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Related papers: Gravitino Dark Matter and the Cosmic Lithium Abund…

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We analyze the possibility that the lighter stop {\tilde t_1} could be the next-to-lightest supersymmetric particle (NLSP) in models where the gravitino is the lightest supersymmetric particle (LSP). We do not find any possibility for a…

High Energy Physics - Phenomenology · Physics 2009-11-13 J. L. Diaz-Cruz , John Ellis , Keith A. Olive , Yudi Santoso

The low-scale gauge mediation scenario of supersymmetry breaking predicts very light gravitino, which makes the next lightest supersymmetric particle (NLSP) quasi stable. We study the LHC phenomenology of the case that the NLSP is the stau.…

High Energy Physics - Phenomenology · Physics 2015-06-03 Masaki Asano , Takumi Ito , Shigeki Matsumoto , Takeo Moroi

The `$\mu$ from $\nu$' supersymmetric standard model ($\mu\nu$SSM) solves the $\mu$ problem of supersymmetric models and reproduces neutrino data, simply using couplings with the three families of right-handed neutrinos $\nu$'s. Novel…

High Energy Physics - Phenomenology · Physics 2016-08-30 Carlos Muñoz

The catalysis of nuclear reactions by negatively charged relics leads to increased outputs of primordial ^6Li and ^9Be. In combination with observational constraints on the primordial fractions of ^6Li and ^9Be, this imposes strong…

High Energy Physics - Phenomenology · Physics 2010-04-30 Maxim Pospelov , Josef Pradler , Frank Daniel Steffen

In this work, we explore the "degenerate gravitino" scenario where the mass difference between the gravitino and the lightest MSSM particle is much smaller than the gravitino mass itself. In this case, the energy released in the decay of…

High Energy Physics - Phenomenology · Physics 2010-05-27 Lotfi Boubekeur , Ki Young Choi , Roberto Ruiz de Austri , Oscar Vives

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

We point out that the cosmological abundance of ${}^7$Li can be reduced down to observed values if during its formation Big Bang Nucleosynthesis is modified by the presence of light electrically neutral particles $X$ that have substantial…

High Energy Physics - Phenomenology · Physics 2016-06-01 Andreas Goudelis , Maxim Pospelov , Josef Pradler

Motivated by the absence of signals of new physics in both searches for new particles at LHC and for a Weakly Interacting Massive Particle (WIMP) dark matter candidate, we consider a scenario where supersymmetry is broken at a scale above…

High Energy Physics - Phenomenology · Physics 2017-05-10 Karim Benakli , Yifan Chen , Emilian Dudas , Yann Mambrini

We investigate the possibility that right-handed (RH) sneutrinos and gravitinos can coexist and explain the dark matter (DM) problem. We compare extensions of the minimal supersymmetric standard model (MSSM) and the next-to-MSSM (NMSSM)…

High Energy Physics - Phenomenology · Physics 2023-04-28 Jong Soo Kim , Daniel E. Lopez-Fogliani , Andres D. Perez , Roberto Ruiz de Austri

We present a solution to the gravitino problem, which arises in the NMSSM, allowing for sparticle spectra from ordinary gravity-mediated supersymmetry breaking with weak-scale gravitino dark matter. The coupling, which links the singlet to…

High Energy Physics - Phenomenology · Physics 2015-06-16 Jasper Hasenkamp , Martin Wolfgang Winkler

Big-bang nucleosynthesis (BBN) theory, together with the precise WMAP cosmic baryon density, makes tight predictions for the abundances of the lightest elements. Deuterium and 4He measurements agree well with expectations, but 7Li…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-19 Brian D. Fields

Supersymmetric (SUSY) standard models in which the lightest SUSY particle (LSP) is an ultralight gravitino (m_{3/2}=O(1) eV) are very attractive, since they are free from the cosmological gravitino problems. If the neutralino is the next…

High Energy Physics - Phenomenology · Physics 2009-10-06 Satoshi Shirai , T. T. Yanagida

A new scheme for lightest supersymmetric particle (LSP) dark matter is introduced and studied in theories of TeV supersymmetry with a QCD axion, $a$, and a high reheat temperature after inflation, $T_R$. A large overproduction of axinos…

High Energy Physics - Phenomenology · Physics 2017-03-20 Raymond T. Co , Francesco D'Eramo , Lawrence J. Hall

A search for sleptons, neutralinos, charginos, sgoldstinos and heavy stable charged sleptons in the context of scenarios where the lightest supersymmetric particle is the gravitino, is presented. Data collected during 2000 with the DELPHI…

High Energy Physics - Experiment · Physics 2008-11-26 The DELPHI Collaboration , J. Abdallah

We discuss the prospects for detecting supersymmetric particles in variants of the minimal supersymmetric extension of the Standard Model (MSSM), in light of laboratory and cosmological constraints. We first assume that the lightest…

High Energy Physics - Phenomenology · Physics 2009-09-11 John Ellis , Keith A. Olive , Yudi Santoso , Vassilis C. Spanos

The cosmological moduli problem for relatively heavy moduli fields is reinvestigated. For this purpose we examine the decay of a modulus field at a quantitative level. The modulus dominantly decays into gauge bosons and gauginos, provided…

High Energy Physics - Phenomenology · Physics 2011-07-18 Shuntaro Nakamura , Masahiro Yamaguchi

In the realm of natural supersymmetric models, higgsinos are typically the lightest electroweakinos. In gauge-mediated supersymmetry breaking models, the lightest higgsino-dominated particles decay into a $Z$-boson or a Higgs boson ($h$),…

High Energy Physics - Phenomenology · Physics 2024-08-15 Jian-Peng Dai , Song Li , Jin-Min Yang , Yang Zhang , Pengxuan Zhu , Rui Zhu

Based on the R-parity violation option of the minimal supersymmetric Standard Model, we examine the scenario where the massive gravitino, relic from the hot big-bang, is the lightest supersymmetric particle and can decay through one or…

High Energy Physics - Phenomenology · Physics 2007-05-23 G. Moreau

The identity of dark matter has not been solved up to this date, a problem that became the main topic of this conference. There are many theoretical candidates for dark matter particle, including gravitino from supergravity models. For…

High Energy Physics - Phenomenology · Physics 2010-02-17 Yudi Santoso

Recently, both the ATLAS and CMS experiments have observed an excess of events that could be the first evidence for a 125 GeV Higgs boson. We investigate an implication of the CP-even Higgs boson with mass around 125 GeV in the context of…

High Energy Physics - Phenomenology · Physics 2012-05-29 Nobuchika Okada