The Weak Interaction: A Drama in Many Acts

Transcription

1 Th Wak Intraction: A Drama in Many Acts 1890 s: Rontgn discovrs rays Thought Uranium salts wr affctd by th sun but rainy Paris soon hlpd showing othrwis. 190 s: Pauli proposs To xplain continuous spctrum: only way to sav consrvation of nrgy s Parity Violation To xplain idntical proprtis of and particls. Thn clarly provn in Madam Wu s xprimnt s P-Violation

2 Parity Violation x -x p -p r p r p J J Parity Mirror Madam Wu s xprimnt: Polariz 60 o and look at th dirction of th mittd s. In a Parity-symmtric world w would s as many lctrons mittd in th dirction of J as opposit J. p p

3 Parity Violation x -x p -p r p r p J J Parity Mirror Madam Wu s xprimnt: Polariz 60 o and look at th dirction of th mittd s. But in th ral world w s only lctrons mittd in th dirction opposit J. p

4 P,,T P: x -x : particls anti-particls T: t f -t i (running th movi backwards) PT thorm: all Lorntz-invariant local fild thoris ar symmtric with rspct to PT

5 Tim-rvrsal symmtry braking in nutron bta dcay mit ollaboration NIST, Gaithrsburg P. Mumm, J. Nico, A. K. Thomson Univrsity of Washington A. Garcia, J.F. Wilkrson ( Prsntly at UN) Univrsity of Michigan T. hupp, R.L. oopr, K. oultr Tulan Univrsity. Trull, F.E. Witfldt Hamilton ollg G.L. Jons Univrsity of alifornia, Brkly/ LBL S.J. Frdman, B.K. Fujikawa

6 L L A i f L L V i f H 5 5 Rsulting dcay rat: Standard Modl Intraction at low nrgis: E p E p D E p B E p A J J E m b E p E p a dw dw sin D Snsitiv to a phas btwn th axial and vctor (or T and S) currnts

7 hapr than sarchs at Bll ( ) or Babar ($$$), mit is a `null xprimnt. Modl D KM phas <10-1 Thta-QD <10-14 Suprsymmtry < Lft-Right symmtry < Exotic Frmion < Lptoquark <prsnt limit ~10-3

8 Th basic ida: polarizd nutrons; dtct protons and lctrons. Som challngs: 1) Polariz/flip nutrons; ) Dtct <1 kv protons; 3) Dtct lctrons down to 90 kv with minimal backscattr; Solutions: 1) Suprmirrors (polariz n s by magntic componnt in scattring); flippr=currnt sht. ) Acclrat protons to Si dtctors (8 kv); 3) Scintillators with low thrshold and position rsolution (achivd via timing).

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11 Dvlopd a proton sourc (duo-plasm) to tst dtctor. Dtctor showd good prformanc and good signal abov nois. F. Naab t al. NIM 197, 78 (00)

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13 Proton thrshold ffct W inv ~0.01 Largly ancls in v - corrction: (-0.9±0.41)x10-4 (M and fits to spctra) thrshold variations, tc.

14 1 1, 1,, 1, a a a a a N N N N R v To xtract signal Expct numbr of coincidncs btwn a proton and bta dtctor: R D R B R A R a R p R R J D K B K A K J ak K N N. 1 1,

15 Spin transport Grad. coils 6 LiF Fluxgats High nutron flux (1.7 x 10 8 cm - s -1 at ) fission chambr.masurmnt 560 μt guid fild, monitord during run Bam profil at 3 positions via Dysprosium foil activation Polarization masurd with suprmirror analyzr flipping ratio masurmnt

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17 V factors omparison btwn data and xpctations look good

18 Anothr subtl issu: bta and proton backscattring Data at 45 dgrs

19 Rsults vrsus tim (run numbr) Th xprimnt was stabl. Rsults vrsus axial coordinat Th avrag of all ths rsults is our final valu.

20 orrctions (10-4 ) All studis compltd whil data wr still blind Sourc orrction Uncrtainty BR asymmtry uppr limit 0.30 BR subtraction Elctron Backscattring Proton Backscattring uppr limit 0.03 Bta thrshhold uniformity Proton thrshhold ffct Bam Expansion/B-fild Pol uniformity uppr limit 0.10 Asymmtric-bam/Trans. Pol (ATP) ATP twist uppr limit 0.4 Spin corrlatd flux < Spin corrlatd polarization a < Polarization (95±5%) Includd in D 0.04 K D (0.378±0.019) Includd in D 0.05 Total a Includs spin-flip tim, cycl asymmtry, and flux variation. ~ ~

21 Prvious rsults: D( 19 N) Hallin t al., Phys. Rv. Ltt. 5, 337 (1984). D( n) syst stat Lising t al., Phys. Rv. 81, 49 (000). D( n) Soldnr t al., Phys. Ltt. B581, 49 (004). D( n) syst stat Mumm t al., Phys. Rv. Ltt., in prss

22 Sarchs for Scalar and Tnsor currnts in bta dcay 3Ar With E. G. Adlbrgr, D. Mlconian, O. Tngblad, M. J. G. Borg, I. Martl 6H With A. Kncht, P. Mullr, Z.-T. Lu, O. Navillat-uncic, H. Robrtson, D. Zumwalt

