**CONTRIBUTIONS ACCEPTED FOR ORAL PRESENTATION **
1
Raya
Alfredo
Instituto de Ciencias Nucleares, UNAM
raya@nucleares.unam.mx
Circuito Exterior C. U. Apartado Postal 70-543
Mexico, D. F.
04510
Mexico
+(52)555-622-4690 Ext. 372
+(52)555-622-4693
Post_Doc
Dynamical Mass Generation in Quantum Electrodynamics in weak magnetic fields
We study the dynamical generation of masses for fundamental fermions in
quenched quantum electrodynamics in the presence of magnetic fields using
Schwinger-Dyson equations. We show that, contrary to the case where the magnetic
field is strong, in the weak field limit masses are generated above a critical
value of the coupling and that this value is the same as in the case with no
magnetic field. The findings of this work might be relevant for processes
involving dynamical properties of fermion during the evolution of the early
universe where weak magnetic fields could be present.
*******************************************************************************
2
> Name: J. Lorenzo Diaz Cruz
> e-mail address: jldiaz@fcfm.buap.mx
> Institution: FCFM-BUAP
> Postal address:
> Student? If yes specify BS, MS, or PhD.
> Title: Unificacion Higgs-Gauge
> Author(s): A. Aranda, J.L. Diaz Cruz, A. Rosado
> Abstract (less than 150 words):
In this talk we present an alternative approach to the search
for unification of the fundamental interaction. We postulate that
the electroweak interactions unify with the Higgs self-interactions
at an scale lower than the usual GUT scale. Complete unification with
the strong force occurs after extra-dimensions of GUT^-1 size open up.
A specific realization of the above ideas is presented whith a gauge
symmetry of the type SU(3)xSU(3) in 6D.
************************************************************************************
3
Jose Luis Lucio Martinez.
USING B DECAYS TO STUDY LOW LYING 0^++ MESONS
D. Delepine^1, J.L. Lucio Martinez^1 and C Ramirez^2.
1) INSTITUTO DE FISICA, UNIVERSIDAD DE GUANAJUATO
LOMA DEL BOSQUE 103, LOMAS DEL CAMPESTRE
37160 LEON, GUANAJUATO; MEXICO.
2) Universidad Industrial de Santander
Carrera 27 Calle 9 Ciudad Universitaria
PBX 57- 7 6344000
Bucaramanga Colombia
We consider decays B ---> SP within the factorization approximation.
For particular channels (B a0 + pi, B -> f0 + K ) we present
predictions for the two and four quark state structure of the scalars.
We parameterize the annihilation contribution and indicate processes
for which the two and four quark structure lead different predictions.
*********************************************************************************
4
Amore
Paolo
Universidad de Colima
paolo@ucol.mx
Bernal Diaz del Castillo 340, Col. Villa San Sebastian
Colima
29845
Mexico
3123161000 ext 48006
Nonperturbative extensions of perturbative series
We review different possible techniques which can be used to improve the
convergence of certain mathematical series or even to extract the
non-perturbative behaviour of a perturbative series. The application to a few
physical examples is discussed and a comparison with well-known techniques is
performed.
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5
"A second order formalism for the description of spin 3/2 fields"
Mauro Napsuciale, Mariana Kirchbach
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6
- Dr. Marco A. Reyes
- Instituto de Fisica
- Univ. de Guanajuato
"Status of pentaquark candidates"
Abstract:
We present a review of the evidence for the existance of pentaquark states,
the old searches, and the predictions that lead to the 2003 boom of
sightings. In particular, we will talk about the status of the
\theta^+(1540), \cascade^{--}(1862), and \theta_c(3100).
**********************************************************************************
7
Name: Ricardo Gaitan Lozano
e-mail address: rgaitan@servidor.unam.mx
Institution: Fes-Cuautitlan, UNAM.
Postal address: Fes-Cautitlan, Campo 1, Centro de Investigaciones
Teoricas, Edificio A1, Planta Baja.
Student? NO
Title: Rare top decays in extended models.
Author(s): Ricardo Gaitan, Omar Miranda y Luis Cabral
Abstract (less than 150 words):
The extensions of the Standard Model with exotic quark singlets and
doublets introduces flavor changing neutral couplings between ordinary
fermions. Top quarks decays induced by flavor-changing neutral currents
(FCNC) are very much suppressed in the Standard Model. Their detection in
colliders such as LHC, NLC, or tevatron would be a signal of new physcis.
We evaluate several FCNC in the context of alternative left-right
symmetric models with extra isosinglet heavy fermions; In this case, FCNC
occur at tree level, and they are suppressed by the mixing between
ordinary top and charm quarks, which is poorly constrained by current
experimental values.
********************************************************************************
8
Hofmann
Christoph Peter
Facultad de Ciencias, Universidad de Colima
hofmann@ucol.mx
Bernal Diaz del Castillo #340
Colima
28045
Mexico
(312) 316-1000 Ext.:48009
Nonperturbative calculation of the Casimir effect
The Casimir energy for a massive scalar field in d dimensions between parallel
plates is calculated within the framework of variational perturbation theory. We
compare the results obtained with our regularization procedure with the
literature and discuss the advantages of our method.
**********************************************************************************
9
Name: S.R. Juárez W.
e-mail address:rebeca@esfm.ipn.mx
Institution: Escuela Superior de Física y Matemáticas del IPN
Postal address:
Departamento de Física de la ESFM,
Unidad Profesional "Adolfo López Mateos"
Edificio 9, Col. Lindavista,
CP 07738, México, D.F.
