Jelena Ninkovic - Academia.edu (original) (raw)

Papers by Jelena Ninkovic

SciPost Physics Proceedings

In the search for dark matter particle candidates, the mass region below 1 GeV/c^22 is relatively... more In the search for dark matter particle candidates, the mass region below 1 GeV/c^22 is relatively unprobed. Utilizing a low-noise silicon sensor as a sensitive target material, we aim to study the event signature of recoils between dark matter candidates and bound electrons. As the deposited energy is only a few eV, a sensor capable of detecting these low signals is required. We present first measurements on a prototype pixel matrix. It is based on the RNDR DePFET principle and provides a deep sub-electron readout noise of 0.2e^-− and below.

arXiv (Cornell University), Nov 18, 2022

Potassium-40 is a widespread, naturally occurring isotope whose radioactivity impacts estimated g... more Potassium-40 is a widespread, naturally occurring isotope whose radioactivity impacts estimated geological ages spanning billions of years, nuclear structure theory, and subatomic rare-event searches-including those for dark matter and neutrinoless double-beta decay. The decays of this long-lived isotope must be precisely known for its use as a geochronometer, and to account for its presence in low-background experiments. There are several known decay modes for potassium-40, but a predicted electron-capture decay directly to the ground state of argon-40 has never been observed. The existence of this decay mode impacts several fields, while theoretical predictions span an order of magnitude. Here we report on the first, successful observation of this rare decay mode, obtained by the KDK (potassium decay) Collaboration using a novel combination of a low-threshold X-ray detector surrounded by a tonne-scale, high-efficiency γ-ray tagger at Oak Ridge National Laboratory. A blinded analysis reveals a distinctly non-zero ratio of intensities of ground-state electron-captures (I EC 0) over excited-state ones (I EC*) of I EC 0 /I EC* = 0.0095 stat ± 0.0022 sys ± 0.0010 (68%CL), with the null hypothesis rejected at 4σ [Stukel et al., Phys. Rev. Lett. 131, 05203 (2023)]. In terms of branching ratio, this unambiguous signal yields I EC 0 = 0.098% stat ± 0.023% sys ± 0.010%, roughly half of the commonly used prediction. This first observation of a third-forbidden unique electron capture improves our understanding of low-energy backgrounds in dark-matter searches and has implications for nuclear-structure calculations. For example, a shell-model based theoretical estimate for the neutrinoless double-beta decay half-life of calcium-48 is increased by a factor of 7 +3 −2. Our non-zero measurement shifts geochronological ages by up to a percent; implications are illustrated for Earth and solar system chronologies.

arXiv (Cornell University), Oct 24, 2022

arXiv (Cornell University), Sep 20, 2022

We report a measurement of decay-time dependent CP-violating parameters in B 0 → K 0 S K 0 S K 0 ... more We report a measurement of decay-time dependent CP-violating parameters in B 0 → K 0 S K 0 S K 0 S decays. We use (198.0 ± 3.0) × 10 6 BB pairs collected at the Υ(4S) resonance with the Belle II detector at the SuperKEKB asymmetric-energy e + e − collider. The observed mixing-induced and direct CP violation parameters are S = −1.86 +0.91 −0.46 (stat) ± 0.09 (syst) and A = −0.22 +0.30 −0.27 (stat) ± 0.04 (syst), respectively.

