1. Search for New Physics with the LHCb Detector
Niels Tuning
NIKHEF/ Free University Amsterdam
On behalf of the LHCb collaboration
MIAMI2005, December 15th 2005
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

2. Outline
Let’s consider a GUT scenario and show the possibilities for the LHCb experiment…
GUT + Neutrino mixing
Predictions for bs
Signatures in LHCb
LHCb signatures:
The Box Diagram
Bs mixing: BsDs-π+
CP phase: BsJ/ψφ
The Penguin Diagram/Rare Decay
Rare decays: B(s)(K*)μμ
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

3. Grand Unified Theories
Can the large neutrino mixing angles be transferred to the hadronic sector?
GUT unifies quarks and leptons
Add reference
15 Fermions
Simplest GUT: SU(5)
Down type quarks with leptons in mulitplet:
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

4. To SUSY or not to SUSY Non-SUSY SUSY SUSY GUT vs non-SUSY GUT:
Amaldi, de Boer, Furstenau
Phys.Lett.B260(447),1991
Non-SUSY
SUSY
SUSY GUT vs non-SUSY GUT:
Unification: 3σ vs 12σ
Scale: vs 1015 GeV
τ p decay ~ MGUT4
R-parity in SUSY can prevent unwanted baryon number violation
sin2θW from SUSY in better agreement with data
Phys.Lett.B592(1),2004
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

5. The model: SUSY SO(10) Why SO(10) ?? Small extension of SU(5)
SO(10)  SU(5) x U(1)
16 = 10 +5 + 1
It nicely incorporates the right-handed ν
The see-saw mechanism “explains” small non-zero neutrino mass, and even relates MνRMGUT
It relates neutrino mixing to squark mixing!
Chang, Masiero, Murayama
Phys.Rev.D67 (075013), 2003,
hep-ph/
Barbieri, Hall Phys.Lett.B338(212),1994,
hep-ph/
Jager, Nierste
Eur.Phys.J.C33(256),2004
hep-ph/
Harnik,Larson,Murayama,Pierce
Phys.Rev.D69(094024),2004
hep-ph/
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

6. The model: SUSY SO(10) ~ Superpotential: (16 are fermions, 10 Higgses)
Chang, Masiero, Murayama
Phys.Rev.D67 (075013), 2003,
hep-ph/
YU contains the large top coupling
YU can be symmetric. In Yu diagonal basis we have:
Just as in the SM, we
rotate the d-quarks
Break to SU(5)
Break to MSSM (+rh ν):
Neutrino mixing
angle bR ~
Without neutrino mass, UMNS could be rotated away
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

7. Neutrino mixing: Super Kamiokande
Oscillation:
νμ↔ντ
CC reaction:
νμ→μ
μ-detection
Cosmic ray on
atmosphere:
π-→ e-νeνμνμ
Courtesy Univ.of Hawaii
νμ↔ντ
L/E (km/GeV)
Phys.Rev.D71:112005,2005, hep-ex/
Phys.Rev.Lett.81 (1562),1998, hep-ex/
Δm2= eV2, sin2θ23=1
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

8. Neutrino mixing  squark smixing
Consequences:
No effect in sR↔bR (i.e. CKM), because there is no right handed coupling
Observable effects in mixing between s̃↔b̃
The Box Diagram:
Bs mixing: BsDs-π+
CP phase: BsJ/ψφ LHCb
The Penguin Diagram/Rare decay:
Rare decays: B(s)(K*)μ+μ-
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

9. Size of the Box: Bs mixing (Δms)
New particles can affect the Box:
Phys.Lett.B192:245,1987
msSM  |Vts2|
Bs–Bs oscillations: “Box” diagram –
ms  |Vts+VNP|2 ?
Remember B0d oscillations:
Predicted heavy particle…
 mtop>50 GeV
Needed to break GIM cancellations
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

10. Phase of the Box: BsJ/ψφ
Δms is senstive to |A(B0B0)|
We can also probe the phase of A(B0B0)|
Interference of two diagrams
Ball et al,Phys.Rev.D69(115011),2004
hep-ph/
B0sJ/ψφ: Golden decay
Theoretically clean
sinφs = -Aηλ4/Aλ2 = -2ηλ2  -0.03
Any larger asymmetry means new physics…
New physics appears in the box, as before:
B0sJ/ψφ
|e |
i(φs + φNP ) ?
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

