Download presentation
Presentation is loading. Please wait.
Published byElfreda Bell Modified over 8 years ago
3
Era of Discovery with CMS Detector TAMU Group Teruki Kamon, Alexei Safonov, David Toback Special Colloquium, LHC… Alexei Safonov 09/17/08 (Next Wednesday)
4
Precision Cosmology at the Large Hadron Collider Bhaskar Dutta Texas A&M University 311 th September ’ 08 Based on plenary talks at Cosmo’08, IDM’08, Santa Fe’08, DM’08
5
LHC Days… 4 The mechanism for generating masses We will try to understand: The physics behind the scale of W, Z boson mass scale ~ electroweak scale The origin of dark matter Do we have any further evidence of grand unification? Is there any particle physics connection? Precision Cosmology at the LHC M planck >>M W
6
The Standard Model (SM) describes all these particles and 3 of 4 forces. We have confirmed the existence of those in the laboratory experiments. The Standard Model + Higgs boson Higgs has not yet been discovered The mass is constrained from LEP and Tevatron data: 114 GeV<M H <154 GeV Precision Cosmology at the LHC 5
7
SM problems and solutions The Standard Model : Cannot provide a dark matter candidate. Has a serious Higgs mass divergence problem due to quantum correction. Cannot accommodate masses for neutrinos. Cannot provide enough matter- antimatter asymmetry. Standard Model has fallen! 6 Precision Cosmology at the LHC Solves the Higgs mass problem in a very elegant way. Supersymmetric grand unified models include neutrinos! Dutta, Mimura, Moahapatra, PRL 100 (2008); 96, (2006) 061801; 94, (2005) 091804; PRD 72 (2005) 075009. Can produce correct matter- antimatter asymmtery Dutta, Kumar, PLB 643 (2006) 284 Can provide Inflation Can provide new sources of CP violation, e.g., B s Dutta, Kumar, Leblond, JHEP 0707 (2007) 045; Allahverdi, Dutta and Mazumdar, PRL99 (2007) 261301., PRD (2008) to appear. Dutta, Mimura, PRL 97 (2006) 241802; PRD (Rapid Com) 77 (2008)051701. Supersymmetry : Provides a candidate for dark matter ~ neutralino. What is the new model? Goldberg’ 83; Ellis, Hagelin, Nanopoulos, Olive, Srednicki’84
8
Particle Physics and Cosmology SUSY is an interesting class of models to provide a weakly interacting massive neutral particle (M ~ 100 GeV). SUSY CDM = Neutralino ( ) Astrophysics LHC 2016/2/207 LHC LHC LHC Precision Cosmology at the LHC
9
The fundamental law(s) of nature is hypothesized to be symmetric between bosons and fermions. Fermion Boson Have they been observed? ➩ Not yet. Supersymmetrized SM Precision Cosmology at the LHC 8
10
SUSY partner of Z boson: neutralino SUSY partner of W boson: chargino Lightest neutralinos are always in the final state! This neutralino is the dark matter candidate!! SUSY partner of lepton: stau SUSY Interaction Diagrams Precision Cosmology at the LHC 9
11
The grand unification of forces occur in SUSY models. Dream of the Unification ☺ U(1) Y Force Precision Cosmology at the LHC Unification scale can also be pushed to 10 17-18 GeV Ameliorates Proton decay problem in the very successful SO(10) model Dutta, Mimura, Mohapatra, Phys.Rev.Lett.100:181801,2008 10
12
Search for SUSY-upcoming days 11 Precision Cosmology at the LHC Large Hadron Collider- susy particles will be directly produced Higgs mass in the well motivated SUSY models: < 150 GeV Current experimental bound: 114 - 154 GeV Direct detection experiment, CDMS, Xenon 100, LUX etc Indirect detection experiments, e.g., PAMELA has already observed excess of positron excess in cosmic ray Fermi Gamma Ray Space Telescope: Sensitive to gamma ray from Dark Matter annihilation Tevatron search for B s highest reach on SUSY masses) Existence of Higgs will be explored IceCube: Sensitive to neutrinos from DM annihilation Arnowitt, Dutta, Kamon and Tanaka, Phys.Lett.B538 (2002) 121. e+e+ …
13