HAL (Le Centre pour la Communication Scientifique Directe), Sep 22, 2021

Measurements of branching fractions and CP-violating charge asymmetries in multibody charmless B ... more Measurements of branching fractions and CP-violating charge asymmetries in multibody charmless B decays reconstructed in 2019-2020 Belle II data

We present a reconstruction in early data of the semileptonic decay B+ → π`ν`, and first results ... more We present a reconstruction in early data of the semileptonic decay B+ → π`ν`, and first results of a reconstruction of the decays B+ → ρ`ν` and B0 → ρ`ν` in a sample corresponding to 62.8 fb−1 of Belle II data using hadronic B-tagging via the full-event-interpretation algorithm. We determine the total branching fractions via fits to the distribution of the square of the missing mass, and find B(B+ → π`ν`) = (8.29 ± 1.99(stat) ± 0.46(syst)) ×10−5. We obtain 95% CL upper limits on the branching fractions with B(B0 → ρ`ν`) < 3.37× 10−4 and B(B+ → ρ`ν`) < 19.7×10−5. We also obtain an updated branching fraction for the B0 → π`ν` decay, B(B0 → π`ν`) = (1.47 ± 0.29(stat) ± 0.05(syst)) ×10−4, based on the sum of the partial branching fractions in three bins of the squared momentum transfer to the leptonic system.

The reconstruction of tau-pair production, e+e−totau+tau−e^{+}e^{-} \to \tau^{+}\tau^{-}e+e−totau+tau−, from the subsequent... more The reconstruction of tau-pair production, e+e−totau+tau−e^{+}e^{-} \to \tau^{+}\tau^{-}e+e−totau+tau−, from the subsequent 3-prong ($\tau^{+} \rightarrow \pi^{+} \pi^{-} \pi^{+} \bar{\nu}_{\tau}$) and 1-prong ($\tau^{-} \to \ell^{-} \bar{\nu}_{\ell} \nu_{\tau}$, tau−toh−nutau\tau^{-} \to h^{-} \nu_{\tau}tau−toh−nutau or tau−topi−pi0nutau\tau^{-} \to \pi^{-} \pi^0 \nu_{\tau}tau−topi−pi0nutau) decays, is presented using 8.8 fb$^{-1}$ of e+e−e^{+}e^{-}e+e− collision data of Belle II at the center-of-mass energy sqrts=mUpsilon(4S)\sqrt{s} = m_{\Upsilon(4S)}sqrts=mUpsilon(4S). The pseudomass technique developed by the ARGUS experiment is used to measure the tau\tautau-lepton mass mtaum_{\tau}mtau in the 3-prong tau+topi+pi−pi+barnutau\tau^{+} \to \pi^{+} \pi^{-} \pi^{+} \bar{\nu}_{\tau} tau+topi+pi−pi+barnutau decay, resulting in mtau=1777.28pm0.75rm(stat.)˜pm0.33rm(sys.)˜rmMeV/rmc2˜m_{\tau} = 1777.28 \pm 0.75~{\rm (stat.)} \pm 0.33 ~{\rm (sys.)}~{\rm{MeV}/\rm{c}^2}mtau=1777.28pm0.75rm(stat.)˜​pm0.33rm(sys.)˜​rmMeV/rmc2˜​.

We report on the first calibration of the standard Belle II BBB-flavor tagger using the full data... more We report on the first calibration of the standard Belle II BBB-flavor tagger using the full data set collected at the Upsilon(4rmS)\Upsilon(4{\rm S})Upsilon(4rmS) resonance in 2019 with the Belle II detector at the SuperKEKB collider, corresponding to 8.7 fb$^{-1}$ of integrated luminosity. The calibration is performed by reconstructing various hadronic charmed BBB-meson decays with flavor-specific final states. We use simulation to optimize our event selection criteria and to train the flavor tagging algorithm. We determine the tagging efficiency and the fraction of wrongly identified tag-side BBB~candidates from a measurement of the time-integrated B0−overlineB0B^0-\overline{B}^0B0−overlineB0 mixing probability. The total effective efficiency is measured to be varepsilonrmeff=big(33.8pm3.6(textstat)pm1.6(textsys)big)\varepsilon_{\rm eff} = \big(33.8 \pm 3.6(\text{stat}) \pm 1.6(\text{sys})\big)\%varepsilonrmeff=big(33.8pm3.6(textstat)pm1.6(textsys)big), which is in good agreement with the predictions from simulation and comparable with the best one obtained by the Belle experiment. The results show a good understanding of the detector p...

