Phenomenology of iQCD
Tzu-Chiang Yuan (阮自強)
Academia Sinica, Taipei
Collaborators: Kingman Cheung and Wai-Yee Keung
Seminar@NTHU
Jan 8 (2009)
1
Outline
to infracolor QCD -• Introduction
Kang and Luty, arXiv:0805.4642
Simple Model -• ACheung,
Keung and Yuan, Nucl.Phys. B in press,
arXiv:0810.1524
(a) iQuark Production at LHC
(b) Prompt Annihilation of iQuarkonium
• Summary
2
Quirky papers
•
•
•
•
•
•
•
Kang and Luty, arXiv:0805.4642
Jacoby and Nussinov, arXiv:0712.2681
Kang, Luty and Nasri, JHEP 0809, 086 (2008) hep-ph/0611322
Burdman, Chacko, Goh, Harnik and Krenke, PRD78:075028 (2008) [arXiv:0805.4667]
Cheung, Keung and Yuan, Nucl.Phys. B in press [arXiv:0810.1524]
Harnik and Wizansky, arXiv:0810.3948
Cai, Cheng and Terning, arXiv:0812.0843
Older papers
•
•
•
Bjorken, SLAC-PUB-2372 (1979)
Okun, JETP Lett. 31, 144 (1980); Nucl. Phys. B173, 1 (1980)
Gupta and Quinn, PRD 25, 838 (1982)
3
Introduction to infracolor QCD
4
Un-motivation
Hidden Strongly Interacting Sector ?
Or New Physics NOT (directly) related to
EW symmetry breaking ?
• A Familiar Example: Extra Z boson models
• Hidden Valley Models (Strassler)
• Unparticle (Georgi)
• Quirks and infracolor QCD (Luty)
5
Nuclear Phystcs B173 (1980) 1-12
© North-Holland P u b h s h m g C o m p a n y
THETA PARTICLES
L.B. O K U N
Institute of Theorettcal and Experimental Physics, Moscow, 117259 USSR
Received 4 March 1980
The hypothesis is considered, according to whtch there exist elementary particles of a new
type, theta parttcles, thetr gauge interaction being characterized by a macroscopic radius of
confinement. The quanta of the corresponding gauge held, thetons, are massless vector parttcles,
analogous to gluons. The bound systems of two or three thetons have macroscopic dimensions.
The existence of such objects is not excluded by experiment, as the Interaction of thetons wtth
ordinary particles must be very weak. However, the production of heavy theta leptons and theta
quarks at accelerators would open the way to intensive creataon of thetons and theta strings.
1. Introduction: what we call O-particles
. In a recent letter [1] a hypothesis was put forward on the existence of a new type
of particle, the interaction of which has a macroscopic confinement radius. This
interaction is caused by non-abelian gauge fields, whose quanta (we denote them 0
and call thetons) are massless neutral vector particles, analogous to gluons. At
distances of the order of 1 G e V - 1 (we use units, in which h = ¢ = 1), the interaction
between thetons is characterized by a coupling constant of the order of a ( a = - 137
- I )"
The strength of this interaction, however, does not drop as two thetons go apart,
and the interaction energy grows. This leads to a number of very unusual physical
p h e n o m e n a which are displayed at macroscopic distances. The aim of this paper is
6
0-particles are imposed by the big bang cosmology. We shall consider them at the
end of this paper. As we shall see, these limits are so stringent that they practically
leave no place for such particles as theta-neutrinos and not very heavy theta
quarks.
2. Why a new local group S U ( N ) 0 is not implausible
As is well-known, the existing theory of electroweak [2] and strong [3, 4] interactions is based on gauge groups U ( 1 ) x SU(2)w! SU(3)¢, their quanta being
7, W, Z, g. Alongside these groups, a number of other groups is considered in
literature: for instance, the so-called "technicolor" [5] S U ( N ) t ¢ with its technigluons, and the so-called horizontal [6] group SU(N)h. A vast literature exasts on
the so-called models of grand unification [7] SU(5),SO(10),SO(14) . . . . In the
highest of these groups there are dozens and even hundreds of gauge particles. In
this atmosphere the hypothesis on existence of another three (SU(2)s) or eight
(SU(3)0) gauge particles does not look very courageous. So we postulate that the
entire local group has the form:
U(1) ! SU(2)w ! SU(3)c ! . . . ! S U ( N ) a .
