Searching evidences of new physics in the light

Transcription

1 Searching evidences of new physics in the light of the µνssm Pradipta Ghosh IFT, UAM Physics Challenges in the face of LHC-14 Madrid, September 25, 2014 Pradipta Ghosh (IFT/UAM) New physics with µνssm 1 / 20

2 Together... PG, Daniel E. López-Fogliani, Vasiliki A. Mitsou, Carlos Muñoz and Roberto Ruiz de Austri Hunting physics beyond the standard model with unusual W ± and Z decay arxiv: [hep-ph] Probing the µ-from-ν supersymmetric standard model with displaced multileptons from the decay of a Higgs boson at the LHC Phys. Rev. D 88 (2013) , arxiv: [hep-ph] Pradipta Ghosh (IFT/UAM) New physics with µνssm 2 / 20

3 The Standard Model, The LHC and us... At last a new scalar PLB 716(2012) 1, 30 µ (ATLAS) = , µ (CMS) = ATLAS-CONF , CMS-PAS-HIG m Higgs (ATLAS) = , m Higgs (CMS) = PRD 90 (2014) , CMS-PAS-HIG Pradipta Ghosh (IFT/UAM) New physics with µνssm 3 / 20

4 The Standard Model, The LHC and us... Γ H < 22 MeV PLB 736 (2014) 64 Br(H X BSM X BSM ) < 0.41 (ATLAS), <0.58 (CMS) ATLAS-CONF , EPJ. C74 (2014) 2980 Large window for µ(h b b) An extension beyond the SM is still necessary Pradipta Ghosh (IFT/UAM) New physics with µνssm 3 / 20

5 Beyond the SM with supersymmetry... Need two Higgs doublets... Higgs mass is protected with super-partners The lightest supersymmetric particle as cold dark matter candidate... Pradipta Ghosh (IFT/UAM) New physics with µνssm 3 / 20

6 Not the end of story... W MSSM = ɛ ab (Y ij u Ĥb u ˆQ a i ûc j + Y ij d Ĥa ˆQ b ˆd c + Y ij d i j e ĤaˆL b d i êc µĥ a j d Ĥb u ) µ determine EW-scale higgsino masses.. enters into EWSB µ must be around EW scale µ belongs to superpotential.. respects SUSY µ can be as high as M Planck So why the scale of µ M Planck µ-problem Kim, Nilles, PLB 138 (1984) 150 m ν extra elds or broken R p bilinear R P, MSSM + ɛ i ˆL a i Ĥb u ɛ-problem... Loop corrections are essential.. trilinear R P, MSSM λ ˆL ijk aˆl b i j êc k and/or λ ˆL a ˆQ b ˆd c Loop generated mν..., ijk i j k Many parameters, Less predictive... Need an economic way to accommodate everything together... Pradipta Ghosh (IFT/UAM) New physics with µνssm 3 / 20

7 Introducing µνssm m Dij =Y νij H 0 u R R P with L=1 P with L=3 z } { z } { z } { W = W MSSM ɛ ab µĥ a d Ĥb u + ɛ ab ( Y νij Ĥu bˆl a i ˆνc j λ i ˆν c 1 i {z } Ĥa d Ĥb u ) + {z } 3 κ ijk ˆν c i ˆν c j ˆν c k {z } ɛ i e =Yν ij νc j µ e =λ i ν c i =2 κ ijk ν c k m ν c ij López-Fogliani, Muñoz, PRL 97 (2006) Escudero, López-Fogliani, Muñoz, Ruiz de Austri, JHEP 12 (2008) 099 VEVs after EWSB: H 0 d = v d, H 0 u = vu, ν i = ν i, ν c i = νc i µ-problem is solved with R P term PG, Roy JHEP 04 (2009) 069; Fidalgo, López-Fogliani, Muñoz, Ruiz de Austri JHEP 08 (2009) 105; PG, Dey, Mukhopadhyaya, Roy JHEP 05 (2010) 087 Pradipta Ghosh (IFT/UAM) New physics with µνssm 4 / 20

