Transcript Welcome to the “Scales Beyond 1 TeV” (P3) Group!

Out-of-this-World Physics:
From Particles to Black Holes
Greg Landsberg
L.G.Landsberg Symposium
December 19, 2005
Outline
A Word on Hierarchies
Standard Model: Beauty and the Beast
How to Make Gravity Strong?
Looking for Extra Dimensions…
Production of Black Holes at Colliders
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
2
N.B. Large Hierarchies Tend to
Collapse...
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Hierarchy of the Standard Model
Beauty … and the Beast
RGE evolution
Inverse Strength
Gravitational
Force
EM/Hypercharge
Force
Weak Force
Strong Force
vev
102
MGUT
MPl
1016 1019 E [GeV]
Extra dimensions might get rid of the beast while preserving
the beauty!
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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But Keep in Mind…
Fine tuning (required to keep a large hierarchy
stable) exists in Nature:



Solar eclipse: angular size of the sun is the same as the
angular size of the moon within 2.5% (pure coincidence!)
Politics: Florida recount, 2,913,321/2,913,144 =
1.000061
Numerology: 987654321/123456789 =
8.000000073
(HW Assignment: is it really numerology?)
But: beware the anthropic principle


Properties of the universe are special because we exist in it
Don’t give up science for philosophy: so far we have been
able to explain how the universe works entirely by science
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Math Meets Physics
Math physics: some dimensionalities are quite special
Example: Laplace equation in two dimensions has a
logarithmic solution; for any higher number of
dimensions it obeys the power law
Some of these peculiarities exhibit themselves in
condensed matter physics, e.g. diffusion equation
solution allows for long-range correlations in 2Dsystems (cf. flocking)
Modern view in topology: one dimension is trivial; two
and three spatial dimensions are special (properties
are defined by the topology); any higher number is not
Do we live in a special space, or only believe that we
are special?
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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The ADD Model
SM fields are localized on the
(3+1)-brane; gravity is the only
force that “feels” the bulk space
What about Newton’s law?
V r  
1 m1m2
1

MPl2 r
MPl3n 


n2
1
M   
December 19, 2005
3 n n  2
Pl
G’N = 1 / MPl[ 3n ]   1/MD2; MD  1 TeV
2
m1m2
r n1
Ruled out for infinite extra
dimensions, but does not apply for
sufficiently small compact ones
V r  
Gravity is fundamentally strong
force, bit we do not feel that as it is
diluted by the volume of the bulk
m1m2
for r  R
n
R r
M Dn 2  M Pl2 R n
More precisely, from Gauss’s law:
1  MPl 


R
2 MD  MD 
2/n
8  1012 m, n  1

0.7 mm, n  2

3 nm, n  3
6  1012 m, n  4
Amazing as it is, but no one has
tested Newton’s law to distances
less than  1mm (as of 1998)
Thus, the fundamental Planck scale
could be as low as 1 TeV for n > 1
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Longitudinal ED
Simultaneously, another
idea has appeared:
Gravitational
Force
Inverse Strength

Real
GUT Scale
EM/Hypercharge
Force
Virtual
Image
Weak Force

MPl=1/GN
Strong Force
L ~ 1 TeV
MZ
December 19, 2005
MS
M’Pl
M’GUT
MGUT
logE
Explore modification of the
RGE in (4+n)-dimensions to
achieve low-energy
unification of the gauge
forces [Dienes, Dudas,
Gherghetta, PL B436, 55
(1998)]
To achieve that, allow gauge
bosons (g, g, W, and Z) to
propagate in an extra
dimension, which is
“longitudinal” to the SM
brane and compactified on a
“natural” EW scale:
R ~ 1 TeV-1
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Randall-Sundrum Scenario
Randall-Sundrum (RS) scenario [PRL 83,
3370 (1999); PRL 83, 4690 (1999)]



AdS
+ brane – no low energy effects
+– branes – TeV Kaluza-Klein modes of
graviton
Low energy effects on SM brane are
given by L; for krc ~ 10, L ~ 1 TeV
and the hierarchy problem is solved
naturally
2 kr 
2

