Analysis of the Higgs boson through
CIMA MasterClass: an educational experience with
Modern Physics students at the Central University of Ecuador
José Ricardo Aulestia-Ortiz
Universidad Central del Ecuador, Quito, Ecuador, Facultad de Filosofía
Letras y Ciencias de la Educación
jraulestia@uce.edu.ec, https://orcid.org/0000-0001-5825-2487
William Arnulfo Meneses-Rodríguez
Universidad Central del Ecuador. Quito Ecuador, Facultad de Filosofía
Letras y Ciencias de la Educación
wameneses@uce.edu.ec, https://orcid.org/0009-0006-2411-600X
Claudia Tonato-Ortiz
Universidad Central del Ecuador, Quito, Ecuador Centro de Física crtonato@uce.edu.ec
https://orcid.org/0009-0004-9977-9444.
Fernanda Gissela Imbaquingo-Andrango
Universidad Tecnológica ECOTEC, Quito, Ecuador Carrera de Educación fimbaquingoa@ecotec.edu.ec
https://orcid.org/0009-0004-8589-0600
Higgs
and other physicists as part of the Standard Model of particle physics. Its
existence explains the mechanism by which elementary particles acquire mass,
postulating the presence of an invisible field, the Higgs field, that permeates
the entire universe. When particles interact with this field, they obtain mass
proportional to the intensity of their interaction. For decades, scientists
searched for experimental evidence of this particle. Finally, in 2012,
experiments conducted at the Large Hadron Collider (LHC) at CERN confirmed its
existence, validating the Standard Model and marking a milestone in modern
physics. Due to its importance in understanding the universe, the Higgs boson
was nicknamed the "God particle," although this term generated some
controversy within the scientific community. Its discovery allowed scientists
to delve deeper into the origin of matter's fundamental properties and explore
new frontiers in physics, such as its relationship with dark energy and the
fate of the universe. This study aims to demonstrate collaborative work and the
identification of elementary particles using the CIMA simulator, available at
www.i2u2.org/elab/cms/, with the collaboration of students from the Physics and
Mathematics program at the Central University of Ecuador during the 2024-2025
academic period, enabling an interactive exploration of particle physics.
Keywords: Higgs boson,
Standard Model, Energía Oscura, Dark Energy, Campo de Higgs, Higgs
Field.
Resumen
El
bosón de Higgs es una partícula fundamental propuesta teóricamente en 1964 por
Peter Higgs y otros físicos como parte del Modelo Estándar de la física de
partículas. Su existencia explica el mecanismo por el cual las partículas
elementales adquieren masa, postulando la presencia de un campo invisible, el
campo de Higgs, que permea todo el universo. Cuando las partículas interactúan
con este campo, obtienen una masa proporcional a la intensidad de su
interacción. Durante décadas, los científicos buscaron evidencia experimental
de esta partícula. Finalmente, en 2012, los experimentos realizados en el Gran
Colisionador de Hadrones (LHC) del CERN confirmaron su existencia, validando el
Modelo Estándar y marcando un hito en la física moderna. Debido a su importancia
en la comprensión del universo, el bosón de Higgs fue apodado "la
partícula de Dios", aunque este término generó cierta controversia en la
comunidad científica. Su descubrimiento permitió profundizar en el origen de
las propiedades fundamentales de la materia y explorar nuevas fronteras en la
física, como su relación con la energía oscura y el destino del universo. Este
estudio tiene como objetivo evidenciar el valor del trabajo colaborativo y la
identificación de partículas elementales mediante el uso del simulador CIMA,
promoviendo una aproximación interactiva y formativa a la física de partículas
en estudiantes universitarios. El paradigma que subyace en la búsqueda del
bosón de Higgs, disponible en www.i2u2.org/elab/cms/,con la colaboración
de los estudiantes de la carrera de Física y Matemática de la Universidad
Central del Ecuador durante el período 2024-2025, permitiendo explorar la
física de partículas de manera interactiva
Palabras clave Bosón de Higgs, Modelo Estándar, Energía
Oscura, Campo de Higgs
Introduction
Advances in modern physics
have been driven by the integration of innovative technology with teaching
methods that foster the connection between theory and practice. In this
context, Masterclass's CIMA simulator has established itself as an essential
tool for exploring elementary particles, enabling real-time measurement and
analysis of events related to the Higgs boson.
In the search for the Higgs boson, students
not only acquire theoretical knowledge about the interaction of fundamental
particles, but also apply concepts in simulated experimental environments,
reinforce their understanding through direct observation of physical processes.
This experience facilitates active learning, where participation and analysis
are essential for the construction of knowledge.
In addition, the approach used in CIMA's
Masterclass highlights the interconnection between the Higgs boson and
particles such as quarks (especially the top quark) and gauge bosons, offering
a detailed view of how the Higgs boson confers mass on other fundamental
particles. The ability to visualize and study these phenomena within a
simulated environment transforms teaching into a meaningful process, in which
theory comes to life through experimentation and critical analysis.
