BSM PHYSICS AT LHC by R Alemany LIPCMS
BSM PHYSICS AT LHC by R. Alemany (LIP/CMS) on behalf of Outline: 1. Introduction 2. Some experimental remarks 3. Extra Dimensions (ADD, Te. V-1, RS, UED, BH) 4. Extra Gauge Bosons 5. How to discriminate between models 6. Conclusion 06. 07. 2006 BSM Physics @LHC - R. Alemany
1. Introduction ■ Theorist argue in different ways, as we heard from S. Pokorski’s talk, that there should exist physics Beyond the Standard Model. This is one of the reasons why the LHC and its detectors are being built. ■ During this talk I will review the most recent results, from the experimental (simulation) point of view, on: q Extra Dimensions q Extra Gauge Bosons ■ … but one must keep in mind that nature may prove to be more creative than we are, and that something completely unexpected may be discovered at LHC… 06. 07. 2006 BSM Physics @LHC - R. Alemany 2/23
2. Some experimental remarks n Theoretical uncertainties: uncertainties q Parton Distribution Functions (PDF) q Hard process scale (Q 2) q NNLO vs LO calculations (K factors) affect the S and B magnitudes, the cut efficiency, the significance. . . n Detector uncertainties: uncertainties q Alignment: Alignment key element in the performance of track reconstruction: n tracker (~ 10 μm) n muon system (~100– 500 μm) Misalignment spoils the intrinsic resolution of the tracking detectors. Misalignment sources are: n Detector construction tolerances n Detector assembly, Magnetic and Gravitational Field effects (~ cm for μ-chambers) n During operation: thermal instabilities, e. g. CMS TRK will be operated at ~ -20°C, humidity effects, . . . 06. 07. 2006 BSM Physics @LHC - R. Alemany 3/23
n Detector uncertainties: uncertainties q Energy Calibration: Calibration key element in the performance of e/ /hadrons energy reconstruction. It is composed of: § § absolute energy scale: a global component channel-to-channel energy scale: relative component ( intercalibration). The energy reconstruction has also a systematic uncertainty component coming from misaligned/miscalibrated tracker. Drift time and drift velocities (e. g. μ-chambers: t 0*(± 2 ns), drift velocity scaling (± 3%)). q 06. 07. 2006 BSM Physics @LHC - R. Alemany 4/23
3. Extra Dimensional Models The main motivation for the development of theories BSM is the Hierarchy Problem: Gravity/EW&Strong ~ 1019/103? n n Several possibilities have been suggested to solve this “naturality” problem: q q n Perturvative solutions: Supersymmetry Non- Perturvative solutions: Compositeness and Technicolor Alternatively, one can exploit the geometry of space-time via Extra Dimensional Theories 06. 07. 2006 ■ k ea w g ng rav o ity r st em Large ED (ADD) ED Graviton ■ Randall-Sundrum(Warped ED) ck lan ■P rφ=0 ■ ED φ SM rφ=r Te. V-1 size ED ED Gauge bosons ■ Universal ED BSM Physics @LHC - R. Alemany fermions ED 5/23
