Model-independent Z' searches at modern colliders
The model-independent constraints on the Abelian Z' couplings from the LEP data are applied to estimate the Z' production in experiments at hadron colliders. The Z' contribution to the Drell-Yan process at modern hadron colliders is analyzed. The results are compared with model-depend...
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| Опубліковано в: : | Вопросы атомной науки и техники |
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| Дата: | 2012 |
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| Цитувати: | Model-independent Z' searches at modern colliders / A.V. Gulov, A.A. Kozhushko, V.V. Skalozub, A.A. Pankov, A.V. Tsytrinov // Вопросы атомной науки и техники. — 2012. — № 1. — С. 48-52. — Бібліогр.: 16 назв. — англ. |
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Digital Library of Periodicals of National Academy of Sciences of Ukraine| _version_ | 1859520394036248576 |
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| author | Gulov, A.V. Kozhushko, A.A. Skalozub, V.V. Pankov, A.A. Tsytrinov, A.V. |
| author_facet | Gulov, A.V. Kozhushko, A.A. Skalozub, V.V. Pankov, A.A. Tsytrinov, A.V. |
| citation_txt | Model-independent Z' searches at modern colliders / A.V. Gulov, A.A. Kozhushko, V.V. Skalozub, A.A. Pankov, A.V. Tsytrinov // Вопросы атомной науки и техники. — 2012. — № 1. — С. 48-52. — Бібліогр.: 16 назв. — англ. |
| collection | DSpace DC |
| container_title | Вопросы атомной науки и техники |
| description | The model-independent constraints on the Abelian Z' couplings from the LEP data are applied to estimate the Z' production in experiments at hadron colliders. The Z' contribution to the Drell-Yan process at modern hadron colliders is analyzed. The results are compared with model-dependent predictions and present experimental data from the Tevatron and the LHC. The lower bounds on the Z' mass are derived and the Z' discovery limit in the LHC experiments is found.
С помощью модельно-независимых ограничений на константы связи абелевого Z'-бозона получены оценки процессов рождения Z' в экспериментах на адронных коллайдерах. Изучен вклад Z'-бозона в процесс Дрелла-Яна. Проведено сравнение полученных результатов с модельно-зависимыми предсказаниями и экспериментальными данными ускорителей Tevatron и LHC. Получена нижняя граница значения массы Z'-бозона, а также предельные значения массы, при которых Z' будет обнаружен в эксперименте LHC.
За допомогою модельно-незалежних обмежень констант зв’язку абелевого Z'-бозона отримано оцінки процесів народження Z'-бозона в експериментах на гадронних колайдерах. Досліджено внесок Z' в процес Дрелла-Яна. Виконано порівняння отриманих результатів з модельно-залежними результатами та експериментальними даними прискорювачів Tevatron та LHC. Отримана нижня границя маси Z'-бозона, а також граничні значення маси, при яких Z'-бозон буде знайдено в експериментах LHC.
|
| first_indexed | 2025-11-25T20:53:29Z |
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| fulltext |
MODEL-INDEPENDENT Z ′ SEARCHES AT MODERN
COLLIDERS
A.V. Gulov 1, A.A. Kozhushko 1∗, V.V. Skalozub 1,
A.A. Pankov 2, A.V. Tsytrinov 2
1Dnipropetrovsk National University, Dnipropetrovsk, Ukraine
2The Abdus Salam ICTP Affiliated Centre at the Technical University of Gomel, Gomel, Belarus
(Received October 31, 2011)
The model-independent constraints on the Abelian Z′ couplings from the LEP data are applied to estimate the Z′
production in experiments at hadron colliders. The Z′ contribution to the Drell-Yan process at modern hadron
colliders is analyzed. The results are compared with model-dependent predictions and present experimental data
from the Tevatron and the LHC. The lower bounds on the Z′ mass are derived and the Z′ discovery limit in the LHC
experiments is found.
