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H.Evans Physics in Collision: 28 June, 2004 1 Heavy Flavor Production in Hadron Collisions (with a few leptons & photons thrown in) Harold Evans Columbia.

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Presentation on theme: "H.Evans Physics in Collision: 28 June, 2004 1 Heavy Flavor Production in Hadron Collisions (with a few leptons & photons thrown in) Harold Evans Columbia."— Presentation transcript:

1 H.Evans Physics in Collision: 28 June, Heavy Flavor Production in Hadron Collisions (with a few leptons & photons thrown in) Harold Evans Columbia University XXIV Physics in Collision Boston, MAJune 28, 2004

2 H.Evans Physics in Collision: 28 June, Why Study QCD at All ? QCD is the Theory of the Strong Force So why aren’t we still at lunch ? 1.Because of non-perturbative effects we can’t make accurate predictions using QCD for a large range of observables 2.This is Bad… a.on an intellectual level b.because QCD proc’s are intimately entwined with other SM effects  backgrounds, corrections to EW observables,… 3.Fortunately, QCD can be studied using many processes  this talk will review how heavy flavor production helps

3 H.Evans Physics in Collision: 28 June, What’s so Great about Q Production ? Arbitrary Definitions:Heavy Flavorc and b Obese Flavort see talk by Andy Hocker f i (x 1 ) f j (x 2 ) D Q H (z) A B Incoming Particles Hard Interaction Parton Shower / Fragmentation M(Q) >>  qcd means perturb calc for (NLO is normal) higher order effects from dep on  R,F Universal non-perturb parts PDFs and fragmentation take from other meas’s or meas using Q-prod

4 H.Evans Physics in Collision: 28 June, What I’ll Talk About / What I’ll Skip Concentrate on  Hera, Tevatron, some Fixed Target  very recent results  areas where our understanding has changed substantially  surprises Tragically Ignore  nearly all e + e - results  feeble excuse: no hadrons in initial state  cursory view of fixed target  mainly as it overlaps collider  detailed survey of advances in theory Focus of Talk  previous status of  what we (thought) understood  problems  how this has changed recently  improvements in understanding  remaining problems  where we go from here  how new exp’s can help Outline 1.Open b & c Production 2.Heavy Quarkonia 3.New Resonances 4.The Future Problem: Too many New Results ! My Apologies if I’ve Left Out your Favorite Topic

5 H.Evans Physics in Collision: 28 June, Acknowledgements & Warnings Many Thanks to  H.Cheung, M.Corradi, R.Galik, V.Jain, R.Jesik, G.Landsberg, M.Leitch, M.zur Nedden, P.Newman, C.Paus, J.Russ, L.Silvestris, M.Smizanska, K.Stenson, A.Zieminski, D.Zieminska, A.Zoccoli  all those whose work I am presenting  and of course, the conference organizers ! Some Warnings 1.I blithely combine results and make Data vs Theory comp’s  these always assume no error correlations  often use spread in theoretical predictions as error 2.This is not the fault of those listed above

6 H.Evans Physics in Collision: 28 June, Heavy Quarks in the Wild Exp. or FacilityBeams (GeV)√s / N [GeV] RunsRecorded Data FOCUS/E831  (175) – BeO B int’s NuSea/E866P(800) – Cu M J/  SELEX/E781  -,  - (600) – C,Cu B int’s Hera-BP(920) – C,Al,Ti,W4100, K J/  HERA Ie ± (27.6) – p(820,920)300/ pb -1 HERA IIe ± (27.6) – p(920) ~70 pb -1 Tevatron I pb -1 Tevatron II ~400 pb -1 LEPe + (45,~100) – e - (45,~100)90– M bb

