A. Gil

Inclusive Dielectron Production in Ar+KCl Collisions at 1.76 AGeV studied with HADES

The HADES Collaboration, F. Krizek, G. Agakishiev +110

Results of the HADES measurement of inclusive dielectron production in Ar+KCl collisions at a kinetic beam energy of 1.76 AGeV are presented. For the first time, high mass resoluti…

Asymptotic computation of classical orthogonal polynomials

A. Gil, J. Segura, N. M. Temme

The classical orthogonal polynomials (Hermite, Laguerre and Jacobi) are involved in a vast number of applications in physics and engineering. When large degrees $n$ are needed, the…

Present status and future perspectives of the NEXT experiment

The NEXT Collaboration, J. J. GÃ³mez-Cadenas, V. Ãlvarez +74

NEXT is an experiment dedicated to neutrinoless double beta decay searches in xenon. The detector is a TPC, holding 100 kg of high-pressure xenon enriched in the $^{136}$ Xe isotope…

Near-Intrinsic Energy Resolution for 30 to 662 keV Gamma Rays in a High Pressure Xenon Electroluminescent TPC

NEXT Collaboration, V. Ãlvarez, F. I. G. M. Borges +75

We present the design, data and results from the NEXT prototype for Double Beta and Dark Matter (NEXT-DBDM) detector, a high-pressure gaseous natural xenon electroluminescent time…

math.CA2015

Computing the Kummer function U(a,b,z) for small values of the arguments

A. Gil, J. Segura, N. M. Temme

We describe methods for computing the Kummer function $U (a, b, z)$ for small values of $z$ , with special attention to small values of $b$ . For these values of $b$ the connection form…

astro-ph.SR2015

A stochastic method of solution of the Parker transport equation

A. Wawrzynczak, R. Modzelewska, A. Gil

We present the stochastic model of the galactic cosmic ray (GCR) particles transport in the heliosphere. Based on the solution of the Parker transport equation we developed models…

Performances of multi-gap timing RPCs for relativistic ions in the range Z=1-6

P. Cabanelas, M. Morales, J. A. Garzon +12

We present the performance of Multi-gap timing RPCs under irradiation by fully stripped relativistic ions (gamma*beta=2.7, Z=1-6). A time resolution of 80 ps at high efficiency has…

Measurement of charged pions in 12C + 12C collisions at 1A GeV and 2A GeV with HADES

The HADES Collaboration, G. Agakishiev, C. Agodi +123

We present the results of a study of charged pion production in 12C + 12C collisions at incident beam energies of 1A GeV and 2A GeV using the HADES spectrometer at GSI. The main em…

The asymptotic and numerical inversion of the Marcum $Q -$ function

A. Gil, J. Segura, N. M. Temme

The generalized Marcum functions appear in problems of technical and scientific areas such as, for example, radar detection and communications. In mathematical statistics and proba…

physics.ins-det2011

The NEXT-100 experiment for neutrinoless double beta decay searches (Conceptual Design Report)

NEXT Collaboration, V. Ãlvarez, M. Ball +80

We propose an EASY (Electroluminescent ApparatuS of high Yield) and SOFT (Separated Optimized FuncTion) time-projection chamber for the NEXT experiment, that will search for neutri…

astro-ph.SR2015

Stochastic approach to the numerical solution of the non-stationary Parker's transport equation

A. Wawrzynczak, R. Modzelewska, A. Gil

We present the newly developed stochastic model of the galactic cosmic ray (GCR) particles transport in the heliosphere. Mathematically Parker transport equation (PTE) describing n…

nucl-ex2010

In-Medium Effects on K0 Mesons in Relativistic Heavy-Ion Collisions

G. Agakishiev, A. Balanda, B. Bannier +108

We present the transverse momentum spectra and rapidity distributions of $I ¨ ^{-}$ and K $_{S}^{0}$ in Ar+KCl reactions at a beam kinetic energy of 1.756 A GeV measured with the spectrom…

hep-ex2009

NEXT, a HPGXe TPC for neutrinoless double beta decay searches

The NEXT Collaboration, F. Granena, T. Lux +61

We propose a novel detection concept for neutrinoless double-beta decay searches. This concept is based on a Time Projection Chamber (TPC) filled with high-pressure gaseous xenon,…

math.NA2016

Efficient algorithms for the inversion of the cumulative central beta distribution

