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Related papers: Minimal Supergravity with m_0^2 < 0

200 papers

We investigate the minimal supergravity (mSUGRA) signals at the LHC in the context of supercritical string cosmology (SSC). In this theory, the presence of a time dependent dilaton provides us with a smoothly evolving dark energy and…

High Energy Physics - Phenomenology · Physics 2009-05-12 Bhaskar Dutta , Alfredo Gurrola , Teruki Kamon , Abram Krislock , A. B. Lahanas , N. E. Mavromatos , D. V. Nanopoulos

From general supergravity theory with unified gauge symmetry, we obtain the low-energy effective Lagrangian by taking the flat limit and integrating out the superheavy fields in model-independent manner. The scalar potential possesses some…

High Energy Physics - Phenomenology · Physics 2009-10-28 Yoshiharu Kawamura

I advocate the virtues of a very economical version of the minimal supersymmetric standard model which avoids cosmological problems often encountered in dynamical SUSY-breaking and solves the SUSY-CP problem. Imposing $m_Z=91$ GeV and $m_t…

High Energy Physics - Phenomenology · Physics 2007-05-23 Glennys R. Farrar

We argue for a relation between the supersymmetry breaking scale and the measured value of the dark energy density $\Lambda$. We derive it by combining two quantum gravity consistency swampland constraints, which tie the dark energy density…

High Energy Physics - Theory · Physics 2023-05-17 Luis A. Anchordoqui , Ignatios Antoniadis , Niccolò Cribiori , Dieter Lust , Marco Scalisi

We analyse the role, on large cosmological scales and laboratory experiments, of the leading curvature squared contributions to the low energy effective action of gravity. We argue for a natural relationship $c_0\lambda^2\simeq 1$ at…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Philippe Brax , Patrick Valageas , Pierre Vanhove

We investigate the superWIMP scenario in the framework of supersymmetry, in which the lightest supersymmetric particle is a stable gravitino. We consider slepton, sneutrino or neutralino being the next-lightest supersymmetric particle, and…

High Energy Physics - Phenomenology · Physics 2007-05-23 Jonathan L. Feng , Shufang Su , Fumihiro Takayama

The E989 experiment at the Fermi National Laboratory reported a 4.2$\sigma$ discrepancy between the measured magnetic dipole moment of the muon, and its prediction in the Standard Model (SM). In this study, we address the anomaly by…

High Energy Physics - Phenomenology · Physics 2021-12-17 Jan Tristram Acuña , Patrick Stengel , Piero Ullio

Arguments are given that the lightest supersymmetric particle should be a neutralino $\chi$. Minimizing the fine tuning of the gauge hierarchy favours $\Omega_{\chi} h^2 \sim 0.1$. There are important constraints on the parameter space of…

Astrophysics · Physics 2009-10-31 John Ellis

A new approach is proposed to phenomenological study of a generic unified supergravity model, which reduces to the minimal supersymmetric standard model. The model is effectively parametrized in terms of five low energy observables. In…

High Energy Physics - Phenomenology · Physics 2009-10-22 M. Olechowski , S. Pokorski

We consider the possibility that the lightest supersymmetric particle is a heavy gluino. After discussing models in which this is the case, we demonstrate that the gluino-LSP could evade cosmological and other constraints by virtue of…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. Baer , K. Cheung , J. F. Gunion

An update of the search for sleptons, neutralinos and charginos in the context of scenarios where the lightest supersymmetric particle is the gravitino and the next-to-lightest supersymmetric particle is a slepton, is presented, together…

High Energy Physics - Experiment · Physics 2010-04-08 The DELPHI Collaboration , P. Abreu

Scalar fields with inverse power-law effective potentials may provide a negative pressure component to the energy density of the universe today, as required by cosmological observations. In order to be cosmologically relevant today, the…

High Energy Physics - Phenomenology · Physics 2016-09-06 Nicola Bartolo , Massimo Pietroni

Dark matter is examined within the ``golden region'' of the Minimal Supersymmetric Standard Model. This region satisfies experimental constraints, including a lower bound on the Higgs mass of 114 GeV, and minimizes fine-tuning of the Z…

High Energy Physics - Phenomenology · Physics 2009-03-12 Junya Kasahara , Katherine Freese , Paolo Gondolo

We study the light gluino scenario giving special attention to constraints from the masses of the light CP-even neutral Higgs $m_h$, the lightest chargino $m_{\chi^{\pm}_1}$, and the second lightest neutralino $m_{\chi^0_2}$, and from the…

High Energy Physics - Phenomenology · Physics 2014-11-17 Marco Aurelio Diaz

In mSUGRA models the lightest supersymmetric particle (assumed to be the lightest neutralino) provides an excellent cold dark matter (CDM) candidate. The supersymmetric parameter space is significantly reduced, if the limits on the CDM…

High Energy Physics - Phenomenology · Physics 2007-05-23 Luisa Sabrina Stark , Petra Hafliger , Adrian Biland , Felicitas Pauss

Several parameters of the minimal supergravity model are estimated by the method of the renormalization group. In this model, five arbitrary parameters $(m_0, m_{1/2}, \tan{\beta}, A_0, {sig}(\mu))$ are contained. $\tan{\beta}$ is evaluated…

High Energy Physics - Phenomenology · Physics 2007-05-23 Jun Tabei , Hiroshi Hotta

We investigate supergravity models in which the lightest supersymmetric particle (LSP) is a stable gravitino. We assume that the next-lightest supersymmetric particle (NLSP) freezes out with its thermal relic density before decaying to the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Jonathan L. Feng , Shufang Su , Fumihiro Takayama

The identity of dark matter is one of the greatest puzzles of our Universe. Its solution may be associated with supersymmetry which is a fundamental space-time symmetry that has not been verified experimentally so far. In many…

High Energy Physics - Phenomenology · Physics 2007-08-28 Frank Daniel Steffen

Weak scale supersymmetry has a generic problem of fine-tuning in reproducing the correct scale for electroweak symmetry breaking. The problem is particularly severe in the minimal supersymmetric extension of the standard model (MSSM). We…

High Energy Physics - Phenomenology · Physics 2009-09-29 Ryuichiro Kitano , Yasunori Nomura

One of the key features of the $R^2$-gravity is the embedding of a scalar field, scalaron, into the gravity sector. The scalaron interacts with the Standard Model (SM) matter fields through Planck-suppressed couplings. If the scalaron…

High Energy Physics - Phenomenology · Physics 2026-05-26 Shibendu Gupta Choudhury , Koushik Dutta , Deep Ghosh