singlet from the hidden sector plays the role of inflaton, due to their large couplings to gravity. This implies that the quartic couplings satisfy certain constraints which leads to distinct low energy phenomenology, including Higgs signals at the LHC. We also address the unitarity issues and show that our analysis survives the unitarization procedure.

  19. From photons to Higgs a story of light

    CERN Document Server

    Han, Moo-Young

    2014-01-01

    This book presents a brief introduction to the quantum field theory of the Standard Model for quarks and leptons. With minimal use of mathematics, it covers the basics of quantum field theory, local gauge field theory, spontaneous symmetry breaking mechanism, the Higgs mechanism and quantum chromodynamics. From the time when the first edition was published until today, the field of particle physics has seen some major break-through with the possible discovery of Higgs particle, also known as the Higgs boson. In the second edition, the famous Higgs mechanism is included to explain the symmetry breaking in the Standard Model and the origin of mass, and all of this is explained in high-school level algebra. Aimed at both scientists and non-specialists, it requires only some rudimentary knowledge of the Lagrangian and Hamiltonian formulation of Newtonian mechanics as well as a basic understanding of the special theory of relativity and quantum mechanics to enjoy this book.

  20. Testing the Higgs sector directly in the non-relativistic domain

    CERN Document Server

    Zhang, Zhentao

    2016-01-01

    Directly measuring the Higgs self-coupling is of great importance for testing the Brout-Englert-Higgs mechanism in the Standard Model. As a scattering that contains the direct information from the Higgs self-coupling, we investigate the process $\\mu^-\\mu^+\\rightarrow HH$ in the threshold region. We calculate the one-loop corrections to the cross section and consider the non-perturbative contribution from the Higgs self-interactions in the final state. It is found that the scattering in the non-relativistic domain could be an especial process to testing the Higgs sector directly.

  1. Twin Jet

    Science.gov (United States)

    Henderson, Brenda; Bozak, Rick

    2010-01-01

    Many subsonic and supersonic vehicles in the current fleet have multiple engines mounted near one another. Some future vehicle concepts may use innovative propulsion systems such as distributed propulsion which will result in multiple jets mounted in close proximity. Engine configurations with multiple jets have the ability to exploit jet-by-jet shielding which may significantly reduce noise. Jet-by-jet shielding is the ability of one jet to shield noise that is emitted by another jet. The sensitivity of jet-by-jet shielding to jet spacing and simulated flight stream Mach number are not well understood. The current experiment investigates the impact of jet spacing, jet operating condition, and flight stream Mach number on the noise radiated from subsonic and supersonic twin jets.

  2. Academic training: The Hunt for the Higgs Particle

    CERN Multimedia

    2007-01-01

    2006-2007 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 27, 28 February, 1st March, from 11:00 to 12:00 Main Auditorium, bldg. 500 The Hunt for the Higgs Particle F. ZWIRNER, University and INFN, Padova, Italy With the advent of the LHC, the hunt for the Higgs boson is entering its crucial phase. These three lectures will review: the Higgs mechanism; its implementation in the minimal Standard Model; possible alternatives with and without elementary scalar fields; the presently available information on electroweak gauge symmetry breaking and the Higgs particle; the properties of the Higgs boson(s) in the Standard Model and its supersymmetric extensions; the strategies for direct searches at colliders, with emphasis on the LHC, and comments on the possible scenarios that may emerge.

  3. Creating the fermion mass hierarchies with multiple Higgs bosons

    Science.gov (United States)

    Bauer, Martin; Carena, Marcela; Gemmler, Katrin

    2016-12-01

    After the Higgs boson discovery, it was established that the Higgs mechanism explains electroweak symmetry breaking and generates the masses of all particles in the Standard Model, with the possible exception of neutrino masses. The hierarchies among fermion masses and mixing angles, however, remain unexplained. We propose a new class of two Higgs doublet models in which a flavor symmetry broken at the electroweak scale addresses this problem. The models are strongly constrained by electroweak precision tests and the fact that they produce modifications to Higgs couplings and flavor-changing neutral currents; they are also constrained by collider searches for extra scalar bosons. The surviving models are very predictive, implying unavoidable new physics signals at the CERN Large Hadron Collider, e.g., extra Higgs bosons with masses M <700 GeV .

  4. Creating the fermion mass hierarchies with multiple Higgs bosons

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Martin; Carena, Marcela; Gemmler, Katrin

    2016-12-28

    After the Higgs boson discovery, it is established that the Higgs mechanism explains electroweak symmetry breaking and generates the masses of all particles in the Standard Model, with the possible exception of neutrino masses. The hierarchies among fermion masses and mixing angles remain however unexplained. We propose a new class of two Higgs doublet models in which a flavor symmetry broken at the electroweak scale addresses this problem. The models are strongly constrained by electroweak precision tests and the fact that they produce modifications to Higgs couplings and flavor changing neutral currents; they are also constrained by collider searches for extra scalar bosons. The surviving models are very predictive, implying unavoidable new physics signals at the CERN Large Hadron Collider, e.g. extra Higgs Bosons with masses $M < 700$ GeV.

  5. Creating the Fermion Mass Hierarchies with Multiple Higgs Bosons

    CERN Document Server

    Bauer, Martin; Gemmler, Katrin

    2015-01-01

    After the Higgs boson discovery, it is established that the Higgs mechanism explains electroweak symmetry breaking and generates the masses of all particles in the Standard Model, with the possible exception of neutrino masses. The hierarchies among fermion masses and mixing angles remain however unexplained. We propose a new class of two Higgs doublet models in which a flavor symmetry broken at the electroweak scale addresses this problem. The models are strongly constrained by electroweak precision tests and the fact that they produce modifications to Higgs couplings and flavor changing neutral currents; they are also constrained by collider searches for extra scalar bosons. The surviving models are very predictive, implying unavoidable new physics signals at the CERN Large Hadron Collider, e.g. extra Higgs Bosons with masses $M < 700$ GeV.

  6. The Private Higgs

    CERN Document Server

    Porto, Rafael A

    2007-01-01

    We introduce Higgs democracy in the Yukawa sector by constructing a model with a private Higgs field for each fermion, and an O(1) Yukawa coupling between them, thus addressing the large hierarchy among fermion masses. The Standard Model phenomenology is recovered, in particular no tree level FCNCs are present. We discuss some phenomenological implications which include new Higgses at the TeV scale and a candidate for dark matter.

  7. Beyong the Higgs

    CERN Document Server

    Abdullah, Wan Ahmad Tajuddin Wan

    2012-01-01

    A Higgs-compatible boson has been observed at the LHC at CERN. We briefly review the role of the Higgs in particle physics and describe some of the current challenges in understanding the fundamental structure of the universe. Is there supersymmetry and is it instrumental in uniting gravity with the other three fundamental forces? What makes up dark matter and dark energy? We also report on the efforts in experimental particle physics by Malaysian collaborators to answer some of these questions.

  8. Higgs portal valleys, stability and inflation

    CERN Document Server

    Ballesteros, Guillermo

    2015-01-01

    The measured values of the Higgs and top quark masses imply that the Standard Model potential is very likely to be unstable at large Higgs values. This is particularly problematic during inflation, which sources large perturbations of the Higgs. The instability could be cured by a threshold effect induced by a scalar with a large vacuum expectation value and directly connected to the Standard Model through a Higgs portal coupling. However, we find that in a minimal model in which the scalar generates inflation, this mechanism does not stabilize the potential because the mass required for inflation is beyond the instability scale. This conclusion does not change if the Higgs has a direct weak coupling to the scalar curvature. On the other hand, if the potential is absolutely stable, successful inflation in agreement with current CMB data can occur along a valley of the potential with a Mexican hat profile. We revisit the stability conditions, independently of inflation, and clarify that the threshold effect ca...

  9. Higgs Boson Properties and Search for Additional Resonances

    CERN Document Server

    You, Can

    The Higgs boson was predicted by the Standard Model of particle physics and jointly discovered by the CMS and ATLAS experiments at LHC, in 2012. Following its discovery, the property measurements of the Higgs boson and the search for additional resonances become important research goals. The Standard Model is not the complete theory and leaves many questions unanswered, therefore it is important to search for any evidence of new physics beyond the SM. This thesis will briefly introduce the theoretical motivation for the Higgs boson, the production and decay mechanisms of the Higgs boson, and the methods used for analysis of the Higgs boson properties. The spin-1 and spin-2 Higgs hypotheses are tested in H->ZZ->4l channel, using the data recorded by CMS in Run1 of LHC. The exotic spin models were excluded and the Higgs boson is shown to agree with the Standard Model prediction of spin-0. The search for high-mass Higgs-like resonance is performed in H->ZZ->4l and H->ZZ->2l2q channels, using data recorded by CMS...

  10. Charged Higgs Boson Searches

    CERN Document Server

    The ATLAS collaboration

    2009-01-01

    The discovery of a charged Higgs boson would be tangible proof of physics beyond the Standard Model. This note presents the ATLAS potential for discovering a charged Higgs boson, utilizing five different final states of the signal arising from the three dominating fermionic decay modes of the charged Higgs boson. The search covers the region below the top quark mass, taking into account the present experimental constraints, the transition region with a charged Higgs boson mass of the order of the top quark mass, and the high-mass region with a charged Higgs boson mass up to 600 GeV. All studies are performed with a realistic simulation of the detector response including all three trigger levels and taking into account all dominant systematic uncertainties. Results are given in terms of discovery and exclusion contours for each channel individually and for all channels combined, showing that the ATLAS experiment is capable of detecting the charged Higgs boson in a significant fraction of the (tan beta , mH+-) ...

  11. Higgs boson pizza

    CERN Multimedia

    Cinzia De Melis

    2016-01-01

    Four years after the historic announcement of the Higgs boson discovery at CERN, a collaboration between INFN and CERN has declared 4 July 2016 as “Higgs Boson Pizza Day”. The idea was born in Naples, by Pierluigi Paolucci and INFN president Fernando Ferroni, who inspired the chef of the historic “Ettore” pizzeria in St. Lucia to create the Higgs boson pizza in time for the opening of a Art&Science exhibition on 15 September 2015 in Naples. The animation shows the culinary creation of a Higgs boson in form of a vegetarian and ham&salami pizza. Ham&Salami: A two asparagus (proton-proton) collision produces a spicy Higgs boson (chorizo) decaying into two high-energy salami (photon) clusters and a lot of charged (sliced ham) and neutral (olive) particles that are detected in the pizza (detector) entirely covered with mozzarella sensors. A two asparagus (proton-proton) collision produces a juicy Higgs boson (cherry tomato) decaying into four high-energy (charged) peppers producing a tasty sign...

  12. Higgs Physics at CLIC

    CERN Document Server

    AUTHOR|(CDS)2073690

    2016-01-01

    The Compact Linear Collider (CLIC) is an attractive option for a future multi-TeV linear electron-positron collider, offering the potential for a rich precision physics programme, combined with sensitivity to a wide range of new phenomena. The physics reach of CLIC has been studied in the context of three distinct centre-of-mass energies, √s = 350 GeV, 1.4 TeV and 3.0 TeV. This staged scenario provides an excellent environment for precise studies of the properties of the 126 GeV Higgs boson. Operation at √s = 350 GeV allows, on the one hand, for a determination of the couplings and width of the Higgs boson in a model-independent manner through the study of the Higgsstrahlung process, and on the other hand, for a study of Higgs bosons produced in W+W− fusion for the most common Higgs decay modes. Operation at higher centre-of-mass energies, √s = 1.4 TeV and 3 TeV, provides high statistics W+W− fusion samples allowing for high precision measurements of many Higgs couplings and a study of rare Higgs de...

  13. Higgs ultraviolet softening

    Science.gov (United States)

    Brivio, I.; Éboli, O. J. P.; Gavela, M. B.; Gonzalez-García, M. C.; Merlo, L.; Rigolin, S.

    2014-12-01

    We analyze the leading effective operators which induce a quartic momentum dependence in the Higgs propagator, for a linear and for a non-linear realization of electroweak symmetry breaking. Their specific study is relevant for the understanding of the ultraviolet sensitivity to new physics. Two methods of analysis are applied, trading the Lagrangian coupling by: i) a "ghost" scalar, after the Lee-Wick procedure; ii) other effective operators via the equations of motion. The two paths are shown to lead to the same effective Lagrangian at first order in the operator coefficients. It follows a modification of the Higgs potential and of the fermionic couplings in the linear realization, while in the non-linear one anomalous quartic gauge couplings, Higgs-gauge couplings and gauge-fermion interactions are induced in addition. Finally, all LHC Higgs and other data presently available are used to constrain the operator coefficients; the future impact of pp → 4 leptons data via off-shell Higgs exchange and of vector boson fusion data is considered as well. For completeness, a summary of pure-gauge and gauge-Higgs signals exclusive to non-linear dynamics at leading-order is included.

  14. Composite Higgs models, Dark Matter and Lambda

    CERN Document Server

    Diaz-Cruz, J Lorenzo

    2009-01-01

    We suggest that dark matter can be identified with a stable composite fermion X^0, that arises within the holographic AdS/CFT models, where the Higgs boson emerges as a composite pseudo-goldstone boson. The predicted properties of X^0 satisfies the cosmological bounds, with m_X = O(TeV). Thus, through a deeper understanding of the mechanism of electroweak symmetry breaking, a resolution of the Dark Matter enigma is found. Furthermore, by proposing a discrete structure of the Higgs vacuum, one can get a distinct approach to the cosmological constant problem.

  15. Diffractive Higgs Production from Intrinsic Heavy Flavors in the Proton

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, Stanley J.; Kopeliovich, Boris; Schmidt, Ivan; Soffer, Jacques

    2006-03-31

    We propose a novel mechanism for exclusive diffractive Higgs production pp {yields} pHp in which the Higgs boson carries a significant fraction of the projectile proton momentum. This mechanism will provide a clear experimental signal for Higgs production due to the small background in this kinematic region. The key assumption underlying our analysis is the presence of intrinsic heavy flavor components of the proton bound state, whose existence at high light-cone momentum fraction x has growing experimental and theoretical support. We also discuss the implications of this picture for exclusive diffractive quarkonium and other channels.

  16. Tensile Properties of Cu with Deformation Twins Induced by SMAT

    Institute of Scientific and Technical Information of China (English)

    Jinyu GUO; Ke WANG; Lei LU

    2006-01-01

    High density nano-scale deformation twins were introduced in the surface layer of Cu sample by means of surface mechanical attrition treatment (SMAT) at room temperature. The Cu sample with deformation twins shows a yield strength of about 470 MPa in tension tests. The significant strengthening may be attributed to the effective inhibition of slip dislocations by abundant twin boundaries.

  17. Hardening by twin boundary during nanoindentation in nanocrystals.

    Science.gov (United States)

    Qu, Shaoxing; Zhou, Haofei

    2010-08-20

    The atomistic deformation processes of nanocrystals embedded with nanoscale twin boundaries during nanoindentation are studied by molecular dynamics simulations. Load-displacement curves are obtained and the hardening mechanisms associated with the nanoscale twin boundaries are revealed. Johnson's theoretical indentation model is adopted to estimate the elastic stage of the nanoindentation. In addition, twin boundary-mediated dislocation nucleation is observed and analyzed.

  18. Higgsed Stueckelberg vector and Higgs quadratic divergence

    Directory of Open Access Journals (Sweden)

    Durmuş Ali Demir

    2015-01-01

    Full Text Available Here we show that, a hidden vector field whose gauge invariance is ensured by a Stueckelberg scalar and whose mass is spontaneously generated by the Standard Model Higgs field contributes to quadratic divergences in the Higgs boson mass squared, and even leads to its cancellation at one-loop when Higgs coupling to gauge field is fine-tuned. In contrast to mechanisms based on hidden scalars where a complete cancellation cannot be achieved, stabilization here is complete in that the hidden vector and the accompanying Stueckelberg scalar are both free from quadratic divergences at one-loop. This stability, deriving from hidden exact gauge invariance, can have important implications for modeling dark phenomena like dark matter, dark energy, dark photon and neutrino masses. The hidden fields can be produced at the LHC.

  19. Microstructure Evolution and Mechanical Behavior of a Hot-Rolled High-Manganese Dual-Phase Transformation-Induced Plasticity/Twinning-Induced Plasticity Steel

    Science.gov (United States)

    Fu, Liming; Shan, Mokun; Zhang, Daoda; Wang, Huanrong; Wang, Wei; Shan, Aidang

    2017-05-01

    The microstructures and deformation behavior were studied in a high-temperature annealed high-manganese dual-phase (28 vol pct δ-ferrite and 72 vol pct γ-austenite) transformation-induced plasticity/twinning-induced plasticity (TRIP/TWIP) steel. The results showed that the steel exhibits a special Lüders-like yielding phenomenon at room temperature (RT) and 348 K (75 °C), while it shows continuous yielding at 423 K, 573 K and 673 K (150 °C, 300 °C and 400 °C) deformation. A significant TRIP effect takes place during Lüders-like deformation at RT and 348 K (75 °C) temperatures. Semiquantitative analysis of the TRIP effect on the Lüders-like yield phenomenon proves that a softening effect of the strain energy consumption of strain-induced transformation is mainly responsible for this Lüders-like phenomenon. The TWIP mechanism dominates the 423 K (150 °C) deformation process, while the dislocation glide controls the plasticity at 573 K (300 °C) deformation. The delta-ferrite, as a hard phase in annealed dual-phase steel, greatly affects the mechanical stability of austenite due to the heterogeneous strain distribution between the two phases during deformation. A delta-ferrite-aided TRIP effect, i.e., martensite transformation induced by localized strain concentration of the hard delta-ferrite, is proposed to explain this kind of Lüders-like phenomenon. Moreover, the tensile curve at RT exhibits an upward curved behavior in the middle deformation stage, which is principally attributed to the deformation twinning of austenite retained after Lüders-like deformation. The combination of the TRIP effect during Lüders-like deformation and the subsequent TWIP effect greatly enhances the ductility in this annealed high-manganese dual-phase TRIP/TWIP steel.

  20. Microstructure Evolution and Mechanical Behavior of a Hot-Rolled High-Manganese Dual-Phase Transformation-Induced Plasticity/Twinning-Induced Plasticity Steel

    Science.gov (United States)

    Fu, Liming; Shan, Mokun; Zhang, Daoda; Wang, Huanrong; Wang, Wei; Shan, Aidang

    2017-02-01

    The microstructures and deformation behavior were studied in a high-temperature annealed high-manganese dual-phase (28 vol pct δ-ferrite and 72 vol pct γ-austenite) transformation-induced plasticity/twinning-induced plasticity (TRIP/TWIP) steel. The results showed that the steel exhibits a special Lüders-like yielding phenomenon at room temperature (RT) and 348 K (75 °C), while it shows continuous yielding at 423 K, 573 K and 673 K (150 °C, 300 °C and 400 °C) deformation. A significant TRIP effect takes place during Lüders-like deformation at RT and 348 K (75 °C) temperatures. Semiquantitative analysis of the TRIP effect on the Lüders-like yield phenomenon proves that a softening effect of the strain energy consumption of strain-induced transformation is mainly responsible for this Lüders-like phenomenon. The TWIP mechanism dominates the 423 K (150 °C) deformation process, while the dislocation glide controls the plasticity at 573 K (300 °C) deformation. The delta-ferrite, as a hard phase in annealed dual-phase steel, greatly affects the mechanical stability of austenite due to the heterogeneous strain distribution between the two phases during deformation. A delta-ferrite-aided TRIP effect, i.e., martensite transformation induced by localized strain concentration of the hard delta-ferrite, is proposed to explain this kind of Lüders-like phenomenon. Moreover, the tensile curve at RT exhibits an upward curved behavior in the middle deformation stage, which is principally attributed to the deformation twinning of austenite retained after Lüders-like deformation. The combination of the TRIP effect during Lüders-like deformation and the subsequent TWIP effect greatly enhances the ductility in this annealed high-manganese dual-phase TRIP/TWIP steel.

  1. Deformation twinning in monazite

    Energy Technology Data Exchange (ETDEWEB)

    Hay, R.S.; Marshall, D.B

    2003-10-20

    Polycrystalline monazite (LaPO{sub 4}) was deformed at room temperature by a spherical indenter. Deformation twins were identified by TEM in 70 grains. Five twin planes were found: (100) was by far the most common; (001) and (120) were less common; (122-bar)was rare, and kinks in (120) twins were identified as irrational '(483)' twin planes. The twinning modes on these planes were inferred from the expression of twinning shear at free surfaces, predictions of classical deformation twinning theory, and various considerations of twin morphology and crystal structure. Atomic shuffle calculations that allow formation of either a glide plane or a mirror plane at the twin interface were used to analyze twin modes. The inferred twin modes all have small atomic shuffles. For (001) twins, the smallest shuffles were obtained with a glide plane at the interface, with displacement vector R=((1)/(2))[010]. The results do not uniquely define a twin mode on (100), leaving open the possibility of more than one mode operating on this plane. Factors that may determine the operative deformation twinning modes are discussed. Crystal structure considerations suggest that the relative abundance of twinning modes may correlate with low shear modulus on the twin plane in the direction of twinning shear, and with a possible low-energy interface structure consisting of a layer of xenotime of one half-unit-cell thickness that could form at (100) and (001) twins. The three most common twins have low strains to low {sigma} coincidence site lattices (CSLs)

  2. The Norwegian Twin Registry.

    Science.gov (United States)

    Nilsen, Thomas S; Brandt, Ingunn; Magnus, Per; Harris, Jennifer R

    2012-12-01

    Norway has a long-standing tradition in twin research, but the data collected in several population-based twin studies were not coordinated centrally or easily accessible to the scientific community. In 2009, the Norwegian Twin Registry was established at the Norwegian Institute of Public Health (NIPH) in Oslo with the purpose of creating a single research resource for Norwegian twin data. As of today, the Norwegian Twin Registry contains 47,989 twins covering birth years 1895-1960 and 1967-1979; 31,440 of these twins consented to participate in health-related research. In addition, DNA from approximately 4,800 of the twins is banked at the NIPH biobank and new studies are continually adding new data to the registry. The value of the Norwegian twin data is greatly enhanced by the linkage opportunities offered by Norway's many nationwide registries, spanning a broad array of medical, demographic, and socioeconomic information.

  3. Nanoscale growth twins in sputtered metal films

    Energy Technology Data Exchange (ETDEWEB)

    Misra, Amit [Los Alamos National Laboratory; Anderoglu, Osman [Los Alamos National Laboratory; Hoagland, Richard G [Los Alamos National Laboratory; Zhang, X [TEXAS A& M

    2008-01-01

    We review recent studies on the mechanical properties of sputtered Cu and 330 stainless steel films with {l_brace}1 1 1{r_brace} nanoscale growth twins preferentially oriented perpendicular to growth direction. The mechanisms of formation of growth twins during sputtering and the deformation mechanisms that enable usually high strengths in nanotwinned structures are highlighted. Growth twins in sputtered films possess good thermal stability at elevated temperature, providing an approach to extend the application of high strength nanostructured metals to higher temperatures.

  4. Myocardial hypertrophy in the recipient with twin-to-twin transfusion syndrome

    DEFF Research Database (Denmark)

    Jeppesen, D.L.; Jorgensen, F.S.; Pryds, O.A.

    2008-01-01

    In a set of monochorionic-diamniotic twins with twin-to-twin transfusion syndrome, systemic hypertension and biventricular myocardial hypertrophy were found in the recipient. The infant developed mild respiratory distress. A partial exchange transfusion was performed because of polycytaemia. Blood...... pressure measurements revealed persistent systemic hypertension. Biventricular hypertrophy was demonstrated by echocardiography. Blood pressure normalised after treatment with Nifedipine and the cardiac hypertrophy subsided over the following weeks. A potential contributing mechanism is intrauterine...

  5. Myocardial hypertrophy in the recipient with twin-to-twin transfusion syndrome

    DEFF Research Database (Denmark)

    Jeppesen, D.L.; Jorgensen, F.S.; Pryds, O.A.

    2008-01-01

    pressure measurements revealed persistent systemic hypertension. Biventricular hypertrophy was demonstrated by echocardiography. Blood pressure normalised after treatment with Nifedipine and the cardiac hypertrophy subsided over the following weeks. A potential contributing mechanism is intrauterine......In a set of monochorionic-diamniotic twins with twin-to-twin transfusion syndrome, systemic hypertension and biventricular myocardial hypertrophy were found in the recipient. The infant developed mild respiratory distress. A partial exchange transfusion was performed because of polycytaemia. Blood...

  6. Working Group Report: Higgs Boson

    Energy Technology Data Exchange (ETDEWEB)

    Dawson, Sally; Gritsan, Andrei; Logan, Heather; Qian, Jianming; Tully, Chris; Van Kooten, Rick [et al.

    2013-10-30

    This report summarizes the work of the Energy Frontier Higgs Boson working group of the 2013 Community Summer Study (Snowmass). We identify the key elements of a precision Higgs physics program and document the physics potential of future experimental facilities as elucidated during the Snowmass study. We study Higgs couplings to gauge boson and fermion pairs, double Higgs production for the Higgs self-coupling, its quantum numbers and $CP$-mixing in Higgs couplings, the Higgs mass and total width, and prospects for direct searches for additional Higgs bosons in extensions of the Standard Model. Our report includes projections of measurement capabilities from detailed studies of the Compact Linear Collider (CLIC), a Gamma-Gamma Collider, the International Linear Collider (ILC), the Large Hadron Collider High-Luminosity Upgrade (HL-LHC), Very Large Hadron Colliders up to 100 TeV (VLHC), a Muon Collider, and a Triple-Large Electron Positron Collider (TLEP).

  7. On the origins and the historical roots of the Higgs boson research from a bibliometric perspective

    CERN Document Server

    Barth, Andreas; Bornmann, Lutz; Mutz, Ruediger

    2014-01-01

    Subject of our present paper is the analysis of the origins or historical roots of the Higgs boson research from a bibliometric perspective, using a segmented regression analysis in a reference publication year spectroscopy (RPYS). Our analysis is based on the references cited in the Higgs boson publications published since 1974. The objective of our analysis consists of identifying concrete individual publications in the Higgs boson research context to which the scientific community frequently had referred to. As a consequence, we are interested in seminal works which contributed to a high extent to the discovery of the Higgs boson. Our results show that researchers in the Higgs boson field preferably refer to more recently published papers - particular papers published since the beginning of the sixties. For example, our analysis reveals seven major contributions which appeared within the sixties: Englert and Brout (1964), Higgs (1964, 2 papers), and Guralnik et al. (1964) on the Higgs mechanism as well as ...

  8. Tools for charged Higgs bosons

    Energy Technology Data Exchange (ETDEWEB)

    Staal, Oscar

    2010-12-15

    We review the status of publicly available software tools applicable to charged Higgs physics. A selection of codes are highlighted in more detail, focusing on new developments that have taken place since the previous charged Higgs workshop in 2008. We conclude that phenomenologists now have the tools ready to face the LHC data. A new web page collecting charged Higgs resources is presented. (orig.)

  9. Higgs ultraviolet softening

    CERN Document Server

    Brivio, I; Gavela, M B; Gonzalez-Garcia, M C; Merlo, L; Rigolin, S

    2014-01-01

    We analyze the leading effective operators which induce a quartic momentum dependence in the Higgs propagator, for a linear and for a non-linear realization of electroweak symmetry breaking. Their specific study is relevant for the understanding of the ultraviolet sensitivity to new physics. Two methods of analysis are applied, trading the Lagrangian coupling by: i) a "ghost" scalar, after the Lee-Wick procedure; ii) other effective operators via the equations of motion. The two paths are shown to lead to the same effective Lagrangian at first order in the operator coefficients. It follows a modification of the Higgs potential and of the fermionic couplings in the linear realization, while in the non-linear one anomalous quartic gauge couplings, Higgs-gauge couplings and gauge-fermion interactions are induced in addition. Finally, all LHC Higgs and other data presently available are used to constrain the operator coefficients; the future impact of $pp\\rightarrow\\text{4 leptons}$ data via off-shell Higgs excha...

  10. Qui attrapera le Higgs?

    CERN Multimedia

    Colas, Paul

    2003-01-01

    The Higgs boson was theoretically created about 40 years ago by a Scott Peter Higgs who wanted to explain why some particles get a mass. Since then the Higgs boson has taken consistency and has become an important point of the standard model theory. Its experimental discovery would be a milestone of modern physics. The search for the Higgs boson is an international challenge that takes place around 2 huge machines: the Tevatron near Chicago and the LHC (large hadron collider) that is being built in CERN. The Tevatron is in fact the upgrading of an old particle accelerator, it is a proton collider and its narrow range of energy is compensated by a low background noise. On the other hand the LHC will begin operating only in 2007 and its full power will be reached a few years later, the energy available to create particles will be then 7 times higher than for the Tevatron. Both machines have chance of succeeding by being the first to detect the Higgs boson. Time plays in favor of the Tevatron but in any case if ...

  11. The Concordance and Heritability of Type 2 Diabetes in 34,166 Twin Pairs From International Twin Registers

    DEFF Research Database (Denmark)

    Willemsen, G.; Ward, K. J.; Bell, C. G.

    2015-01-01

    Twin pairs discordant for disease may help elucidate the epigenetic mechanisms and causal environmental factors in disease development and progression. To obtain the numbers of pairs, especially monozygotic (MZ) twin pairs, necessary for in-depth studies while also allowing for replication, twin...... studies worldwide need to pool their resources. The Discordant Twin (DISCOTWIN) consortium was established for this goal. Here, we describe the DISCOTWIN Consortium and present an analysis of type 2 diabetes (T2D) data in nearly 35,000 twin pairs. Seven twin cohorts from Europe (Denmark, Finland, Norway......, the Netherlands, Spain, Sweden, and the United Kingdom) and one from Australia investigated the rate of discordance for T2D in same-sex twin pairs aged 45 years and older. Data were available for 34,166 same-sex twin pairs, of which 13,970 were MZ, with T2D diagnosis based on self-reported diagnosis...