7 H.Evans Physics in Collision: 28 June, Issues in b & c Production 1.NLO terms are important, NNLO ~impossible  vary factorization, renormalization scales  est NNLO effects 2.Q mass definition / uncertainties  generally: m b = 4.5–5.0 GeV m c = 1.2–1.8 GeV 3.Large log(p T /m) resummation important at Tevatron, LHC  must be matched to NLO calc (e.g. FONLL) 4.Soft gluon corrections near thresholdimportant at Fixed Target  require some NNLO + NNNLL 5.Non-Perturbative parts  Structure Functions & Fragmentation Functions consistent w/ perturb calc. Heavy Q Prod in hadron-hadron Leading Order Next to LO Heavy Q Prod in ep PhP: Q 2 < 1 GeV 2 DIS: Q 2 > 1 GeV 2  structure p structure Perturbative Worries

8 H.Evans Physics in Collision: 28 June, some History – b,c Cross-Sections DØ Forward b CDF, DØ Run I ZEUS D * prod in DIS  at LEP charm beauty b Production vs NLO QCD shape in good agreement norm off by factors of 2–3 (nearly w/in exp & theory errors) b Production vs NLO QCD shape in good agreement norm off by factors of 2–3 (nearly w/in exp & theory errors) c Production vs NLO QCD agreement much better c Production vs NLO QCD agreement much better

9 H.Evans Physics in Collision: 28 June, New b,c-Production Results Reported b Production CDFb-Hadron inclusive cross-section in Run II using H b  J/  XPreliminary (2003) Hera-Bb b-bar production cross-section in pN collisionsPreliminary (2004) H1Beauty photoproduction using semi-muonic decaysPreliminary (2003) ZEUSBeauty photoproduction using muon + dijet eventshep-ex/ H1Beauty production in DISPreliminary (2004) H1Charm & beauty production in DIS at high Q 2 Preliminary (2004) ZEUSBeauty production in DIShep-ex/ c Production CDFPrompt charm production cross-section at  s = 1.96 TeVPRL 91, (2003) Hera-BOpen charm production using D-mesonsPreliminary (2004) FOCUSCharm – anticharm baryon production asymmetriesPLB 581, 39 (2004) H1Inclusive D * + dijet production in DISPreliminary (2003) ZEUSD * production in DISPRD 69, (2004) H1Photoproduction of D * Preliminary (2003) ZEUSMeasurement of D * photoproductionPreliminary (2002) ZEUSCharm jet photoproductionPreliminary (2004)

10 H.Evans Physics in Collision: 28 June, The Road to Enlightenment ? 1.B-hadrons instead of b-quarks 2.FONLL Calculation Cacciari, Greco, Nason: 1998 a.full, massive NLO calc. b.NLL resum of log(p T /m) 3.Consist. treatment of fragm. Binnewies, Kniehl, Kramer: 1998 Cacciari, Nason: 2002 a.FONLL framework used to extract FF from e + e - data b.Tevatron data sensitive to N=3–5 moments of FF  param’s of FF change

11 H.Evans Physics in Collision: 28 June, CDF H b  J/  Cross Section Run II J/    +  - Data37 pb -1  Feb-Sep 2002 H b  J/  fract. vs. P T (J/  )  pos. of J/  vtx w.r.t. prim vtx  1.25 < P T (J/  ) < 17 GeV d  (H b )/dP T (H b ) from  incl (J/  )  unfold P T (H b ) from P T (J/  )  to P T (H b ) = 0 Main Systematics  acc.,  incl (J/  ), vtx res. Total x-section corr. to quark level Good agreement w/ FONLL pred large error dominated by  R,F dependence syst. limited Cacciari,Frixione,Mangano,Nason,Ridolfi: hep-ph/ |y| < 0.6 ~10% of current data

12 H.Evans Physics in Collision: 28 June, Other Possible Explanations Berger, Harris, Kaplan, Sullivan, Tait, Wagner: 2001 From good Old Friends… Intrinsic K T …To exotic New Ones Light gluinos Shabelski, Shuvaev: hep-ph/  DØ Data:  & 2- 