F. Abudinén, I. Adachi, 22 R. Adak, K. Adamczyk, P. Ahlburg, J. K. Ahn, H. Aihara, N. Akopov, A. ... more F. Abudinén, I. Adachi, 22 R. Adak, K. Adamczyk, P. Ahlburg, J. K. Ahn, H. Aihara, N. Akopov, A. Aloisio, 42 F. Ameli, L. Andricek, N. Anh Ky, 14 D. M. Asner, H. Atmacan, V. Aulchenko, 76 T. Aushev, V. Aushev, T. Aziz, V. Babu, S. Bacher, S. Baehr, S. Bahinipati, A. M. Bakich, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, G. Batignani, 45 J. Baudot, A. Beaulieu, J. Becker, P. K. Behera, M. Bender, J. V. Bennett, E. Bernieri, F. U. Bernlochner, M. Bertemes, E. Bertholet, M. Bessner, S. Bettarini, 45 V. Bhardwaj, B. Bhuyan, F. Bianchi, 48 T. Bilka, S. Bilokin, D. Biswas, A. Bobrov, 76 A. Bondar, 76 G. Bonvicini, A. Bozek, M. Bračko, 88 P. Branchini, N. Braun, R. A. Briere, T. E. Browder, D. N. Brown, A. Budano, L. Burmistrov, S. Bussino, 47 M. Campajola, 42 L. Cao, G. Caria, G. Casarosa, 45 C. Cecchi, 44 D. Červenkov, M.-C. Chang, P. Chang, R. Cheaib, V. Chekelian, C. Chen, Y. Q. Chen, Y.-T. Chen, B. G. Cheon, K. Chilikin, K. Chirapatpimol, H.-E. Cho, K. Cho, S.-J. Cho, S.-K. Choi,...

The Astrophysical Journal, 2007

During its first observation cycle, between April 2005 and March 2006, the MAGIC telescope was ab... more During its first observation cycle, between April 2005 and March 2006, the MAGIC telescope was able to observe nine different GRB events since their early beginning. Other observations have been performed during the following months in its second observation cycle. The observations, with an energy threshold spanning from 80 to 200 GeV, did not reveal any gamma-ray emission. The computed upper limits are compatible with a power law extrapolation, where intrinsic fluxes are evaluated taking into account the attenuation due to the scattering in the Metagalactic Radiation Field (MRF).

Journal of Physics: Conference Series, 2020

Potassium-40 (40K) is a background in many rare-event searches and may well play a role in interp... more Potassium-40 (40K) is a background in many rare-event searches and may well play a role in interpreting results from the DAMA dark-matter search. The electron-capture decay of 40K to the ground state of 40 Ar has never been measured and contributes an unknown amount of background. The KDK (potassium decay) collaboration will measure this branching ratio using a 40K source, an X-ray detector, and the Modular Total Absorption Spectrometer at Oak Ridge National Laboratory.

… Research Section A: …, 2006

We present first significant limits on WIMP dark matter by the phonon-light technique, where comb... more We present first significant limits on WIMP dark matter by the phonon-light technique, where combined phonon and light signals from a scintillating cryogenic detector are used to suppress the non-nuclear recoil background. The performance of the detectors developed ...

New Astronomy …, 2005

The CRESST Phase II experiment at Gran Sasso is using 300 g scintillating CaWO 4 crystals as abso... more The CRESST Phase II experiment at Gran Sasso is using 300 g scintillating CaWO 4 crystals as absorbers for direct WIMP (weakly interactive massive particles) detection. The phonon signal in the CaWO 4 crystal is registered in coincidence with the light signal, which is measured with a separate cryogenic light detector. The absorber crystal and the silicon light detector are read out by tungsten superconducting phase transition thermometers (W-SPTs). As a result an active discrimination of the electron recoils against nuclear recoils is achieved. Results on the properties of the detector modules and on the WIMP sensitivity are presented.