It may turn out that the 0-group may help to solve some problems on the way to
grand unification, but we will not pursue this possibility here.
3. Why the existence of a large radius of confinement is not implausible
The main difference between the group S U ( N ) and other gauge groups, considered in the literature, is that the 0-group has a very large and maybe even
macroscopic radius of confinement. Let us show by tracing the analogy with QCD,
that this assumption also does not look fantastic. As is well-known, confinement
for QCD is not yet proved; nevertheless, the excellent quantitative agreement of
QCD with experiment, and the absence [8] of free quarks around us (see, however,
ref. [9]) make us believe that SU(3)c confines. Furthermore, QCD phenomenology
suggests that A c is not far from 0.1 GeV, where 1 / A c is the confinement radius. It
is this quantity which determines the scale of masses of light mesons and baryons
(light means consisting of u- and d-quarks). It is essential, that the so-called
7
Infracolor QCD of Kang and Luty [arXiv:0805.4642]
New confining strong interaction
with
Λ ! TeV
In particular
Λ ! MQ
!
!
In infracolor QCD, quarks becomes quirks,
gluons becomes infracolor gluons.
Quirks carries both infracolor and SM quantum numbers
In infracolor QCD, there are no light quirks.
In QCD ΛQCD > mπ , light quark-antiquark pairs can be easily created
from the vacuum by string breaking
Heavy quirk-antiquirk pairs created from the vacuum by string breaking
are exponentially suppressed.
8
Unbreakable Strings
Unbreakable
Strings
Unconfined
Couloumb potential dominates for
small r
Confined breakable string => Independent fragmentation
Λ ! 2mq
light quark pair creation
Unbreakable Strings
Confined unbreakable string (Λ ! 2mQ )
!
confinement radius
!
Tension ≈ Λ!2
9
Suppression of soft hadronization in iQCD
[Bjorken (1979); Gupta and Quinn (1982)]
QCD
iQCD
unbreakable string
NP stringy effect is important,
not suppressed at high Q squared
x
10
Trendy names suggested
quirk
infracolor gluon
infracolor glueball
↔
↔
↔
etc
iquark
igluon
iglueball
infracolor Object ↔ iObject
(e.g. iMesons, iBaryons, etc. However, stringent
cosmological bounds existed!)
11
Size of the string
Kinetic Energy of iQuark ~ String Potential Energy
K.E. =
√
ŝ − 2MQ ∼ MQ
String potential energy ≈ Λ!2 L
MQ
L ≈ !2 ≈ 10 m
Λ
!
MQ
TeV
"!
Λ
100 eV
!
"−2
Phenomenology depends sensitively on size of string!
12
Quirks in the detector
(Luty, Kang and Nasri)
Macroscopic String
For values of ! of order 100 eV or less there is a
significant probability for quirks to enter the detector. The
string
! tension causes their tracks to bend differently than
those of muons and other charged particles. In such a
scenario a single event might suffice for discovery!
100 eV ≤ Λ ≤ 10 keV <==> mm ≤ L ≤ 10 m
quirky tracks
(Luty’s Talk)
String tension causes the quirky tracks bent differently from those
SM charged particles
Reconstruction algorithms fail to identify quirky tracks → Missing Energy
Energy loss mechanism: bremsstrahlung, ionization,
light hadron emission, etc.
Large lever arm =>Angular momentum de-coherence
=> iQuarks pair NOT easily meet to form bound states.
But one single quirky track event is sufficient for its discovery.
13
Mesoscopic String
o
10 keV ≤ Λ! ≤ MeV ↔ A ≤ L ≤ mm
•
Too small to be resolved in detector but larger than
atomic scale
•
iQuark-anti-iQuark pair appears as single particle in
the detector (along beam-pipe at leading order)
•
Matter interaction might be efficient to randomize
angular momentum and prevent annihilation
•
Otherwise, might lead to displaced vertex before
annihilation
iQuarkonium as single entity
Hard jet, photon
14
Microscopic String
o
MeV ≤ Λ ≤ GeV ↔ 100 fm ≤ L ≤ 100 A
!
iQuarks are confined into bound states
Salient features:
K.E. ≈ MQ ↔ highly excited
L!Λ
!−1
↔ classical string
−1
J ≈ rp ≈ MQ
MQ ≈ 1 => nearly spherical
No large lever arm to randomize angular mom
Prompt annihilation of these highly excited states?
