Philipe Mota - Academia.edu (original) (raw)

Papers by Philipe Mota

Research paper thumbnail of An hydrodynamic approach of two particle correlations in high energy nuclear collisions

Research paper thumbnail of Light vector mediator search in the low-energy data of the CONNIE reactor neutrino experiment

The CONNIE experiment is located at a distance of 30 m from the core of a commercial nuclear reac... more The CONNIE experiment is located at a distance of 30 m from the core of a commercial nuclear reactor, and has collected a 3.7 kg-day exposure using a CCD detector array sensitive to an ∼1 keV threshold for the study of coherent neutrino-nucleus elastic scattering. Here, we use the results previously published by the CONNIE collaboration to constrain the allowed region in the parameter space of a Standard Model extension with a light vector mediator. We obtain new world-leading constraints for a light vector mediator with mass M_Z^'< 10 MeV. These results constitute the first use of the CONNIE data as a probe for physics beyond the Standard Model.

Research paper thumbnail of Decomposition of fluctuating initial conditions and flow harmonics

Journal of Physics G: Nuclear and Particle Physics, 2013

Research paper thumbnail of Search for coherent elastic neutrino-nucleus scattering at a nuclear reactor with CONNIE 2019 data

The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) is taking data at the Angra 2 nucle... more The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) is taking data at the Angra 2 nuclear reactor with the aim of detecting the coherent elastic scattering of reactor antineutrinos with silicon nuclei using charge-coupled devices (CCDs). In 2019 the experiment operated with a hardware binning applied to the readout stage, leading to lower levels of readout noise and improving the detection threshold down to 50 eV. The results of the analysis of 2019 data are reported here, corresponding to the detector array of 8 CCDs with a fiducial mass of 36.2 g and a total exposure of 2.2 kg-days. The difference between the reactor-on and reactor-off spectra shows no excess at low energies and yields upper limits at 95% confidence level for the neutrino interaction rates. In the lowest-energy range, 50− 180 eV, the expected limit stands at 34 (39) times the standard model prediction, while the observed limit is 66 (75) times the standard model prediction with Sarkis (Chavarria) quenchi...

Research paper thumbnail of Search for light mediators in the low-energy data of the CONNIE reactor neutrino experiment

Journal of High Energy Physics, Apr 1, 2020

The CONNIE experiment is located at a distance of 30 m from the core of a commercial nuclear reac... more The CONNIE experiment is located at a distance of 30 m from the core of a commercial nuclear reactor, and has collected a 3.7 kg-day exposure using a CCD detector array sensitive to an ∼1 keV threshold for the study of coherent neutrino-nucleus elastic scattering. Here we demonstrate the potential of this low-energy neutrino experiment as a probe for physics Beyond the Standard Model, by using the recently published results to constrain two simplified extensions of the Standard Model with light mediators. We compare the new limits with those obtained for the same models using neutrinos from the Spallation Neutron Source. Our new constraints represent the best limits for these simplified models among the experiments searching for CEνNS for a light vector mediator with mass M Z < 10 MeV, and for a light scalar mediator with mass M φ < 30 MeV. These results constitute the first use of the CONNIE data as a probe for physics Beyond the Standard Model.

Research paper thumbnail of On the Boundary Condition and Related Instability in the Smoothed Particle Hydrodynamics

Communications in Theoretical Physics

Research paper thumbnail of Exploring low-energy neutrino physics with the Coherent Neutrino Nucleus Interaction Experiment

