The LHCb RICH system: Detector performance Matteuzzi, C.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2014, Volume:
766
Journal Article
Peer reviewed
The LHCb experiment has been taking data at the Large Hadron Collider (LHC) at CERN since the end of 2009. One of its key detector components is the Ring-Imaging Cherenkov (RICH) system. It provides ...charged particle identification over a wide momentum range, from 2 to 100 GeV/c. The LHCb RICH system has been performing extremely well and is providing the LHCb experiment with a robust, reliable and precise particle identification for all the hadronic processes. The particle identification performance is presented, as measured using data from the LHC. Excellent separation of hadronic particle types ( pi , K, p) is achieved.
We propose a new experiment to measure the running of the electromagnetic coupling constant in the space-like region by scattering high-energy muons on atomic electrons of a low-
Z
target through the ...elastic process
μ
e
→
μ
e
. The differential cross section of this process, measured as a function of the squared momentum transfer
t
=
q
2
<
0
, provides direct sensitivity to the leading-order hadronic contribution to the muon anomaly
a
μ
HLO
. By using a muon beam of 150 GeV, with an average rate of
∼
1.3
×
10
7
muon/s, currently available at the CERN North Area, a statistical uncertainty of
∼
0.3% can be achieved on
a
μ
HLO
after two years of data taking. The direct measurement of
a
μ
HLO
via
μ
e
scattering will provide an independent determination, competitive with the time-like dispersive approach, and consolidate the theoretical prediction for the muon
g
-2 in the Standard Model. It will allow therefore a firmer interpretation of the measurements of the future muon
g
-2 experiments at Fermilab and J-PARC.
Technological implications for RICH performance Matteuzzi, C.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/2011, Volume:
639, Issue:
1
Journal Article
Peer reviewed
Open access
I will review in this talk some examples of RICH detectors operating or being about to, from the point of view of the parameters which determine the Cherenkov angle resolution. The RICH technique is ...extremely powerful and widely used nowadays in experiments which have to perform particle identification. Depending on the technologies chosen for the detector design, the design resolution can be achieved if important efforts are made, keeping under control the stability of the different components contributing to the Cherenkov angle resolution.
The history of LHCb Belyaev, I.; Carboni, G.; Harnew, N. ...
European physical journal H,
12/2021, Volume:
46, Issue:
1
Journal Article
Peer reviewed
Open access
In this paper, we describe the history of the LHCb experiment over the last three decades, and its remarkable successes and achievements. LHCb was conceived primarily as a
b
-physics experiment, ...dedicated to
CP
violation studies and measurements of very rare
b
decays; however, the tremendous potential for
c
-physics was also clear. At first data taking, the versatility of the experiment as a general-purpose detector in the forward region also became evident, with measurements achievable such as electroweak physics, jets and new particle searches in open states. These were facilitated by the excellent capability of the detector to identify muons and to reconstruct decay vertices close to the primary
pp
interaction region. By the end of the LHC Run 2 in 2018, before the accelerator paused for its second long shut down, LHCb had measured the CKM quark mixing matrix elements and
CP
violation parameters to world-leading precision in the heavy-quark systems. The experiment had also measured many rare decays of
b
and
c
quark mesons and baryons to below their Standard Model expectations, some down to branching ratios of order 10
-
9
. In addition, world knowledge of
b
and
c
spectroscopy had improved significantly through discoveries of many new resonances already anticipated in the quark model, and also adding new exotic four and five quark states. The paper describes the evolution of the LHCb detector, from conception to its operation at the present time. The authors’ subjective summary of the experiment’s important contributions is then presented, demonstrating the wide domain of successful physics measurements that have been achieved over the years.
A RICH with aerogel for a hadron collider Matteuzzi, C.
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2005, Volume:
553, Issue:
1
Journal Article
Peer reviewed
Open access
Operating a RICH detector with an aerogel radiator is a significant challenge at a hadron collider such as the LHC due to the high event rate and multiplicity of the produced charged tracks. ...Large-size tiles of silica aerogel with excellent optical quality have recently been produced for the LHCb RICH detector. The photon yield and Cherenkov angle resolution from these tiles have been maximized. Results of laboratory measurements and beam tests are reported. The uniformity of the index of refraction within a tile has also been studied.
The characterization of the new Hamamatsu R11265-103-M64 multi-anode photomultiplier tube is presented. The sample available in our laboratory was tested and in particular the response to single ...photon was extensively studied. The gain, the anode uniformity and the dark current were measured. The tube behaviour in a longitudinal magnetic field up to 100 G was studied and the gain loss due to the ageing was quantified. The characteristics and performance of the photomultiplier tube make the R11265-103-M64 particularly tailored for an application in high energy physics experiments, such as in the LHCb Ring Imaging Cherenkov (RICH) detector at LHC.
Refractive index of silica aerogel: Uniformity and dispersion law Bellunato, T.; Calvi, M.; Matteuzzi, C. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2008, Volume:
595, Issue:
1
Journal Article
Peer reviewed
Open access
Two methods for the measurement of the uniformity of the refractive index
n
within a single block of silica aerogel are described. One is based on the deflection of a laser beam induced by transverse ...index gradients. The second exploits the Cherenkov effect, measuring the emission angle of photons radiated by 500
MeV electrons traversing the aerogel. The beam can scan the full aerogel surface providing information on point to point variations of
n
.
The measurement of the dispersion law
n
(
λ
)
is also reported. An Xe lamp coupled to a diffraction grating provides the monochromatic source. The index for each
λ
is measured by the prism method at a corner of an aerogel sample. A Sellmeier functional form for
n
(
λ
)
is assumed, and the parameters best fitting the experimental data are given.
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