15
Energy Loss when 2 iQuarks cross (Prevent Annihilation)
Soft Energy
Lossmuck/imuck’’ NP interactions
QCD/iQCD ``brown
==> Energy Loss
energy loss
own muck” interactions
Bjorken’s picture
hard SM stuff
R ∼ Λ−1 or Λ"−1
Soft stuff
Geometric cross section
Fig. 9. Schematic depiction of hadronic fireball and hard annihilation
into muons. Note that the the asymmetry of the muons and the fireball
are in the same direction.
Wave function overlapp
3
Total number
of crossings
M
∼ 10
particle invariant
mass distribution ∼
of the
produced
This gives an additio
Q /Λquirks.
handle on these events.
NP interaction effective up to lmax ∼ MQ /Λ ∼ 103
Angular
Decoheren
∆E ∼ GeV or Λ per crossing
5.7 Non-perturbative Infracolor Interactions
(i)glueballs
hadronic fireball
photons
each crossing
∆E ∼ GeV
We now consider non-perturbative
infracolor interactions of the quirks. There
!
many analogies with the non-perturbative QCD interactions of colored quirks d
cussed in the previous subsection, so our discussion will be brief and highlight t
important differences.
each crossing
The infracolor “brown muck” has a geometrical cross section for interaction, so
also expect ∼ 1 interaction per classical crossing
1 time. As argued in Subsection 3
radiationProb(J
of infracolor glueballs
takes
place
only while
the quirkcrossings
separation is l
√
=
0)
∼
after
N
(Kang
Luty) Ninfracolor interactions will therefore g
than or
of order Λ . and
The non-perturbative
rise to the emission of only ∼ 1 infracolor gluons with total energy ∼ Λ.
Energy loss (visible or invisible)
−1
One important difference with the QCD case is that the infracolor hadrons
Losing
all kinetic energy to soft hadrons: 16g
indirect constraints from precision electroweak constraints and cosmology.
ussion is fairly standard, and our conclusion is that there are no strong
dependent constraints on quirks from these considerations.
Can iGlueballs produce easily and detectable?
iGluons do not carry SM charge ==> Loop Effects
2.1 Coupling to the Infracolor Sector
we assume that the scale of infracolor strong interactions is below the weak
hadrons of the infracolor sector are kinematically accessible to existing exs. However, the standard model is uncharged under infracolor, and therefore
oop is required to couple the sectors. Since the quirks are heavy, this leads
suppressed couplings to the infracolor sector.
eading coupling between the standard model and the infracolor sector at
ies
arises
from
the contributing
diagram
of to
Fig.
Thisofof
gives
rise to model
the
dimension-8
Fig.
1.
graphs
coupling
the
Fig.
1. Loop
Loop
graphs
contributing
tothe
the1a.
coupling
thestandard
standard
model
operator
and
and infracolor
infracolor sector.
sector.
Needs 2 loop to couple
to SM fermions
2 !2
g graphs
Fig. 1.g Loop
2
!2contributing to the coupling of the standard model
F
F
(2.1)
L
∼
eff infracolor
µν ρσ .decay, for example
4
2
e
operator
Eq.
(2.1)
mediates
glueball
to
photons
iGluons
are
hard to produce
and
infracolor
sector.
he operator Eq. (2.1) mediates infracolor
16π mQ glueball decay, for example to photons
at LHC too.
ons.
ons. The
The rate
rate isis ofof order
order
!! the infracolor
"2
op diagram of Fig 1b can couple
gauge fields to dimension-3
22 !2!2 "
2
1
g
g
1
gEq.
g (2.1)Λmediates
operator
infracolor glueball decay,
for example to photons
99
ΓThe
.
(2.2)
Γ∼
∼ 8π
Λ
.
(2.2)
ilinears, but these have
an
additional
helicity
suppression
in
addition
to
the
22m44
16π
or gluons.8πThe
rate
is
of
order
16π mQQ
l loop suppression, and are therefore suppressed. For
! mQ >
" 100 GeV this
2 !2 ∼ 2
hat
this
is
very
sensitive
to
both
Λ
and
m
.
We
have
g g
that this is very sensitive to both Λ and mQQ . We have1
9
Γ
∼
Λ
.