ADD Model n ED Graviton MPl is not a fundamental scale, but MEW Gravity propagates in a bulk of 4+ extra dimensions of radius R seen as an infinite tower of KK states in 4 -dim. n Model parameters: 1. : number of extra dimensions 2. MPl(4+ ) (=MD): fundamental scale (above which new physics enters and modifies the results): M 2 Pl ~ M 2+ Pl(4+ ) R n n n for MPl ~ 1019 Ge. V and MD ~ MEW R ~ 1032/ 10 -17 cm m. G n/R light G Gnn for R < mm m. G(KK, KK+1) [~ e. V, Me. V] Gn couplings MPl-1 … but m. G<< high density of KK modes produced >> ADD Model Ref: [ADD 1, ADD 2, ADD 3] 06. 07. 2006 BSM Physics @LHC - R. Alemany 6/23
ADD expectations in Direct production of GKK jet (E >500 Ge. V) p p G (p. Tmiss >500 Ge. V) jet+Z jet+W jet l + veto on e, μ & τ (iso+ID) Graviton (high p. T, central η) Z W e(μ, τ) , W e +jets, QCD, di - , Z 0+jets p p back-to-back G (high p. Tmiss) S= 2( (S+B) - B) > 5 [SIG 2] j. W(e/μ ) j. W(τ ) j. Z( ) Tot back =2 MD=4 Te. V =2 MD=8 Te. V =3 MD=5 Te. V =4 MD=5 Te. V Gen (S+B): ISAJET UVCUT CTEQ 3 L Sim/Rec: Fast For L=100 fb-1 MD= 7. 7: 6. 2: 5. 2 = 2: 3: 4 (S/ B>5, S>100, Ejet. Tcut>1 Te. V) 2001 s=14 Te. V L=100 fb-1 J. Phys. , G 27 (2001) 1839 -50 ETmiss (Ge. V) MD/ 2 3 4 5 2006 T ED 6 l tica e r o s The ematic syst luded inc Gen (S): PYTHIA vs SHERPA, CTEQ 6 L Gen (B): PYTHIA vs SHERPA vs Comp. HEP vs Madgraph(dis) Sim/Rec: Full J. Weng et al. CMS NOTE 2006/129 7/23
ADD expectations in Virtual production of GKK ED Graviton μ (2 OS-μ, mμμ>1 Te. V) p GKK p S= 2( (S+B) - B) > 5 [SIG 2] μ Z/ μμ ZZ, W W, tt [3, 6] ~ ~ 5. 5 Te. V ~ 4 Te. V 06. 07. 2006 ~ 8. 3 Te. V BSM Physics @LHC - R. Alemany Gen (S): @LO+ K=1. 38 STAGEN+ PYTHIA ISR&FSR 5. 5 Te. V CTEQ 6 L Sim/Rec: Full Syst Uncert: theoretical + μ & TRK I. Belotelov et al. misalignment CMS NOTE 2006/076 TRG system CMS PTDR 2006 = SM+ INT + KK 2 = f(MD, , s) 8/23
RS(1) model n n ■ nck Pla rφ=0 ED φ SM rφ=r Gravity propagates in a 5 -dim bulk of finite extent with two rigid boundaries of (3+1) dim that extend infinitely SM fields are constraint on one of the 3 -brane (y = R ) m(Gn) = kxne-k. R = xn(k/M Te. V (k/ Pl) ~ Te. V couplings Gn couplings -1 -1 (n 1) Model parameters: 1. : the scale of physical processes in the Te. V brane 2. c=k/MPl, k is a scale of the order of the Planck scale ■ ck n a Pl rφ=0 ED φ SM rφ=r pp Gn ll c=1 c=0. 5 c=0. 1 Drell-Yan production of a 1. 5 Te. V Gn and its subsequent tower states c=0. 05 c=0. 01 Ref: [RS 1, RS 2] 06. 07. 2006 BSM Physics @LHC - R. Alemany 9/23
RS(1) expectations in eμ G 1 rφ=0 c p ED φ G 1 didi- +jets, QCD, DY(e) 2006 eμ Full simulation and reconstruction S= (2[(S+B)log(1+S/B)-S]) [SIG 1] SM rφ=r R. Clerbaux et al. CMS NOTE 2006/083 CMS PTDR 2006 p nck Pla MG (Te. V/c 2) G 1 μ+μ- c R. Clerbaux et al. CMS NOTE 2006/083 CMS PTDR 2006 Z/ ee +jets, QCD MG (Te. V/c 2) 2006 1 syst. uncert. Z/ μμ ZZ, WW WZ, tt I. Belotelov et al. CMS NOTE 2006/104 CMS PTDR 2006 G 1 e+e- c MG (Ge. V/c 2) 10/23
RS(1) expectations in nck Pla rφ=0 ED φ SM rφ=r c 10 fb-1 CMS PTDR ~ 3. 2 Te. V ~ 3. 3 Te. V ~ 3. 5 Te. V 2006 e e μ μ MG (Te. V/c 2) 06. 07. 2006 BSM Physics @LHC - R. Alemany 11/23
