Miguel A. Sanchis-Lozano- Searching for Physics in Bottomonium Decays

8/3/2019 Miguel A. Sanchis-Lozano- Searching for Physics in Bottomonium Decays

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July 21-27, 2005

HEP2005 Conference, Lisboa

Miguel A. Sanchis-Lozano

(IFIC Valencia)

1

Searching for NNeeww Physicsin

Bottomonium Decays

Department of Theoretical Physics & IFICUniversity of Valencia CSIC

Spain


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Lepton Universality Breaking?

0.00 0.132.03 0.28 %2.03 0.08 %(2S)

0.06 0.042.64 0.16 %2.49 0.07 %(1S)

0.30 1.231.70 1.60 %1.31 0.21 %(2S)

0.12 0.082.67 0.16 %2.38 0.11 %(1S)

0.08 0.072.67 0.16 %2.48 0.06 %(1S)

0.05 0.092.51 0.26 %2.39 0.12 %(3S)

0.27 1.201.70 1.60 %1.34 0.20 %(2S)

R/BF[+-]BF[+ -]BF[e+e-]Channel: *

Four first rows: from 2004 PDG listing without recent CLEO measurements Three last rows: from new CLEO data (talk by J. Duboscq)

Statistical and systematic (conservative) errors are summed in quadrature

LU

=

=

=


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LU

R/l0.0 0.1 0.2- 0.1

All seven independent experimental measurements of R/l(nS)

R/e(1S)

R/(1S)

R/e(2S)

R/

(2S)

R/(1S)

R/(2S)

R/(3S)

0.3 1.5

Hypothesis test:Lepton universality can be rejected

at a level of significance of 5%


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(nS) s A0 ( )

Such NP contribution would be unwittingly ascribed tothe leptonic branching fraction (photon undetected!):

actually only for the tauonic decay mode

A leptonic mass dependence of the decay width would

break lepton universality. The importance of the

NP contribution can be assessed using the ratio

!

=

+=

Van Royen-Weisskopf formula

Notice that a light non-standard Higgs

boson has not been excluded by LEP

direct searches for a broad range ofmodel parameters in different scenarios

n=1,2,3 and A0 stands for a light (possibly CP-odd) Higgs particle

-

+A0

s

M1 transition

Prejudice against a light Higgs?

b intermediatestate or bb continuum"

"

Tree-level NP processtheoretically very simple!

Our conjecture to interpret a possible Lepton Universality breakdown

photon unseen!

LU

+

Key ideas:

=

=

=


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###### $!

==

###### $

!

==

A large value of tan would imply a large A0 coupling to the bottom quark but a small coupling

(i.e. small cot ) to the charm quark. Therefore, in the quest for NP effects we will focus onbottomonium decays and spectroscopy but not on charmonium

tan stands for the 2 Higgs VEVs ratio/ and v=246 GeV

*The MSSM is a particular 2HDM(II) realizationCPC: 1 CP-odd Higgs (A0)

2 CP-even Higgses

h0 =-1sin +2cos

H0= 1sin -2cos2 charged H

At tree level:

In a general 2HDM:

Coupling of fermions and the CP-odd Higgs A0

In a 2HDM of type II

CPV MSSM

Two-Higgs Doublet Model (II)*

Higgs sector

=

=

++

!!%#%

At one-loop level, MSSM with complex parameters is not CP conserving

The three Higgs neutral bosons mix together and the resulting three physical mass eigenstatesH1, H2 and H3 (MH1 < MH2 < MH3) have mixed parities

Higgs couplings to the Z boson would vary: the H1ZZ coupling can be significantly suppressed

raising the possibility of a relatively light H1 boson having evaded detection at LEP [hep-ph/0211467]

composite Higgs [hep-ph/0008192]extra dimensions: e.g. graviscalars, radions [hep-ph/9811350]

&

' +=

( ) $

'

! +=

Other scenarios

Kyle Hollingsworths CD"Never odd or even"


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Light Higgs windows at LEP (2HDM(II))

hep-ex/0408097hep-ex/0408097

Excluded (mA,mh) region independent of the CP even Higgs

mixing angle , from flavor-independent and b-taggingsearches at LEP interpreted according to a 2HDM(II)

Excluded regions in the (mA,tan) plane for different choices of .In the MSSM -/2 0 ; in a general 2HDM(II) -/2 /2


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Light Higgs windows at LEP (MSSM CPV)

hep-ex/0406057hep-ex/0406057

hep-ex/0406057

CPX MSSM 95% exclusion areas using scans with different values

of arg (At,b). The region excluded by Yukawa searches, Z-widthconstraints or decay independent searches is shown in red

CPX MSSM 95% exclusion areas using scans with different

values of the top mass

Diagram illustrating the effective coupling of a Higgsmass eigenstate H1 to the Z. Only the CP-even admixtureh and H couple to Z while the CP-odd A does not: hencethe coupling of the H1 is reduced wrt a CPC scenario.


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Next-to-Minimal Supersymmetric Standard Model (NMSSM)

Higgs sector in the NMSSM: (seven)

2 neutral CP-odd Higgs bosons (a1,2)3 neutral CP-even Higgs bosons (h1,2,3 )2 charged Higgs bosons (h)

A new singlet superfield is added to the Higgs sector:

>


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Contribution from the continuum

[ ]

)

!*

=

+

( )

(

(

+

+ =

Let us perform a perturbative calculation of the contribution from the continuum, i.e.

without formation of intermediate bound states assuming the Higgs boson off-shell

(

*

!

!