The signal : jets + leptons + missing Energy SUSY at the LHC (or l + l -, ) DM Colored particles get produced and decay into weakly interacting stable particles High energy jet [mass difference is large] The energy of jets and leptons depend on the sparticle masses which are given by models R-parity conserving 12 Precision Cosmology at the LHC (or l + l -, ) M W,M Z
14
Excess in E T miss + Jets R-parity conserving SUSY M eff Measurement of the SUSY scale at 10-20%. Excess in E T miss + Jets Hinchliffe and Paige, Phys. Rev. D 55 (1997) 5520 q The heavy SUSY particle mass is measured by combining the final state particles q q q E T j1 > 100 GeV, E T j2,3,4 > 50 GeV M eff > 400 GeV (M eff E T j1 +E T j2 +E T j3 +E T j4 + E T miss ) E T miss > max [100, 0.2 M eff ] Precision Cosmology at the LHC13 Since squarks and gluinos are heavier than W,Zs
15
SUSY scale can be measured with an accuracy of 10-20% This measurement does not tell us whether the model can generate the right amount of dark matter The dark matter content is measured to be 23% with an accuracy less than 4% at WMAP Question: To what accuracy can we calculate the relic density based on the measurements at the LHC? Relic Density and M eff Precision Cosmology at the LHC 14
16
15 + …. A near degeneracy occurs naturally for light stau in mSUGRA. + + …. Co-annihilation (CA) Process Griest, Seckel ’91 Anatomy of ann Precision Cosmology at the LHC
17
Dark Matter Allowed Region 16 Co-annihilation Region Precision Cosmology at the LHC
18
4 parameters + 1 sign tan / at M Z m 1/2 Common gaugino mass at M GUT m 0 Common scalar mass at M GUT A 0 Trilinear couping at M GUT sign( ) Sign of in W (2) = H u H d M Higgs > 114 GeV M chargino > 104 GeV 2.2x10 4 < B ( b s ) <4.5x10 4 (g 2) deviation from SM Key Experimental Constraints Minimal Supergravity (mSUGRA) <Hd><Hd> <Hu><Hu> = 246 GeV SUSY model in the framework of unification: + Arnowitt, Chamesdinne, Nath, PRL 49 (1982) 970; NPB 227 (1983) 121. Barbieri, Ferrara, Savoy, PLB 119 (1982) 343. Lykken, Hall, Weinberg, PRD 27 (1983) 2359. Precision Cosmology at the LHC 17
19
DM Allowed Regions in mSUGRA [Stau-Neutralino CA region] [Focus point region] the lightest neutralino has a larger Higgsino component Feng, Matchev, Wilczek, PLB482 388,2000. [A-annihilation funnel region] This appears for large values of m 1/2 [Bulk region] is almost ruled out 18 Precision Cosmology at the LHC Arnowitt, Dutta, Santoso, NPB 606:59,2001. Ellis, Falk, Olive, PLB 444:367,1998. Overdense region
20
Signals of the Allowed Regions Neutralino-stau coannihilation region: jets + taus (low energy) + missing energy Arnowitt, Dutta, Gurrola, Kamon, Krislock, Toback, PRL, 100, (2008) 231802 [ Arnowitt, Dutta, Gurrola, Kamon, Krislock, Toback, PRL, 100, (2008) 231802 ; Arnowitt, Dutta, Kamon, Kolev, Toback, PLB 639 (2006) 46 ; Arnowitt, Aurisano, Dutta, Kamon, Kolev, Simeon, Toback, Wagner; PLB 649 (2007)73 Arnowitt, Aurisano, Dutta, Kamon, Kolev, Simeon, Toback, Wagner; PLB 649 (2007)73 ] Focus point: jets+ leptons +missing energy Crockett, Dutta, Flanagan, Gurrola, Kamon, Kolev, VanDyke, 08; [ Crockett, Dutta, Flanagan, Gurrola, Kamon, Kolev, VanDyke, 08; Tovey, PPC 2007; Baer, Barger, Salughnessy, Summy, Wang, PRD, 75, 095010 (2007) ] Bulk region: jets+ leptons +missing energy [ Nojiri, Polsello, Tovey’05 ] Annihilation funnel: mass of pseudo scalar Higgs = 2 mass of DM [Dutta, Gurrola, Kamon, Krislock, Lahanas, Mavromatos, Nanopoulos, arXiv:0808.1372 ] Overdense regions: Higgs+Jets, Z+jets, taus+jets+missing energy [Dutta, Gurrola, Kamon, Krislock, Lahanas, Mavromatos, Nanopoulos, arXiv:0808.1372 ] 19 Precision Cosmology at the LHC
21
Goal for the analysis E stablish the “dark matter allowed region” signal M easure SUSY masses D etermine mSUGRA parameters P redict h 2 and compare with CDM h 2 20 Precision Cosmology at the LHC
22
Smoking Gun of CA Region 100% 97% SUSY Masses (CDM) 2 quarks+2 ’s +missing energy Unique kinematics 21 Low energy taus exist in the CA region However, one needs to measure the model parameters to predict the dark matter content in this scenario Precision Cosmology at the LHC