8 Particle spectrum of the µνssm R P + new superelds enhanced mass spectrum h 0, H eν c i + 3 eν L i = 8 CP-even states hα A eν c i + 3 eν L i = 7 CP-odd states Pα H ± + 3 e i L + 3 ei R = 7 charged states S± α e H 0 u,d, f W 0 3, e B ν Ri + 3 ν Li = 10 neutralinos eχ 0 α e H ± u,d, f W ± + 3 e i L,R = 5 charginos eχ± α eχ 0 1, 2, 3 ν L i and eχ ± 1, 2, 3 e, µ, τ Lightest neutralino eχ 0 4 and Lightest chargino eχ± 4 Pradipta Ghosh (IFT/UAM) New physics with µνssm 5 / 20

9 Novel signals with the µνssm... The proposal... Low mass ( < m W ) unstable LSP (eχ 0 ) decays mainly through l ± W, νz while l DL 1/m 4 χ 0... When m χ 0 < 40 GeV... l DL > 10 m d ATLAS 25 m = light eχ 0 ( < 40 GeV)... R P is an impostor to R pc Decay length of χ 0 1 [m] m( χ 0 1) [GeV] Bartl, Hirsch, Vicente, Liebler, Porod, JHEP 0905, 120 Pradipta Ghosh (IFT/UAM) New physics with µνssm 6 / 20

10 Novel signals with the µνssm... The proposal... A light eχ 0 through eχ 0 h i /P i + ν i L can yield mesoscopic DV (1 cm < l DL < 3 m) Light h i, P i are possible in the µνssm... A very light eχ 0 ( < 20 GeV) is detectable!.. PG, López-Fogliani, Mitsou, Muñoz, Ruiz de Austri, PRD 88 (2013) PG et al. to appear in arxiv How about Z eχ 0 eχ 0, h i P j, W ± eχ 0 eχ ± 1,2,3 at colliders...? PG, López-Fogliani, Mitsou, Muñoz, Ruiz de Austri, arxiv: [hep-ph] And nally Higgs eχ 0 eχ 0 at the LHC and further... PG, López-Fogliani, Mitsou, Muñoz, Ruiz de Austri, PRD 88 (2013) Pradipta Ghosh (IFT/UAM) New physics with µνssm 6 / 20

11 Setting up the convention... the signals Small κ, A κ, λ i = light singlet-like h i, P i, eχ 0 i+3 (i = 1, 2, 3) Formulas are coming... PG, López-Fogliani, Mitsou, Muñoz, Ruiz de Austri, to appear in arxiv h 4 is the lightest doublet-like Higgs while eχ 0 4 is the lightest neutralino Fidalgo, López-Fogliani, Muñoz, Ruiz de Austri JHEP 1110, 020 (2011) ν R ν R H u,d 0 λvd,u H u,d 0 λvd,u Zµ g2 2cθW W µ ± g2 H u,d 0 λvd,u ν R H ± u,d Yνν c or Ylν l ± ν c ν c H u,d 0 λ 2 ν c vu,d H u,d 0 Aλλvd,u Zµ g2pµ 2cθW Zµ g2pµ 2cθW H u,d 0 λ 2 ν c vu,d ν c H u,d 0 Aλλvd,u or λ 2 ν c vu,d ν c Prompt + Displaced yet detectable multi-leptons/jets/photons at the LHC Z eχ 0 4 eχ0 4 2h i /P i + 2ν 2l + D l D /2q D q D + 2ν Z h i P j 2l + P l P, l+ P l P q P q P...etc.. W ± eχ 0 4 eχ± 1,2,3 l+ D l D /q D q D + ν + l ± P τ or b-jet rich signals with 2m τ < m S 0 i, P0 i < M Z /2 PG, López-Fogliani, Mitsou, Muñoz, Ruiz de Austri, arxiv: [hep-ph] Pradipta Ghosh (IFT/UAM) New physics with µνssm 7 / 20

