Black Holes at colliders: progress since 2002

1
Black Holes at collidersprogress since 2002

• Seong Chan Park (SNU)
• SUSY08,
• COEX, SEOUL June 21, 2008

2
Whats BH? (1 min summary)

• Best known as classical solutions to the Einstein
  equation.
• Classically stable (nothing can come out)
• Quantum mechanically unstable (Hawking
  radiationThermal radiation, anything can come
  out of it)
• Tsurface gravity1/r (smaller hotter)
• Ssurface area r(D-2)
• BH is unique (4D), not unique (Dgt4)
• Black Ring (S2XS), Black String (S2XR) etc.

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Black hole is interesting

• Everybody knows it is interesting.
• Perfect place to do quantum gravity
• Has provided a nice testing ground for
• theory calculations
• (e.g. microscopic entropy counting of
• stringy-BH etc.)
• Has deep implication to
• energy-distance relation.
• Even it is real!!

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Observed Black Holes in the sky
Black Hole Candidates in Binary Star Systems

The list goes more than 100 now.
Cygnus X-1
Circinus galaxy
Thats great. But notice that they all Indirectly
observed ?.

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energy-distance relation

• To probe smaller distance,
• you need higher energy
• 
  W. Heisenberg
• This is exactly the reason why we want to
  build big colliders.

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Big Question

• Does this curve keep going and touch 0??
• Will this program go on forever?

Answer No!
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t Hooft picture of Trans-Planckian domain
t Hooft (1987)

• Gravity becomes strong/dominate in
  Ultrahigh-Energy Scattering. New window of bh
  production opens.
• The smallest distance scale we can probe is now
  determined by the size of event horizon (GE)
  which becomes larger with higher E!

distance
energy
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The big PictureHeisenberg-t Hooft
distance
UV-IR duality
energy
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Dgt4
If MDTeV, as is the case in ADD(1998) and
RS(1999), the Heisenberg-t Hooft picture is
actually relevant at the LHC
TeV dimension was first suggested by I.
Antoniadis(1990)
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LHC a BH factory
Banks-Fischler (1999), Dimopoulos- Lansberg
(PRL87,2001), Giddings-Thomas(PRD65, 2002)

• Large Cross-Section. Because there is no small
  dimensionless
• constant, analogous to alpha, suppress the
  production of BHs.
• 105 fb (Mgt5TeV, 10D), 10fb (Mgt10TeV, 10D)
• Hard, Prompt, Charged Leptons and Photons Because
  thermal
• decays are flavor-blind. This signature has
  practically vanishing SM background.
• Little Missing Energy.

gt
G. Landsberg SUSY02
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Around 2002

• Several different communities started
• talking about Mini-Black holes
• Particle physics, String theory,
• GR community even SF-community etc..
• People got excited

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Seoul in 2002
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Some people concerns if bh eats us a survey by
BBC
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Official comment by the CERN
CERN homepage
http//public.web.cern.ch/Public/en/LHC/Safety-en.
html
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BHs from cosmic rays

• Anchordoqui-Feng-Goldberg-Shapere (PRD 2002)

Pierre-Auger Ice Cube Etc.. are searching for
these events.
If the LHC can produce microscopic black holes,
cosmic rays of much higher energies would
already have produced many more. Since the Earth
is still here, there is no reason to believe
that collisions inside the LHC are harmful.
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Two major Progresses since 2002

• Production

• Decay

• BH production
• by collision proved.
• (b0,Dgt4) Eardley-Giddings
• (2002)
• (bgt0, Dgt4) Yoshino-Nambu
• (2003)

• Greybody factors of
• black hole in Dgt4 for brane fields with spin
  s0,1/2,1
• (i.e. for all the SM particles)
• obtained
• Ida-Oda-SCP
• (2003,2004,2005,2006)
• Duffy-Harris-Kanti-Winstanley(2005),
  Casals-Kanti-Winstanley (2006),
  Casals-Dolan-Kanti-Winstanley(2007)

Penrose (b0, D4) long ago
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Production Hoop Conjecture(Kip Thorne 1972)

• An imploding object forms a Black Hole when, and
  only when, a circular hoop with a specific
  critical circumference could be placed around the
  object and rotated. The critical circumference is
  given by 2 times Pi times the Schwarzschild
  Radius corresponding to the objects mass.
• big energy in a small space,
• BH always appears!!