A. Gil, J. Segura, N. M. Temme

Accurate and efficient algorithms for the inversion of the cumulative central beta distribution are described. The algorithms are based on the combination of a fourth-order fixed p…

nucl-ex2015

Study of the quasi-free $n p \to n p I ¨ ^{+} I ¨ ^{-}$ reaction with a deuterium beam at 1.25 GeV/nucleon

G. Agakishiev, A. Balanda, D. Belver +102

The tagged quasi-free $n p \to n p I ¨ ^{+} I ¨ ^{-}$ reaction has been studied experimentally with the High Acceptance Di-Electron Spectrometer (HADES) at GSI at a deuteron incident beam ener…

On the complex zeros of Airy and Bessel functions and those of their derivatives

A. Gil, J. Segura

We study the distribution of zeros of general solutions of the Airy and Bessel equations in the complex plane. Our results characterize the patterns followed by the zeros for any s…

math.CA2017

Computation of asymptotic expansions of turning point problems via Cauchy's integral formula: Bessel functions

T. M. Dunster, A. Gil, J. Segura

Linear second order differential equations having a large real parameter and turning point in the complex plane are considered. Classical asymptotic expansions for solutions involv…

math.LO2009

Logics preserving degrees of truth from varieties of residuated lattices

F. Bou, F. Esteva, J. M. Font +4

Let K be a variety of (commutative, integral) residuated lattices. The substructural logic usually associated with K is an algebraizable logic that has K as its equivalent algebrai…

math.NA2025

Fast and accurate computation of classical Gaussian quadratures

A. Gil, J. Segura, N. M. Temme

Algorithms for computing the classical Gaussian quadrature rules (Gauss--Jacobi, Gauss--Laguerre, and Gauss--Hermite) are presented, based on globally convergent fourth-order itera…

Future perspectives at SIS-100 with HADES-at-FAIR

The HADES Collaboration, I. Froehlich, G. Agakishiev +110

Currently, the HADES spectrometer undergoes un upgrade program to be prepared for measurements at the upcoming SIS-100 synchrotron at FAIR. We describe the current status of the HA…

math.NA2025

A numerical algorithm for computing the zeros of parabolic cylinder functions in the complex plane

T. M. Dunster, A. Gil, D. Ruiz-AntolÃn +1

A numerical algorithm (implemented in Matlab) for computing the zeros of the parabolic cylinder function $U (a, z)$ in domains of the complex plane is presented. The algorithm uses a…

math.NA2016

Efficient computation of Laguerre polynomials

A. Gil, J. Segura, N. M. Temme

An efficient algorithm and a Fortran 90 module (LaguerrePol) for computing Laguerre polynomials $L_{n}^{(I^\pm)} (z)$ are presented. The standard three-term recurrence relation satisfied…

In-situ calibration of a PMT inside a scintillation detector by means of primary scintillation detection

NEXT Collaboration, V. Ãlvarez, F. I. G. M. Borges +75

We have investigated the possibility of calibrating the PMTs of scintillation detectors, using the primary scintillation produced by X-rays to induce single photoelectron response…

math.CA2022

Complete asymptotic expansions for the relativistic Fermi-Dirac integral

A. Gil, J. Segura, N. M. Temme

Fermi-Dirac integrals appear in problems in nuclear astrophysics, solid state physics or in the fundamental theory of semiconductor modeling, among others areas of application. In…

math.CA2017

Asymptotic approximations to the nodes and weights of Gauss-Hermite and Gauss-Laguerre quadratures

A. Gil, J. Segura, N. M. Temme

Asymptotic approximations to the zeros of Hermite and Laguerre polynomials are given, together with methods for obtaining the coefficients in the expansions. These approximations c…

cs.MS2017

Conical: an extended module for computing a numerically satisfactory pair of solutions of the differential equation for conical functions

