1 / 38

The eccentricities of flow

The eccentricities of flow. Direct evidence for color strings?. S. Manly University of Rochester. International Workshop on Hadron Physics and Properties of High Baryon Density Matter Xi’An, China November 23, 2006. The eccentricities of flow. ec·cen·tric·i·ty ( k s n-tr s -t ) 

cwen
Download Presentation

The eccentricities of flow

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The eccentricities of flow Direct evidence for color strings? S. Manly University of Rochester International Workshop on Hadron Physics and Properties of High Baryon Density Matter Xi’An, China November 23, 2006 S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  2. The eccentricities of flow • ec·cen·tric·i·ty ( k s n-tr s -t )  • n.pl.ec·cen·tric·i·ties • The quality of being eccentric. • Deviation from the normal, expected, or established. • An example or instance of eccentric behavior. • Physics. The distance between the center of an eccentric and its axis. • Mathematics. The ratio of the distance of any point on a conic section from a focus to its distance from the corresponding directrix. This ratio is constant for any particular conic section. From American Heritage Dictionary S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  3. The PHOBOS Collaboration Burak Alver, Birger Back, Mark Baker, Maarten Ballintijn, Donald Barton, Russell Betts, Richard Bindel, Wit Busza (Spokesperson), Vasundhara Chetluru, Edmundo García,Tomasz Gburek, Joshua Hamblen, Conor Henderson, David Hofman, Richard Hollis, Roman Hołyński, Burt Holzman, Aneta Iordanova, Chia Ming Kuo, Wei Li, Willis Lin, Constantin Loizides, Steven Manly, Alice Mignerey, Gerrit van Nieuwenhuizen, Rachid Nouicer, Andrzej Olszewski, Robert Pak, Corey Reed, Christof Roland, Gunther Roland,Joe Sagerer, Peter Steinberg, George Stephans, Andrei Sukhanov, Marguerite Belt Tonjes, Adam Trzupek,Sergei Vaurynovich, Robin Verdier, Gábor Veres,Peter Walters, Edward Wenger, Frank Wolfs, Barbara Wosiek, Krzysztof Woźniak, Bolek Wysłouch ARGONNE NATIONAL LABORATORY BROOKHAVEN NATIONAL LABORATORY INSTITUTE OF NUCLEAR PHYSICS PAN, KRAKOW MASSACHUSETTS INSTITUTE OF TECHNOLOGY NATIONAL CENTRAL UNIVERSITY, TAIWAN UNIVERSITY OF ILLINOIS AT CHICAGO UNIVERSITY OF MARYLAND UNIVERSITY OF ROCHESTER S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  4. I offer a humble apology for some repetition to those of you who saw the PHOBOS talks in Shanghai … S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  5. Paddle trigger Spectrometer arm Octagon Ring counter Vertex detector Average Flow in PHOBOS S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  6. Average Flow in PHOBOS Correlate reaction plane determined from azimuthal pattern of hits in one part of detector Subevent A S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  7. Average Flow in PHOBOS with azimuthal pattern of hits in another part of the detector Subevent B S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  8. Average Flow in PHOBOS Or with tracks identified in the spectrometer arms Tracks S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  9. Average Flow in PHOBOS Separation of correlated subevents typically large in  S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  10. Flow in PHOBOS • PHOBOS has made differential measurements of the average flow: • Centrality • pT • Pseudorapidity • Energy • Species I will give you an update of ongoing work on understanding how flow scales from species to species and a new event-by-event measurement of fluctuations in v2 S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  11. Elliptic Flow: new results for Cu-Cu at 22.4 GeV Au+Au Cu+Cu Au+Au:PHOBOS CollaborationPRL. 94 (2005) 122303 Cu+Cu:PHOBOS CollaborationPRL: nucl-ex/0610037 Preliminary S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  12. Elliptic Flow: new results for Cu-Cu at 22.4 GeV Au+Au:PHOBOS CollaborationPRL 97, 012301 (2006) Cu+Cu at 200, 62.4 GeV:PHOBOS CollaborationPRL: nucl-ex/0610037 Statistical errors only Statistical errors only S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  13. 0-20% 20-40% Preliminary Au+Au Au+Au Preliminary Cu+Cu Cu+Cu Elliptic Flow: Au+Au and Cu+Cu v2 vs pt comparison • Track-based method 0 < h < 1.6 S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  14. Standard Eccentricity Statistical errors only PHOBOS CollaborationPRL: nucl-ex/0610037 Cu+Cu 200 GeV Au+Au 200 GeV Scaling out the geometry Statistical errors only 200 GeV Au+Au 200 GeV Cu+Cu 200 GeV PRL: nucl-ex/0610037 PRC C72, 051901R (2005) S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  15. Participant Eccentricity Statistical errors only Au+Au 200 GeV Cu+Cu 200 GeV Au+Au 200 GeV Cu+Cu 200 GeV PHOBOS CollaborationPRL: nucl-ex/0610037 PHOBOS CollaborationPRL: nucl-ex/0610037 Scaling out the geometry S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  16. 2 ε part ε part What is the appropriate form of the eccentricity scaling? It has been suggested that v2 may scale as instead of • -Bhalerao, Ollitrault – PLB 641, 260 (2006) • - Ollitrault – private communications (2006) The difference between • PHOBOS MC is as small as our estimate of the robustness of the calculation … will ignore for now. • In Collaboration with Ulrich Heinz S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  17. Au+Au at 200, 130, 62.4 and 19.6 GeV :PHOBOS CollaborationPRL 97, 012301 (2006) STAR, NA49 and E877 data taken from STAR Collaboration, Phys.Rev. C66 (2002) 034904 with no adjustments Cu+Cu at 200, 62.4 GeV:PHOBOS CollaborationPRL: nucl-ex/0610037 Statistical errors only Cu+Cu at 22.4 GeV PHOBOS Preliminary S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  18. Similar area density (1/S)dN/dy and scaled by epart Similar area