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Author LHCb Collaboration (Aaij, R. et al); Jaimes Elles, S.J.; Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Rebollo De Miguel, M.; Ruiz Vidal, J.; Sanderswood, I.
Title Measurement of the Λb0 → Λ(1520)μ+μ- Differential Branching Fraction Type Journal Article
Year 2023 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 131 Issue 15 Pages (down) 151801 - 12pp
Keywords
Abstract The branching fraction of the rare decay Lambda(0 )(b)-> Lambda(1520)mu(+)mu(-) is measured for the first time, in the squared dimuon mass intervals q(2), excluding the J/psi and psi(2S) regions. The data sample analyzed was collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb(-1). The result in the highest q(2) interval, q(2) > 15.0 GeV2/c(4), where theoretical predictions have the smallest model dependence, agrees with the predictions.
Address [Baptista de Souza Leite, J.; Bediaga, I. B.; Cruz Torres, M.; De Freitas Carneiro Da Graca, U.; De Miranda, J. M.; dos Reis, A. C.; Falcao, L. N.; Gomes, A.; Massafferri, A.; Torres Machado, D.] Ctr Brasileiro Pesquisas Fis, Rio De Janeiro, Brazil, Email: juan.baptista.leite@cern.ch
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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:001102939300004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5965
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Author Lazarides, G.; Reig, M.; Shafi, Q.; Srivastava, R.; Valle, J.W.F.
Title Spontaneous Breaking of Lepton Number and the Cosmological Domain Wall Problem Type Journal Article
Year 2019 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 122 Issue 15 Pages (down) 151301 - 5pp
Keywords
Abstract We show that if global lepton number symmetry is spontaneously broken in a postinflation epoch, then it can lead to the formation of cosmological domain walls. This happens in the well-known “Majoron paradigm” for neutrino mass generation. We propose some realistic examples that allow spontaneous lepton number breaking to be safe from such domain walls.
Address [Lazarides, George] Aristotle Univ Thessaloniki, Sch Elect & Comp Engn, Fac Engn, Thessaloniki 54124, Greece, Email: lazaride@eng.auth.gr;
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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000464756200002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3985
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Author Figueroa, D.G.; Lizarraga, J.; Urio, A.; Urrestilla, J.
Title Strong Backreaction Regime in Axion Inflation Type Journal Article
Year 2023 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 131 Issue 15 Pages (down) 151003 - 7pp
Keywords
Abstract We study the nonlinear dynamics of axion inflation, capturing for the first time the inhomogeneity and full dynamical range during strong backreaction, till the end of inflation. Accounting for inhomogeneous effects leads to a number of new relevant results, compared to spatially homogeneous studies: (i) the number of extra efoldings beyond slow-roll inflation increases very rapidly with the coupling, (ii) oscillations of the inflaton velocity are attenuated, (iii) the tachyonic gauge field helicity spectrum is smoothed out (i.e., the spectral oscillatory features disappear), broadened, and shifted to smaller scales, and (iv) the nontachyonic helicity is excited, reducing the chiral asymmetry, now scale dependent. Our results are expected to impact strongly on the phenomenology and observability of axion inflation, including gravitational wave generation and primordial black hole production.
Address [Figueroa, Daniel G.] CSIC, Inst Fis Corpuscular IFIC, Valencia 46980, Spain, Email: daniel.figueroa@ific.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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:001093422100002 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5783
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Author Brzezinski, K. et al
Title Detection of range shifts in proton beam therapy using the J-PET scanner: a patient simulation study Type Journal Article
Year 2023 Publication Physics in Medicine and Biology Abbreviated Journal Phys. Med. Biol.
Volume 68 Issue 14 Pages (down) 145016 - 17pp
Keywords proton therapy; positron emission tomography; in vivo range verification; J-PET; Monte Carlo
Abstract Objective. The Jagiellonian positron emission tomography (J-PET) technology, based on plastic scintillators, has been proposed as a cost effective tool for detecting range deviations during proton therapy. This study investigates the feasibility of using J-PET for range monitoring by means of a detailed Monte Carlo simulation study of 95 patients who underwent proton therapy at the Cyclotron Centre Bronowice (CCB) in Krakow, Poland. Approach. Discrepancies between prescribed and delivered treatments were artificially introduced in the simulations by means of shifts in patient positioning and in the Hounsfield unit to the relative proton stopping power calibration curve. A dual-layer, cylindrical J-PET geometry was simulated in an in-room monitoring scenario and a triple-layer, dual-head geometry in an in-beam protocol. The distribution of range shifts in reconstructed PET activity was visualized in the beam's eye view. Linear prediction models were constructed from all patients in the cohort, using the mean shift in reconstructed PET activity as a predictor of the mean proton range deviation. Main results. Maps of deviations in the range of reconstructed PET distributions showed agreement with those of deviations in dose range in most patients. The linear prediction model showed a good fit, with coefficient of determination r (2) = 0.84 (in-room) and 0.75 (in-beam). Residual standard error was below 1 mm: 0.33 mm (in-room) and 0.23 mm (in-beam). Significance. The precision of the proposed prediction models shows the sensitivity of the proposed J-PET scanners to shifts in proton range for a wide range of clinical treatment plans. Furthermore, it motivates the use of such models as a tool for predicting proton range deviations and opens up new prospects for investigations into the use of intra-treatment PET images for predicting clinical metrics that aid in the assessment of the quality of delivered treatment.
