NASA Astrophysics Data System (ADS)
Passarino, Giampiero
2014-05-01
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 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.
NASA Astrophysics Data System (ADS)
Croteau, Etienne
L'objectif de ce projet de doctorat est de developper des outils quantitatifs pour le suivi des traitements de chimiotherapie pour le cancer du sein et de leurs effets cardiotoxiques a l'aide de l'imagerie TEP dynamique. L'analyse cinetique en TEP dynamique permet l'evaluation de parametres biologiques in vivo. Cette analyse peut etre utilise pour caracteriser la reponse tumorale a la chimiotherapie et les effets secondaires nefastes qui peuvent en resulter. Le premier article de cette these decrit la mise au point des techniques d'analyse cinetique qui utilisent la fonction d'entree d'un radiotraceur derive de l'image dynamique. Des corrections de contamination radioactive externe (epanchement) et de l'effet de volume partiel ont ete necessaires pour standardiser l'analyse cinetique et la rendre quantitative. Le deuxieme article porte sur l'evaluation d'un nouveau radiotraceur myocardique. Le 11C-acetoacetate, un nouveau radiotraceur base sur un corps cetonique, a ete compare au 11C-acetate, couramment utilise en imagerie cardiaque TEP. L'utilisation de 3H-acetate et 14C-acetoacetate ont permis d'elucider la cinetique de ces traceurs depuis la fonction d'entree et la captation par les mitochondries cardiaques qui reflete la consommation en oxygene, jusqu'a la liberation de leurs principaux metabolites reciproques (3H20 et 14CO2). Le troisieme et dernier article de cette these presente l'integration d'un modele qui evalue la reserve cardiaque de perfusion et de consommation en oxygene. Un modele de cardiomyopathie a ete etabli a l'aide d'un agent chimiotherapeutique contre le cancer du sein, la doxorubicine, reconnu comme etant cardiotoxique. Un protocole de repos/effort a permis d'evaluer la capacite d'augmentation de perfusion et de consommation en oxygene par le coeur. La demonstration d'une reserve cardiaque reduite caracterise la cardiotoxicite. La derniere contribution de cette these porte sur la mise au point de methodes peu invasives pour mesurer la
Peters, Krisztian
2009-11-01
We present the status and prospects of Higgs searches at the Tevatron and the LHC. Results from the Tevatron are using up to 5 fb{sup -} of data collected with the CDF and D0 detectors. The major contributing processes include associated production (WH {yields} l{nu}bb, ZH {yields} {nu}{nu}bb, ZH {yields} llbb) and gluon fusion (gg {yields} H {yields} WW{sup (*)}). Improvements across the full mass range resulting from the larger data sets, improved analyses techniques and increased signal acceptance are discussed. Recent results exclude the SM Higgs boson in a mass range of 160 < m{sub H} < 170 GeV. Searches for the neutral MSSM Higgs boson in the region 90 < m{sub A} < 200 GeV exclude tan {beta} values down to 30 for several benchmark scenarios.
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.
ERIC Educational Resources Information Center
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)
ERIC Educational Resources Information Center
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)
NASA Astrophysics Data System (ADS)
Matone, Marco
2017-09-01
We consider two related formulations for mass generation in the U (1) Higgs-Kibble model and in the Standard Model (SM). In the first formulation there are no scalar self-interactions and, in the case of the SM, the formulation is related to the normal subgroup of G = SU (3) × SU (2) × U (1), generated by (e 2 πi / 3 I , - I ,e πi / 3) ∈ G, that acts trivially on all the fields of the SM. The key step of our construction is to relax the non-negative definiteness condition for the Higgs field due to the polar decomposition. This solves several stringent problems, that we will shortly review, both at the non-perturbative and perturbative level. We will show that the usual polar decomposition of the complex scalar doublet Φ should be done with U ∈ SU (2) /Z2 ≃ SO (3), where Z2 is the group generated by -I, and with the Higgs field ϕ ∈ R rather than ϕ ∈R≥0. As a byproduct, the investigation shows how Elitzur theorem may be avoided in the usual formulation of the SM. It follows that the simplest lagrangian density for the Higgs mechanism has the standard kinetic term in addition to the mass term, with the right sign, and to a linear term in ϕ. The other model concerns the scalar theories with normal ordered exponential interactions. The remarkable property of these theories is that for D > 2 the purely scalar sector corresponds to a free theory.
NASA Astrophysics Data System (ADS)
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.
Diaz Cruz, J. Lorenzo
2008-07-02
This paper intends to review the subject of Higgs Physics. I start from the early stages, including its phenomenology and the current expectations for the possible Higgs discovery at the coming LHC. Then, I discuss the proposals for new physics that attempt to solve the hierarchy problem, where the Higgs boson can be either a fundamental or composite field. Finally, I also comment on the hardest questions, namely on the possible connection between the Higgs mechanism, the Standard Model parameters and gravity.
NASA Astrophysics Data System (ADS)
Kling, Felix
Many models of physics beyond the Standard Model include an extended Higgs sector, responsible for electroweak symmetry breaking, and predict the existence of additional Higgs bosons. The Type II Two-Higgs-Doublet Model (2HDM) is a particularly well motivated scenario and a suitable framework for phenomenological studies of extended Higgs sectors. Its low energy spectrum includes two CP-even Higgses h and H, one CP-odd Higgs A, and a pair of charged Higgses H +/-. We study the implication of the LHC Higgs search re- sults on the Type II 2HDM and identify regions of parameter space which are consistent with all experimental and theoretical constraints and can accommo- date the observed 125 GeV Higgs signal. This includes parameter space with a distinctive mass hierarchy which permit a sizable mass splitting between the undiscovered non-Standard Model Higgs states. If this mass splitting is large enough, exotic Higgs decay channels into either a Higgs plus a Standard Model gauge boson or two lighter Higgses open up. This can significantly weaken the reach of the conventional Higgs decay channels into Standard Model particles but also provide the additional opportunity to search for exotic Higgs decay channels. We provide benchmark planes to explore exotic Higgs decay scenar- ios and perform detailed collider analyses to study the exotic decay channels H/A → AZ/HZ and H+/- → AW/HW. We find that these exotic decays offer complementary discovery channels to the conventional modes for both neutral and charged Higgs searches and permit exclusion and discovery in large regions of parameter space.
NASA Astrophysics Data System (ADS)
Donato, Silvio; CMS Collaboration
2017-07-01
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.
Lincoln, Don
2016-11-16
The Higgs boson burst into the public arena on July 4, 2012, when scientists working at the CERN laboratory announced the particle’s discovery. However the initial discovery was a bit tentative, with the need to verify that the discovered particle was, indeed, the Higgs boson. In this video, Fermilab’s Dr. Don Lincoln looks at the data from the perspective of 2016 and shows that more recent analyses further supports the idea that the Higgs boson is what was discovered.
Dawson, S.; Haber, H.E.; Rindani, S.D.
1989-05-01
This is the summary report of the Higgs Boson Working Group. We discuss a variety of search techniques for a Higgs boson which is lighter than the Z. The processes K /yields/ /pi/H, /eta//prime/ /yields/ /eta/H,/Upsilon/ /yields/ H/gamma/ and e/sup +/e/sup /minus// /yields/ ZH are examined with particular attention paid to theoretical uncertainties in the calculations. We also briefly examine new features of Higgs phenomenology in a model which contains Higgs triplets as well as the usual doublet of scalar fields. 33 refs., 6 figs., 1 tab.
LHC diphoton Higgs signal predicted by little Higgs models
Wang Lei; Yang Jinmin
2011-10-01
Little Higgs theory naturally predicts a light Higgs boson whose most important discovery channel at the LHC is the diphoton signal pp{yields}h{yields}{gamma}{gamma}. In this work, we perform a comparative study for this signal in some typical little Higgs models, namely, the littlest Higgs model, two littlest Higgs models with T-parity (named LHT-I and LHT-II), and the simplest little Higgs models. We find that compared with the standard model prediction, the diphoton signal rate is always suppressed and the suppression extent can be quite different for different models. The suppression is mild (< or approx. 10%) in the littlest Higgs model but can be quite severe ({approx_equal}90%) in other three models. This means that discovering the light Higgs boson predicted by the little Higgs theory through the diphoton channel at the LHC will be more difficult than discovering the standard model Higgs boson.
NASA Astrophysics Data System (ADS)
Duerr, Michael; Grohsjean, Alexander; Kahlhoefer, Felix; Penning, Bjoern; Schmidt-Hoberg, Kai; Schwanenberger, Christian
2017-04-01
We discuss a novel signature of dark matter production at the LHC resulting from the emission of an additional Higgs boson in the dark sector. The presence of such a dark Higgs boson is motivated simultaneously by the need to generate the masses of the particles in the dark sector and the possibility to relax constraints from the dark matter relic abundance by opening up a new annihilation channel. If the dark Higgs boson decays into Standard Model states via a small mixing with the Standard Model Higgs boson, one obtains characteristic large-radius jets in association with missing transverse momentum that can be used to efficiently discriminate signal from backgrounds. We present the sensitivities achievable in LHC searches for dark Higgs bosons with already collected data and demonstrate that such searches can probe large regions of parameter space that are inaccessible to conventional mono-jet or di-jet searches.
Minimally symmetric Higgs boson
Low, Ian
2015-06-17
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)(L) x U(1)(Y) 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 among all models where the Higgs arises as a pseudo-Nambu-Goldstone boson. Very high energy scatterings of vector bosons could provide smoking gun signals of a minimally symmetric Higgs boson.
General composite Higgs models
NASA Astrophysics Data System (ADS)
Marzocca, David; Serone, Marco; Shu, Jing
2012-08-01
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 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 models to successfully pass the electroweak precision tests. Interestingly enough, the latter can also be passed by models with a heavy Higgs around 320 GeV. The composite Higgs models of the moose-type considered in the literature can be seen as particular limits of our class of models.
Lincoln, Don
2016-12-14
The Higgs boson burst into the public arena on July 4, 2012, when scientists working at the CERN laboratory announced the particleâs discovery. However the initial discovery was a bit tentative, with the need to verify that the discovered particle was, indeed, the Higgs boson. In this video, Fermilabâs Dr. Don Lincoln looks at the data from the perspective of 2016 and shows that more recent analyses further supports the idea that the Higgs boson is what was discovered.
NASA Astrophysics Data System (ADS)
Holdom, B.
2014-07-01
We suggest that the Higgs boson is a light composite state that does not emerge from TeV scale strong dynamics for any generic reason, such as when it is pseudo-Goldstone boson. Instead, a state that is Higgs-like and fairly decoupled from heavier states may simply be a reflection of very particular strong dynamics, with properties quite distinct from more familiar large-Nc type gauge dynamics. We elaborate on this picture in the context of a strongly interacting fourth family and an effective 4-Higgs-doublet model. The origin of a decoupling limit and the corrections to it are discussed.
Asymptotically safe Higgs inflation
Xianyu, Zhong-Zhi; He, Hong-Jian E-mail: hjhe@tsinghua.edu.cn
2014-10-01
We construct a new inflation model in which the standard model Higgs boson couples minimally to gravity and acts as the inflaton. Our construction of Higgs inflation incorporates the standard model with Einstein gravity which exhibits asymptotic safety in the ultraviolet region. The slow roll condition is satisfied at large field value due to the asymptotically safe behavior of Higgs self-coupling at high energies. We find that this minimal construction is highly predictive, and is consistent with both cosmological observations and collider experiments.
Higgs scalaron mixed inflation
NASA Astrophysics Data System (ADS)
Ema, Yohei
2017-07-01
We discuss the inflationary dynamics of a system with a non-minimal coupling between the Higgs and the Ricci scalar as well as a Ricci scalar squared term. There are two scalar modes in this system, i.e. the Higgs and the spin-zero mode of the graviton, or the scalaron. We study the two-field dynamics of the Higgs and the scalaron during inflation, and clarify the condition where inflation is dominated by the Higgs/scalaron. We also find that the cut-off scale at around the vacuum is as large as the Planck scale, and hence there is no unitarity issue, although there is a constraint on the couplings from the perturbativity of the theory at around the vacuum.
NASA Astrophysics Data System (ADS)
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.
Higgs dynamics during inflation
Enqvist, Kari; Meriniemi, Tuukka; Nurmi, Sami E-mail: tuukka.meriniemi@helsinki.fi
2014-07-01
We investigate inflationary Higgs dynamics and constraints on the Standard Model parameters assuming the Higgs potential, computed to next-to-next leading order precision, is not significantly affected by new physics. For a high inflationary scale H ∼ 10{sup 14} GeV suggested by BICEP2, we show that the Higgs is a light field subject to fluctuations which affect its dynamics in a stochastic way. Starting from its inflationary value the Higgs must be able to relax to the Standard Model vacuum well before the electroweak scale. We find that this is consistent with the high inflationary scale only if the top mass m{sub t} is significantly below the best fit value. The region within 2σ errors of the measured m{sub t}, the Higgs mass m{sub h} and the strong coupling α{sub s} and consistent with inflation covers approximately the interval m{sub t}∼<171.8 GeV+0.538(m{sub h}−125.5 GeV) with 125.4 GeV∼
Origins of inert Higgs doublets
Kephart, Thomas W.; Yuan, Tzu -Chiang
2016-03-24
Here, 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.
Working Group Report: Higgs Boson
Dawson, Sally; Gritsan, Andrei; Logan, Heather; Qian, Jianming; Tully, Chris; Van Kooten, Rick
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).
Higgs searches at the Tevatron
Qizhong Li
2003-06-10
One of the highest priority physics goals for the upgraded Tevatron experiments, CDF and D0, is the search for the Higgs boson. We present the initial results from both experiments, based on 40-90 pb{sup -1} integrated luminosity, of Higgs searches in several final states, including WH and ZH, H {yields} WW, and doubly-charged Higgs.
Harnik, Roni
2004-10-27
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.
Dominguez, Aaron
2009-12-17
We present the latest results of searches for the production of Higgs bosons at the Tevatron collider in the D0 and CDF experiments. Cross section times branching ratios have been measured in many different topologies and have been interpreted in both the standard model and other models. No evidence for the production of Higgs bosons has been observed, but limits have been set. The D0 and CDF searches in the standard model have been combined and for the first time we exclude part of the possible mass range, 160 GeV to 170 GeV at the 95% confidence level.
NASA Astrophysics Data System (ADS)
Bellazzini, Brando; Csáki, Csaba; Hubisz, Jay; Lee, Seung J.; Serra, Javi; Terning, John
2016-10-01
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 anti-de Sitter space. For both of these models, we consider the processes g g →Z Z and g g →h h , which can be used to gain information about the Higgs scaling dimension and IR transition scale from the experimental data.
CDF's Higgs sensitivity status
Junk, Tom; /Illinois U., Urbana
2005-10-01
The combined sensitivity of CDF's current Standard Model Higgs boson searches is presented. The expected 95% CL limits on the production cross section times the relevant Higgs boson branching ratios are computed for the W{sup {+-}}H {yields} {ell}{sup {+-}}{nu}b{bar b}, ZH {yields} {nu}{bar {nu}}b{bar b}, gg {yields} H {yields} W{sup +}W{sup -} W{sup {+-}}H {yields} W{sup {+-}}W{sup +}W{sup -} channels as they stand as of the October 2005, using results which were prepared for Summer 2005 conferences and a newer result form the gg {yields} H {yields} W{sup +}W{sup -} channel. Correlated and uncorrelated systematic uncertainties are taken into account, and the luminosity requirements for 95% CL exclusion, 3{sigma} evidence, and 5{sigma} discovery are computed for median experimental outcomes. A list of improvements required to achieve the sensitivity to a SM Higgs boson as quantified in the Higgs Sensitivity Working Group's report is provided.
Anatomizing Exotic Production of the Higgs Boson
Yu, Felix
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.
The Higgs portal above threshold
Craig, Nathaniel; Lou, Hou Keong; McCullough, Matthew; Thalapillil, Arun
2016-02-18
The discovery of the Higgs boson opens the door to new physics interacting via the Higgs Portal, including motivated scenarios relating to baryogenesis, dark matter, and electroweak naturalness. In this study, we systematically explore the collider signatures of singlet scalars produced via the Higgs Portal at the 14TeV LHC and a prospective 100TeV hadron collider. We focus on the challenging regime where the scalars are too heavy to be produced in the decays of an on-shell Higgs boson, and instead are produced primarily via an o ff-shell Higgs. Assuming these scalars escape the detector, promising channels include missing energy in association with vector boson fusion, monojets, and top pairs. In addition, we forecast the sensitivity of searches in these channels at √s = 14 & 100 TeV and compare collider reach to the motivated parameter space of singlet-assisted electroweak baryogenesis, Higgs Portal dark matter, and neutral naturalness.
Higgs searches at the Tevatron
L. Moneta
2001-06-22
This paper describes the searches for the Higgs boson performed by the CDF and DO collaborations at the Tevatron p{bar p} Collider using the data collected in the 1992-95 run. Searches for standard model Higgs and as well for neutral and charged minimal SUSY Higgs bosons are also presented. No signal has been observed and limits are set for production cross sections.
Draper, P.; Liu, T.; Wagner, C. E. M.; Wang, L.-T.; Zhang, H.
2011-03-24
We study a limit of the nearly Peccei-Quinn-symmetric next-to-minimal supersymmetric standard model possessing novel Higgs and dark matter (DM) properties. In this scenario, there naturally coexist three light singletlike particles: a scalar, a pseudoscalar, and a singlinolike DM candidate, all with masses of order 0.1-10 GeV. The decay of a standard model-like Higgs boson to pairs of the light scalars or pseudoscalars is generically suppressed, avoiding constraints from collider searches for these channels. For a certain parameter window annihilation into the light pseudoscalar and exchange of the light scalar with nucleons allow the singlino to achieve the correct relic density and a large direct-detection cross section consistent with the DM direct-detection experiments, CoGeNT and DAMA/LIBRA, preferred region simultaneously. This parameter space is consistent with experimental constraints from LEP, the Tevatron, ?, and flavor physics.
NASA Astrophysics Data System (ADS)
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.
Schafer-Nameki, Sakura; Tamarit, Carlos; Torroba, Gonzalo; /SLAC /Santa Barbara, KITP
2010-08-26
We construct composite Higgs models admitting a weakly coupled Seiberg dual description. We focus on the possibility that only the up-type Higgs is an elementary field, while the down-type Higgs arises as a composite hadron. The model, based on a confining SQCD theory, breaks supersymmetry and electroweak symmetry dynamically and calculably. This simultaneously solves the {mu}/B{sub {mu}} problem and explains the smallness of the bottom and tau masses compared to the top mass. The proposal is then applied to a class of models where the same confining dynamics is used to generate the Standard Model flavor hierarchy by quark and lepton compositeness. This provides a unified framework for flavor, supersymmetry breaking and electroweak physics. The weakly coupled dual is used to explicitly compute the MSSM parameters in terms of a few microscopic couplings, giving interesting relations between the electroweak and soft parameters. The RG evolution down to the TeV scale is obtained and salient phenomenological predictions of this class of 'single-sector' models are discussed.
Constraining the Littlest Higgs
Petriello, Frank J
2002-11-18
Little Higgs models offer a new way to address the hierarchy problem, and give rise to a weakly-coupled Higgs sector. These theories predict the existence of new states which are necessary to cancel the quadratic divergences of the Standard Model. The simplest version of these models, the Littlest Higgs, is based on an SU(5)/SO(5) non-linear sigma model and predicts that four new gauge bosons, a weak isosinglet quark, t{prime}, with Q=2/3, as well as an isotriplet scalar field exist at the TeV scale. We consider the contributions of these new states to precision electroweak observables, and examine their production at the Tevatron. We thoroughly explore the parameter space of this model and find that small regions are allowed by the precision data where the model parameters take on their natural values. These regions are, however, excluded by the Tevatron data. Combined, the direct and indirect effects of these new states constrain the ''decay constant'' f {approx}> 3.5 TeV and m{sub t{prime}} {approx}> 10 TeV. These bounds imply that significant fine-tuning be present in order for this model to resolve the hierarchy problem.
Quantum dissipative Higgs model
Amooghorban, Ehsan Mahdifar, Ali
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.
NASA Astrophysics Data System (ADS)
Maity, Debaprasad
2017-06-01
In this paper we propose minimal Higgs inflation scenarios by non-polynomial modification of the Higgs potential. 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 μ ≃(λ) 1 / 4 α. Assuming the perturbative Higgs quartic coupling, λ ≃ O (1), our model prediction for all the cosmologically relevant quantities, (ns , r , dnsk), fit extremely well with observations made by PLANCK. For both the models the inflation energy scale turned out to be μ ≃ (1014 ,1015) GeV. Considering observed central value of the scalar spectral index, ns = 0.968, 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 (≤10-5) is far below the current experimental limit. The prediction for the running of scalar spectral index, dnsk, remains very small. We also computed the background field dependent unitarity scale Λ (h), which turned out to be much larger than the aforementioned inflationary energy scale.
NASA Astrophysics Data System (ADS)
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
C. Neu
2004-03-04
The Higgs boson is predicted to play a crucial role in the dynamics of electroweak symmetry breaking. The search for this yet-unseen state is an important part of the Run 2 physics program at the Tevatron. Herein is offered a brief description of the latest Run 1 Higgs results from CDF, as well as an early Run 2 result.
Higgs Boson Discovery and Properties
Rowson, Peter C.
2003-06-02
We outline issues examined and progress made by the Light Higgs Snowmass 1996 working group regarding discovering Higgs bosons and measuring their detailed properties. We focused primarily on what could be learned at LEP2, the Tevatron (after upgrade), the LHC, a next linear e{sup +}e{sup -} collider and a {mu}{sup +}{mu}{sup -} collider.
Top, Higgs and Electroweak Physics
Tipton, Paul L.
2006-11-17
Hadron colliders are, and will continue to be, an excellent venue for testing the standard model of particle physics. We describe the status of top-quark physics and the direct search for a standard model Higgs boson. We briefly describe the use of Tevatron and LEP data to indirectly infer the standard model Higgs mass through precision electroweak measurements.
Higgs production through sterile neutrinos
NASA Astrophysics Data System (ADS)
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.
Rani, K.Jyothsna; /Tata Inst.
2005-06-01
We have searched for the Standard Model (SM) and non Standard Model Higgs bosons using of about 200-260 pb{sup -1} of data collected with the upgraded Run II D0 detector at Fermilab Tevatron. Low-mass SM Higgs boson is searched in the associated production with W or Z and limits are placed on the cross section and the kinematic properties of the W or Z plus heavy flavor production. SM Higgs boson with mass greater than 135 GeV is searched for in its dominant decay mode WW with W's decaying into electron or muon final states. Non SM Higgs searches are done in the associated production of neutral SUSY Higgs with b quarks. Data are compared to various predictions and the limits are derived on model parameters.
Higgs precision (Higgcision) era begins
NASA Astrophysics Data System (ADS)
Cheung, Kingman; Lee, Jae Sik; Tseng, Po-Yan
2013-05-01
After the discovery of the Higgs boson at the LHC, it is natural to start the research program on the precision study of the Higgs-boson couplings to various standard model (SM) particles. We provide a generic framework for the deviations of the couplings from their SM values by introducing a number of parameters. We show that a large number of models beyond the SM can be covered, including two-Higgs-doublet models, supersymmetric models, little-Higgs models, extended Higgs sectors with singlets, and fourth generation models. We perform global fits to the most updated data from CMS, ATLAS, and Tevatron under various initial conditions of the parameter set. In particular, we have made explicit comparisons between the fitting results before and after the Moriond 2013 meetings. Highlights of the results include: (i) the nonstandard decay branching ratio of the Higgs boson is less than 22%; (ii) the most efficient way to achieve the best fit for the data before the Moriond update is to introduce additional particle contributions to the triangular-loop functions of Hγγ and Hgg vertices; (iii) the 1σ allowed range of the relative coupling of HVV is 1.01_{-0.14}^{+0.13 } , which means that the electroweak-symmetry breaking contribution from the observed Higgs boson leaves only a small room for other Higgs bosons; (iv) the current data do not rule out pseudoscalar couplings nor pseudoscalar contributions to the Hγγ and Hgg vertices; and (v) the SM Higgs boson provides the best fit to all the current Higgs data.
Handbook of LHC Higgs Cross Sections: 3. Higgs Properties
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.
Exotic Higgs decay via charged Higgs
NASA Astrophysics Data System (ADS)
Li, Tong; Su, Shufang
2015-11-01
The most common search channel for heavy neutral Higgses in models with an extension of the Standard Model Higgs sector is A/H 0 → ττ which becomes ineffective when new decay modes of A/H 0 open. In this paper, we analyzed two such channels involving charged Higgses in the final states: A/H 0 → W ± H ∓ and H 0 → H + H -. With the consequent decay of H ± → τν, we found that the limits for σ × BR( gg → A/H 0 → W ± H ∓) × BR( H ± → τν) vary from 30 to 10fb for m A/ H 0 between 300 and 1000GeV for 95% C.L. exclusion, and about 80 to 30 fb for 5 σ discovery. For H + H - mode, 95% C.L. limits on σ × BR( gg → H 0 → H + H -) × BR2( H ± → τν) vary from 9 to 4 fb for m H 0 between 400 and 1000 GeV, while the 5σ reach is about 20 to 10 fb. We further interpret the cross section limits in the Type II 2HDM parameter space. While A → W ± H ∓ offers great sensitivity in both sin( β - α) versus tan β and m A versus tan β parameter space, H 0 → H + H - can cover most of the parameter space for H 0. Reach in H 0 → W ± H ∓ is more limited, especially for m H 0 > 2 m H ± . It is, however, complementary to H 0 → H + H - when BR( H 0 → H + H -) is accidentally suppressed.
Electroweak Baryogenesis and Higgs Properties
Cohen, Timothy; Morrissey, David E.; 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.
Les Brulures Chimiques Par Le Laurier Rose
Bakkali, H.; Ababou, M.; Nassim Sabah, T.; Moussaoui, A.; Ennouhi, A.; Fouadi, F.Z.; Siah, S.; Ihrai, H.
2010-01-01
Summary Le laurier rose ou Nerium oleander est un arbuste qui pousse naturellement dans les régions méditerranéennes. Au Maroc on le trouve dans les lieux humides. Il est réputé par ses risques de toxicité systémique en cas d'empoisonnement à cause de la présence de deux alcaloïdes, surtout l'oléandrine. La littérature illustre des cas d'utilisation locale des feuilles de cette plante contre la gale, les hémorroïdes et les furoncles. Nous rapportons deux cas de brûlures chimiques par le laurier rose de gravité différente. Cela doit aboutir à une information élargie de la population, ainsi qu'une réglementation stricte de sa commercialisation. PMID:21991211
Leptogenesis via Higgs condensate relaxation
NASA Astrophysics Data System (ADS)
Yang, Louis; Pearce, Lauren; Kusenko, Alexander
2015-08-01
An epoch of Higgs relaxation may occur in the early universe during or immediately following postinflationary reheating. It has recently been pointed out that leptogenesis may occur in minimal extensions of the standard model during this epoch [A. Kusenko, L. Pearce, and L. Yang, Phys. Rev. Lett. 114, 061302 (2015)]. We analyze Higgs relaxation taking into account the effects of perturbative and nonperturbative decays of the Higgs condensate, and we present a detailed derivation of the relevant kinetic equations and of the relevant particle interaction cross sections. We identify the parameter space in which a sufficiently large asymmetry is generated.
The Higgs Portal and Cosmology
Assamagan, Ketevi; Chien-Yi Chen; Chou, John Paul; Curtin, David; Fedderke, Michael A.; Gershtein, Yuri; He, Xiao-Gang; Klute, Markus; Kozaczuk, Jonathon; 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
2016-04-18
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.
New Higgs production mechanism in composite Higgs models
NASA Astrophysics Data System (ADS)
Carmona, Adrián; Chala, Mikael; Santiago, José
2012-07-01
Composite Higgs models are only now starting to be probed at the Large Hadron Collider by Higgs searches. We point out that new resonances, abundant in these models, can mediate new production mechanisms for the composite Higgs. The new channels involve the exchange of a massive color octet and single production of new fermion resonances with subsequent decays into the Higgs and a Standard Model quark. The sizable cross section and very distinctive kinematics allow for a very clean extraction of the signal over the background with high statistical significance. Heavy gluon masses up to 2.8 TeV can be probed with data collected during 2012 and up to 5 TeV after the energy upgrade to sqrt {s} = {14} TeV.
Computer simulations and experiments: The case of the Higgs boson
NASA Astrophysics Data System (ADS)
Massimi, Michela; Bhimji, Wahid
2015-08-01
Simulations have been at the center of an important literature that has debated the extent to which they count as epistemologically on a par with traditional experiments. Critics have raised doubts about simulations being genuine experiments, on the ground that simulations seem to lack a distinctive feature of traditional experiments: i.e., the ability to causally interact with a target system. In this paper, we defend the view that simulations are indeed epistemologically on a par with traditional experiments. We first identify three possible ways of understanding the causal interaction claim. We then focus on the use of simulation in the discovery of the Higgs boson to show that in this paradigmatic case, simulations satisfy all three possible readings of the causal interaction claim.
Lincoln, Don
2016-07-12
Fermilab scientist Don Lincoln describes the nature of the Higgs boson. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass.
Higgs searches at the Tevatron
Mastrandrea, Paolo; /INFN, Siena
2010-09-01
The search for the Standard Model Higgs boson in p{bar p} collisions at 1.96 TeV performed by CDF and D0 collaborations at the Tevatron collider is reported in this paper. The Higgs candidate events are reconstructed using different final states in order to optimize the sensitivity in the full range of the Higgs mass. The presented results use different statistical samples collected by the Tevatron up to 5.9 fb{sup -1}. Combining the most updated limits provided by the two experiments for all the final states analyzed, the Standard Model Higgs boson is excluded at 95% C.L. in the mass range 158-175 GeV/c{sup 2}, in good agreement with the prediction for the analyzed data sample.
Lincoln, Don
2011-07-07
Fermilab scientist Don Lincoln describes the nature of the Higgs boson. Several large experimental groups are hot on the trail of this elusive subatomic particle which is thought to explain the origins of particle mass.
Cosmological stochastic Higgs field stabilization
NASA Astrophysics Data System (ADS)
Gong, Jinn-Ouk; Kitajima, Naoya
2017-09-01
We show that the stochastic evolution of an interacting system of the Higgs field and a spectator scalar field naturally gives rise to an enhanced probability of settling down at the electroweak vacuum at the end of inflation. Subsequent destabilization due to parametric resonance between the Higgs field and the spectator field can be avoided in a wide parameter range. We further argue that the spectator field can play the role of dark matter.
The Higgs portal above threshold
Craig, Nathaniel; Lou, Hou Keong; McCullough, Matthew; ...
2016-02-18
The discovery of the Higgs boson opens the door to new physics interacting via the Higgs Portal, including motivated scenarios relating to baryogenesis, dark matter, and electroweak naturalness. In this study, we systematically explore the collider signatures of singlet scalars produced via the Higgs Portal at the 14TeV LHC and a prospective 100TeV hadron collider. We focus on the challenging regime where the scalars are too heavy to be produced in the decays of an on-shell Higgs boson, and instead are produced primarily via an o ff-shell Higgs. Assuming these scalars escape the detector, promising channels include missing energy inmore » association with vector boson fusion, monojets, and top pairs. In addition, we forecast the sensitivity of searches in these channels at √s = 14 & 100 TeV and compare collider reach to the motivated parameter space of singlet-assisted electroweak baryogenesis, Higgs Portal dark matter, and neutral naturalness.« less
NASA Astrophysics Data System (ADS)
Marzocca, D.
2017-07-01
One of the most important ways to explore BSM at the LCH Run-2 is to study the properties of the Higgs boson. In order to do so in a consistent and model-independent framework, we introduce a set of pseudo-observables (PO), defined from on-shell amplitudes, characterising the properties of Higgs production and decay processes in generic extensions of the Standard Model with no new particles below the Higgs mass. These PO provide a generalisation of the κ -framework used by the LHC experiments and allow for the systematic inclusion of higher-order QED corrections. Symmetries of the new-physics sector, such as CP invariance and fermion universality imply relations among the PO, that could be tested directly from Higgs data. The further assumption that the Higgs is part of an electroweak doublet allows for the introduction of the linear effective field theory (SMEFT) to describe the effect of new physics at low energy. In this context, PO can be matched to the Wilson coefficients of the SMEFT, providing a way to test experimentally the SMEFT predictions by combining Higgs data with other electroweak processes.
T-Parity in Little Higgs Models
Krohn, David
2008-11-23
We examine quantum anomalies in the context of little Higgs theories. In particular, we investigate the restrictions imposed upon little Higgs models when one requires an exact T-parity. Applications to LHC phenomenology are briefly discussed.
Sakurai Prize: The Future of Higgs Physics
NASA Astrophysics Data System (ADS)
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.
Higgs couplings in noncommutative Standard Model
NASA Astrophysics Data System (ADS)
Batebi, S.; Haghighat, M.; Tizchang, S.; Akafzade, H.
2015-06-01
We consider the Higgs and Yukawa parts of the Noncommutative Standard Model (NCSM). We explore the NC-action to give all Feynman rules for couplings of the Higgs boson to electroweak gauge fields and fermions.
Twin Higgs mechanism and a composite Higgs boson
NASA Astrophysics Data System (ADS)
Low, Matthew; Tesi, Andrea; Wang, Lian-Tao
2015-05-01
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.
New decay modes of heavy Higgs bosons in a two Higgs doublet model with vectorlike leptons
Dermíšek, Radovan; Lunghi, Enrico; Shin, Seodong
2016-05-25
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. Here, we investigate new decay topologies of heavy neutral Higgses in two Higgs doublet model with vectorlike leptons. We also discus 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.
THE HIGGS WORKING GROUP: SUMMARY REPORT.
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.
Fat jets for a light higgs boson.
Plehn, Tilman; Salam, Gavin P; Spannowsky, Michael
2010-03-19
At the LHC associated top quark and Higgs boson production with a Higgs boson decay to bottom quarks has long been a heavily disputed search channel. Recently, it has been found not to be viable. We show how it can be observed by tagging massive Higgs bosons and top jets. For this purpose we construct boosted top and Higgs taggers for standard-model processes in a complex QCD environment.
Is the Higgs boson composed of neutrinos?
Krog, Jens; Hill, Christopher T.
2015-11-09
We show that conventional Higgs compositeness conditions can be achieved by the running of large Higgs-Yukawa couplings involving right-handed neutrinos that become active at ~1013–1014 GeV. Together with a somewhat enhanced quartic coupling arising by a Higgs portal interaction to a dark matter sector, we can obtain a Higgs boson composed of neutrinos. Furthermore, this is a “next-to-minimal” dynamical electroweak symmetry breaking scheme.
Electroweak Gauge-Higgs Unification Scenario
Hosotani, Yutaka
2008-11-23
In the gauge-Higgs unification scenario 4D Higgs fields are unified with gauge fields in higher dimensions. The electroweak model is constructed in the Randall-Sundrum warped space. The electroweak symmetry is dynamically broken by the Hosotani mechanism due to the top quark contribution. The Higgs mass is predicted to be around 50 GeV with the vanishing ZZH and WWH couplings so that the LEP2 bound for the Higgs mass is evaded.
Measuring Higgs couplings from LHC data.
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.
Bound states in the Higgs model
NASA Astrophysics Data System (ADS)
di Leo, Leo; Darewych, Jurij W.
1994-02-01
We derive relativistic wave equations for the bound states of two Higgs bosons within the Higgs sector of the minimal standard model. The variational method and the Hamiltonian formalism of QFT are used to obtain the equations using a simple ||hh>+||hhh> Fock-space ansatz. We present approximate solutions of these equations for a range of Higgs boson masses, and explore the parameter space which corresponds to the existence of two-Higgs-boson bound states.
Is the Higgs boson composed of neutrinos?
Krog, Jens; Hill, Christopher T.
2015-11-09
We show that conventional Higgs compositeness conditions can be achieved by the running of large Higgs-Yukawa couplings involving right-handed neutrinos that become active at ~10^{13}–10^{14} GeV. Together with a somewhat enhanced quartic coupling arising by a Higgs portal interaction to a dark matter sector, we can obtain a Higgs boson composed of neutrinos. Furthermore, this is a “next-to-minimal” dynamical electroweak symmetry breaking scheme.
Radion and Higgs masses in gauge-Higgs unification
Sakamura, Yutaka
2011-02-01
We evaluate the radion and Higgs masses in the gauge-Higgs unification models on the warped geometry, in which the modulus is stabilized by the Casimir energy. We analyze the one-loop effective potential and clarify the dependences of those masses on the Wilson line phase {theta}{sub H}. The radion mass varies 1-30 GeV for 0.06{<=}sin{theta}{sub H{<=}}0.3, while the Higgs mass is 150-200 GeV and depends on {theta}{sub H} only logarithmically. The radion couplings to the standard model particles are sensitive to the warp factor, and are too small to detect at colliders in the region where the five-dimensional description is valid.
NASA Astrophysics Data System (ADS)
Frouin, R. J.; Franz, B.
2009-12-01
The solar energy available for photosynthesis, known as PAR, controls the growth of phytoplankton and, therefore, regulates the composition and evolution of marine ecosystems. Knowing the spatial and temporal distribution of PAR over the oceans is critical to understanding biogeochemical cycles of carbon, nutrients, and oxygen, and to address important climate and global change issues such as the fate of anthropogenic atmospheric carbon dioxide. In view of this, a 12-year time series of PAR at the ocean surface, starting in September 1997, is being produced by the NASA Ocean Biology Processing Group from SeaWiFS, MODIS-Terra, and MODIS-Aqua data. The product covers the global oceans, with a spatial resolution of about 9.3x9.3 km (equal area grid) and a temporal resolution of one day. PAR is computed as the difference between the 400-700 nm solar flux incident on the top of the atmosphere (known) and reflected back to space by the atmosphere and surface (derived from satellite radiance), taking into account atmospheric absorption (modeled). Knowledge of pixel composition is not required, eliminating the need for cloud screening and arbitrary assumptions about sub-pixel cloudiness. Combining data from satellite sensors with different equatorial crossing times accounts for the diurnal variability of clouds and, therefore, increases accuracy on a daily time scale. The processing system, including routine check of accuracy and control of quality, is designed to operate during the entire lifetime of SeaWiFS and MODIS, and to accommodate future sensors with ocean-color capabilities. Maps of daily, weekly, and monthly PAR obtained from individual sensors are presented, as well as merged products. Accuracy is quantified in comparisons with other satellite estimates, the National Centers for Environmental Prediction reanalysis product, and in-situ measurements from fixed buoys and platforms. The good statistical performance makes the satellite PAR product suitable for large
NASA Astrophysics Data System (ADS)
Connolly, Amy; SalSA Collaboration
2009-06-01
I review the status of SalSA, a proposed antenna array in a large volume salt formation for detecting ultra-high energy neutrinos. We report on measurements taken in 2007 of attenuation lengths in the 125-900 MHz frequency range at the Cote Blanche salt mine near New Iberia, Louisiana, which is the most precise in situ measurement of attenuation lengths in salt to date. We comment on the impact of these measurements on the feasibility of SalSA.
The Higgs of the Higgs and the diphoton channel
NASA Astrophysics Data System (ADS)
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.
NASA Astrophysics Data System (ADS)
Ema, Yohei; Karčiauskas, Mindaugas; Lebedev, Oleg; Zatta, Marco
2017-06-01
Apparent metastability of the electroweak vacuum poses a number of cosmological questions. These concern evolution of the Higgs field to the current vacuum, and its stability during and after inflation. Higgs-inflaton and non-minimal Higgs-gravity interactions can make a crucial impact on these considerations potentially solving the problems. In this work, we allow for these couplings to be present simultaneously and study their interplay. We find that different combinations of the Higgs-inflaton and non-minimal Higgs-gravity couplings induce effective Higgs mass during and after inflation. This crucially affects the Higgs stability considerations during preheating. In particular, a wide range of the couplings leading to stable solutions becomes allowed.
NASA Astrophysics Data System (ADS)
Bentov, Yoni; Zee, A.
2013-11-01
We study the LHC phenomenology of a general class of "Private Higgs" (PH) models, in which fermions obtain their masses from their own Higgs doublets with {O}(1) Yukawa couplings, and the mass hierarchy is translated into a dynamical chain of vacuum expectation values. This is accomplished by introducing a number of light gauge-singlet scalars, the "darkons," some of which could play the role of dark matter. These models allow for substantial modifications to the decays of the lightest Higgs boson, for instance through mixing with TeV-scale PH fields and light darkons: in particular, one could accommodate {O}(10%) flavor-uncorrelated deviations from the SM hf\\bar f vertices with TeV-scale degrees of freedom. We also discuss a new implementation of the PH framework, in which the quark and neutrino mixing angles arise as one-loop corrections to the leading order picture.
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.
Higgs triplets and limits from precision measurements
Chen, Mu-Chun; Dawson, Sally; Krupovnickas, Tadas; /Brookhaven
2006-04-01
In this letter, they present the results on a global fit to precision electroweak data in a Higgs triplet model. In models with a triplet Higgs boson, a consistent renormalization scheme differs from that of the Standard Model and the global fit shows that a light Higgs boson with mass of 100-200 GeV is preferred. Triplet Higgs bosons arise in many extensions of the Standard Model, including the left-right model and the Little Higgs models. The result demonstrates the importance of the scalar loops when there is a large mass splitting between the heavy scalars. It also indicates the significance of the global fit.
Topics in little Higgs physics
NASA Astrophysics Data System (ADS)
Chang, Spencer
The Standard Model is the currently accepted model of elementary particle interactions as determined by many years of particle physics experiments. It is both highly predictive and successful in its predictions, which is one of the great achievements of the last half century of science. However, there are indications that the Standard Model is incomplete with the main evidence being the so called hierarchy problem. In general terms, the hierarchy problem suggests that the parameters of the Standard Model have to be severely fine tuned in order to describe the real world. Motivated by the naturalness issues the hierarchy problem provokes, many theories of beyond the Standard Model physics have been proposed that alleviate the fine tuning. Continuing this approach, recently a new scenario called "Little Higgs" theories has been suggested as a viable alternative to the Standard Model, which has some novel features compared to the other competitive theories. The fact that these Little Higgs models may describe the real world is interesting and motivates their study. In the first chapter, an introduction describing in elementary terms what the hierarchy problem is and how Little Higgs theories are a solution to this problem is presented. After this short introduction, two topics in Little Higgs theories are analyzed. The first subject is determining if Little Higgs theories are consistent with the precision experiments performed to date. This is covered in chapters two and three, where two different Little Higgs models with approximate custodial SU(2) symmetry are presented. This symmetry increases the range of parameter space where these Little Higgs theories are both consistent with precision tests and are natural under the sense of the hierarchy problem. Thus, these theories are viable candidates for beyond the Standard Model physics. The fourth chapter is on the second subject, which is analyzing the constraints that unitarity places upon the Little Higgs theories
Twin Higgs model with T parity
NASA Astrophysics Data System (ADS)
Yu, Jiang-Hao
2017-05-01
In twin Higgs models, a discrete Z2 symmetry between the standard model Higgs and the twin Higgs is introduced to address the hierarchy problem. In this work, we propose another discrete symmetry in twin Higgs: the T parity, which maps the twin Higgs quadruplet into its mirror copy. The T parity brings us a whole group of T -odd particles, and leads to a promising dark matter candidate. We present one realization of the T -parity twin Higgs scenario by implementing the S U (2 )L×S U (2 )R×U (1 )1×U (1 )2 gauge symmetry in the left-right twin Higgs model. In this specific setup, the T -odd U (1 ) gauge boson could be the dark matter candidate, and the T -odd particles have very distinct and interesting phenomenology.
NASA Astrophysics Data System (ADS)
Low, Ian; Schwaller, Pedro; Shaughnessy, Gabe; Wagner, Carlos E. M.
2012-01-01
Current limits from the Large Hadron Collider exclude a standard model-like Higgs mass above 150 GeV, by placing an upper bound on the Higgs production rate. We emphasize that, alternatively, the limit could be interpreted as a lower bound on the total decay width of the Higgs boson. If the invisible decay width of the Higgs is of the same order as the visible decay width, a heavy Higgs boson could be consistent with null results from current searches. We propose a method to infer the invisible decay of the Higgs by using the width of the measured h→ZZ→4ℓ line shape, and study the effect on the width extraction due to a reduced signal strength. Assuming the invisible decay product is the dark matter, we show that minimal models are tightly constrained by limits from Higgs searches at the LHC and direct detection experiments of dark matter, unless the relic density constraint is relaxed.
Double Higgs production in the Two Higgs Doublet Model at the linear collider
Arhrib, Abdesslam; Benbrik, Rachid; Chiang, C.-W.
2008-04-21
We study double Higgs-strahlung production at the future Linear Collider in the framework of the Two Higgs Doublet Models through the following channels: e{sup +}e{sup -}{yields}{phi}{sub i}{phi}{sub j}Z, {phi}{sub i} = h deg., H deg., A deg. All these processes are sensitive to triple Higgs couplings. Hence observations of them provide information on the triple Higgs couplings that help reconstructing the scalar potential. We discuss also the double Higgs-strahlung e{sup +}e{sup -}{yields}h deg. h deg. Z in the decoupling limit where h deg. mimics the SM Higgs boson.
Higgs masses and stability in the standard and the two Higgs doublet models
Juarez W, S. R.; Morales C, D.; Kielanowski, P.
2010-07-29
Within the framework of the standard model (SM) of elementary particles and the two Higgs doublet extension to this model (2DHM), we obtained analytical and numerical solutions for the gauge couplings, the vacuum expectation values (VEV) of the Higgs fields, the quark Yukawa couplings and quark masses, the quartic Higgs couplings, and the running Higgs masses, considering the renormalization group equations. The bounds on the SM Higgs running mass have been fixed, and the region of validity of the SM was determined through it, at the one and two loop approximations, using the triviality and stability conditions for the Higgs quartic coupling {lambda}{sub H}.
Lee, Hye Sung; Sher, Marc
2013-06-01
We perform a detailed study of a specific Two Higgs Doublet Model (2HDM) with a U(1) gauge symmetry, instead of a typical Z{sub 2} discrete symmetry, containing a very light gauge boson Z' (GeV scale or below). The Standard Model (SM) fermions do not carry U(1) charges, but induced couplings to the Z' (called the dark Z) are generated through mixing with the SM neutral gauge bosons. Such a light Z' could explain some astrophysical anomalies as well as the muon g-2 deviation, and has been the subject of great experimental interest. We consider the scenario in which the 125 GeV SM-like Higgs (H) is the heavier scalar state, and focus on the lighter neutral state (h) as well as charged Higgs. We analyze the constraints on the model from various experiments and predict novel channels to search for these Higgs scalars at the LHC. In particular, experiments looking for lepton-jets are among potentially important searches.
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.
NASA Astrophysics Data System (ADS)
García García, Isabel; Lasenby, Robert; March-Russell, John
2015-09-01
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) Z2 symmetry, and interacting with the SM via a specific Higgs portal. We focus on the minimal realization of the TH mechanism, the fraternal twin Higgs, with only a single generation of twin quarks and leptons, and the S U (3 )'×S U (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 τ' lepton with a mass mτ'>mHiggs/2 , although spin-1 W'± DM and multicomponent DM are also possible (twin baryons are strongly disfavored 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 the number of relativistic degrees of freedom, Δ Neff . Direct detection signals are below current bounds but accessible in near-future experiments. Indirect detection phenomenology is rich and requires detailed studies of twin hadronization and fragmentation to twin glueballs and quarkonia and their subsequent decay to SM, and possible light twin sector states.
Fermiophobic Higgs boson and supersymmetry
NASA Astrophysics Data System (ADS)
Gabrielli, E.; Kannike, K.; Mele, B.; Racioppi, A.; Raidal, M.
2012-09-01
If a light Higgs boson with mass 125 GeV is fermiophobic, or partially fermiophobic, then the minimal supersymmetric standard model is excluded. The minimal supersymmetric fermiophobic Higgs scenario can naturally be formulated in the context of the next-to-minimal supersymmetric standard model (NMSSM) that admits Z3 discrete symmetries. In the fermiophobic NMSSM, the supersymmetry naturalness criteria are relaxed by a factor Ncyt4/g4˜25, removing the little hierarchy problem and allowing sparticle masses to be naturally of order 2-3 TeV. This scale motivates wino or Higgsino dark matter. The SUSY flavor and CP problems as well as the constraints on sparticle and Higgs boson masses from b→sγ, Bs→μμ and direct LHC searches are relaxed in the fermiophobic NMSSM. The price to pay is that a new, yet unknown, mechanism must be introduced to generate fermion masses. We show that in the fermiophobic NMSSM the radiative Higgs boson branchings to γγ, γZ can be modified compared to the fermiophobic and ordinary standard model predictions, and fit present collider data better. Suppression of dark matter scattering off nuclei explains the absence of signal in XENON100.
The Higgs boson and cosmology.
Shaposhnikov, Mikhail
2015-01-13
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.
Spano, Frank; Donovan, Jeff C.
2015-01-01
Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre l’épidémiologie, la pathogenèse, l’histologie et l’approche clinique au diagnostic de la pelade par plaques. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant la pathogenèse, le diagnostic et le pronostic de la pelade par plaques. Message principal La pelade par plaques est une forme de perte pileuse auto-immune dont la prévalence durant une vie est d’environ 2 %. Des antécédents personnels ou familiaux de troubles auto-immuns concomitants, comme le vitiligo ou une maladie de la thyroïde, peuvent être observés dans un petit sous-groupe de patients. Le diagnostic peut souvent être posé de manière clinique en se fondant sur la perte de cheveux non cicatricielle et circulaire caractéristique, accompagnée de cheveux en « point d’exclamation » en périphérie chez ceux dont le problème en est aux premiers stades. Le diagnostic des cas plus complexes ou des présentations inhabituelles peut être facilité par une biopsie et un examen histologique. Le pronostic varie largement et de mauvais résultats sont associés à une apparition à un âge précoce, une perte importante, la variante ophiasis, des changements aux ongles, des antécédents familiaux ou des troubles auto-immuns concomitants. Conclusion La pelade par plaques est une forme auto-immune de perte de cheveux périodiquement observée en soins primaires. Les médecins de famille sont bien placés pour identifier la pelade par plaques, déterminer la gravité de la maladie et poser le diagnostic différentiel approprié. De plus, ils sont en mesure de renseigner leurs patients à propos de l’évolution clinique de la maladie ainsi que du pronostic général selon le sous-type de patients.
Theoretical constraints on the Higgs effective couplings.
Low, I.; Rattazzi, R.; Vichi, A.; High Energy Physics; Northwestern Univ; EPFL
2010-04-01
We derive constraints on the sign of couplings in an effective Higgs Lagrangian using prime principles such as the naturalness principle, global symmetries, and unitarity. Specifically, we study four dimension-six operators, {Omicron}{sub H}, {Omicron}{sub y}, {Omicron}{sub g}, and {Omicron}{sub {gamma}} which contribute to the production and decay of the Higgs boson at the Large Hadron Collider (LHC), among other things. Assuming the Higgs is a fundamental scalar, we find: (1) the coefficient of {Omicron}{sub H} is positive except when there are triplet scalars, resulting in a reduction in the Higgs on-shell coupling from their standard model (SM) expectations if no other operators contribute, (2) the linear combination of {Omicron}{sub H} and {Omicron}{sub y} controlling the overall Higgs coupling to fermion is always reduced, (3) the sign of {Omicron}{sub g} induced by a new colored fermion is such that it interferes destructively with the SM top contribution in the gluon fusion production of the Higgs, if the new fermion cancels the top quadratic divergence in the Higgs mass, and (4) the correlation between naturalness and the sign of {Omicron}{sub {gamma}} is similar to that of {Omicron}{sub g}, when there is a new set of heavy electroweak gauge bosons. Next considering a composite scalar for the Higgs, we find the reduction in the on-shell Higgs couplings persists. If further assuming a collective breaking mechanism as in little Higgs theories, the coefficient of {Omicron}{sub H} remains positive even in the presence of triplet scalars. In the end, we conclude that the gluon fusion production of the Higgs boson is reduced from the SM rate in all composite Higgs models. Our study suggests a wealth of information could be revealed by precise measurements of the Higgs couplings, providing strong motivations for both improving on measurements at the LHC and building a precision machine such as the linear collider.
