bhaskar dutta

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Bhaskar Dutta

Texas A&M University

Phenomenology Projects

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QuestionsSome Outstanding Issues of High Energy Theory

1. Dark Matter content ( is 27%)

2. Electroweak Scale

3. Baryon Content ( is 5%)

4. Rapid Expansion of the Early Universe

5. Neutrino Mass . . . Need: Theory, Experiment and Observation

DM

b

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Current StatusCollider Experiments: LHCDirect Detection Experiments: DAMA, CDMS, XENON 100, CoGeNT, LUX etc.Indirect Detection Experiments: Fermi, AMS, PAMELACosmic Microwave Sky: PlanckNeutrino Experiments: T2K, Daya Bay, Double CHOOZ, RENO etc.

What have we learnt? What is the status of theory models? What do we expect in the near future?Are we closing in?

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LHC: SupersymmetryMost models predict: 1-3 TeV (colored particle masses)So far: No colored particle up to 1.5 TeV

Non-colored SUSY particles: 100 GeV to 1-2 TeV (Major role in the DM content of the Universe) Weak LHC bound for non-colored particles hole in searches!

Trouble in Models with very tight correlation between colored and non-colored particles , e.g., minimal SUGRA/CMSSM

LHC + Direct Detection + Indirect Detection quite constraining

Origin of Dark Matter-ThermalProduction of thermal DM:

Thermal ModelsFreeze-Out: Hubble expansion dominates over the interaction rate

Non-relativistic

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v1~DM

20~ DM

fmT

Dark Matter Content:

Assuming : 2

2

~v

mf~O(10-2) with m ~ O(100) GeV leads to the correct relic abundance

m/Tfreeze out

ffDMDM

scm3

26103v

Thermal Dark MatterDM particle + DM Particle SM particles

Annihilation Cross-section Rate:

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vann

DM

DM

DM

DM

f: SM particles; h, H, A: various Higgs, : SUSY particleNote: All the particles in the diagram are colorless

v1~DM

DM Abundance:

f~

scm3

26103v We need to satisfy thermal DM requirement

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Suitable DM Candidate: Weakly Interacting Massive Particle (WIMP)

Typical in Physics beyond the SM (LSP, LKP, …)

Most Common: Neutralino (SUSY Models)

Neutralino: Mixture of Wino, Higgsino and Bino

Larger/Smaller Annihilation Non-thermal Models

Thermal Dark Matter

Larger annihilation cross-section

smaller annihilation cross-section

v1~DM

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Dark Matter at the LHCAnnihilation of lightest neutralinos quarks, leptons etc.At the LHC: proton + proton DM particles

DM Annihilation diagrams: mostly non-colored particles e.g., sleptons, staus, charginos, neutralinos, etc.

How do we produce these non-colored particles and the DM particle at the LHC? Can we measure the annihilation cross-section ? 1. Cascade decays of squarks and gluinos2. Monojet Searches3. Via stop squark4. Vector Boson fusion

TAMU Theory+ Experiment Collaboration

vann

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The signal : jets + leptons+ t’s +W’s+Z’s+H’s + missing ET

1. Via Cascade decays at the LHC

(or l+l-, tt)

DM

DMColored particles are produced and they decay finally into the weakly interacting stable particle

High PT jet

High PT jet

[mass difference is large]

The pT of jets and leptons depend on the sparticle masses which are given by models

R-parity conserving

(or l+l-, tt)LHC is very complicated

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1. Via Cascade decays at the LHCAmbitious Goal:

Final states Masses Model Parameters Calculate dark matter density

We may not be able to solve for masses of all the sparticles in a model

Challenge: Solving for the MSSM

01

~~ lqQ 01

~~ lL0

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4,3,2~,,~ llhZ etc. Identifying one side

is very tricky!

Not all the sparticles appear in cascade decays

Problem 1:

Problem 2:Apply :Bi-Event Subtraction Technique (BEST)Dutta, Kamon, Krislock, ‘12

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1fb 10 L

1fb 50

1111

1. Via Cascade decays at the LHCmSUGRA Non Universal Higgs Model

@ 200 fb-1

1fb 001

Mirage Mediation Model

Determine DM content at14 TeV LHC with high luminosityIf squarks are produced

Arnowitt, Dutta, Kamon, Gurrola, Krislock, Toback: PRL 100 (2008) 231802

Dutta, Kamon, Krislock, Sinha, Wang: Phys.Rev. D85 (2012) 115007

Dutta, Gurrola,Kamon, Krislock, Mavromatos, Nanopoulos: Phys.Rev. D79 (2009) 055002