Te. V-1 -size ED models The results shown in the following assume: ■ Higgs in the bulk the VEV of H 0 SSB m(gaugen)=[m 02+nn/R 2]1/2 ■ ■ =1 Fermions localized at specific points in the Te. V-1 dim but not on a rigid brane (suppress of a number of dangerous processes). Two models: M 1 All SM fermions localized at the same orbifold point KK gauge states coupling to SM fermions is 2 g destructive interf. between SM gauge bosons and KK excitations. 06. 07. 2006 bosons ED Ref: [TEV 1] M 2: M 2 quark and leptons localized at opposite fixed orbifold points constructive interference. G. Azuelos, G. Polesello EPJ Direct 10. 1140 (2004) BSM Physics @LHC - R. Alemany pp Z 1/ 1 e+e- me+e- (Ge. V) 12/23
Te. V-1 expectations in Invariant mass analyses high p. T, HCAL Ee leak, Iso, ID e ED S= (2[(S+B)log(1+S/B)-S]) > 5 [SIG 1] e Z 1 / 1 p bosons Gen (S+B): Ext+PYTHIA PHOTOS CTEQ 6. 1 M Sim/Rec: Full Pile-up @low Lumi (1033) Syst Uncert: Theoretical 5 discovery limit of p (M 1 model) Z/ ee 2006 R. Clerbaux et al. CMS NOTE 2006/083 CMS PTDR 2006 CMS events corrected for: • ECAL electronics saturation (MGPA) for ET>1. 7 Te. V (3 Te. V Endcaps) ATLAS expectations for e and μ: (S=(S-B)/ B > 5 & S > 10 (e, μ)) Fast simu/reco G. Azuelos, G. Polesello R-1 = 5. 8 Te. V @100 fb-1 EPJ Direct 10. 1140 (2004) 06. 07. 2006 BSM Physics @LHC - R. Alemany 13/23
Te. V-1 expectations in p high p. T > 200 Ge. V ml > 1 Te. V Iso, ID, jet veto W 1 ATLAS: g 1 tt, bb Fast simu/reco tt R-1 = 3. 3 Te. V bb R-1 = 2. 7 Te. V for 300 fb-1 S=(S-B)/ B > 5 & S > 10 (e, μ) p W 1 e -1 =4 R Te. V -1 =5 R R-1 = 6 Te. V @100 fb-1 Te. V -1 =6 R SM SM Te. V G. Polesello, M. Prata EPJ Direct C 32 Sup. 2 (2004) pp. 55 -67 W l tt, WW, WZ, ZZ ED 2003 l bosons L. March, E. Ros, B. Salvachua, ATL-PHYS-PUB-2006 -002 06. 07. 2006 BSM Physics @LHC - R. Alemany 14/23
UED Scenarios ED Standard (M)UED mass degeneration except if radiative corrections included: ● If radiative corrections mass degeneracy is broken and leptons are produced. 600 570 Z 1 L 1 ■ Model Ref: [UED 1] 06. 07. 2006 1000 900 800 700 600 [UED 5] Q 1 Lower bounds on UED [UED 4] g 1 [UED 3] ■ ■ [UED 2] ■ SM brane is endowed with a finite thickness in the ED. KK parity conservation the ■ Gravity-matter interactions lightest massive KK particle (LKP) LKP break KK number conservation: is stable (dark matter candidate). ● 1 st level KK states decay to G+SM. All particles propagate in ED R-1 (Ge. V) ■ Fat brane G bosons fermions (@ 95% CL) EW Heavy Water (@ 90% CL, mh=115 Ge. V) 500 1 400 =2 300 parameters: (= 1), R, BSM Physics @LHC - R. Alemany =1 (mh>>) 2006 2001 2004 (13. 05) (18. 05) year 15/23
UED expectations in l l g 1 1 l G jet 1 , g 1 Z( )jj* W( l )jj p (l: e, μ, τ) q Geoaccep L 1, HLT 22 OSSF 44 ISO b-tagveto l l pp. T T<< miss EETmiss T ZZveto jet p S=S/ B > 5 S [UED 6] P. H. Beauchemin, G. Azuelos ATL-PHYS-PUB-2005 -003 Full simu/reco Fat brane model with Te. V-1 size ED 100 fb-1 5 Poster 1 2 back-to-back energetic jets + ETmiss > 775 Ge. V No ISO leptons G S 2006 l 1 2005 g 1 tt+nj (n: 0, 1, 2) q 1 L 1 4 b q Q 1 ZZ, Zbb p p q Q 1 q L 1 Z 1 G bosons fermions q, 1 g 1 Z ED ~2. 7 Te. V Gen(S+B): CTEQ 5 L B: Estimate of PYTHIA using Z/W+j(+nj from ISR&FSR) Sim/Reco: - Fast - Cascade decays suppr. - n 2 kinem. suppr. - Proton top flavour content ignored 16/23
