Mini Black Holes at CMS and Muon Collider

Transcription

1 Mini Black Holes at CMS and Muon Collider CMS Collaboration & Muon Collider Collaboration Mini Black Holes at CMS and Muon Collider (page 1)

2 Black Holes Motivation We have observed Astronomical Black Holes (BH): Hubble Space Telescope uncovers dust disk around a massive Black Hole 3,700 light-year-diameter dust disk This result encourages us to explore mini BH production in a Laboratory BH discovery is the most promising signal of TeV-scale quantum gravity Mini Black Holes at CMS and Muon Collider (page 2)

3 Cosmic Ray Showers LHC collisions aren t dangerous to the Earth Cosmic rays can far exceed LHC energies The Universe performs 10 million LHC-like experiments every second Measured for 70 years by scientists Mini Black Holes at CMS and Muon Collider (page 3)

4 Cosmic Ray Showers Cosmic rays are caused by protons (yellow) from outer space Muons live long enough that some reach the Earth In November 2007, Pierre Auger Collaboration: Most likely the source of cosmic rays are Active Galactic Nuclei (AGN) AGN are thought to be powered by Super-massive Black Holes Mini Black Holes at CMS and Muon Collider (page 4)

5 Current Understanding of The Universe Astronomy tell us: Matter is only 5% of the Universe The rest is dark matter and dark energy A lot of things need to be understood and discovered Mini Black Holes at CMS and Muon Collider (page 5)

6 What Else Is Out There? In the beginning of time, matter and antimatter were created equal Matter and Anti-Matter should have annihilated leaving nothing but we and the universe are exist Are there extra dimensions of space? Can we produce mini black holes in laboratory? Are there particles and forces that we have not even dream of? Mini Black Holes at CMS and Muon Collider (page 6)

7 What are Extra Dimensions? In the 1920s there was a theory so called String Theory This theory was created by Theodor Kaluza and Oskar Klein They were inspired by Albert Einstein (General Theory of Relativity) They predicted Extra Dimensions: up to 5 Dimensions In 1970s, scientists developed the String Theory SuperString Theory so called Theory of Everything It known as Calabi-Yau space It was predicted the world has up to 11 Dimensions The big question: How could this be possible? Mini Black Holes at CMS and Muon Collider (page 7)

8 Extra Dimensions Think about a brave acrobat and a flea (ant) on a tight rope (cable suspension) The acrobat can only move forward and backward along the rope The acrobat has one dimension The flea can move forward and backward as well as side to side The flea has two dimensions The acrobat can only detect one dimension of the rope Mini Black Holes at CMS and Muon Collider (page 8)

9 Extra Dimensions In large extra dimensions at TeV energy-scale (Planck scale), Gravitons can propagate in n = D 4 extra dimensions The BH is characterized by the Schwarzschild radius [ r s = 1 πm 8Γ( n+3 2 ) (2+n) ] 1 n+1 ( ) 1 MBH n+1 M If the impact parameter b < r s, an Event Horizon is formed i r s 4 dim spacetime j 4 dim spacetime Mini Black Holes at CMS and Muon Collider (page 9)

10 Hawking s Evaporation After Black Hole formed it will decay via Hawking evaporation process (Hawking radiation) The Black Holes emits into two modes : 1. Along the brane (brane mode): Standard Model fields 2. Into the extra dimensions (bulk mode): gravitons (invisible) Hawking radiation Mini Black Holes at CMS and Muon Collider (page 10)

11 ADD and RS Models Hierarchy problem is one of the outstanding challenges in particle physics Hierarchy problem (both forces involve constants of nature): Electroweak energy scale ( 1 TeV) Planck energy scale ( TeV) SUSY and ED could address the hierarchy problem ADD (Arkani-Hamed, Dimopoulos and Dvali) Model: A large volume extra dimensions RS (Randall-Sundrum) Model: A single warped extra dimension w/ 2 branes, one at each end Consequences of the existence of ED is the production of black hole (BH) Mini Black Holes at CMS and Muon Collider (page 11)

