|   | 
Details
   web
Records
Author (down) Ma, E.; De Romeri, V.
Title Radiative seesaw dark matter Type Journal Article
Year 2021 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 104 Issue 5 Pages 055004 - 5pp
Keywords
Abstract The singlet Majoron model of seesaw neutrino mass is appended by one dark Majorana fermion singlet chi with L = 2 and one dark complex scalar singlet zeta with L = 1. This simple setup allows chi to obtain a small radiative mass anchored by the same heavy right-handed neutrinos, whereas the one-loop decay of the standard model Higgs boson to chi chi + (chi) over bar(chi) over bar provides the freeze-in mechanism for chi to be the light dark matter of the Universe.
Address [Ma, Ernest] Univ Calif Riverside, Dept Phys & Astron, Riverside, CA 92521 USA
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000693636500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4959
Permanent link to this record
 

 
Author (down) LUX-ZEPLIN Collaboration (Akerib, D.S. et al); Bailey, A.J.
Title Identification of radiopure titanium for the LZ dark matter experiment and future rare event searches Type Journal Article
Year 2017 Publication Astroparticle Physics Abbreviated Journal Astropart Phys.
Volume 96 Issue Pages 1-10
Keywords
Abstract The LUX-ZEPLIN (LZ) experiment will search for dark matter particle interactions with a detector containing a total of 10 tonnes of liquid xenon within a double -vessel cryostat. The large mass and proximity of the cryostat to the active detector volume demand the use of material with extremely low intrinsic radioactivity. We report on the radioassay campaign conducted to identify suitable metals, the determination of factors limiting radiopure production, and the selection of titanium for construction of the LZ cryostat and other detector components. This titanium has been measured with activities of U-238(e) < 1.6 mBq/kg, U-238(I) < 0.09 mBq/kg, Th-232(e) = 0.28 +/- 0.03 mBq/kg, Th-232(I) = 0.25 +/- 0.02 mBq/kg, K-40 <0.54 mBq/kg, and (60) Co <0.02 mBq/kg (68% CL). Such low intrinsic activities, which are some of the lowest ever reported for titanium, enable its use for future dark matter and other rare event searches. Monte Carlo simulations have been performed to assess the expected background contribution from the LZ cryostat with this radioactivity. In 1,000 days of WIMP search exposure of a 5.6-tonne fiducial mass, the cryostat will contribute only a mean background of 0.160 +/- 0.001(stat) +/- 0.030(sys) counts.
Address [Akerib, D. S.; Biesiadzinski, T. P.; Bramante, R.; Craddock, W. W.; Ignarra, C. M.; Ji, W.; Krebs, H. J.; Lee, C.; Linehan, R. E.; Luitz, S.; Mizrachi, E.; Monzani, M. E.; Ratcliff, B. N.; Shutt, T. A.; Skarpaas, K.; To, W. H.; Va'vra, J.; Whitis, T. J.; Wisniewski, W. J.] SLAC Natl Accelerator Lab, POB 20450, Stanford, CA 94309 USA, Email: sally.shaw.13@ucl.ac.uk;
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0927-6505 ISBN Medium
Area Expedition Conference
Notes WOS:000416185400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3384
Permanent link to this record
 

