-
K. Barth,
A. Belov,
B. Beltran,
H. Brauninger,
J. M. Carmona,
J. I. Collar,
T. Dafni,
M. Davenport,
L. Di Lella,
C. Eleftheriadis, [......],
J. Ruz,
I. Savvidis,
Y. Semertzidis,
L. Stewart,
K. Van Bibber,
J. D. Vieira,
J. A. Villar,
J. K. Vogel,
L. Walckiers,
K. Zioutas
[show abstract]
[hide abstract]
ABSTRACT: In non-hadronic axion models, which have a tree-level axion-electron
interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton
scattering, and axio-recombination, the "BCA processes." Based on a new
calculation of this flux, including for the first time axio-recombination, we
derive limits on the axion-electron Yukawa coupling g_ae and axion-photon
interaction strength g_ag using the CAST phase-I data (vacuum phase). For m_a <
10 meV/c2 we find g_ag x g_ae< 8.1 x 10^-23 GeV^-1 at 95% CL. We stress that a
next-generation axion helioscope such as the proposed IAXO could push this
sensitivity into a range beyond stellar energy-loss limits and test the
hypothesis that white-dwarf cooling is dominated by axion emission.
02/2013;
-
K. Ackerstaff,
A. Airapetian,
I. Akushevich,
N. Akopov,
M. Amarian,
E.C. Aschenauer,
R. Avakian,
H. Avakian,
A. Avetisian,
B. Bains, [......],
M.C. Vetterli,
E. Volk,
W. Wander,
T.P. Welch,
S.E. Williamson,
T. Wise,
T. Wolfel,
K. Zapfe-Duren,
G. Zograbian,
R. Zurmuhle
[show abstract]
[hide abstract]
ABSTRACT: Results are reported from the HERMES experiment at HERA on a measurement of the neutron spin structure function g1 n(x,Q 2) in deep inelastic scattering using 27.5 GeV longitudinally polarized positrons incident on a polarized 3He internal gas target. The data cover the kinematic range 0.023<x<0.6 and 1(GeV/c) 2<Q 2<15(GeV/c) 2. The integral ∫0.023 0.6g1 n(x)dx evaluated at a fixed Q 2 of 2.5(GeV/c) 2 is −0.034±0.013(stat.)±0.005(syst.). Assuming Regge behavior at low x, the first moment Γ1 n=∫0 1g1 n(x)dx is −0.037±0.013(stat.)±0.005(syst.)±0.006(extrapol.).
Physics Letters B 02/2013; 404(3-4):383-389. · 3.95 Impact Factor
-
K. Ackerstaff,
A. Airapetian,
N. Akopov,
I. Akushevich,
M. Amarian,
E.C. Aschenauer,
H. Avakian,
R. Avakian,
A. Avetisian,
B. Bains, [......],
M.G. Vincter,
J. Visser,
E. Volk,
W. Wander,
J. Wendland,
S.E. Williamson,
T. Wise,
K. Woller,
S. Yoneyama,
H. Zohrabian
[show abstract]
[hide abstract]
ABSTRACT: Cross section ratios for deep-inelastic scattering from 14N and 3He with respect to 2H have been measured by the HERMES experiment at DESY using a 27.5 GeV positron beam. The data cover a range in the Bjorken scaling variable x between 0.013 and 0.65, while the negative squared four-momentum transfer Q^2 varies from 0.5 to 15 GeV^2. The data are compared to measurements performed by NMC, E665, and SLAC on 4He and 12C, and are found to be different for x < 0.06 and Q^2 < 1.5 GeV^2. The observed difference is attributed to an A-dependence of the ratio R = sigma_L / sigma_T of longitudinal to transverse deep-inelastic scattering cross sections at low x and low Q^2.