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3. DM via Monojet at LHC

1 2

Monojet Dijet

Dutta, Gao, Kamon: In preparation

Allahverdi, Dutta: Phys.Rev. D88 (2013) 023525

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3. DM via Monojet at LHC

:Dijet pair

Dutta, Gao, Kamon: In preparation

3. DM via Stop at 8 TeV LHC

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LHC Stop pair productions up to ~ 600 GeV @ 8 TeV LHCUtilize Stop decay modes to search charginos, sleptons, neutralinos

Ex. 1 is mostly bino and is wino

Topness variable to identify stops

2 jets+ 2 leptons (OSSF-OSDF)+missing energy

Existence and type of DM particle, hard to calculate the DM content

Stop can identified via fully hadronic or 1 lepton plus multijet final states

Ex. 3 is mostly Bino-Higgsino Correct relic density

01 0

2

Ex. 2 are mostly Higgsino02,1

01

For lighter sleptons

[Yang Bai, Cheng, Gallichio, Gu, 1203.4813;Han, Katz, Krohn, Reece, 1205.5808;Plehn, Spannowsky, Takeuchi, 1205.2696;Kaplan, Rehermann, Stolarski, 1205.5816; Dutta, Kamon, Kolev, Sinha, Wang, 1207.1893]

Grasser, Shelton, 2012

Dutta, Kamon, Kolev, Wang, Wu, Phys.Rev. D87 (2013) 095007

3. DM via Stop at 8 TeV LHC

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Bino-Higgsino dark matter

GeV6501

02

mm

GeV11001

m

Correct dark matter content

5 (s/(s+B)) : for lightest stop mass ~ 600 GeV at 30 fb-1

Dilepton end-point after OSSF-OSDF including background

Dutta, Kamon, Kolev, Wang, Wu, Phys.Rev. D87 (2013) 095007

4. DM at the LHC Via VBF

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LHC has a blind spot for productions of non-colored particle

The W boson (colorless) coming out of high energy protons can produce colorless particlesVector Boson Fusion(VBF)

Special search strategy needed to extract the signal

New way of understanding DM or new physics sector at the LHC

Theory + Experiment Collaboration

Delannoy, Dutta, Kamon, Sinha, Wang, Wu et al; Phys.Rev.Lett. 111 (2013) 061801Dutta, Gurrola, Kamon, John, Sinha, Shledon; Phys.Rev. D87 (2013) 035029Dutta, Eusebi, Gao, Ghosh, Kamon: In preparationDutta, Flanagan, Johns, Kamon, Gurrola, Sheldon, Sinha, Wang, Wu: arXiv:1312.1348; In preparationDutta, Gao, Kamon, Shakya: In preparation

4. DM at the LHC Via VBF

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jjjjjjjjpp 02

02

0211111

~~,~~,~~,~~

Signal: missing energy,

t22 j missing energy

22 j

For : 01

021

~,mmmm l

LHC 8 TeV data (expected): 260 GeV [ 180 GeV [

jjpp ~~

LHC 14 TeV data (expected): To appear soon

Signal: missing energy,

22 j

22 j missing energy] t22 j missing energy]

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Cross Sections via VBFDM via VBFDM at the LHCjjpp 0

10

1~~

CDM

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DM Content via VBFSimultaneous fit of the observed rate, shape of missing energy distribution:

Phys.Rev.Lett. 111 (2013) 061801

4. DM at the LHC Via VBF

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Direct probes of colorless charginos, neutralinos and sleptons do not have strong limits from the LHC

The weak Bosons from protons can produce

P + P

Two high ET forward jets in opposite hemispheres with large dijet invariant mass

DM

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Ongoing Projects

1. Double charged Higgs Boson search: VBF This model arises in the context of L-R symmetry [Dutta, Eusebi, Gao, Ghosh, Kamon, In progress]

2. NMSSM : 126 GeV Higgs is easily explainedVBF production of the neutralino sector: 2 jet+4 b signal[Dutta, Gao, Ghosh, Shakya, In progress]

3. VBF searches for light sbottom, In preparation

4. VBF searches for 3 body decay modes of stop, In preparation

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Concluding Insights Model ideas have constraints from LHC, Planck, Neutrino data, direct and indirect detection constraints Higgs mass is within the supersymmetry model prediction window LHC measurements so far seem to be preferring large DM annihilation cross-section Non-thermal DM

Non-thermal scenarios can accommodate both large and small annihilation cross-sections and can allow us to understand the baryon-DM coincidence puzzle

Determination of the DM Annihilation Cross-section is crucial: LHC and Indirect detections identify DM modelNeed to investigate colorless particles (suitable for DM calculation) at the LHC using vector Boson technique