With the establishment and maturation of the experimental programs searching for new physics with sizeable couplings at the LHC, there is an increasing interest in the broader particle and ...astrophysics community for exploring the physics of light and feebly-interacting particles as a paradigm complementary to a New Physics sector at the TeV scale and beyond. FIPs 2020 has been the first workshop fully dedicated to the physics of feebly-interacting particles and was held virtually from 31 August to 4 September 2020. The workshop has gathered together experts from collider, beam dump, fixed target experiments, as well as from astrophysics, axions/ALPs searches, current/future neutrino experiments, and dark matter direct detection communities to discuss progress in experimental searches and underlying theory models for FIPs physics, and to enhance the cross-fertilisation across different fields. FIPs 2020 has been complemented by the topical workshop “Physics Beyond Colliders meets theory”, held at CERN from 7 June to 9 June 2020. This document presents the summary of the talks presented at the workshops and the outcome of the subsequent discussions held immediately after. It aims to provide a clear picture of this blooming field and proposes a few recommendations for the next round of experimental results.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We study the possibility of observing a light pseudo-scalar
a
at LHCb. We target the mass region
2.5
GeV
≲
m
a
≲
60
GeV
and various decay channels, some of which have never been considered before: ...muon pairs, tau pairs,
D
meson pairs, and di-photon. We interpret the results in the context of models of 4D Composite Higgs and Partial Compositeness in particular.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A
bstract
This report details the capabilities of LHCb and its upgrades towards the study of kaons and hyperons. The analyses performed so far are reviewed, elaborating on the prospects for some key ...decay channels, while proposing some new measurements in LHCb to expand its strangeness research program.
In this paper, we describe the potential of the LHCb experiment to detect stealth physics. This refers to dynamics beyond the standard model that would elude searches that focus on energetic objects ...or precision measurements of known processes. Stealth signatures include long-lived particles and light resonances that are produced very rarely or together with overwhelming backgrounds. We will discuss why LHCb is equipped to discover this kind of physics at the Large Hadron Collider and provide examples of well-motivated theoretical models that can be probed with great detail at the experiment.
Abstract
A method for calibrating the momentum scale in a particle physics detector is described. The method relies on the determination of the masses of the final state particles in two-body decays ...of neutral particles, which can then be used to obtain corrections in the momentum scale. A modified version of the Armenteros-Podolanski plot and the K
S
0
→ π
+
π
-
decay is used as a proof of principle for this method.
A precision at the 10
-6
–10
-8
level is achieved in simplified simulations.
The performance of the muon identification in LHCb is extracted from data using muons and hadrons produced in J/psi arrow right mu super(+) mu super(-) , Lambda super(0) arrow right ppi super(-) and ...D* super(+) arrow right pi super(+)D super(0)(K super(-)pi super(+)) decays. The muon identification procedure is based on the pattern of hits in the muon chambers. A momentum dependent binary requirement is used to reduce the probability of hadrons to be misidentified as muons to the level of 1%, keeping the muon efficiency in the range of 95-98%. As further refinement, a likelihood is built for the muon and non-muon hypotheses. Adding a requirement on this likelihood that provides a total muon efficiency at the level of 93%, the hadron misidentification probabilities are below 0.6%.
This paper presents the design of the LHCb trigger and its performance on data taken at the LHC in 2011. A principal goal of LHCb is to perform flavour physics measurements, and the trigger is ...designed to distinguish charm and beauty decays from the light quark background. Using a combination of lepton identification and measurements of the particles' transverse momenta the trigger selects particles originating from charm and beauty hadrons, which typically fly a finite distance before decaying. The trigger reduces the roughly 11MHz of bunch-bunch crossings that contain at least one inelastic pp interaction to 3 kHz. This reduction takes place in two stages; the first stage is implemented in hardware and the second stage is a software application that runs on a large computer farm. A data-driven method is used to evaluate the performance of the trigger on several charm and beauty decay modes.
LHCb VELO Timepix3 telescope Akiba, K.; Beuzekom, M. van; Boterenbrood, H. ...
Journal of instrumentation,
05/2019, Letnik:
14, Številka:
5
Journal Article
Recenzirano
Odprti dostop
The LHCb VELO Timepix3 telescope is a silicon pixel tracking system constructed initially to evaluate the performance of LHCb VELO Upgrade prototypes. The telescope consists of eight hybrid pixel ...silicon sensor planes equipped with the Timepix3 ASIC . The planes provide excellent charge measurement, timestamping and spatial resolution and the system can function at high track rates. This paper describes the construction of the telescope and its data acquisition system and offline reconstruction software. A timing resolution of 350 ps was obtained for reconstructed tracks. A pointing resolution of better than 2\mum was determined for the 180 GeV/c mixed hadron beam at the CERN SPS . The telescope has been shown to operate at a rate of 5 million particles s−1ċcm−2 without a loss in efficiency.
Proton beams have been colliding at 7 TeV in the Large Hadron Collider (LHC) since 30 March 2010, meaning that the LHC research programme is underway. Particle physicists around the world are looking ...forward to using the data from these collisions, as the LHC is running at an energy three and a half times higher than previously achieved at any particle accelerator. There are some important questions to be answered by the LHC experiments. What is the origin of mass? What is 96% of the universe made of? Why is there no more antimatter? To avoid colliding with gas molecules inside the accelerator, the beams of particles travel in an ultra-high vacuum--a cavity as empty as interplanetary space. The internal pressure of the LHC is 10superscript -9 Pa, one hundred times less than the pressure on the Moon! The aim of this article is to introduce a few simple physical calculations about some physics phenomena related to pressure that take place in the LHC, so that they can be directly used in the secondary school classroom and stimulate the students' interest in the greatest experiment in history. (Contains 2 figures.)
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