Determination of Non-Universal Supergravity Models at the LHC

Transcription

1 Determination of Non-Universal Supergravity Models at the LHC B. Dutta 1, T. Kamon 1, 2, 3, N. Kolev 4, *, A. Krislock 1, Y. Oh 3 1 Texas A&M U., 2 Fermilab, 3 Kyungpook National U., 4 U. of Regina * kolev20n@uregina.ca

2 State of Affairs We are in a very exciting period with the start of the LHC. LHC will run at 3.5 TeV beam energy till the end of 2012 and new physics is expected (both in the Higgs sector and supersymmetry). A long shutdown will follow to prepare to run at 7 TeV beam energy. We have last months or years now to work on simulation scenarios, before 14 TeV data appear. Here our results from a study for determining the parameters in a non-universal SUGRA scenario are presented. 19/02/2011 WNPPC 2011, Banff, Alberta 2

3 Supersymmetry (SUSY) Symmetry between fermions and bosons. Superparticles are called squarks, gluinos, etc. Apart from being very attractive in terms of solving some inconsistencies in the Standard Model, SUSY offers a natural dark matter 0 candidate: χ 1, stable, neutral, very weakly interacting. γ, Z, h, H χ, χ, χ, χ W, H χ1, χ2, ν e, µ, µ, ν τ R, L, ν e, µ R, µ L, νµ, ντ e v e e τ τ1, τ2 udsc,,, u, u, d, d, s, s, c, c b b 1, b 2 t t, t R L R L R L R L /02/2011 WNPPC 2011, Banff, Alberta 3

4 SM Problems and SUSY SM: Cannot provide a dark matter candidate. Has a serious Higgs mass divergence problem. Cannot accommodate masses for neutrinos. Cannot provide enough matterantimatter asymmetry. SUSY Provides a dark matter candidate- neutralino. Solves the Higgs mass problem in an elegant way. SUSY grand unified models include neutrinos. Can provide enough matter-antimatter asymmetry. More (inflation, new sources of CP violation,...) 19/02/2011 WNPPC 2011, Banff, Alberta 4

5 msugra and nusugra MSSM has of the order of 100 parameters, so it is difficult to extract them from LHC data. But we can be lucky and have other scenarios. We can also start with understanding the simple cases and work on. msugra: Unified masses at the Grand Unification scale; determined by only 4 parameters and one sign: m, m, A, tan, sign( ) β µ 0 1/2 0 nusugra (next step): Unified masses at the Grand Unification scale except for Higgs parameters: m, m, A, tan β, µ ( m ) H 0 1/2 0 Small makes neutralino Higgs-like, annihilation cross-section large enough to have the right amount of dark matter. 19/02/2011 WNPPC 2011, Banff, Alberta 5

6 Details To find useful observables for extracting nusugra parameters from data. 14 TeV. Using Pythia, Isajet, ISASUGRA, PGS4 simultaions. Signal comes from jets, leptons and missing transverse energy. The energies of jets and leptons depend on sparticle masses, which are given by different models. 19/02/2011 WNPPC 2011, Banff, Alberta 6

7 SUSY Masses Base Point 19/02/2011 WNPPC 2011, Banff, Alberta 7

8 Smoking Gun Signals Non-U - UCase SSC2 ~ ~ 0 χ ± 1 W ± χ1 42% 2. 4% ντ~ 1 58% 98% ~ 0 χ ττ~ 92% 99% /02/2011 WNPPC 2011, Banff, Alberta 8

9 Bi-Event Subtraction Technique (BEST) Dijet mass for any jet pair from different events. Background subtracted; still some BG, but much easier to extract W. 19/02/2011 WNPPC 2011, Banff, Alberta 9

10 Observable 1: M eff Used to determine m ½ : M = p ( jet1) + p ( jet2) + p ( jet3) + p ( jet4) + E/ eff T T T T T 19/02/2011 WNPPC 2011, Banff, Alberta 10

11 Observable 2: M WJ Mass of W plus jet. Used to determine m H and m ½. 787 ± 15 GeV 19/02/2011 WNPPC 2011, Banff, Alberta 11

12 Observable 3: M JTT Mass of jet plus tau plus tau. Used to determine m 0, m H and m ½ ± 7.5 GeV 19/02/2011 WNPPC 2011, Banff, Alberta 12

13 Observable 4: M TT Mass of tau plus tau. Used to determine m 0, A 0, m H and m ½. 87.1± 3.4 GeV 19/02/2011 WNPPC 2011, Banff, Alberta 13

14 Observable 5: M JT Mass of jet plus tau. Used to determine m 0, A 0, m H, m ½ and tanβ. 536 ± 24 GeV 19/02/2011 WNPPC 2011, Banff, Alberta 14

15 Model Parameter Extraction ( Base point : m 1/2 = 360, m H = 732, m 0 = 360, A 0 = 0, tanβ = 40 ) Observable Model Parameters M peak eff m 1/2 M end JW m 1/2, m H M peak Jττ m 1/2, m H, m 0 M end ττ m 1/2, m H, m 0,A 0 M end Jτ m 1/2, m H, m 0,A 0, tanβ 19/02/2011 WNPPC 2011, Banff, Alberta 15

16 Comparison to Other Scenarios Non-universal case is more difficult than coannihilation region, where we have obtained: 0 1 ( 2 h ) χ δ Ω 0 1 Ω h = 0.1 = 6% at 30 fb χ Ω h χ /02/2011 WNPPC 2011, Banff, Alberta 16

17 Summary One more SUGRA scenario with cosmological implications. Procedure for determining non-universal SUGRA parameters. 14 TeV data: m 0, m ½, m H, tanβ can be determined with less than 10%; A 0 with 15%. Cosmological numbers more difficult to extract, larger errors, but values coincide with WMAP. BEST technique for background subtraction. 19/02/2011 WNPPC 2011, Banff, Alberta 17

18 Collaborators In 2002, R. Arnowitt, B. Dutta, and T. Kamon launched a global phenomenology project to study cosmologically-motivated SUSY signals at the Tevatron, ILC and LHC. Richard Arnowitt Teruki Kamon Youngdo Oh Bhaskar Dutta Abram Krislock 19/02/2011 WNPPC 2011, Banff, Alberta 18

19 Backup 1: 7 TeV 1 fb -1 : can be applied at 7 TeV. 19/02/2011 WNPPC 2011, Banff, Alberta 19

20 Backup 2: Error Ellipse 19/02/2011 WNPPC 2011, Banff, Alberta 20

21 Backup 3: more SUSY Things More dark matter SUSY candidates: sneutrino, gravitino. Low scale in inflation models can be tied to SUSY symmetry breaking. 19/02/2011 WNPPC 2011, Banff, Alberta 21