Beyond SM and Heavy Flavor Physics Results from Tevatron - - PowerPoint PPT Presentation

▶
beyond sm and heavy flavor physics results from tevatron
SMART_READER_LITE
LIVE PREVIEW

Beyond SM and Heavy Flavor Physics Results from Tevatron - - PowerPoint PPT Presentation

Feb 26, 2024 198 likes •592 views

Beyond SM and Heavy Flavor Physics Results from Tevatron Introduction Collider experiments support a synergy between exotics searches and heavy flavor physics in their quest for physics Beyond Standard Model. Exotics searches exploit

slide-1
SLIDE 1

Beyond SM and Heavy Flavor Physics Results from Tevatron

slide-2
SLIDE 2

Introduction

  • Collider experiments support a synergy between exotics

searches and heavy flavor physics in their quest for physics Beyond Standard Model.

  • Exotics searches exploit direct production of new states of

matter / couplings which can manifest themselves as excesses over expected backgrounds.

  • Heavy Flavor analyses probe higher energy scales

indirectly through exploration of effects of virtual massive particles that could alter the phenomenology of SM

  • processes. In absence of NP, they provide precision

measurement of SM fundamental parameters (e.g. CKM couplings...)

June 1, 2011 2

  • S. Behari, Tevatron BSM and HF Results
slide-3
SLIDE 3

Contents of this talk

slide-4
SLIDE 4

June 1, 2011 4

  • S. Behari, Tevatron BSM and HF Results

Exotic Searches

Medieval pilgrim exploring the Extra Dimension!

slide-5
SLIDE 5

June 1, 2011 5

Motivation for Extra Dimensions (ED)

  • L. Randall, R. Sundrum,
  • Phys. Rev. Lett. 83, 3370 (1999)
  • S. Behari, Tevatron BSM and HF Results
  • A fundamental (hierarchy) problem in Standard Model:

Electroweak and Planck scales are O(1016) apart.

slide-6
SLIDE 6

June 1, 2011 6

Search for RS-Gravitons

slide-7
SLIDE 7

June 1, 2011 7

Combined γγ+ee+µµ RS-Graviton Limit

  • S. Behari, Tevatron BSM and HF Results

_

slide-8
SLIDE 8

Search for RS-Gravitons (Di-bosons)

June 1, 2011

  • S. Behari, Tevatron BSM and HF Results

8

slide-9
SLIDE 9

Like-sign Di-lepton Search

June 1, 2011

  • S. Behari, Tevatron BSM and HF Results

9

slide-10
SLIDE 10

Photon + Jets + MET Search

June 1, 2011 10

  • S. Behari, Tevatron BSM and HF Results
slide-11
SLIDE 11

Photon + Jets + MET Search

June 1, 2011 11

Consistent with SM.

≥ 1 Jet ≥ 2 Jets MET MET

slide-12
SLIDE 12

June 1, 2011 12

  • S. Behari, Tevatron BSM and HF Results

A Heavy Flavor Treat!

Mashed potato, gravy and sausage ice-cream

slide-13
SLIDE 13

Search for NP in Bs decays

June 1, 2011 13

_

  • S. Behari, Tevatron BSM and HF Results
slide-14
SLIDE 14

1) CPV from mixing in Bs → J/ψφ decays

  • Best way of probing CPV due to NP in Bs mixing
  • BUT.. angular analysis to disentangle CP even and odd

components.

June 1, 2011 14

  • DØ: 6.1 fb-1 data

 Sees 1.1σ deviation from SM

  • CDF: 5.2 fb-1 data

 Sees 0.8σ deviation from SM

φs

J /ψφ = −2βs

  • S. Behari, Tevatron BSM and HF Results
slide-15
SLIDE 15

A simpler way: Bs→J/ψ f0(980) BR

  • Use multivariate techniques to suppress
  • background. Then perform a log-likelihood

fit on signal and normalization mode, Bs→J/ψ Φ, simultaneously.

  • Measured:

(Theory: 0.1 – 0.5)

June 1, 2011 15

Rf 0 /φ = BF(Bs → J /ψf0(980))⋅ BF( f0(980) → π +π −) BF(Bs → J /ψφ)⋅ BF(φ → K +K−) = 0.292 ± 0.020(stat) ± 0.017(sys) = 0.210 ± 0.032(stat) ± 0.036(sys)

  • S. Behari, Tevatron BSM and HF Results

571±37(stat)±25(sys) 498±74(stat)

slide-16
SLIDE 16

2) Dimuon charge asymmetry recap

  • DØ 6.1 fb-1 result:
  • Differs from SM by ~3.2σ:
  • Indication of large Bs mixing phase?