4. Extra Gauge Bosons (Z’, W’) ■ Predicted by: q Super-string inspired and GUT theories; q Left-Right Symmetric Models based on the gauge group SU(3)Cx. SU(2)Lx. SU(2)Rx. U(1)B-L predicting substructures of the known “elementary particles”; q Little Higgs Models. stringent limits from precision EW experiments and direct searches ■ ■TEVATRON 06. 07. 2006 ~ 1 Te. V BSM Physics @LHC - R. Alemany 17/23
e Extra Gauge Bosons expectations in μ p μ 2006 SL= (2 ln(LS+B/LB) > 5 R. Cousins et al. CMS NOTE 2006/062 CMS PTDR 2006 06. 07. 2006 p Z’ Z/ ee (TRG, OSSF, Eμ recov. from em processes) Z’ p e Same analysis as Z 1/ 1 @CMS S= (2[(S+B)log(1+S/B)-S]) > 5 [SIG 1] 2006 Z/ μμ p Gen (S+B): - PYTHIA - CTEQ 6 L - K=1. 35 Sim/Rec: - Full - pile-up (ine+dif) for low (5 evt) & high (25 evt) lumi. Systemat. uncert. : - Theoretical - Muon+TRK missalignment MZ’ (Te. V/c 2) BSM Physics @LHC - R. Alemany B. Clerbaux et al. CMS NOTE 2006/083 MZ’ (Te. V/c 2) 18/23
2006 Extra Gauge Bosons expectations in R. Cousins et al. CMS NOTE 2006/062 CMS PTDR 2006 Z’ μμ Effects of 1 theoretical uncertainties on the integrated luminosity need to reach a 5 significance for two Z’ models: - Asymmetric Left-Right Model (ALRM) - GUT theory ( ) MZ’ (Te. V/c 2) 06. 07. 2006 BSM Physics @LHC - R. Alemany 19/23
Extra Gauge Bosons expectations in μ p W’ Single μ trg high p. T p Iso-μ ID (BR ~ 10%) W μ Z μμ, WW incl. , ZW incl. ttbar incl (ETmiss) 06. 07. 2006 L ~ 1033 cm-2 s-1, with pile-up of 3. 5 BSM Physics @LHC - R. Alemany C. Hof et al. CMS PTDR 2006 CMS looks for charged spin-1 boson, W’ from the Reference Model by Altarelli. 20/23
M 1=/=Z’ 45% M 1=/=GKK 91% of the times at 95% CL M 2 Z 1 M 1 Z’ GKK GKK AFB Z’ Z’ M 2 vs G KK For higher resonance masses (e. g. 5 Te. V) need more luminosity to keep discrimination power Mreso (Ge. V) Z 1 (M 1 M 2) 2003 100 fb-1 2003 Events/50 Ge. V 5. How to discriminate models Z 1(M 2) Z’ Z vs Z’ 2003 1 GKK (qq&gg) [DIS 1] cos lep-beam Mreso (Ge. V) 21/23
How to discriminate models Method: unbinned likelihood ratio statistics incorporating the angles of the decay products [DIS 3]. ■ The statististical technique has been applied to fully simu/reco events. ■ Two spin hypothesis are treated symmetrically. ■ (G 1) = (Z’) CMS PTDR 2006 fb -1 2 Spin-1 (Z’) Exclusion vs G 1 2006 300 fb -1 100 10 fb -1 ■ [DIS 2, DIS 3] 06. 07. 2006 BSM Physics @LHC - R. Alemany 22/23
Conclusions n We have revised the most recent results on different Extra Dimensions scenarios and Extra Gauge Bosons: Model Mass reach ADD Direct GKK MD~2. 5 Te. V 10 Theo ADD Virtual GKK MD~5 - 4 Te. V [3 -6] 1 Theo+Exp RS MG 1~3. 5 Te. V, Te. V c=0. 1 (~all the allowed region) 10 Theo(+Exp di-μ) Te. V-1 (Z 1/ 1) Mz 1 ~ 5 Te. V 10 Theo Te. V-1 (W 1) MW 1 ~ 6 Te. V 100 m. UED R-1 ~ 900 Ge. V ( R=20) 10 Fat brane R-1 = 2. 7 Te. V 100 GUT, SSM, (A)LR Z’ MZ’ ~ 3 - 4 Te. V, Te. V f(model) 10 Theo+Exp Altarelli MW’ ~ 3 - 4 Te. V 10 Theo+Exp 06. 07. 2006 BSM Physics @LHC - R. Alemany Int. Lum. (fb-1) Syst. Includ Theo+Exp 23/23
