Hunt down Higgs .


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Rutgers UniversitySeptember 7,2005. What is the Higgs?. Short reply: Field/Particle in charge of mass.Longer answer: Completes the Standard Model of Particles and Fields.So what is this Standard Model of P
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Scan for Higgs Amitabh Lath Rutgers The State University of NJ Rutgers University September 7 2005

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What is the Higgs? Short answer : Field/Particle in charge of mass. Longer answer : Completes the Standard Model of Particles and Fields. So what is this Standard Model of P & F? Rutgers University September 7,2005

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Our Periodic Table Rutgers University September 7,2005

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Our Periodic Table Quark stuff: hadrons. 3q  baryon q-anti(q)  meson Q=2/3 - 1/3 0 1 + Higgs! (not yet discovered) Rutgers University September 7,2005

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Experimentalist View: Prologue Einstein, photoelectric impact J.J. Thomson, 1897 Street and Stevenson, 1937 cloud chamber Rutgers University September 7,2005

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Experimentalist View: Weak Effects Reines and Cowan Reactor (beta rot) Lederman, Schwartz and Steinberger bunch utilizing AGS pion shaft Rutgers University September 7,2005

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Experimentalist View: Quarks Kendall, Friedman, Taylor amass at SLAC. Gell-Mann\'s quarks Feynman\'s "partons" Rutgers University September 7,2005

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Experimentalist View: Quarks Gell-Mann predicts Omega-molecule. Found by air pocket chamber assemble at BNL (Samios et al) Rutgers University September 7,2005

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Experimentalist View: Quarks The abnormal molecule rot, K L  mm not as productive as anticipated Glashow, Iliopoulos, and Maiani set "another" molecule. (GIM Mechanism) Diagrams with "appeal" damagingly meddle. Found by Ting, Richter bunches (at the same time) at BNL, SLAC. Rutgers University September 7,2005

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Experimentalist View: 3 rd Generation Note: S q for every era = 0 Fermilab collider program (cast of hundreds) Fermilab settled target explore (Lederman) Beautiful investigation by Martin Perl at SLAC\'s SPEAR Rutgers University September 7,2005

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Experimentalist View: Weak Bosons Glashow, Weinberg and Salaam present two primordial fields: Weak Isospin Weak Hypercharge that blend (powerless blending edge) to give  W,Z and g + Higgs! They likewise present a scalar field (Higgs). W, Z found by UA2 Rutgers University September 7,2005

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Electro-Weak Unification Weak Isospin (3-segment) W 1 + iW 2 = W + W 1 – iW 2 = W - Weak Hypercharge (1-part) g cos q w - sin q W 3 Z sin q w cos q w B 0 Left Handed Int. just ! = Weak Mixing Angle Rutgers University September 7,2005

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Higgs and ElectroWeak Unification Adding scalar field to Lagrangian gives mass-like terms, prompting to  Masses of bosons dictated by couplings, and parameters of the scalar field potential (v, l ). M higgs is a free parameter. Each of the three things in this condition can be measured by analyses. M W/M Z = cos q W Rutgers University September 7,2005

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What is Higgs? Scalar Field. Presented in : A MODEL OF LEPTONS Steven Weinberg , Phys.Rev.Lett.19:12641266,1967 . Offers mass to everything, except Higgs boson not seen. Fermion masses? Require (self-assertive) couplings. Called G i in Halzen & Martin. M H < 246 GeV/c 2 (attack of all EW information and top mass) Rutgers University September 7,2005

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Different Types of Higgs SM Higgs One (complex) doublet. Cross segment for direct creation at Tevatron depressingly low. Hypothetical issues. Past SM Higgs Different models settle (a few) SM issues. Tevatron can contend in a few sections of parameter space . Rutgers University September 7,2005

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Problems with Higgs Fundamental Scalar Field has issues. What are the redresses to its mass? Two essential sorts of arrangements: Higgs is a composite (Technicolor) Other outlines wipe out issues. (SUSY) Rutgers University September 7,2005

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Beyond SM Higgs (Technicolor) "pion" like composite Higgs. Techniquarks make technipions QCD-like solid compel ( thus "technicolor" ). Precluded! The electron-positron asymmetries at the Z post were not kind to this hypothesis. Nonetheless, a great deal of physicists have a weakness for compositeness . T = isospin breaking terms Rutgers University September 7,2005 S = Isospin cons. terms

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Beyond SM Higgs (Supersymmetry) The "GIM Mechanism" answer for the Higgs issue. Got an issue graph? Add another to offset it. Fermion  sFermion Boson  Bosino An extremely costly hypothesis. Duplicates the molecule range. Incidental awards: LSP Dark Matter? Unification of couplings? Rutgers University September 7,2005

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The MSSM Higgs Minimal SuperSymmetric Standard Model. Least difficult practical SUSY hypothesis. 3 impartial( h,A,H ), 2 charged Higgs Bosons (masses related). tan b  proportion of up/down sort couplings . The LEP explore (e+e-collider) secured a vast swath of parameter space by decision out higgs up to 90 GeV. Rutgers University September 7,2005