June 1, 2011 16

Asl

b = Nb ++ − Nb −−

Nb

++ + Nb −−

  • Where, Nb

++,-- are number of same sign dimuon

events produced due to the b hadrons decaying semileptonically, one before and the other after mixing.

  • Is close to zero if mixing rates

(SM expectation is a few 10-4).

B → B = B → B

Asl

b = (−0.957 ± 0.251(stat) ± 0.146(syst))%

Asl

b (SM) = (−0.023−0.006 +0.005)%

  • S. Behari, Tevatron BSM and HF Results
slide-17
SLIDE 17

CDF on the way to measuring Ab

sl

  • CDF is pursuing an alternate path for independent

verification of the interesting DØ result.

  • Use muon impact parameter (IP) information to fit for

sample composition, separating same-sign dimuons µ+µ+ and µ-µ- that originate from B decays (i.e. are long lived).

  • IP fitter is a standard robust technique demonstrated in the

correlated BB cross-section measurement: PRD 77, 072004 (2008).

  • As a first step: measure time-integrated mixing probability

 Comparison to LEP validates the IP fitter.

June 1, 2011 17

χ

χ

_

  • S. Behari, Tevatron BSM and HF Results
slide-18
SLIDE 18

Time integrated mixing prob. measurement

June 1, 2011 18

χ

_

  • S. Behari, Tevatron BSM and HF Results

χ = 0.126 ± 0.008

slide-19
SLIDE 19

Evidence for Bs→π+π- decays

June 1, 2011 19

NEW!

  • S. Behari, Tevatron BSM and HF Results
slide-20
SLIDE 20

Evidence for Bs→π+π- decays

June 1, 2011 20

BR(Bs

0 → π +π −) =[0.57 ± 0.15(stat) ± 0.10(sys)]⋅10-6

BR(B0 → K +K−) =[0.23± 0.10(stat) ± 0.10(sys)]⋅10-6 BR(B0 → K +K−) ∈ [0.05,0.46]⋅10-6@90% C.L.

  • S. Behari, Tevatron BSM and HF Results
slide-21
SLIDE 21

BR and ACP in B±→D0 h± decays

  • The angle γ is the least well determined angle of CKM

matrix  Not sure yet if the triangle closes properly

  • The cleanest measurement method uses highly

suppressed B- → D0K- decays:  Technique pioneered at e+e- colliders (Atwood- Dunietz-Soni method)  Deemed unfeasible in hadron collider experiments

  • CDF measures of B- → D0 (K+π- or K-π+) K-, where

interference between D0 or D0 is sensitive to γ through a combination of decay rates and some inputs from other experiments.

June 1, 2011 21

_

  • S. Behari, Tevatron BSM and HF Results
slide-22
SLIDE 22

BR and ACP in B±→D0 h± decays

June 1, 2011 22

  • S. Behari, Tevatron BSM and HF Results
slide-23
SLIDE 23

ADS Method: Results

June 1, 2011 23

RADS(π) = (4.1± 0.8 (stat) ± 0.4 (syst))⋅10−3 RADS(K) = (22.5 ± 8.4 (stat) ± 7.9 (syst))⋅10−3 AADS(π) = 0.22 ± 0.18 (stat) ± 0.06 (syst) AADS(K) = −0.63± 0.40 (stat) ± 0.23 (syst)

First time in a

hadron machine!

  • S. Behari, Tevatron BSM and HF Results
slide-24
SLIDE 24

June 1, 2011 24

  • S. Behari, Tevatron BSM and HF Results
slide-25
SLIDE 25

CPV in charm

June 1, 2011 25

  • S. Behari, Tevatron BSM and HF Results
  • ACP(D0 → π+π ‐)=

+0.22±0.24 ±0.11 %

  • ACP(D0 → K+K‐)=

‐0.24±0.22 ±0.10 %

Belle 2008: [+0.43±0.52(stat.)±0.12(syst.)]% Belle 2008: [-0.43±0.30(stat.)±0.11(syst.)]%

slide-26
SLIDE 26

Beyond SM + HF Outlook

  • The LHC experiments would weigh-in on most of the

traditional BSM exotics searches by summer 2011.

