Presentation is loading. Please wait.

Presentation is loading. Please wait.

Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 1 Recent Results in Rare Heavy Flavor Decays at CDF Hans Wenzel for the CDF Collaboration.

Published byLaureen Gardner Modified over 9 years ago

Similar presentations

Presentation on theme: "Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 1 Recent Results in Rare Heavy Flavor Decays at CDF Hans Wenzel for the CDF Collaboration."— Presentation transcript:

1 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 1 Recent Results in Rare Heavy Flavor Decays at CDF Hans Wenzel for the CDF Collaboration ( Fermilab) Motivation: The decays B s,d  e  B sd  e + e - and D 0   +  - The Measurements: B sd  e +    Measurement B sd  e + e - Measurement D 0   +  - Measurement Summary

2 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 Thanks Thanks to the accelerator division for keeping the data coming! Thanks to the CDF collaboration for operating such a complex detector and providing many excellent studies to build upon.

3 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 Motivation Why do we search for rare decays? Rare particle decays could provide a unique glimpse of subatomic processes that elude the direct reach of even the most powerful particle colliders on Earth. Their observation could answer questions about the nature of matter and energy, shine light on the evolution of the early universe, and explain the subtle differences between matter and antimatter. …….. Robert Tschirrhart Symmetry mar/apr 08 Sounds pretty exciting  Let’s do it

4 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 4 The decays B s,d  e +  - B s,d  e +   decays are forbidden within the “original” SM org. But the observation of neutrino oscillations has shown that lepton flavour changes actually occur in nature  standard model needed to be modified to incorporate this. Still SM NG prediction very small < 1.0 x 10 -15. The decays are possible in some theoretic models containing lepton-flavour violating tree-level couplings mediated by leptoquarks. R-parity violating SUSY or ED models can give contributions.

5 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 5 One example model: Pati-Salam Leptoquarks Grand Unification Theory (GUT) by J. Pati and A. Salam predicts spin 1 gauge bosons the so called “Pati Salam Leptoquarks”, PS LQ, that carry both colour and lepton quantum numbers [PRD 10,275 (1974)] It is the simplest model based on SU(4) c where the lepton number is the fourth “colour”

6 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 6 Br( B s  e +    and LQ Mass 

7 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 7 Current Status CDF Run I published limits @ 90 (95) % C.L. [PRL (81) 1998] B-factories (90% CL): MLQ (Bd) > 53.1 TeV/c2 (BABAR 2007)‏ LQ from Kaon decays: Br(K L →  e) 100 TeV/c 2 Most of direct searches for LQ (different properties) set limits in the order of : M LQ > 200-300GeV/c 2

8 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 8 The decays B s,d  e + e - While B s,d       starts to put serious constraints on various models there is plenty of wiggle room left in case of B s,d  e + e -

9 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 9 The FCNC decay D 0  +  - R-parity violating SUSY allows enhancements up to 3.5 x 10 -6 Previous CDF run II measurement based on 69 pb -1 : Br(D 0   +  - ) < 2.1(3.1) x 10 -6 @ 90(95) % C.L.

10 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 The CDF detector Muon Chambers Calorimeters Central Drift Chamber dE/dx, XFT Trigger Silicon Vertex Detector SVT: Silicon Vertex Trigger

11 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 Things in Common All searches presented here have the following in common: Based on two track data samples triggered by the Silicon Vertex Trigger, using the long lifetimes of B and D–mesons to reject prompt events. Leptonic final states (e  ). All measurements are relative measurements normalizing to a well known similar hadronic decay mode.