 
Author (down) Luo, X.L. et al; Agramunt, J.; Egea, F.J.; Gadea, A.; Huyuk, T.
Title Pulse pile-up identification and reconstruction for liquid scintillator based neutron detectors Type Journal Article
Year 2018 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 897 Issue Pages 59-65
Keywords Pile-up; Digital; First-order derivative; Neutron-gamma discrimination; Liquid scintillator
Abstract The issue of pulse pile-up is frequently encountered in nuclear experiments involving high counting rates, which will distort the pulse shapes and the energy spectra. A digital method of off-line processing of pile-up pulses is presented. The pile-up pulses were firstly identified by detecting the downward-going zero-crossings in the first-order derivative of the original signal, and then the constituent pulses were reconstructed based on comparing the pile-up pulse with four models that are generated by combining pairs of neutron and.. standard pulses together with a controllable time interval. The accuracy of this method in resolving the pile-up events was investigated as a function of the time interval between two pulses constituting a pile-up event. The obtained results show that the method is capable of disentangling two pulses with a time interval among them down to 20 ns, as well as classifying them as neutrons or gamma rays. Furthermore, the error of reconstructing pile-up pulses could be kept below 6% when successive peaks were separated by more than 50 ns. By applying the method in a high counting rate of pile-up events measurement of the NEutron Detector Array (NEDA), it was empirically found that this method can reconstruct the pile-up pulses and perform neutron-gamma discrimination quite accurately. It can also significantly correct the distorted pulse height spectrum due to pile-up events.
Address [Luo, X. L.] Acad Mil Med Sci, Natl Innovat Inst Def Technol, Beijing 100010, Peoples R China, Email: delongtmac@163.com
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes WOS:000433206800010 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3591
Permanent link to this record
 

 
Author (down) Lubicz, V.; Melis, A.; Simula, S.
Title Masses and decay constants of D-(s)* and B-(s)* mesons with N-f=2+1+1 twisted mass fermions Type Journal Article
Year 2017 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 96 Issue 3 Pages 034524 - 10pp
Keywords
Abstract We present a lattice calculation of the masses and decay constants of D-(s)* and B-(s)* mesons using the gauge configurations produced by the European Twisted Mass Collaboration (ETMC) with N-f=2+1+1 dynamical quarks at three values of the lattice spacing a similar to(0.06-0.09) fm. Pion masses are simulated in the range M-pi similar or equal to(210-450) MeV, while the strange and charm sea-quark masses are close to their physical values. We compute the ratios of vector to pseudoscalar masses and decay constants for various values of the heavy-quark mass mh in the range 0.7m(c)(phys) less than or similar to m(h) less than or similar to 3m(c)(phys). In order to reach the physical b-quark mass, we exploit the Heavy Quark Effective Theory prediction that, in the static limit of infinite heavy-quark mass, the considered ratios are equal to one. At the physical point our results are: M-D*/M-D=1.0769(79), M-D*(s)/M-Ds=1.0751(56), f(D)*/f(D)=1.078(36), f(D)*s/f(Ds)=1.087(20), M-B*/M-B=1.0078(15), M-B*(s)/M-Bs=1.0083(10), f(B)*/f(B)=0.958(22) and f(B)*s/f(Bs)=0.974(10). Combining them with the experimental values of the pseudoscalar meson masses (used as input to fix the quark masses) and the values of the pseudoscalar decay constants calculated by ETMC, we get: M-D*=2013(14) MeV, M-D*(s)=2116(11) MeV, f(D)*=223.5(8.4) MeV, f(D)*(s)=268.8(6.6) MeV, M-B*=5320.5(7.6) MeV, M-B*(s)=5411.36(5.3) MeV, f(B)*=185.9(7.2) MeV and f(B)*(s)=223.1(5.4) MeV.
Address [Lubicz, V.] Univ Roma Tre, Dip Matemat & Fis, I-00146 Rome, Italy
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000408626300006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3282
Permanent link to this record
 