Bibliography [ADD 1] [ADD 2] [ADD 3] [ADD 4] [CHR] [DIS 1] [DIS 2] [DIS 3] [RES 1] [RS 2] [SIG 1] [SIG 2] [TEV 1] [UED 2] [UED 3] [UED 4] [UED 5] [UED 6] 06. 07. 2006 N. Arkani-Hamed, S. Dimopoulos and G. R. Dvali, Phys. Rev. D 59, 086004 (1999), Phys. Lett. B 429, 263 (1998); I. Antoniadis, N. Arkani-Hamed, S. Dimopoulos and G. R. Dvali, Phys. Lett. B 436, 257 (1998). T. Han, J. D. lykken and R. J. Zhang, Phys. Rev. D 59, 105006 (1999); G. F. Giudice, R. Rattazzi and J. D. Wells, Nucl. Phys. B 544, 3 (1999). J. L. Hewett, Phys. Rev. Lett. 82, 4765 (1999); E. A. Mirabelli, M. Perelstein and M. E. Peskin, Phys. Rev. Let. 82, 2236 (1999); T. G. Rizzo, Phys. Rev. D 59, 115010 (1999). B. Abbott et al. Phys. Rev. Lett. 86 1156 (2001); B. Abbott et al. Phys. Rev. Lett. 82 4769 (1999). C. M. Harris, P. Richardson, B. R. Webber, JHEP 08 033 (2003), hep-ph/0007304. SN-ATLAS-2003 -023, SN-ATLAS-2003 -036. B. Clerbaux, T. Mahmoud, C. Collard, P. Mine, CMS Note 2006 -083; R. Cousins, J. Mumford, V. Valuev, CMS NOTE 2005 -022. B. C. Allanach, K. Odagiri, M. A. Parker, B. R. Webber, JHEP 09 (2000) 019; hep-ph/0006114; R. Cousins, J. Mumford, J. Tucker, V. Valuev, JHEP 11 (2005) 046; doi: 10. 1088/1126 -6708/2005/11/046. B. Clerbaux, T. Mahmoud, C. Collard, P. Mine, CMS Note 2006 -083. l. Randall and R. Sundrum, Phys. Rev. Lett. 83 3370 -3373 (1999); l. Randall and R. Sundrum, Phys. Rev. Lett. 83 4690 -4693 (1999). Davoudiasl, Hewett, Rizzo, Phys. Rev. D 63, 075004 (2001). V. Bartsch, G. Quast, CMS Note 2005 -004. R. Cousins, J. Mumford, V. Valuev, CMS Note 2005 -002. T. G. Rizzo, Phys. Rev. D 61 055005 (2000). H. C. Cheng, K. T. Matchev, and M. Schmaltz, Phys. Rev. D 66, 056006 (2002). T. Appelquist et al. Phys. Rev. D 64, 035002 (2001). M. Byrne, Phys. Lett. B 583 309 (2004). Flacke, T; Hooper, D; March-Russell, J; hep-ph/0509352. I. Gogoladze, C. Macesanu, hep-ph/0605207. S. I. Bitykov, S. F. Frofeeva, N. V. Krasnikov, A. N. Nikitenko; Proceedings of the Statistical Problems in Particle Physics, Astrophysics and Cosmology Conference, PHYSTAT 05. BSM Physics @LHC - R. Alemany
Talk shortenings n n n n n ADD: Arkani-Hamed, Dimopoulos and Dvali model RS: Randall and Sundrum model UED: Universal Extra Dimensions BH: Black Holes Iso: Isolation algorithm ID: Lepton Identification S: Number of signal events that survive the selection cuts B: Number of background events that survive the selection cuts Ext. : external generator interfaced to PYTHIA IP: Interaction Point SSB: Spontaneous Symmetry Breaking VEV: Vacuum Expectation Value. g: SM coupling MET: Missing Transverse Energy TRK: Tracker detector TRG: Trigger EW: Electroweak 06. 07. 2006 BSM Physics @LHC - R. Alemany
Back up slides 06. 07. 2006 BSM Physics @LHC - R. Alemany