PACS: 11.10.Gh, 12.60.Cn, 14.70.Pw
1. INTRODUCTION
A new heavy neutral vector boson (Z ′ boson) is prob-
ably the most perspective intermediate state in scat-
tering processes of quarks and leptons which could be
discovered in experiments at modern hadron collid-
ers. At the parton level it can appear in the annihi-
lation channel carrying a large part of energy of the
colliding particles, its mass is allowed to be of order
1 TeV by current experimental constraints, and it is
a necessary component of popular grand unification
theories and other models with extended gauge sector
(see [1–3] for review).
The most accurate description of resonances re-
quires to calculate scattering amplitudes with inter-
mediate virtual states. But if the resonance is a nar-
row one, then it can be described by the production
cross-section of the on-shell particle and by the decay
widths (total and partial). These parameters can be
easily constrained from previous experiments giving a
possibility to estimate the perspectives of the current
experiments.
The Tevatron and LHC collaborations usually
perform the model-dependent fits trying to discover
Z ′ boson hints. Of course, effects of Z ′ boson can
be calculated in details for each specific model be-
yond the SM. Some set of popular E6 based models
and left-right models is usually considered in this ap-
proach. However, probing the set we can still miss
the actual Z ′ model. In this regard, it is useful to
complement model-dependent Z ′ searching by some
kind of model-independent analysis, i.e. the analysis
covering a lot of models.
Almost all of the usually considered models be-
long to the models with so-called Abelian Z ′ boson.
In Ref. [4,5] we found the relations which hold in any
model containing the Abelian Z ′ boson and satisfying
the following conditions: 1) only one neutral vector
boson exists at the energy scale about 1... 10 TeV;
2) the Z ′ boson can be phenomenologically described
by the effective Lagrangian [1–3] at low energies;
3) the Z ′ boson and other possible heavy particles
are decoupled at considered energies, and the the-
ory beyond the Z ′ decoupling scale is either one- or
two-Higgs-doublet standard model (THDM); 4) the
SM gauge group is a subgroup of a possible extended
gauge group of the underlying theory. So, the only
origin of possible tree-level Z ′ interactions to the SM
vector bosons is the Z–Z ′ mixing. The relations re-
duce significantly the number of unknown Z ′ para-
meters. This allows to constrain the parameters by
existing experiments as well as to predict the quan-
tities used in the analysis of the Tevatron and LHC
experiments.
Recently we summarized the information about
Z ′ couplings to leptons and quarks which can be ex-
tracted from the LEP experiments [7, 8]. The Z ′
coupling to axial-vector currents was constrained by
both LEP I and LEP II μ+μ−, τ+τ− data. In differ-
ent processes it shows hints at about 1σ confidence
level (CL) with approximately the same maximum-
likelihood value. This value can be used in estimates
of observables in the Tevatron and LHC experiments.
As for the couplings to vector currents, the Z ′ cou-
pling constant to electron can be constrained by the
LEP II e+e− data only. Although the backward scat-
tering shows a signal at the 2σ CL, the maximum-
likelihood value is outside of the 95% CL interval cal-
culated by the complete set of bins. In this situation
we refrain from using that maximum-likelihood value
∗Corresponding author E-mail address: a.kozhushko@yandex.ru
48 PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY, 2012, N 1.
Series: Nuclear Physics Investigations (57), p. 48-52.
in our estimates. Nevertheless, the vector coupling
is constrained at the 95% CL. The upper bound on
the electron vector coupling agrees closely with the
corresponding upper bound on the axial-vector cou-
pling. This fact allows us to suppose the rest of vector
couplings to be constrained by the same value, since
no evident signals were discovered in other scatter-
ing processes measured by the LEP collaborations.
It is worth to note that all the conclusions derived
from the LEP data are also valid if one considers the
THDM as the low-energy theory instead of the usual
minimal SM.
Our main goal is to obtain estimates for the Z ′ pa-
rameters used in searching for the narrow resonance
by applying the LEP constraints on the Z ′ couplings.
Both the minimal SM and the THDM will be consid-
ered as the low-energy theory. Also we compare these
results to the Tevatron and the LHC experimental
data and model-dependent predictions.