This initiative is carried out by the
teachers and students of the ninth semester of the Optics and Modern Physics
course, belonging to the Experimental Sciences, Mathematics, and Physics
Education program at the Central University of Ecuador. Through the use of
advanced technology such as the CIMA simulator, participants strengthen their
understanding of particle physics, promoting deep and applied learning, which
is essential in 21st-century scientific education.
In summary, these research activities promote
participatory, contextualized, and research-oriented higher education, where
students become protagonists in the process of discovery.
Methodology
The methodological approach
of this research is based on a constructivist and scientific inquiry paradigm,
in which students actively participate in the construction of knowledge through
the analysis of simulated data and its comparison with the Standard Model.
By involving students in real simulations of
particle collisions, experiential learning is promoted that goes beyond
abstract theory. The search for the Higgs boson integrates knowledge of
physics, mathematics, statistics, computing, and the philosophy of science,
which enriches the student's comprehensive education. Analyzing experimental
data, interpreting results, and contrasting them with theoretical predictions
strengthens key skills in scientific training.
Studying a discovery as recent and
revolutionary as that of the Higgs boson awakens interest in research and shows
that modern physics is alive and evolving. The use of tools such as CERN
simulators or CIMA Masterclasses brings cutting-edge research closer to the
university classroom.
The formation of student participants in the
CIMA Masterclasses platform, whose objective was to carry out an experimental
simulation aimed at searching for the Higgs boson, based on the principles of
the Standard Model of particle physics.
During the activity, a specialized simulator
was used that replicates high-energy proton collisions, similar to those that
occur in the Large Hadron Collider (LHC). In total, 100 simulated proton-proton
collision events were analyzed, seeking to identify signals compatible with the
decay of the Higgs boson.
Since the Higgs boson is highly unstable and
decays almost instantaneously, its direct detection is not possible. Instead,
the particles generated after its decay are analyzed, identifying
characteristic patterns—such as invariant mass—that match the theoretical
predictions of the Standard Model. To increase the reliability of the results,
it was necessary to repeat the experiment multiple times and perform
statistical analyses on the collected observations.
Results
ATLAS (A Apparatus for the
Investigation of Lepton and Hadron Scattering) is a particle detector located
at the Large Hadron Collider (LHC) at CERN in Geneva, Switzerland. It is one of
the two largest detectors at the LHC, along with CMS.
ATLAS is made up of 3,000 scientists from 180
institutions around the world, representing 38 countries from every inhabited
continent. It is one of the largest collaborative efforts ever undertaken.
Nearly 1,200 doctoral students are involved in detector development, data
acquisition, and analysis. The collaboration depends on the efforts of
countless engineers, technicians, and administrative staff. ATLAS is the
largest detector ever built for a particle collider. It is 46 meters long and
25 meters in diameter, and is located in a cavern nearly 100 meters
underground.
The detector consists of six different
subsystems located in concentric layers around the collision point to measure
the trajectory, momentum, and energy of the particles, allowing them to be
identified and measured individually. A gigantic system of magnets curves the
trajectory of the charged particles so that their momentum can be measured as
accurately as possible.
Beams of particles traveling in the LHC at
energies of up to 7 trillion electron volts, or speeds of up to 99.9999991%
that of light, collide in the center of the ATLAS detector, producing new
particles that are emitted in all directions from the collision point. Every
second, more than a billion interactions occur in ATLAS, which is equivalent to
all the people on Earth having 20 telephone conversations simultaneously. Of
these collisions, only one in a million is selected as potentially interesting
for recording and further study.
The detector records and identifies particles
to investigate a wide variety of physical processes, from the study of the
Higgs boson and the top quark to the search for extra dimensions and particles
that may constitute dark matter. ATLAS explores a wide variety of physics
topics, with the main goal of improving our understanding of the elementary
constituents of matter. Some of the key questions ATLAS seeks to answer are:
Structure of
the ATLAS Detector
The four main components of the ATLAS
detector are:
1. Internal Detector: measures the momentum
of each charged particle.
2. Calorimeter: measures the energy of
neutral and charged particles.
3. Muon Spectrometer: identifies and measures
the momentum of muons.
4. Magnet System: curves the trajectories of
each charged particle, allowing their momentum to be measured.
Integrated with the detector components are:
· Event Selection (Trigger) and Data
Acquisition System: a specialized multi-level computing system that selects
physics events with specific characteristics.
· Computing System: develops and improves the
software used to store, process, and analyze the immense amount of data in 100
computing centers located around the world.
Figure 1. ATLAS structure. Source: European Organization for Nuclear Research
Figure 2. Detector components. Source: European Organization for Nuclear Research
(CERN), 2019.
Applications
in everyday life
The search for answers to fundamental
questions about the properties of matter and forces requires cutting-edge
technological developments, which often lead to important innovations. Some
examples of how ATLAS's knowledge and technological innovation have been
applied in everyday life are:
Energy
storage with superconducting magnets
ATLAS's knowledge in the manufacture of
superconducting magnets may open up the possibility of developing new
high-performance energy storage systems.
Hadron
therapy
The diamond sensors developed for future
upgrades to ATLAS are also used to monitor hadron beams used in therapy, which
are more efficient at destroying tumors than X-rays or electron beams, with
less impact on nearby healthy tissue.