T. M. Dunster, A. Gil, J. Segura +1

Conical functions appear in a large number of applications in physics and engineering. In this paper we describe an extension of our module CONICAL for the computation of conical f…

astro-ph.SR2021

Recurrence of galactic cosmic rays intensity and anisotropy in solar minima 23/24 and 24/25 by ACE/CRIS, STEREO, SOHO/EPHIN and neutron monitors. Fourier and wavelet analysis. Dedicated to the Memory of Michael Alania

R. Modzelewska, A. Gil

Aims. We study the 27-day variations of galactic cosmic rays (GCRs) based on neutron monitor (NM), ACE/CRIS, STEREO and SOHO/EPHIN measurements, in solar minima 23/24 and 24/25 cha…

Origin of the low-mass electron pair excess in light nucleus-nucleus collisions

The HADES Collaboration, G. Agakishiev, A. Balanda +97

We report measurements of electron pair production in elementary p+p and d+p reactions at 1.25 GeV/u with the HADES spectrometer. For the first time, the electron pairs were recons…

nucl-th1994

The Axial Charge Renormalization in a Relativistic Description of Finite Nuclei

A. Gil, M. Kleinmann, H. M"uther +1

Starting from a realistic One-Boson-Exchange model of the nucleon nucleon interaction the relativistic mean field for nucleons is determined within the Dirac Brueckner Hartree Fock…

cs.MS2015

GammaCHI: a package for the inversion and computation of the gamma and chi-square cumulative distribution functions (central and noncentral)

A. Gil, J. Segura, N. M. Temme

A Fortran 90 module (GammaCHI) for computing and inverting the gamma and chi-square cumulative distribution functions (central and noncentral) is presented. The main novelty of thi…

math.NA2020

Fast and reliable high accuracy computation of Gauss--Jacobi quadrature

A. Gil, J. Segura, N. M. Temme

Iterative methods with certified convergence for the computation of Gauss--Jacobi quadratures are described. The methods do not require a priori estimations of the nodes to guarant…

Description and commissioning of NEXT-MM prototype: first results from operation in a Xenon-Trimethylamine gas mixture

NEXT Collaboration, V. Ãlvarez, F. Aznar +82

A technical description of NEXT-MM and its commissioning and first performance is reported. Having an active volume of ~35 cm drift $\times$ 28 cm diameter, it constitutes the larg…

Radiopurity control in the NEXT-100 double beta decay experiment: procedures and initial measurements

V. Alvarez, I. Bandac, A. Bettini +77

The Neutrino Experiment with a Xenon TPC (NEXT) is intended to investigate the neutrinoless double beta decay of 136Xe, which requires a severe suppression of potential backgrounds…

Ionization and scintillation response of high-pressure xenon gas to alpha particles

NEXT Collaboration, V. Ãlvarez, F. I. G. M. Borges +70

High-pressure xenon gas is an attractive detection medium for a variety of applications in fundamental and applied physics. In this paper we study the ionization and scintillation…

Asymptotic inversion of the binomial and negative binomial cumulative distribution functions

A. Gil, J. Segura, N. M. Temme

The computation and inversion of the binomial and negative binomial cumulative distribution functions play a key role in many applications. In this paper, we explain how methods us…

Sharp error bounds for turning point expansions

T. M. Dunster, A. Gil, J. Segura

Computable and sharp error bounds are derived for asymptotic expansions for linear differential equations having a simple turning point. The expansions involve Airy functions and s…

nucl-ex2010

Lambda-p femtoscopy in collisions of Ar+KCl at 1.76 AGeV

G. Agakishiev, A. Balanda, R. Bassini +103

Results on $I^$ p femtoscopy are reported at the lowest energy so far. At a beam energy of 1.76A~GeV, the reaction Ar+KCl was studied with the High Acceptance Di-Electron Spectromet…

physics.space-ph2016

Analysis of Ground Level Enhancements (GLE): Extreme solar energetic particle events have hard spectra

