Large Hadron Collider Probe of Supersymmetric Neutrinoless Double-Beta-Decay Mechanism

Abstract

In the minimal supersymmetric extension to the standard model, a nonzero lepton number violating coupling lambda(111);(') predicts both neutrinoless double-beta-decay and resonant single slepton production at the LHC. We show that, in this case, if neutrinoless double beta decay is discovered in the next generation of experiments, there exist good prospects to observe single slepton production at the LHC. Neutrinoless double beta decay could otherwise result from a different source (such as a nonzero Majorana neutrino mass). Resonant single slepton production at the LHC can therefore discriminate between the lambda(111);(') neutrinoless double-beta-decay mechanism and others.

Neutrinoless double-beta decay and physics beyond the standard model

“…Similar to the situation in left-right symmetric models, also in R-parity violating SUSY scenarios interesting and complementary information can be obtained from the neutrinoless double beta decay analogue at the LHC, namely resonant single selectron production with two like sign electrons in the final state [56,57]. The color and spin-averaged parton total cross section of a single slepton production is given by [58] …”

“…Region in the mSUGRA parameter space (vertical axis: M 1/2 in GeV, horizontal axis: M 0 in GeV) in which single slepton production may be observed at the LHC for tan β = 10, A 0 = 0 and 10fb −1 of integrated luminosity. In the top left-hand black triangle, the stau is the LSP, a case not discussed in [56]. The black region at the bottom is ruled out by direct search constraints.…”

“…In [56,57] it has been shown that much of the parameter space allowed by 0νββ decay in simple models of supersymmetry breaking actually predicts observable single slepton production at the LHC (compare Fig. 7).…”

“…[59], and indicate the search reach given by the corresponding value of λ ′ 111 . The white, dark-shaded and light-shaded regions demonstrate that observation of single slepton production at the 5σ level would imply T 0νββ 1/2 < 1.9 · 10 25 yrs, 100 > T 0νββ 1/2 /10 25 yrs > 1.9 and T 0νββ 1/2 > 1 × 10 27 yrs, respectively (right, from [56]). …”

“…In principle and depending on nuclear matrix element uncertainties the LHC information could be combined to predict an associated inverse double beta decay half life coming from λ ′ 111 , which could be compared with the experimental half life measurement in order to see if additional contributions were necessary. [56]) . Region in the mSUGRA parameter space (vertical axis: M 1/2 in GeV, horizontal axis: M 0 in GeV) in which single slepton production may be observed at the LHC for tan β = 10, A 0 = 0 and 10fb −1 of integrated luminosity.…”