MÉXICO
Title:
Predictions for the Higgs mass from the stability and triviality
conditions in the SM
Author(s): S.R. Juárez W., H.G. Solís-Rodríguez, P. Kielanowski
Abstract :
We solve the renormalization group equation for the Higgs quartic
coupling to one and two loops. The energy dependence of the gauge and
Yukawa couplings is considered at the same order of approximation.
From the properties of the quartic coupling, precise bounds on the
Higgs boson mass are obtained by requiring the validity of the SM in
the whole range of energies from the top quark mass to the gran
unificatios scale.
*****************************************************************************************************************
10
Caceres
Elena
Universidad de Colima
elenac@zippy.ph.utexas.edu
Bernal Díaz del Castillo No. 340 Col. Villas San Sebastián
Colima
28045
Mexico
Status of Glueball Spectrum calculations from Supergravity.
We review the current status of glueball spectra obtained via the Gravity/Gauge
duality in different supergravity backgrounds. We compare the advantages and
shortcomings of the Klebanov-Strassler, Maldacena-Nuñez and Black Hole
backgrounds.
***********************************************************************************
11
Name: Eric Vazquez Jauregui
e-mail address: ericvj@ifisica.uaslp.mx
Institution: Instituto de Fisica, Universidad Autonoma de San Luis Potosi
Postal address: Manuel Nava #6, Zona Universitaria,
San Luis Potosi, SLP 78240
Student? If yes specify BS, MS, or PhD. PhD Student
Title: New Decay Modes of the charmed strange baryon Xi_c+
Author(s): Eric Vazquez Jauregui, Jurgen Engelfried, SELEX Collaboration
Abstract (less than 150 words):
We report on the search for new decay modes of the Xi_c+, using data
from the SELEX experiment (Fermilab E781). After studying in detail
the reconstruction of hyperons in the SELEX apparatus, we are able to
observe new decay modes of te charmed strange baryons. First results
of this search will be reported.
*************************************************************************************
12
Name: Arturo Fernandez Tellez
e-mail address: afernand@fcfm.buap.mx
Institution:Fac. Ciencias Fisico Matematicas, BUAP
Postal address: C. U., Av. San Claudio y Rio Verde, Puebla, Pue.
Student? If yes specify BS, MS, or PhD.
Title: Progress on ACORDE-ALICE detector.
Author(s): Arturo Fernandez, for the Mexican ACORDE group.
Abstract (less than 150 words): The ACORDE-ALICE detector is on
development. In this talk we report on the progress of the ACORDE
scintillator module array and the physics topics of interes on cosmic ray
using ACORDE and other ALICE detectors.
*************************************************************************************
13
Recent Results from H1 (HERA)
A summary on some of the recent measurements made by the H1 collaboration
in ep collisions at HERA will be given. That will include studies on
electroweak parameters, charm and beauty structure functions of the
proton, and heavy quark production. First results on charged current cross
sections with polarised lepton beam will be presented also.
Name: Ricardo Lopez-Fernandez
e-mail address: lopezr@fis.cinvestav.mx
Institution: CINVESTAV
Postal address: Av. IPN 2508 CP 07360 Mexico DF
Student? No
Title: Recent Results from H1 (HERA)
Author(s): Ricardo Lopez-Fernandez
***************************************************************************
14
Name:Genaro Toledo Sanchez
e-mail address:toledo@fisica.unam.mx
Institution:IFUNAM
Postal address:Instituto de Fisica, UNAM
A.P. 20-364, Mexico 01000 D. F.
Mexico
Student? No
Title:Determination of the bag parameter as a function of density in a
model for quark matter
Author(s):G. Toledo Sanchez and J. Piekarewicz
Abstract (less than 150 words):
Studies of the quark matter phase usually relies on the value of bag
constant, which can be fixed from fits to hadrons properties. Attemps to
include a density dependent bag parameter to account for the effects of
the medium are based on the expected phenomenological behavior dictated by
the strong interaction rather than by effectively including the
interaction. In this work we model the quark matter in terms of quarks and
colors degrees of freedom and the gluons are considered by optimally
pairing the quarks via a many body potential. We determine, using
variational Monte Carlo techniques, the system conditions at high
densities from where we are able to obtain a bag parameter as a function
of density by performing a comparison of the bag model and our results,
here the nature of the bag parameter has the same spirit but is
dynamically generated through the potential interaction.
*********************************************************************
15
Aranda
Alfredo
Universidad de Colima
fefo@ucol.mx
Av. Universidad # 333
Colima, Colima
28049
Mexico
52 312 316 1135
52 312 316 1135
Ideas on electroweak symmetry breaking from extra dimensions
We will present a brief summary of some recent ideas regarding EWSB in the
context of extra dimensions. In prticular we will present a specific scenario
where the Higgs boson is identified with gauge bosons in higher dimensions.
***********************************************************************************
16
Rafael G. Campos
TITLE: The Schwinger model on an unbounded lattice
AUTHORS: Rafael G. Campos and Eduardo S. Tútuti
Abstract:
We put the Schwinger model on a nonperiodic lattice constructed with zeros
of the Hermite polynomials as nodes. Such a lattice has a well--defined
fermion derivative and a finite Fourier transform with a number of
properties. By using the Hamiltonian formalism it is possible to solve the
Schwinger model on this lattice and
to obtain asymptotically the exact value of the boson mass associated to
this model when the spacing of the lattice goes to zero.
***********************************************************************************
17
Name:Juan Jose Godina Nava
e-mail address: jj@fis.cinvestav.mx
Institution:CINVESTAV IPN
Postal address:07370
Student? PhD.
