Exotics searches at CMS Ezio Torassa INFN Padova

Exotics searches at CMS Ezio Torassa INFN Padova on behalf of the CMS collaboration Interplay between Particle and Astrophysics 2014 18 -22 August 2014, Queen Mary University of 1

Overview • • • 2 The CMS detector and the data taking Introduction W’ and Z’ searches Graviton searches with extra dimensions Excited fermions Microscopic black holes Heavy neutrinos and WR Dark matter with top quarks Conclusions 18 -22 August 2014 IPA 2014 Queen Mary University of London

The CMS detector Theand CMS Detector the data taking -2 -1 0 +1 Pixel & Tracker: 66 M pixel channels 9. 6 M strips, 210 m 2 ECAL: 76 k Pb. WO 4 crystals. HCAL: 15 k scint/brass ch. Muon system: Drift tubes (170 k wires), RPC, Cathode Strip Ch. (200 k wires) +2

pp collisions December 2012 Integrated Luminosity 2012 8 Te. V Delivered 23. 3 fb-1 Recorded 21. 8 fb-1 Integrated Luminosity 2011 7 Te. V Delivered 6. 13 fb-1 Recorded 5. 55 fb-1 4 18 -22 August 2014 IPA 2014 Queen Mary University of London

The pileup is the multiple interaction in the same bunch crossing. Increasing the luminosity (i. e. with more protons / beam) will produce also higher pileup environment for the triggered events Average PU 2011 RUNA 5 7 Te. V Average PU 2011 RUNB 8 Average PU 2012 all 21 8 Te. V Expected PU 2015 50 – 100 13 Te. V (25 ns – 50 ns) 5 18 -22 August 2014 IPA 2014 Queen Mary University of London

Introduction CMS publications (updated 21 July 2014) Total 323 Exotica 72 2014 Exotica Searches 6 published 8 submitted 15 preliminary PAS (physics analysis summary) 2014 B 2 G Searches 1 published 3 submitted 17 preliminary PAS 6 18 -22 August 2014 B 2 G physics analysis is an offshoot of the CMS exotica program, is dedicated to searches involving quarks beyond the second generation IPA 2014 Queen Mary University of London

Introduction The Exotica searches cover the beyond Standard Model but SUSY studies Mee Mmm , MT high p. T e, m - additional heavy gauge bosons (W’, Z’) Mee Mmm Mlljj Mjjjj p. Tg high p. T e, m, jets, g - graviton with extra dimensions Mge Mgm M gj high p. T e, m, j, g - excited fermions (compositeness) ∑ ET high p. T - microscopic black holes e, m, j, g Mlljj high p. T e, m, jets 7 - WR LR symmetric theory Mjj high p. T j - generic searches with dijets ETmiss - dark matter with top quarks 18 -22 August 2014 IPA 2014 Queen Mary University of London

W’ , Z’ searches W’ bosons arise in models with an extra SU(2) gauge group i. e. SU(2)L SU(2)R U(1)B-L Z’ bosons arise in models with new U(1) gauge symmetries i. e. E 6 → SO(10) U(1)y → SU(5) U(1)c U(1)y → GSM U(1)c U(1)y Z’ is a combination of the fields Z’y e Z’c Z’SSM Sequential Standard Model: same coupling to fermions as the SM bosons Wn. KK Kaluza-Klein excitations of the SM bosons in the framework of universal extra dimensions (UED) model with bulk mass (m) fermions n-th KK excitation mode R radius of fifth dimension parameters 8 18 -22 August 2014 IPA 2014 Queen Mary University of London

W’ W’ en, mn lepton, n transverse invariant mass CMS PAS EXO-12 -060 ar. Xiv: 1408. 2745 Submitted 12 August 2014 Limit in the SSM 3. 3 Te. V Limit in the W 2 KK m =0. 05 Te. V 9 m of 0. 05 Te. V 1. 7 SSM 18 -22 August 2014 W 2 KK m =10 Te. V IPA 2014 Te. V m of 10 Te. V Queen Mary University of London 3. 7

Z’ 10 Z’ ee, mm dilepton invariant mass spectrum 18 -22 August 2014 IPA 2014 CMS PAS EXO-12 -061 Limit in the sequential SM 2. 96 Te. V Limit for Z’ 2. 60 Te. V Queen Mary University of London