… Research Section A: …, 2005

Although it is well known that CaWO4 is a scintillator it is not often used, mainly because it ha... more Although it is well known that CaWO4 is a scintillator it is not often used, mainly because it has a slow light response. However, a high Z and a good light output make this crystal a candidate for use in direct dark matter search experiments. The Cryogenic Rare Event ...

… Research Section A: …, 2004

CRESST-II detector modules rely on the ability to actively discriminate electron recoils from nuc... more CRESST-II detector modules rely on the ability to actively discriminate electron recoils from nuclear recoils via simultaneous measurement of phonons and scintillation light. The scintillation light produced in each target crystal is detected via an associated calorimeter ...

… Research Section A: …, 2004

In the CRESST-II experiment, scintillating CaWO4 crystals are used as absorbers for direct weakly... more In the CRESST-II experiment, scintillating CaWO4 crystals are used as absorbers for direct weakly interacting massive particles (WIMP) detection. Nuclear recoils can be discriminated against electron recoils by measuring phonons and scintillation light simultaneously. The ...

Czechoslovak Journal of Physics, 2006

Nuclear Instruments and Methods in Physics Research …, 2007

A novel type of avalanche photodetector with Geiger mode operation, known as a Silicon PhotoMulti... more A novel type of avalanche photodetector with Geiger mode operation, known as a Silicon PhotoMultiplier (SiPM) provides an interesting advance in photodetection and is already an alternative to traditional PMTs in many applications. The state of the art of the SiPMs-their main properties and problems-are discussed.

Nuclear Instruments and …, 2006

We present a new technique developed for the measurement of the scintillation efficiency of nucle... more We present a new technique developed for the measurement of the scintillation efficiency of nuclear recoils in solid scintillators. Using this technique we measured the quenching of the scintillation efficiency for the various recoiling nuclei in CaWO 4 crystals which are used in direct Dark Matter searches.

SciPost Physics Proceedings

In the search for dark matter particle candidates, the mass region below 1 GeV/c^22 is relatively... more In the search for dark matter particle candidates, the mass region below 1 GeV/c^22 is relatively unprobed. Utilizing a low-noise silicon sensor as a sensitive target material, we aim to study the event signature of recoils between dark matter candidates and bound electrons. As the deposited energy is only a few eV, a sensor capable of detecting these low signals is required. We present first measurements on a prototype pixel matrix. It is based on the RNDR DePFET principle and provides a deep sub-electron readout noise of 0.2e^-− and below.

arXiv (Cornell University), Nov 18, 2022

Potassium-40 is a widespread, naturally occurring isotope whose radioactivity impacts estimated g... more Potassium-40 is a widespread, naturally occurring isotope whose radioactivity impacts estimated geological ages spanning billions of years, nuclear structure theory, and subatomic rare-event searches-including those for dark matter and neutrinoless double-beta decay. The decays of this long-lived isotope must be precisely known for its use as a geochronometer, and to account for its presence in low-background experiments. There are several known decay modes for potassium-40, but a predicted electron-capture decay directly to the ground state of argon-40 has never been observed. The existence of this decay mode impacts several fields, while theoretical predictions span an order of magnitude. Here we report on the first, successful observation of this rare decay mode, obtained by the KDK (potassium decay) Collaboration using a novel combination of a low-threshold X-ray detector surrounded by a tonne-scale, high-efficiency γ-ray tagger at Oak Ridge National Laboratory. A blinded analysis reveals a distinctly non-zero ratio of intensities of ground-state electron-captures (I EC 0) over excited-state ones (I EC*) of I EC 0 /I EC* = 0.0095 stat ± 0.0022 sys ± 0.0010 (68%CL), with the null hypothesis rejected at 4σ [Stukel et al., Phys. Rev. Lett. 131, 05203 (2023)]. In terms of branching ratio, this unambiguous signal yields I EC 0 = 0.098% stat ± 0.023% sys ± 0.010%, roughly half of the commonly used prediction. This first observation of a third-forbidden unique electron capture improves our understanding of low-energy backgrounds in dark-matter searches and has implications for nuclear-structure calculations. For example, a shell-model based theoretical estimate for the neutrinoless double-beta decay half-life of calcium-48 is increased by a factor of 7 +3 −2. Our non-zero measurement shifts geochronological ages by up to a percent; implications are illustrated for Earth and solar system chronologies.

