We study gauge mediation of supersymmetry breaking in SU(5) supersymmetric grand unified theory with gauge fields as messengers. The generated soft supersymmetry breaking parameters lead to close to maximal mixing scenario for the Higgs mass and highly red
PreprinttypesetinJHEPstyle-HYPERVERSION
arXiv:hep-ph/0607169v2 14 Sep 2006RadovanDerm´ ˇsek ,HyungDoKim andIan-WooKim SchoolofNaturalSciences,InstituteforAdvancedStudy,Princeton,NJ08540,U.S.A. SchoolofPhysicsandAstronomyandCenterforTheoreticalPhysics,SeoulNationalUniversity,Seoul,151-747,KoreaE-mail:dermisek@ias.edu,hdkim@phya.snu.ac.kr,iwkim@phya.snu.ac.krAbstract:WestudygaugemediationofsupersymmetrybreakinginSU(5)supersymmet-ricgranduni edtheorywithgauge eldsasmessengers.ThegeneratedsoftsupersymmetrybreakingparametersleadtoclosetomaximalmixingscenariofortheHiggsmassandhighlyreducethe netuningofelectroweaksymmetrybreaking.Allgaugino,squarkandslep-tonmassesaredeterminedbyoneparameter–thesupersymmetrybreakingscale.Thecharacteristicfeaturesare:negativeandnon-universalsquarkandsleptonmassessquaredattheuni cationscale,non-universalgauginomasses,andsizablesoft-trilinearcouplings.Inthisscenario,allsoftsupersymmetrybreakingparametersattheuni cationscalecanbesmallerthan400GeVandallthesuperpartnerscanbelighterthan400GeVandstill
satisfyallthelimitsfromdirectsearchesforsuperpartnersandalsothelimitontheHiggsmass.Thelightestsupersymmetricparticleisgravitinoorasizablemixtureofbino,winoandhiggsino.Wealsoconsiderapossiblecontributionsfromadditionalmessengersinvector-likerepresentations,andacontributionfromgravitymediation,whichisestimatedtobecomparable.