Physical Review D

The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) uses low-noise fully depleted charg... more The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) uses low-noise fully depleted charge-coupled devices (CCDs) with the goal of measuring low-energy recoils from coherent elastic scattering (CEνNS) of reactor antineutrinos with silicon nuclei and testing nonstandard neutrino interactions (NSI). We report here the first results of the detector array deployed in 2016, considering an active mass 47.6 g (8 CCDs), which is operating at a distance of 30 m from the core of the Angra 2 nuclear reactor, with a thermal power of 3.8 GW. A search for neutrino events is performed by comparing data collected with reactor on (2.1 kg-day) and reactor off (1.6 kg-day). The results show no excess in the reactor-on data, reaching the world record sensitivity down to recoil energies of about 1 keV (0.1 keV electron-equivalent). A 95% confidence level limit for new physics is established at an event rate of 40 times the one expected from the standard model at this energy scale. The results presented here provide a new window to low-energy neutrino physics, allowing one to explore for the first time the energies accessible through the low threshold of CCDs. They will lead to new constrains on NSI from the CEνNS of antineutrinos from nuclear reactors.

Research paper thumbnail of A Derivation of the Entropy-Based Relativistic Smoothed Particle Hydrodynamics by Variational Principle

Communications in Theoretical Physics

View the article online for updates and enhancements.

Research paper thumbnail of Effects of causal dissipative hydrodynamics in 1D system

Research paper thumbnail of Causality, memory effect and relativistic dissipative hydrodynamics

The ideal hydrodynamical description for the dynamics of hot and dense matter achieved in RHIC ex... more The ideal hydrodynamical description for the dynamics of hot and dense matter achieved in RHIC experiments works amazingly well, particularly for the behavior of collective flow parameters. However, we know that there still exist several open problems in the interpretation of data in terms of the hydrodynamical model [1]. These questions require careful examination to extract quantitative and precise information on the properties of QGP. In particular, we should study the effect of dissipative processes on the collective flow variables. Several works have ...

Research paper thumbnail of Causal structure of relativistic dissipative hydrodynamics

We present a new formalism for the relativistic dissipative hydrodynamics consistent with causali... more We present a new formalism for the relativistic dissipative hydrodynamics consistent with causality. We start from the physical analysis of the irreversible currents according to the Landau-Lifshitz theory. Then, the irreversible currents are given by integral expressions which take into account the relaxation time. Only one additional parameter was introduced, the relaxation time, τ R. We verified that the linearized equation of motion for small perturbations in the homogeneous, static background coincides with Hiscock-Lindblom

Research paper thumbnail of Shock waves in Euler and Lagrangian dissipative hydrodynamics

Research paper thumbnail of Shock wave propagation in dissipative relativistic hydrodynamics

Research paper thumbnail of Landau model for rapidity and multiplicity distributions-the role of viscosity

Research paper thumbnail of Effects of expansion and equation of state on the conical propagation in the QGP

Journal of Physics G: Nuclear and Particle Physics, 2010

Abstract We study the dynamics of the QGP fluid in terms of the momentum-weighted angular distrib... more Abstract We study the dynamics of the QGP fluid in terms of the momentum-weighted angular distribution generated by a fast parton propagating in the medium. We analyze the effects of the change of the speed of sound during the expansion of the system. We also discuss the effect of transverse expansion and energy–momentum deposition rates on the appearance of peaks in the distribution.

Research paper thumbnail of The Landau initial condition and the role of viscosity in relativistic heavy-ion collisions

Journal of Physics G: Nuclear and Particle Physics, 2008

ABSTRACT We study the effect of viscosity on the rapidity distribution of produced mesons through... more ABSTRACT We study the effect of viscosity on the rapidity distribution of produced mesons through a hydrodynamical expansion. We show that the dissipative mechanism affects substantially the longitudinal velocity profile and Gaussian-type rapidity distributions can be obtained from the Landau-type initial condition even at high energies.