Medical
imaging
Three-dimensional silicon sensors developed
for future upgrades to ATLAS enable higher-resolution X-ray imaging. Most
medical imaging techniques require the detection of photons in different energy
ranges.
Retina
project
Based on the technology used in ATLAS silicon
microstrip detectors, a large-scale recording system for neuronal activity has
been developed. These experiments are capable of understanding how living
neural systems process and encode information, which could in the future
provide artificial vision to blind people.
Augmented
reality
ATLAS is researching innovative pattern
recognition technologies, a key component of augmented reality applications,
which allow workers involved in delicate maintenance operations to virtually
visualize work procedures, minimizing intervention time and the risk of errors.
This technology has various industrial applications.
Sound
reproduction
The high-precision optical image processing
methods used to measure and align each of the 16,000 silicon detectors in the
ATLAS internal detector can be used to measure with great precision the grooves
of mechanical sound carriers, such as vinyl records or phonograph cylinders.
This technology is being developed for use in sound recording collections and
archives to restore and preserve samples of great historical value.
Standard
Model
The Standard Model of Particles is a
fundamental theory of physics that describes the elementary particles that make
up matter and the fundamental forces that govern them. It is a quantum field
theory that has been experimentally confirmed with great precision and has
revolutionized our understanding of the universe at the subatomic level. The
Standard Model divides elementary particles into two large groups: fermions,
which are the particles that constitute matter, and bosons, which are the
particles that transmit forces. In addition, the model describes three of the
four known fundamental forces: the electromagnetic force, the strong nuclear
force, and the weak nuclear force. One of the key pieces of the Standard Model
is the Higgs mechanism, which explains the origin of the mass of elementary
particles. This mechanism postulates the existence of a Higgs field that
permeates all space and interacts with particles, giving them mass. The Higgs
boson is the elementary particle associated with the Higgs field and was first detected
at the Large Hadron Collider (LHC) in 2012, confirming the validity of the
Higgs mechanism and completing the Standard Model.
Structure
The Standard Model consists of 17 types of
fundamental particles, which are distributed as follows:
· Quarks: These are
considered subatomic particles that make up nuclear matter and hadrons. They
have a fractional electric charge and can be combined to form other particles.
There are six types of quarks.
· Leptons: Their conformation
is due to the basic components of matter. They are classified into three
generations, each with a charged lepton and a neutrino. Charged leptons refer
to electrons, muons, and tau, while neutrinos are neutral, and both can
generate various combinations. Like quarks, there are six types of leptons.
· Bosons: These are subatomic
particles that are responsible for transporting energy and forces, such as
electroweak, gravitational, and strong interactions. They also play a
fundamental role in the functioning of the universe. There are four types of
bosons.
An essential fact about these particles is
that each one has an antiparticle, which when they interact with each other,
they destroy each other and generate other particles. To better understand this
classification, we will refer to the following illustration.
Figure 3. Classification of particles. Source: Spanish Nuclear Society
Elementary
Particles
These are the smallest components of matter
and are therefore believed to be indivisible, as they are not made up of
smaller structures and have no internal composition.
Throughout the history of physics, different
models have considered different particles to be elementary. The atomic model
held that the atom was the smallest unit of matter, while the nuclear model
postulated that the components of the atom were indivisible. Currently, the
standard model is the theoretical framework used to describe these particles.
Elementary particles are classified into two
large groups:
Figure 4. Classification of particles Source: Student Congress of Physics and
Mathematics
· Fermions: These are the particles that
constitute matter and obey the Pauli exclusion principle. They are divided into
quarks (which form protons and neutrons) and leptons (such as electrons and
neutrinos).
· Bosons: These are the particles responsible
for transmitting the fundamental interactions of nature. Among them are the
photon (electromagnetic force), the W and Z bosons (weak force), the gluon
(strong force), and the Higgs boson, which gives mass to other particles.
On the other hand, hadrons are particles
composed of other more fundamental particles, as they are made up of quarks,
antiquarks, and gluons. They are classified into two types:
ü Baryons: These are made up of three quarks,
along with some gluons and antiquarks. Most of them are unstable, with the
exception of nucleons, i.e., protons and neutrons. In addition, baryons belong
to the fermion group.
ü Mesons: These are composed of a quark, an
antiquark, and a gluon. Although they are all unstable, they can exist in
isolation. Mesons are also part of the bosons.
It should be noted that there are other
particles that are important to address, such as:
o Hypothetical particles: These have been
proposed theoretically, but their existence has not yet been confirmed
experimentally.
o Superpartner
particles: Suggested by supersymmetry theory, these would be the symmetrical
counterparts of known particles.
o Quasiparticles: These are specific entities
identified in the study of condensed matter.
Magnetic
field of particles
This is a property that arises from their
moving electric charge and their intrinsic magnetic moment, which is related to
their quantum spin. This field is fundamental in the interaction of particles
with external fields and in many electromagnetic and quantum phenomena.
Two important aspects involved in the
magnetic field must be addressed:
ü Movement of a charged particle: An
elementary particle with an electric charge, such as an electron or muon,
generates a magnetic field when it is in motion. This field is described by Biot-Savart's law, which states that the magnitude and
direction of the field depend on the speed of the particle and its charge.