 
Author (down) Lu, J.N.; Liu, X.G.; Ding, G.J.
Title Modular symmetry origin of texture zeros and quark-lepton unification Type Journal Article
Year 2020 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 101 Issue 11 Pages 115020 - 27pp
Keywords
Abstract The even-weight modular forms of level N can be arranged into the common irreducible representations of the inhomogeneous finite modular group Gamma(N) and the homogeneous finite modular group Gamma(N)' which is the double covering of Gamma(N) , and the odd-weight modular forms of level N transform in the new representations of Gamma(N)'. We find that the above structure of modular forms can naturally generate texture zeros of the fermion mass matrices if we properly assign the representations and weights of the matter fields under the modular group. We perform a comprehensive analysis for the Gamma(3)' congruent to T' modular symmetry. The three generations of left-handed quarks are assumed to transform as a doublet and a singlet of T', and we find six possible texture-zero structures of the quark mass matrix up to row and column permutations. We present five benchmark quark models which can produce very good fits to the experimental data. These quark models are further extended to include the lepton sector, and the resulting models can give a unified description of both quark and lepton masses and flavor mixing simultaneously, although they contain a smaller number of free parameters than the observables.
Address [Lu, Jun-Nan; Liu, Xiang-Gan; Ding, Gui-Jun] Univ Sci & Technol China, Interdisciplinary Ctr Theoret Study, Hefei 230026, Anhui, Peoples R China, Email: hitman@mail.ustc.edu.cn;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000540658300007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4434
Permanent link to this record
 

 
Author (down) Loya Villalpando, A.A.; Martin-Albo, J.; Chen, W.T.; Guenette, R.; Lego, C.; Park, J.S.; Capasso, F.
Title Improving the light collection efficiency of silicon photomultipliers through the use of metalenses Type Journal Article
Year 2020 Publication Journal of Instrumentation Abbreviated Journal J. Instrum.
Volume 15 Issue 11 Pages P11021 - 13pp
Keywords Optical detector readout concepts; Solid state detectors; Dark Matter detectors (WIMPS, axions, etc); Double-beta decay detectors
Abstract Metalenses are optical devices that implement nanostructures as phase shifters to focus incident light. Their compactness and simple fabrication make them a potential cost-effective solution for increasing light collection efficiency in particle detectors with limited photosensitive area coverage. Here we report on the characterization and performance of metalenses in increasing the light collection efficiency of silicon photomultipliers (SiPM) of various sizes using an LED of 630 nm, and find a six to seven-fold increase in signal for a 1.3 x 1 3 mm(2) SiPM when coupled with a 10-mm-diameter metalens manufactured using deep ultraviolet stepper lithography. Such improvements could be valuable for future generations of particle detectors, particularly those employed in rare-event searches such as dark matter and neutrinoless double beta decay.
Address [Villalpando, A. A. Loya; Martin-Albo, J.; Guenette, R.; Lego, C.] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA, Email: aloyavil@caltech.edu
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1748-0221 ISBN Medium
Area Expedition Conference
Notes WOS:000595650800009 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4634
Permanent link to this record
 

 
Author (down) Lopez-Ibañez, M.L.; Melis, A.; Meloni, D.; Vives, O.
Title Lepton flavor violation and neutrino masses from A(5) and CP in the non-universal MSSM Type Journal Article
Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 06 Issue 6 Pages 047 - 34pp
Keywords Beyond Standard Model; Neutrino Physics; Quark Masses and SM Parameters; Supersymmetric Standard Model
Abstract We analyze the phenomenological consequences of embedding a flavor symmetry based on the groups A(5) and CP in a supersymmetric framework. We concentrate on the leptonic sector, where two different residual symmetries are assumed to be conserved at leading order for charged and neutral leptons. All possible realizations to generate neutrino masses at tree level are investigated. Sizable flavor violating effects in the charged lepton sector are unavoidable due to the non-universality of soft-breaking terms determined by the symmetry. We derive testable predictions for the neutrino spectrum, lepton mixing and flavor changing processes with non-trivial relations among observables.
Address [Lopez-Ibanez, M. L.; Meloni, Davide] Univ Roma Tre, Dipartimento Matemat & Fis, Via Vasca Navale 84, I-00146 Rome, Italy, Email: maloi2@uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000471630100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4057
Permanent link to this record
 