Research paper thumbnail of New Formulation of Dissipative Relativistic Hydrodynamics: A minimal theory

[摘要]: 正One of the most important questions to be clarified in the hydrodynamical approach to the ... more [摘要]: 正One of the most important questions to be clarified in the hydrodynamical approach to the relativistic heavy ion physics is that the effect of dissipative processes. However, relativistic dissipative hydrodynamics introduces several difficulties, both conceptual and technical. Among them the 14 filed theory formulated by Muller, Israel and Stewart has been considered standard

Research paper thumbnail of Decomposition of fluctuating initial conditions and flow harmonics

Journal of Physics G: Nuclear and Particle Physics, 2014

ABSTRACT Collective flow observed in heavy ion collisions is largely attributed to initial geomet... more ABSTRACT Collective flow observed in heavy ion collisions is largely attributed to initial geometrical fluctuations, and it is the hydrodynamic evolution of the system that transforms those initial spatial irregularities into final state momentum anisotropies. Cumulant analysis provides a mathematical tool to decompose those initial fluctuations in terms of radial and azimuthal components. It is usually thought that a specified order of azimuthal cumulant, for the most part, linearly produces flow harmonic of the same order. In this work, we carry out a systematic study on the connection between cumulants and flow harmonics using a hydrodynamic code called NeXSPheRIO. We conduct three types of calculations, by explicitly decomposing the initial conditions into components corresponding to a given eccentricity and studying the out-coming flow through hydrodynamic evolution. It is found that for initial conditions deviating significantly from Gaussian, such as those from NeXuS, the linearity between eccentricities and flow harmonics partially breaks down. Combining with the effect of coupling between cumulants of different orders, it causes the production of extra flow harmonics of higher orders. We argue that these results can be seen as a natural consequence of the non-linear nature of hydrodynamics, and they can be understood intuitively in terms of the peripheral-tube model.

Research paper thumbnail of An hydrodynamic approach of two particle correlations in high energy nuclear collisions

Research paper thumbnail of Causality, memory effect and relativistic dissipative hydrodynamics

The ideal hydrodynamical description for the dynamics of hot and dense matter achieved in RHIC ex... more The ideal hydrodynamical description for the dynamics of hot and dense matter achieved in RHIC experiments works amazingly well, particularly for the behavior of collective flow parameters. However, we know that there still exist several open problems in the interpretation of data in terms of the hydrodynamical model [1]. These questions require careful examination to extract quantitative and precise information on the properties of QGP. In particular, we should study the effect of dissipative processes on the collective flow variables.

Research paper thumbnail of An hydrodynamic approach of two particle correlations in high energy nuclear collisions

Research paper thumbnail of Light vector mediator search in the low-energy data of the CONNIE reactor neutrino experiment

The CONNIE experiment is located at a distance of 30 m from the core of a commercial nuclear reac... more The CONNIE experiment is located at a distance of 30 m from the core of a commercial nuclear reactor, and has collected a 3.7 kg-day exposure using a CCD detector array sensitive to an ∼1 keV threshold for the study of coherent neutrino-nucleus elastic scattering. Here, we use the results previously published by the CONNIE collaboration to constrain the allowed region in the parameter space of a Standard Model extension with a light vector mediator. We obtain new world-leading constraints for a light vector mediator with mass M_Z^'< 10 MeV. These results constitute the first use of the CONNIE data as a probe for physics beyond the Standard Model.

Research paper thumbnail of Decomposition of fluctuating initial conditions and flow harmonics

Journal of Physics G: Nuclear and Particle Physics, 2013

Research paper thumbnail of Search for coherent elastic neutrino-nucleus scattering at a nuclear reactor with CONNIE 2019 data

The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) is taking data at the Angra 2 nucle... more The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) is taking data at the Angra 2 nuclear reactor with the aim of detecting the coherent elastic scattering of reactor antineutrinos with silicon nuclei using charge-coupled devices (CCDs). In 2019 the experiment operated with a hardware binning applied to the readout stage, leading to lower levels of readout noise and improving the detection threshold down to 50 eV. The results of the analysis of 2019 data are reported here, corresponding to the detector array of 8 CCDs with a fiducial mass of 36.2 g and a total exposure of 2.2 kg-days. The difference between the reactor-on and reactor-off spectra shows no excess at low energies and yields upper limits at 95% confidence level for the neutrino interaction rates. In the lowest-energy range, 50− 180 eV, the expected limit stands at 34 (39) times the standard model prediction, while the observed limit is 66 (75) times the standard model prediction with Sarkis (Chavarria) quenchi...