(2.2)
is far weaker than the weak
interactions,
so
production
of
infracolor
gauge
2 m4
##
$$−9
#
$
8π
16π
−8
#
$
−9 mQ
Q
−8
ΛΛ
m
Q
colliders with energy
below
the
quirk
mass
is
completely
negligible.
Probing
cτ
10
m
..
(2.3)
cτ ∼
∼
10
m
(2.3)
Note that this
is very sensitive
to both Λ and mQ . We have
50
GeV
TeV
50
GeV
TeV
r at colliders requires sufficient energy to produce#quirks directly.
$−9 #
$
Better bet: iQuarks
−8>
ee that
for
>
Λdetector
that the
the infracolor
infracolor glueballs
glueballs can
can decay
decay inside
inside aa particle
particle
detectorm
for
Q ΛΛ ∼
cτ ∼ 10 m
.∼
(2.3)
<
V,
while
the
lifetime
becomes
longer
than
the
age
of
the
universe
for
Λ
50
GeV
TeV
<
V, while the
becomes
longerdecays
than the
agedetector
of the universe for Λ ∼∼
Λ! lifetime
≥ 50 GeV,
iglueball
inside
V.
We see that the infracolor glueballs can decay inside a particle detector for Λ >
V.
∼
50 GeV, while the lifetime becomes longer than the age of the universe for Λ <
∼
3
17
Electromagnetic Shower
Soft photons of this energy can be picked up by the
tracking system, as seen in this picture from the ATLAS
event display. (Cheu and Parnell-Lampen)
Taken from Chacko’s talk
18
Harnik and Wizansky [arXiv:0810.3948]
a)
100 % energy loss to photons
b)
6
6
5
5
4
4
3
3
2
2
1
1
0
-800
0
-800
-400
0
400
c)
800
10 % energy loss to photons
90 % to invisible
-400
0
400
800
800
CMB-like analysis
SM background
6
5
!
4
3
2
1
0
-800
-400
0
z
400
Figure 5: Calorimeter energy deposition in the toy detector simulation. The distribution is shown
for (a) bound state radiation with 100% of the energy released in photons, (b) bound state radiation
with 10% of the energy in photons and (c) a minimum bias event. Brighter squares indicate a higher
energy deposition in the cell, however, the scale itself is arbitrary for each figure separately.
19
Cartoon from Harnik and Wizansky [arXiv:0810.3948]
`Antenna Pattern’
Figure 1: A schematic cartoon of the initial and final states of an LHC event with squirk production
via an s-channel W ± . The two protons are incoming along the horizontal axis. The squirks are
produced and oscillate along the dashed axis. The final state includes an antenna pattern of
soft photons (two cone like shapes aligned with the squirk production axis) and a pair of hard
annihilation products, W γ in this case. The search strategy will first involve discovering a resonance
in W γ and then searching for signals of patterns of soft photons in the candidate signal events.
20
A Simple Model
21
DQ denotes a heavy quirk doublet. The quantum number ass
L,R
y Qquirk
doublet.
thebyquirk doublet
under
SUC ! (NThe
SUC (3) ×number
SUL (2)assignment
× UY (1) is for
given
IC ) ×quantum
! (NIC ) × SUC (3) × SUL (2) × UY (1) is given by
tions are given by Q under SUC


C ) × SUC (3) × SUL (2) × UY (1) is given by
(
'
U
1
TCY, NPB
)
 in press, 0810.1524]

 * [Cheung, Keung and 
 µ
.
(1)
Q
=
∼
N
,
1,
2,
" "a
µ a
µ
µ


IC
L,R
− gs Gµ Qγ T Q − eA
e
Uγ
U
+
e
Dγ
D
(
'
'
D
3
U U
D
1
U

!

*
)
*
)
L,R
.
(1)
∼
N
,
1,
2,
g QL,R = µ 
g
Assume
MeV
≤
Λ
"
M
IC
µ
+
µ
−
µ= 
Q
∼
NQIC , 1, 2,

L,R
−
(2)
Zµ vU Uγ UD+ vD Dγ D − √ W3µ Uγ D + Wµ Dγ U
cos θgauge
W
D string scenario)
The
interactionsL,R
are given by 2
(Microscopic
Vectorial
L,R
Gauge Group:
ppressed
mixings among
ctions
are generation
given by indices and ignored possible
)
* quirks.
