scholarly journals Sigma-assisted low scale composite Goldstone–Higgs

2020 ◽  
Vol 80 (1) ◽  
Author(s):  
Diogo Buarque Franzosi ◽  
Giacomo Cacciapaglia ◽  
Aldo Deandrea
Keyword(s):  
Higgs Boson ◽  
Misalignment Angle ◽  
Partial Compositeness ◽  
Scalar Resonance ◽  
The Common ◽  
Walking Dynamics ◽  
Compositeness Scale ◽  
Flavour Physics

AbstractWe show that the presence of a lightish scalar resonance, $$\sigma $$σ, that mixes with the composite Goldstone–Higgs boson can relax the typical bounds found in this class of models. This mechanism, inbred in models with a walking dynamics above the condensation scale, allows for a low compositeness scale $$f \gtrsim 400$$f≳400 GeV, corresponding to a misalignment angle $$s_\theta \lesssim 0.6$$sθ≲0.6, contrary to the common lore of a smaller angle. According to recent lattice results, the light $$\sigma $$σ emerges thanks to a near-conformal phase above the condensation scale, consistent to the requirements from flavour physics. We study this effect in a general way, showing that it appears in all cosets emerging from an underlying gauge-fermion dynamics, in the presence of top partial compositeness. The scenario is testable both on the Lattice and experimentally, as it requires the presence of a second broad Higgs-like resonance, below 1 TeV, that can be revealed at the LHC in the ZZ and $$t\bar{t}$$tt¯ channels.

scholarly journals Neutrino masses from low scale partial compositeness

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Zackaria Chacko ◽  
Patrick J. Fox ◽  
Roni Harnik ◽  
Zhen Liu
Keyword(s):  
Beta Decay ◽  
Form Factors ◽  
Neutrinoless Double Beta Decay ◽  
Double Beta Decay ◽  
Neutrino Masses ◽  
Hidden Sector ◽  
Partial Compositeness ◽  
Order Of Magnitude ◽  
Partially Composite ◽  
Compositeness Scale

Abstract We consider a class of models in which the neutrinos acquire Majorana masses through mixing with singlet neutrinos that emerge as composite states of a strongly coupled hidden sector. In this framework, the light neutrinos are partially composite particles that obtain their masses through the inverse seesaw mechanism. We focus on the scenario in which the strong dynamics is approximately conformal in the ultraviolet, and the compositeness scale lies at or below the weak scale. The small parameters in the Lagrangian necessary to realize the observed neutrino masses can naturally arise as a consequence of the scaling dimensions of operators in the conformal field theory. We show that this class of models has interesting implications for a wide variety of experiments, including colliders and beam dumps, searches for lepton flavor violation and neutrinoless double beta decay, and cosmological observations. At colliders and beam dumps, this scenario can give rise to striking signals involving multiple displaced vertices. The exchange of hidden sector states can lead to observable rates for flavor violating processes such as μ → eγ and μ → e conversion. If the compositeness scale lies at or below a hundred MeV, the rate for neutrinoless double beta decay is suppressed by form factors and may be reduced by an order of magnitude or more. The late decays of relic singlet neutrinos can give rise to spectral distortions in the cosmic microwave background that are large enough to be observed in future experiments.

scholarly journals The twisted dark matter halo of the Milky Way

2020 ◽  
Author(s):  
Shi Shao ◽  
Marius Cautun ◽  
Alis Deason ◽  
Carlos S Frenk
Keyword(s):  
Dark Matter ◽  
Milky Way ◽  
Orbital Plane ◽  
Minor Axis ◽  
Dark Matter Halo ◽  
Misalignment Angle ◽  
Stellar Disc ◽  
Confidence Levels ◽  
The Common ◽  
Inner Parts

Abstract We analyse systems analogous to the Milky Way (MW) in the eagle cosmological hydrodynamics simulation in order to deduce the likely structure of the MW’s dark matter halo. We identify MW-mass haloes in the simulation whose satellite galaxies have similar kinematics and spatial distribution to those of the bright satellites of the MW, specifically systems in which the majority of the satellites (8 out of 11) have nearly co-planar orbits that are also perpendicular to the central stellar disc. We find that the normal to the common orbital plane of the co-planar satellites is well aligned with the minor axis of the host dark matter halo, with a median misalignment angle of only 17.3○. Based on this result, we infer that the minor axis of the Galactic dark matter halo points towards (l, b) = (182○, −2○), with an angular uncertainty at the 68 and 95 percentile confidence levels of 22○ and 43○ respectively. Thus, the inferred minor axis of the MW halo lies in the plane of the stellar disc. The halo, however, is not homologous and its flattening and orientation vary with radius. The inner parts of the halo are rounder than the outer parts and well aligned with the stellar disc (that is the minor axis of the halo is perpendicular to the disc). Further out, the halo twists and the minor axis changes direction by 90○. This twist occurs over a very narrow radial range and reflects variations in the filamentary network along which mass was accreted into the MW.

scholarly journals A HIGGS OR NOT A HIGGS? WHAT TO DO IF YOU DISCOVER A NEW SCALAR PARTICLE

2002 ◽  
Vol 17 (14) ◽  
pp. 1841-1918 ◽  
Author(s):  
C. P. BURGESS ◽  
J. MATIAS ◽  
M. POSPELOV
Keyword(s):  
Higgs Boson ◽  
Decision Tree ◽  
A Priori ◽  
Scalar Particle ◽  
Common Assumption ◽  
Theoretical Assumptions ◽  
The Common