13 H.Evans Physics in Collision: 28 June, Open Beauty at Hera-B Soft g corr’s important near thresh  new calculation: NNLO soft-g + NNNLL terms  kinematics & scale dep. reduced Use displaced vertices to extract b-comp from J/  (ee,  ) sample Runprompt J/  ’s b’sTotal x-sect [nb/nucleon] 00 ee5.7K  2.9K1.9 02/03 * ee150K (stat)  170K38 * prelim: 35% of 02/03 data Kidonakis, Vogt: hep-ph/ Hera-B ‘00 E789 E771 N 2 LO-N 2 LL N 2 LO-N 3 LL+  exact NLO m=4.5–5 Gev

14 H.Evans Physics in Collision: 28 June, Beauty in ep Collisions H1 finds b’s with: P t rel &  In: DIS: Q 2 > 1 GeV 2 PhP: Q 2 < 1 GeV 2 ZEUS uses P t rel In: DIS PhP H1 & ZEUS look for b’s in  + jet(s) data

15 H.Evans Physics in Collision: 28 June, b Photoproduction YearsLumi [pb -1 ]Sample [evts]Main Systematics H1 (prelim) ± 36  -ID, trk & vtx res. ZEUS ± 62  -ID, P T rel, dijet sel. Data-NLO agreement quite good but problems at low P T & low x ? syst. limited

16 H.Evans Physics in Collision: 28 June, b Deep Inelastic Scattering YearsLumi [pb -1 ]Sample [evts]Main Systematics H1 (prelim) ± 29  -ID, trk res., phys. model ZEUS ± 36sel. cuts,  -ID, signal extr. ZEUS probs at low Q 2 & x ?

17 H.Evans Physics in Collision: 28 June, Measuring F 2 cc & F 2 bb at H1 (prelim)  Intrinsic c and b in proton  Inclusive Data Sample  track  -tagging  high Q 2 (> 150 GeV 2 )  X-Sect (Q 2 >150 GeV 2, 0.1

18 H.Evans Physics in Collision: 28 June, b-Production Scorecard Improved Data-Theory at CDF 1.use B-hadrons20% 2.FONLL calc20% 3.consist fragm20% 4.fragm params20% Agreement slightly worse at HERA  but no huge prob’s Experiments largely syst dominated  scale w/ stat’s ? Theory err’s > Exp err’s  exp constrains theory

19 H.Evans Physics in Collision: 28 June, Charm Production at CDF  Run II J/    +  - Data  Feb-Mar pb -1  uses SVT 2-Track-Trigger  Separate prompt-c from b  c  Imp. par. of c-candidate  Main Systematics  1-track eff., 2-track eff. corr’s P T > Xcand’s  (D, P T >X, |y|<1) [  b] D0D ± 0.2 ± 1.5 D * ± 0.1 ± 0.8 D+D ± 0.1 ± 0.7 DsDs ± 0.05 ± 0.22 D 0  K -  + D *+  D 0  + D +  K -  +  + Ds   +Ds   +  Reasonable agreement w/ FONLL theory Cacciari, Nason: JHEP 0309, 006 (2003) Kniehl, Kramer, Potter: NPB 597, 337 (2001) syst. limited 3% of curr data

20 H.Evans Physics in Collision: 28 June, Open Charm at Hera-B  2002/03 Min Bias data210M evts  D + /D 0 x-section ratioexpect ~ 1/3  diff. largely due to feed-down from D *  BR(D *0  D 0 X) ~ 100%  BR(D *+  D 0 X) ~ 70%  prev. meas’s not entirely compatible (with large uncertainties)  new Hera-B meas D + /D 0 = 0.54 ± 0.11 ± 0.14 N  (-0.1