12 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 12 Who is looking for an emu? Kaori Maeshima, Ting Miao, Hans Wenzel The decay B sd  e +  

13 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 13 Run-II Search Strategy SVT two-track-trigger (TTT sample) Relative to B  hh: B 0  Kπ / Bs  K K http://www-cdf.fnal.gov/physics/new/bottom/060921.blessed-bhh_1fb/ 66% of the sample

14 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 14 Run-II Search Strategy (ingredients)‏ The Result Relative efficiency: MC for kinematics and mass window efficiency CDF measurements (J/Psi,photon conversions) for lepton ID efficiency and acceptance Events (or Events @ limit) surviving all selection criteria (incl. Lepton ID)‏ World average Bs only: biggest contribution to systematic uncertainty Fit to B->hh spectrum of evts. surviving all but lepton ID selection

15 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 15 Event Selection SVT Trigger sample –Use only tracks which actually fired the trigger Standard selections as B→hh analysis –Two good tracks with pT>2GeV –100  m<d0<1mm –d0_B<140  m,  2 3D (B vertex)<5 –L xy (B)>200  m –Isolation = pT_B/ (pT_B+∑pT_i in R 0.4 –Pointing angle d  < 0.2 The last three are optimized for this analysis dd Beam spot P T (e  )‏ P T (  )‏ P T (e)‏ Decay Vertex

16 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 16 Cut Optimization Giovanni Punzi: physics/0308063 ( FOM :Figure of Merit )

17 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 17 B  hh with Optimized Cuts (Lxy>375  m, Iso>0.675 and d  <0.11)‏ 9648.4+/- 224.7 B->hh 6387.0+/-214.4 B d ->K +   ‏ Three body B decays Combinatorial backg. B  hh ~66%

18 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 18 Monte Carlo Data Monte Carlo Detailed Simulation of the CDF detector including: Trigger simulation Detector response Event reconstruction Used to model kinematics and mass window efficiency. B  hh Signal only!

19 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 19 Monte Carlo (kinematical variables)‏ pT of B Pointing Angle transverse decay length pT of Kaon

20 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 20 Signature of B→e  Long tail due to Bremsstrahlung Search window for B s (0) →e  as 3σ around B s (0) mass Signal Events: full simulation

21 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 21 Muon Identification Used the standard algorithm: –Extrapolate track into the muon chambers select on matching –Energy deposit in calorimeter required to be consistent with minimum ionizing particle Acceptance and efficiency estimated with J/Psi- events.

22 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 22 Electron Identification Electron ID combines Tracker (dE/dx and momentum) and calorimeter Information Requires match of track with shower in calorimeter. E/P > 0.7. E had /E em < 0.05. Requires shower profile is consistent with electron. dE/dx and calorimeter efficiency from photon conversions:   e + e 

23 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 23 Relative efficiency:  (B  e  )/e(B  K  ) Includes: Muon acceptance and identification efficiency Electron acceptance and identification efficiency dE/dx efficiency Mass window selection efficiency Kinematics ….

24 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 24 Background from double fakes expected: 0.229 +/- 0.046

25 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 25 M(e-  ): after all selections Excellent mass resolution allows for tight search windows

26 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 26 Systematic Uncertainties CDF CDF Run II preliminary (2fb -1 )

27 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 27 Limit Calculation for Br(B sd →e  ) Br(B 0 →Kπ)=(19.4±0.6) x 10 -6 (world average )‏ N(B 0 →Kπ)= 6387.0+/-214.4 ε Rel (B s ) = 0.2071±0.0003±0.0158 f Bd /f Bs = (39.8±1.2)%/(10.3±1.4)% =3.86 ±0.59 N limit (B s →e  ) = 3.60 (4.57) @ 90(95) % C.L. N Bgr (B s →e  ) = 0.81 +/- 0.63 ε Rel (B d ) = 0.2097±0.0023±0.0123 N Bgr (Bd→e  ) = 0.94 +/- 0.63 N limit (B d →e  ) = 4.44 (5.44) @ 90(95) % C.L.