23
Low Energy and M Low energy ’s are an enormous challenge for the detectors Precision cosmology at the LHC22 Number of Counts / 1 GeV E T vis (true) > 20, 20 GeV E T vis (true) > 40, 20 GeV E T vis (true) > 40, 40 GeV Arnowitt, Dutta, Kamon, Kolev, Toback PLB 639 (2006) 46 We need to involve the low energy ’s In our analysis Low energy
24
23 We use ISAJET + PGS4 PLB 639 (2006) 46 Precision Cosmology at the LHC Arnowitt, Dutta, Kamon, Kolev, Toback E T miss +2 +2j Analysis
25
OS LS M Distribution Clean peak even for low M 24 First, our goal is to determine all the masses Precision Cosmology at the LHC
26
SUSY Anatomy M j M p T( ) 100% 97% SUSY Masses (CDM) 25 M eff Precision Cosmology at the LHC
27
M eff, M eff (b)Distribution 26 Precision Cosmology at the LHC E T j1 > 100 GeV, E T j2,3,4 > 50 GeV [No e ’s, ’s with p T > 20 GeV] M eff > 400 GeV (M eff E T j1 +E T j2 +E T j3 +E T j4 + E T miss [No b jets; b ~ 50%]) E T miss > max [100, 0.2 M eff ] At Reference Point M eff peak = 1274 GeV Arnowitt, Dutta, Gurrola, Kamon, Krislock, Toback, PRL, 100, (2008) 231802 M eff (b) > 400 GeV (M eff (b) E T j1=b +E T j2 +E T j3 +E T j4 + E T miss [j1 = b jet]) M eff (b)peak = 1026 GeV M eff (b) M eff (b) can be used to determine A 0 and tan
28
Observables SM+SUSY Background gets reduced Ditau invariant mass: M Jet- - invariant mass: M j Jet- invariant mass: M j P T of the low energy M eff : 4 jets +missing energy M eff (b) : 4 jets +missing energy Since we are using 7 variables, we can measure the model parameters and the grand unified scale symmetry (a major ingredient of this model) 1.Sort ’s by E T (E T 1 > E T 2 > …) Use OS LS method to extract pairs from the decays All these variables depend on masses model parameters 27 Precision Cosmology at the LHC
29
7 Eqs (as functions of SUSY parameters) Invert the equations to determine the masses Determining SUSY Masses (10 fb 1 ) 1 ellipse 10 fb -1 28 Phys. Rev. Lett. 100, (2008) 231802 M eff (b) = f 7 (g, q L, t, b) ~~~~ Precision Cosmology at the LHC Arnowitt, Dutta, Gurrola, Kamon, Krislock, Toback
30
GUT Scale Symmetry We can probe the physics at the Grand unified theory (GUT) scale The masses,, unify at the grand unified scale in SUGRA models 0 1 ~ m 1/2 mass MZMZ M GUT Log[Q] g ~ 0 1 ~ 0 2 ~ 0 2 ~ g ~ Gaugino universality test at ~15% (10 fb -1 ) Another evidence of a symmetry at the grand unifying scale! Use the masses measured at the LHC and evolve them to the GUT scale using mSUGRA 29 Precision Cosmology at the LHC
31
[1] Established the CA region by detecting low energy ’s (p T vis > 20 GeV) [2] Determined SUSY masses using: M , Slope, M j , M j , M eff e.g., Peak(M ) = f (M gluino, M stau, M, M ) [3] Predict the dark matter relic density by determining m 0, m 1/2, tan , and A 0 DM Relic Density in mSUGRA 0 1 ~ 0 2 ~ 30 Precision Cosmology at the LHC [4] We can also predict the dark matter-nucleon scattering cross section but it has large theoretical error
32
Determining mSUGRA Parameters Solved by inverting the following functions: 10 fb -1 31 Phys. Rev. Lett. 100, (2008) 231802 Precision Cosmology at the LHC Direct Detection
33
Focus Point (FP)-II m 0 is large, m 1/2 can be small, e.g., m 0 = 3550 GeV, m 1/2 =314 GeV, tan =10, A0=0 32 M(gluino) = 889 GeV, ΔM(χ 3 0 - χ 1 0 ) = 81 GeV, ΔM(χ 2 0 - χ 1 0 ) = 59 GeV, ΔM(χ 3 0 - χ 2 0 ) = 22 GeV Br(g → χ 2 0 tt) = 10.2% Br(g → χ 2 0 uu) = 0.8% Br(g → χ 3 0 tt) = 11.1% Br(g → χ 3 0 uu) = 0.009% ~ ~ ~ ~ - - - - Precision Cosmology at the LHC
34
33 Dilepton Mass at FP M(ll) (GeV) Events/GeV Tovey, talk at PPC 2007 Baer, Barger, Salughnessy, Summy, Wang, PRD 75, 095010 (2007) Crockett, Dutta, Flanagan, Gurrola, Kamon, Kolev, Krislock, VanDyke (2008) Precision Cosmology at the LHC Relic density calculation depends on , tan and m 1/2 m 1/2 and tan can be solved from M(gluino), ΔM (χ 3 0 - χ 1 0 ) and ΔM (χ 2 0 - χ 1 0 ) Errors of (300 fb -1 ): M(gluino) 4.5% ΔM (χ 3 0 - χ 1 0 ) 1.2% ΔM (χ 2 0 - χ 1 0 ) 1.7% Chargino masses can be measured! Work in Progress … tan 22% 0.1%