Light charged Higgs boson scenario in 3-Higgs doublet models
NASA Astrophysics Data System (ADS)
Akeroyd, A. G.; Moretti, Stefano; Yagyu, Kei; Yildirim, Emine
2017-08-01
The constraints from the measurements of the B → Xsγ decay rate on the parameter space of 3-Higgs Doublet Models (3HDMs), where all the doublets have nonzero vacuum expectation values, are studied at the next-to-leading order in QCD. In order to naturally avoid the presence of flavour changing neutral currents at the tree level, we impose two softly-broken discrete Z2 symmetries. This gives rise to five independent types of 3HDMs that differ in their Yukawa couplings. We show that in all these 3HDMs (including the case of type-II-like Yukawa interactions) both masses of the two charged Higgs bosons mH1± and mH2± can be smaller than the top mass mt while complying with the constraints from B → Xsγ. As an interesting phenomenological consequence, the branching ratios of the charged Higgs bosons decay into the cb final states can be as large as 80% when their masses are taken to be below mt in two of the five 3HDMs (named as Type-Y and Type-Z). This light charged Higgs boson scenario provides a hallmark 3HDM signature that cannot be realised in Z2 symmetric 2-Higgs doublet models. We find that in the Type-Y and Type-Z 3HDMs the scenario with 90GeV < mH1±, mH2± < mt is ruled out by the direct searches at the LHC, but in the Type-Y 3HDM 80GeV < mH1± < 90GeV and 90GeV < mH2± < mt is allowed by B → Xsγ and direct searches at LEP2, Tevatron and LHC due to the reduced sensitivity of these searches to the degenerate case mH1±≈ mW±. The cases where only one or both charged Higgs bosons are above the top quark mass are also naturally allowed in the both Type-Y and Type-Z 3HDMs.
Spano, Frank; Donovan, Jeff C.
2015-01-01
Résumé Objectif Présenter aux médecins de famille des renseignements de base pour faire comprendre les schémas thérapeutiques et les résultats des traitements pour la pelade par plaques, de même que les aider à identifier les patients pour qui une demande de consultation en dermatologie pourrait s’imposer. Sources des données Une recension a été effectuée dans PubMed pour trouver des articles pertinents concernant le traitement de la pelade par plaques. Message principal La pelade par plaques est une forme auto-immune de perte pileuse qui touche à la fois les enfants et les adultes. Même s’il n’y a pas de mortalité associée à la maladie, la morbidité découlant des effets psychologiques de la perte des cheveux peut être dévastatrice. Lorsque la pelade par plaques et le sous-type de la maladie sont identifiés, un schéma thérapeutique approprié peut être amorcé pour aider à arrêter la chute des cheveux et possiblement faire commencer la repousse. Les traitements de première intention sont la triamcinolone intralésionnelle avec des corticostéroïdes topiques ou du minoxidil ou les 2. Les médecins de famille peuvent prescrire ces traitements en toute sécurité et amorcer ces thérapies. Les cas plus avancés ou réfractaires pourraient avoir besoin de diphénylcyclopropénone topique ou d’anthraline topique. On peut traiter la perte de cils avec des analogues de la prostaglandine. Les personnes ayant subi une perte de cheveux abondante peuvent recourir à des options de camouflage ou à des prothèses capillaires. Il est important de surveiller les troubles psychiatriques en raison des effets psychologiques profonds de la perte de cheveux. Conclusion Les médecins de famille verront de nombreux patients qui perdent leurs cheveux. La reconnaissance de la pelade par plaques et la compréhension du processus pathologique sous-jacent permettent d’amorcer un schéma thérapeutique approprié. Les cas plus graves ou r
Graceful exit from Higgs G inflation
NASA Astrophysics Data System (ADS)
Kamada, Kohei; Kobayashi, Tsutomu; Kunimitsu, Taro; Yamaguchi, Masahide; Yokoyama, Jun'ichi
2013-12-01
Higgs G inflation is a Higgs inflation model with a generalized Galileon term added to the standard model Higgs field, which realizes inflation compatible with observations. Recently, it was claimed that the generalized Galileon term induces instabilities during the oscillation phase and that the simplest Higgs G-inflation model inevitably suffers from this problem. In this paper, we extend the original Higgs G-inflation Lagrangian to a more general form, namely introducing a higher-order kinetic term and generalizing the form of the Galileon term, so that the Higgs field can oscillate after inflation without encountering instabilities. Moreover, it accommodates a large region of the ns-r plane, most of which is consistent with current observations, leading us to expect the detection of B-mode polarization in the cosmic microwave background in the near future.
Extended Higgs sectors in radiative neutrino models
NASA Astrophysics Data System (ADS)
Antipin, Oleg; Čuljak, Petar; Kumerički, Krešimir; Picek, Ivica
2017-05-01
Testable Higgs partners may be sought within the extensions of the SM Higgs sector aimed at generating neutrino masses at the loop level. We study a viability of extended Higgs sectors for two selected models of radiative neutrino masses: a one-loop mass model, providing the Higgs partner within a real triplet scalar representation, and a three-loop mass model, providing it within its two-Higgs-doublet sector. The Higgs sector in the one-loop model may remain stable and perturbative up to the Planck scale, whereas the three-loop model calls for a UV completion around 106 GeV. Additional vector-like lepton and exotic scalar fields, which are required to close one- and three-loop neutrino-mass diagrams, play a decisive role for the testability of the respective models. We constrain the parameter space of these models using LHC bounds on diboson resonances.
Collider signatures of flavorful Higgs bosons
NASA Astrophysics Data System (ADS)
Altmannshofer, Wolfgang; Eby, Joshua; Gori, Stefania; Lotito, Matteo; Martone, Mario; Tuckler, Douglas
2016-12-01
Motivated by our limited knowledge of the Higgs couplings to the first two generation fermions, we analyze the collider phenomenology of a class of two Higgs doublet models (2HDMs) with a nonstandard 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 →c c ,t c ,μ μ ,τ μ and H±→c b ,c s ,μ ν . Searches for low-mass dimuon resonances are currently among the best probes of the heavy Higgs bosons in this setup.
A Historical Profile of the Higgs Boson
Ellis, John; Gaillard, Mary K.; Nanopoulos, Dimitri V.
2012-01-31
The Higgs boson was postulated in 1964, and phenomenological studies of its possible production and decays started in the early 1970s, followed by studies of its possible productionin e{sup +} e{sup -}, {anti p}p and pp collisions, in particular. Until recently, the most sensitive searches for the Higgs boson were at LEP between 1989 and 2000, which have been complemented bysearches at the Fermilab Tevatron. The LHC has recently entered the hunt, excluding a Higgs boson over a large range of masses and revealing a tantalizing hint in the range 119 to125 GeV, and there are good prospects that the existence or otherwise of the Higgs boson will soon be established. One of the most attractive possibilities is that the Higgs bosonis accompanied by supersymmetry, though composite options have yet to be excluded. This article reviews some of the key historical developments in Higgs physics over the past half-century.
Handbook of LHC Higgs Cross Sections: 4. Deciphering the Nature of the Higgs Sector
de Florian, D.
2016-10-25
This Report summarizes the results of the activities of the LHC Higgs Cross Section Working Group in the period 2014-2016. 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. The first part compiles the most up-to-date predictions of Higgs boson production cross sections and decay branching ratios, parton distribution functions, and off-shell Higgs boson production and interference effects. The second part discusses the recent progress in Higgs effective field theory predictions, followed by the third part on pseudo-observables, simplified template cross section and fiducial cross section measurements, which give the baseline framework for Higgs boson property measurements. The fourth part deals with the beyond the Standard Model predictions of various benchmark scenarios of Minimal Supersymmetric Standard Model, extended scalar sector, Next-to-Minimal Supersymmetric Standard Model and exotic Higgs boson decays. This report follows three previous working-group reports: Handbook of LHC Higgs Cross Sections: 1. Inclusive Observables (CERN-2011-002), Handbook of LHC Higgs Cross Sections: 2. Differential Distributions (CERN-2012-002), and Handbook of LHC Higgs Cross Sections: 3. Higgs properties (CERN-2013-004). The current report serves as the baseline reference for Higgs physics in LHC Run 2 and beyond.
NMSSM Higgs boson search strategies at the LHC and the mono-Higgs signature in particular
NASA Astrophysics Data System (ADS)
Baum, Sebastian; Freese, Katherine; Shah, Nausheen R.; Shakya, Bibhushan
2017-06-01
We study the collider phenomenology of the extended Higgs sector of the next-to-minimal supersymmetric Standard Model (NMSSM). The region of NMSSM parameter space favored by a 125 GeV SM-like Higgs and naturalness generically features a light Higgs and neutralino spectrum as well as a large O (1 ) coupling between the Higgs doublets and the NMSSM singlet fields. In such regimes, the heavier Higgs bosons can decay dominantly into lighter Higgs bosons and neutralinos. We study the prospects of observing such decays at the 13 TeV LHC, focusing on mono-Higgs signatures as probes of such regions of parameter space. We present results for the mono-Higgs reach in a framework easily applicable to other models featuring similar decay topologies. In the NMSSM, we find that the mono-Higgs channel can probe TeV scale Higgs bosons and has sensitivity even in the low tan β , large mA regime that is difficult to probe in the MSSM. Unlike for many conventional Higgs searches, the reach of the mono-Higgs channel will improve significantly with the increased luminosity expected to be collected at the LHC in the ongoing and upcoming runs.
Standard Model Higgs searches at the Tevatron
Herner, Kenneth; /Michigan U.
2010-04-01
We report results of searches for the Standard Model Higgs Boson at the Fermilab Tevatron using up to 5.4 fb{sup -1} of data taken with the CDF and D0 detectors. There is no significant excess in the mass range of interest and the experiments set upper limits on the Higgs boson production cross section, including an exclusion of the Standard Model Higgs in the mass range 162-166 GeV.
Recent Higgs results from the ATLAS experiment
Brendlinger, Kurt; Collaboration: ATLAS Collaboration
2014-06-24
This paper presents recent results on the Higgs boson from the ATLAS experiment at the Large Hadron Collider. The Collaboration reports on measurements of the signal strength, couplings, and spin of the Higgs in several decay channels. We find all measurements to be consistent with Standard Model predictions. The Higgs branching fraction to invisible particles is constrained and no evidence of physics beyond the Standard Model is found.
Higgs Boson Property Shifts from Radion Mixing
Rizzo, Thomas G.
2002-07-09
We discuss how mixing between the Standard Model Higgs boson, h, and the radion of the Randall-Sundrum model can lead to significant shifts in the expected properties of the Higgs boson. In particular we show that the total and partial decay widths of the Higgs, as well as the h {yields} gg branching fraction, can be substantially altered from their SM expectations, while the remaining branching fractions are modified less than {approx}< 5% for most of the parameter space volume. Precision measurements of Higgs boson properties at a Linear Collider are shown to probe a large region of the Randall-Sundrum model parameter space.
CP violation in heavy MSSM Higgs scenarios
Carena, M.; Ellis, J.; Lee, J. S.; Pilaftsis, A.; Wagner, C. E. M.
2016-02-18
We introduce and explore new heavy Higgs scenarios in the Minimal Supersymmetric Standard Model (MSSM) with explicit CP violation, which have important phenomenological implications that may be testable at the LHC. For soft supersymmetry-breaking scales M_{S} above a few TeV and a charged Higgs boson mass M_{H}+ above a few hundred GeV, new physics effects including those from explicit CP violation decouple from the light Higgs boson sector. However, such effects can significantly alter the phenomenology of the heavy Higgs bosons while still being consistent with constraints from low-energy observables, for instance electric dipole moments. To consider scenarios with a charged Higgs boson much heavier than the Standard Model (SM) particles but much lighter than the supersymmetric particles, we revisit previous calculations of the MSSM Higgs sector. We compute the Higgs boson masses in the presence of CP violating phases, implementing improved matching and renormalization-group (RG) effects, as well as two-loop RG effects from the effective two-Higgs Doublet Model (2HDM) scale M_{H}± to the scale M_{S}. Here, we illustrate the possibility of non-decoupling CP-violating effects in the heavy Higgs sector using new benchmark scenarios named.
Invisible decays in Higgs boson pair production
NASA Astrophysics Data System (ADS)
Banerjee, Shankha; Batell, Brian; Spannowsky, Michael
2017-02-01
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 b ¯+ ET channel. We demonstrate that probing invisible branching ratios of order 10% during the LHC's high-luminosity run will be challenging, but in resonance enhanced di-Higgs production, this final state can become crucial to establish the existence of physics beyond the Standard Model at collider energies. We also briefly discuss the outlook for other exotic Higgs decay modes and the potential to observe such exotic decays in the di-Higgs channel.
Bound states in the Higgs model
Di Leo, L.; Darewych, J.W. )
1994-02-01
We derive relativistic wave equations for the bound states of two Higgs bosons within the Higgs sector of the minimal standard model. The variational method and the Hamiltonian formalism of QFT are used to obtain the equations using a simple [vert bar][ital hh][r angle]+[vert bar][ital hhh][r angle] Fock-space ansatz. We present approximate solutions of these equations for a range of Higgs boson masses, and explore the parameter space which corresponds to the existence of two-Higgs-boson bound states.
CP violation in heavy MSSM Higgs scenarios
Carena, M.; Ellis, J.; Lee, J. S.; ...
2016-02-18
We introduce and explore new heavy Higgs scenarios in the Minimal Supersymmetric Standard Model (MSSM) with explicit CP violation, which have important phenomenological implications that may be testable at the LHC. For soft supersymmetry-breaking scales MS above a few TeV and a charged Higgs boson mass MH+ above a few hundred GeV, new physics effects including those from explicit CP violation decouple from the light Higgs boson sector. However, such effects can significantly alter the phenomenology of the heavy Higgs bosons while still being consistent with constraints from low-energy observables, for instance electric dipole moments. To consider scenarios with amore » charged Higgs boson much heavier than the Standard Model (SM) particles but much lighter than the supersymmetric particles, we revisit previous calculations of the MSSM Higgs sector. We compute the Higgs boson masses in the presence of CP violating phases, implementing improved matching and renormalization-group (RG) effects, as well as two-loop RG effects from the effective two-Higgs Doublet Model (2HDM) scale MH± to the scale MS. Here, we illustrate the possibility of non-decoupling CP-violating effects in the heavy Higgs sector using new benchmark scenarios named.« less
Higgs Measurements at a Muon Collider
Conway, Alexander; Wenzel, Hans
2013-04-18
In light of the recent discovery of an approximately 126 GeV Higgs boson at the LHC, the particle physics community is beginning to explore the possibilities for a next-generation Higgs factory particle accelerator. In this report we study the s-channel resonant Higgs boson production and Standard Model backgrounds at a proposed \\mu+\\mu- collider Higgs factory operating at center-of-mass energy sqrt(s) = M_H with a beam width of 4.2 MeV. We study PYTHIA-generated Standard Model Higgs and background events at the generator level to identify and evaluate important channels for discovery and measurement of the Higgs mass, width, and branching ratios. We find that the H^0 -> bb and H^0 -> WW^* channels are the most useful for locating the Higgs peak. With an integrated luminosity of 1 fb^-1 we can measure a 126 GeV Standard Model Higgs mass accurately to within 0.25 MeV and its total width to within 0.45 MeV. Our results demonstrate the value of the high Higgs cross section and narrow beam resolution potentially achievable at a muon collider.
The Higgs Machine Learning Challenge
NASA Astrophysics Data System (ADS)
Adam-Bourdarios, C.; Cowan, G.; Germain-Renaud, C.; Guyon, I.; Kégl, B.; Rousseau, D.
2015-12-01
The Higgs Machine Learning Challenge was an open data analysis competition that took place between May and September 2014. Samples of simulated data from the ATLAS Experiment at the LHC corresponding to signal events with Higgs bosons decaying to τ+τ- together with background events were made available to the public through the website of the data science organization Kaggle (kaggle.com). Participants attempted to identify the search region in a space of 30 kinematic variables that would maximize the expected discovery significance of the signal process. One of the primary goals of the Challenge was to promote communication of new ideas between the Machine Learning (ML) and HEP communities. In this regard it was a resounding success, with almost 2,000 participants from HEP, ML and other areas. The process of understanding and integrating the new ideas, particularly from ML into HEP, is currently underway.
Draper, Patrick; Liu Tao; Wagner, Carlos E. M.; Wang, Lian-Tao; Zhang Hao
2011-03-25
We study a limit of the nearly Peccei-Quinn-symmetric next-to-minimal supersymmetric standard model possessing novel Higgs and dark matter (DM) properties. In this scenario, there naturally coexist three light singletlike particles: a scalar, a pseudoscalar, and a singlinolike DM candidate, all with masses of order 0.1-10 GeV. The decay of a standard model-like Higgs boson to pairs of the light scalars or pseudoscalars is generically suppressed, avoiding constraints from collider searches for these channels. For a certain parameter window annihilation into the light pseudoscalar and exchange of the light scalar with nucleons allow the singlino to achieve the correct relic density and a large direct-detection cross section consistent with the DM direct-detection experiments, CoGeNT and DAMA/LIBRA, preferred region simultaneously. This parameter space is consistent with experimental constraints from LEP, the Tevatron, {Upsilon}, and flavor physics.
Lincoln, Don
2014-04-28
With the discovery of what looks to be the Higgs boson, LHC researchers are turning their attention to the next big question, which is the predicted mass of the newly discovered particles. When the effects of quantum mechanics is taken into account, the mass of the Higgs boson should be incredibly high...perhaps upwards of a quadrillion times higher than what was observed. In this video, Fermilab's Dr. Don Lincoln explains how it is that the theory predicts that the mass is so large and gives at least one possible theoretical idea that might solve the problem. Whether the proposed idea is the answer or not, this question must be answered by experiments at the LHC or today's entire theoretical paradigm could be in jeopardy.
Lincoln, Don
2016-07-12
With the discovery of what looks to be the Higgs boson, LHC researchers are turning their attention to the next big question, which is the predicted mass of the newly discovered particles. When the effects of quantum mechanics is taken into account, the mass of the Higgs boson should be incredibly high...perhaps upwards of a quadrillion times higher than what was observed. In this video, Fermilab's Dr. Don Lincoln explains how it is that the theory predicts that the mass is so large and gives at least one possible theoretical idea that might solve the problem. Whether the proposed idea is the answer or not, this question must be answered by experiments at the LHC or today's entire theoretical paradigm could be in jeopardy.
Inflation and the Higgs Scalar
Green, Dan
2014-12-05
This note makes a self-contained exposition of the basic facts of big bang cosmology as they relate to inflation. The fundamental problems with that model are then explored. A simple scalar model of inflation is evaluated which provides the solution of those problems and makes predictions which will soon be definitively tested. The possibility that the recently discovered fundamental Higgs scalar field drives inflation is explored.
Neutrino Oscillations, the Higgs Boson, and the Private Higgs Model
NASA Astrophysics Data System (ADS)
BenTov, Jonathan
"CESR, PEP, PETRA, ISABELLE, p-bar p colliders, LEP, the tevatron, and ep machines are at various levels of design or construction. They will study the properties of b-matter, see weak intermediaries, and perhaps find the t-quark and the Higgs boson. Never before was there such a bestiary waiting to be discovered; and what surprises will be found!" - S. L. Glashow ("The Future of Elementary Particle Physics," Quarks and Leptons, NATO Advanced Study Institutes Series Volume 61, 1980, pp 687-713) The situation in 1980 was clearly different from the present situation in 2013, in which we face the very real possibilty that no new degrees of freedom will ever again be within reach of a collider. In an intriguing twist of fate, this very fact results in a sharp paradox for fundamental physics: the Higgs mass should be MP/m h ˜ 1017 times larger than it actually is, and the vacuum energy density of the universe should be (M P/A)4 ˜ (1031)4 times larger than it actually is, and apparently nature refuses to give us any more clues as to why. These together are what I would call the main problem of 21st century physics: despite all of the predictive success of particle physics so far, we must find a way to suitably modify the rules of quantum field theory, lest we accept the unproductive defeatist attitude that our universe is simply fine-tuned. In the meantime, there is much interesting work to be done in more "traditional" particle physics: we have learned that neutrinos actually have tiny but nonzero masses, which is clear and unambiguous evidence for physics beyond the Standard Model. I will allocate the first third of this document to phenomena related to neutrino oscillations. In particular, I would like to argue that some of the apparent differences between neutrino mixing and quark mixing are to an extent illusory, and actually many aspects of the two sectors can be understood in a coherent framework for extending the Standard Model. The remaining two-thirds of this
Exploring holographic Composite Higgs models
NASA Astrophysics Data System (ADS)
Croon, Djuna; Dillon, Barry M.; Huber, Stephan J.; Sanz, Veronica
2016-07-01
Simple Composite Higgs models predict new vector-like fermions not too far from the electroweak scale, yet LHC limits are now sensitive to the TeV scale. Motivated by this tension, we explore the holographic dual of the minimal model, MCHM5, to try and alleviate this tension without increasing the fine-tuning in the Higgs potential. Interestingly, we find that lowering the UV cutoff in the 5D picture allows for heavier top partners and less fine-tuning. In the 4D dual this corresponds to increasing the number of "colours" N , thus increasing the decay constant of the Goldstone Higgs. This is essentially a `Little Randall-Sundrum Model', which are known to reduce some flavour and electroweak constraints. Furthermore, in anticipation of the ongoing efforts at the LHC to put bounds on the top Yukawa, we demonstrate that deviations from the SM can be suppressed or enhanced with respect to what is expected from mere symmetry arguments in 4D. We conclude that the 5D holographic realisation of the MCHM5 with a small UV cutoff is not in tension with the current experimental data.
Higgs couplings and new signals from Flavon-Higgs mixing effects within multi-scalar models
NASA Astrophysics Data System (ADS)
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.
Neutral Supersymmetric Higgs Boson Searches
Robinson, Stephen Luke
2008-07-01
In some Supersymmetric extensions of the Standard Model, including the Minimal Supersymmetric Standard Model (MSSM), the coupling of Higgs bosons to b-quarks is enhanced. This enhancement makes the associated production of the Higgs with b-quarks an interesting search channel for the Higgs and Supersymmetry at D0. The identification of b-quarks, both online and offline, is essential to this search effort. This thesis describes the author's involvement in the development of both types of b-tagging and in the application of these techniques to the MSSM Higgs search. Work was carried out on the Level-3 trigger b-tagging algorithms. The impact parameter (IP) b-tagger was retuned and the effects of increased instantaneous luminosity on the tagger were studied. An extension of the IP-tagger to use the z-tracking information was developed. A new b-tagger using secondary vertices was developed and commissioned. A tool was developed to allow the use of large multi-run samples for trigger studies involving b-quarks. Offline, a neural network (NN) b-tagger was trained combining the existing offline lifetime based b-tagging tools. The efficiency and fake rate of the NN b-tagger were measured in data and MC. This b-tagger was internally reviewed and certified by the Collaboration and now provides the official b-tagging for all analyses using the Run IIa dataset at D0. A search was performed for neutral MSSM Higgs bosons decaying to a b{bar b} pair and produced in association with one or more b-quarks. Limits are set on the cross-section times the branching ratio for such a process. The limits were interpreted in various MSSM scenarios. This analysis uses the NN b-tagger and was the first to use this tool. The analysis also relies on triggers using the Level-3 IP b-tagging tool described previously. A likelihood discriminant was used to improve the analysis and a neural network was developed to cross-check this technique. The result of the analysis has been submitted to PRL and
Production of light Higgs pairs in 2-Higgs doublet models via the Higgs-strahlung process at the LHC
NASA Astrophysics Data System (ADS)
Moretti, M.; Moretti, S.; Piccinini, F.; Pittau, R.; Rathsman, J.
2010-11-01
At the Large Hadron Collider, we prove the feasibility to detect pair production of the lightest CP -even Higgs boson h of a Type II 2-Higgs Doublet Model through the process q{overline q^{left( ' right)}} to Vhh (Higgs-strahlung, V = W ± ,Z), in presence of two h to boverline b decays. We also show that, through such production and decay channels, one has direct access to the following Higgs self-couplings, thus enabling one to distinguish between a standard and the Supersymmetric version of the above model: λ Hhh — which constrains the form of the Higgs potential — as well as λ W ± H ∓ h and λ Z Ah — which are required by gauge invariance. Unfortunately, such claims cannot be extended to the Minimal Supersymmetric Standard Model, where the extraction of the same signals is impossible.
Gross, E.; Yepes, P. )
1993-01-30
The best Higgs hunting machine ever built, LEP, started operation in the summer of 1989. Since then the mass region explored in searching for the Standard Model Higgs boson has been extended by more than an order of magnitude. An overview of the searches performed by the four LEP collaborations by the end of 1991 is presented.
Higgs Boson Mass, Neutrino Oscillations and Inflation
Shafi, Qaisar
2008-11-23
Finding the Standard Model scalar (Higgs) boson is arguably the single most important mission of the LHC. I review predictions for the Higgs boson mass based on stability and perturbativity arguments, taking into account neutrino oscillations. Primordial inflation based on the Coleman-Weinberg potential is briefly discussed.
(SUSY) Higgs Search at the LHC
Muehlleitner, M. Margarete
2008-11-23
The discovery of the Standard Model (SM) or supersymmetric (SUSY) Higgs bosons belongs to the main endeavors of the Large Hadron Collider (LHC). In this article the status of the signal and background calculations for Higgs boson production at the LHC is reviewed.
Higgs portal valleys, stability and inflation
NASA Astrophysics Data System (ADS)
Ballesteros, Guillermo; Tamarit, Carlos
2015-09-01
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 cannot work if the Higgs portal coupling is too small. We also show that inflation in a false Higgs vacuum appearing radiatively for a tuned ratio of the Higgs and top masses leads to an amplitude of primordial gravitational waves that is far too high, ruling out this possibility.
Higgs Boson Mass, New Physics and Inflation
Shafi, Qaisar
2008-05-13
Finding the Standard Model scalar (Higgs) boson is arguably the single most important mission of the LHC. I review predictions for the Higgs boson mass based on stability and perturbativity arguments, taking into account neutrino oscillations. Other topics that are briefly discussed include the CMSSM, extra dimensions, higher dimensional orbifold GUTS, and primordial inflation based on the Coleman-Weinberg potential.
Higgs boson masses in supersymmetric models
Berger, M.S.
1991-04-01
Imposing supersymmetry on a Higgs potential constrains the parameters that define the potential. In supersymmetric extensions to the stranded model containing only Higgs SU(2){sub L} doublets there exist Higgs boson mass sum rules and bounds on the Higgs masses at tree level. The prescription for renormalizing these sum rules is derived. An explicit calculation is performed in the minimal supersymmetric extension to the standard model (MSSM). In this model at tree level the mass sum rule is M{sub H}{sup 2} + M{sub h}{sup 2} = M{sub A}{sup 2} + M{sub Z}{sup 2}. The results indicate that large corrections to the sum rules may arise from heavy matter fields, e.g. a heavy top quark. Squarks significantly heavier than their fermionic partners contribute large contributions when mixing occurs in the squark sector. These large corrections result from squark-Higgs couplings that become large in this limit. Contributions to individual Higgs boson masses that are quadratic in the squark masses cancel in the sum rule. Thus the naturalness constraint on Higgs boson masses is hidden in the combination of Higgs boson masses that comprise the sum rule. 39 refs., 13 figs.
Physics opportunities at mu+ mu- Higgs factories
C. Blochinger et al.
2004-01-12
We update theoretical studies of the physics opportunities presented by {mu}{sup +} {mu}{sup -} Higgs factories. Interesting measurements of the Standard Model Higgs decays into {bar b}b, {tau}{sup +} {tau}{sup -} and WW* may be possible if the Higgs mass is less than about 160 GeV, as preferred by the precision electroweak data, the mass range being extended by varying appropriately the beam energy resolution. A suitable value of the beam energy resolution would also enable the uncertainty in the b-quark mass to be minimized, facilitating measurements of parameters in the MSSM at such a first {mu}{sup +} {mu}{sup -} Higgs factory. These measurements would be sensitive to radiative corrections to the Higgs-fermion-antifermion decay vertices, which may violate CP. Radiative corrections in the MSSM may also induce CP violation in Higgs-mass mixing, which can be probed via various asymmetries measurable using polarized {mu}{sup +} {mu}{sup -} beams. In addition, Higgs-chargino couplings may be probed at a second {mu}{sup +} {mu}{sup -} Higgs factory.
Higgs bosons in standard model extensions
NASA Astrophysics Data System (ADS)
Gurskaya, A. V.; Dolgopolov, M. V.; Rykova, E. N.
2017-09-01
Several possibilities for extending the scalar sector of the Standard Model are considered. The conditions of calculation of Higgs bosons masses in the Next-to-Minimal Supersymmetric Standard Model are discussed. The probable limits on mass parameters of Higgs bosons are analyzed. The role of minimum conditions as a physical criterion in a model with an extended scalar sector is defined.
Bounding the Higgs boson width through interferometry.
Dixon, Lance J; Li, Ye
2013-09-13
We study the change in the diphoton-invariant-mass distribution for Higgs boson decays to two photons, due to interference between the Higgs resonance in gluon fusion and the continuum background amplitude for gg→γγ. Previously, the apparent Higgs mass was found to shift by around 100 MeV in the standard model in the leading-order approximation, which may potentially be experimentally observable. We compute the next-to-leading-order QCD corrections to the apparent mass shift, which reduce it by about 40%. The apparent mass shift may provide a way to measure, or at least bound, the Higgs boson width at the Large Hadron Collider through "interferometry." We investigate how the shift depends on the Higgs width, in a model that maintains constant Higgs boson signal yields. At Higgs widths above 30 MeV, the mass shift is over 200 MeV and increases with the square root of the width. The apparent mass shift could be measured by comparing with the ZZ* channel, where the shift is much smaller. It might be possible to measure the shift more accurately by exploiting its strong dependence on the Higgs transverse momentum.
Probing the non-minimal Higgs sector at the SSC
Gunion, J.F.; Haber, H.E.; Komamiya, S.; Yamamoto, H.; Barbaro-Galtieri, A.
1987-11-01
Non-minimal Higgs sectors occur in the Standard Model with more than one Higgs doublet, as well as in theories that go beyond the Standard Model. In this report, we discuss how Higgs search strategies must be altered, with respect to the Standard Model approaches, in order to probe the non-minimal Higgs sectors at the SSC.
Minimal flavour violation and multi-Higgs models
NASA Astrophysics Data System (ADS)
Botella, F. J.; Branco, G. C.; Rebelo, M. N.
2010-04-01
We propose an extension of the hypothesis of Minimal Flavour Violation (MFV) to general multi-Higgs models without the assumption of Natural Flavour Conservation (NFC) in the Higgs sector. We study in detail under what conditions the neutral Higgs couplings are only functions of VCKM and propose a MFV expansion for the neutral Higgs couplings to fermions.
Degenerate, strong and stable Yang-Mills-Higgs pairs
NASA Astrophysics Data System (ADS)
Hu, Zhi; Huang, Pengfei
2017-10-01
In this paper, we introduce some notions on the Hitchin pair consisting of a Chern connection and a Higgs field closely related to the first and second variations of Yang-Mills-Higgs functional, such as degenerate Hitchin pair, (strong) Yang-Mills-Higgs pair, and stable Yang-Mills-Higgs pair. We investigate some properties of such pairs under the various contexts.
The Minimal Supersymmetric Fat Higgs Model
Harnik, Roni; Kribs, Graham D.; Larson, Daniel T.; Murayama, Hitoshi
2003-11-26
We present a calculable supersymmetric theory of a composite"fat'" Higgs boson. Electroweak symmetry is broken dynamically through a new gauge interaction that becomes strong at an intermediate scale. The Higgs mass can easily be 200-450 GeV along with the superpartner masses, solving the supersymmetric little hierarchy problem. We explicitly verify that the model is consistent with precision electroweak data without fine-tuning. Gauge coupling unification can be maintained despite the inherently strong dynamics involved in electroweak symmetry breaking. Supersymmetrizing the Standard Model therefore does not imply a light Higgs mass, contrary to the lore in the literature. The Higgs sector of the minimal Fat Higgs model has a mass spectrum that is distinctly different from the Minimal Supersymmetric Standard Model.
Gauge-Higgs EW and Grand Unification
NASA Astrophysics Data System (ADS)
Hosotani, Yutaka
Four-dimensional Higgs field is identified with the extra-dimensional component of gauge potentials in the gauge-Higgs unifiation scenario. SO(5) × U(1) gauge-Higgs EW unification in the Randall-Sundrum warped space is successful at low energies. The Higgs field appears as an Aharonov-Bohm phase θH in the fifth dimension. Its mass is generated at the quantum level and is finite. The model yields almost the same phenomenology as the standard model for θH < 0.1, and predicts Z' bosons around 6-10 TeV with very broad widths. The scenario is generalized to SO(11) gauge-Higgs grand unification. Fermions are introduced in the spinor and vector representations of SO(11). Proton decay is naturally forbidden.
The problem with false vacuum Higgs inflation
NASA Astrophysics Data System (ADS)
Fairbairn, Malcolm; Grothaus, Philipp; Hogan, Robert
2014-06-01
We investigate the possibility of using the only known fundamental scalar, the Higgs, as an inflaton with minimal coupling to gravity. The peculiar appearance of a plateau or a false vacuum in the renormalised effective scalar potential suggests that the Higgs might drive inflation. For the case of a false vacuum we use an additional singlet scalar field, motivated by the strong CP problem, and its coupling to the Higgs to lift the barrier allowing for a graceful exit from inflation by mimicking hybrid inflation. We find that this scenario is incompatible with current measurements of the Higgs mass and the QCD coupling constant and conclude that the Higgs can only be the inflaton in more complicated scenarios.
Gauge-Higgs EW and grand unification
NASA Astrophysics Data System (ADS)
Hosotani, Yutaka
2016-07-01
Four-dimensional Higgs field is identified with the extra-dimensional component of gauge potentials in the gauge-Higgs unification scenario. SO(5) × U(1) gauge-Higgs EW unification in the Randall-Sundrum warped space is successful at low energies. The Higgs field appears as an Aharonov-Bohm phase 𝜃H in the fifth dimension. Its mass is generated at the quantum level and is finite. The model yields almost the same phenomenology as the standard model for 𝜃H < 0.1, and predicts Z‧ bosons around 6-10 TeV with very broad widths. The scenario is generalized to SO(11) gauge-Higgs grand unification. Fermions are introduced in the spinor and vector representations of SO(11). Proton decay is naturally forbidden.
Minimal Composite Higgs Models at the LHC
Carena, Marcela; Da Rold, Leandro; Pontón, Eduardo
2014-06-26
We consider composite Higgs models where the Higgs is a pseudo-Nambu Goldstone boson arising from the spontaneous breaking of an approximate global symmetry by some underlying strong dynamics. We focus on the SO(5) → SO(4) symmetry breaking pattern, assuming the “partial compositeness” paradigm. We study the consequences on Higgs physics of the fermionic representations produced by the strong dynamics, that mix with the Standard Model (SM) degrees of freedom. We consider models based on the lowest-dimensional representations of SO(5) that allow for the custodial protection of the Z b ¯ b coupling, i.e. the 5, 10 and 14. We find a generic suppression of the gluon fusion process, while the Higgs branching fractions can be enhanced or suppressed compared to the SM. Interestingly, a precise measurement of the Higgs boson couplings can distinguish between different realizations in the fermionic sector, thus providing crucial information about the nature of the UV dynamics.
Higgs coupling measurements at the LHC
NASA Astrophysics Data System (ADS)
Englert, Christoph; Kogler, Roman; Schulz, Holger; Spannowsky, Michael
2016-07-01
Due to the absence of tantalising hints for new physics during the LHC's Run 1, the extension of the Higgs sector by dimension-six operators will provide the new phenomenological standard for searches of non-resonant extensions of the Standard Model. Using all dominant and subdominant Higgs production mechanisms at the LHC, we compute the constraints on Higgs physics-relevant dimension-six operators in a global and correlated fit. We show in how far these constraints can be improved by new Higgs channels becoming accessible at higher energy and luminosity, both through inclusive cross sections as well as through highly sensitive differential distributions. This allows us to discuss the sensitivity to new effects in the Higgs sector that can be reached at the LHC if direct hints for physics beyond the SM remain elusive. We discuss the impact of these constraints on well-motivated BSM scenarios.
The problem with false vacuum Higgs inflation
Fairbairn, Malcolm; Grothaus, Philipp; Hogan, Robert E-mail: philipp.grothaus@kcl.ac.uk
2014-06-01
We investigate the possibility of using the only known fundamental scalar, the Higgs, as an inflaton with minimal coupling to gravity. The peculiar appearance of a plateau or a false vacuum in the renormalised effective scalar potential suggests that the Higgs might drive inflation. For the case of a false vacuum we use an additional singlet scalar field, motivated by the strong CP problem, and its coupling to the Higgs to lift the barrier allowing for a graceful exit from inflation by mimicking hybrid inflation. We find that this scenario is incompatible with current measurements of the Higgs mass and the QCD coupling constant and conclude that the Higgs can only be the inflaton in more complicated scenarios.
Benbrahim, A.; Jerrah, H.; Diouri, M.; Bahechar, N.; Boukind, E.H.
2009-01-01
Summary La flamme de diluant est une cause non rare de brûlure dans le contexte marocain. Nous avons jugé intéressant de faire une étude épidémiologique sur la brûlure par flamme de diluant (BFD) au centre national des brûlés (CNB) du CHU Ibn-Rochd de Casablanca. Ce travail a été réalisé sur une période de 10 mois (septembre 2007/juin 2008). Le but du travail est de montrer les caractéristiques de ce type de brûlures pour les prévenir et ce par l'information sur le diluant, produit causant ces brûlures, et ses différents dangers, la brûlure notamment. Durant cette période, nous avons colligé 17 cas de BFD sur un total de 356 patients admis au CNB pour brûlures aiguës toute étiologie confondue. La moyenne d'age des patients concernés est de 32 ans. Ils sont presque tous de sexe masculin (16 hommes/1 femme) et ont des antécédents de toxicomanie et/ou de délinquance. Tous nos patients sont de bas niveau socio-économique et habitent dans des bidonvilles pour la plupart. La brûlure est souvent secondaire à une agression dans la rue (92% des cas). Concernant les caractéristiques de la brûlure, la surface cutanée brûlée moyenne est de 23%; elle est souvent profonde et siège surtout au niveau des membres supérieurs et du tronc. PMID:21991179
Perturbative Higgs coupling C P violation, unitarity, and phenomenology
NASA Astrophysics Data System (ADS)
Englert, Christoph; Nordström, Karl; Sakurai, Kazuki; Spannowsky, Michael
2017-01-01
Perturbative probability conservation provides a strong constraint on the presence of new interactions of the Higgs boson. In this work we consider C P -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 C P violation in the Higgs sector can be directly constrained through collider searches for either characteristic new states or telltale enhancements in multi-Higgs processes.
Sakurai Prize: Extended Higgs Sectors--phenomenology and future prospects
NASA Astrophysics Data System (ADS)
Gunion, John
2017-01-01
The discovery of a spin-0 state at 125 GeV with properties close to those predicted for the single Higgs boson of the Standard Model does not preclude the existence of additional Higgs bosons. In this talk, models with extended Higgs sectors are reviewed, including two-Higgs-doublet models with and without an extra singlet Higgs field and supersymmetric models. Special emphasis is given to the limit in which the couplings and properties of one of the Higgs bosons of the extended Higgs sector are very close to those predicted for the single Standard Model Higgs boson while the other Higgs bosons are relatively light, perhaps even having masses close to or below the SM-like 125 GeV state. Constraints on this type of scenario given existing data are summarized and prospects for observing these non-SM-like Higgs bosons are discussed. Supported by the Department of Energy.
Bulk stabilization, the extra-dimensional Higgs portal and missing energy in Higgs events
NASA Astrophysics Data System (ADS)
Diener, Ross; Burgess, C. P.
2013-05-01
To solve the hierarchy problem, extra-dimensional models must explain why the new dimensions stabilize to the right size, and the known mechanisms for doing so require bulk scalars that couple to the branes. Because of these couplings the energetics of dimensional stabilization competes with the energetics of the Higgs vacuum, with potentially observable effects. These effects are particularly strong for one or two extra dimensions because the bulk-Higgs couplings can then be super-renormalizable or dimensionless. Experimental reach for such extra-dimensional Higgs `portals' are stronger than for gravitational couplings because they are less suppressed at low-energies. We compute how Higgs-bulk coupling through such a portal with two extra dimensions back-reacts onto properties of the Higgs boson. When the KK mass is smaller than the Higgs mass, mixing with KK modes results in an invisible Higgs decay width, missing-energy signals at high-energy colliders, and new mechanisms of energy loss in stars and supernovae. Astrophysical bounds turn out to be complementary to collider measurements, with observable LHC signals allowed by existing constraints. We comment on the changes to the Higgs mass-coupling relationship caused by Higgs-bulk mixing, and how the resulting modifications to the running of Higgs couplings alter vacuum-stability and triviality bounds.
Higgs pair productions in the CP-violating two-Higgs-doublet model
NASA Astrophysics Data System (ADS)
Bian, Ligong; Chen, Ning
2016-09-01
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 the CP-violating mixing angles are related to the Higgs cubic self couplings in this setup. Based on these constraints, we suggest benchmark models for the future high-energy collider searches for the Higgs pair productions. The e + e - colliders operating at √{s} = (500 GeV, 1 TeV) are capable of measuring the Higgs cubic self couplings of the benchmark models directly. Afterwards, we estimate the cross sections of the resonance contributions to the Higgs pair productions for the benchmark models at the future LHC and SppC/Fcc-hh runs. Other possible decay modes for the heavy Higgs bosons are also discussed.
Higgs-portal assisted Higgs inflation with a sizeable tensor-to-scalar ratio
NASA Astrophysics Data System (ADS)
Kim, Jinsu; Ko, Pyungwon; Park, Wan-Il
2017-02-01
We show that the Higgs portal interactions involving extra dark Higgs field can save generically the original Higgs inflation of the standard model (SM) from the problem of a deep non-SM vacuum in the SM Higgs potential. Specifically, we show that such interactions disconnect the top quark pole mass from inflationary observables and allow multi-dimensional parameter space to save the Higgs inflation, thanks to the additional parameters (the dark Higgs boson mass mphi, the mixing angle α between the SM Higgs H and dark Higgs Φ, and the mixed quartic coupling) affecting RG-running of the Higgs quartic coupling. The effect of Higgs portal interactions may lead to a larger tensor-to-scalar ratio, 0.08 lesssim r lesssim 0.1, by adjusting relevant parameters in wide ranges of α and mphi, some region of which can be probed at future colliders. Performing a numerical analysis we find an allowed region of parameters, matching the latest Planck data.
The Higgs Working Group: Summary report
D. Cavalli et al.
2004-03-18
In this working group we have investigated the prospects for Higgs boson searches at the Tevatron and LHC and, in particular, the potential of these colliders to determine the Higgs properties once these particles have been found. The analyses were done in the framework of the Standard Model (SM) and its supersymmetric extensions as the minimal (MSSM) and next-to-minimal (NMSSM) supersymmetric extensions. The work for the discovery potential of the LHC mainly concentrated on the difficult regions of previous analyses as those which are plagued by invisible Higgs decays and Higgs decays into supersymmetric particles. Moreover, the additional signatures provided by the weak vector-boson fusion process (WBF) have been addressed and found to confirm the results of previous analyses. A major experimental effort has been put onto charged Higgs boson analyses. The final outcome was a significant improvement of the discovery potential at the Tevatron and LHC than previous analyses suggested. For an accurate determination of Higgs boson couplings, the theoretical predictions for the signal and background processes have to be improved. A lot of progress has been made during and after this workshop for the gluon-fusion gg {yields} H + (0, 1, 2jets) and the associated t{bar t}H production process. A thorough study of the present theoretical uncertainties of signal and background processes has been initialized, culminating in a list of open theoretical problems. A problem of major experimental interest is the proper treatment of processes involving bottom quark densities, which is crucial for some important signal and background processes. Further theoretical improvements have been achieved for the MSSM Higgs boson masses and Higgs bosons in the NMSSM. This report summarizes our work. The first part deals with theoretical developments for the signal and background processes. The second part gives an overview of the present status of Higgs boson searches at the Tevatron. The
Black holes and Higgs stability
Tetradis, Nikolaos
2016-09-20
We study the effect of primordial black holes on the classical rate of nucleation of AdS regions within the standard electroweak vacuum. We find that the energy barrier for transitions to the new vacuum, which characterizes the exponential suppression of the nucleation rate, can be reduced significantly in the black-hole background. A precise analysis is required in order to determine whether the the existence of primordial black holes is compatible with the form of the Higgs potential at high temperature or density in the Standard Model or its extensions.
(Higgs) vacuum decay during inflation
NASA Astrophysics Data System (ADS)
Joti, Aris; Katsis, Aris; Loupas, Dimitris; Salvio, Alberto; Strumia, Alessandro; Tetradis, Nikolaos; Urbano, Alfredo
2017-07-01
We develop the formalism for computing gravitational corrections to vacuum decay from de Sitter space as a sub-Planckian perturbative expansion. Non-minimal coupling to gravity can be encoded in an effective potential. The Coleman bounce continuously deforms into the Hawking-Moss bounce, until they coincide for a critical value of the Hubble constant. As an application, we reconsider the decay of the electroweak Higgs vacuum during inflation. Our vacuum decay computation reproduces and improves bounds on the maximal inflationary Hubble scale previously computed through statistical techniques.
Probing the Higgs self coupling via single Higgs production at the LHC
Degrassi, G.; Giardino, P. P.; Maltoni, F.; Pagani, D.
2016-12-16
Here, we propose a method to determine the trilinear Higgs self coupling that is alternative to the direct measurement of Higgs pair production total cross sections and differential distributions. Furthermore, the method relies on the effects that electroweak loops featuring an anomalous trilinear coupling would imprint on single Higgs production at the LHC. We first calculate these contributions to all the phenomenologically relevant Higgs production (ggF, VBF, WH, ZH, t$\\bar{t}$ ) and decay (γγ,WW*/ZZ*→ 4f, b$\\bar{b}$,ττ) modes at the LHC and then estimate the sensitivity to the trilinear coupling via a one-parameter fit to the single Higgs measurements at the LHC 8 TeV. We also found that the bounds on the self coupling are already competitive with those from Higgs pair production and will be further improved in the current and next LHC runs.
Probing the Higgs self coupling via single Higgs production at the LHC
Degrassi, G.; Giardino, P. P.; Maltoni, F.; ...
2016-12-16
Here, we propose a method to determine the trilinear Higgs self coupling that is alternative to the direct measurement of Higgs pair production total cross sections and differential distributions. Furthermore, the method relies on the effects that electroweak loops featuring an anomalous trilinear coupling would imprint on single Higgs production at the LHC. We first calculate these contributions to all the phenomenologically relevant Higgs production (ggF, VBF, WH, ZH, tmore » $$\\bar{t}$$ ) and decay (γγ,WW*/ZZ*→ 4f, b$$\\bar{b}$$,ττ) modes at the LHC and then estimate the sensitivity to the trilinear coupling via a one-parameter fit to the single Higgs measurements at the LHC 8 TeV. We also found that the bounds on the self coupling are already competitive with those from Higgs pair production and will be further improved in the current and next LHC runs.« less
Probing the Higgs self coupling via single Higgs production at the LHC
NASA Astrophysics Data System (ADS)
Degrassi, G.; Giardino, P. P.; Maltoni, F.; Pagani, D.
2016-12-01
We propose a method to determine the trilinear Higgs self coupling that is alternative to the direct measurement of Higgs pair production total cross sections and differential distributions. The method relies on the effects that electroweak loops featuring an anomalous trilinear coupling would imprint on single Higgs production at the LHC. We first calculate these contributions to all the phenomenologically relevant Higgs production ( ggF, VBF, WH, ZH, toverline{t}H ) and decay (γ γ, W{W}^{ast }/Z{Z}^{ast}to 4f,boverline{b},τ τ ) modes at the LHC and then estimate the sensitivity to the trilinear coupling via a one-parameter fit to the single Higgs measurements at the LHC 8 TeV. We find that the bounds on the self coupling are already competitive with those from Higgs pair production and will be further improved in the current and next LHC runs.
A tale of twin Higgs: natural twin two Higgs doublet models
Yu, Jiang-Hao
2016-12-28
In original twin Higgs model, vacuum misalignment between electroweak and new physics scales is realized by adding explicit Z_{2} breaking term. Introducing additional twin Higgs could accommodate spontaneous Z_{2} breaking, which explains origin of this misalignment. We introduce a class of twin two Higgs doublet models with most general scalar potential, and discuss general conditions which trigger electroweak and Z_{2} symmetry breaking. Various scenarios on realising the vacuum misalignment are systematically discussed in a natural composite two Higgs double model framework: explicit Z_{2} breaking, radiative Z_{2} breaking, tadpole-induced Z_{2} breaking, and quartic-induced Z_{2} breaking. Finally, we investigate the Higgs mass spectra and Higgs phenomenology in these scenarios.
Gauge invariant one-loop corrections to Higgs boson couplings in nonminimal Higgs models
NASA Astrophysics Data System (ADS)
Kanemura, Shinya; Kikuchi, Mariko; Sakurai, Kodai; Yagyu, Kei
2017-08-01
We comprehensively evaluate renormalized Higgs boson couplings at one-loop level in nonminimal Higgs models such as the Higgs singlet model (HSM) and the four types of two Higgs doublet models (THDMs) with a softly broken Z2 symmetry. The renormalization calculation is performed in the on-shell scheme improved by using the pinch technique to eliminate the gauge dependence in the renormalized couplings. We first review the pinch technique for scalar boson two-point functions in the standard model (SM), the HSM and the THDMs. We then discuss the difference in the results of the renormalized Higgs boson couplings between the improved on-shell scheme and the ordinal one with a gauge dependence appearing in mixing parameters of scalar bosons. Finally, we widely investigate how we can identify the HSM and the THDMs focusing on the pattern of deviations in the renormalized Higgs boson couplings from predictions in the SM.
A tale of twin Higgs: natural twin two Higgs doublet models
Yu, Jiang-Hao
2016-12-28
In original twin Higgs model, vacuum misalignment between electroweak and new physics scales is realized by adding explicit Z2 breaking term. Introducing additional twin Higgs could accommodate spontaneous Z2 breaking, which explains origin of this misalignment. We introduce a class of twin two Higgs doublet models with most general scalar potential, and discuss general conditions which trigger electroweak and Z2 symmetry breaking. Various scenarios on realising the vacuum misalignment are systematically discussed in a natural composite two Higgs double model framework: explicit Z2 breaking, radiative Z2 breaking, tadpole-induced Z2 breaking, and quartic-induced Z2 breaking. Finally, we investigate the Higgs massmore » spectra and Higgs phenomenology in these scenarios.« less
NASA Astrophysics Data System (ADS)
Falkowski, A.; Grojean, C.; Kamińska, A.; Pokorski, S.; Weiler, A.
2011-11-01
In the absence of a Higgs boson, the perturbative description of the Standard Model ceases to make sense above a TeV. Heavy spin-1 fields coupled to W and Z bosons can extend the validity of the theory up to higher scales. We carefully identify regions of parameter space where a minimal addition — a single spin-1 SU(2)custodial-triplet resonance — allows one to retain perturbative control in all channels. Elastic scattering of longitudinal W and Z bosons alone seems to permit a very large cut-off beyond the Naive Dimensional Analysis expectation. We find however that including scattering of the spin-1 resonances then leads to an earlier onset of strong coupling. Most importantly for LHC searches, we define a self-consistent set-up with a well-defined range of validity without recourse to unitarization schemes whose physical meaning is obscure. We discuss the LHC phenomenology and the discovery reach for these electroweak resonances and mention the possibility of a nightmare scenario with no Higgs nor resonance within the LHC reach. Finally, we discuss the effects of parity breaking in the heavy resonance sector which reduces the contributions to the S parameter.