12 Hengstberger Symposium, Heidelberg University, Germany 2009 EXTRA DIMENSIONS AND MINI BLACK HOLES Mini Black Holes at CMS and Muon Collider (page 12)

13 BH Generators C. Issever BH Generators Time Line and Plan Results from Hengstberger Symposium July 2009 Mini Black Holes at CMS and Muon Collider (page 13)

14 BH Generators Comparison Unknown Quantum Gravity Corrections Model CHARYBDIS CATFISH BLACKMAX CHARYBDIS 2 Release Beam p, p p, µ p, e p, p PDF CTEQ CTEQ CTEQ/LHAPDF CTEQ/LHAPDF Extra Dim Beam Remnant No Yes No Yes Inelastic Effect Yes Yes Yes Yes Quantum Grav. No No Yes Yes Final Burst 1 Choice 2 Choices 1 Choice 4 Choices Output LHE PYTHIA LHE LHE Mini Black Holes at CMS and Muon Collider (page 14)

15 First BH Study G. Landsberg Mini Black Holes at CMS and Muon Collider (page 15)

16 CATFISH: Black Hole Generator BH generators: Truenoir, Charybdis, CATFISH, and BlackMax We wrote a BH MC generator called CATFISH CATFISH (Collider gravitational FIeld Simulator for black Holes) CATFISH authors: M. Cavaglià, R. Godang, L. Cremaldi, D. Summers Published Journal of High Energy Physics, JHEP06, 055, 2007 Published Computer Physics Communications 177, 506, 2007 Mini Black Holes at CMS and Muon Collider (page 16)

17 CATFISH Website CATFISH is well documented and available for public Mini Black Holes at CMS and Muon Collider (page 17)

18 BH Cross Section BH cross section can be estimated from the geometrical cross section (Black Disk) σ ij BH πr 2 s = 1 M 2 [ ( M BH M 8Γ( n+3 2 ) (2+n) )] 2 n+1 LHC (p p collider), we need to consider its cross section at the parton level (hampered by parton distributions) σ pp BH ij 1 x m dx 1 x dy y f i(y, Q)f j (x /y, Q)σ ij BH (x, s, n) x m = M 2 BH(min) /s, s = M 2 and Q = the momentum transfer f i, f j = Parton Distribution Function (PDF) At CLIC (e + e collider), beamstrahlung smears the collision energy unlike Muon Collider At Muon Collider (µ + µ ), the BH cross section is relatively simple σ µµ BH σ BH (s, n) (it does not depend on the minimum M BH ) Mini Black Holes at CMS and Muon Collider (page 18)

19 Cross Section at CLIC BH Cross Section of 5 TeV (e + e ) collider at CLIC Courtesy of Landsberg and Dimopoulos (hep-ph ) dσ/dm BH, pb/gev M P = 1 TeV M P = 2 TeV M P = 3 TeV M P = 4 TeV j) The extra dimension n = 4 M BH, GeV The CM-energy s = 5 T ev The beamstrahlung-corrected energy spectrum for CLIC machine is peaking at the nominal energy (5 TeV) Mini Black Holes at CMS and Muon Collider (page 19)

20 Cross Section at Muon Collider BH Cross Section for 4 T ev (µ + µ ) 10 2 σ BH (4 x cm -2 ) 10 1 n = 4 n = 5 n = 6 n = s (TeV) 3.9 n = D 4 extra dimensions s = 4 TeV CM-energy = σ BH 7 nb Using L µ + µ 1033 (cm 2 s 1 ) = BH production rate 7 BH/s = τ BH s Mini Black Holes at CMS and Muon Collider (page 20)

21 Horizon Formation Horizon formation of CM-energy of 4 TeV with impact parameter b M BH / s 0.40 n = 7 n = n = b/b max The energy trapped by the horizon is a function of the impact parameter For head-on collision, 60% of CM-energy trapped by the horizon When extra dimension increases = M BH / s decreases [ We use Yoshino and Nambu s model (PRD 67, , 2003) ] Mini Black Holes at CMS and Muon Collider (page 21)