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MSSM Higgs Production At huge tan b , both gg and bb creation contribute. s rises like tanb 2 . An, and h/H are created all the while. ~100 pb! For comprehensive mode , tt rot is extremely fascinating. Twofold this! ~SM Higgs Rutgers University September 7,2005

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Higgs Decays Higgs rots to bb 90% and tt 10% (Higgs couples to mass) higgs bb? No desire for comprehensive. higgs  tt ? Yes! Rots to WW, ZZ assume control if Higgs is sufficiently overwhelming. Rutgers University September 7,2005

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Higgs Decays Most Higgs scans search for b-quarks. SM, SUSY higgses (ask SVS). Issue: "genuine" b-quarks from hadronic communication overwhelm those from Higgs. Around 6 requests of greatness! Regular arrangement: Look at "related" stuff: (Higgs+W/Z, Higgs+extra b-quarks) Our answer: Forget b. Search for tt. Surrender (a few) affectability to SM Higgs. Pick up a perfect channel for MSSM Higgs. Rutgers University September 7,2005

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CDF Tevatron Main Injector The Tevatron Accelerator p-pbar impacts at 1.96 TeV C.M. Vitality Rutgers University September 7,2005

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CDF Collaboration Missing Conway … Rutgers University September 7,2005

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The CDF Detector beampipe Collision point Superconducting Magnet Rutgers University September 7,2005

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Particle Detection Electron track, contained group, E/P~1 g , no track Quark matter ( p ) - track, amplified (hadron) bunch Muon infiltrating track Weak, no charge ( n ) Missing momenta Rutgers University September 7,2005

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Particle Detection s Electron track, contained bunch, E/P~1 g , no track Quark matter ( p ) - track, developed (hadron) bunch Muon entering track Weak, no charge ( n ) Missing momenta ~nb ~mb ~nb HIGGS? ~pb Rutgers University September 7,2005

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The tau lepton. 3 rd era lepton. Substantial. Mass = 1.77 GeV/c 2 Lots of rots Leptonic: t  e nn , t  mnn (17% each) Hadronic: t  pn , pp 0 n , pppn , pp 0 p 0 n (64%) Shorthand: t e , t m , t h Rutgers University September 7,2005

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Looking for Higgs t n H n p , quark matter e or m Signal: One t goes to electron or muon. We know how to identify e, m Second t goes to pions Backgrounds? Z  tt (irreducible) W e, m + "planes" (quark stuff including p ) Rutgers University September 7,2005

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Detecting taus? Taus are leptons that can rot to "planes" of pions. planes from q,g are fatter. Flag cone. Confinement cone (annulus). Up to 30 o . Veto tracks, p 0 … Should get: Characteristic 1,3 track improvement. |Q| = 1 m < 1.8 t e , t m Rutgers University September 7,2005 Standard cuts

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Problem with taus. Fakes from planes (as with nearly everything at hadron machines). t h IS a stream; but a limited one (pencil fly). Fly generation 100\'s m b. Contrast with 100\'s of pb for t creation. Don\'t know enough about JETS  require fake rate from information . This is the place the issues begin. Distinctive wellsprings of planes give altogether different fake appraisals. Rutgers University September 7,2005

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Fake Rates. Preamble. CDF Run 1 (U.C. Berkeley) Jet activated specimens give bring down fake rates than lepton activated ones. Fake rates ascending with stream E T . What is going on? Enormous distinction! Rutgers University September 7,2005

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Solution: Multi-Parameter. Rather than parameterizing fake rate in one variable, we now utilize a few. Huge inconsistency in rates vanishes. Is this the proper thing to do? Why trouble? "Relative" fake rates Rutgers University September 7,2005

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Check of Fake Rate Predictor Newfangled multi-parameter fake rate capacity is unnerving. Fly factors (vitality, course, and so on)  BLACK BOX  likelihood of a fake t . We should test it on various specimens of planes. Stream activated specimen (expect one fly is "lepton") Photon+jet (utilize photon as lepton) W+jet. MC Jets. We should take a gander at various disseminations, not simply total numbers. Rutgers University September 7,2005

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Pure example of planes Predictor Fake rate forecast Checking Jet  t Fake Rates Pure specimen of planes t reconst Fake rate measured Rutgers University September 7,2005

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Checking Fake Rates (QCD) This is an once-over to verify everything is ok, best case scenario, since we constructed our "black box" - fake indicator - utilizing Jet Triggered information. Rutgers University September 7,2005

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Checking Fake Rates ( g +jet) This is the most encouraging arrangement of plots . Rutgers University September 7,2005

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Checking Fake Rate (W+jet) Rutgers University September 7,2005

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tt signature Classic Hadronic tau signature Both t e t h and t m t h are incorporated into these plots N tracks = 1,3 and |Q

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