21 H.Evans Physics in Collision: 28 June, Charm Baryon Asymmetries at FOCUS Perturb. QCD  small charm asym in Fixed Target exp’s “Leading Particle” effects can change this  - (dds) N  c + (udc)  c 0 (ddc)  c ++ (uuc) Leading particle: common valence q’s w/ target/projectile focusMeas AsymmetryPYTHIA c+c ±0.018±  c ±0.073± c0c ±0.089±  c ++* 0.181±0.105±  c 0* 0.298±0.165±  c ±0.087±0.021n/a Poor Agreement data vs PYTHIA Braaten, Kusunoki, Jia, Mehen: hep-ph/ FOCUS 2003 A(  c + )  c + : E791  c + : SELEX Heavy-Q Recomb. Þ better descrip. of prev. data also describes A(D)

22 H.Evans Physics in Collision: 28 June, D * Production in DIS YearsLumi [pb -1 ]Sample [evts]Main Systematics H1 (prelim) ± 77track reco. eff. ZEUS ± 129D * reco, accept. good agreement w/ NLO QCD Open Charm contrib to F 2 useful to constrain gluon density in proton ! syst. limited

23 H.Evans Physics in Collision: 28 June, D * (+jets) Photoproduction H1 (prelim) ZEUS (prelim) ZEUS (prelim) Jet X-Sect: ZEUS less sens. to hadr. effects extend further forward mild discrep’s remain Years Lumi [pb -1 ]Sample [evts]Main Systematics H1 prelim ± 76track reco ZEUS prelim ± 190signal extr., MC model Data – NLO Discrepancies mid-Pt & high 

24 H.Evans Physics in Collision: 28 June, c-Production Scorecard FONLL calc agrees very well with CDF data  but theory errs large Latest HERA meas’s ~agree with NLO  no improve w/ FONLL Experiments largely syst dominated  scale w/ stat’s ? Theory err’s > Exp err’s  especially for newest calc’s (CDF) n.b. PYTHIA  poor descrip of FOCUS Asym Q-recombination models much better

25 H.Evans Physics in Collision: 28 June, We should Understand J/  &   quarkonium meson retains quantum numbers of hard scatter  for any S/color/L state n  (non-perturb) NRQCD matrix elements from fits to data g g g  g  e p  g g g g e p  hadron-hadron collisions ep collisions Other production mechanisms also possible…

26 H.Evans Physics in Collision: 28 June, The J/  Production Crisis CDF 1997 the CSM doesn’t work ! COM to the Rescue ! Braaten, Kniehl, Lee: PRD 62, (2000) and Tevatron Run II B Working Group DIS – H PhP – H1,ZEUS 2003 So we all feel fairly Smug …but things get confusing ! maybe in ep too ?

27 H.Evans Physics in Collision: 28 June, COM Means Polarization ExpIntE [GeV]Pol COM0.35 – 0.65 E672/E706  - Be515  0.01±0.08 p Be ±0.15 p Be800  0.11±0.15 E711p Si800  0.09±0.12 WA92  - Cu350  0.01±0.19 CDF sees no Polarization in J/  or  (2S) (largely from data at high P T ) CDF 2000 J/   (2S) Fixed Target meas’s also lower than COM Caution: most exp results include large contrib from decay J/  ’s, which have NO polarization CDF 2002 U situation even less clear CDF consist w/ NRQCD (large errors) NuSea finds: pol  (1S) ~ 0 pol  (2S,3S) ~ 1

28 H.Evans Physics in Collision: 28 June, New Quarkonium Results Reported NuSeaJ/  polarization in 800 GeV p-Cu interactionsPRL 91, (2003) ZEUSDIS production of J/  Preliminary (2003) ZEUSJ/  helicity in DISPreliminary (2003) CDFInclusive J/  cross-section (start point of H b result)Preliminary (2003) see talk by Rich Galik for more on Quarkonia