Twin Higgs Asymmetric Dark Matter.
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.
SM Higgs properties measurement at ATLAS
Murray, William
2010-02-10
The discovery of a new particle in the Higgs searches being prepared for LHC will not guarantee that the Standard Model Higgs boson has been seen. This paper discusses the possibilities for measuring the spin, parity and couplings of the particle, under the assumption that it does in fact behave like the Standard Model Higgs. The key question, which cannot alas be answered, is: if it looks like a dog, and barks like a dog, how much of the DNA must we analyse to be sure that it is a dog?
Beyond the discovery: Higgs results from CMS
NASA Astrophysics Data System (ADS)
Mankel, Rainer
2016-11-01
The observation of a Higgs boson at a mass near 125 GeV in the year 2012 has been a milestone for elementary particle physics. Since this fundamental discovery, the CMS collaboration has scrutinized the complete LHC Run I dataset in depth, and studied the properties of the observed state in full detail. This includes investigations of more elusive production and decay modes, as well as searches for first indications of an extended Higgs sector, which would represent very likely a promising gateway to new physics. This article summarizes recent Higgs results from the CMS experiment.
Higgs boson at LHC: a diffractive opportunity
Ducati, M. B. Gay; Silveira, G. G.
2009-03-23
An alternative process is presented for diffractive Higgs boson production in peripheral pp collisions, where the particles interact through the Double Pomeron Exchange. The event rate is computed as a central-rapidity distribution for Tevatron and LHC energies leading to a result around 0.6 pb, higher than the predictions from previous approaches. Therefore, this result arises as an enhanced signal for the detection of the Higgs boson in hadron colliders. The predictions for the Higgs boson photoproduction are compared to the ones obtained from a similar approach proposed by the Durham group, enabling an analysis of the future developments of its application to pp and AA collisions.
Craig, Nathaniel; Knapen, Simon; Longhi, Pietro; ...
2016-07-01
Here, 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.
Topological Physics of Little Higgs Bosons
Hill, Christopher T.; Hill, Richard J.; /Fermilab
2007-01-01
Topological interactions will generally occur in composite Higgs or Little Higgs theories, extra-dimensional gauge theories in which A5 plays the role of a Higgs boson, and among the pNGB's of technicolor. This phenomena arises from the chiral and anomaly structure of the underlying UV completion theory, and/or through chiral delocalization in higher dimensions. These effects are described by a full Wess-Zumino-Witten term involving gauge fields and pNGB's. We give a general discussion of these interactions, some of which may have novel signatures at future colliders, such as the LHC and ILC.
Magnetic Soliton, Homotopy and Higgs Theory,
1986-04-24
OD-AL67 366 NAGETIC SOLITON ONOTOPY ND HIGGS THEORY(U) FOREIGNI n1/ 1TECHNOLOGY D V NRIGHT-PATTERSON AFD ON Y LI ET AL. UNCLSSIIED24 APR 86 FTD-ID...MAGNETIC SOLITON, HOMOTOPY AND HIGGS THEORY by Li Yuanjie and Lei Shizu *. . * . .%..**% . . .-..C./ ~~~Approved for public release; -," Distribution...HOMOTOPY AND HIGGS THEORY By: Li Yuanjie and Lei Shizu English pages: 9 Source: Huazhong Gongxueyuan Xuebao, Vol. 11, Nr. 6, 1983, pp. 65-70 Country of
Spacetime Curvature and Higgs Stability after Inflation.
Herranen, M; Markkanen, T; Nurmi, S; Rajantie, A
2015-12-11
We investigate the dynamics of the Higgs field at the end of inflation in the minimal scenario consisting of an inflaton field coupled to the standard model only through the nonminimal gravitational coupling ξ of the Higgs field. Such a coupling is required by renormalization of the standard model in curved space, and in the current scenario also by vacuum stability during high-scale inflation. We find that for ξ≳1, rapidly changing spacetime curvature at the end of inflation leads to significant production of Higgs particles, potentially triggering a transition to a negative-energy Planck scale vacuum state and causing an immediate collapse of the Universe.
Craig, Nathaniel; Knapen, Simon; Longhi, Pietro; Strassler, Matthew
2016-07-01
Here, 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.
Searching heavier Higgs boson via di-Higgs production at LHC Run-2
NASA Astrophysics Data System (ADS)
Lü, Lan-Chun; Du, Chun; Fang, Yaquan; He, Hong-Jian; Zhang, Huijun
2016-04-01
The discovery of a light Higgs particle h0 (125 GeV) opens up new prospect for searching heavier Higgs boson(s) at the LHC Run-2, which will unambiguously point to new physics beyond the standard model (SM). We study the detection of a heavier neutral Higgs boson H0 via di-Higgs production channel at the LHC (14 TeV), H0 →h0h0 → WW* γγ. This directly probes the Hhh cubic Higgs interaction, which exists in most extensions of the SM Higgs sector. For the decay products of final states WW*, we include both pure leptonic mode WW* → ℓ ν bar ℓ bar ν and semi-leptonic mode WW* → qqbar‧ ℓν. We analyze signals and backgrounds by performing fast detector simulation for the full process pp → H → hh → WW* γγ → ℓ ν bar ℓ bar νγγ and pp → H → hh → WW* γγ → ℓνqqbar‧ γγ, over the mass range MH = 250- 600 GeV. For generic two-Higgs-doublet models (2HDM), we present the discovery reach of the heavier Higgs boson at the LHC Run-2, and compare it with the current Higgs global fit of the 2HDM parameter space.
Vector-boson production of light Higgs pairs in 2-Higgs doublet models
NASA Astrophysics Data System (ADS)
Moretti, M.; Moretti, S.; Piccinini, F.; Pittau, R.; Rathsman, J.
2007-12-01
At the Large Hadron Collider, we prove the feasibility to detect pair production of the lightest CP-even Higgs boson h of Type II 2-Higgs Doublet Models through qq(') → qq(')hh (vector-boson fusion). We also show that, through the hh → 4b decay channel in presence of heavy-flavour tagging, further exploiting forward/backward jet sampling, one has direct access to the λHhh triple Higgs coupling—which constrains the form of the Higgs potential.
Radiative-Z2-breaking twin Higgs model
NASA Astrophysics Data System (ADS)
Yu, Jiang-Hao
2016-12-01
In the twin Higgs model, the Higgs boson mass is protected by a Z2 symmetry. The Z2 symmetry needs to be broken either explicitly or spontaneously to obtain misalignment between electroweak and new physics vacua. We propose a novel Z2 breaking mechanism, in which the Z2 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. Because of 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.
Par Pond vegetation status 1996
Mackey, H.E. Jr.; Riley, R.S.
1996-12-01
The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995, and into the early spring and late summer of 1996. Communities similar to the pre-drawdown, Par Pond aquatic plant communities continue to become re-established. Emergent beds of maidencane, lotus, waterlily, watershield, and Pontederia are extensive and well developed. Measures of percent cover, width of beds, and estimates of area of coverage with satellite data indicate regrowth within two years of from 40 to 60% of levels prior to the draw down. Cattail occurrence continued to increase during the summer of 1996, especially in the former warm arm of Par Pond, but large beds common to Par Pond prior to the draw down still have not formed. Lotus has invaded and occupies many of the areas formerly dominated by cattail beds. To track the continued development of macrophytes in Par Pond, future surveys through the summer and early fall of 1997, along with the evaluation of satellite data to map the extent of the macrophyte beds of Par Pond, are planned.
A fat Higgs with a magnetic personality
NASA Astrophysics Data System (ADS)
Craig, Nathaniel; Stolarski, Daniel; Thaler, Jesse
2011-11-01
We introduce a novel composite Higgs theory based on confining supersymmetric QCD. Supersymmetric duality plays a key role in this construction, with a "fat" Higgs boson emerging as a dual magnetic degree of freedom charged under the dual magnetic gauge group. Due to spontaneous color-flavor locking in the infrared, the electroweak gauge symmetry is aligned with the dual magnetic gauge group, allowing large Yukawa couplings between elementary matter fields and the composite Higgs. At the same time, this theory exhibits metastable supersymmetry breaking, leading to low-scale gauge mediation via composite messengers. The Higgs boson is heavier than in minimal supersymmetric theories, due to a large F -term quartic coupling as well as small non-decoupling D-terms. This theory predicts quasi-stable TeV-scale pseudo-modulini, some of which are charged under standard model color, possibly giving rise to long-lived R-hadrons at the LHC.
UV-complete composite Higgs models
NASA Astrophysics Data System (ADS)
Agugliaro, Alessandro; Antipin, Oleg; Becciolini, Diego; De Curtis, Stefania; Redi, Michele
2017-02-01
We study confining gauge theories with fermions vectorial under the Standard Model (SM) that produce a Higgs doublet as a Nambu-Goldstone boson. The vacuum misalignment required to break the electroweak 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 flavor problems but with interesting effects for electric dipole moments of SM particles. We also discuss how ideas on the relaxation of the electroweak scale could be realized within this framework.
Nonsingular cosmology from an unstable Higgs field
NASA Astrophysics Data System (ADS)
Brandenberger, Robert H.; Cai, Yi-Fu; Wan, Youping; Zhang, Xinmin
The observed value of the Higgs mass indicates an instability of the Higgs scalar at large energy scales, and hence also at large field values. In the context of early universe cosmology, this is often considered to lead to problems. Here, we point out that we can use the instability of the Higgs field to generate an ekpyrotic phase of contraction. In the context of string theory, it is possible that at very high energy densities, extra states become massless leading to an S-brane which causes the transition between a contracting phase in the past and the current expanding phase. Thus, the Higgs field may be useable to generate a nonsingular bouncing cosmology in which the anisotropy problem of usual bouncing scenarios is mitigated.
Results from CMS on Higgs boson physics
NASA Astrophysics Data System (ADS)
Azzurri, Paolo; CMS Collaboration
2017-07-01
A selection of measurements and results of Higgs physics obtained by the CMS experiment are presented, obtained with proton collision data collected in 2015 and 2016 at the center-of-mass energy of 13 TeV.
Top partner probes of extended Higgs sectors
NASA Astrophysics Data System (ADS)
Kearney, John; Pierce, Aaron; Thaler, Jesse
2013-08-01
Natural theories of the weak scale often include fermionic partners of the top quark. If the electroweak symmetry breaking sector contains scalars beyond a single Higgs doublet, then top partners can have sizable branching ratios to these extended Higgs sector states. In fact, top partner decays may provide the most promising discovery mode for such scalars, especially given the large backgrounds to direct and associated production. In this paper, we present a search strategy for top partner decays to a charged Higgs boson and a bottom quark, focusing on the case where the charged Higgs dominantly decays to third-generation quarks to yield a multi- b final state. We also discuss ways to extend this search to exotic neutral scalars decaying to bottom quark pairs.
Higgs Effects in Top Quark Pair Production
Kuhn, J.H.
2003-06-13
Top quark production in p{bar p} and e{sup +}e{sup -} collisions is enhanced by the exchange of a Higgs boson. The enhancement factors are calculated in the threshold region using the Greens function method.
Standard model Higgs boson searches at CDF
Stancari, Michelle
2012-01-01
We present recent results from searches for a standard model Higgs boson by the CDF experiment at the Tevatron $p\\bar{p}$ collider with the full Run II data set. An excess of events above the expected background is observed and is the strongest in the associated production search channels where the Higgs is produced together with a W or Z boson, and then decays to a bottom-antibottom quark pair, with a global significance of 2.5$\\sigma$. Both limits and best fit values of the Higgs production cross section are presented. For a Higgs mass of 125~GeV/c$^2$, the best agreement with data in the $(\\sigma_{WH}+\\sigma_{ZH})\\times Br(H\\rightarrow b\\overline{b})=291\\pm^{118}_{113}$~fb.
Top and higgs physics at the Tevatron
Pierre Savard
2002-12-23
We present a summary of our experimental understanding of the top quark and discuss the significant improvements expected in Run II at the Fermilab Tevatron Collider. We also discuss prospects for a Higgs boson discovery at the Tevatron.
Partially natural two Higgs doublet models
Draper, Patrick; Haber, Howard E.; Ruderman, Joshua T.
2016-06-21
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. Furthermore, 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.
Lykken, Joseph; Spiropulu, Maria
2013-12-15
Experimentalists and theorists are still celebrating the Nobel-worthy discovery of the Higgs boson that was announced in July 2012 at CERN’s Large Hadron Collider. Now they are working on the profound implications of that discovery.
Minimal conformal extensions of the Higgs sector
NASA Astrophysics Data System (ADS)
Helmboldt, Alexander J.; Humbert, Pascal; Lindner, Manfred; Smirnov, Juri
2017-07-01
In this work we find the minimal extension of the Standard Model's Higgs sector which can lead to a light Higgs boson via radiative symmetry breaking and is consistent with the phenomenological requirements for a low-energy realization of a conformal theory. The model which turns out to be stable under renormalization group translations is an extension of the Standard Model by two scalar fields, one of which acquires a finite vacuum expectation value and therefore mixes into the physical Higgs. We find that the minimal model predicts a sizable amount of mixing which makes it testable at a collider. In addition to the physical Higgs, the theory's scalar spectrum contains one light and one heavy boson. The heavy scalar's properties render it a potential dark matter candidate.
Higgs boson productions at the CERN LHC as a probe of different littlest Higgs models with T parity
Wang Lei; Yang Jinmin
2008-01-01
Higgs boson productions at the LHC will serve as a sensitive probe of various little Higgs models. In this work we comparatively study two littlest Higgs models with different T-parity constructions through examining their effects in three production processes of the Higgs boson at the LHC, namely, the productions of a single Higgs, a Higgs-pair, as well as a Higgs boson associated with a pair of top and antitop quarks. The two models are characterized by predicting a top partner with, respectively, even and odd T-parity, which cancels the Higgs mass quadratic divergence caused by the top quark. We find that both models can alter the standard model cross sections sizably and their corrections also differ significantly. Therefore, the Higgs boson productions at the LHC might shed some light on these two models or even distinguish them.
Prospects for 2HDM charged Higgs searches
NASA Astrophysics Data System (ADS)
Krawczyk, M.; Moretti, S.; Osland, P.; Pruna, GM; Santos, R.
2017-07-01
We discuss the prospects for charged Higgs boson searches at the LHC, within the two-Higgs-doublet models (2HDM). The 2HDM is generally less constrained than the corresponding sector of the MSSM, but there are still severe theoretical and experimental constraints that already exclude significant regions of the naive parameter space. Explicit searches in the H + → τ+ν and H + → t\\bar{b} channels are further restricting parts of the 2HDM parameter space.
Discovering uncolored naturalness in exotic Higgs decays
NASA Astrophysics Data System (ADS)
Curtin, David; Verhaaren, Christopher B.
2015-12-01
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 the LHC and a potential future 100TeV collider. Our findings indicate that mirror glueballs are the smoking gun signature of natural FS and QLH type theories, in analogy to tree-level Higgs coupling shifts for the TH. We show that glueball masses in the ˜ 10-60 GeV mass range are theoretically preferred. Careful treatment of lifetime, mirror-hadronization and non-perturbative uncertainties is required to perform meaningful collider studies. We outline several new search strategies for exotic Higgs decays of the form h → XX → 4 f at the LHC, with X having lifetimes in the 10 μm to km range. We find that FS stops can be probed with masses up to 600 (1100) GeV at the LHC with 300 (3000) fb-1 of data, and TH top partners could be accessible with masses up to 900 (1500) GeV. This makes exotic Higgs decays the prime discovery channel for uncolored naturalness at the LHC.
Probing the Higgs vacuum with general relativity
NASA Technical Reports Server (NTRS)
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.
A Search for Dark Higgs Bosons
Lees, J.P.
2012-06-08
Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb{sup -1} of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the Standard Model-dark sector mixing angle and the dark sector coupling constant.
Improving acceptance for Higgs events at CDF
Sforza, Federico; /INFN, Pisa
2008-03-01
The Standard Model of elementary particles predicts the existence of the Higgs boson as the responsable of the electroweak symmetry breaking, the process by which fermions and vector bosons acquire mass. The Higgs existence is one of the most important questions in the present high energy physics research. This work concerns the search of W H associate production at the CDF II experiment (Collider Detector at Fermilab).
Higgs results from the Tevatron Run II
Tuchming, B.; /DAPNIA, Saclay
2005-01-01
The data taken at the Tevatron experiments have been analyzed to search for Higgs bosons. For the Standard Model Higgs searches, no excess is observed, the data are in good agreement with the expectations, so that limits are set on the production rates. For various theoretical models beyond the Standard Model, there is no excess either, which allows to derive constraints in their respective parameter spaces.
Probing the Higgs vacuum with general relativity
NASA Technical Reports Server (NTRS)
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.
The Higgs boson in the Standard Model
NASA Astrophysics Data System (ADS)
Djouadi, Abdelhak; Grazzini, Massimiliano
2016-10-01
The major goal of the Large Hadron Collider is to probe the electroweak symmetry breaking mechanism and the generation of the elementary particle masses. In the Standard Model this mechanism leads to the existence of a scalar Higgs boson with unique properties. We review the physics of the Standard Model Higgs boson, discuss its main search channels at hadron colliders and the corresponding theoretical predictions. We also summarize the strategies to study its basic properties.
Standard model and supersymmetric Higgs searches at CDF
Kilminster, Ben; /Ohio State U.
2005-10-01
We present the results on the searches for the SM and the MSSM Higgs boson production in proton-antiproton collisions at {radical}s = 1.96 GeV with the CDF detector. The Higgs bosons are searched for in various production and decay channels, with data samples corresponding to 400 pb{sup -1}. Using these measurements, we set an upper limit on the production cross section times branching fraction for the Standard Model Higgs as a function of the Higgs mass, and we obtain exclusion regions in the tan{beta} vs mass for the neutral MSSM Higgs, and branching fraction vs mass for the charged Higgs.
Higgs potential from derivative interactions
NASA Astrophysics Data System (ADS)
Quadri, A.
2017-06-01
A formulation of the linear σ model with derivative interactions is studied. The classical theory is on-shell equivalent to the σ model with the standard quartic Higgs potential. The mass of the scalar mode only appears in the quadratic part and not in the interaction vertices, unlike in the ordinary formulation of the theory. Renormalization of the model is discussed. A nonpower-counting renormalizable extension, obeying the defining functional identities of the theory, is presented. This extension is physically equivalent to the tree-level inclusion of a dimension-six effective operator ∂μ(Φ†Φ)∂μ(Φ†Φ). The resulting UV divergences are arranged in a perturbation series around the power-counting renormalizable theory. The application of the formalism to the Standard Model in the presence of the dimension-six operator ∂μ(Φ†Φ)∂μ(Φ†Φ) is discussed.
NASA Astrophysics Data System (ADS)
Reece, Matthew
2016-10-01
I give an overview of the physics potential at possible future e+e- colliders, including the ILC, FCC-ee, and CEPC. The goal is to explain some of the measurements that can be done in the context of electroweak precision tests and Higgs couplings, to compare some of the options under consideration, and to put the measurements in context by summarizing their implications for some new physics scenarios. This is a writeup of a plenary talk at the Hong Kong University of Science and Technology Jockey Club Institute for Advanced Study Program on High Energy Physics Conference, 18-21 January 2016. Some previously unpublished electroweak precision results for FCC-ee and CEPC are included.
Supersymmetric Sneutrino-Higgs inflation
NASA Astrophysics Data System (ADS)
Deen, Rehan; Ovrut, Burt A.; Purves, Austin
2016-11-01
It is shown that in the phenomenologically realistic supersymmetric B - L MSSM theory, a linear combination of the neutral, up Higgs field with the third family left- and right-handed sneutrinos can play the role of the cosmological inflaton. Assuming that supersymmetry is softly broken at a mass scale of order 1013 GeV, the potential energy associated with this field allows for 60 e-foldings of inflation with the cosmological parameters being consistent with all Planck2015 data. The theory does not require any non-standard coupling to gravity and the physical fields are all sub-Planckian during the inflationary epoch. It will be shown that there is a "robust" set of initial conditions which, in addition to satisfying the Planck data, simultaneously are consistent with all present LHC phenomenological requirements.
NASA Astrophysics Data System (ADS)
Reece, Matthew
I give an overview of the physics potential at possible future e+e- colliders, including the ILC, FCC-ee, and CEPC. The goal is to explain some of the measurements that can be done in the context of electroweak precision tests and Higgs couplings, to compare some of the options under consideration, and to put the measurements in context by summarizing their implications for some new physics scenarios. This is a writeup of a plenary talk at the Hong Kong University of Science and Technology Jockey Club Institute for Advanced Study Program on High Energy Physics Conference, 18-21 January 2016. Some previously unpublished electroweak precision results for FCC-ee and CEPC are included.
Sphalerons in composite and nonstandard Higgs models
NASA Astrophysics Data System (ADS)
Spannowsky, Michael; Tamarit, Carlos
2017-01-01
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 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 SO (5 )/SO (4 ) or an elementary Higgs with a deformed electroweak potential, we calculate the change of the sphaleron energy compared to the Standard Model prediction. We find that the sphaleron energy would have to be measured to O (10 )% accuracy to exclude sizeable global deviations from the Standard Model Higgs potential. We further find that because of the periodicity of the scalar potential in composite Higgs models a second sphaleron branch with larger energy arises.
Collider signatures of flavorful Higgs bosons
Altmannshofer, Wolfgang; Eby, Joshua; Gori, Stefania; Lotito, Matteo; Martone, Mario; Tuckler, Douglas
2016-12-30
Motivated by our limited knowledge of the Higgs couplings to the first two generation fermions, we analyze the collider phenomenology of a class of two Higgs doublet models (2HDMs) with a nonstandard 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,μμ,τμ and H^{±} → cb,cs,μν. As a result, searches for low-mass dimuon resonances are currently among the best probes of the heavy Higgs bosons in this setup.
A Historical Profile of the Higgs Boson
NASA Astrophysics Data System (ADS)
Ellis, John; Gaillard, Mary K.; Nanopoulos, Dimitri V.
2016-10-01
The Higgs boson was postulated in 1964, and phenomenological studies of its possible production and decays started in the early 1970s, followed by studies of its possible production in e+ e-, bar pp and pp collisions, in particular. Until recently, the most sensitive searches for the Higgs boson were at LEP between 1989 and 2000, which were complemented by searches at the Fermilab Tevatron. Then the LHC experiments ATLAS and CMS entered the hunt, announcing on July 4, 2012 the discovery of a "Higgs-like" particle with a mass of about 125 GeV. This identification has been supported by subsequent measurements of its spin, parity and coupling properties. It was widely anticipated that the Higgs boson would be accompanied by supersymmetry, although other options, like compositeness, were not completely excluded. So far there are no signs of any new physics, and the measured properties of the Higgs boson are consistent with the predictions of the minimal Standard Model. This article reviews some of the key historical developments in Higgs physics over the past half-century.
Light exotic Higgs bosons at the LHC
NASA Astrophysics Data System (ADS)
Munir, Shoaib
2017-07-01
Most models of new physics contain extended Higgs sectors with multiple Higgs bosons. The observation of an additional Higgs boson, besides the ∼ 125 GeV ‘hobs ’, will thus serve as an irrefutable evidence of physics beyond the Standard Model (SM). However, even when fairly light, these additional Higgs bosons may still have escaped detection at the Large Electron-Positron (LEP) collider, the Tevatron and the Large Hadron Collider (LHC) hitherto, owing to their highly reduced couplings to the SM particles. Therefore, in addition to the searches based on the conventional production processes of these Higgs bosons, such as gluon or vector boson fusion, possible new search modes need to be exploited at collider experiments in order to establish their signatures. We investigate here the phenomenology of pseudoscalars, with masses ranging from {O}(1) GeV to about 150 GeV, in the Next-to-Minimal Supersymmetric SM (NMSSM) and the Type-I 2-Higgs Doublet Model (2HDM) in some such atypical search channels at the LHC Run-II.
Enhanced Higgs mass in Compact Supersymmetry
NASA Astrophysics Data System (ADS)
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.
Long lived fourth generation and the Higgs
NASA Astrophysics Data System (ADS)
Keung, Wai-Yee; Schwaller, Pedro
2011-06-01
A chiral fourth generation is a simple and well motivated extension of the standard model, and has important consequences for Higgs phenomenology. Here we consider a scenario where the fourth generation neutrinos are long lived and have both a Dirac and Majorana mass term. Suchneutrinoscanbeaslightas40GeVandcanbethedominant decay mode of the Higgs boson for Higgs masses below the W-boson threshold. We study the effect of the Majorana mass term on the Higgs branching fractions and reevaluate the Tevatron constraints on the Higgs mass. We discuss the prospects for the LHC to detect the semi-invisible Higgs decays into fourth generation neutrino pairs. Under the assumption that the lightest fourth generation neutrino is stable, its thermal relic density can be up to 20% of the observed dark matter density in the universe. This is in agreement with current constraints on the spin dependent neutrino-neutron cross section, but can be probed by the next generation of dark matter direct detection experiments.
New signatures of flavor violating Higgs couplings
NASA Astrophysics Data System (ADS)
Buschmann, Malte; Kopp, Joachim; Liu, Jia; Wang, Xiao-Ping
2016-06-01
We explore several novel LHC signatures arising from quark or lepton flavor violating couplings in the Higgs sector, and we constrain such couplings using LHC data. Since the largest signals are possible in channels involving top quarks or tau leptons, we consider in particular the following flavor violating processes: (1) pp → thh (top plus di-Higgs final state) arising from a dimension six coupling of up-type quarks to three insertions of the Higgs field. We develop a search strategy for this final state and demonstrate that detection is possible at the high luminosity LHC if flavor violating top-up-Higgs couplings are not too far below the current limit. (2) pp → tH 0, where H 0 is the heavy neutral CP-even Higgs boson in a two Higgs doublet model (2HDM). We consider the decay channels H 0 → tu, WW, ZZ, hh and use existing LHC data to constrain the first three of them. For the fourth, we adapt our search for the thh final state, and we demonstrate that in large regions of the parameter space, it is superior to other searches, including searches for flavor violating top quark decays ( t → hq). (3) H 0 → τ μ, again in the context of a 2HDM. This channel is particularly well motivated by the recent CMS excess in h → τ μ, and we use the data from this search to constrain the properties of H 0.
Alignment limit of the NMSSM Higgs sector
Carena, Marcela; Haber, Howard E.; Low, Ian; Shah, Nausheen R.; Wagner, Carlos E. M.
2016-02-17
The Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM) with a Higgs boson of mass 125 GeV can be compatible with stop masses of order of the electroweak scale, thereby reducing the degree of fine-tuning necessary to achieve electroweak symmetry breaking. Moreover, in an attractive region of the NMSSM parameter space, corresponding to the \\alignment limit" in which one of the neutral Higgs fields lies approximately in the same direction in field space as the doublet Higgs vacuum expectation value, the observed Higgs boson is predicted to have Standard- Model-like properties. We derive analytical expressions for the alignment conditions and show that they point toward a more natural region of parameter space for electroweak symmetry breaking, while allowing for perturbativity of the theory up to the Planck scale. Additionally, the alignment limit in the NMSSM leads to a well defined spectrum in the Higgs and Higgsino sectors, and yields a rich and interesting Higgs boson phenomenology that can be tested at the LHC. Here, we discuss the most promising channels for discovery and present several benchmark points for further study.
Alignment limit of the NMSSM Higgs sector
Carena, Marcela; Haber, Howard E.; Low, Ian; ...
2016-02-17
The Next-to-Minimal Supersymmetric extension of the Standard Model (NMSSM) with a Higgs boson of mass 125 GeV can be compatible with stop masses of order of the electroweak scale, thereby reducing the degree of fine-tuning necessary to achieve electroweak symmetry breaking. Moreover, in an attractive region of the NMSSM parameter space, corresponding to the \\alignment limit" in which one of the neutral Higgs fields lies approximately in the same direction in field space as the doublet Higgs vacuum expectation value, the observed Higgs boson is predicted to have Standard- Model-like properties. We derive analytical expressions for the alignment conditions andmore » show that they point toward a more natural region of parameter space for electroweak symmetry breaking, while allowing for perturbativity of the theory up to the Planck scale. Additionally, the alignment limit in the NMSSM leads to a well defined spectrum in the Higgs and Higgsino sectors, and yields a rich and interesting Higgs boson phenomenology that can be tested at the LHC. Here, we discuss the most promising channels for discovery and present several benchmark points for further study.« less
Collider signatures of flavorful Higgs bosons
Altmannshofer, Wolfgang; Eby, Joshua; Gori, Stefania; ...
2016-12-30
Motivated by our limited knowledge of the Higgs couplings to the first two generation fermions, we analyze the collider phenomenology of a class of two Higgs doublet models (2HDMs) with a nonstandard 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 quarksmore » can become dominant. The most interesting decay modes include H/A → cc,tc,μμ,τμ and H± → cb,cs,μν. As a result, searches for low-mass dimuon resonances are currently among the best probes of the heavy Higgs bosons in this setup.« less
Higgs-to-Higgs boson decays in a 2HDM at next-to-leading order
NASA Astrophysics Data System (ADS)
Krause, Marcel; Mühlleitner, Margarete; Santos, Rui; Ziesche, Hanna
2017-04-01
The detailed investigation of the Higgs sector at present and future colliders necessitates from the theory side as precise predictions as possible, including higher-order corrections. An important ingredient for the computation of higher-order corrections is the renormalization of the model parameters and fields. In this paper we complete the renormalization of the two-Higgs-doublet model (2HDM) Higgs sector launched in a previous contribution with the investigation of the renormalization of the mixing angles α and β . Here, we treat the renormalization of the mass parameter m122 that softly breaks the Z2 symmetry of the 2HDM Higgs sector. We investigate the impact of two different renormalization schemes on the sample Higgs-to-Higgs decay H →h h . This decay also allows us to analyze the renormalization of the mixing angles and to confirm the properties extracted before in other Higgs decays. In conclusion we find that a gauge-independent, process-independent and numerically stable renormalization of the 2HDM Higgs sector is given by the application of the tadpole-pinched scheme for the mixing angles α and β and by the use of the modified minimal subtraction scheme for m122.
Radiative corrections to the triple Higgs coupling in the inert Higgs doublet model
NASA Astrophysics Data System (ADS)
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.
Carena, Marcela; Haber, Howard E.; Low, Ian; ...
2015-02-03
Precision measurements of the Higgs boson properties at the LHC provide relevant constraints on possible weak-scale extensions of the Standard Model (SM). In the context of the minimal supersymmetric Standard Model (MSSM) these constraints seem to suggest that all the additional, non-SM-like Higgs bosons should be heavy, with masses larger than about 400 GeV. This article shows that such results do not hold when the theory approaches the conditions for “alignment independent of decoupling,” where the lightest CP-even Higgs boson has SM-like tree-level couplings to fermions and gauge bosons, independently of the nonstandard Higgs boson masses. In addition, the combinationmore » of current bounds from direct Higgs boson searches at the LHC, along with the alignment conditions, have a significant impact on the allowed MSSM parameter space yielding light additional Higgs bosons. In particular, after ensuring the correct mass for the lightest CP-even Higgs boson, we find that precision measurements and direct searches are complementary and may soon be able to probe the region of non-SM-like Higgs boson with masses below the top quark pair mass threshold of 350 GeV and low to moderate values of tanβ.« less
Carena, Marcela; Haber, Howard E.; Low, Ian; Shah, Nausheen R.; Wagner, Carlos E. M.
2015-02-03
Precision measurements of the Higgs boson properties at the LHC provide relevant constraints on possible weak-scale extensions of the Standard Model (SM). In the context of the minimal supersymmetric Standard Model (MSSM) these constraints seem to suggest that all the additional, non-SM-like Higgs bosons should be heavy, with masses larger than about 400 GeV. This article shows that such results do not hold when the theory approaches the conditions for “alignment independent of decoupling,” where the lightest CP-even Higgs boson has SM-like tree-level couplings to fermions and gauge bosons, independently of the nonstandard Higgs boson masses. In addition, the combination of current bounds from direct Higgs boson searches at the LHC, along with the alignment conditions, have a significant impact on the allowed MSSM parameter space yielding light additional Higgs bosons. In particular, after ensuring the correct mass for the lightest CP-even Higgs boson, we find that precision measurements and direct searches are complementary and may soon be able to probe the region of non-SM-like Higgs boson with masses below the top quark pair mass threshold of 350 GeV and low to moderate values of tanβ.
Carena, Marcela; Haber, Howard E.; Low, Ian; Shah, Nausheen R.; Wagner, Carlos E.M.
2015-02-03
Precision measurements of the Higgs boson properties at the LHC provide relevant constraints on possible weak-scale extensions of the Standard Model (SM). In the context of the minimal supersymmetric Standard Model (MSSM) these constraints seem to suggest that all the additional, non-SM-like Higgs bosons should be heavy, with masses larger than about 400 GeV. This article shows that such results do not hold when the theory approaches the conditions for “alignment independent of decoupling,” where the lightest CP -even Higgs boson has SM-like tree-level couplings to fermions and gauge bosons, independently of the nonstandard Higgs boson masses. The combination of current bounds from direct Higgs boson searches at the LHC, along with the alignment conditions, have a significant impact on the allowed MSSM parameter space yielding light additional Higgs bosons. In particular, after ensuring the correct mass for the lightest CP -even Higgs boson, we find that precision measurements and direct searches are complementary and may soon be able to probe the region of non-SM-like Higgs boson with masses below the top quark pair mass threshold of 350 GeV and low to moderate values of tanβ
Cornering a hyper Higgs boson: Angular kinematics for boosted Higgs bosons with top pairs
NASA Astrophysics Data System (ADS)
Bramante, Joseph; Delgado, Antonio; Martin, Adam
2014-05-01
In the wake of the Higgs discovery and over the long haul of the LHC run, one should keep a lookout for kinematic anomalies in the most massive known trio of coupled particles, tt¯h. After surveying the scope of prior constraints on chromomagnetic dipole and Higgs-gluon kinetic couplings, we focus on surpluses of boosted-pT Higgs bosons fomented by these momentum-dependent dimension-six operators in tt¯h final states. We uncover a number of simple, pT-weighted angular variables useful for discriminating Standard Model from dimension-six boosted Higgs distributions, and we make headway by arguing that one of these variables may improve the reach of existing Standard Model top-Higgs searches. The approach we take is model independent because we just consider a set of effective operators that contribute to the same three-body final state.
Charged Higgs phenomenology in the flipped two-Higgs-doublet model
Logan, Heather E.; MacLennan, Deanna
2010-04-01
We study the phenomenology of the charged Higgs boson in the flipped two-Higgs-doublet model, in which one doublet gives mass to up-type quarks and charged leptons, and the other gives mass to down-type quarks. We present the charged Higgs branching ratios and summarize the indirect constraints. We extrapolate existing LEP searches for H{sup +}H{sup -} and Tevatron searches for tt with t{yields}H{sup +}b into the flipped model and extract constraints on M{sub H}{sup +} and the parameter tan{beta}. We finish by reviewing existing LHC charged Higgs searches and suggest that the LHC reach in this model could be extended for charged Higgs masses below the tb threshold by considering tt with t{yields}H{sup +}b and H{sup +{yields}}qq{sup '}, as has been used in Tevatron searches.
Special Mixing of the Neutral Higgs Bosons States in the Standard Model with Two Higgs Doublets
Juarez W, S. R.; Morales C, D.
2008-07-02
The Higgs sector of the Standard Model (SM) requires careful investigation in order to look for new physics. In the SM the masses of the physical particles arise, after the spontaneous symmetry breaking (SSB), through its couplings with a single Higgs doublet. In the simplest extension of the SM, called the Two Higgs Doublet Model (2HDM), a second Higgs doublet is introduced, with a potential dependent on seven parameters, which are related to five Higgs bosons, whose existence is predicted by the model. In this context, we obtain the masses and the physical eigenstates of the new scalar particles: two charged ones (H{sup {+-}}) and three neutral (A{sup 0}), (h{sup 0},H{sup 0}). We explore a particular situation in which very simple relations between the parameters and the masses are satisfied.
125 GeV Higgs state in the context of four generations with two Higgs doublets
NASA Astrophysics Data System (ADS)
Geller, Michael; Bar-Shalom, Shaouly; Eilam, Gad; Soni, Amarjit
2012-12-01
We interpret the recent discovery of a 125 GeV Higgs-like state in the context of a two-Higgs-doublet model with a heavy fourth sequential generation of fermions, in which one Higgs doublet couples only to the fourth-generation fermions, while the second doublet couples to the lighter fermions of the first three families. This model is designed to accommodate the apparent heaviness of the fourth-generation fermions and to effectively address the low-energy phenomenology of a dynamical electroweak-symmetry-breaking scenario. The physical Higgs states of the model are, therefore, viewed as composites primarily of the fourth-generation fermions. We find that the lightest Higgs, h, is a good candidate for the recently discovered 125 GeV spin-zero particle, when tanβ˜O(1), for typical fourth-generation fermion masses of M4G=400-600GeV, and with a large t-t' mixing in the right-handed quark sector. This, in turn, leads to BR(t'→th)˜O(1), which drastically changes the t' decay pattern. We also find that, based on the current Higgs data, this two-Higgs-doublet model generically predicts an enhanced production rate (compared to the Standard Model) in the pp→h→ττ channel, and reduced rates in the VV→h→γγ and pp¯/pp→V→hV→Vbb channels. Finally, the heavier CP-even Higgs is excluded by the current data up to mH˜500GeV, while the pseudoscalar state, A, can be as light as 130 GeV. These heavier Higgs states and the expected deviations from the Standard Model din some of the Higgs production channels can be further excluded or discovered with more data.
Models of little Higgs and electroweak precision tests
Chen, Mu-Chun; /Fermilab
2006-01-01
The little Higgs idea is an alternative to supersymmetry as a solution to the gauge hierarchy problem. In this note, the author reviews various little Higgs models and their phenomenology with emphasis on the precision electroweak constraints in these models.
Higgs-induced spectroscopic shifts near strong gravity sources
Onofrio, Roberto
2010-09-15
We explore the consequences of the mass generation due to the Higgs field in strong gravity astrophysical environments. The vacuum expectation value of the Higgs field is predicted to depend on the curvature of spacetime, potentially giving rise to peculiar spectroscopic shifts, named hereafter 'Higgs shifts'. Higgs shifts could be searched through dedicated multiwavelength and multispecies surveys with high spatial and spectral resolution near strong gravity sources such as Sagittarius A* or broad searches for signals due to primordial black holes. The possible absence of Higgs shifts in these surveys should provide limits to the coupling between the Higgs particle and the curvature of spacetime, a topic of interest for a recently proposed Higgs-driven inflationary model. We discuss some conceptual issues regarding the coexistence between the Higgs mechanism and gravity, especially for their different handling of fundamental and composite particles.
Got a Minute? Which Higgs did we find?
Stupak, John
2014-06-26
Dr. John Stupak talks about the discovery of the Higgs boson. Did scientists find the Higgs boson predicted back in 1964 or did they find just one of a group of particles, with the others still to be found?
Got a Minute? Which Higgs did we find?
Stupak, John
2016-07-12
Dr. John Stupak talks about the discovery of the Higgs boson. Did scientists find the Higgs boson predicted back in 1964 or did they find just one of a group of particles, with the others still to be found?
Exploration of locomotion in the ParA/ParB system
NASA Astrophysics Data System (ADS)
Jindal, Lavisha; Emberly, Eldon
2015-03-01
In many bacteria the ParA/ParB system is responsible for actively segregating DNA during replication. ParB precessively moves by hydrolyzing DNA bound ParA-ATP forming a depleted ParA region in its wake. Recent in-vitro experiments have shown that a ParB covered bead can traverse a ParA bound DNA substrate. It has been suggested that the formation of a gradient in ParA leads to diffusion-ratchet like motion of the ParB bead but its origin and potential consequences requires investigation. We have developed a deterministic model for the in-vitro ParA/ParB system and show that any amount of spatial noise in ParA can lead to the spontaneous formation of its gradient. The velocity of the bead is independent of this noise but depends on the scale over which ParA exerts a force on the bead and the scale over which ParB hydrolyzes ParA from the substrate. There is a particular ratio of these scales at which the velocity is a maximum. We also explore the effects of cooperative vs independent rebinding of ParA to the substrate. Our model shows how the driving force for ParB originates and highlights necessary conditions for directed motion in the in-vitro system that may provide insight into the in-vivo behaviour of the ParA/ParB system.
Manifestations of CP Violation in the MSSM Higgs Sector
Lee, Jae Sik
2008-11-23
We demonstrate how CP violation manifests itself in the Higgs sector of the minimal supersymmetric extension of the Standard Model (MSSM). Starting with a brief introduction to CP violation in the MSSM and its effects on the Higgs sector, we discuss some phenomenological aspects of the Higgs sector CP violation based on the two scenarios called CPX and Trimixing.
Resonant Higgs enhancement at the First Muon Collider
Kamal, B.; Marciano, W.J.; Parsa, Z.
1998-03-01
The effect of beam polarization on Higgs resonance signals and backgrounds (b{anti b}, {tau}{anti {tau}}, c{anti c}) at the First Muon Collider is studied. Angular distributions (forward-backward charge asymmetries) are examined. The resulting effective enhancement of the Higgs signal relative to the background is investigated as is the reduction in scan time required for Higgs discovery.
On the exotic Higgs decays in effective field theory.
Bélusca-Maïto, Hermès; Falkowski, Adam
2016-01-01
We discuss exotic Higgs decays in an effective field theory where the Standard Model is extended by dimension-6 operators. We review and update the status of two-body lepton- and quark-flavor-violating decays involving the Higgs boson. We also comment on the possibility of observing three-body flavor-violating Higgs decays in this context.
The flavor of the Composite Twin Higgs
NASA Astrophysics Data System (ADS)
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.
Decaying Higgs Fields and Cosmological Dark Energy
NASA Astrophysics Data System (ADS)
Patla, B.; Nemiroff, R. J.
2005-05-01
The observed dark energy in the universe might give particles inertial mass. We investigate one realization of this idea, that the dark energy field might be a decayed scalar component of a scalar field in the early universe that creates inertial mass through spontaneous symmetry breaking, e.g. a Higgs field. To investigate this possibility, the cosmological Friedmann equation of energy balance is augmented in a standard way to incorporate a minimally coupled cosmological Higgs. For epochs where the expansion of the universe is driven by matter and radiation and not the scalar field, the observed hidden nature of the Higgs field can be codified into a single differential equation that we call the ``hidden higgs" condition. The resulting differential equation is solved for the time dependant scalar field and a simple and interesting solution is found analytically. Such a Higgs field decays from Planck scale energies rapidly and approximately exponentially from onset, leaving only the initially negligible constant term of the potential as a final cosmological constant. Such evolution replaces the hierarchy problem with the problem of explaining why such evolution is physically justified, leaving the coincidence problem still unresolved.
Minimal Composite Higgs Models at the LHC
Carena, Marcela; Da Rold, Leandro; Pontón, Eduardo
2014-06-26
We consider composite Higgs models where the Higgs is a pseudo-Nambu Goldstone boson arising from the spontaneous breaking of an approximate global symmetry by some underlying strong dynamics. We focus on the SO(5) → SO(4) symmetry breaking pattern, assuming the “partial compositeness” paradigm. We study the consequences on Higgs physics of the fermionic representations produced by the strong dynamics, that mix with the Standard Model (SM) degrees of freedom. We consider models based on the lowest-dimensional representations of SO(5) that allow for the custodial protection of the Z b ¯ b coupling, i.e. the 5, 10 and 14. We findmore » a generic suppression of the gluon fusion process, while the Higgs branching fractions can be enhanced or suppressed compared to the SM. Interestingly, a precise measurement of the Higgs boson couplings can distinguish between different realizations in the fermionic sector, thus providing crucial information about the nature of the UV dynamics.« less
The Higgs Boson Search and Discovery
NASA Astrophysics Data System (ADS)
Bernardi, Gregorio; Konigsberg, Jacobo
2016-10-01
We present a brief account of the search for the Higgs boson at the three major colliders that have operated over the last three decades: LEP, the Tevatron, and the LHC. The experimental challenges encountered stemmed from the distinct event phenomenology as determined by the colliders energy and the possible values for the Higgs boson mass, and from the capability of these colliders to deliver as much collision data as possible to fully explore the mass spectrum within their reach. Focusing more on the hadron collider searches during the last decade, we discuss how the search for the Higgs boson was advanced through mastering the experimental signatures of standard theory backgrounds, through the comprehensive utilization of the features of the detectors involved in the searches, and by means of advanced data analysis techniques. The search culminated in 2012 with the discovery, by the ATLAS and CMS collaborations, of a Higgs-like particle with mass close to 125 GeV, confirmed more recently to have properties consistent with those expected from the standard theory Higgs boson.
Higgs EFT for 2HDM and beyond.
Bélusca-Maïto, Hermès; Falkowski, Adam; Fontes, Duarte; Romão, Jorge C; Silva, João P
2017-01-01
We discuss the validity of the Standard Model Effective Field Theory (SM EFT) as the low-energy effective theory for the two-Higgs-doublet Model (2HDM). Using the up-to-date Higgs signal strength measurements at the LHC, one can obtain a likelihood function for the Wilson coefficients of dimension-6 operators in the EFT Lagrangian. Given the matching between the 2HDM and the EFT, the constraints on the Wilson coefficients can be translated into constraints on the parameters of the 2HDM Lagrangian. We discuss under which conditions such a procedure correctly reproduces the true limits on the 2HDM. Finally, we employ the SM EFT to identify the pattern of the Higgs boson couplings that are needed to improve the fit to the current Higgs data. To this end, one needs, simultaneously, to increase the top Yukawa coupling, decrease the bottom Yukawa coupling, and induce a new contact interaction of the Higgs boson with gluons. We comment on how these modifications can be realized in the 2HDM extended by new colored particles.
NASA Astrophysics Data System (ADS)
Bélusca-Maïto, Hermès; Falkowski, Adam; Fontes, Duarte; Romão, Jorge C.; Silva, João P.
2017-03-01
We discuss the validity of the Standard Model Effective Field Theory (SM EFT) as the low-energy effective theory for the two-Higgs-doublet Model (2HDM). Using the up-to-date Higgs signal strength measurements at the LHC, one can obtain a likelihood function for the Wilson coefficients of dimension-6 operators in the EFT Lagrangian. Given the matching between the 2HDM and the EFT, the constraints on the Wilson coefficients can be translated into constraints on the parameters of the 2HDM Lagrangian. We discuss under which conditions such a procedure correctly reproduces the true limits on the 2HDM. Finally, we employ the SM EFT to identify the pattern of the Higgs boson couplings that are needed to improve the fit to the current Higgs data. To this end, one needs, simultaneously, to increase the top Yukawa coupling, decrease the bottom Yukawa coupling, and induce a new contact interaction of the Higgs boson with gluons. We comment on how these modifications can be realized in the 2HDM extended by new colored particles.
COSMOLOGICAL CONSTRAINTS ON THE HIGGS BOSON MASS
Popa, L. A.; Caramete, A.
2010-11-01
For a robust interpretation of upcoming observations from PLANCK and Large Hadron Collider experiments it is imperative to understand how the inflationary dynamics of a non-minimally coupled Higgs scalar field with gravity may affect the determination of the inflationary observables. We make a full proper analysis of the Wilkinson Microwave Anisotropy Probe, Type Ia supernova distance-redshift relation, and the baryon acoustic oscillations data sets in a context of the non-minimally coupled Higgs inflation field with gravity. For the central value of the top quark pole mass m{sub T} = 171.3 GeV, the fit of the inflation model with a non-minimally coupled Higgs scalar field leads to a Higgs boson mass in the range 143.7 GeV {<=} m{sub H} {<=} 167 GeV (95% CL). We show that the inflation driven by a non-minimally coupled scalar field to the Einstein gravity leads to significant constraints on the scalar spectral index n{sub S} and the tensor-to-scalar ratio R when compared with a tensor with similar constraints to form the standard inflation with a minimally coupled scalar field. We also show that an accurate reconstruction of the Higgs potential in terms of inflationary observables requires an improved accuracy of other parameters of the standard model of particle physics such as the top quark mass and the effective QCD coupling constant.
Search for heavy neutral MSSM Higgs bosons with CMS: reach and Higgs mass precision
NASA Astrophysics Data System (ADS)
Gennai, S.; Heinemeyer, S.; Kalinowski, A.; Kinnunen, R.; Lehti, S.; Nikitenko, A.; Weiglein, G.
2007-10-01
The search for MSSM Higgs bosons will be an important goal at the LHC. We analyze the search reach of the CMS experiment for the heavy neutral MSSM Higgs bosons with an integrated luminosity of 30 or 60 fb-1. This is done by combining the latest results for the CMS experimental sensitivities based on full simulation studies with state-of-the-art theoretical predictions of the MSSM Higgs-boson properties. The results are interpreted in MSSM benchmark scenarios in terms of the parameters tan β and the Higgs-boson mass scale, MA. We study the dependence of the 5σ discovery contours in the MA tan β plane on variations of the other supersymmetric parameters. The largest effects arise from a change in the higgsino mass parameter μ, which enters both via higher-order radiative corrections and via the kinematics of Higgs decays into supersymmetric particles. While the variation of μ can shift the prospective discovery reach (and correspondingly the ”LHC wedge” region) by about Δtan β=10, we find that the discovery reach is rather stable with respect to the impact of other supersymmetric parameters. Within the discovery region we analyze the accuracy with which the masses of the heavy neutral Higgs bosons can be determined. We find that an accuracy of 1 4% should be achievable, which could make it possible in favorable regions of the MSSM parameter space to experimentally resolve the signals of the two heavy MSSM Higgs bosons at the LHC.
Probing triple Higgs couplings of the two Higgs doublet model at a linear collider
Arhrib, Abdesslam; Benbrik, Rachid; Chiang, C.-W.
2008-06-01
We study double Higgs production at the future linear collider in the framework of the two Higgs doublet models through the following channels: e{sup +}e{sup -}{yields}{phi}{sub i}{phi}{sub j}Z, {phi}{sub i}=h{sup 0}, H{sup 0}, A{sup 0}, H{sup {+-}}. All these processes are sensitive to triple Higgs couplings. Hence observations of them provide information on the triple Higgs couplings that help reconstructing the scalar potential. We also discuss the double Higgs-Strahlung e{sup +}e{sup -}{yields}h{sup 0}h{sup 0}Z in the decoupling limit where h{sup 0} mimics the standard model Higgs boson. The processes e{sup +}e{sup -}{yields}h{sup 0}h{sup 0}Z and e{sup +}e{sup -}{yields}h{sup 0}H{sup 0}Z are also discussed in the fermiophobic limit where distinctive signatures such as 4{gamma}+X, 2{gamma}+X, and 6{gamma}+X are expected in the Type-I two Higgs doublet model.
Neutral Higgs boson pair production in photon-photon annihilation in the two Higgs doublet model
Arhrib, Abdesslam; Benbrik, Rachid; Chen, C.-H.; Santos, Rui
2009-07-01
We study double Higgs production in photon-photon collisions as a probe of the new dynamics of Higgs interactions in the framework of two Higgs doublet models. We analyze neutral Higgs bosons production and decay in the fusion processes, {gamma}{gamma}{yields}S{sub i}S{sub j}, S{sub i}=h{sup 0}, H{sup 0}, A{sup 0}, and show that both h{sup 0}h{sup 0} and A{sup 0}A{sup 0} production can be enhanced by threshold effects in the region E{sub {gamma}}{sub {gamma}}{approx_equal}2m{sub H{+-}}. Resonant effects due to the heavy Higgs H{sup 0} can also play a role in the cross section enhancement when it is allowed to decay to two light CP-even h{sup 0} or to two light CP-odd A{sup 0} scalars. We have scanned the allowed parameter space of the two Higgs doublet model and found a vast region of the parameter space where the cross section is 2 orders of magnitude above the standard model cross section. We further show that the standard model experimental analysis can be used to discover or to constrain the two Higgs doublet model parameter space.