28 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 28 Limits for different scenarios

29 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 29 B s →e +    with 2fb -1

30 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 30 B 0 →e +    with 2 fb -1

31 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 31 B sd →e + e - with 2 fb -1  Identical to B sd  e +  - now both tracks have to be identified as electron candidates. To compensate for the large Bremstrahlungs tail we use asymmetric mass windows (-6 ,3  ) B  e + e - Signal Events: full simulation

32 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 32 B sd →e + e - with 2 fb -1 

33 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 33 Systematic uncertainties CDF Run II preliminary (2fb -1 )

34 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 34 Limit Calculation for Br(B sd →e + e - ) Br(B 0 →Kπ)=(19.4±0.6) x 10 -6 (world average )‏ N(B 0 →Kπ)= 6387.0+/-214.4 ε Rel (B s ) = 0.1290±0.0002±0.011 f Bd /f Bs = (39.8±1.2)%/(10.3±1.4)% =3.86 ±0.59 N limit (B s →ee) = 3.11 (4.03) @ 90(95) % C.L. N Bgr (B s →ee) = 2.66 +/- 1.80 ε Rel (B d ) = 0.1278±0.0017±0.011 for B0 N Bgr (Bd→ee) = 2.66 +/- 1.80 N limit (B d →ee) = 3.51 (4.47) @ 90(95) % C.L. Run II Preliminary (L= 2fb -1 ): Br(B s →e + e - ) < 2.8 (3.7) x 10 -7 Br(B d →e + e - ) < 8.3(10.6) x 10 -8

35 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 Search for the decay D 0   +  - E. Berry, I.K. Furic, R.F. Harr, Y.K. Kim http://www-cdf.fnal.gov/physics/new/bottom/080228.blessed-d0-mumu/

36 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 Search for the decay D 0   +  - B(D 0 →  +  - )=(1.364 ± 0.032) x 10 -3 (world average )‏ D 0 →K +  - : Control sample

37 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 Search for the decay D 0   +  - ~ 45000 Events, D 0   +  - is the reference mode but can also fake D 0   +  - if both  ‘s are misidentified as  ’s. To minimize the misidentification rate a likelihood function is used to identify  ’s: The function combines: dE/dx (tracker), calorimeter information (EM and Had) and  detector information. Maintains high efficiency and achieves additional hadron suppression!!

38 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 Fake Rate The probabilities for pions and kaons to be misidentified as muons is estimated for the D * tagged D0→K +  - : control sample

39 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 Background from B-decays Background is dominated by cascade semimuonic B-decays.To reduce this Bgr.: Use Probability ratio: - maintains 85 % of signal - reduces Background by 60%,.

40 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 Observed events and expected Bgr. dominant Background

41 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 D 0   +  - Result This limit is a multichannel, Bayesian calculation. Credibility levelFrequentist: Confidence level this translates into a limit on the R parity violating couplings λ 21k λ 22k = 1.5 √ B(D 0 → μ + μ - ) < 9.8 × 10 -4

42 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 42 Summary & Conclusion All measurements represent the current world best limits!

43 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 43 Backup slides

44 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 44 Limit Calculation for Br(D0→e  ) Br(D 0 →     )=(1.364±0.032) x 10 -3 (world average )‏ N(D 0 →     )= 6387.0+/-214.4 ε Rel (B s ) = 0.2071±0.0003±0.0158 f Bd /f Bs = (39.8±1.2)%/(10.3±1.4)% =3.86 ±0.59 N limit (B s →e  ) = 3.60 (4.57) @ 90(95) % C.L. N Bgr (B s →e  ) = 0.81 +/- 0.63 ε Rel (B d ) = 0.2097±0.0023±0.0123 N Bgr (Bd→e  ) = 0.94 +/- 0.63 N limit (B d →e  ) = 4.44 (5.44) @ 90(95) % C.L.

45 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 45 Selection Variables Signal (B->hh sb-subtracted)‏ background (B-> sidebands)‏ L xy ( B )‏ Pointing angle d  IsoIso

46 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 46 Pati-Salam Leptoquarks (cont.)‏ The Pati-Salam model allows for cross-generation couplings Bs  e  decay probes two Types of LQ: –e  b-quark coupling –   s-quark coupling Bd  e  probes –e  b and   d

47 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 47 Cut Optimization (cont.) Lxy iso dd