 
Author (down) Lopez-Ibañez, M.L.; Melis, A.; Jay Perez, M.; Vives, O.
Title Slepton non-universality in the flavor-effective MSSM Type Journal Article
Year 2017 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 11 Issue 11 Pages 162 - 27pp
Keywords Quark Masses and SM Parameters; Supersymmetric Standard Model; Super-symmetry Breaking; Supersymmetric Effective Theories
Abstract Supersymmetric theories supplemented by an underlying flavor-symmetry G(f) provide a rich playground for model building aimed at explaining the flavor structure of the Standard Model. In the case where supersymmetry breaking is mediated by gravity, the soft-breaking Lagrangian typically exhibits large tree-level flavor violating e ff ects, even if it stems from an ultraviolet flavor-conserving origin. Building on previous work, we continue our phenomenological analysis of these models with a particular emphasis on leptonicflavor observables. We consider three representative models which aim to explain the flavor structure of the lepton sector, with symmetry groups G(f) = Delta (27), A(4); and S-3.
Address [Luisa Lopez-Ibanez, M.; Melis, Aurora; Jay Perez, M.; Vives, Oscar] Univ Valencia, Dept Fis Teor, Dr Moliner 50, Burjassot, Valencia, Spain, Email: m.luisa.lopez-ibanez@uv.es;
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1029-8479 ISBN Medium
Area Expedition Conference
Notes WOS:000416356500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3382
Permanent link to this record
 

 
Author (down) Lopez-Ibañez, M.L.; Melis, A.; Jay Perez, M.; Rahat, M.H.; Vives, O.
Title Constraining low-scale flavor models with (g-2)(mu) and lepton flavor violation Type Journal Article
Year 2022 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 105 Issue 3 Pages 035021 - 21pp
Keywords
Abstract We present here two concrete examples of models where a sub-TeV scale breaking of their respective T-13 and A(5) flavor symmetries is able to account for the recently observed discrepancy in the muon anomalous magnetic moment, (g – 2)(mu). Similarities in the flavor structures of the charged-lepton Yukawa matrix and dipole matrix yielding (g – 2)(mu) give rise to strong constraints on low-scale flavor models when bounds from lepton flavor violation (LFV) are imposed. These constraints place stringent limits on the off- diagonal Yukawa structure, suggesting a mostly (quasi)diagonal texture for models with a low flavor breaking scale A(f). We argue that many of the popular flavor models in the literature designed to explain the fermion masses and mixings are not suitable for reproducing the observed discrepancy in (g – 2)(mu), which requires a delicate balance of maintaining a low flavor scale while simultaneously satisfying strong LFV constraints.
Address [Lopez-Ibanez, M. L.] Chinese Acad Sci, Inst Theoret Phys, CAS Key Lab Theoret Phys, Beijing 100190, Peoples R China, Email: maloi2@uv.es;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000767363800008 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5167
Permanent link to this record
 

 
Author (down) Lopez-Honorez, L.; Mena, O.; Villanueva-Domingo, P.
Title Dark matter microphysics and 21 cm observations Type Journal Article
Year 2019 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 99 Issue 2 Pages 023522 - 12pp
Keywords
Abstract Dark matter interactions with massless or very light standard model particles, as photons or neutrinos, may lead to a suppression of the matter power spectrum at small scales and of the number of low mass haloes. Bounds on the dark matter scattering cross section with light degrees of freedom in such interacting dark matter (IDM) scenarios have been obtained from e.g., early time cosmic microwave background physics and large scale structure observations. Here we scrutinize dark matter microphysics in light of the claimed 21 cm EDGES 78 MHz absorption signal. IDM is expected to delay the 21 cm absorption features due to collisional damping effects. We identify the astrophysical conditions under which the existing constraints on the dark matter scattering cross section could be largely improved due to the IDM imprint on the 21 cm signal, providing also an explicit comparison to the WDM scenario.
Address [Lopez-Honorez, Laura] Univ Libre Bruxelles, Serv Phys Theor, CP225,Blvd Triomphe, B-1050 Brussels, Belgium, Email: llopezho@ulb.ac.be;
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000456291400001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3885
Permanent link to this record