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11 results on '"Martínez Santos, Diego"'

1. Measurement of the J/ψ pair production cross-section in pp collisions at √s=13 TeV

Author

LHCb Collaboration, Adeva Andany, Bernardo, Borsato, Martino, Chobanova, Veronika, Cid Vidal, Xabier, Dosil Suárez, Álvaro, Fernández Prieto, Antonio, Gallas Torreira, Abraham Antonio, Lemos Cid, Edgar, Lucio Martínez, Miriam, Martínez Santos, Diego, Plo Casasus, Máximo, Prisciandaro, Jessica, Ramos Pernas, Miguel, Romero Vidal, Antonio, Saborido Silva, Juan José, Sanmartín Sedes, Brais, Santamarina Ríos, Cibrán, Vázquez Regueiro, Pablo, Vieites Díaz, María, Vázquez Sierra, Carlos, Universidade de Santiago de Compostela. Departamento de Física de Partículas, and Universidade de Santiago de Compostela. Instituto Galego de Física de Altas Enerxías (IGFAE)

Subjects
Hadron-Hadron scattering (experiments), Quarkonium, High Energy Physics::Experiment, Particle and resonance production, Proton-proton scattering, QCD
Abstract

The production cross-section of J/ψ pairs is measured using a data sample of pp collisions collected by the LHCb experiment at a centre-of-mass energy of √s=13 TeV, corresponding to an integrated luminosity of 279 ±11 pb−1. The measurement is performed for J/ψ mesons with a transverse momentum of less than 10 GeV/c in the rapidity range 2.0 < y < 4.5. The production cross-section is measured to be 15.2 ± 1.0 ± 0.9 nb. The first uncertainty is statistical, and the second is systematic. The differential cross-sections as functions of several kinematic variables of the J/ψ pair are measured and compared to theoretical predictions. SI

Published
2017

2. Study of bb¯correlations in high energy proton-proton collisions

Author

LHCb Collaboration, Adeva Andany, Bernardo, Borsato, Martino, Chobanova, Veronika, Cid Vidal, Xabier, Dosil Suárez, Álvaro, Fernández Prieto, Antonio, García Pardiñas, Julián, Lemos Cid, Edgar, Lucio Martínez, Miriam, Martínez Santos, Diego, Plo Casasus, Máximo, Prisciandaro, Jessica, Ramos Pernas, Miguel, Romero Vidal, Antonio, Saborido Silva, Juan José, Sanmartín Sedes, Brais, Santamarina Ríos, Cibrán, Vázquez Regueiro, Pablo, Vieites Díaz, María, Vázquez Sierra, Carlos, Universidade de Santiago de Compostela. Departamento de Física de Partículas, and Universidade de Santiago de Compostela. Instituto Galego de Física de Altas Enerxías (IGFAE)

Subjects
Heavy quark production, Hadron-Hadron scattering (experiments), Forward physics, High Energy Physics::Experiment, Particle and resonance production, QCD
Abstract

Kinematic correlations for pairs of beauty hadrons, produced in high energy proton-proton collisions, are studied. The data sample used was collected with the LHCb experiment at centre-of-mass energies of 7 and 8 TeV and corresponds to an integrated luminosity of 3 fb−1. The measurement is performed using inclusive b → J/ψX decays in the rapidity range 2 < yJ/ψ < 4.5. The observed correlations are in good agreement with theoretical predictions. SI

Published
2017

3. Measurements of prompt charm production cross-sections in pp collisions at √s=5 TeV

Author

LHCb Collaboration, Adeva Andany, Bernardo, Borsato, Martino, Chobanova, Veronika, Cid Vidal, Xabier, Dosil Suárez, Álvaro, Fernández Prieto, Antonio, García Pardiñas, Julián, Hernando Morata, José Ángel, Lemos Cid, Edgar, Lucio Martínez, Miriam, Martínez Santos, Diego, Plo Casasus, Máximo, Prisciandaro, Jessica, Ramos Pernas, Miguel, Romero Vidal, Antonio, Saborido Silva, Juan José, Sanmartín Sedes, Brais, Santamarina Ríos, Cibrán, Vázquez Regueiro, Pablo, Vieites Díaz, María, Vázquez Sierra, Carlos, Universidade de Santiago de Compostela. Departamento de Física de Partículas, and Universidade de Santiago de Compostela. Instituto Galego de Física de Altas Enerxías (IGFAE)

Subjects
Heavy quark production, Hadron-Hadron scattering (experiments), Forward physics, QCD, Charm physics
Abstract