29 H.Evans Physics in Collision: 28 June, J/  Polarization at NuSea NuSea meas: 800 GeV p on Cu  9M J/    +  -  1 st proton meas with enough stat’s to meas. x F dep  no sep of direct & decay J/  Systematics limited  P T dep of production x-sect  P T dep of acc vs. decay ang NuSea consistent w/ prev meas’s of J/  pol at F.T.  significantly more accurate All point to small J/  pol  n.b. most include significant contrib from decay J/  ’s Disagreement w/ COM should be regarded w/ Caution ExpIntE [GeV]Pol COM0.35 – 0.65 E672/E706  - Be515  0.01±0.08 p Be ±0.15 p Be800  0.11±0.15 E711p Si800  0.09±0.12 WA92  - Cu350  0.01±0.19 NuSea/E866p Cu ±0.004±0.080 My Ave.0.00±0.04 Nu Sea

30 H.Evans Physics in Collision: 28 June, DIS Production of J/  Shape of ZEUS and H1 Data favor CSM but model uncertainties are large YearsLumi [pb -1 ]N(J  )Main Systematics H (ee,  )458 ± 30Non-res bgrd, acc. & eff. ZEUS (prelim) (  )203 ± 19MC model of acc, diffr evts ZEUS J/    +  -

31 H.Evans Physics in Collision: 28 June, J/  Helicity at HERA YearsLumi [pb -1 ]N(J  )Main Systematics H (  )Non-res bgrd, acc. & eff. ZEUS (prelim) (  )203 ± 19MC model of acc, diffr evts not statistically significant – yet !

32 H.Evans Physics in Collision: 28 June, Quarkonium Scorecard Production  COM required by Tevatron  but not by HERA Polarization  no signif J/  pol obs  few  meas’s  prompt vs non-prompt an issue in some meas’s Experiments largely syst dominated  scale w/ stat’s ? Theory uncert’s very larg  quantitative statements difficult Agreement: Data vs COM Agreement: Data vs CSM goodfairbad good fair bad TeV  -prod TeV  -pol FT  -pol FT  -pol ep  -PhP ep  -DIS norm ep  -DIS shape COM wins CSM wins Subjective Comparison of Results w/ Models

33 H.Evans Physics in Collision: 28 June, New Particles with Heavy Flavor CDFX(3872)hep-ex/ CDFCharmed pentaquark searchPreliminary (2004) DØDØX(3872)hep-ex/ H1Charmed pentaquark searchhep-ex/ ZEUSCharmed pentaquark searchPreliminary (2004) FOCUDCharmed pentaquark searchPreliminary (2004) SELEXDouble charm baryonhep-ex/ SELEXFirst observation of a narrow charm-strange mesonhep-ex/ see talks by Rich Galik & Takashi Nakano for more on New Particles

34 H.Evans Physics in Collision: 28 June, The X(3872) in p-pbar ExpLumi [pb -1 ]rangeMass [MeV]M resSignalSignif CDF220|y| < ± 0.7 ± ±  DØDØ230|y| < ± 3.1 ± ±  X(3872)  J/   +  - 1 st obs by Belle: M = ±0.5±0.6 MeV (previous hints at E705,E706,E672: ) Open question – what is it ? cc-bar? D 0 -D * “molecule”? ccg hybrid? something else? M(  ) > 500 MeV prod. characteristics similar to  (2S) but low stat’s M(  ) > 520 MeV P T (  ) >15 GeV |y| <1 dec len <100  mhel.  < 0.4 Sample Fractions Isolated X hel.  < 0.4

35 H.Evans Physics in Collision: 28 June, Charmed Pentaquarks Strange Pentaquark:  observations by  LEPS, DIANA, CLAS-1/2, SAPHIR, Asratyan, et al, HERMES, SVD, COSY-TOF, ZEUS, Spring-8  not seen by  BaBar, BES, Hera-B, PHENIX  = ± 2.0 MeV  but not all meas’s consistent Charm Pentaquark:  critical issue: p/K/  separation: D **  D *  YearsLumi [pb -1 ]N(D * )N(  c )SignifMass [MeV]M res H K51 ±  3099 ± 3 ± 512 ZEUS K——— CDF K< 29 (90%CL) —— FOCUS K———