2. THEORETICAL AND EXPERIMENTAL
CONSTRAINTS ON THE Z ′ COUPLINGS
In this paper we discuss mainly the Z ′ couplings
to the vector and axial-vector fermion currents de-
scribed by the Lagrangian
LZf̄f =
1
2
Zμf̄γ
μ
[
(vSM
fZ + γ5aSM
fZ ) cos θ0+
+(vf + γ5af ) sin θ0
]
f,
LZ′f̄f =
1
2
Z ′
μf̄γ
μ
[
(vf + γ5af ) cos θ0−
−(vSM
fZ + γ5aSM
fZ ) sin θ0
]
f, (1)
where f is an arbitrary SM fermion state; af and vf
are the Z ′ couplings to the axial-vector and vector
fermion currents; θ0 is the Z–Z ′ mixing angle; vSM
fZ ,
aSM
fZ are the SM couplings of the Z-boson. Such a
parametrization is suggested by a number of natural
conditions. First of all, the Z ′ interactions of renor-
malizable types are to be dominant at low energies
∼ mW . The non-renormalizable interactions gener-
ated at high energies due to radiation corrections are
suppressed by the inverse heavy mass 1/mZ′ (or by
other heavier scales 1/Λi � 1/mZ′) and therefore at
low energies can be neglected. It is also assumed that
the Z ′ is the only neutral vector boson with the mass
∼ mZ′ . The Z ′ interactions to the SM gauge fields
at the tree level are possible due to the Z–Z ′ mixing
only. The explicit Lagrangian describing Z ′ couplings
to the SM fields can be found in [6].
The parameters af , vf , and θ0 must be fitted in
experiments. In a particular model, one has some
specific values for them. In case when the model is
unknown, these parameters remain potentially arbi-
trary numbers. In most investigations they are usu-
ally considered as independent ones. However, this is
not the case if one assumes that the underlying ex-
tended model is a renormalizable one. In Refs. [4, 5]
it was shown that these parameters are correlated as
vf − af = vf∗ − af∗ , af = T3f g̃Ỹφ, (2)
where f and f∗ are the partners of the SU(2)L
fermion doublet (l∗ = νl, ν
∗ = l, q∗u = qd and q∗d =
qu), T3f is the third component of the weak isospin,
and g̃Ỹφ determines the Z ′ interactions to the SM
scalar fields (see [7] for details). The parameter g̃Ỹφ
defines also the Z–Z ′ mixing angle in (1).
As it was discussed in [7,8], the relations (2) cover
a popular class of models based on the E6 group (the
so called LR, χ-ψ models) and other models, such as
the Sequential SM. Thus, they describe correlations
between Z ′ couplings for a wide set of models be-
yond the SM. That is the reason to call the relations
model-independent ones.
At low energies the Z ′ couplings enter the cross-
section together with the inverse Z ′ mass, so it is
convenient to introduce the dimensionless couplings
āf =
mZ√
4πmZ′
af , v̄f =
mZ√
4πmZ′
vf , (3)
which are constrained by experiments. Since the
axial-vector coupling is universal, we will use the no-
tation
ā = ād = āe− = −āu = −āν . (4)
Then the Z–Z ′ mixing is
θ0 ≈ −2ā
sin θW cos θW√
αem
mZ
mZ′
. (5)
It also follows from (2) that for each fermion doublet
only one vector coupling is independent:
v̄fd
= v̄fu + 2ā. (6)
As a result, Z ′ couplings can be parameterized by
seven independent constants ā, v̄u, v̄c, v̄t, v̄e, v̄μ, v̄τ .
Recently we obtained limits on Z ′ couplings from
the LEP I and LEP II data [7, 8]. We found some
hints of Z ′ boson at 1-2σ CL. Namely, the constants ā
and v̄e show non-zero maximum-likelihood (ML) val-
ues. The axial-vector coupling ā can be constrained
by the LEP I data (through the mixing angle) and
by the LEP II e+e− → μ+μ−, τ+τ− data. The cor-
responding ML values are very close to each other.