=

Numerica

lestima

tes

Rather large values of tan (are needed to obtain R ~ 10%

[ ]

+ >

#

! !

!

!

(

where the square amplitude is

and the decay width (leading term):

(nS) A0 ( )

Higgs boson on-shell

=

"

!

Wilczek formula

R=0.1

tan ~ 15

Somewhat higher values of tanfor the relativistic treatment

""

One should also consider:

Experimentally excluded region +nothing:BF < 1.3 x10-5 for MA0 < 5 GeV

[CLEO, PRD 51, 2053 (1995)]

!

+

,- !

+ B(A0 + -) 1

even for moderate tan

Eschers sky and waterImage source:

National Gallery of Canada

. !

!.

MY-MA=0.25 GeV


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Intermediate bound states

""++

"

("

"(

"

=

=

(nS) s b ( A0* (H1

*) )

""

!(

!"

= +

("

+

+

/!

For tan

We consider that a prior magnetic dipole transition of the Upsilon yields an intermediatebound state, subsequently annihilating into a lepton pair via A0 (or H1)-exchange

A cascade decay formula applies:

The NP contribution would almost saturate the b decay rateeven for moderate tan ! Direct M1 transition

Numerica

lestima

tes

Fock states

Higher Fock components beyond the heavy quark-antiquark pair can play animportant role in both production and decays of heavy quarkonium (NRQCD)

"!0

""0""

+!

(

++=

( ) ( )++ = 1"1" !

In a 2HDM(II)

$(

1" !!

!Factorization la NRQCD

M (GeV)

hep-ph/0407320

[hep-ph/9407339]

Range of tan fora given M value

++= ""0 ! replacing a gluon by a photon

Defining

"! =

Mass difference betweenthe Higgs boson and the b

Analog of a quark-antiquarkbound state

Intermediate real 0-+ state


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(nS) b0 ( ! + -)

n=2,3 ( H1 + -)

!!(!!!! "!"! ++

CPCP--even Higgs bosoneven Higgs boson

R 0.1tan ~ 15

2("

! +

!3

!!

= +

Using M=0.25 GeV, tan 15, B( b0) 3-6% (PDG) and B

as reference values,we get:

h0-mediated decay width under the assumption that sin(-) 0

i.e. non-decoupling limit: h0 couplings deviate maximally from SM

whereas the H0 becomes a SM-like Higgs:

Cascade decay viaCascade decay via b0b0 resonancesresonances

Numeric

alesti

mates

[ ]

2

!

!

!

!)*

=Normalizing the above partial width to

Again only for the tauonic modewould the NP contribution be significant

leading to lepton universality breaking!

A light CP-even Higgs boson is not excluded by LEP searches for parameter ranges of the MSSM

A CP-even Higgs boson can couple to an intermediate b0 resonance after a E1 transition of the

setting s(M) = 0.15 and |Rn(0)|2 = 1.5 GeV5 45(!

!

Available only for (2S) and (3S) resonances

Possible discrimination among differentsorts of Higgs bosons

Intermediate real 0++ state

67""

=+


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Possible spectroscopic consequences in bottomonium

Searches for b states at CLEO: No signal found!

A0-b

mixing? Mass shift yielding larger hyperfine splitting thanexpected in the SM (i.e. more than 100 MeV).

Higgs Yukawa couplings to fermions canbe affected too, allowing quite large tanfor special Higgs mass values

hep-ex/0207057

Broad b states? Widths of order 50 MeV could be expectedeven for moderate values of tan ( ~ 40)

hep-ex/0207057 hep-ex/0207057

tan

(LEP)hep-ex/0111010

Is there any point to which you would wish to draw my attention?To the curious incident of the dog in the night-time

The dog did nothing in the night-timeThat was the curious incident, remarked Sherlock Holmes

from Silver Blaze by A.C.D.

Most theoretical modelsare ruled out !

The search for b states would

eventually be a way of hunting

a light non-standard Higgs!

If b decay happens to be

saturated by theA0-mediatedchannel

b A0* + -

Drees and Hikasa,PRD 41, 1547 (1990)


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Conclusions

The simplest explanation to any problem isthe best explanation William of Ockham

Things should be as simple aspossible but not simpler A. Einstein

Keep also an eye on the related issue:

g-2 muon anomaly (which might require a CP-odd light Higgs contribution in a two-loop

calculation) but still controversial

If lepton universality is found to be (slightly) broken in Upsilon decays, the simplestexplanation would require a light non-standard mediated Higgs contribution (subsequent to

a M1 transition of the resonance) unwittingly ascribed to the tauonic decay mode

If not, those light Higgs mass windows could be closed using CLEO data!

Probably too hard a job for the LHC!

Reasonable values of tan in a 2HDM(II) are needed to yield R of order 10%

Different scenarios beyond the SM could explain (quite naturally) such a LU breaking

Further exp tests suggested: - search for soft photons in the +

-

sub-sample- polarization studies

Based on:hep-ph/0503266hep-ph/0407320hep-ph/0307313hep-ph/0210364hep-ph/0206156


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Miguel A. Sanchis-Lozano(IFIC Valencia)

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g-2 muon anomaly in a 2HDM(II)

hep-ph/0302111

The 2 allowed regions in the (mA,mh) plane due to the constraints of aand Rb for tan=40. The blue region is where the total

2 is less than 4while the yellow region is where the total 2 is less than the 2 (SM)

One.loop vertex correction

Two-loop vertex correction

h,A

h,A

f

Miguel A. Sanchis-Lozano- Searching for Physics in Bottomonium Decays

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