- 161 Views
- Uploaded on

Download Presentation
## PowerPoint Slideshow about 'Radioactive Ion traps and High energy physics' - calder

Download Now**An Image/Link below is provided (as is) to download presentation**

Download Now

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

### Radioactive Ion traps and High energy physics

### Ion Traps: Operate at mili-KelvinLHC: operates at 7 TeV i.e at an energy Higher by 10^20!

Fun-Traps 2012- and the “Higgs” discovery at the LHC

IT see 10^6 radioactive decays.

LHC found the O( 100) Higgs decay events after ~ 10^15 pp collisions!

A)High precision low intensity experiments vs. B) high intensity& high energy experiments

- The ultimate example of A- measuring the g-2 of the electron with a precision of 1 in 10^12 in agreement with Kinoshita’s QED calculation.

A related g-2 measurement for the muon suggests a 3 standard deviations from the QED and QCD based calculation-

indicates new particles in the triangle loop??!!

The searches for Dark matter and for proton decay or for neutrino-less double beta decays under-ground experiments - a yet different class where a signal of vey few events is expected .

An intermediate class: High intensity not so high energy

- In passing recall experiments of just high intensity: monitoring up to 10^15 decays of positive muons in order to extract G(Fermi) to high precision or to limit the branching of muon electron + gamma by 10 ^{-12}.

Also in KATRIN ~ 10^23 Tritium decays need to be monitored to extract from the endpoint spectrum sub eV neutrino masses!

Plan of talk:

- How certain rare particle decays e.g. Second class cur.

tau neutrino + pion + eta (or eta’) with rates limited by BABAR and BELL complement precision measurements of beta decay spectra in IT’s

( Based on joint works with AvnerSoffer at TAU estimating the expected SM decay rates and subsequent discussions with Danny Ashery) .

- Some comments about the new 125 GeV “ Higgs” particle discovered at the LHC .
- And finally:

Can the Higgs discovery be relevant to IT physics

Precision weak decays tests of the S.M V-A form- some general background .

- New scalar ( or pseudo-scalar) particles of mass M and with couplings g’ to e-nu(e) and to u-d quarks add S , P decay amplitudes

~ r= [g’M(W)/gM(S)]^2

this will:

a) modify beta decay spectra which IT using also nuclear recoils can measure with high precision , and

b)modify the rate or other features of certain weak decays- a stronger effect when the standard V-A amplitude for this process is supressed .

Two examples

- The small Br{pi e nu / (pi mu nu)} ~1.4 10^{-4} is measured with a precision of 4.10^{-3} [similar to the E.M. correction) follows from the SM . Hence:
- r(P)^2 < 6.10 ^{-7} ( there is NO A-P interference since the lepton trace vanishes)
- The Br{ tau pi +eta+nu } is small { estimated within the S.M. to be ~ 10^{-5} by Xiralpertrubation and by us ( AvnerSoffer and me)…

unfortunately the experimental bounds from BABAR and BELL are ~ 10^{-4} which may be a bit inferior to the IT bounds –but will greatly improve at S.B factories

Limits on New Physics

- B(t-hp-n) can be used to put bounds on new scalar interactions up to the SM expectation B(t-hp-n) ~ 10-5
- A limit B(t-hp-n) < 3 10-5 implies

for the same couplings as in the SM.

- Competitive with limits from angular distributions in nuclear b decay, ~4 (expected to improve to ~7 and then to ~15)
- The two limits are complementary:
- b-decay: 1st-generation couplings
- t-hp-n: 3rd-generation couplings

Back to the Future - the “Higgs”

- A narrow state at ~ 125 GeVwas discovered by ATLAS and CMS at the LHC BOTH in the gamma-gamma AND the Z-Z^*,W-W^* channels. Most likely it couples strongly also to the top quark.
- Most likely it is the S.M “Higgs” particle whose

main role is to generate the vector boson masses m(W) ,m(Z) and to ensure renormalize-ability .

This role can be fulfilled by a fundamental, point-like scalar particle or in dynamical schemes with composite Higgs. ( Technicolor – but…)

Is the new H(125) particle THE SM Higgs-or does it suggest new physics?

- Since NO N.P. ( new SUSY, KK, Z’, DM or any other beyond the SM particles ) have been discovered yet(!) at the LHC- this is a key for the future of HE physics…..
- An equally important related question is:

If indeed J(H)=0 is it composite or FUNDAMENTAL??

NO elementary J=0 particles have been seen - may be for a good reason….

Suggested answer : If the H has even/odd parity it is (un) likely to be FUNDAMENTAL.

The argument presented uses only the low m(H) mass relative to the scale up to which there is no N.P

The Unbearable Lightness of a Composite, Scalar H particle.(S.N &R.S)

- Assume that H is related to the EWSB then it has E.W. Charges. It then can be composed only of a fermion ( Q(i) )and an anti-fermion \bar Q(j) and a \bar Q-Q condensate generates SEW SB. The size < Q-Q(bar) > ~ (½ TeV)^3 is fixed by the W and Z masses it needs to generate.
- A DEFINITE parity is measured for the H particle.
- A non-Abelian gauge theory provides the underlying dynamics which binds and confines the new fermions and the lack of N.P at the LHC implies Lambda’ >~ ½ TeV. THEN:

The claimed result:

- The light ( relative to 2\Lambda’) H particle is extremely unlikely to be composite if it is a scalar, but can be a composite pseudo- scalar.
- Outline of arguments:
- 1) using ‘Constituent fermions” of mass O(1/2 TeV) which the \bar Q-Q condensate generates along with a smooth confining potential and the strong H.F. Interactions required to bind a 0^- S wave state to ~0, we show that 0^+ ,P wave state is NOT strongly bound.
- 2) we use the QCD mass inequalities.

