Tevatron versus LHC physics Giorgio Bellettini Lecture at
Tevatron versus LHC physics Giorgio Bellettini Lecture at the “VIII Seminario sul Software per la Fisica Nucleare, Subnucleare e Applicata”. Alghero, June 6 to 10, 2011
The very fast LHC progess
MSugra mass limits from the early ATLAS With 35 pb-1 the LHC is surpassing the Tevatron MSugra squark/gluino searches in jets + missing Et 35 pb-1
ATLAS search for a contact qq interaction in DY μμ Quarks and leptons may share constituents interacting at a scale >> M. This interaction would interfere with the electroweak interaction causing the coupling to change well below M = . The onset of the new interaction can be modeled by adding a point interaction term to the lagrangian. ATLAS 42 pb-1 Λ > 4, 9 (4, 5) Te. V for constructive (destructive) interference Best CDF limits Λ > 4, 2 (2, 9) Te. V
Bs μμ search at LHCb had a tremendous start in the search for rare processes • Standard Model: B(B 0 S μμ)SM = (0, 32 ± 0, 002)x 10 -8 • CDF: B(B 0 S μμ)SM < 4. 0 x 10 -8 95% c. l. with 3, 7 fb-1 • LHCb: B(B 0 S μμ)SM < 5, 6 x 10 -8 with 37 pb-1
B 0 – B 0 Mixing: a CDF big score 2006 PRL 97, 242003 2006 DØ Run II Preliminary 3. 1 s significance CDF: DØ: CDF: Theoretical uncertainty ~ 10 x Experimental uncertainty Young-Kee 6 Talks by Hildreth, Tollefeson
Producing the SM Higgs at hadron collider “gluon fusion” (via fermion loop) “Higgs-strahlung” (radiated by a VB) pp 2 Te. V VB-fusion 7
SM Higgs production at the LHC Gluon fusion dominates
Higgs search at LHC versus Tevatron
Some WW Search Channels used at Tevatron Channel Main Signal Main Background Most Important kinematic variables OS dileptons, 0 Jets gg H WW LRHWW, ΔRll, HT OS dileptons, 1 Jet gg H DY ΔRll, m. T(ll, ET), ET OS dileptons, 2+ Jets Mixture t-tbar HT, ΔRll, Mll OS dileptons, low Mll, 0 or 1 Jet gg H W+γ p. T(l 2), p. T(l 1), E(l 1) SS dileptons, 1+ Jet WH WWW W+Jets ET, ∑ETjets, Mll Tri-leptons, no Z candidate WH WWW WZ ET, ΔRllclose, Type(lll) Tri-leptons, Z candidate, 1 Jet ZH ZWW WZ Jet ET, ΔRlj, ET Tri-leptons, Z candidate, 2+ Jets ZH ZWW Z+Jets Mjj, MTH, ΔRWW OS dilepton, electron + hadronic tau gg H W+Jets ΔRlτ, τ id variables OS dilepton, muon + hadronic tau gg H W+Jets ΔRlτ, τ id variables Breakdown by #jets Associated production W
H b-bbar
The role of the b-bbar channel
Tagging b-flavor of jets
May 2011 Tevatron limits in the b-bbar channel
H γγ at the Tevatron (May 2011)
Tevatron Higgs limit in spring 2011
Tevatron Higgs at program end
SM Higgs search at the LHC
CMS results on the WW mode (2010)
Indirect m. H from W mass versus Top mass
Electroweak Fit + LEP +Tevatron exclusion bands • MH from fit indirect measurements Central value ± 1 s 2 s interval: 115 - 152 Ge. V § Green error band from including / excluding theoretical errors in fit 22
Global SM electroweak fit+ direct searches In the assumption of SM Higgs, one should keep into account indirect contraints as well § LEP + Tevatron (Fall 2010) : • 2 s interval: [115, 152] Ge. V § § LEP + Tevatron (Moriond 2011): • 2 s interval: [115, 138] Ge. V § Fit with LEP + Tevatron + LHC (H WW) searches (Moriond 2011) : • 2 s interval: [115, 137] Ge. V LEP & Tevatron upto 8. 2 fb-1 If SM is correct, Higgs mass is determined to <10% 23
At LHC at low mass rely primarily on Higgs γγ CMS simulation
H γγ at ATLAS (38 pb-1) Measured with 38 pb-1 Projected to 1 fb-1
ATLAS Higgs limits (May 2011)
ATLAS versus Tevatron (May 2011) Tevatron
Higgs sensitivity projections at CMS
H ττ much larger in the MSSM
1 fb-1 CMS projections
5 fb-1 CMS prospects
CMS+ATLAS Higgs sensitivity up to 10 fb-1 For m. H = 120 Ge. V need 10 fb-1 to reach a 4σ sensitivity How can one find the right vertex among many in a γγ event at high luminosity?
Multiple interactions at LHC (2011)
CDF jj anomaly in exclusive Wjj (March 2011)
CDF new data set on jj anomaly in exclusive Wjj (June 2011)
CDF JJ anomaly in exclusive Wjj (June 2011)
Conclusions: the Tevatron has still an edge In selected physics areas of great importance 1) precision measurements on Bs 2) low mass SM Higgs search 3) jet spectroscopy at the EW scale Tevatron will compete with LHC for several years to come
BACKUP SLIDES
Tevatron prospects 2011 >2. 4 s for m. H<185 Ge. V 3 s for m. H~115 Ge. V 39
The di-boson path at the Tevatron • • Measurements of the various di-boson processes are stepping stones towards H->diboson reconstruction CDF and D 0 went through all those steps H
Tevatron limits to SUSY masses CDF~D 0 MSugra squark/gluino searches in jets + missing Et
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