- 119 Views
- Uploaded on
- Presentation posted in: General

Radioactive Ion traps and High energy physics

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 - - - - - - - - - - - - - - - - - - - - - - - - - -

Radioactive Ion traps and High energy physics

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

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

IT see 10^6 radioactive decays.

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

- 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 .

- 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!

- 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

- 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 .

- 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

- 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

- 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…)

- 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

- 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 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.

- 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.

- 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))

- 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}

- 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^- !

- 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 ??

- 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 !

Backup Slides

- 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

- 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

Q mh – 3mp

Dalitz plot variables

Write vector part as:

The coupling we are after

- Expand squared amplitude to 3rd order in
- Obtain total rate relative to scalar part:
- Where

- Dalitz-plot parameters measured by KLOE (arXiv:0707.2355):

Taken to be real

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

Consistent w. Ametller & Bramon

- 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::

- 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

- 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