Physics Letters B 02/2013; 475:386-394. · 3.95 Impact Factor
-
C. Adolph,
M. G. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. A. Antonov,
A. Austregesilo,
B. Badelek,
F. Balestra, [......],
G. K. Mallot,
A. Mann,
C. Marchand,
A. Martin,
J. Marzec,
T. Matsuda,
G. Meshcheryakov,
W. Meyer,
T. Michigami,
Yu. V. Mikhailov
-
C. Adolph,
M. G. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. A. Antonov,
A. Austregesilo,
B. Badelek,
F. Balestra, [......],
M. Wilfert,
R. Windmolders,
W. Wislicki,
H. Wollny,
K. Zaremba,
M. Zavertyaev,
E. Zemlyanichkina,
M. Ziembicki,
N. Zhuravlev,
A. Zvyagin
[show abstract]
[hide abstract]
ABSTRACT: The gluon polarisation in the nucleon was measured using open charm
production by scattering 160 GeV/c polarised muons off longitudinally polarised
protons or deuterons. The data were taken by the COMPASS collaboration between
2002 and 2007. A detailed account is given of the analysis method that includes
the application of neural networks. Several decay channels of D^0 mesons are
investigated. Longitudinal spin asymmetries of the D meson production
cross-sections are extracted in bins of D^0 transverse momentum and energy. At
leading order QCD accuracy the average gluon polarisation is determined as
(Delta g/G)^LO=-0.06 +/- 0.21 (stat.) +/- 0.08 (syst.) at the scale <mu^2> ~13
(GeV/c)^2 and an average gluon momentum fraction ~ 0.11. For the first time,
the average gluon polarisation is also obtained at next-to-leading order QCD
accuracy as (Delta g/G)^NLO = -0.13 +/- 0.15 (stat.) +/- 0.15 (syst.) at the
scale <mu^2> ~ 13 (\GeV/c)^2 and ~ 0.20.
11/2012;
-
C. Adolph,
M. G. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. A. Antonov,
A. Austregesilo,
B. Badelek,
F. Balestra, [......],
M. Wilfert,
R. Windmolders,
W. Wislicki,
H. Wollny,
K. Zaremba,
M. Zavertyaev,
E. Zemlyanichkina,
M. Ziembicki,
N. Zhuravlev,
A. Zvyagin
[show abstract]
[hide abstract]
ABSTRACT: The production of D* and D mesons in inelastic scattering of 160 GeV/c muons
off a ^6LiD target has been investigated with the COMPASS spectrometer at CERN
for 0.003 (GeV/c)^2 < Q^2 < 10 (GeV/c)^2 and 3x10^-5< x_Bj < 0.1. The study is
based on 8100 events where a D^0 or anti D^0 is detected subsequently to a D*+
or D*- decay, and on 34000 events, where only a D^0 or anti D^0 is detected.
Kinematic distributions of D*, D and K*_2 are given as a function of their
energy E, transverse momentum p_T, energy fraction z, and of the virtual photon
variables nu, Q^2 and x_Bj. Semi-inclusive differential D* production
cross-sections are compared with theoretical predictions for D* production via
photon-gluon fusion into open charm. The total observed production
cross-section for D*+/- mesons with laboratory energies between 22 and 86 GeV
is 1.9 nb. Significant cross-section asymmetries are observed between D*+ and
D*- production for nu<40 GeV and z>0.6.
European Physical Journal C 11/2012; 72(12). · 3.63 Impact Factor
-
C. Adolph,
M. G. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. A. Antonov,
A. Austregesilo,
B. Badełek,
F. Balestra, [......],
M. Wilfert,
R. Windmolders,
W. Wiślicki,
H. Wollny,
K. Zaremba,
M. Zavertyaev,
E. Zemlyanichkina,
M. Ziembicki,
N. Zhuravlev,
A. Zvyagin
[show abstract]
[hide abstract]
ABSTRACT: The transverse target spin azimuthal asymmetry A_UT in hard exclusive
production of rho^0 mesons was measured at COMPASS by scattering 160 GeV/c
muons off transversely polarised protons and deuterons. The measured asymmetry
is sensitive to the nucleon helicity-flip generalised parton distributions E^q,
which are related to the orbital angular momentum of quarks in the nucleon. The
Q^2, x_B and p_t^2 dependence of A_UT is presented in a wide kinematic range.
Results for deuterons are obtained for the first time. The measured asymmetry
is small in the whole kinematic range for both protons and deuterons, which is
consistent with the theoretical interpretation that contributions from GPDs E^u
and E^d approximately cancel.