35
Bulk Region-III The most part of this region in mSUGRA is experimentally (Higgs mass limit, b s ) ruled out mSUGRA point: The error of relic density: 0.108 ± 0.1(stat + sys) sparticlemass 97.2 398 189 607 533 End ptsvalueerror m ll 81.20.09 M lq( (max)3652.1 M lq (min)266.91.6 Ml lq (max)4252.5 M llq (min)2071.9 M (max)62.25.0 Relic density is mostly satisfied by t channel selectron, stau and sneutrino exchange Perform the end point analysis to determine the masses 0101 ~ 0202 ~ l ~ g ~ uLuL ~ m 0 =70; A 0 =-300 m 1/2 =250; >0; tan =10; [With a luminosity 300 fb -1, edge controlled to 1 GeV] Nojiri, Polsello, Tovey’05 ~ Includes: (+0.00,−0.002 )M(A); (+0.001, −0.011) tan β; (+0.002,−0.005) m( 2 ) Precision Cosmology at the LHC 34
36
Overdense Region-IV 35 m0m0 The final states contain Z, Higgs, staus Lahanas, Mavromatos, Nanopoulos, Phys.Lett.B649:83-90,2007. Dilaton effect creates new parameter space Precision Cosmology at the LHC Overdense region (Large ): Too much dark matter In some models, this overdense region is not really overdense, e.g., Allowed region is moved up
37
Observables involving Z and Higgs We can solve for masses by using the end-points Precision Cosmology at the LHC Observables: Effective mass: M eff (peak): f 1 (m 0,m 1/2 ) Effective mass with 1 b jet: M eff (b) (peak): f 2 (m 0,m 1/2, A 0, tan ) Effective mass with 2 b jets: M eff (2b) (peak): f 3 (m 0,m 1/2, A 0, tan ) Higgs plus jet invariant mass: M bbj (end-point): f 4 (m 0,m 1/2 ) 4 observables => 4 mSUGRA parameters Dutta, Gurrola, Kamon, Krislock, Lahanas, Mavromatos, Nanopoulos, arXiv:0808.1372 36
38
Determining mSUGRA Parameters Solved by inverting the following functions: 1000 fb -1 37 Precision Cosmology at the LHC
39
2 tau + missing energy dominated regions: Solved by inverting the following Observables: 500 fb -1 For 500 fb -1 of data Dutta, Gurrola, Kamon, Krislock, Lahanas, Mavromatos, Nanopoulos, arXiv:0808.1372 Precision Cosmology at the LHC 38
40
Dark Matter particle DM Particle: Direct Detection? detector µ (*) The TAMU group is one of the leading institutions in the US. (*) The measurement at the LHC will pinpoint the parameters of SUSY models. We can predict the direct detection probability of dark matter particles. Complementary measurements ! 39 James White Precision Cosmology at the LHC
41
Ongoing/future projects: CDMS, LUX, XENON100, ZEPLIN Status: –DAMA group (Italy) – claims to have observed some events. –CDMS, ZEPLIN, XENON10, Cogent – dispute their claim. Status - Direct Detection James White Close to the current sensitivity Accomando, Arnowitt, Dutta, Santoso, NPB 585 (2000) 124 10 -8 pb 40 Rupak Mohapatra ZEPLIN CDMS DAMA XENON Bob Webb
42
Conclusion 41 SM of particle physics has fallen. Supersymmetry seems to be natural in the rescue act and the dark matter content of the universe can be explained in this theory. The minimal SUGRA model is consistent with the existing experimental results. [1] LHC can probe the minimal SUGRA model directly. All the dark matter allowed regions can be probed at the LHC The dark matter content can be measured with an accuracy of 6% in the stau-neutralino coannihilation region This accuracy depends on the final states [2] This analysis can be applied to any SUSY model Precision Cosmology at the LHC
43
Conclusion… [3] Direct detection experiments will simultaneously confirm the existence of these models. [4] Indirect detection experiments will also confirm the existence of SUSY models [5] Very exciting time ahead… 42 Precision Cosmology at the LHC
44
Brahma
45
2016/2/2044 All of these will be supersymmetry phenomenology/model papersConclusion…
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.