" "a
µ a
µ
µ
µ
Lgauge = −The
gs Gµ gauge
Qγ T Qinteractions
− eA eU Uγ Uare
+ eDgiven
Dγ D by
− 1) are the generators)of the )SUC ! (NIC ) in*the defining
representation
*
)
*
g
" "a
µ a
µ g
µ
µ
µ
µ
+
µ
−
µ
− gs Gµ Qγ" T Q −−eA eU Uγ
U + e Dγ D
Wµ Uγ D + Wµ Dγ U
(2)
Z
µ vU UγD U + vD Dγ D − √
lives and gs is) its coupling.
For
vector
quirk
Q
=
U
or
D,
we
have
)
cos θW
2
*
)
*
g
g
µ− a µ
µ
µ
µ
µ
+ " µ "a
√
−
D
−
W
Uγ
D
+
W
Dγ
U
(2)
Zµ vU Uγ µ U + vD DγL
=
−
g
G
Qγ
T
Q
−
eA
e
Uγ
U
+
e
Dγ
D
µ s
µ
U
gauge
D
µ
cos θWwe have
1 suppressed generation 2indices
where
ignored possible mixings
among quirks.
vQ = (T3 (QL ) + T3 (QR )) − eQ sin2 θW . and
(3)
*
)
)
g
g
2
µ
µ
a
2
!
T (a = 1,
· · · , NIC
−indices
1) are the
(N
)
in
the
defining
representation
−of the SU
Uγ
U
+
v
Dγ
D −√ W
Z
v
uppressed
generation
and generators
ignored possible
mixings
among
quirks.
C µ IC U
D
cos
θ
2
W
"
he−
third-component
of
the
weak
isospin
for
the
left(right-)
handed
quirk
Okun
where
each
livescharged
and
g isSU
itsθ-leptons
coupling.
vector
quirk
Q = U or D, we have
! (N
1) Fractional
are
thequirk
generators
of the
) in For
theof
defining
representation
C
s
C
IC
me
T
Twe
), they
have
the
same
value
for each
"
3 (Q
L ) = For
3 (Q
R
where
have
suppressed
generation
indices and ignored p
livesvector
and gquirks,
is
its
coupling.
vector
quirk
Q
=
U
or
D,
we
have
1
s
2
Vectorial
=>
Escape
constraints
from
LEP
EW
precision
data
v
=
(T
(Q
)
+
T
(Q
))
−
e
sin
θ
.
(3)
Q
3
L
3
R
Q
W
For each vectorial quirk
doublet,
we
can
also
have
a
Dirac
bare
mass
2
a
2
1
T
(a
=
1,
·
·
·
,
N
2 − 1) are the generators of the SUC ! (NIC )
IC
vQ = (T3 (QL ) + T3 (QR )) − eQ sin θW .
(3)
coupling
withof SM
Higgs
2) is the third-component
Here No
T3 (QYukawa
the weak
isospin
for the left- (right-) handed quirk
L,R
3
"
where each quirk lives and gs is its coupling. For vector quir
Q.third-component
Since we assumeofvector
quirks,
T3 (Q
=T
have the
same value for each
L )the
3 (Q(right-)
R ), they
the
the
weak
isospin
for
lefthanded
quirk
But a Dirac bare mass term is possible
component
of Q. T3For
quirk doublet, we can
1 alsoforhave
me
vector quirks,
(QLeach
) = Tvectorial
eacha Dirac bare mass
3 (QR ), they have the same value
vbeta
(T3 (Q
− eQ sin
Q = decay.
L ) + T3 (Qfor
R )) DM.
Lightest
iQuark
is
stable.
No
weak
Candidate
2 bare mass
For each vectorial quirk doublet, we can also have a Dirac
3
22
iQuark Production at LHC
23
Embedded into GUT
Vector iQuarks can arise in complete SU(5)
5 ⊕ 5̄ → (3, 1) 13 ⊕ (3̄, 1)− 13 ⊕ (1, 2) 12 ⊕ (1, 2)− 12
colored
uncolored
For example, vector-like Higgs in SUSY GUT
In SUSY, any dynamics that generates the supersymmetric
µ term will give mass to the vector iQuarks as well
Scalar quirks (siquarks) appear in models in folded supersymmetry
[Burdman et al, JHEP 0702, 009 (2007)]
24
Quarkonium Production in Hadron Collider
Plus fragmentation, color octet mechanism as well.