A light Higgs scalar in the NMSSM confronted with the latest LHC Higgs data
NASA Astrophysics Data System (ADS)
Cao, Junjie; Ding, Fangfang; Han, Chengcheng; Yang, Jin Min; Zhu, Jingya
2013-11-01
In the Next-to-Minimal Supersymemtric Standard Model (NMSSM), one of the neutral Higgs scalars (CP-even or CP-odd) may be lighter than half of the SM-like Higgs boson. In this case, the SM-like Higgs boson h can decay into such a light scalar pair and consequently the γγ and ZZ * signal rates at the LHC will be suppressed. In this work, we examine the constraints of the latest LHC Higgs data on such a possibility. We perform a comprehensive scan over the parameter space of the NMSSM by considering various experimental constraints and find that the LHC Higgs data can readily constrain the parameter space and the properties of the light scalar, e.g., at 3 σ level this light scalar should be highly singlet dominant and the branching ratio of the SM-like Higgs boson decay into the scalar pair should be less than 30%. Also we investigate the detection of this scalar at various colliders. Through a detailed Monte Carlo simulation we find that under the constraints of the current Higgs data this light scalar can be accessible at the LHC-14 with an integrated luminosity over 300 fb-1.
Search for a lighter Higgs boson in Two Higgs Doublet Models
NASA Astrophysics Data System (ADS)
Cacciapaglia, Giacomo; Deandrea, Aldo; Gascon-Shotkin, Suzanne; Le Corre, Solène; Lethuillier, Morgan; Tao, Junquan
2016-12-01
We consider present constraints on Two Higgs Doublet Models, both from the LHC at Run 1 and from other sources in order to explore the possibility of constraining a neutral scalar or pseudo-scalar particle lighter than the 125 GeV Higgs boson. Such a lighter particle is not yet completely excluded by present data. We show with a simplified analysis that some new constraints could be obtained at the LHC if such a search is performed by the experimental collaborations, which we therefore encourage to continue carrying out light diphoton resonance searches at √{s}=13 TeV in the context of Two Higgs Doublet Models.
Beyond the standard Higgs after the 125 GeV Higgs discovery
Grojean, C.
2015-01-01
An elementary, weakly coupled and solitary Higgs boson allows one to extend the validity of the Standard Model up to very high energy, maybe as high as the Planck scale. Nonetheless, this scenario fails to fill the universe with dark matter and does not explain the matter–antimatter asymmetry. However, amending the Standard Model tends to destabilize the weak scale by large quantum corrections to the Higgs potential. New degrees of freedom, new forces, new organizing principles are required to provide a consistent and natural description of physics beyond the standard Higgs.
Ian Hinchliffe Answers Your Higgs Boson Questions
Hinchliffe, Ian
2012-01-01
contingent with the ATLAS experiment at CERN, answers many of your questions about the Higgs boson. Ian invited viewers to send in questions about the Higgs via email, Twitter, Facebook, or YouTube in an "Ask a Scientist" video posted July 3: http://youtu.be/xhuA3wCg06s CERN's July 4 announcement that the ATLAS and CMS experiments at the Large Hadron Collider have discovered a particle "consistent with the Higgs boson" has raised questions about what scientists have found and what still remains to be found -- and what it all means. If you have suggestions for future "Ask a Scientist" videos, post them below or send ideas to askascientist@lbl.gov
Light quark Yukawa couplings from Higgs kinematics
Soreq, Yotam; Zhu, Hua Xing; Zupan, Jure
2016-12-13
We show that the normalized Higgs production pT and yh distributions are sensitive probes of Higgs couplings to light quarks. For up and/or down quark Yukawa couplings comparable to the SM b quark Yukawa themore » $$\\bar{u}u$$ or $$\\bar{d}d$$ fusion production of the Higgs could lead to appreciable softer pT distribution than in the SM. The rapidity distribution, on the other hand, becomes more forward. Here, we find that, owing partially to a downward fluctuation, one can derive competitive bounds on the two couplings using ATLAS measurements of normalized pT distribution at 8TeV. With 300 fb-1 at 13TeV LHC one could establish flavor non-universality of the Yukawa couplings in the down sector.« less
Higgs CP violation from vectorlike quarks
Chen, Chien-Yi; Dawson, S.; Zhang, Yue
2015-10-20
We explore CP violating aspects in the Higgs sector of models where new vectorlike quarks carry Yukawa couplings mainly to the third generation quarks of the Standard Model. We point out that in the simplest model, Higgs CP violating interactions only exist in the hWW channel. At low energy, we nd that rare B decays can place similarly strong constraints as those from electric dipole moments on the source of CP violation. These observations offer a new handle to discriminate from other Higgs CP violating scenarios such as scalar sector extensions of the Standard Model, and imply an interesting futuremore » interplay among limits from different experiments.« less
Unveiling the Higgs mechanism to students
NASA Astrophysics Data System (ADS)
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.
Ian Hinchliffe Answers Your Higgs Boson Questions
Hinchliffe, Ian
2016-07-12
contingent with the ATLAS experiment at CERN, answers many of your questions about the Higgs boson. Ian invited viewers to send in questions about the Higgs via email, Twitter, Facebook, or YouTube in an "Ask a Scientist" video posted July 3: http://youtu.be/xhuA3wCg06s CERN's July 4 announcement that the ATLAS and CMS experiments at the Large Hadron Collider have discovered a particle "consistent with the Higgs boson" has raised questions about what scientists have found and what still remains to be found -- and what it all means. If you have suggestions for future "Ask a Scientist" videos, post them below or send ideas to askascientist@lbl.gov
Searching for displaced Higgs boson decays
NASA Astrophysics Data System (ADS)
Csáki, Csaba; Kuflik, Eric; Lombardo, Salvator; Slone, Oren
2015-10-01
We study a simplified model of the Standard Model (SM) Higgs boson decaying to a degenerate pair of scalars which travel a macroscopic distance before decaying to SM particles. This is the leading signal for many well-motivated solutions to the hierarchy problem that do not propose additional light colored particles. Bounds for displaced Higgs boson decays below 10 cm are found by recasting existing tracker searches from Run I. New tracker search strategies, sensitive to the characteristics of these models and similar decays, are proposed with sensitivities projected for Run II at √{s }=13 TeV . With 20 fb-1 of data, we find that Higgs branching ratios down to 2 ×1 0-4 can be probed for centimeter decay lengths.
Dissertori, G
2015-01-13
Enormous efforts at accelerators and experiments all around the world have gone into the search for the long-sought Higgs boson, postulated almost five decades ago. This search has culminated in the discovery of a Higgs-like particle by the ATLAS and CMS experiments at CERN's Large Hadron Collider in 2012. Instead of describing this widely celebrated discovery, in this article I will rather focus on earlier attempts to discover the Higgs boson, or to constrain the range of possible masses by interpreting precise data in the context of the Standard Model of particle physics. In particular, I will focus on the experimental efforts carried out during the last two decades, at the Large Electron Positron collider, CERN, Geneva, Switzerland, and the Tevatron collider, Fermilab, near Chicago, IL, USA.
Charged Particle Optics in Circular Higgs Factory
Cai, Yunhai
2015-02-26
Similar to a super B-factory, a circular Higgs factory will require strong focusing systems near the interaction points and a low-emittance lattice in arcs to achieve a factory luminosity. At electron beam energy of 120 GeV, beamstrahlung effects during the collision pose an additional challenge to the collider design. In particular, a large momentum acceptance at 2 percent level is necessary to retain an adequate beam lifetime. This turns out to be the most challenging aspect in the design of circular Higgs factory. In this paper, an example will be provided to illustrate the beam dynamics in circular Higgs factory, emphasizing on the chromatic optics. Basic optical modules and advanced analysis will be presented. Most important, we will show that 2% momentum aperture is achievable
Muon specific two-Higgs-doublet model
NASA Astrophysics Data System (ADS)
Abe, Tomohiro; Sato, Ryosuke; Yagyu, Kei
2017-07-01
We investigate a new type of a two-Higgs-doublet model as a solution of the muon g - 2 anomaly. We impose a softly-broken Z 4 symmetry to forbid tree level flavor changing neutral currents in a natural way. This Z 4 symmetry restricts the structure of Yukawa couplings. As a result, extra Higgs boson couplings to muons are enhanced by a factor of tan β, while their couplings to all the other standard model fermions are suppressed by cot β. Thanks to this coupling property, we can avoid the constraint from leptonic τ decays in contrast to the lepton specific two-Higgs-doublet model, which can explain the muon g - 2 within the 2 σ level but cannot within the 1 σ level due to this constraint. We find that the model can explain the muon g - 2 within the 1 σ level satisfying constraints from perturbative unitarity, vacuum stability, electroweak precision measurements, and current LHC data.
Factorization for substructures of boosted Higgs jets
NASA Astrophysics Data System (ADS)
Isaacson, Joshua; Li, Hsiang-nan; Li, Zhao; Yuan, C.-P.
2017-08-01
We present a perturbative QCD factorization formula for substructures of an energetic Higgs jet, taking the energy profile resulting from the H → b b bar decay as an example. The formula is written as a convolution of a hard Higgs decay kernel with two b-quark jet functions and a soft function that links the colors of the two b quarks. We derive an analytical expression to approximate the energy profile within a boosted Higgs jet, which significantly differs from those of ordinary QCD jets. This formalism also extends to boosted W and Z bosons in their hadronic decay modes, allowing an easy and efficient discrimination of fat jets produced from different processes.
Light quark Yukawa couplings from Higgs kinematics
NASA Astrophysics Data System (ADS)
Soreq, Yotam; Zhu, Hua Xing; Zupan, Jure
2016-12-01
We show that the normalized Higgs production p T and y h distributions are sensitive probes of Higgs couplings to light quarks. For up and/or down quark Yukawa couplings comparable to the SM b quark Yukawa the ūu or overline{d}d fusion production of the Higgs could lead to appreciable softer p T distribution than in the SM. The rapidity distribution, on the other hand, becomes more forward. We find that, owing partially to a downward fluctuation, one can derive competitive bounds on the two couplings using ATLAS measurements of normalized p T distribution at 8 TeV. With 300 fb-1 at 13 TeV LHC one could establish flavor non-universality of the Yukawa couplings in the down sector.
Light quark Yukawa couplings from Higgs kinematics
Soreq, Yotam; Zhu, Hua Xing; Zupan, Jure
2016-12-13
We show that the normalized Higgs production p_{T} and y_{h} distributions are sensitive probes of Higgs couplings to light quarks. For up and/or down quark Yukawa couplings comparable to the SM b quark Yukawa the $\\bar{u}u$ or $\\bar{d}d$ fusion production of the Higgs could lead to appreciable softer p_{T} distribution than in the SM. The rapidity distribution, on the other hand, becomes more forward. Here, we find that, owing partially to a downward fluctuation, one can derive competitive bounds on the two couplings using ATLAS measurements of normalized p_{T} distribution at 8TeV. With 300 fb^{-1} at 13TeV LHC one could establish flavor non-universality of the Yukawa couplings in the down sector.
Effective field theory analysis of Higgs naturalness
Bar-Shalom, Shaouly; Soni, Amarjit; Wudka, Jose
2015-07-20
Assuming the presence of physics beyond the Standard Model ( SM) with a characteristic scale M ~ O (10) TeV, we investigate the naturalness of the Higgs sector at scales below M using an effective field theory (EFT) approach. We obtain the leading 1 -loop EFT contributions to the Higgs mass with a Wilsonian-like hard cutoff, and determine t he constraints on the corresponding operator coefficients for these effects to alleviate the little hierarchy problem up to the scale of the effective action Λ < M , a condition we denote by “EFT-naturalness”. We also determine the types of physics that can lead to EFT-naturalness and show that these types of new physics are best probed in vector-boson and multiple-Higgs production. The current experimental constraints on these coefficients are also discussed.
Holographic dark matter and Higgs models.
Díaz-Cruz, J Lorenzo
2008-06-06
We propose a dark matter candidate within the class of models where electroweak symmetry breaking is triggered by a light composite Higgs boson. In these dual anti-de Sitter/conformal field theory models, the Higgs boson emerges as a holographic pseudo-Goldstone boson, while dark matter can be identified with a stable composite fermion X0. The effective Lagrangian description of the Higgs and X0-multiplets, including higher-dimensional operators, can be tested at future colliders (LHC, ILC) and through astrophysical signals (ultrahigh-energy cosmic rays). The expected mass of X0, mX0 < or approximately 4pif approximately O (TeV), satisfies the bounds extracted from the cosmological relic density, while the experimental searches for dark matter further constrains the possible models.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-28
... Model EC 155B, EC155B1, SA-360C, SA-365C, SA-365C1, SA-365C2, SA-365N, SA-365N1, AS- 365N2, AS 365 N3... additional crack has been found in the MGB planet gear carrier of a Eurocopter Model EC 155 helicopter. That.... Applicability Model EC 155B, EC155B1, SA-360C, SA-365C, SA-365C1, SA-365C2, SA-365N, SA-365N1, AS-365N2, AS...
PAR3-aPKC regulates Tiam1 by modulating suppressive internal interactions.
Matsuzawa, Kenji; Akita, Hiroki; Watanabe, Takashi; Kakeno, Mai; Matsui, Toshinori; Wang, Shujie; Kaibuchi, Kozo
2016-05-01
Tiam1 is one of the most extensively analyzed activators of the small GTPase Rac. However, fundamental aspects of its regulation are poorly understood. Here we demonstrate that Tiam1 is functionally suppressed by internal interactions and that the PAR complex participates in its full activation. The N-terminal region of Tiam1 binds to the protein-binding and catalytic domains to inhibit its localization and activation. Atypical PKCs phosphorylate Tiam1 to relieve its intramolecular interactions, and the subsequent stabilization of its interaction with PAR3 allows it to exert localized activity. By analyzing Tiam1 regulation by PAR3-aPKC within the context of PDGF signaling, we also show that PAR3 directly binds PDGF receptor β. Thus we provide the first evidence for the negative regulation of Tiam1 by internal interactions, elucidate the nature of Tiam1 regulation by the PAR complex, and reveal a novel role for the PAR complex in PDGF signaling. © 2016 Matsuzawa et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).
NASA Astrophysics Data System (ADS)
Baglio, Julien; Eberhardt, Otto; Nierste, Ulrich; Wiebusch, Martin
2014-07-01
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 (2HDM) of type II. Using current constraints from flavor, 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 Standard Model (SM) value, but can be reduced by a factor of 0.56 at the 2σ 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 a lighter Higgs boson are possible and if the mass of the decaying Higgs is below the tt ¯ threshold. To facilitate future studies of collider signatures in 2HDM scenarios with large triple-Higgs couplings or decay modes of the heavy Higgs bosons not covered by the SM Higgs searches we provide a set of benchmark points which exhibit these features and agree with all current constraints. We also discuss the effect of the heavy Higgs bosons on the gg→hh cross section at a 14 TeV LHC for some of these benchmarks. For mH below the hh threshold we see a reduction of the SM gg→hh cross section due to destructive interference, but for mH above the hh threshold current constraints allow enhancement factors above 50. An enhancement factor of 6 is still possible in scenarios in which the heavy Higgs particles would not be discovered by standard searches after 300 fb-1 of data.
NASA Astrophysics Data System (ADS)
Burda, Philipp; Gregory, Ruth; Moss, Ian G.
2016-06-01
We have recently suggested that tiny black holes can act as nucleation seeds for the decay of the metastable Higgs vacuum. Previous results applied only to the nucleation of thin-wall bubbles, and covered a very small region of parameter space. This paper considers bubbles of arbitrary profile and reaches the same conclusion: black holes seed rapid vacuum decay. Seeded and unseeded nucleation rates are compared, and the gravitational back reaction of the bubbles is taken into account. The evolution of the bubble interior is described for the unseeded nucleation. Results are presented for the renormalisation group improved Standard Model Higgs potential, and a simple effective model representing new physics.
Higgs vacuum stability and modified chaotic inflation
NASA Astrophysics Data System (ADS)
Saha, Abhijit Kumar; Sil, Arunansu
2017-02-01
The issue of electroweak vacuum stability is studied in presence of a scalar field which participates in modifying the minimal chaotic inflation model. It is shown that the threshold effect on the Higgs quartic coupling originating from the Higgs-inflaton sector interaction can essentially make the electroweak vacuum stable up to the Planck scale. On the other hand we observe that the new physics parameters in this combined framework are enough to provide deviation from the minimal chaotic inflation predictions so as to keep it consistent with recent observation by Planck 2015.
Supersymmetric Higgs Bosons in Weak Boson Fusion
Hollik, Wolfgang; Plehn, Tilman; Rauch, Michael; Rzehak, Heidi
2009-03-06
We compute the complete supersymmetric next-to-leading-order corrections to the production of a light Higgs boson in weak-boson fusion. The size of the electroweak corrections is of similar order as the next-to-leading-order corrections in the standard model. The supersymmetric QCD corrections turn out to be significantly smaller than expected and than their electroweak counterparts. These corrections are an important ingredient to a precision analysis of the (supersymmetric) Higgs sector at the LHC, either as a known correction factor or as a contribution to the theory error.
Exclusive window onto Higgs Yukawa couplings.
Kagan, Alexander L; Perez, Gilad; Petriello, Frank; Soreq, Yotam; Stoynev, Stoyan; Zupan, Jure
2015-03-13
We show that both flavor-conserving and flavor-violating Yukawa couplings of the Higgs boson to first- and second-generation quarks can be probed by measuring rare decays of the form h→MV, where M denotes a vector meson and V indicates either γ, W or Z. We calculate the branching ratios for these processes in both the standard model and its possible extensions. We discuss the experimental prospects for their observation. The possibility of accessing these Higgs couplings appears to be unique to the high-luminosity LHC and future hadron colliders, providing further motivation for those machines.
Le Higgs avec de grandes dimensions supplementaires
NASA Astrophysics Data System (ADS)
Benakli, Karim; Quirós, Mariano
2003-04-01
Transverse (submillimeter) and longitudinal (TeV) extra dimensions can help in dealing with the Higgs hierarchy problem. On the one hand large transverse dimensions can lower the fundamental scale of quantum gravity from the Planck scale to the TeV range. On the other hand longitudinal dimensions can provide genuine extra-dimensional symmetries (higher dimensional gauge symmetry and/or supersymmetry) to protect the Higgs mass against ultraviolet sensitivity. In this article we review recent developments along these directions. To cite this article: K. Benakli, M. Quirós, C. R. Physique 4 (2003).
ASSOCIATED HIGGS BOSON PRODUCTION WITH HEAVY QUARKS.
DAWSON,S.ORR,L.H.REINA,L.WACKEROTH,D.
2003-03-15
The production of a Higgs boson in association with a pair of e quarks will play a very important role at both hadron and lepton colliders. We review the status of theoretical predictions and their relevance to Higgs boson studies, with particular emphasis on the recently calculated NLO QCD corrections to the inclusive cross section for p{bar p}, pp {yields} t{bar t}h. We conclude by briefly discussing the case of exclusive b{bar b}h production and the potential of this process in revealing signals of new physics beyond the Standard Model.
Composite Higgs models, Dark Matter and {lambda}
Diaz Cruz, J. Lorenzo
2009-04-20
We suggest that dark matter can be identified with a stable composite fermion X{sup 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{sup 0} satisfies the cosmological bounds, with m{sub X{sup 0}}{approx}4{pi}f{approx_equal}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.
Higgs boson photoproduction at the LHC
Ducati, M. B. Gay; Silveira, G. G.
2011-07-15
We present the current development of the photoproduction approach for the Higgs boson with its application to pp and pA collisions at the LHC. We perform a different analysis for the Gap Survival Probability, where we consider a probability of 3% and also a more optimistic value of 10% based on the HERA data for dijet production. As a result, the cross section for the exclusive Higgs boson production is about 2 fb and 6 fb in pp collisions and 617 and 2056 fb for pPb collisions, considering the gap survival factor of 3% and 10%, respectively.
Suppression or knockout of SaF/SaM overcomes the Sa-mediated hybrid male sterility in rice.
Xie, Yongyao; Niu, Baixiao; Long, Yunming; Li, Gousi; Tang, Jintao; Zhang, Yaling; Ren, Ding; Liu, Yao-Guang; Chen, Letian
2017-09-01
Hybrids between the indica and japonica subspecies of rice (Oryza sativa) are usually sterile, which hinders utilization of heterosis in the inter-subspecific hybrid breeding. The complex locus Sa comprises two adjacently located genes, SaF and SaM, which interact to cause abortion of pollen grains carrying the japonica allele in japonica-indica hybrids. Here we showed that silencing of SaF or SaM by RNA interference restored male fertility in indica-japonica hybrids with heterozygous Sa. We further used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based genome editing to knockout the SaF and SaM alleles, respectively, of an indica rice line to create hybrid-compatible lines. The resultant artificial neutral alleles did not affect pollen viability and other agricultural traits, but did break down the reproductive barrier in the hybrids. We found that some rice lines have natural neutral allele Sa-n, which was compatible with the typical japonica or indica Sa alleles in hybrids. Our results demonstrate that SaF and SaM are required for hybrid male sterility, but are not essential for pollen development. This study provides effective approaches for the generation of hybrid-compatible lines by knocking out the Sa locus or using the natural Sa-n allele to overcome hybrid male sterility in rice breeding. © 2017 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc. © 2017 Institute of Botany, Chinese Academy of Sciences.
Postinflationary vacuum instability and Higgs-inflaton couplings
Enqvist, Kari; Karčiauskas, Mindaugas; Lebedev, Oleg; Rusak, Stanislav; Zatta, Marco
2016-11-11
The Higgs-inflaton coupling plays an important role in the Higgs field dynamics in the early Universe. Even a tiny coupling generated at loop level can have a dramatic effect on the fate of the electroweak vacuum. Such Higgs-inflaton interaction is present both at the trilinear and quartic levels in realistic reheating models. In this work, we examine the Higgs dynamics during the preheating epoch, focusing on the effects of the parametric and tachyonic resonances. We use lattice simulations and other numerical tools in our studies. We find that the resonances can induce large fluctuations of the Higgs field which destabilize the electroweak vacuum. Our considerations thus provide an upper bound on quartic and trilinear interactions between the Higgs and the inflaton. We conclude that there exists a favorable range of the couplings within which the Higgs field is stabilized during both inflation and preheating epochs.
Light Higgs bosons and muon g - 2 in THDM
NASA Astrophysics Data System (ADS)
Niş, Büşra; ćiçi, Ali; Ün, Cem Salih; Kirca, Zerrin
2017-02-01
As well as having a significant impact on models beyond the Standard Model, the Higgs boson discovery has opened a new era in both experimental and phenomenological searches. For instance, observed anomalies in Higgs decays into two photons and four leptons and muon anomalous magnetic moment (muon g - 2) may imply more Higgs-like scalars. In this work, we study Two Higgs Doublet Model-TypeIII, in which one Higgs doublet develops a zero vacuum expectation value. we find the mass spectrum include five Higgs bosons each of which is lighter than about 350 GeV. We consider the contributions to muon g - 2 from these light extra Higgs bosons, and we find that the discrepancy between the SM and the experimental measurements can be resolved if mH, mA, mH± ≲ 150 GeV.
Postinflationary vacuum instability and Higgs-inflaton couplings
NASA Astrophysics Data System (ADS)
Enqvist, Kari; Karčiauskas, Mindaugas; Lebedev, Oleg; Rusak, Stanislav; Zatta, Marco
2016-11-01
The Higgs-inflaton coupling plays an important role in the Higgs field dynamics in the early Universe. Even a tiny coupling generated at loop level can have a dramatic effect on the fate of the electroweak vacuum. Such Higgs-inflaton interaction is present both at the trilinear and quartic levels in realistic reheating models. In this work, we examine the Higgs dynamics during the preheating epoch, focusing on the effects of the parametric and tachyonic resonances. We use lattice simulations and other numerical tools in our studies. We find that the resonances can induce large fluctuations of the Higgs field which destabilize the electroweak vacuum. Our considerations thus provide an upper bound on quartic and trilinear interactions between the Higgs and the inflaton. We conclude that there exists a favorable range of the couplings within which the Higgs field is stabilized during both inflation and preheating epochs.
NLO electroweak corrections in extended Higgs sectors with RECOLA2
NASA Astrophysics Data System (ADS)
Denner, Ansgar; Lang, Jean-Nicolas; Uccirati, Sandro
2017-07-01
We present the computer code RECOLA2 along with the first NLO electroweak corrections to Higgs production in vector-boson fusion and updated results for Higgs strahlung in the Two-Higgs-Doublet Model and Higgs-Singlet extension of the Standard Model. A fully automated procedure for the generation of tree-level and one-loop matrix elements in general models, including renormalization, is presented. We discuss the application of the Background-Field Method to the extended models. Numerical results for NLO electroweak cross sections are presented for different renormalization schemes in the Two-Higgs-Doublet Model and the Higgs-Singlet extension of the Standard Model. Finally, we present distributions for the production of a heavy Higgs boson.
Direct and indirect constraints on CP-violating Higgs-quark and Higgs-gluon interactions
Chien, Y. T.; Cirigliano, V.; Dekens, W.; de Vries, J.; Mereghetti, E.
2016-02-01
Here we investigate direct and indirect constraints on the complete set of anomalous CP-violating Higgs couplings to quarks and gluons originating from dimension-6 operators, by studying their signatures at the LHC and in electric dipole moments (EDMs). We also show that existing uncertainties in hadronic and nuclear matrix elements have a significant impact on the interpretation of EDM experiments, and we quantify the improvements needed to fully exploit the power of EDM searches. Currently, the best bounds on the anomalous CP-violating Higgs interactions come from a combination of EDM measurements and the data from LHC Run 1. We argue that Higgs production cross section and branching ratios measurements at the LHC Run 2 will not improve the constraints significantly. But, the bounds on the couplings scale roughly linearly with EDM limits, so that future theoretical and experimental EDM developments can have a major impact in pinning down interactions of the Higgs.
The Higgs boson resonance width from a chiral Higgs-Yukawa model on the lattice
NASA Astrophysics Data System (ADS)
Gerhold, Philipp; Jansen, Karl; Kallarackal, Jim
2012-04-01
The Higgs boson is a central part of the electroweak theory and is crucial to generate masses for quarks, leptons and the weak gauge bosons. We use a 4-dimensional Euclidean lattice formulation of the Higgs-Yukawa sector of the electroweak model to compute physical quantities in the path integral approach which is evaluated by means of Monte Carlo simulations thus allowing for fully non-perturbative calculations. The chiral symmetry of the model is incorporated by using the Neuberger overlap Dirac operator. The here considered Higgs-Yukawa model does not involve the weak gauge bosons and furthermore, only a degenerate doublet of top- and bottom quarks are incorporated. The goal of this work is to study the resonance properties of the Higgs boson and its sensitivity to the strength of the quartic self-coupling.
Higgs boson pair production at a photon-photon collision in the two Higgs doublet model
NASA Astrophysics Data System (ADS)
Asakawa, Eri; Harada, Daisuke; Kanemura, Shinya; Okada, Yasuhiro; Tsumura, Koji
2009-03-01
We calculate the cross section of Higgs boson pair production at a photon collider in the two Higgs doublet model. We focus on the scenario in which the lightest CP even Higgs boson (h) has the Standard Model like couplings to the gauge bosons. We take into account the one-loop correction to the hhh coupling as well as additional one-loop diagrams due to charged Higgs bosons to the γγ → hh helicity amplitudes. It is found that the full cross section can be enhanced by both these effects to a considerable level. We discuss the impact of these corrections on the hhh coupling measurement at the photon collider.
Maximizing the significance in Higgs boson pair analyses [Mad-Maximized Higgs Pair Analyses
Kling, Felix; Plehn, Tilman; Schichtel, Peter
2017-02-22
Here, we study Higgs pair production with a subsequent decay to a pair of photons and a pair of bottoms at the LHC. We use the log-likelihood ratio to identify the kinematic regions which either allow us to separate the di-Higgs signal from backgrounds or to determine the Higgs self-coupling. We find that both regions are separate enough to ensure that details of the background modeling will not affect the determination of the self-coupling. Assuming dominant statistical uncertainties we determine the best precision with which the Higgs self-coupling can be probed in this channel. We finally comment on the samemore » questions at a future 100 TeV collider.« less
Direct and indirect constraints on CP-violating Higgs-quark and Higgs-gluon interactions
Chien, Y. T.; Cirigliano, V.; Dekens, W.; ...
2016-02-01
Here we investigate direct and indirect constraints on the complete set of anomalous CP-violating Higgs couplings to quarks and gluons originating from dimension-6 operators, by studying their signatures at the LHC and in electric dipole moments (EDMs). We also show that existing uncertainties in hadronic and nuclear matrix elements have a significant impact on the interpretation of EDM experiments, and we quantify the improvements needed to fully exploit the power of EDM searches. Currently, the best bounds on the anomalous CP-violating Higgs interactions come from a combination of EDM measurements and the data from LHC Run 1. We argue thatmore » Higgs production cross section and branching ratios measurements at the LHC Run 2 will not improve the constraints significantly. But, the bounds on the couplings scale roughly linearly with EDM limits, so that future theoretical and experimental EDM developments can have a major impact in pinning down interactions of the Higgs.« less
Higgs phenomenology in Type-I 2HDM with U(1) H Higgs gauge symmetry
NASA Astrophysics Data System (ADS)
Ko, P.; Omura, Yuji; Yu, Chaehyun
2014-01-01
It is well known that generic two-Higgs-doublet models (2HDMs) suffer from potentially large Higgs-mediated flavor-changing neutral current (FCNC) problem, unless additional symmetries are imposed on the Higgs fields thereby respecting the Natural Flavor Conservation Criterion (NFC) by Glashow and Weinberg. A common way to respect the NFC is to impose Z 2 symmetry which is softly broken by a dim-2 operator. Another new way is to introduce local U(1) H Higgs flavor symmetry that distinguishes one Higgs doublet from the other. In this paper, we consider the Higgs phenomenology in Type-I 2HDMs with the U(1) H symmetry with the simplest U(1) H assignments that the SM fermions are all neutral under U(1) H , and we make detailed comparison with the ordinary Type-I 2HDM. After imposing various constraints such as vacuum stability and perturbativity as well as the electroweak precision observables and collider search bounds on charged Higgs boson, we find that the allowed Higgs signal strengths in our model are much broader than those in the ordinary Type-I 2HDM, because of newly introduced U(1) H -charged singlet scalar and U(1) H gauge boson. Still the ATLAS data on gg → h → γγ cannot be accommodated. Our model could be distinguished from the ordinary 2HDM with the Z 2 symmetry in a certain parameter region and some channels. If the couplings of the new boson turn out to be close to those in the SM, it would be essential to search for extra U(1) H gauge boson and/or one more neutral scalar boson to distinguish two models.
NASA Astrophysics Data System (ADS)
Dubinin, M. N.; Petrova, E. Yu.
2017-03-01
In the framework of the effective field theory approach to heavy supersymmetry radiative corrections in the Higgs sector of the minimal supersymmetric standard model (MSSM) for the effective potential decomposition up to the dimension-six operators are calculated. Symbolic expressions for the threshold corrections induced by F - and D -soft supersymmetry breaking terms are derived, and the Higgs boson mass spectrum respecting the condition mh=125 GeV for the lightest C P -even scalar is evaluated.
Par Pond Fish, Water, and Sediment Chemistry
Paller, M.H.; Wike, L.D.
1996-06-01
The objectives of this report are to describe the Par Pond fish community and the impact of the drawdown and refill on the community, describe contaminant levels in Par Pond fish, sediments, and water and indicate how contaminant concentrations and distributions were affected by the drawdown and refill, and predict possible effects of future water level fluctuations in Par Pond.
Directed and persistent movement arises from mechanochemistry of the ParA/ParB system
NASA Astrophysics Data System (ADS)
Hu, Longhua; Vecchiarelli, Anthony G.; Mizuuchi, Kiyoshi; Neuman, Keir C.; Liu, Jian
The segregation of DNA prior to cell division is essential for faithful genetic inheritance. In many bacteria, segregation of the low-copy-number plasmids involves an active partition system composed of ParA ATPase and its stimulator protein ParB. Recent experiments suggest that ParA/ParB system motility is driven by a diffusion-ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. We develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA-nucleoid affinity to the motion of the ParB bound cargo. Paradoxically, the resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work sheds light on a new emergent phenomenon in which non-motor proteins work collectively via mechanochemical coupling to propel cargos -- an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria.
Higgs instability and de Sitter radiation
NASA Astrophysics Data System (ADS)
Goswami, Gaurav; Mohanty, Subhendra
2015-12-01
If the Standard Model (SM) of elementary particle physics is assumed to hold good to arbitrarily high energies, then, for the best fit values of the parameters, the scalar potential of the Standard Model Higgs field turns negative at a high scale μinst. If the physics beyond the SM is such that it does not modify this feature of the Higgs potential and if the Hubble parameter during inflation (Hinf) is such that Hinf ≫μinst, then, quantum fluctuations of the SM Higgs during inflation make it extremely unlikely that after inflation it will be found in the metastable vacuum at the weak scale. In this work, we assume that (i) during inflation, the SM Higgs is in Bunch-Davies vacuum state, and, (ii) the question about the stability of the effective potential must be answered in the frame of the freely falling observer (just like in Minkowski spacetime), and then use the well-known fact that the freely falling observer finds Bunch-Davies vacuum to be in thermal state to show that the probability to end up in the electroweak vacuum after inflation is reasonably high.
Inclusive Standard Model Higgs searches with ATLAS
Polci, Francesco
2008-11-23
The update of the discovery potential for a Standard Model Higgs boson through the inclusive searches H{yields}{gamma}{gamma}, H{yields}ZZ* and H{yields}WW with the ATLAS detector is reported. The analysis are based on the most recent available simulations of signal, backgrounds as well as the detector response.
Higgs mass from neutrino-messenger mixing
NASA Astrophysics Data System (ADS)
Byakti, Pritibhajan; Khosa, Charanjit K.; Mummidi, V. S.; Vempati, Sudhir K.
2017-03-01
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 [1, 2] 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 9 of them can lead to Higgs mass within the observed value without raising the sfermion masses significantly. The successful models have stop masses ˜1.5 TeV with small or negligible mixing and yet a light CP even Higgs at 125 GeV.
Bulk Higgs with a heavy diphoton signal
NASA Astrophysics Data System (ADS)
Frank, Mariana; Pourtolami, Nima; Toharia, Manuel
2017-02-01
We consider scenarios of warped extra dimensions with all matter fields in the bulk and in which both the hierarchy and the flavor puzzles of the Standard Model are addressed. Inspired by the puzzling excess of diphoton events at 750 GeV reported in the early LHC Run II data (since then understood as a statistical excess), we consider here the general question as to whether the simplest extra-dimensional extension of the Standard Model Higgs sector, i.e., a five-dimensional bulk Higgs doublet, can lead to an intermediate mass resonance (between 500 GeV and 1.5 TeV) of which the first signature would be the presence of diphoton events. This surprising phenomenology can happen if the resonance is the lightest C P -odd state coming from the Higgs sector. No new matter content is required, the only new ingredient being the presence of (positive) brane localized kinetic terms associated to the five-dimensional bulk Higgs (which reduce the mass of the C P -odd states). Production and decay of this resonance can naturally give rise to observable diphoton signals, keeping dijet production under control, with very low ZZ and WW signals and with a highly reduced top pair production in an important region of parameter space. We use the 750 GeV excess as an example case scenario.
Meromorphic Higgs bundles and related geometries
NASA Astrophysics Data System (ADS)
Dalakov, Peter
2016-11-01
The present note is mostly a survey on the generalised Hitchin integrable system and moduli spaces of meromorphic G-Higgs bundles. We also fill minor gaps in the existing literature, outline a calculation of the infinitesimal period map and review some related geometries.
Unraveling the Higgs Boson Discovery - Rik Yoshida
Rik Yoshida
2016-07-12
Argonne physicist Rik Yoshida explains what the Higgs boson is and what its discovery means for physics, the universe, and life. The third of Argonne's "OutLoud" public lecture series, held at the lab on September 27, 2012. Find out when the next one is at http://www.anl.gov/community/outloud
Assumed Higgs Boson Discovery Proved Einstein Right
NASA Astrophysics Data System (ADS)
Morales, Manuel
2012-12-01
The selection-based Tempt Destiny experiment has provided evidence that the fundamental acts of selection are a dichotomy as are their effects. By applying this knowledge to evaluate the preliminary findings of the Higgs boson discovery, we find an omission error has taken place.
Electroweak and higgs physics at D0
Nikos Varelas
2004-01-21
We present recent results from the D0 experiment on W and Z boson production using {approx} 50 pb{sup -1} of Run II data recorded at the center of mass energy of 1.96 TeV at the Fermilab Tevatron. Initial studies of W/Z + 2 jets production that are relevant to Higgs searches are also discussed.
Has the Higgs boson been discovered?
Renton, Peter
2004-03-11
The standard model of particle physics describes the strong and electroweak interactions of fermions (spin-1/2), gauge bosons (spin-1) and a final vital ingredient--the spin-0 Higgs boson, which gives masses to the other particles. But the Higgs boson has yet to be discovered, and its own mass is not specified by the theory. There is some evidence (although statistically not very significant) for its detection at a mass of about 115 GeV/c2, from electron-positron interactions at LEP (the Large Electron Positron collider). Indirect methods can also be used to constrain the mass of the Higgs boson, because it affects other observable quantities (for example, the mass of the W boson and some measurable properties of the Z boson). An indirect determination of the Higgs boson mass from the most recent measurements of such quantities yields a value compatible with 115 GeV/c2, but with some important caveats arising from inconsistencies in the present data.
On the trail of the Higgs boson
Peskin, Michael E.
2015-09-11
I review theoretical issues associated with the Higgs boson and the mystery of spontaneous breaking of the electroweak gauge symmetry. In addition, this essay is intended as an introduction to the special issue of Annalen der Physik, “Particle Physics after the Higgs”.
Cosmological perturbations from the Standard Model Higgs
Simone, Andrea De; Riotto, Antonio E-mail: antonio.riotto@unige.ch
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.
Search for Charged Higgs in CDF
NASA Astrophysics Data System (ADS)
CDF Collaboration
1996-05-01
We present results of a search for charged Higgs production from pbarp collisions at √s=1.8 TeV at Fermilab's Tevatron collider using the CDF detector. An expanded Higgs sector containing charged Higgs bosons is a persistent feature of candidate theories to replace the Standard Model. The minimal supersymmetric extention of the Standard Model, for example, predicts that the dominant decay mode of the top quark is tarrow H+barrow τ+ν b for large values of tanβ. We use the hadronic decays of the tau lepton in this channel to set a new limit on charged Higgs production. *We thank the Fermilab staff and the technical staffs of the participating institutions for their vital contributions. This work was supported by the U.S. Department of Energy and National Science Foundation; the Italian Istituto Nazionale di Fisica Nucleare; the Ministry of Education, Science and Culture of Japan; the Natural Sciences and Engineering Research Council of Canada; the National Science Council of the Republic of China; and the A. P. Sloan Foundation. Supported by U.S. NSF NSF-94-17820.
On the trail of the Higgs boson
Peskin, Michael E.
2015-09-11
I review theoretical issues associated with the Higgs boson and the mystery of spontaneous breaking of the electroweak gauge symmetry. In addition, this essay is intended as an introduction to the special issue of Annalen der Physik, “Particle Physics after the Higgs”.
Unraveling the Higgs Boson Discovery - Rik Yoshida
Rik Yoshida
2012-10-02
Argonne physicist Rik Yoshida explains what the Higgs boson is and what its discovery means for physics, the universe, and life. The third of Argonne's "OutLoud" public lecture series, held at the lab on September 27, 2012. Find out when the next one is at http://www.anl.gov/community/outloud
Partially natural two Higgs doublet models
Draper, Patrick; Haber, Howard E.; Ruderman, Joshua T.
2016-06-21
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 atmore » the electroweak scale, and the models possess a rich electroweak vacuum structure. Furthermore, 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.« less
Higgs boson couplings: Measurements and theoretical interpretation
NASA Astrophysics Data System (ADS)
Mariotti, Chiara; Passarino, Giampiero
2017-02-01
This report will review the Higgs boson properties: the mass, the total width and the couplings to fermions and bosons. The measurements have been performed with the data collected in 2011 and 2012 at the LHC accelerator at CERN by the ATLAS and CMS experiments. Theoretical frameworks to search for new physics are also introduced and discussed.
Parallel Climate Analysis Toolkit (ParCAT)
Smith, Brian Edward
2013-06-30
The parallel analysis toolkit (ParCAT) provides parallel statistical processing of large climate model simulation datasets. ParCAT provides parallel point-wise average calculations, frequency distributions, sum/differences of two datasets, and difference-of-average and average-of-difference for two datasets for arbitrary subsets of simulation time. ParCAT is a command-line utility that can be easily integrated in scripts or embedded in other application. ParCAT supports CMIP5 post-processed datasets as well as non-CMIP5 post-processed datasets. ParCAT reads and writes standard netCDF files.
Number of SA Astronomy Researchers
NASA Astrophysics Data System (ADS)
Glass, I. S.
2015-12-01
The SA professional astronomical community has grown enormously in recent years with the advent of SALT, SKA/MeerKAT/KAT and HESS (Namibia). In this article I have made an attempt to list the people involved, namely those with doctorates working in fields of astronomy and related technologies, cosmic rays, cosmology and space science.
The light and heavy Higgs interpretation of the MSSM
NASA Astrophysics Data System (ADS)
Bechtle, Philip; Haber, Howard E.; Heinemeyer, Sven; Stål, Oscar; Stefaniak, Tim; Weiglein, Georg; Zeune, Lisa
2017-02-01
We perform a parameter scan of the phenomenological Minimal Supersymmetric Standard Model (pMSSM) with eight parameters taking into account the experimental Higgs boson results from Run I of the LHC and further low-energy observables. We investigate various MSSM interpretations of the Higgs signal at 125 GeV. First, we consider the case where the light CP-even Higgs boson of the MSSM is identified with the discovered Higgs boson. In this case it can impersonate the SM Higgs-like signal either in the decoupling limit, or in the limit of alignment without decoupling. In the latter case, the other states in the Higgs sector can also be light, offering good prospects for upcoming LHC searches and for searches at future colliders. Second, we demonstrate that the heavy CP-even Higgs boson is still a viable candidate to explain the Higgs signal - albeit only in a highly constrained parameter region, that will be probed by LHC searches for the CP-odd Higgs boson and the charged Higgs boson in the near future. As a guidance for such searches we provide new benchmark scenarios that can be employed to maximize the sensitivity of the experimental analysis to this interpretation.
Overproduction and localization of Mycobacterium tuberculosis ParA and ParB proteins
Maloney, Erin; Madiraju, Murty; Rajagopalan, Malini
2011-01-01
SUMMARY The ParA and ParB family proteins are required for accurate partitioning of replicated chromosomes. The Mycobacterium tuberculosis genome contains parB, parA and two parA homologs, Rv1708 and Rv3213c. It is unknown if parA and its homologs are functionally related. To understand the roles of ParA and ParB proteins in M. tuberculosis cell cycle, we have evaluated the consequences of their overproduction and visualized their localization patterns in M. smegmatis. We show that cells overproducing of ParA, Rv1708 and Rv3213c and ParB are filamentous and multinucleoidal indicating defects in cell cycle progression. Visualization of green-fluorescent protein fusions of ParA and its homologues showed similar localization patterns with foci at poles, quarter-cell, midcell positions and spiral-like structures indicating that they are functionally related. On the other hand, the ParBGFP fusion protein localized only to the cell poles. The cyan and yellow fluorescent fusion proteins of ParA and ParB, respectively, colocalized at the cell poles indicating that these proteins interact and possibly associate with the chromosomal origin of replication. Collectively our results suggest that the M. tuberculosis Par proteins play important roles in cell cycle progression. PMID:20006309
suPAR: The Molecular Crystal Ball
Thunø, Maria; Macho, Betina; Eugen-Olsen, Jesper
2009-01-01
soluble urokinase Plasminogen Activator Receptor (suPAR) levels reflect inflammation and elevated suPAR levels are found in several infectious diseases and cancer. suPAR exists in three forms; suPARI-III, suPARII-III and suPARI which show different properties due to structural differences. Studies suggest that full-length suPAR is a regulator of uPAR/uPA by acting as uPA-scavenger, whereas the cleaved suPARII-III act as a chemotactic agent promoting the immune response via the SRSRY sequence in the linker-region. This review focus on the various suPAR fragments and their involvement in inflammation and pathogenic processes. We focus on the molecular mechanisms of the suPAR fragments and the link to the inflammatory process, as this could lead to medical applications in infectious and pathological conditions. PMID:19893210
Probing new physics scales from Higgs and electroweak observables at e + e - Higgs factory
NASA Astrophysics Data System (ADS)
Ge, Shao-Feng; He, Hong-Jian; Xiao, Rui-Qing
2016-10-01
New physics beyond the standard model (SM) can be model-independently formulated via dimension-6 effective operators, whose coefficients (cutoffs) characterize the scales of new physics. We study the probe of new physics scales from the electroweak precision observables (EWPO) and the Higgs observables (HO) at the future e + e - Higgs factory (such as CEPC). To optimize constraints of new physics from all available observables, we establish a scheme-independent approach. With this formulation, we treat the SM electroweak parameters and the coefficients of dimension-6 operators on equal footing, which can be fitted simultaneously by the same χ 2 function. As deviations from the SM are generally small, we can expand the new physics parameters up to linear order and perform an analytical χ 2 fit to derive the potential reach of the new physics scales. We find that the HO from both Higgs produnction and decay rates can probe the new physics scales up to 10 TeV (and to 44 TeV for the case of gluon-involved operator O_g ), and the new physics scales of Yukawa-type operators can be probed by the precision Higgs coupling measurements up to (13 - 25) TeV. Further including the EWPO can push the limit up to 35 TeV. From this prospect, we demonstrate that the EWPO measured in the early phase of a Higgs factory can be as important as the Higgs observables. These indirect probes of new physics scales at the Higgs factory can mainly cover the energy range to be directly explored by the next generation hadron colliders of pp (50 -100 TeV), such as the SPPC and FCC-hh.
Directed and persistent movement arises from mechanochemistry of the ParA/ParB system
Hu, Longhua; Vecchiarelli, Anthony G.; Mizuuchi, Kiyoshi; Neuman, Keir C.; Liu, Jian
2015-01-01
The segregation of DNA before cell division is essential for faithful genetic inheritance. In many bacteria, segregation of low-copy number plasmids involves an active partition system composed of a nonspecific DNA-binding ATPase, ParA, and its stimulator protein ParB. The ParA/ParB system drives directed and persistent movement of DNA cargo both in vivo and in vitro. Filament-based models akin to actin/microtubule-driven motility were proposed for plasmid segregation mediated by ParA. Recent experiments challenge this view and suggest that ParA/ParB system motility is driven by a diffusion ratchet mechanism in which ParB-coated plasmid both creates and follows a ParA gradient on the nucleoid surface. However, the detailed mechanism of ParA/ParB-mediated directed and persistent movement remains unknown. Here, we develop a theoretical model describing ParA/ParB-mediated motility. We show that the ParA/ParB system can work as a Brownian ratchet, which effectively couples the ATPase-dependent cycling of ParA–nucleoid affinity to the motion of the ParB-bound cargo. Paradoxically, this resulting processive motion relies on quenching diffusive plasmid motion through a large number of transient ParA/ParB-mediated tethers to the nucleoid surface. Our work thus sheds light on an emergent phenomenon in which nonmotor proteins work collectively via mechanochemical coupling to propel cargos—an ingenious solution shaped by evolution to cope with the lack of processive motor proteins in bacteria. PMID:26647183
Mono-Higgs detection of dark matter at the LHC
NASA Astrophysics Data System (ADS)
Berlin, Asher; Lin, Tongyan; Wang, Lian-Tao
2014-06-01
Motivated by the recent discovery of the Higgs boson, we investigate the possibility that a missing energy plus Higgs final state is the dominant signal channel for dark matter at the LHC. We consider examples of higher-dimension operators where a Higgs and dark matter pair are produced through an off-shell Z or γ, finding potential sensitivity at the LHC to cutoff scales of around a few hundred GeV. We generalize this production mechanism to a simplified model by introducing a Z' as well as a second Higgs doublet, where the pseudoscalar couples to dark matter. Resonant production of the Z' which decays to a Higgs plus invisible particles gives rise to a potential mono-Higgs signal. This may be observable at the 14 TeV LHC at low tan β and when the Z' mass is roughly in the range 600 GeV to 1.3 TeV.
Charged-Higgs collider signals with or without flavor
Dittmaier, Stefan; Hiller, Gudrun; Plehn, Tilman; Spannowsky, Michael
2008-06-01
A charged Higgs boson is a clear signal for an extended Higgs sector, as, for example, predicted by supersymmetry. Squark mixing can significantly change the pattern of charged-Higgs production and most notably circumvent the chiral suppression for single Higgs production. We evaluate the CERN LHC discovery potential in the light of flavor physics, in the single-Higgs production channel and in association with a hard jet for small and moderate values of tan{beta}. Thoroughly examining current flavor constraints we find that nonminimal flavor structures can have a sizable impact but tend to predict moderate production rates. Nevertheless, charged-Higgs searches will probe flavor structures not accessible to rare kaon, bottom, or charm experiments and can invalidate the assumption of minimal flavor violation.
Sakurai Prize: Beyond the Standard Model Higgs Boson
NASA Astrophysics Data System (ADS)
Haber, Howard
2017-01-01
The discovery of the Higgs boson strongly suggests that the first elementary spin 0 particle has been observed. Is the Higgs boson a solo act, or are there additional Higgs bosons to be discovered? Given that there are three generations of fundamental fermions, one might also expect the sector of fundamental scalars of nature to be non-minimal. However, there are already strong constraints on the possible structure of an extended Higgs sector. In this talk, I review the theoretical motivations that have been put forward for an extended Higgs sector and discuss its implications in light of the observation that the properties of the observed Higgs boson are close to those predicted by the Standard Model. supported in part by the U.S. Department of Energy Grant Number DE-SC0010107.
Higgs Boson Searches at Hadron Colliders (1/4)
None
2016-07-12
In these Academic Training lectures, the phenomenology of Higgs bosons and search strategies at hadron colliders are discussed. After a brief introduction on Higgs bosons in the Standard Model and a discussion of present direct and indirect constraints on its mass the status of the theoretical cross section calculations for Higgs boson production at hadron colliders is reviewed. In the following lectures important experimental issues relevant for Higgs boson searches (trigger, measurements of leptons, jets and missing transverse energy) are presented. This is followed by a detailed discussion of the discovery potential for the Standard Model Higgs boson for both the Tevatron and the LHC experiments. In addition, various scenarios beyond the Standard Model, primarily the MSSM, are considered. Finally, the potential and strategies to measured Higgs boson parameters and the investigation of alternative symmetry breaking scenarios are addressed.
Some scenarios with non-homogeneous Higgs vacuum
Diaz Cruz, J. Lorenzo
2010-07-29
The standard Higgs mechanism employed in the Standard Model (SM) for electroweak symmetry breaking, relies on a homogenous Higgs vacuum expectation value (v.e.v.), i.e. a vacuum that does not depend on the position or the time coordinates. However, other non-homogeneous structures could also be considered, either at long or short distances. For instance, spatial variations of the Higgs v.e.v. on cosmological scales, would induce variations of the fundamental constants, and are severely constrained. Other possibilities, such as a discrete microscopic structure of the Higgs vacuum, or a confined Higgs mechanism associated with a strongly interacting Higgs sector, could be tested and give some light on the electroweak-scale contributions to the cosmological constant.
Searching for stoponium along with the Higgs boson.
Barger, Vernon; Ishida, Muneyuki; Keung, Wai-Yee
2012-02-24
Stoponium, a bound state of the top squark and its antiparticle in a supersymmetric model, may be found in the ongoing Higgs searches at the LHC. Its WW and ZZ detection ratios relative to the standard model Higgs boson can be more than unity from the WW* threshold to the two Higgs threshold. The γγ channel is equally promising. Some regions of the stoponium mass below 150 GeV are already being probed by the ATLAS and CMS experiments.
