Grand unified theory constrained supersymmetry and neutrinoless doubleβdecay

Abstract

We analyze the contributions to the neutrinoless double β decay (0νββ-decay) coming from the Grand Unified Theory (GUT) constrained Minimal Supersymmetric Standard Model (MSSM) with trilinear R-parity breaking. We discuss the importance of two-nucleon and pion-exchange realizations of the quark-level 0νββ-decay transitions. In this context, the questions of reliability of the calculated relevant nuclear matrix elements within the Renormalized Quasiparticle Random Phase Approximation (pn-RQRPA) for several medium and heavy open-shell nuclei are addressed. The importance of gluino and neutralino contributions to 0νββ-decay is also analyzed. We review the present experiments and deduce limits on the trilinear R-parity breaking parameter λ ′ 111 from the non-observability of 0νββ-decay for different GUT constrained SUSY scenarios. In addition, a detailed study of limits on the MSSM parameter space coming from the B → X s γ processes by using the recent CLEO and OPAL results is performed. Some studies in respect to the future 0νββ-decay project GENIUS are also presented.12.60. Jv,11.30.Er,23.40.Bw Typeset using REVT E X 1 .

Minimal supersymmetric standard model with gauge mediated supersymmetry breaking and neutrinoless doubleβdecay

“…In the previous studies such estimates were performed in the framework of / RMSSM with supergravity mediated SUSY breaking by means of GUT constraints [17,19] or additional assumptions relating sfermions and gauginos masses [15,16]. We will show that one can find quantitatively new constraints [18] within GMSB models.…”

“…The formulae (17) and (18) may therefore serve as boundary conditions for evolution of soft parameters at the electroweak scale. Our procedure resulting in low energy spectrum of SUGRA and GMSB MSSM models and its application to the description of 0νββ decay can be found in our previous papers [18,19], so here we only sketch its most important features.…”

(μ−,μ+)conversion in nuclei as a probe of new physics

“…Random Phase Approximation [12,18,14] and analyzed the full 0 − 3hω shells plus 2s 1/2 , 0g 7/2 and 0g 9/2 levels as a single-particle model space both for protons and neutrons. The single particle energies have been obtained by using a Coulomb-corrected Woods-Saxon potential.…”

“…We carried out a detailed analysis of the nuclear structure effects in the (µ − , µ + ) conversion within the renormalized quasiparticle random phase approximation (RQRPA) [12][13][14]. The theoretical upper bounds on the branching ratios are evaluated using the current constraints on the relevant LNV parameters.…”

High sensitivity GEM experiment on 2β decay of76Ge

“…Moreover, there are also possible 0ν2β decay mechanisms based on the supersymmetric (SUSY) interactions: exchange of squarks, etc., within R-parity violating [69,70,71,72] and exchange of sneutrinos, etc. in R-parity conserving SUSY models [73].…”