This value
ā2 = 1.3 × 10−5 (7)
will be used in our estimates. The 95% CL intervals
were also obtained by the experimental data:
0 < ā2 < 3.61 × 10−4,
4 × 10−5 < v̄2
e < 1.69 × 10−4. (8)
Other Z ′ coupling constants cannot be severely
constrained by existing data. Among them v̄u, v̄c,
and v̄μ play an important role in the process qq̄ →
Z ′ → μ+μ− which is most perspective to discover the
Z ′ resonance. Taking into account that no evident
signals of new physics were found by the LEP col-
laborations in the processes involving quarks, muons
and tau-leptons, we constrain the values of v̄u, v̄c, v̄t,
49
v̄μ, and v̄τ by the widest interval from the 95% CL
intervals for ā and v̄e:
0 < v̄2
other f < 4 × 10−4. (9)
Due to the existence of the ML value for the axial-
vector coupling we perform the so called maximum-
likelihood estimate for the production cross-section
and decay widths. In this approach the axial-
vector coupling is substituted by its ML value ā =√
1.3 × 10−5. The vector coupling v̄u is varied in its
95% CL interval. The uncertainty from the parton
distribution functions should be also added. This es-
timate scheme can be considered as an ‘optimistic’
scenario to discover the Z ′ boson.
The knowledge of possible values of the Z ′ cou-
plings allows to estimate the Z ′ production cross-
section at the LHC and Tevatron and the Z ′ decay
width without specifying the model beyond the SM.
3. Z ′ PRODUCTION CROSS-SECTION
AND WIDTH
In modern experiments Z ′ bosons are expected
to be produced in proton-antiproton collisions pp̄ →
Z ′ (Tevatron) or proton-proton collisions pp → Z ′
(LHC). At the parton level both the processes are de-
scribed by the annihilation of a quark-antiquark pair,
qq̄ → Z ′. The Z ′ production cross-section is the re-
sult of usual integration of the partonic cross-section
σqq̄→Z′ with the parton distribution functions. We
use the parton distribution functions provided by the
MSTW PDF package [9] taking into account the 90%
CL uncertainties of the parton distribution functions
provided by the package.
The Z ′ decay width ΓZ′ can be calculated by us-
ing the optical theorem:
ΓZ′ = −ImG(m2
Z′ )/mZ′ , (10)
where G(p2) is the two-point one-particle-irreducible
Green’s function. We compute ΓZ′ at the one-loop
level with the help of the FeynArts, FormCalc and
LoopTools software [10, 11]. As a result, we obtain
also all the partial widths corresponding to Z ′ decays
into two SM particles.
All the Z ′ couplings to the SM scalar and vec-
tor bosons can be determined by the universal axial-
vector constant af and can be constrained. Then the
partial widths corresponding to Z ′ decays into scalar
and vector bosons are proportional to a2
f . As for the
fermionic decays, the width can be written in the
form
ΓZ′→f̄f = a2
fΓa2
f
+ afvfΓafvf
+ v2
fΓv2f . (11)
Now we are able to estimate the Z ′ contribution to
the Drell-Yan process at the Tevatron and the LHC.
4. COMPARISON TO TEVATRON AND
LHC DATA
The recent experiments at the LEP gave some
hints of the Abelian Z ′ boson. It is interesting to
speculate about the question how can those hints look
like at Tevatron and LHC experiments. Taking the
LEP ML value of the axial-vector coupling we can
give predictions under the assumption that a signal
of the Abelian Z ′ boson has been probably observed
in the LEP data.
10-1
1
10
102
0.2 0.4 0.6 0.8 1
mZ', TeV
σ(pp→Z’)×BR(Z’→e+e-), fb-
Obs Exp Mod ML
ML
Exp.
Obs.
Mod.
a
1
10
102
0.2 0.4 0.6 0.8 1
mZ', TeV
σ(pp→Z’)×BR(Z’→e+e-), fb-
Obs Exp Mod ML
Exp. σ2±
ML
Exp.
Obs.
Mod.
b
10
102
0.2 0.4 0.6 0.8 1 1.2 1.4
mZ', TeV
σ(pp→Z’)×BR(Z’→µ+
µ
-), fb-
Obs Exp Mod ML
Exp. σ2±
ML
Exp.
Obs.