11. Rare decays: B(s)(K*)μ+μ-
s̃↔b̃ also appears in Penguin Diagram
Affects rare decay B0K*μ+μ- μ+ μ- s̃
Tevatron: BR <
SM: BR=
Similarly, Bsμ+μ- is very promising
SO(10) unifies fermion masses, and predicts:
 tan β = mt(MZ)/mb(MZ)~ 40-50 s μ- μ+
The “smoking gun” of SO(10) Yukawa unification...
Blazek,Dermisek,Raby
Phys.Rev.D65(115004),2002
hep-ph/
Dedes,Dreiner,Nierste
Phys.Rev.Lett.87(251804),2001
hep-ph/
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

12. Neutrino mixing  squark smixing
Consequences:
No effect in sR↔bR (i.e. CKM), because there is no right handed coupling
Observable effects in mixing between s̃↔b̃
The Box Diagram:
Bs mixing: BsDs-π+
CP phase: BsJ/ψφ LHCb
The Penguin Diagram/Rare decay:
Rare decays: B(s)(K*)μ+μ-
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

13. What is LHCb? Aim: measure CP violation and rare decays Bs mixing
pp with s =14 TeV
L = cm-2s-1
1012 b-hadrons per year
Start in July 2007
10 meter
20 meter
Aim:
measure CP violation and rare decays
Bs mixing
CKM angles α, β, γ
Small branching fractions …
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

14. Cryogenic services line
Status
LHC accelerator:
LHCb experiment :
Magnet
Muon Filter
RICH
LHC tunnel
LHC dipole
Cryogenic services line
1 December 2005
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

15. LHCb spectrometer 10-300 mrad horizontal 10-250 mrad vertical B
VELO: Vertex Locator
TT, T1, T2, T3: Tracking stations
RICH1-2: Ring Imaging Cherenkov detectors
ECAL, HCAL: Calorimeters
M1–M5: Muon stations
LHCb spectrometer
Dipole
magnet
VELO
proton beam
proton beam
collision point
mrad horizontal
mrad vertical
~1 cm B
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

16. Why LHCb? pT of B-hadron η of B-hadron High cross section LHC energy
Large acceptance
b’s produced forward
Trigger
↓ Low pT
Leptons+hadrons
Particle identification with RICH
pT of B-hadron
η of B-hadron
Tevatron
LHCb
ATLAS/CMS
√s (TeV) 2 14
σ(pp bb)(μb)
100
500
L (cm-2s-1) 2008
4.1031
2.1032
1033
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

17. Bs mixing, Δms in LHCb bt ,K Bs K K Ds  Measure B0sB0s
Need to know how B0s was produced: flavour tagging
Need to know how B0s decayed: use BsDs-π+ bt Bs K K
,K  Ds
Primary vertex
Bs→Ds-π+ (tagged as Bs)
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

18. Bs mixing, Δms in LHCb
BsDs-+ proper time resolution τ ~ 40 fs
Measurement of ms is one of the first physics goals
Expect 80k Bs  Ds-π+ events per year (2 fb–1)
Excellent proper time resolution is vital:
Average τ ~ 40 fs
5σ observation for Δms=20 ps-1:
Tevatron fb–1 all years?
ATLAS/CMS fb– years
LHCb 1/4 fb– months
Standard Model: ps-1 UT fit
Present experimental limit: >14.5 ps-1 Tevatron
5σ observation in 1 year: <68 ps LHCb
 5 observation of Bs oscillations for ms < 68 ps–1 with 2 fb–1
Prediction for Δms from UT fit:
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

19. Phase: BsJ/ψφ in LHCb - + A = CP odd & A0,|| = CP even B0sJ/ψφ:
Dunietz et al,
Phys.Rev.D63(114015),2001
hep-ph/
A = CP odd & A0,|| = CP even
B0sJ/ψφ:
Theoretically clean and experimentally easy:
J/ψ→µµ : trigger
J/ψ(µµ)φ(KK): 4 charged tracks
Annual yield: 120k events, S/B~3
But need angular analysis
Final state contains a mixture of CP-odd and CP-even
Fit for sin fs, DGs and CP-odd fraction
(needs external ms) + -
~1-cos2θ
~1+cos2θ
 cos(θ)
BsJ/ψφ (Bs tagged)
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning
 Proper time τ (ps)

20. Rare Decays: B(s)(K*)μ+μ- in LHCb
Thesis P.Koppenburg
Hurth, Rev.Mod.Phys.75(1159),
2003. hep-ph/
B0K*μ+μ-
Annual yield: 4400 events, S/B~3
BR(BK*μ+μ- )~
Sign for new physics: FB-asymmetry
Theory
LHCb
Bsμ+μ-
Maybe LHCb first hot result!
BR(Bsμ+μ- )~ : 30 evts/year
Background estimate difficult:
Generate 107 (b→μ, b→μ)-events
0 events pass selection
But in 1 year we have 1010 (b→μ, b→μ)…
(mμμ)2
(mμμ/mB)2
LHCb Bsμ+μ- mass resolution:
Exclude BR> with 8 fb-1
CDF+D0
R.Bernhard et al
hep-ex/
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

