scholarly journals Lightest Visible-Sector Supersymmetric Particle is Likely to be Unstable

2016 ◽  
Vol 117 (18) ◽  
Author(s):  
Bobby S. Acharya ◽  
Sebastian A. R. Ellis ◽  
Gordon L. Kane ◽  
Brent D. Nelson ◽  
Malcolm J. Perry
Keyword(s):  
Supersymmetric Particle ◽  
Visible Sector

scholarly journals A decaying neutralino as dark matter and its gamma ray spectrum

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
Amin Aboubrahim ◽  
Tarek Ibrahim ◽  
Michael Klasen ◽  
Pran Nath
Keyword(s):  
Dark Matter ◽  
Radiative Decay ◽  
Gamma Ray ◽  
Indirect Detection ◽  
Supersymmetric Particle ◽  
Unified Framework ◽  
Dark Matter Annihilation ◽  
Hidden Sector ◽  
Visible Sector ◽  
The Universe

AbstractIt is shown that a decaying neutralino in a supergravity unified framework is a viable candidate for dark matter. Such a situation arises in the presence of a hidden sector with ultraweak couplings to the visible sector where the neutralino can decay into the hidden sector’s lightest supersymmetric particle (LSP) with a lifetime larger than the lifetime of the universe. We present a concrete model where the MSSM/SUGRA is extended to include a hidden sector comprised of $$U(1)_{X_1} \times U(1)_{X_2}$$ U ( 1 ) X 1 × U ( 1 ) X 2 gauge sector and the LSP of the hidden sector is a neutralino which is lighter than the LSP neutralino of the visible sector. We compute the loop suppressed radiative decay of the visible sector neutralino into the neutralino of the hidden sector and show that the decay can occur with a lifetime larger than the age of the universe. The decaying neutralino can be probed by indirect detection experiments, specifically by its signature decay into the hidden sector neutralino and an energetic gamma ray photon. Such a gamma ray can be searched for with improved sensitivity at Fermi-LAT and by future experiments such as the Square Kilometer Array (SKA) and the Cherenkov Telescope Array (CTA). We present several benchmarks which have a natural suppression of the hadronic channels from dark matter annihilation and decays and consistent with measurements of the antiproton background.

scholarly journals Search for squarks and gluinos in final states with jets and missing transverse momentum using 139 fb−1 of $$ \sqrt{s} $$ = 13 TeV pp collision data with the ATLAS detector

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
G. Aad ◽  
◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Hadron Collider ◽  
Atlas Detector ◽  
Simplified Model ◽  
Supersymmetric Particle ◽  
Final States ◽  
Proton Proton ◽  
Missing Transverse Momentum ◽  
First And Second Generation ◽  
Proton Proton Collisions

Abstract A search for the supersymmetric partners of quarks and gluons (squarks and gluinos) in final states containing jets and missing transverse momentum, but no electrons or muons, is presented. The data used in this search were recorded by the ATLAS experiment in proton-proton collisions at a centre-of-mass energy of $$ \sqrt{s} $$ s = 13 TeV during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb−1. The results are interpreted in the context of various R-parity-conserving models where squarks and gluinos are produced in pairs or in association and a neutralino is the lightest supersymmetric particle. An exclusion limit at the 95% confidence level on the mass of the gluino is set at 2.30 TeV for a simplified model containing only a gluino and the lightest neutralino, assuming the latter is massless. For a simplified model involving the strong production of mass-degenerate first- and second-generation squarks, squark masses below 1.85 TeV are excluded if the lightest neutralino is massless. These limits extend substantially beyond the region of supersymmetric parameter space excluded previously by similar searches with the ATLAS detector.

scholarly journals Searching for elusive dark sectors with terrestrial and celestial observations

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Roberto Contino ◽  
Kevin Max ◽  
Rashmish K. Mishra
Keyword(s):  
Field Theory ◽  
Broad Class ◽  
High Energy ◽  
Effective Field ◽  
Dark Sector ◽  
Minimum Requirement ◽  
Conformal Field ◽  
Starting Point ◽  
The Standard Model ◽  
Visible Sector

Abstract We consider the possible existence of a SM-neutral and light dark sector coupled to the visible sector through irrelevant portal interactions. Scenarios of this kind are motivated by dark matter and arise in various extensions of the Standard Model. We characterize the dark dynamics in terms of one ultraviolet scale Λuv, at which the exchange of heavy mediator fields generates the portal operators, and by one infrared scale ΛIR, setting the mass gap. At energies ΛIR « E « Λuv the dark sector behaves like a conformal field theory and its phenomenology can be studied model independently. We derive the constraints set on this scenario by high- and low-energy laboratory experiments and by astrophysical observations. Our results are conservative and serve as a minimum requirement that must be fulfilled by the broad class of models satisfying our assumptions, of which we give several examples. The experimental constraints are derived in a manner consistent with the validity of the effective field theory used to define the portal interactions. We find that high-energy colliders give the strongest bounds and exclude UV scales up to a few TeV, but only in specific ranges of the IR scale. The picture emerging from current searches can be taken as a starting point to design a future experimental strategy with broader sensitivity.