  12. Littlest Higgs model and pair production at international linear collider

    Indian Academy of Sciences (India)

    P Poulose

    2007-11-01

    Among the viable alternatives to the standard Higgs mechanism is the recently proposed Little Higgs model. The advantage here is that the model has an elementary light neutral scalar particle, which arises dynamically as against its ad hoc introduction in the standard model. The model also avoids hierarchy problem. We have investigated the pair production at ILC to study the littlest Higgs model using different observables. Specifically, polarization fraction of boson is expected to be measured very accurately at ILC. We use this to put limit on the scale parameter, , in the model.

  13. The Danish Twin Register

    DEFF Research Database (Denmark)

    Kyvik, K O; Christensen, Kaare; Skytthe, A;

    1996-01-01

    BACKGROUND: Population based twin registers represent a valuable tool for genetic epidemiological research, since twin studies aim at separating the effect of genes and environment for complex traits. The Danish Twin Register's history, size, ascertainment and completeness of data, as well as data...... accessibility and availability are described. RESULTS: The Danish Twin Register comprises 14,051 twin pairs born 1870-1930, representing all twins surviving to age six years, and 20,888 twin pairs born 1953-1982, representing 75% of those born 1953-1967 and 95% of those born 1968-1982. The birth cohorts 1931......-1952 og 1983-1993 are being ascertained at the moment. The register is available for research given certain conditions are fulfilled. CONCLUSION: This register will in a few years be the most comprehensive twin register in the world. It is a very valuable Danish research resource....

  14. The Danish Twin Register

    DEFF Research Database (Denmark)

    Kyvik, K O; Christensen, Kaare; Skytthe, A

    1996-01-01

    BACKGROUND: Population based twin registers represent a valuable tool for genetic epidemiological research, since twin studies aim at separating the effect of genes and environment for complex traits. The Danish Twin Register's history, size, ascertainment and completeness of data, as well as data...... accessibility and availability are described. RESULTS: The Danish Twin Register comprises 14,051 twin pairs born 1870-1930, representing all twins surviving to age six years, and 20,888 twin pairs born 1953-1982, representing 75% of those born 1953-1967 and 95% of those born 1968-1982. The birth cohorts 1931......-1952 og 1983-1993 are being ascertained at the moment. The register is available for research given certain conditions are fulfilled. CONCLUSION: This register will in a few years be the most comprehensive twin register in the world. It is a very valuable Danish research resource....

  15. Discriminators of 2 Higgs Doublets at the LHC14, ILC and MuonCollider(125): A Snowmasss White Paper

    CERN Document Server

    Barger, Vernon; Logan, Heather E; Shaughnessy, Gabe

    2013-01-01

    The historic LHC discovery of the 125 GeV particle with properties that closely resemble the Standard Model (SM) Higgs boson verifies our understanding of electroweak symmetry breaking, but solidifies the need for a resolution to the hierarchy problem. Many extensions of the SM that address the hierarchy problem contain a non-minimal Higgs sector. Therefore, as a benchmark alternative to the SM Higgs mechanism, we study a general 2 Higgs doublet model (2HDM-G) framework for evaluating future sensitivity to Higgs couplings. We study how well it can be distinguished from the SM Higgs boson by future measurements at LHC14, ILC (250, 500,1000 GeV) and a Muon Collider (125 GeV). Additionally, our study bears on singlet Higgs extensions of two Higgs doublet models through predicted coupling relationships.

  16. Cosmological perturbations from the Standard Model Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Simone, Andrea De [SISSA, Via Bonomea 265, I-34136 Trieste (Italy); Riotto, Antonio, E-mail: andrea.desimone@sissa.it, E-mail: antonio.riotto@unige.ch [Department of Theoretical Physics and Center for Astroparticle Physics (CAP), 24 quai E. Ansermet, CH-1211 Geneva 4 (Switzerland)

    2013-02-01

    We propose that the Standard Model (SM) Higgs is responsible for generating the cosmological perturbations of the universe by acting as an isocurvature mode during a de Sitter inflationary stage. In view of the recent ATLAS and CMS results for the Higgs mass, this can happen if the Hubble rate during inflation is in the range (10{sup 10}−10{sup 14}) GeV (depending on the SM parameters). Implications for the detection of primordial tensor perturbations through the B-mode of CMB polarization via the PLANCK satellite are discussed. For example, if the Higgs mass value is confirmed to be m{sub h} = 125.5 GeV and m{sub t},α{sub s} are at their central values, our mechanism predicts tensor perturbations too small to be detected in the near future. On the other hand, if tensor perturbations will be detected by PLANCK through the B-mode of CMB, then there is a definite relation between the Higgs and top masses, making the mechanism predictive and falsifiable.

  17. Higgs Triplet Model with Classically Conformal Invariance

    CERN Document Server

    Okada, Hiroshi; Yagyu, Kei

    2015-01-01

    We discuss an extension of the minimal Higgs triplet model with a classically conformal invariance and with a gauged $U(1)_{B-L}$ symmetry. In our scenario, tiny masses of neutrinos are generated by a hybrid contribution from the type-I and type-II seesaw mechanisms. The shape of the Higgs potential at low energies is determined by solving one-loop renormalization group equations for all the scalar quartic couplings with a set of initial values of parameters at the Planck scale. We find a successful set of the parameters in which the $U(1)_{B-L}$ symmetry is radiatively broken via the Coleman-Weinberg mechanism at the ${\\cal O}$(10) TeV scale, and the electroweak symmetry breaking is also triggered by the $U(1)_{B-L}$ breaking. Under this configuration, we can predict various low energy observables such as the mass spectrum of extra Higgs bosons, and the mixing angles. Furthermore, using these predicted mass parameters, we obtain upper limits on Yukawa couplings among an isospin triplet Higgs field and lepton...

  18. The Supersymmetric Fat Higgs

    CERN Document Server

    Harnik, R

    2004-01-01

    Supersymmetric models have traditionally been assumed to be perturbative up to high scales due to the requirement of calculable unification. In this note I review the recently proposed `Fat Higgs' model which relaxes the requirement of perturbativity. In this framework, an NMSSM-like trilinear coupling becomes strong at some intermediate scale. The NMSSM Higgses are meson composites of an asymptotically-free gauge theory. This allows us to raise the mass of the Higgs, thus alleviating the MSSM of its fine tuning problem. Despite the strong coupling at an intermediate scale, the UV completion allows us to maintain gauge coupling unification.

  19. Spying an invisible Higgs

    CERN Document Server

    Bernaciak, Catherine; Schichtel, Peter; Tattersall, Jamie

    2014-01-01

    We investigate the potential of multivariate techniques to improve the LHC search for invisible Higgs decays in weak boson fusion. We find that in the coming runs the LHC will be able to probe an invisible Higgs width of 28% within a year and 3.5% during a high luminosity run. A significant improvement over these estimates requires an analysis of QCD radiation patterns down to 10 GeV. Such an analysis can improve the reach at the high luminosity run to 2%. Throughout our analysis we employ a conservative, data driven background determination.

  20. ALEPH: Higgs candidate

    CERN Multimedia

    Photolab

    2000-01-01

    This track is an example of real data collected from the ALEPH detector on the Large Electron-Positron (LEP) collider at CERN, which ran between 1989 and 2000. Four jets of hadrons can be seen in the detector that could have resulted from the associated production and decay of a Z0 and a Higgs boson into quark-antiquark pairs, which appear in the detector as jets of hadrons. However, other processes can produce similiar tracks so this is not conclusive evidence for the Higgs.

  1. Monochorionic twin pregnancies

    NARCIS (Netherlands)

    Hack, K.E.A.

    2008-01-01

    Following widespread application of assisted reproductive technology modalities and the increased age of motherhood, the incidence of twin gestations has increased markedly. Twins are either monozygotic or dizygotic. Dizygotic (i.e. fraternal) twins result from the fertilization of two different egg

  2. Severe preeclampsia cured by heparin in a patient with twin-twin transfusion syndrome

    Institute of Scientific and Technical Information of China (English)

    CHU Hong-nü; ZHOU Cai-yun

    2007-01-01

    @@ Heparin therapy for preeclampsia has been reported frequently.1-3 Most of the authors used heparin to prevent thrombosis and achieved good results. But its mechanism is not clear.4 Here we describe a case of severe early-onset preeclampsia complicated with hypercoagulable state, fetal growth restriction, and twin-twin transfusion syndrome, that responded well to heparin.

  3. Search for Multiphoton Signatures of a Higgs Boson

    Energy Technology Data Exchange (ETDEWEB)

    Atramentov, Oleksiy Vladimirovich [Iowa State Univ., Ames, IA (United States)

    2006-07-01

    In this thesis we describe a search for a fermiophobic Higgs boson in 3γ+X events. The study has been performed on 0.83 fb-1 of data collected with the D0 detector that resides at one of the interaction regions of the Tevatron collider, the world's highest energy accelerator. This study was motivated by a fairly recent phenomenological paper [33] where it was noticed that in certain class of models (2HDM Type I and THM) the multi-photon final states like this one become detectable at the luminosity that has been collected by the D0 experiment by 2006. The mechanism that permits such final state becomes available when the conventional higgs production mechanism (higgs strahlung) are suppressed. This leads to the fact that Higgs boson with mass (mhf < 90 GeV/c2) lower than the current limit has not been excluded.

  4. Higgs production from sterile neutrinos at future lepton colliders

    CERN Document Server

    Antusch, Stefan; Fischer, Oliver

    2015-01-01

    In scenarios with sterile (right-handed) neutrinos that are subject to an approximate "lepton-number-like" symmetry, the heavy neutrinos (i.e. the mass eigenstates) can have masses around the electroweak scale and couple to the Higgs boson with, in principle, unsuppressed Yukawa couplings while accounting for the smallness of the light neutrinos' masses. In these scenarios, the on-shell production of heavy neutrinos and their subsequent decays into a light neutrino and a Higgs boson constitutes a hitherto unstudied resonant contribution to the Higgs production mechanism. We investigate the relevance of this resonant mono-Higgs production mechanism in leptonic collisions, including the present experimental constraints on the neutrino Yukawa couplings, and we determine the sensitivity of future lepton colliders to the heavy neutrinos. With Monte Carlo event sampling and a simulation of the detector response we find that, at future lepton colliders, neutrino Yukawa couplings below the percent level can lead to o...

  5. Future prospects of Higgs Physics at CMS

    OpenAIRE

    2014-01-01

    The Higgs boson physics reach of the CMS detector with 300(0) fb-1 of proton-proton collisions at sqrt{s} = 14 TeV is presented. Precision measurements of the Higgs boson properties, Higgs boson pair production and self-coupling, rare Higgs boson decays, and the potential for additional Higgs bosons are discussed.

  6. Electroweak symmetry breaking and Higgs physics. Basic concepts

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Bock, G.; Noriega-Papaqui, R.; Pedraza, I. [Benemerita Univ. Auton. de Puebla, Pue (Mexico). Inst. de Fisica ' ' LRT' ' ; Mondragon, M. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Fisica; Muehlleitner, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)]|[Laboratoire d' Annecy-le-Vieux Physique Theorique, LAPTH, Annecy-le-Vieux (France); Spira, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Zerwas, P.M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2005-09-01

    We present an introduction to the basic concepts of electroweak symmetry breaking and Higgs physics within the Standard Model and its supersymmetric extensions. A brief overview will also be given on alternative mechanisms of symmetry breaking. In addition to the theoretical basis, the present experimental status of Higgs physics and implications for future experiments at the LHC and e{sup +}e{sup -} linear colliders are discussed. (orig.)

  7. Natural extensions of electroweak geometry and Higgs interactions

    CERN Document Server

    Canarutto, Daniel

    2014-01-01

    We explore the possibility that the Higgs boson of the standard model be actually a member of a larger family, by showing that a more elaborate internal structure naturally arises from geometrical arguments, in the context of a partly original handling of gauge fields which was put forward in previous papers. A possible mechanism yielding the usual Higgs potential is proposed. New types of point interactions, arising in particular from two-spinor index contractions, are shown to be allowed.

  8. Concepts of electroweak symmetry breaking and Higgs physics

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Bock, M. [Benemerita Univ., Puebla (Mexico). Inst. de Fisica; Mondragon, M. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Fisica; Muehlleitner, M. [Laboratoire d' Annecy-Le-Vieux de Physique Theorique, 74 (France)]|[CERN - European Organization for Nuclear Research, Geneva (Switzerland). Theory Div.; Spira, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Zerwas, P.M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[RWTH Aachen (Germany). Inst. Theor. Physik E]|[Univ. Paris- Sud, Orsay (France). Laboratoire de Physique Theorique

    2007-12-15

    We present an introduction to the basic concepts of electroweak symmetry breaking and Higgs physics within the Standard Model and its supersymmetric extensions. A brief overview will also be given on alternative mechanisms of electroweak symmetry breaking. In addition to the theoretical basis, the present experimental status of Higgs physics and prospects at the Tevatron, the LHC and e{sup +}e{sup -} linear colliders are discussed. (orig.)

  9. In situ nanoindentation study on plasticity and work hardening in aluminium with incoherent twin boundaries.

    Science.gov (United States)

    Bufford, D; Liu, Y; Wang, J; Wang, H; Zhang, X

    2014-09-10

    Nanotwinned metals have been the focus of intense research recently, as twin boundaries may greatly enhance mechanical strength, while maintaining good ductility, electrical conductivity and thermal stability. Most prior studies have focused on low stacking-fault energy nanotwinned metals with coherent twin boundaries. In contrast, the plasticity of twinned high stacking-fault energy metals, such as aluminium with incoherent twin boundaries, has not been investigated. Here we report high work hardening capacity and plasticity in highly twinned aluminium containing abundant Σ3{112} incoherent twin boundaries based on in situ nanoindentation studies in a transmission electron microscope and corresponding molecular dynamics simulations. The simulations also reveal drastic differences in deformation mechanisms between nanotwinned copper and twinned aluminium ascribed to stacking-fault energy controlled dislocation-incoherent twin boundary interactions. This study provides new insight into incoherent twin boundary-dominated plasticity in high stacking-fault energy twinned metals.

  10. Can the 750-GeV diphoton resonance be the singlet Higgs boson of custodial Higgs triplet model?

    Science.gov (United States)

    Chiang, Cheng-Wei; Kuo, An-Li

    2016-09-01

    The observation of diphoton excess around the mass of 750 GeV in LHC Run-II motivates us to consider whether the singlet Higgs boson in the custodial Higgs triplet model can serve as a good candidate because an earlier study of comprehensive parameter scan shows that it can have the right mass in the viable mass spectra. By assuming the singlet Higgs mass at 750 GeV, its total width less than 50 GeV and imposing constraints from the LHC 8-TeV data, we identify an approximately linear region on the (vΔ , α) plane along which the exotic Higgs boson masses satisfy a specific hierarchy and have lower possible spectra, where vΔ denotes the triplet vacuum expectation value and α is the mixing angle between the singlet Higgs boson and the standard model-like Higgs boson. Although the diphoton decay rate can be enhanced by charged Higgs bosons running in the loop in this region, it is mostly orders of magnitude smaller than that required for the observed production rate, except for the small vΔ region when the diphoton fusion production mechanism becomes dominant. Nonetheless, this part of parameter space suffers from the problems of breakdown of perturbativity and large uncertainties in the photon parton distribution function of proton.

  11. Higgs physics at CLIC

    CERN Document Server

    AUTHOR|(SzGeCERN)613844

    2016-01-01

    The Compact Linear Collider CLIC is an option for a future multi-TeV electron-positron collider, offering the potential for a rich precision physics programme, combined with sensitivity to a wide range of new phenomena. The CLIC physics potential for measurements of the 125 GeV Higgs boson has been studied using full detector simulations for several centre-of-mass energies. The presented results provide crucial input to the energy staging strategy for the CLIC accelerator. The complete physics program for measurements of accessible Higgs boson couplings is presented in this talk. All measurements available at a given centre-of-mass energy were included in combined fits. Operation at a few hundred GeV allows the couplings and width of the Higgs boson to be determined in a model-independent manner through the study of the Higgsstrahlung and WW-fusion processes. At a lepton collider, the measurement of the Higgsstrahlung cross section using the recoil mass technique sets the absolute scale for all Higgs coupling...

  12. Higgs Factory Concepts

    CERN Document Server

    Zimmermann, Frank

    2016-01-01

    Designs for future high-energy circular electron-positron colliders are based on both established and novel concepts. An appropriate design will enable these facilities to serve not only as “Higgs factories”, but also as Z, W and top factories, and, in addition, to become a possible first step to a higher-energy hadron collider.

  13. Higgs Discovery Movie

    CERN Multimedia

    2014-01-01

    The ATLAS & CMS Experiments Celebrate the 2nd Anniversary of the Discovery of the Higgs boson. Here, are some images of the path from LHC startup to Nobel Prize, featuring a musical composition by Roger Zare, performed by the Donald Sinta Quartet, called “LHC”. Happy Discovery Day!

  14. The Leptonic Higgs Portal

    CERN Document Server

    Batell, Brian; McKeen, David; Pospelov, Maxim; Ritz, Adam

    2016-01-01

    An extended Higgs sector may allow for new scalar particles well below the weak scale. In this work, we present a detailed study of a light scalar $S$ with enhanced coupling to leptons, which could be responsible for the existing discrepancy between experimental and theoretical determinations of the muon anomalous magnetic moment. We present an ultraviolet completion of this model in terms of the lepton-specific two-Higgs doublet model and an additional scalar singlet. We then analyze a plethora of experimental constraints on the universal low energy model, and this UV completion, along with the sensitivity reach at future experiments. The most relevant constraints originate from muon and kaon decays, electron beam dump experiments, electroweak precision observables, rare $B_d$ and $B_s$ decays and Higgs branching fractions. The properties of the leptonic Higgs portal imply an enhanced couplings to heavy leptons, and we identify the most promising search mode for the high-luminosity electron-positron collider...

  15. Disentangling a dynamical Higgs

    CERN Document Server

    Brivio, I; Éboli, O J P; Gavela, M B; Gonzalez-Fraile, J; Gonzalez-Garcia, M C; Merlo, L; Rigolin, S

    2013-01-01

    The pattern of deviations from Standard Model predictions and couplings is different for theories of new physics based on a non-linear realization of the $SU(2)_L\\times U(1)_Y$ gauge symmetry breaking and those assuming a linear realization. We clarify this issue in a model-independent way via its effective Lagrangian formulation in the presence of a light Higgs particle, up to first order in the expansions: dimension-six operators for the linear expansion and four derivatives for the non-linear one. Complete sets of pure gauge and gauge-Higgs operators are considered, implementing the renormalization procedure and deriving the Feynman rules for the non-linear expansion. We establish the theoretical relation and the differences in physics impact between the two expansions. Promising discriminating signals include the decorrelation in the non-linear case of signals correlated in the linear one: some pure gauge versus gauge-Higgs couplings and also between couplings with the same number of Higgs legs. Furthermo...

  16. Minimal Higgs inflation

    CERN Document Server

    Maity, Debaprasad

    2016-01-01

    In this paper we propose two simple minimal Higgs inflation scenarios through a simple modification of the Higgs potential, as opposed to the usual non-minimal Higgs-gravity coupling prescription. The modification is done in such a way that it creates a flat plateau for a huge range of field values at the inflationary energy scale $\\mu \\simeq (\\lambda)^{1/4} \\alpha$. Assuming the perturbative Higgs quartic coupling, $\\lambda \\simeq {\\cal O}(1)$, for both the models inflation energy scale turned out to be $\\mu \\simeq (10^{14}, 10^{15})$ GeV, and prediction of all the cosmologically relevant quantities, $(n_s,r,dn_s^k)$, fit extremely well with observations made by PLANCK. Considering observed central value of the scalar spectral index, $n_s= 0.968$, our two models predict efolding number, $N = (52,47)$. Within a wide range of viable parameter space, we found that the prediction of tensor to scalar ratio $r (\\leq 10^{-5})$ is far below the current experimental sensitivity to be observed in the near future. The ...

  17. APS Quantum Critical Higgs

    CERN Document Server

    Bellazzini, Brando; Hubisz, Jay; Lee, Seung J.; Serra, Javi; Terning, John

    2016-01-01

    The appearance of the light Higgs boson at the LHC is difficult to explain, particularly in light of naturalness arguments in quantum field theory. However light scalars can appear in condensed matter systems when parameters (like the amount of doping) are tuned to a critical point. At zero temperature these quantum critical points are directly analogous to the finely tuned standard model. In this paper we explore a class of models with a Higgs near a quantum critical point that exhibits non-mean-field behavior. We discuss the parametrization of the effects of a Higgs emerging from such a critical point in terms of form factors, and present two simple realistic scenarios based on either generalized free fields or a 5D dual in AdS space. For both of these models we consider the processes $gg\\to ZZ$ and $gg\\to hh$, which can be used to gain information about the Higgs scaling dimension and IR transition scale from the experimental data.

  18. Disentangling a dynamical Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Brivio, I. [Departamento de Física Teórica and Instituto de Física Teórica, IFT-UAM/CSIC,Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid (Spain); Corbett, T. [C.N. Yang Institute for Theoretical Physics and Department of Physics and Astronomy,SUNY at Stony Brook, Stony Brook, NY 11794-3840 (United States); Éboli, O.J.P. [Instituto de Física, Universidade de São Paulo,C.P. 66318, 05315-970, São Paulo SP (Brazil); Gavela, M.B. [Departamento de Física Teórica and Instituto de Física Teórica, IFT-UAM/CSIC,Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid (Spain); Gonzalez-Fraile, J. [Departament d’Estructura i Constituents de la Matèria and ICC-UB, Universitat de Barcelona,647 Diagonal, E-08028 Barcelona (Spain); Gonzalez-Garcia, M.C. [Institució Catalana de Recerca i Estudis Avançats (ICREA),Passeig Lluís Companys, 23, E-08010 Barcelona (Spain); Departament d’Estructura i Constituents de la Matèria and ICC-UB, Universitat de Barcelona,647 Diagonal, E-08028 Barcelona (Spain); C.N. Yang Institute for Theoretical Physics and Department of Physics and Astronomy,SUNY at Stony Brook, Stony Brook, NY 11794-3840 (United States); Merlo, L. [Departamento de Física Teórica and Instituto de Física Teórica, IFT-UAM/CSIC,Universidad Autónoma de Madrid, Cantoblanco, 28049, Madrid (Spain); Rigolin, S. [Dipartimento di Fisica e Astronomia “G. Galilei”, Università di Padova and INFN, Sezione di Padova, Via Marzolo 8, I-35131 Padua (Italy)

    2014-03-05

    The pattern of deviations from Standard Model predictions and couplings is different for theories of new physics based on a non-linear realization of the SU(2){sub L}×U(1){sub Y} gauge symmetry breaking and those assuming a linear realization. We clarify this issue in a model-independent way via its effective Lagrangian formulation in the presence of a light Higgs particle, up to first order in the expansions: dimension-six operators for the linear expansion and four derivatives for the non-linear one. Complete sets of gauge and gauge-Higgs operators are considered, implementing the renormalization procedure and deriving the Feynman rules for the non-linear expansion. We establish the theoretical relation and the differences in physics impact between the two expansions. Promising discriminating signals include the decorrelation in the non-linear case of signals correlated in the linear one: some pure gauge versus gauge-Higgs couplings and also between couplings with the same number of Higgs legs. Furthermore, anomalous signals expected at first order in the non-linear realization may appear only at higher orders of the linear one, and vice versa. We analyze in detail the impact of both type of discriminating signals on LHC physics.

  19. Higgs vacua behind barriers

    CERN Document Server

    Tamarit, Carlos

    2014-01-01

    Scenarios in which the Higgs vacuum arises radiatively and separated from the origin by a potential barrier at zero temperature are known to be attainable in models with extra singlet scalars, which in the limit of zero barrier height give rise to Coleman-Weinberg realizations of electroweak symmetry breaking. However, this requires large values of Higgs-portal couplings or a large number N of singlets. This is quantified in detail by considering, for varying N, the full two-loop effective potential at zero temperature, as well as finite temperature effects including the dominant two-loop corrections due to the singlets. Despite the large couplings, two-loop effects near the electroweak scale are under control, and actually better behaved in models with larger couplings yet fewer singlets. Strong first-order phase transitions are guaranteed even in the Coleman-Weinberg scenarios. Cubic Higgs couplings and Higgs associated-production cross sections exhibit deviations from the Standard Model predictions which c...

  20. Enhanced Higgs Mass in Compact Supersymmetry

    CERN Document Server

    Tobioka, Kohsaku; Murayama, Hitoshi

    2015-01-01

    The current LHC results make weak scale supersymmetry difficult due to relatively heavy mass of the discovered Higgs boson and the null results of new particle searches. Geometrical supersymmetry breaking from extra dimensions, Scherk-Schwarz mechanism, is possible to accommodate such situations. A concrete example, the Compact Supersymmetry model, has a compressed spectrum ameliorating the LHC bounds and large mixing in the top and scalar top quark sector with $|A_t|\\sim 2m_{\\tilde{t}}$ which radiatively raises the Higgs mass. While the zero mode contributions of the model has been considered, in this paper we calculate the Kaluza-Klein tower effect to the Higgs mass. Although such contributions are naively expected to be as small as a percent level for 10 TeV Kaluza-Klein modes, we find the effect significantly enhances the radiative correction to the Higgs quartic coupling by from 10 to 50 %. This is mainly because the top quark wave function is pushed out from the brane, which makes the top Yukawa couplin...

  1. In Situ Studies on the Irradiation-Induced Twin Boundary-Defect Interactions in Cu

    Science.gov (United States)

    Fan, C.; Li, Jin; Fan, Zhe; Wang, H.; Zhang, X.

    2017-08-01

    Polycrystalline Cu films with nanoscale annealing twins are subjected to in situ Kr++ ion irradiation at room temperature inside a transmission electron microscope up to a dose of 1 displacement-per-atom. Radiation induces prominent migration of incoherent twin boundaries. Depending on twin thickness, three types of twin boundary evolutions are observed, including rapid detwinning, gradual detwinning, and self-healing. The mechanism of twin thickness-dependent evolution of microstructures is discussed. This study provides further evidence on twin boundary-defect interactions and may assist the design of radiation-tolerant twinned metallic materials.

  2. Higgs Boson Mass and Complex Snuetrino Dark Matter in the Supersymmetric Inverse Seesaw Models

    CERN Document Server

    Guo, Jun; Li, Tianjun; Liu, Yandong

    2014-01-01

    The discovery of a relatively heavy Standard Model (SM) -like Higgs boson challenges naturalness of the minimal supersymmetric standard model (MSSM) from both Higgs and dark matter (DM) sectors. We study these two aspects in the MSSM extended by the low-scale inverse seesaw mechanism. Firstly, it admits a sizable radiative correction on the Higgs boson mass m_h, up to \\sim 4 GeV in the case of an IR-fixed point of the coupling Y_\

  3. Implications of the discovery of a Higgs triplet on electroweak right-handed neutrinos

    CERN Document Server

    Aranda, Alfredo; Hung, P Q

    2008-01-01

    Electroweak scale active right-handed neutrinos such as those proposed in a recent model necessitate the enlargement of the SM Higgs sector to include Higgs triplets with doubly charged scalars. The search for and constraints on such Higgs sector has implications not only on the nature of the electroweak symmetry breaking but also on the possibility of testing the seesaw mechanism at colliders such as the LHC and the ILC.

  4. Microstructure and mechanical properties of twin-wire arc sprayed Ni-Al composite coatings on 6061-T6 aluminum alloy sheet

    Institute of Scientific and Technical Information of China (English)

    Ji-xiao Wang; Jing-shun Liu; Lun-yong Zhang; Jian-fei Sun; Zhi-ping Wang

    2014-01-01

    We have systematically studied the microstructure and mechanical properties of Ni-5wt%Al and Ni-20wt%Al composite coat-ings fabricated on 6061-T6 aluminum alloy sheet by twin-wire arc spraying under different experimental conditions. The abrasive wear be-havior and interface diffusion behavior of the composite coatings were evaluated by dry/wet rubber wheel abrasive wear tests and heat treat-ment, respectively. Experimental results indicate that the composite coatings exhibit features of adhesive wear. Besides, the Vickers micro-hardness of NiAl and Ni3Al intermetallic compounds is relatively larger than that of the substrate, which is beneficial for enhancing the wear resistance. With the increase of annealing temperature and time, the interface diffusion area between the Ni-Al coating and the substrate gradually expands with the formation of NiAl3 and Ni2Al3 phases, and is controlled by diffusion of aluminum atoms. The grain growth ex-ponent n of diffusion kinetics of the Ni-Al coating, calculated via a high-temperature diffusion model at 400, 480, and 550°C, is between 0.28 and 0.38. This satisfies the cubic law, which is consistent with the general theoretical relationship of high-temperature diffusion.