QCD Inequalities-Lightening Review

- All the information in QCD is encoded in the Euclidean many point functions: <B(x) C(y) D(z) ..>= F(xyz..). In a two point function Let
- C=B^+(x)= \bar \psi(x) \Gamma(i) \ psi(x)
- with \Gamma(i) the 16 Dirac matrices When acting on the vacuum it creates all the sates with the corresponding quantum numbers : S(0^+) ,P(0^-) , V (1^-), A(1^+). The states propagate from x to y where they are annihilated back by B^+(y). Taking x-y to be imaginary Euclidean time the propagation involves a factor exp {- m (x-y) } with m the mass of the state in interest . Summing over states spectral decomposition.

QCD Inequalities Cont

- The T.P. corellatorsF(|x-y|) can be expressed as a functional integral over gauge fields A configurations weighed with exp {-S(A) } (and a determinant which also is positive for Vectorial underlying gauge theories ( Xiral G. theories will lead to H with no definite parity)
- the integrands are:

Tr(\Gamma(i) S_{A}(x,y} \Gamma(i) S_{A}(y,x) and for \Gamma(i) = \gamma(5) become the positive Tr( S^+ (x,y) S (x,y))

Final Result of inequalities:

- F_P(x-y) > all other correllators.

Using the asymptotic form we then conclude m^0 (0^-) < all other m^0(i) namely the lightest pseudo scalar is the lightest hadron.

In particular m(0^-) < m (0^+) VW theorem. But we can argue further that the scalars are indeed a LOT heavier by say 2 Lambda’ a composite light scalar is impossible. Hence

If H=scalar than it is most likely Fundamental no difficulty for a S.M Higgs due to the relatively small lambda H^4 coupling}

A Brave New Scalar World?

- Interesting consequences of just a 125 GeV SM Higgs:
- i) Possible new “Fatal” scalar attraction of top quarks not just t-t(bar) but t^N ( Bar.GenShur)
- ii) excluding 4 th heavy generation ( loop) etc.
- Q: consequences for beta Spectrain Ion Traps?
- Not for a neutral H. But In SUSY extensions two Higgs doublets give masses to the up/down sectors leaving five scalars including H^+ , H^- !

Yet S-SUSY Higgs cut no ice even in cool ion traps!

- In S.M Yukawa H couplings , proportional to the fermion masses - are tiny for the first u,d,enu(e) generation. ( The rational for a muon collider) But there could be other charged scalars with different patterns of couplings, say three Higgs doublets for the three generations…
- So who wins? Can Ion Traps be more sensitive to new charged scalars than the LHC ??

Yes , You CAN !

- If you measure via the (V-A).S Interference in the shape of spectra the amplitude of S –so as to be sensitive to r= (g’/g)^2 (M(W)/{M(S)})^2 ( #6) of 10 ^ -2 or even 10^{-3}. Take g~g’ than the reach of Ion traps is up to

M(S) = 0.8 – 2.5 TeV !

Vector contribution

- Note: B(t-p-p0nt) is large (25.5%) and completely dominated by r-contribution
- So expect r-to also dominate the vector contribution to t-hp-nt, with branching fraction

1 power from phase space,

2 from vector amplitude

Obtaining grhp Coupling

- r-hp- has not been observed, but we can obtain grhp from the Dalitz-plot distribution of h p+p-p0
- Method used by Ametller & Bramon, PRD 24, 1325 (1981)
- Now more precise data, access to more terms in Dalitz-plot distribution
- Assume the decay has 3 contributions: scalar, r+ and r-:
- (r0isforbidden due to C conservation)
- Scalar part has flat distribution in the p+p-p0 Dalitz plot, and is also the only contribution to h3p0

Expand squared amplitude to 3rd order in

- Obtain total rate relative to scalar part:
- Where

- Comparing the Y coefficients, get:
- Extract grpp from rpp width:
- So the vector contribution to B(thpn) is

Consistent w. Ametller & Bramon

Cross-checks

- The other coefficients are a test of the model:
- Compare with KLOE measurement:
- Floating arg(MS) = 15 improves agreement only slightly
- Also check ratio of BR’s::

Scalar Contribution to B(t-hp-nt)

- Chiral perturbation theory calculates assumed a0(980) is a qq state and are complicated
- We conduct a simpler estimate and arrive at a similar result:
- Vector current is conserved up to md- mu:
- We estimate the scalar matrix element by relating the P-wave states a0(980) & a1(1260):

Phase space

~1, since fixed by quark-model wave functions

BL=0 ~ 10-5

Conclusions

- Our estimates
- BL=0(t-hp-n) ~ 10-5
- BL=1(t-hp-n) 3 10-6

imply the following for the measured value of BL=0(t-hp-n):

- 3 10-6, especially with a r-(770) peak
- No surprises
- 10 10-6, especially with a a0-(980) peak
- a0-(980) is a qq state after all
- > ~30 10-6,especially with scalar dominance
- Possibly new scalar interactions, MS ~ 13 MW for weak coupling
- Note that BaBar has limit B(t-h’p-n) < 7.2 10-6
- Contributions from additional intermediate resonances

Download Presentation

Connecting to Server..