21. So, what do we have: Bs  Ds-π+ Bs→J/ψφ: B0→K*μ+μ- Bs→μ+μ- μ+ μ- s μ+
Additional contribution in box diagram
80k events per year
proper time resolution is excellent τ ~ 40 fs
Bs→J/ψφ:
Additional phase in box diagram
120k events per year
Theoretically clean and experimentally easy
B0→K*μ+μ-
Annual yield: 4400 events, S/B~3
Sign for new physics: FB-asymmetry
Bs→μ+μ-
Annual yield: 30 evts/year
Very sensitive to new physics μ+ μ- s̃ s μ+ μ-
CP: CKM angles
angle γ (Bs→DsK, B→D0K*, B(s)→ππ/KK)
angle α (B→πππ)
angle β (B→J/ψKs B→φKs,…)
BR(B→K*γ), Bc, …, …
Many other things…
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

22. Summary + = νµντ mixing SO(10) GUT Observable effect in LHCb
Neutrino mixing, combined with SO(10) GUT, predicts visible effects in LHCb:
The Box Diagram
Bs mixing: BsDs-π+
CP phase: BsJ/ψφ
The Penguin Diagram/Rare Decay
Rare decays: B(s)(K*)μμ + =
νµντ mixing
SO(10) GUT
Observable effect in LHCb
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

23. Backup Slides
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

24. bsγ Experimental constraints Example: mg~200 GeV, mR3~1200 GeV:
BR(bsγ)SM = (3.6±0.3) 10-4
BR(bsγ)exp = (3.3±0.3) 10-4
BR(BK*γ)exp = (4.01±0.20) 10-5
It is possible to increase Δms, given BR(bsγ):
Example: mg~200 GeV, mR3~1200 GeV:
BR(bsγ) : +16%
Δms : 30 ps-1
sin2β B→φKs : -0.5
Harnik,Larson,Murayama
Phys.Rev.D69(094024),2004
hep-ph/
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

25. SM vs MSSM: Bsμ+μ- SM MSSM Tevatron excluded MSSM parameter scan:
A.Dedes, Mod.Phys.Lett.A18(2627),2003,
hep-ph/
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

26. B0Xsμμ μ BR(B0Xsμμ) well measured Additional handle: FB-asymmetry
Annual yield: 4400 events, S/B~3 μ
Ali et al
Phys.Rev.D61(074024),2000,
hep-ph/
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

27. Comparison to other experiments
GENERAL
Tevatron
LHCb
ATLAS/CMS
√s (TeV) 2 14
σ(pp bb)(μb)
100
500
L (cm-2s-1) 2008
4.1031
2.1032
1033
BsDsπ
Tevatron
LHCb
ATLAS
Mass resolution (MeV) 20 14 46
τ resolution (fs)
100 40
Tagging εD2 (%)
1.4 6 4
L (fb-1)
0.4 2 30
years 1 3
900
80k 8k
S/B
>1
Numbers obtained from various presentations in the last year
No explicit blessing, just implicit...
Bsμμ
Tevatron
LHCb
ATLAS
CMS
PTμ min (trigger) 2
1.2 6 3
L (fb-1) 10
Mass resolution (MeV) 90 18 80 46
Bsμμ / year 1 30 9 7
background / year 4
<100
<20
<1
BsJ/ψφ
Tevatron
LHCb
ATLAS
CMS
L (fb-1)
0.260 2 30 10
years - 1 3
203
120k
300k
50k
S/B ~2
σ(sinφs)
0.06
0.04
0.028
<7.10-9
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

28. SU(5): The simplest GUT The simplest GUT is SU(5) Structure:
24 gauge bosons
8 gluons
4 W,Z,γ
12 bosons
3 coloured Y (q=-1/3)
3 coloured X (q=-4/3)
X,Y sometimes called leptoquarks or Higgs triplets
B, L violated, but B-L conserved
24 Bosons
Structure:
Fermions: 10 +5
5 = ( 1,2) + (3,1)
10 = ( 1,1) + (3,1) + ( 3,2)
Add reference
15 Fermions
Note:
From5 follows: qd=1/3 qe
From 10 follows: qu=-2 qd
Relation between charge and color
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

29. GUT: Proton decay… p π0 e+ mp=935 MeV Super-Kamiokande limits:
Data
Proton Decay MC
mp=935 MeV
Super-Kamiokande limits:
τp> years
Corresponding to <1 kg of the earth
Phys.Rev.Lett.81 (3319) 1998, hep-ex/
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