  5. Prospects for Higgs physics at energies up to 100 TeV

    Science.gov (United States)

    Baglio, Julien; Djouadi, Abdelhak; Quevillon, Jérémie

    2016-11-01

    We summarize the prospects for Higgs boson physics at future proton-proton colliders with centre of mass (c.m.) energies up to 100 TeV. We first provide the production cross sections for the Higgs boson of the Standard Model from 13 TeV to 100 TeV, in the main production mechanisms and in subleading but important ones such as double Higgs production, triple production and associated production with two gauge bosons or with a single top quark. We then discuss the production of Higgs particles in beyond the Standard Model scenarios, starting with the one in the continuum of a pair of scalar, fermionic and vector dark matter particles in Higgs-portal models in various channels with virtual Higgs exchange. The cross sections for the production of the heavier CP-even and CP-odd neutral Higgs states and the charged Higgs states in two-Higgs doublet models, with a specific study of the case of the Minimal Supersymmetric Standard Model, are then given. The sensitivity of a 100 TeV proton machine to probe the new Higgs states is discussed and compared to that of the LHC with a c.m. energy of 14 TeV and at high luminosity.

  6. Glide twinning and pseudotwinning in peristerite: twin morphology and propagation

    Science.gov (United States)

    Brown, William L.

    1989-07-01

    Optically visible Albite glide “twins” in a peristerite (˜An9Or1.6), identified from their tapering shape and relationship to grain boundaries, were studied by transmission electron microscopy. Near the tips in sections ⊥ a, the microstructure consists of small (˜400 nm long) lensshaped Albite twins centred exclusively on the oligoclase lamellae. The lenses extend partly outwards into the two adjacent low albite lamellae and induce strong inhomogeneous strain. Where the lenses are closer together, they form, depending on the sense of shear, nearly linear left or right-stepping en échelon arrays, with overlap of the strain fields. Slightly farther in from the tip, the twin domains coalesce to form continuous pinch-and-swell lamellae, being always thicker in the oligoclase. Because of Si,Al order, only elastic glide pseudotwins are possible in low albite. In oligoclase glide pseudotwins may be mechanically stable (metastable relative to Si,Al order) and may deviate only slightly from true twins. Pseudotwins develop first in the oligoclase, propagate dynamically by jumping across the intervening albite lamellae, extend lengthways and thicken sideways and finally coalesce. They are stabilized by diffusion-controlled inversion of Si,Al order giving rise to true twins described in a companion paper.

  7. Discrete symmetries in the three-Higgs-doublet model

    CERN Document Server

    Ivanov, I P

    2012-01-01

    N-Higgs-doublet models (NHDM) are among the most popular examples of electroweak symmetry breaking mechanisms beyond the Standard Model. Discrete symmetries imposed on the NHDM scalar potential play a pivotal role in shaping the phenomenology of the model, and various symmetry groups have been studied so far. However, in spite of all efforts, the classification of finite Higgs-family symmetry groups realizable in NHDM for any N>2 is still missing. Here, we solve this problem for the three-Higgs-doublet model. Using recently found realizable abelian groups and applying Burnside's theorem and other group-theoretic tools, we find the full list of finite symmetry groups of Higgs-family transformations which are realizable in the scalar sector of 3HDM.

  8. Low scale thermal leptogenesis in neutrinophilic Higgs doublet models

    CERN Document Server

    Haba, Naoyuki

    2011-01-01

    It is well-known that leptogenesis in low energy scale is difficult in the conventional Type-I seesaw mechanism with hierarchical right-handed neutrino masses. We show that in a class of two Higgs doublet model, where one Higgs doublet generates masses of quarks and charged leptons whereas the other Higgs doublet with a tiny vacuum expectation value generates neutrino Dirac masses, large Yukawa couplings lead to a large enough CP asymmetry of the right-handed neutrino decay. Thermal leptogenesis suitably works at low energy scale as keeping no enhancement of lepton number violating wash out effects. We will also point out that thermal leptogenesis works well without confronting gravitino problem in a supersymmetric neutrinophilic Higgs doublet model with gravity mediated supersymmetry breaking. Neutralino dark matter and baryon asymmetry generation by thermal leptogenesis are easily compatible in our setup.

  9. Sphalerons in composite and non-standard Higgs models

    CERN Document Server

    Spannowsky, Michael

    2016-01-01

    After the discovery of the Higgs boson and the rather precise measurement of all electroweak boson's masses the local structure of the electroweak symmetry breaking potential is already quite well established. However, despite being a key ingredient to a fundamental understanding of the underlying mechanism of electroweak symmetry breaking, the global structure of the electroweak potential remains entirely unknown. The existence of sphalerons, unstable solutions of the classical action of motion that are interpolating between topologically distinct vacua, is a direct consequence of the Standard Model's $\\mathrm{SU}(2)_L$ gauge group. Nevertheless, the sphaleron energy depends on the shape of the Higgs potential away from the minimum and can therefore be a litmus test for its global structure. Focusing on two scenarios, the minimal composite Higgs model $\\mathrm{SO}(5)/\\mathrm{SO}(4)$ or an elementary Higgs with a deformed electroweak potential, we calculate the change of the sphaleron energy compared to the S...

  10. Charged Higgs Analysis in CMS

    CERN Document Server

    Eysermans, Jan

    2016-01-01

    In this talk an overview is given of the possible searches of the Charged Higgs Boson during run 2 of the LHC data taking period. The Charged Higgs boson emerges in several (minimal) Standard Model (SM) extensions such as the 2 Doublet Higgs Model, which predicts 5 physical Higgs bosons, consistent with the SM Higgs boson. Based on the main production and decay modes, the possible intermediate and final state particles are predicted for a Charged Higgs mass higher than the top quark mass ($m_{H^{\\pm}} > m_t$). In particular, the dominant H to tau nu and H to tb channels are discussed in more detail together with their associated background.

  11. Higgs Inflation as a Mirage

    CERN Document Server

    Barbon, J L F; Elias-Miro, J; Espinosa, J R

    2015-01-01

    We discuss a simple unitarization of Higgs inflation that is genuinely weakly coupled up to Planckian energies. A large non-minimal coupling between the Higgs and the Ricci curvature is induced dynamically at intermediate energies, as a simple ratio of mass scales. Despite not being dominated by the Higgs field, inflationary dynamics simulates the `Higgs inflation' one would get by blind extrapolation of the low-energy effective Lagrangian, at least qualitatively. Hence, Higgs inflation arises as an approximate `mirage' picture of the true dynamics. We further speculate on the generality of this phenomenon and show that, if Higgs-inflation arises as an effective description, the details of the UV completion are necessary to extract robust quantitative predictions.

  12. Higgs Precision Measurements with ATLAS

    CERN Document Server

    Boumediene, Djamel Eddine; The ATLAS collaboration

    2017-01-01

    After the discovery of the Higgs boson, precise measurements of its properties are of particular importance to understand the true nature of the found particle, which could be the Standard Model predicted Higgs, or indeed offering to be a portal for new physics beyond the Standard Model. In this talk measurement of the mass, cross sections and the couplings of the Higgs boson in bosonic and fermionic decay channels with the ATLAS detector will be presented and compared with Standard Model predictions.

  13. Light Higgs from Scalar See-Saw in Technicolor

    DEFF Research Database (Denmark)

    Foadi, Roshan; Frandsen, Mads Toudal

    2012-01-01

    We consider a TeV scale see-saw mechanism leading to light scalar resonances in models with otherwise intrinsically heavy scalars. The mechanism can provide a 125 GeV technicolor Higgs in e.g. two-scale TC models......We consider a TeV scale see-saw mechanism leading to light scalar resonances in models with otherwise intrinsically heavy scalars. The mechanism can provide a 125 GeV technicolor Higgs in e.g. two-scale TC models...

  14. The use of rheology to elucidate the granulation mechanisms of a miscible and immiscible system during continuous twin-screw melt granulation.

    Science.gov (United States)

    Monteyne, Tinne; Heeze, Liza; Mortier, Séverine Thérèse F C; Oldörp, Klaus; Nopens, Ingmar; Remon, Jean-Paul; Vervaet, Chris; De Beer, Thomas

    2016-08-20

    Twin-screw hot melt granulation (TS HMG) is a valuable, but still unexplored alternative to granulate temperature and moisture sensitive drugs in a continuous way. Recently, the material behavior of an immiscible drug-binder blend during TS HMG was unraveled by using a rheometer and differential scanning calorimetry (DSC). Additionally, vibrational spectroscopic techniques proved the link between TS HMG and rheology since equal interactions at molecular level did occur in both processes. This allowed to use a rheometer to gain knowledge of the material behavior during hot melt processing of an immiscible drug-binder blend. However, miscibility of a drug-binder formulation and drug-binder interactions appear to influence the rheological properties and, hence conceivably also the granulation mechanism. The aim of this research was to examine if the TS HMG process of a miscible formulation system is comparable with the mechanism of an immiscible system and to evaluate whether rheology still serves as a useful tool to understand and optimize the hot melt granulation (HMG) process. The executed research (thermal analysis, rheological parameters and spectroscopic data) demonstrated the occurrence of a high and broad tan(δ) curve without a loss peak during the rheological temperature ramp which implies a higher material deformability without movement of the softened single polymer chains. Spectroscopic analysis revealed drug-polymer interactions which constrain the polymer to flow independently. As a result, the binder distribution step, which generally follows the immersion step, was hindered. This insight assisted the understanding of the granule properties. Inhomogeneous granules were produced due to large initial nuclei or adhesion of multiple smaller nuclei. Consequently, a higher granulation temperature was required in order to get the binder more homogeneously distributed within the granules. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Deformation Twinning During Nanoindentation of Nanocrystalline Ta

    OpenAIRE

    Wang, Y. M.; Hodge, A. M.; Biener, J.; Hamza, A.V.; Barnes, D E; Liu, Kai; Nieh, T. G.

    2005-01-01

    The deformation mechanism of body-centered cubic (bcc) nanocrystalline tantalum with grain sizes of 10–30 nm is investigated by nanoindentation, scanning electron microscopy and high-resolution transmission electron microscopy. In a deviation from molecular dynamics simulations and existing experimental observations on other bcc nanocrystalline metals, the plastic deformation of nanocrystalline Ta during nanoindentation is controlled by deformation twinning. The observation of multiple twin i...

  16. TASI 2013 lectures on Higgs physics within and beyond the Standard Model

    CERN Document Server

    Logan, Heather E

    2014-01-01

    These lectures start with a detailed pedagogical introduction to electroweak symmetry breaking in the Standard Model, including gauge boson and fermion mass generation and the resulting predictions for Higgs boson interactions. I then survey Higgs boson decays and production mechanisms at hadron and e+e- colliders. I finish with two case studies of Higgs physics beyond the Standard Model: two-Higgs-doublet models, which I use to illustrate the concept of minimal flavor violation, and models with isospin-triplet scalar(s), which I use to illustrate the concept of custodial symmetry.

  17. Lines of Constant Physics in a Five-Dimensional Gauge-Higgs Unification Scenario

    CERN Document Server

    Alberti, Maurizio; Knechtli, Francesco; Moir, Graham

    2016-01-01

    We report on the progress in the study of a five-dimensional SU(2) Gauge-Higgs Unification model. In this non-perturbative study, the Higgs mechanism is triggered by the spontaneous breaking of a global symmetry. In the same region of the phase diagram, we observe both dimensional reduction and the ratio of Higgs and Z boson masses to take the value known from experiment. We present the first results on the construction of a line of constant physics in this region, including the prediction for the mass scale of the first excited states of the Higgs and gauge bosons.

  18. Dynamical CP violation in composite Higgs models

    OpenAIRE

    Hashimoto, S.; Inagaki, Tomohiro; Muta, Taizo

    1993-01-01

    The dynamical origin of the CP violation in electroweak theory is investigated in composite Higgs models. The mechanism of the spontaneous CP violation proposed in other context by Dashen is adopted to construct simple models of the dynamical CP violation. Within the models the size of the neutron electric dipole moment is estimated and the constraint on the $\\varepsilon$-parameter in K-meson decays is discussed.

  19. Malaysian Twin Registry.

    Science.gov (United States)

    Jahanfar, Shayesteh; Jaffar, Sharifah Halimah

    2013-02-01

    The National Malaysian Twin Registry was established in Royal College of Medicine, Perak, University Kuala Lumpur (UniKL) in June 2008 through a grant provided by UniKL. The general objective is to facilitate scientific research involving participation of twins and their family members in order to answer questions of health and wellbeing relevant to Malaysians. Recruitment is done via mass media, poster, and pamphlets. We now have 266 adult and 204 children twins registered. Several research projects including reproductive health study of twins and the role of co-bedding on growth and development of children are carried out. Registry holds annual activities for twins and seeks to provide health-related information for twins. We seek international collaboration.

  20. Integrating over Higgs branches

    Energy Technology Data Exchange (ETDEWEB)

    Moore, G. [Yale Univ., New Haven, CT (United States). Dept. of Physics; Nekrasov, N. [Institute of Theoretical and Experimental Physics, 117259, Moscow (Russian Federation); Shatashvili, S. [Lyman Laboratory of Physics, Harvard University, Cambridge, MA (United States)

    2000-01-01

    We develop some useful techniques for integrating over Higgs branches in supersymmetric theories with 4 and 8 supercharges. In particular, we define a regularized volume for hyperkaehler quotients. We evaluate this volume for certain ALE and ALF spaces in terms of the hyperkaehler periods. We also reduce these volumes for a large class of hyperkaehler quotients to simpler integrals. These quotients include complex coadjoint orbits, instanton moduli spaces on R{sup 4} and ALE manifolds, Hitchin spaces, and moduli spaces of (parabolic) Higgs bundles on Riemann surfaces. In the case of Hitchin spaces the evaluation of the volume reduces to a summation over solutions of Bethe ansatz equations for the non-linear Schroedinger system. We discuss some applications of our results. (orig.)

  1. Perinatal hepatic infarction in twin-twin transfusion.

    LENUS (Irish Health Repository)

    O'Sullivan, M J

    2012-02-03

    We report a case of a twin pregnancy which was complicated by a twin-twin transfusion in which the recipient twin was noted to have an intra-abdominal echogenic mass. This twin died at two days of age of hepatic infarction. The donor twin was healthy at birth, at thirty weeks\\' gestation, and did not have any subsequent problems. Fetal intra-abdominal echogenicity may be a marker of hepatic infarction.

  2. Higgs-photon resonances

    Energy Technology Data Exchange (ETDEWEB)

    Dobrescu, Bogdan A. [Fermilab; Fox, Patrick J. [Fermilab; Kearney, John [Fermilab

    2017-05-23

    We study models that produce a Higgs boson plus photon ($h^0 \\gamma$) resonance at the LHC. When the resonance is a $Z'$ boson, decays to $h^0 \\gamma$ occur at one loop. If the $Z'$ boson couples at tree-level to quarks, then the $h^0 \\gamma$ branching fraction is typically of order $10^{-5}$ or smaller. Nevertheless, there are models that would allow the observation of $Z' \\to h^0 \\gamma$ at $\\sqrt{s} = 13$ TeV with a cross section times branching fraction larger than 1 fb for a $Z'$ mass in the 200--450 GeV range, and larger than 0.1 fb for a mass up to 800 GeV. The 1-loop decay of the $Z'$ into lepton pairs competes with $h^0 \\gamma$, even if the $Z'$ couplings to leptons vanish at tree level. We also present a model in which a $Z'$ boson decays into a Higgs boson and a pair of collimated photons, mimicking an $h^0 \\gamma$ resonance. In this model, the $h^0 \\gamma$ resonance search would be the discovery mode for a $Z'$ as heavy as 2 TeV. When the resonance is a scalar, although decay to $h^0 \\gamma$ is forbidden by angular momentum conservation, the $h^0$ plus collimated photons channel is allowed. We comment on prospects of observing an $h^0 \\gamma$ resonance through different Higgs decays, on constraints from related searches, and on models where $h^0$ is replaced by a nonstandard Higgs boson.

  3. Higgs Boson Properties

    CERN Document Server

    David, André

    2016-01-01

    This chapter presents an overview of the measured properties of the Higgs boson discovered in 2012 by the ATLAS and CMS collaborations at the CERN LHC. Searches for deviations from the properties predicted by the standard theory are also summarised. The present status corresponds to the combined analysis of the full Run 1 data sets of collisions collected at centre-of-mass energies of 7 and 8 TeV.

  4. Higgs Boson Properties

    Science.gov (United States)

    David, André Dührssen, Michael

    2016-10-01

    This chapter presents an overview of the measured properties of the Higgs boson discovered in 2012 by the ATLAS and CMS collaborations at the CERN LHC. Searches for deviations from the properties predicted by the standard theory are also summarised. The present status corresponds to the combined analysis of the full Run 1 data sets of collisions collected at centre-of-mass energies of 7 and 8 TeV.

  5. DELPHI: Higgs candidate

    CERN Multimedia

    2001-01-01

    This track is an example of real data collected from the DELPHI detector on the Large Electron-Positron (LEP) collider at CERN, which ran between 1989 and 2000. Its topology is compatible with what is expected from the associated production of a Z boson and Higgs boson of mass 113 GeV that each decay into two jets. A different pairing of the jets could lead to an interpretation compatible with the production of two Z bosons.

  6. Deformation twinning characteristic of mechanically alloyed Cu-Nb alloy powders%机械合金化法制备Cu-Nb合金过程中的形变孪生特性

    Institute of Scientific and Technical Information of China (English)

    雷若姗; 汪明朴; 郭明星; 李周; 魏海根

    2011-01-01

    The microstructure evolution and deformation twinning characteristics of nanocrystalline Cu-10%Nb alloy during mechanical alloying (MA) were investigated by microhardness measurements, transmission electron microscopy (TEM) and high resolution TEM (HRTEM) observation. A local stress concentration model was proposed to explain the deformation twin nucleation mechanism of Cu-Nb alloy. The results show that the Vickers microhardness of the powders increases gradually with the increase of milling time, and reaches 4.8 GPa after 120 h milling. The main structure of the powders is the dislocation cells in the initial milling. After 50 h milling, the average Cu grain size decreases to about 50 nm, and nano-deformation twins begin to form in some regions. With the continued increase of the milling time, the number of twin increases, and the twin boundary strengthening enhances accordingly. Due to the deformation twinning will contribute to further refine the nano-grains, after 120 h milling, the nano-crystalline size decreases to below 20 nm.%采用机械合金化法制备纳米Cu-10%Nb合金,通过显微硬度测量以及高分辨透射电镜观察,对该合金粉末在室温球磨过程中的微观结构演变和形变孪生特性进行研究;利用局部应力集中模型分析形变孪晶的形核机制.结果表明:随着球磨时间的增加,该合金硬度(HV)不断升高,球磨120 h后可达4.8 GPa;该合金在球磨初期以位错胞结构为主;球磨50 h后,Cu平均晶粒尺寸减小至约50 nm,部分区域出现纳米形变孪晶;继续增加球磨时间,孪晶数量增加,孪晶界强化效果显著;由于孪生将促进纳米晶粒的进一步细化,球磨120 h后,纳米晶尺寸减小到20nm以下.

  7. Colorless top partners, a 125 GeV Higgs boson, and the limits on naturalness

    Energy Technology Data Exchange (ETDEWEB)

    Burdman, Gustavo; Chacko, Zackaria; Harnik, Roni; de Lima, Leonardo; Verhaaren, Christopher B.

    2015-03-01

    Theories of physics beyond the Standard Model that address the hierarchy problem generally involve top partners, new particles that cancel the quadratic divergences associated with the Yukawa coupling of the Higgs to the top quark. With extensions of the Standard Model that involve new colored particles coming under strain from collider searches, scenarios in which the top partners carry no charge under the strong interactions have become increasingly compelling. Although elusive for direct searches, these theories predict modified couplings of the Higgs boson to the Standard Model particles. This results in corrections to the Higgs production and decay rates that can be detected at the Large Hadron Collider (LHC) provided the top partners are sufficiently light, and the theory correspondingly natural. In this paper we consider three theories that address the little hierarchy problem and involve colorless top partners, specifically the Mirror Twin Higgs, Folded Supersymmetry, and the Quirky Little Higgs. For each model we investigate the current and future bounds on the top partners, and the corresponding limits on naturalness, that can be obtained from the Higgs program at the LHC. We conclude that the LHC will not be able to strongly disfavor naturalness, with mild tuning at the level of about one part in ten remaining allowed even with 3000 fb$^{-1}$ of data at 14 TeV.

  8. Invisible Higgs decay in the LRTH model confronted with latest LHC, XENON100 and LUX date

    CERN Document Server

    Liu, Yao-Bei

    2014-01-01

    In the left-right twin Higgs (LRTH) model, the neutral $\\hat{S}$ is a candidate for weakly interacting massive particle (WIMP) dark matter. If its mass is lighter than half of the SM-like Higgs boson, the SM-like Higgs boson $h$ can have new invisible decay $h\\rightarrow \\hat{S}\\hat{S}$ which consequently suppress the diphoton signal rates at the LHC. In this paper, we examine the status of a light dark matter ($\\hat{S}$) under current experimental constraints including the latest LHC Higgs data, the XENON100 and LUX limit on the dark matter scattering off the nucleon. The following observations have been obtained: (i) The current ATLAS (CMS) measurements $R_{\\gamma\\gamma}$ can exclude the invisible Higgs branching ratio ${\\rm Br}_{\\rm inv}$ about 34% (48%) at $2\\sigma$ level; (ii) Global fits to the latest LHC and Tevatron Higgs data provide a strong constraint on ${\\rm Br}_{\\rm inv}<20%(30%)$ at $2(3)\\sigma$ level, which can be tested at the 14 TeV LHC experiment; (iii) For the spin-independent scatterin...

  9. Colorless Top Partners, a 125 GeV Higgs, and the Limits on Naturalness

    Energy Technology Data Exchange (ETDEWEB)

    Burdman, Gustavo [Sao Paulo U.; Chacko, Zackaria [Maryland U.; Harnik, Roni [Fermilab; de Lima, Leonardo [Sao Paulo, IFT; Verhaaren, Christopher B. [Maryland U.

    2015-03-09

    Theories of physics beyond the Standard Model that address the hierarchy problem generally involve top partners, new particles that cancel the quadratic divergences associated with the Yukawa coupling of the Higgs to the top quark. With extensions of the Standard Model that involve new colored particles coming under strain from collider searches, scenarios in which the top partners carry no charge under the strong interactions have become increasingly compelling. Although elusive for direct searches, these theories predict modified couplings of the Higgs boson to the Standard Model particles. This results in corrections to the Higgs production and decay rates that can be detected at the Large Hadron Collider (LHC) provided the top partners are sufficiently light, and the theory correspondingly natural. In this paper we consider three theories that address the little hierarchy problem and involve colorless top partners, specifically the Mirror Twin Higgs, Folded Supersymmetry, and the Quirky Little Higgs. For each model we investigate the current and future bounds on the top partners, and the corresponding limits on naturalness, that can be obtained from the Higgs program at the LHC. We conclude that the LHC will not be able to strongly disfavor naturalness, with mild tuning at the level of about one part in ten remaining allowed even with 3000 fb$^{-1}$ of data at 14 TeV.

  10. The Higgs Bridge

    CERN Document Server

    Allen, Roland E

    2013-01-01

    The particle recently discovered at the Large Hadron Collider near Geneva is almost certainly a Higgs boson, the long-sought completion of the Standard Model of particle physics. But this discovery, an achievement by more than six thousand scientists (including students), is actually much more than a mere capstone of the Standard Model. It instead represents a bridge from the Standard Model to exciting discoveries of the future, at higher energies or in other experiments, and to the properties of matter at very low temperatures. The mere existence of a particle with zero spin implies a need for new physics, with the most likely candidate being supersymmetry, which requires that every known particle has a superpartner yet to be discovered. And phenomena similar to the Higgs are seen in superconducting metals and superfluid gases at low temperatures, which extend down to a millionth or even a billionth of a degree Kelvin. So the discovery of a Higgs boson has a central place in our attempts both to achieve a tr...

  11. Higgs physics at CLIC

    CERN Document Server

    Lukić, Strahinja

    2016-01-01

    The Compact Linear Collider CLIC is an option for a future multi-TeV electron-positron collider, offering the potential for a rich precision physics programme, combined with sensitivity to a wide range of new phenomena. The CLIC physics potential for measurements of the 125 GeV Higgs boson has been studied using full detector simulations for several centre-of-mass energies. The presented results provide crucial input to the energy staging strategy for the CLIC accelerator. The complete physics program for measurements of accessible Higgs boson couplings is presented in this contribution. The ultimate measurement precision is reached when all measurements available at a given centre-of-mass energy are included in combined fits. Operation at a few hundred GeV allows the couplings and width of the Higgs boson to be determined in a model-independent manner through the study of the Higgsstrahlung and WW-fusion processes. At a lepton collider, the measurement of the Higgsstrahlung cross section using the recoil mas...

  12. The Brazilian Twin Registry.

    Science.gov (United States)

    Ferreira, Paulo H; Oliveira, Vinicius C; Junqueira, Daniela R; Cisneros, Lígia C; Ferreira, Lucas C; Murphy, Kate; Ordoñana, Juan R; Hopper, John L; Teixeira-Salmela, Luci F

    2016-12-01

    The Brazilian Twin Registry (BTR) was established in 2013 and has impelled twin research in South America. The main aim of the initiative was to create a resource that would be accessible to the Brazilian scientific community as well as international researchers interested in the investigation of the contribution of genetic and environmental factors in the development of common diseases, phenotypes, and human behavior traits. The BTR is a joint effort between academic and governmental institutions from Brazil and Australia. The collaboration includes the Federal University of Minas Gerais (UFMG) in Brazil, the University of Sydney and University of Melbourne in Australia, the Australian Twin Registry, as well as the research foundations CNPq and CAPES in Brazil. The BTR is a member of the International Network of Twin Registries. Recruitment strategies used to register twins have been through participation in a longitudinal study investigating genetic and environmental factors for low back pain occurrence, and from a variety of sources including media campaigns and social networking. Currently, 291 twins are registered in the BTR, with data on demographics, zygosity, anthropometrics, and health history having been collected from 151 twins using a standardized self-reported questionnaire. Future BTR plans include the registration of thousands of Brazilian twins identified from different sources and collaborate nationally and internationally with other research groups interested on twin studies.

  13. Delivery in Twin Gestation

    Directory of Open Access Journals (Sweden)

    Mark T. Peters

    1995-01-01

    Full Text Available Objective: The objective of this study was to determine whether prophylactic treatment with oral broad-spectrum antimicrobial therapy improves pregnancy outcomes in twin gestations.

  14. Twinning in shear and uniaxial loading in five layered martensite Ni-Mn-Ga single crystals

    Science.gov (United States)

    Aaltio, Ilkka; Ge, Yanling; Hannula, Simo-Pekka

    2013-02-01

    Five-layered martensite Ni-Mn-Ga single crystals are known for their exceptionally mobile twin boundaries allowing a shape change under mechanical stress and by magnetic field. The mechanically measured twinning stress has usually been studied in uniaxial mode, however the twinning and detwinning is generally accepted to be resulted by the shear component. We have studied the twinning behavior at uniaxial and shear stress. In addition we have applied the shear stress at different angles in relation to the expected twinning direction [ {10bar 1} ]. The results show that the onset of twinning lays at similar stress levels in both uniaxial and shear modes.

  15. SEARCH FOR MODEL INDEPENDENT DI-HIGGS PRODUCTION IN THE bb$\\tau_{h}\\tau_{h}$ CHANNEL AT CMS

    CERN Document Server

    Dewanjee, Ram Krishna

    2017-01-01

    The discovery of the Standard Model (SM) scalar of mass 125 GeV was a clear experimental evidence of the Brout-Englert-Higgs mechanism. However the true nature of electroweak symmetry breaking can be probed by studying higher order terms in the Higgs potential. The tri-linear Higgs self coupling can be analyzed at the LHC by searching for non resonant di-Higgs production. Besides, a number of exotic theories (e.g. WED models) predict heavy resonances that can decay into two SM Higgs bosons. In this talk, I will be describing searches for both resonant and non-resonant di-Higgs production in which one of the Higgs bosons decays into two b-quarks and the other to two (hadronically decaying) tau leptons. Both the searches use full Run-1 luminosity (18.3 $fb ^{-1}$ ) at $\\sqrt{s}$ = 8 TeV collected by the CMS experiment in 2012.

  16. Gravitational effects on the Higgs field within the Solar System

    CERN Document Server

    Albareti, Franco D; Prada, Francisco

    2016-01-01

    The Higgs mechanism predicts, apart from the existence of a new scalar boson, the presence of a constant Higgs field that permeates all of space. The vacuum expectation value (VEV) of this field is affected by quantum corrections which are mainly generated by the self-interactions and couplings of the Higgs field to gauge bosons and heavy quarks. In this work we show that gravity can affect, in a non-trivial way, these quantum corrections through the finite parts of the one-loop contributions to the effective potential. In particular, we consider the corrections generated by the Standard Model Higgs self-interactions in slowly-varying weak gravitational backgrounds. The obtained results amount to the existence of non-negligible inhomogeneities in the Higgs VEV. Such inhomogeneities translate into spatial variations of the particle masses, and in particular of the proton-to-electron mass ratio. We find that these Higgs perturbations in our Solar System are controlled by the Eddington parameter, and are absent ...

  17. Enhancing the Higgs associated production with a top quark pair

    CERN Document Server

    Badziak, Marcin

    2016-01-01

    It is pointed out that in a wide class of models reminiscent of type-II Two-Higgs-Doublet Models (2HDM) the signal of the Higgs produced in association with a top-antitop quark pair ($tth$) and decaying into gauge bosons can be significantly larger than the Standard Model (SM) prediction without violating any experimental constraints. The crucial feature of these models is enhanced (suppressed) Higgs coupling to top (bottom) quarks and existence of light colored particles that give negative contribution to the effective Higgs coupling to gluons resulting in the gluon fusion rates in the gauge boson decay channels close to SM predictions. We demonstrate this mechanism in NMSSM with light stops and show that $tth$ signal in the $WW$ decay channel can be two times larger than the SM prediction, as suggested by the excesses observed by ATLAS and CMS, provided that the Higgs-singlet superpotential coupling $\\lambda\\gtrsim0.8$ and the MSSM-like Higgs boson masses are in the range of 160 to 300 GeV.

