Noncommuta5ve Black Holes at the LHC Elena Villhauer Karl - PowerPoint PPT Presentation

Noncommuta5ve Black Holes at the LHC Elena Villhauer Karl Schwartzschild Mee5ng 2017 25/07/2017

Outline • Hierarchy Problem • Condi2ons for black hole Produc2on at the LHC • Brief tour of results from searches for TeV- scale gravity at the LHC • Theory of Noncommuta2ve Black Holes • Experimental approach to Noncommuta2ve Black Holes

Hierarchy Problem Four fundamental forces Force Rela2ve Strength Strong nuclear 1 Weak nuclear 10 -5 Electromagne2c 1/137 Gravita2onal 6 x 10 -39 Fundamental Planck scale: 10 19 GeV Solu5on : The existence of extra dimensions would lower the Planck scale and account for the discrepancy in gravity’s rela2ve strength

Extra Dimensional Models in LHC BH Searches • ADD model – M 2 P ~ M * n+2 R n – Large, flat extra dimensions – Standard Model fields are confined to a 4-D brane – Gravity alone propagates in bulk • RS1 model – M 2 P ~ M * 3 (1 – e -2kL )/k – Standard Model par2cles are confined to a 4-D brane – One Extra Dimension • Tiny, warped, compac2fied • Lives in AdS space Figures from arXiv:0802.2218 (Kan2)

Black Hole Forma5on at the LHC • Condi2ons: – Fundamental Planck scale is lowered to the TeV scale via the existence of extra dimensions – Hoop Conjecture Theory is sa2sfied Circumference = 2πR S b Center-of-mass energy of each parton > M * Mass is enclosed in a region with a circumference < 2πR S σ = πR S 2

Semiclassical Black Holes at the LHC • Condi2on: M BH >> M P • Semiclassical black holes are believed to be beyond the reach of the LHC • Thermal: emit Hawking radia2on • Signature : mostly high pT jets, should contain a lepton • Modeled by Charybdis2, BlackMax, TRUENOIR, CATFISH

LHC Semi-classical BH Results ATLAS CMS Mul5jet arXiv:1705.01403 BlackMax Lepton + Jets arXiv:1606.02265 Charybdis2 Mul5jet Charybdis2 Mul5jets arXiv:1512.02586 Charybdis2

Quantum Black Holes • Condi2on: M BH ~ M P • Signature of quantum gravity • Nonthermal • Strong preference for two body decays • Modeled by generator “QBH” as 2-body decay • Signature : high pT

LHC QBH Results ATLAS CMS Photon + Jet arXiv:1512.05910 Mul5jet Dijet arXiv:1703.09127 arXiv:1705.01403, QBH Dijet Model Observed Lower Limit (TeV) Expected Lower Limit (TeV) High-mass dilepton arXiv:1607.08079

String Balls • Highly excited string states that arise when weakly coupled string theory is embedded in the paradigm of ADD-type dimensions • Signature of quantum gravity • Planck mass M p and string mass scale M s : possibly ~ TeV with extra dimensions • Signature : Lots of high pT jets, should also have lepton – Signature is not very different from GR black holes – Different cross sec2ons than GR black holes

LHC String Ball Results ATLAS CMS Mul5jet Mul5jet

Why extra dimensions have not yet been discovered at the LHC • Extra dimensions do not exist :( • Extra dimensions DO exist, but we need – Higher energy to produce black holes • Black holes have been produced at the LHC, but we have missed them – Different signatures than those we have been searching for – Produced at a very low rate – Not properly understanding backgrounds

Start of Run II • June 2015: Great Hope for BHs Figure from ATLAS Weekly Mee2ng

Second Stage of Run II Cross sec5on ra5os 14 TeV / 13 TeV • Diminishing returns Figure from ATLAS Weekly Mee2ng

LHC Schedule 14 TeV 13 TeV Figure from ATLAS Weekly Mee2ng

What we need • More ENERGY – New magnet: can push energy up to 18 TeV • Unlikely to happen in the immediate 2me frame – Scheduled to jump to 14 TeV next year – Luminosity increases do not provide the exponen2al increases in discovery poten2al that energy increases provide Failing that, • Different signatures • Different cross sec2ons

