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1.
Phys Rev Lett ; 133(12): 122501, 2024 Sep 20.
Article in English | MEDLINE | ID: mdl-39373418

ABSTRACT

Current bounds on the neutrino Majorana mass are affected by significant uncertainties in the nuclear calculations for neutrinoless double-beta decay. A key issue for a data-driven improvement of the nuclear theory is the actual value of the axial coupling constant g_{A}, which can be investigated through forbidden ß decays. We present the first measurement of the 4th-forbidden ß decay of ^{115}In with a cryogenic calorimeter based on indium iodide. Exploiting the enhanced spectrum-shape method for the first time to this isotope, our study accurately determines simultaneously spectral shape, g_{A}, and half-life. The interacting shell model, which best fits our data, indicates a half-life for this decay at T_{1/2}=(5.26±0.06)×10^{14} yr.

2.
Phys Rev Lett ; 131(5): 052503, 2023 Aug 04.
Article in English | MEDLINE | ID: mdl-37595241

ABSTRACT

Potassium-40 is a widespread, naturally occurring isotope whose radioactivity impacts subatomic rare-event searches, nuclear structure theory, and estimated geological ages. A predicted electron-capture decay directly to the ground state of argon-40 has never been observed. The KDK (potassium decay) collaboration reports strong evidence of this rare decay mode. A blinded analysis reveals a nonzero 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±[over stat]0.0022±[over sys]0.0010 (68% C.L.), with the null hypothesis rejected at 4σ. In terms of branching ratio, this signal yields I_{EC^{0}}=0.098%±[over stat]0.023%±[over sys]0.010%, roughly half of the commonly used prediction, with consequences for various fields [27L. Hariasz et al., companion paper, Phys. Rev. C 108, 014327 (2023)PRVCAN2469-998510.1103/PhysRevC.108.014327].

3.
Phys Rev Lett ; 128(1): 011801, 2022 Jan 07.
Article in English | MEDLINE | ID: mdl-35061499

ABSTRACT

Dark matter with Planck-scale mass (≃10^{19} GeV/c^{2}) arises in well-motivated theories and could be produced by several cosmological mechanisms. A search for multiscatter signals from supermassive dark matter was performed with a blind analysis of data collected over a 813 d live time with DEAP-3600, a 3.3 t single-phase liquid argon-based detector at SNOLAB. No candidate signals were observed, leading to the first direct detection constraints on Planck-scale mass dark matter. Leading limits constrain dark matter masses between 8.3×10^{6} and 1.2×10^{19} GeV/c^{2}, and ^{40}Ar-scattering cross sections between 1.0×10^{-23} and 2.4×10^{-18} cm^{2}. These results are interpreted as constraints on composite dark matter models with two different nucleon-to-nuclear cross section scalings.

5.
Phys Rev Lett ; 121(5): 051301, 2018 Aug 03.
Article in English | MEDLINE | ID: mdl-30118251

ABSTRACT

We present the first limits on inelastic electron-scattering dark matter and dark photon absorption using a prototype SuperCDMS detector having a charge resolution of 0.1 electron-hole pairs (CDMS HVeV, a 0.93 g CDMS high-voltage device). These electron-recoil limits significantly improve experimental constraints on dark matter particles with masses as low as 1 MeV/c^{2}. We demonstrate a sensitivity to dark photons competitive with other leading approaches but using substantially less exposure (0.49 g d). These results demonstrate the scientific potential of phonon-mediated semiconductor detectors that are sensitive to single electronic excitations.

6.
Phys Rev Lett ; 120(6): 061802, 2018 Feb 09.
Article in English | MEDLINE | ID: mdl-29481237

ABSTRACT

We report the result of a blinded search for weakly interacting massive particles (WIMPs) using the majority of the SuperCDMS Soudan data set. With an exposure of 1690 kg d, a single candidate event is observed, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP-nucleon cross section of 1.4×10^{-44} (1.0×10^{-44}) cm^{2} at 46 GeV/c^{2}. These results set the strongest limits for WIMP-germanium-nucleus interactions for masses >12 GeV/c^{2}.