  18. Higgs Phenomenology in the Standard Model and Beyond

    CERN Document Server

    Field, Bryan Jonathan; Dawson, Sally

    2005-01-01

    The way in which the electroweak symmetry is broken in nature is currently unknown. The electroweak symmetry is theoretically broken in the Standard Model by the Higgs mechanism which generates masses for the particle content and introduces a single scalar to the particle spectrum, the Higgs boson. This particle has not yet been observed and the value of it mass is a free parameter in the Standard Model. The observation of one (or more) Higgs bosons would confirm our understanding of the Standard Model. In this thesis, we study the phenomenology of the Standard Model Higgs boson and compare its production observables to those of the Pseudoscalar Higgs boson and the lightest scalar Higgs boson of the Minimally Supersymmetric Standard Model. We study the production at both the Fermilab Tevatron and the future CERN Large Hadron Collider (LHC). In the first part of the thesis, we present the results of our calculations in the framework of perturbative QCD. In the second part, we present our resummed calculations.

  19. Different Higgs models and the number of Higgs particles

    Energy Technology Data Exchange (ETDEWEB)

    Marek-Crnjac, L. [University of Maribor, Faculty of Mechanical Engineering, Smetanova ulica 17, SI-2000 Maribor (Slovenia)] e-mail: fs.taj06@uni-mb.si

    2006-02-01

    In this short paper we discuss some interesting Higgs models. It is concluded that the most likely scheme for the Higgs particles consists of five physical Higgs particles. These are two charged H{sup +}, H{sup -} and three neutrals h {sup 0}, H{sup 0}, A{sup 0}. Further more the most probably total number of elementary particles for each model is calculated [El Naschie MS. Experimental and theoretical arguments for the number of the mass of the Higgs particles. Chaos, Solitons and Fractals 2005;23:1091-8; El Naschie MS. Determining the mass of the Higgs and the electroweak bosons. Chaos, Solitons and Fractals 2005;24:899-905; El Naschie MS. On 366 kissing spheres in 10 dimensions, 528 P-Brane states in 11 dimensions and the 60 elementary particles of the standard model. Chaos, Solitons and Fractals 2005;24:447-57].

  20. Detection of Charged Higgs Bosons in e+e-(γγ) → t(b-)φ-Production at the ILC

    Institute of Scientific and Technical Information of China (English)

    HAN Jin-Zhong; LI Bing-Zhong

    2013-01-01

    In the context of the left-right twin Higgs (LRTH) model,we have studied the charged Higgs bosons production processes e+e-(γγ) → t(b-)φ-at the International Linear Collider (ILC).It is found that the cross sections of these two processes could reach a few fb with reasonable parameter values.With the yearly integrated luminosity of L =500 fb-1 expected at the ILC,one could collect hundreds up to thousands of charged Higgs events via these two processes.Therefore,our researches in this paper can help us search for charged Higgs bosons,and furthermore,to test the LRTH model.

  1. Prevention of preterm delivery in twin pregnancy.

    Science.gov (United States)

    Rode, Line; Tabor, Ann

    2014-02-01

    The incidence of twin gestation has increased markedly over the past decades, mostly because of increased use of assisted reproductive technologies. Twin pregnancies are at increased risk of preterm delivery (i.e. birth before 37 weeks of gestation). Multiple gestations therefore account for 2-3% of all pregnancies but constitute at least 10% of cases of preterm delivery. Complications from preterm birth are not limited to the neonatal period, such as in retinopathy of prematurity, intraventricular haemorrhage, necrotising enterocolitis, respiratory disorder and sepsis; they can also constitute sequelae such as abnormal neurophysiological development in early childhood and underachievement in school. Several treatment modalities have been proposed in singleton high-risk pregnancies. The mechanism of initiating labour may, however, be different in singleton and twin gestations. Therefore, it is mandatory to evaluate the proposed treatments in randomised trials of multiple gestations. In this chapter, we describe the results of trials to prevent preterm delivery in twin pregnancies.

  2. Higgs Decay to Two Photons

    OpenAIRE

    Marciano, William J.; Zhang, Cen; Willenbrock, Scott

    2011-01-01

    The amplitude for Higgs decay to two photons is calculated in renormalizable and unitary gauges using dimensional regularization at intermediate steps. The result is finite, gauge independent, and in agreement with previously published results. The large Higgs mass limit is examined using the Goldstone-boson equivalence theorem as a check on the use of dimensional regularization and to explain the absence of decoupling.

  3. Higgs Couplings after the Discovery

    OpenAIRE

    Plehn, Tilman; Rauch, Michael

    2012-01-01

    Following the ATLAS and CMS analyses presented around ICHEP 2012 we determine the individual Higgs couplings. The new data allow us to specifically test the effective coupling to photons. We find no significant deviation from the Standard Model in any of the Higgs couplings.

  4. Origins of inert Higgs doublets

    Directory of Open Access Journals (Sweden)

    Thomas W. Kephart

    2016-05-01

    Full Text Available We consider beyond the standard model embedding of inert Higgs doublet fields. We argue that inert Higgs doublets can arise naturally in grand unified theories where the necessary associated Z2 symmetry can occur automatically. Several examples are discussed.

  5. Higgs particle searches at LEP

    Energy Technology Data Exchange (ETDEWEB)

    Martin, J.P.

    1996-12-31

    Results on searches for the Higgs particle performed by the four LEP experiments are received in the framework of the Standard Model, Two Doublet Model, and Minimal Supersymmetric Model. The combined mass lower limit for the standard Higgs boson is 66 GeV/c{sup 2} at 95 % CL for a statistics of 14.6 Million hadronic Z decays. (authors). 24 refs.

  6. Grand Unification, Higgs Bosons, and Baryogenesis

    Science.gov (United States)

    Sher, Marc

    2004-03-01

    My task in these lectures is to discuss "Grand Unification and Higgs Bosons". Given that each of these subjects has had books written about them, this is a daunting task. My goal will be to introduce the basics of each topic, and provide references for those who wish to explore the topics further. I'll begin with a general motivation for grand unification, followed with an elementary review of SU(N) group algebra. The seminal SU(5) model will be discussed, followed by the supersymmetric version. On the second day, we'll look at other grand unified theories, and then look at the various methods of supersymmetry breaking in the context of grand unification. The third day, we'll turn to the Higgs mechanism, the effective potential, and mass bounds in the Standard Model and the MSSM. Finally, we'll look at baryogenesis, first in grand unified theories and then in the electroweak model.

  7. Effect of Twinning and Detwinning on Mechanical Proprieties of AZ3 1 Magnesium Alloy%孪晶和解孪晶对AZ31镁合金力学性能的影响

    Institute of Scientific and Technical Information of China (English)

    陈强强; 宋广胜; 徐勇; 张士宏

    2015-01-01

    以商用热轧AZ31镁合金板材为研究对象,室温下通过沿轧制方向(Rolling Direction)、轧板法向(Normal Direc-tion)以及RD-ND 3种压缩变形试验,研究了AZ3 1镁合金在压缩变形过程中的孪晶、解孪晶现象及其对力学性能的影响。结果表明,沿RD压缩后晶粒取向发生变化,变形后的组织中出现了明显的平行带状和透镜状孪晶带。沿 ND 压缩时,{1012}拉伸孪晶没有发生,且无论压缩变形量大小,金相组织中均无孪晶出现,塑性变形主要依靠滑移产生。解孪晶时屈服应力下降明显,且完全解孪晶所需应变比孪晶小。%Twinning,detwinning and their effects on mechanical properties of commercial hot-rolled AZ31 Mg alloy were investigated under three compression along rolling direction (RD ),normal direction (ND)and RD-ND at room temperature,respectively.The results show that the grain orientation is changed and there exists many distinctly parallel and lenticular twinning bands in microstructure after compression along RD.While compression along ND,no matter how much the specimens was com-pressed,the absence of {1012}extension twinning and any twinning microstructure can be observed, which reveals that plastic deformation is mainly dependent on slips under compression along ND.The yield stress is decreased significantly during detwinning process,and the strain needed by complete de-twinning is smaller than that of twinning.

  8. The minimal curvaton-Higgs model

    Energy Technology Data Exchange (ETDEWEB)

    Enqvist, Kari [Helsinki Univ. and Helsinki Institute of Physics (Finland). Physics Dept.; Lerner, Rose N. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Helsinki Univ. and Helsinki Institute of Physics (Finland). Physics Dept.; Takahashi, Tomo [Saga Univ. (Japan). Dept. of Physics

    2013-10-15

    We present the first full study of the minimal curvaton-Higgs (MCH) model, which is a minimal interpretation of the curvaton scenario with one real scalar coupled to the standard model Higgs boson. The standard model coupling allows the dynamics of the model to be determined in detail, including effects from the thermal background and from radiative corrections to the potential. The relevant mechanisms for curvaton decay are incomplete non-perturbative decay (delayed by thermal blocking), followed by decay via a dimension-5 non-renormalisable operator. To avoid spoiling the predictions of big bang nucleosynthesis, we find the ''bare'' curvaton mass to be m{sub {sigma}}{>=}8 x 10{sup 4} GeV. To match observational data from Planck there is an upper limit on the curvaton-higgs coupling g, between 10{sup -3} and 10{sup -2}, depending on the mass. This is due to interactions with the thermal background. We find that typically non-Gaussianities are small but that if f{sub NL} is observed in the near future then m{sub {sigma}}mechanism is specified.

  9. Twinning Behavior of a Basal Textured Commercially Pure Titanium Alloy TA2 at Ambient and Cryogenic Temperatures

    Institute of Scientific and Technical Information of China (English)

    Jin-ru LUO; Xiao SONG; Lin-zhong ZHUANG; Ji-shan ZHANG

    2016-01-01

    Twinning greatly affects the microstructure and mechanical performance of titanium alloys.The twinning behavior of a basal textured commercially pure titanium TA2 plates rolled to 4% reduction at the ambient and cryo-genic temperatures has been investigated.Microstructures of the rolled samples were investigated by optical micro-scope (OM)and the twinning analysis was carried out based on orientation data collected by electron back-scatter diffraction (EBSD).{1 122}contraction twins,{1 124}contraction twins and {1012}extension twins have been ob-served.Twinning mode activity varied with rolling temperature.Twinning is considered as the dominant deformation mechanism during rolling at both temperatures for the strain condition.Larger proportion of grains activates twin-ning during cryorolling,and greater number and more diverse types of twins are observed;manifestly related to the suppression of dislocation slips at the cryogenic temperature.{1 122 }contraction twins are the dominate twin type within samples rolled at both temperatures.Several {1 124}contraction twins are observed in the cryorolled sample while there are only a few in the sample rolled at room temperature.A few tiny {1012}twins have been identified in both samples.{1 124}contraction twins are preferentially activated at cryogenic deformation temperature and the{1012}extension twins may result in local strain accommodation.

  10. A Minimally Symmetric Higgs Boson

    CERN Document Server

    Low, Ian

    2014-01-01

    Models addressing the naturalness of a light Higgs boson typically employ symmetries, either bosonic or fermionic, to stabilize the Higgs mass. We consider a setup with the minimal amount of symmetries: four shift symmetries acting on the four components of the Higgs doublet, subject to the constraints of linearly realized SU(2)xU(1) electroweak symmetry. Up to terms that explicitly violate the shift symmetries, the effective lagrangian can be derived, irrespective of the spontaneously broken group G in the ultraviolet, and is universal in all models where the Higgs arises as a pseudo-Nambu-Goldstone boson (PNGB). Very high energy scatterings of vector bosons could provide smoking gun signals of a minimally symmetric Higgs boson.

  11. Twin anemia polycythemia sequence

    NARCIS (Netherlands)

    Slaghekke, Femke

    2014-01-01

    In this thesis we describe that Twin Anemia Polycythemia Sequence (TAPS) is a form of chronic feto-fetal transfusion in monochorionic (identical) twins based on a small amount of blood transfusion through very small anastomoses. For the antenatal diagnosis of TAPS, Middle Cerebral Artery – Peak Syst

  12. The Danish Twin Registry

    DEFF Research Database (Denmark)

    Skytthe, Axel; Ohm Kyvik, Kirsten; Vilstrup Holm, Niels

    2011-01-01

    Introduction: The Danish Twin Registry is a unique source for studies of genetic, familial and environmental factors on life events, health conditions and diseases. Content: More than 85,000 twin pairs born 1870-2008 in Denmark. Validity and coverage: Four main ascertainment methods have been emp...

  13. Twin anemia polycythemia sequence

    NARCIS (Netherlands)

    Slaghekke, Femke

    2014-01-01

    In this thesis we describe that Twin Anemia Polycythemia Sequence (TAPS) is a form of chronic feto-fetal transfusion in monochorionic (identical) twins based on a small amount of blood transfusion through very small anastomoses. For the antenatal diagnosis of TAPS, Middle Cerebral Artery – Peak

  14. Perturbative Higgs CP violation, unitarity and phenomenology

    CERN Document Server

    Englert, Christoph; Sakurai, Kazuki; Spannowsky, Michael

    2016-01-01

    Perturbative probability conservation provides a strong constraint on the presence of new interactions of the Higgs boson. In this work we consider CP violating Higgs interactions in conjunction with unitarity constraints in the gauge-Higgs and fermion-Higgs sectors. Injecting signal strength measurements of the recently discovered Higgs boson allows us to make concrete and correlated predictions of how CP-violation in the Higgs sector can be directly constrained through collider searches for either characteristic new states or tell-tale enhancements in multi-Higgs processes.

  15. Learning what the Higgs is mixed with

    CERN Document Server

    Killick, Ryan; Logan, Heather E

    2013-01-01

    The Standard Model Higgs boson may be mixed with another scalar that does not couple to fermions. The electroweak quantum numbers of such an additional scalar can be determined by measuring the quartic Higgs-Higgs-vector-vector couplings, which contribute---along with the coveted triple Higgs coupling---to double Higgs production in $e^+e^-$ collisions. We show that simultaneous sensitivity to the quartic Higgs-Higgs-vector-vector coupling and the triple Higgs coupling can be obtained using measurements of the double Higgs production cross section at two different $e^+e^-$ center-of-mass energies. Kinematic distributions of the two Higgs bosons in the final state could provide additional discriminating power.

  16. Higgs potential and hidden light Higgs scenario in two Higgs doublet models

    CERN Document Server

    Chang, Sanghyeon; Lee, Jong-Phil; Song, Jeonghyeon

    2015-01-01

    In two Higgs doublet models (2HDM), there exists an interesting possibility, the hidden light Higgs scenario, that the discovered SM-like Higgs boson is the heavier CP-even Higgs boson $H^0$ and the lighter CP-even $h^0$ has not been observed yet in any experiment. We study the current status of this scenario in Types I, II, X, and Y, through the scans of the 2HDM parameters with all relevant theoretical and experimental constraints. We employ not only the most up-to-date Higgs signal strength measurements with the feed-down effects, but also all the available LHC exclusion limits from heavy Higgs searches. Adjusting the heavier $H^0$ to the 125 GeV state while hiding the lighter $h^0$ from the LEP Higgs search prohibits the extreme decoupling limit: there exist upper bounds on the masses of the pseudoscalar $A^0$ and the charged Higgs $H^\\pm$ below about 550 GeV. In addition, the $Z_2$ symmetry, which was introduced to avoid the tree-level FCNC, is shown to be a good approximate symmetry since the soft $Z_2$...

  17. Mass Generation, the Cosmological Constant Problem, Conformal Symmetry, and the Higgs Boson

    CERN Document Server

    Mannheim, Philip D

    2016-01-01

    In 2013 the Nobel Prize in Physics was awarded to Francois Englert and Peter Higgs for their work in 1964 along with the late Robert Brout on the mass generation mechanism (the Higgs mechanism) in local gauge theories. This mechanism requires the existence of a massive scalar particle, the Higgs boson, and in 2012 the Higgs boson was finally discovered at the Large Hadron Collider after being sought for almost half a century. In this article we review the work that led to the discovery of the Higgs boson and discuss its implications. We approach the topic from the perspective of a dynamically generated Higgs boson that is a fermion-antifermion bound state rather than an elementary field that appears in an input Lagrangian. In particular, we emphasize the connection with the Barden-Cooper-Schrieffer theory of superconductivity. We identify the double-well Higgs potential not as a fundamental potential but as a mean-field effective Lagrangian with a dynamical Higgs boson being generated through a residual inter...

  18. Handbook of LHC Higgs Cross Sections: 3. Higgs Properties

    Energy Technology Data Exchange (ETDEWEB)

    Heinemeyer, S; et al.

    2013-01-01

    This Report summarizes the results of the activities in 2012 and the first half of 2013 of the LHC Higgs Cross Section Working Group. The main goal of the working group was to present the state of the art of Higgs Physics at the LHC, integrating all new results that have appeared in the last few years. This report follows the first working group report Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002) and the second working group report Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002). After the discovery of a Higgs boson at the LHC in mid-2012 this report focuses on refined prediction of Standard Model (SM) Higgs phenomenology around the experimentally observed value of 125-126 GeV, refined predictions for heavy SM-like Higgs bosons as well as predictions in the Minimal Supersymmetric Standard Model and first steps to go beyond these models. The other main focus is on the extraction of the characteristics and properties of the newly discovered particle such as couplings to SM particles, spin and CP-quantum numbers etc.

  19. The mechanism of twinning in zincblende structure crystals: New insights on polarity effects from a study of magnetic liquid encapsulated Czochralski grown InP single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Dudley, M.; Raghothamachar, B.; Guo, Y. [State Univ. of New York, Stony Brook, NY (United States). Dept. of Materials Science and Engineering] [and others

    1998-12-31

    Synchrotron White Beam X-ray Topography (SWBXT) and synchrotron X-ray anomalous scattering have been employed to determine the polarity of {l_brace}111{r_brace} edge facets, anchored to the three phase boundary (TPB) on which twinning is observed to nucleate in Magnetic Liquid Encapsulated Czochralski (MLEC) grown sulfur doped, <001> InP single crystals. Analysis of the results indicates that both the formation of edge facets and the nucleation of twins occur preferentially on {l_brace}{bar 1}{bar 1}{bar 1}{r_brace}{sub P} faces. Of the four possible sets of edge facets, belonging to the {l_brace}{bar 1}{bar 1}{bar 1}{r_brace}{sub P} form, which are oriented so as to be thermodynamically favored to be anchored to the TPB, two can give rise to a {l_brace}115{r_brace} to {l_brace}{bar 1}{bar 1}{bar 1}{r_brace}{sub P} external should facet conversion upon twinning, while the other two can give rise to a {l_brace}114{r_brace} to {l_brace}110{r_brace} conversion. For these cases, twinning is only observed when the {l_brace}{bar 1}{bar 1}{bar 1}{r_brace}{sub P} edge facets are anchored to the TPB in a region where the shoulder angle is close to 74.21{degree} or 70.53{degree}, facilitating the production of the {l_brace}115{r_brace} and {l_brace}114{r_brace} external should facets, respectively, prior to twinning. These observations are discussed in light of calculated surface energies of the various internal and external facets.

  20. Induced gravity with Higgs potential. Elementary interactions and quantum processes

    Energy Technology Data Exchange (ETDEWEB)

    Bezares Roder, Nils Manuel

    2010-07-01

    This work is intended to first serve as introduction in fundamental subjects of physics in order to be then able to review the mechanism of symmetry breakdown and its essential character in physics. It introduces the concept of scalar-tensor theories of gravity based on Bergmann-Wagoner models with a Higgs potential. The main physical context aimed is the problem of Dark Matter and Dark Energy. On the one hand, there is gravitation. Within this context, we have Dark Matter as an especially relevant concept. This work entails the following main contributions: - General features of Einstein's theory are introduced together with generalities of the different elementary interactions of physics from which the concepts of dark sectors and Higgs Mechanism are derived. - The concept of symmetry breaking and especially the Higgs Mechanism of mass generation are discussed in their relevance for the most different subjects of physics, especially in relation to the Standard Model of elementary particle physics with elementary Higgs fields. - Scalar-Tensor Theories are introduced in order to build in them the process of Higgs Mechanism. This is then fulfilled with a theory of induced gravity with a Higgs potential which seems renormalizable according to deWitt's power counting criterion, and with mass-generating Higgs fields which only couple gravitationally as well as with Higgs fields which act analogously to cosmon fields. - Further, the energy density of the gravitational field is derived for the specific model of induced gravity from an analogy to electrodynamics. It is shown that a nonvanishing value of pressure related to the scalar field is necessary in order to reproduce standard linear solar-relativistic dynamics. Within astrophysical considerations for flat rotation curves of galaxies, a possible dark-matter behavior is concluded within spherical symmetry. The scalar field and the dark-matter profile of total energy density are derived. An analogous

  1. Acoustic Emission of Deformation Twinning in Magnesium

    Directory of Open Access Journals (Sweden)

    Chengyang Mo

    2016-08-01

    Full Text Available The Acoustic Emission of deformation twinning in Magnesium is investigated in this article. Single crystal testing with combined full field deformation measurements, as well as polycrystalline testing inside the scanning electron microscope with simultaneous monitoring of texture evolution and twin nucleation were compared to testing at the laboratory scale with respect to recordings of Acoustic Emission activity. Single crystal testing revealed the formation of layered twin boundaries in areas of strain localization which was accompanied by distinct changes in the acoustic data. Testing inside the microscope directly showed twin nucleation, proliferation and growth as well as associated crystallographic reorientations. A post processing approach of the Acoustic Emission activity revealed the existence of a class of signals that appears in a strain range in which twinning is profuse, as validated by the in situ and ex situ microscopy observations. Features extracted from such activity were cross-correlated both with the available mechanical and microscopy data, as well as with the Acoustic Emission activity recorded at the laboratory scale for similarly prepared specimens. The overall approach demonstrates that the method of Acoustic Emission could provide real time volumetric information related to the activation of deformation twinning in Magnesium alloys, in spite of the complexity of the propagation phenomena, the possible activation of several deformation modes and the challenges posed by the sensing approach itself when applied in this type of materials evaluation approach.

  2. Periodic segregation of solute atoms in fully coherent twin boundaries.

    Science.gov (United States)

    Nie, J F; Zhu, Y M; Liu, J Z; Fang, X Y

    2013-05-24

    The formability and mechanical properties of many engineering alloys are intimately related to the formation and growth of twins. Understanding the structure and chemistry of twin boundaries at the atomic scale is crucial if we are to properly tailor twins to achieve a new range of desired properties. We report an unusual phenomenon in magnesium alloys that until now was thought unlikely: the equilibrium segregation of solute atoms into patterns within fully coherent terraces of deformation twin boundaries. This ordered segregation provides a pinning effect for twin boundaries, leading to a concomitant but unusual situation in which annealing strengthens rather than weakens these alloys. The findings point to a platform for engineering nano-twinned structures through solute atoms. This may lead to new alloy compositions and thermomechanical processes.

  3. Hydride formation on deformation twin in zirconium alloy

    Science.gov (United States)

    Kim, Ju-Seong; Kim, Sung-Dae; Yoon, Jonghun

    2016-12-01

    Hydrides deteriorate the mechanical properties of zirconium (Zr) alloys used in nuclear reactors. Intergranular hydrides that form along grain boundaries have been extensively studied due to their detrimental effects on cracking. However, it has been little concerns on formation of Zr hydrides correlated with deformation twins which is distinctive heterogeneous nucleation site in hexagonal close-packed metals. In this paper, the heterogeneous precipitation of Zr hydrides at the twin boundaries was visualized using transmission electron microscopy. It demonstrates that intragranular hydrides in the twinned region precipitates on the rotated habit plane by the twinning and intergranular hydrides precipitate along the coherent low energy twin boundaries independent of the conventional habit planes. Interestingly, dislocations around the twin boundaries play a substantial role in the nucleation of Zr hydrides by reducing the misfit strain energy.

  4. Twinning interactions induced amorphisation in ultrafine silicon grains

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Y. [School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Zhang, L.C., E-mail: liangchi.zhang@unsw.edu.au [School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, NSW 2052 (Australia); Zhang, Y. [School of Mechatronics Engineering, Harbin Institute of Technology (China)

    2016-03-21

    Detailed transmission electron microscopy analysis on a severely deformed Al-Si composite material has revealed that partial dislocation slips and deformation twinning are the major plastic deformation carriers in ultrafine silicon grains. This resembles the deformation twinning activities and mechanisms observed in nano-crystalline face-centred-cubic metallic materials. While deformation twinning and amorphisation in Si were thought unlikely to co-exist, it is observed for the first time that excessive twinning and partial dislocation interactions can lead to localised solid state amorphisation inside ultrafine silicon grains.

  5. Is cosmological constant needed in Higgs inflation?

    Directory of Open Access Journals (Sweden)

    Chao-Jun Feng

    2014-11-01

    Full Text Available The detection of B-mode shows a very powerful constraint to theoretical inflation models through the measurement of the tensor-to-scalar ratio r. Higgs boson is the most likely candidate of the inflaton field. But usually, Higgs inflation models predict a small value of r, which is not quite consistent with the recent results from BICEP2. In this paper, we explored whether a cosmological constant energy component is needed to improve the situation. And we found the answer is yes. For the so-called Higgs chaotic inflation model with a quadratic potential, it predicts r≈0.2, ns≈0.96 with e-folds number N≈56, which is large enough to overcome the problems such as the horizon problem in the Big Bang cosmology. The required energy scale of the cosmological constant is roughly Λ∼(1014 GeV2, which means a mechanism is still needed to solve the fine-tuning problem in the later time evolution of the universe, e.g. by introducing some dark energy component.

  6. Toward realistic gauge-Higgs grand unification

    Science.gov (United States)

    Furui, Atsushi; Hosotani, Yutaka; Yamatsu, Naoki

    2016-09-01

    The SO(11) gauge-Higgs grand unification in the Randall-Sundrum warped space is presented. The 4D Higgs field is identified as the zero mode of the fifth-dimensional component of the gauge potentials, or as the fluctuation mode of the Aharonov-Bohm phase θ along the fifth dimension. Fermions are introduced in the bulk in the spinor and vector representations of SO(11). SO(11) is broken to SO(4)×SO(6) by the orbifold boundary conditions, which is broken to SU2×U1×SU3 by a brane scalar. Evaluating the effective potential V(θ), we show that the electroweak symmetry is dynamically broken to U1. The quark-lepton masses are generated by the Hosotani mechanism and brane interactions, with which the observed mass spectrum is reproduced. Proton decay is forbidden thanks to the new fermion number conservation. It is pointed out that there appear light exotic fermions. The Higgs boson mass is determined with the quark-lepton masses given; however, it turns out to be smaller than the observed value.

  7. Toward Realistic Gauge-Higgs Grand Unification

    CERN Document Server

    Furui, Atsushi; Yamatsu, Naoki

    2016-01-01

    The $SO(11)$ gauge-Higgs grand unification in the Randall-Sundrum warped space is presented. The 4D Higgs field is identified as the zero mode of the fifth dimensional component of the gauge potentials, or as the fluctuation mode of the Aharonov-Bohm phase $\\theta_H$ along the fifth dimension. Fermions are introduced in the bulk in the spinor and vector representations of $SO(11)$. $SO(11)$ is broken to $SO(4) \\times SO(6)$ by the orbifold boundary conditions, which is broken to $SU(2)_L \\times U(1)_Y \\times SU(3)_C$ by a brane scalar. Evaluating the effective potential $V_{\\rm eff} (\\theta_H)$, we show that the electroweak symmetry is dynamically broken to $U(1)_{\\rm EM}$. The quark-lepton masses are generated by the Hosotani mechanism and brane interactions, with which the observed mass spectrum is reproduced. The proton decay is forbidden thanks to the new fermion number conservation. It is pointed out that there appear light exotic fermions. The Higgs boson mass is determined with the quark-lepton masses ...

  8. Higgs mass from neutrino-messenger mixing

    CERN Document Server

    Byakti, Pritibhajan; Mummidi, V Suryanarayana; Vempati, Sudhir K

    2016-01-01

    The discovery of the Higgs particle at 125 GeV has put strong constraints on minimal messenger models of gauge mediation, pushing the stop masses into the multi-TeV regime. Extensions of these models with matter-messenger mixing terms have been proposed to generate a large trilinear parameter, $A_t$, relaxing these constraints. The detailed survey of these models \\cite{Byakti:2013ti,Evans:2013kxa} so far considered messenger mixings with only MSSM superfields. In the present work, we extend the survey to MSSM with inverse-seesaw mechanism. The neutrino-sneutrino corrections to the Higgs mass in the inverse seesaw model are not significant in the minimal gauge mediation model, unless one considers messenger-matter interaction terms. We classify all possible models with messenger-matter interactions and perform thorough numerical analysis to find out the promising models. We found that out of the 17 possible models 15 of them can lead to Higgs mass within the observed value without raising the sfermion masses s...

  9. Higgs Boson Searches @ LHC Dedicated to Engin

    CERN Document Server

    Kourkoumelis, C

    2008-01-01

    The Higgs boson is the only particle missing to complete the successful description of the elementary ingredients of our world. Its existence and its associated mechanism are predicted by the Standard Model (SM) in order to help give masses to the otherwise massless elementary particles. As of yet, it escapes experimental detection despite the enormous worldwide efforts. The new Large Hadron Collider (LHC) at CERN will provide enough collision energy for its formation, if it exists. The large experiments already installed are equipped with excellent detector capabilities in order to confirm (or reject) its existence. The late Professor Engin Arik and her group have strongly contributed to decade-long efforts of the ATLAS detector realization. The mass of the Higgs boson is not predicted by the SM, but in any case, it is above the existing experimental lower bound of 114.4 GeV/c2 at 95%CL. The Higgs particle decays in a number of different ways. Depending on its mass, different decay modes and decay particle i...