Title: High-accuracy critical exponents for O(N) hierarchical models
Author(s): L. Li, Y. Meurice, M.B. Oktay, and J.J. Godina Nava
Abstract (less than 150 words):
We perform high-accuracy calculations of the critical exponents of
the 3D O(N) Dyson's hierarchical model for N up to 20. We calculate
the critical temnperatures for the measure . We discuss the rate at
which the degree of polynomial truncations used in the calculations
need to be increased with N. We discuss the possibility of extracting
the coefficients of the 1/N expansion from high-accuracy data.
We show that the leading and subleading exponents agree with
Polchinsky equation with 4 digit and with Litim eauqtion with 5 digits.
******************************************************************************
18
Name: Eleazar Cuautle Flores
e-mail address: ecuautle@nucleares.unam.mx
Institution: Instituto de Ciencias Nucleares, UNAM
Postal address: Circuito exterior S/N, C.U.,
C.P. 04510, Mexico, D.F.
Title: Identified particle ratio in pp collisions and hadronisation scenarios
Author(s): E. Cuautle and G. Paic
Abstract
The hadronization of partons into mesons and baryons is a theoretically
open problem. The ratios of baryons to meson as well as of antibaryons to
baryons measured both, in heavy ion, and nucleon-nucleon collisions are
not explained with the present algorithms, although new and interesting
scenarios based on the importance of multiple parton interactions do
exist. In the present work we will concentrate on the p/pi and pbar/p
ratios in nucleon-nucleon collisions using Pythia incorporating different
hadronisation scenarios for baryons. Two energies will be considered: 200
GeV where some results exist and the planned pp energy of 14 TeV at LHC.
********************************************************************************
19
Name: Andres Sandoval Espinosa
e-mail address: asandoval@fisica.unam.mx
Institution: Instituto de Fisica, UNAM
Postal address: Instituto de Fisica
Universidad Nacional Autonoma de Mexico
Apartado Postal 20-364
Ciudad Universitaria
01000 Mexico, D.F.
Student? No
Title: Construction of the ALICE V0A Trigger Detector
Author(s):
R. Alfaro (a), E. Belmont (a), E. Camacho (b), G. Contreras (b),
E. Cuautle (c), V. Grabski (a), G. Herrera (b), M. Linarez (a),
A. Martinez (a), M.I. Martinez (c), A. Menchaca (a), L.M. Montano (c),
G. Paic (c), A. Sandoval (a), S. Vergara (c)
(a) I. Fisica UNAM, (b) Cinvestav, (c) I. Ciencias Nucleares UNAM
Abstract.
The ALICE experiment at the CERN LHC collider requires fast detectors that
can provide an interaction trigger for proton-proton and Lead-Lead
collisions. They should also be able to discriminate between bean-beam and
beam-gas interactions.
We have designed a scintillator hodoscope with a wavelength shifting
fiber readout, that coupled to fine mesh anode photomultipliers can
satisfy the ALICE requirements.
Test results with various prototypes and the construction of the final
detector will be presented.
**********************************************************************
20
Effect of hard processes on momentum
correlations in pp and p¯p collisions
Guy Paic
Instituto de Ciencias Nucleares, UNAM, Mexico City, Mexico
Piotr Krzysztof Skowro´nski
CERN, CH-1211 Geneva 23, Switzerland and
Warsaw University of Technology, Faculty of Physics,
ul. Koszykowa 75, 00-662 Warsaw, Poland
Abstract
The HBT radii extracted in p¯p and pp collisions at SPS and Tevatron
show a clear correlation with the charged particle rapidity density. We
propose to explain the correlation using a simple model where the distance
from the initial hard parton-parton scattering to the hadronization point
depends on the energy of the partons emitted. Since the particle multi-
plicity is correlated with the mean energy of the partons produced we can
explain the experimental observations without invoking scenarios that as-
sume a thermal fireball. The model has been applied with success to the
existing experimental data both in the magnitude and the intensity of the
correlation. As well, the model has been extended to pp collisions at the
LHC energy of 14 TeV. The possibilities of a better insight into the string
spatial development using 3D HBT analysis is discussed.
********************************************************************************
21
Name: Mario Ivan Martinez Hernandez
e-mail address: mim@nucleares.unam.mx
Institution: Instituto de Ciencias Nucleares - UNAM
Postal address: Circuito Exterior C. U., A. Postal 70-543, 04510 Mexico, D. F.
Student? No
Title: Radiation Tolerance Tests of a Scintillation Detector Readout by
Wavelength Shifting Fibers
Author(s): R. Alfaro, M. I. Martinez, L. M. Montaño, G. Paic and A. Sandoval
Abstract (less than 150 words):
We have performed radiation tolerance tests on the BCF-99-29MC wavelength
shifting fibers and the BC404 plastic scintillator from Bicron as well as on
optical couplers from Silicon Rubber. We used the 60Co gamma source at the
Instituto de Ciencias Nucleares facility to irradiate 30-cm fiber samples with
doses from 50 Krad to 1 Mrad. We also irradiated a 10x10 cm2 scintillator
detector with the WLS fibers embedded on it with a 200 krad dose and the
optical conectors between the scintillator and the PMT with doses from 100 to
300 krad. We measured the radiation damage on the materials by comparing the
pre- and post-irradiation optical transparency as a function of time.
****************************************************************************
22
Herrera-Aguilar
Alfredo
IFM, UMSNH
herrera@ifm.umich.mx
IFM, Edificio C-3, Ciudad Universitaria
Morelia
58040
Mexico
(443)3223500 ext. 4131
(443)3223500 ext. 4144
Towards the establishment of nonlinear hidden symmetries of the Skyrme model
The Skyrme model represents a SU(N) Lagrangian that includes nonlinear
interaction (higher order derivative) terms. Because of this peculiarity, the
field equations constitute nonlinear differential equations that are, in
general, hard to solve (only a few set of exact solutions is known). However,
this model has a remarkable property: it possesses regular, stable field
configurations that attain an energy minimum, the so-called solitons. The aim of
the present talk is to formulate an
approach that could lead to the establishment of nonlinear symmetries of the
Skyrme\'s field equations which, in turn, will lead to their integration. An
explicit SU(2) example is illustrated.