We show how to systematically analyze what may be inferred should a new scalar particle be discovered in collider experiments. Our approach is systematic in the sense that we perform the analysis in a manner which minimizes a priori theoretical assumptions as to the nature of the scalar particle. For instance, we do not immediately make the common assumption that a new scalar particle is a Higgs boson, and so must interact with a strength proportional to the mass of the particles with which it couples. We show how to compare different observables, and so to develop a decision tree from which the nature of the new particle may be discerned. We define several categories of models, which summarize the kinds of distinctions which the first experiments can make.

scholarly journals Uncovering the relation of a scalar resonance to the Higgs boson

2017 ◽  
Vol 95 (9) ◽  
Author(s):  
Adrián Carmona ◽  
Florian Goertz ◽  
Andreas Papaefstathiou
Keyword(s):  
Higgs Boson ◽  
Scalar Resonance

scholarly journals Reconstruction and identification of boosted di-τ systems in a search for Higgs boson pairs using 13 TeV proton-proton collision data in ATLAS

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Hadron Collider ◽  
Gluon Fusion ◽  
Mass Range ◽  
Proton Collision ◽  
Final State ◽  
Proton Proton ◽  
Scalar Resonance ◽  
Proton Proton Collision ◽  
A New Technique

Abstract In this paper, a new technique for reconstructing and identifying hadronically decaying τ+τ− pairs with a large Lorentz boost, referred to as the di-τ tagger, is developed and used for the first time in the ATLAS experiment at the Large Hadron Collider. A benchmark di-τ tagging selection is employed in the search for resonant Higgs boson pair production, where one Higgs boson decays into a boosted $$ b\overline{b} $$ b b ¯ pair and the other into a boosted τ+τ− pair, with two hadronically decaying τ-leptons in the final state. Using 139 fb−1 of proton-proton collision data recorded at a centre-of-mass energy of 13 TeV, the efficiency of the di-τ tagger is determined and the background with quark- or gluon-initiated jets misidentified as di-τ objects is estimated. The search for a heavy, narrow, scalar resonance produced via gluon-gluon fusion and decaying into two Higgs bosons is carried out in the mass range 1–3 TeV using the same dataset. No deviations from the Standard Model predictions are observed, and 95% confidence-level exclusion limits are set on this model.

Catalogue reduction techniques

1978 ◽  
Vol 48 ◽  
pp. 389-390 ◽  
Author(s):  
Chr. de Vegt
Keyword(s):  
Adjustment Process ◽  
Proper Motions ◽  
Measuring Process ◽  
Aerial Photogrammetry ◽  
Reduction Techniques ◽  
Observational Technique ◽  
The Common ◽  
Astrometric Data

AbstractReduction techniques as applied to astrometric data material tend to split up traditionally into at least two different classes according to the observational technique used, namely transit circle observations and photographic observations. Although it is not realized fully in practice at present, the application of a blockadjustment technique for all kind of catalogue reductions is suggested. The term blockadjustment shall denote in this context the common adjustment of the principal unknowns which are the positions, proper motions and certain reduction parameters modelling the systematic properties of the observational process. Especially for old epoch catalogue data we frequently meet the situation that no independent detailed information on the telescope properties and other instrumental parameters, describing for example the measuring process, is available from special calibration observations or measurements; therefore the adjustment process should be highly self-calibrating, that means: all necessary information has to be extracted from the catalogue data themselves. Successful applications of this concept have been made already in the field of aerial photogrammetry.

Renilla Bioluminescence: A Morphologic Approach to the Location of Photocytes

1974 ◽  
Vol 32 ◽  
pp. 208-209
Author(s):  
Ben O. Spurlock ◽  
Milton J. Cormier
Keyword(s):  
Excited State ◽  
Ground State ◽  
Molecular Basis ◽  
Light Emission ◽  
Chemical Basis ◽  
Electronic Excited State ◽  
Colonial Form ◽  
The Common ◽  
Eighteenth And Nineteenth Centuries ◽  
Catalyzed Oxidation

The phenomenon of bioluminescence has fascinated layman and scientist alike for many centuries. During the eighteenth and nineteenth centuries a number of observations were reported on the physiology of bioluminescence in Renilla, the common sea pansy. More recently biochemists have directed their attention to the molecular basis of luminosity in this colonial form. These studies have centered primarily on defining the chemical basis for bioluminescence and its control. It is now established that bioluminescence in Renilla arises due to the luciferase-catalyzed oxidation of luciferin. This results in the creation of a product (oxyluciferin) in an electronic excited state. The transition of oxyluciferin from its excited state to the ground state leads to light emission.

Mammalian Bone Marrow Acetylcholinesterase

1982 ◽  
Vol 40 ◽  
pp. 44-45
Author(s):  
Ezzatollah Keyhani
Keyword(s):  
Central Nervous System ◽  
Bone Marrow ◽  
Nervous System ◽  
Common Property ◽  
Extracellular Medium ◽  
The Central Nervous System ◽  
The Common ◽  
Mammalian Bone

Acetylcholinesterase (EC 3.1.1.7) (ACHE) has been localized at cholinergic junctions both in the central nervous system and at the periphery and it functions in neurotransmission. ACHE was also found in other tissues without involvement in neurotransmission, but exhibiting the common property of transporting water and ions. This communication describes intracellular ACHE in mammalian bone marrow and its secretion into the extracellular medium.

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