AdS5
ds  e
r

k: AdS curvature
SM brane
(  )
December 19, 2005
Planck brane
( = 0)
G
x5


 dx dx  r d
2
2
L   M Pl e  kr
Reduced Planck mass:
M Pl  M Pl
8
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Differences Between the Models
TeV-1 Scenario:
ADD Model:
Pro: “Eliminates” the
hierarchy problem by
stating that physics
ends at a TeV scale
Only gravity lives in
the “bulk” space
Size of ED’s (n=2-7)
between ~100 m
and ~1 fm
Black holes at the
LHC and in the
interactions of UHE
cosmic rays
Con: Doesn’t explain
why ED are so large
Pro: Lowers GUT
scale by changing
running of the
couplings
Only gauge bosons
(g/g/W/Z) “live” in
ED’s
Size of ED’s ~1 TeV-1
or ~10-19 m
Con: Gravity is not in
the picture
RS Model:
Pro: A rigorous solution
to the hierarchy
problem via
localization of gravity
Gravitons (and
possibly other
particles) propagate in
a single ED, w/ special
metric
Con: Size of ED as
small as ~1/MPl or
~10-35 m
G
x5
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Kaluza-Klein Spectrum
TeV-1 Scenario:
ADD Model:
Winding modes with
energy spacing ~1/r,
i.e. 1 meV – 100 MeV
Can’t resolve these
modes – they appear
as continuous
spectrum
Gravitational coupling
per mode; many modes
Winding modes with
nearly equal energy
spacing ~1/r, i.e.
~TeV
Can excite individual
modes at colliders or
look for indirect
effects
Mi  M  i r
2
0
E
E
~1 TeV
2
2
RS Model:
“Particle in a box” with
a special metric
Energy eigenvalues
are given by zeroes of
Bessel function J1
Light modes might be
accessible at colliders
M 0  0; M i  M 1 xi x1  M 1 , 1.83M 1 ,
2.66 M 1 , 3.48M 1 , 4.30 M 1 , ...
E
~MGUT
GN for zero-mode;
~1/L for others
…
ge …
Mi
M0
December 19, 2005
~MPl
Mi
M1
M0
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Using the ED Paradigm
EWSB from extra dimensions:





Hall, Kolda [PL B459, 213 (1999)] (lifted
Higgs mass constraints)
Antoniadis, Benakli, Quiros [NP B583, 35
(2000)] (EWSB from strings in ED)
Cheng, Dobrescu, Hill [NP B589, 249
(2000)] (strong dynamics from ED)
Mirabelli, Schmaltz [PR D61, 113011
(2000)] (Yukawa couplings from split leftand right-handed fermions in ED)
Barbieri, Hall, Namura
[hep-ph/0011311] (radiative EWSB via tquark in the bulk)
Flavor/CP physics from ED:


Arkani-Hamed, Hall, Smith, Weiner [PRD
61, 116003 (2000)] (flavor/CP breaking
fields on distant branes in ED)
Huang, Li, Wei, Yan [hep-ph/0101002]
(CP-violating phases from moduli fields
in ED)
December 19, 2005
Neutrino masses and oscillations from
ED:



Arkani-Hamed, Dimopoulos, Dvali,
March-Russell [hep-ph/9811448] (light
Dirac neutrinos from right-handed
neutrinos in the bulk or light Majorana
neutrinos from lepton number breaking
on distant branes)
Dienes, Dudas, Gherghetta
[NP B557, 25 (1999)] (light neutrinos
from right-handed neutrinos in ED or
ED see-saw mechanism)
Dienes, Sarcevic [PL B500, 133
(2001)] (neutrino oscillations w/o
mixing via couplings to bulk fields)
Many other topics from Higgs to dark
matter
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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ED and Flavor Physics
via gravity
bulk
bulk
SM
December 19, 2005
big
bang
ED models offer a powerful
paradigm for explaining flavor
sector and CP-violation
New amplitudes and phases could
be transmitted to our world via
gravity (or other bulk fields), thus
naturally introducing small
parameters needed for description
of CP-violation, flavor physics, etc.
Some realizations of this class of
models give realistic CKM matrix
(e.g., Arkani-Hamed, Hall, Smith,
Weiner [PRD 61, 116003 (2000)])
The idea of “shining” mentioned in
the original ADD papers could
explain why these effects were
stronger in early universe
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Flavor Physics from Geometry
Arkani-Hamed/Schmaltz [Phys. Rev. D61, 033005 (2000)] – split fermions
embedded in a “fat” brane
Wave-functions of different families of quarks and leptons are spatially offset, thus
the overlap areas are reduced exponentially
A fruitful paradigm to build models of flavor and mixing with automatically
suppressed FCNC and stable proton
Possible to construct realistic CKM matrices via geometry of extra brane
Similar attempts in Randall-Sundrum class of models
In some of these models LFV decays of kaons are predicted and could be sought
Huber [NP 666, 269 (2003)]
Quark doublets
of 3 generations
Quark singlets
of 3 generations
Branco/de Gouvea/Rebelo [Phys. Lett. B506, 115 (2001)]
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Tabletop Gravity Experiments
[J. Long, J. Price, hep-ph/0303057]
E.Adelberger et al.
PRL 86, 1418 (2001)
Sub-millimeter gravity
measurements could probe
only n=2 case only within
the ADD model
The best sensitivity so far
have been achieved in the U
of Washington torsion
balance experiment – a hightech “remake” of the 1798
Cavendish experiment