***********************************************************
23
Abstract title: Search for gamma-ray bursts at 4550 m.a.s.l.
Presenter Oscar Martinez FCFM-BUAP
Authors: C. Alvarez, O. Martínez, R. Conde, T. Murrieta, O.
Saavedra, H.
Salazar, L. Villaseñor
University: BENEMERITA UNIVERSIDAD AUTONOMA DE PUEBLA
Address: Facultad de Fisico-Matematicas, Benemerita
Universidad Autonoma
de Puebla
Apartado Postal 1364
City: Puebla
State: Puebla
Zip Code: 72000
Country: MEXICO
contact:Oscar Martinez omartin@fcfm.buap.mx
Text of the Abstract:
We present results from a search for GRBs in the energy
range from tens of GeVs
to one TeV with an array of 6 water Cherenkov detectors
located at 4500 m
a.s.l. as part of the high mountain observatory of Sierra
Negra (N18o59.1, W97
o 18.76) near Puebla city in Mexico. The detectors consist
of light-tight
cylindrical containers of 1 m 2 cross section filled with
750 l of purified
water; they are spaced 25 m and have a 5^Ô photomultiplier
(EMI model 9030A)
facing down along the cylindrical axis. We describe the
expected rate (charged
particles and muon components) and compare it with
preliminary experimental
results obtained by using a single-particle counting
technique for a data
taking period of several months, and their dependence with
atmospheric pressure
and other weather parameters.
***********************************************************************
24
Hamiltonian Noether theorem for gauge systems
V M Villanueva
Instituto de Fisica y Matematicas, Universidad Michoacana de
San Nicolas de Hidalgo,
PO Box 2-82, Morelia, Michoacan, Mexico
vvillanu@ifm.umich.mx
Abstract
The Noether theorem for Hamiltonian constrained systems is re
visited. In
particular, our review presents a novel method to show that t
he gauge
transformations are generated by the conserved quantities ass
ociated with the
first class constraints. We apply these results to the non Ab
elian Yang-Mills and the bosonic string theories.
********************************************************************
25
Name: Christian Schubert
e-mail address: schubert@ifm.umich.mx
Institution: IfM, UMSNH
Postal Address:
Dr. Christian Schubert
IfM, UMSNH
Ciudad Universitaria
Edificio C-3, Apdo. Postal 2-82
C.P. 58040, Morelia, Michoacan, Mexico
Student? No
Title: Pair creation in inhomogeneous fields from worldline
instantons
Author(s): Gerald V. Dunne and Christian Schubert
Abstract:
We show how to do semiclassical nonperturbative computations
within the
worldline approach to quantum field theory using ``worldline
instantons''.
These worldline instantons are classical solutions to the
Euclidean
worldline loop equations of motion, and are closed spacetime
loops
parametrized by the proper-time. Specifically, we compute
the imaginary
part of the one loop effective action in scalar and spinor
QED using
``worldline instantons'', for a wide class of inhomogeneous
electric field backgrounds. The connection with the more usual WKB approach
is shortly discussed.
******************************************************************************
26
Mondragon
Miguel N.
CINVESTAV-Merida. Dep. de Fisica Aplicada
mmondra@karin.mda.cinvestav.mx
A. Postal 73 (Cordemex)
MERIDA, Yuc
97310
Mexico
(999) 981 2960 ext. 250
(999) 981 2917
Graduate_student
Extension of Geometric Scaling for the $\\gamma^*p$ Cross-section to Large $x$
Geometric scaling for the $\\gamma^*p(x,Q^2)$ cross-section has been
extensively studied in the past years. Geometric scaling means that
experimental data in the region of small Bjorken variable $x$ lie on a universal
curve, as a function of a single variable $\\tau$. In this work a detailed
analysis on the validity of geometric scaling is presented. It is shown that the
cross-section behaviour can be described as the product of two functions, a
function S describing the region of large $x$, and a function W describing the
region of low $x$. This leads to a new understanding of the success of the low
$x$ geometric scaling. Furthermore, an extension to large $x$ is achieved by
defining a reduced cross-section $\\sigma_ {\\gamma^*p}= \\gamma^*p/S$. In this
way, geometric scaling up to the highest measured values of $x$ and $Q^2$ is
observed.
**CONTRIBUTIONS ACCEPTED FOR POSTER PRESENTATION **
1
Abstract title: Hybrid Extensive Air Shower Detector Array at the
University of Puebla to Study Cosmic Rays
Presenter Gonzalo Perez
FCFM-BUAP, Estudiante de Doctorado
Authors: Martinez, Oscar; Perez, Gonzalo; Salazar, Humberto and
Villaseñor Luis.
University: BENEMERITA UNIVERSIDAD AUTONOMA DE PUEBLA
Address: Facultad de Fisico-Matematicas, Benemerita Universidad Autonoma
de Puebla
Apartado Postal 1364
City: Puebla
State: Puebla
Zip Code: 72000
Country: MEXICO
contact: Gonzalo Perez
Text of the Abstract:
We describe the performance of a hybrid extensive air shower (EAS)
detector array built on the Campus of the University of Puebla (19oN,
90oW, 800 g/cm2) to measure the energy, arrival direction and composition
of primary cosmic rays with energies around the knee of the cosmic-ray
energy spectrum. The array consists of 6 water Cherenkov detectors of
1.86m2 cross section and 12 liquid scintillator detectors of 1 m2
distributed in a square grid with a detector spacing of 20 m over an area
of 4000 m2. We discuss and report on measurements and reconstruction of
the LDF for the electromagnetic and muonic components of extensive air
showers. We also discuss the ways in which the hybrid character of the
array can be used to study inclined EASs, i.e., zenithal angle > 60
degree; and also to measure mass composition of the primary cosmic rays,
i.e., by estimating the relative contents of muons with respect to the EM
component.