Mod.
c
Fig. 1. The ML domains for σ(pp̄ → Z ′) × BR(Z ′ → e+e−) and σ(pp̄ → Z ′) × BR(Z ′ → μ+μ−)
at
√
s = 1.96 TeV together with the experimentally obtained upper limits on these contributions and
E6-model-based predictions. In all plots the filled areas represent the ML estimates; the E6-model predictions
are plotted in solid lines. The models are (corresponding to the plotted lines from left to right): Z ′
I, Z
′
sec,
Z ′
N, Z ′
ψ, Z ′
χ, Z
′
η and SSM Z ′. The expected and observed 95% CL upper limits on the Z ′ contribution are
shown as the dashed lines and line charts, respectively, and the hatched areas are the 2σ standard deviation
bands for the expected values. The estimates for the dielectron channel compared to the data from CDF [12]
and D0 [14] are presented in Figs. (a) and (b). In Fig. (c) the dimuon channel estimate and the CDF
results [13] are shown
50
1
10
10
2
10
3
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
mZ’, TeV
σ(pp→Z’) BR (Z’→l
+
l
-
), fb 7 TeV
Obs Exp Mod ML µ δe
Exp. σ2�
Exp.
Mod.
µ µ+ -
e e+ -
Fig. 2. The same as in Fig. 1 at
√
s = 7 TeV. The
filled areas represent the ML estimates (light filling
is for dimuons, dark filling is for dielectrons; the E6
and SSM model predictions are plotted in solid lines
(from left to right: Z ′
ψ, Z ′
χ, Z
′
SSM). The expected
95% CL upper limit on the Z ′ contribution is shown
is the dashed lines, and the hatched area is the 2σ
standard deviation band for the expected value. The
estimates for the combined dilepton channel are com-
pared to the data from ATLAS [15]
On the other hand the 95% CL bounds on possi-
ble Z ′ couplings to the SM particles are left behind
the LEP experiments. Taking these bounds for all
the Z ′ couplings we can exclude some values of the
observables at hadron colliders. In this scheme the
values outside of the predicted intervals are forbid-
den for the Abelian Z ′ boson. Being measured in
experiments, such values have to be interpreted as a
signal of new physics which is something else than the
Z ′ boson. For example, considering the Z ′ width, we
can expect ΓZ′ ×(1 TeV/mZ′)3 � 10... 150 GeV from
the ML estimate, and we can think about the NWA
for mZ′ ≤ 2 TeV.
Now let us present the ML estimate for the Drell-
Yan cross-section for the Tevatron experiments. As
it was mentioned, in this case the NWA can be ap-
plied and the Z ′ contribution to the cross-section of
the pp (pp̄) → ll̄ process reads σ(pp (pp̄) → Z ′) ×
BR(Z ′ → ll̄) where the branching ratio can be ex-
tracted from the total and partial Z ′ decay widths.
The experimental bounds on the Z ′ contribution to
the Drell-Yan process at the Tevatron are available
in [12–14] together with the predictions from popu-
lar Z ′ models. The comparison between those results
and our ML estimate for σ(pp̄→ Z ′ → e+e−, μ+μ−)
is presented in Fig. 1.
In Fig. 2 the same estimations are presented for
the LHC case. The experimental data together with
the model predictions are taken from [15].
Our model-independent maximum-likelihood es-
timates cover the predictions of all the popular Z ′
models. The model-independent lower bound on the
Z ′ mass is still about 400 GeV for the Tevatron data
and 700 GeV for the LHC data whereas the popular
models give larger values.
Fig. 3. The model-independent discovery limit of
the Z ′ boson in the LHC experiments at 14 TeV with
the luminosity 100 fb−1. The predictions from the
popular models are also shown
In addition to the lower bound on mZ′ we can
also estimate the discovery limit for the Abelian Z ′
boson at the LHC experiments [16]. We define the
Z ′ boson discovery in experiments as at least ten Z ′
events, and no less than the 5σ excess over the SM
background must be detected. At any value of mZ′
this condition sets the minimal number of Z ′ events
necessary for the Z ′ discovery. In Fig. 3 we compare
the minimal necessary number of Z ′ events with the
largest number of Z ′ events which can be realized un-
der the model-independent LEP constraints on the
Z ′ couplings. As it is seen the discovery of the Z ′
with mZ′ > 8 TeV is excluded in the LHC experi-
ments at 14 TeV with the luminosity 100 fb−1. The
model-independent discovery limit is naturally higher
than the values predicted by the popular models also
shown in Fig. 3.
