scholarly journals Precision tests of the Standard Model: Rare B-meson decays

2017 ◽  
Vol 32 (09) ◽  
pp. 1741015 ◽  
Author(s):  
Ahmed Ali
Keyword(s):  
Standard Model ◽  
Model Building ◽  
B Meson ◽  
Hadron Collider ◽  
Theoretical Physics ◽  
Concrete Form ◽  
The Standard Model ◽  
Theoretical Physicist ◽  
Lively Debate ◽  
The Government

The charge given to me by the organisers of the memorial meeting for Prof. Abdus Salam’s 90th birthday is to recall my personal impressions of him and review an aspect of the standard model (SM) physics related to my work. Salam was, first and foremost, a brilliant theoretical physicist whose work is still very much en vogue, currently being tested precisely by the experiments at the Large Hadron Collider (LHC). Salam was, however, equally effective as a scientific advisor to many institutions, such as IAEA and CERN, but also to the government of Pakistan as the chief scientific strategist. He was also an untiring advocate of scientific research and higher education in developing countries, which took a concrete form in the International Centre for Theoretical Physics (ICTP) in Trieste. I discuss these aspects of his scientific life seen from my perspective in the first part. In the second part of my talk, which may appear as a disjoint piece to the first, I summarise some selected topics in rare B-decays — the current flavour physics frontier. Experiments carried out over several decades are largely in agreement with the SM, thanks also to dedicated theoretical effort in their interpretation. However, this field is undergoing an anomalous phase in a number of key measurements, in particular reported by LHCb, triggering a very lively debate and model building. These anomalies, which I review here, are too numerous to be ignored, but none is individually significant enough to announce a breakdown of the SM.

scholarly journals B PHYSICS AT LHCb

2008 ◽  
Vol 23 (32) ◽  
pp. 5117-5136 ◽  
Author(s):  
MONICA PEPE ALTARELLI ◽  
FREDERIC TEUBERT
Keyword(s):  
Large Hadron Collider ◽  
Standard Model ◽  
B Physics ◽  
Hadron Collider ◽  
New Physics ◽  
Concise Review ◽  
The Standard Model ◽  
And Performance ◽  
Detector Design

LHCb is a dedicated detector for b physics at the LHC (Large Hadron Collider). In this paper we present a concise review of the detector design and performance together with the main physics goals and their relevance for a precise test of the Standard Model and search of New Physics beyond it.

Forces of the World Unite!

2019 ◽  
pp. 54-63
Author(s):  
Nicholas Mee
Keyword(s):  
Standard Model ◽  
Particle Physics ◽  
Hadron Collider ◽  
Particle Accelerators ◽  
Strong Force ◽  
Fundamental Particles ◽  
The Standard Model ◽  
Small Collection ◽  
Electroweak Force ◽  
Structure Of Matter

The structure of matter and the forces that are important in particle physics are now understood in terms of the Standard Model, which is currently being tested at the Large Hadron Collider (LHC). Since the 1930s, physicists have used particle accelerators to investigate the structure of matter. Three forces are important in particle interactions, the strong force, the weak force and the electromagnetic force. The weak and electromagnetic forces are now recognized as two components of a unified electroweak force. The strong force and the electroweak force act on a small collection of fundamental particles that include quarks, the subcomponents of protons, neutrons and many other particles. The final missing piece of the Standard Model, the Higgs boson, was discovered by the LHC in 2012.

scholarly journals The dark phases of the N2HDM

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Isabell Engeln ◽  
Pedro Ferreira ◽  
M. Margarete Mühlleitner ◽  
Rui Santos ◽  
Jonas Wittbrodt
Keyword(s):  
Dark Matter ◽  
Large Hadron Collider ◽  
Standard Model ◽  
Hadron Collider ◽  
Higgs Doublet ◽  
Tree Level ◽  
Vacuum Structure ◽  
The Standard Model ◽  
Doublet Model ◽  
Specific Phase

Abstract We discuss the dark phases of the Next-to-2-Higgs Doublet model. The model is an extension of the Standard Model with an extra doublet and an extra singlet that has four distinct CP-conserving phases, three of which provide dark matter candidates. We discuss in detail the vacuum structure of the different phases and the issue of stability at tree-level of each phase. Taking into account the most relevant experimental and theoretical constraints, we found that there are combinations of measurements at the Large Hadron Collider that could single out a specific phase. The measurement of h125 → γγ together with the discovery of a new scalar with specific rates to τ+τ− or γγ could exclude some phases and point to a specific phase.