Address [Brzezinski, Karol; Gajewski, Jan; Kopec, Renata; Olko, Pawel; Stasica, Paulina; Rucinski, Antoni] Polish Acad Sci, Inst Nucl Phys, Krakow, Poland, Email: karol.brzezinski@ific.uv.es
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 0031-9155 ISBN Medium
Area Expedition Conference
Notes WOS:001026535700001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5616
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Author Roser, J.; Muñoz, E.; Barrientos, L.; Barrio, J.; Bernabeu, J.; Borja-Lloret, M.; Etxebeste, A.; Llosa, G.; Ros, A.; Viegas, R.; Oliver, J.F.
Title Image reconstruction for a multi-layer Compton telescope: an analytical model for three interaction events Type Journal Article
Year 2020 Publication Physics in Medicine and Biology Abbreviated Journal Phys. Med. Biol.
Volume 65 Issue 14 Pages (down) 145005 - 17pp
Keywords Compton camera; Compton imaging; hadron therapy; image reconstruction; lm-mlem; monte carlo simulations; multi-layer Compton telescope
Abstract Compton Cameras are electronically collimated photon imagers suitable for sub-MeV to few MeV gamma-ray detection. Such features are desirable to enablein vivorange verification in hadron therapy, through the detection of secondary Prompt Gammas. A major concern with this technique is the poor image quality obtained when the incoming gamma-ray energy is unknown. Compton Cameras with more than two detector planes (multi-layer Compton Cameras) have been proposed as a solution, given that these devices incorporate more signal sequences of interactions to the conventional two interaction events. In particular, three interaction events convey more spectral information as they allow inferring directly the incident gamma-ray energy. A three-layer Compton Telescope based on continuous Lanthanum (III) Bromide crystals coupled to Silicon Photomultipliers is being developed at the IRIS group of IFIC-Valencia. In a previous work we proposed a spectral reconstruction algorithm for two interaction events based on an analytical model for the formation of the signal. To fully exploit the capabilities of our prototype, we present here an extension of the model for three interaction events. Analytical expressions of the sensitivity and the System Matrix are derived and validated against Monte Carlo simulations. Implemented in a List Mode Maximum Likelihood Expectation Maximization algorithm, the proposed model allows us to obtain four-dimensional (energy and position) images by using exclusively three interaction events. We are able to recover the correct spectrum and spatial distribution of gamma-ray sources when ideal data are employed. However, the uncertainties associated to experimental measurements result in a degradation when real data from complex structures are employed. Incorrect estimation of the incident gamma-ray interaction positions, and missing deposited energy associated with escaping secondaries, have been identified as the causes of such degradation by means of a detailed Monte Carlo study. As expected, our current experimental resolution and efficiency to three interaction events prevents us from correctly recovering complex structures of radioactive sources. However, given the better spectral information conveyed by three interaction events, we expect an improvement of the image quality of conventional Compton imaging when including such events. In this regard, future development includes the incorporation of the model assessed in this work to the two interaction events model in order to allow using simultaneously two and three interaction events in the image reconstruction.
Address [Roser, J.; Munoz, E.; Barrientos, L.; Barrio, J.; Bernabeu, J.; Borja-Lloret, M.; Etxebeste, A.; Llosa, G.; Ros, A.; Viegas, R.; Oliver, J. F.] Inst Fis Corpuscular IFIC CSIC UVEG, Valencia, Spain, Email: Jorge.Roser@ific.uv.es
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 0031-9155 ISBN Medium
Area Expedition Conference
Notes WOS:000552701600001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 4481
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Author Borja-Lloret, M.; Barrientos, L.; Bernabeu, J.; Lacasta, C.; Muñoz, E.; Ros, A.; Roser, J.; Viegas, R.; Llosa, G.
Title Influence of the background in Compton camera images for proton therapy treatment monitoring Type Journal Article
Year 2023 Publication Physics in Medicine and Biology Abbreviated Journal Phys. Med. Biol.
