New Muon Lifetime and the Fermi Coupling Constant G F. Kevin Giovanetti James Madison University

Transcription

1 Nw Muon Liftim and th Frmi Coupling Constant G F Kvin Giovantti Jams Madison Univrsity HallC mting, JLAB, Aug 10, 007

2 a µ = g µ / Prcision FUNDAMENTAL Muon Phyiscs SYMMETRIES Prcision Masurmnts of Standard Modl Proprtis Th Of all wak th rcnt mixing muon angl xprimnts, θ W, paramtrizs th masurmnt th mixing of th btwn Th muonfrmi anomalous nutral constant, magntic SU G L F and momnt,, masurd U1 a Y µ =g gaug via µ -/ th bosons by µ xprimnt liftim in th High Standard will E81 b at Elctrowak prcision improvd BNL Modl. stands lctrowak It by out is, Prcision a both arguably, factor xprimntally xprimnts of Masurmnts 0 th at most PSI. and important provid That thortically. stringnt paramtr tsts in is usd lctrowak of th to Standard normaliz physics. Modl all Whn wak SM chargd combind at th currnt tr with and quantum That masurmnt prcision and most loop masurmnts wak lvls. was statistics limitd and could b furthr nutral currnt of a, Gamplituds. F th Frmi It constant is also improvd. Indd, an upgrad proposal by th collaboration and minstrumntal outlins Z, it can a plan b usd for to rduc comparison to prob th rror quantum with in by and a loop about othr corrctions factor prcision of. from havy lctrowak frmions, masurmnts. th Higgs scalar, and various nw physics ffcts. HallC mting, JLAB, Aug 10, 007

3 a µ = g µ / Prcision FUNDAMENTAL Muon Phyiscs SYMMETRIES MUONS PSI TRIUMF BNL FNAL? Michl parm ρ, δ, η, P µ ξ Liftim G F 1 ppm µ p captur Λ S -> g P µ d captur L1A g- SUSY, BSM µa->a LFV, BSM HallC mting, JLAB, Aug 10, 007

4 MUON Physics Physical Rviw Lttrs, 0 July 007,Volum 99, Numbr 3 Improvd Masurmnt of th Positiv-Muon Liftim and Dtrmination of th Frmi Constant D. B. Chitwood t al. MuLan Collaboration Publishd 16 July 007 Masurmnt of th Muon Captur Rat in Hydrogn Gas and Dtrmination of th Proton's Psudoscalar Coupling gp V. A. Andrv t al. MuCap Collaboration Publishd 16 July Elctrowak Radiativ Corrctions to Muon Captur Andrzj Czarncki, William J. Marciano, and Albrto Sirlin Publishd 16 July HallC mting, JLAB, Aug 10, 007

5 Standard Modl Elctrowak Intraction 4 paramtrs g U1 g SU M H Higgs v xpctation valu of th Higgs fild α G F M z M H Fin structur constant Frmi coupling constant Mass of th Z boson Higgs mass ppm ppm ppm constraind m i masss of quarks and lptons 1 CKM quark mass mixing matrix, [Cabbibo] Kobayashi-Maskawa 4 MKS mass matrix for nutrinos, Maki-Nakagawa-Sakata matrix 4 Cosmological Constant 1 QCD Coupling 1 6 dimnsionlss constants for standard modl Ritnbrgn and Stuart, Nucl. Phys. B PDG, Particl Data Group

6 Elctrowak Intraction = = µ ν ν µ ν ν β µ αβ α β µ α α αβ α u u M g u u g L u u M k M k k g u u g L W W W W W ν µ ν µ W µ ν µ ν µ ν ν µ = µ ν ν β µ α u u u u G L F F

7 Frmi Coupling constant G m 5 F µ 5 1 µ = 1 τ 19 π 3 τ δ ν µ µ ν ν µ G F g = M W r µ W Z 0 ν Th thortical uncrtainty on G F as xtractd from th muon liftim is < 0.3 ppm.