Production cross-sections of prompt charm mesons are measured using data from pp collisions at the LHC at a centre-of-mass energy of 5 TeV. The data sample corresponds to an integrated luminosity of 8.60 ± 0.33 pb−1 collected by the LHCb experiment. The production cross-sections of D 0, D +, D +s, and D ∗+ mesons are measured in bins of charm meson transverse momentum, p T, and rapidity, y. They cover the rapidity range 2.0 < y < 4.5 and transverse momentum ranges 0 < p T < 10 GeV/c for D 0 and D + and 1 < p T < 10 GeV/c for D +s and D ∗+ mesons. The inclusive cross-sections for the four mesons, including charge-conjugate states, within the range of 1 < p T < 8 GeV/c are determined to be σ(pp→D0X)=1004±3±54μb,σ(pp→D+X)=402±2±30μb,σ(pp→D+sX)=170±4±16μb,σ(pp→D∗+X)=421±5±36μb, where the uncertainties are statistical and systematic, respectively. SI

Published
2017

4. Bose-Einstein correlations of same-sign charged pions in the forward region in pp collisions at √s=7 TeV

Author

LHCb Collaboration, Adeva Andany, Bernardo, Borsato, Martino, Chobanova, Veronika, Cid Vidal, Xabier, Dosil Suárez, Álvaro, Fernández Prieto, Antonio, García Pardiñas, Julián, Lemos Cid, Edgar, Lucio Martínez, Miriam, Martínez Santos, Diego, Plo Casasus, Máximo, Prisciandaro, Jessica, Ramos Pernas, Miguel, Romero Vidal, Antonio, Saborido Silva, Juan José, Sanmartín Sedes, Brais, Santamarina Ríos, Cibrán, Vázquez Regueiro, Pablo, Vieites Díaz, María, Vázquez Sierra, Carlos, Universidade de Santiago de Compostela. Departamento de Física de Partículas, and Universidade de Santiago de Compostela. Instituto Galego de Física de Altas Enerxías (IGFAE)

Subjects
Condensed Matter::Quantum Gases, Hadron-Hadron scattering (experiments), Particle correlations and fluctuations, QCD
Abstract

Bose-Einstein correlations of same-sign charged pions, produced in proton-proton collisions at a 7 TeV centre-of-mass energy, are studied using a data sample collected by the LHCb experiment. The signature for Bose-Einstein correlations is observed in the form of an enhancement of pairs of like-sign charged pions with small four-momentum difference squared. The charged-particle multiplicity dependence of the Bose-Einstein correlation parameters describing the correlation strength and the size of the emitting source is investigated, determining both the correlation radius and the chaoticity parameter. The measured correlation radius is found to increase as a function of increasing charged-particle multiplicity, while the chaoticity parameter is seen to decrease. SI

Published
2017

5. Study of the D0 p amplitude in Λ0b → D0 pπ − decays

Author

LHCb Collaboration, Adeva Andany, Bernardo, Borsato, Martino, Chobanova, Veronika, Cid Vidal, Xabier, Dosil Suárez, Álvaro, Fernández Prieto, Antonio, Gallas Torreira, Abraham Antonio, García Pardiñas, Julián, Lemos Cid, Edgar, Lucio Martínez, Miriam, Martínez Santos, Diego, Plo Casasus, Máximo, Prisciandaro, Jessica, Ramos Pernas, Miguel, Romero Vidal, Antonio, Saborido Silva, Juan José, Sanmartín Sedes, Brais, Santamarina Ríos, Cibrán, Vázquez Regueiro, Pablo, Vieites Díaz, María, Vázquez Sierra, Carlos, Universidade de Santiago de Compostela. Departamento de Física de Partículas, and Universidade de Santiago de Compostela. Instituto Galego de Física de Altas Enerxías (IGFAE)

Subjects
Hadron-Hadron scattering (experiments), QCD, B physics, Spectroscopy, Charm physics
Abstract

An amplitude analysis of the decay Λ0b → D0 pπ − is performed in the part of the phase space containing resonances in the D0 p channel. The study is based on a data sample corresponding to an integrated luminosity of 3.0 fb−1 of pp collisions recorded by the LHCb experiment. The spectrum of excited Λ +c states that decay into D0 p is studied. The masses, widths and quantum numbers of the Λc(2880)+ and Λc(2940)+ resonances are measured. The constraints on the spin and parity for the Λc(2940)+ state are obtained for the first time. A near-threshold enhancement in the D0 p amplitude is investigated and found to be consistent with a new resonance, denoted the Λc(2860)+, of spin 3/2 and positive parity. SI

Published
2017

6. Measurement of the Y(nS) polarizations in pp collisions at √s=7 and 8 TeV

Author

LHCb Collaboration, Adeva Andany, Bernardo, Borsato, Martino, Chobanova, Veronika, Cid Vidal, Xabier, Dosil Suárez, Álvaro, Fernández Prieto, Antonio, Gallas Torreira, Abraham Antonio, García Pardiñas, Julián, Lemos Cid, Edgar, Lucio Martínez, Miriam, Martínez Santos, Diego, Plo Casasus, Máximo, Prisciandaro, Jessica, Ramos Pernas, Miguel, Romero Vidal, Antonio, Saborido Silva, Juan José, Santamarina Ríos, Cibrán, Vázquez Regueiro, Pablo, Vieites Díaz, María, Vázquez Sierra, Carlos, Universidade de Santiago de Compostela. Departamento de Física de Partículas, and Universidade de Santiago de Compostela. Instituto Galego de Física de Altas Enerxías (IGFAE)