12 Probing new W ± decays... Challenges... τ /b jet rich signal... Detection of soft, collimated and often displaced objects... Need better statistics... better detection Br(W ± x D y D + E/ T + l ± ) P O(10 13 ) or less.. Dicult at the LHC... also in future.. MegaW (linear collider) and OkuW (TLEP) mode (MegaW) (OkuW) W ± events/year = need much lower sensitivity.. PG, López-Fogliani, Mitsou, Muñoz, Ruiz de Austri, arxiv: [hep-ph] Hope... techniques from avour observables... LHCb Br(B 0 s µ + µ ) O(10 10 ) sensitive to η... work in progress.. Pradipta Ghosh (IFT/UAM) New physics with µνssm 8 / 20

13 Probing new Z decays... Challenges... τ /b jet rich signal... Detection of soft, collimated and often displaced objects... Need better statistics... better detection Br(Z 2x D 2y D + E/ T ) or Br(Z 2x P 2y P + E/ T ) < O(10 5 )... x, y = l, τ, q, γ Z 4b with Br 10 5, E CM = 8 TeV, L = 20.3 fb 1 1% detection eciency N event = 52 events The same with SM Nevent = 1853 ± 669 events Similarly Z 4l from Z 4τ (i.e. with τ lν L ν L ) with Br 10 5 at parton level N event 77 events while from the SM N event Lost within the errors of the SM... without proper detection Detection is possible at the LHC... novel future with LC-GigaZ and TLEP-TeraZ modes (GigaZ) (TeraZ) Z events/year = sensitive to much lower Br hep-ph/ ; hep-ex/ ; JHEP 01 (2014) 164 Experimental attention is needed to constrain 2m τ < m S 0 i, P0 i < M Z /2 region Pradipta Ghosh (IFT/UAM) New physics with µνssm 8 / 20

14 The signals...contd.. back with Higgs Masses Values in GeV m h m P1, m P2, m P3 3.6, 3.8, 5.5 m h1, m h2, m h3 7.5, 8.0, 19.6 m eχ 0, m 4 eχ 0, m 5 eχ , 11.5, 11.9 Displaced yet detectable multi-leptons/jets/photons at the LHC gg h 4 eχ 0 4 eχ0 4 2h i /P i + 2ν 2τ + D 2τ D 2ν Prompt multi-leptons/jets/photons or mixed states are also possible from Higgs to Higgs cascades... h 4 h i h j, P i P j... like the NMSSM Cerdeño, PG, Park, JHEP 1306 (2013) 031 Pradipta Ghosh (IFT/UAM) New physics with µνssm 9 / 20

15 τ fb 1 No. of Events τ had multiplicity τ had multiplicity for PT > 10 GeV τ had 's are clearly the best bet... next one is of course µ... careful about PLB 726 (2013) 564 e, µs are from leptonic τ decay.. although h i /P i µ + µ is possible 4e, 4µs from τ 1.5% while 4τ had 18% Highly collimated QCD jets faking τ had... = n τhad > 4... disappears with higher p τhad T cut p τ had T distribution for 1 st and 3 rd leading τhad 10 5 hardest τ had rd hardest τ had No. of Events / 10 GeV pt of tau had (GeV ) PG, López-Fogliani, Mitsou, Muñoz, Ruiz de Austri, PRD 88 (2013) Pradipta Ghosh (IFT/UAM) New physics with µνssm 10 / 20

16 E/ T, DL... No. of Events / 10 GeV E/ T and DL distribution ET / (GeV ) No. of Events Decay length (m) Moderately high MET > 6 neutrinos from eχ 0 4 and τ decays... cτ eχ 0 30 cm... large number of 4 events appear inside charge tracker z DV vs ρdv A large fraction of DVs appear within z DV < 2.5 m and ρ DV < 1 m, i.e, in the range of inner tracker PG, López-Fogliani, Mitsou, Muñoz, Ruiz de Austri, PRD 88 (2013) Pradipta Ghosh (IFT/UAM) New physics with µνssm 11 / 20

17 E/ T, DL... No. of Events / 10 GeV E/ T and DL distribution ET / (GeV ) No. of Events Decay length (m) Moderately high MET > 6 neutrinos from eχ 0 4 and τ decays... cτ eχ 0 30 cm... large number of 4 events appear inside charge tracker z DV vs ρdv A large fraction of DVs appear within z DV < 2.5 m and ρ DV < 1 m, i.e, in the range of inner tracker ATLAS-CONF Pradipta Ghosh (IFT/UAM) New physics with µνssm 11 / 20