§ Overview k ea w g ng rav ity ro t s em - 30 th q The first ED ideas appeared when gravity and the electromagnetism were the only known interactions (1 ED theories): G. Nordström (1912), T. Kaluza (1919) & O. Klein and H. Mandel (1926) 50 -70 th 80 th q The discovery of new interactions complicated more the overall picture: using a single extra dimension, as a mean of reaching a unified description, was not able to accommodate the strong and weak forces. Therefore physics research focused on gauge theories. q The development of new theories: string theories and supergravity, changed the interpretation of ED theories in the sense they were given a “physical” meaning. q In recent years, ED quantum field theories have received a great deal of attention: q 90 th q 06. 07. 2006 The scale at which the ED effects can be relevant could be around a few Te. V, even hundreds of Ge. V, clearly a challenge for the next accelerators (e. g. LHC). It is a new point of view to study many long-standing problems in physics: hierarchy, neutrino physics, new candidates for dark matter. . . BSM Physics @LHC - R. Alemany
ADD expectations in Virtual production of GKK p GKK p 06. 07. 2006 BSM Physics @LHC - R. Alemany ED Graviton
Te. V-1 expectations Off-peak region analyses in If R-1 beyond the LHC reach via direct mass peak reconstruction study the offpeak region How? ■ bosons ED Event kinematics analyses ■ Results using event kinematic variables (only e+e-): q Fraction of the proton momentum carried by parton i q Scattering angle in the partonic c. m. e ■ An optimal measurement of R-1 can be obtained by a likelihood fit to the reconstructed kinematical variables: q For one lepton flavour: R-1 = 9. 5, 11 & 12 Te. V @100, 200 & 300 fb-1 respectively. q Assuming similar sensitivity for e & μ: R-1 13. 5 Te. V @ 300 fb-1 ■ Studied systematics : q how p. Te scales with energy for > Te. V? “rule” experimental limit reduces by 2% for each % of uncertainty in the energy calibration of 2 Te. V electrons. q QCD higher order corrections (main effect modification of the p. Tll distribution due to ISR). q EW corrections. G. Azuelos, G. Polesello q PDFs. EPJ Direct 10. 1140 (2004) look at the TOT/event_rate w. r. t. DY background for a mll range as a f( R-1). Very sensitive to the degree of systematic uncertainties. 100 fb-1 2003 (M 1) G. Azuelos, G. Polesello EPJ Direct 10. 1140 2004) ■ mee (Ge. V) ATLAS 5 reach for R-1: q ~ 8 Te. V @100 fb-1 (15% SM deviation) q ~10. 5 Te. V @300 fb-1 (~ 10% deviation) ■ 06. 07. 2006 BSM Physics @LHC - R. Alemany 2003 ■
Te. V-1 expectations in bosons b, t p g 1 bb, tt, jj, Wj b: 2 b-tagged jets with p. Tb cut =f(m(g 1)) t: one t lepton decay (p. Tlep>25 Ge. V), ETmiss>25 Ge. V, 2 b-tagged jets with R(b 1(2)-lep)<2(>2), p. Tb cut =f(m(g 1)) Gen(S): PYTHIA, CTEQ 5 L Sim(S): Fast L. March, E. Ros, B. Salvachua, ATL-PHYS-PUB-2006 -002 300 fb-1 R-1 = 3. 3 Te. V 2006 b, t p ED R-1 = 2. 65 Te. V (Note: heavy quarks appearing in the light quark sample as a result of gluon splitting are excluded in this analysis; the enhancement of the signal due to the contribution of Z 1/ 1 production (lower than g 1) is not taken into account in this analysis)