Volume 68 Issue 14 Pages (down) 144001 - 16pp
Keywords Compton imaging; Compton camera; proton therapy; treatment monitoring; Monte Carlo simulation; image reconstruction; background
Abstract Objective. Background events are one of the most relevant contributions to image degradation in Compton camera imaging for hadron therapy treatment monitoring. A study of the background and its contribution to image degradation is important to define future strategies to reduce the background in the system. Approach. In this simulation study, the percentage of different kinds of events and their contribution to the reconstructed image in a two-layer Compton camera have been evaluated. To this end, GATE v8.2 simulations of a proton beam impinging on a PMMA phantom have been carried out, for different proton beam energies and at different beam intensities. Main results. For a simulated Compton camera made of Lanthanum (III) Bromide monolithic crystals, coincidences caused by neutrons arriving from the phantom are the most common type of background produced by secondary radiations in the Compton camera, causing between 13% and 33% of the detected coincidences, depending on the beam energy. Results also show that random coincidences are a significant cause of image degradation at high beam intensities, and their influence in the reconstructed images is studied for values of the time coincidence windows from 500 ps to 100 ns. Significance. Results indicate the timing capabilities required to retrieve the fall-off position with good precision. Still, the noise observed in the image when no randoms are considered make us consider further background rejection methods.
Address [Borja-Lloret, M.; Barrientos, L.; Bernabeu, J.; Lacasta, C.; Munoz, E.; Ros, A.; Roser, J.; Viegas, R.; Llosa, G.] Inst Fis Corpuscular IFIC, CSIC UV, Valencia, Spain, Email: Marina.Borja@csic.es
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 0031-9155 ISBN Medium
Area Expedition Conference
Notes WOS:001022671300001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 5571
Permanent link to this record
 

 
Author n_TOF Collaboration (Guerrero, C. et al); Domingo-Pardo, C.; Tain, J.L.
Title Neutron Capture on the s-Process Branching Point Tm-171 via Time-of-Flight and Activation Type Journal Article
Year 2020 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 125 Issue 14 Pages (down) 142701 - 8pp
Keywords
Abstract The neutron capture cross sections of several unstable nuclides acting as branching points in the s process are crucial for stellar nucleosynthesis studies. The unstable Tm-171 (t(1/2) = 1.92 yr) is part of the branching around mass A similar to 170 but its neutron capture cross section as a function of the neutron energy is not known to date. In this work, following the production for the first time of more than 5 mg of Tm-171 at the high-flux reactor Institut Laue-Langevin in France, a sample was produced at the Paul Scherrer Institute in Switzerland. Two complementary experiments were carried out at the neutron time-of-flight facility (nTOF) at CERN in Switzerland and at the SARAF liquid lithium target facility at Soreq Nuclear Research Center in Israel by time of flight and activation, respectively. The result of the time -of-flight experiment consists of the first ever set of resonance parameters and the corresponding average resonance parameters, allowing us to make an estimation of the Maxwellian-averaged cross sections (MACS) by extrapolation. The activation measurement provides a direct and more precise measurement of the MACS at 30 keV: 384 (40) mb, with which the estimation from the nTOF data agree at the limit of 1 standard deviation. This value is 2.6 times lower than the JEFF-3.3 and ENDF/B-VIII evaluations, 25% lower than that of the Bao et al. compilation, and 1.6 times larger than the value recommended in the KAlloNiS (v1) database, based on the only previous experiment. Our result affects the nucleosynthesis at the A similar to 170 branching, namely, the Yb-171 abundance increases in the material lost by asymptotic giant branch stars, providing a better match to the available pre-solar SiC grain measurements compared to the calculations based on the current JEFF-3.3 model-based evaluation.
Address [Guerrero, C.; Lerendegui-Marco, J.; Quesada, J. M.; Cortes-Giraldo, M. A.; Millan-Callado, M. A.; Praena, J.; Rodriguez-Gonzalez, T.; Sabate-Gilarte, M.] Univ Seville, Seville, Spain, Email: cguerrero4@us.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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000574781200004 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4551
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Author LHCb Collaboration (Aaij, R. et al); Jashal, B.K.; Martinez-Vidal, F.; Oyanguren, A.; Remon Alepuz, C.; Ruiz Vidal, J.
Title Measurement of the Nuclear Modification Factor and Prompt Charged Particle Production in p-Pb and pp Collisions at root s(NN )=5 TeV Type Journal Article
Year 2022 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 128 Issue 14 Pages (down) 142004 - 12pp
Keywords
Abstract The production of prompt charged particles in proton-lead collisions and in proton-proton collisions at the nucleon-nucleon center-of-mass energy root s(NN) = 5 TeV is studied at LHCb as a function of pseudorapidity (eta) and transverse momentum (p(T) ) with respect to the proton beam direction. The nuclear modification factor for charged particles is determined as a function of eta between -4.8 < eta < -2.5 (backward region) and 2.0 < eta < 4.8 (forward region), and p(T) between 0.2 < p(T) < 8.0 GeV/c. The results show a suppression of charged particle production in proton-lead collisions relative to proton-proton collisions in the forward region and an enhancement in the backward region for p(T) larger than 1.5 GeV/c. This measurement constrains nuclear PDFs and saturation models at previously unexplored values of the parton momentum fraction down to 10(-6).
