One of the challenges of the modern physics
is the description of the internal structure
of the baryons and mesons.
The electromagnetic structure
of the nucleon $N$ and the nucleon resonances $N^\ast$ can be accessed
through the $\gamma^\ast N \to N^\ast$ reactions,
which deppend of the (photon) transfer momentum squared $Q^2$ [1--4].
The data associated with those transitions
are represented in terms of helicity amplitudes and have been collected in the recent years at Jefferson Lab, with increasing $Q^2$.
The new data demands the development of theoretical models
based in the underlying structure
of quarks and mesons states [3,4].
Those models can be also very useful
to predict the results of the future
Jlab--12 GeV upgrade, particularly
for resonances in the second and third resonance region
(energy $W =1400$--$1750$ GeV) [4].
In that region there are several resonances $N^\ast$
from the supermultiplet $[70,1^-]$ of $SU(6)\otimes O(3)$,
characterized by a negative parity [5].
According with the single quark transition model,
when the electromagnetic interaction
is the result of the photon coupling with just one quark,
the helicity amplitudes of the $[70,1^-]$ members
depend only of three independent functions of $Q^2$:
$A,B$ and $C$ [5,6].
In this work we use the
covariant spectator quark model [4,6,7]
developed for the $\gamma^\ast N \to N^\ast (1520)$
and $\gamma^\ast N \to N^\ast (1535)$ transitions [8],
also members of $[70,1^-]$,
to calculate those functions.
With the knowledge of the functions $A,B$, and $C$
we predict the helicity amplitudes for the
transitions $\gamma^\ast N \to N^\ast(1650)$, $\gamma^\ast N \to N^\ast(1700)$,
$\gamma^\ast N \to \Delta(1620)$,
and $\gamma^\ast N \to \Delta(1700)$ [6].
To facilitate the comparison with
future experimental data at high $Q^2$,
we provide also simple parametrizations
of the amplitudes $A_{1/2}$ and $A_{3/2}$
for the different transitions, compatible with the expected
falloff at high $Q^2$ [6].
[1] I.G. Aznauryan et al. [CLAS Collaboration],
Phys. Rev. C 80, 055203 (2009);
V.I. Mokeev et al. [CLAS Collaboration],
Phys. Rev. C 86, 035203 (2012).
[2] L. Tiator, D. Drechsel, S.S. Kamalov and M.Vanderhaeghen,
Eur. Phys. J. ST 198, 141 (2011).
[3] I.G. Aznauryan and V.D. Burkert,
Prog. Part. Nucl. Phys. 67, 1 (2012).
[4] I.G. Aznauryan et al.
Int. J. Mod. Phys. E 22, 1330015 (2013).
[5] V. D. Burkert, R. De Vita, M. Battaglieri, M. Ripani and V. Mokeev,
Phys. Rev. C 67, 035204 (2003).
[6] G. Ramalho,
Phys. Rev. D 90, 033010 (2014).
[7] F. Gross, G. Ramalho and M.T.~Peña,
Phys. Rev. C 77, 015202 (2008);
Phys. Rev. D 85, 093005 (2012).
[8] G. Ramalho and M.T. Peña,
Phys. Rev. D 89, 094016 (2014);
Phys. Rev. D 84, 033007 (2011);
G. Ramalho and K. Tsushima,
Phys. Rev. D 84, 051301 (2011).