G searches Graviton searches with extra dimensions - Randall-Sundrum model (RS) smal 5 th extra dimesion of of the order of l. PL ~ 10 -33 cm - Arkani–Hamed Dimopoulos Dvali model (ADD) R large extra dimensions (4+n) with radius R r >> R MD = 1 Te. V 11 r << R n=1 R = 1011 cm n=2 R = 10 -2 cm 18 -22 August 2014 IPA 2014 n 2 Queen Mary University of London

G searches with leptons G G ee , mm CMS-EXO-12 -027 , CMS-EXO-12 -031 Search in framework of the ADD model The virtual graviton exchange is expected to have interference with the Standard Model Drell-Yan process. The LO cross section is controlled: in the Giudice, Wells, Rattazzi (GWR) convention by the paramater T in the Han, Lykken, Zhang (HLZ) convention by the parameters Ms and n 12 18 -22 August 2014 IPA 2014 Queen Mary University of London

mm Mmm > 1. 8 Te. V Data Bkg 1 evts 0. 7 evts Mee > 1. 8 Te. V Data Bkg 0 evts 0. 6 evts mm T > 3. 8 Te. V ee T > 4. 0 Te. V ee+mm T > 4. 1 Te. V ee+mm mm Ms > 4. 5 Te. V ee Ms > 4. 8 Te. V ee+mm Ms > 4. 9 Te. V 13 18 -22 August 2014 IPA 2014 n=3 Queen Mary University of London ADD - GWR ADD - HLZ

G searches with jets Massive resonances decaying into pairs of boosted bosons CMS PAS EXO-13 -009 ar. Xiv: 1405. 3447 Submitted 14 May 2014 (combined WW/WZ and ZZ) G WW/WZ ln jj , jjjj G ZZ ll jj mn jj en jj 14 18 -22 August 2014 IPA 2014 Queen Mary University of London

mm jj eejj Randall–Sundrum graviton extended to the bulk model Coupling to light fermions suppressed Parameters - MG - k/MPL MG mass of the first mode of KK graviton lljj 15 lnjj 18 -22 August 2014 k curvature scale of the extra dimens. jjjj IPA 2014 Queen Mary University of London

G searches with photons qq g G CMS PAS EXO-12 -47 the graviton G escapes detection Missing transverse energy Pg. T > 145 Ge. V ETmiss > 140 Ge. V Data Bkg 653 evts 613 50 evts high p. T photon ADD model n. D=6 n. D=4 n. D 3 4 5 6 16 18 -22 August 2014 IPA 2014 Queen Mary University of London Obs Limit MD > 2. 3 Te. V MD > 2. 2 Te. V MD > 2. 0 Te. V

Excited fermions CMS PAS EXO-13 -003 ar. Xiv: 1406. 5171 submitted 19 June 2014 Search for exited quarks in photon + jet final state According to the compositeness theory quark and leptons are composed of more basic entities termed as preons. The most compelling evidence of quark substructure would be provided by the discovery of an excited state of a quark. The dominant q* production in p-p interaction is the quark-gluon fusion. The excited quark can decay into a quark and a gauge boson (g, W, Z, g ) The g+jet invariant mass would give a resonance peaking at Mq* Simplified model: - only spin ½ excited states of the first generation u*, d* are considered - couplings between excited quarks and gauge bosons in general can have different scaling factors gs , g’ fs gs , f g , f’ g’ exclusion limits are for f = fs = f’ 17 18 -22 August 2014 IPA 2014 Queen Mary University of London

at least one photon with p. Tg > 170 Ge. V leading jet with p. Tjet > 170 Ge. V Observed limit Mq* > 3. 5 Te. V for f=1 decreases for smaller coupling 18 18 -22 August 2014 IPA 2014 Queen Mary University of London

Microscopic black holes CMS PAS EXO-12 -009 JHEP 07(2013)122 In the large extra dimension model MD is the reduced Plank mass: One possible process that enter in higher dimension spaces is the formation of microscopic black hokes (BH) with production cross section proportional to the squared Schwarzshild radius: Samples of semiclassical black holes were generated with the MC generators BLACKMAX and CHARYBDIS. Samples of quantum black holes were generated with the MC generator QBH. The black holes can be produced in accordance with different models: 19 18 -22 August 2014 IPA 2014 Queen Mary University of London

8 -jet candidate ST=3. 0 Te. V Microscopic black holes decays into all kind of objects (quarks, gluons, leptons, photons). The search for black holes is based on a search for a deviation from the SM background in the ST spectra. ST = ∑ ET for all the objects For MD between 1. 5 - 5 Te. V The limit for the black hole mass is MBH > 6. 2 - 4. 3 Te. V 20 18 -22 August 2014 IPA 2014 Queen Mary University of London