7.
Phys Rev Lett ; 116(7): 071301, 2016 Feb 19.
Article in English | MEDLINE | ID: mdl-26943526

ABSTRACT

The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5 GeV/c^{2}.

8.
Phys Rev Lett ; 114(11): 111302, 2015 Mar 20.
Article in English | MEDLINE | ID: mdl-25839256

ABSTRACT

While the standard model of particle physics does not include free particles with fractional charge, experimental searches have not ruled out their existence. We report results from the Cryogenic Dark Matter Search (CDMS II) experiment that give the first direct-detection limits for cosmogenically produced relativistic particles with electric charge lower than e/6. A search for tracks in the six stacked detectors of each of two of the CDMS II towers finds no candidates, thereby excluding new parameter space for particles with electric charges between e/6 and e/200.

9.
Phys Rev Lett ; 112(4): 041302, 2014 Jan 31.
Article in English | MEDLINE | ID: mdl-24580434

ABSTRACT

SuperCDMS is an experiment designed to directly detect weakly interacting massive particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this Letter, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage-assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for ten live days at the Soudan Underground Laboratory. A low energy threshold of 170 eVee (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6 GeV/c2.

10.
Phys Rev Lett ; 112(24): 241302, 2014 Jun 20.
Article in English | MEDLINE | ID: mdl-24996080

ABSTRACT

We report a first search for weakly interacting massive particles (WIMPs) using the background rejection capabilities of SuperCDMS. An exposure of 577 kg days was analyzed for WIMPs with mass <30 GeV/c(2), with the signal region blinded. Eleven events were observed after unblinding. We set an upper limit on the spin-independent WIMP-nucleon cross section of 1.2×10(-42) cm(2) at 8 GeV/c(2). This result is in tension with WIMP interpretations of recent experiments and probes new parameter space for WIMP-nucleon scattering for WIMP masses <6 GeV/c(2).

11.
Phys Rev Lett ; 111(15): 154301, 2013 Oct 11.
Article in English | MEDLINE | ID: mdl-24160603

ABSTRACT

Prompted by intriguing events observed in certain particle-physics searches for rare events, we study light and acoustic emission simultaneously in some inorganic scintillators subject to mechanical stress. We observe mechanoluminescence in Bi4Ge3O12, CdWO4, and ZnWO4, in various mechanical configurations at room temperature and ambient pressure. We analyze the temporal and amplitude correlations between the light emission and the acoustic emission during fracture. A novel application of the precise energy calibration of Bi4Ge3O12 provided by radioactive sources allows us to deduce that the fraction of elastic energy converted to light is at least 3×10(-5).

12.
Phys Rev Lett ; 106(13): 131302, 2011 Apr 01.
Article in English | MEDLINE | ID: mdl-21517371

ABSTRACT

We report results from a reanalysis of data from the Cryogenic Dark Matter Search (CDMS II) experiment at the Soudan Underground Laboratory. Data taken between October 2006 and September 2008 using eight germanium detectors are reanalyzed with a lowered, 2 keV recoil-energy threshold, to give increased sensitivity to interactions from weakly interacting massive particles (WIMPs) with masses below ∼10 GeV/c(2). This analysis provides stronger constraints than previous CDMS II results for WIMP masses below 9 GeV/c(2) and excludes parameter space associated with possible low-mass WIMP signals from the DAMA/LIBRA and CoGeNT experiments.

13.
Eur Phys J C Part Fields ; 81(9): 823, 2021.
Article in English | MEDLINE | ID: mdl-34720726

ABSTRACT

The DEAP-3600 detector searches for the scintillation signal from dark matter particles scattering on a 3.3 tonne liquid argon target. The largest background comes from 39 Ar beta decays and is suppressed using pulse-shape discrimination (PSD). We use two types of PSD estimator: the prompt-fraction, which considers the fraction of the scintillation signal in a narrow and a wide time window around the event peak, and the log-likelihood-ratio, which compares the observed photon arrival times to a signal and a background model. We furthermore use two algorithms to determine the number of photons detected at a given time: (1) simply dividing the charge of each PMT pulse by the mean single-photoelectron charge, and (2) a likelihood analysis that considers the probability to detect a certain number of photons at a given time, based on a model for the scintillation pulse shape and for afterpulsing in the light detectors. The prompt-fraction performs approximately as well as the log-likelihood-ratio PSD algorithm if the photon detection times are not biased by detector effects. We explain this result using a model for the information carried by scintillation photons as a function of the time when they are detected.