ü Intrinsic magnetic moment (spin): Even when
an elementary particle is at rest, it can possess an intrinsic magnetic moment
associated with its quantum spin. In the case of the electron, the spin
magnetic moment is a fundamental property that influences its interaction with
external magnetic fields.
Higgs field
Figure 5. Higgs field. Source: Astronomy.exe
Concept of
the Higgs field
It is a fundamental field in particle physics
that permeates all space. Its existence was proposed by British physicist Peter
Higgs in 1964 as part of an explanation for why some elementary particles have
mass, while others do not.
The Higgs field is related to the standard
model theory of particle physics, which describes the interactions of subatomic
particles. This field is different from other fields in nature, such as the
electromagnetic field, in that it not only interacts with charged particles,
but also gives mass to particles through its interaction with them.
Relationship between the
Higgs field and particle mass
The Higgs field is directly related to the
mass of particles. Elementary particles, such as electrons and quarks, obtain
mass through their interaction with this field. The intensity with which a
particle interacts with the Higgs field determines the magnitude of its mass.
The stronger a particle's interaction with the Higgs field, the greater its
mass. Below is a graph that demonstrates this relationship:
Figure 6. Higgs field and particle mass. Source: Relationship of Higgs bodies.
This phenomenon can be understood by analogy
with a particle moving through a field as if it were a person walking through a
crowd. If the person interacts a lot with the crowd (with a strong Higgs
field), they will move with more difficulty (greater mass). Conversely, if the
person interacts less (a weak Higgs field), they will move more easily (less
mass).
Spontaneous
symmetry breaking mechanism
Figure 7. Spontaneous symmetry breaking. Source: Beyond Science
The spontaneous symmetry breaking mechanism
is a key concept in particle physics and is fundamental to understanding how
the Higgs field gives mass to particles. Symmetry is a property of physical
laws that establishes that certain characteristics of the system do not change
under specific transformations. In the case of the standard model, the symmetry
of fundamental interactions, such as the symmetry between charged and uncharged
particles, is maintained at high energies.
However, as the universe cooled after the Big
Bang, a spontaneous symmetry breaking occurred. The Higgs field, in its initial
state, has perfect symmetry, but when it acquires a non-zero value in the
vacuum (the Higgs field “stabilizes” at a value other than zero), this symmetry
is broken. This process of spontaneous symmetry breaking causes some particles,
such as the Higgs boson, to obtain mass, while others, such as the photon, do
not.
This mechanism also explains the emergence of
particle interactions with the Higgs field, which is essential for the
formation of mass. However, the mechanism of spontaneous symmetry breaking
describes how an initially symmetric field can give rise to an asymmetric
structure, which, in turn, gives particles physical properties such as mass.
Higgs boson
The Higgs boson is an elementary particle
proposed in the Standard Model of particle physics, whose existence was
experimentally confirmed in 2012 by the Large Hadron Collider (LHC) at CERN.
Its importance lies in its relationship to the Higgs mechanism, which explains
the origin of the mass of elementary particles.
Definition
and Characteristics
The Higgs boson is a scalar particle, which
means it has zero spin. In the Standard Model, it is the quantum excitation of
the Higgs field, a field that is omnipresent in the universe. Its mass has been
measured at approximately 125 GeV/ (giga electron volts per square of the speed
of light).
Due to its short half-life, the Higgs boson
decays rapidly into other particles, such as photons, W and Z bosons, and
bottom quarks.
Figure 8. Higgs boson. Source: National Geographic
Another fundamental property of the Higgs
boson is its coupling with other particles through the Higgs mechanism, which
is related to the spontaneous breakdown of electroweak symmetry. This property
allows particles with greater coupling to the Higgs field to acquire greater
mass. In addition, its discovery has led to the exploration of new
possibilities in particle physics, such as the existence of possible new
interactions and theories beyond the Standard Model.
Relationship
with the Higgs Field
The Higgs field is a scalar quantum field
that permeates all space. Through the Higgs mechanism, elementary particles
acquire mass by interacting with this field. Without this mechanism, particles
such as quarks and leptons would be massless, which would prevent the formation
of atoms and, consequently, the existence of the universe as we know it. The
discovery of the Higgs boson has been a fundamental experimental confirmation
of this mechanism.
The Higgs mechanism is also related to
quantum vacuum energy and the stability of the universe. Some theoretical
models suggest that the mass of the Higgs boson could be related to the
possibility that the universe is in a metastable state, which could lead to a
phase transition at extremely high energy scales.
Particle
Accelerator
The particle accelerator is
a crucial device in scientific research, used to study the structure of matter
at the subatomic level. This technology has revolutionized our understanding of
the universe, leading to numerous discoveries in physics, chemistry, and
biology.
Figure 9. A. of particles. Source: Ok Diario.
The history of particle accelerators dates
back to the 1930s. During this period, the first models of linear and circular
accelerators were developed. One of the most notable inventors was Ernest O.