30. SO(10) 1
SO(10)  SU(5) x U(1)
16 = 10 +5 + 1
Fermions: 10=[Q,uc,ec] 5 = [dc,L] 1 = νR
Multiplets like: (srR,sbR,sgR,νμL,μL) and (brR,bbR,bgR,ντL,τL) 10
So, SO(10)…
… unifies all fermions in 1 multiplet
… breaks simply to the Standard Model
… explains bizarre charge assignments
… obtains unification (in its supersymmetric version)
… accomodates p decay bounds (due to big MGUT)
… includes the right-handed neutrino
SU(5)
Question:
What does the presence of the right-handed neutrino imply, given the neutrino mixing? 5
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

31. The model: SUSY SO(10) Why SO(10) ?? Small extension of SU(5)
SO(10)  SU(5) x U(1)
16 = 10 +5 + 1
It nicely incorporates the right-handed ν
The see-saw mechanism “explains” small non-zero neutrino mass, and even relates MνRMGUT
It relates neutrino mixing to squark mixing
Superpotential: (16 are fermions, 10 Higgses)
YU contains the large top coupling
YU can be symmetric. In Yu diagonal basis we have:
Break to SU(5):
Break to MSSM (+rh ν):
Hu, Hd …
vu/vd=tanβ
Neutrino mixing
angle bR
Chang, Masiero, Murayama
Phys.Rev.D67 (075013), 2003,
hep-ph/
Without neutrino mass, UMNS could be rotated away
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

32. S0(10) and see-saw So SO(10) … …contains the right handed neutrino
Its mass arrises naturally through the see-saw mechanism
MνR ~v2/mν
MνR = (246 GeV)2/0.05eV =1015GeV
GUT scale: 1015 GeV
 coincedence?
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

33. Neutrino masses: seesaw
Dirac masses:
Majorana mass for right-handed ν:
ν =ν
From neutrino mixing:
Relation between
mν, MEW, MGUT …
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

34. Neutrino mixing: SNO 8B →νe νe→νμτ MSW oscillations:
Δm2= eV2, tan2θ12=0.45
Δm2= eV2, tan2θ12=0.34
SNO Coll., Q.R. Ahmad et al.
Phys.Rev.Lett.89 (011302),2002,
nucl-ex/
SNO Coll., Q.R. Ahmad et al.
Phys.Rev.Lett.89 (011302),2002,
nucl-ex/ , nucl-ex/
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

35. EDM of the Neutron Larmor spin Precession
Standard Model: dn<10-31 e cm
A nonzero value is forbidden by P- and T-invariance
SUSY: dn<10-25 e cm
Larmor spin Precession
Laboratory
Limit
year
ILL
<
‘90
PNPI
<
‘96
<
‘99
<
‘04
PSI
<
‘05
LANL,ILL
<
’10?
Phys.Rev.Lett.82(907),1999
J.Ellis, Nucl.Instrum.Meth.A284(33),1989
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

36. µ→e γ BR(µ→e γ)SM=0 Experimental Limit (MEG Coll. At PSI)
J.Hisano et al.,Phys. Lett. B391 (1997) 341
R. Barbieri et al.,Nucl. Phys. B445(1995) 215
Experimental Limit (MEG Coll. At PSI)
BR(µ→e γ)<
BR(µ→e γ)SM=0
SU(5) with right-handed neutrinos
Experimental Bound
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

37. Not only SUSY can cause observable effects…
Composing new models which seek to explain the observed
hierarchy of masses and the CKM matrix is a cottage industry,
with very fruitful discussions between theory and experiment…
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

38. B mixing Probability that B0 decays asB0, or B0 : P(B0 B0) P(B0B0)
Decay probability
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

39. CKM
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

40. Computing Dmd: Mixing Diagrams
GIM(i.e. VCKM unitarity):
if u,c,t same mass,
everything cancels!
Highly non-trivial calculation. Eta_B is a QCD factor~0.55. The decay constant f_B ~ 175 MeV , the bag factor B_B~1.3
Dominated by top quark mass:
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

41. LHCb yields and background
Nominal year = 1012 bb pairs produced (107 s at L=21032 cm2s1 with bb=500 b)
Yields include factor 2 from CP-conjugated decays
Branching ratios from PDG or SM predictions
R.Forty, CKM 2005
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning

42. Baryon Asssymetry Leptogenesis Baryogenesis through sphaleron
Buchmüller, Wyler
Phys.Lett.B521 (291),2001
hep-ph/
Leptogenesis
Baryogenesis through sphaleron
15 Dec 2005
Search for New Physics with the LHCb detector - MIAMI Niels Tuning