BOUNDS ON THE COUPLING CONSTANTS OF THE MAJORON TO TWO NEUTRINOS IN EXTRA DIMENSIONS FROM Z → νν(J) DECAY

2005 ◽  
Vol 20 (27) ◽  
pp. 6247-6257
Author(s):  
SHERIF MOUSSA ◽  
SALAH NASRI ◽  
FRANCESCO SANNINO ◽  
JOSEPH SCHECHTER
Keyword(s):  
Z Boson ◽  
Extra Dimensions ◽  
Higher Dimensions ◽  
Upper Bounds ◽  
Partial Width ◽  
Coupling Constants ◽  
Expected Increase ◽  
Kaluza Klein ◽  
The Invisible

We give an overview for the bounds of Majoron-neutrino coupling constants from supernova and accelerators. Using the accurate known value for the invisible partial width for Z boson we obtained constraints on the coupling of the Majoron to two neutrinos, for singlet Majoron model, in case of 3+1 dimensions as well as in extra dimensions, where we assumed the singlet Majoron can propagate in higher dimensions. We found that the predicted coupling constants are far below these upper bounds if a natural see-saw is adopted. Also, the expected increase in Z partial width due to many Kaluza-Klein excitations has been suppressed due to the decrease of the coupling constants.

scholarly journals Z boson decay to photon plus Kaluza-Klein graviton in large extra dimensions

2007 ◽  
Vol 2007 (11) ◽  
pp. 089-089 ◽  
Author(s):  
Benjamin C Allanach ◽  
Jordan P Skittrall ◽  
K Sridhar
Keyword(s):  
Z Boson ◽  
Extra Dimensions ◽  
Large Extra Dimensions ◽  
Kaluza Klein

scholarly journals Unitarity in KK-graviton production, a case study in warped extra-dimensions

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
A. de Giorgi ◽  
S. Vogl
Keyword(s):  
Extra Dimensions ◽  
Sum Rules ◽  
Effective Theory ◽  
Higher Dimensional ◽  
Massive Spin ◽  
The Matrix ◽  
Dimensional Gravity ◽  
Warped Extra Dimensions ◽  
Kaluza Klein

Abstract The Kaluza-Klein (KK) decomposition of higher-dimensional gravity gives rise to a tower of KK-gravitons in the effective four-dimensional (4D) theory. Such massive spin-2 fields are known to be connected with unitarity issues and easily lead to a breakdown of the effective theory well below the naive scale of the interaction. However, the breakdown of the effective 4D theory is expected to be controlled by the parameters of the 5D theory. Working in a simplified Randall-Sundrum model we study the matrix elements for matter annihilations into massive gravitons. We find that truncating the KK-tower leads to an early breakdown of perturbative unitarity. However, by considering the full tower we obtain a set of sum rules for the couplings between the different KK-fields that restore unitarity up to the scale of the 5D theory. We prove analytically that these are fulfilled in the model under consideration and present numerical tests of their convergence. This work complements earlier studies that focused on graviton self-interactions and yields additional sum rules that are required if matter fields are incorporated into warped extra-dimensions.

KALUZA–KLEIN BOTTLE COUPLED TO TOLMAN–HAWKING WORMHOLE

1991 ◽  
Vol 06 (17) ◽  
pp. 1547-1552
Author(s):  
A. DAVIDSON ◽  
Y. VERBIN
Keyword(s):  
Scalar Field ◽  
Klein Bottle ◽  
Gauge Coupling ◽  
Coupling Constants ◽  
Five Dimensions ◽  
Symmetric Configuration ◽  
Kaluza Klein

Asymptotically Euclidean regions connected by a wormhole may differ by their associated gauge coupling constants. This idea is realized in a field-theoretical manner using a conformally coupled scalar field in five dimensions. An SO (4) × U (1) e.m. -symmetric configuration is derived, describing a Kaluza–Klein bottle coupled to a Tolman–Hawking wormhole.

scholarly journals ON THE QUANTUM CHROMODYNAMICS OF A MASSIVE VECTOR FIELD IN THE ADJOINT REPRESENTATION

2013 ◽  
Vol 28 (14) ◽  
pp. 1350054 ◽  
Author(s):  
ALFONSO R. ZERWEKH
Keyword(s):  
Vector Field ◽  
Quantum Chromodynamics ◽  
Extra Dimensions ◽  
Scalar Fields ◽  
Discrete Symmetry ◽  
Adjoint Representation ◽  
Coupling Constants ◽  
Gauge Symmetries ◽  
Gauge Fixing ◽  
Definition Of

In this paper, we explore the possibility of constructing the quantum chromodynamics of a massive color-octet vector field without introducing higher structures like extended gauge symmetries, extra dimensions or scalar fields. We show that gauge invariance is not enough to constraint the couplings. Nevertheless, the requirement of unitarity fixes the values of the coupling constants, which otherwise would be arbitrary. Additionally, it opens a new discrete symmetry which makes the coloron stable and avoid its resonant production at a collider. On the other hand, a judicious definition of the gauge fixing terms modifies the propagator of the massive field making it well-behaved in the ultraviolet limit. The relation between our model and the more general approach based on extended gauge symmetries is also discussed.