Lawrence, who created the cyclotron, a type of accelerator that allowed
physicists to bombard atomic nuclei and, thus, discover new elements.
As technology advanced, new types of
accelerators were developed, such as the synchrotron and the collider. These
devices allow much higher energies to be reached, resulting in the generation
of new subatomic components.
Description
of the LHC and its detectors
The Large Hadron Collider, known as the LHC,
is the world's largest particle accelerator. Located on the border between
France and Switzerland, it is part of the European Laboratory for Particle
Physics, or CERN.
The LHC extends for approximately 27
kilometers. Its design consists of a circular tunnel where protons collide at
speeds close to the speed of light. The protons are accelerated through a
series of steps in different accelerators before entering the LHC. One of the
most impressive features of the LHC is its ability to collide proton beams
traveling in opposite directions. This interaction produces a large amount of
energy.
Figure 10. Particle accelerator. Source: InfoEscola
To study the products of these collisions,
the LHC is equipped with four main detectors: ATLAS, CMS, LHCb, and ALICE. Each
of these detectors has a different focus, optimized to detect different types
of particles.
ATLAS (A Toroidal LHC ApparatuS)
is one of the largest and most versatile detectors in the world. It is designed
to study a wide variety of particles, including those that could indicate the
existence of additional dimensions or new forces of nature. On the other hand,
CMS (Compact Muon Solenoid) is also a general-purpose detector, although its
construction is more compact, allowing data to be obtained in a smaller space.
LHCb (Large Hadron Collider beauty) focuses
on flavor physics research, specifically the differences between particles and
antiparticles. This is fundamental to understanding the asymmetry between
matter and antimatter in our universe. ALICE (A Large Ion Collider Experiment)
specializes in heavy ion collisions. This detector studies quark-gluon plasma,
a form of matter that existed shortly after the Big Bang.
Particle
Collisions
These are interactions that occur when two or
more subatomic particles collide with each other. These collisions take place
in particle accelerators, such as the Large Hadron Collider (LHC), where atomic
nuclei are accelerated to speeds close to that of light before being directed
at each other. Studying these collisions allows scientists to investigate the
most basic components of matter, such as quarks, electrons, and neutrinos, as
well as to explore the fundamental forces: gravity, electromagnetism, strong
nuclear force, and weak nuclear force.
Research into particle collisions has been
influenced by notable figures such as Richard Feynman, Murray Gell-Mann, and
more recently, Fabiola Gianotti, the current director of CERN. Feynman
introduced diagrams that simplified the representation of particle
interactions. Gell-Mann, for his part, created the classification of quarks.
Gianotti has led projects that have achieved significant milestones in the
field, becoming a role model for future generations of scientists.
Discovery of
the Higgs Boson
The Higgs boson, proposed by physicist Peter
Higgs in the 1960s, is a key piece in the Standard Model of particle physics.
This theory describes how fundamental particles interact with each other and
how they acquire mass through the Higgs mechanism. The existence of the boson
provides evidence that the Higgs field, which permeates the entire universe,
gives mass to subatomic particles.
One of the most remarkable aspects of the
discovery of the Higgs boson is the international effort that went into it. In
1996, construction began on the Large Hadron Collider at CERN, which would
become the laboratory where the necessary research to confirm the existence of
the boson would be carried out. This particle accelerator, the largest and most
powerful in the world, was designed to collide protons at speeds close to that
of light, generating conditions similar to those of the early universe. The infrastructure
and collaboration of thousands of scientists from various disciplines were
essential to the success of the project.
Figure 11. ATLAS experiment. Source: LiveScience
On July 4, 2012, CERN announced the discovery
of a particle consistent with the Higgs boson. This finding was received with
enthusiasm by the scientific community and marked an outbreak of optimism
regarding particle physics. The confirmation of the boson not only validated a
long-standing theory, but also became a cornerstone for future research.
The ATLAS and CMS experiments, two of the LHC
detectors, conducted exhaustive analyses. For months, scientists reviewed the
data, looking for additional evidence. Finally, in March 2013, the discovery
was considered definitive when properties of the boson were measured that
matched the predictions of the Standard Model. This was a moment of intense
excitement and celebration in the scientific community.
Higgs boson
Experimental confirmation
of the Higgs boson
The Higgs boson, proposed theoretically in
1964 by Peter Higgs and others, is a fundamental particle that explains how
other particles acquire mass through the Higgs mechanism. Its existence was
experimentally confirmed on July 4, 2012, by CERN, using the Large Hadron
Collider (LHC). The ATLAS and CMS experiments detected a new particle with a
mass around 125 GeV/c², consistent with the predictions of the Higgs boson.
This discovery validated an essential piece of the Standard Model of particle
physics.
Limitations
of the Standard Model
Although the Standard Model has been
successful in describing fundamental interactions and known elementary
particles, it has several limitations:
Ø Gravity: It does not incorporate
gravitational interaction, since general relativity, which describes gravity,
is not integrated into the quantum framework of the Standard Model.
Ø Dark matter and dark energy: It does not
provide an explanation for dark matter and dark energy, which make up most of
the universe.
Ø Neutrinos: It does not adequately explain
the properties of neutrinos, such as their masses and oscillations.