Extra Gauge Bosons (Z’, W’) Predicted by: q Super-string inspired and GUT theories; ■ Thus the limits from precision experiments vary significantly from q Left-Right Symmetric Models based on model to model because of the different chiral couplings to the gauge group ordinary fermions. SU(3)Cx. SU(2)Lx. SU(2)Rx. U(1)B-L predicting ■ Typically: substructures of the known “elementary q m. Z’ >~ 400 Ge. V and Z-Z’ mixing angle < few 10 -3 for particles”; and models in which the Z’ couples significantly to charged q Little Higgsfrom Models. leptons. ■ stringent limits precision electro-weak (EW) q m. Z’ >~ 300 -600 Ge. V for models with suppressed couplings experiments and direct searches. to charged leptons can tolerate much larger mixings (several ■ The existence of a Z’ affects EW data: %) but with the dominant constraint from the shift in the light q Because Z-Z’ mixing pushes the Z mass. below the SM expectations. q SM expectations are themselves modified by ■ At LHC should be possible to discover a heavy Z’ with mass up to mixing since = f(weak angle), and this angle is 5 Te. V through its leptonic decay. confused or distorted by the effects of mixing ■ If a Z’ exists it should be possible to deeply study its couplings via: on other observables. q F-B asymmetries q Both the mixing and heavy particle q rapidity distributions exchange lead as well to other changes in the q rare decays (Z’ Wl ) predictions for the various observables, q associated productions with a Z, W or implying new terms in the effective interactions relevant to each process and leading to different apparent vales of the weak angle determined in different processes. ■ 06. 07. 2006 BSM Physics @LHC - R. Alemany
Extra Gauge Bosons expectations in 2006 Combined expectation from: Z’ e+e. Z’ μ+μfor Sequential SM (SSM) and one GUT theory ( ). 06. 07. 2006 CMS PTDR 2006 BSM Physics @LHC - R. Alemany
§ Mini (quantum) Black Holes (Exploring energies above the fundamental theory scale: the transplanckian region ( s >> MPl(4+ )) One of the consequences of large ED is the possibility to produce BH @LHC. ■ A BH produced in the 4+ dimensions has a Schwarzschild radius given by: Rs(4+ ) = f(MPl(4+ ), MBH, ) ■ If the IP of a p-p collision is smaller than Rs(4+ ), BH can be produced at LHC with (MBH) = R 2 s(4+ ) at parton level and in the semiclassical approach. ■ 06. 07. 2006 k ea w g ng rav ity ro t s em E. g. for MPl(4+ )~ 2 Te. V, ~ pb. ■ Once produced, it is expected that they decay thermally via Hawking radiation, with a typical life time of 10 -27 s. ■ BH events are expected to evaporate democratically by emission of all particle types, therefore BH can be a source of new particles. ■ Characteristic signatures: ■ events are spherical q jet/lepton decay ratio 5: 1 q high multiplicity q BSM Physics @LHC - R. Alemany
J. Tanaka et al. Eur. Phys. J. C 41 19 -33 (2005) MPl (Te. V) BH expectations in 1 fb-1 Cuts: Cuts ISR-cut, p. T thresholds, multip. (with E>300 Ge. V)>3, at 100 pb-1 least one: e. OR. , R 2(Fox. Wolfram moments)<0. 8 10 pb-1 lower values of R 2 means more spherical events; ETmiss<100 Ge. V qq, qqbar, qg, gg 1 pb-1 ttbar S/ B > 5, S > 10 WW, WZ, ZZ, , V (V: W, Z, *) q. V (V: W, Z, (*)) CMS Results =3, MBHmin=1 Te. V 106 104 MPl = 1 Te. V B S+B 105 103 MPl = 3 Te. V 102 103 10 1 102 104 MPl = 7 Te. V 10 -1 10 -2 10 2 4 06. 07. 2006 6 8 10 12 14 MBH (Te. V) 2 4 6 8 10 12 14 BSM Physics @LHC - M R. Alemany (Te. V) BH 2 4 6 8 10 12 14 MBH (Te. V)
- Slides: 34