E. Asvestari, T. Willamo, A. Gil +4

Nearly 70 Ground Level Enhancements (GLEs) of cosmic rays have been recorded by the worldwide neutron monitor network since the 1950s depicting a big variety of energy spectra of s…

nucl-ex2008

Study of dielectron production in C+C collisions at 1 AGeV

HADES Collaboration, G. Agakishiev, C. Agodi +117

The emission of e+e- pairs from C+C collisions at an incident energy of 1 GeV per nucleon has been investigated. The measured production probabilities, spanning from the pi0-Dalitz…

math.NA2019

Fast, reliable and unrestricted iterative computation of Gauss--Hermite and Gauss--Laguerre quadratures

A. Gil, J. Segura, N. M. Temme

Methods for the computation of classical Gaussian quadrature rules are described which are effective both for small and large degree. These methods are reliable because the iterati…

nucl-ex2011

Cross section in deuteron-proton elastic scattering at 1.25 GeV/u

HADES Collaboration, P. K. Kurilkin, G. Agakishiev +98

First results of the differential cross section in dp elastic scattering at 1.25 GeV/u measured with the HADES over a large angular range are reported. The obtained data correspond…

math.NA2022

Computation of parabolic cylinder functions having complex argument

T. M. Dunster, A. Gil, J. Segura

Numerical methods for the computation of the parabolic cylinder $U (a, z)$ for real $a$ and complex $z$ are presented. The main tools are recent asymptotic expansions involving expon…

SiPMs coated with TPB : coating protocol and characterization for NEXT

V. Ãlvarez, J. Agramunt, M. Ball +91

Silicon photomultipliers (SiPM) are the photon detectors chosen for the tracking readout in NEXT, a neutrinoless Î²Î² decay experiment which uses a high pressure gaseous xenon time…

nucl-th1994

A theoretical approach to the (pion^{-}, gamma gamma) reaction in nuclei

A. Gil, E. Oset

We have studied the pion^{-} capture in nuclei leading to two photons, using improved many body methods which have been tested with success in one photon pion^{-} radiative capture…

Simplified error bounds for turning point expansions

T. M. Dunster, A. Gil, J. Segura

Recently, the present authors derived new asymptotic expansions for linear differential equations having a simple turning point. These involve Airy functions and slowly varying coe…

nucl-ex2011

Hyperon production in Ar+KCl collisions at 1.76A GeV

G. Agakishiev, A. Balanda, B. Bannier +111

We present transverse momentum spectra, rapidity distribution and multiplicity of Lambda-hyperons measured with the HADES spectrometer in the reaction Ar(1.76A GeV)+KCl. The yield…

physics.ins-det2014

Ionization and scintillation of nuclear recoils in gaseous xenon

J. Renner, V. M. Gehman, A. Goldschmidt +75

Ionization and scintillation produced by nuclear recoils in gaseous xenon at approximately 14 bar have been simultaneously observed in an electroluminescent time projection chamber…

nucl-th1997

Many Body approach to the inclusive $(e, e^{'})$ reaction from the quasielastic to the $I^$ excitation region

A. Gil, J. Nieves, E. Oset

We have performed a many body calculation of the inclusive (e,e') cross section which runs over the three traditional regions at intermediate energies: the quasielastic peak, the d…

Design and characterization of the SiPM tracking system of NEXT-DEMO, a demonstrator prototype of the NEXT-100 experiment

NEXT Collaboration, V. Ãlvarez, M. Ball +86

NEXT-100 experiment aims at searching the neutrinoless double-beta decay of the Xe-136 isotope using a TPC filled with a 100 kg of high-pressure gaseous xenon, with 90% isotopic en…

The High-Acceptance Dielectron Spectrometer HADES

The HADES Collaboration, G. Agakishiev, A. Balanda +110

HADES is a versatile magnetic spectrometer aimed at studying dielectron production in pion, proton and heavy-ion induced collisions. Its main features include a ring imaging gas Ch…

math.CA2024

Uniform asymptotic expansions for the zeros of parabolic cylinder functions

T. M. Dunster, A. Gil, D. Ruiz-Antolin +1

The real and complex zeros of the parabolic cylinder function $U (a, z)$ are studied. Asymptotic expansions for the zeros are derived, involving the zeros of Airy functions, and thes…

nucl-th1997

Inclusive $(e, e^{'} N)$ , $(e, e^{'} N N)$ , $(e, e^{'} I ¨ )$ ... reactions in nuclei