07/2012;
-
C. Adolph,
M. G. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. A. Antonov,
A. Austregesilo,
B. Badełek,
F. Balestra, [......],
L. Wang,
R. Windmolders,
W. Wislicki,
H. Wollny,
K. Zaremba,
M. Zavertyaev,
E. Zemlyanichkina,
M. Ziembicki,
N. Zhuravlev,
A. Zvyagin
[show abstract]
[hide abstract]
ABSTRACT: The cross section for production of charged hadrons with high transverse
momenta in scattering of 160 GeV/c muons off nucleons at low photon
virtualities has been measured at the COMPASS experiment at CERN. The results,
which cover transverse momenta from 1.1 to 3.6 GeV/c, are compared to a
next-to-leading order perturbative Quantum Chromodynamics (NLO pQCD)
calculation in order to evaluate the applicability of pQCD to this process in
the kinematic domain of the experiment. The shape of the calculated
differential cross section as a function of transverse momentum is found to be
in good agreement with the experimental data, but the normalization is
underestimated by NLO pQCD. This discrepancy may point towards the relevance of
terms beyond NLO in the pQCD framework. The dependence of the cross section on
the pseudo-rapidity and on the charge of the hadrons is also discussed.
07/2012;
-
C. Adolph,
M. G. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. A. Antonov,
A. Austregesilo,
B. Badelek,
F. Balestra, [......],
M. Wilfert,
R. Windmolders,
W. Wislicki,
H. Wollny,
K. Zaremba,
M. Zavertyaev,
E. Zemlyanichkina,
M. Ziembicki,
N. Zhuravlev,
A. Zvyagin
[show abstract]
[hide abstract]
ABSTRACT: The COMPASS Collaboration at CERN has measured the transverse spin azimuthal
asymmetry of charged hadrons produced in semi-inclusive deep inelastic
scattering using a 160 GeV positive muon beam and a transversely polarised NH_3
target. The Collins asymmetry of the proton was extracted in the Bjorken x
range 0.003<x<0.7. These new measurements confirm with higher accuracy previous
measurements from the COMPASS and HERMES collaborations, which exhibit a
definite effect in the valence quark region. The asymmetries for negative and
positive hadrons are similar in magnitude and opposite in sign. They are
compatible with model calculations in which the u-quark transversity is
opposite in sign and somewhat larger than the d-quark transversity distribution
function. The asymmetry is extracted as a function of Bjorken $x$, the relative
hadron energy $z$ and the hadron transverse momentum p_T^h. The high statistics
and quality of the data also allow for more detailed investigations of the
dependence on the kinematic variables. These studies confirm the leading-twist
nature of the Collins asymmetry.
05/2012;
-
C. Adolph,
M. G. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. A. Antonov,
A. Austregesilo,
B. Badelek,
F. Balestra, [......],
M. Wilfert,
R. Windmolders,
W. Wislicki,
H. Wollny,
K. Zaremba,
M. Zavertyaev,
E. Zemlyanichkina,
M. Ziembicki,
N. Zhuravlev,
A. Zvyagin
[show abstract]
[hide abstract]
ABSTRACT: The COMPASS Collaboration at CERN has measured the transverse spin azimuthal
asymmetry of charged hadrons produced in semi-inclusive deep inelastic
scattering using a 160 GeV positive muon beam and a transversely polarised NH_3
target. The Sivers asymmetry of the proton has been extracted in the Bjorken x
range 0.003<x<0.7. The new measurements have small statistical and systematic
uncertainties of a few percent and confirm with considerably better accuracy
the previous COMPASS measurement. The Sivers asymmetry is found to be
compatible with zero for negative hadrons and positive for positive hadrons, a
clear indication of a spin-orbit coupling of quarks in a transversely polarised
proton. As compared to measurements at lower energy, a smaller Sivers asymmetry
for positive hadrons is found in the region x > 0.03. The asymmetry is
different from zero and positive also in the low x region, where sea-quarks
dominate. The kinematic dependence of the asymmetry has also been investigated
and results are given for various intervals of hadron and virtual photon
fractional energy. In contrast to the case of the Collins asymmetry, the
results on the Sivers asymmetry suggest a strong dependence on the
four-momentum transfer to the nucleon, in agreement with the most recent
calculations.