I am a BH (M)
This is the hoop r GM
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Its like putting an elephant into a freezer..
It is hard to do this. But once you can do it,
you will have a BH.
R RBH(M)
MassM
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Classical BH formation provedusing two
Aichelberg-Sexl shocks
Eardley-Giddings 2002 Yoshino-Nambu PRD66,
2003 Yoshino-Nambu PRD67, 2003 Yoshino-Rychkov
PRD71, 2005
t-z
tz

• Boundary Value Problem
• Setup two particles (BHs) with
• boost?8,
• mass?0,
• energy fixed.

t
z

• Close Trapped Surface forms when bltb(max)
• (CTSa closed spacelike surface on which the
  outgoing
• orthogonal null geodesics converge)
• The Area Theorem Classically the horizon area
  of the ultimate bh must be
• greater than the original CTS. i.e. BH really
  forms

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Latest result bmax/rs
Yoshino-Rychkov PRD71, 2005
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Another approach(based on Hoop conjecture,
taking angular momentum into account)
SCP-Song 2001 Ida-Oda-SCP 2003
M/2
b
M/2
Hoop Conjecture
Error 3 (D5)-17(D11)
This picture is essentially correct
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Angular momentum
Most of BHs are produced with large angular
momentum!
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Signal How will we know if weve seen one?

• Black hole decays by emitting Hawking radiation.
• We will see the radiated particles.
• Smaller black holes are hotter and radiate more
  efficiently. (T TeV, every SM particles can come
  out of the bh!)
• Live short!! Life Time10-25 sec or shorter.
• So please dont worry about the possible destroy
  of the earth by mini black holes. ?

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Closer look Hawking radiation

• Here is the master equation

S. Hawking (1975)
T surface gravity 1/rh Smaller bh is hotter
The probability is not equal to every
particle but crucially depends on spin and
angular mode .
Anisotropic and nontrivial Hawking radiation is
expected. We have to know this greybody factor
to understand Hawking Radiation.
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Greybody factor
Modification factor to take the curved geometry
NH into account. Absorption Probability of
wave mode (s, l, m)
Looks not black to me. It looks Grey!
T
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Brief History of greybody factors for rotating
BHs

• Derivation of Teukolsky equation (Kerr)
• Wave equation for general (s,l,m) wave for 4D
  Kerr BH
• S. Teukolsky 1972,1973)
• Generalized to (D4n, Meyers-Perry) for brane
  fields
• Ida-Oda-SCP, PRD67(2003)

Solution to Teukolsky eq./ Greybody Factors (D4,
Kerr) Analytic and Numerical methods were
developed by Teukolsky-Press, Starobinsky, Unruh,
Page in 1973-1976 Analytic sol.(5D),low energy
limit,s0,1/2,1
Ida-Oda-SCP, PRD67(2003)

• Numerical (Dgt4),full energy,s0
• Ida-Oda-SCP PRD71(2005)
• Result Presented at JGRG meeting by SCP
• (Dec.2004,
  arXiv0501210)
• Duffy-Harris-Kanti-Winstanley
• (arXiv0507274,
  JHEP0509, 2005)

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For s0,Dgt4 Ida, Oda, SCP (s1/2,1,
arXiv0602188, PRD73, 2006)
Casals,Kanti,Winstanley (for s1 only) (arXiv
0511163 JHEP 0602, 2006) Casals, Dolan,
kanti,Winstanley (s1/2) JHEP 0703, (2007)
Finally!! Hawking radiation and its evolution
Hawking 1975, Page 1976 (4D) Ida, Oda, SCP
,PRD73, 2006(Dgt4) including all the SM fields.
Still sgt1 modes (i.e. s3/2, 2) missing Graviton
part can be important when Dgtgt4 Because of large
number of helicity states
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Generalized Teukolsky eq.
Ida,Oda,SCP PRD67, 2003

• Meyers-Perry sol. (rating Dgt4 BH)
• Define Null tetrad
• Use Newman-Penrose formalism, derive the
  equation
• Turned out to be separable
• (Petrov Type-D)
• angular part? spin-weighted
• spheroidal harmonics
• radial ? 2nd order ODE with singular BCs.