A. Gil, J. Nieves, E. Oset

We study the inclusive $(e, e^{'} N)$ , $(e, e^{'} N N)$ , $(e, e^{'} I ¨ )$ , $(e, e^{'} I ¨ N)$ reactions in nuclei using a Monte Carlo simulation method to treat the multichanne…

nucl-ex2011

Single and double pion production in np collisions at 1.25 GeV with HADES

The HADES Collaboration, A. K. Kurilkin, G. Agakishiev +98

The preliminary results on charged pion production in np collisions at an incident beam energy of 1.25 GeV measured with HADES are presented. The np reactions were isolated in dp c…

Deep sub-threshold $I^^{-}$ production in Ar+KCl reactions at 1.76A GeV

G. Agakishiev, A. Balanda, R. Bassini +101

We report first results on a deep sub-threshold production of the doubly strange hyperon $I^^{-}$ in a heavy-ion reaction. At a beam energy of 1.76A GeV the reaction Ar+KCl was studi…

NEXT-100 Technical Design Report (TDR). Executive Summary

NEXT Collaboration, V. Ãlvarez, F. I. G. M. Borges +84

In this Technical Design Report (TDR) we describe the NEXT-100 detector that will search for neutrinoless double beta decay (bbonu) in Xe-136 at the Laboratorio Subterraneo de Canf…

Characterization of a medium size Xe/TMA TPC instrumented with microbulk Micromegas, using low-energy $I^^{3}$ -rays

The NEXT collaboration, V. Alvarez, F. I. G. M. Borges +87

NEXT-MM is a general-purpose high pressure (10 bar, $\sim 25$ l active volume) Xenon-based TPC, read out in charge mode with an 8 cm $\times$ 8 cm-segmented 700 cm $^{2}$ plane (1152 ch…

Operation and first results of the NEXT-DEMO prototype using a silicon photomultiplier tracking array

The NEXT Collaboration, V. Ãlvarez, F. I. G. Borges +75

NEXT-DEMO is a high-pressure xenon gas TPC which acts as a technological test-bed and demonstrator for the NEXT-100 neutrinoless double beta decay experiment. In its current config…

Computation of a numerically satisfactory pair of solutions of the differential equation for conical functions of non-negative integer orders

T. M. Dunster, A. Gil, J. Segura +1

We consider the problem of computing satisfactory pairs of solutions of the differential equation for Legendre functions of non-negative integer order $I^¼$ and degree $-\frac12+iÏ…

Charged pion production in C+C and Ar+KCl collisions measured with HADES

The HADES Collaboration, P. Tlusty, G. Agakishiev +110

Results of a study of charged pion production in 12C+12C collisions at incident beam energies of 1A GeV and 2A GeV, and 40Ar+natKCl at 1.76AGeV, using the spectrometer HADES at GSI…

math.CA2017

Uniform asymptotic expansions for Laguerre polynomials and related confluent hypergeometric functions

T. M. Dunster, A. Gil, J. Segura

Uniform asymptotic expansions involving exponential and Airy functions are obtained for Laguerre polynomials $L_{n}^{(I^\pm)} (x)$ , as well as complementary confluent hypergeometric fu…

Initial results of NEXT-DEMO, a large-scale prototype of the NEXT-100 experiment

NEXT Collaboration, V. Ãlvarez, F. I. G. M. Borges +75

NEXT-DEMO is a large-scale prototype of the NEXT-100 detector, an electroluminescent time projection chamber that will search for the neutrinoless double beta decay of Xe-136 using…

Recent software developments for special functions in the Santander-Amsterdam project

A. Gil, J. Segura, N. M. Temme

We give an overview of published algorithms by our group and of current activities and future plans. In particular, we give details on methods for computing special functions and d…

cs.MS2013

Computation of the Marcum Q-function

A. Gil, J. Segura, N. M. Temme

Methods and an algorithm for computing the generalized Marcum $Q -$ function ( $Q_{I^} ¼ (x, y)$ ) and the complementary function ( $P_{I^} ¼ (x, y)$ ) are described. These functions appear in probl…