Higgs mode in electric-field-induced superconductors
NASA Astrophysics Data System (ADS)
Koyama, Tomio
2014-08-01
We develop a theory for the Higgs (gap-amplitude) mode excitation in electric-field-induced (EFI) superconductors. The Higgs mode can be excited directly by an oscillating electric field in EFI superconductors since the gap value depends sensitively on the external electric field that induces superconducting carriers. The mass of the Higgs mode in EFI superconductors does not coincide with the threshold energy of pair-breaking two-particle excitations.
Prospects for MSSM Higgs searches at the Fermilab Tevatron.
Draper, P.; Liu, T.; Wagner, C. E. M.; High Energy Physics; Univ. of Chicago
2009-01-01
We analyze the Tevatron reach for neutral Higgs bosons in the minimal supersymmetric standard model, using current exclusion limits on the standard model Higgs. We study four common benchmark scenarios for the soft supersymmetry-breaking parameters of the minimal supersymmetric standard model, including cases where the Higgs decays differ significantly from the standard model, and provide projections for the improvements in luminosity and efficiency required for the Tevatron to probe sizeable regions of the (m{sub A},tan-{beta}) plane.
Discovering Higgs Bosons of the MSSM using Jet Substructure
Kribs, Graham D.; Martin, Adam; Roy, Tuhin S.; Spannowsky, Michael
2010-06-01
We present a qualitatively new approach to discover Higgs bosons of the MSSM at the LHC using jet substructure techniques applied to boosted Higgs decays. These techniques are ideally suited to the MSSM, since the lightest Higgs boson overwhelmingly decays to b{bar b} throughout the entire parameter space, while the heavier neutral Higgs bosons, if light enough to be produced in a cascade, also predominantly decay to b{bar b}. The Higgs production we consider arises from superpartner production where superpartners cascade decay into Higgs bosons. We study this mode of Higgs production for several superpartner hierarchies: m{sub {tilde q}},m{sub {tilde g}} > m{sub {tilde W}},{sub {tilde B}} > m{sub h} + {mu}; m{tilde q};m{sub {tilde q}},m{sub {tilde g}} > m{sub {tilde W}},{sub {tilde B}} > m {sub h,H,A} + {mu}; and m{sub {tilde q}},m{sub {tilde g}} > m{sub {tilde W}} > m{sub h} + {mu} with m{sub {tilde B}} {approx} {mu}. In these cascades, the Higgs bosons are boosted, with pT > 200 GeV a large fraction of the time. Since Higgs bosons appear in cascades originating from squarks and/or gluinos, the cross section for events with at least one Higgs boson can be the same order as squark/gluino production. Given 10 fb{sup -1} of 14 TeV LHC data, with m{sub {tilde q}} {approx}< 1 TeV, and one of the above superpartner mass hierarchies, our estimate of S{radical} B of the Higgs signal is sufficiently high that the b{bar b} mode can become the discovery mode of the lightest Higgs boson of the MSSM.
Determining the CP properties of the Higgs boson.
Bhupal Dev, P S; Djouadi, A; Godbole, R M; Mühlleitner, M M; Rindani, S D
2008-02-08
The search and the probe of the fundamental properties of Higgs boson(s) and, in particular, the determination of their charge conjugation and parity (CP) quantum numbers, are the main tasks of future high-energy colliders. We demonstrate that the CP properties of a standard model-like Higgs particle can be unambiguously assessed by measuring just the total cross section and the top polarization in associated Higgs boson production with top quark pairs in e(+)e(-) collisions.
Discrete and continuous symmetries in multi-Higgs-doublet models
Ferreira, P. M.; Silva, Joao P.
2008-12-01
We consider the Higgs sector of multi-Higgs-doublet models in the presence of simple symmetries relating the various fields. We construct basis-invariant observables which may in principle be used to detect these symmetries for any number of doublets. A categorization of the symmetries into classes is required, which we perform in detail for the case of two and three Higgs doublets.
Dynamical gauge-Higgs unification in the electroweak theory
NASA Astrophysics Data System (ADS)
Hosotani, Yutaka; Noda, Shusaku; Takenaga, Kazunori
2005-02-01
SU(2 doublet Higgs fields are unified with gauge fields in the U(3×U(3 model of Antoniadis, Benakli and Quirós' on the orbifold M×(T/Z). The effective potential for the Higgs fields (the Wilson line phases) is evaluated. The electroweak symmetry is dynamically broken to U(1 by the Hosotani mechanism. There appear light Higgs particles. There is a phase transition as the moduli parameter of the complex structure of T is varied.
Prospects for MSSM Higgs boson searches at the Fermilab Tevatron
Draper, Patrick; Liu, Tao; Wagner, Carlos E. M.
2009-08-01
We analyze the Tevatron reach for neutral Higgs bosons in the minimal supersymmetric standard model, using current exclusion limits on the standard model Higgs. We study four common benchmark scenarios for the soft supersymmetry-breaking parameters of the minimal supersymmetric standard model, including cases where the Higgs decays differ significantly from the standard model, and provide projections for the improvements in luminosity and efficiency required for the Tevatron to probe sizeable regions of the (m{sub A},tan{beta}) plane.
Phenomenological comparison of models with extended Higgs sectors
NASA Astrophysics Data System (ADS)
Mühlleitner, Margarete; Sampaio, Marco O. P.; Santos, Rui; Wittbrodt, Jonas
2017-08-01
Beyond the Standard Model (SM) extensions usually include extended Higgs sectors. Models with singlet or doublet fields are the simplest ones that are compatible with the ρ parameter constraint. The discovery of new non-SM Higgs bosons and the identification of the underlying model requires dedicated Higgs properties analyses. In this paper, we compare several Higgs sectors featuring 3 CP-even neutral Higgs bosons that are also motivated by their simplicity and their ability to solve some of the flaws of the SM. They are: the SM extended by a complex singlet field (CxSM), the singlet extension of the 2-Higgs-Doublet Model (N2HDM), and the Next-to-Minimal Supersymmetric SM extension (NMSSM). In addition, we analyse the CP-violating 2-Higgs-Doublet Model (C2HDM), which provides 3 neutral Higgs bosons with a pseudoscalar admixture. This allows us to compare the effects of singlet and pseudoscalar admixtures. Through dedicated scans of the allowed parameter space of the models, we analyse the phenomenologically viable scenarios from the view point of the SM-like Higgs boson and of the signal rates of the non-SM-like Higgs bosons to be found. In particular, we analyse the effect of singlet/pseudoscalar admixture, and the potential to differentiate these models in the near future. This is supported by a study of couplings sums of the Higgs bosons to massive gauge bosons and to fermions, where we identify features that allow us to distinguish the models, in particular when only part of the Higgs spectrum is discovered. Our results can be taken as guidelines for future LHC data analyses, by the ATLAS and CMS experiments, to identify specific benchmark points aimed at revealing the underlying model.
Double Higgs boson production in the models with isotriplets
Godunov, S. I. Vysotsky, M. I. Zhemchugov, E. V.
2015-12-15
The enhancement of double Higgs boson production in the extensions of the Standard Model with extra isotriplets is studied. It is found that in see-saw type II model decays of new heavy Higgs can contribute to the double Higgs production cross section as much as Standard Model channels. In Georgi–Machacek model the cross section can be much larger since the custodial symmetry is preserved and the strongest limitation on triplet parameters is removed.
OVERVIEW OF HIGGS BOSON STUDIES AT THE TEVATRON
Zivkovic, Lidija
2014-05-01
The CDF and D0 experiments at the Tevatron p¯p Collider collected data between 2002 and 2011, accumulating up to 10 fb-1 of data. During that time, an extensive search for the standard model Higgs boson was performed. Combined results from the searches for the standard model Higgs boson with the final dataset are presented, together with results on the Higgs boson couplings and spin and parity.
Axion-Higgs interplay in the two-Higgs-doublet model
NASA Astrophysics Data System (ADS)
Espriu, Domènec; Mescia, Federico; Renau, Albert
2015-11-01
The Zhitnitsky and Dine, Fischler and Srednicki (DFSZ) model is a natural extension of the two-Higgs-doublet model containing an additional singlet, endowed with a Peccei-Quinn symmetry, and leading to a physically acceptable axion. In this paper we reexamine this model in the light of some new developments. For generic couplings the model reproduces the minimal Standard Model showing only tiny deviations (extreme decoupling scenario) and all additional degrees of freedom (with the exception of the axion) are very heavy. Recently it has been remarked that the limit where the coupling between the singlet and the two doublets becomes very small is technically natural. Combining this limit with the requirement of exact or approximate custodial symmetry, we may obtain an additional 0+ Higgs at the weak scale, accompanied by relatively light charged and neutral pseudoscalars. The mass spectrum would then resemble that of a generic two-Higgs-doublet model, with naturally adjustable masses in spite of the large scale that the axion introduces. However, the couplings are nongeneric in this model. We use the recent constraints derived from the Higgs-W W coupling together with oblique corrections to constrain the model as much as possible. As an additional result, we work out the nonlinear parametrization of the DFSZ model in the generic case where all scalars except the lightest Higgs and the axion have masses at or beyond the TeV scale.
Bound states via Higgs exchanging and heavy resonant di-Higgs
NASA Astrophysics Data System (ADS)
Kang, Zhaofeng
2017-08-01
The existence of Higgs boson h predicted by the standard model (SM) was established and hunting for clues to new physics (NP) hidden in h has become the top priority in particle physics. In this paper we explore an intriguing phenomenon that prevails in NP associated with h, bound state (Bh, referring to the ground state only) of relatively heavy particles ϕ out of NP via interchanging h. This is well-motivated due to the intrinsic properties of h: It has zero spin and light mass, capable of mediating Yukawa interactions; moreover, it may be strongly coupled to ϕ in several important contexts, from addressing the naturalness problem by compositeness/supersymmetry (SUSY)/classical scale invariance to understanding neutrino mass origin radiatively and matter asymmetry by electroweak baryogensis. The new resonance Bh, being a neutral scalar boson, has important implications to the large hadron collider (LHC) di-Higgs search because it yields a clear resonant di-Higgs signature at the high mass region (≳ 1 TeV). In other words, searching for Bh offers a new avenue to probe the hidden sector with a Higgs-portal. For illustration in this paper we concentrate on two examples, the stop sector in SUSY and an inert Higgs doublet from a radiative neutrino model. In particular, h-mediation opens a new and wide window to probe the conventional stoponium and the current date begins to have sensitivity to stoponium around TeV.
Single Higgs boson production at the ILC in the left-right twin Higgs model
NASA Astrophysics Data System (ADS)
Liu, Yao-Bei; Xiao, Zhen-Jun
2015-06-01
In this work, we analyze three dominant single SM-like Higgs boson production processes in the left-right twin Higgs model (LRTHM): the Higgs-strahlung (HS) process {{e}+}{{e}-}\\to Zh, the vector boson fusion (VBF) process {{e}+}{{e}-}\\to ν \\bar{ν }h and the associate production with top pair process {{e}+}{{e}-}\\to t\\bar{t}h for three possible energy stages of the International Linear Collider (ILC), and compared our results with the expected experimental accuracies for various accessible Higgs decay channels. The following observations have been obtained. (1) In the reasonable parameter space, the LRTHM can generate moderate contributions to theses processes with polarized beams. (2) Among various Higgs boson decay channels, the b\\bar{b} signal strength is the most sensitive to the LRTHM due to the high expected precision. For the t\\bar{t}h production process, the absolute value of {{μ }b\\bar{b}} may deviate from the SM prediction by over 8.7% and thus may be detectable at the proposed ILC with \\sqrt{s}=1 TeV. (3) ILC experiments may give a strong limit on the scale parameter f: for the case of ILC-250 GeV, for example, the lower limit for parameter f of the LRTHM is f > 1150 GeV at the 2σ level.
Radiative corrections to Higgs coupling constants in two Higgs doublet models
NASA Astrophysics Data System (ADS)
Kikuchi, Mariko
2016-04-01
A pattern of deviations in the Standard Model (SM) like Higgs boson (h) couplings from their SM predictions depends on the structure of the Higgs sector and the Yukawa interaction. In particular, in Two Higgs Doublet Models (THDMs) with a softly-broken Z2 symmetry, different characteristic patterns of deviation in Yukawa coupling constants (hf f ‾) can be allowed depending on four types of Yukawa interactions. We calculate hf f ‾ coupling constants at the one-loop level in all the types of THDMs. Even if there is no deviation in the hf f ‾ couplings at the tree level, they can deviate from the SM predictions by a few percent due to extra Higgs boson loop contributions. We find that if the deviations in the gauge couplings hVV (V = Z , W) are found with an enough large to be measured at the International Linear Collider (ILC), the scale factors for the hf f ‾ couplings do not overlap among the THDMs with four types of Yukawa interactions even taking into account the radiative corrections. Therefore, in such a case, we can indirectly determine the type of the THDMs at the ILC even without information from direct searches of the additional Higgs bosons.
Ren, Jing; Xianyu, Zhong-Zhi; He, Hong-Jian E-mail: xianyuzhongzhi@gmail.com
2014-06-01
We study gravitational interaction of Higgs boson through the unique dimension-4 operator ξH{sup †}HR, with H the Higgs doublet and R the Ricci scalar curvature. We analyze the effect of this dimensionless nonminimal coupling ξ on weak gauge boson scattering in both Jordan and Einstein frames. We explicitly establish the longitudinal-Goldstone equivalence theorem with nonzero ξ coupling in both frames, and analyze the unitarity constraints. We study the ξ-induced weak boson scattering cross sections at O(1−30) TeV scales, and propose to probe the Higgs-gravity coupling via weak boson scattering experiments at the LHC (14 TeV) and the next generation pp colliders (50-100 TeV). We further extend our study to Higgs inflation, and quantitatively derive the perturbative unitarity bounds via coupled channel analysis, under large field background at the inflation scale. We analyze the unitarity constraints on the parameter space in both the conventional Higgs inflation and the improved models in light of the recent BICEP2 data.
Pion-Graff, Joëlle; Bonnichon, Philippe
2010-01-01
Paré is well-known through many papers. His incomes allowed him to have a middle-class Parisian living. It is impossible to have an accurate knowledge of his fortune before his death but we have a good idea of his landed property. In fact as a Parishioner of Saint-Andre-des-Arts Church he probably was a landlord only in Paris and its vicinity with a building (rue de l'Hirondelle), two houses (rue Garancière), Meudon, Cormeille-en-Parisis and La-Ville-Du-Bois which the authors describe the present state of.
Detection of Higgs bosons decaying to bottom quarks
Gilman, F.J.; Price, L.E.
1986-11-01
Several developments affecting the possibility of Higgs detection are discussed. These include the level of certainty about the t quark mass, Monte Carlo programs to generate both signal and background events, and separation and/or enhancement of heavy quark jets from jets due to light quarks or gluons, and the possibility that the neutral Higgs decay into bottom quarks might be the decay mode of choice for detecting the intermediate mass Higgs. Possible means of detection of an intermediate mass Higgs at the SSC, particularly if a prominent decay mode is to bottom quarks, are examined, using the PYTHIA Monte Carlo program to generate both signal and background events. For the signal, events were generated in which Higgs bosons are created in proton-proton collisions, with the Higgs decaying into bottom quarks. The presence of W or Z bosons, created in the same proton-proton collision, is used to enhance the likelihood of Higgs production and to reduce the potentially enormous background. It is found that the Higgs decay to bottom quarks, if important, would be more favorable for detection of the Higgs than decay to top quarks was found to be because of the smaller background. 3 refs., 4 figs. (LEW)
Effects of Radion Mixing on the Standard Model Higgs Boson
Rizzo, Thomas G.
2002-09-09
We discuss how mixing between the Standard Model Higgs boson and the radion of the Randall-Sundrum model can lead to significant shifts in the expected properties of the Higgs boson. In particular we show that the total and partial decay widths of the Higgs, as well as the h {yields} gg branching fraction, can be substantially altered from their SM expectations, while the remaining branching fractions are modified less than about 5% for most of the parameter space volume. Precision measurements of Higgs boson properties at at a Linear Collider are shown to probe a large region of the Randall-Sundrum model parameter space.
Search for charged Higgs Bosons at D0
Peters, Yvonne
2008-11-23
In both Supersymmetry and in generic Two Higgs Doublet models (2HDM), the charged Higgs boson H{sup {+-}} exhibits a unique phenomenological signature. We report on a search for charged Higgs bosons, performed using 0.9 fb{sup -1} of data collected with the D0 detector at the Fermilab Tevatron pp-bar collider with a center-of-mass energy of {radical}(s) = 1.96 TeV. No evidence for a charged Higgs boson is found and we set limits on its production cross section or the branching fraction.
Higgs Bosons in the NMSSM and its U(1) Extensions
Gunion, John F.
2008-11-23
I specify the characteristics of a Higgs boson that would be 'ideal' in the light of current data and theoretical attractiveness. I then review why it is that the Higgs bosons of the Standard Model and the Minimal Supersymmetric Model cannot be ideal whereas the lightest Higgs boson of the Next to Minimal Supersymmetric Model can be ideal. Experimental consequences for Higgs and supersymmetry discovery are then reviewed. I then examine the alternatives to the NMSSM in which the MSSM is extended via an extra U(1) symmetry.
Baryogenesis and dark matter through a Higgs asymmetry.
Servant, Géraldine; Tulin, Sean
2013-10-11
In addition to explaining the masses of elementary particles, the Higgs boson may have far-reaching implications for the generation of the matter content in the Universe. For instance, the Higgs boson plays a key role in two main theories of baryogenesis, namely, electroweak baryogenesis and leptogenesis. In this Letter, we propose a new cosmological scenario where the Higgs chemical potential mediates asymmetries between visible and dark matter sectors, either generating a baryon asymmetry from a dark matter asymmetry or vice versa. We illustrate this mechanism with a simple model with two new fermions coupled to the Higgs boson and discuss the associated signatures.
Vector Dark Matter through a radiative Higgs portal
DiFranzo, Anthony; Fox, Patrick J.; Tait, Tim M. P.
2016-04-21
We study a model of spin-1 dark matter which interacts with the Standard Model predominantly via exchange of Higgs bosons. We propose an alternative UV completion to the usual Vector Dark Matter Higgs Portal, in which vector-like fermions charged under SU(2)more » $$_W \\times$$ U(1)$$_Y$$ and under the dark gauge group, U(1)$$^\\prime$$, generate an effective interaction between the Higgs and the dark matter at one loop. Furthermore, we explore the resulting phenomenology and show that this dark matter candidate is a viable thermal relic and satisfies Higgs invisible width constraints as well as direct detection bounds.« less
Tevatron searches for Higgs bosons beyond the standard model
Nielsen, Jason; /UC, Santa Cruz
2007-06-01
Theoretical frameworks beyond the standard model predict a rich Higgs sector with multiple charged and neutral Higgs bosons. Both the CDF II and D0 experiments at the Tevatron have analyzed 1 fb{sup -1} of p{bar p} collisions at {radical}s = 1.96TeV in search of Higgs boson production. A complete suite of results on searches for neutral, charged, and fermiophobic Higgs bosons limit the allowed production rates and constrain extended models, including the minimal supersymmetric standard model.
Vector Dark Matter through a radiative Higgs portal
DiFranzo, Anthony; Fox, Patrick J.; Tait, Tim M. P.
2016-04-21
We study a model of spin-1 dark matter which interacts with the Standard Model predominantly via exchange of Higgs bosons. We propose an alternative UV completion to the usual Vector Dark Matter Higgs Portal, in which vector-like fermions charged under SU(2)$_W \\times$ U(1)$_Y$ and under the dark gauge group, U(1)$^\\prime$, generate an effective interaction between the Higgs and the dark matter at one loop. Furthermore, we explore the resulting phenomenology and show that this dark matter candidate is a viable thermal relic and satisfies Higgs invisible width constraints as well as direct detection bounds.
Total width of 125 GeV Higgs boson.
Barger, Vernon; Ishida, Muneyuki; Keung, Wai-Yee
2012-06-29
By using the LHC and Tevatron measurements of the cross sections to various decay channels relative to the standard model Higgs boson, the total width of the putative 125 GeV Higgs boson is determined as 6.1(-2.9)(+7.7) MeV. We describe a way to estimate the branching fraction for the Higgs-boson decay to dark matter. We also discuss a no-go theorem for the γγ signal of the Higgs boson at the LHC.
Higgs constraints from vector boson fusion and scattering
Campbell, John M.; Ellis, R. Keith
2015-04-07
We present results on 4-lepton + 2-jet production, the partonic processes most commonly described as vector boson pair production in the Vector Boson Fusion (VBF) mode. That final state contains diagrams that are mediated by Higgs boson exchange. We focus particularly on the high-mass behaviour of the Higgs boson mediated diagrams, which unlike on-shell production, gives information about the Higgs couplings without assumptions on the Higgs boson total width. We assess the sensitivity of the high-mass region to Higgs coupling strengths, considering all vector boson pair channels, W - W +, W ± W ±, W ± Z and ZZ.more » Because of the small background, the most promising mode is W + W + which has sensitivity to Higgs couplings because of Higgs boson exchange in the t-channel. Furthermore, using the Caola-Melnikov (CM) method, the off-shell couplings can be interpreted as bounds on the Higgs boson total width. We estimate the bound that can be obtained with current data, as well as the bounds that could be obtained at √s=13 TeV in the VBF channel for data samples of 100 and 300 fb-1. The CM method has already been successfully applied in the gluon fusion (GGF) production channel. The VBF production channel gives important complementary information, because both production and decay of the Higgs boson occur already at tree graph level.« less
Applying EFT to Higgs pair production in universal extra dimensions
NASA Astrophysics Data System (ADS)
Edelhäuser, Lisa; Knochel, Alexander; Steeger, Thomas
2015-11-01
We investigate single Higgs and Higgs pair production at the LHC in models of Universal Extra Dimensions. After calculating the relevant cross sections, we use the UED model as a testing ground for the Effective Field Theory approach to physics beyond the Standard Model. We show how the UED contributions to Higgs production can be matched to a dimension-6 operator. We then discuss the range of validity of this approach, in particular for Higgs pair production, and determine the sensitivity to the number of KK modes in the loop.
Carena, M.; Heinemeyer, S.; Stål, O.; Wagner, C.E.M.; Weiglein, G.
2013-09-01
A Higgs-like particle with a mass of about 125.5 GeV has been discovered at the LHC. Within the current experimental uncertainties, this new state is compatible with both the predictions for the Standard Model (SM) Higgs boson and with the Higgs sector in the Minimal Supersymmetric Standard Model (MSSM). We propose new low-energy MSSM benchmark scenarios that, over a wide parameter range, are compatible with the mass and production rates of the observed signal. These scenarios also exhibit interesting phenomenology for the MSSM Higgs sector. We propose a slightly updated version of the well-known mh-max scenario, and a modified scenario (mh-mod), where the light CP-even Higgs boson can be interpreted as the LHC signal in large parts of the MA-tan \\beta\\ plane. Furthermore, we define a light stop scenario that leads to a suppression of the lightest CP-even Higgs gluon fusion rate, and a light stau scenario with an enhanced decay rate of h to \\gamma\\gamma\\ at large tan \\beta. We also suggest a \\tau-phobic Higgs scenario in which the lightest Higgs can have suppressed couplings to down-type fermions. We propose to supplement the specified value of the \\mu\\ parameter in some of these scenarios with additional values of both signs. This has a significant impact on the interpretation of searches for the non SM-like MSSM Higgs bosons. We also discuss the sensitivity of the searches to heavy Higgs decays into light charginos and neutralinos, and to decays of the form H to hh. Finally, in addition to all the other scenarios where the lightest CP-even Higgs is interpreted as the LHC signal, we propose a low-MH scenario, where instead the heavy CP-even Higgs boson corresponds to the new state around 125.5 GeV.
W${'}$ signatures with odd Higgs particles
Dobrescu, Bogdan A.; Peterson, Andrea D.
2014-08-13
We point out that W' bosons may decay predominantly into Higgs particles associated with their broken gauge symmetry. We demonstrate this in a renormalizable model where the W' and W couplings to fermions differ only by an overall normalization. This "meta-sequential" W' boson decays into a scalar pair, with the charged one subsequently decaying into a W boson and a neutral scalar. These scalars are odd under a parity of the Higgs sector, which consists of a complex bidoublet and a doublet. Finally, the W' and Z' bosons have the same mass and branching fractions into scalars, and may show up at the LHC in final states involving one or two electroweak bosons and missing transverse energy.
W$${'}$$ signatures with odd Higgs particles
Dobrescu, Bogdan A.; Peterson, Andrea D.
2014-08-13
We point out that W' bosons may decay predominantly into Higgs particles associated with their broken gauge symmetry. We demonstrate this in a renormalizable model where the W' and W couplings to fermions differ only by an overall normalization. This "meta-sequential" W' boson decays into a scalar pair, with the charged one subsequently decaying into a W boson and a neutral scalar. These scalars are odd under a parity of the Higgs sector, which consists of a complex bidoublet and a doublet. Finally, the W' and Z' bosons have the same mass and branching fractions into scalars, and may showmore » up at the LHC in final states involving one or two electroweak bosons and missing transverse energy.« less
Cosmological signals of a mirror twin Higgs
NASA Astrophysics Data System (ADS)
Craig, Nathaniel; Koren, Seth; Trott, Timothy
2017-05-01
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.
Phenomenology of relaxion-Higgs mixing
NASA Astrophysics Data System (ADS)
Flacke, Thomas; Frugiuele, Claudia; Fuchs, Elina; Gupta, Rick S.; Perez, Gilad
2017-06-01
We show that the relaxion generically stops its rolling at a point that breaks CP leading to relaxion-Higgs mixing. This opens the door to a variety of observational probes since the possible relaxion mass spans a broad range from sub-eV to the GeV scale. We derive constraints from current experiments (fifth force, astrophysical and cosmological probes, beam dump, flavour, LEP and LHC) and present projections from future experiments such as NA62, SHiP and PIXIE. We find that a large region of the parameter space is already under the experimental scrutiny. All the experimental constraints we derive are equally applicable for general Higgs portal models. In addition, we show that simple multiaxion (clockwork) UV completions suffer from a mild fine tuning problem, which increases with the number of sites. These results favour a cut-off scale lower than the existing theoretical bounds.
Inclusive Higgs Production at Large Transverse Momentum
NASA Astrophysics Data System (ADS)
Zhang, Hong; Braaten, Eric
2017-01-01
The transverse momentum (pT) distribution of Higgs is important to check our understanding of the Standard Model, and study new physics. The effective field theory for Higgs, obtained by integrating out the top quark, breaks down when pT is larger than 200 GeV. We calculate the pT distribution at much larger pT using the framework of factorization, in which the cross section is expressed as convolutions of hard-scattering cross sections and fragmentation functions, with the leading logarithms of pT2 /mH2 resummed to all orders. By separating the scales mH and pT, the higher order radiative correction can be greatly simplified.
Higgs boson studies at the tevatron
Herner, Kenneth
2016-05-31
We present the combination of searches for the Standard Model Higgs boson at a center-of-mass energy of √s = 1.96 TeV , using the full Run 2 dataset collected with the CDF and D0 detectors at the Fermilab Tevatron collider. We also present combined measurements of Higgs Boson production cross sections, branching ratios, and couplings to fermions and bosons. Lastly, we present tests of different spin and parity hypotheses for a particle H of mass 125 GeV produced in association with a vector boson and decaying into a pair of b quarks, and place constraints on such hypotheses using the D0 data.
Higgs boson studies at the tevatron
Herner, Kenneth
2016-05-31
We present the combination of searches for the Standard Model Higgs boson at a center-of-mass energy of √s = 1.96 TeV , using the full Run 2 dataset collected with the CDF and D0 detectors at the Fermilab Tevatron collider. We also present combined measurements of Higgs Boson production cross sections, branching ratios, and couplings to fermions and bosons. Lastly, we present tests of different spin and parity hypotheses for a particle H of mass 125 GeV produced in association with a vector boson and decaying into a pair of b quarks, and place constraints on such hypotheses using the D0more » data.« less
Stability, Higgs boson mass, and new physics.
Branchina, Vincenzo; Messina, Emanuele
2013-12-13
Assuming that the particle with mass ∼126 GeV discovered at LHC is the standard model Higgs boson, we find that the stability of the electroweak (EW) vacuum strongly depends on new physics interaction at the Planck scale MP, despite of the fact that they are higher-dimensional interactions, apparently suppressed by inverse powers of MP. In particular, for the present experimental values of the top and Higgs boson masses, if τ is the lifetime of the EW vacuum, new physics can turn τ from τ≫TU to τ≪TU, where TU is the age of the Universe, thus, weakening the conclusions of the so called metastability scenario.
Spherical parametrization of the Higgs boson candidate.
Gainer, James S; Lykken, Joseph; Matchev, Konstantin T; Mrenna, Stephen; Park, Myeonghun
2013-07-26
The latest results from the ATLAS and CMS experiments at the CERN Large Hadron Collider unequivocally confirm the existence of a resonance X with mass near 125 GeV which could be the Higgs boson of the standard model. Measuring the properties (quantum numbers and couplings) of this resonance is of paramount importance. Initial analyses by the LHC Collaborations disfavor specific alternative benchmark hypotheses, e.g., pure pseudoscalars or gravitons. However, this is just the first step in a long-term program of detailed measurements. We consider the most general set of operators in the decay channels X→ZZ, WW, Zγ, γγ, and derive the constraint implied by the measured rate. This allows us to provide a useful parametrization of the orthogonal independent Higgs coupling degrees of freedom as coordinates on a suitably defined sphere.
Little Higgs after the little one
NASA Astrophysics Data System (ADS)
Choudhury, Debajyoti; Ghosh, Dilip Kumar; Rai, Santosh Kumar; Saha, Ipsita
2016-06-01
At the LHC, the Littlest Higgs Model with T-parity is characterised by various production channels. If the T-odd quarks are heavier than the exotic partners of the W and the Z, then associated production can be as important as the pair-production of the former. Studying both, we look for final states comprising at least one lepton, jets and missing transverse energy. We consider all the SM processes that could conspire to contribute as background to our signals, and perform a full detector level simulation of the signal and background to estimate the discovery potential at the current run as well as at the scheduled upgrade of the LHC. We also show that, for one of the channels, the reconstruction of two tagged b-jets at the Higgs mass ( M h = 125 GeV) provides us with an unambiguous hint for this model.
Flavor mixing in gauge-Higgs unification
Adachi, Y.; Kurahashi, N.; Lim, C. S.; Maru, N.; Tanabe, K.
2012-07-27
Gauge-Higgs unification is the fascinating scenario solving the hierarchy problem without supersymmetry. In this scenario, the Standard Model (SM) Higgs doublet is identified with extra component of the gauge field in higher dimensions and its mass becomes finite and stable under quantum corrections due to the higher dimensional gauge symmetry. On the other hand, Yukawa coupling is provided by the gauge coupling, which seems to mean that the flavor mixing and CP violation do not arise at it stands. In this talk, we discuss that the flavor mixing is originated from simultaneously non-diagonalizable bulk and brane mass matrices. Then, this mechanism is applied to various flavor changing neutral current (FCNC) processes via Kaluza-Klein (KK) gauge boson exchange at tree level and constraints for compactification scale are obtained.
Probing the two-Higgs-doublet wedge region with charged Higgs boson decays to boosted jets
NASA Astrophysics Data System (ADS)
Pedersen, Keith; Sullivan, Zack
2017-02-01
Two-Higgs-doublet extensions of the standard model, such as supersymmetry, predict the existence of charged Higgs bosons. We explore the reach for TeV-scale charged Higgs bosons through their associated production with top quarks, and their decay to boosted top jets and μx -tagged boosted bottom jets, at a 14 TeV CERN Large Hadron Collider and at a 100 TeV Future Circular Collider. In particular, we show the moderate tan β "wedge" region of parameter space cannot be probed at the Large Hadron Collider for TeV-scale H± because the cross section is too small. However, a 100 TeV future proton collider can close the wedge region below 2 TeV, and search for H± up to 6 TeV.
Extraction of the Susy and Higgs parameters
Adam-Bourdarios, Claire
2010-02-10
If supersymmetry is discovered by the next generation of collider experiments, it will be crucial to determine its fundamental high-scale parameters. Three scenarios have been recently investigated by the SFitter collaboration : the case where the LHC 'only' measures a light Higgs like signal, the case where SUSY signal are discovered at the LHC, and the dream scenario, where LHC and ILC measurements can be combined.
Bounding the Higgs Width at the LHC
Campbell, John M.; Ellis, R. Keith; Williams, Ciaran
2014-08-07
We present results for the Standard model description of the four-lepton production, mediated both by Higgs boson production and by other one-loop standard model processes. The description of four-lepton final states in MCFM v6.8 is reviewed, with special reference to the interference effects that can occur for identical species of leptons. We present results both for interference in the $l^+l^- l^- l^+$ and in the $l^-l^+ \
Searching the Higgs with the neurochip TOTEM
NASA Astrophysics Data System (ADS)
Dusini, S.; Ferrari, F.; Lazzizzera, I.; Sartori, A.; Sidoti, A.; Tecchiolli, G.
1998-06-01
We show that neural network classifiers can be helpful in discriminating Higgs production events from the huge background at LHC, assuming the case of a mass value M H ˜ 200 GeV. We use the high performance neurochip TOTEM, trained by the Reactive Tabu Search algorithm (RTS), which could be used for on-line purposes. Two different sets of input variables are compared.
Exotic quarks in Twin Higgs models
Cheng, Hsin -Chia; Jung, Sunghoon; Salvioni, Ennio; ...
2016-03-14
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 themore » 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 with long lifetimes, giving spectacular displaced vertex signals in combination with the prompt top quarks. This happens in the Fraternal Twin Higgs scenario with typical parameters, and sometimes is even necessary for cosmological reasons. We study the potential displaced vertex signals from the decays of the twin bottomonia, twin glueballs, and twin leptons in the Fraternal Twin Higgs scenario. As a result, depending on the details of the twin sector, the exotic quarks may be probed up to ~ 2.5 TeV at the LHC and beyond 10 TeV at a future 100 TeV collider, providing a strong test of this class of ultraviolet completions.« less
The Kaehler potential of Abelian Higgs vortices
Chen, H.-Y.; Manton, N.S.
2005-05-01
We calculate the Kaehler potential for the Samols metric on the moduli space of Abelian Higgs vortices on R{sub 2}, in two different ways. The first uses a scaling argument. The second depends on a variant of the relationship between accessory parameters and the regularized action in Liouville field theory. The Kaehler potential on the moduli space of vortices on H{sub 2} is also derived, and we are led to a geometrical reinterpretation of these vortices.
Exotic quarks in Twin Higgs models
Cheng, Hsin -Chia; Jung, Sunghoon; Salvioni, Ennio; Tsai, Yuhsin
2016-03-14
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 with long lifetimes, giving spectacular displaced vertex signals in combination with the prompt top quarks. This happens in the Fraternal Twin Higgs scenario with typical parameters, and sometimes is even necessary for cosmological reasons. We study the potential displaced vertex signals from the decays of the twin bottomonia, twin glueballs, and twin leptons in the Fraternal Twin Higgs scenario. As a result, depending on the details of the twin sector, the exotic quarks may be probed up to ~ 2.5 TeV at the LHC and beyond 10 TeV at a future 100 TeV collider, providing a strong test of this class of ultraviolet completions.
Invisible Decays of Supersymmetric Higgs Bosons
Aparicio Mendez, M. del R; Guevara, J. E. Barradas; Beltran, O. Felix
2009-04-20
We study the detection of the complete spectrum of Higgs bosons of the minimal supersymmetric standard model, through their decays into chargino ({chi}-tilde{sub i}{sup {+-}}) and neutralinos ({chi}-tilde{sub i}{sup o}), for several parametric scenarios. In the minimal supersymmetric model there are two charginos and four neutralinos, and the Higgs boson spectrum contains three neutral scalars, two CP-even (h{sup 0} and H{sup 0} with m{sub H{sup 0}}>m{sub h{sup 0}}) and one CP-odd (A{sup 0}, with m{sub A{sup 0}} as a free parameter); as well as a charged pair (H{sup {+-}}). An interesting signal comes from the decays of the Higgs bosons into invisible SUSY modes (h{sup 0}, H{sup 0},A{sup 0}{yields}{chi}-tilde{sub 1}{sup o}{chi}-tilde{sub 1}{sup o}), which could be detected at present and future high energy machines.
Tempered two-Higgs-doublet model
NASA Astrophysics Data System (ADS)
Grzadkowski, B.; Osland, P.
2010-12-01
We discuss the phenomenological consequences of requiring the cancellation of quadratic divergences up to the leading two-loop order within the two-Higgs-doublet model. Taking into account existing experimental constraints, allowed regions in the parameter space, permitting the cancellation, are determined. A degeneracy between masses of scalar bosons is observed for tanβ≳40. The possibility for CP violation in the scalar potential is discussed and regions of tanβ-MH± with a substantial amount of CP violation are determined. In order to provide a source for dark matter in a minimal manner, a scalar gauge singlet is introduced and discussed. The model allows to ameliorate the little hierarchy problem by lifting the minimal scalar Higgs-boson mass and by suppressing the quadratic corrections to scalar masses. The cutoff originating from the naturality arguments is therefore lifted from ˜0.6TeV in the standard model to ≳2.5TeV in two-Higgs-doublet model depending on the mass of the lightest scalar.
Toward realistic gauge-Higgs grand unification
NASA Astrophysics Data System (ADS)
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.
Higgs CP properties from early LHC data
NASA Astrophysics Data System (ADS)
Freitas, A.; Schwaller, P.
2013-03-01
In this paper, we constrain CP violation in the Higgs sector using the measured signal strengths in the various Higgs search channels. To this end, we introduce a general parametrization for a resonance which is an admixture of a CP-even Higgs-like state and a CP-odd scalar. By performing a fit to the available data from the Tevatron and LHC experiments, one obtains constraints on the mixing angle and the couplings of the resonance to Standard Model fields. Depending on the couplings, sizable mixing angles are still compatible with the data, but small mixing is in general preferred by the fit. In particular, we find that a pure CP-odd state is disfavored by the current data at the 3σ level. Additionally, we consider a mixed fermiophobic resonance and a model with two degenerate mixed resonances and find that both scenarios can successfully fit the data within current errors. Finally, we estimate that the mixing angle can be constrained to α<1.1 (0.7) in the full 8 TeV (14 TeV) run of the LHC.
Unitarity check in gravitational Higgs mechanism
NASA Astrophysics Data System (ADS)
Berezhiani, Lasha; Mirbabayi, Mehrdad
2011-03-01
The effective field theory of massive gravity has long been formulated in a generally covariant way [N. Arkani-Hamed, H. Georgi, and M. D. Schwartz, Ann. Phys. (N.Y.)APNYA60003-4916 305, 96 (2003).]. Using this formalism, it has been found recently that there exists a class of massive nonlinear theories that are free of the Boulware-Deser ghosts, at least in the decoupling limit [C. de Rham and G. Gabadadze, Phys. Rev. DPRVDAQ1550-7998 82, 044020 (2010).10.1103/PhysRevD.82.044020]. In this work we study other recently proposed models that go under the name of “gravitational Higgs theories” [A. H. Chamseddine and V. Mukhanov, J. High Energy Phys.JHEPFG1029-8479 08 (2010) 011.10.1007/JHEP08(2010)011]. We show that these models, although seemingly different from the effective field theories of massive gravity, are in fact equivalent to them. Furthermore, based on the results obtained in the effective field theory approach, we conclude that the gravitational Higgs theories need the same adjustment of the Lagrangian to avoid the ghosts. We also show the equivalence between the noncovariant mode decomposition used in the Higgs theories, and the covariant Stückelberg parametrization adopted in the effective field theories, thus proving that the presence or absence of the ghost is independent of the parametrization used in either theory.
The minimal curvaton-higgs model
Enqvist, Kari; Lerner, Rose N.; Takahashi, Tomo E-mail: rose.lerner@desy.de
2014-01-01
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 σ} ≥ 8 × 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 σ}∼<5 × 10{sup 9}GeV, depending on Hubble scale during inflation. In a thermal dark matter model, the lower bound on m{sub σ} can increase substantially. The parameter space may also be affected once the baryogenesis mechanism is specified.
Unitarity check in gravitational Higgs mechanism
Berezhiani, Lasha; Mirbabayi, Mehrdad
2011-03-15
The effective field theory of massive gravity has long been formulated in a generally covariant way [N. Arkani-Hamed, H. Georgi, and M. D. Schwartz, Ann. Phys. (N.Y.) 305, 96 (2003).]. Using this formalism, it has been found recently that there exists a class of massive nonlinear theories that are free of the Boulware-Deser ghosts, at least in the decoupling limit [C. de Rham and G. Gabadadze, Phys. Rev. D 82, 044020 (2010).]. In this work we study other recently proposed models that go under the name of 'gravitational Higgs theories' [A. H. Chamseddine and V. Mukhanov, J. High Energy Phys. 08 (2010) 011.]. We show that these models, although seemingly different from the effective field theories of massive gravity, are in fact equivalent to them. Furthermore, based on the results obtained in the effective field theory approach, we conclude that the gravitational Higgs theories need the same adjustment of the Lagrangian to avoid the ghosts. We also show the equivalence between the noncovariant mode decomposition used in the Higgs theories, and the covariant Stueckelberg parametrization adopted in the effective field theories, thus proving that the presence or absence of the ghost is independent of the parametrization used in either theory.
Hidden sector DM models and Higgs physics
Ko, P.
2014-06-24
We present an extension of the standard model to dark sector with an unbroken local dark U(1){sub X} symmetry. Including various singlet portal interactions provided by the standard model Higgs, right-handed neutrinos and kinetic mixing, we show that the model can address most of phenomenological issues (inflation, neutrino mass and mixing, baryon number asymmetry, dark matter, direct/indirect dark matter searches, some scale scale puzzles of the standard collisionless cold dark matter, vacuum stability of the standard model Higgs potential, dark radiation) and be regarded as an alternative to the standard model. The Higgs signal strength is equal to one as in the standard model for unbroken U(1){sub X} case with a scalar dark matter, but it could be less than one independent of decay channels if the dark matter is a dark sector fermion or if U(1){sub X} is spontaneously broken, because of a mixing with a new neutral scalar boson in the models.
Higgs production and decay in models of a warped extra dimension with a bulk Higgs
Archer, Paul R.; Carena, Marcela; Carmona, Adrian; ...
2015-01-13
Warped extra-dimension models in which the Higgs boson is allowed to propagate in the bulk of a compact AdS5 space are conjectured to be dual to models featuring a partially composite Higgs boson. They offer a framework with which to investigate the implications of changing the scaling dimension of the Higgs operator, which can be used to reduce the constraints from electroweak precision data. In the context of such models, we calculate the cross section for Higgs production in gluon fusion and the H → γγ decay rate and show that they are finite (at one-loop order) as a consequencemore » of gauge invariance. The extended scalar sector comprising the Kaluza-Klein excitations of the Standard Model scalars is constructed in detail. The largest effects are due to virtual KK fermions, whose contributions to the cross section and decay rate introduce a quadratic sensitivity to the maximum allowed value y* of the random complex entries of the 5D anarchic Yukawa matrices. We find an enhancement of the gluon-fusion cross section and a reduction of the H → γγ rate as well as of the tree-level Higgs couplings to fermions and electroweak gauge bosons. As a result, we perform a detailed study of the correlated signal strengths for different production mechanisms and decay channels as functions of y*, the mass scale of Kaluza-Klein resonances and the scaling dimension of the composite Higgs operator.« less
Higgs production and decay in models of a warped extra dimension with a bulk Higgs
Archer, Paul R.; Carena, Marcela; Carmona, Adrian; Neubert, Matthias
2015-01-13
Warped extra-dimension models in which the Higgs boson is allowed to propagate in the bulk of a compact AdS_{5} space are conjectured to be dual to models featuring a partially composite Higgs boson. They offer a framework with which to investigate the implications of changing the scaling dimension of the Higgs operator, which can be used to reduce the constraints from electroweak precision data. In the context of such models, we calculate the cross section for Higgs production in gluon fusion and the H → γγ decay rate and show that they are finite (at one-loop order) as a consequence of gauge invariance. The extended scalar sector comprising the Kaluza-Klein excitations of the Standard Model scalars is constructed in detail. The largest effects are due to virtual KK fermions, whose contributions to the cross section and decay rate introduce a quadratic sensitivity to the maximum allowed value y_{*} of the random complex entries of the 5D anarchic Yukawa matrices. We find an enhancement of the gluon-fusion cross section and a reduction of the H → γγ rate as well as of the tree-level Higgs couplings to fermions and electroweak gauge bosons. As a result, we perform a detailed study of the correlated signal strengths for different production mechanisms and decay channels as functions of y_{*}, the mass scale of Kaluza-Klein resonances and the scaling dimension of the composite Higgs operator.
Higgs Boson Decay and Quasi-Bound States in the Higgs Model
NASA Astrophysics Data System (ADS)
di Leo, Leo; Darewych, Jurij W.
We calculate two-Higgs bound states (Higgsonium) as resonances in Z0-Z0 scattering using a |Z0Z0>+|h>+|hh>+|hhh>+|hhhhh> Fock-space ansatz in a Hamiltonian formalism of the Higgs model. The variational method is used to obtain coupled integral equations connecting the various channels. Reduced forms of these equations are solved analytically in the case of the Z0Z0-h channels, and numerically for the Z0Z0-hh channels for particular choices of the coupling parameters.
Higgs-mediated e→μ transitions in II Higgs doublet model and supersymmetry
NASA Astrophysics Data System (ADS)
Paradisi, Paride
2006-08-01
We study the phenomenology of the e-μ lepton flavor violation (LFV) in a general two Higgs Doublet Model (2HDM) including the supersymmetric case. We compute the decay rate expressions of μ→eγ, μ→eee, and μ→e conversion in nuclei at two loop level. In particular, it is shown that μ→eγ is generally the most sensitive channel to probe Higgs-mediated LFV. The correlations among the decay rates of the above processes are also discussed.
Top Quark Properties in Little Higgs Models
Berger, C.F.; Perelstein, M.; Petriello, F.; /Wisconsin U., Madison
2005-12-08
Identifying the mechanism which breaks electroweak symmetry and generates fermion masses is one of the main physics goals for both the LHC and the ILC. Studies of the top quark have the potential to illuminate this issue; since it is the heaviest of the Standard Model (SM) fermions, the top is expected to couple strongly to the symmetry-breaking sector. Consequently, the structure of that sector can have significant, potentially observable effects on the properties of the top. for example, it is well known that the vector and axial t{bar t}Z form factors receive large corrections (of order 5-10%) in certain models of dynamical electroweak symmetry breaking [1]. At future colliders such as the LHC and the ILC, we will be able to pursue a program of precision top physics, similar to the program studying the Z at LEP and SLC. In this manuscript, they study the corrections to the top quark properties in ''Little Higgs'' models of electroweak symmetry breaking [2], and compare the expected deviations from the SM predictions with expected sensitivities of experiments at the LHC and the ILC. In the Little Higgs models, electroweak symmetry is driven by the radiative effects from the top sector, including the SM-like top and its heavy counterpart, a TeV-scale ''heavy top'' T. Probing this structure experimentally is quite difficult. While the LHC should be able to discover the T quark, its potential for studying its couplings is limited [3,4]. Direct production of the T will likely be beyond the kinematic reach of the ILC. However, we will show below that the corrections to the gauge couplings of the SM top, induced by its mixing with the T, will be observable at the ILC throughout the parameter range consistent with naturalness. Measuring these corrections will provide a unique window on the top sector of the Little Higgs. Many Little Higgs models have been proposed in the literature. We will consider two examples in this study, the ''Littlest Higgs'' model [5], and its
PAR for the Course: A Congruent Pedagogical Approach for a PAR Methods Class
ERIC Educational Resources Information Center
Hammond, Joyce D.; Hicks, Maria; Kalman, Rowenn; Miller, Jason
2005-01-01
In the past two years, three graduate students and a senior faculty member have co-taught a participatory action research (PAR) course to undergraduate and graduate students. In this article the co-teachers advocate a set of pedagogical principles and practices in a PAR-oriented classroom that establishes congruency with community PAR projects in…
NASA Astrophysics Data System (ADS)
Yang, Bing-Fang; Liu, Zhi-Yong; Liu, Ning
2017-04-01
Motivated by the search for flavor-changing neutral current (FCNC) top quark decays at the LHC, we calculate the rare Higgs three body decay H → Wbc induced by top-Higgs FCNC coupling in the littlest Higgs model with T-parity (LHT). We find that the branching ratio of H → Wbc in the LHT model can reach O(10-7) in the allowed parameter space. Supported by National Natural Science Foundation of China (11305049, 11405047), Startup Foundation for Doctors of Henan Normal University (11112, qd15207) and Education Department Foundation of Henan Province(14A140010)
Dimension-six triple gluon operator in Higgs +jet observables
NASA Astrophysics Data System (ADS)
Ghosh, Diptimoy; Wiebusch, Martin
2015-02-01
Recently a lot of progress has been made towards a full classification of new physics effects in Higgs observables by means of effective dimension-six operators. Specifically, Higgs production in association with a high transverse momentum jet has been suggested as a way to discriminate between operators that modify the Higgs-top coupling (Ot) and operators that induce an effective Higgs-gluon coupling (Og)—a distinction that is hard to achieve with signal strength measurements alone. With this article we would like to draw attention to another source of new physics in Higgs +jet observables: the triple gluon operator O3 g (consisting of three factors of the gluon field strength tensor). We compute the distortions of kinematic distributions in Higgs +jet production at a 14 TeV LHC due to O3 g and compare them with the distortions due to Ot and Og. We find that the transverse momentum distributions alone cannot discriminate between O3 g and Og if the coefficient of the operator Ot treated as an unknown parameter. We further show that the jet rapidity and the difference between the Higgs and jet rapidity are well suited to remove this new degeneracy. Using rough estimates for the expected bounds we find that allowed distortions in kinematic distributions due to Og are of similar size as those due to O3 g. We conclude that a full analysis of new physics in Higgs +jet observables must take the contributions from O3 g into account.
The light and heavy Higgs interpretation of the MSSM
Bechtle, Philip; Haber, Howard E.; Heinemeyer, Sven; ...
2017-02-03
We perform a parameter scan of the phenomenological Minimal Supersymmetric Standard Model (pMSSM) with eight parameters taking into account the experimental Higgs boson results from Run I of the LHC and further low-energy observables. We investigate various MSSM interpretations of the Higgs signal at 125 GeV. First, the light CP-even Higgs boson being the discovered particle. In this case it can impersonate the SM Higgslike signal either in the decoupling limit, or in the limit of alignment without decoupling. In the latter case, the other states in the Higgs sector can also be light, offering good prospects for upcoming LHCmore » searches and for searches at future colliders. Second, we demonstrate that the heavy CP-even Higgs boson is still a viable candidate to explain the Higgs signal | albeit only in a highly constrained parameter region, that will be probed by LHC searches for the CP-odd Higgs boson and the charged Higgs boson in the near future. As a guidance for such searches we provide new benchmark scenarios that can be employed to maximize the sensitivity of the experimental analysis to this interpretation.« less
Maxwell-Higgs equation on higher dimensional static curved spacetimes
Mulyanto; Akbar, Fiki Taufik Gunara, Bobby Eka
2015-09-30
In this paper we consider a class of solutions of Maxwell-Higgs equation in higher dimensional static curved spacetimes called Schwarzchild de-Sitter spacetimes. We obtain the general form of the electric fields and magnetic fields in background Schwarzchild de-Sitter spacetimes. However, determining the interaction between photons with the Higgs scalar fields is needed further studies.
ATLAS Search for the MSSM Charged Higgs Boson
Potter, Chris
2008-11-23
The discovery of a charged Higgs boson would be definitive evidence of new physics beyond the Standard Model. The discovery potential of a MSSM charged Higgs boson with the ATLAS detector at the Large Hadron Collider is presented. The study is based on the analysis of signal and background simulated in detail through the experimental apparatus.