R<
~ 0.16 mm (MD > 1.7 TeV)
Sensitivity vanishes quickly
with the distance –~ can’t
push limits further down
significantly
Started restricting ADD with
2 extra dimensions; can’t
probe any higher number
Ultimately push the
sensitivity by a factor of two
in terms of the distance
No sensitivity to the TeV-1
and RS models
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Astrophysical and Cosmological
Constraints
Supernova cooling due to graviton
emission – an alternative cooling
mechanism that would decrease the
dominant cooling via neutrino emission




Tightest limits on any additional cooling
sources come from the measurement
of the SN1987A neutrino flux by the
Kamiokande and IMB
Application to the ADD scenario [Cullen
and Perelstein, PRL 83, 268 (1999);
Hanhart, Phillips, Reddy, and Savage,
Nucl. Phys. B595, 335 (2001)]:
MD > 25-30 TeV (n=2)
MD > 2-4 TeV (n=3)
Distortion of the cosmic diffuse gamma
radiation (CDG) spectrum due to the
GKK  gg decays [Hall and Smith, PRD
60, 085008 (1999)]:


MD > 100 TeV (n=2)
MD > 5 TeV (n=3)
December 19, 2005
Overclosure of the universe, matter
dominance in the early universe
[Fairbairn, Phys. Lett. B508, 335
(2001); Fairbairn, Griffiths, JHEP 0202,
024 (2002)]


MD > 86 TeV (n=2)
MD > 7.4 TeV (n=3)
Neutron star g-emission from radiative
decays of the gravitons trapped during
the supernova collapse [Hannestad
and Raffelt, PRL 88, 071301 (2002)]:


MD > 1700 TeV (n=2)
MD > 60 TeV (n=3)
Caveat: there are many known (and
unknown!) uncertainties, so the
cosmological bounds are reliable only
as an order of magnitude estimate
Still, n=2 is largely disfavored
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Collider Signatures for Large ED
Kaluza-Klein gravitons couple to the
energy-momentum tensor, and therefore
contribute to most of the SM processes
For Feynman rules for GKK see:


[Han, Lykken, Zhang, PRD 59, 105006
(1999)]
[Giudice, Rattazzi, Wells, NP B544, 3
(1999)]
Since graviton can propagate in the bulk,
energy and momentum are not conserved
in the GKK emission from the point of view
of our 3+1 space-time
Depending on whether the GKK leaves our
world or remains virtual, the collider
signatures include single photons/Z/jets
with missing ET or fermion/vector boson
pair production
Graviton emission: direct sensitivity to the
fundamental Planck scale MD
Virtual effects: sensitive to the ultraviolet
cutoff MS, expected to be ~MD (and likely
< MD)
The two processes are complementary
December 19, 2005
Real Graviton Emission
Monojets at hadron colliders
q
g
g
g
q
GKK
g
GKK
Single VB at hadron or e+e- colliders
V
GKK
GKK
V
GKK
GKK
V
V
Virtual Graviton Effects
Fermion or VB pairs at hadron or e+e- colliders
f
f
GKK
f
V
GKK
f
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
V
17
L’EPilogue (Large ED)
ee  gG
ee  ZG
Experiment
n=2 n=3 n=4 n=5 n=6 n=2 n=3 n=4 n=5
n=6
Color coding
ALEPH
1.28
0.97
0.78
0.66
0.57
0.12
184 GeV
DELPHI
1.38
1.02
0.84
0.68
0.58
L3
1.02
0.81
0.67
0.58
0.51
OPAL
1.09
0.86
0.71
0.61
0.53
Experiment
ee  tt
ALEPH
1.04
0.81
L3
OPAL
December 19, 2005
0.98
1.06
1.15
1.00
0.22
0.17
0.14
189 GeV
0.60
0.38
0.29
0.24
0.21
qq
0.65 0.60
0.53/0.57
0.67 0.62 0.46/0.46 (bb)
0.59 0.56
0.73 0.65
0.56 0.58
0.49
0.69 0.54
0.49
0.62
0.66
ff
gg
1.05
0.84
0.60
0.76
0.84
1.00
0.62
0.66
0.81
0.82
0.83
0.91
0.99
0.84
0.89
0.83
WW
>200 GeV
l=-1
GL
Virtual Graviton Exchange
All limits are in TeV
DELPHI
0.35
ZZ
l=+1
Combined
0.75/1.00 (<189)
0.60/0.76 (ff) (<202)
0.68
0.79
1.0/1.1 (<202)
0.63 1.17/1.03 (<209)
0.74
LEP Combined: 1.2/1.1 TeV
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Colliders: Graviton Emission
ee  g + GKK at LEP


g + MET final state
MP > 1.4-0.5 TeV (ADLO), for n=2…7
qq/gg  q/g + GKK at the Tevatron






jets + MET final state
Z()+jets is irreducible background
Challenging signature due to large
instrumental backgrounds from jet
mismeasurement, cosmics, etc.
DØ pioneered this search and set limits
[PRL, 90 251802 (2003)] MP > 1.0-0.6
TeV for n=2…7
Later, CDF achieved slightly better limits
Expected reach for Run II/LHC:
n
MD reach,
Run I
MD reach,
Run II
MD reach,
LHC 100 fb-1
2
1100 GeV
1400 GeV
8.5 TeV
3
950 GeV
1150 GeV
6.8 TeV
4
850 GeV
1000 GeV
5.8 TeV
5
700 GeV
900 GeV
5.0 TeV
December 19, 2005
Theory:
[Giudice, Rattazzi, Wells, Nucl. Phys. B544, 3 (1999)
and corrected version, hep-ph/9811291]
[Mirabelli, Perelstein, Peskin, PRL 82, 2236 (1999)]
85 pb-1
[PRL 90, 251802 (2003)]
q
g
q
GKK
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Tevatron: Virtual Graviton Effects
f
f
GKK
Expect an interference with the SM
fermion or boson pair production
V
d 2
d 2SM


d cos q* dM d cos q* dM
a n 
bn 
*


f
cos
q
,
M

f 2 cos q* , M 
1
4
8
MP
MP
GKK
f
f
V
Run II, 200 pb-1
High-mass, low |cosq*| tail is a
characteristic signature of LED
[Cheung, GL, PRD 62 076003 (2000)]
Best limits on the effective Planck
scale come from new DØ Run II data:

MPl > 1.1-1.6 TeV (n=2-7)
Combined with the Run I DØ result:

MPl > 1.1-1.7 TeV – tightest to date
Sensitivity in Run II and at the LHC:
Run II, 2 fb-1 LHC, 100 fb-1
e+e- + +gg
1.3-1.9 TeV 6.5-10 TeV
1.5-2.4 TeV 7.5-12 TeV
e+e- + +- + gg 1.5-2.5 TeV 7.9-13 TeV
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Interesting Candidate Events
While the DØ data are consistent with the SM, the two highestmass candidates have anomalously low value of cosq* typical
of ED signal:
Event Callas: Mee = 475 GeV, cos* = 0.01 Event Farrar: Mgg = 436 GeV, cos* = 0.03
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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TeV-1 Extra Dimensions
Intermediate-size extra
dimensions with TeV-1 radius
Introduced by Antoniadis [PL
B246, 377 (1990)] in the string
theory context; used by Dienes,
Dudas, Gherghetta [PL B436, 55
(1998)] to allow for low-energy
unification