Ø Matter-antimatter asymmetry: It does not
address the reason why the observable universe is composed mainly of matter,
even though the Big Bang is expected to have produced equal amounts of matter
and antimatter.
These limitations suggest the need for
theories beyond the Standard Model to fully describe fundamental physics.
How do we know if there is
a Higgs in the data taken in the CIMA (CMS Instrument for masterclass analysis)
simulator?
CIMA is an educational tool that allows
students and enthusiasts to analyze real data from the CMS experiment at the
LHC. To identify events that could correspond to the Higgs boson, the following
steps are taken:
· Event selection: The data
is filtered to select events with specific characteristics, such as the
presence of two high-energy photons or four leptons (electrons or muons), which
are common signatures of Higgs boson decay.
· Reconstruction of invariant
masses: From the detected particles, the invariant mass of the system is
calculated. A peak around 125 GeV/c² in the invariant mass distribution
indicates the possible presence of the Higgs boson.
· Statistical analysis: Statistical
analyses are performed to distinguish the Higgs boson signal from the
background of other physical processes.
This approach allows CIMA users to experience
the discovery and analysis process that led to the confirmation of the Higgs
boson in 2012.
Data
acquisition method
The table below shows the results obtained in
the 100 events, distributed as follows: Table 1 events 1 to 31; Table 2 events
32 to 60; Table 3 events 61 to 90; and Table 4 events 91 to 100.
Table 1. Data obtained from CIMA
|
Event index |
Event number |
Final state |
Primary state |
Mass |
|
6001 |
10.1-01 |
uv |
W- |
|
|
6002 |
10.1-02 |
ev |
W+ |
|
|
6003 |
10.1-03 |
4μ |
W+ |
|
|
6004 |
10.1-04 |
uv |
W- |
|
|
6005 |
10.1-5 |
uv |
W+ |
|
|
6006 |
10.1-6 |
ev |
W- |
|
|
6007 |
10.1-7 |
ee |
Partícula neutra |
44,84 |
|
6008 |
10.1-8 |
2u2e |
Partícula neutra |
44,84 |
|
6009 |
10.1-9 |
ev |
W+ |
|
|
6010 |
10.1-10 |
μμ |
neutral |
90.33 |
|
6011 |
10.1-11 |
μv |
W+ |
|
|
6012 |
10.1-12 |
2e |
neutral |
88.35 |
|
6013 |
10.1-13 |
2e 2μ |
Partícula neutra |
228.79 |
|
6014 |
10.1-14 |
μv |
W- |
|
|
6015 |
10.1-15 |
ev |
W+ |
|
|
6016 |
10.1-16 |
μv |
W+ |
|
|
6017 |
10.1-17 |
ev |
W+ |
|
|
6018 |
10.1-18 |
ev |
W+ |
|
|
6019 |
10.1-23 |
2e |
Partícula neutra |
2.28 |
|
6020 |
10.1-20 |
2e |
Partícula neutra |
88.35 |
|
6021 |
10.1-21 |
μv |
W+ |
|
|
6022 |
10.1-22 |
ev |
W- |
|
|
6023 |
10.1-23 |
μμ |
Partícula neutra |
5.46 |
|
6024 |
10.1-24 |
μμ |
Partícula neutra |
9.72 |
|
6029 |
10.1-29 |
ev |
W- |
|
|
6030 |
10.1-30 |
μv |
W- |
|
|
6031 |
10.1-31 |
μv |
W- |
|
Prepared by: Research group
The results in Table 2 reflect events from 32
to 60.
Table 2. Data obtained from CIMA
|
Event index |
Event number |
Final state |
Primary state |
Mass |
|
6032 |
10.1-32 |
2e |
neutral |
6.87 |
|
6033 |
10.1-33 |
4u |
W+ |
|
|
6034 |
10.1-34 |
ev |
W- |
|
|
6035 |
10.1-35 |
4u |
Partícula neutra |
44,84 |
|
6036 |
10.1-36 |
uv |
Partícula neutra |
44,84 |
|
6037 |
10.1-37 |
uv |
W- |
|
|
6038 |
10.1-38 |
ev |
W+ |
|
|
6039 |
10.1-39 |
4μ |
W+ |
|
|
6040 |
10.1-40 |
uv |
W- |
|
|
6041 |
10.1-41 |
4μ |
W- |
|
|
6042 |
10.1-42 |
ev |
Zoo |
|
|
6043 |
10.1-43 |
μv |
W+ |
|
|
6044 |
10.1-04 |
4μ |
W- |
|
|
6045 |
10.1-45 |
uv |
W- |
|
|
6046 |
10.1-46 |
ev |
W+ |
|
|
6047 |
10.1-47 |
4μ |
W+ |
|
|
6048 |
10.1-48 |
uv |
W- |
|
|
6049 |
10.1-49 |
2e2μ |
neutral |
178,72 |
|
6050 |
10.1-50 |
4μ |
W+ |
|
|
6051 |
10.1-51 |
4μ |
W+ |
|
|
6052 |
10.1-52 |
4μ |
W- |
|
|
6053 |
10.1-53 |
μv |
w- |
|
|
6054 |
10.1-54 |
ev |
w+ |
|
|
6055 |
10.1-55 |
μμ |
w- |
|
|
6056 |
10.1-56 |
μμ |
w- |
|
|
6057 |
10.1-57 |
ev |
W+ |
|
|
6058 |
10.1-58 |
uv |
W- |
|
|
6059 |
10.1-59 |
2e |
W+ |
|
|
6060 |
10.1-60 |
uu |
W- |
|
Prepared by: Research group
The results in Table 3 reflect events from 61
to 90.
