This contribution reports on the latest status of the feasibility studies for the measurement of time-like proton electromagnetic form factors (FF’s) at the PANDA experiment [1] at FAIR (Germany). Electromagnetic FF’s are fundamental quantities parameterizing the electric and magnetic structure of hadrons. In the time-like region proton FF’s can be accessed experimentally through the annihilation processes p¯pl+l (l = e, μ), assuming that the interaction takes place through the exchange of one virtual photon.

Due to the low luminosity available at colliders in the past, an individual determination of the time-like electric and magnetic proton FF’s was not feasible. The statistical precision, at which the proton FF’s will be determined at PANDA, is estimated for both signal processes p¯pl+l (l = e, μ) using the PandaRoot software, which encompasses full detector simulation and event reconstruction. The signal identification and suppression of the main background process (p¯pπ+π) is studied. Different methods have been used to generate and analyze the processes of interest. The results from the different analyses show that time-like electromagnetic FF’s can be measured at PANDA with unprecedented statistical accuracy.

1.
M.
Lutz
 et al. (
PANDA Collaboration
), (
2009
), arXiv:0903.3905 [hep-ex].
2.
A.
Dbeyssi
,
E.
Tomasi-Gustafsson
,
G.
Gakh
, and
M.
Konchatnyi
,
Nucl.Phys. A
894
(
2012
).
3.
G.
Bardin
,
G.
Burgun
,
R.
Calabrese
,
G.
Capon
,
R.
Carlin
, et al.,
Nucl.Phys. B
411
,
3
32
(
1994
).
4.
J.
Lees
 et al., “
Measurement of the e+ + e → p+p¯ cross section in the energy range from 3.0 to 6.5 GeV
,”
Tech. Rep.
(BaBar,
2013
).
5.
M.
Ablikim
 et al.,
Phys.Rev. D
91
(
2015
).
6.
S.
Spataro
 et al.,
J. Phys.: Conf. Series
396
, p.
9
(
2012
).
7.
D.
Khaneft
,
A.
Dbeyssi
, et al., “
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
”, (in preparation).
8.
E.
Eisenhandler
,
W.
Gibson
,
C.
Hojvat
,
P.
Kalmus
,
L. L. C.
Kwong
, et al.,
Nucl.Phys. B
96
, p.
109
(
1975
).
9.
J.
Van de Wiele
and
S.
Ong
,
Eur.Phys.J. A
46
,
291
298
(
2010
).
10.
M.
Zambrana
 et al., “
twoPionGen: a Monte Carlo event generator for π+π production in p¯p interactions
,”
Tech. Rep.
(HIM Mainz,
2011
).
11.
A.
Eide
,
P.
Lehmann
,
A.
Lundby
,
C.
Baglin
,
P.
Briandet
, et al.,
Nucl.Phys. B
60
,
173
220
(
1973
).
12.
T.
Buran
,
A.
Eide
,
P.
Helgaker
,
P.
Lehmann
,
A.
Lundby
, et al.,
Nucl.Phys. B
116
, p.
51
(
1976
).
13.
T.
Armstrong
 et al.,
Nucl.Phys. B
284
, p.
643
(
1987
).
14.
C.
White
,
R.
Appel
,
D.
Barton
,
G.
Bunce
,
A.
Carroll
, et al.,
Phys.Rev. D
49
,
58
78
(
1994
).
15.
A.
Zichichi
,
S.
Berman
,
N.
Cabibbo
, et al.,
Nuovo Cim.
24
,
170
180
(
1962
).
16.
E.
Tomasi-Gustafsson
and
M.
Rekalo
,
Phys.Lett. B
504
,
291
295
(
2001
).
17.
R.
Baldini
,
C.
Bini
,
P.
Gauzzi
,
M.
Mirazita
,
M.
Negrini
, et al.,
Eur. Phys. J. C
46
,
421
428
(
2006
).
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