14.
Sci Rep ; 9(1): 9249, 2019 Jun 25.
Article in English | MEDLINE | ID: mdl-31239455

ABSTRACT

Light-matter interaction, and the understanding of the fundamental physics behind, is the scenario of emerging quantum technologies. Solid state devices allow the exploration of new regimes where ultrastrong coupling strengths are comparable to subsystem energies, and new exotic phenomena like quantum phase transitions and ground-state entanglement occur. While experiments so far provided only spectroscopic evidence of ultrastrong coupling, we propose a new dynamical protocol for detecting virtual photon pairs in the dressed eigenstates. This is the fingerprint of the violated conservation of the number of excitations, which heralds the symmetry broken by ultrastrong coupling. We show that in flux-based superconducting architectures this photon production channel can be coherently amplified by Stimulated Raman Adiabatic Passage, providing a unique tool for an unambiguous dynamical detection of ultrastrong coupling in present day hardware. This protocol could be a benchmark for control of the dynamics of ultrastrong coupling architectures, in view of applications to quantum information and microwave quantum photonics.

15.
Comput Biol Med ; 70: 202-209, 2016 Mar 01.
Article in English | MEDLINE | ID: mdl-26851728

ABSTRACT

This paper proposes a new automatic approach to determine the accurate measure of human teeth. The aim of the proposed computer based method is to reduce inaccuracy of measurement with respect to traditional approaches. Starting from a 3D model of the teeth which is obtained from 3D scanning, the method algorithmically evaluates the most important dimensional features detectable in central incisors. For this purpose, specific rules are put forward and implemented in original software with a view to identifying repere points, from which to detect dimensional features both unambiguously and accurately. The automatic method which is proposed here is verified by means of the analysis of real teeth and is then compared with the current state-of-the-art methods for teeth measurement.


Subject(s)
Imaging, Three-Dimensional/methods , Incisor/anatomy & histology , Models, Dental , Software , Female , Humans , Male
16.
Comput Methods Programs Biomed ; 121(1): 36-48, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25985887

ABSTRACT

In this paper a new automatic approach to determine the accurate measure of human vertebrae is proposed. The aim is to speed up the measurement process and to reduce the uncertainties that typically affect the measurement carried out by traditional approaches. The proposed method uses a 3D model of the vertebra obtained from CT-scans or 3D scanning, from which some characteristic dimensions are detected. For this purpose, specific rules to identify morphological features, from which to detect dimensional features unambiguously and accurately, are put forward and implemented in original software. The automatic method which is here proposed is verified by analysing real vertebrae and is then compared with the state-of-the-art methods for vertebra measurement.


Subject(s)
Automation , Models, Anatomic , Spine/anatomy & histology , Humans
17.
Anticancer Res ; 13(6B): 2485-8, 1993.
Article in English | MEDLINE | ID: mdl-8135487

ABSTRACT

We report a case of carcinosarcoma and separate neuroendocrine malignant tumor of the gastric stump. The case is interesting because of its unique pathological features and it confirms the role of the gastric stump as a very important "malignancy promoter".