density (1/S)dN/dy Statistical errors only Statistical errors only S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  19. Same area density (1/S)dN/dy and Scaled by epart Au+Au vs. Cu+Cu at 62.4 GeV Au+Au vs. Cu+Cu at 200 GeV Statistical errors only Statistical errors only Npart=82 Npart=80 S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  20. Scaled by epart Same area density (1/S)dN/dy Scaled by epart Same centrality (40%) Statistical errors only Statistical errors only PHOBOS PHOBOS S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  21. Elliptic flow develops event-by-event with respect to the participant ellipse S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  22. Expected fluctuations from the part model Elliptic flow develops event-by-event with respect to the participant ellipse S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  23. A new event-by-event flow analysis from PHOBOS S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  24. A new event-by-event flow analysis from PHOBOS Determine v2obs S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  25. A new event-by-event flow analysis from PHOBOS Determine v2obs S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  26. A new event-by-event flow analysis from PHOBOS Construct kernel S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  27. A new event-by-event flow analysis from PHOBOS Determine dynamical fluctuations S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  28. <v2> |η|<1 PRC 72, 051901 (2005) Number of participants Event-by-event mean v2 vs published results <v2>(|η|<1) = 0.5 x (11/12 <v2triangular> + <v2trapezodial>) Very good agreement of the event-by-event measured mean v2 with the hit- and tracked-based, event averaged, published results S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  29. |η|<1 PHOBOS preliminary (90% C.L.) PHOBOS preliminary (90% C.L.) • <v2> • σv2 Au+Au 200 GeV Au+Au 200 GeV Number of participants Number of participants Elliptic flow fluctuations: <v2> and σv2 Dynamical flow fluctuations Mean elliptic flow |η|<1 Systematic errors: • Variation in η-shape • Variation of f(v2) • MC response • Vertex binning • Ф0 binning “Scaling” errors cancel in the ratio: relative fluctuations, σv2/<v2> S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  30. |η|<1 PHOBOS preliminary (90% C.L.) Au+Au 200 GeV • σv2/<v2> Number of participants Elliptic flow fluctuations: σv2/ <v2> S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  31. MC with no fluctuations Elliptic flow fluctuations: σv2/ <v2> |η|<1 |η|<1 PHOBOS preliminary (90% C.L.) Au+Au 200 GeV PHOBOS preliminary (90% C.L.) Au+Au 200 GeV • σv2/<v2> • σv2/<v2> Number of participants Number of participants S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  32. |η|<1 PHOBOS preliminary (90% C.L.) Au+Au 200 GeV • σv2/<v2> Number of participants Elliptic flow fluctuations: σv2/ <v2> Participant eccentricity model prediction MC with no fluctuations S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  33. Number of participants Things to consider and naïve questions How seriously should we take this Glauber-driven participant eccentricity model? Allows us to make sense of both the system size scaling and fluctuations in the data Really need Cu-Cu fluctuations measurement where the eccentricity fluctuations will be larger … let’s hope the measurements can be made S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  34. Number of participants Things to consider and naïve questions How seriously should we take this Glauber-driven participant eccentricity model? PHOBOS fluctuations analysis depends on MC … things not yet in the MC used to determine the kernel (such as short range correlations) can show up as fluctuations Fortunately, the wonderful and complementary STAR measurement (P. Sorensen – QM2006) provides a consistency check. Data-driven and independent. Agrees well. Measurement will likely hold up S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  35. Number of participants Things to consider and naïve questions How seriously should we take this Glauber-driven participant eccentricity model? Participant eccentricity model calculation has proven to be robust during studies that followed its introduction at QM2005 It seems we should take it seriously Should we be bothered that we don’t have much room for other sources of fluctuations? S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  36. Things to consider and naïve questions If we take the participant eccentricity model seriously, what do we learn? Whatever the form of the matter in the early stage of the collision, it seems the relevant interactions that drive the flow signal are initially localized transversely in a way similar to the participant nucleons. Inconsistent with any picture where the initial state is driven by a large number of low-x partons that fill the nuclear transverse area. S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  37. Things to consider and naïve questions If we take the participant eccentricity model seriously, what do we learn? It seems we are seeing transversely localized parton production with a granularity not so different from the interacting nucleons! Something like color strings? Is this telling us something about the reality of some models vs. others? This seems rather fundamental … are there other measurements that show “stringiness” so directly? S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

  38. Perhaps it seems obvious that this might happen, but it is incredibly cool to see it … and it contradicts the naïve view many of us might have had (well, me anyway) of a densely packed initial transverse distribution S. Manly – U. Rochester Xi’an, China, Nov. 23, 2006

More Related