Research paper thumbnail of Search for light mediators in the low-energy data of the CONNIE reactor neutrino experiment

Journal of High Energy Physics, Apr 1, 2020

The CONNIE experiment is located at a distance of 30 m from the core of a commercial nuclear reac... more The CONNIE experiment is located at a distance of 30 m from the core of a commercial nuclear reactor, and has collected a 3.7 kg-day exposure using a CCD detector array sensitive to an ∼1 keV threshold for the study of coherent neutrino-nucleus elastic scattering. Here we demonstrate the potential of this low-energy neutrino experiment as a probe for physics Beyond the Standard Model, by using the recently published results to constrain two simplified extensions of the Standard Model with light mediators. We compare the new limits with those obtained for the same models using neutrinos from the Spallation Neutron Source. Our new constraints represent the best limits for these simplified models among the experiments searching for CEνNS for a light vector mediator with mass M Z < 10 MeV, and for a light scalar mediator with mass M φ < 30 MeV. These results constitute the first use of the CONNIE data as a probe for physics Beyond the Standard Model.

Research paper thumbnail of On the Boundary Condition and Related Instability in the Smoothed Particle Hydrodynamics

Communications in Theoretical Physics

Research paper thumbnail of Exploring low-energy neutrino physics with the Coherent Neutrino Nucleus Interaction Experiment

Physical Review D

The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) uses low-noise fully depleted charg... more The Coherent Neutrino-Nucleus Interaction Experiment (CONNIE) uses low-noise fully depleted charge-coupled devices (CCDs) with the goal of measuring low-energy recoils from coherent elastic scattering (CEνNS) of reactor antineutrinos with silicon nuclei and testing nonstandard neutrino interactions (NSI). We report here the first results of the detector array deployed in 2016, considering an active mass 47.6 g (8 CCDs), which is operating at a distance of 30 m from the core of the Angra 2 nuclear reactor, with a thermal power of 3.8 GW. A search for neutrino events is performed by comparing data collected with reactor on (2.1 kg-day) and reactor off (1.6 kg-day). The results show no excess in the reactor-on data, reaching the world record sensitivity down to recoil energies of about 1 keV (0.1 keV electron-equivalent). A 95% confidence level limit for new physics is established at an event rate of 40 times the one expected from the standard model at this energy scale. The results presented here provide a new window to low-energy neutrino physics, allowing one to explore for the first time the energies accessible through the low threshold of CCDs. They will lead to new constrains on NSI from the CEνNS of antineutrinos from nuclear reactors.

Research paper thumbnail of A Derivation of the Entropy-Based Relativistic Smoothed Particle Hydrodynamics by Variational Principle

Communications in Theoretical Physics

View the article online for updates and enhancements.

Research paper thumbnail of Effects of causal dissipative hydrodynamics in 1D system

Research paper thumbnail of Causality, memory effect and relativistic dissipative hydrodynamics

The ideal hydrodynamical description for the dynamics of hot and dense matter achieved in RHIC ex... more The ideal hydrodynamical description for the dynamics of hot and dense matter achieved in RHIC experiments works amazingly well, particularly for the behavior of collective flow parameters. However, we know that there still exist several open problems in the interpretation of data in terms of the hydrodynamical model [1]. These questions require careful examination to extract quantitative and precise information on the properties of QGP. In particular, we should study the effect of dissipative processes on the collective flow variables. Several works have ...