05/2012;
-
M. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. Austregesilo,
B. Badełek,
F. Balestra,
J. Ball,
J. Barth, [......],
Q. Weitzel,
R. Windmolders,
W. Wiślicki,
H. Wollny,
K. Zaremba,
E. Zemlyanichkina,
M. Ziembicki,
J. Zhao,
N. Zhuravlev,
A. Zvyagin
[show abstract]
[hide abstract]
ABSTRACT: The longitudinal polarisation transfer from muons to Λand
[`\varLambda]\bar{\varLambda}
hyperons,
DLL\varLambda([`\varLambda])D_{LL}^{\varLambda(\bar{\varLambda})}
, has been studied in deep-inelastic scattering off an unpolarised isoscalar target at the COMPASS experiment at CERN. The
spin transfers to Λand
[`\varLambda]\bar{\varLambda}
produced in the current fragmentation region exhibit different behaviours as a function of x and x
F
. The measured x and x
F
dependences of D
LL
Λ
are compatible with zero, while
DLL[`\varLambda]D_{LL}^{\bar{\varLambda}}
tends to increase with x
F
, reaching values of 0.4–0.5. The resulting average values are D
LL
Λ
= −0.012±0.047±0.024 and
DLL[`\varLambda]D_{LL}^{\bar{\varLambda}}
= 0.249±0.056±0.049. These results are discussed in the frame of recent model calculations.
European Physical Journal C 04/2012; 64(2):171-179. · 3.63 Impact Factor
-
The COMPASS Collaboration,
M. G. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. Austregesilo,
B. Badełek,
F. Balestra,
J. Barth, [......],
R. Windmolders,
W. Wiślicki,
H. Wollny,
K. Zaremba,
M. Zavertyaev,
E. Zemlyanichkina,
M. Ziembicki,
J. Zhao,
N. Zhuravlev,
A. Zvyagin
[show abstract]
[hide abstract]
ABSTRACT: Azimuthal asymmetries in semi-inclusive production of positive (h
+) and negative hadrons (h
−) have been measured by scattering 160 GeV muons off longitudinally polarised deuterons at CERN. The asymmetries were decomposed
in several terms according to their expected modulation in the azimuthal angle φ of the outgoing hadron. Each term receives contributions from one or several spin and transverse-momentum-dependent parton
distribution and fragmentation functions. The amplitudes of all φ-modulation terms of the hadron asymmetries integrated over the kinematic variables are found to be consistent with zero within
statistical errors, while the constant terms are nonzero and equal for h
+ and h
− within the statistical errors. The dependencies of the φ-modulated terms versus the Bjorken momentum fraction x, the hadron fractional momentum z, and the hadron transverse momentum phTp_{h}^{T} were studied. The x dependence of the constant terms for both positive and negative hadrons is in agreement with the longitudinal double-spin
hadron asymmetries, measured in semi-inclusive deep-inelastic scattering. The x dependence of the sin φ-modulation term is less pronounced than that in the corresponding HERMES data. All other dependencies of the φ-modulation amplitudes are consistent with zero within the statistical errors.
European Physical Journal C 04/2012; 70(1):39-49. · 3.63 Impact Factor
-
C. Adolph,
M. G. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. A. Antonov,
A. Austregesilo,
B. Badellek,
F. Balestra, [......],
L. Wang,
R. Windmolders,
W. Wislicki,
H. Wollny,
K. Zaremba,
M. Zavertyaev,
E. Zemlyanichkina,
M. Ziembicki,
N. Zhuravlevd,
A. Zvyagin
[show abstract]
[hide abstract]
ABSTRACT: First measurements of azimuthal asymmetries in hadron-pair production in
deep-inelastic scattering of muons on transversely polarised ^6LiD (deuteron)
and NH_3 (proton) targets are presented. The data were taken in the years
2002-2004 and 2007 with the COMPASS spectrometer using a muon beam of 160 GeV/c
at the CERN SPS. The asymmetries provide access to the transversity
distribution functions, without involving the Collins effect as in single
hadron production. The sizeable asymmetries measured on the NH_ target indicate
non-vanishing u-quark transversity and two-hadron interference fragmentation
functions. The small asymmetries measured on the ^6LiD target can be
interpreted as indication for a cancellation of u- and d-quark transversities.