Noncommuta5ve Black Holes • Very different experimental signatures than other LHC black hole searches • Lots of rela2vely sos par2cles: stark contrast to high pT par2cles of other BH searches • The result of incorpora2ng noncommuta2ve geometry into the paradigm of extra dimensions • Forms an effec2ve theory to quantum gravity • Creates a new mass threshold above the Planck scale – New regime for new physics

Noncommuta5ve Black Holes • Assumes commutator of space2me coordinates ≠ 0 where = NC mass scale = dimensional, frame-independent an2symmetric matrix with real and constant entries (generated due to background magne2c or electric type fields) = NC parameter arXiv : gr - qc / 0612035v1 (Ansoldi, Nicolini, Smailagic, Spallucci)

Noncommuta5ve Black Holes in Higher Dimensions • Effect of noncommuta2vity: smears mass distribu2ons – A point mass, M, characterized by a δ-func2on distribu2on (Mδ) becomes a spherically symmetric, sta2c, Gaussian smeared mawer source are << compac2fica2on scale R c where BH horizon size and ~ arXiv:hep-ph/0606051 (Tom Rizzo)

A nonsingular solu5on • Effect of noncommuta2vity: noncommuta2ve coordinate fluctua2ons at short distance cause a regular deSiwer vacuum to replace the curvature singularity at r = 0 arXiv : gr - qc / 0612035v1 (Ansoldi, Nicolini, Smailagic, Spallucci)

2010 NC BH Study at 8 TeV • Analysis of neutral, nonrota2ng noncommuta2ve BH model (arXiv:1003.1798, Douglas Gingrich) – Model based on arXiv:hep-ph/0606051 (Tom Rizzo) – Trigger level analysis only – Rela2vely low transverse momentum spectrum blended into the QCB background; no further ac2on was undertaken and the analysis was stopped – Search strategy must be revised

Noncommuta5ve vs. Commuta5ve BH Parton Cross Sec5on Proton Cross Sec5on Temperature Figures from arXiv:1003.1798, Douglas Gingrich

NC BH HT and Invariant Mass Figures from arXiv:1003.1798, Douglas Gingrich

NC BH Jet Mul5plicity and leading- lepton pT Figures from arXiv:1003.1798, Douglas Gingrich

NC BH Before Cuts Figures from arXiv:1003.1798, Douglas Gingrich

NC BH A^er MET/sqrt(HT) Cuts Figures from arXiv:1003.1798, Douglas Gingrich

Ini5al Black Hole Characteris5cs Figures from arXiv:1003.1798, Douglas Gingrich

Remnant Characteris5cs Figures from arXiv:1003.1798, Douglas Gingrich

Event Characteris5cs Figures from arXiv:1003.1798, Douglas Gingrich

Par5cle Characteris5cs Figures from arXiv:1003.1798, Douglas Gingrich

Cross sec5ons for various Figures from arXiv:1003.1798, Douglas Gingrich

My Intended NC Black Hole Search • Charged, rota2ng NC BH model in ADD-type extra dimensions using Charybdis2 generator – Improvement from neutral, nonrota2ng BH model used in 2010 Trigger-level analysis • Rota2on plays a huge role in accurate modeling, charge contributes as well • Revise search strategy – Figure out a way to separate the low pT signal from the QCD background • Machine Learning, Deep Learning – Noncommuta2ve black holes are predicted to decay to a stable remnant • Search directly for the remnant – Remnant characteris2cs: resembles those of corresponding BH – Remnant Charge

Conclusion • Public ATLAS and CMS results have not indicated any significant excessed in analyses using 13 TeV data • Noncommuta2ve Black Holes offer a much different signature than any other TeV-scale gravity model in use • Exci2ng search for a charge, nonrota2ng noncommuta2ve black holes in ADD-type extra dimensions using ATLAS data will be undertaken

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