22 LHC Site at CERN LHC at CERN is using the same tunnel as LEP Mini Black Holes at CMS and Muon Collider (page 22)

23 Large Hadron Collider LHC: p p collisions with CM-energy s = 14 TeV, σ pp = 100 mb CMS Collaboration: 3000 scientists with 183 institutes in 38 countries Search for Higgs and SUSY Search for Black Holes, Extra Dimensions, and Gravitons Mini Black Holes at CMS and Muon Collider (page 23)

24 CMS and ATLAS Detectors Mini Black Holes at CMS and Muon Collider (page 24)

25 Extra Dimensions at LHC Mini Black hole production at LHC At TeV-energy scale, LHC could observe BH production: 1. E observable M : Gravitons escapes into extra dimensions pp Jet + Gravitons Jet + E miss T 2. E observable M : Mini BH production pp BH spectacular decays (High P T leptons, Jets) Mini Black Holes at CMS and Muon Collider (page 25)

26 Black Hole Events at CMS and ATLAS E observable M : Mini black hole production at LHC Mini Black Holes at CMS and Muon Collider (page 26)

27 ADD Large Extra Dimensions: A. De Roeck Mini Black Holes at CMS and Muon Collider (page 27)

28 ADD Selection Cut PAS EXO MHT is a good variable to distinguish between signal and backgrounds MHT = p T (jet) i >P 0 T P T (jet) i, P 0 T = 30 GeV Pre-selection on jets: P T > 50 GeV and η < 3 Left: MHT distribution MHT > 250 GeV Right: Number of jets normalized to the same area Mini Black Holes at CMS and Muon Collider (page 28)

29 ADD Monojets + Missing ET: Backgrounds PAS EXO Estimate Z νν + jets from W lν + jets Selected Z(νν) + jets estimated from W (lν) + jets N(Z(νν + jets) from W (lν)+jets = 163 ± 22 stat ± 13 syst ± 17 MC N(Z(νν + jets) MC = 182 ± 13 stat Ratio of N(Z(νν) + jets) over N(W (νν) + jets) is consistent with 1 Mini Black Holes at CMS and Muon Collider (page 29)

30 ADD Monojets: Discovery Reach PAS EXO Discovery potential as a function of M D and δ using 200 pb 1 10 TeV: M D within 3σ and 5σ with δ = 2 (lines) δ = 4 (dot) 7 TeV: M D within 3σ and 5σ with δ = 2 (lines) δ = 4 (dot) Mini Black Holes at CMS and Muon Collider (page 30)

31 ADD Extra Dimensions via Diphotons PAS EXO Extra Dimensions (ED) are an intriguing solution of the hierarchy problem of SM (left) Virtual KK Graviton production via q q γγ (last two diagrams) Standard Model diphoton productions Type of Backgrounds Irreducible SM diphoton (dominant bkg) MC and normalized to data Dijet Jet-faking-photon rate f jet γ calculated as a function of (E jet T ) Photon + Jet Σm (γ,i) f jet γ (E jet T ) High Mass Drell-Yan (e + e ) electron fake rate Mini Black Holes at CMS and Muon Collider (page 31)

32 ADD Diphotons: Exclusion Limits PAS EXO Expected 95% limit on the cross section for various ED models Cross Section for various ED Models Left: 95% CL limit as a function of η with M γγ > 600 GeV Right: 95% CL limit as a function of M γγ with η > 1.5 Mini Black Holes at CMS and Muon Collider (page 32)

33 ADD Diphotons: Cross Section PAS EXO Signal cross section parameterization as a function of ED effect Left: As function of ED effect: η G = F M 4 s and n ED > 2 where F 1 Right: As a function of 1/M 4 s for n ED = 2 where M s = String scale Mini Black Holes at CMS and Muon Collider (page 33)