25
Colored/Uncolored iQuarks are produced via
QCD/Electroweak hard processes
q
iQ’
QCD: gluon
EW: photon,Z,W
unbreakable string
Λ! ! M
q’
iQ
26
in order to form a quarkonium. Therefore, the quirkonium production rates are not inferior
to the quarkonium, although quirks are only produced via electroweak interactions. We
Open
production cross section for iQuarks at LHC
will discuss more about these interesting phenomena in the next section.
[Cheung, Keung and TCY, NPB in press, 0810.1524]
Cross Sections (pb)
101
100
LHC
-
UU
10-1
-
UD
-
10-2
10-3
100
DD
200
300
400
500
MU or MD (GeV)
-
DU
600
700
800
FIG. 1: Production cross sections for pp → U U, DD, UD and DU at the LHC. The label MU
on the x-axis is for UU, U D and DU production while MD is for DD production. We assume
MU − MD = 10 GeV and set NIC = 3.
27
Open squirk (siquark) production in folded SUSY
(Burdman, Chacko, Goh, Harnik and Krenke, PRD78:075028 (2008) arXiv:0805.4667)
1
0.1
0.01
! (pb)
nomenology associated
quark partners in this
s and strong dynamics
are very different from
hidden valley models.
where there is a large
the matter fields and
e rise to very unusual
reason the quarks (or
ve been dubbed quirks
is, let us first recall the
ider two heavy quarks
in a hard process. As
rt and their distance
mics sets in and some
ic flux tube extending
energy density in the
ergetically favorable to
uark pair, ripping the
adronization allows the
parately.
er hand, such a soft
nt because there are no
omparable to Λ! . The
be, or more simply, the
exceed Λ!2 which is far
wavelength needed to
0.001
0.0001
1e-05
200
400
600
squirk mass (GeV)
800
FIG. 1:
The total cross-section for production of first
generation squirk anti-squirk pairs via an s-channel W + (top
curve) and W − (bottom curve) at the LHC as a function of
the squirk mass. The up and down squirks have been taken
to be degenerate.
iQuark hasthelarger
production
rate
than
scalar
iQuark!
corresponding quarks, but are charged under QCD ,
!
not under QCD. Specifically, under SU(3)C! × SU(3)C ×
!
!
28
Open production of top quirk in Quirky Little Higgs Model
(Cai, Cheng and Terning 0812.0843)
Figure 1: Total cross-sections vs. mass of top quirk
top quirk mass MXT = 800 GeV, about one hundred events with quirk pairs can be
produced.
29
Prompt Annihilation of
iQuarkonium
30
iQuark Annihilations/iQuarkonium Decays
iQuark-antiiQuark annihilation is a hard process -calculable using perturbation theory + factorization
wave function
at origin
Hard kernel
Projection op
W
/
Annihilation Amplitudes
Generic diagrams for 2-body decays
31
We present the decay branching ratios of the S-wave 1 S0 and 3 S1 quirkonium of UU , DD,
1
S neutral iquarkonium
0 2 – 4. In these plots, we have set NIC = 3 and give a small
and the charged UD in Figs.
mass difference of MU − MD = 10 GeV for the cases of charged quirkonium.
-
-
U U 1S0 quirkonium
D D 1S0 quirkonium
1
1
g’ g’ (!’=10 MeV)
Branching Ratios
Branching Ratios
g’ g’ (!’=10 MeV)
W+ W0.1
Z"
W+ W-
0.1
ZZ
Z"
0.01
ZZ
0.01
100
""
150
200
250
300
350
M (GeV)
0.001
400
450
500
100
""
150
200
250
300
M (GeV)
350
400
450
500
FIG. 2: Branching fractions of the quirkonium of (a) 1 S0 (UU) and (b) 1 S0 (DD) versus the quirkonium mass M . We have chosen nQ = 1 and Λ! = 10 MeV in the running α!s .