23 L R S S R L S S i f L L V i f H ) ( ) ( ' ' Do ths xist? onsqunc: Intraction: E m b E p E p a dw dw 1 0 with: ' ' S S V S S V a and: ' ' R S S V S S V b

24 Dtcting Scalar currnts in wak dcays Th - corrlation dpnds strongly on th natur of th carrir (w tak a transition). spins hav to coupl to zro + Standard Modl Vctor urrnts spins Nw Physics? Scalar urrnts + momnta + dw/d= 1+ p. p /E E dw/d= 1- p. p /E E

25 A trick to avoid dtcting th nutrino 3 Ar 31 S+p 3 l Instad of dtcting th nutrino

26 A trick to avoid dtcting th nutrino 3 Ar 31 S+p 3 l Instad of dtcting th nutrino W dtct th proton that contains th info about th 3 l rcoil (Dopplr)

27 A trick to avoid dtcting th nutrino 3 Ar 31 S+p 3 l Instad of dtcting th nutrino W dtct th proton that contains th info about th 3 l rcoil (Dopplr) Mont-arlo calculation of proton nrgy vctor scalar

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29 Exprimntal st-up Supr-conducting solnoid B=3.5 Tsla

30 onsquncs for couplings

31 Sarchs for scalar currnts: still looking. From Svrinjns t al. RMP 78, 991 (006) 0.01 ( S + S )/ V ( S - S )/ V

32 Enrgy calibration with 33 Ar lins known from 3 S(p, g)

33 Thanks to Lothar Buchmann

34 Simultanous fit rquiring 33 Ar to yild width in agrmnt with 3 S(p,p) masurmnts Prliminary rsult: ã=0.9980(51)

35 Spctroscopic data that affctd th xtraction of ã Data Prcision Publication Width of 33 l(t=3/) stat 9 V P.G. Ikossi t al., Phys. Rv. Ltt. 36, 1357 (1976); J.F. Wilkrson t al. Nucl. Phys. A549, 3 (199); Mass of 3 Ar 1.8 kv K. Blaum t al., Phys. Rv. Ltt. 91, (003). Mass of rsonancs in 33 l kv M.. Pyl t al. Phys. Rv. Ltt. 88, 1501 (00); S. Triambak t al., Phys. Rv. 74, (006). Mass of 31 S 0.65 kv Wrd t al. Phys. Rv. 81, (010); A. Kankainn t al. Phys. Rv. 8, (010);

36 Futur plans: Mlconian t al. In th short trm w can improv dtrmination of a in 3Ar by a factor of 5! This dvic can b usd in FRIB as a spctroscopic tool to dtrmin particl branchs with high prcision.

37 L R T T R L T T i f L L A i f H ) ( ) ( ' ' 5 5 E m b E p E p a dw dw 1 0 Dcay rat: ' ' 3 1 T T A T T A a ' ' R T T A T T A b Intraction for GT transitions

38 Sarching for tnsor currnts in 6 H: Littl a H Intns & stabl sourc Simpl dcay Light nuclus Larg ndpoint (3.5 MV) Li Nd to dtct 6 Li rcoil with kintic E=1- kv. Not possibl by implantation Solution: can us optical (MOT, dipol) traps.

39 Production of 6 H at ENPA Now hav a rliabl sourc of 6 H yilding 10 9 atoms/s in a clan room! A. Kncht t al. submittd to NIM.

40 Liftim of 6 H and ga Two prvious xprimnts disagr by 9 ms Togthr with nutron and 3 H shd light on ga rnormalization by using ab initio (Wiringa t al. s) calculations. Good grounds for bginning studnts to train on data analysis issus. Hav alrady takn data that narrow statistical uncrtainty to bttr than 0.1 ms!

41 Trapping of 6 H RF discharg in xnon/krypton to xcit into mtastabl stat ycling on 1083 nm transition to transvrsly cool, slow down and trap magnto-optically Trappd atoms transfrrd to dtction chambr with dipol trap Basd on xprinc from 6 H, 8 H charg radius masurmnts by ANL collaborators: L.-B. Wang t al., PRL 93, (004) P. Mullr t al., PRL 99, 5501 (007)

42 6 H Littl a, dtction Elctron and 6 Li rcoil nuclus dtctd in coincidnc E-E scintillator systm for lctron dtction (nrgy, start of tim-of-flight) Micro-channl plat dtctor for dtction of rcoil nuclus (position, tim-of-flight)

43 6H: masuring th spctrum in sarch of th `Firz intrfrnc Us TP to Idntify backscattring Vto non-containd vnts, backgrounds, Obliqu-incidnc vnts alibration of lin shaps vry important. Follow Tsung, Kaspar, Tolich, arxiv: v1: Us 1 (p,p ) to gnrat 4.4 MV photons an thn scattr in TP to gnrat ompton lctrons. Ongoing simulations to undrstand th limits of our mthods

44 Lasr trapping of 6H at ENPA should start this yar!

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