Download presentation

Presentation is loading. Please wait.

Published byScott Poppy Modified over 2 years ago

1
Result of T-violating Muon Polarization Measurement in the K + → 0 + Decay C. Rangacharyulu Saskatoon, SK for the KEK-E246 collaboration June 7, ‘04 DAPHNE-04 Transverse muon polarization E246 experiment Analysis Result of the total data

2
E246 collaboration Japan ● KEK ● Univ. of Tsukuba, ● Tokyo Institute of Technology ● Univ. of Tokyo ● Osaka Univ. Russia ● Institute for Nuclear Research Canada ● TRIUMF ● Univ. of British Columbia ● Univ. of Saskatchewan ● Univ. of Montreal Korea ● Yonsei Univ. ● Korea Univ. U.S.A. ● Virginia Polytech Institute ● Princeton Univ. Taiwan ● National Taiwan Univ.

3
Transverse Muon Polarization in K + → 0 + K 3 decay form factors and T violation History of K 3 transverse polarization experiments K L → − + Bevatron 1967 Im = -0.02 ±0.08 K L → − + Argonne 1973 Im = -0.085 ±0.064 K L → − + BNL-AGS 1980 Im = 0.009 ±0.030 K + → 0 + BNL-AGS 1983 Im = -0.016 ±0.025

4
KEK E246 experiment ■ Stopped K + experiment with a SC toroidal spectrometer ■ Measurement of all decay kinematics directions –Double ratio measurement with small systematic errors Features History ■ 1992-1995 : detector construction ■ 1996-2000 : data taking ■ 1999 : first result published with 1/4 of data Im = -0.023 ± 0.007(stat) ± 0.003(syst) [M.Abe et al., Phys.Rev.Lett. 83(1999) 4253] ■ 2001-2003 : analysis ■ 2004 (this conference) : report of the final result Byproducts ■ K + → P T = -0.0064 ± 0.0185(stat) ± 0.0010(syst) [V.Anisimovsky et al., Phys.Lett. B562 (2003) 166] ■ e3 e4

5
E246 experimental setup End viewSide view [J.Macdonald et al.; NIM A506 (2003) 60] K + → 0 +

6
Muon polarimeter Cross section One-sector view y(cm)

7
CsI(Tl) and kinematics CsI barrel fwd and bwd 0 / P T directions fwd - bwd - Double ratio measurement

8
Experimental data K + 3 event selection e + time spectra CsI(Tl) analysis : TOF analysis Momentum analysis e + time spectrum

9
Two independent analyses ■ Two analyses by two teams with their own analysis policy and event selection methods Comparison of good K 3 event e.g. :1998 2 events 1 events A2 1221 k 1264 k A1 918 k 909 k ■ Combination of the two analyses by resorting of events to 6 data sets — A1 A2 A1 A2 A1 A2 — 22 11 Merits of two analysis method Cross check of data quality by A 0, decay plane rotation r and z and P T Comparison of sensitivity by normal asymmetry A N and Check of data quality in e.g. A1 by comparing A1 A2 and A1 A2-bar Estimate of systematic error by comparing of A1 A 2 from A1 and A2 Improvement of statistical error

10
Data quality check Null asymmetry check A 0 =[(N cw /N ccw ) total -1]/2 Sensitivity check A N =(A left - A right )/2 A left = [(N cw /N ccw ) left -1]/2 A right = [(N cw /N ccw ) right -1]/2 total = fwd + bwd 6 data sets for each period Open circles are 2 events and dots are 1 events. Null asymmetry is canceled by double ratio ( fwd-bwd ).

11
Result P T = - 0.0017 ± 0.0023(stat) ± 0.0011(syst) ( |P T | < 0.0050 : 90% C.L. ) Im = - 0.0053± 0.0071(stat) ± 0.0036(syst) ( |Im | <0.016 : 90% C.L. )

12
Systematics check ● =1996-1997; o=1998; ★ =1999-2000 Im = -0.0053±0.0071 d.o.f ● = 2 ; o =1 ; Consistency among data Sector dependence Decay plane rotation r (fwd)- r (bwd) ≤ 4.6×10 -4 rad z (fwd)- z (bwd) ≤ 2.6×10 -4 rad

13
Systematic errors Source of Error 12fwd/bwd P T x 10 4 e + counter r-rotationxo0.5 e + counter z-rotationxo0.2 e + counter f-offsetxo2.8 e + counter r-offsetoo<0.1 e + counter z-offsetoo<0.1 + counter f-offsetxo<0.1 MWPC -offset (C4)xo2.0 CsI misalignmentoo1.6 B offset ( )xo3.0 B rotation ( x )xo0.4 B rotation ( z )xx5.3 K + stopping distributionoo<3.0 + multiple scatteringxx 7.1 Decay plane rotation ( r )xo1.2 Decay plane rotation ( z )xx0.7 K 2 DIF backgroundxo0.6 K + DIF backgroundox< 1.9 Analysis--4.0 Total<11.4 12 : 12-fold rotational cancellation fwd/bwd : 0 forward/backward cancellation

14
Model implications L = (2√(2)G F ) 1/2 [ i U L KM D D R + i U R M U KD L + i N L M E E R ] H i + + h.c. Im = Im( 1 1 * ) × ( v 2 / v 3 ) 2 × (m K / m H + ) 2 = Im( 1 1 * ) × (m K / m H + ) 2 v i : vacuum expectation values i, i, i : mixing matrix elements Three Higgs doublet model |Im | < 0.016 (90% C.L.) ⇒ Im( 1 1 * ) < 544 (at m H =m Z ) cf. BR (B→X ) ⇒ Im( 1 1 * ) < 1900 (at m H =m Z ) Neutron EDM in 3HD model d n ≈ 4/3 d d ∝ Im( 1 1 * ) × m d / m H 2 v 2 / v 3 = m t /m [R.Garisto and G.Kane, Phys. Rev. D44 (1991)2789 ] |Im | < 0.016 (90% C.L.) ⇒ d n < 9 × 10 -27 e cm cf. d n exp < 6.3 × 10 -26 e cm −

15
Summary ■ Transverse muon polarization in K + → 0 + decay is a good probe of CP violation beyond the standard model. ■ The final result of the KEK-E246 experiment showed no evidence for T violation with Im = - 0.0053± 0.0071(stat) ± 0.0036(syst), or |Im | <0.016 (90% C.L. ). ■ This limit constrains the parameters of some non-standard CP violation models with high sensitivity. ■ We are going to propose a next generation P T experiment at the high intensity accelerator J-PARC.

Similar presentations

OK

Deuteron polarimetry from 1.0 to 1.5 GeV/c Ed Stephenson, IUCF EDM discussion April 14, 2006 Based on work from: France:POMME B. Bonin et al. Nucl. Inst.

Deuteron polarimetry from 1.0 to 1.5 GeV/c Ed Stephenson, IUCF EDM discussion April 14, 2006 Based on work from: France:POMME B. Bonin et al. Nucl. Inst.

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on wireless network sensor Download ppt on emerging modes of business Ppt on water activity meter View my ppt online training Ppt on digital media broadcasting korea Ppt on online shopping cart project Run ppt on ipad Ppt on id ego superego theory Ppt on class c power amplifier Ppt on hydro power plant in india