CPphases in correlated production and decay of neutralinos in the minimal supersymmetric standard model

Abstract

We investigate the associated production of neutralinos e ϩ e Ϫ → 1 0 2 0 accompanied by the neutralino leptonic decay 2 0 → 1 0 l ϩ l Ϫ , taking into account initial beam polarization and production-decay spin correlations in the minimal supersymmetric standard model with general CP phases but without generational mixing in the slepton sector. The stringent constraints from the electron EDM on the CP phases are also included in the discussion. Initial beam polarizations lead to three CP-even distributions and one CP-odd distribution, which can be studied independently of the details of the neutralino decays. We find that the production cross section and the branching fractions of the leptonic neutralino decays are very sensitive to the CP phases. In addition, the production-decay spin correlations lead to several CP-even observables such as lepton invariant mass distribution, and lepton angular distribution, and one interesting T-odd (CP-odd͒ triple product of the initial electron momentum and two final lepton momenta, the size of which might be large enough to be measured at the high-luminosity future electron-positron collider or can play a complementary role in constraining the CP phases with the EDM constraints.PACS number͑s͒: 14.80.Ly, 12.60.Jv, 13.85.Qk 0 may be, for some time, the only chargino and neutralino PHYSICAL REVIEW D, VOLUME 61, 075004

A comprehensive analysis of electric dipole moment constraints on CP-violating phases in the MSSM

“…To mention a few, the new sources of CP violation can participate in the generation of the baryon asymmetry of the universe in the context of supersymmetric electroweak baryogenesis [3][4][5][6][7][8][9][10][11]. They can generate observable CP asymmetries at the CERN Large Hadron Collider (LHC) [12][13][14] as well as at future linear colliders [15][16][17][18][19][20][21]. They could manifest themselves in B physics (see ref.…”

Neutralino production and decay at ane+e−linear collider with transversely polarized beams

“…[11], Q (′) 6 probe Dirac-type phases, which vanish in the absence of nontrivial mixing between neutralino current eigenstates, whereas Q (′) 4 probe Majorana-type phases, which survive in this limit. In the generic case of small gaugino-higgsino mixing, therefore, the size of Q (′) 4 is much larger than that of Q (′) 6 . In the case of strong gaugino-higgsino mixing, however, Q (′) 6 , which can only be probed with transversely polarized beams, could exceed Q 4 and/or Q …”

“…In the generic case of small gaugino-higgsino mixing, therefore, the size of Q (′) 4 is much larger than that of Q (′) 6 . In the case of strong gaugino-higgsino mixing, however, Q (′) 6 , which can only be probed with transversely polarized beams, could exceed Q 4 and/or Q …”

“…Analytic expressions for N using this expansion, given in Ref. [4], help to estimate the sizes of the Q Q (′) 4,6 . In particular, the last term contributing to Q .…”

“…* In contrast, large values of Φ 1 are allowed even for rather small selectron masses. The CP-violating phase Φ 1 can therefore play a significant role in the production and decay of neutralinos, which is most easily investigated at (linear) e + e − colliders [5,6,7,4,8].…”