Subjects
Hadron-Hadron scattering (experiments), Polarization, High Energy Physics::Experiment, Particle and resonance production, QCD
Abstract

The polarization of the Y(1S), Y(2S) and Y(3S) mesons, produced in pp collisions at centre-of-mass energies √s=7 and 8 TeV, is measured using data samples collected by the LHCb experiment, corresponding to integrated luminosities of 1 and 2 fb−1, respectively. The measurements are performed in three polarization frames, using Y → μμ decays in the kinematic region of the transverse momentum p ΥT

Published
2017

7. Measurement of the ratio of branching fractions B(B+c→J/ψK+)/B(B+c→J/ψπ+)

Author

LHCb Collaboration, Adeva Andany, Bernardo, Borsato, Martino, Chobanova, Veronika, Cid Vidal, Xabier, Dosil Suárez, Álvaro, Fernández Albor, Víctor Manuel, Gallas Torreira, Abraham Antonio, García Pardiñas, Julián, Hernando Morata, José Ángel, Lemos Cid, Edgar, Lucio Martínez, Miriam, Martínez Santos, Diego, Plo Casasus, Máximo, Prisciandaro, Jessica, Ramos Pernas, Miguel, Romero Vidal, Antonio, Saborido Silva, Juan José, Sanmartín Sedes, Brais, Santamarina Ríos, Cibrán, Vázquez Regueiro, Pablo, Vieites Díaz, María, Vázquez Sierra, Carlos, Universidade de Santiago de Compostela. Departamento de Física de Partículas, and Universidade de Santiago de Compostela. Instituto Galego de Física de Altas Enerxías (IGFAE)

Subjects
Hadron-Hadron scattering (experiments), Branching fraction, QCD
Abstract

The ratio of branching fractions RK/π≡B(B+c→J/ψK+)/B(B+c→J/ψπ+) is measured with pp collision data collected by the LHCb experiment at centre-of-mass energies of 7 TeV and 8 TeV, corresponding to an integrated luminosity of 3 fb−1. It is found to be R K/π = 0.079 ± 0.007 ± 0.003, where the first uncertainty is statistical and the second is systematic. This measurement is consistent with the previous LHCb result, while the uncertainties are significantly reduced. SI

Published
2016

8. Measurement of forward W → eν production in pp collisions at √s=8 TeV

Author

LHCb Collaboration, Adeva Andany, Bernardo, Borsato, Martino, Chobanova, Veronika, Cid Vidal, Xabier, Dosil Suárez, Álvaro, Fernández Albor, Víctor Manuel, Fernández Prieto, Antonio, Gallas Torreira, Abraham Antonio, García Pardiñas, Julián, Hernando Morata, José Ángel, Lemos Cid, Edgar, Lucio Martínez, Miriam, Martínez Santos, Diego, Plo Casasus, Máximo, Prisciandaro, Jessica, Ramos Pernas, Miguel, Romero Vidal, Antonio, Saborido Silva, Juan José, Sanmartín Sedes, Brais, Santamarina Ríos, Cibrán, Vázquez Regueiro, Pablo, Vieites Díaz, María, Vázquez Sierra, Carlos, Universidade de Santiago de Compostela. Departamento de Física de Partículas, and Universidade de Santiago de Compostela. Instituto Galego de Física de Altas Enerxías (IGFAE)

Subjects
Hadron-Hadron scattering (experiments), Electroweak interaction, QCD
Abstract

A measurement of the cross-section for W → eν production in pp collisions is presented using data corresponding to an integrated luminosity of 2 fb−1 collected by the LHCb experiment at a centre-of-mass energy of √s=8 TeV. The electrons are required to have more than 20 GeV of transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The inclusive W production cross-sections, where the W decays to eν, are measured to be σW+→e+νe=1124.4±2.1±21.5±11.2±13.0pb, σW−→e−ν¯e=809.0±1.9±18.1±7.0±9.4pb, where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. Differential cross-sections as a function of the electron pseudorapidity are measured. The W + /W − cross-section ratio and production charge asymmetry are also reported. Results are compared with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. Finally, in a precise test of lepton universality, the ratio of W boson branching fractions is determined to be B(W→eν)/B(W→μν)=1.020±0.002±0.019, where the first uncertainty is statistical and the second is systematic. SI