*********************************************************************************
2
González Canales
Félix Franciscco
Instituto de Física UNAM
felixfcoglz@gmail.com
Apdo. Postal 20-364
México D.F.
01000
México
(+52) 55 56 22 50 14
(+52) 55 56 22 50 15
Graduate_student
Complementarity of quark and lepton mixing matrices
Recent measurements of the neutrino solar mixing angle and the Cabbibo angle
satisfy the empirical relation $\\theta_{sol} + \\theta_{C} \\simeq
\\frac{\\pi}{4}$. This empirical datum suggests the existence of a correlation
between the mixing matrices of neutrinos and quarks, the so called
complementarity of quarks and leptons. Here, we examine the possibility that
this correlation between the mixing angles of quarks and leptons originates in
the similar hierarchy of quark and charged lepton masses and the seesaw
mechanism that gives mass to the
Majorana neutrinos. We assume that the similar mass hierarchies of charged
lepton masses and quark masses allows one to represent all the mass matrices of
the Dirac fermions in terms of a Fritzsch texture.
*************************************************************************
3
Analysis of the Endpoint of the Tritium Beta Decay in a
Left-Right Symmetric Model
A. Guti¶errez-Rodr¶³guez 1;a, M. A. Hern¶andez-Ru¶³z 2;b and F. Ram¶³rez-S¶anchez 1
(1) Facultad de F¶³sica, Universidad Aut¶onoma de Zacatecas
Apartado Postal C-580, 98060 Zacatecas, Zacatecas M¶exico.
(a) Cuerpo Acad¶emico de Part¶³culas, Campos y Astrof¶³sica.
(2) Facultad de Ciencias Qu¶³micas, Universidad Aut¶onoma de Zacatecas
C¶odigo Postal 98068, Zacatecas, Zacatecas M¶exico.
(b) Cuerpo Acad¶emico de Ciencias B¶asicas de Q.F.B..
Abstract
We start with a Left-Right Symmetric Model and we analyze the endpoint
of the beta decay of the tritium 3H ! 3He + e¡ + ¹ºe. We applied this
model to incorporate the right currents, whereby we propose an amplitude
whose leptonic part contains the parameter ¸ de¯ned as a left-right asymmetry
parameter which measures the parity violation. We realized the numerical
computation to the sensibility of the experiments Mainz & Troitsk of mºe =
2:2 eV , and for the future beta decay experiment KATRIN, which will reach
a sensitivity of mºe » 0:2 eV . We ¯nd that the spectrum of energy of the
electrons for this experiments it is not a®ected by the left-right asymmetry
parameter.
***********************************************************************************
4
Rojas
Eduardo
ICN
eduardor@nucleares.unam.mx
calle jilocingo No 15
Mexico D.F
04369
México
56224739 Ext 301,302
Graduate_student
Dinamical mass generation in Quantum Electrodynamics with weak magnetic fields
We study the dynamical generation of masses for fundamental fermions in
quenched quantum electrodynamics in the presence of magnetic fields using
Schwinger-Dyson equations. We show that, contrary to the case where the
magnetic field is strong, in the weak field limit masses are generated above a
critical value of the coupoling and that this value is the same as the case
with no magnetic field. Under simplifying assumptions, we use bifurcation
theory to analytically find the value of critical coupling costant and use
this input to carry aut the numerical analysis. The findings of this
work might be relevant for processes involving dynamical properties of
fermion during the evolution of the early universe where weak magnetic
fields could be present.
**********************************************************************************
5
Concha
Yajaira
Instituto de Física y Matemáticas. UMSNH
yajaira@ifm.umich.mx
Edificio C-3. Ciudad Universitaria
Morelia, Mich.
58040
Mexico
(01) 443 3 22 35 00 Ext. 4138
(01) 443 3 22 35 00 Ext. 4144
Graduate_student
Scalar QED at the One-loop Level
Authors: A. Bashir, Y. Concha Sánchez and L.X. Gutierrez Guerrero
Scalar Quantum Electrodynamics (SQED) is one of the simplest gauge
theories. Although fundamental scalars have not yet been observed,
several popular theoretical scenarios rely on such fields. Higgs of the
standard model is an obvious example. However, in many of its extensions,
charged scalars also arise naturally.
Moreover, electromagnetic interactions of the charged scalars are believed
to play an important role in the dynamics of inflation in the early
universe. In this work, we present one-loop evaluation of two-, three- and
four-point Green\'s functions in SQED and also study their gauge-covariance
properties.
**********************************************************************************
6
Zavala
Jesus
Instituto de Ciencias Nucleares, UNAM
jzavala@nucleares.unam.mx
Prado Norte 226A int. 1, Col. Casa Blanca
Metepec
52175
Mexico
722 2115351
Graduate_student
Tsallis thermodynamics and dark matter halos
We present an alternative for the description of galactic dark matter halos
based in Tsallis thermodynamics. This proposal is statistically tested against
the current paradigm, the NFW scheme, and against observational results coming
from a resent compiled sample of disk galaxies.
***************************************************
7
"Description of charge conjugation from first principles"
Carolina Luján Peschard, Mauro Napsuciale
IFUG
We show tha Dirac equation is just the eigenvalue equation for intrinsic
parity in 1/2,0)+(0,1/2) representation. We study the analogous
construction for charge conjugation operator in this irrep and obtain a
new equation which in principle is appropriate for the description of
neutral particles.
