Flavored co-annihilations

Abstract

Neutralino dark matter in supersymmetric models is revisited in the presence of flavor violation in the soft supersymmetry breaking sector. We focus on flavor violation in the sleptonic sector and study the implications for the co-annihilation regions. Flavor violation is introduced by a singleμ R −τ R insertion in the slepton mass matrix. Limits on this insertion from BR(τ → µ + γ) are weak in some regions of the parameter space where cancellations happen within the amplitudes. We look for overlaps in parameter space where both the co-annihilation condition as well as the cancellations within the amplitudes occur. In mSUGRA, such overlap regions are not existent, whereas they are present in models with non-universal Higgs boundary conditions (NUHM). The effect of flavor violation is two fold: (a) it shifts the co-annihilation regions towards lighter neutralino masses (b) the co-annihilation cross sections would be modified with the inclusion of flavor violating diagrams which can contribute significantly. Even if flavor violation is within the presently allowed limits, this is sufficient to modify the thermally averaged cross-sections by about (10-15)% in mSUGRA and (20-30)% in NUHM, depending on the parameter space. In the overlap regions, the flavor violating cross sections become comparable and in some cases even dominant to the flavor conserving ones. A comparative study of the channels is presented for mSUGRA and NUHM cases.

Phenomenology of anomaly-mediated supersymmetry-breaking scenarios with nonminimal flavor violation

“…[75], this has been studied for the case of minimal supergravity scenarios, where flavor-violating couplings can modify the annihilation and coannihilation modes that enter the Boltzmann equation in the typical scenario with thermal production of neutralinos. Similar conclusions have been found for flavor nondiagonal entries in the leptonic soft matrices [76]. Flavor-violating effects are, of course, also present in the discussed cases of moduli or gravitino decay.…”

Data-driven analysis of a SUSY GUT of flavour

“…Extensive studies have shown that the MSSM parameter space can accomodate NMFV in both the squark and the slepton sectors despite the numerous experimental and theoretical constraints [12][13][14]. In addition, NMFV may lead to specific collider signatures [15][16][17][18][19][20][21][22][23][24][25], weaken the current mass limits derived from the non-observation of superpartners [26][27][28], and, although to some lesser extend, affect the dark matter phenomenology [29][30][31][32].…”

Non-minimal flavour violation in A4 × SU(5) SUSY GUTs with smuon assisted dark matter

“…In recent years, the possibility of NMFV has received considerable attention in the context of studies of TeV scale physics [7], mainly concerning collider signatures [8][9][10][11][12][13][14][15][16][17][18][19][20][21], but also dark-matter-related aspects [22][23][24][25] and precision data [26][27][28][29]. Moreover, a considerable amount of work has been realized on flavour violation aspects within ultraviolet frameworks [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46].…”