arXiv (Cornell University), Oct 24, 2022

arXiv (Cornell University), Sep 20, 2022

We report a measurement of decay-time dependent CP-violating parameters in B 0 → K 0 S K 0 S K 0 ... more We report a measurement of decay-time dependent CP-violating parameters in B 0 → K 0 S K 0 S K 0 S decays. We use (198.0 ± 3.0) × 10 6 BB pairs collected at the Υ(4S) resonance with the Belle II detector at the SuperKEKB asymmetric-energy e + e − collider. The observed mixing-induced and direct CP violation parameters are S = −1.86 +0.91 −0.46 (stat) ± 0.09 (syst) and A = −0.22 +0.30 −0.27 (stat) ± 0.04 (syst), respectively.

HAL (Le Centre pour la Communication Scientifique Directe), Sep 22, 2021

Measurements of branching fractions and CP-violating charge asymmetries in multibody charmless B ... more Measurements of branching fractions and CP-violating charge asymmetries in multibody charmless B decays reconstructed in 2019-2020 Belle II data

We present a reconstruction in early data of the semileptonic decay B+ → π`ν`, and first results ... more We present a reconstruction in early data of the semileptonic decay B+ → π`ν`, and first results of a reconstruction of the decays B+ → ρ`ν` and B0 → ρ`ν` in a sample corresponding to 62.8 fb−1 of Belle II data using hadronic B-tagging via the full-event-interpretation algorithm. We determine the total branching fractions via fits to the distribution of the square of the missing mass, and find B(B+ → π`ν`) = (8.29 ± 1.99(stat) ± 0.46(syst)) ×10−5. We obtain 95% CL upper limits on the branching fractions with B(B0 → ρ`ν`) < 3.37× 10−4 and B(B+ → ρ`ν`) < 19.7×10−5. We also obtain an updated branching fraction for the B0 → π`ν` decay, B(B0 → π`ν`) = (1.47 ± 0.29(stat) ± 0.05(syst)) ×10−4, based on the sum of the partial branching fractions in three bins of the squared momentum transfer to the leptonic system.

The reconstruction of tau-pair production, e+e−totau+tau−e^{+}e^{-} \to \tau^{+}\tau^{-}e+e−totau+tau−, from the subsequent... more The reconstruction of tau-pair production, e+e−totau+tau−e^{+}e^{-} \to \tau^{+}\tau^{-}e+e−totau+tau−, from the subsequent 3-prong ($\tau^{+} \rightarrow \pi^{+} \pi^{-} \pi^{+} \bar{\nu}_{\tau}$) and 1-prong ($\tau^{-} \to \ell^{-} \bar{\nu}_{\ell} \nu_{\tau}$, tau−toh−nutau\tau^{-} \to h^{-} \nu_{\tau}tau−toh−nutau or tau−topi−pi0nutau\tau^{-} \to \pi^{-} \pi^0 \nu_{\tau}tau−topi−pi0nutau) decays, is presented using 8.8 fb$^{-1}$ of e+e−e^{+}e^{-}e+e− collision data of Belle II at the center-of-mass energy sqrts=mUpsilon(4S)\sqrt{s} = m_{\Upsilon(4S)}sqrts=mUpsilon(4S). The pseudomass technique developed by the ARGUS experiment is used to measure the tau\tautau-lepton mass mtaum_{\tau}mtau in the 3-prong tau+topi+pi−pi+barnutau\tau^{+} \to \pi^{+} \pi^{-} \pi^{+} \bar{\nu}_{\tau} tau+topi+pi−pi+barnutau decay, resulting in mtau=1777.28pm0.75rm(stat.)˜pm0.33rm(sys.)˜rmMeV/rmc2˜m_{\tau} = 1777.28 \pm 0.75~{\rm (stat.)} \pm 0.33 ~{\rm (sys.)}~{\rm{MeV}/\rm{c}^2}mtau=1777.28pm0.75rm(stat.)˜​pm0.33rm(sys.)˜​rmMeV/rmc2˜​.