************************************************************************************
8
"Fermions odd space-time dimensions from first principles"
Mauro Napsuciale, Ma. Georgina Carrillo Ruiz.
IFUG
In this work we wonder about the difference between the description of
fermions in arbitrary dimensions as irreps of the corresponding Poincaré
group, and their current description as irreps of the corresponding
Clifford algebra. As a first step in this direction, we study here
exhaustively the specific case d=1+2. We recalculate the irreps of the
proper orthochronous Lorentz subgroup of HLG which turn out to be of
dimension 2c+1, with c integer or semi-integer. We show that if we follow
the current definition of parity as an improper transformation, then Dirac
equation is not the covariant form of the eigenvalue equation for the
intrinsic parity operator as in the d=1+3 case. However, if we define
parity in the same way as in d=1+3 i.e. as the reversing of all the
spatial coordinates , then Dirac equation is just the covariant form of
the eigenvalue equation for intrinsic parity just like in d=1+3, in spite
of the fact that under this definition parity is a proper transformation.
An explicit construction of the charge conjugation operator, and a
non-relativistic expansion of the gauged Dirac equation shows that "spin"
has only one degree of freedom in d=1+2. Finally we show that if we define
chirality operator based on its anti-commutator with parity operator, we
can define chiral fermions, whenever we promote chirality to a true
space-time transformation, i.e. one composed of an intrinsic part and a
space-time part. It turns out that the space-time part of chirality is
precisely the improper transformation connecting the proper orthochronous
subgroup to the improper orthochronous piece i.e. the transformation
adopted as "parity" in the current literature.
*************************************************************************************
9
NOMBRE:MA. DE JESUS ANGUIANO GALICIA
INSTITUCION: INSTITUTO DE FISCA Y MATEMATICAS DE LA UMSNH, ESTOY ESTUDIANDO
LA MAESTRIA EN EL AREA DE FISICA.
SEMESTRE:TERCERO.
PROCEDENCIA: MORELIA, MICHOACAN.
Solo necesitaria beca de inscripcion pues vivo en la ciudad sede.
TITLE:
Fermions in Odd Space-Time Dimensions: Back to Basics
ABSTRACT:
It is a well-known feature of odd space-time dimensions d that
there exist two inequivalent fundamental representations A and B of the
Dirac gamma matrices. Moreover, the parity transformation swaps the fermion
fields living in A and B. As a consequence, a parity-invariant Lagrangian
can only be constructed by incorporating both the representations. Based
upon these ideas and contrary to long-held belief, show that in addition
to a discrete exchange symmetry for the massless case, we can also define
chiral symmetry provided the Lagrangian contains fields corresponding to
both the inequivalent representations.Also study the transformation
properties of the corresponding chiral currents under parity and charge-
conjugation operations. I work explicitly in 2 + 1 dimensions and later
show how some of these ideas generalize to an arbitrary number of odd
dimensions.
**********************************************************************************
10
Name : Juan Carlos Arteaga Velazquez
e-mail : jarteaga@fis.cinvestav.mx
Institution: Department of Physics, Cinvestav
Address : Av. IPN 2508, Col. Zacatenco, Del. Gustavo
A. Madero, Mexico, DF, 07000
Post Doctoral Fellow
Title: Influence of the regeneration by neutral currents
in the observable flux of upward-going muons induced
by astrophysical neutrinos
Authors: J. C. Arteaga-Velazquez and A. Zepeda
Abstract:
The telescopes of astrophysical high-energy neutrinos
based on the Cherenkov technique are very different
from the conventional telescopes in that the first ones
look down, to the interior of the Earth. These Cherenkov
detectors are designed to observe the upward-going
muons produced by muon neutrinos that traverse through
our planet, when they interact weakly with matter
around the detector. In order to interpret the data from
upward-going muons it is important to understand how
the neutrino flux is modified when it travels through
the Earth. Besides absorption, the neutrino flux can
be altered by other mechanisms, for example, regeneration
by means of neutral currents. In this work we explore
the effect of the regeneration through neutral currents
in the propagation of neutrinos and its influence on
the observable flux of upward-going muons for different
astrophysical and exotic models of high-energy neutrinos.
****************************************************************************
11
Name : Juan Carlos Arteaga Velazquez
e-mail : jarteaga@fis.cinvestav.mx
Institution: Department of Physics, Cinvestav
Address : Av. IPN 2508, Col. Zacatenco, Del. Gustavo
A. Madero, Mexico, DF, 07000
Post Doctoral Fellow
Title: Estimation of the detectable flux of astrophysical
neutrinos at the Pierre Auger observatory by means of
horizontal air showers
Authors: J. C. Arteaga-Velazquez and A. Zepeda
When the Pierre Auger Observatory is completed, it will be
able to detect ultrahigh energy astrophysical neutrinos
(E > 1 EeV) by observing the air showers of secondary
particles induced by the neutrinos in collisions
with the atmosphere on their route to the detector. In
particular, the observatory will look for those events
traveling near the horizontal direction. In this work we
calculated the detectable flux of ultrahigh energy muon
neutrinos at the Pierre Auger Observatory for several particle
physics and astrophysical models. Based on these estimates,
we found that, in some scenarios, the diffuse flux of active
galactic nuclei and topological defects have the greatest
possibility of detection of all the spectra which we analyzed and
that the muon neutrinos from the GZK cut off will be very
difficult to observe by using the above technique and only muon
neutrinos.
**************************************************************************
12
*Name: Ricardo Perez Martinez
*e-mail address: rperez@fis.cinvestav.mx
*Institution: Physics Department, CINVESTAV.