34 ADD Diphotons: Discovery Reach PAS EXO Luminosity required for signal discovery for 1, 3, and 5 events 7 TeV est. using parton luminosity 10 TeV: M s = 2.5 TeV/c 2, n ED pb 1 but 7 TeV: a factor of 10? 7 TeV: M s = 2.0 TeV/c 2, n ED = pb 1 Mini Black Holes at CMS and Muon Collider (page 34)

35 Randall-Sundrum Gravitons: A. De Roeck Mini Black Holes at CMS and Muon Collider (page 35)

36 RS Diphoton Resonance PAS EXO High Energy Diphoton Resonance for RS graviton masses Event selection: Photon p T > 50 GeV, η < 1.5, and M γγ > 700 GeV RS Graviton masses (M G ) = 0.75, 1.0, 1.25, 1.5 TeV/c 2, 100 pb 1 Mini Black Holes at CMS and Muon Collider (page 36)

37 RS Diphotons: Discovery Reach PAS EXO M 1 = RS Graviton mass, k = k M pl, k = warp factor 10 TeV: M 1 = 1 TeV/c 2 (30 pb 1 ); M 1 = 1.25 TeV/c 2 (130 pb 1 ) k = TeV: the luminosity increases by a factor of 1.5 Mini Black Holes at CMS and Muon Collider (page 37)

38 CATFISH BH Mass BH Mass distribution for fundamental Planck scale M = 1 TeV, n p = M = 1 TeV 10 5 M = 1 TeV BD n = 6 YR n = n = n = 5 Number of Events n = 4 n = 3 Number of Events n = 4 n = Black Hole Mass (GeV) Black Hole Mass (GeV) CATFISH results : (left) Black Disk model (BD) = no Gravitons loss (right) Yoshino-Rychkov TS model (YR) = with Gravitons loss Mini Black Holes at CMS and Muon Collider (page 38)

39 BH Events Shape BH events are expected to be highly spherical due to the spherical nature of Hawking radiation 10 5 Number of Events M = 1 TeV, n = 6 M min = 1 TeV n p = 2, BD n p = 4, BD n p = 2, YR n p = 4, YR Number of Events M = 1 TeV, n = 6 M min = 1 TeV n p = 2, BD n p = 4, BD n p = 2, YR n p = 4, YR Sphericity R 2 H 2 /H 0 Experimentally one needs to distinguish between BH events shape with q q events as BH-backgrounds (back-to-back events shape) (left) Sphericity BH events shape S > 0.30 (depends on M min ) (right) Fox-Wolfram moment R 2 < 0.50 Mini Black Holes at CMS and Muon Collider (page 39)

40 Effects of Fundamental Scale Visible energy and missing transverse momentum for n = 6, n p = 4, YR n = 6 YR M = 1 TeV M = 2 TeV M = 3 TeV n = 6 YR M = 1 TeV M = 2 TeV M = 3 TeV Number of Events Number of Events Visible Energy (GeV) Missing Transverse Momentum (GeV) Increasing M leads to higher M min (M min = 2M ) : Larger visible energy in Hawking phase Larger missing transverse momentum M could be measured to a certain degree of precision at LHC Mini Black Holes at CMS and Muon Collider (page 40)

41 Effects of Final BH Decay BH Mass distribution for M = 1 TeV, (n =3 or 6), BD M = 1 TeV n = 3, BD n p = 0 n p = 2 n p = M = 1 TeV n = 6, BD n p = 0 n p = 2 n p = 4 Number of Events Number of Events Black Hole Mass (GeV) Black Hole Mass (GeV) The initial BH mass is obviously unaffected by the detail of final decay (left) We vary number of quanta at the end of BH decay for n = 3 (right) We vary number of quanta at the end of BH decay for n = 6 This is a nice consistency check of CATFISH generator Mini Black Holes at CMS and Muon Collider (page 41)

