Neut rino Propert ies Which Probe Physics Beyond t he St andard - PowerPoint PPT Presentation

Neut rino Propert ies Which Probe Physics Beyond t he St andard Model A.B. Balant ekin Universit y of Wisconsin Hawaii05 Double Beta Decay and Neutrino Mass Workshop

Neut rino Magnet ic Moment 1 = ψ σ β + ε γ ψ + αβ ( ) . . L F h c αβ int j 5 ij ij i 2 µ ≡ β − ε ij ij ij ∑ ∑ − µ ν = µ 2 iE L 2 ( , , ) | ν | L E U e ν ν l li ij j i

Neut rino mixing: ν f 〉 = ∑ i U f i ν i 〉 Magnet ic moment operat or: µ σ ∝ ∑ i 〈ν i  µν e 〉  2 = 〈ν e µ t µν e 〉 Dirac magnet ic moment : µ t = µ Maj orana magnet ic moment : µ T = - µ diagonal Dirac magnet ic moment

Neut rino Magnet ic Moment Symmet ry Principles ⇒ µ ν ∝ m ν St andard Model

Combined solar, react or, and at mospheric experiment s imply a def init e limit on neut rino magnet ic moment µ ≥ (4 x 10 -20 ) µ B

Physical Processes wit h a Neut rino Magnet ic Moment ν -e scat t ering Spin-f lavor precession Plasmon decay Neut rino decay

weak magnet ic g v = 2 sin 2 θ W + 1/ 2 +1/ 2 f or elect ron neut rinos g A = -1/ 2 f or elect ron ant ineut rinos

µ ν =10 -10 µ B elect roweak µ ν =10 -11 µ B µ ν =10 -12 µ B

addit ional µ ν < 10 -10 µ B µ ν =10 -10 µ B weak only SuperK: µ ν ≤ (3.6 x 10 -10 ) µ B at 90%C.L. SuperK + KamLAND: µ ν ≤ (1.1 x 10 -10 ) µ B at 90%C.L.

MUNU React or Experiment f or magnet ic moment µ ν = 9 x 10 -11 µ B µ ν < 9 x 10 -11 µ B at 90% C.L. weak only

Bet a-beams? Fut ure possibilit ies? SNS ?

Observat ional limit s on µ ν ν R ’s are produced in magnet ic moment scat t ering • Core-collapse supernovae: • Early Universe: Morgan. Dirac ν R increase t he Lat t imer and Cooperst ein; Barbieri and Mohapat ra. I f ef f ect ive degr ees of µ ν is suf f icient ly large t he f reedom alt ering neut rino prot o-neut ron st ar can count ing t hrough big-bang cool f ast er since right - nucleosynt hesis yields. handed component s are (Not so f or t he Maj orana st erile. µ ≥ 10 -12 µ B would be case since ant ipart icles are inconsist ent wit h t he already count ed). observed cooling t ime of SN1987A.

Bound f rom t he red-giant st ars (Raf f elt ) A large enough neut rino magnet ic moment implies enhanced plasmon decay rat e: γ→νν . Since t he neut rinos f reely escape t he st ar t his is t urn cools a red giant st ar f ast er delaying helium ignit ion. µ ν = (3 x 10 -12 ) µ B

Balant ekin, Loret i, Pakvasa, Raghavan. Spin-f lavor precession changes neut rino helicit y. I f t he neut rinos are of Maj orana t ype t his yields a solar ant ineut rino f lux. Kamland and SNO bounds on solar ant ineut rino f lux: ϕ ant ineut rino ≤ 3 x 10 -4 ϕ B8-neut rino

Spin-f lavor precession Dirac neut rinos

Maj orana neut rinos

Locat ions of t he SFP and MSW resonances in t he sun

f or t he limit ing case of N n = 0, one get s A.B. Balant ekin and C. Volpe, Phys. Rev. D72, 033008 (2005)

Solar magnet ic f ields 10 8 G. • St andard Solar Model requires B < 10 7 G, sound speed prof ile • Helioseismology: I f B > would deviat e f rom t he observed values Turck- Chieze. • Solar neut rino f lux variat ions wit h heliographic lat it ude may imply magnet ic f ields Caldwell.

P=0.1 P=0.9 Dirac Maj orana Cl-det ect or Ga-det ect or A.B. Balant ekin, P. Hat chell, F. Loret i, Phys. Rev. D41, 3583 (1990)

SNO Salt Result s , Balant ekin and Yuksel, PRD 68, 113002 (2003)

Af t er t he recent KamLAND result s announced at NEUTRI NO2004 Balant ekin, et al., PLB 613, 61 (2005)

• µ = 10 -11 µ B • B = 10 5 G • δ m 2 = 8 x 10 -5 eV 2 • t an 2 θ = 0.4 For t hese paramet ers t he dif f erence bet ween MSW only and SFP+MSW is less t han 10 -5 . A.B. Balant ekin and C. Volpe, Phys. Rev. D72, 033008 (2005)

Conclusions • Neut rino magnet ic moment is known t o be in t he range (9 x 10 -11 ) µ B ≥ µ ≥ (4 x 10 -20 ) µ B The widt h of t his range represent s physics beyond t he st andard model. • The ef f ect of µ ν on solar neut rino f lux is miniscule. Even a f ield as large as 10 5 G and magnet ic moment 10 -11 µ B would change t he observed solar neut rino f lux in part per 10 5 .