5. CONCLUSIONS
The model-independent relations for the Z ′ cou-
plings give a good possibility to reduce the number
of unknown Z ′ parameters. As a consequence, the
Z ′ width and the production cross-sections of the
processes at modern hadron colliders can be esti-
mated using the constraints on the Z ′ couplings ob-
tained from previous experiments at LEP. A com-
bined analysis of the LEP, Tevatron and LHC data
seems to be possible.
Our new model-independent results are comple-
mentary to the usual model-dependent schemes. The
predictions of all the popular Z ′ models agree with
our model-independent bounds.
Finally the Z ′ hints observed in the LEP data
can be still hidden as the resonance in the Tevatron
and LHC experiments. The model-independent lower
bound is near 400 GeV/700 GeV from Tevatron/LHC
data. The LHC experiments at 14 TeV with the lu-
minosity 100 fb−1 can discover the Z ′ boson with the
mass no more than 8 TeV.
51
References
1. A. Leike. The phenomenology of extra neutral
gauge bosons // Physics Reports. 1999, v. 317,
p. 143.
2. P. Langacker. The Physics of Heavy Z ′ Gauge
Bosons // Rev. Mod. Phys. 2008, v. 81, p. 1199-
1228; arXiv : 0801.1345 [hep-ph].
3. T. Rizzo. Z ′ Phenomenology and the LHC //
arXiv : hep-ph/0610104.
4. A.V. Gulov, V.V. Skalozub. Renormalizability
and model independent description of Z ′ signals
at low energies // Eur. Phys. J. 2000, v. C17,
p. 685; arXiv : hep-ph/0004038v2.
5. A.V. Gulov, V.V. Skalozub. Renormalizability
and the model independent observables for
abelian Z ′ search // Phys. Rev. 2000, v. D61,
055007; arXiv : hep-ph/9906213v1.
6. A.V. Gulov, A.A. Kozhushko. Model-indepen-
dent estimates for the Abelian Z ′ boson at mod-
ern hadron colliders // Int. J. Mod. Phys. 2011,
v. A26, p. 4083-4100; arXiv : 1105.3025v1 [hep-
ph].
7. A.V. Gulov, V.V. Skalozub. Model independent
search for Z ′-boson signals // arXiv : 0905.2596v2
[hep-ph].
8. A.V. Gulov, V.V. Skalozub. Fitting of Z ′ pa-
rameters // Int. J. Mod. Phys. 2010, v. A25,
p. 5787-5815; arXiv : 1009.2320v1 [hep-ph].
9. A.D. Martin, W.J. Stirling, R.S. Thorne,
G. Watt. Parton distributions for the LHC
// Eur. Phys. J. 2009, v. C63, p. 189;
http://projects.hepforge.org/mstwpdf/.
10. T. Hahn. Generating Feynman Diagrams and
Amplitudes with FeynArts 3 // Comput. Phys.
Commun. 2001, v. 140, p. 418; arXiv : hep-
ph/0012260v2; http://www.feynarts.de/.
11. T. Hahn, M. Perez-Victoria. Automatized
One-Loop Calculations in 4 and D dimen-
sions // Comput. Phys. Commun. 1999,
v. 118, p. 153; arXiv : hep-ph/9807565v1;
http://www.feynarts.de/formcalc/;
http://www.feynarts.de/looptools/.
12. T. Aaltonen et al. [CDF Collaboration]. Search
for High-Mass e+e− Resonances in pp̄ Collisions
at
√
s =1.96 TeV // Phys. Rev. Lett. 2009, v. 102,
031801; arXiv : 0810.2059.
13. T. Aaltonen et al. [CDF Collaboration]. A search
for high-mass resonances decaying to dimuons at
CDF // Phys. Rev. Lett. 2009, v. 102, 091805;
arXiv : 0811.0053.