  10. Perinatal risk factors and neonatal complications in discordant twins admitted to the neonatal intensive care unit

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-rui; LIU Jie; ZENG Chao-mei

    2013-01-01

    Background Many studies have shown a relationship between birth weight discordance and adverse perinatal outcomes.This study aimed to investigate the perinatal risk factors and neonatal complications of discordant twins who are admitted to the neonatal intensive care unit.Methods A total of 87 sets of twins were enrolled in this retrospective study,of which 22 sets were discordant twins and 65 sets were concordant twins.Binary Logistic regression analysis was used to identify the risk factors associated with the occurrence of discordant twins.The common neonatal complications of discordant twins were also investigated.Results Multivariate analysis showed that the use of assisted reproductive techniques,pregnancy-induced hypertension,and unequal placental sharing were risk factors for the occurrence of discordant twins.The incidence of small for gestational age infants and very low birth weight infants of discordant twins was significantly higher,while the birth weight of discordant twins was significantly lower than those of concordant twins.The duration of hospitalization of discordant twins was longer than that of concordant twins.The incidence of several neonatal complications,such as neonatal respiratory distress syndrome and intracranial hemorrhage,was higher in discordant twins than that in concordant twins.The percentage of those requiring pulmonary surfactant and mechanical ventilation was significantly higher in discordant twins than that in concordant twins.Conclusions Use of assisted reproductive techniques,pregnancy-induced hypertension,and unequal placental sharing are perinatal risk factors of discordant twins who are admitted to the neonatal intensive care unit.These infants are also much more likely to suffer from various neonatal complications,especially respiratory and central nervous system diseases.It is important to prevent the occurrence of discordant twins by decreasing these risk factors and timely treatment should be given to discordant

  11. Electroweak Baryogenesis and Higgs Signatures

    CERN Document Server

    Cohen, Timothy; Pierce, Aaron

    2012-01-01

    We explore the connection between the strength of the electroweak phase transition and the properties of the Higgs boson. Our interest is in regions of parameter space that can realize electroweak baryogenesis. We do so in a simplified framework in which a single Higgs field couples to new scalar fields charged under SU(3)_c by way of the Higgs portal. Such new scalars can make the electroweak phase transition more strongly first-order, while contributing to the effective Higgs boson couplings to gluons and photons through loop effects. For Higgs boson masses in the range 115 GeV < m_h < 130 GeV, whenever the phase transition becomes strong enough for successful electroweak baryogenesis, we find that Higgs boson properties are modified by an amount observable by the LHC. We also discuss the baryogenesis window of the minimal supersymmetric standard model (MSSM), which appears to be under tension. Furthermore, we argue that the discovery of a Higgs boson with standard model-like couplings to gluons and p...

  12. Electroweak Baryogenesis and Higgs Properties

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, Timothy; /SLAC; Morrissey, David E.; /TRIUMF; Pierce, Aaron; /Michigan U., MCTP

    2012-03-13

    We explore the connection between the strength of the electroweak phase transition and the properties of the Higgs boson. Our interest is in regions of parameter space that can realize electroweak baryogenesis. We do so in a simplified framework in which a single Higgs field couples to new scalar fields charged under SU(3){sub c} by way of the Higgs portal. Such new scalars can make the electroweak phase transition more strongly first-order, while contributing to the effective Higgs boson couplings to gluons and photons through loop effects. For Higgs boson masses in the range 115 {approx}< m{sub h} {approx}< 130 GeV, whenever the phase transition becomes strong enough for successful electroweak baryogenesis, we find that Higgs boson properties are modified by an amount observable by the LHC. We also discuss the baryogenesis window of the minimal supersymmetric standard model (MSSM), which appears to be under tension. Furthermore, we argue that the discovery of a Higgs boson with standard model-like couplings to gluons and photons will rule out electroweak baryogenesis in the MSSM.

  13. Neonatal status of twins

    Directory of Open Access Journals (Sweden)

    Božinović Dragica

    2012-01-01

    Full Text Available Multiple pregnancy is a pregnancy where more than one fetus develops simultaneously in the womb, as a result of the ovulation and fertilization of more than one egg. It is relatively rare in humans and represents the rest of the phylogenetic stages. The most common are twins and they indicate the development of two fetuses in the womb. The frequency of twin pregnancies is about 1%. Multiple pregnancies belong to a group of high-risk pregnancies because of the many complications that occur during the pregnancy: higher number of premature deliveries, bleeding, early neonatal complications and higher perinatal morbidity and mortality. Such pregnancies and infants require greater supervision and monitoring. The aim of this study was to determine the percentage of baby twins born at the maternity ward of the General Hospital in Prokuplje and their morbidity and mortality. Data on the total number of deliveries, number of twins, parity and maternal age, gestational age, body weight of twins, method of delivery, Apgar score and perinatal mortality were collected and statistically analyzed by means of retrospective analysis of operative birth and neonatal protocol for 6 years (2005 of 2010. Out of 4527 mothers who gave birth 43 were pairs of twins, or 0.95% of women gave birth to twins. These babies are more likely born by Caesarean section, but delivered with slightly lower birth weight.

  14. Tevatron Higgs results

    CERN Document Server

    Tuchming, Boris

    2013-01-01

    We present the combination of searches for the Standard Model Higgs boson, using up to 10 \\invfb\\ of $p\\bar p$ collisions at $\\sqrts$=1.96 TeV collected with the CDF and \\dzero\\ detectors at the Fermilab Tevatron collider. The major contributing channels are optimized for the main production modes, the associated production with a vector boson ($VH$, with $V=W,Z$), the vector boson fusion, and the gluon-gluon fusion, and the different decay modes $H\\to b\\bar b$, $H\\to\\tau^+\\tau^-$, $H\\to W^+W^-$, and $H\\to \\gamma\\gamma$. A significant excess of events is observed in the mass range $115Higgs boson of mass 125 \\gev. We also present prospects for spin/parity tests to be performed in the $VH \\to V b\\bar b$ channels.

  15. Trilogy of LHC Higgs Cross Section Working Group

    CERN Document Server

    Tanaka, R; The ATLAS collaboration

    2013-01-01

    Slide shown at Aspen 2013 - Higgs Quo Vadis, March 10-15, 2013, Aspen, CO, USA. The activity of LHC Higgs Cross Section Woking Group was reported putting emphasis on current theoretical issues in Higgs physics towards precision Higgs measurements.

  16. Observable Heavy Higgs Dark Matter

    CERN Document Server

    Keus, Venus; Moretti, Stefano; Sokolowska, Dorota

    2015-01-01

    Dark Matter (DM), arising from an Inert Higgs Doublet, may either be light, below the $W$ mass, or heavy, above about 525 GeV. While the light region may soon be excluded, the heavy region is known to be very difficult to probe with either Direct Detection (DD) experiments or the Large Hadron Collider (LHC). We show that adding a second Inert Higgs Doublet helps to make the heavy DM region accessible to both DD and the LHC, by either increasing its couplings to the observed Higgs boson, or lowering its mass to $360 \\gev \\lesssim m_{DM}$, or both.

  17. Observable heavy Higgs dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Keus, Venus [Department of Physics and Helsinki Institute of Physics,Gustaf Hallstromin katu 2, FIN-00014 University of Helsinki (Finland); School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); King, Stephen F. [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); Moretti, Stefano [School of Physics and Astronomy, University of Southampton,Southampton, SO17 1BJ (United Kingdom); Particle Physics Department, Rutherford Appleton Laboratory,Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Sokolowska, Dorota [University of Warsaw, Faculty of Physics, Pasteura 5,02-093 Warsaw (Poland)

    2015-11-04

    Dark Matter (DM), arising from an Inert Higgs Doublet, may either be light, below the W mass, or heavy, above about 525 GeV. While the light region may soon be excluded, the heavy region is known to be very difficult to probe with either Direct Detection (DD) experiments or the Large Hadron Collider (LHC). We show that adding a second Inert Higgs Doublet helps to make the heavy DM region accessible to both DD and the LHC, by either increasing its couplings to the observed Higgs boson, or lowering its mass to 360 GeV≲m{sub DM}, or both.

  18. Twin-twin Transfusion Syndrome with a Single Ectopic Kidney in a Twin Donor. Case Presentation

    Directory of Open Access Journals (Sweden)

    Gerardo Rogelio Robaina Castellanos

    2016-10-01

    Full Text Available Twin-twin Transfusion Syndrome presents more frequently in diamniotic monochromic twins. In advanced stages and without prenatal intervention, is associated to high rates of peri natal mortality and neurological sequel in the survivors. It is presented a case of a pair of twins with severe depression at birth in which it was diagnosed a Twin-twin Transfusion Syndrome, later confirmed with the presence of anemia in the donor twin and polycythemia in the receptor twin. Both twins had an unfavourable evolution with an early neonatal death. Necropsy findings were comparable with secondary damage to the syndrome, with the particularity that both had evidences of pulmonary infection and a renal malformation in the donor twin which is not included in the proper malformations of this syndrome. The objective of this work is to point out the essential elements for the diagnosis and antenatal treatment for this disease through the peculiarities of the presented case.

  19. Fullerton Virtual Twin Study.

    Science.gov (United States)

    Segal, Nancy L

    2006-12-01

    Virtual twins (VTs; same-age unrelated siblings reared together from early infancy) have been studied at California State University (CSU), Fullerton since 1991. The current sample includes over 130 pairs. Past and current research have research have focused on siblings' similarities and differences in general intelligence and body size. Future research in these areas will continue as new pairs continue to be identified. These studies will be supplemented by analyses of personality, social relations and adjustment using monozygotic (MZ) twins, dizygotic (DZ) twins, full siblings and friends, as well as new VTs, who have participated in Twins, Adoptees, Peers and Siblings (TAPS), a collaborative project conducted between CSU Fullerton and the University of San Francisco, from 2002 to 2006.

  20. CERN NEWS : HIGGS UPDATE 2011

    CERN Multimedia

    CERN video productions

    2011-01-01

    In a seminar held at CERN today, the ATLAS and CMS experiments presented the status of their searches for the Standard Model Higgs boson. Their results are based on the analysis of considerably more data than those presented at the summer conferences, sufficient to make significant progress in the search for the Higgs boson, but not enough to make any conclusive statement on the existence or non-existence of the elusive Higgs. The main conclusion is that the Standard Model Higgs boson, if it exists, is most likely to have a mass constrained to the range 116-130 GeV by the ATLAS experiment, and 115-127 GeV by CMS. Tantalising hints have been seen by both experiments in this mass region, but these are not yet strong enough to claim a discovery.

  1. Physics of Higgs Boson Family

    Science.gov (United States)

    Chang, Ngee-Pong

    In the Standard Model, there is the single Higgs field, ϕ, which gives rise to constituent quark and lepton masses. The Yukawa coupling is a highly complex set of 3×3 matrices, resulting in many textures of quark and lepton masses. In this talk, I present a model which transfers the complexity of the Yukawa coupling matrices to a family of Higgs fields, so that the Yukawa coupling itself becomes a simple interaction. In the context of this Enriched Standard Model, we introduce a new r-symmetry in the extended SU(2)L × U(1)Y × U(1)R model and show how the 125 GeV and 750 GeV resonances may be identified with H and H', the key members of the Higgs family, with H being in every way identifed with the SM Higgs. There are interesting consequences of their 2γ decay widths.

  2. Composite Taus and Higgs Decays

    CERN Document Server

    Carmona, Adrian

    2013-01-01

    In this talk, we describe the effects of extended fermion sectors, respecting custodial symmetry, on Higgs production and decay. The resulting protection for the Z->b_L b_L and Z->\\tau_R \\tau_R decays allows for potentially interesting signals in Higgs physics, while maintaining the good agreement of the Standard Model with precision tests. The setups can be motivated as the low energy effective theories of the composite Higgs models MCHM_5 and MCHM_10, where the spectra can be identified with the light custodians present in these theories. We will show that these describe the relevant physics in the fermion sectors in a simplified and transparent way. In contrast to previous studies of composite models, the impact of a realistic lepton sector on the Higgs decays is taken into account.

  3. Physics of Higgs Boson Family

    CERN Document Server

    Chang, Ngee-Pong

    2016-01-01

    In the Standard Model, there is the single Higgs field, $\\phi$, which gives rise to constituent quark and lepton masses. The Yukawa coupling is a highly complex set of $3 \\times 3$ matrices, resulting in many textures of quark and lepton masses. In this talk, I present a model which transfers the complexity of the Yukawa coupling matrices to a family of Higgs fields, so that the Yukawa coupling itself becomes a simple interaction. In the context of this Enriched Standard Model, we introduce a new $r$-symmetry in the extended $SU(2)_L \\times U(1)_Y \\times U(1)_R$ model and show how the $125 \\;GeV$ and $750 \\;GeV$ resonances may be identified with $H$ and $H'$, the key members of the Higgs family, with $H$ being in every way identifed with the SM Higgs. There are interesting consequences of their $2 \\gamma$ decay widths.

  4. Supersymmetric Higgs Bosons and Beyond

    Energy Technology Data Exchange (ETDEWEB)

    Carena, Marcela; /Fermilab /Chicago U., EFI; Kong, Kyoungchul; /Fermilab /SLAC; Ponton, Eduardo; /Columbia U.; Zurita, Jose; /Fermilab /Buenos Aires U.

    2010-08-26

    We consider supersymmetric models that include particles beyond the Minimal Supersymmetric Standard Model (MSSM) with masses in the TeV range, and that couple significantly to the MSSM Higgs sector. We perform a model-independent analysis of the spectrum and couplings of the MSSM Higgs fields, based on an effective theory of the MSSM degrees of freedom. The tree-level mass of the lightest CP-even state can easily be above the LEP bound of 114 GeV, thus allowing for a relatively light spectrum of superpartners, restricted only by direct searches. The Higgs spectrum and couplings can be significantly modified compared to the MSSM ones, often allowing for interesting new decay modes. We also observe that the gluon fusion production cross section of the SM-like Higgs can be enhanced with respect to both the Standard Model and the MSSM.

  5. Reheating with a Composite Higgs

    CERN Document Server

    Croon, Djuna; Tarrant, Ewan R M

    2015-01-01

    The flatness of the inflaton potential and lightness of the Higgs could have the common origin of the breaking of a global symmetry. This scenario provides a unified framework of Goldstone Inflation and Composite Higgs, where the inflaton and the Higgs both have a pseudo--Goldstone boson nature. The inflaton reheats the Universe via decays to the Higgs and subsequent secondary production of other SM particles via the top and massive vector bosons. We find that inflationary predictions and perturbative reheating conditions are consistent with CMB data for sub--Planckian values of the fields, as well as opening up the possibility of inflation at the TeV scale. We explore this exciting possibility, leading to an interplay between collider data and cosmological constraints.

  6. UV complete composite Higgs models

    CERN Document Server

    Agugliaro, Alessandro; Becciolini, Diego; De Curtis, Stefania; Redi, Michele

    2016-01-01

    We study confining gauge theories with fermions vectorial under the SM that produce a Higgs doublet as a Nambu-Goldstone boson. The vacuum misalignment required to break the electro-weak symmetry is induced by an elementary Higgs doublet with Yukawa couplings to the new fermions. The physical Higgs is a linear combination of elementary and composite Higgses while the SM fermions remain elementary. The full theory is renormalizable and the SM Yukawa couplings are generated from the ones of the elementary Higgs allowing to eliminate all flavour problems but with interesting effects for Electric Dipole Moments of SM particles. We also discuss how ideas on the relaxation of the electro-weak scale could be realised within this framework.

  7. Higgs Searches at the Tevatron

    CERN Document Server

    Evans, H G

    2000-01-01

    Higgs hunting is a world-wide sport and the Tevatron is set to become the next field of play when Run II starts in March 2001. To set the stage, we summarize results of searches for standard and non-standard Higgs bosons by CDF and Dzero in Run I at the Tevatron. Progress has been made in quantifying the requirements on the Tevatron Collider and on the upgraded experiments in Run II for extending the excellent work done at LEP. Armed with parameterizations of expected detector performance, the Tevatron Higgs Working group has made predictions of the sensitivity of CDF and Dzero to Higgs bosons in the Standard Model and in its Minimal Supersymmetric extension as a function of integrated luminosity. These predictions are presented to underscore the excitement being generated by Run II, and to highlight the need for the highest possible luminosity.

  8. Production and detection of heavy matter anti-matter from Higgs decays

    CERN Document Server

    Srivastava, Y N; Swain, J

    2011-01-01

    The one-loop Higgs coupling to two gluons has been invoked in the past to estimate that the fraction of the nucleon mass which is due to the Higgs is rather small but calculable (approximately 8 percent). To test the veracity of this hypothesis, we employ the same mechanism to compute the Higgs coupling to an arbitrary stable nucleus $A$ and its anti-nucleus $\\bar{A}$. We find that the physical decay rate of a Higgs into a spin zero $A\\bar{A}$ pair near the threshold corresponding to the Higgs mass is quite substantial, once we include the final state Coulomb corrections as well as possible form factor effects. If true, observation of even a few such decay events would be truly spectacular (with no competing background) since we are unaware of any other interaction which might lead to the production of a very heavy nucleus accompanied by its anti nucleus in nucleon-(anti-) nucleon scattering.

  9. Buckets of Higgs and Tops

    CERN Document Server

    Buckley, Matthew R; Schell, Torben; Takeuchi, Michihisa

    2013-01-01

    We show that associated production of a Higgs with a top pair can be observed in purely hadronic decays. Reconstructing the top quarks in the form of jet buckets allows us to control QCD backgrounds as well as signal combinatorics. The background can be measured from side bands in the reconstructed Higgs mass. We back up our claims with a detailed study of the QCD event simulation, both for the signal and for the backgrounds.

  10. Higgs decay to fermions (CMS)

    CERN Document Server

    Saxena, Pooja

    2016-01-01

    A search for high mass Higgs boson of the MSSM decaying into two fermions using the first 2015 data at 13 TeV is presented. The four final decay channels of mu \\tau_h, e \\tau_h, \\tau_h \\tau_h and e mu is used. The limits on production cross section times branching ratio has been set.Other results from Run1 and different searches and measurements involving Higgs decays fermions will also be reviewed.

  11. Higgs in bosonic channels (CMS

    Directory of Open Access Journals (Sweden)

    Gori Valentina

    2015-01-01

    The Higgs boson mass measurement from the combination of H → ZZ → 4ℓ and H → γγ channels gives a value mH = 125.03+0.26−0.27 (stat. +0.13−0.15 (syst.. An upper limit ΓH < 22 MeV can be put on the Higgs boson width thanks to the new indirect method.

  12. Higgs boson measurements at ATLAS

    CERN Document Server

    Hays, Chris; The ATLAS collaboration

    2016-01-01

    A comprehensive set of Higgs boson measurements has been performed in pp collisions produced by the Large Hadron Collider at centre-of-mass energies of 7 and 8 TeV, and the results combined between the ATLAS and CMS experiments. Recent results from ATLAS at a centre-of-mass energy of 13 TeV are consistent with expectations. With more data available, additional Higgs boson processes are on the cusp of observation, while measured processes promise improved precision.

  13. Buckets of Higgs and tops

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, Matthew R. [Center for Particle Astrophysics, Fermi National Accelerator Laboratory,Batavia, IL (United States); Department of Physics and Astronomy, Rutgers University,Piscataway, NJ (United States); Plehn, Tilman; Schell, Torben [Institut für Theoretische Physik, Universität Heidelberg,Heidelberg (Germany); Takeuchi, Michihisa [Theoretical Particle Physics and Cosmology Group, Department of Physics,King’s College London, London WC2R 2LS (United Kingdom)

    2014-02-28

    We show that associated production of a Higgs with a top pair can be observed in purely hadronic decays. Reconstructing the top quarks in the form of jet buckets allows us to control QCD backgrounds as well as signal combinatorics. The background can be measured from side bands in the reconstructed Higgs mass. We back up our claims with a detailed study of the QCD event simulation, both for the signal and for the backgrounds.

  14. Standard Model Higgs at LEP

    CERN Document Server

    Ferrer-Ribas, E

    2000-01-01

    In 1999 the LEP experiments collected data at centre of mass energies between 192 and 202 GeV for about 900 pb-1 integrated luminosity. Combined results are presented for the search for the Standard Model Higgs boson. No statistically significant excess has been observed when compared to Standard Model background expectation which can be translated into a lower bound on the mass of the Higgs boson at 107.9 GeV/c^2 at 95 % confidence level.

  15. Invisible Decays in Higgs Pair Production

    CERN Document Server

    Banerjee, Shankha; Spannowsky, Michael

    2016-01-01

    Observation of Higgs pair production is an important long term objective of the LHC physics program as it will shed light on the scalar potential of the Higgs field and the nature of electroweak symmetry breaking. While numerous studies have examined the impact of new physics on di-Higgs production, little attention has been given to the well-motivated possibility of exotic Higgs decays in this channel. Here we investigate the consequences of exotic invisible Higgs decays in di-Higgs production. We outline a search sensitive to such invisible decays in the $b\\bar b+{\

  16. Searches for BSM Higgs Bosons with ATLAS

    CERN Document Server

    Navarro, Gabriela; The ATLAS collaboration

    2015-01-01

    The discovery of a Higgs-like boson with a mass of about 125GeV has prompted the question of whether or not this particle is part of a much larger and more complex Higgs sector than that envisioned in the Standard Model. In this talk, the current results from the ATLAS Experiment regarding Beyond-the-Standard Model (BSM) Higgs hypothesis tests are outlined. Searches for additional Higgs bosons are presented and interpreted in well-motivated BSM Higgs frameworks, such as two-Higgs-doublet Models and the Minimal Supersymmetric Standard Model.

  17. Vacuum stability in neutrinophilic Higgs doublet model

    Energy Technology Data Exchange (ETDEWEB)

    Haba, Naoyuki [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Horita, Tomohiro, E-mail: tomohiro@het.phys.sci.osaka-u.ac.jp [Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2011-11-03

    A neutrinophilic Higgs model has tiny vacuum expectation value (VEV), which can naturally explain tiny masses of neutrinos. There is a large energy scale hierarchy between a VEV of the neutrinophilic Higgs doublet and that of usual standard model-like Higgs doublet. In this Letter we at first analyze vacuum structures of Higgs potential in both supersymmetry (SUSY) and non-SUSY neutrinophilic Higgs models, and next investigate a stability of this VEV hierarchy against radiative corrections. We will show that the VEV hierarchy is stable against radiative corrections in both Dirac neutrino and Majorana neutrino scenarios in both SUSY and non-SUSY neutrinophilic Higgs doublet models.

  18. Craniofacial anomalies in twins.

    Science.gov (United States)

    Keusch, C F; Mulliken, J B; Kaplan, L C

    1991-01-01

    Studies of twins provide insight into the relative contribution of genetic and environmental factors in the causality of structural anomalies. Thirty-five affected twin pairs were identified from a group of 1114 patients with congenital craniofacial deformities evaluated from 1972 to 1989. Forty-three of these 70 twins exhibited one or more craniofacial anomalies; these were analyzed for dysmorphic characteristics, zygosity, concordance, and family history. The anomalies were categorized into two groups: malformations and deformations. The malformations (n = 36) included hemifacial microsomia (n = 10), cleft lip and palate (n = 8), cleft palate (n = 4), rare facial cleft (n = 2), craniosynostosis (n = 2), Binder syndrome (n = 2), Treacher Collins syndrome (n = 2), craniopagus (n = 2), CHARGE association (n = 1), frontonasal dysplasia (n = 2), and constricted ears (n = 1). The deformations (n = 7) included plagiocephaly (n = 5), hemifacial hypoplasia (n = 1), and micrognathia (n = 1). Twenty-one monozygotic and 14 dizygotic twin pairs were identified. The concordance rate was 33 percent for monozygotic twins and 7 percent for dizygotic twins.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Higgs inflation, seesaw physics and fermion dark matter

    Directory of Open Access Journals (Sweden)

    Nobuchika Okada

    2015-07-01

    Full Text Available We present an inflationary model in which the Standard Model Higgs doublet field with non-minimal coupling to gravity drives inflation, and the effective Higgs potential is stabilized by new physics which includes a dark matter particle and right-handed neutrinos for the seesaw mechanism. All of the new particles are fermions, so that the Higgs doublet is the unique inflaton candidate. With central values for the masses of the top quark and the Higgs boson, the renormalization group improved Higgs potential is employed to yield the scalar spectral index ns≃0.968, the tensor-to-scalar ratio r≃0.003, and the running of the spectral index α=dns/dln⁡k≃−5.2×10−4 for the number of e-folds N0=60 (ns≃0.962, r≃0.004, and α≃−7.5×10−4 for N0=50. The fairly low value of r≃0.003 predicted in this class of models means that the ongoing space and land based experiments are not expected to observe gravity waves generated during inflation.

  20. Higgs Inflation, Seesaw Physics and Fermion Dark Matter

    CERN Document Server

    Okada, Nobuchika

    2015-01-01

    We present an inflationary model in which the Standard Model Higgs doublet field with non-minimal coupling to gravity drives inflation, and the effective Higgs potential is stabilized by new physics which includes a dark matter particle and right-handed neutrinos for the seesaw mechanism. All of the new particles are fermions, so that the Higgs doublet is the unique inflaton candidate. With central values for the masses of the top quark and the Higgs boson, the renormalization group improved Higgs potential is employed to yield the scalar spectral index $n_s \\simeq 0.968$, the tensor-to-scalar ratio $r \\simeq 0.003$, and the running of the spectral index $\\alpha=dn_s/d \\ln k \\simeq -5.2 \\times 10^{-4}$ for the number of e-folds $N_0=60$ ($n_s \\simeq 0.962$, $r \\simeq 0.004$, and $\\alpha \\simeq -7.5 \\times 10^{-4}$ for $N_0=50$). The fairly low value of $r \\simeq 0.003$ predicted in this class of models means that the ongoing space and land based experiments are not expected to observe gravity waves generated ...

  1. Gauge turbulence, topological defect dynamics, and condensation in Higgs models

    Energy Technology Data Exchange (ETDEWEB)

    Gasenzer, Thomas [Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany); ExtreMe Matter Institute EMMI, GSI, Planckstraße 1, D-64291 Darmstadt (Germany); McLerran, Larry [Physics Department, Bldg. 510A, Brookhaven National Laboratory, Upton, NY 11973 (United States); RIKEN BNL Research Center, Bldg. 510A, Brookhaven National Laboratory, Upton, NY 11973 (United States); Physics Department, China Central Normal University, Wuhan (China); Pawlowski, Jan M.; Sexty, Dénes [Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, 69120 Heidelberg (Germany); ExtreMe Matter Institute EMMI, GSI, Planckstraße 1, D-64291 Darmstadt (Germany)

    2014-10-15

    The real-time dynamics of topological defects and turbulent configurations of gauge fields for electric and magnetic confinement are studied numerically within a 2+1D Abelian Higgs model. It is shown that confinement is appearing in such systems equilibrating after a strong initial quench such as the overpopulation of the infrared modes. While the final equilibrium state does not support confinement, metastable vortex defect configurations appearing in the gauge field are found to be closely related to the appearance of physically observable confined electric and magnetic charges. These phenomena are seen to be intimately related to the approach of a non-thermal fixed point of the far-from-equilibrium dynamical evolution, signaled by universal scaling in the gauge-invariant correlation function of the Higgs field. Even when the parameters of the Higgs action do not support condensate formation in the vacuum, during this approach, transient Higgs condensation is observed. We discuss implications of these results for the far-from-equilibrium dynamics of Yang–Mills fields and potential mechanisms of how confinement and condensation in non-Abelian gauge fields can be understood in terms of the dynamics of Higgs models. These suggest that there is an interesting new class of dynamics of strong coherent turbulent gauge fields with condensates.

  2. Twin delivery: how should the second twin be delivered?

    Science.gov (United States)

    Olofsson, P; Rydhström, H

    1985-11-01

    In a series of 803 pairs of twins born between 1973 and 1982, 0.33% of second twins were delivered by cesarean section after vaginal delivery of the first twin. During the last year the frequency has increased to 7%, calling attention to the problem of declining obstetric skills and experience. This has caused us to update the routines of intrapartum management of twin gestations. In the present program only commonly available obstetric techniques are used. The potentially hazardous twin delivery is excluded from a trial of vaginal delivery. Hopefully, the program will help other obstetricians to decide in favor of vaginal delivery in selected twin gestations.

  3. Mooses, Topology and Higgs

    CERN Document Server

    Gregoire, T; Gregoire, Thomas; Wacker, Jay G.

    2002-01-01

    New theories of electroweak symmetry breaking have recently been constructed that stabilize the weak scale and do not rely upon supersymmetry. In these theories the Higgs boson is a weakly coupled pseudo-Goldstone boson. In this note we study the class of theories that can be described by theory spaces and show that the fundamental group of theory space describes all the relevant classical physics in the low energy theory. The relationship between the low energy physics and the topological properties of theory space allow a systematic method for constructing theory spaces that give any desired low energy particle content and potential. This provides us with tools for analyzing and constructing new theories of electroweak symmetry breaking.

  4. Off-the-Wall Higgs in the Universal Randall-Sundrum Model

    CERN Document Server

    Davoudiasl, H; Rizzo, T G; Davoudiasl, Hooman; Lillie, Ben; Rizzo, Thomas G.