Subject(s)
Carcinosarcoma/pathology , Endocrine Gland Neoplasms/pathology , Gastrectomy/adverse effects , Stomach Neoplasms/pathology , Aged , Carcinosarcoma/chemistry , DNA, Neoplasm/analysis , Endocrine Gland Neoplasms/chemistry , Humans , Male , Stomach Neoplasms/chemistry , Time Factors
18.
Anticancer Res ; 14(3B): 1457-60, 1994.
Article in English | MEDLINE | ID: mdl-8067721

ABSTRACT

Levels of a 90,000 daltons monoclonal antibody-defined tumor-associated antigen, termed 90K, were measured in the serum from 649 patients with various types of cancer and 1215 patients infected by the human immunodeficiency virus (HIV). Significantly increased 90K serum levels (12.1 +/- 0.5 U/ml) were found in cancer patients with respect to healthy controls (5.7 +/- 0.3 U/ml), with the highest levels in neoplasms of the breast, lung and gastrointestinal tract. In 355 patients with breast cancer, the elevation of serum 90K levels was more pronounced at advanced stages of disease. Mean levels of 90K for 1215 HIV-infected subjects (21.2 +/- 0.8 U/ml) were significantly higher than controls and cancer patients, and the levels progressively increased with disease worsening from asymptomatic infection to full blown AIDS. These data suggest that 90K is not merely a tumor-associated antigen and lead us to postulate it to be a signalling molecule whose production might be related to the immune deficit caused by pathogenetic events such as neoplastic progression and virus infection.


Subject(s)
Antigens, Neoplasm/blood , HIV Infections/blood , Neoplasms/blood , Female , Humans , Male , Molecular Weight , Prospective Studies
19.
Int J Gynecol Cancer ; 3(5): 271-278, 1993 Sep.
Article in English | MEDLINE | ID: mdl-11578357

ABSTRACT

The immunohistochemical expression of HER-2/neu and cytofluorimetric data were retrospectively analyzed in a group of primary advanced ovarian cancers. Thirty-three out of 94 (35%) cases showed a specific p185/neu immunoreaction. No correlation between p185/neu expression and any of the clinico-pathologic parameters examined was observed. As far as cytofluorimetric data are concerned, 38 out of 69 (55%) of the tumors were diploid (DNA index = 1) while 31 (45%) were aneuploid (DNA index from 1.10 to 2.50 with a median value of 1.50). Ovarian tumors were defined as of low and high S-phase fraction in 68% and 32% of the cases, respectively. Tumor ploidy and S-phase fraction did not correlate with the clinico-pathologic characteristics or p185/neu oncoprotein expression. Aneuploid tumors had a higher S-phase fraction (mean: 15.81 +/- 13.44) than diploid tumors (mean: 8.89 +/- 7.98) (P < 0.01). p185/neu expression failed to affect significantly both overall and progression free survival. On the other hand tumor ploidy was found to be related to the prognosis of advanced ovarian cancer patients although the difference was not statistically significant. As far as progression free survival is concerned, the median time to recurrence was not reached for diploid cases whereas it was 21 months for aneuploid cases (P < 0.05). The 5-year survival for patients with a low S-phase fraction (58%) was significantly higher than for patients with high S-phase fraction tumors (28%) (P < 0.01). Median time to recurrence was 48 and 17 months for low and high S-phase fraction tumor patients, respectively (P < 0.05). However, in a multivariate analysis both tumor ploidy and S-phase fraction did not retain their prognostic value. The assessment of the role of the parameters examined in improving the prognostic characterization of ovarian cancer patients should be investigated in large multicenter clinical trials.

20.
Pediatr Med Chir ; 19(3): 219-21, 1997.
Article in Italian | MEDLINE | ID: mdl-9340615

ABSTRACT

The case is described of a 6 1/2-year-old child with pseudohyperaldosteronism due to excessive and prolonged liquorice ingestion. The authors debate its differential diagnosis, its physiopathological mechanism (glycyrrhetinic acid, the active metabolite of liquorice, inhibits the conversion of cortisol in cortisone) and its unusual association with haemorrhagic gastritis never observed in the course of liquorice intoxication.


Subject(s)
Candy/poisoning , Gastritis/etiology , Gastrointestinal Hemorrhage/etiology , Glycyrrhetinic Acid/poisoning , Glycyrrhiza , Hyperaldosteronism/etiology , Plants, Medicinal , Child , Diagnosis, Differential , Gastritis/diagnosis , Gastrointestinal Hemorrhage/diagnosis , Humans , Hyperaldosteronism/diagnosis , Male , Poisoning/complications , Poisoning/diagnosis , Poisoning/etiology , Time Factors
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