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Jan, 2007M. Block, Aspen Winter Physics Conference 1 Imposing the Froissart bound on DIS ---> New PDF's for the LHC Martin Block Northwestern University
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Jan, 2007M. Block, Aspen Winter Physics Conference 2 1) Data selection: The “Sieve” Algorithm---“Sifting data in the real world”, M. Block, Nucl. Instr. and Meth. A, 556, 308 (2006). 3) Fitting the accelerator data---“New evidence for the Saturation of the Froissart Bound”, M. Block and F. Halzen, Phys. Rev. D 72, 036006 (2005). OUTLINE 2)New fitting constraints---“New analyticity constraints on hadron-hadron cross sections”, M. Block, Eur. Phys. J. C 47, 697 (2006). No time to talk about these. But they are important!
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Jan, 2007M. Block, Aspen Winter Physics Conference 3 4) The Proton Structure Function F 2 p (x,Q 2 ) : “Small-x Behavior of Parton Distributions from the Observed Froissart Energy Dependence of the Deep-Inelastic-Scattering Cross Sections”, M. M. Block, Edmund L. Berger and Chung-I tan, Phys.Rev. Lett. 308 (2006). 5) Global Structure Function Fit and New Gluon Distributions using the Froissart Bound : Work in progress for this meeting ! M. M. Block, Edmund L. Berger and Chung-I Tan,
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Jan, 2007M. Block, Aspen Winter Physics Conference 4 Part 1: “Sifting Data in the Real World”, M. Block, arXiv:physics/0506010 (2005); Nucl. Instr. and Meth. A, 556, 308 (2006). “Fishing” for Data
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Jan, 2007M. Block, Aspen Winter Physics Conference 5 Lorentzian Fit used in “Sieve” Algorithm
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Jan, 2007M. Block, Aspen Winter Physics Conference 11 You are now finished! No more outliers. You have: 1) optimized parameters 2) corrected goodness-of-fit 3) squared error matrix.
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Jan, 2007M. Block, Aspen Winter Physics Conference 12 This is FESR(2) derived by Igi and Ishida, which follows from analyticity, just as dispersion relations do.
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Jan, 2007M. Block, Aspen Winter Physics Conference 13 so that: exp’t ( ( 0 ), d exp’t ( d d ( 0 ) d, or, its practical equivalent, exp’t ( ( 0 ), exp’t ( ( 1 ), for for both pp and pbar-p exp’t cross sections We can also prove that for odd amplitudes: odd ( 0 ) = odd ( 0 ).
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Jan, 2007M. Block, Aspen Winter Physics Conference 14 Francis, personally funding ICE CUBE Part 3: Fitting the accelerator data---“New evidence for the Saturation of the Froissart Bound”, M. Block and F. Halzen, Phys. Rev. D 72, 036006 (2005).
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Jan, 2007M. Block, Aspen Winter Physics Conference 15 ln 2 (s/s 0 ) fit =0.5, Regge- descending trajectory 7 parameters needed, including f + (0), a dispersion relation subtraction constant
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Jan, 2007M. Block, Aspen Winter Physics Conference 16 Only 3 Free Parameters However, only 2, c 1 and c 2, are needed in cross section fits ! These anchoring conditions, just above the resonance regions, are analyticity conditions!
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Jan, 2007M. Block, Aspen Winter Physics Conference 17 Cross section fits for E cms > 6 GeV, anchored at 4 GeV, pp and pbar p, after applying “Sieve” algorithm
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Jan, 2007M. Block, Aspen Winter Physics Conference 18 -value fits for E cms > 6 GeV, anchored at 4 GeV, pp and pbar p, after applying “Sieve” algorithm
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Jan, 2007M. Block, Aspen Winter Physics Conference 19 What the “Sieve” algorithm accomplished for the pp and pbar p data Before imposing the “Sieve algorithm: 2 /d.f.=5.7 for 209 degrees of freedom; Total 2 =1182.3. After imposing the “Sieve” algorithm: Renormalized 2 /d.f.=1.09 for 184 degrees of freedom, for 2 i > 6 cut; Total 2 =201.4. Probability of fit ~0.2. The 25 rejected points contributed 981 to the total 2, an average 2 i of ~39 per point.
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Jan, 2007M. Block, Aspen Winter Physics Conference 20 Cross section and -value predictions for pp and pbar-p The errors are due to the statistical uncertainties in the fitted parameters LHC prediction Cosmic Ray Prediction
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Jan, 2007M. Block, Aspen Winter Physics Conference 21 More LHC predictions, from the Aspen Eikonal Model Nuclear slope B = 19.39 ± 0.13 (GeV/c) -2 elastic = 30.79 ± 0.34 mb Differential Elastic Scattering
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Jan, 2007M. Block, Aspen Winter Physics Conference 22 Saturating the Froissart Bound pp and pbar-p log 2 ( /m) fits, with world’s supply of data Cosmic ray points & QCD-fit from Block, Halzen and Stanev: Phys. Rev. D 66, 077501 (2000).
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Jan, 2007M. Block, Aspen Winter Physics Conference 23 Conclusions From hadron-hadron scattering The Froissart bound for p, p and pp collisions is saturated at high energies. 3) At cosmic ray energies, we can make accurate estimates of pp and B pp from collider data. 4) Using a Glauber calculation of p-air from pp and B pp, we now have a reliable benchmark tying together colliders to cosmic rays. 2) At the LHC, tot = 107.3 1.2 mb, = 0.132 0.001.
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Jan, 2007M. Block, Aspen Winter Physics Conference 24 Proton Structure Function F 2 (x,Q 2 ), from Deep Inelastic Scattering, Block, Berger & Tan, PRL 99, 88 (2006).
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Jan, 2007M. Block, Aspen Winter Physics Conference 25 Reduced Virtual Photon Total Cross Section
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Jan, 2007M. Block, Aspen Winter Physics Conference 30 Froissart bound fit, ln 2 W, to reduced cross sections
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Jan, 2007M. Block, Aspen Winter Physics Conference 33 Scaling Point Global (Simultaneous) Fit of F 2 (x,Q 2 ) to x and Q 2
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Jan, 2007M. Block, Aspen Winter Physics Conference 34 What the “Sieve” algorithm accomplished for F 2 (x,Q 2 ) Before imposing the “Sieve algorithm: 2 /d.f.=1.30 for 177 degrees of freedom; Total 2 =229.4. After imposing the “Sieve” algorithm: Renormalized 2 /d.f.=1.09 for 169 degrees of freedom, for 2 i > 6 cut; Total 2 =184.2. Probability of fit ~0.2. The 8 rejected points contributed 63.45 to the total 2, an average 2 i of ~8 per point.
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Jan, 2007M. Block, Aspen Winter Physics Conference 36 Predictions are made using ZEUS data in global fit Experimental data are from H1 collaboration NO RENORMALIZATION made! 1 Q 2 GeV 2
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Jan, 2007M. Block, Aspen Winter Physics Conference 37 SUMMARY.
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Jan, 2007M. Block, Aspen Winter Physics Conference 38 To be done: 1.Include H1 in global fit, simultaneously fitting F2, dF 2 /d(logQ2), d(logF 2 ) /d(log x) 2. More gluon distributions 3. Quark distributions 4. Recalculate cosmic ray neutrino cross sections; current values are much too big! Needs x~10 -8 and Q 2 ~6400 GeV 2 ! Enormous extrapolation.
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