Research paper thumbnail of Causal structure of relativistic dissipative hydrodynamics

We present a new formalism for the relativistic dissipative hydrodynamics consistent with causali... more We present a new formalism for the relativistic dissipative hydrodynamics consistent with causality. We start from the physical analysis of the irreversible currents according to the Landau-Lifshitz theory. Then, the irreversible currents are given by integral expressions which take into account the relaxation time. Only one additional parameter was introduced, the relaxation time, τ R. We verified that the linearized equation of motion for small perturbations in the homogeneous, static background coincides with Hiscock-Lindblom

Research paper thumbnail of Shock waves in Euler and Lagrangian dissipative hydrodynamics

Research paper thumbnail of Shock wave propagation in dissipative relativistic hydrodynamics

Research paper thumbnail of Landau model for rapidity and multiplicity distributions-the role of viscosity

Research paper thumbnail of Effects of expansion and equation of state on the conical propagation in the QGP

Journal of Physics G: Nuclear and Particle Physics, 2010

Abstract We study the dynamics of the QGP fluid in terms of the momentum-weighted angular distrib... more Abstract We study the dynamics of the QGP fluid in terms of the momentum-weighted angular distribution generated by a fast parton propagating in the medium. We analyze the effects of the change of the speed of sound during the expansion of the system. We also discuss the effect of transverse expansion and energy–momentum deposition rates on the appearance of peaks in the distribution.

Research paper thumbnail of The Landau initial condition and the role of viscosity in relativistic heavy-ion collisions

Journal of Physics G: Nuclear and Particle Physics, 2008

ABSTRACT We study the effect of viscosity on the rapidity distribution of produced mesons through... more ABSTRACT We study the effect of viscosity on the rapidity distribution of produced mesons through a hydrodynamical expansion. We show that the dissipative mechanism affects substantially the longitudinal velocity profile and Gaussian-type rapidity distributions can be obtained from the Landau-type initial condition even at high energies.

Research paper thumbnail of New Formulation of Dissipative Relativistic Hydrodynamics: A minimal theory

[摘要]: 正One of the most important questions to be clarified in the hydrodynamical approach to the ... more [摘要]: 正One of the most important questions to be clarified in the hydrodynamical approach to the relativistic heavy ion physics is that the effect of dissipative processes. However, relativistic dissipative hydrodynamics introduces several difficulties, both conceptual and technical. Among them the 14 filed theory formulated by Muller, Israel and Stewart has been considered standard

Research paper thumbnail of Decomposition of fluctuating initial conditions and flow harmonics

Journal of Physics G: Nuclear and Particle Physics, 2014

ABSTRACT Collective flow observed in heavy ion collisions is largely attributed to initial geomet... more ABSTRACT Collective flow observed in heavy ion collisions is largely attributed to initial geometrical fluctuations, and it is the hydrodynamic evolution of the system that transforms those initial spatial irregularities into final state momentum anisotropies. Cumulant analysis provides a mathematical tool to decompose those initial fluctuations in terms of radial and azimuthal components. It is usually thought that a specified order of azimuthal cumulant, for the most part, linearly produces flow harmonic of the same order. In this work, we carry out a systematic study on the connection between cumulants and flow harmonics using a hydrodynamic code called NeXSPheRIO. We conduct three types of calculations, by explicitly decomposing the initial conditions into components corresponding to a given eccentricity and studying the out-coming flow through hydrodynamic evolution. It is found that for initial conditions deviating significantly from Gaussian, such as those from NeXuS, the linearity between eccentricities and flow harmonics partially breaks down. Combining with the effect of coupling between cumulants of different orders, it causes the production of extra flow harmonics of higher orders. We argue that these results can be seen as a natural consequence of the non-linear nature of hydrodynamics, and they can be understood intuitively in terms of the peripheral-tube model.

Research paper thumbnail of An hydrodynamic approach of two particle correlations in high energy nuclear collisions

Research paper thumbnail of Causality, memory effect and relativistic dissipative hydrodynamics

The ideal hydrodynamical description for the dynamics of hot and dense matter achieved in RHIC ex... more The ideal hydrodynamical description for the dynamics of hot and dense matter achieved in RHIC experiments works amazingly well, particularly for the behavior of collective flow parameters. However, we know that there still exist several open problems in the interpretation of data in terms of the hydrodynamical model [1]. These questions require careful examination to extract quantitative and precise information on the properties of QGP. In particular, we should study the effect of dissipative processes on the collective flow variables.