*Postal address: Av. IPN 2508 Col. San Pedro Zacatenco CP 07300
Mexico,D.F.
*Student? If yes specify BS, MS, or PhD.
Yes. MS.
*Title: Testing nonstandard interactions in IceCube.
*Author(s): Ricardo Perez Martinez.
Arnulfo Zepeda.
Omar Miranda.
*Abstract.
The strong evidence of a nonzero mass for neutrinos suggest
us a natural way of the existence of physics beyond the standard model
(SM). Exists a phenomenological manner to parametrize a great variety of
interactions that appear in physics beyond the SM, these parameters
currently have a wide freedom in the neutrino sector, so whatever effort
in order to bound them is of great interest. In this poster we
present and discuss the possibilities that the future detector IceCube
will have in order to improve the current bounds.
**************************************************************************
13
Martinez
Mauricio
ICN-UNAM
maumag@nucleares.unam.mx
Calle Jilocingo 15, Col. Pedregal de Santo Domingo, Del. Coyoacan
Mexico D.F.
04369
Mexico
56224739 Ext. 301
56224693
Graduate_student
Dynamical Thermal Recombination of Partons in Relativistic Heavy-Ion Collisions
AUTHORS:A. Ayala (ICN-UNAM), M. Martinez (ICN-UNAM), G. Paic (ICN-UNAM), G.
Toledo (IF-UNAM)
In relativistic heavy ion collisions, an anomalously large proton/pion ratio has
been found at intermediate values of transverse momentum. This experimental fact
has been called the \"baryon puzzle\", in the sense that if one thinks that
hadrons are produced by the fragmentation of fast moving partons, it is more
likely to produce mesons than baryons. The explanation for this result invokes
the existence of another hadron production mechanism that takes place in a
thermalized, dense parton medium and has been given the name \"thermal
recombination\". The standar recombination mechanism attempts to explain the
behavior of the proton/pion ratio assuming that thermal quarks combine
statistically within a hadron ignoring the detailed dynamics that govern such
process. In this work we present a model that incorporates the dynamics of a
dense thermal system of partons to extract the probability to create either
pions or protons as a function of the system\'s temperature.
*************************************************************************************
14
NAME: Dominguez Jimenez Isabel
E-MAIL: isabel@nucleares.unam.mx
INSTITUTION: Instituto de Ciencias Nucleares.
Universidad Nacional Autonoma de Mexico
POSTAL ADDRESS: Circuito Extrior C.U. A.Postal 70-543 04510 Mexico D.F.
STUDENT?: YES, PhD student
TITLE: Azimuthal Correlation in pp collision
AUTHORS: Guillermo Contreras, Eleazar Cuautle, Isabel Dominguez, Guy Paic.
ABSTRACT: Partons traveling trough a medium in extreme conditions of
temperature and density, such as the created in collisions of heavy ions, lose
energy by bremstalung. This phenomenon results in suppressions of leading
partons. Experimentally, this is observed via the suppression of high pt
hadrons spectra compared to the spectra generated in proton-proton collisions
and the azimuthal correlations among particles. Since the basis of comparison
with the nucleon-nucleon data we will show the expected azimuthal correlations
obtained at 14TeV using Pythia, choosing different leading particles.
**********************************************************************
15
Compean Jasso
Cliffor Benjamin
I.F. UASLP
cliffor@ifisica.uaslp.mx
Av. Manuel Nava 6, Zona Universitaria.
San Luis Potosí
78290
Mexico
(444) 8262362
(444) 8133874
Undergraduate_student
Barion Spectra from a O(4) Symmetric Quark-Diquark Model with the Trigonometric
Rosen-Morse Potential
We study non-strange baryon spectra within a O(4) symmetric Quark-Diquark model.
We solve the Schrödinger equation with a trigonometric Rosen-Morse potential
(TRMP) and find energies and wave functions analytically. The TRMP is obtained
from the Eckart potential by a complexification of the argument and one expects
the wave functions of the former potential to be those of the latter, i.e. the
Jacobi polynomials but with complex parameters. However, in turns out that
the Jacobi polynomials with complex parameters are of no use in spectroscopy due
to path dependence of their orthogonality properties. Therefore, we searched and
encountered a different orthogonal polynomial solution. At first glance, these
polynomials seem not to belong to any of the orthogonal polynomial families
treated in the standard textbooks. Our model predicts correctly the observed
resonance masses and their spin- and parity degeneracy. Calculation of
electromagnetic transitions is our next goal.
*******************************************************************************
16
"Spin > 1 fields: a new approach"
Selim Gómez , Mauro Napsuciale
IFUG
Abstract
In this work we propose a general formalism for the description of high
spin fields based on projection over the appropriate eigensubsapces of the
Pauli-Lubanski operator. the case of spin 2 is discussed in detail.
*********************************************************************************
17
Name: Angel de Jesus Flores Castillo
e-mail address: shiru@ifisica.uaslp.mx
Institution: Instituto de Fisica, Universidad Autonoma de San Luis Potosi
Postal address: Manuel Nava #6, Zona Universitaria,
San Luis Potosi, SLP 78240
Student? If yes specify BS, MS, or PhD. MS Student
Title: Search for narrow baryon resonances in Xi pi
Author(s): Angel de Jesus Flores Castillo, Jurgen Engelfried, SELEX
collaboration
Abstract (less than 150 words):
We report the results of a high statistics search for narrow baryon
resonances decaying to the channels Xi-pi-, Xi-pi+, aXi+pi-, and aXi+pi+.
with data from the hadroproduction experiment SELEX (Fermilab E781).