Heavy neutrinos and WR Left-Right Symmetric extensions to the Standard Model: SUR(2) was introduced to explain the origin of parity violation in weak interactions: parity is conserved in the LR symmetric Lagrangian and is broken spontaneously together with the gauge symmetry. The new symmetry group includes three additional gauge bosons WR± and Z’ Due to neutrino oscillations right handed neutrinos should exist. SUR(2) naturally introduces right-handed neutrinos (Nl ): right-handle fermions are doublets under SUR(2) Simplified model: - strict LR symmetry: g. L=g. R - the mixing angles WR – WL , Z 0 – Z’ , Nl - Nl` are small - the right-handed CKM matrix is identical to the left-handed one - only one neutrino flavour (Ne , Nm , Nt) contributes to the WR decay 21 18 -22 August 2014 IPA 2014 Queen Mary University of London

Heavy neutrinos and WR CMS PAS EXO-13 -008 ar. Xiv: 1407. 3683 Nl : heavy right-handle neutrino PTl 1 > 60 Ge. V PTl 2 > 40 Ge. V PTjet > 40 Ge. V Mll > 200 Ge. V Q=0 I 3 L=0 I 3 R=1/2 eejj 22 18 -22 August 2014 mm jj IPA 2014 Queen Mary University of London

An excess is observed in the electron channel with a local significance of 2. 8 s at Meejj 2. 1 Te. V. The excess does not appear to be consistent with expectations from left -right symmetric theory. MWR > 2. 5 Ge. V from KL–KS mass difference 23 18 -22 August 2014 IPA 2014 Queen Mary University of London

Generic searches using dijet mass spectrum CMS PAS EXO-12 -59 n jets PT > 30 Ge. V the 2 leading jets are used as seeds to aggregate the other jets (“wide jets”) Mjjwide > 890 Ge. V ETmis < 0. 5 ∑ ET Impact of the signal to the Djet mass: - narrow resonances (width negligible compared to dijet resolution) - type of parton (qq, qg, gg) does affect the shape 24 18 -22 August 2014 IPA 2014 Queen Mary University of London

MG MZ’ MW’ Ms 8 Mq* MD MS 25 18 -22 August 2014 > 1. 58 Te. V > 1. 68 Te. V > 2. 29 Te. V > 2. 79 Te. V > 3. 50 Te. V > 4. 75 Te. V > 5. 08 Te. V IPA 2014 (RS Graviton) (Z’ boson) (W’ boson) (Color octet scalar) (Excited quark) (E 6 Diquark) (String resonance) Queen Mary University of London

Search of dark matter with top quarks Simplified model: - only 1 new fermion - M* scale of interaction with quarks CMS PAS B 2 G-14 -04 Selection: p. Tlepton > 30 Ge. V PTjet > 30 Ge. V 1 lepton n jets ≥ 3 ETmiss > 320 Ge. V M* =100 Ge. V M* > 120 Ge. V Mc = 100 Ge. V Mc > 250 Ge. V M* = 100 Ge. V 26 18 -22 August 2014 IPA 2014 Queen Mary University of London

Summary Exotica 27 18 -22 August 2014 IPA 2014 Queen Mary University of London

Summary B 2 G 28 18 -22 August 2014 IPA 2014 Queen Mary University of London

Conclusions • Dark matter / energy and the neutrino oscillations are evidence of new physics beyond the SM. The Higgs hierarchy problem also suggests the presence of new physics at higher energy scale with respect to the electroweak scale. • A wide set of final states have been studied at CMS with the full statistics collected at LHC with 8 Te. V proton-proton collisions. There’s no evidence of new physics ( signal excess > 5 s) and no hints of new physics (signal excess > 3 s) • The exotica program allowed to increase the limits on the mass scale in a large variety of scenarios: W’SSM (3. 3 Te. V), Z’SSM (2. 9 Te. V), large extra-dimensions MDADD(3 Te. V), excided quarks q*f=1 (3. 5 Te. V) • Exotica searches will benefit from the higher center-of-mass energy starting in beginning 2015 (13 Te. V then 14 Te. V) and from the expected increase of the integrated luminosity up to the end of the LHC program (~300 fb-1 in 2022) and the HL-LHC (~3000 fb-1 in 2030) 29 18 -22 August 2014 IPA 2014 Queen Mary University of London