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LVD and the CNGS beam M. Selvi for the LVD Collaboration INFN Bologna

LVD and the CNGS beam M. Selvi for the LVD Collaboration INFN Bologna. Outline. Run 1 summary Some inconsistency in the database Run 2 results MC simulation: m flux from the rock. L arge V olume D etector.

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LVD and the CNGS beam M. Selvi for the LVD Collaboration INFN Bologna

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  1. LVD and the CNGS beamM. Selvi for the LVD Collaboration INFN Bologna M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  2. Outline • Run 1 summary • Some inconsistency in the database • Run 2 results • MC simulation: m flux from the rock M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  3. Large Volume Detector CNGS BEAM MONITOR WITH THE LVD DETECTOR.Nucl. Instrum. Meth. A516, 96-103 (2004)e-Print Archive: hep-ex/0304018LNGS/EXP-05/03 *March 03* M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  4. Run1 summary M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  5. LVD monitor of the CNGS beam We select events where there is at least one scintillator counter with an energy release larger than 100 MeV. We can discriminate CNGS event from cosmic muons requiring: • time coincidence of the event with the CNGS time spill (cosmic muon background is then about 0.1 events/day) From the Montecarlo simulation we expect 7.147 10-16 events/proton on target (p.o.t.) -> 160 events/day (at nominal intensity) Nominal values of the beam performances are taken from: A. Ferrari at al., An updated Monte Carlo calculation of the CNGS neutrino beam, CERN-AB-Note-2006-038, EDMS No 745389 M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  6. LVD detector performances during August 2006 M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  7. CNGS beam First Run From Aug 18th, 11:30 UTC to Aug 30th, 3:00 UTC, the CNGS beam started with an intensity of about 1.4 x 1013 p.o.t./spill, (about 60% of the nominal intensity). Total integrated number of p.o.t.: about 7.6 x 1017 542 events are expected M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  8. Time event distribution We search for CNGS events around the time of the spill +/- 15 ms 569 events are identified. The time distribution of the LVD CNGS events agrees with the duration of the spill (10.5 ms) M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  9. LVD rate During the CNGS run LVD has collected 569 CNGS events (542 expected). Agreement between the observed events and the expected from the beam intensity! M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  10. The first CNGS event M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  11. Internal n interaction in LVD M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  12. m generated in the rock M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  13. Number of hit counters Black: LVD data Red: MC simulation M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  14. Total energy released Black: LVD data Red: MC simulation M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  15. Muon direction: side view 332 events (over 569) are reconstructed with a good c2 Black: LVD data Red: MC simulation Side view z m LVD qzy y n Hall A axis The beam direction is about 3.5o over the horizon M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  16. Muon direction: top view 332 events (over 569) are reconstructed with a good c2 Black: LVD data Red: MC simulation Top view x LVD m y qxy n Hall A axis The beam direction is aligned with the hall A axis M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  17. Conclusion The analisys of data taking with the LVD detector shows that: the CNGS beam is working very well and the LVD monitor too M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  18. Inconsistency in the DB M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  19. DB time bias in RUN1 After correcting for the CERN-LNGS distance and for the optic fiber lenght a difference still remains between the LVD and the DB time • 18 Aug 11:30 UTC  18 Aug 16:00 UTC Bias= +100 ms • 18 Aug 16:00 UTC  22 Aug 9:00 UTC Bias= +10 ms • 22 Aug 9:00 UTC  23 Aug 05:30 UTC Bias= -2000 ms • 25 Aug 18:30 UTC  30 Aug 3:30 UTC No bias M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  20. Events with p.o.t. = 0 Looking around the CNGS beam spill time (± 15 ms) we found 589 LVD events. But for 20 of them the p.o.t. data in the database appears to be zero (those events has been visually checked and they seem good CNGS candidate) M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  21. Horizontal events with no spill We look for horizontal muons in the CNGS beam direction with a strong selection cut in the track fit results. There are some horizontal events which are not in spill Black: all events Red: events in spill M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  22. Horizontal events with no spill We look for horizontal muons in the CNGS beam direction with a strong selection cut in the track fit results. There are 25 horizontal (q>80°) events which are not in spill Black: all events Red: events in spill M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  23. Horizontal events with no spill But it is very unlikely to find horizontal events in the cosmic muon sample. No events here ! M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  24. Horizontal events with no spill The closest spill time for these 25 horizontal events in the database is 16.8 s or 22.8 s which is the CNGS cycle duration 16.8 22.8 22.8 16.8 It seems that these events