Search for gauge extensions of the MSSM at the LHC

Abstract

The extensions of the minimal supersymmetric model (MSSM), driving mainly from the need to solve the problem, involve novel matter species and gauge groups. These extended MSSM models can be searched for at the LHC via the effects of the gauge and Higgs bosons or their fermionic partners. Traditionally, the focus has been on the study of the extra forces induced by the new gauge and Higgs bosons present in such models. An alternative way of studying such effects is through the superpartners of matter species and the gauge forces. We thus consider a Uð1Þ 0 gauge extension of the MSSM, and perform an extensive study of the signatures of the model through the production and decays of the scalar quarks and gluino, which are expected to be produced copiously at the LHC. After a detailed study of the distinctive features of such models with regard to the signatures at the LHC, we carry out a detailed Monte Carlo analysis of the signals from the process pp ! n leptons þ m jets þ E 6 T , and compare the resulting distributions with those predicted by the MSSM. Our results show that the searches for the extra gauge interactions in the supersymmetric framework can proceed not only through the forces mediated by the gauge and Higgs bosons but also through the superpartner forces mediated by the gauge and Higgs fermions. Analysis of the events induced by the squark/gluino decays presented here is complementary to the direct Z 0 searches at the LHC.

Neutralino and chargino production in U(1)′ at the LHC

“…In the minimal U(1) ′ model, explored in Ref. [30], the difficulty to induce a small µ e f f while satisfying the Z ′ mass bound, which is around 1 TeV, stems from the fact that both are proportional to the VEV of the additional scalar field S. The resolution is provided in a nonminimal version of the U(1) ′ extended MSSM, in which several singlet fields (S i ) are introduced to resolve the conflict between maintaining the electroweak scale and developing a large enough mass for Z ′ . One needs three additional scalars to ameliorate the picture, and the VEVs of the new scalars must be kept large [14,15].…”

Scalar neutrinos at the LHC

“…Using these considerations, we can estimate the production cross section, the products of decay and estimate the sneutrino masses. The MSSM production differs both in the number of events expected, cross section, E [7,15,25], we include the complete model information for consistency, and to help future studies. The total Lagrangian incorporates kinetic terms and various interaction terms among the fields.…”

“…[15] where there is difficulty with inducing a small µ ef f while satisfying the Z ′ mass bound, which is around 1 TeV. This is because both µ ef f and m Z ′ are proportional to the vacuum expectation value of the additional scalar field S. One needs three additional scalars to ameliorate the picture the VEVs of the new scalars are kept large large.…”

Sneutrino dark matter: Symmetry protection and cosmic ray anomalies

“…At hadron colliders, the right-handed up-type quarks (u R and c R ) can undergo Drell-Yan annihilation through Z 0 to produce Higgs fields. The decays of the up-type squarks also exhibit novel branchings due toZ 0 exchange [30]. We now explore the possibility that the excess positron flux observed in the cosmic ray data is due to the presence of sneutrino DM.…”

“…With this charge assignment, scattering processes that involveĤ u ,Ŝ, andÛ are influenced by the Uð1Þ 0 gauge boson (Z 0 ) and the Uð1Þ 0 gaugino (Z 0 ) [30]. At hadron colliders, the right-handed up-type quarks (u R and c R ) can undergo Drell-Yan annihilation through Z 0 to produce Higgs fields.…”