02/2012;
-
C. Adolph,
M. G. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. A. Antonov,
A. Austregesilo,
B. Badelek,
F. Balestra, [......],
L. Wang,
R. Windmolders,
W. Wislicki,
H. Wollny,
K. Zaremba,
M. Zavertyaev,
E. Zemlyanichkina,
M. Ziembicki,
N. Zhuravlev,
A. Zvyagin
[show abstract]
[hide abstract]
ABSTRACT: We present a determination of the gluon polarisation Delta g/g in the
nucleon, based on the longitudinal double-spin asymmetry of DIS events with a
pair of large transverse-momentum hadrons in the final state. The data were
obtained by the COMPASS experiment at CERN using a 160 GeV/c polarised muon
beam scattering off a polarised ^6LiD target. The gluon polarisation is
evaluated by a Neural Network approach for three intervals of the gluon
momentum fraction x_g covering the range 0.04 < x_g < 0.27. The values obtained
at leading order in QCD do not show any significant dependence on x_g. Their
average is Delta g/g = 0.125 +/- 0.060 (stat.) +/- 0.063 (syst.) at x_g=0.09
and a scale of mu^2 = 3 (GeV/c)^2.
02/2012;
-
M Alexeev,
F Barbosa,
R Birsa,
F Bradamante,
A Bressan,
M Chiosso,
P Ciliberti,
S Dalla Torre,
O Denisov,
V Duic, [......],
C Schill,
S Schopferer,
M Slunecka,
F Sozzi,
L Steiger,
M Sulc,
S Takekawa,
F Tessarotto,
J F C A Veloso,
H Wollny
[show abstract]
[hide abstract]
ABSTRACT: The photon detectors based on MPGD (MicroPattern Gaseous Detector) represent the new generation of gaseous photon detectors. We report about an R&D programme dedicated to study both the principles and the engineering aspects of photon detectors based on Thick GEMs (THGEM) electron multipliers coupled to a CsI photoconverting coating. The goal is the development of a gaseous detector of single UV photons, able to stably operate at high gain and high rate, to provide good time resolution and insensitive to magnetic field to be used in the Cherenkov imaging counter RICH-1 of the COMPASS experiment at CERN SPS.
Journal of Instrumentation 02/2012; 7(02):C02014. · 1.87 Impact Factor
-
M Alexeev,
R Birsa,
F Bradamante,
A Bressan,
M Chiosso,
P Ciliberti,
S Dalla Torre,
O Denisov,
V Duic,
M Finger, [......],
C Schill,
S Schopferer,
M Slunecka,
F Sozzi,
L Steiger,
M Sulc,
S Takekawa,
F Tessarotto,
J F C A Veloso,
H Wollny
Physics Procedia 01/2012; 37:781-788.
-
M. G. Alekseev,
V. Yu. Alexakhin,
Yu. Alexandrov,
G. D. Alexeev,
A. Amoroso,
A. Austregesilo,
B. Badelek,
F. Balestra,
J. Barth,
G. Baum, [......],
N. V. Vlassov,
R. Windmolders,
W. Wiślicki,
H. Wollny,
K. Zaremba,
M. Zavertyaev,
E. Zemlyanichkina,
M. Ziembicki,
N. Zhuravlev,
A. Zvyagin
[show abstract]
[hide abstract]
ABSTRACT: The COMPASS collaboration at CERN has investigated the \pi^- \gamma -> \pi^-
\pi^- \pi^+ reaction at center-of-momentum energy below five pion masses,
sqrt(s) < 5 m(\pi), embedded in the Primakoff reaction of 190 GeV pions
impinging on a lead target. Exchange of quasi-real photons is selected by
isolating the sharp Coulomb peak observed at smallest momentum transfers, t' <
0.001 (GeV/c)^2. Using partial-wave analysis techniques, the scattering
intensity of Coulomb production described in terms of chiral dynamics and its
dependence on the 3\pi-invariant mass m(3\pi) = sqrt(s) were extracted. The
absolute cross section was determined in seven bins of $\sqrt{s}$ with an
overall precision of 20%. At leading order, the result is found to be in good
agreement with the prediction of chiral perturbation theory over the whole
energy range investigated.