On the model dependence of fiducial cross-section measurements

2019 ◽  
Vol 34 (38) ◽  
pp. 2050065
Author(s):  
Gabriel Facini ◽  
Kyrylo Merkotan ◽  
Matthias Schott ◽  
Alexander Sydorenko
Keyword(s):  
Standard Model ◽  
Cross Section ◽  
Production Cross ◽  
Hadron Collider ◽  
New Physics ◽  
Effective Field ◽  
Model Bias ◽  
Systematic Uncertainties ◽  
Standard Model Cross Section ◽  
The Standard Model

Fiducial production cross-section measurements of Standard Model processes, in principle, provide constraints on new physics scenarios via a comparison of the predicted Standard Model cross-section and the observed cross-section. This approach received significant attention in recent years, both from direct constraints on specific models and the interpretation of measurements in the view of effective field theories. A generic problem in the reinterpretation of Standard Model measurements is the corrections application of to data to account for detector effects. These corrections inherently assume the Standard Model to be valid, thus implying a model bias of the final result. In this work, we study the size of this bias by studying several new physics models and fiducial phase–space regions. The studies are based on fast detector simulations of a generic multi-purpose detector at the Large Hadron Collider. We conclude that the model bias in the associated reinterpretations is negligible only in specific cases, however, typically on the same level as systematic uncertainties of the available measurements.

scholarly journals η′K PUZZLE OF B MESON DECAYS AND NEW PHYSICS EFFECTS IN THE TC2 MODEL

2001 ◽  
Vol 16 (07) ◽  
pp. 441-455 ◽  
Author(s):  
ZHENJUN XIAO ◽  
WENJUN LI ◽  
GONGRU LU ◽  
LIBO GUO
Keyword(s):  
Standard Model ◽  
B Meson ◽  
New Physics ◽  
Decay Rates ◽  
Low Energy ◽  
Effective Hamiltonian ◽  
B Meson Decays ◽  
The Standard Model ◽  
Model Predictions ◽  
Input Parameters

Using the low energy effective Hamiltonian with the generalized factorization, we calculate the new physics contributions to B→π+π-, Kπ and Kη′ in the topcolor-assisted-technicolor (TC2) model, and compare the results with the available data. By using [Formula: see text] preferred by the CLEO data of B→π+π-decay, we find that the new physics enhancements to B→ Kη′ decays are significant in size, ~ 50% with respect to the standard model predictions, insensitive to the variations of input parameters and hence provide a simple and plausible new physics interpretation for the observed unexpectedly large B→ Kη′ decay rates.

scholarly journals AFTER THE STANDARD MODEL: NEW RESONANCES AT THE LHC

2009 ◽  
Vol 24 (01) ◽  
pp. 1-15 ◽  
Author(s):  
GUSTAAF BROOIJMANS
Keyword(s):  
Large Hadron Collider ◽  
Standard Model ◽  
Hadron Collider ◽  
Center Of Mass ◽  
New Physics ◽  
Mass Energy ◽  
High Expectations ◽  
Center Of Mass Energy ◽  
Energy Regime ◽  
The Standard Model

Experiments will soon start taking data at CERN's Large Hadron Collider (LHC) with high expectations for discovery of new physics phenomena. Indeed, the LHC's unprecedented center-of-mass energy will allow the experiments to probe an energy regime where the standard model is known to break down. Here, the experiments' capability to observe new resonances in various channels is reviewed.

scholarly journals Exploring CP-Violation Through B Decays

2003 ◽  
Vol 18 (21) ◽  
pp. 1413-1433 ◽  
Author(s):  
Robert Fleischer
Keyword(s):  
Cp Violation ◽  
Standard Model ◽  
B Meson ◽  
Model Description ◽  
B Decays ◽  
Unitarity Triangle ◽  
The Standard Model ◽  
B Factory ◽  
Meson System

The B-meson system provides many strategies to perform stringent tests of the Standard-Model description of CP-violation. In this brief review, we discuss implications of the currently available B-factory data on the angles α, β and γ of the unitarity triangle, emphasize the importance of Bsstudies at hadronic B experiments, and discuss new, theoretically clean strategies to determine γ.

scholarly journals Early physics results

2012 ◽  
Vol 370 (1961) ◽  
pp. 933-949 ◽  
Author(s):  
Peter Jenni
Keyword(s):  
Standard Model ◽  
Hadron Collider ◽  
High Energy ◽  
New Physics ◽  
General Purpose ◽  
Good Shape ◽  
The Standard Model ◽  
Breaking Mechanism ◽  
Bsm Physics ◽  
Energy Frontier

For the past year, experiments at the Large Hadron Collider (LHC) have started exploring physics at the high-energy frontier. Thanks to the superb turn-on of the LHC, a rich harvest of initial physics results have already been obtained by the two general-purpose experiments A Toroidal LHC Apparatus (ATLAS) and the Compact Muon Solenoid (CMS), which are the subject of this report. The initial data have allowed a test, at the highest collision energies ever reached in a laboratory, of the Standard Model (SM) of elementary particles, and to make early searches Beyond the Standard Model (BSM). Significant results have already been obtained in the search for the Higgs boson, which would establish the postulated electro-weak symmetry breaking mechanism in the SM, as well as for BSM physics such as Supersymmetry (SUSY), heavy new particles, quark compositeness and others. The important, and successful, SM physics measurements are giving confidence that the experiments are in good shape for their journey into the uncharted territory of new physics anticipated at the LHC.

Sign in / Sign up

Export Citation Format

Share Document