Nonexistence of global solution to Chern-Simons-Higgs system
Yuan, Jianjun
2013-12-15
In this paper, we show that for a class of Higgs potentials V, the 2+1-dimensional Chern-Simons-Higgs system with negative energy or zero energy together with (d/(dt) ∫|ϕ(t,x)|{sup 2}dx)(0)>0 blows up in finite time.
Impersonating the Standard Model Higgs boson: Alignment without decoupling
Carena, Marcela; Low, Ian; Shah, Nausheen R.; Wagner, Carlos E. M.
2014-04-03
In models with an extended Higgs sector there exists an alignment limit, in which the lightest CP-even Higgs boson mimics the Standard Model Higgs. The alignment limit is commonly associated with the decoupling limit, where all non-standard scalars are significantly heavier than the Z boson. However, alignment can occur irrespective of the mass scale of the rest of the Higgs sector. In this work we discuss the general conditions that lead to “alignment without decoupling”, therefore allowing for the existence of additional non-standard Higgs bosons at the weak scale. The values of tan β for which this happens are derived in terms of the effective Higgs quartic couplings in general two-Higgs-doublet models as well as in supersymmetric theories, including the MSSM and the NMSSM. In addition, we study the information encoded in the variations of the SM Higgs-fermion couplings to explore regions in the m_{A} – tan β parameter space.
Impersonating the Standard Model Higgs boson: Alignment without decoupling
Carena, Marcela; Low, Ian; Shah, Nausheen R.; ...
2014-04-03
In models with an extended Higgs sector there exists an alignment limit, in which the lightest CP-even Higgs boson mimics the Standard Model Higgs. The alignment limit is commonly associated with the decoupling limit, where all non-standard scalars are significantly heavier than the Z boson. However, alignment can occur irrespective of the mass scale of the rest of the Higgs sector. In this work we discuss the general conditions that lead to “alignment without decoupling”, therefore allowing for the existence of additional non-standard Higgs bosons at the weak scale. The values of tan β for which this happens are derivedmore » in terms of the effective Higgs quartic couplings in general two-Higgs-doublet models as well as in supersymmetric theories, including the MSSM and the NMSSM. In addition, we study the information encoded in the variations of the SM Higgs-fermion couplings to explore regions in the mA – tan β parameter space.« less
Linearly polarized gluons and the Higgs transverse momentum distribution.
Boer, Daniël; den Dunnen, Wilco J; Pisano, Cristian; Schlegel, Marc; Vogelsang, Werner
2012-01-20
We study how gluons carrying linear polarization inside an unpolarized hadron contribute to the transverse momentum distribution of Higgs bosons produced in hadronic collisions. They modify the distribution produced by unpolarized gluons in a characteristic way that could be used to determine whether the Higgs boson is a scalar or a pseudoscalar particle.
Searches for Standard Model Higgs at the Tevatron
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.
Searches for standard model Higgs at the Tevatron
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.
Higgs physics at the CLIC electron-positron linear collider
NASA Astrophysics Data System (ADS)
Abramowicz, H.; Abusleme, A.; Afanaciev, K.; Alipour Tehrani, N.; Balázs, C.; Benhammou, Y.; Benoit, M.; Bilki, B.; Blaising, J.-J.; Boland, M. J.; Boronat, M.; Borysov, O.; Božović-Jelisavčić, I.; Buckland, M.; Bugiel, S.; Burrows, P. N.; Charles, T. K.; Daniluk, W.; Dannheim, D.; Dasgupta, R.; Demarteau, M.; Díaz Gutierrez, M. A.; Eigen, G.; Elsener, K.; Felzmann, U.; Firlej, M.; Firu, E.; Fiutowski, T.; Fuster, J.; Gabriel, M.; Gaede, F.; García, I.; Ghenescu, V.; Goldstein, J.; Green, S.; Grefe, C.; Hauschild, M.; Hawkes, C.; Hynds, D.; Idzik, M.; Kačarević, G.; Kalinowski, J.; Kananov, S.; Klempt, W.; Kopec, M.; Krawczyk, M.; Krupa, B.; Kucharczyk, M.; Kulis, S.; Laštovička, T.; Lesiak, T.; Levy, A.; Levy, I.; Linssen, L.; Lukić, S.; Maier, A. A.; Makarenko, V.; Marshall, J. S.; Martin, V. J.; Mei, K.; Milutinović-Dumbelović, G.; Moroń, J.; Moszczyński, A.; Moya, D.; Münker, R. M.; Münnich, A.; Neagu, A. T.; Nikiforou, N.; Nikolopoulos, K.; Nürnberg, A.; Pandurović, M.; Pawlik, B.; Perez Codina, E.; Peric, I.; Petric, M.; Pitters, F.; Poss, S. G.; Preda, T.; Protopopescu, D.; Rassool, R.; Redford, S.; Repond, J.; Robson, A.; Roloff, P.; Ros, E.; Rosenblat, O.; Ruiz-Jimeno, A.; Sailer, A.; Schlatter, D.; Schulte, D.; Shumeiko, N.; Sicking, E.; Simon, F.; Simoniello, R.; Sopicki, P.; Stapnes, S.; Ström, R.; Strube, J.; Świentek, K. P.; Szalay, M.; Tesař, M.; Thomson, M. A.; Trenado, J.; Uggerhøj, U. I.; van der Kolk, N.; van der Kraaij, E.; Vicente Barreto Pinto, M.; Vila, I.; Vogel Gonzalez, M.; Vos, M.; Vossebeld, J.; Watson, M.; Watson, N.; Weber, M. A.; Weerts, H.; Wells, J. D.; Weuste, L.; Winter, A.; Wojtoń, T.; Xia, L.; Xu, B.; Żarnecki, A. F.; Zawiejski, L.; Zgura, I.-S.
2017-07-01
The Compact Linear Collider (CLIC) is an option for a future {e+}{e-} collider operating at centre-of-mass energies up to 3 {TeV} , providing sensitivity to a wide range of new physics phenomena and precision physics measurements at the energy frontier. This paper is the first comprehensive presentation of the Higgs physics reach of CLIC operating at three energy stages: √{s} = 350 {GeV} , 1.4 and 3 {TeV} . The initial stage of operation allows the study of Higgs boson production in Higgsstrahlung (e+e- → ZH) and {W} {W} -fusion (e+e- → H ν_{!e} {\\bar{{ν }}_{!e} ), resulting in precise measurements of the production cross sections, the Higgs total decay width Γ_{{H}}, and model-independent determinations of the Higgs couplings. Operation at √{s} > 1 {TeV} provides high-statistics samples of Higgs bosons produced through {W} {W} -fusion, enabling tight constraints on the Higgs boson couplings. Studies of the rarer processes {e+}{e-} → t {\\bar{t}} {H} and {e+}{e-} → {H} {H} {{ν}}_{!e} {\\bar{{ν }}}_{!e} allow measurements of the top Yukawa coupling and the Higgs boson self-coupling. This paper presents detailed studies of the precision achievable with Higgs measurements at CLIC and describes the interpretation of these measurements in a global fit.
Observational consequences of the standard model Higgs inflation variants
Popa, L.A.
2011-10-01
We consider the possibility to observationally differentiate the Standard Model (SM) Higgs driven inflation with non-minimal coupling to gravity from other variants of SM Higgs inflation based on the scalar field theories with non-canonical kinetic term such as Galileon-like kinetic term and kinetic term with non-minimal derivative coupling to the Einstein tensor. In order to ensure consistent results, we study the SM Higgs inflation variants by using the same method, computing the full dynamics of the background and perturbations of the Higgs field during inflation at quantum level. Assuming that all the SM Higgs inflation variants are consistent theories, we use the MCMC technique to derive constraints on the inflationary parameters and the Higgs boson mass from their fit to WMAP7+SN+BAO data set. We conclude that a combination of the SM Higgs mass measurement by the LHC and accurate determination by the PLANCK satellite of the spectral index of curvature perturbations and tensor-to-scalar ratio will enable to distinguish among these models. We also show that the consistency relations of the SM Higgs inflation variants are distinct enough to differentiate among them.
Review of Physics Results from the Tevatron: Higgs Boson Physics
Junk, Thomas R.; Juste, Aurelio
2015-02-17
We review the techniques and results of the searches for the Higgs boson performed by the two Tevatron collaborations, CDF and DØ. The Higgs boson predicted by the Standard Model was sought in the mass range 90 GeV < mH < 200 GeV in all main production modes at the Tevatron: gluon–gluon fusion, WH and ZH associated production, vector boson fusion, and tt- H production, and in five main decay modes: H→ bb-, H→τ+τ-, H→WW(*), H→ZZ(*) and H→γγ. An excess of events was seen in the H→ bb- searches consistent with a Standard Model Higgs boson with a mass inmore » the range 115 GeV < mH < 135 GeV. We assume a Higgs boson mass of mH = 125 GeV, studies of Higgs boson properties were performed, including measurements of the product of the cross section times the branching ratio in various production and decay modes, constraints on Higgs boson couplings to fermions and vector bosons, and tests of spin and parity. We also summarize the results of searches for supersymmetric Higgs bosons, and Higgs bosons in other extensions of the Standard Model.« less
Review of Physics Results from the Tevatron: Higgs Boson Physics
Junk, Thomas R.; Juste, Aurelio
2015-02-17
We review the techniques and results of the searches for the Higgs boson performed by the two Tevatron collaborations, CDF and DØ. The Higgs boson predicted by the Standard Model was sought in the mass range 90 GeV < m_{H} < 200 GeV in all main production modes at the Tevatron: gluon–gluon fusion, WH and ZH associated production, vector boson fusion, and tt^{-} H production, and in five main decay modes: H→ bb^{-}, H→τ^{+}τ^{-}, H→WW^{(*)}, H→ZZ^{(*)} and H→γγ. An excess of events was seen in the H→ bb^{-} searches consistent with a Standard Model Higgs boson with a mass in the range 115 GeV < m_{H} < 135 GeV. We assume a Higgs boson mass of m_{H} = 125 GeV, studies of Higgs boson properties were performed, including measurements of the product of the cross section times the branching ratio in various production and decay modes, constraints on Higgs boson couplings to fermions and vector bosons, and tests of spin and parity. We also summarize the results of searches for supersymmetric Higgs bosons, and Higgs bosons in other extensions of the Standard Model.
Particlelike distributions of the Higgs field nonminimally coupled to gravity.
Füzfa, André; Rinaldi, Massimiliano; Schlögel, Sandrine
2013-09-20
When the Higgs field is nonminimally coupled to gravity, there exists a family of spherically symmetric particlelike solutions to the field equations. These monopoles are the only globally regular and asymptotically flat distributions with finite energy of the Higgs field around compact objects. Moreover, spontaneous scalarization is strongly amplified for specific values of their mass and compactness.
NASA Technical Reports Server (NTRS)
1963-01-01
The Saturn I (SA-4) flight lifted off from Kennedy Space Center launch Complex 34, March 28, 1963. The fourth launch of Saturn launch vehicles developed at the Marshall Space Flight Center (MSFC), under the direction of Dr. Wernher von Braun, incorporated a Saturn I, Block I engine. The typical height of a Block I vehicle was approximately 163 feet and had only one live stage. It consisted of eight tanks, each 70 inches in diameter, clustered around a central tank, 105 inches in diameter. Four of the external tanks were fuel tanks for the RP-1 (kerosene) fuel. The other four, spaced alternately with the fuel tanks, were liquid oxygen tanks as was the large center tank. All fuel tanks and liquid oxygen tanks drained at the same rates respectively. The thrust for the stage came from eight H-1 engines, each producing a thrust of 165,000 pounds, for a total thrust of over 1,300,000 pounds. The engines were arranged in a double pattern. Four engines, located inboard, were fixed in a square pattern around the stage axis and canted outward slightly, while the remaining four engines were located outboard in a larger square pattern offset 40 degrees from the inner pattern. Unlike the inner engines, each outer engine was gimbaled. That is, each could be swung through an arc. They were gimbaled as a means of steering the rocket, by letting the instrumentation of the rocket correct any deviations of its powered trajectory. The block I required engine gimabling as the only method of guiding and stabilizing the rocket through the lower atmosphere. The upper stages of the Block I rocket reflected the three-stage configuration of the Saturn I vehicle. Like SA-3, the SA-4 flight's upper stage ejected 113,560 liters (30,000 gallons) of ballast water in the upper atmosphere for 'Project Highwater' physics experiment. Release of this vast quantity of water in a near-space environment marked the second purely scientific large-scale experiment. The SA-4 was the last Block I rocket
NASA Technical Reports Server (NTRS)
1963-01-01
The Saturn I (SA-4) flight lifted off from Kennedy Space Center launch Complex 34, March 28, 1963. The fourth launch of Saturn launch vehicles, developed at the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun, incorporated a Saturn I, Block I engine. The typical height of a Block I vehicle was approximately 163 feet and had only one live stage. It consisted of eight tanks, each 70 inches in diameter, clustered around a central tank, 105 inches in diameter. Four of the external tanks were fuel tanks for the RP-1 (kerosene) fuel. The other four, spaced alternately with the fuel tanks, were liquid oxygen tanks as was the large center tank. All fuel tanks and liquid oxygen tanks drained at the same rates respectively. The thrust for the stage came from eight H-1 engines, each producing a thrust of 165,000 pounds, for a total thrust of over 1,300,000 pounds. The engines were arranged in a double pattern. Four engines, located inboard, were fixed in a square pattern around the stage axis and canted outward slightly, while the remaining four engines were located outboard in a larger square pattern offset 40 degrees from the inner pattern. Unlike the inner engines, each outer engine was gimbaled. That is, each could be swung through an arc. They were gimbaled as a means of steering the rocket, by letting the instrumentation of the rocket correct any deviations of its powered trajectory. The block I required engine gimabling as the only method of guiding and stabilizing the rocket through the lower atmosphere. The upper stages of the Block I rocket reflected the three-stage configuration of the Saturn I vehicle. Like SA-3, the SA-4 flight's upper stage ejected 113,560 liters (30,000 gallons) of ballast water in the upper atmosphere for 'Project Highwater' physics experiment. Release of this vast quantity of water in a near-space environment marked the second purely scientific large-scale experiment. The SA-4 was the last Block I rocket
Par Pond vegetation status Summer 1995 -- Summary
Mackey, H.E. Jr.; Riley, R.S.
1996-01-01
The water level of Par Pond was lowered approximately 20 feet in mid-1991 in order to protect downstream residents from possible dam failure suggested by subsidence on the downstream slope of the dam and to repair the dam. This lowering exposed both emergent and nonemergent macrophyte beds to drying conditions resulting in extensive losses. A survey of the newly emergent, shoreline aquatic plant communities of Par Pond began in June 1995, three months after the refilling of Par Pond to approximately 200 feet above mean sea level. These surveys continued in July, September, and late October, 1995. Communities similar to the pre-drawdown, Par Pond aquatic plant communities are becoming re-established. Emergent beds of maidencane, lotus, waterlily, and watershield are extensive and well developed. Cattail occurrence continued to increase during the summer, but large beds common to Par Pond prior to the drawdown have not formed. Estimates from SPOT HRV, remote sensing satellite data indicated that as much as 120 hectares of emergent wetlands vegetation may have been present along the Par Pond shoreline by early October, 1995. To track the continued development of macrophytes in Par Pond, future surveys throughout 1996 and 1997, along with the continued evaluation of satellite data to map the areal extent of the macrophyte beds of Par Pond, are planned.
On the Concepts of Vacuum and Mass and the Search for Higgs
NASA Astrophysics Data System (ADS)
Okun, L. B.
2012-12-01
This review gives some recollections on the recent history of the concepts of vacuum and mass and the search for higgs. According to the widely spread terminology, the Higgs field permeates vacuum and serves as the origin of masses of all fundamental particles including the Higgs boson — the higgs.
NASA Astrophysics Data System (ADS)
Dehkissia, Soumaine
Le projet de la these est defini par rapport a la recente exploitation commerciale du brut lourd de Doba, une region du Tchad, pays enclave d'ou le brut ainsi produit doit etre achemine par pipeline. Le but dans ce travail est de caracteriser ce brut et de determiner une strategie thermique de transformation en vue de reduire de la facon la plus economique, la viscosite du brut pour permettre son transport par pipeline. Concernant la partie caracterisation, nous avons utilise entre autres, un rheometre rotatif et des analyseurs (LECO CHN-2000 & LECO S-144DR Elemental Analyzers) pour evaluer respectivement la viscosite et les elements tels que C, H, N, O, S. Sur la base des methodes de transformation disponibles, nous avons determine une strategie simple de transformation thermique par hydroviscoreduction , strategie dans laquelle, la fraction legere du brut comme le naphta (80--180°C), pourrait constituer la source d'hydrogene a utiliser. Le brut de Doba, a une faible teneur en soufre (0.14%) et sa densite specifique de 0.940 a 15.6°C, soit 18.8° API, le classe parmi les bruts lourds. Outre le point initial se situant a 85°C, la distillation du brut a revele que la fraction distillant avant 250°C ne represente que 10% (v/v) et que le craquage thermique du substrat debute a 300°C. Par ailleurs, outre son caractere Newtonien, les densites specifiques de la fraction lourde de l'essence (100--200°C) et de la fraction distillant au-dessus 350°C, etant respectivement de 0.813 (0.813 > 0.800) et de 0.951 (0.930 < 0.951 < 0.975), le brut de Doba est donc de type aromatique. Les viscosites du brut et du brut desasphalte, sont respectivement de 184.4 cSt et 152.4 cSt a 50°C, suggerant que le desasphaltage ne constitue pas une methode efficace pouvant aider au pompage du brut par pipeline, d'ou la necessite de transformation. Les resultats des travaux en autoclave montrent que, si le brut doit etre traite entierement, la viscosite de 25cSt 50°C, recommandee pour le
Novel Higgs decay signals in R-parity violating models
Sierra, D. Aristizabal; Porod, W.; Restrepo, D.; Yaguna, Carlos E.
2008-07-01
In supersymmetric models the lightest Higgs boson may decay with a sizable branching ratio into a pair of light neutralinos. We analyze such decays within the context of the minimal supersymmetric standard model with R-parity violation, where the neutralino itself is unstable and decays into standard model fermions. We show that the R-parity violating couplings induce novel Higgs decay signals that might facilitate the discovery of the Higgs boson at colliders. At the LHC, the Higgs may be observed, for instance, through its decay--via two neutralinos--into final states containing missing energy and isolated charged leptons such as l{sup {+-}}l{sup {+-}}, l{sup {+-}}l{sup {+-}}, 3l, and 4l. Another promising possibility is the search for the displaced vertices associated with the neutralino decay. We also point out that Higgs searches at the LHC might additionally provide the first evidence of R-parity violation.
Leptogenesis, radiative neutrino masses and inert Higgs triplet dark matter
Lu, Wen-Bin; Gu, Pei-Hong
2016-05-18
We extend the standard model by three types of inert fields including Majorana fermion singlets/triplets, real Higgs singlets/triplets and leptonic Higgs doublets. In the presence of a softly broken lepton number and an exactly conserved Z{sub 2} discrete symmetry, these inert fields together can mediate a one-loop diagram for a Majorana neutrino mass generation. The heavier inert fields can decay to realize a successful leptogenesis while the lightest inert field can provide a stable dark matter candidate. As an example, we demonstrate the leptogenesis by the inert Higgs doublet decays. We also perform a systematic study on the inert Higgs triplet dark matter scenario where the interference between the gauge and Higgs portal interactions can significantly affect the dark matter properties.
Eternal Higgs inflation and the cosmological constant problem
NASA Astrophysics Data System (ADS)
Hamada, Yuta; Kawai, Hikaru; Oda, Kin-ya
2015-08-01
We investigate the Higgs potential beyond the Planck scale in the superstring theory, under the assumption that the supersymmetry is broken at the string scale. We identify the Higgs field as a massless state of the string, which is indicated by the fact that the bare Higgs mass can be zero around the string scale. We find that, in the large field region, the Higgs potential is connected to a runaway vacuum with vanishing energy, which corresponds to opening up an extra dimension. We verify that such universal behavior indeed follows from the toroidal compactification of the nonsupersymmetric S O (16 )×S O (16 ) heterotic string theory. We show that this behavior fits in the picture that the Higgs field is the source of the eternal inflation. The observed small value of the cosmological constant of our universe may be understood as the degeneracy with this runaway vacuum, which has vanishing energy, as is suggested by the multiple point criticality principle.
Same-sign W pair production in composite Higgs models
NASA Astrophysics Data System (ADS)
Englert, Christoph; Schichtel, Peter; Spannowsky, Michael
2017-03-01
Nonminimal composite Higgs scenarios can contain exotic Higgs states which, if observed at the Large Hadron Collider, will help to constrain the underlying UV structure of the strong dynamics. Doubly charged Higgs bosons are well-motivated scalar degrees of freedom in this context. Their phenomenology in typical composite scenarios can differ from well-established Higgs triplet extensions of the SM. Related search strategies are not necessarily adapted to such a scenario as a consequence. In this paper we discuss the sensitivity reach to doubly charged Higgs bosons with decays into pairs of same-sign W bosons. While production cross sections are small, we show that significant constraints on H±±→W±W± can be obtained, providing a new opportunity to constrain the potential composite structure of the TeV scale up to mH±±≃800 GeV .
Diffractive Higgs boson photoproduction in {gamma}p process
Ducati, M. B. Gay; Silveira, G. G.
2008-12-01
We explore an alternative process for diffractive Higgs boson production in peripheral pp collisions arising from double Pomeron exchange in photon-proton interaction. We introduce the impact factor formalism in order to enable the gluon ladder exchange in the photon-proton subprocess, and to permit central Higgs production. The event rate for diffractive Higgs production in central rapidity is estimated to be about 0.6 pb at Tevatron and LHC energies. This result is higher than predictions from other approaches of diffractive Higgs production, showing that the alternative production process leads to an enhanced signal for the detection of the Higgs boson at hadron colliders. Our results are compared with those obtained from a similar approach proposed by the Durham Group. In this way, we may examine future developments in its application to pp and AA collisions.
Constraints on the trilinear Higgs self coupling from precision observables
NASA Astrophysics Data System (ADS)
Degrassi, G.; Fedele, M.; Giardino, P. P.
2017-04-01
We present the constraints on the trilinear Higgs self coupling that arise from loop effects in the W boson mass and the effective sine predictions. We compute the contributions to these precision observables of two-loop diagrams featuring an anomalous trilinear Higgs self coupling. We explicitly show that the same anomalous contributions are found if the analysis of m W and sin2 θ eff lep is performed in a theory in which the scalar potential in the Standard Model Lagrangian is modified by an (in)finite tower of (Φ†Φ) n terms with Φ the Higgs doublet. We find that the bounds on the trilinear Higgs self coupling from precision observables are competitive with those coming from Higgs pair production.
Creating the fermion mass hierarchies with multiple Higgs bosons
NASA Astrophysics Data System (ADS)
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 .
Higgs Mode in a Trapped Superfluid Fermi Gas
NASA Astrophysics Data System (ADS)
Tokimoto, Jun; Tsuchiya, Shunji; Nikuni, Tetsuro
2017-03-01
In quantum many-body systems with spontaneous breaking of a continuous symmetry, Higgs modes emerge as collective amplitude oscillations of order parameters. Recently, Higgs modes have been observed in superconductors and in Bose gases in optical lattices. However, it has yet to be observed in Fermi gases. In the present paper, we use the time-dependent Bogoliubov-de Gennes equations to investigate Higgs amplitude oscillations of the superfluid order parameter in a trapped Fermi gas induced by a sudden changes of the { s} -wave scattering length. In particular, we investigate the Higgs mode with different values of the initial scattering length and discuss how the frequency and damping of the Higgs mode changes around the unitarity regime.
Search for neutral MSSM Higgs bosons at LEP
NASA Astrophysics Data System (ADS)
Schael, S.; Barate, R.; Brunelière, R.; de Bonis, I.; Decamp, D.; Goy, C.; Jézéquel, S.; Lees, J.-P.; Martin, F.; Merle, E.; Minard, M.-N.; Pietrzyk, B.; Trocmé, B.; Bravo, S.; Casado, M. P.; Chmeissani, M.; Crespo, J. M.; Fernandez, E.; Fernandez-Bosman, M.; Garrido, L.; Martinez, M.; Pacheco, A.; Ruiz, H.; Colaleo, A.; Creanza, D.; de Filippis, N.; de Palma, M.; Iaselli, G.; Maggi, G.; Maggi, M.; Nuzzo, S.; Ranieri, A.; Raso, G.; Ruggieri, F.; Selvaggi, G.; Silvestris, L.; Tempesta, P.; Tricomi, A.; Zito, G.; Huang, X.; Lin, J.; Ouyang, Q.; Wang, T.; Xie, Y.; Xu, R.; Xue, S.; Zhang, J.; Zhang, L.; Zhao, W.; Abbaneo, D.; Barklow, T.; Buchmüller, O.; Cattaneo, M.; Clerbaux, B.; Drevermann, H.; Forty, R. W.; Frank, M.; Gianotti, F.; Hansen, J. B.; Harvey, J.; Hutchcroft, D. E.; Janot, P.; Jost, B.; Kado, M.; Mato, P.; Moutoussi, A.; Ranjard, F.; Rolandi, L.; Schlatter, D.; Teubert, F.; Valassi, A.; Videau, I.; Badaud, F.; Dessagne, S.; Falvard, A.; Fayolle, D.; Gay, P.; Jousset, J.; Michel, B.; Monteil, S.; Pallin, D.; Pascolo, J. M.; Perret, P.; Hansen, J. D.; Hansen, J. R.; Hansen, P. H.; Kraan, A. C.; Nilsson, B. S.; Kyriakis, A.; Markou, C.; Simopoulou, E.; Vayaki, A.; Zachariadou, K.; Blondel, A.; Brient, J.-C.; Machefert, F.; Rougé, A.; Videau, H.; Ciulli, V.; Focardi, E.; Parrini, G.; Antonelli, A.; Antonelli, M.; Bencivenni, G.; Bossi, F.; Capon, G.; Cerutti, F.; Chiarella, V.; Mannocchi, G.; Laurelli, P.; Mannocchi, G.; Murtas, G. P.; Passalacqua, L.; Kennedy, J.; Lynch, J. G.; Negus, P.; O'Shea, V.; Thompson, A. S.; Wasserbaech, S.; Cavanaugh, R.; Dhamotharan, S.; Geweniger, C.; Hanke, P.; Hepp, V.; Kluge, E. E.; Putzer, A.; Stenzel, H.; Tittel, K.; Wunsch, M.; Beuselinck, R.; Cameron, W.; Davies, G.; Dornan, P. J.; Girone, M.; Marinelli, N.; Nowell, J.; Rutherford, S. A.; Sedgbeer, J. K.; Thompson, J. C.; White, R.; Ghete, V. M.; Girtler, P.; Kneringer, E.; Kuhn, D.; Rudolph, G.; Bouhova-Thacker, E.; Bowdery, C. K.; Clarke, D. P.; Ellis, G.; Finch, A. J.; Foster, F.; Hughes, G.; Jones, R. W. L.; Pearson, M. R.; Robertson, N. A.; Smizanska, M.; van der Aa, O.; Delaere, C.; Leibenguth, G.; Lemaitre, V.; Blumenschein, U.; Hölldorfer, F.; Jakobs, K.; Kayser, F.; Müller, A.-S.; Renk, B.; Sander, H.-G.; Schmeling, S.; Wachsmuth, H.; Zeitnitz, C.; Ziegler, T.; Bonissent, A.; Coyle, P.; Curtil, C.; Ealet, A.; Fouchez, D.; Payre, P.; Tilquin, A.; Ragusa, F.; David, A.; Dietl, H.; Ganis, G.; Hüttmann, K.; Lütjens, G.; Männer, W.; Moser, H.-G.; Settles, R.; Villegas, M.; Wolf, G.; Boucrot, J.; Callot, O.; Davier, M.; Duflot, L.; Grivaz, J.-F.; Heusse, P.; Jacholkowska, A.; Serin, L.; Veillet, J.-J.; Azzurri, P.; Bagliesi, G.; Boccali, T.; Foà, L.; Giammanco, A.; Giassi, A.; Ligabue, F.; Messineo, A.; Palla, F.; Sanguinetti, G.; Sciabà, A.; Sguazzoni, G.; Spagnolo, P.; Tenchini, R.; Venturi, A.; Verdini, P. G.; Awunor, O.; Blair, G. A.; Cowan, G.; Garcia-Bellido, A.; Green, M. G.; Medcalf, T.; Misiejuk, A.; Strong, J. A.; Teixeira-Dias, P.; Clifft, R. W.; Edgecock, T. R.; Norton, P. R.; Tomalin, I. R.; Ward, J. J.; Bloch-Devaux, B.; Boumediene, D.; Colas, P.; Fabbro, B.; Lançon, E.; Lemaire, M.-C.; Locci, E.; Perez, P.; Rander, J.; Tuchming, B.; Vallage, B.; Litke, A. M.; Taylor, G.; Booth, C. N.; Cartwright, S.; Combley, F.; Hodgson, P. N.; Lehto, M.; Thompson, L. F.; Böhrer, A.; Brandt, S.; Grupen, C.; Hess, J.; Ngac, A.; Prange, G.; Borean, C.; Giannini, G.; He, H.; Putz, J.; Rothberg, J.; Armstrong, S. R.; Berkelman, K.; Cranmer, K.; Ferguson, D. P. S.; Gao, Y.; González, S.; Hayes, O. J.; Hu, H.; Jin, S.; Kile, J.; McNamara, P. A., III; Nielsen, J.; Pan, Y. B.; von Wimmersperg-Toeller, J. H.; Wiedenmann, W.; Wu, J.; Wu, S. L.; Wu, X.; Zobernig, G.; Dissertori, G.; Abdallah, J.; Abreu, P.; Adam, W.; Adzic, P.; Albrecht, T.; Alderweireld, T.; Alemany-Fernandez, R.; Allmendinger, T.; Allport, P. P.; Amaldi, U.; Amapane, N.; Amato, S.; Anashkin, E.; Andreazza, A.; Andringa, S.; Anjos, N.; Antilogus, P.; Apel, W.-D.; Arnoud, Y.; Ask, S.; Asman, B.; Augustin, J. E.; Augustinus, A.; Baillon, P.; Ballestrero, A.; Bambade, P.; Barbier, R.; Bardin, D.; Barker, G. J.; Baroncelli, A.; Battaglia, M.; Baubillier, M.; Becks, K.-H.; Begalli, M.; Behrmann, A.; Ben-Haim, E.; Benekos, N.; Benvenuti, A.; Berat, C.; Berggren, M.; Berntzon, L.; Bertrand, D.; Besancon, M.; Besson, N.; Bloch, D.; Blom, M.; Bluj, M.; Bonesini, M.; Boonekamp, M.; Booth, P. S. L.; Borisov, G.; Botner, O.; Bouquet, B.; Bowcock, T. J. V.; Boyko, I.; Bracko, M.; Brenner, R.; Brodet, E.; Bruckman, P.; Brunet, J. M.; Buschbeck, B.; Buschmann, P.; Calvi, M.; Camporesi, T.; Canale, V.; Carena, F.; Castro, N.; Cavallo, F.; Chapkin, M.; Charpentier, P.; Checchia, P.; Chierici, R.; Chliapnikov, P.; Chudoba, J.; Chung, S. U.; Cieslik, K.; Collins, P.; Contri, R.; Cosme, G.; Cossutti, F.; Costa, M. J.; Crennell, D.; Cuevas, J.; D'Hondt, J.; Dalmau, J.; da Silva, T.; da Silva, W.; Della Ricca, G.; de Angelis, A.; de Boer, W.; de Clercq, C.; de Lotto, B.; de Maria, N.; de Min, A.; de Paula, L.; di Ciaccio, L.; di Simone, A.; Doroba, K.; Drees, J.; Eigen, G.; Ekelof, T.; Ellert, M.; Elsing, M.; Espirito Santo, M. C.; Fanourakis, G.; Fassouliotis, D.; Feindt, M.; Fernandez, J.; Ferrer, A.; Ferro, F.; Flagmeyer, U.; Foeth, H.; Fokitis, E.; Fulda-Quenzer, F.; Fuster, J.; Gandelman, M.; Garcia, C.; Gavillet, P.; Gazis, E.; Gokieli, R.; Golob, B.; Gomez-Ceballos, G.; Goncalves, P.; Graziani, E.; Grosdidier, G.; Grzelak, K.; Guy, J.; Haag, C.; Hallgren, A.; Hamacher, K.; Hamilton, K.; Haug, S.; Hauler, F.; Hedberg, V.; Hennecke, M.; Herr, H.; Hoffman, J.; Holmgren, S.-O.; Holt, P. J.; Houlden, M. A.; Hultqvist, K.; Jackson, J. N.; Jarlskog, G.; Jarry, P.; Jeans, D.; Johansson, E. K.; Johansson, P. D.; Jonsson, P.; Joram, C.; Jungermann, L.; Kapusta, F.; Katsanevas, S.; Katsoufis, E.; Kernel, G.; Kersevan, B. P.; Kerzel, U.; King, B. T.; Kjaer, N. J.; Kluit, P.; Kokkinias, P.; Kourkoumelis, C.; Kouznetsov, O.; Krumstein, Z.; Kucharczyk, M.; Lamsa, J.; Leder, G.; Ledroit, F.; Leinonen, L.; Leitner, R.; Lemonne, J.; Lepeltier, V.; Lesiak, T.; Liebig, W.; Liko, D.; Lipniacka, A.; Lopes, J. H.; Lopez, J. M.; Loukas, D.; Lutz, P.; Lyons, L.; MacNaughton, J.; Malek, A.; Maltezos, S.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J.-C.; Mariotti, C.; Markou, A.; Martinez-Rivero, C.; Masik, J.; Mastroyiannopoulos, N.; Matorras, F.; Matteuzzi, C.; Mazzucato, F.; Mazzucato, M.; Mc Nulty, R.; Meroni, C.; Migliore, E.; Mitaroff, W.; Mjoernmark, U.; Moa, T.; Moch, M.; Moenig, K.; Monge, R.; Montenegro, J.; Moraes, D.; Moreno, S.; Morettini, P.; Mueller, U.; Muenich, K.; Mulders, M.; Mundim, L.; Murray, W.; Muryn, B.; Myatt, G.; Myklebust, T.; Nassiakou, M.; Navarria, F.; Nawrocki, K.; Nicolaidou, R.; Nikolenko, M.; Oblakowska-Mucha, A.; Obraztsov, V.; Olshevski, A.; Onofre, A.; Orava, R.; Osterberg, K.; Ouraou, A.; Oyanguren, A.; Paganoni, M.; Paiano, S.; Palacios, J. P.; Palka, H.; Papadopoulou, T. D.; Pape, L.; Parkes, C.; Parodi, F.; Parzefall, U.; Passeri, A.; Passon, O.; Peralta, L.; Perepelitsa, V.; Perrotta, A.; Petrolini, A.; Piedra, J.; Pieri, L.; Pierre, F.; Pimenta, M.; Piotto, E.; Podobnik, T.; Poireau, V.; Pol, M. E.; Polok, G.; Pozdniakov, V.; Pukhaeva, N.; Pullia, A.; Rames, J.; Read, A.; Rebecchi, P.; Rehn, J.; Reid, D.; Reinhardt, R.; Renton, P.; Richard, F.; Ridky, J.; Rivero, M.; Rodriguez, D.; Romero, A.; Ronchese, P.; Roudeau, P.; Rovelli, T.; Ruhlmann-Kleider, V.; Ryabtchikov, D.; Sadovsky, A.; Salmi, L.; Salt, J.; Sander, C.; Savoy-Navarro, A.; Schwickerath, U.; Segar, A.; Sekulin, R.; Siebel, M.; Sisakian, A.; Smadja, G.; Smirnova, O.; Sokolov, A.; Sopczak, A.; Sosnowski, R.; Spassov, T.; Stanitzki, M.; Stocchi, A.; Strauss, J.; Stugu, B.; Szczekowski, M.; Szeptycka, M.; Szumlak, T.; Tabarelli, T.; Taffard, A. C.; Tegenfeldt, F.; Timmermans, J.; Tkatchev, L.; Tobin, M.; Todorovova, S.; Tome, B.; Tonazzo, A.; Tortosa, P.; Travnicek, P.; Treille, D.; Tristram, G.; Trochimczuk, M.; Troncon, C.; Turluer, M.-L.; Tyapkin, I. A.; Tyapkin, P.; Tzamarias, S.; Uvarov, V.; Valenti, G.; van Dam, P.; van Eldik, J.; van Remortel, N.; van Vulpen, I.; Vegni, G.; Veloso, F.; Venus, W.; Verdier, P.; Verzi, V.; Vilanova, D.; Vitale, L.; Vrba, V.; Wahlen, H.; Washbrook, A. J.; Weiser, C.; Wicke, D.; Wickens, J.; Wilkinson, G.; Winter, M.; Witek, M.; Yushchenko, O.; Zalewska, A.; Zalewski, P.; Zavrtanik, D.; Zhuravlov, V.; Zimin, N. I.; Zintchenko, A.; Zupan, M.; Achard, P.; Adriani, O.; Aguilar-Benitez, M.; Alcaraz, J.; Alemanni, G.; Allaby, J.; Aloisio, A.; Alviggi, M. G.; Anderhub, H.; Andreev, V. P.; Anselmo, F.; Arefiev, A.; Azemoon, T.; Aziz, T.; Bagnaia, P.; Bajo, A.; Baksay, G.; Baksay, L.; Baldew, S. V.; Banerjee, S.; Banerjee, Sw.; Barczyk, A.; Barillère, R.; Bartalini, P.; Basile, M.; Batalova, N.; Battiston, R.; Bay, A.; Becattini, F.; Becker, U.; Behner, F.; Bellucci, L.; Berbeco, R.; Berdugo, J.; Berges, P.; Bertucci, B.; Betev, B. L.; Biasini, M.; Biglietti, M.; Biland, A.; Blaising, J. J.; Blyth, S. C.; Bobbink, G. J.; Böhm, A.; Boldizsar, L.; Borgia, B.; Bottai, S.; Bourilkov, D.; Bourquin, M.; Braccini, S.; Branson, J. G.; Brochu, F.; Burger, J. D.; Burger, W. J.; Cai, X. D.; Capell, M.; Cara Romeo, G.; Carlino, G.; Cartacci, A.; Casaus, J.; Cavallari, F.; Cavallo, N.; Cecchi, C.; Cerrada, M.; Chamizo, M.; Chang, Y. H.; Chemarin, M.; Chen, A.; Chen, G.; Chen, G. M.; Chen, H. F.; Chen, H. S.; Chiefari, G.; Cifarelli, L.; Cindolo, F.; Clare, I.; Clare, R.; Coignet, G.; Colino, N.; Costantini, S.; de La Cruz, B.; Cucciarelli, S.; de Asmundis, R.; Déglon, P.; Debreczeni, J.; Degré, A.; Dehmelt, K.; Deiters, K.; Della Volpe, D.; Delmeire, E.; Denes, P.; Denotaristefani, F.; de Salvo, A.; Diemoz, M.; Dierckxsens, M.; Dionisi, C.; Dittmar, M.; Doria, A.; Dova, M. T.; Duchesneau, D.; Duda, M.; Echenard, B.; Eline, A.; El Hage, A.; El Mamouni, H.; Engler, A.; Eppling, F. J.; Extermann, P.; Falagan, M. A.; Falciano, S.; Favara, A.; Fay, J.; Fedin, O.; Felcini, M.; Ferguson, T.; Fesefeldt, H.; Fiandrini, E.; Field, J. H.; Filthaut, F.; Fisher, P. H.; Fisher, W.; Forconi, G.; Freudenreich, K.; Furetta, C.; Galaktionov, Yu.; Ganguli, S. N.; Garcia-Abia, P.; Gataullin, M.; Gentile, S.; Giagu, S.; Gong, Z. F.; Grenier, G.; Grimm, O.; Gruenewald, M. W.; Guida, M.; Gupta, V. K.; Gurtu, A.; Gutay, L. J.; Haas, D.; Hatzifotiadou, D.; Hebbeker, T.; Hervé, A.; Hirschfelder, J.; Hofer, H.; Hohlmann, M.; Holzner, G.; Hou, S. R.; Hu, J.; Jin, B. N.; Jindal, P.; Jones, L. W.; de Jong, P.; Josa-Mutuberría, I.; Kaur, M.; Kienzle-Focacci, M. N.; Kim, J. K.; Kirkby, J.; Kittel, W.; Klimentov, A.; König, A. C.; Kopal, M.; Koutsenko, V.; Kräber, M.; Kraemer, R. W.; Krüger, A.; Kunin, A.; Ladron de Guevara, P.; Laktineh, I.; Landi, G.; Lebeau, M.; Lebedev, A.; Lebrun, P.; Lecomte, P.; Lecoq, P.; Le Coultre, P.; Le Goff, J. M.; Leiste, R.; Levtchenko, M.; Levtchenko, P.; Li, C.; Likhoded, S.; Lin, C. H.; Lin, W. T.; Linde, F. L.; Lista, L.; Liu, Z. A.; Lohmann, W.; Longo, E.; Lu, Y. S.; Luci, C.; Luminari, L.; Lustermann, W.; Ma, W. G.; Malgeri, L.; Malinin, A.; Ma Na, C.; Mans, J.; Martin, J. P.; Marzano, F.; Mazumdar, K.; McNeil, R. R.; Mele, S.; Merola, L.; Meschini, M.; Metzger, W. J.; Mihul, A.; Milcent, H.; Mirabelli, G.; Mnich, J.; Mohanty, G. B.; Muanza, G. S.; Muijs, A. J. M.; Musicar, B.; Musy, M.; Nagy, S.; Natale, S.; Napolitano, M.; Nessi-Tedaldi, F.; Newman, H.; Nisati, A.; Novak, T.; Nowak, H.; Ofierzynski, R.; Organtini, G.; Pal, I.; Palomares, C.; Paolucci, P.; Paramatti, R.; Passaleva, G.; Patricelli, S.; Paul, T.; Pauluzzi, M.; Paus, C.; Pauss, F.; Pedace, M.; Pensotti, S.; Perret-Gallix, D.; Piccolo, D.; Pierella, F.; Pieri, M.; Pioppi, M.; Piroué, P. A.; Pistolesi, E.; Plyaskin, V.; Pohl, M.; Pojidaev, V.; Pothier, J.; Prokofiev, D.; Rahal-Callot, G.; Rahaman, M. A.; Raics, P.; Raja, N.; Ramelli, R.; Rancoita, P. G.; Ranieri, R.; Raspereza, A.; Razis, P.; Rembeczki, S.; Ren, D.; Rescigno, M.; Reucroft, S.; Riemann, S.; Riles, K.; Roe, B. P.; Romero, L.; Rosca, A.; Rosemann, C.; Rosenbleck, C.; Rosier-Lees, S.; Roth, S.; Rubio, J. A.; Ruggiero, G.; Rykaczewski, H.; Sakharov, A.; Saremi, S.; Sarkar, S.; Salicio, J.; Sanchez, E.; Schäfer, C.; Schegelsky, V.; Schopper, H.; Schotanus, D. J.; Sciacca, C.; Servoli, L.; Shevchenko, S.; Shivarov, N.; Shoutko, V.; Shumilov, E.; Shvorob, A.; Son, D.; Souga, C.; Spillantini, P.; Steuer, M.; Stickland, D. P.; Stoyanov, B.; Straessner, A.; Sudhakar, K.; Sultanov, G.; Sun, L. Z.; Sushkov, S.; Suter, H.; Swain, J. D.; Szillasi, Z.; Tang, X. W.; Tarjan, P.; Tauscher, L.; Taylor, L.; Tellili, B.; Teyssier, D.; Timmermans, C.; Ting, S. C. C.; Ting, S. M.; Tonwar, S. C.; Tóth, J.; Tully, C.; Tung, K. L.; Ulbricht, J.; Valente, E.; van de Walle, R. T.; Vasquez, R.; Vesztergombi, G.; Vetlitsky, I.; Viertel, G.; Vivargent, M.; Vlachos, S.; Vodopianov, I.; Vogel, H.; Vogt, H.; Vorobiev, I.; Vorobyov, A. A.; Wadhwa, M.; Wang, Q.; Wang, X. L.; Wang, Z. M.; Weber, M.; Wynhoff, S.; Xia, L.; Xu, Z. Z.; Yamamoto, J.; Yang, B. Z.; Yang, C. G.; Yang, H. J.; Yang, M.; Yeh, S. C.; Zalite, An.; Zalite, Yu.; Zhang, Z. P.; Zhao, J.; Zhu, G. Y.; Zhu, R. Y.; Zhuang, H. L.; Zichichi, A.; Zimmermann, B.; Zöller, M.; Abbiendi, G.; Ainsley, C.; Åkesson, P. F.; Alexander, G.; Allison, J.; Amaral, P.; Anagnostou, G.; Anderson, K. J.; Asai, S.; Axen, D.; Azuelos, G.; Bailey, I.; Barberio, E.; Barillari, T.; Barlow, R. J.; Batley, R. J.; Bechtle, P.; Behnke, T.; Bell, K. W.; Bell, P. J.; Bella, G.; Bellerive, A.; Benelli, G.; Bethke, S.; Biebel, O.; Boeriu, O.; Bock, P.; Boutemeur, M.; Braibant, S.; Brigliadori, L.; Brown, R. M.; Buesser, K.; Burckhart, H. J.; Campana, S.; Carnegie, R. K.; Carter, A. A.; Carter, J. R.; Chang, C. Y.; Charlton, D. G.; Ciocca, C.; Csilling, A.; Cuffiani, M.; Dado, S.; de Jong, S.; de Roeck, A.; de Wolf, E. A.; Desch, K.; Dienes, B.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I. P.; Etzion, E.; Fabbri, F.; Feld, L.; Ferrari, P.; Fiedler, F.; Fleck, I.; Ford, M.; Frey, A.; Gagnon, P.; Gary, J. W.; Gascon-Shotkin, S. M.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Giunta, M.; Goldberg, J.; Gross, E.; Grunhaus, J.; Gruwé, M.; Günther, P. O.; Gupta, A.; Hajdu, C.; Hamann, M.; Hanson, G. G.; Harel, A.; Hauschild, M.; Hawkes, C. M.; Hawkings, R.; Hemingway, R. J.; Herten, G.; Heuer, R. D.; Hill, J. C.; Hoffman, K.; Horváth, D.; Igo-Kemenes, P.; Ishii, K.; Jeremie, H.; Jost, U.; Jovanovic, P.; Junk, T. R.; Kanaya, N.; Kanzaki, J.; Karlen, D.; Kawagoe, K.; Kawamoto, T.; Keeler, R. K.; Kellogg, R. G.; Kennedy, B. W.; Kluth, S.; Kobayashi, T.; Kobel, M.; Komamiya, S.; Krämer, T.; Krieger, P.; von Krogh, J.; Kruger, K.; Kuhl, T.; Kupper, M.; Lafferty, G. D.; Landsman, H.; Lanske, D.; Layter, J. G.; Lellouch, D.; Letts, J.; Levinson, L.; Lillich, J.; Lloyd, S. L.; Loebinger, F. K.; Lu, J.; Ludwig, A.; Ludwig, J.; Mader, W.; Marcellini, S.; Martin, A. J.; Masetti, G.; Mashimo, T.; Mättig, P.; McKenna, J.; McPherson, R. A.; Meijers, F.; Menges, W.; Merritt, F. S.; Mes, H.; Meyer, N.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D. J.; Moed, S.; Mohr, W.; Mori, T.; Mutter, A.; Nagai, K.; Nakamura, I.; Nanjo, H.; Neal, H. A.; Nisius, R.; O'Neale, S. W.; Oh, A.; Oreglia, M. J.; Orito, S.; Pahl, C.; Pásztor, G.; Pater, J. R.; Pilcher, J. E.; Pinfold, J.; Plane, D. E.; Poli, B.; Pooth, O.; Przybycień, M.; Quadt, A.; Rabbertz, K.; Rembser, C.; Renkel, P.; Roney, J. M.; Rozen, Y.; Runge, K.; Sachs, K.; Saeki, T.; Sarkisyan, E. K. G.; Schaile, A. D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schörner-Sadenius, T.; Schröder, M.; Schumacher, M.; Scott, W. G.; Seuster, R.; Shears, T. G.; Shen, B. C.; Sherwood, P.; Skuja, A.; Smith, A. M.; Sobie, R.; Söldner-Rembold, S.; Spano, F.; Stahl, A.; Strom, D.; Ströhmer, R.; Tarem, S.; Tasevsky, M.; Teuscher, R.; Thomson, M. A.; Torrence, E.; Toya, D.; Tran, P.; Trigger, I.; Trócsányi, Z.; Tsur, E.; Turner-Watson, M. F.; Ueda, I.; Ujvári, B.; Vollmer, C. F.; Vannerem, P.; Vértesi, R.; Verzocchi, M.; Voss, H.; Vossebeld, J.; Ward, C. P.; Ward, D. R.; Watkins, P. M.; Watson, A. T.; Watson, N. K.; Wells, P. S.; Wengler, T.; Wermes, N.; Wilson, G. W.; Wilson, J. A.; Wolf, G.; Wyatt, T. R.; Yamashita, S.; Zer-Zion, D.; Zivkovic, L.; Heinemeyer, S.; Pilaftsis, A.; Weiglein, G.
2006-09-01
The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric standard model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are used to set upper bounds on the cross-sections of various Higgs-like event topologies. The results are interpreted within the MSSM in a number of “benchmark” models, including CP-conserving and CP-violating scenarios. These interpretations lead in all cases to large exclusions in the MSSM parameter space. Absolute limits are set on the parameter cosβ and, in some scenarios, on the masses of neutral Higgs bosons.
Standard model Higgs boson searches at CDF in Run II
Chuang, Shan-Huei; /Wisconsin U., Madison
2004-10-01
The SM Higgs boson has been searched in two channels: (1) q{bar q} {yields} WH {yields} {ell}{nu}b{bar b} for Higgs masses 110 < M{sub H} < 150 GeV and (2) gg {yields} H {yields} WW {yields} {ell}{nu}{ell}{nu} for 140 M{sub H} < 180 GeV, where {ell} {element_of} {l_brace}e,{mu}{r_brace}, using about 200 pb{sup -1} CDF Run II data. 95% C.L. limits on each Higgs production at Tevatron at {radical}s = 1.96 TeV were set as a function of Higgs mass by fitting the distribution of dijet mass (1) and dilepton azimuthal angular separation (2). They have significantly advanced the sensitivity to the SM Higgs boson cf. Run I.
Creating the fermion mass hierarchies with multiple Higgs bosons
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.
Constraints on the trilinear Higgs self coupling from precision observables
Degrassi, G.; Fedele, M.; Giardino, P. P.
2017-04-27
We present the constraints on the trilinear Higgs self coupling that arise from loop effects in the W boson mass and the effective sine predictions. Here, we compute the contributions to these precision observables of two-loop diagrams featuring an anomalous trilinear Higgs self coupling. We explicitly show that the same anomalous contributions are found if the analysis of mW and sin2θmore » $$lep\\atop{eff}$$ is performed in a theory in which the scalar potential in the Standard Model Lagrangian is modified by an (in)finite tower of (Φ†Φ)n terms with Φ the Higgs doublet. Lastly, we find that the bounds on the trilinear Higgs self coupling from precision observables are competitive with those coming from Higgs pair production.« less
Lepton flavor changing Higgs decays in the littlest Higgs model with T-parity
NASA Astrophysics Data System (ADS)
del Aguila, Francisco; Ametller, Lluis; Illana, Jose Ignacio; Santiago, Jose; Talavera, Pere; Vega-Morales, Roberto
2017-08-01
We calculate loop induced lepton flavor violating Higgs decays in the Littlest Higgs model with T-parity. We find that a finite amplitude is obtained only when all contributions from the T-odd lepton sector are included. This is in contrast to lepton flavor violating processes mediated by gauge bosons where the partners of the right-handed mirror leptons can be decoupled from the spectrum. These partners are necessary to cancel the divergence in the Higgs mass introduced by the mirror leptons but are otherwise unnecessary and assumed to be decoupled in previous phenomenological studies. Further-more, as we emphasize, including the partner leptons in the spectrum also introduces a new source of lepton flavor violation via their couplings to the physical pseudo-Goldstone electroweak triplet scalar. Although this extra source also affects lepton flavor changing gauge transitions, it decouples from these amplitudes in the limit of heavy mass for the partner leptons. We find that the corresponding Higgs branching ratio into taus and muons can be as large as ˜ 0.2 × 10-6 for T-odd masses of the order a few TeV, a demanding challenge even for the high luminosity LHC.