11/2011;
-
[show abstract]
[hide abstract]
ABSTRACT: This article describes the implementation of a mean-timer and coincidence
logic on a Virtex-5 FPGA for trigger purposes in a particle physics experiment.
The novel feature is that the mean-timing and the coincidence logic are not
synchronized with a clock which allows for a higher resolution of approximately
400 ps, not limited by a clock frequency.
09/2011;
-
[show abstract]
[hide abstract]
ABSTRACT: With present-day detectors in high energy physics one often faces fast analog pulses of a few nanoseconds length which cover large dynamic ranges. In many experiments both amplitude and timing information have to be measured with high accuracy. Additionally, the data rate per readout channel can reach several MHz, which leads to high demands on the separation of pile-up pulses. For an upgrade of the COMPASS experiment at CERN we have designed the GANDALF transient recorder with a resolution of 12 bit@1 GS/s and an analog bandwidth of 500 MHz. Signals are digitized with high precision and processed by fast algorithms to extract pulse arrival times and amplitudes in real-time and to generate trigger signals for the experiment. With up to 16 analog channels, deep memories and a high data rate interface, this 6U-VME64x/VXS module is not only a dead-time free digitization unit but also has huge numerical capabilities provided by the implementation of a Virtex5-SXT FPGA. Fast algorithms implemented in the FPGA may be used to disentangle possible pile-up pulses and determine timing information from sampled pulse shapes with a time resolution better than 50 ps.
IEEE Transactions on Nuclear Science 09/2011; · 1.45 Impact Factor
-
S. Aune,
K. Barth,
A. Belov,
S. Borghi,
H. Brauninger,
G. Cantatore,
J.M. Carmona,
S.A. Cetin,
J.I. Collar,
T. Dafni, [......],
A. Tomas,
M. Tsagri,
K. van Bibber,
T. Vafeiadis,
J. Villar,
J.K. Vogel,
L. Walckiers,
Y.Y.Y. Wong,
S.C. Yildiz,
K. Zioutas
[show abstract]
[hide abstract]
ABSTRACT: The CERN Axion Solar Telescope (CAST) is searching for solar axions which could be produced in the core of the Sun via the so-called Primakoff effect. Not only would these hypothetical particles solve the strong CP problem, but they are also one of the favored candidates for dark matter. In order to look for axions originating from the Sun, CAST uses a decommissioned LHC prototype magnet. In its 10 m long magnetic field region of 9 Tesla, axions could be reconverted into X-ray photons. Different X-ray detectors are installed on both ends of the magnet, which is mounted on a structure built to follow the Sun during sunrise and sunset for a total of about 3 hours per day. The analysis of the data acquired during the first phase of the experiment with vacuum in the magnetic field region yielded the most restrictive experimental upper limit on the axion-to-photon coupling constant for axion masses up to about 0.02 eV. In order to extend the sensitivity of the experiment to a wider mass range, the CAST experiment continues its search for axions with helium in the magnet bores. In this way it is possible to restore coherence of conversion for larger masses. Changing the pressure of the helium gas enables the experiment to scan different axion masses in the range of up to about 1.2 eV. Especially at high pressures, a precise knowledge of the gas density distribution is crucial to obtain accurate results. In the first part of this second phase of CAST, <sup>4</sup>He was used and the axion mass region was extended up to 0.39 eV, a part of phase space favored by axion models. In CAST's ongoing <sup>3</sup>He phase the studied mass range is now being extended further. In this contribution the final results of CAST's <sup>4</sup>He phase will be presented and the current status of the <sup>3</sup>He run will be given. This includes latest results as well as prospects of future axion experiments.
Nuclear Science Symposium Conference Record (NSS/MIC), 2010 IEEE; 12/2010
