Download presentation
Presentation is loading. Please wait.
Published byCharity Theresa Wade Modified over 8 years ago
1
New Results on Diffractive and Exclusive Production from CDF Konstantin Goulianos The Rockefeller University (for the CDF Collaboration) DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 1 http://dis2013.in2p3.fr/ http://physics.rockefeller.edu/dino/my.html
2
CONTENTS Introduction Diffraction in QCD Diffraction at CDF Definitions Factorization breaking in soft diffraction Exclusive production of: dijet-2008, dimuon c -J/ (2s)-2009, -2012 Central Exclusive Production of + - NEW! DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 2
3
DIFFRACTION IN QCD Diffractive events Colorless vacuum exchange -gaps not suppressed Non-diffractive events color-exchange -gaps exponentially suppressed POMERONPOMERON Goal : probe the QCD nature of the diffractive exchange rapidity gap p ppp p DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 3
4
DIFFRACTION AT CDF Single Diffraction or Single Dissociation Double Diffraction or Double Dissociation Double Pom. Exchange or Central Dissociation Single + Double Diffraction (SDD) SD DD DPE/CD SDD Elastic scatteringTotal cross section T =Im f el (t=0) OPTICAL THEOREM gap JJ, b, J/ W p p JJ …ee… exclusive DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 4
5
DEFINITIONS MXMX dN/d ,t,t p’ rap-gap =-ln 0 ln s ln Mx 2 ln s since no radiation no price paid for increasing diffractive-gap width pp p MXMX p p’ SINGLE DIFFRACTION DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 5 Forward momentum loss
6
Factor of ~8 (~5) suppression at √s = 1800 (540) GeV diffractive x-section suppressed relative to Regge prediction as √s increases see KG, PLB 358, 379 (1995) 1800 GeV 540 GeV M ,t,t p p p’ √s=22 GeV RENORMALIZATION Regge FACTORIZATION BREAKING IN SOFT DIFFRACTION CDFCDF DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 6 Interpret flux as gap formation probability that saturates when it reaches unity
7
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 7 EXCLUSIVE Dijet Excl. Higgs T HEORY CALIBRATION p p _ } JJ c Exclusive dijets PRD 77, 052004 (2008) PRL 102, 242001 (2009)
8
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 8 Exclusive c Exclusive dimuon production 3 GeV/c 2 <M <4 GeV/c 2 p+p →p+ + - +p PRL 102, 242001 (2009) Several physics processes in this dataset: _ _
9
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 9 Exclusive c Exclusive c →J/ (→ + - )+ Allowing EM towers (E T >80MeV) large increase in the J/ peak & minor change in the (2s ) peak Evidence for: c →J/ + production J/ 286 352 = +66 events (2s) 39 40 = +1 event d /dy| y=0 = 75 ± 14 nb, compatible with theoretical predictions 160 nb (Yuan 01) 90 nb (KMR01) Allow extra EM tower PRL 102, 242001 (2009)
10
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 10 Exclusive c Exclusive J/ and (2s) J/ producton 243 21 events d /dy| y=0 = 3.92± 0.62 nb Theoretical Predictions 2.8 nb [Szczurek07,], 2.8 nb [Szczurek07,], 2.7 nb [Klein&Nystrand04], 2.7 nb [Klein&Nystrand04], 3.0 nb [Conclaves&Machado05], and 3.0 nb [Conclaves&Machado05], and 3.4 nb [Motkya&Watt08]. 3.4 nb [Motkya&Watt08]. s production 34 7 events 0.54 d /dy| y=0 = 0.54 ± 0.15 nb R = (2s)/J/ = 0.14 ± 0.05 In agreement with HERA: R = 0.166 ± 0.012 in a similar kinematic region J/ (2s) QED continuum
11
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 11 Exclusive production-2012 PRL 108, 081801 (2012)
12
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 12 Exclusive and e + e - events
13
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 13 Exclusive data vs MC
14
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 14 Exclusive cross section 14
15
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 15 Exclusive event candidate
16
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 16 Central Exclusive Poroduction of + - DETECTOR NOT USED NOT UED use only | |=5.4-5.9
17
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 17 Central Exclusive Production of + - TRIGGERS Two Central Calorimeter towers (| |<1.3) w/E≥0.5 GeV (a very low threshold) and no energy in BSC (| |=5.4-5.9) and in the Forward Plug Calorimeters (| |=2.11-3.64 ). “zero-bias” bunch crossing events with no tracks to study noise/exclusivity cuts. DATA SETS Recorded 90(22)×10 6 events at√s=1960 (900) GeV. PRELIMINARY RESULTS |y( + - )|<1.0, M + - <0.8 where there is some acceptance at all p T. Notice: no particle ID is (yet) being used and the observed tracks are assumed to be due to pions (until further notice – stay tuned!). NEW DATA
18
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 18 “Empty” events detector noise levels Detector noise levels: Determined separately for interaction and no-interaction events Rejected “noise” events below vertical dashed lines Empty-event selection Select region of bunch luminosity with low overlaps and high yied use data only here
19
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 19 M + - distributions at 1960 GeV not-corrected for acceptance corrected for acceptance we clearly see f 0 (980), f 2 (1270) and f 0 (1370). the small but significant peak at 3.1 GeV is understood to be from J/ e + e - with masses assumed as m + m -.
20
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 20 Event ratio of 1960/900 GeV and average P T at 1960 GeV Ratio of candidates at √s=1960/900 GeV vs M(pair) Mean p T (pair) in GeV/c as a function of M(pair)
21
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 21 Comparisons of d /dM events per bin The structures observed in the mass region of less than ≈1 GeV are under investigation.
22
DIS-2013, Marseille Diffractive and Exclusive Production at CDF K. Goulianos 22 SUMMARY Reviewed briefly exclusive production at CDF. Measured exclusive + - production (no particle ID yet, tracks assumed to be due to pions) at √s=900 GeV and √s=1960 GeV with higher statistics than in earlier studies. Explored the low mass region: found well known structures from AFS at ISR at √s=63 GeV for M - 1.5 GeV. Partial wave analysis currently underway – stay tuned! Thank you for your attention
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.