18 Squark and Slepton pair production... in the µνssm No longer required light h i, P i and eχ 0 i+3 moderate to large values of λ, κ and A κ parameters remain feasible Also possible with the µνssm, following similar eq, e l decay Pradipta Ghosh (IFT/UAM) New physics with µνssm 12 / 20

19 Summary and conclusion... and beyond Light singlet-sector can produce novel and/or indirect (decays of heavier SM particles) evidence of new physics = need experimental attention µνssm... least extension beyond the MSSM to solve the µ-problem and reproduce correct neutrino physics Novel signals are well expected with enriched mass spectrum and broken R p Displaced and/or soft objects at the LHC lesser backgrounds.. new signs are well envisaged but with sophisticated collider analyses of soft and/or displaced objects Unique SUSY signatures ( e l, eg) are also possible With new data and up-gradation to 14 TeV and beyond... more phenomenological wonder with µνssm are awaiting... Dreaming the future.. Pradipta Ghosh (IFT/UAM) New physics with µνssm 13 / 20

20 Pradipta Ghosh (IFT/UAM) New physics with µνssm 14 / 20

21 Loop corrections in SUSY f L(R) (a) f L(R) (b) h 0 λ h 0 f h 0 v λ h 0 f v λ f f L(R) New one-loop radiative corrections to Higgs boson in SUSY Certain restrictions on masses and couplings of new states = radiative correction vanishes Symmetry between states of dierent spin quantum numbers = Higgs (scalar) mass is protected Pradipta Ghosh (IFT/UAM) New physics with µνssm 15 / 20

22 R-Parity R p, a discrete symmetry = prevents too fast proton decay through sparticle mediated process R p = ( 1) L+3B+2S with L(B) as lepton(baryon) and S as spin Sparticles R p = 1 Particles Sparticles R p = +1 R p = 1 Sparticles R p = 1 Particles Particles R p = +1 R p = +1 R p conserved R p violated R p conservation = stable Lightest Supersymmetric Particle (LSP) Most general MSSM superpotential with bilinear and trilinear R P W = ɛ ab (Yu ij Ĥb u ˆQ i aûc j + Y ij d Ĥa d ˆQ i b ˆd j c + Ye ij Ĥa d ˆL b i êc j µĥd aĥb u ) L=1, B=0 L=0, B=1 z } { L=1 B=0, z } { ɛ ab ( ɛ i ˆL a i Ĥb 1 u + {z } 2 λijk ˆL a i ˆL b j êc k + λ ˆL a ijk i ˆQ j b ˆd k c {z } ) + λ ijk ûi c ˆd j c ˆd k c L=1, B=0 Pradipta Ghosh (IFT/UAM) New physics with µνssm 16 / 20

23 The soft terms The Lagrangian L soft, containing the soft-supersymmetry-breaking terms is given by L soft = (m 2 eq ) ij e Q a i fq a j + (m 2 eu c ) ij eu c i eu c j + (m 2e d c ) ij e d c i ed j c + (mel 2) ij e L a i fl a j + (me 2 ) c ij ei c ej c + mh 2 H a d d Ha d + m2 H u Hu a Hu a + (m 2 eν ) c ij eν i c eν j c + ɛ ab h(a uy u) ij Hu b Q e i aeuc j + (A d Y d ) ij Hd a Q e i b ed j c + (A ey e) ij Hd ae i L b i ec j + H.c. + hɛ ab (A νy ν) ij Hu be i L a i eνc j ɛ ab (A λ λ) i eν i cha d Hb u (Aκκ) ijk eν i c eνc j eνc k + H.c. h i 1 M 2 1B e B e + M2W f W f + M3 eg eg + H.c. Pradipta Ghosh (IFT/UAM) New physics with µνssm 17 / 20

24 The W ± and Z decays... a broader perspective q q Z/γ Z /γ q l l l + l + q Z /γ Z /γ l Br(Z 4l) < Br(Z 4b) < l PDG, PRD 86 (2012) l Latest LHC reporting... only e, µ Br(Z 4l) = PRL 112 (2014) l + Pradipta Ghosh (IFT/UAM) New physics with µνssm 18 / 20

