Light Stop Decays.

Transcription

1 Ligh Sop Decays Alexander Wlozka in collaboraion wih R. Gröber, M. Mühlleiner and E. Popenda 28 h Sepember 26 Eur.Phys.J. C75 (25) 9, 42 (arxiv: ), Phys.Le. B747 (25) 44-5 (arxiv: ) INSTITUTE FOR THEORETICAL PHYSICS KIT The Research Universiy in he Helmholz Associaion

2 Ouline Inroducion 2 Calculaion 3 Resuls Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 2/2

3 Inroducion: Supersymmery Supersymmery (SUSY) exension of he Sandard Model (SM) Dark Maer, gauge coupling unificaion, sabilizaion of Higgs mass SM gauge group enhanced space-ime symmery enriched paricle specrum superparners, exended Higgs secor conserved SUSY masses of superparners = masses of SM paricles sof SUSY breaking erms: general paramerizaion R-pariy lighes SUSY paricle (LSP) sable, producion of SUSY paricles in pairs, decays of SUSY paricles have odd numbers of SUSY paricles in he final sae Inroducion Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 3/2

4 Inroducion: Ligh Sops and Their Decays Ligh Sops and Their Decays large mass spliing possible for sops m = m m χ ; m < m exising work: c χ elecroweak one-loop process [Hikasa, Kobayashi 87][Jahn 98][Mühlleiner, Popenda ] four-body decay wihou FV [Boehm, Djouadi, Mambrini 99] hree-body-decay wihou FV [Porod, Wohrmann 97][Porod 98][Djouadi, Mambrini ] here: FCNC decay ũ (c, u) χ a NLO SUSY-QCD four-body decay ũ χ d i f f wih final sae mass effecs hree-body decay ũ χ d i W general flavor srucure hreshold effecs beween hree- and four-body decay aken ino accoun MSSM; LSP: χ ; NLSP: ũ Inroducion Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 4/2

5 Inroducion: Experimenal Saus m χ χ χ / χ / χ producion, b f f' / c W b ATLAS Preliminary χ / W b χ χ W b χ c χ - s=8 TeV, 2 fb s=3 TeV - L 3.2 fb [CONF-26-77] - L 3.2 fb - 2L 3.3 fb - MJ 3.2 fb [CONF-26-5] [CONF-26-76] [ ] Run [56.866] Saus: ICHEP 26 Observed limis Expeced limis All limis a 95% CL 3 m(, χ ) <,χ ) < m b + m W m(,χ ) < m 2 c χ m( b f f' χ W b χ m Inroducion Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 5/2

6 Inroducion: Experimenal Saus χ m CMS Preliminary pp, χ ICHEP 26 miss SUS-6-4, -lep (H T ), 2.9 fb - SUS-6-5, -lep (M T2 ), 2.9 fb - SUS-6-6, -lep (α T ), 2.9 fb - SUS-6-29, -lep sop, 2.9 fb SUS-6-3, -lep (op ag), 2.9 fb - SUS-6-28, -lep sop, 2.9 fb Combinaion -lep and -lep sop, 2.9 fb TeV Expeced Observed m = m + m χ m Inroducion Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 6/2

7 Inroducion: Experimenal Saus (GeV) m LSP CMS fb (8 TeV) pp c χ Observed bff' χ Expeced χ ± b χ (m =.25m +.75m ) ± χ χ ± b χ (m =.75m +.25m ) ± χ χ m (GeV) ), χ m ( - CMS Preliminary.-2.9 fb (3 TeV) pp, bff χ 9 Observed ± σ heory Expeced ± σ experimen ± 2 σ experimen m 2 95% CL upper limi on cross secion [pb] [CMS-SUS-4-6, arxiv: ] [CMS-PAS-SUS-6-25] Inroducion Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 7/2

8 Calculaion: Only Seleced Facs and Examples g u,c ũ ũ,c,u,c,u ũ...6 χ χ d i general flavor srucure: ũ U U 6 ũ L ũ c L ũ 3 = ũ L ũ ũ R.. c R W + f f ũ 6 U U 66 overall-facor-scheme: R χ [Baur, Vermaseren, Zeppenfeld 92] ũ,c,u d i pw 2 m2 W p 2 #W propagaors W m2 W + im W Γ W W + Calculaion Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 8/2