Believe me. This guy is tough!
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Schematic view of the greybody factor calculation
Ida, Oda, SCP I, II, III
Generalized Teukolsky Eq.
Far from the Horizon Sol (FF)
Near the Horizon Purely ingoing Sol (NH)
Analytic or Numeric integration
Matching
Sol (whole space)
Greybody factor (Absorption Probability)
In/Out
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D5,S1/2
Non-rotating
rotating
Highly Rotating
Greybody
Number
Energy
Angular mom
Ida, Oda, Park PRD 06
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Non-rotating
rotating
Highly Rotating
D10,s1/2
Greybody
Number
Energy
Angular mom
Ida, Oda, Park PRD 06
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D5, s1
Non-rotating
rotating
Highly Rotating
Greybody
Energy
Angular mom
Ida, Oda, Park PRD 06
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D10, s1
Non-rotating
rotating
Highly Rotating
Greybody
Energy
Angular mom
Ida, Oda, Park PRD 06
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Evolution of BH
Obtained by integrating Hawkings Formula with
the calculated Greybody Factors.

• The full result (SM) is almost
• exactly described by Vector.
• Vector emission is the most efficient
• way to extract angular momentum.
• Large Gluon emission
• 10D similar

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Black Holes Life made simple
Balding Phase
(Production of BHs. Study Dynamics required.)
Spin Down Phase
(Losing energy and angular momentum 60-80
Energy lost For Dgt4, to mostly gluons,
anisotropic)
Schwarzschild Phase
(Losing Mass 20-40 energy, spherical, to every
fields)
Planck Phase
(Remnant ???, Stringy study required )
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New MC event generators are available.

• BlackMax arXiv0711.3012 ,
• 
  Dai,Stojkovic,Issever,Rizvi,Tseng
• Greybody factors for rotating BH implemented.
• Most realistic MC simulation for bh events at
  the LHC.
• (N.B.)Yesterday (James Frosts talk P6 (on behalf
  of ATLAS))
• Ive learned that BlackMax has some bugs which
  should be removed.
• CHARIBDIS ver.2. is under development with
  Greybody factors for rotating BH.

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It seems we are more or lessready now but..

• There are still rooms to be improved (mostly
  theoretical)
• Balding phase should be understood by dynamical
  simulation (most probably numerical) (cf) success
  of Bh-Bh merging process (this is important!!)
• For Dgtgt4, spin-2 graviton emission can be
  sizable. non-rotating case done for Dgt4
• BH final state Full QG (string theory
  )calculation is required.
• Many other issues Chromosphere (Alig-Drees-Oda ,
  Anchordoqui et.at.), recoil(Stojkovic et.al),
  split-brane (Stojkovic), etc
• Unification of convention required.

Cardoso,Cavaglia,Gualtieri JHEP0602(2006)
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Conventions

• Planck scale (I would take PDG convention)
• In the PDG convention

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Physical quantities (PDG convention)
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Two most importantcharacteristics of BH signal

• Large Entropy ? high Multiplicity.
• Thermal radiation? Flavor Blind.

Typically, BH signals contains -Many
jets -Statistically, N(e)N(mu)N(tau)
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Multi-hard-jet
J. -H. Kim, SCP, S. Schumann (in preparation)
BlackMax1.0
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Multi-harder-jet
J. -H. Kim, SCP, S. Schumann (in preparation)
BlackMax1.0
Again, there is Chromospher issue here. Dense
jets look not really like Jets but fuzzy
Chromospher. (Alig,Drees,Oda JHEP0612 (2006)
Anchordoqui , Goldberg PRD67 (2003) )
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SM background (Njet 6)
Message from Steffen Schumann

• For the background calculation I used Sherpa.
• In my setup I combined matrix element
  calculations for 2,3 and 4jet production with
  parton showers attached.
• The underlying method is referred to as CKKW
  (Catani-Krauss-Kuhn-Webber) and it avoids any
  double counting of jet configuration emerging
  from the matrix element or the parton shower.
• However, in this approach the 5th jet is produced
  from the parton shower, what means it may be
  underestimated and a full matrix element
  calculation could yield a higher rate here, but
  this is a very complicated computation and
  cutting edge with present day tools.
• Anyhow, at some point we may want to include
  higher matrix elements yielding an improved
  background estimate for Njetgt5. However, I do not
  expect the overall pattern to change and the
  difference between the QCD background and your
  multijet rates is significant.