Address [Leite, J. Baptista; Bediaga, I; Torres, M. Cruz; De Miranda, J. M.; dos Reis, A. C.; Gomes, A.; Massafferri, A.; Machado, D. Torres] Ctr Brasileiro Pesquisas Fis CBPF, Rio De Janeiro, Brazil
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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000792795000003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 5233
Permanent link to this record
 

 
Author Belle II Collaboration (Adachi, I. et al); Gomis, P.; Marinas, C.
Title Search for an Invisibly Decaying Z ' Boson at Belle II in e(+)e(-) -> mu(+)mu(-) (e(+/-)mu(-/+)) Plus Missing Energy Final States Type Journal Article
Year 2020 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 124 Issue 14 Pages (down) 141801 - 9pp
Keywords
Abstract Theories beyond the standard model often predict the existence of an additional neutral boson, the Z'. Using data collected by the Belle II experiment during 2018 at the SuperKEKB collider, we perform the first searches for the invisible decay of a Z' in the process e(+)e(-) -> mu(+)mu(-) Z' and of a lepton-flavor-violating Z' in e(+) e(-) -> e(+/-)mu(-/+)Z'. We do not find any excess of events and set 90% credibility level upper limits on the cross sections of these processes. We translate the former, in the framework of an L, – L, theory, into upper limits on the Z' coupling constant at the level of 5 x 10(-2) – 1 for M-z' <= 6 GeV/c(2).
Address [Jia, S.; Shen, C. P.; Zhou, X. Y.] Beihang Univ, Beijing 100191, Peoples R China
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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000523637800002 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4362
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Author ATLAS Collaboration (Aad, G. et al); Aparisi Pozo, J.A.; Bailey, A.J.; Cabrera Urban, S.; Cardillo, F.; Castillo, F.L.; Castillo Gimenez, V.; Costa, M.J.; Didenko, M.; Escobar, C.; Estrada Pastor, O.; Ferrer, A.; Fiorini, L.; Fullana Torregrosa, E.; Fuster, J.; Garcia, C.; Garcia Navarro, J.E.; Gonzalez de la Hoz, S.; Gonzalvo Rodriguez, G.R.; Guerrero Rojas, J.G.R.; Higon-Rodriguez, E.; Lacasta, C.; Lozano Bahilo, J.J.; Mamuzic, J.; Marti-Garcia, S.; Martinez Agullo, P.; Miralles Lopez, M.; Mitsou, V.A.; Moreno Llacer, M.; Navarro-Gonzalez, J.; Poveda, J.; Prades Ibañez, A.; Rodriguez Bosca, S.; Ruiz-Martinez, A.; Sabatini, P.; Salt, J.; Santra, A.; Sanchez Sebastian, V.; Sayago Galvan, I.; Soldevila, U.; Sanchez, J.; Torro Pastor, E.; Valero, A.; Valls Ferrer, J.A.; Villaplana Perez, M.; Vos, M.
Title Search for New Phenomena in Final States with Two Leptons and One or No b-Tagged Jets at root s=13 TeV Using the ATLAS Detector Type Journal Article
Year 2021 Publication Physical Review Letters Abbreviated Journal Phys. Rev. Lett.
Volume 127 Issue 14 Pages (down) 141801 - 23pp
Keywords
Abstract A search for new phenomena is presented in final states with two leptons and one or no b-tagged jets. The event selection requires the two leptons to have opposite charge, the same flavor (electrons or muons), and a large invariant mass. The analysis is based on the full run-2 proton-proton collision dataset recorded at a center-of-mass energy off root S = 13 TeV by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 139 fb(-1). No significant deviation from the expected background is observed in the data. Inspired by the B-meson decay anomalies, a four-fermion contact interaction between two quarks (b, s) and two leptons (ee or μmu) is used as a benchmark signal model, which is characterized by the energy scale and coupling, Lambda and g(*), respectively. Contact interactions with Lambda/g(*) lower than 2.0 (2.4) TeV are excluded for electrons (muons) at the 95% confidence level, still far below the value that is favored by the B-meson decay anomalies. Model-independent limits are set as a function of the minimum dilepton invariant mass, which allow the results to be reinterpreted in various signal scenarios.
Address [Duvnjak, D.; Jackson, P.; Kong, A. X. Y.; Oliver, J. L.; Potti, H.; Ruggeri, T. A.; Sharma, A. S.; White, M. J.] Univ Adelaide, Dept Phys, Adelaide, SA, Australia
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 0031-9007 ISBN Medium
Area Expedition Conference
Notes WOS:000704691300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 4997
Permanent link to this record