48 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 48 Summary With 2fb -1 CDF data (@90(95) % C.L.)‏ –Br(Bs→e  ) < 2.0 (2.6) x 10 -7 –M LQ (Bs) > 47.7(44.6) TeV –Br(B 0 →e  ) < 6.4(7.9) x 10 -8 –M LQ (B 0 ) > 58.6 TeV –Br(Bs→ee) < 2.77x 10 -7 –Br(B 0 →ee) < 8.32x 10 -8 Improvements over current limits –Br(Bs→e  ) < 6.1 x 10 -6 (CDF Run I)‏ –M LQ (Bs) > 21.7 TeV (CDF Run I)‏ –Br(B 0 →e  ) < 9.2 x 10 -8 (BABAR 2007)‏ –M LQ (B 0 ) > 53.1TeV (BABAR 2007)‏ –Br(B 0 →ee) <1.13 x 10 -7 (BABAR 2007)‏

49 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 49  Rel Systematic uncertainties

50 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 50 M(e-  ): Closed Box Lxy > 375  m, iso>0.675,d  <0.11 but before e/  ID  After  -ID   After e/  ID ↓-----blocked-----↓

51 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 51 I wish we were so lucky! Some things never change!

52 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 52 ee - Limits for different scenarios

53 Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008

54 54 Electron Identification Electron ID uses dE/dx and CEM/CES/CPR –CEM/CES coverage: 80.28±0.78 % –Track-based algorithm for low pT electrons –pT>2GeV, |  |<1.0 dE/dx and calorimeter efficiency from   e + e  –dE/dx: ~90% –CEM/CES/CPR: ~70%

Download ppt "Hans Wenzel, Joint Experimental-Theoretical Seminar June 20 th 2008 1 Recent Results in Rare Heavy Flavor Decays at CDF Hans Wenzel for the CDF Collaboration."

Similar presentations

Tau dilepton channel The data sample used in this analysis comprises high-p T inclusive lepton events that contain an electron with E T >20 GeV or a muon.

Tau dilepton channel The data sample used in this analysis comprises high-p T inclusive lepton events that contain an electron with E T >20 GeV or a muon.
August 12, 2000DPF 20001 Search for B +  K + l + l - and B 0  K* 0 l + l - Theoretical predictions and experimental status Analysis methods Signal.

August 12, 2000DPF Search for B +  K + l + l - and B 0  K* 0 l + l - Theoretical predictions and experimental status Analysis methods Signal.
Search for 7-prong  Decays Ruben Ter-Antonyan on behalf of the BaBar Collaboration Tau04 Workshop, Sep 14, 2004, Nara, Japan Outline:  Introduction 

Search for 7-prong  Decays Ruben Ter-Antonyan on behalf of the BaBar Collaboration Tau04 Workshop, Sep 14, 2004, Nara, Japan Outline:  Introduction 
1 Rare Decays of B Hadrons at CDF Matthew Jones October 3, 2005.

1 Rare Decays of B Hadrons at CDF Matthew Jones October 3, 2005.
FPCP 2002, 05/16-18/2002 p. 1 Richard E. Hughes, The Ohio State UniversityCDF Run II Status Status of CDF and Prospects Flavor Physics and CP Violation.

FPCP 2002, 05/16-18/2002 p. 1 Richard E. Hughes, The Ohio State UniversityCDF Run II Status Status of CDF and Prospects Flavor Physics and CP Violation.
J. Whitmore BEACH 2004 June 30, 2004 KTeV Results: K L    ( =e, , ) BEACH 2004 June 30, 2004 Julie Whitmore, Fermilab l Physics Motivation - Direct.

J. Whitmore BEACH 2004 June 30, 2004 KTeV Results: K L    ( =e, , ) BEACH 2004 June 30, 2004 Julie Whitmore, Fermilab l Physics Motivation - Direct.
Recent Electroweak Results from the Tevatron Weak Interactions and Neutrinos Workshop Delphi, Greece, 6-11 June, 2005 Dhiman Chakraborty Northern Illinois.

Recent Electroweak Results from the Tevatron Weak Interactions and Neutrinos Workshop Delphi, Greece, 6-11 June, 2005 Dhiman Chakraborty Northern Illinois.
1 Measurement of f D + via D +   + Sheldon Stone, Syracuse University  D o D o, D o  K -  + K-K- K+K+ ++  K-K- K+K+ “I charm you, by my once-commended.

