  The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) performs
studies of diffractive processes with the focus on the exclusive production of
particles in central range of rapidity. In 2015 STAR collected 18 pb$^{-1}$ of
data in polarized proton+proton collisions at $\sqrt{s}$=200 GeV to measure
Central Exclusive Production (CEP) process $pp\to pXp$ through Double Pomeron
Exchange (DPE) mechanism. The intact protons moving inside the RHIC beampipe
after the collision were measured in silicon strip detectors (SSD), which were
placed in the Roman Pot vessels. This enables full control over interaction
kinematics and verification of the exclusivity of the reaction by measuring the
total (missing) transverse momenta of all final state particles: the central
diffractive system in the Time Projection Chamber (TPC) and the forward protons
in the Roman Pots. With the use of ionization energy loss in the TPC,
d$E$/d$x$, it was possible to discriminate various production channels in
$pp\to pXp$ reaction. This paper presents results on exclusive production of
two charged particles ($\pi^{+}\pi^{-}$ and $K^{+}K^{-}$) in mid-rapidity
region, $-1<\eta<1$, with small squared four-momentum transfer of forward
protons, $0.03<-t<0.3~(\textrm{GeV}/c)^{2}$, obtained using 2.5% of full
statistics.