    2006-01-01

    We outline a consistent Randall-Sundrum (RS) framework in which a fundamental 5-dimensional Higgs doublet induces electroweak symmetry breaking (EWSB). In this framework of a warped Universal Extra Dimension, the lightest Kaluza-Klein (KK) mode of the bulk Higgs is tachyonic leading to a vacuum expectation value (vev) at the TeV scale. The consistency of this picture imposes a set of constraints on the parameters in the Higgs sector. A novel feature of our scenario is the emergence of an adjustable bulk profile for the Higgs vev. We also find a tower of non-tachyonic Higgs KK modes at the weak scale. We consider an interesting implementation of this ``Off-the-Wall Higgs'' mechanism where the 5-dimensional curvature-scalar coupling alone generates the tachyonic mode responsible for EWSB. In this case, additional relations among the parameters of the Higgs and gravitational sectors are established. We discuss the experimental signatures of the bulk Higgs in general, and those of the ``Gravity-Induced'' EWSB in ...

  5. On the origins and the historical roots of the Higgs boson research from a bibliometric perspective

    Science.gov (United States)

    Barth, A.; Marx, W.; Bornmann, L.; Mutz, R.

    2014-06-01

    The subject of our present paper is the analysis of the origins or historical roots of the Higgs boson research from a bibliometric perspective, using a segmented regression analysis in combination with a method named reference publication year spectroscopy (RPYS). Our analysis is based on the references cited in the Higgs boson publications published since 1974. The objective of our analysis consists of identifying specific individual publications in the Higgs boson research context to which the scientific community frequently had referred to. We are interested in seminal works which contributed to a high extent to the discovery of the Higgs boson. Our results show that researchers in the Higgs boson field preferably refer to more recently published papers —particularly papers published since the beginning of the sixties. For example, our analysis reveals seven major contributions which appeared within the sixties: Englert and Brout (1964), Higgs (1964, 2 papers), and Guralnik et al. (1964) on the Higgs mechanism as well as Glashow (1961), Weinberg (1967), and Salam (1968) on the unification of weak and electromagnetic interaction. Even if the Nobel Prize award highlights the outstanding importance of the work of Peter Higgs and Francois Englert, bibliometrics offer the additional possibility of getting hints to other publications in this research field (especially to historical publications), which are of vital importance from the expert point of view.

  6. Evading Direct Dark Matter Detection in Higgs Portal Models

    CERN Document Server

    Arcadi, Giorgio; Lebedev, Oleg; Pokorski, Stefan; Toma, Takashi

    2016-01-01

    Many models of Higgs portal Dark Matter (DM) find themselves under pressure from increasingly tight direct detection constraints. In the framework of gauge field DM, we study how such bounds can be relaxed while retaining the thermal WIMP paradigm. When the hidden sector gauge symmetry is broken via the Higgs mechanism, the hidden sector generally contains unstable states which are lighter than dark matter. These states provide DM with an efficient annihilation channel. As a result, the DM relic abundance and the direct detection limits are controlled by different parameters, and the two can easily be reconciled. This simple setup realizes the idea of `secluded' dark matter naturally.

  7. Higgs-flavon mixing and h→μτ

    Energy Technology Data Exchange (ETDEWEB)

    Huitu, Katri; Keus, Venus; Koivunen, Niko; Lebedev, Oleg [Department of Physics and Helsinki Institute of Physics,Gustaf Hällströmin katu 2, FIN-00014 University of Helsinki (Finland)

    2016-05-04

    ATLAS and CMS have reported an excess in the flavor violating decay of the Higgs boson, h→μτ. We show that this result can be accommodated through a mixing of the Higgs with a flavon, the field responsible for generating the Yukawa matrices in the lepton sector. We employ a version of the Froggatt-Nielsen mechanism at the electroweak scale, with only the leptons and the flavon transforming non-trivially under the corresponding symmetry group. Non-observation of charged lepton flavor violation (LFV) in other processes imposes important constraints on the model, which we find to be satisfied in substantial regions of parameter space.

  8. Higgs--Flavon Mixing and $h \\rightarrow \\mu\\tau$

    CERN Document Server

    Huitu, Katri; Koivunen, Niko; Lebedev, Oleg

    2016-01-01

    ATLAS and CMS have reported an excess in the flavor violating decay of the Higgs boson, $h \\rightarrow \\mu \\tau$. We show that this result can be accommodated through a mixing of the Higgs with a flavon, the field responsible for generating the Yukawa matrices in the lepton sector. We employ a version of the Froggatt-Nielsen mechanism at the electroweak scale, with only the leptons and the flavon transforming non--trivially under the corresponding symmetry group. Non--observation of charged lepton flavor violation (LFV) in other processes imposes important constraints on the model, which we find to be satisfied in substantial regions of parameter space.

  9. What is the probability of the Higgs boson discovery?

    Energy Technology Data Exchange (ETDEWEB)

    Unzicker, Alexander [Pestalozzi-Gymnasium Muenchen (Germany)

    2010-07-01

    The standard model of particle physics requires the existence of the Higgs boson which provides a mechanism for the appearance of masses. Its detection is one of the most important goals of high energy physics, and enormous efforts have been undertaken at Tevatron and specially at the Large Hadron Collider. But how sure can we be that the Higgs exits at all? At such controversial questions, the German philosopher Immanuel Kant recommended a bet, and nowadays this can be realized using online prediction markets like Intrade.com. Such platforms have been proven useful for giving estimates of unknown probabilities, and the application for evaluating scientific research is discussed in general.

  10. Cosmological constraints on decoupled dark photons and dark Higgs

    Science.gov (United States)

    Berger, Joshua; Jedamzik, Karsten; Walker, Devin G. E.

    2016-11-01

    Any neutral boson such as a dark photon or dark Higgs that is part of a non-standard sector of particles can mix with its standard model counterpart. When very weakly mixed with the Standard Model, these particles are produced in the early Universe via the freeze-in mechanism and subsequently decay back to standard model particles. In this work, we place constraints on such mediator decays by considering bounds from Big Bang nucleosynthesis and the cosmic microwave background radiation. We find both nucleosynthesis and CMB can constrain dark photons with a kinetic mixing parameter between log epsilon ~ -10 to -17 for masses between 1 MeV and 100 GeV . Similarly, the dark Higgs mixing angle epsilon with the Standard Model Higgs is constrained between log epsilon ~ -6 to -15. Dramatic improvement on the bounds from CMB spectral distortions can be achieved with proposed experiments such as PIXIE.

  11. Abelian symmetries in multi-Higgs-doublet models

    CERN Document Server

    Ivanov, Igor P; Vdovin, Evgeny

    2011-01-01

    N-Higgs-doublet models (NHDM) are a popular framework to construct electroweak symmetry breaking mechanisms beyond the Standard model. Usually, one builds an NHDM scalar sector which is invariant under a certain symmetry group. Although several such groups have been used, no general analysis of symmetries possible in the NHDM scalar sector exists. Here, we describe a strategy that identifies all abelian groups which are realizable as symmetry groups of the NHDM Higgs potential. We consider both the groups of Higgs-family transformations only and the groups which also contain generalized CP transformations. We illustrate this strategy with the examples of 3HDM and 4HDM and prove several statements for arbitrary N.

  12. Cosmological constraints on decoupled dark photons and dark Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Joshua [Physics Department, University of Wisconsin-Madison,1150 University Ave, Madison, WI 53706 (United States); Jedamzik, Karsten [Laboratoire Univers et Particules de Montpellier, UMR5299-CNRS,Université Montpellier II,Place Eugène Bataillon, CC 72, 34095 Montpellier Cédex 05 (France); Walker, Devin G.E. [Department of Physics and Astronomy, Dartmouth College,6127 Wilder Laboratory, Hanover, NH 03755 (United States); Department of Physics, University of Washington,Box 351560, Seattle, WA 98195 (United States)

    2016-11-16

    Any neutral boson such as a dark photon or dark Higgs that is part of a non-standard sector of particles can mix with its standard model counterpart. When very weakly mixed with the Standard Model, these particles are produced in the early Universe via the freeze-in mechanism and subsequently decay back to standard model particles. In this work, we place constraints on such mediator decays by considering bounds from Big Bang nucleosynthesis and the cosmic microwave background radiation. We find both nucleosynthesis and CMB can constrain dark photons with a kinetic mixing parameter between log ϵ∼−10 to −17 for masses between 1 MeV and 100 GeV. Similarly, the dark Higgs mixing angle ϵ with the Standard Model Higgs is constrained between log ϵ∼−6 to −15. Dramatic improvement on the bounds from CMB spectral distortions can be achieved with proposed experiments such as PIXIE.

  13. Cosmological Constraints on Decoupled Dark Photons and Dark Higgs

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Joshua [Univ. of Wisconsin, Madison, WI (United States); Jedamzik, Karsten [Univ. Montpellier II (France). Lab. Univers. et Particules de Monpellier; Walker, Devin G.E. [Univ. of Washington, Seattle, WA (United States). Dept. of Physics

    2016-05-23

    Any neutral boson such as a dark photon or dark Higgs that is part of a non-standard sector of particles can mix with its standard model counterpart. When very weakly mixed with the Standard Model, these particles are produced in the early Universe via the freeze-in mechanism and subsequently decay back to standard model particles. In this work, we place constraints on such mediator decays by considering bounds from Big Bang nucleosynthesis and the cosmic microwave background radiation. We find both nucleosynthesis and CMB can constrain dark photons with a kinetic mixing parameter between log ϵ ~ -10 to -17 for masses between 1 MeV and 100 GeV. Similarly, the dark Higgs mixing angle ϵ with the Standard Model Higgs is constrained between log ϵ ~ -6 to -15. Dramatic improvement on the bounds from CMB spectral distortions can be achieved with proposed experiments such as PIXIE.

  14. Vector boson fusion NNLO in QCD. SM Higgs and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Bolzoni, Paolo [Hamburg Univ. (Germany). 2. Inst. fuer Theoretische Physik; Maltoni, Fabio; Zaro, Marco [Catholique Univ. Louvain-la-Neuve (BE). Center for Cosmology, Particle Phyics and Phenomenology (CP3); Moch, Sven-Olaf [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2011-09-15

    Weak vector boson fusion provides a unique channel to directly probe the mechanism of electroweak symmetry breaking at hadron colliders. We present a method that allows to calculate total cross sections to next-to-next-to-leading order (NNLO) in QCD for an arbitrary V{sup *}V{sup *}{yields}X process, the so-called structure function approach. By discussing the case of Higgs production in detail, we estimate several classes of previously neglected contributions and we argue that such method is accurate at a precision level well above the typical residual scale and PDF uncertainties at NNLO. Predictions for cross sections at the Tevatron and the LHC are presented for a variety of cases: the Standard Model Higgs (including anomalous couplings), neutral and charged scalars in extended Higgs sectors and (fermiophobic) vector resonance production. Further results can be easily obtained through the public use of the VBF rate at NNLO code. (orig.)

  15. The Higgs Boson in the Standard Model - From LEP to LHC: Expectations, Searches, and Discovery of a Candidate

    CERN Document Server

    Dittmaier, S

    2012-01-01

    The quest for the Higgs boson of the Standard Model, which was a cornerstone in the physics programme at particle colliders operating at the energy frontier for several decades, is the subject of this review. After reviewing the formulation of electroweak symmetry breaking via the Higgs mechanism within the Standard Model, the phenomenology of the Higgs boson at colliders and the theoretical and phenomenological constraints on the Standard Model Higgs sector are discussed. General remarks on experimental searches and the methodology of statistical interpretation are followed by a description of the phenomenology of Higgs-boson production and the corresponding precise predictions. The strategies of the experimental searches and their findings are discussed for the Large Electron Positron Collider (LEP) at CERN, the proton-antiproton collider Tevatron at Fermilab, and the proton-proton Large Hadron Collider (LHC) at CERN. The article concludes with the description of the observation of a Higgs-like boson at the...

  16. Higgs, di-Higgs and tri-Higgs production via SUSY processes at the LHC with 14 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Beekveld, Melissa van [Institute for Mathematics, Astrophysics and Particle Physics, Faculty of Science,Radboud University Nijmegen,Mailbox 79, P.O. Box 9010, NL-6500 GL Nijmegen (Netherlands); Nikhef,Science Park, Amsterdam (Netherlands); Beenakker, Wim [Institute for Mathematics, Astrophysics and Particle Physics, Faculty of Science,Radboud University Nijmegen,Mailbox 79, P.O. Box 9010, NL-6500 GL Nijmegen (Netherlands); Nikhef,Science Park, Amsterdam (Netherlands); Institute of Physics, University of Amsterdam,Science Park 904, 1018 XE Amsterdam (Netherlands); Caron, Sascha; Castelijn, Remco; Lanfermann, Marie; Struebig, Antonia [Institute for Mathematics, Astrophysics and Particle Physics, Faculty of Science,Radboud University Nijmegen,Mailbox 79, P.O. Box 9010, NL-6500 GL Nijmegen (Netherlands); Nikhef,Science Park, Amsterdam (Netherlands)

    2015-05-08

    We have systematically investigated the production of a Higgs boson with a mass of about 125 GeV in the decays of supersymmetric particles within the phenomenological MSSM (pMSSM). We find regions of parameter space that are consistent with all world data and that predict a sizeable rate of anomalous Higgs, di-Higgs and even tri-Higgs events at the 14 TeV LHC. All relevant SUSY production processes are investigated. We find that Higgs bosons can be produced in a large variety of SUSY processes, resulting in a large range of different detector signatures containing missing transverse momentum. Such Higgs events are outstanding signatures for new physics already for the early 14 TeV LHC data. SUSY processes are also important to interprete deviations found in upcoming Standard Model Higgs and di-Higgs production measurements.

  17. Neutrinos in the time of Higgs

    Indian Academy of Sciences (India)

    Srubabati Goswami

    2016-02-01

    In this paper, the recent progress in the determination of neutrino oscillation parameters and future prospects have been discussed. The tiny neutrino masses as inferred from oscillation data and cosmology cannot be explained naturally by the Higgs mechanism and warrant some new physics. The latter can be connected to the Majorana nature of the neutrinos which can be probed by neutrinoless double beta decay (0). The paper also summarizes the latest experimental results in 0 and discusses some implications for the left–right symmetric model which could be a plausible new physics scenario for the generation of neutrino masses.

  18. Theoretical Survey of Higgs Boson and Axions

    Energy Technology Data Exchange (ETDEWEB)

    Morales, Robert O.

    2000-04-05

    The success as well as the problems of the minimal Standard Model are recalled. The authors survey essentially this Model and the theory of the standard axion (Nambu-Goldstone boson). Possible invisible and visualized (theoretical) axions are discussed as are certain astrophysical aspects of the existence of an axion. They survey also axion cosmology in superstring models and its consequence, in the new anomaly cancellation mechanism to the sense of Green and Schwarz. Recent results for the search of the Higgs boson, and the axion are resumed. A great important is reserved for discussion of the Standard Model.

  19. Measurement of Higgs decay in Bosonic final states at LHC

    CERN Document Server

    Ferrari, P; The ATLAS collaboration

    2014-01-01

    A summary of the measurements of the Higgs decay in bosonic final states by ATLAS and CMS is given. The analyses include the full data set of run I and are performed with improved detector calibrations and object identification. More decay channels and categories sensitive to to the VBF and VH production mechanisms have been added with respect to older results.

  20. Post-ACME2013 CP-violation in Higgs Physics and Electroweak Baryogenesis

    CERN Document Server

    Bian, Ligong; Shu, Jing

    2014-01-01

    We present a class of cancellation mechanisms to suppress the total contributions of Barr-Zee diagrams to the electron electric dipole moment (eEDM). This class of mechanisms are of particular significance after the new eEDM upper limit, which strongly constrains the allowed magnitude of CP-violation in Higgs couplings and hence the feasibility of electroweak baryogenesis (EWBG), were released by the ACME collaboration in 2013. We point out: if both the CP-odd Higgs-photon-photon ($Z$ boson) and the CP-odd Higgs-electron-positron couplings are turned on, a cancellation may occur either between the contributions of a CP-mixing Higgs boson, with the other Higgs bosons being decoupled, or between the contributions of a CP-even and a CP-odd Higgs bosons. With the assistance of the cancellation mechanisms, a large CP-phase in Higgs couplings with viable electroweak baryogenesis (EWBG) is still allowed. The reopened parameter regions would be probed by the future neutron, mercury EDM measurements, and direct measur...

  1. Dependency of deformation twinning on grain orientation in an FCC and a HCP metal

    Institute of Scientific and Technical Information of China (English)

    YANG Ping

    2007-01-01

    Twinning plays important roles in HCP metals and those FCC metals with low stacking fault energy.The structural difierence of two types of metals makes quite different contributions of twinning to plasticity The variety of grain orientation in polycrystalline metals causes the inhomogeneous occurrence of twinning and further distinct transformation kinetics of twinning as strain increases and texture develops.This changes finally the work hardening behavior and mechanical properties.This Paper reveals the dependency of twinning on grain orientation in an FCC TWIP(twinning induced plasticity)steel with high Mn content and in a magnesium alloy using electron-backscatter-difiraction(EBSD) technique,and analyzes the characteristies of twinning in the two types of metals by Schmid factor calculation.In addition,the relation of twinning and shear banding, as well as their influence on properties are discussed.

  2. Characterizing the boundary lateral to the shear direction of deformation twins in magnesium

    Science.gov (United States)

    Liu, Y.; Li, N.; Shao, S.; Gong, M.; Wang, J.; McCabe, R. J.; Jiang, Y.; Tomé, C. N.

    2016-06-01

    The three-dimensional nature of twins, especially the atomic structures and motion mechanisms of the boundary lateral to the shear direction of the twin, has never been characterized at the atomic level, because such boundary is, in principle, crystallographically unobservable. We thus refer to it here as the dark side of the twin. Here, using high-resolution transmission electron microscopy and atomistic simulations, we characterize the dark side of deformation twins in magnesium. It is found that the dark side is serrated and comprised of coherent twin boundaries and semi-coherent twist prismatic-prismatic boundaries that control twin growth. The conclusions of this work apply to the same twin mode in other hexagonal close-packed materials, and the conceptual ideas discussed here should hold for all twin modes in crystalline materials.

  3. Deformation twinning and the role of amino acids and magnesium in calcite hardness from molecular simulation.

    Science.gov (United States)

    Côté, A S; Darkins, R; Duffy, D M

    2015-08-21

    We employ classical molecular dynamics to calculate elastic properties and to model the nucleation and propagation of deformation twins in calcite, both as a pure crystal and with magnesium and aspartate inclusions. The twinning is induced by applying uniaxial strain to the crystal and relaxing all stress components except the uniaxial component. A detailed analysis of the atomistic processes reveal that the twinning mechanism involves small displacements of the Ca ions and cooperative rotations of the CO3 ions. The volume of the twinned region expands under increased uniaxial strain via the propagation of steps along the twin boundaries. The energy cost of the twin boundaries is compensated by the reduced hydrostatic stress and strain energy. The presence of biogenic impurities is shown to decrease the strain required to induce twin formation in calcite and, thus, the yield stress. This increased propensity for twinning provides a possible explanation for the increased hardness and penetration resistance observed experimentally in biominerals.

  4. Benchmarks for Higgs Pair Production and Heavy Higgs Searches in the Two-Higgs-Doublet Model of Type II

    CERN Document Server

    Baglio, Julien; Nierste, Ulrich; Wiebusch, Martin

    2014-01-01

    The search for additional Higgs particles and the exact measurements of Higgs (self-)couplings is a major goal of future collider experiments. In this paper we investigate the possible sizes of new physics signals in these searches in the context of the $CP$-conserving two-Higgs doublet model of type II. Using current constraints from flavour, electroweak precision, and Higgs signal strength data, we determine the allowed sizes of the triple Higgs couplings and the branching fractions of the heavy Higgs bosons into lighter Higgs bosons. Identifying the observed Higgs resonance with the light $CP$-even 2HDM Higgs boson $h$, we find that the $hhh$ coupling cannot exceed its SM value, but can be reduced by a factor of 0.56 at the 2 $\\sigma$ level. The branching fractions of the heavy neutral Higgs bosons $H$ and $A$ into two-fermion or two-vector-boson final states can be reduced by factors of 0.4 and 0.01, respectively, if decays into lighter Higgs boson are possible and if the mass of the decaying Higgs is bel...

  5. Sakurai Prize: The Future of Higgs Physics

    Science.gov (United States)

    Dawson, Sally

    2017-01-01

    The discovery of the Higgs boson relied critically on precision calculations. The quantum contributions from the Higgs boson to the W and top quark masses suggested long before the Higgs discovery that a Standard Model Higgs boson should have a mass in the 100-200 GeV range. The experimental extraction of Higgs properties requires normalization to the predicted Higgs production and decay rates, for which higher order corrections are also essential. As Higgs physics becomes a mature subject, more and more precise calculations will be required. If there is new physics at high scales, it will contribute to the predictions and precision Higgs physics will be a window to beyond the Standard Model physics.

  6. Best of Higgs Field Theory physicists

    CERN Multimedia

    CERN Video Productions

    2012-01-01

    Soundbytes from the interviews to Peter Higgs, Francois Englert, Carl Hagen and Gerald Guralnik, recorded at CERN on the announcement of the latest results from ATLAS and CMS on the Higgs boson searches.

  7. Coupling dynamic of twin supersonic jets

    Science.gov (United States)

    Kuo, Ching-Wen; Cluts, Jordan; Samimy, Mo

    2015-11-01

    In a supersonic shock-containing jet, the interaction of large-scale structures in the jet's shear layer with the shock waves generates acoustic waves. The waves propagate upstream, excite the jet initial shear layer instability, establish a feedback loop at certain conditions, and generate screech noise. The screech normally contains different modes of various strengths. Similarly, twin-jet plumes contain screech tones. If the dynamics of the two jet plumes are synchronized, the screech amplitude could be significantly amplified. There is a proposed analytical model in the literature for screech synchronization in twin rectangular jets. This model shows that with no phase difference in acoustic waves arriving at neighboring nozzle lips, twin-jet plumes feature a strong coupling with a significant level of screech tones. In this work the maximum nozzle separation distance for sustained screech synchronization and strong coupling is analytically derived. This model is used with our round twin-jet experiments and the predicted coupling level agrees well with the experimental results. Near-field microphone measurements and schlieren visualization along with the analytical model are used to investigate the coupling mechanisms of twin supersonic jets. Supported by ONR.

  8. HiggsSignals. Confronting arbitrary Higgs sectors with measurements at the Tevatron and the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Bechtle, Philip [Bonn Univ. (Germany). Physikalisches Inst.; Heinemeyer, Sven [Instituto de Fisica de Cantabria (CSIC-UC), Santander (Spain); Staal, Oscar [Stockholm Univ. (Sweden). The Oskar Klein Centre; Stefaniak, Tim [Bonn Univ. (Germany). Physikalisches Inst.; Bonn Univ. (Germany). Bethe Center for Theoretical Physics; Weiglein, Georg [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-05-15

    HiggsSignals is a Fortran90 computer code that allows to test the compatibility of Higgs sector predictions against Higgs rates and masses measured at the LHC or the Tevatron. Arbitrary models with any number of Higgs bosons can be investigated using a model-independent input scheme based on HiggsBounds. The test is based on the calculation of a {chi}{sup 2} measure from the predictions and the measured Higgs rates and masses, with the ability of fully taking into account systematics and correlations for the signal rate predictions, luminosity and Higgs mass predictions. It features two complementary methods for the test. First, the peak-centered method, in which each observable is defined by a Higgs signal rate measured at a specific hypothetical Higgs mass, corresponding to a tentative Higgs signal. Second, the mass-centered method, where the test is evaluated by comparing the signal rate measurement to the theory prediction at the Higgs mass predicted by the model. The program allows for the simultaneous use of both methods, which is useful in testing models with multiple Higgs bosons. The code automatically combines the signal rates of multiple Higgs bosons if their signals cannot be resolved by the experimental analysis. We compare results obtained with HiggsSignals to official ATLAS and CMS results for various examples of Higgs property determinations and find very good agreement. A few examples of HiggsSignals applications are provided, going beyond the scenarios investigated by the LHC collaborations. For models with more than one Higgs boson we recommend to use HiggsSignals and HiggsBounds in parallel to exploit the full constraining power of Higgs search exclusion limits and the measurements of the signal seen at m{sub H} {approx} 125.5 GeV.

  9. New decay modes of heavy Higgs bosons in a two Higgs doublet model with vectorlike leptons

    CERN Document Server

    Dermisek, Radovan; Shin, Seodong

    2015-01-01

    In models with extended Higgs sector and additional matter fields, the decay modes of heavy Higgs bosons can be dominated by cascade decays through the new fermions rendering present search strategies ineffective. We investigate new decay topologies of heavy neutral Higgses in two Higgs doublet model with vectorlike leptons. We also discuss constraints from existing searches and discovery prospects. Among the most interesting signatures are monojet, mono Z, mono Higgs, and Z and Higgs bosons produced with a pair of charged leptons.

  10. Fat Jets for a Light Higgs

    CERN Document Server

    Plehn, Tilman; Spannowsky, Michael

    2009-01-01

    At the LHC associated top quark and Higgs boson production with a Higgs decay to bottom quarks has long been a heavily disputed search channel. Recently, it has been found to not be viable. We show how it can be observed by tagging massive Higgs and top jets. For this purpose we construct boosted top and Higgs taggers for Standard Model processes in a complex QCD environment.

  11. THE HIGGS WORKING GROUP: SUMMARY REPORT.

    Energy Technology Data Exchange (ETDEWEB)

    DAWSON, S.; ET AL.

    2005-08-01

    This working group has investigated Higgs boson searches at the Tevatron and the LHC. Once Higgs bosons are found their properties have to be determined. The prospects of Higgs coupling measurements at the LHC and a high-energy linear e{sup +}e{sup -} collider are discussed in detail within the Standard Model and its minimal supersymmetric extension (MSSM). Recent improvements in the theoretical knowledge of the signal and background processes are presented and taken into account. The residual uncertainties are analyzed in detail. Theoretical progress is discussed in particular for the gluon-fusion processes gg {yields} H(+j), Higgs-bremsstrahlung off bottom quarks and the weak vector-boson-fusion (VBF) processes. Following the list of open questions of the last Les Houches workshop in 2001 several background processes have been calculated at next-to-leading order, resulting in a significant reduction of the theoretical uncertainties. Further improvements have been achieved for the Higgs sectors of the MSSM and NMSSM. This report summarizes our work performed before and after the workshop in Les Houches. Part A describes the theoretical developments for signal and background processes. Part B presents recent progress in Higgs boson searches at the Tevatron collider. Part C addresses the determination of Higgs boson couplings, part D the measurement of tan {beta} and part E Higgs boson searches in the VBF processes at the LHC. Part F summarizes Higgs searches in supersymmetric Higgs decays, part G photonic Higgs decays in Higgs-strahlung processes at the LHC, while part H concentrates on MSSM Higgs bosons in the intense-coupling regime at the LHC. Part I presents progress in charged Higgs studies and part J the Higgs discovery potential in the NMSSM at the LHC. The last part K describes Higgs coupling measurements at a 1 TeV linear e{sup +}e{sup -} collider.

  12. Measuring Higgs couplings from LHC data.

    Science.gov (United States)

    Klute, Markus; Lafaye, Rémi; Plehn, Tilman; Rauch, Michael; Zerwas, Dirk

    2012-09-07

    Following recent ATLAS and CMS publications we interpret the results of their Higgs searches in terms of standard model operators. For a Higgs boson mass of 125 GeV we determine several Higgs couplings from published 2011 data and extrapolate the results towards different scenarios of LHC running. Even though our analysis is limited by low statistics we already derive meaningful constraints on modified Higgs sectors.

  13. The Texas Twin Project.

    Science.gov (United States)

    Harden, K Paige; Tucker-Drob, Elliot M; Tackett, Jennifer L

    2013-02-01

    Socioeconomic position, racial/ethnic minority status, and other characteristics of the macro-environment may be important moderators of genetic influence on a wide array of psychosocial outcomes. Designed to maximize representation of low socioeconomic status families and racial/ethnic minorities, the Texas Twin Project is an ongoing study of school-age twins (preschool through 12th grade) enrolled in public schools in the Austin, Texas and Houston, Texas metropolitan areas. School rosters are used to identify twin families from a target population with sizable populations of African American (18%), Hispanic/Latino (48%), and non-Hispanic White (27%) children and adolescents, over half of whom meet US guidelines for classification as economically disadvantaged. Initial efforts have focused on a large-scale, family-based survey study involving both parent and child reports of personality, psychopathology, physical health, academic interests, parent-child relationships, and aspects of the home environment. In addition, the Texas Twin Project is the basis for an in-laboratory study of adolescent decision-making, delinquency, and substance use. Future directions include geographic expansion of the sample to the entire state of Texas (with a population of over 25 million) and genotyping of participating twins.

  14. Hypoalbuminemia in Donors with Twin-Twin Transfusion Syndrome

    NARCIS (Netherlands)

    Verbeek, L.; Middeldorp, J. M.; Hulzebos, C. V.; Oepkes, D.; Walther, F. J.; Lopriore, E.

    2013-01-01

    Objective: To estimate the differences in albumin levels between donors and recipients with twin-twin transfusion syndrome (TTTS). Methods: We performed a matched case-control study including twin pairs with TTTS treated conservatively (conservative group) or with fetoscopic laser surgery (laser gro

  15. Electroweak Chiral Lagrangian for Neutral Higgs Boson

    Institute of Scientific and Technical Information of China (English)

    WANG Shun-Zhi; WANG Qing

    2008-01-01

    A neutral Higgs boson is added into the traditional electroweak chiral Lagrangian by writing down all possible high dimension operators. The matter part of the Lagrangian is investigated in detail. We find that if Higgs field dependence of Yukawa couplings can be factorized out, there will be no flavour changing neutral couplings; neutral Higgs can induce coupling between light and heavy neutrinos.