  • Tevatron experiments would wrap-up / publish current work

with as much statistics as possible.

26

Exotics Heavy Flavor

  • Tevatron has pioneered Heavy Flavor physics in hadron

collisions and has led the field through crucial measurements, Bs mixing, sin2βs and Ab

sl to name a few.

  • HF programs continue to have a major share in the Tevatron

physics output Many results over the last year.

slide-27
SLIDE 27

Heavy Flavor Outlook (continued..)

  • By the end of 2011 CDF/DØ plan on publishing high profile

measurements, e.g. B → µµ., with maximum data samples.

  • Between summer 2011 to winter 2012 several world’s best

measurements would be overtaken by LHCb.

  • Beyond that the focus moves to measurements unique to pp

collisions at 2TeV, e.g.  Production and polarization (quarkonia, exotic hadrons, baryons, …)  Very high precision CPV (where CP-symmetry of initial state matters).

June 1, 2011 27

_

  • S. Behari, Tevatron BSM and HF Results
slide-28
SLIDE 28

Summary

June 1, 2011 28

_

  • S. Behari, Tevatron BSM and HF Results
slide-29
SLIDE 29

BACKUP SLIDES

June 1, 2011 29

  • S. Behari, Tevatron BSM and HF Results
slide-30
SLIDE 30

DØ Search for RS Gravitons

June 1, 2011

  • S. Behari, Tevatron BSM and HF Results

30

_

slide-31
SLIDE 31

Graviton mass-dependent k-factors

  • K-factors are used to scale the

LO Pythia cross-sections to include NLO effects.

  • For Tevatron energy the k-

factors are graviton mass dependent.

  • CDF uses a calculation by P.

Mathews, V. Ravindran, and K. Sridhar made specifically for CDF.

  • These variable k-factors are

more realistic and give smaller value of limit than the fixed ones.

June 1, 2011

  • S. Behari, Tevatron BSM and HF Results

31

G→γγ G→ll

slide-32
SLIDE 32

Search for Universal ED

June 1, 2011 32

slide-33
SLIDE 33

Like-sign Di-lepton Search

June 1, 2011

  • S. Behari, Tevatron BSM and HF Results

33

Chirality Mode Limits on like-sign top quark pair production Limits on squark pair production

  • Similar analyses also set…
slide-34
SLIDE 34

A simpler way to access βs

June 1, 2011 34

  • S. Behari, Tevatron BSM and HF Results
slide-35
SLIDE 35

Chi-bar: IP fit projections (with standard silicon requirements)

  • When muons are selected with standard silicon requirement,

the tail region of data is not fitted well.

  • This is understood as the source of discrepancy between

Run I and LEP results.

June 1, 2011 35

  • S. Behari, Tevatron BSM and HF Results
slide-36
SLIDE 36

Evidence for Bs→π+π- decays

June 1, 2011 36

  • S. Behari, Tevatron BSM and HF Results
slide-37
SLIDE 37

BR and ACP in DCS B±→D0 h± decays

  • BR and ACP in B-→D0 K- allow for a theoretically-clean way of

measuring the CKM angle γ (known to 10-20o level)

  • Atwood-Dunietz-Soni method: Interference between

 B- → D0K- (color allowed); D0

DCS→K+π-

 B- → D0K- (color suppressed); D0

CF→K+π-

can lead to large ACP.

  • Define DCS fractions and asymmetries:

June 1, 2011 37

_ _

RADS(K) = (BR(B-→[K+ π-]DK-) + BR(B+→[K- π+]DK+)) ⁄ (BR(B-→[K- π+]DK-) + BR(B+→[K+ π-]DK+)) = rD

2 + rB 2 + rDrB cos γ cos(δB+δD)

AADS(K) = (BR(B-→[K+ π-]DK-) - BR(B+→[K- π+]DK+)) ⁄ (BR(B-→[K+ π-]DK-) + BR(B+→[K- π+]DK+)) = 2 rBrD sin γ sin(δB+δD) ⁄ RADS(K) rB = |A(b→u)/A(b→c)| and δB = arg[A(b→u)/A(b→c)] rD and δD: For D decays [ Similar for RADS(π) and AADS(π) ]

  • S. Behari, Tevatron BSM and HF Results
slide-38
SLIDE 38

ACP in D0→ h+ h- : Extraction method

June 1, 2011 38

δ(X): Detector induced asymmetry due to the particle/state X

  • S. Behari, Tevatron BSM and HF Results