Published
2016

9. Production of associated Y and open charm hadrons in pp collisions at √s=7 and 8 TeV via double parton scattering

Author

LHCb Collaboration, Dosil Suárez, Álvaro, Fernández Albor, Víctor Manuel, Gallas Torreira, Abraham Antonio, García Pardiñas, Julián, Lemos Cid, Edgar, Lucio Martínez, Miriam, Martínez Santos, Diego, Plo Casasus, Máximo, Prisciandaro, Jessica, Ramos Pernas, Miguel, Romero Vidal, Antonio, Saborido Silva, Juan José, Sanmartín Sedes, Brais, Santamarina Ríos, Cibrán, Vázquez Regueiro, Pablo, Vázquez Sierra, Carlos, Vieites Díaz, María, Universidade de Santiago de Compostela. Departamento de Física de Partículas, and Universidade de Santiago de Compostela. Instituto Galego de Física de Altas Enerxías (IGFAE)

Subjects
Hard scattering, Heavy quark production, Hadron-Hadron scattering (experiments), Forward physics, QCD
Abstract

Associated production of bottomonia and open charm hadrons in pp collisions at √s=7 and 8 TeV is observed using data corresponding to an integrated luminosity of 3 fb−1 accumulated with the LHCb detector. The observation of five combinations, Y(1S)D0, Y(2S)D0, Y(1S)D+, Y(2S)D+ and Y(1S)D +s, is reported. Production crosssections are measured for Y(1S)D0 and Y(1S)D+ pairs in the forward region. The measured cross-sections and the differential distributions indicate the dominance of double parton scattering as the main production mechanism. SI

Published
2016

10. Measurement of forward W and Z boson production in association with jets in proton-proton collisions at √s=8 TeV

Author

LHCb Collaboration, Adeva Andany, Bernardo, Borsato, Martino, Chobanova, Veronika, Cid Vidal, Xabier, Dosil Suárez, Álvaro, Fernández Albor, Víctor Manuel, Gallas Torreira, Abraham Antonio, García Pardiñas, Julián, Hernando Morata, José Ángel, Lemos Cid, Edgar, Lucio Martínez, Miriam, Martínez Santos, Diego, Plo Casasus, Máximo, Prisciandaro, Jessica, Ramos Pernas, Miguel, Romero Vidal, Antonio, Saborido Silva, Juan José, Sanmartín Sedes, Brais, Santamarina Ríos, Cibrán, Vieites Díaz, María, Vázquez Sierra, Carlos, Universidade de Santiago de Compostela. Departamento de Física de Partículas, and Universidade de Santiago de Compostela. Instituto Galego de Física de Altas Enerxías (IGFAE)

Subjects
Jet physics, Hadron-Hadron scattering (experiments), Astrophysics::High Energy Astrophysical Phenomena, High Energy Physics::Phenomenology, Electroweak interaction, Forward physics, High Energy Physics::Experiment, QCD
Abstract

The production of W and Z bosons in association with jets is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 ± 0.02 fb−1. The W boson is identified using its decay to a muon and a neutrino, while the Z boson is identified through its decay to a muon pair. Total cross-sections are measured and combined into charge ratios, asymmetries, and ratios of W +jet and Z+jet production cross-sections. Differential measurements are also performed as a function of both boson and jet kinematic variables. All results are in agreement with Standard Model predictions. SI

Published
2016

11. Forward production of Υ mesons in pp collisions at √s=7 and 8 TeV

Author

LHCb Collaboration, Adeva Andany, Bernardo, Dosil Suárez, Álvaro, Fernández Albor, Víctor Manuel, Gallas Torreira, Abraham Antonio, García Pardiñas, Julián, Lemos Cid, Edgar, Lucio Martínez, Miriam, Martínez Santos, Diego, Plo Casasus, Máximo, Prisciandaro, James J., Ramos Pernas, Miguel, Romero Vidal, Antonio, Saborido Silva, Juan José, Sanmartín Sedes, Brais, Santamarina Ríos, Cibrán, Vázquez Regueiro, Pablo, Vázquez Sierra, Carlos, Vieites Díaz, María, Universidade de Santiago de Compostela. Departamento de Física de Partículas, and Universidade de Santiago de Compostela. Instituto Galego de Física de Altas Enerxías (IGFAE)

Subjects
Hadron-Hadron Scattering, Hard scattering, Quarkonium, High Energy Physics::Experiment, Nuclear Experiment, QCD, Spectroscopy
Abstract

The production of Υ mesons in pp collisions at √s=7 and 8 TeV is studied with the LHCb detector using data samples corresponding to an integrated luminosity of 1 fb−1 and 2 fb−1 respectively. The production cross-sections and ratios of cross-sections are measured as functions of the meson transverse momentum p and rapidity y, for p < 30 GeV/c and 2.0 < y < 4.5 SI

Published
2015

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