Expect ZKK, WKK, gKK resonances
at the LHC energies
At lower energies, can study
effects of virtual exchange of the
Kaluza-Klein modes of vector
bosons
Antoniadis, Benaklis, Quiros [PL B460, 176 (1999)]
ZKK
Current indirect constraints come
from precision EW measurements:
1/r ~ 6 TeV
No dedicated experimental
searches at colliders to date
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
22
First Dedicated Search for TeV-1
Extra Dimensions
200 pb-1, e+eEvent
Callas
Interference effect
1/R = 0.8 TeV
While the Tevatron sensitivity is
inferior to indirect limits, it explores
the effects of virtual KK modes at
higher energies, i.e. complementary
to those in the EW data
DØ has performed the first dedicated
search of this kind in the dielectron
channel based on 200 pb-1 of Run II
data (ZKK, gKK  e+e-)
The 2D-technique similar to the
search for ADD effects in the virtual
exchange yields the best sensitivity in
the DY production [Cheung, GL, PRD
65, 076003 (2002)]
Data agree with the SM predictions,
which resulted in the following limit:


December 19, 2005
1/R > 1.12 TeV @ 95% CL
R < 1.75 x 10-19 m
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Randall-Sundrum Model
Observables
Need only two parameters to
define the model: k and rc
Equivalent set of parameters:


The mass of the first KK mode,
M1
Dimensionless coupling k / MPl
To avoid fine-tuning and nonperturbative regime, coupling
can’t be too large or too small
0.01 ≤ k / MPl≤ 0.10 is the
expected range
Gravitons are narrow
Expected Run II
sensitivity in DY
k / MPl
Drell-Yan at the LHC
M1
Davoudiasl, Hewett, Rizzo [PRD 63, 075004 (2001)]
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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First Search for RS Gravitons
Already better limits than sensitivity for Run II,
as predicted by phenomenologists!
[PRL 95, 091801 (2005)]
Assume fixed K-factor of 1.3 for the signal
The tightest limits on RS gravitons to date
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Black Holes on Demand
NYT, 9/11/01
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
26
Theoretical Framework
Based on the work done with Dimopoulos a
few years ago [PRL 87, 161602 (2001)] and
a related study by Giddings/Thomas [PRD
65, 056010 (2002)]
Extends previous theoretical studies by
Argyres/Dimopoulos/March-Russell [PL
B441, 96 (1998)], Banks/Fischler [JHEP,
9906, 014 (1999)], Emparan/Horowitz/Myers
[PRL 85, 499 (2000)] to collider
phenomenology
Big surprise: BH production is not an exotic
remote possibility, but the dominant effect!
Main idea: when the c.o.m. energy reaches
the fundamental Planck scale, a BH is
formed; cross section is given by the black
disk approximation:
2
 ~ RS ~ 1 TeV
2
~ 10
2
m ~ 100 pb
M2 = ^s
parton
RS
December 19, 2005
38
parton
Geometrical cross section approximation
was argued in early follow-up work by
Voloshin [PL B518, 137 (2001) and PL B524,
376 (2002)]
More detailed studies showed that the
criticism does not hold:





Dimopoulos/Emparan – string theory
calculations [PL B526, 393 (2002)]
Eardley/Giddings – full GR calculations for
high-energy collisions with an impact
parameter [PRD 66, 044011 (2002)]; extends
earlier d’Eath and Payne work
Yoshino/Nambu - further generalization of the
above work [PRD 66, 065004 (2002); PRD 67,
024009 (2003)]
Hsu – path integral approach w/ quantum
corrections [PL B555, 29 (2003)]
Jevicki/Thaler – Gibbons-Hawking action used
in Voloshin’s paper is incorrect, as the black
hole is not formed yet! Correct Hamiltonian
was derived: H = p(r2 – M)  ~ p(r2 – H),
which leads to a logarithmic, and not a powerlaw divergence in the action integral. Hence,
there is no exponential suppression [PRD 66,
024041 (2002)]
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
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Assumptions and Approximation
Fundamental limitation: our lack of knowledge of quantum
gravity effects close to the Planck scale
Consequently, no attempts for partial improvement of the
results, e.g.:



Grey body factors
BH spin, charge, color hair
Relativistic effects and time-dependence
The underlying assumptions rely on two simple qualitative
properties:


The absence of small couplings;
The “democratic” nature of BH decays
We expect these features to survive for light BH
Use semi-classical approach strictly valid only for MBH » MP;
only consider MBH > MP
Clearly, these are important limitations, but there is no way
around them without the knowledge of QG
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
28
Black Hole Production
Schwarzschild radius is given by Argyres
et al., hep-th/9808138 [after Myers/Perry, [Dimopoulos, GL, PRL 87, 161602 (2001)]
Ann. Phys. 172 (1986) 304]; it leads to:
tot = 0.5 nb
2
(MP = 2 TeV, n=7)

 n  3   n 1
8



1  M BH  2  
2
2

( sˆ  M BH )  RS  2 
MP  MP
n2 
LHC


n=4
Hadron colliders: use parton luminosity
tot = 120 fb
w/ MRSD-’ PDF (valid up to the VLHC
(MP = 6 TeV, n=3)
energies)
d pp  BH  X 
dL

ˆ ab  BH  sˆ  M 2
BH
dM BH
dM BH
dL
2M BH

dM BH
s
2
 M BH
dxa
f a xa  f b 
xa
 sxa
1
 
a ,b M 2
BH



s
Note: at c.o.m. energies ~1 TeV the
dominant contribution is from qq’
interactions
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
29
Black Hole Decay
Hawking temperature: RSTH = (n+1)/4
(in natural units  = c = k = 1)
BH radiates mainly on the brane
[Emparan/Horowitz/Myers, hepth/0003118]



l ~ 2/TH > RS; hence, the BH is a point
radiator, producing s-waves, which
depends only on the radial component
The decay into a particle on the brane
and in the bulk is thus the same
Since there are much more particles on
the brane, than in the bulk, decay into
gravitons is largely suppressed
[Dimopoulos, GL, PRL 87, 161602 (2001)]
Note that the formula for N is
strictly valid only for N » 1 due
to the kinematic cutoff E < MBH/2;
If taken into account, it increases
multiplicity at low N
Democratic couplings to ~120 SM d.o.f.
yield probability of Hawking evaporation
into g, l±, and  ~2%, 10%, and 5%
respectively
Averaging over the BB spectrum gives
average multiplicity of decay products:
N 
December 19, 2005
M BH
2TH
Stefan’s law: t ~ 10-26 s
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
30
Black Hole Factory
[Dimopoulos, GL, PRL 87, 161602 (2001)]
Black-Hole Factory
n=2
n=7
Drell-Yan
g+X
Spectrum of BH produced at the LHC with subsequent decay into final states
tagged with an electron or a photon
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
31
Shape of Gravity at the LHC
log TH  
1
log M BH  const
n 1
[Dimopoulos, GL, PRL 87, 161602 (2001)]
Relationship between logTH and logMBH allows to find the number of ED,
This result is independent of their shape!
This approach drastically differs from analyzing other collider signatures
and would constitute a “smoking cannon” signature for a TeV Planck scale
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
32
Black Hole Events
First studies already initiated by ATLAS and CMS


ATLAS –CHARYBDIS HERWIG-based generator with more
elaborated decay model [Harris/Richardson/Webber]
CMS – TRUENOIR [GL]
Simulated black hole event in the
Simulated black hole event in the
ATLAS detector [from ATLAS-Japan Group] CMS detector [A. de Roeck & S. Wynhoff]
December 19, 2005
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
33
Conclusions
If you still think that gravity is
weak force, you may be spending
too much time in the lab!
December 19, 2005
Stay tuned – next generation of
collider experiments has a good
chance to solve the mystery of
large extra dimensions!
If large extra dimensions are
realized in nature, black hole
production at future colliders is
likely to be the first signature for
quantum gravity at a TeV
Many other exciting
consequences from effects on
precision measurements to
detailed studies of quantum
gravity
If any of these new ideas is
correct, we might see a true
“Grand Unification” – that of
particle physics, astrophysics and
cosmology – in just a few years
from now!
Greg Landsberg - Out-of-this-World Physics: From Particles to Black Holes
34