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Bhaskar Dutta

Phenomenology Projects. Bhaskar Dutta. Texas A&M University. Questions. Some 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

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Bhaskar Dutta

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  1. Phenomenology Projects BhaskarDutta Texas A&M University

  2. Questions Some 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

  3. Current Status Collider Experiments: LHC Direct Detection Experiments: DAMA, CDMS, XENON 100, CoGeNT, LUX etc. Indirect Detection Experiments: Fermi, AMS, PAMELA Cosmic Microwave Sky: Planck Neutrino 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?

  4. LHC: Supersymmetry Most 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

  5. Origin of Dark Matter-Thermal Production of thermal DM: Non-relativistic Thermal Models Freeze-Out: Hubble expansion dominates over the interaction rate Dark Matter Content: freeze out  m/T  ac~O(10-2) with mc ~ O(100) GeV leads to the correct relic abundance Assuming :

  6. Thermal Dark Matter DM particle + DM Particle SM particles Annihilation Cross-section Rate: DM Abundance: DM DM DM DM f: SM particles; h, H, A: various Higgs, : SUSY particle Note: All the particles in the diagram are colorless • We need to satisfy thermal DM requirement

  7. Thermal Dark Matter 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 smaller annihilation cross-section Larger annihilation cross-section

  8. Dark Matter at the LHC • Annihilation 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 ? • Cascade decays of squarks and gluinos • Monojet Searches • Via stop squark • Vector Boson fusion TAMU Theory + Experiment Collaboration

  9. 1. Via Cascade decays at the LHC LHC is very complicated (or l+l-, t+t-) High PT jet [mass difference is large] DM Colored particles are produced and they decay finally into the weakly interacting stable particle The pTof jets and leptons depend on the sparticle masses which are given by models DM R-parity conserving (or l+l-, t+t-) High PT jet The signal : jets + leptons+ t’s +W’s+Z’s+H’s + missing ET

  10. 1. Via Cascade decays at the LHC Ambitious Goal: Final states  Masses  Model Parameters  Calculate dark matter density Problem 1: Identifying one side is very tricky! etc. We may not be able to solve for masses of all the sparticlesin a model Apply : Bi-Event Subtraction Technique (BEST) Dutta, Kamon, Krislock, ‘12 Problem 2: Not all the sparticles appear in cascade decays Challenge: Solving for the MSSM

  11. 1. Via Cascade decays at the LHC mSUGRA Non Universal Higgs Model @ 200 fb-1 Arnowitt, Dutta, Kamon, Gurrola, Krislock, Toback: PRL 100 (2008) 231802 Mirage Mediation Model Dutta, Gurrola,Kamon, Krislock, Mavromatos, Nanopoulos: Phys.Rev. D79 (2009) 055002 Determine DM content at 14 TeV LHC with high luminosity If squarks are produced Dutta, Kamon, Krislock, Sinha, Wang: Phys.Rev. D85 (2012) 115007 11 11

  12. 3. DM via Monojet at LHC 1 2 Allahverdi, Dutta: Phys.Rev. D88 (2013) 023525 Dijet Monojet Dutta, Gao, Kamon: In preparation

  13. 3. DM via Monojet at LHC :Dijet pair Dutta, Gao, Kamon: In preparation

  14. 3. DM via Stop at 8 TeV LHC LHC Stop pair productions up to ~ 600 GeV @ 8 TeV LHC Utilize Stop decay modes to search charginos, sleptons, neutralinos Ex. 1 is mostly bino and is wino Ex. 3 is mostly Bino-Higgsino Correct relic density For lighter sleptons Stop can identified via fully hadronic or 1 lepton plus multijet final states [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] Dutta, Kamon, Kolev, Wang, Wu, Phys.Rev. D87 (2013) 095007 Ex. 2 are mostly Higgsino 2 jets+ 2 leptons (OSSF-OSDF) +missing energy Topness variable to identify stops Grasser, Shelton, 2012  Existence and type of DM particle, hard to calculate the DM content

  15. 3. DM via Stop at 8 TeV LHC Bino-Higgsino dark matter Dilepton end-point after OSSF-OSDF including background  Correct dark matter content Dutta, Kamon, Kolev, Wang, Wu, Phys.Rev. D87 (2013) 095007 5s (s/(s+B)) : for lightest stop mass ~ 600 GeV at 30 fb-1

  16. 4. DM at the LHC Via VBF • LHC has a blind spot for productions of non-colored particle • The W boson (colorless) coming out of high energy protons • can produce colorless particlesVector Boson Fusion(VBF) • Special search strategy needed to extract the signal • New way of understanding DM or new physics • sector at the LHC Delannoy, Dutta, Kamon, Sinha, Wang, Wu et al; Phys.Rev.Lett. 111 (2013) 061801 Dutta, Gurrola, Kamon, John, Sinha, Shledon; Phys.Rev. D87 (2013) 035029 Dutta, Eusebi, Gao, Ghosh, Kamon: In preparation Dutta, Flanagan, Johns, Kamon, Gurrola, Sheldon, Sinha, Wang, Wu: arXiv:1312.1348; In preparation Dutta, Gao, Kamon, Shakya: In preparation Theory + ExperimentCollaboration

  17. 4. DM at the LHC Via VBF Signal: missing energy, For : LHC 8 TeV data (expected): 260 GeV [ 180 GeV [ missing energy] missing energy] Signal: missing energy, LHC 14 TeV data (expected): To appear soon missing energy

  18. Cross Sections via VBF DM via VBFDM at the LHC CDM 18

  19. DM Content via VBF Simultaneous fit of the observed rate, shape of missing energy distribution: 19 Phys.Rev.Lett. 111 (2013) 061801

  20. 4. DM at the LHC Via VBF • Direct probes of colorless charginos, neutralinos and • sleptons do not have strong limits from the LHC • The weak Bosons from protons can produce DM P + P  Two high ET forward jets in opposite hemispheres with large dijet invariant mass

  21. Ongoing Projects 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 explained VBF 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

  22. 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 model • Need to investigate colorless particles (suitable for DM • calculation) at the LHC using vector Boson technique

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