1 Measurement of f D + via D +   + Sheldon Stone, Syracuse University  D o D o, D o  K -  + K-K- K+K+ ++  K-K- K+K+ “I charm you, by my once-commended.
1 Rare Decays At the Tevatron Cheng-Ju S. Lin (Fermilab ) BEAUTY 2006 OXFORD 28 September 2006.

1 Rare Decays At the Tevatron Cheng-Ju S. Lin (Fermilab ) BEAUTY 2006 OXFORD 28 September 2006.
CHARM 2007, Cornell University, Aug. 5-8, 20071Steven Blusk, Syracuse University D Leptonic Decays near Production Threshold Steven Blusk Syracuse University.

CHARM 2007, Cornell University, Aug. 5-8, 20071Steven Blusk, Syracuse University D Leptonic Decays near Production Threshold Steven Blusk Syracuse University.
1 B Physics at CDF Junji Naganoma University of Tsukuba “New Developments of Flavor Physics“ Workshop Tennomaru, Aichi, Japan.

1 B Physics at CDF Junji Naganoma University of Tsukuba “New Developments of Flavor Physics“ Workshop Tennomaru, Aichi, Japan.
B s and Λ b Lifetimes and BRs at the Tevatron Satyajit Behari (For the CDF Collab.) Johns Hopkins Univ., Baltimore,USA 25 th September 2006 Beauty 2006,

B s and Λ b Lifetimes and BRs at the Tevatron Satyajit Behari (For the CDF Collab.) Johns Hopkins Univ., Baltimore,USA 25 th September 2006 Beauty 2006,
Radiative and Rare B-Decays at BaBar All results are preliminary unless journal ref. is given limit values are 90% CL unless otherwise specified Carsten.

Radiative and Rare B-Decays at BaBar All results are preliminary unless journal ref. is given limit values are 90% CL unless otherwise specified Carsten.
Sergio Grancagnolo Activity Summary 9 Jan 2003 2003 work in BaBar The apparatus Physics with BaBar Data analysis.

Sergio Grancagnolo Activity Summary 9 Jan work in BaBar The apparatus Physics with BaBar Data analysis.
B Production and Decay at DØ Brad Abbott University of Oklahoma BEACH 2004 June 28-July 3.

B Production and Decay at DØ Brad Abbott University of Oklahoma BEACH 2004 June 28-July 3.
Donatella Lucchesi1 B Physics Review: Part II Donatella Lucchesi INFN and University of Padova RTN Workshop The 3 rd generation as a probe for new physics.

Donatella Lucchesi1 B Physics Review: Part II Donatella Lucchesi INFN and University of Padova RTN Workshop The 3 rd generation as a probe for new physics.
B S Mixing at Tevatron Donatella Lucchesi University and INFN of Padova On behalf of the CDF&D0 Collaborations First Workshop on Theory, Phenomenology.

B S Mixing at Tevatron Donatella Lucchesi University and INFN of Padova On behalf of the CDF&D0 Collaborations First Workshop on Theory, Phenomenology.
Heavy charged gauge boson, W’, search at Hadron Colliders YuChul Yang (Kyungpook National University) (PPP9, NCU, Taiwan, June 04, 2011) June04, 2011,

Heavy charged gauge boson, W’, search at Hadron Colliders YuChul Yang (Kyungpook National University) (PPP9, NCU, Taiwan, June 04, 2011) June04, 2011,
Alexander Khanov 25 April 2003 DIS’03, St.Petersburg 1 Recent B Physics results from DØ The B Physics program in D Ø Run II Current analyses – First results.

Alexander Khanov 25 April 2003 DIS’03, St.Petersburg 1 Recent B Physics results from DØ The B Physics program in D Ø Run II Current analyses – First results.
W properties AT CDF J. E. Garcia INFN Pisa. Outline Corfu Summer Institute Corfu Summer Institute September 10 th 2 1.CDF detector 2.W cross section measurements.

W properties AT CDF J. E. Garcia INFN Pisa. Outline Corfu Summer Institute Corfu Summer Institute September 10 th 2 1.CDF detector 2.W cross section measurements.

Similar presentations

Ads by Google