8 ELctrowak Basic paramtrs [006].g. PDG Standard Modl Elctrowak Intraction α G F M z Fin structur constant Frmi coupling constant Bfor currnt ffort Mass of th Z boson ppm ppm ppm δg G F F = 1 δτ τ 5 δm m µ µ 1 δ 1 q 1 q 9 ppm 0.08 ppm 0.3 ppm

9 MuLan Collaboration Univrsity of Illinois at Urbana Champaign UIUC Boston Univrsity BU Univrsity of California, Brkly UCB and LBNL Univrsity of Kntucky, Lxington TRIUMF, Vancouvr Jams Madison Univrsity, JMU KVI Groningn, Nthrlands HallC mting, Istanbul JLAB, Tchnical Aug 10, Univrsity, 007 Turky

10 HallC mting, JLAB, Aug 10, 007

11 Th xprimntal concpt Ral datakickr On Numbr log scal Masurmnt Priod Fill Priod tim -1.5 kv 1.5 kv

12 Rats 1ppm rquirs at last 10 1 obsrvd dcays Probability for a st of masurmnts t 1, t, dp t1, t... τ = ρ t1 τ ρ t τ... dt1dt... Probability that a paramtr has a valu basd on t1, t, L τ t, t... = ρ t1 τ ρ t 1 τ

13 Rats and Uncrtainty For a simpl distribution on can find th valu for τ that mak th xprimntal rsult highly probabl and stimat th uncrtainty. sam rsult from fitting N t t t d t t dl t , 1 1 = = = τ τ ρ τ τ τ N N dt τ τ τ ρ ρ τ = = 1 1

14 Uncrtainty with Background Assum masurmnt priod of 10τ

15 Uncrtainty Uncrtainty is incrasd du to nw trms in th distribution Liftim is distortd du to an incorrct distribution Th avrag is no longr an unbiasd stimator for th liftim whn thr is background Rduc your uncrtainty through statistics thrfor an unbiasd masurmnt of t is critical Individual prcis masurmnts ar not critical KNOW YOUR DISTRIBUTION REMOVE SYSTEMTICS

16 Rats To accumulat th statistics ncssary in a on month priod 4.0x10 5 muon dcays/sc 1 muon vry 3 µs Nd mor than 1 muon in targt at a givn tim. Granularity FAST approach Pulsd bam µlan Approach Duty facor 35 µs -total /5 µs on [factor of 7] 3x10 6 muons/sc Bam rat of a FEW MHz

17 MuLan Exprimnt at th Paul Schrrr Institut Villign, Switzrland 1.8 ma cyclotron, 590 MV protons Nutrons SINQ Swiss Light Sourc

18 π3 bamlin Surfac Muon Bam 9 MV/c Ddicatd bam studis for svral yars A Bam Rat > 11 MHz; Spot at targt, only fw cm. Sparator lavs about 5 10% positron background. Many lmnts to tun. Straight bam is tricky. Extinction fraction looks rasonabl quads kickr plats sparator Expt. 1.5 kv kv triplt slits triplt 11.3 m

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21 Subsystm #1 Quads PSI πe3 4. MV muon sourc Kickr Plats N S 10 kv 0-10 kv Kickr HV supply; 50 khz cycl tim Subsystm # Subsystm #6 Simulations: Tuns GEANT 4 t 500 MHz WFD Bank outr innr LEDs outr Systmatics Onlin DAQ and Analysis Farm Subsystm #3 Fitting Subsystm #3#4 innr Subsystm #5

22 5 kv /- 1.5 on ach plat kick, 1 cm gap, 30 khz: a gift from TRIUMF Triggr Supprssion Adjustabl Extinction ~ 1000 Accumulation Masuring Priod

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24 -sidd, soccr-ball gomtry Hx-hous Outr smallr Pnt-hous Innr largr Puls Ara outr Analog Pulss Puls Ara innr

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