U U 3S1 quirkonium
atios
u -u + c -c
# $ -$
0.1
D D 3S1 quirkonium
1
d -d + s -s + b b
d -d + s -s + b b
u -u + c -c
# l+ latios
1
Dominant
Decay Mode: Invisible g ! g- ! mode
0.1
# $ -$
# l+ l-
32
FIG. 2: Branching fractions of the quirkonium of (a) 1 S0 (UU) and (b) 1 S0 (DD) versus the quirko-
3
S neutral iquarkonium
! = 10 MeV in the running α! .
nium mass M . We have chosen
n
=
1
and
Λ
Q
s
1
-
1
# $ -$
Branching Ratios
# l+ l-
t t-
W+ W-
0.1
# $ -$
# l+ lt tW+ W-
0.01
g’ g’ g’
Z g’ g’
g’ g’ g’
Z g’ g’
" g’ g’
100
d -d + s -s + b b
u -u + c -c
0.1
0.01
D D 3S1 quirkonium
1
d -d + s -s + b b
u -u + c -c
Branching Ratios
-
U U 3S1 quirkonium
150
200
250
300
M (GeV)
350
400
450
" g’ g’
0.001
500
100
150
200
250
300
M (GeV)
350
400
450
500
FIG. 3: Branching fractions of the quirkonium of (a) 3 S1 (UU) and (b) 3 S1 (DD) versus the quirkonium mass M . We have chosen nQ = 1 and Λ! = 10 MeV in the running α!s .
Dominant decay mode: 2-jet
13
No ZZ, Zγ and γγ modes
WW mode has large cancellation among amplitudes for vector iQuarks
33
Comparison with superheavy Quarkonium
(Barger et al PRD 35, 3366 (1987))
2-jet
WW (no large cancellation)
34
S wave charged iquarkonium
-
-
U D 1S0 quirkonium
1
U D 3S1 quirkonium
1
u -d + c -s
" l+ #
W+ !
Branching Ratios
Branching Ratios
0.8
0.6
+
W Z
0.4
tb
0.1
W+ Z
0.01
W+ g’ g’
0.2
0
100
150
200
250
300
M (GeV)
350
400
450
500
100
150
200
250
300
350
M (GeV)
400
450
500
FIG. 4: Branching fractions of the charged quirkonium of (a) 1 S0 (UD) and (b) 3 S1 (UD) versus the
quirkonium mass M . We have chosen nQ = 1 and Λ! = 10 MeV in the running α!s .
The pseudoscalar state, 1 S0 , only decays into a pair of gauge bosons for both UU and
Similar to charged quarkonium
DD, as shown in Fig. 2. When the mass M of the quirkonium is below 2mW , the γγ
and Zγ mode dominate; especially for UU the γγ mode is important because of the larger
electric charge of U quirk. When the mass M of the quirkonium is above 2mW , the W + W −
35
Summary
Phenomenology of iQuarkonium is quite different from quarkonium.
iQuarkonium collider signals involve 3 steps:
(1) iQuark pair production
(2) Soft energy loss (visible and invisible)
(3) Hard annihilation in SM particles
iQuarks linked by macroscopic string may lead to hidden tracks.
Detailed analysis is missing but interesting string dynamics.
iQuarks linked by microscopic string annihilates promptly into
SM final states; distinguishable from superheavy quarkonium.
Energy loss via (i)glueballs and soft photon emission are important
signals since the iQuarkonium was formed in highly excited state.
NP QCD effects for colored iQuarks can give rise to even
more spectacular signals of hadronic fireball from energy loss
along with dijet and dilepton resonances.
36
iQuarks are not un-interesting stuff!
37
Backup Slides
38
Comparison with folded supersymmetry
(Burdman, Chacko, Goh, Harnik and Krenke, PRD78:075028 (2008) arXiv:0805.4667)
FIG. 2: Branching ratios for a charged squirk-antisquirk pair
into various final states, as a function of the relative velovity
of the pair.
Qualitative the same ?
threshold the most important channel is to W + photon,
with annihilation to two fermions becoming significant
the W+photon ann
Before moving
briefly comment o
W+glueball.
Th
naively vanishes b
portional to the
Annihilating to W
least two gluons, an
However, there ma
hilation to occur. I
QCD [17]. These e
states consisting of
gluon. Lattice stud
a variety of spin an
some states that m
and some that do n
not mix with meso
pions. However in
semi-stable. In par
mass splitting bet
corresponding (sam
smaller than the e
this is indeed the
be stable to glueb
39
will thus annihilat