  16. Higgs into the heart of imagination

    CERN Document Server

    Van den Bergh, Hannie

    2010-01-01

    Higgs is the documentary about the quest for the Higgs particle, also known as "The God Particle". It is considered the missing link in particle physics. Higgs is a film about the curiosity, the passion, and the imaginative power of silence.

  17. LHC Higgs boson results involving fermions

    CERN Document Server

    Chen, X; The ATLAS collaboration

    2013-01-01

    Following the discovery of a Higgs-like particle in the bosonic decay modes, the fermionic decay modes need to be seen to prove this particle is a Standard Model (SM) Higgs. In this presentation, an overview of the recent Higgs search results in the fermionic decays of $\\tau\\tau$, $b\\bar{b}$, $\\mu\\mu$ and $\\tau\

  18. Single Higgs-boson production through gamma-gamma scattering within the general 2HDM

    CERN Document Server

    Bernal, Nicolas; Sola, Joan

    2009-01-01

    The production of a single neutral Higgs boson h through (loop-induced) gamma-gamma collisions is explored in the context of the linear colliders within the general Two-Higgs-Doublet Model (2HDM). Two different mechanisms are analyzed: on the one hand, the scattering gamma gamma-> h of two real photons in a gamma-gamma collider; on the other, the more traditional mechanism of virtual photon fusion, e+e- -->e+e- + h. Owing to the peculiar properties of the Higgs boson self-interactions within the general 2HDM, we find that the overall production rates can be boosted up significantly, provided the charged Higgs mass is not too heavy. For example, if the latter is slightly above 100 GeV and, in addition, the lightest CP-even Higgs boson falls in the ballpark of the LEP bound on the SM Higgs mass up to a few hundred GeV, the cross-sections may typically render \\sigma(gamma gamma-> h)= 0.1-1 pb and \\sigma(e+e- --> e+e- + h)\\sim 0.01 pb -- in both cases well above the SM prediction. Although for charged Higgs masse...

  19. Dialysis for twins

    DEFF Research Database (Denmark)

    Gramkow, Ann-Maria; Aarup, Michael; Andersen, L. L. T.

    2014-01-01

    A 32-year-old woman with known stage-4 chronic kidney disease due to lupus nephritis presented with twin pregnancy after in vitro fertilization at a gestational age of 24 weeks + 3 days because of imminent preterm labour. Repeated ultrasound evaluations confirmed intrauterine growth restriction...... in both twins and polyhydramnios as the cause of imminent preterm labour. After initiation of haemodialysis treatment, ultrasound evaluation showed a significant decrease in amniotic fluids, and also reduction in blood urea nitrogen and in clinical complaints could be observed. At a gestational age of 28...... weeks + 4 days, delivery was performed by Caesarean section. This case study shows that effective treatment of elevated uraemic toxins significantly reduced the morbidity risks of the twins....

  20. The Danish Twin Registry

    DEFF Research Database (Denmark)

    Skytthe, Axel; Christiansen, Lene; Kyvik, Kirsten Ohm;

    2013-01-01

    decade of combining questionnaire and survey data with national demographic, social, and health registers in Statistics Denmark. Second, we describe our most recent data collection effort, which was conducted during the period 2008-2011 and included both in-person assessments of 14,000+ twins born 1931......Over the last 60 years, the resources and the research in the Danish Twin Registry (DTR) have periodically been summarized. Here, we give a short overview of the DTR and a more comprehensive description of new developments in the twenty-first century. First, we outline our experience over the last......-1969 and sampling of biological material, hereby expanding and consolidating the DTR biobank. Third, two examples of intensively studied twin cohorts are given. The new developments in the DTR in the last decade have facilitated the ongoing research and laid the groundwork for new research directions....

  1. Fundamental Composite (Goldstone) Higgs Dynamics

    DEFF Research Database (Denmark)

    Cacciapaglia, G.; Sannino, Francesco

    2014-01-01

    We provide a unified description, both at the effective and fundamental Lagrangian level, of models of composite Higgs dynamics where the Higgs itself can emerge, depending on the way the electroweak symmetry is embedded, either as a pseudo-Goldstone boson or as a massive excitation of the conden......We provide a unified description, both at the effective and fundamental Lagrangian level, of models of composite Higgs dynamics where the Higgs itself can emerge, depending on the way the electroweak symmetry is embedded, either as a pseudo-Goldstone boson or as a massive excitation...... of the condensate. We show that, in general, these states mix with repercussions on the electroweak physics and phenomenology. Our results will help clarify the main differences, similarities, benefits and shortcomings of the different ways one can naturally realize a composite nature of the electroweak sector...... transforming according to the fundamental representation of the gauge group. This minimal choice enables us to use recent first principle lattice results to make the first predictions for the massive spectrum for models of composite (Goldstone) Higgs dynamics. These results are of the upmost relevance to guide...

  2. Maternal nutrition in twin pregnancy.

    Science.gov (United States)

    Campbell, D M; MacGillivray, I; Tuttle, S

    1982-01-01

    Energy and protein intake as measured by 24-hour urinary nitrogen values are similar in twin and singleton pregnancies. The relationship between urinary nitrogen and nitrogen intake is equally significant in twin and singleton pregnancies. Dietary zinc, copper, and iron are not different in women with twins, nor are the levels of these elements in plasma. These observations are surprising in view of the extra fetal demands on the mother and the different adaptation of twin pregnancies.

  3. Five-fold twin formation during annealing of nanocrystalline Cu

    Energy Technology Data Exchange (ETDEWEB)

    Bringa, E M; Farkas, D; Caro, A; Wang, Y M; McNaney, J; Smith, R

    2009-05-20

    Contrary to the common belief that many-fold twins, or star twins, in nanophase materials are due to the action of significant external stresses, we report molecular dynamics simulations of annealing in 5 nm grain size samples annealed at 800 K for nearly 0.5 nsec at 0 external pressure showing the formation of five-fold star twins during annealing under the action of the large internal stresses responsible for grain growth and microstructural evolution. The structure of the many-fold twins is remarkably similar to those we have found to occur under uniaxial shock loading, of samples of nanocrystalline NiW with a grain size of {approx}5-30 nm. The mechanism of formation of the many-fold twins is discussed in the light of the simulations and experiments.

  4. Twins for epigenetic studies of human aging and development

    DEFF Research Database (Denmark)

    Tan, Qihua; Christiansen, Lene; Thomassen, Mads

    2013-01-01

    , our understanding of genetic and environmental influences on the epigenetic processes remains limited. Twins are of special interest for genetic studies due to their genetic similarity and rearing-environment sharing. The classical twin design has made a great contribution in dissecting the genetic...... and environmental contributions to human diseases and complex traits. In the era of functional genomics, the valuable sample of twins is helping to bridge the gap between gene activity and the environments through epigenetic mechanisms unlimited by DNA sequence variations. We propose to extend the classical twin...... design to study the aging-related molecular epigenetic phenotypes and link them with environmental exposures especially early life events. Different study designs and application issues will be highlighted and novel approaches introduced with aim at making uses of twins in assessing the environmental...

  5. Suppression of superconductivity by twin boundaries in FeSe.

    Science.gov (United States)

    Song, Can-Li; Wang, Yi-Lin; Jiang, Ye-Ping; Wang, Lili; He, Ke; Chen, Xi; Hoffman, Jennifer E; Ma, Xu-Cun; Xue, Qi-Kun

    2012-09-28

    Low-temperature scanning tunneling microscopy and spectroscopy are employed to investigate twin boundaries in stoichiometric FeSe films grown by molecular beam epitaxy. Twin boundaries can be unambiguously identified by imaging the 90° change in the orientation of local electronic dimers from Fe site impurities on either side. Twin boundaries run at approximately 45° to the Fe-Fe bond directions, and noticeably suppress the superconducting gap, in contrast with the recent experimental and theoretical findings in other iron pnictides. Furthermore, vortices appear to accumulate on twin boundaries, consistent with the degraded superconductivity there. The variation in superconductivity is likely caused by the increased Se height in the vicinity of twin boundaries, providing the first local evidence for the importance of this height to the mechanism of superconductivity.

  6. The Higgs of the Higgs and the diphoton channel

    Science.gov (United States)

    Kannike, Kristjan; Pelaggi, Giulio Maria; Salvio, Alberto; Strumia, Alessandro

    2016-07-01

    LHC results do not confirm conventional natural solutions to the Higgs mass hierarchy problem, motivating alternative interpretations where a hierarchically small weak scale is generated from a dimension-less quantum dynamics. We propose weakly and strongly-coupled models where the field that breaks classical scale invariance giving mass to itself and to the Higgs is identified with a possible new resonance within the LHC reach. As an example, we identify such resonance with the 750 GeV diphoton excess recently reported by ATLAS and CMS. Such models can be extrapolated up to the Planck scale, provide Dark Matter candidates and eliminate the SM vacuum instability.

  7. The Higgs of the Higgs and the diphoton channel

    CERN Document Server

    Kannike, Kristjan

    2016-01-01

    LHC results do not confirm conventional natural solutions to the Higgs mass hierarchy problem, motivating alternative interpretations where a hierarchically small weak scale is generated from a dimension-less quantum dynamics. We propose weakly and strongly-coupled models where the field that breaks classical scale invariance giving mass to itself and to the Higgs is identified with a possible new resonance within the LHC reach. As an example, we identify such resonance with the 750 GeV diphoton excess recently reported by ATLAS and CMS. Such models can be extrapolated up to the Planck scale, provide Dark Matter candidates and eliminate the SM vacuum instability.

  8. Search for the Standard Model Higgs Boson at DØ in the Final State with Two τ's and Two Jets

    Energy Technology Data Exchange (ETDEWEB)

    Tschann-Grimm, Kathryn [Stony Brook Univ., NY (United States)

    2011-08-01

    The Standard Model (SM) is a very successful description of particle physics, and its predictions have stood up to a multitude of precision experimental tests. But one of the central elements of the SM, the Higgs mechanism, has yet to be verified. The Higgs mechanism (and the associated Higgs Boson) generates electroweak symmetry breaking and consequently allows for W and Z bosons and fermions to be massive. This thesis presents a search for the SM Higgs boson at the D0 experiment using the Tevatron particle accelerator at Fermilab in the final state ττ + jet jet with 4.3 fb-1 of data. This final state is sensitive to the Higgs production mechanisms gluon-gluon fusion and vector-boson fusion, and to the Higgs produced in association with a W or Z, for Higgs masses from 100 to 200 GeV. We see no evidence for the Higgs boson, but by itself our search does not rule out the SM Higgs. When this analysis is combined with other searches at the Tevatron the Higgs can be ruled out at a 95% confidence level for the mass range from 156 to 177 GeV.

  9. Relativistic twins or sextuplets?

    CERN Document Server

    Sheldon, E S

    2003-01-01

    A recent study of the relativistic twin 'paradox' by Soni in this journal affirmed that 'A simple solution of the twin paradox also shows anomalous behaviour of rigidly connected distant clocks' but entailed a pedagogic hurdle which the present treatment aims to surmount. Two scenarios are presented: the first 'flight-plan' is akin to that depicted by Soni, with constant-velocity segments, while the second portrays an alternative mission undertaken with sustained acceleration and deceleration, illustrated quantitatively for a two-way spacecraft flight from Earth to Polaris (465.9 light years distant) and back.

  10. Imaging of conjoined twins

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, Kieran [Great Ormond Street Hospital for Children, Department of Radiology, London (United Kingdom); Kiely, Edward M.; Spitz, Lewis [Great Ormond Street Hospital for Children, Department of Surgery, London (United Kingdom)

    2006-09-15

    The incidence of conjoined twins is estimated to be around 1 in 250,000 live births. There is a distinct female predominance. In this paper the imaging of conjoined twins both antenatally and postnatally is reviewed, in particular taking into consideration recent advances with multidetector CT. Accurate counselling of parents regarding the likely outcome of the pregnancy and the likelihood of successful separation is dependent on good prenatal imaging with ultrasound and MRI. Planning of postnatal surgical separation is aided by accurate preoperative imaging which, depending on the conjoined area, will encompass many imaging modalities, but often relies heavily on CT scanning. (orig.)

  11. Higgs le boson manquant

    CERN Document Server

    Carroll, Sean; Evans, Lyn; Gagnon, Pauline; Bernet, Lison

    2013-01-01

    Ce livre conte l'histoire de la plus fascinante aventure scientifique de notre temps : la quête du "boson de Higgs". La découverte présumée de cette particule élémentaire en juillet 2012 a secoué le monde, tant pour son étrangeté que pour la démesure des moyens déployés. Qu'on en juge : un accélérateur de 27 km de circonférence sous la frontière franco-suisse - le LHC, la plus grande machine jamais construite par l'Homme-, une équipe de 6 000 chercheurs, techniciens, ingénieurs, informaticiens, etc., et un budget de plus de 9 milliards de $ ! L'auteur, cosmologiste et vulgarisateur de renom, nous révèle les enjeux de cette recherche ultime : le boson expliquerait ni plus ni moins pourquoi la matière qui nous entoure a une masse, et lèverait un coin du voile qui entoure la mystérieuse "matière noire". Il détaille surtout sa genèse et les rivalités, les doutes mais aussi les intuitions géniales des acteurs du projet. Cette galerie de personnages hors norme font de la lecture de ce li...

  12. Higgs doublet as a Goldstone boson in perturbative extensions of the Standard Model

    CERN Document Server

    Bellazzini, Brando; Rychkov, Vyacheslav S; Varagnolo, Alvise

    2008-01-01

    We investigate the idea of the Higgs doublet as a pseudo-Goldstone boson in perturbative extensions of the Standard Model, motivated by the desire to ameliorate its hierarchy problem without conflict with the electroweak precision data. Two realistic supersymmetric models with global SU(3) symmetry are proposed, one for large and another for small values of tan\\beta. The two models demonstrate two different mechanisms for EWSB and the Higgs mass generation. Their experimental signatures are quite different. Our constructions show that a pseudo-Goldstone Higgs doublet in perturbative extensions is just as plausible as in non-perturbative ones.

  13. Search for ttH Production with Higgs Decays to b quarks at ATLAS

    CERN Document Server

    Keller, John; The ATLAS collaboration

    2016-01-01

    Observing Higgs boson production in association with a pair of top quarks would allow a direct measurement of the top quark Yukawa coupling and provide an important test of the Higgs mechanism within the Standard Model. A search for this process is presented using pp collisions at sqrt(s) = 13 TeV, collected with the ATLAS detector in 2015 and 2016. Higgs boson decays to two b quarks, and top pair decays with one or two leptons, are considered. The results are combined with ttH searches in other decay channels.

  14. Galilean symmetry in generalized Abelian Schrödinger-Higgs models with and without gauge field interaction

    Science.gov (United States)

    Sourrouille, Lucas

    2015-11-01

    We consider a generalization of non-relativistic Schrödinger-Higgs Lagrangian by introducing a nonstandard kinetic term. We show that this model is Galilean invariant, we construct the conserved charges associated to the symmetries and realize the algebra of the Galilean group. In addition, we study the model in the presence of a gauge field. We also show that the gauged model is Galilean invariant. Finally, we explore relations between the twin models and their solutions.

  15. Dark Matter constraints on composite Higgs models

    Science.gov (United States)

    Fonseca, Nayara; Funchal, Renata Zukanovich; Lessa, Andre; Lopez-Honorez, Laura

    2015-06-01

    In composite Higgs models the pseudo-Nambu-Goldstone Boson (pNGB) nature of the Higgs field is an interesting alternative for explaining the smallness of the electroweak scale with respect to the beyond the Standard Model scale. In non-minimal models additional pNGB states are present and can be a Dark Matter (DM) candidate, if there is an approximate symmetry suppressing their decay. Here we assume that the low energy effective theory (for scales much below the compositeness scale) corresponds to the Standard Model with a pNGB Higgs doublet and a pNGB DM multiplet. We derive general effective DM Lagrangians for several possible DM representations (under the SM gauge group), including the singlet, doublet and triplet cases. Within this framework we discuss how the DM observables (relic abundance, direct and indirect detection) constrain the dimension-6 operators induced by the strong sector assuming that DM behaves as a Weakly Interacting Particle (WIMP) and that the relic abundance is settled through the freeze-out mechanism. We also apply our general results to two specific cosets: SO(6)/SO(5) and SO(6)/SO(4)×SO(2), which contain a singlet and doublet DM candidate, respectively. In particular we show that if compositeness is a solution to the little hierarchy problem, representations larger than the triplet are strongly disfavored. Furthermore, we find that composite models can have viable DM candidates with much smaller direct detection cross-sections than their non-composite counterparts, making DM detection much more challenging.

  16. And what if the Higgs boson did not exist; Si le boson de Higgs n'existait pas

    Energy Technology Data Exchange (ETDEWEB)

    Cho, A.; Daninos, F.; Baruch, J.O

    2008-11-15

    This series of articles presents the quest for the Higgs boson at the LHC (Large Hadron Collider). Different hypothesis are studied. First the Higgs boson is discovered and nothing else: no new particles and no new decay schemes. This hypothesis would mean that there would be no need for new physics. The second hypothesis is that the Higgs boson is not discovered and no new particles has appeared, in that case quantum mechanics and relativity would be seriously questioned. The third hypothesis is that a lot of exotic particles included the Higgs boson are discovered. This hypothesis is by far the most promising because it would solve troublesome issues linked to the standard model and would open the way for more fundamental theories like supersymmetry. The Atlas detector was designed to detect and select events resulting from the decay channels of the Higgs that are shorter than 10{sup -24} seconds. Alternative models that operate without Higgs boson have been studied since long. One of the most recent relies on the existence of a fifth compacted dimension. This model implies the existence of particles similar to W and Z bosons concerning quantum features but with a higher mass: between 500 and 1000 GeV. These particles could be detected in the LHC in its second phase of operation. Scores of physicists are working on the new generation of particle accelerators. The ILC (International Linear Collider) project is based on a 31 km long linear accelerator in which electrons and positrons will collide at an energy ranging from 0.5 to 1 TeV. (A.C.)

  17. An advanced perspective on twin growth in Nickel-Titanium

    Science.gov (United States)

    Ezaz, Tawhid

    2011-12-01

    This work presents an energetic approach to investigate the attributes of twinning in Nickel-Titanium (NiTi) shape memory alloy. In particular, atomistic mechanisms of twin growth in two different phases of NiTi are characterized with barrier energy in this thesis. In addition, energetics of dislocation twin boundary interactions in a face centered cubic (fcc) metal (Copper) that contributes to strengthening is investigated. Density Functional Theory based ab initio calculation and Molecular dynamics (MD) correspond to the right length and time scale for these events, and utilized in this study. The first part of the work elucidates the details of twinning in martensite (B19') and austenite (B2) as the major deformation mode in NiTi undergoing thermoelastic phase transformation. Combined shears, shuffles and interface shifts are operative in a complicated way to generate different twin modes in these two phases. Along with the growth mechanism, we report on generalized planar fault energy and generalized stacking fault energy barriers in NiTi shape memory alloys in the monoclinic martensite state and cubic austenitic state. Specifically, in martensitic regime, we report energy barriers for (001), (100) and (201) type twin nucleation and growth with atomistic details of combined shear and shuffle. Our energetic approach successfully predicts the evolution of deformation twins in martensite that are observed in experimental studies. In addition, we investigate the (112) and (114) deformation twin formation mechanism in austenitic NiTi that provides enhanced ductility in this intermetallic compound. The entire potential energy surface (PES) and mean energy path (MEP) during twinning is an outcome of our simulations, providing the needed insight to the atomistic processes. We suggest that the results provide a quantitative methodology in development of new shape memory alloys where twinning can occur at stress levels far below that corresponding to plastic deformation

  18. The 4D Composite Higgs

    CERN Document Server

    De Curtis, Stefania; Tesi, Andrea

    2012-01-01

    We propose a four dimensional description of Composite Higgs Models which represents a complete framework for the physics of the Higgs as a pseudo-Nambu-Goldstone boson. Our setup captures all the relevant features of 5D models and more in general of composite Higgs models with partial compositeness. We focus on the minimal scenario where we include a single multiplet of resonances of the composite sector, as these will be the only degrees of freedom which might be accessible at the LHC. This turns out to be sufficient to compute the effective potential and derive phenomenological consequences of the theory. Moreover our simplified approach is well adapted to simulate these models at the LHC. We also consider the impact of non-minimal terms in the effective lagrangian which do not descend from a 5D theory and could be of phenomenological relevance, for example contributing to the S-parameter.

  19. Higgs physics at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Margaroli, Fabrizio

    2014-09-15

    We show the latest results from the CDF and D0 collaborations on the study of the Higgs boson, stemming from the analysis of the entire Tevatron Run\\,II dataset. Combining the results of many individual analyses, most of which use the full data set available, an excess with a significance of approximately three standard deviations with respect to the Standard Model hypothesis is observed at a Higgs boson mass of 125\\,GeV/$c^2$. The Tevatron unique environment allows in addition to study for the first time the spin-parity hypothesis of the Higgs boson in events where it decays to quarks. Within the current experimental uncertainties, the newly discovered boson behaves as expected by the SM in the fermionic sector.

  20. Effect of Cr addition on the alloying behavior, microstructure and mechanical properties of twinned CoFeNiAl{sub 0.5}Ti{sub 0.5} alloy

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Zhiqiang, E-mail: kopyhit@163.com; Chen, Weiping; Fang, Sicong; Li, Xiaomei

    2014-03-01

    The effect of Cr addition on alloying behavior, microstructure and mechanical properties of multicomponent CoFeNiAl{sub 0.5}Ti{sub 0.5} high entropy alloy (HEA) was studied in detail. Non-equiatomic CoFeNiAl{sub 0.5}Ti{sub 0.5} and CrCoFeNiAl{sub 0.5}Ti{sub 0.5} alloys were fabricated by the combination of mechanical alloying (MA) and spark plasma sintering (SPS). Alloying behavior, microstructure, phase evolution and mechanical properties of the two alloys were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM), as well as by an Instron testing system. During MA, a supersaturated solid solution consisting of a metastable FCC phase was formed in CoFeNiAl{sub 0.5}Ti{sub 0.5} alloy. With Cr addition, the alloy showed a supersaturated solid solution with an FCC phase and a BCC phase. After SPS, bulk CoFeNiAl{sub 0.5}Ti{sub 0.5} alloy was composed of a main FCC phase, a minor BCC and a tiny unknown phase. The addition of Cr into CoFeNiAl{sub 0.5}Ti{sub 0.5} alloy exhibited two FCC phases (FCC1 and FCC2) with similar lattice constant and a tiny unknown phase, meanwhile selected area electron diffraction (SAED) pattern of the FCC1 phase was the same as that of the FCC phase of CoFeNiAl{sub 0.5}Ti{sub 0.5} alloy. Nanoscale twins presented in both of CoFeNiAl{sub 0.5}Ti{sub 0.5} and CrCoFeNiAl{sub 0.5}Ti{sub 0.5} alloys, but deformation twinning occurred only in the FCC phase of CoFeNiAl{sub 0.5}Ti{sub 0.5} and the FCC1 phase of the Cr added alloy which displayed the same SAED pattern. Moreover, the addition of Cr lowered the formation ability of nanoscale twins evidently. The addition of Cr into CoFeNiAl{sub 0.5}Ti{sub 0.5} alloy could decrease compressive strength and Vickers hardness slightly.

  1. Geneva University: Search for the Higgs Boson at the LHC

    CERN Multimedia

    2011-01-01

    GENEVA UNIVERSITY Ecole de physique Département de physique nucléaire et corspusculaire 24, quai Ernest-Ansermet 1211 Genève 4 Tél.: (022) 379 62 73 Fax: (022) 379 69 92 Wednesday 16 November  2011 SEMINAIRE DE PHYSIQUE CORPUSCULAIRE at 17.00 hrs – Stückelberg Auditorium Search for the Higgs Boson at the LHC Prof Karl Jakobs, Université de Freiburg, Allemagne One of the prime tasks of the physics programme of the LHC is the investigation of electroweak symmetry breaking. In the Standard Model the Higgs mechanism is invoked to give masses to the electroweak gauge bosons and fermions and to restore unitarity of the theory at high energies. Although the Higgs mechanism is one of the cornerstones of the Standard Model it is experimentally not validated and the associated Higgs boson has escaped detection so far. The data accumulated at the LHC in the years 2010/11 allow already to establish tighter constraints on the allow...

  2. Higgs production from sterile neutrinos at future lepton colliders

    Science.gov (United States)

    Antusch, Stefan; Cazzato, Eros; Fischer, Oliver

    2016-04-01

    In scenarios with sterile (right-handed) neutrinos that are subject to an approximate "lepton-number-like" symmetry, the heavy neutrinos (i.e. the mass eigenstates) can have masses around the electroweak scale and couple to the Higgs boson with, in principle, unsuppressed Yukawa couplings while accounting for the smallness of the light neutrinos' masses. In these scenarios, the on-shell production of heavy neutrinos and their subsequent decays into a light neutrino and a Higgs boson constitutes a hitherto unstudied resonant contribution to the Higgs production mechanism. We investigate the relevance of this resonant mono-Higgs production mechanism in leptonic collisions, including thepresent experimental constraints on the neutrino Yukawa couplings, and we determine the sensitivity of future lepton colliders to the heavy neutrinos. With Monte Carlo event sampling and a simulation of the detector response we find that, at future lepton colliders, neutrino Yukawa couplings below the percent level can lead to observable deviations from the SM and, furthermore, the sensitivity improves with higher center-of-mass energies (for identical integrated luminosities).

  3. Degenerate Higgs bosons: hiding a second Higgs at 125 GeV

    CERN Document Server

    Chen, Ning

    2016-01-01

    More than one Higgs boson may be present near the currently discovered Higgs mass, which can not be properly resolved due to the limitations in the intrinsic energy resolution at the Large Hadron Collider. We investigated the scenarios where two $CP$-even Higgs bosons are degenerate in mass. To correctly predict the Higgs signatures, quantum interference effects between the two Higgs bosons must be taken into account, which, however, has been often neglected in the literature. We carried out a global analysis including the interference effects for a variety of Higgs searching channels at the Large Hadron Collider, which suggests that the existence of two degenerate Higgs bosons near 125 GeV is highly likely. Prospects of distinguishing the degenerate Higgs case from the single Higgs case are discussed.

  4. Weighing in on the Higgs

    CERN Document Server

    Erler, Jens

    2012-01-01

    Assuming the validity of the Standard Model, or more generally that possible physics beyond it would have only small effects on production cross sections, branching ratios and electroweak radiative corrections, I determine the mass of the Higgs boson to 124.5 +- 0.8 GeV at the 68% CL. This is arrived at by combining electroweak precision data with the results of Higgs boson searches at LEP 2, the Tevatron, and the LHC. The statistical interpretation of the method does not require a look-elsewhere effect correction.

  5. Chemicals effect on the enzymatic digestibility of rape straw over the thermo-mechanical pretreatment using a continuous twin screw-driven reactor (CTSR).

    Science.gov (United States)

    Um, Byung-Hwan; Choi, Chang Ho; Oh, Kyeong Keun

    2013-02-01

    Rape straw pretreated by a continuous twin screw-driven reactor (CTSR) with hot water presented a distinctive particle-size distribution profile as a function of the operating temperature. The relative amount of finer particle size dramatically increased as the ratio of solid to liquid was increased. Size reduction through physical CTSR process effectively promoted the enzymatic hydrolysis of pretreated rape straw. Meanwhile, the crystallinity of the physically pretreated straw was not a greater factor affecting the enzyme digestibility. The glucose conversion from the enzymatic hydrolysis of the straw pretreated by CTSR with hot water was maximized at 52%. Using the chemicals as catalyst have affected considerably for increasing the digestibility at same condition with hot water pretreatment. The enzymatic digestibilities of the straw pretreated by CTSR with sodium hydroxide and sulfuric acid were 60% and 77%, respectively.

  6. Retinol-binding protein 4 in twins: regulatory mechanisms and impact of circulating and tissue expression levels on insulin secretion and action

    DEFF Research Database (Denmark)

    Ribel-Madsen, Rasmus; Friedrichsen, Martin; Vaag, Allan

    2009-01-01

    OBJECTIVE: Retinol-binding protein (RBP) 4 is an adipokine of which plasma levels are elevated in obesity and type 2 diabetes. The aims of the study were to identify determinants of plasma RBP4 and RBP4 mRNA expression in subcutaneous adipose tissue (SAT) and skeletal muscle and to investigate...... expression was not associated with circulatory RBP4. CONCLUSIONS: In conclusion, our data indicate that RBP4 levels in plasma, skeletal muscle, and fat may be linked to insulin resistance and type 2 diabetes in a secondary and noncausal manner....... the association between RBP4 and in vivo measures of glucose metabolism. RESEARCH DESIGN AND METHODS: The study population included 298 elderly twins (aged 62-83 years), with glucose tolerance ranging from normal to overt type 2 diabetes, and 178 young (aged 25-32 years) and elderly (aged 58-66 years) nondiabetic...