Wonderful Collaboration!
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Finally, some comments onRandall-Sundrum
Scale runs with the position
UV/IR hierarchy is explained by Warping
AdS5
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BH production on UV brane
We will not see this event since it is Mpl
suppressed!
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BH production at an arbitrary y
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BH production on IR brane
Note (E/M) is scale invariant. Cross
section1/TeV2.
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RS1-orginal

• All the SM particles lie on the IR brane.
• They feel strong gravity at the IR scale.
• BH production rate 1/TeV2
• The LHC as a BH factory

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Profile RS1-bulk SM
(See K. Agashes PL talk)
Higgs
Up, Down
Top, bottom
Gluon, W, Z, photon

• Higgs, top, bottom as well as the longitudinal
  components of (W, Z) feel the TeV gravity.
• The IR-tip of gluon, photon and the transverse
  components of (W, Z) feel the TeV gravity.
• Others (such as 1st, 2nd generation fermions)
  feel the Planck weak- gravity.

Zero-mode graviton
KK graviton, KK gluon, Other KK states
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Closer look bbbbbar
x1
x2
Suppressed by PDF!
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Closer look gg

• Only tip of the gluon contribute to the bh
  formation.
• Bulk contribution is exponentially
  suppressed.(negligible)

1/70
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Closer look WL, ZL

• By the equivalence theorem, the longitudinal
  components of the weak gauge bosons are
  effectively the unphysical Higgs.
• Localized on the IR brane and feel the TeV
  gravity.
• Suppressed by

d
d
u
u
WL
WL
WL
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Production Cross section
SCP 2008 Prelim.
Thermal black hole production is highly
suppressed. (See, Meade-Randall
arXiv0708.3017) But still sizable to be detected.
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Summary

• BH plays important role in
• Heisenberg-t Hooft picture.
• BHs can be produced by scattering. (proved for
  Dgt4 cases in 2002-2005)
• Greybody factors for brane-fields are obtained
  for generic spin(lt2), rotating, higher
  dimensional black holes in 2003-2007
• MC gens are available (BlackMax, CHARIBDIS ver.2.
  CATFISH..)
• The LHC will test all these beautiful ideas and
  will show us results for MdTeV case soon.

BHs at ATLAS
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Backups
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Future/open issues

• Dynamics of BH formation by merging two
  particles will be important. We will be able to
  understand balding phase
• Hawking radiation to the Bulk graviton is still
  missing. It can be important if there are several
  large extra dimensions because of large number of
  angular momentum vectors. 2n/2
• Blackhole-String transition (entropy,
  scattering), Information paradox etc.

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The legal defense fund site
Seeking for donations to shut-down the LHC
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Conventions

• Planck scale (I would take PDG convention)
• I would follow the PDG convention

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Thinking experimentwith E106 Mp
(E/2,0,0,E/2)
(E/2,0,0,-E/2)
Once the impact parameter is less than GE
106/Mp, BH forms!! We cannot see behind the
event horizon which is now million times larger
than the Planck length.
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RS1-bulk SM

• To address the hierarchy problem, we would put
  the Higgs boson on the IR brane (or in the
  vicinity of the IR brane)
• For flavor problem, longevity of proton, better
  low energy data fit, etc., we would put 1st,2nd
  generations on the UV brane (or in the vicinity
  of UV brane).
• 3rd generation (bR, tL, tR) may be on the IR
  brane. As a bonus, Large Yukawa for the top is
  also understandable due to the large overlap with
  the Higgs.
• (Massless, zero-mode) Gauge bosons are flat in
  the bulk.
• (Probably) The most realistic set-up in RS1
  models.

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Excellent agreement
Error 3 (D5)-17(D11)