GRAVITATIONAL BAG EFFECTS ON KALUZA KLEIN AND STRING EXCITATIONS

1989 ◽  
Vol 04 (19) ◽  
pp. 5119-5131 ◽  
Author(s):  
E. I. GUENDELMAN
Keyword(s):  
Extra Dimensions ◽  
Blow Up ◽  
Point Of View ◽  
Spherically Symmetric ◽  
Massive String ◽  
Free Objects ◽  
Higher Dimensional ◽  
Central Regions ◽  
The Masses ◽  
Kaluza Klein

Gravitational Bags are spherically symmetric solutions of higher-dimensional Kaluza Klein (K – K) theories, where the compact dimensions become very large near the center of the geometry, although they are small elsewhere. The K – K excitations therefore become very light when located near the center of this geometry and this appears to affect drastically the naive tower of the masses spectrum of K – K theories. In the context of string theories, string excitations can be enclosed by Gravitational Bags, making them not only lighter, but also localized, as observed by somebody, that does not probe the central regions. Strings, however, can still have divergent sizes, as quantum mechanics seems to demand, since the extra dimensions blow up at the center of the geometry. From a projected 4-D point of view, very massive string bits may lie inside their Schwarzschild radii, as pointed out by Casher, Gravitational Bags however are horizon free objects, so no conflict with macroscopic causality arises if the string excitations are enclosed by Gravitational Bags.

scholarly journals A SCREENING MECHANISM FOR EXTRA W AND Z GAUGE BOSONS

2000 ◽  
Vol 15 (21) ◽  
pp. 3369-3394
Author(s):  
JOAQUIM MATIAS ◽  
ALESSANDRO VICINI
Keyword(s):  
Mass Spectrum ◽  
Gauge Boson ◽  
Extra Dimensions ◽  
Boson Mass ◽  
Gauge Bosons ◽  
Gauge Boson Mass ◽  
Kaluza Klein

We generalize a previous construction of a fermiophobic model to the case of more than one extra W and Z gauge bosons. We focus in particular on the existence of screening configurations and their implication on the gauge boson mass spectrum. One of these configurations allows for the existence of a set of relatively light new gauge bosons, without violation of the quite restrictive bounds coming from the ρ NC parameter. The links with Bess and degenerate Bess models are also discussed. Also the signal given here by this more traditional gauge extension of the SM could help to disentangle it from the towers of Kaluza–Klein states over W and Z gauge bosons in extra dimensions.

scholarly journals Minimal surfaces and generalized Einstein–Maxwell-dilaton theory

2019 ◽  
Vol 34 (12) ◽  
pp. 1950061
Author(s):  
M. Butler ◽  
A. M. Ghezelbash
Keyword(s):  
Cosmological Constant ◽  
Physical Properties ◽  
Minimal Surfaces ◽  
Higher Dimensions ◽  
Coupling Constants ◽  
Dilaton Field ◽  
Coupling Constant ◽  
Maxwell Theory ◽  
Five Dimensions ◽  
Cosmological Solutions

We present novel classes of nonstationary solutions to the five-dimensional generalized Einstein–Maxwell-dilaton theory with cosmological constant, in which the Maxwell’s field and the cosmological constant couple to the dilaton field. In the first class of solutions, the two nonzero coupling constants are different, while in the second class of solutions, the two coupling constants are equal to each other. We find consistent cosmological solutions with positive, negative or zero cosmological constant, where the cosmological constant depends on the value of one coupling constant in the theory. Moreover, we discuss the physical properties of the five-dimensional solutions and the uniqueness of the solutions in five dimensions by showing the solutions with different coupling constants cannot be uplifted to any Einstein–Maxwell theory in higher dimensions.

scholarly journals COSMOLOGICAL CONSTANT PROBING SHAPE MODULI THROUGH LARGE EXTRA DIMENSIONS

2006 ◽  
Vol 21 (15) ◽  
pp. 3095-3109 ◽  
Author(s):  
SATOSHI MATSUDA ◽  
SHIGENORI SEKI
Keyword(s):  
Cosmological Constant ◽  
Extra Dimensions ◽  
Vacuum Energy ◽  
Large Extra Dimensions ◽  
Casimir Energy ◽  
Wilkinson Microwave Anisotropy Probe ◽  
Extra Space ◽  
Kaluza Klein

We consider a compactification of extra dimensions and numerically calculate Casimir energy which is provided by the mass of Kaluza–Klein modes. For the extra space we consider a torus with shape moduli and show that the corresponding vacuum energy is represented as a function of the moduli parameter of the extra dimensions. By assuming that the Casimir energy may be identified with cosmological constant, we evaluate the size of extra dimensions in terms of the recent data given by the Wilkinson Microwave Anisotropy Probe (WMAP) measurement and the supernovae observations. We suggest that the observed cosmological constant may probe the shape moduli of the extra space by the study of the Casimir energy of the compactified extra dimensions.

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