are “in spill” but their spill time is not written in the database M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  25. Run2: October 2006 M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  26. Run 2: Beam Intensity The run duration was about 22 hours. Total integrated intensity: 5.77 x 1016 p.o.t. This intensity corresponds to 41 exepected events in LVD M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  27. LVD detector performances during October 2006 M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  28. Run 2: LVD results Looking for events around the spill time we found 46 LVD events M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  29. Run 2: LVD results M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  30. Run 2: LVD results M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  31. Run 2: LVD results M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  32. MC simulation comparison M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  33. MC simulation comparison Gran Sasso rock LVD nm * m CNGS beam A good comparison number is the flux of muon coming out from a plane orthogonal to the beam direction. In our MC calculation it is 190 muons/m2/y , when considering 4.5 1019 pot/y Or, alternatively, 4.22 10-18 muons/m2/pot M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  34. Backups .... M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  35. Large Volume Detector @ LNGS M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  36. LVD detector • 3 identical towers in the detector • 35 active modules in a tower • 8 counters in one module M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  37. Construction and data acquisition • Start construction and installation: 1990 • First tower - Start data acquisition: june, 11th 1992 • Second tower – Start data acquisition : june, 1st 1994 • Third tower – Start data acquisition: december, 13th 2000 1 2 3 LVD is huge: 1000 tons of liquid scintillator LVD is highly modular: 840 independent counters M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  38. The detector: basic elements The scintillation counter: External dimensions: 1.5 x 1 x 1 m3 Scint. composition: CnH2n+2 <n>=9.6 +1 g/l PPO+ 0.03 g/l POPOP Scint. density: ~ 0.8 g/cm3 Attenuation lenght: > 15m @ l=420 nm Flash point at: ~39oC PMT: FEU-49B Photocathode diameter: d=15 cm Quantum efficiency: 10-15% M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  39. Main goal of the experiment ne ne nmnm ntnt Detection of neutrinos from a gravitational core collapse SN-II. 99% of the available energy (EB ~ 1053 erg) is released through the emission of neutrinos of all flavours One SN each 30-50 years is expected in our galaxy. Typical energy  0 - 100 MeV M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  40. LVD detector performances Most recently analyzed data set: 4.2.2005 - 13.4.2006 Effective time: 430.5 days Average trigger mass: 940 t Duty cycle: 99.98 % M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  41. LVD detector performances during August 2006 M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  42. The SNEWS system Scientific community SuperNova Early Warning System: working group between experiments looking for SN burst (currently LVD, SK, SNO, Amanda; Borexino,MiniBoone and KamLAND expected to join) SK Every experiment looks for SN burst and send alarm at an average rate of 1/month LVD Since July ‘05 BROOKHAVEN server Give prompt information to astronomical comunity. Doing online twofold coincidence allows to send a prompt alarm and to reduce to zero fake alarm! AMANDA SNO http://snews.bnl.gov/alert.html to get your own SN alarm !! M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  43. LVD and the CNGS beam M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  44. M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  45. The CNGS beam The CNGS beam provides about 2800 CC/kt/year at nominal beam intensity at the Gran Sasso Labs. CERN-SL-2000-063EA and CERN-SL-2001-016EAA.E.Ball et al. propose to build a large area muon monitor at GS En (GeV) M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  46. Why a monitor at LNGS ? M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  47. Large Volume Detector CNGS BEAM MONITOR WITH THE LVD DETECTOR.Nucl. Instrum. Meth. A516, 96-103 (2004)e-Print Archive: hep-ex/0304018LNGS/EXP-05/03 *March 03* M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  48. Large Volume Detector 3 2 1 CNGS beam z Front area: ~ 13 m x 11 m y x M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  49. LVD monitor of the CNGS beam Neutrinos from CNGS are observed through: • the detection of muonsproduced in neutrino CC interactions in the surrounding rock • the detection of the products of the neutrino NC and CC interactions in the detector Gran Sasso rock LVD nm * m CNGS beam M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

  50. LVD monitor of the CNGS beam We select events where there is at least one scintillator counter with an energy release larger than 100 MeV. We can discriminate CNGS event from cosmic muons requiring: • time coincidence of the event with the CNGS time spill (cosmic muon background is then about 0.1 events/day) From the Montecarlo simulation we expect 7.147 10-16 events/proton on target (p.o.t.) -> 160 events/day (at nominal intensity) Nominal values of the beam performances are taken from: A. Ferrari at al., An updated Monte Carlo calculation of the CNGS neutrino beam, CERN-AB-Note-2006-038, EDMS No 745389 M. Selvi, LVD and the CNGS beam, LNGS CNGS meeting, January 16th 2007

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