36 H.Evans Physics in Collision: 28 June,  c 0 Search Results DIS PhP H1 DIS & Photo-Prod ZEUS Inclusive lo P(p)hi P(p) CDF Run II Preliminary D*pD*p D-pD-p FOCUS Preliminary H1 Signal not observed by other exp’s with similar or greater sensitivity

37 H.Evans Physics in Collision: 28 June, New Particles at SELEX confirm obs of  cc + (3520)1 st obs of D sJ + (2632) StateEventsMass [MeV]Signif  cc + (3520)   c + K -  ± 16.3   cc + (3520)  p D + K ± 3~4  D s + (2573)  D 0 K + 14 ± ±  D s + (2632)  D s +  45 ± ±  D s + (2632)  D 0 K + 14 ± ±  not obs in FOCUS or E791  cc + (3520)  (pDK)/  (  K  ) = 0.078±0.045 phase space  ~0.22 lifetimes appear lower than expect D sJ (2632)  (D s  )/  (D 0 K) ~ 6 phase space  ~0.5 very narrow:  < 17 MeV see talk by Peter Cooper

38 H.Evans Physics in Collision: 28 June, What’s Next ? ExperimentBeamE [TeV]RunsLumi [fb -1 ]  tot (bb)Sample Stat’s H1,ZEUS Ie ± p0.30/ D * : 5x10 4 H1,ZEUS IIe ± p ~0.7D * : 3.5x10 5 CDF,DØ I  bJ/  : 1.8x10 5 CDF,DØ II – %J/  : 3.1–6.9x10 7 BTeV1.9609–2 / y~100  bReco B: ~10 7 /y Atlas,CMSpp / y500  bB  J/  : ~2x10 6 /y LHCbpp1407–2 / y500  bB  J/  (  ): ~2x10 6 /y Fixed Target: continuing analysis of existing data  possibility of new runs beyond 2009 ? New collider exp’s aim mainly at EW aspects of B-Physics  Production studies will use exclusive final states  Triggers are the critical issue  Muon PT  but keep an eye on the BTeV displaced vertex trigger !

39 H.Evans Physics in Collision: 28 June, A Taste of What’s to Come Panikashvili, Smizanska: 2003 Atlas: pp  J/  X pTpT xFxF BTeV: flat B trigg accept Cheung: 2004 (n.b. low stat’s) CMS: B  J/  Silvestris: 2004 Ruiz: 2004 LHCb: evt yields DØ J/  pb -1 84K / 10 fb -1

40 H.Evans Physics in Collision: 28 June, Where do We Stand ? 1.b-Production  big steps forward in understanding recently  especially at the Tevatron, Fixed Target  mild data-theory disagreement at HERA  exp meas’s syst limited, theory errors quite large 2.c-Production  data-theory agreement remains fairly good  but some discrepancies developing in new measurements  again exp and theory uncertainties are large 3.Heavy Quarkonia Production  confusion regarding details of prod mechanism remains  inconsistent(?) results for both production and polarization 4.New Particles  studies of their existence/properties starting

41 H.Evans Physics in Collision: 28 June, Where are We Going (soon) ? New Data is rolling inCDF,DØ,H1,ZEUS New Analyses are ProceedingFixed Target 1.b,c Production  use new theoretical and analysis tools more widely  extend kinematic reach of studies  study correlations in production  use production measurements to constrain PDFs 2.Quarkonia  better polarization measurements (prompt vs. non-prompt)  more  studies 3.New Particles  confirm/refute observations in question  understand properties of those particles that survive

42 H.Evans Physics in Collision: 28 June, and Further Down the Road  Upcoming collider exp’sAtlas,CMS,LHCb,BTeV  superb detector capabilities  huge heavy flavor samples  But…  focus mainly on EW measurements in Q-sector  rely critically on aggressive triggers  Nevertheless…  there is an active heavy flavor effort (Hera-LHC Workshops) Look for Exciting Heavy Flavor Reviews for many Physics in Collisions to come Look for Exciting Heavy Flavor Reviews for many Physics in Collisions to come


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