We report on the first calibration of the standard Belle II BBB-flavor tagger using the full data... more We report on the first calibration of the standard Belle II BBB-flavor tagger using the full data set collected at the Upsilon(4rmS)\Upsilon(4{\rm S})Upsilon(4rmS) resonance in 2019 with the Belle II detector at the SuperKEKB collider, corresponding to 8.7 fb$^{-1}$ of integrated luminosity. The calibration is performed by reconstructing various hadronic charmed BBB-meson decays with flavor-specific final states. We use simulation to optimize our event selection criteria and to train the flavor tagging algorithm. We determine the tagging efficiency and the fraction of wrongly identified tag-side BBB~candidates from a measurement of the time-integrated B0−overlineB0B^0-\overline{B}^0B0−overlineB0 mixing probability. The total effective efficiency is measured to be varepsilonrmeff=big(33.8pm3.6(textstat)pm1.6(textsys)big)\varepsilon_{\rm eff} = \big(33.8 \pm 3.6(\text{stat}) \pm 1.6(\text{sys})\big)\%varepsilonrmeff=big(33.8pm3.6(textstat)pm1.6(textsys)big), which is in good agreement with the predictions from simulation and comparable with the best one obtained by the Belle experiment. The results show a good understanding of the detector p...

F. Abudinén, I. Adachi, 22 R. Adak, K. Adamczyk, P. Ahlburg, J. K. Ahn, H. Aihara, N. Akopov, A. ... more F. Abudinén, I. Adachi, 22 R. Adak, K. Adamczyk, P. Ahlburg, J. K. Ahn, H. Aihara, N. Akopov, A. Aloisio, 42 F. Ameli, L. Andricek, N. Anh Ky, 14 D. M. Asner, H. Atmacan, V. Aulchenko, 76 T. Aushev, V. Aushev, T. Aziz, V. Babu, S. Bacher, S. Baehr, S. Bahinipati, A. M. Bakich, P. Bambade, Sw. Banerjee, S. Bansal, M. Barrett, G. Batignani, 45 J. Baudot, A. Beaulieu, J. Becker, P. K. Behera, M. Bender, J. V. Bennett, E. Bernieri, F. U. Bernlochner, M. Bertemes, E. Bertholet, M. Bessner, S. Bettarini, 45 V. Bhardwaj, B. Bhuyan, F. Bianchi, 48 T. Bilka, S. Bilokin, D. Biswas, A. Bobrov, 76 A. Bondar, 76 G. Bonvicini, A. Bozek, M. Bračko, 88 P. Branchini, N. Braun, R. A. Briere, T. E. Browder, D. N. Brown, A. Budano, L. Burmistrov, S. Bussino, 47 M. Campajola, 42 L. Cao, G. Caria, G. Casarosa, 45 C. Cecchi, 44 D. Červenkov, M.-C. Chang, P. Chang, R. Cheaib, V. Chekelian, C. Chen, Y. Q. Chen, Y.-T. Chen, B. G. Cheon, K. Chilikin, K. Chirapatpimol, H.-E. Cho, K. Cho, S.-J. Cho, S.-K. Choi,...