Exciting (the) Vacuum: Possible Manifestations of the Higgs particle at the LHC
David Kaplan
2016-07-12
The Higgs boson is the particle most anticipated at the LHC. However, there is currently no leading theory of electroweak symmetry breaking (and the 'Higgs mechanism'). The many possibilities suggest many ways the Higgs could appear in the detectors, some of which require non-standard search methods. I will review the current state of beyond the standard model physics and the implication for Higgs physics. I then discuss some non-standard Higgs decays and suggest (perhaps naive) new experimental strategies for detecting the Higgs in such cases. In some models, while part of the new physics at the weak scale would be visible, the Higgs would be nearly impossible to detect.
Yukawa textures and charged Higgs boson phenomenology in the type-III two-Higgs-doublet model
Diaz-Cruz, J. L.; Hernandez-Sanchez, J.; Moretti, S.; Noriega-Papaqui, R.; Rosado, A.
2009-05-01
We discuss the implications of assuming a four-zero Yukawa texture for the properties of the charged Higgs boson within the context of the general two-Higgs-doublet model of type III. We begin by presenting a detailed analysis of the charged Higgs boson couplings with heavy quarks and the resulting pattern for its decays. The production of charged Higgs bosons is also sensitive to the modifications of its couplings, so that we also evaluate the resulting effects on the top decay t{yields}bH{sup +} as well as on 'direct'cb{yields}H{sup +}+c.c. and 'indirect'qq,gg{yields}tbH{sup +}+c.c. production. A significant scope exists at the Large Hadron Collider for several H{sup {+-}} production and decay channels combined to enable one to distinguish between such a model and alternative two-Higgs-doublet scenarios.
Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-07
... Model SA-365N, SA- 365N1, AS-365N2, AS-365N3, SA-366G1, EC 155B, EC155B1, SA-365C, SA- 365C1, SA-365C2... of a Eurocopter Model EC 155 helicopter. That crack was caused by a progressive fatigue failure...-13965; Docket No. FAA-2005-20294; Directorate Identifier 2004-SW-39-AD. Applicability: Model EC...
Natural SUSY and the Higgs boson
Huang, Peisi
2014-01-01
Supersymmetry (SUSY) solves the hierarchy problem by introducing a super partner to each Standard Model(SM) particle. SUSY must be broken in nature, which means the fine-tuning is reintroduced to some level. Natural SUSY models enjoy low fine-tuning by featuring a small super potential parameter μ ~ 125 GeV, while the third generation squarks have mass less than 1.5 TeV. First and second generation sfermions can be at the multi-TeV level which yields a decoupling solution to the SUSY flavor and CP problem. However, models of Natural SUSY have difficulties in predicting a m{sub h} at 125 GeV, because the third generation is too light to give large radiative correction to the Higgs mass. The models of Radiative Natural SUSY (RNS) address this problem by allowing for high scale soft SUSY breaking Higgs mass m{sub Hu} > m{sub 0}, which leads to automatic cancellation by the Renormalization Group (RG) running effect. Coupled with the large mixing in the stop sector, RNS allows low fine-tuning at 3-10 % level and a 125 GeV SM-like Higgs. RNS can be reached at the LHC, and a linear collider. If the strong CP problem is solved by the Peccei-Quinn mechanism, then RNS accommodates mixed axion-Higgsino cold dark matter, where the Higgsino-like WIMPs, which in this case make up only a fraction of the relic abundance, can be detectable at future WIMP detectors.
Cosmological constraints on Higgs-dilaton inflation
NASA Astrophysics Data System (ADS)
Trashorras, Manuel; Nesseris, Savvas; García-Bellido, Juan
2016-09-01
We test the viability of the Higgs-dilaton model (HDM) compared to the evolving dark energy (w0waCDM ) model, in which the cosmological constant model Λ CDM is also nested, by using the latest cosmological data that include the cosmic microwave background temperature, polarization and lensing data from the Planck satellite (2015 data release), the BICEP and Keck Array experiments, the Type Ia supernovae from the JLA catalog, the baryon acoustic oscillations from CMASS, LOWZ and 6dF, the weak lensing data from the CFHTLenS survey, and the matter power spectrum measurements from the SDSS (data release 7). We find that the values of all cosmological parameters allowed by the Higgs-dilaton model inflation are well within the Planck satellite (2015 data release) constraints. In particular, we have that w0=-1.000 1-0.0074+0.0072 , wa=0.0 0-0.16+0.15, ns=0.969 3-0.0082+0.0083, αs=-0.00 1-0.014+0.013 and r0.05=0.002 5-0.0016+0.0017 (95.5% C.L.). We also place new stringent constraints on the couplings of the Higgs-dilaton model and we find that ξχ<0.00328 and ξh/√{λ }=5920 0-20000+30000 (95.5% C.L.). Furthermore, we report that the HDM is on slightly better footing than the w0waCDM model, as they both have practically the same chi-square, i.e. Δ χ2=χw0waCDM 2-χHDM2=0.18 , with the HDM model having two fewer parameters. Finally, Bayesian evidence favors equally the two models, with the HDM being preferred by the AIC and DIC information criteria.
Finding the Higgs boson through supersymmetry
Campos, F. de; Eboli, O. J. P.; Magro, M. B.; Restrepo, D.; Valle, J. W. F.
2009-07-01
The study of displaced vertices containing two b-jets may provide a double discovery at the Large Hadron Collider (LHC): we show how it may not only reveal evidence for supersymmetry, but also provide a way to uncover the Higgs boson necessary in the formulation of the electroweak theory in a large region of the parameter space. We quantify this explicitly using the simplest minimal supergravity model with bilinear breaking of R-parity, which accounts for the observed pattern of neutrino masses and mixings seen in neutrino oscillation experiments.
Waiting for the W and the Higgs
Tannenbaum, Michael J.
2016-10-06
The search for the left-handed W± bosons, the proposed quanta of the weak interaction, and the Higgs boson, which spontaneously breaks the symmetry of unification of electromagnetic and weak interactions, has driven elementary-particle physics research from the time that I entered college to the present and has led to many unexpected and exciting discoveries which revolutionized our view of subnuclear physics over that period. In this article I describe how these searches and discoveries have intertwined with my own career.
Search for Higgs shifts in white dwarfs
Onofrio, Roberto; Wegner, Gary A. E-mail: gary.a.wegner@dartmouth.edu
2014-08-20
We report on a search for differential shifts between electronic and vibronic transitions in carbon-rich white dwarfs BPM 27606 and Procyon B. The absence of differential shifts within the spectral resolution and taking into account systematic effects such as space motion and pressure shifts allows us to set the first upper bound of astrophysical origin on the coupling between the Higgs field and the Kreschmann curvature invariant. Our analysis provides the basis for a more general methodology to derive bounds to the coupling of long-range scalar fields to curvature invariants in an astrophysical setting complementary to the ones available from high-energy physics or table-top experiments.
Polarization test of Higgs spin and parity
Arash, Firooz
2015-04-10
Photon polarization measurements provide a model independent determination of the spin and the parity of the Higgs resonance. The test described here is based on very general principles and is completely independent of dynamical assumptions. A set of observables are identified that discriminate resonances with J{sup P} = 0{sup +}, 0{sup −}, 2{sup −} and 2{sup +}. Furthermore, the same set can be used to gain useful and important information on the magnitude of each helicity amplitude contributing to the gg → γγ process.
Theoretical Survey of Higgs Boson and Axions
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.
Waiting for the W. and the Higgs
NASA Astrophysics Data System (ADS)
Tannenbaum, M. J.
2016-12-01
The search for the left-handed W± bosons, the proposed quanta of the weak interaction, and the Higgs boson, which spontaneously breaks the symmetry of unification of electromagnetic and weak interactions, has driven elementary-particle physics research from the time that I entered college to the present and has led to many unexpected and exciting discoveries which revolutionized our view of subnuclear physics over that period. In this article I describe how these searches and discoveries have intertwined with my own career.
Solutions of the coupled Higgs field equations.
Talukdar, Benoy; Ghosh, Swapan K; Saha, Aparna; Pal, Debabrata
2013-07-01
By an appropriate choice for the phase of the complex nucleonic field and going over to the traveling coordinate, we reduce the coupled Higgs equations to the Hamiltonian form and treat the resulting equation using the dynamical system theory. We present a phase-space analysis of its stable points. The results of our study demonstrate that the equation can support both traveling- and standing-wave solutions. The traveling-wave solution appears in the form of a soliton and resides in the midst of doubly periodic standing-wave solutions.
L'analyse par activation de neutrons de réacteur
NASA Astrophysics Data System (ADS)
Meyer, G.
2003-02-01
Quand les neutrons traversent la matière, certains sont transmis sans interaction, les autres interagissent avec le milieu traversé par diffusion et par absorption. Ce phénomène d'absorption est utilisé pour se protéger des neutrons, mais aussi pour les détecter; il peut également être utilisé pour identifier les noyaux “absorbants" et ainsi analyser le milieu traversé. En effet par différentes réactions nucléaires (n,γ), (n,p), (n,α), (n,fission), on obtient des noyaux résiduels qui sont souvent radioactifs; on dit que l'échantillon est “activé". Si l'on connaît le rendement d'activation et donc le pourcentage de noyaux ainsi “transmutés", les mesures de radioactivité induite vont permettre de déterminer la composition de l'échantillon irradié. Cette méthode dite d'analyse par activation neutronique est pratiquée depuis la découverte du neutron. Elle a permis grâce à sa sélectivité et à sa sensibilité d'avoir accès au domaine des traces et des ultra-traces dans des champs d'application très divers comme la métallurgie, l'archéologie, la biologie, la géochimie etc...
Beyond SaGMRotI: Conversion to SaArb, SaSN, and SaMaxRot
Watson-Lamprey, J. A.; Boore, D.M.
2007-01-01
In the seismic design of structures, estimates of design forces are usually provided to the engineer in the form of elastic response spectra. Predictive equations for elastic response spectra are derived from empirical recordings of ground motion. The geometric mean of the two orthogonal horizontal components of motion is often used as the response value in these predictive equations, although it is not necessarily the most relevant estimate of forces within the structure. For some applications it is desirable to estimate the response value on a randomly chosen single component of ground motion, and in other applications the maximum response in a single direction is required. We give adjustment factors that allow converting the predictions of geometric-mean ground-motion predictions into either of these other two measures of seismic ground-motion intensity. In addition, we investigate the relation of the strike-normal component of ground motion to the maximum response values. We show that the strike-normal component of ground motion seldom corresponds to the maximum horizontal-component response value (in particular, at distances greater than about 3 km from faults), and that focusing on this case in exclusion of others can result in the underestimation of the maximum component. This research provides estimates of the maximum response value of a single component for all cases, not just near-fault strike-normal components. We provide modification factors that can be used to convert predictions of ground motions in terms of the geometric mean to the maximum spectral acceleration (SaMaxRot) and the random component of spectral acceleration (SaArb). Included are modification factors for both the mean and the aleatory standard deviation of the logarithm of the motions.
Singlet-like Higgs boson in the NMSSM
NASA Astrophysics Data System (ADS)
Jeong, Kwang Sik
2017-01-01
We study the properties of the singlet-like Higgs boson in the next-to-minimal supersymmetric standard model. Scalar mixing depends on the higgsino mass parameter and the coupling of the singlet to the Higgs bilinear in the superpotential, which are constrained by the Large Electron-Positron Collider bound on the chargino mass and the perturbativity of the model to high energy scales, respectively. Using the relations between these parameters and mixing angles, we examine how strongly the singlet-like Higgs boson can couple to the standard model sector depending on its mass. In this paper, we consider the case in which the observed 125-GeV Higgs boson has properties very close to those predicted in the standard model, for which the singlet-like Higgs boson couples to the standard model sector via mixing with the heavy doublet Higgs boson. Interestingly the mixing turns out to be large either if the singlet-like Higgs boson is below a few hundred GeV or if tan β is moderate or large.
Natural Alignment in the Two Higgs Doublet Model
NASA Astrophysics Data System (ADS)
Bhupal Dev, P. S.; Pilaftsis, Apostolos
2017-07-01
As the LHC Higgs data persistently suggest the couplings of the observed 125 GeV Higgs boson to be consistent with the Standard Model (SM) expectations, any extended Higgs sector must lead to the so-called SM alignment limit, where one of the Higgs bosons behaves exactly like that of the SM. In the context of the Two Higgs Doublet Model (2HDM), this alignment is often associated with either decoupling of the heavy Higgs sector or accidental cancellations in the 2HDM potential. We present a novel symmetry justification for ‘natural’ alignment without necessarily decoupling or fine-tuning. We show that there exist only three different symmetry realizations of the natural alignment scenario in 2HDM. We identify the 2HDM parameter space satisfying the natural alignment condition up to the Planck scale. We also analyze new collider signals for the heavy Higgs sector in the natural alignment limit, which dominantly lead to third-generation quarks in the final state and can serve as a useful observational tool during the Run-II phase of the LHC.
Nonstandard Yukawa couplings and Higgs portal dark matter
Bishara, Fady; Brod, Joachim; Uttayarat, Patipan; ...
2016-01-04
We study the implications of non-standard Higgs Yukawa couplings to light quarks on Higgs-portal dark matter phenomenology. Saturating the present experimental bounds on up-quark, down-quark, or strange-quark Yukawa couplings, the predicted direct dark matter detection scattering rate can increase by up to four orders of magnitude. The effect on the dark matter annihilation cross-section, on the other hand, is subleading unless the dark matter is very light — a scenario that is already excluded by measurements of the Higgs invisible decay width. We investigate the expected size of corrections in multi-Higgs-doublet models with natural flavor conservation, the type-II two-Higgs-doublet model,more » the Giudice-Lebedev model of light quark masses, minimal flavor violation new physics models, Randall-Sundrum, and composite Higgs models. We find that an enhancement in the dark matter scattering rate of an order of magnitude is possible. In conclusion, we point out that a discovery of Higgs-portal dark matter could lead to interesting bounds on the light-quark Yukawa couplings.« less
Nonstandard Yukawa couplings and Higgs portal dark matter
Bishara, Fady; Brod, Joachim; Uttayarat, Patipan; Zupan, Jure
2016-01-04
We study the implications of non-standard Higgs Yukawa couplings to light quarks on Higgs-portal dark matter phenomenology. Saturating the present experimental bounds on up-quark, down-quark, or strange-quark Yukawa couplings, the predicted direct dark matter detection scattering rate can increase by up to four orders of magnitude. The effect on the dark matter annihilation cross-section, on the other hand, is subleading unless the dark matter is very light — a scenario that is already excluded by measurements of the Higgs invisible decay width. We investigate the expected size of corrections in multi-Higgs-doublet models with natural flavor conservation, the type-II two-Higgs-doublet model, the Giudice-Lebedev model of light quark masses, minimal flavor violation new physics models, Randall-Sundrum, and composite Higgs models. We find that an enhancement in the dark matter scattering rate of an order of magnitude is possible. In conclusion, we point out that a discovery of Higgs-portal dark matter could lead to interesting bounds on the light-quark Yukawa couplings.
Improving fine-tuning in composite Higgs models
NASA Astrophysics Data System (ADS)
Banerjee, Avik; Bhattacharyya, Gautam; Ray, Tirtha Sankar
2017-08-01
In this paper we investigate the next-to-minimal composite Higgs model with a SO (6 ) /SO (5 ) coset, whose pseudo-Nambu-Goldstone boson sector includes a Standard Model singlet in addition to the usual Higgs doublet. The fermions are embedded in the representation 6 of SO(6). We study the region of parameter space of the model where the radiatively generated potential has global minima with both the doublet and the singlet fields developing vacuum expectation values. We investigate the consequences of kinetic and mass mixing between the Higgs and the singlet scalar that arise in this framework. We demonstrate that the ensuing doublet-singlet mixing can provide a handle to accommodate heavier resonances (top partners) for a given compositeness scale as compared to the minimal composite Higgs model, thus relaxing the tension with the direct LHC bounds. The main phenomenological consequence of this is a sizable deviation of the Higgs couplings from the Standard Model predictions. While the present experimental precision in the measurement of the Higgs couplings still allows for considerable release of this tension, future measurements of the Higgs branching ratios with increased precision would lead to stringent constraints on this setup.
Higgs-stoponium mixing near the stop-antistop threshold
NASA Astrophysics Data System (ADS)
Bodwin, Geoffrey T.; Chung, Hee Sok; Wagner, Carlos E. M.
2017-01-01
Supersymmetric extensions of the standard model contain additional heavy neutral Higgs bosons that are coupled to heavy scalar top quarks (stops). This system exhibits interesting field theoretic phenomena when the Higgs mass is close to the stop-antistop production threshold. Existing work in the literature has examined the digluon-to-diphoton cross section near threshold and has focused on enhancements in the cross section that might arise either from the perturbative contributions to the Higgs-to-digluon and Higgs-to-diphoton form factors or from mixing of the Higgs boson with stoponium states. Near threshold, enhancements in the relevant amplitudes that go as inverse powers of the stop-antistop relative velocity require resummations of perturbation theory and/or nonperturbative treatments. We present a complete formulation of threshold effects at leading order in the stop-antistop relative velocity in terms of nonrelativistic effective field theory. We give detailed numerical calculations for the case in which the stop-antistop Green's function is modeled with a Coulomb-Schrödinger Green's function. We find several general effects that do not appear in a purely perturbative treatment. Higgs-stop-antistop mixing effects displace physical masses from the threshold region, thereby rendering the perturbative threshold enhancements inoperative. In the case of large Higgs-stop-antistop couplings, the displacement of a physical state above threshold substantially increases its width, owing to its decay width to a stop-antistop pair, and greatly reduces its contribution to the cross section.
Phenomenology of a Flavorful Two Higgs Doublet Model
NASA Astrophysics Data System (ADS)
Tuckler, Douglas; Altmannshofer, Wolfgang; Eby, Joshua; Gori, Stefania; Lotito, Matteo; Martone, Mario
2017-01-01
The discovery of the Higgs boson in 2012 gave us the final piece of the SM, and since then there has been a large effort to understand its properties. Current experimental sensitivities allow us to probe the couplings of the Higgs to the 3rd generation of quarks and leptons, and measurements tell us that the Higgs is responsible for generating their mass. However, a lot less is known about the origin of mass of the 1st and 2nd generations: measurements of their couplings to the Higgs are out of experimental reach. With limited experimental sensitivities, one might be led to ask: is the origin of mass of the 1st and 2nd generation fermions due to the SM Higgs at all? In this talk, the idea that the mass of the 1st and 2nd generation fermions is not due to the SM Higgs, but a second source of electroweak symmetry breaking, is investigated. This can be realized simply by a two Higgs doublet model (2HDM), where one doublet couples mainly to the 3rd generations fermions while the second doublet couples mainly to the 1st and 2nd generation. We will see how a non-standard Yukawa texture leads to phenomenology that is markedly different from well studied 2HDMs, enhancing the collider signatures involving 2nd generation quarks and leptons.
LHC Higgs signatures from extended electroweak gauge symmetry
NASA Astrophysics Data System (ADS)
Abe, Tomohiro; Chen, Ning; He, Hong-Jian
2013-01-01
We study LHC Higgs signatures from the extended electroweak gauge symmetry SU(2) ⊗ SU(2) ⊗ U(1). Under this gauge structure, we present an effective UV completion of the 3-site moose model with ideal fermion delocalization, which contains two neutral Higgs states ( h, H) plus three new gauge bosons ( W ' , Z '). We study the unitarity, and reveal that the exact E 2 cancellation in the longitudinal V L V L scattering amplitudes is achieved by the joint role of exchanging both spin-1 new gauge bosons W ' /Z ' and spin-0 Higgs bosons h/H. We identify the lighter Higgs state h with mass 125 GeV, and derive the unitarity bound on the mass of heavier Higgs boson H. The parameter space of this model is highly predictive. We study the production and decay signals of this 125 GeV Higgs boson h at the LHC. We demonstrate that the h Higgs boson can naturally have enhanced signals in the diphoton channel gg → h → γγ, while the event rates in the reactions gg → h → W W ∗ and gg → h → ZZ ∗ are generally suppressed relative to the SM expectation. Searching the h Higgs boson via the associated production and the vector boson fusions are also discussed for our model. We further analyze the LHC signals of the heavier Higgs boson H as a new physics discriminator from the SM. For wide mass-ranges of H, we derive constraints from the existing LHC searches, and study the discovery potential of H at the LHC (8 TeV) and LHC (14 TeV).
Time-resolved study of Higgs mode in superconductors
NASA Astrophysics Data System (ADS)
Shimano, Ryo
The behavior of superconductors far from equilibrium has been intensively studied over decades. Goals of these studies are the elucidation of bosonic fluctuations essential for the pairing mechanisms, the manifestation of competing orders or hidden phases, and the optical manipulation of superconductivity. The study of collective modes is crucially important for these perspectives as it provides the information on the dynamics of order parameters in non-equilibirium states. Generally, collective modes in ordered phases associated with spontaneous symmetry breaking are classified into 1) gapless phase modes and 2) gapped amplitude modes. In superconductors, the phase mode is eaten by gauge field, according to the Anderson-Higgs mechanism. The remaining amplitude mode is recently termed as Higgs mode from its analogy to the Higgs boson in particle physics. Despite its long history of investigation, unambiguous observation of Higgs mode has remained elusive. This is because the Higgs mode does not have a charge nor electric dipole and therefore it does not couple directly to the electromagnetic field. Here we report on our recent observation of Higgs mode in s-wave superconductors by using THz-pump and THz-probe spectroscopy technique. After nonadiabatic excitation near the superconducting gap energy with monocycle THz pulses, Higgs mode was observed as oscillations in the transmission of THz probe pulse. The resonant nonlinear coupling between the Higgs mode and coherent radiation field was also discovered, resulting in an efficient third order harmonic generation of the incident THz radiation. The extension of experiments to multiband superconductors and unconventional superconductors will be discussed. Time-resolved study of Higgs mode in superconductors.
Higgs constraints from vector boson fusion and scattering
Campbell, John M.; Ellis, R. Keith
2015-04-07
We present results on 4-lepton + 2-jet production, the partonic processes most commonly described as vector boson pair production in the Vector Boson Fusion (VBF) mode. That final state contains diagrams that are mediated by Higgs boson exchange. We focus particularly on the high-mass behaviour of the Higgs boson mediated diagrams, which unlike on-shell production, gives information about the Higgs couplings without assumptions on the Higgs boson total width. We assess the sensitivity of the high-mass region to Higgs coupling strengths, considering all vector boson pair channels, W ^{- }W ^{+}, W ^{±} W ^{±}, W ^{±} Z and ZZ. Because of the small background, the most promising mode is W ^{+} W ^{+} which has sensitivity to Higgs couplings because of Higgs boson exchange in the t-channel. Furthermore, using the Caola-Melnikov (CM) method, the off-shell couplings can be interpreted as bounds on the Higgs boson total width. We estimate the bound that can be obtained with current data, as well as the bounds that could be obtained at √s=13 TeV in the VBF channel for data samples of 100 and 300 fb^{-1}. The CM method has already been successfully applied in the gluon fusion (GGF) production channel. The VBF production channel gives important complementary information, because both production and decay of the Higgs boson occur already at tree graph level.
Cosmological signals of a mirror twin Higgs
Craig, Nathaniel; Koren, Seth; Trott, Timothy
2017-05-08
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 ofmore » 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.« less
Inflection-point B -L Higgs inflation
NASA Astrophysics Data System (ADS)
Okada, Nobuchika; Raut, Digesh
2017-02-01
Inflection-point inflation is an interesting possibility to realize a successful slow-roll inflation when inflation is driven by a single scalar field with its initial value below the Planck mass (ϕI≲MPl). In order for a renormalization group (RG) improved effective λ ϕ4 potential to develop an inflection point, the quartic coupling λ (ϕ ) must exhibit a minimum with an almost vanishing value in its RG evolution, namely λ (ϕI)≃0 and βλ(ϕI)≃0 , where βλ is the beta function of the quartic coupling. As an example, we consider the minimal gauged B -L extended Standard Model at the TeV scale, where we identify the B -L Higgs field as the inflaton field. For a successful inflection-point inflation, which is consistent with the current cosmological observations, the mass ratios among the Z' gauge boson, the right-handed neutrinos and the B -L Higgs boson are fixed. Our scenario can be tested in the future collider experiments such as the high-luminosity LHC and the SHiP experiments. In addition, the inflection-point inflation provides a unique prediction for the running of the spectral index α ≃-2.7 ×10-3(60/N) 2 (N is the e -folding number), which can be tested in the near future.
Composite Higgs Dynamics on the Lattice
NASA Astrophysics Data System (ADS)
Pica, Claudio; Drach, Vincent; Hansen, Martin; Sannino, Francesco
2017-03-01
We investigate the spectrum of the SU(2) gauge theory with Nf = 2 flavors of fermions in the fundamental representation, in the continuum, using lattice simulations. This model provides a minimal template which has been used for different strongly coupled extensions of the Standard Model ranging from composite (Goldstone) Higgs models to intriguing types of dark matter candidates, such as the SIMPs. Here we will focus on the composite Goldstone Higgs paradigm, for which this model provides a minimal UV complete realization in terms of a new strong sector with fermionic matter. After introducing the relevant Lattice methods used in our simulations, we will discuss our numerical results. We show that this model features a SU(4)/Sp(4) SO(6)/SO(5) flavor symmetry breaking pattern, and estimate the value of its chiral condensate. Finally, we present our results for the mass spectrum of the lightest spin one and zero resonances, analogue to the QCD ρ, a1, σ η', a0, resonances, which are relevant for searches of new, exotic resonances at the LHC.
Top quark and neutrino composite Higgs bosons
NASA Astrophysics Data System (ADS)
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.
New spectra in the HEIDI Higgs models
NASA Astrophysics Data System (ADS)
van der Bij, J. J.; Puliçe, B.
2011-12-01
We study the so-called HEIDI models, which are renormalizable extensions of the standard model with a higher-dimensional scalar singlet field. As an additional parameter we consider a higher-dimensional mixing mass parameter. This leads to enriched possibilities compared to a previous study. We find effective spectral densities of the Higgs propagator, consisting of one, two or no particle peaks, together with a continuum. We compare with the LEP-2 data and determine for which range of the model parameters the data can be described. Assuming two peaks to be present we find for the new mass scale ν≈56±12 GeV, largely independent of the dimension. In the limiting case of d→6 and two peaks we find a higher-dimensional coupling constant α=0.70±0.18, indicative of strong interactions among the higher-dimensional fields. This Higgs might escape discovery at the LHC. That would provide a strong physics case for building a new lepton collider.
Search for doubly charged Higgs bosons at LEP2
NASA Astrophysics Data System (ADS)
DELPHI Collaboration; Abdallah, J.; Abreu, P.; Adam, W.; Adzic, P.; Albrecht, T.; Alderweireld, T.; Alemany-Fernandez, R.; Allmendinger, T.; Allport, P. P.; Amaldi, U.; Amapane, N.; Amato, S.; Anashkin, E.; Andreazza, A.; Andringa, S.; Anjos, N.; Antilogus, P.; Apel, W.-D.; Arnoud, Y.; Ask, S.; Asman, B.; Augustin, J. E.; Augustinus, A.; Baillon, P.; Ballestrero, A.; Bambade, P.; Barbier, R.; Bardin, D.; Barker, G.; Baroncelli, A.; Battaglia, M.; Baubillier, M.; Becks, K.-H.; Begalli, M.; Behrmann, A.; Ben-Haim, E.; Benekos, N.; Benvenuti, A.; Berat, C.; Berggren, M.; Berntzon, L.; Bertrand, D.; Besancon, M.; Besson, N.; Bloch, D.; Blom, M.; Bluj, M.; Bonesini, M.; Boonekamp, M.; Booth, P. S. L.; Borisov, G.; Botner, O.; Bouquet, B.; Bowcock, T. J. V.; Boyko, I.; Bracko, M.; Brenner, R.; Brodet, E.; Bruckman, P.; Brunet, J. M.; Bugge, L.; Buschmann, P.; Calvi, M.; Camporesi, T.; Canale, V.; Carena, F.; Castro, N.; Cavallo, F.; Chapkin, M.; Charpentier, Ph.; Checchia, P.; Chierici, R.; Chliapnikov, P.; Chudoba, J.; Chung, S. U.; Cieslik, K.; Collins, P.; Contri, R.; Cosme, G.; Cossutti, F.; Costa, M. J.; Crawley, B.; Crennell, D.; Cuevas, J.; D'Hondt, J.; Dalmau, J.; da Silva, T.; da Silva, W.; della Ricca, G.; de Angelis, A.; de Boer, W.; de Clercq, C.; de Lotto, B.; de Maria, N.; de Min, A.; de Paula, L.; di Ciaccio, L.; di Simone, A.; Doroba, K.; Drees, J.; Dris, M.; Eigen, G.; Ekelof, T.; Ellert, M.; Elsing, M.; Espirito Santo, M. C.; Fanourakis, G.; Fassouliotis, D.; Feindt, M.; Fernandez, J.; Ferrer, A.; Ferro, F.; Flagmeyer, U.; Foeth, H.; Fokitis, E.; Fulda-Quenzer, F.; Fuster, J.; Gandelman, M.; Garcia, C.; Gavillet, Ph.; Gazis, E.; Geralis, T.; Gokieli, R.; Golob, B.; Gomez-Ceballos, G.; Goncalves, P.; Graziani, E.; Grosdidier, G.; Grzelak, K.; Guy, J.; Haag, C.; Hallgren, A.; Hamacher, K.; Hamilton, K.; Hansen, J.; Haug, S.; Hauler, F.; Hedberg, V.; Hennecke, M.; Herr, H.; Hoffman, J.; Holmgren, S.-O.; Holt, P. J.; Houlden, M. A.; Hultqvist, K.; Jackson, J. N.; Jarlskog, G.; Jarry, P.; Jeans, D.; Johansson, E. K.; Johansson, P. D.; Jonsson, P.; Joram, C.; Jungermann, L.; Kapusta, F.; Katsanevas, S.; Katsoufis, E.; Kernel, G.; Kersevan, B. P.; Kiiskinen, A.; King, B. T.; Kjaer, N. J.; Kluit, P.; Kokkinias, P.; Kourkoumelis, C.; Kouznetsov, O.; Krumstein, Z.; Kucharczyk, M.; Lamsa, J.; Leder, G.; Ledroit, F.; Leinonen, L.; Leitner, R.; Lemonne, J.; Lepeltier, V.; Lesiak, T.; Liebig, W.; Liko, D.; Lipniacka, A.; Lopes, J. H.; Lopez, J. M.; Loukas, D.; Lutz, P.; Lyons, L.; MacNaughton, J.; Malek, A.; Maltezos, S.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J.-C.; Mariotti, C.; Markou, A.; Martinez-Rivero, C.; Masik, J.; Mastroyiannopoulos, N.; Matorras, F.; Matteuzzi, C.; Mazzucato, F.; Mazzucato, M.; Mc Nulty, R.; Meroni, C.; Meyer, W. T.; Migliore, E.; Mitaroff, W.; Mjoernmark, U.; Moa, T.; Moch, M.; Moenig, K.; Monge, R.; Montenegro, J.; Moraes, D.; Moreno, S.; Morettini, P.; Mueller, U.; Muenich, K.; Mulders, M.; Mundim, L.; Murray, W.; Muryn, B.; Myatt, G.; Myklebust, T.; Nassiakou, M.; Navarria, F.; Nawrocki, K.; Nicolaidou, R.; Nikolenko, M.; Oblakowska-Mucha, A.; Obraztsov, V.; Olshevski, A.; Onofre, A.; Orava, R.; Osterberg, K.; Ouraou, A.; Oyanguren, A.; Paganoni, M.; Paiano, S.; Palacios, J. P.; Palka, H.; Papadopoulou, Th. D.; Pape, L.; Parkes, C.; Parodi, F.; Parzefall, U.; Passeri, A.; Passon, O.; Peralta, L.; Perepelitsa, V.; Perrotta, A.; Petrolini, A.; Piedra, J.; Pieri, L.; Pierre, F.; Pimenta, M.; Piotto, E.; Podobnik, T.; Poireau, V.; Pol, M. E.; Polok, G.; Poropat, P.; Pozdniakov, V.; Pukhaeva, N.; Pullia, A.; Rames, J.; Ramler, L.; Read, A.; Rebecchi, P.; Rehn, J.; Reid, D.; Reinhardt, R.; Renton, P.; Richard, F.; Ridky, J.; Rivero, M.; Rodriguez, D.; Romero, A.; Ronchese, P.; Rosenberg, E.; Roudeau, P.; Rovelli, T.; Ruhlmann-Kleider, V.; Ryabtchikov, D.; Sadovsky, A.; Salmi, L.; Salt, J.; Savoy-Navarro, A.; Schwickerath, U.; Segar, A.; Sekulin, R.; Siebel, M.; Sisakian, A.; Smadja, G.; Smirnova, O.; Sokolov, A.; Sopczak, A.; Sosnowski, R.; Spassov, T.; Stanitzki, M.; Stocchi, A.; Strauss, J.; Stugu, B.; Szczekowski, M.; Szeptycka, M.; Szumlak, T.; Tabarelli, T.; Taffard, A. C.; Tegenfeldt, F.; Timmermans, J.; Tkatchev, L.; Tobin, M.; Todorovova, S.; Tomaradze, A.; Tome, B.; Tonazzo, A.; Tortosa, P.; Travnicek, P.; Treille, D.; Tristram, G.; Trochimczuk, M.; Troncon, C.; Turluer, M.-L.; Tyapkin, I. A.; Tyapkin, P.; Tzamarias, S.; Uvarov, V.; Valenti, G.; van Dam, P.; van Eldik, J.; van Lysebetten, A.; van Remortel, N.; van Vulpen, I.; Vegni, G.; Veloso, F.; Venus, W.; Verbeure, F.; Verdier, P.; Verzi, V.; Vilanova, D.; Vitale, L.; Vrba, V.; Wahlen, H.; Washbrook, A. J.; Weiser, C.; Wicke, D.; Wickens, J.; Wilkinson, G.; Winter, M.; Witek, M.; Yushchenko, O.; Zalewska, A.; Zalewski, P.; Zavrtanik, D.; Zimin, N. I.; Zintchenko, A.; Zupan, M.
2003-01-01
A search for pair-produced doubly charged Higgs bosons has been performed using the data collected by the DELPHI detector at LEP at centre-of-mass energies between 189 and 209 GeV. No excess is observed in the data with respect to the Standard Model background. A lower limit for the mass of 97.3 GeV/c2 at the 95% confidence level has been set for doubly charged Higgs bosons in left-right symmetric models for any value of the Yukawa coupling between the Higgs bosons and the /τ leptons.
Search for doubly charged Higgs bosons at LEP2
NASA Astrophysics Data System (ADS)
Abdallah, J.; Abreu, P.; Adam, W.; Adzic, P.; Albrecht, T.; Alderweireld, T.; Alemany-Fernandez, R.; Allmendinger, T.; Allport, P. P.; Amaldi, U.; Amapane, N.; Amato, S.; Anashkin, E.; Andreazza, A.; Andringa, S.; Anjos, N.; Antilogus, P.; Apel, W.-D.; Arnoud, Y.; Ask, S.; Asman, B.; Augustin, J. E.; Augustinus, A.; Baillon, P.; Ballestrero, A.; Bambade, P.; Barbier, R.; Bardin, D.; Barker, G.; Baroncelli, A.; Battaglia, M.; Baubillier, M.; Becks, K.-H.; Begalli, M.; Behrmann, A.; Ben-Haim, E.; Benekos, N.; Benvenuti, A.; Berat, C.; Berggren, M.; Berntzon, L.; Bertrand, D.; Besancon, M.; Besson, N.; Bloch, D.; Blom, M.; Bluj, M.; Bonesini, M.; Boonekamp, M.; Booth, P. S. L.; Borisov, G.; Botner, O.; Bouquet, B.; Bowcock, T. J. V.; Boyko, I.; Bracko, M.; Brenner, R.; Brodet, E.; Bruckman, P.; Brunet, J. M.; Bugge, L.; Buschmann, P.; Calvi, M.; Camporesi, T.; Canale, V.; Carena, F.; Castro, N.; Cavallo, F.; Chapkin, M.; Charpentier, Ph.; Checchia, P.; Chierici, R.; Chliapnikov, P.; Chudoba, J.; Chung, S. U.; Cieslik, K.; Collins, P.; Contri, R.; Cosme, G.; Cossutti, F.; Costa, M. J.; Crawley, B.; Crennell, D.; Cuevas, J.; D'Hondt, J.; Dalmau, J.; da Silva, T.; da Silva, W.; Della Ricca, G.; de Angelis, A.; de Boer, W.; de Clercq, C.; de Lotto, B.; de Maria, N.; de Min, A.; de Paula, L.; di Ciaccio, L.; di Simone, A.; Doroba, K.; Drees, J.; Dris, M.; Eigen, G.; Ekelof, T.; Ellert, M.; Elsing, M.; Espirito Santo, M. C.; Fanourakis, G.; Fassouliotis, D.; Feindt, M.; Fernandez, J.; Ferrer, A.; Ferro, F.; Flagmeyer, U.; Foeth, H.; Fokitis, E.; Fulda-Quenzer, F.; Fuster, J.; Gandelman, M.; Garcia, C.; Gavillet, Ph.; Gazis, E.; Geralis, T.; Gokieli, R.; Golob, B.; Gomez-Ceballos, G.; Goncalves, P.; Graziani, E.; Grosdidier, G.; Grzelak, K.; Guy, J.; Haag, C.; Hallgren, A.; Hamacher, K.; Hamilton, K.; Hansen, J.; Haug, S.; Hauler, F.; Hedberg, V.; Hennecke, M.; Herr, H.; Hoffman, J.; Holmgren, S.-O.; Holt, P. J.; Houlden, M. A.; Hultqvist, K.; Jackson, J. N.; Jarlskog, G.; Jarry, P.; Jeans, D.; Johansson, E. K.; Johansson, P. D.; Jonsson, P.; Joram, C.; Jungermann, L.; Kapusta, F.; Katsanevas, S.; Katsoufis, E.; Kernel, G.; Kersevan, B. P.; Kiiskinen, A.; King, B. T.; Kjaer, N. J.; Kluit, P.; Kokkinias, P.; Kourkoumelis, C.; Kouznetsov, O.; Krumstein, Z.; Kucharczyk, M.; Lamsa, J.; Leder, G.; Ledroit, F.; Leinonen, L.; Leitner, R.; Lemonne, J.; Lepeltier, V.; Lesiak, T.; Liebig, W.; Liko, D.; Lipniacka, A.; Lopes, J. H.; Lopez, J. M.; Loukas, D.; Lutz, P.; Lyons, L.; MacNaughton, J.; Malek, A.; Maltezos, S.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J.-C.; Mariotti, C.; Markou, A.; Martinez-Rivero, C.; Masik, J.; Mastroyiannopoulos, N.; Matorras, F.; Matteuzzi, C.; Mazzucato, F.; Mazzucato, M.; Mc Nulty, R.; Meroni, C.; Meyer, W. T.; Migliore, E.; Mitaroff, W.; Mjoernmark, U.; Moa, T.; Moch, M.; Moenig, K.; Monge, R.; Montenegro, J.; Moraes, D.; Moreno, S.; Morettini, P.; Mueller, U.; Muenich, K.; Mulders, M.; Mundim, L.; Murray, W.; Muryn, B.; Myatt, G.; Myklebust, T.; Nassiakou, M.; Navarria, F.; Nawrocki, K.; Nicolaidou, R.; Nikolenko, M.; Oblakowska-Mucha, A.; Obraztsov, V.; Olshevski, A.; Onofre, A.; Orava, R.; Osterberg, K.; Ouraou, A.; Oyanguren, A.; Paganoni, M.; Paiano, S.; Palacios, J. P.; Palka, H.; Papadopoulou, Th. D.; Pape, L.; Parkes, C.; Parodi, F.; Parzefall, U.; Passeri, A.; Passon, O.; Peralta, L.; Perepelitsa, V.; Perrotta, A.; Petrolini, A.; Piedra, J.; Pieri, L.; Pierre, F.; Pimenta, M.; Piotto, E.; Podobnik, T.; Poireau, V.; Pol, M. E.; Polok, G.; Poropat, P.; Pozdniakov, V.; Pukhaeva, N.; Pullia, A.; Rames, J.; Ramler, L.; Read, A.; Rebecchi, P.; Rehn, J.; Reid, D.; Reinhardt, R.; Renton, P.; Richard, F.; Ridky, J.; Rivero, M.; Rodriguez, D.; Romero, A.; Ronchese, P.; Rosenberg, E.; Roudeau, P.; Rovelli, T.; Ruhlmann-Kleider, V.; Ryabtchikov, D.; Sadovsky, A.; Salmi, L.; Salt, J.; Savoy-Navarro, A.; Schwickerath, U.; Segar, A.; Sekulin, R.; Siebel, M.; Sisakian, A.; Smadja, G.; Smirnova, O.; Sokolov, A.; Sopczak, A.; Sosnowski, R.; Spassov, T.; Stanitzki, M.; Stocchi, A.; Strauss, J.; Stugu, B.; Szczekowski, M.; Szeptycka, M.; Szumlak, T.; Tabarelli, T.; Taffard, A. C.; Tegenfeldt, F.; Timmermans, J.; Tkatchev, L.; Tobin, M.; Todorovova, S.; Tomaradze, A.; Tome, B.; Tonazzo, A.; Tortosa, P.; Travnicek, P.; Treille, D.; Tristram, G.; Trochimczuk, M.; Troncon, C.; Turluer, M.-L.; Tyapkin, I. A.; Tyapkin, P.; Tzamarias, S.; Uvarov, V.; Valenti, G.; van Dam, P.; van Eldik, J.; van Lysebetten, A.; van Remortel, N.; van Vulpen, I.; Vegni, G.; Veloso, F.; Venus, W.; Verbeure, F.; Verdier, P.; Verzi, V.; Vilanova, D.; Vitale, L.; Vrba, V.; Wahlen, H.; Washbrook, A. J.; Weiser, C.; Wicke, D.; Wickens, J.; Wilkinson, G.; Winter, M.; Witek, M.; Yushchenko, O.; Zalewska, A.; Zalewski, P.; Zavrtanik, D.; Zimin, N. I.; Zintchenko, A.; Zupan, M.; Delphi Collaboration
2003-01-01
A search for pair-produced doubly charged Higgs bosons has been performed using the data collected by the DELPHI detector at LEP at centre-of-mass energies between 189 and 209 GeV. No excess is observed in the data with respect to the Standard Model background. A lower limit for the mass of 97.3 GeV/c2 at the 95% confidence level has been set for doubly charged Higgs bosons in left-right symmetric models for any value of the Yukawa coupling between the Higgs bosons and the τ leptons.
Hunting the Elusive Higgs Boson and the Origin of Mass
Dixon, Lance
2007-12-11
For over 40 years, physicists have been trying to track down a hypothetical particle called the Higgs boson. This particle could explain how known elementary particles like the electron can have mass, and also why one of the basic forces, the weak interaction, is in fact so incredibly weak. However, the Higgs boson has escaped detection so far, even at the most powerful particle accelerators. The next big chance to 'bag' this particle will come when the Large Hadron Collider turns on next year. Will the Higgs boson finally be found? Or will an unexpected explanation for these mysteries be revealed?
The heavy Top Quark Partner in Little Higgs Models
Larios, F.; Perez, M. A.; Penunuri, F.
2008-07-02
Little Higgs models provide a natural explanation for the lightness of the Higgs mass. Through the mechanism of collective symmetry breaking, one loop quadratic divergent contributions to the Higgs mass are avoided. In these models a heavy partner of the Top quark appears as required to cancel out the Top's loop contribution. This heavy Top could be produced at the LHC mainly in the single mode. Because of flavor mixing a large FCNC gtT coupling can be generated at one loop that could boost the single T production mode through gg fusion.
Diffractive Higgs Production from Intrinsic Heavy Flavors in the Proton
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.
ISR effects for resonant Higgs production at future lepton colliders
NASA Astrophysics Data System (ADS)
Greco, Mario; Han, Tao; Liu, Zhen
2016-12-01
We study the effects of the initial state radiation on the s-channel Higgs boson resonant production at μ+μ- and e+e- colliders by convoluting with the beam energy spread profile of the collider and the Breit-Wigner resonance profile of the signal. We assess their impact on both the Higgs signal and SM backgrounds for the leading decay channels h → b b bar , WW*. Our study improves the existing analyses of the proposed future resonant Higgs factories and provides further guidance for the accelerator designs with respect to the physical goals.
Phenomenology of the left-right twin Higgs model
Goh, Hock-Seng; Goh, Hock-Seng; Su, Shufang
2006-11-02
The twin Higgs mechanism was proposed recently to solve the little hierarchy problem. We study the implementation of the twin Higgs mechanism in left-right models. At the TeV scale, heavy quark and gauge bosonsappear, with rich collider phenomenology. In addition, there are extra Higgs bosons, some of which couple to both the standard model fermion sector and the gauge sector, while others couple to the gauge bosons only. We present the particle spectrum and study the general features of the collider phenomenology of this class of model at the Large Hadron Collider.
A theorem on the Higgs sector of the Standard Model
NASA Astrophysics Data System (ADS)
Frasca, Marco
2016-06-01
We provide the solution of the classical theory for the Higgs sector of the Standard Model obtaining the exact Green's function for the broken phase. Solving the Dyson-Schwinger equations for the Higgs field we show that the propagator coincides with that of the classical theory confirming the spectrum also at the quantum level. In this way we obtain a proof of triviality using the Källen-Lehman representation. This has as a consequence that higher excited states must exist for the Higgs particle, representing an internal spectrum for it. Higher excited states have exponentially smaller amplitudes and, so, their production rates are significantly depressed.
Higgs-differential cross section at NNLO in dimensional regularisation
Dulat, Falko; Lionetti, Simone; Mistlberger, Bernhard; ...
2017-07-05
We present an analytic computation of the Higgs production cross section in the gluon fusion channel, which is differential in the components of the Higgs momentum and inclusive in the associated partonic radiation through NNLO in perturbative QCD. Our computation includes the necessary higher order terms in the dimensional regulator beyond the finite part that are required for renormalisation and collinear factorisation at N3LO. We outline in detail the computational methods which we employ. We present numerical predictions for realistic final state observables, specifically distributions for the decay products of the Higgs boson in the γγ decay channel.
Lepton Number Violation in Higgs Decay at LHC.
Maiezza, Alessio; Nemevšek, Miha; Nesti, Fabrizio
2015-08-21
We show that within the left-right symmetric model, lepton number violating decays of the Higgs boson can be discovered at the LHC. The process is due to the mixing of the Higgs boson with the triplet that breaks parity. As a result, the Higgs boson can act as a gateway to the origin of the heavy Majorana neutrino mass. To assess the LHC reach, a detailed collider study of the same-sign dileptons plus jets channel is provided. This process is complementary to the existing nuclear and collider searches for lepton number violation and can probe the scale of parity restoration even beyond other direct searches.
Multiple production of supersymmetric Higgs bosons in Z0 decays
NASA Astrophysics Data System (ADS)
Giudice, G. F.
1990-04-01
Multi-Higgs-boson production in Z0 decays is discussed in the context of low-energy supergravity models. For Higgs-boson masses lighter than about 20 GeV, Z0-->H02H02H03 naturally has a branching ratio in the range 10-4-10-6. Z0-->H02H02ll¯, where l is a neutral or charged lepton, has a branching ratio in the same range if mH2<10 GeV. Detection of these processes will give information about the structure of the Higgs sector and about the HHZZ and HHH couplings.
ISR effects for resonant Higgs production at future lepton colliders
Greco, Mario; Han, Tao; Liu, Zhen
2016-11-04
We study the effects of the initial state radiation on themore » $s$-channel Higgs boson resonant production at $$\\mu^+\\mu^-$$ and $e^+e^-$ colliders by convoluting with the beam energy spread profile of the collider and the Breit-Wigner resonance profile of the signal. We assess their impact on both the Higgs signal and SM backgrounds for the leading decay channels $$h\\rightarrow b\\bar b,\\ WW^*$$. In conclusion, our study improves the existing analyses of the proposed future resonant Higgs factories and provides further guidance for the accelerator designs with respect to the physical goals.« less
Hints for a nonstandard Higgs boson from the LHC
Raidal, Martti; Strumia, Alessandro
2011-10-01
We reconsider Higgs boson invisible decays into Dark Matter in the light of recent Higgs searches at the LHC. Present hints in the Compact Muon Solenoid and ATLAS data favor a nonstandard Higgs boson with approximately 50% invisible branching ratio, and mass around 143 GeV. This situation can be realized within the simplest thermal scalar singlet Dark Matter model, predicting a Dark Matter mass around 50 GeV and direct detection cross section just below present bound. The present runs of the Xenon100 and LHC experiments can test this possibility.
Searches for the standard model Higgs boson at the Tevatron
Dorigo, Tommaso; /Padua U.
2005-05-01
The CDF and D0 experiments at the Tevatron have searched for the Standard Model Higgs boson in data collected between 2001 and 2004. Upper limits have been placed on the production cross section times branching ratio to b{bar b} pairs or W{sup +}W{sup -} pairs as a function of the Higgs boson mass. projections indicate that the Tevatron experiments have a chance of discovering a M{sub H} = 115 GeV Higgs with the total dataset foreseen by 2009, or excluding it at 95% C.L. up to a mass of 135 GeV.
Determining triple gauge boson couplings from Higgs data.
Corbett, Tyler; Éboli, O J P; Gonzalez-Fraile, J; Gonzalez-Garcia, M C
2013-07-05
In the framework of effective Lagrangians with the SU(2)(L)×U(1)(Y) symmetry linearly realized, modifications of the couplings of the Higgs field to the electroweak gauge bosons are related to anomalous triple gauge couplings (TGCs). Here, we show that the analysis of the latest Higgs boson production data at the LHC and Tevatron give rise to strong bounds on TGCs that are complementary to those from direct TGC analysis. We present the constraints on TGCs obtained by combining all available data on direct TGC studies and on Higgs production analysis.
Threshold region for Higgs boson production in gluon fusion.
Bonvini, Marco; Forte, Stefano; Ridolfi, Giovanni
2012-09-07
We provide a quantitative determination of the effective partonic kinematics for Higgs boson production in gluon fusion in terms of the collider energy at the LHC. We use the result to assess, as a function of the Higgs boson mass, whether the large m(t) approximation is adequate and Sudakov resummation advantageous. We argue that our results hold to all perturbative orders. Based on our results, we conclude that the full inclusion of finite top mass corrections is likely to be important for accurate phenomenology for a light Higgs boson with m(H)~125 GeV at the LHC with √s=14 TeV.
Higgs-inflaton coupling from reheating and the metastable Universe
NASA Astrophysics Data System (ADS)
Gross, Christian; Lebedev, Oleg; Zatta, Marco
2016-02-01
Current Higgs boson and top quark data favor metastability of our vacuum which raises questions as to why the Universe has chosen an energetically disfavored state and remained there during inflation. In this Letter, we point out that these problems can be solved by a Higgs-inflaton coupling which appears in realistic models of inflation. Since an inflaton must couple to the Standard Model particles either directly or indirectly, such a coupling is generated radiatively, even if absent at tree level. As a result, the dynamics of the Higgs field can change dramatically.