***************************************************************************************
18
Name: Jose Luis Sanchez Lopez
e-mail address: psanchez@ifisica.uaslp.mx
Institution: Instituto de Fisica, Universidad Autonoma de San Luis Potosi
Postal address: Manuel Nava #6, Zona Universitaria,
San Luis Potosi, SLP 78240
Student? If yes specify BS, MS, or PhD. MS Student
Title: Polarization of inclusively produced Lambda's.
Author(s): Jose Luis Sanchez Lopez, Jurgen Engelfried, SELEX Collaboration
Abstract (less than 150 words):
We present the results of the measurement of the polarization
of the inclusively produced lambda by four different beams particles
(Sigma-minus, proton, pi-minus and pi-plus) incident on cooper
and carbon targets in the experiment E781 (SELEX) at Fermilab.
Two methods are used: Measurement of the acceptance and the
bias cancelling technique.
*******************************************************
19
Name: Isabel Pedraza Morales
e-mail address: mpedraza@fcfm.buap.mx
Institution: Instituto de Fsica BUAP
Postal address: AP J-48, Puebla, Pue.
Student? If yes specify BS, MS, or PhD. Yes, PhD.
Title: PROBING NEW PHYSICS WITH NEUTRINO INTERACCTIONS AT
THE PIERRE
AUGER OBSERVATORY
Author(s): L. Diaz, H. Salazar, M. I. Pedraza
The Pierre Auger Observatory for cosmic rays is sensitive to
ultra-high
energy neutrinos and models for new physics can be explored
by observing
neutrino interactions beyond TeV scale. A deviation of the
neutrino-nucleon cross-section from the Standard Model
expectation can be
constrained by comparing the rate for quasi-horizontal,
deeply penetrating
air showers triggered by all types of neutrinos, with the
rate for
slightly upgoing showers generated by Earth-skimming tau
neutrinos. This
can be used to test models of low-scale quantum gravity, as
well as non-perturbative electroweak instanton mediated processes.
************************************************************
20
Analysis of the efficiency of the VOA detector in the ALICE project
Carlos Pérez Lara, Alberto Gago Medina
Pontificia Universidad Católica del Perú
Gerardo Herrera
Cinvestav-IPN
In this work, we have tested the efficiency of the VOA detector for
the ALICE project under different assumptions in the configurations of
the wavelength shifters (WLS) located within each cell, which compose
the scintillator disk. We have studied three configurations, in two of
them the WLS are on the faces parallel and perpendicular to the axis
beam, and in the last one we have used the megatile technique, in
which the WLS are embedded in the cell. For a fix number of WLS, we
have achieved a 15% of efficiency for the parallel case and a 2% of
efficiency for the perpendicular case. In the megatile case, we have
got 23% of efficiency. In addition, we have studied the optimal number
of WLS according to the area of the cell. All of these simulations
have been done using LITRANI libraries.
21
Name: Juan Carlos Gomez Izquierdo
e-mail address: jcarlos@fis.cinvestav.mx
Institution: Departamento de Fisica. CINVESTAV-IPN, Mexico.
Postal address: Apdo. Post. 14-740, 07000, Mexico, D.F., Mexico
Student? YES If yes specify BS, MS, or PhD.: MS
Title: "Sterile neutrinos and the solar mixing"
Author(s): Juan Carlos Gomez Izquierdo, Abdel Perez-Lorenzana
Abstract:
Neutrino mixing matrix appears to be close to bimaximal bixing, but for
the solar angle which is definitively smaller than 45 degres. Whereas it
seems quite easy to understand bimaximal mixings, as in models using
$L_e - L_\mu - L_\tau$ global symmetries, understanding the 12 degrees of
deviation in the observed solar angle seems less simple. We suggest that
such a deviation could be due to a light sterile netrino that mixes with
the active sector. The mass scale needed to produce the effect is shown to
be smaller than atmospheric scale, and thus, irrelevant for LSND.
Nevertheless, such a light sterile neutrino could have observable effects
that could be measure by low energy solar neutrino experiments.
**********************************************************************************
Sarira Sahu
Instituto de Ciencias Nucleares, UNAM
sarira@nucleares.unam.mx
Instituto de Ciencias Nucleares, UNAM
Mexico City
Title: Growth of magnetic field in a two component plasma
Abstract:
We study the electromagnetic properties of a system that consists of an
electron background and a neutrino gas that may be moving or at rest, as a
whole, relative to the background.
The photon self-energy for this system is characterized by the usual transverse
and longitudinal polarization functions,
and two additional ones which are the focus of our calculations,that give rise
to birefringence and anisotropic effects in the photon dispersion relations. We
also consider the macroscopic electrodynamic equations for this system.As an
illustration, the equations are used to discuss the evolution of a magnetic
field perturbation in such a medium.
Name: Omar Pedraza Ortega
e-mail address: omp@xanum.uam.mx
Institution: UNIVERSIDAD AUTONOMA METROPOLITANA, UNIDAD IZTAPALAPA
Postal address: Av. Michoacán y la Purísima, Col. Vicentina, México, D.F. 09340
Student? yes, PhD student
Title: Casimir effect in a six-dimensional vortex scenario
Authors: Omar Pedraza, Román Linares and Hugo A. Morales-Técotl
Abstract
Recently Randjbar-Daemi and Shaposhnikov put forward a
4-dimensional effective QED coming from a Nielsen-Olesen vortex
solution of the abelian Higgs model with fermions coupled to gravity
in D=6. However, exploring possible physical consequences of such
an effective QED was left open. In this letter we study the
corresponding effective Casimir effect. We find that the extra
dimensions yield fifth and third inverse powers in the separation
between plates for the modified Casimir force which are in conflict
with known experiments, thus reducing the phenomenological viability
of the model.
Last Updated
October 31, 2005 |