  7. The formation of radiation-induced segregation at twin bands in ion-irradiated austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Hyung-Ha; Lee, Gyeong-Geun; Kwon, Junhyun; Hwang, Seong Sik [Nuclear Materials Division, Korea Atomic Energy Research Institute, 1045 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Shin, Chansun, E-mail: c.shin@mju.ac.kr [Department of Materials Science and Engineering, Myongji University, 116 Myongji-ro, Cheoin-gu, Youngin, Gyeonggi-do 449-728 (Korea, Republic of)

    2014-11-15

    Radiation-induced segregation (RIS) at twins was investigated using transmission electron microscopy (TEM) for ion-irradiated austenitic stainless steel. Significant RIS was found to occur at twin boundaries. TEM analysis indicates that interfacial dislocations at partially coherent twin boundaries are potential sites for strong RIS phenomenon. The RIS causes the formation of thin bands having a higher Ni and lower Cr concentration in twin bands with a width less than 15 nm. In wider twin bands, strong RIS occurs only at the outer twin boundaries, but not inside the band. The possible mechanism for the formation of the RIS thin band is discussed.

  8. Identical Twins Raised Apart

    Science.gov (United States)

    Farnsworth, David L.

    2015-01-01

    This article describes a bivariate data set that is interesting to students. Indeed, this particular data set, which involves twins and IQ, has sparked more student interest than any other set that I have presented. Specific uses of the data set are presented.

  9. Sleep Terrors in Twins

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-12-01

    Full Text Available In an attempt to clarify the genetic and environmental causes of sleep terrors in childhood, reasearchers in Canada followed 390 pairs of monozygotic and dizygotic twins by assessing the frequency of sleep terrors at 18 and 30 months of age using a questionnaire administered to the biological mothers.

  10. Twin Hub Network (poster)

    NARCIS (Netherlands)

    Kreutzberger, E.D.; Konings, J.W.

    2014-01-01

    Twin hub network, a European Interreg IVB project, aims at making intermodal rail transport within, to and from North West Europe more competitive, in particular between seaports and inland terminals. Improving rail competitiveness enables to shift freight flows from road to rail, providing a more s

  11. Amelia in Twin Pregnancy

    Directory of Open Access Journals (Sweden)

    Davari Tanha Fatemeh

    2009-04-01

    Full Text Available Limb bud first appears during the third week of gestation with the upper limb buds appearing a few days before the lower limb buds. Complete absence of one or more limbs, called Amelia, occurs prior to the eighth week of gestation. We report a case of Amelia in a twin gestation.

  12. TWIN BLOCK (Studi Pustaka

    Directory of Open Access Journals (Sweden)

    Evie Lamtiur

    2015-08-01

    Full Text Available Young patients with class II skeletal malocclusion are often found. To avoid further discrepancy of this case, myofunctional therapy is one of the options. Functional appliance often used for such treatment. Functional appliance has been modified since activator was introduced by Andresen. With its bulky shape, activator makes difficulty for patient to speak and eat. Patient unable to wear it full time due to uncomfortness and negative facial appearance. In 1977, Clark developed twin block to overcome the weakness of previous appliances. A more simple design allows patient to be more comfortable and willing to wear it longer. Twin block is myofunctional appliance to reposition the mandible forward for skeletal class II correction with retruded mandible. This paper describes the design, clinical management effects of twin block treatment and brief case presentation using twin block appliance. Similar to the study reports found, this case revealed improvement of facial appearance, decrease overjet and overbite, improvement of molar relationship and good compliance of patient.

  13. Twin-twin transfusion syndrome - diagnosis and prognosis

    Directory of Open Access Journals (Sweden)

    Hajrić-Egić Amira

    2003-01-01

    Full Text Available Twin-twin transfusion syndrome is a serious complication of monozygotic, monochorionic, diamniotic twins resulting from transplacental vascular communications. In this syndrome blood is thought to be shunted from one twin - donor,who develops anaemia,growth retardation and oligoamnios, to the other twin - recipient,who becomes plethoric,macrosomic and develops polyhydroamnios. The incidence of twin-twin transfusion syndrome ranges from 5-15% of all twin pregnancies. If this condition develops in the second trimester, it is usually associated with spontaneous abortion and death of one or both fetuses before viability. Developing the syndrome in the third trimester has better perinatal outcome. Mortality rates ranging from 56%-100%, depending on gestational age and severity of the syndrome. The ultrasound criterias for diagnosis, in this study,were the presence of twins of the same sex with discordant growth, with oligohydroamnios in one twin sac and polyhydroamnios in the other one, one placenta and thin membrane between twins. The present study shows clinical course of 14 cases and value of Doppler ultrasound to analyze the usefulness of umbilical artery blood flow velocimetry for predicting the risk of twin-twin transfusion syndrome. 14 twin pregnancies with twin-twin transfusion syndrome were diagnosed during the last four years period and prospectivelly followed. 9 cases were diagnosed before the completion od 28 weeks of gestation.The mean gestational age was 21,6_+4,2 weeks at diagnosis and 23,2+_3,6 weeks at delivery. 5 cases were diagnosed after 28 weeks of gestation. The mean gestational age in this group was 29,6+_2,1 weeks at diagnosis and 33+_3,3 weeks at delivery. The survival rate in this study was 29%(8/28.9 cases ended in spontaneous abortion between 18th and 27th weeks of pregnancy (table 1 and 5 in premature labor (table 2.There were 7 intrauterine death (5 at admission and 2 few days after admission and 13 neonatal deaths

  14. Search for a high mass Higgs boson at 13 TeV using the ATLAS detector

    Energy Technology Data Exchange (ETDEWEB)

    Duda, Dominik; Ferrari, Pamela [Nikhef, Amsterdam (Netherlands)

    2016-07-01

    The Higgs sector in the Standard Model has been chosen such that it is as simple as possible. But indeed there is no theoretical restriction to the number of Higgs fields involved in the process of electroweak symmetry breaking and generation of particle masses. Several extensions of the Standard Model lead to an introduction of additional Higgs bosons into the Brout-Englert-Higgs-mechanism and thus predict the existence of a high mass scalar, as for example in Two Higgs Doublets Models, or Composite Higgs Models. The mass value of such particles extend up to the TeV scale. With the increased centre-of-mass energy √(s) and luminosity of the Run II of the LHC, the sensitivity to search for such particles is significantly enlarged and higher mass ranges become accessible as the size of the collected datasets increases. This talk presents the results of a search for heavy neutral Higgs bosons decaying via H → WW → lνq anti q using data collected at √(s) = 13 TeV by the ATLAS detector. In order to increase the sensitivity to search for particles at the TeV mass scale, boosted event topologies (i.e. events containing a large radius jet that is compatible with the decay of a high-p{sub T} W-boson into a hadronic final state) are studied. The scanned boson mass range extends from 0.5 to 3 TeV.

  15. Mitral valve regurgitation in twins

    DEFF Research Database (Denmark)

    Bakkestrøm, Rine; Larsen, Lisbeth Aagaard; Møller, Jacob Eifer

    2016-01-01

    BACKGROUND: Smaller observational studies have suggested familial clustering of mitral regurgitation (MR). Using a large twin cohort, the aims were to assess MR concordance rates and assess mortality in MR twins and unaffected cotwins. METHODS: Through the Danish Twin Registry, twins...... with an International Classification of Diseases, Eighth Revision and Tenth Revision diagnosis code of MR born 1880-1989 were identified and proband-wise concordance rates were calculated. To assess whether having a cotwin with MR affected survival, 10 matched twins without MR (n = 5,575) were selected for each MR twin...... (n = 562), and all-cause mortality rates were assessed. RESULTS: Among the 87,432 twins alive January 1, 1977, or later, 494 (0.57%) MR individuals were identified. Six MR concordant pairs were found, of which 3 were monozygotic. Proband-wise concordance rate when accounting for right censoring...

  16. 'Twin2twin' an innovative method of empowering midwives to strengthen their professional midwifery organisations.

    Science.gov (United States)

    Cadée, Franka; Perdok, Hilde; Sam, Betty; de Geus, Myrte; Kweekel, Liselotte

    2013-10-01

    midwives need professional support from a national midwifery organisation to be able to provide the services that are by regulatory mechanisms and accreditation expected of them. Not all midwives in the world are united in a professional organisation. The aim of this project was to strengthen the midwifery organisations of Sierra Leone and the Netherlands. During the process of the project it was realised that the development of a platform of exchange at organisational level would be enhanced by introducing personal exchange between individual midwives. In response to this new insight the original project plan was adjusted by incorporating the twin2twin method. twin2twin is a feminist methodology of mutual exchange between twenty pairs of midwives from different organisations (in this case Sierra Leone and the Netherlands). The method can be distinguished by 10 specific steps. It was developed, used and (re)evaluated through focus group discussions, storytelling and written evaluations. twinning of organisations was strengthened by adding a human component to the process. With the use of the 'twin2twin' method, midwives were encouraged to invested in a professional and personal bond with their 'twin sister'. This bond was independent and went beyond the relatively short four year project period. Through personal engagement and mutual exchange of knowledge and skills, midwives empowered each other to build and strengthen their midwifery organisations both in Sierra Leone and the Netherlands. (Empowerment refers to the expansion in people's ability to make strategic life choices in a context where this ability was previously denied to them (Narayan, 2005); organisational empowerment includes processes and structures that enhance members' skills and provides them with the mutual support necessary to effect community level change (Zimmerman, 1995).). despite challenges we are convinced that twin2twin can be of additional benefit for the success of other projects

  17. Prospects On Standard Model And Higgs Physics At The HL-LHC

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00221160; The ATLAS collaboration

    2016-01-01

    The luminosity upgrade of LHC, HL-LHC, will provide a large statistics data set that allows precision measurements of the 125 GeV Higgs boson properties. In particular, couplings to elementary fermions and bosons will be measured at the level of a few \\% accuracy. Searches for Higgs boson pair production and BSM effects in the vector boson scattering, of primary importance in the investigations of the electroweak symmetry breaking mechanism, also represent crucial point in the HL-LHC physics programme.

  18. The symmetry and simplicity of the laws of physics and the Higgs boson

    CERN Document Server

    Maldacena, Juan

    2014-01-01

    We describe the theoretical ideas, developed between the 1950s-1970s, which led to the prediction of the Higgs boson, the particle that was discovered in 2012. The forces of nature are based on symmetry principles. We explain the nature of these symmetries through an economic analogy. We also discuss the Higgs mechanism, which is necessary to avoid some of the naive consequences of these symmetries, and to explain various features of elementary particles.

  19. Brazilian Twin Registry: A Bright Future for Twin Studies/Twin Research: Twin Study of Alcohol Consumption and Mortality; Oxygen Uptake in Adolescent Twins/In the News: Superfecundated Twins In Vietnam; Adolescent Twin Relations; Twin and Triplet Co-Workers; A Special Twin Ultrasound; Monozygotic Twins With Different Skin Color; Identical Twin Returns from Space.

    Science.gov (United States)

    Segal, Nancy L

    2016-06-01

    The establishment of the Brazilian Twin Registry for the study of genetic, social, and cultural influences on behavior is one of eleven newly funded projects in the Department of Psychology at the University of São Paulo. These 11 interrelated projects form the core of the university's Center for Applied Research on Well-Being and Human Behavior. An overview of the planned twin research and activities to date is presented. Next, two recent twin studies are reviewed, one on the relationship between alcohol consumption and mortality, and the other on factors affecting maximal oxygen uptake. Twins cited in the media include the first identified superfecundated twins in Vietnam, adolescent twin relations, twins and triplets who work together, monozygotic twins with different skin tones and a co-twin control study that addresses the effects of space travel.

  20. Top quark and neutrino composite Higgs bosons

    Energy Technology Data Exchange (ETDEWEB)

    Smetana, Adam [Czech Technical University in Prague, Institute of Experimental and Applied Physics, Prague 2 (Czech Republic)

    2013-08-15

    In the context of top-quark condensation models, the top quark alone is too light to saturate the correct value of the electroweak scale by its condensate. Within the seesaw scenario the neutrinos can have their Dirac masses large enough so that their condensates can provide a significant contribution to the value of the electroweak scale. We address the question of a phenomenological feasibility of the top-quark and neutrino condensation conspiracy against the electroweak symmetry. It is mandatory to reproduce the masses of electroweak gauge bosons, the top-quark mass and the recently observed scalar mass of 125 GeV and to satisfy the upper limits on absolute value of active neutrino masses. To accomplish that we design a reasonably simplified effective model with two composite Higgs doublets. Additionally, we work with a general number N of right-handed neutrino flavor triplets participating on the seesaw mechanism. There are no experimental constraints limiting this number. The upper limit is set by the model itself. Provided that the condensation scale is of order 10{sup 17-18} GeV and the number of right-handed neutrinos is O(100-1000), the model predicts masses of additional Higgs bosons below 250 GeV and a suppression of the top-quark Yukawa coupling to the 125 GeV particle at the {proportional_to}60 % level of the Standard model value. (orig.)

  1. Top quark and neutrino composite Higgs bosons

    Science.gov (United States)

    Smetana, Adam

    2013-08-01

    In the context of top-quark condensation models, the top quark alone is too light to saturate the correct value of the electroweak scale by its condensate. Within the seesaw scenario the neutrinos can have their Dirac masses large enough so that their condensates can provide a significant contribution to the value of the electroweak scale. We address the question of a phenomenological feasibility of the top-quark and neutrino condensation conspiracy against the electroweak symmetry. It is mandatory to reproduce the masses of electroweak gauge bosons, the top-quark mass and the recently observed scalar mass of 125 GeV and to satisfy the upper limits on absolute value of active neutrino masses. To accomplish that we design a reasonably simplified effective model with two composite Higgs doublets. Additionally, we work with a general number N of right-handed neutrino flavor triplets participating on the seesaw mechanism. There are no experimental constraints limiting this number. The upper limit is set by the model itself. Provided that the condensation scale is of order 1017-18 GeV and the number of right-handed neutrinos is , the model predicts masses of additional Higgs bosons below 250 GeV and a suppression of the top-quark Yukawa coupling to the 125 GeV particle at the ˜60 % level of the Standard model value.

  2. Higgs boson: the winner takes it all?

    CERN Multimedia

    Antonella Del Rosso

    2015-01-01

    Since its discovery in 2012, the Higgs boson has been in the spotlight for both experimentalists and theorists. In addition to its confirmed role in the mass mechanism, recent papers have discussed its possible role in the inflation of the universe and in the matter-antimatter imbalance. Can a single particle be responsible for everything?   “Since 2012 we have known that the Higgs boson exists, but its inner properties are yet to be completely uncovered,” says Gian Giudice, a member of the CERN Theory Unit. “Precise measurements of its decay modes are still ongoing and the LHC Run 2 will be essential to understand the nature of this particle at a deeper level.” What we know is that this boson is not “yet another particle” among the hundreds that we deal with every day in physics labs. In agreement with the Standard Model theory, the recent experimental data confirms that the particle discovered by the CERN experiments is the key pa...

  3. LHCb Exotica and Higgs searches

    CERN Document Server

    Lucchesi, Donatella

    2016-01-01

    LHCb Collaboration has the unique opportunity to search for Higgs production and new physics in regions not accessible by the other LHC experiments. The latest results obtained by exploiting final states with b and c jets with or without an isolated lepton are presented.

  4. Higgs boson properties in ATLAS

    CERN Document Server

    Mansoulie, Bruno; The ATLAS collaboration

    2017-01-01

    The measurement by the ATLAS collaboration of Higgs boson properties is presented, in terms of production cross-sections, simplified template cross-sections, couplings. The measurements are based on the analysis of the H decay channels to diphoton and 4 leptons, using 36.1 fb-1 of 13 TeV data recorded in 2015 and 2016.

  5. The Higgs boson and cosmology

    Science.gov (United States)

    Shaposhnikov, Mikhail

    2015-01-01

    I will discuss how the Higgs field of the Standard Model may have played an important role in cosmology, leading to the homogeneity, isotropy and flatness of the Universe; producing the quantum fluctuations that seed structure formation; triggering the radiation-dominated era of the hot Big Bang; and contributing to the processes of baryogenesis and dark matter production.

  6. Can A Pseudo-Nambu-Goldstone Higgs Lead To Symmetry Non-Restoration?

    CERN Document Server

    Kilic, Can

    2015-01-01

    The calculation of finite temperature contributions to the scalar potential in a quantum field theory is similar to the calculation of loop corrections at zero temperature. In natural extensions of the Standard Model where loop corrections to the Higgs potential cancel between Standard Model degrees of freedom and their symmetry partners, it is interesting to contemplate whether finite temperature corrections also cancel, raising the question of whether a broken phase of electroweak symmetry may persist at high temperature. It is well known that this does not happen in supersymmetric theories because the thermal contributions of bosons and fermions do not cancel each other. However, for theories with same spin partners, the answer is less obvious. Using the Twin Higgs model as a benchmark, we show that although thermal corrections do cancel at the level of quadratic divergences, subleading corrections still drive the system to a restored phase. We further argue that our conclusions generalize to other well-kn...

  7. The discovery and measurements of a Higgs boson.

    Science.gov (United States)

    Gianotti, F; Virdee, T S

    2015-01-13

    In July 2012, the ATLAS and CMS collaborations at CERN's Large Hadron Collider announced the discovery of a Higgs-like boson, a new heavy particle at a mass more than 130 times the mass of a proton. Since then, further data have revealed its properties to be strikingly similar to those of the Standard Model Higgs boson, a particle expected from the mechanism introduced almost 50 years ago by six theoreticians including British physicists Peter Higgs from Edinburgh University and Tom Kibble from Imperial College London. The discovery is the culmination of a truly remarkable scientific journey and undoubtedly the most significant scientific discovery of the twenty-first century so far. Its experimental confirmation turned out to be a monumental task requiring the creation of an accelerator and experiments of unprecedented capability and complexity, designed to discern the signatures that correspond to the Higgs boson. Thousands of scientists and engineers, in each of the ATLAS and CMS teams, came together from all four corners of the world to make this massive discovery possible.

  8. Evidence of Higgs Boson Production through Vector Boson Fusion

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00333580

    The discovery of the Higgs boson in 2012 provided confirmation of the proposed mechanism for preserving the electroweak $SU(2) \\times U(1)$ gauge symmetry of the Standard Model of particle physics. It also heralded in a new era of precision Higgs physics. This thesis presents a measurement of the rate at which the Higgs boson is produced by vector boson fusion in the \\wwlnln decay channel. With gauge boson couplings in both the production and decay vertices, a VBF measurement in this channel is a powerful probe of the $VVH$ vertex strength. Using $4.5$~fb$^{-1}$ and $20.3$~fb$^{-1}$ of $pp$ collision data collected at respective center-of-mass energies of 7 and $8 \\tev$ in the ATLAS detector, measurements of the statistical significance and the signal strength are carried out in the Higgs mass range $100 \\leq m_H \\leq 200 \\gev$. These measurements are enhanced with a boosted decision tree that exploits the correlations between eight kinematic inputs in order to separate signal and background processes. At the...

  9. Dark photon search and the Higgs-strahlung channel

    Science.gov (United States)

    Jaegle, Igal

    2013-04-01

    Many extensions of the Standard Model introduce an additional U(1) interaction, which is mediated by a U(1) boson, often by a Higgs mechanism adding a dark Higgs (or dark Higgses) to the models. This gauge boson, also known as the ``Dark Photon,'' typically has very weak coupling to Standard Model particles. Experimental results from direct Dark Matter searches, (e.g. DAMA/LIBRA) and other experimental anomalies (e.g. g-2), can be explained by such an additional interaction. Dark gauge bosons are typically of low mass; of order MeV to GeV. The ideal tools to discover such particles are therefore not high-energy collider experiments, but lower-energy high-luminosity collider experiments like Belle and BaBar, or dedicated fixed target experiments, several of which are planned or already under construction at JLAB (Newport News, USA) or at MAMI (Mainz, Germany), for example. In Belle, the search of the dark photon focuses on the so-called Higgs-strahlung channel, where a dark photon and a dark Higgs are produced. Preliminary results will be presented and discussed.

  10. Perturbative Unitarity Bounds in Composite 2-Higgs Doublet Models

    CERN Document Server

    De Curtis, Stefania; Yagyu, Kei; Yildirim, Emine

    2016-01-01

    We study bounds from perturbative unitarity in a Composite 2-Higgs Doublet Model (C2HDM) based on the spontaneous breakdown of a global symmetry $SO(6)\\to SO(4)\\times SO(2)$ at the compositeness scale $f$. The eight pseudo Nambu-Goldstone Bosons (pNGBs) emerging from such a dynamics are identified as two isospin doublet Higgs fields. We calculate the $S$-wave amplitude for all possible 2-to-2-body elastic (pseudo)scalar boson scatterings at energy scales $\\sqrt{s}$ reachable at the Large Hadron Collider (LHC) and beyond it, including the longitudinal components of weak gauge boson states as the corresponding pNGB states. In our calculation, the Higgs potential is assumed to have the same form as that in the Elementary 2-Higgs Doublet Model (E2HDM) with a discrete $Z_2$ symmetry, which is expected to be generated at the one-loop level via the Coleman-Weinberg (CW) mechanism. We find that the $S$-wave amplitude matrix can be block-diagonalized with maximally $2\\times 2$ submatrices in a way similar to the E2HDM...

  11. Hydropic Placenta as a First Manifestation of Twin-Twin Transfusion in a Monochorionic Diamniotic Twin Pregnancy

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Manten, Gwendoline T. R.; Nikkels, Peter G. J.; Stoutenbeek, Philip

    2009-01-01

    Monochorionic twin pregnancies are at a 10% to 1.5% risk of developing twin-twin transfusion syndrome (TTTS).(1) Monitoring such pregnancies is aimed at evaluating the fetal condition by measuring the amount of amniotic fluid, Doppler parameters, and fetal growth. Twin-twin transfusion syndrome may

  12. Hydropic Placenta as a First Manifestation of Twin-Twin Transfusion in a Monochorionic Diamniotic Twin Pregnancy

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Manten, Gwendoline T. R.; Nikkels, Peter G. J.; Stoutenbeek, Philip

    Monochorionic twin pregnancies are at a 10% to 1.5% risk of developing twin-twin transfusion syndrome (TTTS).(1) Monitoring such pregnancies is aimed at evaluating the fetal condition by measuring the amount of amniotic fluid, Doppler parameters, and fetal growth. Twin-twin transfusion syndrome may

  13. Hydropic Placenta as a First Manifestation of Twin-Twin Transfusion in a Monochorionic Diamniotic Twin Pregnancy

    NARCIS (Netherlands)

    de Laat, Monique W. M.; Manten, Gwendoline T. R.; Nikkels, Peter G. J.; Stoutenbeek, Philip

    2009-01-01

    Monochorionic twin pregnancies are at a 10% to 1.5% risk of developing twin-twin transfusion syndrome (TTTS).(1) Monitoring such pregnancies is aimed at evaluating the fetal condition by measuring the amount of amniotic fluid, Doppler parameters, and fetal growth. Twin-twin transfusion syndrome may

  14. Blocking effect of twin boundaries on partial dislocation emission from void surfaces.

    Science.gov (United States)

    Zhang, Lifeng; Zhou, Haofei; Qu, Shaoxing

    2012-03-02

    Recent discovery that nanoscale twin boundaries can be introduced in ultrafine-grained metals to improve strength and ductility has renewed interest in the mechanical behavior and deformation mechanisms of these nanostructured materials. By controlling twin boundary spacing, the effect of twin boundaries on void growth is investigated by using atomistic simulation method. The strength is significantly enhanced due to the discontinuous slip system associated with these coherent interfaces. Atomic-scale mechanisms underlying void growth, as well as the interaction between twin boundaries and the void, are revealed in details.

  15. Reared-Apart Chinese Twins: Chance Discovery/Twin-Based Research: Twin Study of Media Use; Twin Relations Over the Life Span; Breast-Feeding Opposite-Sex Twins/Print and Online Media: Twins in Fashion; Second Twin Pair Born to Tennis Star; Twin Primes; Twin Pandas.

    Science.gov (United States)

    Segal, Nancy L

    2017-04-01

    A January 2017 reunion of 10-year-old reared-apart Chinese twin girls was captured live on ABC's morning talk show Good Morning America, and rebroadcast on their evening news program Nightline. The twins' similarities and differences, and their participation in ongoing research will be described. This story is followed by reviews of twin research concerning genetic and environmental influences on media use, twin relations across the lifespan and the breast-feeding of opposite-sex twins. Popular interest items include twins in fashion, the second twin pair born to an internationally renowned tennis star, twin primes and twin pandas.

  16. Twins for epigenetic studies of human aging and development

    DEFF Research Database (Denmark)

    Tan, Qihua; Christiansen, Lene; Thomassen, Mads

    2013-01-01

    Most of the complex traits including aging phenotypes are caused by the interaction between genome and environmental conditions and the interface of epigenetics may be a central mechanism. Although modern technologies allow us high-throughput profiling of epigenetic patterns already at genome level......, our understanding of genetic and environmental influences on the epigenetic processes remains limited. Twins are of special interest for genetic studies due to their genetic similarity and rearing-environment sharing. The classical twin design has made a great contribution in dissecting the genetic...... and environmental contributions to human diseases and complex traits. In the era of functional genomics, the valuable sample of twins is helping to bridge the gap between gene activity and the environments through epigenetic mechanisms unlimited by DNA sequence variations. We propose to extend the classical twin...

  17. Twinning anisotropy of tantalum during nanoindentation

    Energy Technology Data Exchange (ETDEWEB)

    Goel, Saurav, E-mail: S.GOEL@qub.ac.uk [School of Mechanical and Aerospace Engineering, Queen' s University, Belfast, BT9 5AH (United Kingdom); Beake, Ben [Micro Materials Limited, Willow House, Yale Business Village, Ellice Way, Wrexham LL13 7YL (United Kingdom); Dalton Research Institute, Manchester Metropolitan University, Manchester, M15GD (United Kingdom); Chan, Chi-Wai [School of Mechanical and Aerospace Engineering, Queen' s University, Belfast, BT9 5AH (United Kingdom); Haque Faisal, Nadimul [School of Engineering, Robert Gordon University, Garthdee Road, Aberdeen AB10 7GJ (United Kingdom); Dunne, Nicholas [School of Mechanical and Aerospace Engineering, Queen' s University, Belfast, BT9 5AH (United Kingdom)

    2015-03-11

    Unlike other BCC metals, the plastic deformation of nanocrystalline Tantalum (Ta) during compression is regulated by deformation twinning. Whether or not this twinning exhibits anisotropy was investigated through simulation of displacement-controlled nanoindentation test using molecular dynamics (MD) simulation. MD data was found to correlate well with the experimental data in terms of surface topography and hardness measurements. The mechanism of the transport of material was identified due to the formation and motion of prismatic dislocations loops (edge dislocations) belonging to the 1/2〈111〉 type and 〈100〉 type Burgers vector family. Further analysis of crystal defects using a fully automated dislocation extraction algorithm (DXA) illuminated formation and migration of twin boundaries on the (110) and (111) orientation but not on the (010) orientation and most importantly after retraction all the dislocations disappeared on the (110) orientation suggesting twinning to dominate dislocation nucleation in driving plasticity in tantalum. A significant finding was that the maximum shear stress (critical Tresca stress) in the deformation zone exceeded the theoretical shear strength of Ta (Shear modulus/2π~10.03 GPa) on the (010) orientation but was lower than it on the (110) and the (111) orientations. In light of this, the conventional lore of assuming the maximum shear stress being 0.465 times the mean contact pressure was found to break down at atomic scale.

  18. Distinguishing a SM-like MSSM Higgs boson from SM Higgs boson at muon collider

    Indian Academy of Sciences (India)

    Jai Kumar Singhal; Sardar Singh; Ashok K Nagawat

    2007-06-01

    We explore the possibility of distinguishing the SM-like MSSM Higgs boson from the SM Higgs boson via Higgs boson pair production at future muon collider. We study the behavior of the production cross-section in SM and MSSM with Higgs boson mass for various MSSM parameters tan and A. We observe that at fixed CM energy, in the SM, the total cross-section increases with the increase in Higgs boson mass whereas this trend is reversed for the MSSM. The changes that occur for the MSSM in comparison to the SM predictions are quantified in terms of the relative percentage deviation in cross-section. The observed deviations in cross-section for different choices of Higgs boson masses suggest that the measurements of the cross-section could possibly distinguish the SM-like MSSM Higgs boson from the SM Higgs boson.

  19. The Higgs Pair Productions in The CP-violating Two-Higgs-Doublet Model

    CERN Document Server

    Bian, Ligong

    2016-01-01

    In this work, we study the SM-like Higgs pair productions in the framework of the general CP-violating two-Higgs-doublet model. Several constraints are imposed to the model sequentially, including the SM-like Higgs boson signal fits, the precise measurements of the electric dipole moments, the perturbative unitarity and stability bounds to the Higgs potential, and the most recent LHC searches for the heavy Higgs bosons. We show how are the CP-violating mixing angles related to the Higgs cubic self couplings in this setup. Afterwards, we estimate the cross sections of the future LHC/SppC searches for the Higgs pair productions, as well as other possible decay modes for the heavy Higgs bosons.

  20. The Effect of Twin Grain Boundary Tuned by Temperature on the Electrical Transport Properties of Monolayer MoS2

    OpenAIRE

    Luojun Du; Hua Yu; Li Xie; Shuang Wu; Shuopei Wang; Xiaobo Lu; Mengzhou Liao; Jianling Meng; Jing Zhao; Jing Zhang; Jianqi Zhu; Peng Chen; Guole Wang; Rong Yang; Dongxia Shi

    2016-01-01

    Theoretical calculation and experimental measurement have shown that twin grain boundary (GB) of molybdenum disulphide (MoS2) exhibits extraordinary effects on transport properties. Precise transport measurements need to verify the transport mechanism of twin GB in MoS2. Here, monolayer molybdenum disulphide with a twin grain boundary was grown in our developed low-pressure chemical vapor deposition (CVD) system, and we investigated how the twin GB affects the electrical transport properties ...