42 BH Vs SUSY Using CATFISH How do we distinguish between SUSY and BH events? SUSY and Universal Extra Dimensions (UED) has twin diagrams SUSY: UED: Q 1 Z 1 q χ 0 2 q l L l ± (near) l (far) l 1 χ 0 1 γ 1 SUSY: q q χ 0 2 ql± l L ql+ l χ 0 1 UED: Q 1 qz 1 ql ± l 1 ql+ l γ 1 Both modes produce SM particles: ql + l /E T (KEY) SUSY: slepton is a scalar particle no spin correlation between SM leptons UED: slepton is replaced by a KK lepton it is a fermion Expected a different shape in the dilepton invariant mass distribution Mini Black Holes at CMS and Muon Collider (page 42)

43 msugra Parameters msugra scalar and gaugino masses are in GeV Type m 0 m 1/2 A 0 tanβ µ A B C D E No significant difference between SUSY type (A. Roy & M. Cavaglia, PRD 77, , 2008) Missing P T (GeV) Sphericity Any type [A-E] can be used as SUSY benchmark Mini Black Holes at CMS and Muon Collider (page 43)

44 SUSY OSSF Dilepton The Opposite-sign, Same-Flavor (OSSF) dilepton is a dominant MSSM interaction in SUSY (PYTHIA and ISAJET) χ 0 2 l± l l χ 0 1 The maximum dilepton invariant mass (On-shell point): ( ) ( ) Mll max = m χ m2 l 1 m2 χ 0 m 2 χ 1 0 m 2 l 2 90 GeV The dominant SM backgrounds: W + jets Z + jets t t + jets diboson dijets Mini Black Holes at CMS and Muon Collider (page 44)

45 BH OSSF Dilepton Sources of isolated leptons in BH decays (CATFISH) BH decays (most decays) Z boson (small BR 0.034) t t decays (rare) Z and t t combination (small) BH (line) and SUSY (shaded) of dilepton invariant mass (2 or 4-quanta) 2-quanta 4-quanta M ll (GeV) M ll (GeV) BH peak 90 GeV is due to Z dilepton BH 2-quanta peak 1 TeV is due to final Hawking phase BH long tail is due to t t (rare) and mostly BH decays Mini Black Holes at CMS and Muon Collider (page 45)

46 BH Vs SUSY High P T dilepton distribution can be used to disentangle between SUSY (shaded) and BH (solid) events P T of Isolated Leptons SUSY variables: m 0 = 100, m 1/2 = 300, A 0 = 300, tanβ = 2.1, µ = + The ratio of BH-to-SUSY of P T dilepton is 1:5 P T (dilepton) > 600 GeV reduces the SUSY background substantially Mini Black Holes at CMS and Muon Collider (page 46)

47 SUSY LM1 Dilepton, 14 TeV CM PAS SUS LM1: m 0 = 60 GeV/c 2, m 1/2 = 250 GeV/c 2, A 0 = 0, tanβ = 10.0, µ = + Signal (red), flavor-symmetric bkg, Z-peak bkg: Sample: 1 fb 1 m ll distributions: dielectron (left) and dimuon (right) At least two Opposite-sign, Same-Flavor: P l T > 10 GeV, ηl < 2.4 At least three jets: E jet T > 30 GeV, η jet < 3 Missing Energy Transverse: M miss T > 200 GeV CMS MC result: (theoretical value = GeV/c 2 ) M max ee = ± 1.0 stat GeV/c 2 M max µµ = ± 0.56 stat GeV/c 2 Mini Black Holes at CMS and Muon Collider (page 47)

48 SUSY LM1 Dilepton, 14 TeV CM PAS SUS LM1: m 0 = 60 GeV/c 2, m 1/2 = 250 GeV/c 2, A 0 = 0, tanβ = 10.0, µ = + Simultaneous fit of m ll distributions : M max ll = ± 0.49 stat ± 0.62 syst GeV/c 2 Mini Black Holes at CMS and Muon Collider (page 48)

49 SUSY LMO Dilepton, 10 TeV CM: PAS SUS LMO: m 0 = 200, m 1/2 = 160, A 0 = 400 GeV/c 2, tanβ = 10, µ = + CMS MC result: 200 pb 1 with 10 TeV Center of Mass Energy m ll distributions: dilepton (left) and electron-muon (right) CMS MC result: (theoretical value = 52.7 GeV/c 2 ) M max ll = 51.3 ± 1.5 stat ± 0.9 syst GeV/c 2 Mini Black Holes at CMS and Muon Collider (page 49)