25 The W ± and Z decays... a broader perspective NMSSM + 3ˆν c.. DISPLACED & PROMPT Z decays, DISPLACED W ± decays... Kitano, Oda, PRD 61 (2000) Pradipta Ghosh (IFT/UAM) New physics with µνssm 18 / 20

26 The W ± and Z decays... a broader perspective The µνssm.. minimal extension beyond the MSSM = distinctive collider signatures + correct neutrino physics PG, López-Fogliani, Mitsou, Muñoz, Ruiz de Austri, arxiv: [hep-ph] Pradipta Ghosh (IFT/UAM) New physics with µνssm 18 / 20

27 To kill the backgrounds...higgs Mesoscopic displaced vertex... Displaced charge tracks... Irreducible impostor NMSSM + 3ν c.. Kitano, Oda, PRD 61, (2000) Options.. e.g. MSSM λijk ˆL i ˆL j Êk c.. dicult with, LEP (and LHC) results... but not impossible Dreiner, Kim, Lebedev, PLB 715 (2012) 199 All SM (e.g. ZZ )/SUSY backgrounds (e.g. h 1 P 1 P 1 2l + with prompt l are eaced... also long-lived b/c meson decays NMSSM with 10 3 < λ < light NLSP LSP + h/p, with h/p l + l a possible impostor.. Ellwanger, Hugonie, Eur. Phys. J. C 5, 723 (1998); Eur. Phys. J. C 13, 681 (2000) NLSP LSP + h/p, never produces mesoscopic decay length... Eur. Phys. J. C 13, 681 (2000) Stand-alone muons... Bandyopadhyay, PG, Roy, PRD84, (2011) Pradipta Ghosh (IFT/UAM) New physics with µνssm 19 / 20

28 To kill the backgrounds...higgs Mesoscopic displaced vertex... Displaced charge tracks... Irreducible impostor NMSSM + 3ν c.. Kitano, Oda, PRD 61, (2000) Options.. e.g. MSSM λijk ˆL i ˆL j Êk c.. dicult with, LEP (and LHC) results... but not impossible Dreiner, Kim, Lebedev, PLB 715 (2012) 199 All SM (e.g. ZZ )/SUSY backgrounds (e.g. h 1 P 1 P 1 2l + with prompt l are eaced... also long-lived b/c meson decays NMSSM with 10 3 < λ < light NLSP LSP + h/p, with h/p l + l a possible impostor.. Ellwanger, Hugonie, Eur. Phys. J. C 5, 723 (1998); Eur. Phys. J. C 13, 681 (2000) NLSP LSP + h/p, never produces mesoscopic decay length... Eur. Phys. J. C 13, 681 (2000) Stand-alone muons... Bandyopadhyay, PG, Roy, PRD84, (2011) Pradipta Ghosh (IFT/UAM) New physics with µνssm 19 / 20

29 Probing DVs H l T ( P p l T ) distribution H l T is moderately high for larger lepton multiplicity H l T + E / T can be used as a dierentiator (GeV) l H T Invariant mass of charge tracks (GeV) Charge track mass vs n trk had l lepton (e + µ + τ ) multiplicity with P >10 GeV T A very useful event selection criteria Sensitive for n trk > 4 and vertex mass > 10 GeV... ATLAS-CONF Room for development... sensitivity to low vertex mass Life is better with jets Number of charge tracks in each vertex n vertex trk max = 12, four 3-prong τ decay 0 Pradipta Ghosh (IFT/UAM) New physics with µνssm 20 / 20

30 Probing DVs H l T ( P p l T ) distribution H l T is moderately high for larger lepton multiplicity H l T + E / T can be used as a dierentiator (GeV) l H T had l lepton (e + µ + τ ) multiplicity with P >10 GeV T 1 A very useful event selection criteria Sensitive for n trk > 4 and vertex mass > 10 GeV... ATLAS-CONF Room for development... sensitivity to low vertex mass Life is better with jets Pradipta Ghosh (IFT/UAM) New physics with µνssm 20 / 20