14. V. Abazov, et al. [D0 Collaboration]. Search for
a heavy neutral gauge boson in the dielectron
channel with 5.4 fb−1 of pp̄ collisions at
√
s =
1.96 TeV // Phys. Lett. 2011, v. B695, p. 88;
arXiv : 1008.2023.
15. ATLAS Collaboration. Search for dilepton reso-
nances in pp collisions at
√
s = 7 TeV with the
ATLAS detector // arXiv : 1108.1582v2 [hep-ex].
16. A. Babich et al. Searches for Z ′ bosons and their
identification at the LHC // NAN of Belarus Bul-
letin. 2011, N 2, p. 89.
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| id | nasplib_isofts_kiev_ua-123456789-106980 |
| institution | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| issn | 1562-6016 |
| language | English |
| last_indexed | 2025-11-25T20:53:29Z |
| publishDate | 2012 |
| publisher | Dnipropetrovsk National University |
| record_format | dspace |
| spelling | Gulov, A.V. Kozhushko, A.A. Skalozub, V.V. Pankov, A.A. Tsytrinov, A.V. 2016-10-10T15:49:14Z 2016-10-10T15:49:14Z 2012 Model-independent Z' searches at modern colliders / A.V. Gulov, A.A. Kozhushko, V.V. Skalozub, A.A. Pankov, A.V. Tsytrinov // Вопросы атомной науки и техники. — 2012. — № 1. — С. 48-52. — Бібліогр.: 16 назв. — англ. 1562-6016 PACS: 11.10.Gh, 12.60.Cn, 14.70.Pw https://nasplib.isofts.kiev.ua/handle/123456789/106980 The model-independent constraints on the Abelian Z' couplings from the LEP data are applied to estimate the Z' production in experiments at hadron colliders. The Z' contribution to the Drell-Yan process at modern hadron colliders is analyzed. The results are compared with model-dependent predictions and present experimental data from the Tevatron and the LHC. The lower bounds on the Z' mass are derived and the Z' discovery limit in the LHC experiments is found. С помощью модельно-независимых ограничений на константы связи абелевого Z'-бозона получены оценки процессов рождения Z' в экспериментах на адронных коллайдерах. Изучен вклад Z'-бозона в процесс Дрелла-Яна. Проведено сравнение полученных результатов с модельно-зависимыми предсказаниями и экспериментальными данными ускорителей Tevatron и LHC. Получена нижняя граница значения массы Z'-бозона, а также предельные значения массы, при которых Z' будет обнаружен в эксперименте LHC. За допомогою модельно-незалежних обмежень констант зв’язку абелевого Z'-бозона отримано оцінки процесів народження Z'-бозона в експериментах на гадронних колайдерах. Досліджено внесок Z' в процес Дрелла-Яна. Виконано порівняння отриманих результатів з модельно-залежними результатами та експериментальними даними прискорювачів Tevatron та LHC. Отримана нижня границя маси Z'-бозона, а також граничні значення маси, при яких Z'-бозон буде знайдено в експериментах LHC. en Dnipropetrovsk National University Вопросы атомной науки и техники Section A. Quantum Field Theory Model-independent Z' searches at modern colliders Модельно-независимые поиски Z'-бозона на современных коллайдерах Модельно-незалежні пошуки Z' бозона на сучасних колайдерах Article published earlier |
| spellingShingle | Model-independent Z' searches at modern colliders Gulov, A.V. Kozhushko, A.A. Skalozub, V.V. Pankov, A.A. Tsytrinov, A.V. Section A. Quantum Field Theory |
| title | Model-independent Z' searches at modern colliders |
| title_alt | Модельно-независимые поиски Z'-бозона на современных коллайдерах Модельно-незалежні пошуки Z' бозона на сучасних колайдерах |
| title_full | Model-independent Z' searches at modern colliders |
| title_fullStr | Model-independent Z' searches at modern colliders |
| title_full_unstemmed | Model-independent Z' searches at modern colliders |
| title_short | Model-independent Z' searches at modern colliders |
| title_sort | model-independent z' searches at modern colliders |
| topic | Section A. Quantum Field Theory |
| topic_facet | Section A. Quantum Field Theory |
| url | https://nasplib.isofts.kiev.ua/handle/123456789/106980 |
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