We review the context, the motivations and the expected performances of a comprehensive and ambitious fixed-target programme using the multi-TeV proton and ion LHC beams. We also provide a detailed ...account of the different possible technical implementations ranging from an internal wire target to a full dedicated beam line extracted with a bent crystal. The possibilities offered by the use of the ALICE and LHCb detectors in the fixed-target mode are also reviewed.
We outline the case for heavy-ion-physics studies using the multi-TeV lead LHC beams in the fixed-target mode. After a brief contextual reminder, we detail the possible contributions of AFTER@LHC to ...heavy-ion physics with a specific emphasis on quarkonia. We then present performance simulations for a selection of observables. These show that
Υ
(
n
S
)
,
J
/
ψ
and
ψ
(
2
S
)
production in heavy-ion collisions can be studied in new energy and rapidity domains with the LHCb and ALICE detectors. We also discuss the relevance to analyse the Drell–Yan pair production in asymmetric nucleus–nucleus collisions to study the factorisation of the nuclear modification of partonic densities and of further quarkonium states to restore their status of golden probes of the quark–gluon plasma formation.
Thanks to its multi-TeV LHC proton and lead beams, the LHC complex allows one to perform the most energetic fixed-target experiments ever and to study with high precision pp, pd and pA collisions at ...sNN=115GeV and Pbp and PbA collisions at sNN=72GeV. We present a selection of feasibility studies for the production of quarkonia, open heavy-flavor mesons as well as light-flavor hadrons in pA and PbA collisions using the LHCb and ALICE detectors in a fixed-target mode.
The NA60 experiment has studied low-mass muon pair production in proton–nucleus collisions with a system of Be, Cu, In, W, Pb and U targets, using a 400 GeV proton beam at the CERN SPS. The ...transverse momentum spectra of the
ρ
/
ω
and
ϕ
mesons are measured in the full
p
T
range accessible, from
p
T
=
0
up to
2
GeV/c
. The nuclear dependence of the production cross sections of the
η
,
ω
and
ϕ
mesons has been found to be consistent with the power law
σ
pA
∝
A
α
, with the
α
parameter increasing as a function of
p
T
for all the particles, and an approximate hierarchy
α
η
≈
α
ϕ
>
α
ω
. The cross section ratios
σ
η
/
σ
ω
,
σ
ρ
/
σ
ω
and
σ
ϕ
/
σ
ω
have been studied as a function of the size A of the production target, and an increase of the
η
and
ϕ
yields relative to the
ω
is observed from p–Be to p–U collisions.
Low-mass dimuon production, including light vector mesons ρ, ω, φ, provides key information on the hot and dense state of strongly interacting matter produced in high-energy heavy-ion collisions. In ...particular, strangeness production can be studied via φ meson measurements, while the detailed description of the full dimuon mass spectrum down to the kinematic threshold can be used to reveal in-medium modifications of hadron properties and the thermal emission arising from the medium. Measurements in pp and p-A systems, in absence of hot nuclear matter effects, must be used as a reference to test our knowledge of the processes expected to contribute to dilepton production. Dimuon production is studied with the ALICE apparatus at the LHC at forward rapidity (2.5 < y < 4) with the Muon Spectrometer. In this contribution, results on low-mass dimuon production are shown, for various center-of-mass energies per nucleon pair, in pp, p-Pb, and Pb-Pb collisions.
Hormonal abnormalities in male patients with end-stage renal diseases are primarily organic and related to uremia as well as the other comorbid factors that frequently contribute to chronic renal ...failure and concomitant drug administration. The restoration of hormonal profiles after successful renal transplantation is still controversial. Immunosuppressive drugs may influence hormonal profiles. Our cross-sectional study of 37 male kidney transplant recipients investigated two groups according to their calcineurin inhibitor therapy, namely 21 cyclosporine versus 16 tacrolimus pattents. The two groups were matched for age, graft function, mean duration of dialysis before transplantation, and duration of follow-up after transplantation. There was no statistical significant difference in baseline circulating levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone (TTE), and prolactin (PRL) between the two groups. We found that calcineurin inhibitors have favorable effects on sexual hormone levels of male renal transplant patients and that there is no difference in baseline hormone levels between cyclosporine- and tacrolimus-treated male patients.
Summary
There is strong evidence that altered immunological function entails an increased risk of lymphoma, although the current knowledge of aetiological factors for lymphomas is limited. The CTLA4 ...gene encodes a receptor that provides a negative signal to the T‐cell once an immune response is initiated and completed. We analysed the 2q33 chromosomal region harbouring CD28, CTLA4 and ICOS genes, which are closely linked and have related functions in immune regulation, for association in 100 non‐Hodgkin's lymphoma (NHL) patients and in 128 healthy controls; both groups originated from Sardinia. There was a strong association of the CTLA4 49A and the 3′‐untranslated region (AT)82 alleles with NHL odds ratio (OR) = 2, 95% confidence interval (CI) = 1·2–3·2, and OR = 1·6, 95% CI = 1·1–2·4 respectively. CTLA4‐318C:49A:(AT)82 was the most represented haplotype in the studied population and was associated with NHL (P = 0·0029, OR = 1·76, 95% CI = 1·2–2·5). Strong linkage disequilibrium was detected between CD28, CTLA4 and ICOS and a ‘common’ haplotype was found very frequently among NHLs. However, no independent association between CD28, ICOS, D2S72 markers and NHL was observed. Our findings enable CTLA4 from adjacent functionally related genes as the true causative risk gene for NHL susceptibility at least in Sardinian patients.
ALICE at the CERN LHC will investigate the physics of strongly interacting matter at extreme energy densities where the formation of the Quark Gluon Plasma is expected. Its properties can be studied ...from observations like the production of mesons with charm and beauty quarks. These signals have to be studied as a function of energy density, which is determined by the centrality of collisions. One of the physics observables that is closely related with the centrality of the collision is the number of spectator nucleons that can be measured by the Zero Degree Calorimeters (ZDC). Having a direct geometric interpretation allows to extract the impact parameter with minimal model assumptions. This paper describes the readout system of the ZDC. The ZDC readout consists of a VME system with a ZDC Readout Card, a VME Processor, Discriminators, a ZDC Trigger Card, scalers, QDCs and TDCs. The system was successfully tested during the 2009 ALICE data taking and is currently operational at the LHC.
φ production in In–In collisions at 158 A GeV Arnaldi, R.; Banicz, K.; Borer, K. ...
The European physical journal. C, Particles and fields,
11/2009, Letnik:
64, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The NA60 experiment has measured muon pair production in In–In collisions at 158 AGeV at the CERN SPS. This paper presents a high statistics measurement of
φ
→
μ
μ
meson production. Differential ...spectra, yields, mass and width are measured as a function of centrality and compared to previous measurements in other colliding systems at the same energy. The width of the rapidity distribution is found to be constant as a function of centrality, compatible with previous results. The decay muon polar angle distribution is measured in several reference frames. No evidence of polarization is found as a function of transverse momentum and centrality. The analysis of the
p
T
spectra shows that the
φ
has a small radial flow, implying a weak coupling to the medium. The
T
eff
parameter measured in In–In collisions suggests that the high value observed in Pb–Pb in the kaon channel is difficult to reconcile with radial flow alone. The absolute yield is compared to results in Pb–Pb collisions: though significantly smaller than measured by NA50 in the muon channel, it is found to exceed the NA49 and CERES data in the kaon channel at any centrality. The mass and width are found to be compatible with the PDG values at any centrality and at any
p
T
: no evidence for in-medium modifications is observed.
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