How to abvoid the attraction to a girl ?

I am a 15 year old boy . I have recently completed my 10th std. Now i am in 11 science. and i have been attracted a girl who is my classmate for 2 years. She just avoids to talk with me.yet i am attracted to her.she is not a tall girl.she is shorter than an average 15 yearold girl. yet i find her attractive. others don't find her attractive.. but i do find her attractive. On the other side, I am not attractive at all. I am ok in looks. I am a bit fat. I am clever. and She is also clever. we both got more than 95% of marks in the main subjects in the 10th std. but i got 1 marks more than her. now because of my attraction towards her, i can't concentrate on my studies. i know my studies are more important than attraction to her, yet i daydream her . i always think about her . i also think about her while studying too. so am worried about my studies . and i want to know how i can avoid the attraction to her.