Extension of Standard Model in multi-spinor field formalism — Visible and dark sectors

2016 ◽  
Vol 31 (18) ◽  
pp. 1630027
Author(s):  
Ikuo S. Sogami
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Dark Sector ◽  
Quadratic Interaction ◽  
Inflationary Phase ◽  
The Standard Model ◽  
Visible Sector ◽  
Field Formalism ◽  
Main Component ◽  
Higgs Fields

With multi-spinor fields which behave as triple-tensor products of the Dirac spinors, the Standard Model is extended so as to embrace three families of ordinary quarks and leptons in the visible sector and an additional family of exotic quarks and leptons in the dark sector of our Universe. Apart from the gauge and Higgs fields of the Standard Model symmetry G, new gauge and Higgs fields of a symmetry isomorphic to G are postulated to exist in the dark sector. It is the bi-quadratic interaction between visible and dark Higgs fields that opens a main portal to the dark sector. Breakdowns of the visible and dark electroweak symmetries result in the Higgs boson with mass 125 GeV and a new boson which can be related to the diphoton excess around 750 GeV. Subsequent to a common inflationary phase and a reheating period, the visible and dark sectors follow weakly-interacting paths of thermal histories. We propose scenarios for dark matter in which no dark nuclear reaction takes place. A candidate for the main component of the dark matter is a stable dark hadron with spin 3/2, and the upper limit of its mass is estimated to be 15.1 GeV/c2.

scholarly journals Measuring supersymmetric particle masses at the LHC in scenarios with baryon-number R-parity violating couplings

2001 ◽  
Vol 2001 (03) ◽  
pp. 048-048 ◽  
Author(s):  
Ben C Allanach ◽  
Alan J Barr ◽  
Lee Drage ◽  
Christopher G Lester ◽  
Debbie Morgan ◽  
...  
Keyword(s):  
Baryon Number ◽  
Supersymmetric Particle

Supersymmetric-particle production at electron-positron colliders

1987 ◽  
Vol 35 (7) ◽  
pp. 2110-2123 ◽  
Author(s):  
Xerxes Tata ◽  
Duane A. Dicus
Keyword(s):  
Particle Production ◽  
Supersymmetric Particle ◽  
Electron Positron

scholarly journals PROBING GRAVITATIONAL INTERACTIONS OF ELEMENTARY PARTICLES

2004 ◽  
Vol 13 (10) ◽  
pp. 2355-2359 ◽  
Author(s):  
JONATHAN L. FENG ◽  
ARVIND RAJARAMAN ◽  
FUMIHIRO TAKAYAMA
Keyword(s):  
Dark Matter ◽  
Early Universe ◽  
Particle Physics ◽  
Gravitational Constant ◽  
Planck Scale ◽  
Elementary Particles ◽  
Supersymmetric Particle ◽  
Small Scales ◽  
Physics Experiments ◽  
Shed Light

The gravitational interactions of elementary particles are suppressed by the Planck scale M*~1018 GeV and are typically expected to be far too weak to be probed by experiments. We show that, contrary to conventional wisdom, such interactions may be studied by particle physics experiments in the next few years. As an example, we consider conventional supergravity with a stable gravitino as the lightest supersymmetric particle. The next-lightest supersymmetric particle (NLSP) decays to the gravitino through gravitational interactions after about a year. This lifetime can be measured by stopping NLSPs at colliders and observing their decays. Such studies will yield a measurement of Newton's gravitational constant on unprecedentedly small scales, shed light on dark matter, and provide a window on the early universe.

scholarly journals Flavor physics at large tanβwith a binolike lightest supersymmetric particle

2007 ◽  
Vol 75 (11) ◽  
Author(s):  
G. Isidori ◽  
F. Mescia ◽  
P. Paradisi ◽  
D. Temes
Keyword(s):  
Flavor Physics ◽  
Supersymmetric Particle

scholarly journals Inflation and supersymmetry breaking in Higgs-R2 supergravity

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Shuntaro Aoki ◽  
Hyun Min Lee ◽  
Adriana G. Menkara
Keyword(s):  
Supersymmetry Breaking ◽  
Planck Scale ◽  
Scalar Fields ◽  
Minimal Coupling ◽  
Slow Roll ◽  
New Construction ◽  
Visible Sector ◽  
Higgs Fields ◽  
Chiral Superfields ◽  
Slow Roll Inflation

Abstract We propose a new construction of the supergravity inflation as an UV completion of the Higgs-R2 inflation. In the dual description of R2-supergravity, we show that there appear dual chiral superfields containing the scalaron or sigma field in the Starobinsky inflation, which unitarizes the supersymmetric Higgs inflation with a large non-minimal coupling up to the Planck scale. We find that a successful slow-roll inflation is achievable in the Higgs-sigma field space, but under the condition that higher curvature terms are introduced to cure the tachyonic mass problems for spectator singlet scalar fields. We also discuss supersymmetry breaking and its transmission to the visible sector as a result of the couplings of the dual chiral superfields and the non-minimal gravity coupling of the Higgs fields.

Sign in / Sign up

Export Citation Format

Share Document