Table 3. Data obtained from CIMA
|
Event index |
Event number |
Final state |
Primary state |
Mass |
|
6061 |
10.1-61 |
µv |
W- |
|
|
6062 |
10.1-62 |
µv |
W+ |
|
|
6063 |
10.1-63 |
4e |
W- |
|
|
6064 |
10.1-64 |
µµ |
W± |
|
|
6065 |
10.1-65 |
ev |
W- |
|
|
6066 |
10.1-66 |
μv |
W+ |
|
|
6067 |
10.1-67 |
ev |
W+ |
|
|
6068 |
10.1-68 |
μμ |
neutral |
3.71 |
|
6069 |
10.1-69 |
µv |
W+ |
|
|
6070 |
10.1-70 |
µv |
W+ |
|
|
6071 |
10.1-71 |
µv |
W+ |
|
|
6072 |
10.1-72 |
2e 2µ |
neutral |
128.94 |
|
6073 |
10.1-73 |
2e |
neutral |
87.15 |
|
6074 |
10.1-74 |
2e 2μ |
neutral |
232.96 |
|
6075 |
10.1-75 |
μv |
w+ |
|
|
6076 |
10.1-76 |
4μ |
neutral |
233.29 |
|
6077 |
10.1-79 |
ev |
W- |
|
|
6078 |
10.1-78 |
µv |
W+ |
|
|
6079 |
10.1-77 |
ev |
W+ |
|
|
6080 |
10.1-80 |
ev |
W+ |
|
|
6081 |
10.1-81 |
μv |
W+ |
|
|
6082 |
10.1-82 |
4μ |
Neutral |
502.13 |
|
6083 |
10.1-83 |
µv |
W+ |
|
|
6084 |
10.1-84 |
4e |
W+ |
|
|
6085 |
10.1-85 |
2e |
neutral |
10.24 |
|
6086 |
10.1-86 |
ev |
W+ |
|
|
6087 |
10.1-87 |
2e 2µ |
W+- |
|
|
6088 |
10.1-88 |
2e 2µ |
W+- |
|
|
6089 |
10.1-89 |
4µ |
Neutral |
87.71 |
|
6090 |
10.1-90 |
2e 2µ |
W+ |
|
Prepared by: Research group
The results in Table 4 reflect events from 91
to 100.
Table 4. Data obtained from CIMA
|
Event index |
Event number |
Final state |
Primary state |
Mass |
|
6091 |
10.1-91 |
ev |
W+- |
|
|
6092 |
10.1-92 |
uv |
W- |
|
|
6093 |
10.1-93 |
ev |
W+ |
|
|
6094 |
10.1-94 |
4μ |
W+ |
|
|
6095 |
10.1-95 |
2e 2μ |
W+ |
|
|
6096 |
10.1-96 |
4e |
W- |
|
|
6097 |
10.1-97 |
4μ |
W+- |
|
|
6098 |
10.1-98 |
2e |
Partícula neutra |
0,11 |
|
6099 |
10.1-99 |
4e |
W+ |
|
|
6100 |
10.1-100 |
uu |
W- |
|
Prepared by: Research group
From this, the following results are
obtained:
Of the 100 cases analyzed,
a lepton called an electron neutrino (ev), composed
of an electron and a neutrino, was identified in 23 of them. Of these cases, 7
correspond to the W- particle (with counterclockwise rotation), 15 to the W+particle (with clockwise rotation), and 2 to the W+- particle.
When pairs of identical particles propagating
in opposite directions are detected, the presence of a neutral particle is
inferred, since the charges cancel each other out, maintaining the conservation
of electric charge.
Of the 100 data points, 13 Z bosons were
obtained, which are distributed in pairs of leptons: 8 electron-positron () and
5 muon-antimuon (). Being neutral, their decay products conserve the net charge
in the process.
· decays into an electron () and its
antiparticle, the positron (), maintaining charge conservation.
· decays into a muon () and an antimuon (),
another common decay channel of the Z boson.
These processes are due to the neutral
weak interaction, where the Z boson mediates the interaction without changing
the identity of the leptons.
· Some images obtained in the simulator
showed that the collision between protons generates the most important
elementary particle called the “Higgs boson,” which has an average lifetime of
, a width of 4 MeV, and a mass of 125.2 GeV, which is equivalent to the total
energy possessed by the particle. Furthermore, when this particle decays, there
are two possible outcomes: the first is into two neutral bosons (which decay
into four muons), and the second is into two photons. In this case, the
simulator was limited to detecting the Higgs boson through the first
possibility.