9 Resuls: Two-body and Four-body Decays m < m W [Gröber, Mühlleiner, Popenda, AW 4] K U(3) mũ m χ BR(4 body)/br(4 body) mb=mτ= U(3) mũ m χ (a) K-facor for he wo-body decay (b) Boom quark and Tau lepon mass effecs K = Γ NLO /Γ LO Resuls Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 9/2

10 Resuls: Two-body and Four-body Decays m < m W [Gröber, Mühlleiner, Popenda, AW 4] m χ U(2) m u < m χ + m c m u > m χ + m W + m b mũ BR(2 body) m χ U(3) m u < m χ + m c m u > m χ + m W + m b mũ BR(2 body) (c) U(2) QL U(2) ur U(3) dr symmery (d) U(3) QL U(2) ur U(3) dr symmery Resuls Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 /2

11 Resuls: Three- and Four-body Decay Threshold m [6, 4]GeV [Gröber, Mühlleiner, Popenda, AW 5] Γ body 4 body 3 body mũ m χ (e) Parial decay widhs for he hree decay modes BR(2 body) mũ m χ (f) BR of he wo-body decay a he hreshold Former U(2)-symmery case is used here. Resuls Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 /2

12 Conclusion Conclusion calculaed he wo-, hree- and four-body decays wih FV in he MSSM SUSYHIT [Djouadi, Mühlleiner, Spira 6][Gröber, Mühlleiner, Popenda, AW 5] masses of boom quark and au lepon aken ino accoun hreshold effecs a he W -boson hreshold considered NLO conribuions for he wo-body decay amoun up o 25% wo-body decay can cover he W -hreshold in he case of large FV effecs BRs can deviae significanly from one in all channels complemenary searches in all channels needed σ [pb] BR( c χ b f f χ ) + BR( ) = ATLAS pair prod. cross secion c, L, WW Obs. limi BR( c χ ) = - s = 8 TeV, 2 fb Obs. limi BR( c χ ) =.75 Obs. limi BR( c χ ) =.5 All limis a 95% CL Obs. limi BR( c χ ) =.25 Obs. limi BR( c χ ) = m(, χ ) = 8 GeV [ATLAS Collaboraion 5] Resuls m Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 2/2

13 Backup: Scan Range A [, 2] GeV mũ3 [3, 6] GeV m QL3/(L,L2,L3) [, 5] GeV an β [, 5] M [75, 5] GeV m A [5, ] GeV All oher parameers fixed: M 2 = 65 GeV M 3 = 53 GeV µ = 9 GeV m Slepons = GeV m Squarks = 5 GeV A d = A l = Resuls Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 3/2

14 Backup: Implemenaion and Consrains implemenaion of he decays: SUSYHIT [Djouadi, Mühlleiner, Spira 6] specrum generaor: SPheno [Porod 2] Higgs decays, BRs, effecive couplings: HDECAY [Djouadi, Kalinowski, Mühlleiner, Spira ] Higgs observaion and exclusion bounds: HiggsBounds and HiggsSignals [Bechle, Brein, Heinemeyer, Sål, Sefaniak, Weiglein, Williams 3] Relic Densiy, Ω ch 2 <.2 : SuperIso Relic [Arbey, Mahmoudi ] B-physics observables: SuperIso [Mahmoudi 9] BR(b X sγ), BR(B τν), BR(B (s) µ+ µ ) ρ-parameer: SPheno consrain on he gluino mass m g >.45 TeV limis on mũ : [Porod 2] [CMS-SUS-3-7, ATL-PHYS-PROC-23-79] mũ m χ < 8 GeV: own mehod [Gröber, Mühlleiner, Popenda, AW 5] mũ m χ 8 GeV: SModelS [Kraml e al. 4] Resuls Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 4/2

15 Backup: Two-body and Four-body Decays m < m W [Gröber, Mühlleiner, Popenda, AW 4] m χ Exclusion BR( c χ ) ATLAS exclusion [arxiv:47.68] m < m χ +m c m > m χ +m b +m W m BR( c χ ) Reinerpreed exclusion limis for he wo-body decay Resuls Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 5/2

16 Backup: Two-body and Four-body Decays m < m W [Gröber, Mühlleiner, Popenda, AW 4] m χ Exclusion BR( b χ f f - ) ATLAS exclusion [arxiv:47.68] [arxiv:47.583] m < m χ +m c m > m χ +m b +m W m BR( b χ - f f ) Reinerpreed exclusion limis for he four-body decay Resuls Alexander Wlozka Ligh Sop Decays 28 h Sepember 26 6/2