The Astrophysical Journal, 2007

During its first observation cycle, between April 2005 and March 2006, the MAGIC telescope was ab... more During its first observation cycle, between April 2005 and March 2006, the MAGIC telescope was able to observe nine different GRB events since their early beginning. Other observations have been performed during the following months in its second observation cycle. The observations, with an energy threshold spanning from 80 to 200 GeV, did not reveal any gamma-ray emission. The computed upper limits are compatible with a power law extrapolation, where intrinsic fluxes are evaluated taking into account the attenuation due to the scattering in the Metagalactic Radiation Field (MRF).

Journal of Physics: Conference Series, 2020

Potassium-40 (40K) is a background in many rare-event searches and may well play a role in interp... more Potassium-40 (40K) is a background in many rare-event searches and may well play a role in interpreting results from the DAMA dark-matter search. The electron-capture decay of 40K to the ground state of 40 Ar has never been measured and contributes an unknown amount of background. The KDK (potassium decay) collaboration will measure this branching ratio using a 40K source, an X-ray detector, and the Modular Total Absorption Spectrometer at Oak Ridge National Laboratory.

… Research Section A: …, 2006

We present first significant limits on WIMP dark matter by the phonon-light technique, where comb... more We present first significant limits on WIMP dark matter by the phonon-light technique, where combined phonon and light signals from a scintillating cryogenic detector are used to suppress the non-nuclear recoil background. The performance of the detectors developed ...

New Astronomy …, 2005

The CRESST Phase II experiment at Gran Sasso is using 300 g scintillating CaWO 4 crystals as abso... more The CRESST Phase II experiment at Gran Sasso is using 300 g scintillating CaWO 4 crystals as absorbers for direct WIMP (weakly interactive massive particles) detection. The phonon signal in the CaWO 4 crystal is registered in coincidence with the light signal, which is measured with a separate cryogenic light detector. The absorber crystal and the silicon light detector are read out by tungsten superconducting phase transition thermometers (W-SPTs). As a result an active discrimination of the electron recoils against nuclear recoils is achieved. Results on the properties of the detector modules and on the WIMP sensitivity are presented.

… Research Section A: …, 2005

Although it is well known that CaWO4 is a scintillator it is not often used, mainly because it ha... more Although it is well known that CaWO4 is a scintillator it is not often used, mainly because it has a slow light response. However, a high Z and a good light output make this crystal a candidate for use in direct dark matter search experiments. The Cryogenic Rare Event ...

… Research Section A: …, 2004

CRESST-II detector modules rely on the ability to actively discriminate electron recoils from nuc... more CRESST-II detector modules rely on the ability to actively discriminate electron recoils from nuclear recoils via simultaneous measurement of phonons and scintillation light. The scintillation light produced in each target crystal is detected via an associated calorimeter ...

… Research Section A: …, 2004

In the CRESST-II experiment, scintillating CaWO4 crystals are used as absorbers for direct weakly... more In the CRESST-II experiment, scintillating CaWO4 crystals are used as absorbers for direct weakly interacting massive particles (WIMP) detection. Nuclear recoils can be discriminated against electron recoils by measuring phonons and scintillation light simultaneously. The ...

Czechoslovak Journal of Physics, 2006

Nuclear Instruments and Methods in Physics Research …, 2007

A novel type of avalanche photodetector with Geiger mode operation, known as a Silicon PhotoMulti... more A novel type of avalanche photodetector with Geiger mode operation, known as a Silicon PhotoMultiplier (SiPM) provides an interesting advance in photodetection and is already an alternative to traditional PMTs in many applications. The state of the art of the SiPMs-their main properties and problems-are discussed.

Nuclear Instruments and …, 2006

We present a new technique developed for the measurement of the scintillation efficiency of nucle... more We present a new technique developed for the measurement of the scintillation efficiency of nuclear recoils in solid scintillators. Using this technique we measured the quenching of the scintillation efficiency for the various recoiling nuclei in CaWO 4 crystals which are used in direct Dark Matter searches.