Using the Cima simulator, it was identified
that in the experimental data collection there were 15 Higgs bosons (i.e., of
the 100 events that took place, only 15 of those events gave rise to this
neutral particle). With that said, when two protons collide with sufficient
energy, at that moment of interaction between quarks and gluons, it is unlikely
that this neutral particle will appear ( and much more likely that charged
bosons will be generated 
, (
, o (
.
Conclusions
The CIMA simulator allowed
us to relate these particles, facilitating the observation of their
trajectories, lifetimes, and behaviors in different collisions between
elementary particles, their interaction, and how they transform their energy
into measurable products, thus contributing to the understanding of the
Standard Model of Particle Physics.
The Standard Model of particle physics is the
theory that describes fundamental particles and fundamental forces. The
Standard Model is divided into:
Ø Fermions (constitute matter): Quarks
and Leptons.
Ø Bosons (force mediators):
Ø W⁺, W⁻, and Z⁰ bosons: mediators of the weak interaction.
Ø Higgs boson (H): responsible for
giving mass to particles through the Higgs mechanism.
The W⁺, W⁻, and Z⁰ bosons are fundamental to the weak force, which is responsible for
processes such as radioactive decay.
Ø Z⁰ boson → Mediates neutral
interactions, where particles interact without changing type.
Ø W⁺ and W⁻ bosons → Responsible for charged weak interactions, where a particle changes
type (flavor change).
The Standard Model unifies electromagnetic
interaction and weak interaction into a single theory, called the electroweak
theory.
Finally, the Cima simulator experiment
confirmed the existence of Higgs bosons () by collecting data in the final
table, and in the same way, thanks to the standard model of particle physics,
we were able to understand the relationship between quarks, leptons, and
bosons, where the principle of conservation of mass and charge is fulfilled
regardless of the interaction between them at the moment of collision between
protons.
Acknowledgements
We would like to thank the
students of the ninth semester, parallel B, of the 2024–2025 academic year of
the Modern Physics course in the Experimental Sciences Education: Mathematics
and Physics degree program for their outstanding dedication and enthusiasm in
studying the Higgs boson during the Masterclass experience with the CERN
simulator. Their commitment to understanding one of the fundamental pillars of
particle physics, as well as their ability to link theory and practice in an
international research environment, reflects not only their academic rigor but
also their passion for science. It has been a real privilege to accompany them
in this process of discovery.
Reference
Acercándonos al LHC - Vacío y partículas
virtuales. (s.f.). https://lhccloser.es/taking_a_closer_look_at_lhc/0.void_and_virtual_particles/idioma/es_ES
Centro Nacional de Física de Partículas,
Astropartículas y Nuclear (CPAN). (2011). ATLAS. https://www.i-cpan.es/atlas.php
CERN.
(2021). The Large Hadron Collider. https://home.cern/science/accelerators/large-hadron-collider
Fernández, M. (2019). El campo de Higgs
y su impacto en la física moderna. Anales de la Sociedad Española de Física. 95(1),
12-25.
Gianotti, F. (2018). The Challenges of the LHC and Future Directions.
CERN Press Release. https://home.cern/news/news/article/leaders-lhc-contribution-innovations
González, F. (2015). El bosón de Higgs y
el origen de la masa. Revista Mexicana de Física. 61(2), 98-112.
Griffiths, D. (2018). Introduction
to Elementary Particles. Wiley.
Heurtier, L. (2024, agosto 18). La
partícula de Higgs podría haber acabado ya con el universo: ¿por qué seguimos
aquí? BBC. https://www.bbc.com/mundo/articles/c1l54d8d7v6o
Hewitt,
P. G. (2009). Física
conceptual. Nueva edición
internacional de Pearson.
Kittel,
C., & Kraus, W. (2016). Introduction to Solid State Physics. Wiley.
Merich, J. (s.f). El decaimiento de las
partículas. https://www.jorgeaymerich.com/2015/11/el-decaimiento-de-las-particulas.html
Moreira,
M. (s.f.). O
Modelo Padr̃ao da F́ısica de Part́ıculas. Scielo.br. https://www.scielo.br/j/rbef/a/sMFh5cP7J9S8RzcXGsmV3fR/?format=pdf&lang=pt
Organización Europea para la Investigación
Nuclear (CERN). (2007). ATLAS. https://cds.cern.ch/record/1136918/files/CERN-Brochure-2007-001-Spa.pdf
Organización Europea para la Investigación
Nuclear (CERN). (2019). ATLAS: Explorando los secretos del Universo. https://cds.cern.ch/record/2684509/files/ATLAS-Brochure-2019-001-Spa.pdf
Pérez, J., & Ramírez, L. (2017). Explorando
el bosón de Higgs: implicaciones y descubrimientos recientes. Ciencia y
Tecnología. 32(4), 45-60.
Schaposnik, F., & Reichenbach, M. (1997).
Partículas elementales. Ciencia e investigación, 50(1-2). https://sedici.unlp.edu.ar/handle/10915/110238
The
Nobel Prize in Physics 2015. (s.f.).
Nobelprize.org. https://www.nobelprize.org/prizes/physics/2015/press-release/