50 SUSY LM1 and LM9, 10 TeV CM PAS SUS LM1: m 0 = 60 GeV/c 2, m 1/2 = 250 GeV/c 2, A 0 = 0, tanβ = 10, µ = + LM9: m 0 = 1450 GeV/c 2, m 1/2 = 175 GeV/c 2, A 0 = 0, tanβ = 50, µ = + CMS MC results: 1 fb 1 with 10 TeV Center of Mass Energy LM9: M max ll = 62.8 ± 1.4 stat ± 0.8 syst GeV/c 2 ML1: M max ll = 77.3 ± 0.9 stat. ± 0.9 syst GeV/c 2 Mini Black Holes at CMS and Muon Collider (page 50)

51 BSM Background, 14 TeV CM PAS EXO CMS: (left) Z e + 1 TeV/c 2 (5σ discovery), σ = 30 GeV/c 2 MC sample: 100 pb 1 with 14 TeV Center of Mass Energy SM bkg (blue-dash): Drell-Yan process, t t, W+jet, dijets, γ+jet, and γγ ATLAS: (right) Z e + e (5σ discovery) as a function of Z mass Only statistical uncertainties are included Mini Black Holes at CMS and Muon Collider (page 51)

52 BSM Background, 10 TeV CM PAS EXO CMS MC sample: 100 pb 1 with = 10 TeV Center of Mass Energy Electron selection E e T > 25 GeV Same bkg as 14 TeV: Drell-Yan process, t t, W+jet, dijets, γ+jet, and γγ Left: Sum of the dielectron backgrounds: 40 < M ee < 800 GeV/c 2 Right: Z e + 1 TeV/c 2 (5σ discovery) Mini Black Holes at CMS and Muon Collider (page 52)

53 Results of 0.9 TeV and 2.36 TeV Data JHEP 02 (2010) 041 Measured differential yield of charged hadrons Left: The differential yield of charged hadrons in η < 2.4 in 0.2-unit wide bins Right: Measured yield of charged hadron for η > 2.4 including syst error Mini Black Holes at CMS and Muon Collider (page 53)

54 Results of 0.9 TeV and 2.36 TeV Data JHEP 02 (2010) 041 Average transverse momentum of charged hadrons < P T > and charged-hadrons pseudorapidity density dn ch dη Left: < P T >= 0.46 ± 0.01(stat) ± 0.01(syst) GeV/c at 0.9 TeV < P T >= 0.50 ± 0.01(stat) ± 0.01(syst) GeV/c at 2.36 TeV Right: dn ch dη η < 0.5 = 3.48 ± 0.02(stat) ± 0.13(syst) at 0.9 TeV dn ch dη η < 0.5 = 4.47 ± 0.04(stat) ± 0.16(syst) at 2.36 TeV Mini Black Holes at CMS and Muon Collider (page 54)

55 Summary CATFISH produces consistent results compared to other BH generators CATFISH includes different final BH decays and remnant formation Missing momentum transverse is a good tool to discriminate between BH and BSM including SUSY The Opposite-sign, Same-Flavor (OSSF) dilepton provides a powerful discriminator between BH and BSM The results of < P T > and dn ch dη with the various previous measurements at CMS 0.9 TeV are in a good agreement The study of particle production in pp collision at CMS 2.36 TeV has been extended into a new energy region Expected new results on BH, ED, and Graviton Stay tune! Mini Black Holes at CMS and Muon Collider (page 55)

56 Acknowledgments Special thanks to Greg Landsberg, Albert De Roeck, Christopher Hill, Sarah Eno, Jeff Richman, Lucien Cremaldi, Marco Cavaglia, Don Summer, Gail Hanson, and Arafat Mokhtar Mini Black Holes at CMS and Muon Collider (page 56)

57 T H A N K Y O U Mini Black Holes at CMS and Muon Collider (page 57)