NASA Astrophysics Data System (ADS)
Kanemura, Shinya; Kaneta, Kunio; Machida, Naoki; Odori, Shinya; Shindou, Tetsuo
2016-07-01
In the composite Higgs models, originally proposed by Georgi and Kaplan, the Higgs boson is a pseudo Nambu-Goldstone boson (pNGB) of spontaneous breaking of a global symmetry. In the minimal version of such models, global SO(5) symmetry is spontaneously broken to SO(4), and the pNGBs form an isospin doublet field, which corresponds to the Higgs doublet in the Standard Model (SM). Predicted coupling constants of the Higgs boson can in general deviate from the SM predictions, depending on the compositeness parameter. The deviation pattern is determined also by the detail of the matter sector. We comprehensively study how the model can be tested via measuring single and double production processes of the Higgs boson at the LHC and future electron-positron colliders. The possibility to distinguish the matter sector among the minimal composite Higgs models is also discussed. In addition, we point out differences in the cross section of double Higgs boson production from the prediction in other new physics models.
Higgs pair signal enhanced in the 2HDM with two degenerate 125 GeV Higgs bosons
NASA Astrophysics Data System (ADS)
Han, Xiao-Fang; Wang, Lei; Yang, Jin Min
2016-09-01
We discuss a scenario of the type-II two-Higgs-doublet model (2HDM) in which the bb¯γγ rate of the Higgs pair production is enhanced due to the two nearly degenerate 125 GeV Higgs bosons (h, H). Considering various theoretical and experimental constraints, we figure out the allowed ranges of the trilinear couplings of these two Higgs bosons and calculate the signal rate of bb¯γγ from the productions of Higgs pairs (hh, hH, HH) at the large hadron collider (LHC). We find that in the allowed parameter space some trilinear Higgs couplings can be larger than the Standard Model (SM) value by an order and the production rate of bb¯γγ can be greatly enhanced. We also consider a “decoupling” benchmark point where the light CP-even Higgs has a SM-like cubic self-coupling while other trilinear couplings are very small. With a detailed simulation on the bb¯γγ signal and backgrounds, we find that in such a “decoupling” scenario the hh and hH channels can jointly enhance the statistical significance to 5σ at 14 TeV LHC with an integrated luminosity of 3000 fb-1.
Comparative cactus architecture and par interception
Geller, G.N.; Nobel, P.S. )
1987-07-01
Because CO{sup 2} uptake by cacti can be limited by low levels of photosynthetically active radiation (PAR) and because plant form affects PAR interception, various cactus forms were studied using a computer model, field measurements, and laboratory phototropic studies. Model predictions indicated that CO{sub 2} uptake by individual stems at an equinox was greatest when the stem were vertical, but at the summer and the winter solstice CO{sub 2} uptake was greatest for stems titled 30{degree} away from the equator. Stem tilting depended on form and taxonomic group. Not only can the shape of cacti be affected by PAR, but also shape influences PAR interception and hence CO{sub 2} uptake.
Detecting multimuon jets from the Higgs boson exotic decays in the Higgs portal framework
NASA Astrophysics Data System (ADS)
Chang, Jung; Cheung, Kingman; Hsu, Shih-Chieh; Lu, Chih-Ting
2017-02-01
A muon jet (μ -jet) is a very special feature that consists of a cluster of collimated muons from the decay of a fast-moving light particle of mass about O (1 GeV ) . We will use this feature to search for very light particles from rare decays of the Higgs boson. For such a small angular separation of muons which might come from a long-lived particle, both ATLAS and CMS could have the displaced-vertexing-reconstruction capability. We use two simple models of the Higgs portal type to explore the possibilities of event topologies with two 2 μ -jets, one 2 μ -jet and one 4 μ -jet, and two 4 μ -jets in the final state at LHC-14. We also summarize existing constraints on these models.
Craig, Nathaniel; Gu, Jiayin; Liu, Zhen; Wang, Kechen
2016-03-09
Here, we study angular observables in the $ {e}^{+}{e}^{-}\\to ZH\\to {\\ell}^{+}{\\ell}^{-}b\\overline{b} $ channel at future circular e$^{+}$ e$^{-}$ colliders such as CEPC and FCC-ee. Taking into account the impact of realistic cut acceptance and detector effects, we forecast the precision of six angular asymmetries at CEPC (FCC-ee) with center-of-mass energy $ \\sqrt{s}=240 $ GeV and 5 (30) ab$^{-1}$ integrated luminosity. We then determine the projected sensitivity to a range of operators relevant for he Higgs-strahlung process in the dimension-6 Higgs EFT. Our results show that angular observables provide complementary sensitivity to rate measurements when constraining various tensor structures arising from new physics. We further find that angular asymmetries provide a novel means of both probing BSM corrections to the HZγ coupling and constraining the “blind spot” in indirect limits on supersymmetric scalar top partners.
Effective gauge-Higgs operators analysis of new physics associated with the Higgs boson
NASA Astrophysics Data System (ADS)
Chang, We-Fu; Pan, Wei-Ping; Xu, Fanrong
2013-08-01
We study the new physics related to the recently discovered 125 GeV Higgs by employing an important subset of the standard model (SM) gauge-invariant dimension-6 operators constructed by the SM Higgs and gauge fields. Explicitly, we perform a model-independent study on the production and decays of the Higgs, the electric dipole moments (EDMs) of the neutron and the electron, and we take into account the anomalous magnetic dipole moments of the muon and electron as well. We find that, even if all Higgs decay channels agree with the SM predictions, the SM theoretical uncertainties provide a lot of room to host new phyiscs associated with the 125 GeV boson. A linear relation is revealed in our numerical study that μZZ≃μWW and 0.6≲μZZ,WW≲1.4 at 95% C.L. with or without the EDM constraints. The neutron and electron EDMs severely constrain the relevant Wilson coefficients. Therefore the CP-violating components in the h→WW, ZZ channels are too small, ˜O(10-5), to be detected at the LHC. However, we point out that, even though the parity of the 125 GeV boson has been largely determined to be even in the h→ZZ channel, one should pay special attention to the potentially large CP violation in the h→γγ and h→γZ channels. This should be seriously checked in the future spin correlation experiments.
Lepton flavor violating Higgs boson decay h →μ τ in the littlest Higgs model with T parity
NASA Astrophysics Data System (ADS)
Yang, Bingfang; Han, Jinzhong; Liu, Ning
2017-02-01
Inspired by the recent CMS h →μ τ excess, we calculate the lepton flavor violating Higgs decay h →μ τ in the littlest Higgs model with T parity (LHT). Under the constraints of ℓi→ℓjγ , Z →ℓiℓ¯j and Higgs data, we find that the branching ratio of h →μ τ can maximally reach O (10-4) . We also investigate the correlation between h →μ τ , τ →μ γ , and Z →μ τ , which can be used to test the LHT model at future e+e- colliders.
Lepton flavor violating Higgs couplings and single production of the Higgs boson via eγ collision
NASA Astrophysics Data System (ADS)
Yue, Chong-Xing; Pang, Cong; Guo, Yu-Chen
2015-07-01
Taking into account the constraints on the lepton flavor violation (LFV) couplings of the Standard Model (SM) Higgs boson H with leptons from low energy experiments and the recent Compact Muon Solenoid experiment results, we investigate production of the SM Higgs boson associated with a lepton τ via eγ collision at the International Linear Collider (ILC) and Large Hadron Electron Collider experiments. The production cross sections are calculated and the LFV signals and the relevant SM backgrounds are examined. The LFV signals of the SM Higgs boson might be observed via eγ collision in future ILC experiments.
Intellectual Property and Strategic Agreements (IP/SA) | FNLCR
What does IP/SA handle? IP/SA handles all invention issues including patents and copyrights. All employee inventionreports are filed through the IP/SA office for all activities under the OTS contract.Additionally,&nbs
NASA Technical Reports Server (NTRS)
1962-01-01
The Saturn I (SA-3) flight lifted off from Kennedy Space Center launch Complex 34, November 16, 1962. The third launch of Saturn launch vehicles, developed at the Marshall Space Flight Center (MSFC) under the direction of Dr. Wernher von Braun, incorporated a Saturn I, Block I engine. The typical height of a Block I vehicle was approximately 163 feet. and had only one live stage. It consisted of eight tanks, each 70 inches in diameter, clustered around a central tank, 105 inches in diameter. Four of the external tanks were fuel tanks for the RP-1 (kerosene) fuel. The other four, spaced alternately with the fuel tanks, were liquid oxygen tanks as was the large center tank. All fuel tanks and liquid oxygen tanks drained at the same rates respectively. The thrust for the stage came from eight H-1 engines, each producing a thrust of 165,000 pounds, for a total thrust of over 1,300,000 pounds. The engines were arranged in a double pattern. Four engines, located inboard, were fixed in a square pattern around the stage axis and canted outward slightly, while the remaining four engines were located outboard in a larger square pattern offset 40 degrees from the inner pattern. Unlike the inner engines, each outer engine was gimbaled. That is, each could be swung through an arc. They were gimbaled as a means of steering the rocket, by letting the instrumentation of the rocket correct any deviations of its powered trajectory. The block I required engine gimabling as the only method of guiding and stabilizing the rocket through the lower atmosphere. The upper stages of the Block I rocket reflected the three-stage configuration of the Saturn I vehicle. During the SA-3 flight, the upper stage ejected 113,560 liters (30,000 gallons) of ballast water in the upper atmosphere for 'Project Highwater' physics experiment. The water was released at an altitude of 65 miles, where within only 5 seconds, it expanded into a massive ice cloud 4.6 miles in diameter. Release of this vast
What's in the Loop? The Anatomy of Double Higgs Production
Dawson, S.; Ismail, A.; Low, Ian
2015-06-09
Determination of Higgs self-interactions through the double Higgs production from gluon fusion is a major goal of current and future collider experiments. We point out this channel could help disentangle and resolve the nature of ultraviolet contributions to Higgs couplings to two gluons. Analytic properties of the double Higgs amplitudes near kinematic threshold are used to study features resulting from scalar and fermionic loop particles mediating the interaction. Focusing on the hh invariant mass spectrum, we consider the effect from anomalous top and bottom Yukawa couplings, as well as from scalar and fermionic loop particles. In particular, the spectrum at high hh invariant mass is sensitive to the spin of the particles in the loop.
Learning from a Higgs-like scalar resonance
NASA Astrophysics Data System (ADS)
Bauer, Martin; Butter, Anja; Gonzalez-Fraile, J.; Plehn, Tilman; Rauch, Michael
2017-03-01
Motivated by a diphoton anomaly observed by ATLAS and CMS we develop an SFitter analysis for a combined electroweak-Higgs sector, and a scalar portal at the LHC. The theoretical description is based on the linear effective Lagrangian for the Higgs and gauge fields, combined with an additional singlet scalar. The key target is the extraction of reliable information on the portal structure of the combined scalar potential. For the specific diphoton anomaly we find that the new state might well form such a Higgs portal. To obtain more conclusive results we define and test the connection of the Wilson coefficients in the Higgs and heavy scalar sectors, as suggested by a portal setup.
Lilith: a tool for constraining new physics from Higgs measurements
NASA Astrophysics Data System (ADS)
Bernon, Jérémy; Dumont, Béranger
2015-09-01
The properties of the observed Higgs boson with mass around 125 GeV can be affected in a variety of ways by new physics beyond the Standard Model (SM). The wealth of experimental results, targeting the different combinations for the production and decay of a Higgs boson, makes it a non-trivial task to assess the patibility of a non-SM-like Higgs boson with all available results. In this paper we present Lilith, a new public tool for constraining new physics from signal strength measurements performed at the LHC and the Tevatron. Lilith is a Python library that can also be used in C and C++/ ROOT programs. The Higgs likelihood is based on experimental results stored in an easily extensible XML database, and is evaluated from the user input, given in XML format in terms of reduced couplings or signal strengths.The results of Lilith can be used to constrain a wide class of new physics scenarios.
Status of Higgs Boson Searches at the Tevatron
Sopczak, Andre; /Lancaster U.
2009-03-01
Over the last years the Tevatron Run-II has extended several limits on Higgs boson masses and coupling which were pioneered during the LEP accelerator operation between 1989 and 2000. Higgs boson searches will also be at the forefront of research at the LHC. This review concisely discusses the experimental constraints set by the CDF and D0 collaborations in winter 2008/2009 at the beginning of the LHC era. Model-independent and model-dependent limits on Higgs boson masses and couplings have been set and interpretations are discussed both in the Standard Model and in extended models. Recently, for the first time the Tevatron excludes a SM Higgs boson mass range (160-170 GeV) beyond the LEP limit at 95% CL. The experimental sensitivities are estimated for the completion of the Tevatron program.
Building and testing models with extended Higgs sectors
NASA Astrophysics Data System (ADS)
Ivanov, Igor P.
2017-07-01
Models with non-minimal Higgs sectors represent a mainstream direction in theoretical exploration of physics opportunities beyond the Standard Model. Extended scalar sectors help alleviate difficulties of the Standard Model and lead to a rich spectrum of characteristic collider signatures and astroparticle consequences. In this review, we introduce the reader to the world of extended Higgs sectors. Not pretending to exhaustively cover the entire body of literature, we walk through a selection of the most popular examples: the two- and multi-Higgs-doublet models, as well as singlet and triplet extensions. We will show how one typically builds models with extended Higgs sectors, describe the main goals and the challenges which arise on the way, and mention some methods to overcome them. We will also describe how such models can be tested, what are the key observables one focuses on, and illustrate the general strategy with a subjective selection of results.
Single top and Higgs associated production at the LHC.
Barger, V.; McCaskey, M.; Shaughnessy, G.; High Energy Physics; Univ. of Wisconsin at Madison; Northwestern Univ.
2010-02-01
We study the production of a standard model (SM) Higgs boson in association with a single top quark and either a light jet or W boson at the LHC with a center of mass energy of 14 TeV. Because of the destructive interference of the contributing SM diagrams, the value of the top Yukawa coupling and the sign of the WWh coupling may be probed for Higgs masses above 150 GeV, where WW and ZZ are the dominant Higgs decays. We consider Higgs masses of m{sub h} = 120, 150, 180, and 200 GeV and devise experimental cuts to extract the signal from SM backgrounds and measure the top Yukawa coupling.
Single top and Higgs associated production at the LHC
Barger, Vernon; McCaskey, Mathew; Shaughnessy, Gabe
2010-02-01
We study the production of a standard model (SM) Higgs boson in association with a single top quark and either a light jet or W boson at the LHC with a center of mass energy of 14 TeV. Because of the destructive interference of the contributing SM diagrams, the value of the top Yukawa coupling and the sign of the WWh coupling may be probed for Higgs masses above 150 GeV, where WW and ZZ are the dominant Higgs decays. We consider Higgs masses of m{sub h}=120, 150, 180, and 200 GeV and devise experimental cuts to extract the signal from SM backgrounds and measure the top Yukawa coupling.
Search for Multiphoton Signatures of a Higgs Boson
Atramentov, Oleksiy Vladimirovich
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 (m_{hf} < 90 GeV/c^{2}) lower than the current limit has not been excluded.
Higgs boson production at hadron colliders: Signal and background processes
David Rainwater; Michael Spira; Dieter Zeppenfeld
2004-01-12
We review the theoretical status of signal and background calculations for Higgs boson production at hadron colliders. Particular emphasis is given to missing NLO results, which will play a crucial role for the Tevatron and the LHC.
On-shell interference effects in Higgs boson final states
Englert, Christoph; Low, Ian; Spannowsky, Michael
2015-04-29
Top quark loops in Higgs production via gluon fusion at large invariant final state masses can induce important interference effects in searches for additional Higgs bosons as predicted in, e.g., Higgs portal scenarios and the minimal supersymmetric Standard Model when the heavy scalar is broad or the final state resolution is poor. Currently, the limit setting as performed by both ATLAS and CMS is based on injecting a heavy Higgs-like signal neglecting interference effects. In this study, we perform a study of such “on-shell” interference effects in pp → ZZ and find that they lead to a ≲O(30%) width scheme-dependentmore » modification of the signal strength. Finally, including the continuum contributions to obtain, e.g., the full pp → ZZ → 4l final state, this modification is reduced to the 10% level in the considered intermediate mass range.« less
On-shell interference effects in Higgs boson final states
Englert, Christoph; Low, Ian; Spannowsky, Michael
2015-04-29
Top quark loops in Higgs production via gluon fusion at large invariant final state masses can induce important interference effects in searches for additional Higgs bosons as predicted in, e.g., Higgs portal scenarios and the minimal supersymmetric Standard Model when the heavy scalar is broad or the final state resolution is poor. Currently, the limit setting as performed by both ATLAS and CMS is based on injecting a heavy Higgs-like signal neglecting interference effects. In this study, we perform a study of such “on-shell” interference effects in pp → ZZ and find that they lead to a ≲O(30%) width scheme-dependent modification of the signal strength. Finally, including the continuum contributions to obtain, e.g., the full pp → ZZ → 4l final state, this modification is reduced to the 10% level in the considered intermediate mass range.
Topological vortices in generalized Born-Infeld-Higgs electrodynamics
NASA Astrophysics Data System (ADS)
Casana, R.; Hora, E. da; Rubiera-Garcia, D.; Santos, C. dos
2015-08-01
A consistent BPS formalism to study the existence of topological axially symmetric vortices in generalized versions of the Born-Infeld-Higgs electrodynamics is implemented. Such a generalization modifies the field dynamics via the introduction of three nonnegative functions depending only in the Higgs field, namely, , , and . A set of first-order differential equations is attained when these functions satisfy a constraint related to the Ampère law. Such a constraint allows one to minimize the system's energy in such way that it becomes proportional to the magnetic flux. Our results provides an enhancement of the role of topological vortex solutions in Born-Infeld-Higgs electrodynamics. Finally, we analyze a set of models entailing the recovery of a generalized version of Maxwell-Higgs electrodynamics in a certain limit of the theory.
Gravitational wave background and Higgs false vacuum inflation
NASA Astrophysics Data System (ADS)
Masina, Isabella
2014-06-01
For a narrow band of values of the top quark and Higgs boson masses, the standard model Higgs potential develops a shallow local minimum at energies of about 1016 GeV, where primordial inflation could have started in a cold metastable state. For each point of that band, the highness of the Higgs potential at the false minimum is calculable, and there is an associated prediction for the inflationary gravitational wave background, namely, for the tensor to scalar ratio r. We show that the recent measurement of r by the BICEP2 collaboration, r =0.16-0.05+0.06 at 1σ, combined with the most up-to-date measurements of the top quark and Higgs boson masses, reveals that the hypothesis that a standard model shallow false minimum was the source of inflation in the early Universe is viable.
Probing anomalous Higgs couplings in H → ZV decays
NASA Astrophysics Data System (ADS)
Modak, Tanmoy; Srivastava, Rahul
2017-01-01
We analyze the possibility of probing anomalous Higgs couplings in the rare decays H → ZV, V being a vector quarkonium state. These rare decays involve both gauge as well as the Yukawa sectors and either of them can potentially be anomalous. We show that the branching fractions for H → ZV decays in Standard Model (SM) are small, making it a sensitive probe for anomalous Higgs couplings originating from physics beyond SM. Moreover, as both V and Z can decay into pair of charged leptons, they provide experimentally clean channels and future LHC runs should observe such decays. We perform a model independent analysis and show how angular asymmetries can be used to probe these anomalous Higgs couplings, taking further decays of V and Z to pair of charged leptons into account. The angular asymmetries can provide significant information about anomalous Higgs couplings in both gauge and Yukawa sectors.
Application of fiber laser for a Higgs factory
Chou, W.
2014-06-04
This paper proposes a medium size(~6km) circular Higgs factory based on a photon collider. The recent breakthrough in fiber laser technology by means of a coherent amplifier network makes such a collider feasible and probably also affordable.
Light Higgs and vector-like quarks without prejudice
NASA Astrophysics Data System (ADS)
Fajfer, Svjetlana; Greljo, Admir; Kamenik, Jernej F.; Mustać, Ivana
2013-07-01
Light vector-like quarks with non-renormalizable couplings to the Higgs are a common feature of models trying to address the electroweak (EW) hierarchy problem by treating the Higgs as a pseudo-goldstone boson of a global (approximate) symmetry. We systematically investigate the implications of the leading dimension five operators on Higgs phenomenology in presence of dynamical up- and down-type weak singlet as well as weak doublet vector-like quarks. After taking into account constraints from precision EW and flavour observables we show that contrary to the renormalizable models, significant modifications of Higgs properties are still possible and could shed light on the role of vector-like quarks in solutions to the EW hierarchy problem. We also briefly discuss implications of higher dimensional operators for direct vector-like quark searches at the LHC.
Maximizing the significance in Higgs boson pair analyses
NASA Astrophysics Data System (ADS)
Kling, Felix; Plehn, Tilman; Schichtel, Peter
2017-02-01
We study Higgs pair production with a subsequent decay to a pair of photons and a pair of bottoms at the LHC. We use the log-likelihood ratio to identify the kinematic regions which either allow us to separate the di-Higgs signal from backgrounds or to determine the Higgs self-coupling. We find that both regions are separate enough to ensure that details of the background modeling will not affect the determination of the self-coupling. Assuming dominant statistical uncertainties we determine the best precision with which the Higgs self-coupling can be probed in this channel. We finally comment on the same questions at a future 100 TeV collider.
BMSSM Higgs Bosons at the Tevatron and the LHC
Carena, Marcela; Ponton, Eduardo; Zurita, Jose; /Zurich U.
2010-05-01
We study extensions of the Minimal Supersymmetric Standard Model (MSSM) with new degrees of freedom that couple sizably to the MSSM Higgs sector and lie in the TeV range. After integrating out the physics at the TeV scale, the resulting Higgs spectrum can significantly differ from typical supersymmetric scenarios, thereby providing a window Beyond the MSSM (BMSSM). Taking into account current LEP and Tevatron constraints, we perform an in-depth analysis of the Higgs collider phenomenology and explore distinctive characteristics of our scenario with respect to both the Standard Model and the MSSM. We propose benchmark scenarios to illustrate specific features of BMSSM Higgs searches at the Tevatron and the LHC.
Low Scale Thermal Leptogenesis in Neutrinophilic Higgs Doublet Models
NASA Astrophysics Data System (ADS)
Haba, N.; Seto, O.
2011-06-01
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 the 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 the 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.
What's in the loop? The anatomy of double Higgs production
NASA Astrophysics Data System (ADS)
Dawson, S.; Ismail, A.; Low, Ian
2015-06-01
Determination of Higgs self-interactions through the double Higgs production from gluon fusion is a major goal of current and future collider experiments. We point out this channel could help disentangle and resolve the nature of ultraviolet contributions to Higgs couplings to two gluons. Analytic properties of the double Higgs amplitudes near kinematic threshold are used to study features resulting from scalar and fermionic loop particles mediating the interaction. Focusing on the h h invariant mass spectrum, we consider the effect from anomalous top and bottom Yukawa couplings, as well as from scalar and fermionic loop particles. In particular, the spectrum at high h h invariant mass is sensitive to the spin of the particles in the loop.
Variational study of bound states in the Higgs model
NASA Astrophysics Data System (ADS)
Siringo, Fabio
2000-12-01
The possible existence of Higgs-boson-Higgs-boson bound states in the Higgs sector of the standard model is explored using the \\|hh>+\\|hhh> variational ansatz of Di Leo and Darewych. The resulting integral equations can be decoupled exactly, yielding a one-dimensional integral equation, solved numerically. We thereby avoid the extra approximations employed by Di Leo and Darewych, and we find a qualitatively different mass renormalization. Within the conventional scenario, where a not-too-large cutoff is invoked to avoid ``triviality,'' we find, as usual, an upper bound on the Higgs boson mass. Bound-state solutions are only found in the very strong coupling regime, but at the same time a relatively small physical mass is required as a consequence of renormalization.
Collider constraints on tuning in composite Higgs models
NASA Astrophysics Data System (ADS)
Barnard, James; White, Martin
2015-10-01
Two potential sources of tuning exist in composite Higgs models: one comes from keeping the Higgs VEV below the compositeness scale and one comes from keeping the Higgs light after constraints on the top partner masses are applied. We construct a measure that determines whether these tunings are independent or not and combines them appropriately. We perform a comprehensive scan of the parameter space for three explicit models and report the minimum tuning values compatible with existing collider constraints. Tuning values are given as functions of resonance masses and deviations to the Higgs couplings so the effect of future constraints can easily be quantified. The current minimum tuning in the minimal model is 2.5-5% and will be decreased to around 0.8-3.3% if no top partners are observed over the lifetime of the LHC
Bounce inflation cosmology with Standard Model Higgs boson
Wan, Youping; Huang, Fa Peng; Zhang, Xinmin; Qiu, Taotao; Cai, Yi-Fu; Li, Hong E-mail: qiutt@mail.ccnu.edu.cn E-mail: yifucai@ustc.edu.cn E-mail: xmzhang@ihep.ac.cn
2015-12-01
It is of great interest to connect cosmology in the early universe to the Standard Model of particle physics. In this paper, we try to construct a bounce inflation model with the standard model Higgs boson, where the one loop correction is taken into account in the effective potential of Higgs field. In this model, a Galileon term has been introduced to eliminate the ghost mode when bounce happens. Moreover, due to the fact that the Fermion loop correction can make part of the Higgs potential negative, one naturally obtains a large equation of state(EoS) parameter in the contracting phase, which can eliminate the anisotropy problem. After the bounce, the model can drive the universe into the standard higgs inflation phase, which can generate nearly scale-invariant power spectrum.
Usefulness of effective field theory for boosted Higgs production
Dawson, S.; Lewis, I. M.; Zeng, Mao
2015-04-07
The Higgs + jet channel at the LHC is sensitive to the effects of new physics both in the total rate and in the transverse momentum distribution at high _{pT}. We examine the production process using an effective field theory (EFT) language and discussing the possibility of determining the nature of the underlying high-scale physics from boosted Higgs production. The effects of heavy color triplet scalars and top partner fermions with TeV scale masses are considered as examples and Higgs-gluon couplings of dimension-5 and dimension-7 are included in the EFT. As a byproduct of our study, we examine the region of validity of the EFT. Dimension-7 contributions in realistic new physics models give effects in the high _{pT} tail of the Higgs signal which are so tiny that they are likely to be unobservable.
Living beyond the edge: Higgs inflation and vacuum metastability
Bezrukov, Fedor; Rubio, Javier; Shaposhnikov, Mikhail
2015-10-13
The measurements of the Higgs mass and top Yukawa coupling indicate that we live in a very special universe, at the edge of the absolute stability of the electroweak vacuum. If fully stable, the Standard Model (SM) can be extended all the way up to the inflationary scale and the Higgs field, nonminimally coupled to gravity with strength ξ, can be responsible for inflation. We show that the successful Higgs inflation scenario can also take place if the SM vacuum is not absolutely stable. This conclusion is based on two effects that were overlooked previously. The first one is associated with the effective renormalization of the SM couplings at the energy scale M_{P}/ξ, where M_{P} is the Planck scale. Lastly, the second one is a symmetry restoration after inflation due to high temperature effects that leads to the (temporary) disappearance of the vacuum at Planck values of the Higgs field.
Casimir effect for the Higgs field at finite temperature
NASA Astrophysics Data System (ADS)
Santos, A. F.; Khanna, Faqir C.
2017-08-01
In early 1970, it was postulated that there exists a zero spin quantum field, called Higgs field, that is present in all universe. The potential energy of the Higgs field is transferred to particles. Hence they acquire mass. These ideas were essential in fulfilling the basic need for a particle, called Higgs, with mass. These particles are called Higgs particles with spin zero with its mass to be ˜125 GeV. This raises the question as to its physical effects. If these particles are present, will they exhibit a Casimir effect and also obey the Stefan-Boltzmann Law? Assuming the dynamics of this field, will these effects change with temperature. The present calculation uses thermo field dynamics formalism to calculate temperature effects.
Living beyond the edge: Higgs inflation and vacuum metastability
Bezrukov, Fedor; Rubio, Javier; Shaposhnikov, Mikhail
2015-10-13
The measurements of the Higgs mass and top Yukawa coupling indicate that we live in a very special universe, at the edge of the absolute stability of the electroweak vacuum. If fully stable, the Standard Model (SM) can be extended all the way up to the inflationary scale and the Higgs field, nonminimally coupled to gravity with strength ξ, can be responsible for inflation. We show that the successful Higgs inflation scenario can also take place if the SM vacuum is not absolutely stable. This conclusion is based on two effects that were overlooked previously. The first one is associatedmore » with the effective renormalization of the SM couplings at the energy scale MP/ξ, where MP is the Planck scale. Lastly, the second one is a symmetry restoration after inflation due to high temperature effects that leads to the (temporary) disappearance of the vacuum at Planck values of the Higgs field.« less
Search for Higgs and new phenomena at colliders
Lammel, Stephan; /Fermilab
2006-01-01
The present status of searches for the Higgs boson(s) and new phenomena is reviewed. The focus is on analyses and results from the current runs of the HERA and Tevatron experiments. The LEP experiments have released their final combined MSSM Higgs results for this conference. Also included are results from sensitivity studies of the LHC experiments and lepton flavor violating searches from the B factories, KEKB and PEP-II.
Status of Higgs couplings after run 1 of the LHC
NASA Astrophysics Data System (ADS)
Bernon, Jérémy; Dumont, Béranger; Kraml, Sabine
2014-10-01
We provide an update of the global fits of the couplings of the 125.5 GeV Higgs boson using all publicly available experimental results from run 1 of the LHC as per summer 2014. The fits are done by means of the new public code Lilith 1.0. We present a selection of results given in terms of signal strengths, reduced couplings, and for the two-Higgs-doublet models of type I and II.
Implications of the Higgs discovery for the MSSM.
Djouadi, Abdelhak
The implications of the discovery of the Higgs boson at the LHC with a mass of approximately 125 GeV are summarised in the context of the minimal supersymmetric extension of the Standard Model, the MSSM. Discussed are the implications from the measured mass and production/decay rates of the observed particle and from the constraints in the search for the heavier Higgs states at the LHC.
Little Higgs model effects in gg ® gg
NASA Astrophysics Data System (ADS)
Choudhury, S. Rai; Goyal, Ashok; Cornell, A. S.; Gaur, Naveen
2007-11-01
Though the predictions of the standard model (SM) are in excellent agreement with experiments, there are still several theoretical problems associated with the Higgs sector of the SM, where it is widely believed that some {new physics} will take over at the TeV scale. One beyond the SM theory which resolves these problems is the Little Higgs (LH) model. In this work we have investigated the effects of the LH model on gggg scattering [1].
Searching for doubly-charged Higgs bosons at future colliders
Gunion, J.F.; Loomis, C.; Pitts, K.T.
1996-10-01
Doubly-charged Higgs bosons ({Delta}{sup --}/{Delta}{sup ++}) appear in several extensions to the Standard Model and can be relatively light. We review the theoretical motivation for these states and present a study of the discovery reach in future runs of the Fermilab Tevatron for pair-produced doubly-charged Higgs bosons decaying to like-sign lepton pairs. We also comment on the discovery potential at other future colliders. 16 refs., 3 figs., 1 tab.
Generation of the Higgs condensate and its decay after inflation
Enqvist, Kari; Meriniemi, Tuukka; Nurmi, Sami E-mail: tuukka.meriniemi@helsinki.fi
2013-10-01
We investigate the dynamics of the Standard Model higgs with a minimal coupling to gravity during and after inflation. In the regime where the Standard Model vacuum is stable, we find that the higgs becomes a light spectator field after about 30 efolds of inflation, irrespectively of its initial value. Once the higgs has become light, its root-mean-square value h{sub *} relaxes to equilibrium in about 85 efolds for the inflationary scale of H{sub *} = 10{sup 4} GeV and in 20 efolds for H{sub *} = 10{sup 10} GeV. The equilibrium value is given by h{sub *} ∼ 0.36λ{sub *}{sup −1/4}H{sub *}, where λ{sub *} = 0.09...0.0005 is the higgs self coupling at the scales H{sub *} = 10{sup 4}...10{sup 10} GeV. We show that the main decay channel of the higgs condensate after inflation is the resonant production of Standard Model gauge bosons. For a set of parameters we find that a significant part of the condensate has decayed in between 340 and 630 Hubble times after the onset of higgs oscillations, depending on H{sub *} in a non-trivial way. The higgs perturbations correspond to isocurvature modes during inflation but they could generate significant adiabatic perturbations at a later stage for example through a modulation of the reheating stage. However, this requires that the inflaton(s) decay no later than a few hundred Hubble times after the onset of higgs oscillations.
Search for low-mass dark-sector Higgs bosons.
Lees, J P; Poireau, V; Tisserand, V; Garra Tico, J; Grauges, E; Milanes, D A; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Brown, D N; Kerth, L T; Kolomensky, Yu G; Lynch, G; Koch, H; Schroeder, T; Asgeirsson, D J; Hearty, C; Mattison, T S; McKenna, J A; Khan, A; Blinov, V E; Buzykaev, A R; Druzhinin, V P; Golubev, V B; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Yushkov, A N; Bondioli, M; Kirkby, D; Lankford, A J; Mandelkern, M; Atmacan, H; Gary, J W; Liu, F; Long, O; Vitug, G M; Campagnari, C; Hong, T M; Kovalskyi, D; Richman, J D; West, C A; Eisner, A M; Kroseberg, J; Lockman, W S; Martinez, A J; Schalk, T; Schumm, B A; Seiden, A; Chao, D S; Cheng, C H; Doll, D A; Echenard, B; Flood, K T; Hitlin, D G; Ongmongkolkul, P; Porter, F C; Rakitin, A Y; Andreassen, R; Huard, Z; Meadows, B T; Sokoloff, M D; Sun, L; Bloom, P C; Ford, W T; Gaz, A; Nagel, M; Nauenberg, U; Smith, J G; Wagner, S R; Ayad, R; Toki, W H; Spaan, B; Kobel, M J; Schubert, K R; Schwierz, R; Bernard, D; Verderi, M; Clark, P J; Playfer, S; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Fioravanti, E; Garzia, I; Luppi, E; Munerato, M; Negrini, M; Piemontese, L; Santoro, V; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Contri, R; Guido, E; Lo Vetere, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Bhuyan, B; Prasad, V; Lee, C L; Morii, M; Edwards, A J; Adametz, A; Marks, J; Uwer, U; Lacker, H M; Lueck, T; Dauncey, P D; Behera, P K; Mallik, U; Chen, C; Cochran, J; Meyer, W T; Prell, S; Rubin, A E; Gritsan, A V; Guo, Z J; Arnaud, N; Davier, M; Derkach, D; Grosdidier, G; Le Diberder, F; Lutz, A M; Malaescu, B; Roudeau, P; Schune, M H; Stocchi, A; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Chavez, C A; Coleman, J P; Fry, J R; Gabathuler, E; Hutchcroft, D E; Payne, D J; Touramanis, C; Bevan, A J; Di Lodovico, F; Sacco, R; Sigamani, M; Cowan, G; Brown, D N; Davis, C L; Denig, A G; Fritsch, M; Gradl, W; Hafner, A; Prencipe, E; Bailey, D; Barlow, R J; Jackson, G; Lafferty, G D; Behn, E; Cenci, R; Hamilton, B; Jawahery, A; Roberts, D A; Simi, G; Dallapiccola, C; Cowan, R; Dujmic, D; Sciolla, G; Cheaib, R; Lindemann, D; Patel, P M; Robertson, S H; Schram, M; Biassoni, P; Neri, N; Palombo, F; Stracka, S; Cremaldi, L; Godang, R; Kroeger, R; Sonnek, P; Summers, D J; Nguyen, X; Simard, M; Taras, P; De Nardo, G; Monorchio, D; Onorato, G; Sciacca, C; Martinelli, M; Raven, G; Jessop, C P; Knoepfel, K J; Losecco, J M; Wang, W F; Honscheid, K; Kass, R; Brau, J; Frey, R; Sinev, N B; Strom, D; Torrence, E; Feltresi, E; Gagliardi, N; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Akar, S; Ben-Haim, E; Bomben, M; Bonneaud, G R; Briand, H; Calderini, G; Chauveau, J; Hamon, O; Leruste, Ph; Marchiori, G; Ocariz, J; Sitt, S; Biasini, M; Manoni, E; Pacetti, S; Rossi, A; Angelini, C; Batignani, G; Bettarini, S; Carpinelli, M; Casarosa, G; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Oberhof, B; Paoloni, E; Perez, A; Rizzo, G; Walsh, J J; Lopes Pegna, D; Olsen, J; Smith, A J S; Telnov, A V; Anulli, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Piredda, G; Bünger, C; Grünberg, O; Hartmann, T; Leddig, T; Schröder, H; Voss, C; Waldi, R; Adye, T; Olaiya, E O; Wilson, F F; Emery, S; Hamel de Monchenault, G; Vasseur, G; Yèche, Ch; Aston, D; Bard, D J; Bartoldus, R; Cartaro, C; Convery, M R; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Ebert, M; Field, R C; Franco Sevilla, M; Fulsom, B G; Gabareen, A M; Graham, M T; Grenier, P; Hast, C; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Lewis, P; Lindquist, B; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Muller, D R; Neal, H; Nelson, S; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Snyder, A; Su, D; Sullivan, M K; Va'vra, J; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Wulsin, H W; Young, C C; Ziegler, V; Park, W; Purohit, M V; White, R M; Wilson, J R; Randle-Conde, A; Sekula, S J; Bellis, M; Benitez, J F; Burchat, P R; Miyashita, T S; Alam, M S; Ernst, J A; Gorodeisky, R; Guttman, N; Peimer, D R; Soffer, A; Lund, P; Spanier, S M; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Wray, B C; Izen, J M; Lou, X C; Bianchi, F; Gamba, D; Lanceri, L; Vitale, L; Martinez-Vidal, F; Oyanguren, A; Ahmed, H; Albert, J; Banerjee, Sw; Bernlochner, F U; Choi, H H F; King, G J; Kowalewski, R; Lewczuk, M J; Nugent, I M; Roney, J M; Sobie, R J; Tasneem, N; Gershon, T J; Harrison, P F; Latham, T E; Puccio, E M T; Band, H R; Dasu, S; Pan, Y; Prepost, R; Wu, S L
2012-05-25
Recent astrophysical and terrestrial experiments have motivated the proposal of a dark sector with GeV-scale gauge boson force carriers and new Higgs bosons. We present a search for a dark Higgs boson using 516 fb(-1) of data collected with the BABAR detector. We do not observe a significant signal and we set 90% confidence level upper limits on the product of the standard model-dark-sector mixing angle and the dark-sector coupling constant.
Observation of the Meissner effect in a lattice Higgs model
NASA Technical Reports Server (NTRS)
Damgaard, Poul H.; Heller, Urs M.
1988-01-01
The lattice-regularized U(1) Higgs model in an external electromagnetic field is studied by Monte Carlo techniques. In the Coulomb phase, magnetic flux can flow through uniformly. The Higgs phase splits into a region where magnetic flux can penetrate only in the form of vortices and a region where the magnetic flux is completely expelled, the relativistic analog of the Meissner effect in superconductivity. Evidence is presented for symmetry restoration in strong external fields.
Basis invariant conditions for supersymmetry in the two-Higgs-doublet model
Ferreira, P. M.; Haber, Howard E.; Silva, Joao P.
2010-07-01
The minimal supersymmetric standard model involves a rather restrictive Higgs potential with two Higgs fields. Recently, the full set of classes of symmetries allowed in the most general two-Higgs-doublet model was identified; these classes do not include the supersymmetric limit as a particular class. Thus, a physically meaningful definition of the supersymmetric limit must involve the interaction of the Higgs sector with other sectors of the theory. Here we show how one can construct basis invariant probes of supersymmetry involving both the Higgs sector and the gaugino-Higgsino-Higgs interactions.
Inflation and pseudo-Goldstone Higgs boson
NASA Astrophysics Data System (ADS)
Alanne, Tommi; Sannino, Francesco; Tenkanen, Tommi; Tuominen, Kimmo
2017-02-01
We consider inflation within a model framework where the Higgs boson arises as a pseudo-Goldstone boson associated with the breaking of a global symmetry at a scale significantly larger than the electroweak one. We show that in such a model the scalar self-couplings can be parametrically suppressed and, consequently, the nonminimal couplings to gravity can be of order one or less, while the inflationary predictions of the model remain compatible with the precision cosmological observations. Furthermore, in the model we study, the existence of the electroweak scale is entirely due to the inflaton field. Our model therefore suggests that inflation and low energy particle phenomenology may be more entwined than assumed so far.
Supersymmetric Higgs singlet effects on FCNC observables
Hodgkinson, Robert N.
2008-11-23
Higgs singlet superflelds, usually present in extensions of the Minimal Supersymmetric Standard Model (MSSM) which address the {mu}-problem, such as the Next-to-Minimal Supersymmetric Standard Model (NMSSM) and the Minimal Nonminimal Supersymmetric Standard Model (mnSSM), can have significant contributions to B-meson flavour-changing neutral current observables for large values of tan{beta} > or approx. 50. Illustrative results are presented including effects on the B{sub s} and on the rare decay B{sub s}{yields}{mu}{sup +}{mu}{sup -}. In particular, we find that in the NMSSM, the branching ratio for B{sub s}{yields}{mu}{sup +}{mu}{sup -} can be enhanced or even suppressed with respect to the Standard Model prediction by more than one order of magnitude.
Vortex dynamics in nonrelativistic Abelian Higgs model
NASA Astrophysics Data System (ADS)
Kozhevnikov, A. A.
2015-11-01
The dynamics of the gauge vortex with arbitrary form of a contour is considered in the framework of the nonrelativistic Abelian Higgs model, including the possibility of the gauge field interaction with the fermion asymmetric background. The equations for the time derivatives of the curvature and the torsion of the vortex contour generalizing the Betchov-Da Rios equations in hydrodynamics, are obtained. They are applied to study the conservation of helicity of the gauge field forming the vortex, twist, and writhe numbers of the vortex contour. It is shown that the conservation of helicity is broken when both terms in the equation of the vortex motion are present, the first due to the exchange of excitations of the phase and modulus of the scalar field and the second one due to the coupling of the gauge field forming the vortex, with the fermion asymmetric background.
Higgs Boson: god particle or divine comedy?
NASA Astrophysics Data System (ADS)
Rangacharyulu, Chary
2013-10-01
While particle physicists around the world rejoice the announcement of discovery of Higgs particle as a momentous event, it is also an opportune moment to assess the physicists' conception of nature. Particle theorists, in their ingenious efforts to unravel mysteries of the physical universe at a very fundamental level, resort to macroscopic many body theoretical methods of solid state physicists. Their efforts render the universe a superconductor of correlated quasi-particle pairs. Experimentalists, devoted to ascertain the elementary constituents and symmetries, depend heavily on numerical simulations based on those models and conform to theoretical slang in planning and interpretation of measurements . It is to the extent that the boundaries between theory/modeling and experiment are blurred. Is it possible that they are meandering in Dante's Inferno?
A conceptual design of circular Higgs factory
Cai, Yunhai
2016-11-30
Similar to a super B-factory, a circular Higgs factory (CHF) will require strong focusing systems near the interaction points and a low-emittance lattice in the arcs to achieve a factory luminosity. At electron beam energy of 125 GeV, beamstrahlung effects during the collision pose an additional challenge to the collider design. In particular, a large momentum acceptance at the 2% level is necessary to retain an adequate beam lifetime. This turns out to be the most challenging aspect in the design of a CHF. In this paper, an example will be provided to illustrate the beam dynamics in a CHF, emphasizing the chromatic optics. Basic optical modules and advanced analysis will be presented. Most importantly, we will show that 2% momentum aperture is achievable.
A conceptual design of circular Higgs factory
NASA Astrophysics Data System (ADS)
Cai, Yunhai
2016-11-01
Similar to a super B-factory, a circular Higgs factory (CHF) will require strong focusing systems near the interaction points and a low-emittance lattice in the arcs to achieve a factory luminosity. At electron beam energy of 125 GeV, beamstrahlung effects during the collision pose an additional challenge to the collider design. In particular, a large momentum acceptance at the 2% level is necessary to retain an adequate beam lifetime. This turns out to be the most challenging aspect in the design of a CHF. In this paper, an example will be provided to illustrate the beam dynamics in a CHF, emphasizing the chromatic optics. Basic optical modules and advanced analysis will be presented. Most importantly, we will show that 2% momentum aperture is achievable.
Top partners searches and composite Higgs models
NASA Astrophysics Data System (ADS)
Matsedonskyi, Oleksii; Panico, Giuliano; Wulzer, Andrea
2016-04-01
Colored fermionic partners of the top quark are well-known signatures of the Composite Higgs scenario and for this reason they have been and will be subject of an intensive experimental study at the LHC. Performing an assessment of the theoretical implications of this experimental effort is the goal of the present paper. We proceed by analyzing a set of simple benchmark models, characterized by simple two-dimensional parameter spaces where the results of the searches are conveniently visualized and their impact quantified. We only draw exclusion contours, in the hypothesis of no signal, but of course our formalism could equally well be used to report discoveries in a theoretically useful format.
Introduction to Higgs Sector: Theory and Phenomenology
NASA Astrophysics Data System (ADS)
Demir, Durmus A.
This review is based on lectures delivered at International Summer School on High Energy Physics, in Akyaka, Mugla, Turkey, September 2006. The goal of the review is to introduce junior graduate students, having a some knowledge of field theory, to the problem of mass generation and its physical consequences. The review starts with the statements and a toy model of mass generation in Sect. 2. In Sect. 3 a model of weak interactions is constructed and its predictions are compared with experimental results obtained so far. Given in Sect. 4 is search strategies for Higgs boson, the only remnant of the mechanism that gives mass to matter, by referring to model predictions and experimental facilities. Finally, in Sect. 5, given are a summary of results plus reasons for and expectations from models which rehabilitate the minimal model constructed in Sect. 3.
Softening Higgs Naturalness - an EFT Analysis
NASA Astrophysics Data System (ADS)
Bar-Shalom, Shaouly
2016-04-01
We investigate naturalness in the Standard Model (SM) Higgs sector using effective field theory (EFT) techniques and find the requirements on the new heavy physics that can potentially cure the little hierarchy problem below a scale Λ ≫ O (1 TeV), assuming the new heavy particles have a mass larger than Λ. In particular, we determine the conditions under which the 1-loop corrections to mh from the heavy new physics can balance those created by SM loop effects up to the naturalness scale Λ, a condition we denote by ;EFT Naturalness;. We obtain the higher dimensional (n ≥ 5) operators in the effective Lagrangian that can lead to EFT Naturalness, and classify the underlying heavy theories that can generate such operators at tree-level. We also address the experimental constraints on our EFT Naturalness setup and discuss the expected experimental signals of the new heavy physics associated with EFT Naturalness.
Unquenched flavor on the Higgs branch
NASA Astrophysics Data System (ADS)
Faedo, Antón F.; Mateos, David; Pantelidou, Christiana; Tarrıo, Javier
2016-11-01
We construct the gravity duals of the Higgs branches of three-dimensional (four-dimensional) super Yang-Mills theories coupled to N f quark flavors. The effect of the quarks on the color degrees of freedom is included, and corresponds on the gravity side to the backreaction of N f flavor D6-branes (D7-branes) on the background of N c color D2-branes (D3-branes). The Higgsing of the gauge group arises from the dissolution of some color branes inside the flavor branes. The dissolved color branes are represented by non-Abelian instantons whose backreaction is also included. The result is a cascading-like solution in which the effective number of color branes varies along the holographic direction. In the three-dimensional case the solution may include an arbitrary number of quasi-conformal (walking) regions.
Melatonin: a "Higgs boson" in human reproduction.
Dragojevic Dikic, Svetlana; Jovanovic, Ana Mitrovic; Dikic, Srdjan; Jovanovic, Tomislav; Jurisic, Aleksandar; Dobrosavljevic, Aleksandar
2015-02-01
As the Higgs boson could be a key to unlocking mysteries regarding our Universe, melatonin, a somewhat mysterious substance secreted by the pineal gland primarily at night, might be a crucial factor in regulating numerous processes in human reproduction. Melatonin is a powerful antioxidant which has an essential role in controlling several physiological reactions, as well as biological rhythms throughout human reproductive life. Melatonin, which is referred to as a hormone, but also as an autocoid, a chronobiotic, a hypnotic, an immunomodulator and a biological modifier, plays a crucial part in establishing homeostatic, neurohumoral balance and circadian rhythm in the body through synergic actions with other hormones and neuropeptides. This paper aims to analyze the effects of melatonin on the reproductive function, as well as to shed light on immunological and oncostatic properties of one of the most powerful hormones.
Probing a slepton Higgs on all frontiers
NASA Astrophysics Data System (ADS)
Biggio, Carla; Dror, Jeff Asaf; Grossman, Yuval; Ng, Wee Hao
2016-04-01
We study several aspects of supersymmetric models with a U(1) R symmetry where the Higgs doublet is identified with the superpartner of a lepton. We derive new, stronger bounds on the gaugino masses based on current measurements, and also propose ways to probe the model up to scales of {O} (10 TeV) at future e + e - colliders. Since the U(1) R symmetry cannot be exact, we analyze the effects of R-symmetry breaking on neutrino masses and proton decay. In particular, we find that getting the neutrino mixing angles to agree with experiments in a minimal model requires a UV cutoff for the theory at around 10 TeV.
Next-to-minimal two Higgs Doublet Model
Chen, Chien -Yi; Freid, Michael; Sher, Marc
2014-04-07
The simplest extension of the Two Higgs Doublet Model is the addition of a real scalar singlet, S. The effects of mixing between the singlet and the doublets can be manifested in two ways. It can modify the couplings of the 126 GeV Higgs boson, h, and it can lead to direct detection of the heavy Higgs at the LHC. In this paper, we show that in the type-I Model, for heavy Higgs masses in the 200-600 GeV range, the latter effect will be detected earlier than the former for most of parameter space. Should no such Higgs be discoveredmore » in this mass range, then the upper limit on the mixing will be sufficiently strong such that there will be no significant effects on the couplings of the h for most of parameter space. Thus, the reverse is true in the type-II model, the limits from measurements of the couplings of the h will dominate over the limits from non-observation of the heavy Higgs.« less
Extending Higgs inflation with TeV scale new physics
He, Hong-Jian; Xianyu, Zhong-Zhi
2014-10-10
Higgs inflation is among the most economical and predictive inflation models, although the original Higgs inflation requires tuning the Higgs or top mass away from its current experimental value by more than 2σ deviations, and generally gives a negligible tensor-to-scalar ratio r∼10{sup −3} (if away from the vicinity of critical point). In this work, we construct a minimal extension of Higgs inflation, by adding only two new weak-singlet particles at TeV scale, a vector-quark T and a real scalar S . The presence of singlets (T, S) significantly impact the renormalization group running of the Higgs boson self-coupling. With this, our model provides a wider range of the tensor-to-scalar ratio r=O(0.1)−O(10{sup −3}) , consistent with the favored r values by either BICEP2 or Planck data, while keeping the successful prediction of the spectral index n{sub s}≃0.96 . It allows the Higgs and top masses to fully fit the collider measurements. We also discuss implications for searching the predicted TeV-scale vector-quark T and scalar S at the LHC and future high energy pp colliders.
Searching for composite Higgs models at the LHC
NASA Astrophysics Data System (ADS)
Flacke, Thomas
2016-07-01
Composite Higgs models have the potential to provide a solution to the hierarchy problem and a dynamical explanation for the generation of the Higgs potential. They can be tested at the LHC as the new sector which underlies electroweak symmetry breaking must become strong in the TeV regime, which implies additional bound states beyond the Higgs. In this paper, we first discuss prospects and search strategies for top partners (and other quark partners) in the strongly coupled sector, which we study in an effective field theory setup. In the second part of the proceedings, we go beyond the effective field theory approach. We discuss potential UV embeddings for composite Higgs models which contain a Higgs as well as top partners. We show that in all of these models, additional pseudo-Nambu-Goldstone bosons beyond the Higgs are present. In particular, all of the models contain a pseudoscalar which couples to the Standard Model gauge fields through Wess-Zumino-Witten terms, providing a prime candidate for a di-boson (including a di-photon) resonance. The models also contain colored pNGBs which can be searched for at the LHC.